A whirlpool bath with an inverter-controlled circulating pump

Abstract: A whirlpool bath with an inverter-controlled circulating pump (P) comprises a bathtub body (1), a circulating pump (P) driven by a power-operated motor (M), a hot water circulation path (D) disposed between the bathtub body (1) and the circulating pump (P), the hot water circulation path (D) comprising a hot water suction path (10) and a hot water forced-feed path (11), the hot water forced-feed path (11) having at least one terminal end which is open into the bathtub body (1), at least one injection nozzle (3) which is mounted on the terminal end of the hot water forced-feed path (11), an air intake portion (5) connected to the hot water forced-feed path (11) to permit blowing of bubbling hot water into the bathtub body (1) from the injection nozzles (3), an inverter (E) interposed between a drive circuit (C) of the power-operated motor (M) of the circulating pump (P) and a power source and an electricity insulation means protecting the transfer of high frequency components of inverter-produced current to the hot water in the bathtub body (1). Due to such construction, the circulating pump (P) can be controlled such that the revolution of the motor (M) is readily and smoothly varied by way of a frequency modulation effected by the inverter (E) to provide the injection of hot water in various modes which are different in the injection amount and pressure of the injected hot water, while assuring a maximum degree of safety of a bather.

Description: TECHNICAL FIELD The present invention relates to a whirlpool bath with an inverter-controlled circulating pump. BACKGROUND OF INVENTION For giving a massaging effect to a bather, there has been a whirlpool bath unit which injects air-incorporated water into a bathtub. This known whirlpool bath unit comprises a bathtub, a circulating pump disposed separate from the bathtub, a return passage having one end connected to the circulating pump and the other end opening into the bathtub, a return passage having one end connected to the circulating pump and the other end opening into the bathtub, a water injection passage having one end connected to the circulating pump and the other end connected to branch passages opening into the bathtub, and an air-mixing unit connected to the water injection passage to mix air into the water flowing through the water injection passage. Recently, as one of improvements on such whirlpool bath unit, a whirlpool bath employing an inverter to drive the motor of the circulating pump has been proposed in Japanese laid-open utility-model application 63-100035, wherein the the revolutions of the motor is varied smoothly by the inverter to control the discharge pressure and discharge rate of the blow-off water. The AC output of the inverter, however, includes much high-frequency components as shown in Figs. 51 and 52. The high-frequency components leak into the field core due to the capacitive coupling of the field core and winding of the motor. When the motor is not grounded perfectly, there is the danger of a bathing person bathing in the bathtub being struck by the leakage high-frequency components that flow through the circulating pump into the water contained in the bathtub. Since one of the conductors of a commercial power source is grounded withot exception, the bathing person may possibly be struck by an high-frequency current generated by the inverter when the bathing person touches a grounded part of the whirl pool bath unit, because the high-frequency current flows through a circuit: the inverter →the winding of the motor → (capacitive coupling)→the field core of the motor→ the circulating pump → water→ bathing person →the grounded part→ the ground → the grounded line of the commercial power source → lines connecting the commercial power source to the inverter→the inverter. If the inverter and the circulating pump is connected electrically by a case or the like, the bathing person is struck by a high-frequency current generated by the inverter that flows through a circuit: the inverter→the case→the circulating pump→water →the bathing person→ the grounded part →the ground→the grounded line of the commercial power source→lines connecting the commercial power source to the inverter → inverter. Accordingly, it is an object of this invention to provide a whirlpool bath which can resolve such problems. DE-A-3 447 161 discloses a whirlpool bath having the features specified in the preamble of the appended claim 1. However, it fails to disclose interposing an electrically isolating transformer between the inverter and a commercially available power source and to connect a motor casing of the circulating pump to an intermediate point of the commercially available power source. SUMMARY OF THE INVENTION The invention provides a whirlpool bath having the characterizing features mentioned in the characterizing portion of the appended claim 1. The further following features are optionally considered. (a) The circulating pump and the inverter are accomodated in a functional unit and an electric insulation is provided between the circulating pump and the inverter, as well as between the inverter and the functional casing. (b) A motor portion and a pump portion of the circulating pump are integrally constructed and the motor portion and the pump portion are electrically insulated from each other. (c) The inverter is electrically insulated from a functional casing which accommodates said inverter therein and a capacity coupling between the inverter and the functional casing is minimized. (d) A functional unit is disposed remote from the bathtub body and, in the functional casing, the circulating pump is disposed at the center of the casing, a filter is disposed beside the circulating pump, and above these elements, a motor portion and electric parts such as the control unit and the inverter are disposed. (e) A line filter is interposed between said inverter and a commercially available power source. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 is a perspective view of a whirlpool bath according to the present invention; Fig.2 is a plan view of the whirlpool bath. Fig.3 is a conceptive explanatory view of the construction of the whirlpool bath; Fig.4 is an explanatory view of an air intake piping; Fig.5 is an enlarged sectional view of a blow-off nozzle; Fig.6 is a side elevational view of the blow-off nozzle; Fig.7 is a cross-sectional view taken on line I-I of Fig.5; Fig.8 is an enlarged cross-sectional view of a nozzle valve actuating motor; Fig. 8a is an enplanatory view showing the manner of mixing air into the hot water by a conventional blow-off nozzle. Fig.8b is an enplanatory view showing the manner of mixing air into the hot water by the blow-off nozzle of the present invention. Fig.8c is an enlarged longitudinal cross sectional view of a hot water suction port fitting of the whirlpool bath. Fig.8d is an enlarged explanatory view showing the essential part of the hot water suction port fitting. Fig.8e is an enlarged front view of the decorative cover of the hot water suction port fitting. Fig.9 is an enlarged vertical cross-sectional view of an air intake portion provided with an operating panel on the top thereof. Fig. 9a is an enlarged cross-vertical sectional view of an air intake port provided with an operating panel on the top thereof taken along the line II-II of Fig.9. Fig.9b is a plan view of the air intake port where the operating panel is mounted. Fig.10 is a front cross-sectional elevational view of a functional unit in which a circulating pump is installed. Fig.11 is a cross-sectional plan view of a functional unit taken along the line III-III of Fig.10. Fig.12 is a cross-sectional plan view of a functional unit taken along the line IV-IV of Fig.10. Fig.13 is a partially-cut-away elevational view of the circulating pump provided with a pump-operating motor. Fig. 13a is a schematic view of a filter used for cleaning hot water and filter element periodically. Fig. 14 is a plan view of a remote controller; Fig. 15 is a side view of the remote controller; Fig. 15a is a longitudinal cross-sectional view of the remote controller. Fig.15b is a partially cut-away plan view of the remote controller showing the inner construction thereof. Fig.15c is a transverse cross-sectional side view of the above remote controller. Fig.15d is a rear-side view of the above remote controller showing the batter storage portion. Fig.15e is a partially-cut-away plan view of a modification of the remote controller. Fig.15f is a cross-sectional plan view of the above remote controller showing the inner construction thereof. Fig.15g is a longitudinal cross-sectional side view of the above remote controller taken along the line V-V of Fig.15f. Fig.15h is a blow mode pattern showing the mild blow operation. Fig.15i is a blow mode pattern showing the spot blow operation. Fig.15j is a blow mode pattern showing the pulse blow operation. Fig.15k is a blow mode pattern showing the cycle blow operation. Fig.15l is a blow mode pattern showing the wave blow operation. Fig.15m is a blow mode pattern showing the random blow operation. Figs.16a and 16b are explanatory views of blow-off volume blow-off pressure characteristics; Figs.17a and 17b are explanatory views of blow-off nozzle characteristics; Fig.18 is an operation timing chart of each blow-off nozzle and the circulating pump in a mild blow mode; Fig.19 is an operation timing chart of each blow-off nozzle and the circulating pump in a child safety blow mode; Fig.20 is an operation timing chart of each blow-off nozzle and the circulating pump in a spot blow mode; Fig.21 is an operation timing chart of each blow-off nozzle and the circulating pump in a pulse blow mode; Fig.22 is an operation timing chart of each blow-off nozzle and the circulating pump in a wave blow pattern A; Fig.23 is an operation timing chart of each blow-off nozzle and the circulating pump in a wave blow pattern B; Fig.24 is an operation timing chart of each blow-off nozzle and the circulating pump in a wave blow pattern C; Fig.25 is an operation timing chart of each blow-off nozzle and the circulating pump in cycle blow patterns A and B; Fig.26 is an operation timing chart of each blow-off nozzle and the circulating pump in a cycle blow pattern C; Figs.27 to 32 are operational flow charts of the whirlpool bath; Fig.33 is an explanatory view of reference positions for water level detection; Fig.34 is an explanatory view of a level detecting method; Fig.35 is an explanatory view of a water temperature detecting method; and Fig.36 is an explanatory view of a hot wter blow-off position changing operation. Fig.37 is block diagram of an inverter circuit for controlling the power-operated motor of the circulating pump. Figs.38 to 45 are explanatory views showing the various characteristic curves on the blow-off pressure and volume of the hot water achieved by the inverter-controlled motor of the present invention. Fig.46 is a block diagram of an electricity insulation circuit. Fig.47 and Fig.48 are block diagrams of the essential part of the circuit. Fig.49 and Fig.50 are graphs showing the leakage high-frequency voltage and leakage high-frequency current with time according to the electricity insulation circuit of the present invention. Fig.51 and Fig. 52 are graphs showing the leakage high-frequency voltage and leakage high-frequency current with time of the conventional inverter circuit. Fig.53 to Fig.55 are block diagrams of the circuit of another electricity insulation means. Fig.56 is a block diagram of the circuit of still another electricity insulation means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A whirlpool bath embodying the present invention will be described in detail below according to the following items with reference to the accompanying drawings. [I] Description of the Whole of the Whirlpool Bath [II] Description of the Construction of Various Portions [II-1 ] Description of the Construction of Blow-off Nozzles [II-2 ] Description of the Construction of Hot Water Suction Port [II-3 ] Description of the Construction of Air Intake Portion [II-4 ] Description of Functional Unit [II-5 ] Description of Circulating Pump [II-6 ] Description of Filter [II-7 ] Description of Controller [II-8 ] Description of Operating Panel [II-9 ] Description of Remote Controller [II-10] Description of Inverter [III] Description of Blow-off Modes [III-1 ] Mild Blow [III-2 ] Spot Blow [III-3 ] Pulse Blow [III-4 ] Wave Blow [III-5 ] Cycle Blow [III-6 ] Program Blow [IV] Description of the Operation of the Whirlpool Bath [IV-1 ] Description of Operation Procedure based on Flow charts [IV-2 ] Description of Conditions for Starting Blow Operation [IV-3 ] Description of State Transition of Blow-off Modes [IV-4 ] Description of State Transition of Hot Water Blow-off Positions [IV-5 ] Description of state Transition of Strength Level in Blow Operation [IV-6 ] Description of Priority Main Operations [IV-7 ] Control Timing between Opening/Closing of Blow-off Volume Adjusting Valves and Change of the Number of Revolutions of Circulating Pump [IV-8 ] Electricity insulation against high frequency components of current generated by the inverter [I] Description of the Whole of the Whirlpool Bath First, the construction of the whole of the whirlpool bath according to the invention will be described below. In Figs.1 and 2, the reference mark A denotes the whirlpool bath according to the present invention. The whirlpool bath A has a total of six leg-, back- and belly-side blow-off nozzles 2,2; 3,3; 4,4 formed in the front wall, rear wall, and right and left side walls, respectively, of a bathtub body 1 formed in the shape of a box whose upper surface is open. The bathtub body 1 has a marginal flange-like portion 1a, and an air intake portion 5 is formed in the marginal flange-like portion 1a. Further, a pair of vertically long recesses 1b, 1b which are generally V-shaped in cross section are formed in approximately central portions of the right and left side walls, and the belly-side blow-off nozzles 4,4 are mounted in inclined surfaces 1 ′ b, 1 ′ b of the recesses 1b, 1b which surfaces face the rear wall (back side), the nozzles 4, 4 being mounted toward the central part of the rear wall. The belly-side blow-off nozzles 4, 4 are provided in positions higher than the leg- and back-side blow-off nozzles 2,2, 3,3 so that hot water can surely be applied to the belly, the breast and other portions of the human body. Outside of the whirlpool bath A is disposed a functional unit 9. Within the functional unit 9, as shown in Fig.10 to Fig.12, there are provided a hot water circulating pump P, a filter 43 for filtering the hot water which is circulated by the pump P, a pump driving motor M for driving the pump P, and a control ler C for controlling the operation of the pump driving motor M as well as the operations of later-described nozzle valve actuating motors M1, bubble volume adjusting valve actuating motors M2 and a motor-driven three-way valve 45. The functional unit 9 and the inside construction thereof are described in detail later in conjunction with Fig.10 to Fig.12. Between the circulating pump P and the whirlpool bath A, there is disposed a hot water circulation path D as shown in Fig.1 and Fig.3. The hot water circulation path D is composed of a hot water suction pipe 10 for sucking hot water from the whirlpool bath A into the circulating pump P and a hot water forced-feed pipe 11 for feeding hot water from the circulating pump P to the inside of the bathtub body 1. As shown in Fig.3, one end of the hot water suction pipe 10 is connected to a suction port 1m which is open in a lower part of the bathtub body 1, and the other end thereof is connected to a suction port of the circulating pump P for the suction of hot water into the circulating pump P. On the other hand, the hot water forced-feed pipe 11 is connected at one end thereof to a discharge port of the circulating pump P and it has opposite end portions connected to the blow-off nozzles 2,3,4. The suction port 1m is provided in a position lower than the leg-and back-side blow-off nozzles 2,3. The suction port 1m is explained in detail later in view of Fig.8c and Fig.8d. Between the circulating pump driving motor M and the controller C, there is disposed an inverter E, as shown in Fig. 3. The number of revolutions of the circulating pump P is controlled by varying the output frequency of the inverter E, whereby the change of the number of revolutions of the pump P which corresponds to the change of blow-off volume and pressure of hot water can be done smoothly and with certainty. As shown in Fig.3, moreover, a pressure sensor 48 for detecting the flow pressure of hot water being fed under pressure through the hot water forced-feed pipe 11 is mounted halfway of the pipe 11. The result of detection from the pressure sensor 48 is fed to the controller C, which in turn controls the volume of pressure of hot water to be blown off from the nozzles 2,3,4 by changing the number of revolution of the pump driving motor M and the degree of opening or that of closing of each of those nozzles 2,3,4. The pressure sensor 48 also serves as a level sensor for detecting the level of hot water in the bathtub body 1 when the circulating pump P is not operated. Namely, the whirlpool bath A being considered above is constructed such that, when the hot water level is found to be below a predetermined certain level by the use of the pressure sensor 48 which works as a level sensor, blow operation, freeze proofing operation, filter washing operation and automatic filter washing operation which are started by the controller C as described later are not yet started. A hot water temperature sensor T for detecting the temperature of hot water being fed under pressure through the hot water forced-feed pipe 11 is mounted in a halfway position of the pipe 11, as shown in Fig.3. The result of detection from the temperature sensor T is fed to the controller C, which in turn controls the pump driving motor M and the blow-off nozzles 2,3,4. When the hot water temperature is found to be lower than a predetermined certain temperature by the use of the hot water temperature sensor T, the later-described blow operation, freeze proofing operation, filter washing operation and automatic filter washing operation which are started by the controller C are not started. In other words, so long as the water level and temperature of hot water are lower than the respective predetermined certain levels, the later-described blow operation, freeze proofing operation, filter washing operation and automatic filter washing operation by the controller C are not started. As shown in Figs.1, 4, 9, 9a and 9b, a plurality of air intake pipes 12 are disposed between the air intake portion 5 and the blow-off nozzles 2,3,4. From halfway portions of the air intake pipes 12, there are formed air suction pipes 12a, 12b, 12c toward the blow-off nozzles 2,3,4. The ends of the air suction pipes 12a,12b,12c are connected to the nozzles 2,3,4 respectively. The air which has been taken in from the air intake portion 5 is introduced into the blow-off nozzles 2,3,4 through the air suction pipes 12a,12b,12c of the air intake pipe 12 by utilizing a negative pressure generated at the time of blow-off of hot water from the nozzles 2,3,4 whereby air-mixed bubbling hot water can be blown off into the bathtub body 1 from those nozzles 2,3,4. In the vicinity of the bathtub body 1, there is disposed an operating panel 6, as shown in Figs. 1 and 3 so that the operation of the whirlpool bath A can be done by the operating panel 6. This operating panel 6 will be described later. As shown in Fig. 3b, numeral 30b denotes an infrared ray sensor provided on the operating panel 6. The infrared ray sensor 30b is for sensing infrared ray emitted from a later-described remote controller 30. In the above construction, the gist of the present invention resides in that the of opening and that of closing of each of the leg-, back- and belly-side blow-off nozzles 2,3,4 whose blow-off volumes can be varied automatically, and the number of revolutions of the circulating pump P is varied by employing an inverter between the circulating pump P and a power source and the inverter is contorlled by the controller C to obtain various blow-off modes (mild blow, spot blow, pulse blow, wave blow, cycle blow, and program blow) as will be described in detail later in order to fully satisfy various likings of bathing persons. In this embodiment, however, for obtaining various blow-off modes, the degree of opening and that of closing of blow-off nozzles 2,3,4 and the number of revolutions of the circulating pump P are varied. In this embodiment, the blow strength can be varied by controlling the number of revolutions of the circulating pump P, and further in that various blow-off positions can be selected so that hot water jets of a desired strength can be applied to desired portions of the bathing person's body to obtain a sufficient massaging effect induced by the hot water jets. Particularly, in this embodiment, besides the inverter which is provided for controlling the circulating pump P, an electricity insulation means is provided for assuring the maximum degree of the safety of a bather taking a bath. [II] Description of the Construction of Various Portions [II-1 ] Description of the Construction of Blow-off Nozzles The leg-, back- and belly-side blow-off nozzles 2,3,4 are automatic blow-off volume changeable nozzles of the same construction in which the blow-off volume and pressure of hot water can be changed automatically. The structure of a leg-side blow-off nozzle 2 will be described below with reference to Figs. 5 to 8. The leg-side blow-off nozzle 2 is constructed as follows. A cylindrical nozzle casing 20 is connected to a leg-side blow-off nozzle connection port 1g of the bathtub body 1 in a cantilevered form outside the bathtub body 1 as shown in Fig.5. The interior of the nozzle casing 20 is composed of a hot-water-jet forming portion ( or a turbulent-hot-water-flow forming portion) 50 for forming the hot-water supplied into the nozzle casing 20 from the hot water forced-feed pipe 11 into a hot-water-jet or a turbulent-hot water-flow; an air mixing portion 70 communicating with the air intake portion 5 through the air intake pipe 12 and functioning to mix air into the hotter jet fed from the hotter-jet forming portion 50; and a throat portion 59 which decides the blow-off direction of air-mixed bubbling hot water blown off from the throat portion 59 toward the interior of the bathtub body 1. As shown in Fig. 5, the front end of the nozzle casing 20 is connected in a watertight manner to the leg-side blow-off nozzle connection port 1g which is circular and is open in a lower part of the front wall of the bathtub body 1, while the rear end thereof is extended backwards substantially horizontally. Numeral 1h denotes a ring-shaped packing having the outer circumferential portion thereof snugly and water-tightly fitted in the connection port 1g along the peripheral edge of the same port 1g; numeral 1i denotes a nozzle mounting sleeve which has an enlarged-flange portion 1j at one end thereof and an outer male threaded portion 1k on the other end thereof. The enlarged-flange portion 1j is abutted to the front end surface of the ring-shaped packing 1h while the outer male threaded portion 1k is meshed to an inner threaded portion 1p so as to fixedly mount the nozzle 2 on the side wall of the bathtub body 1. Numeral 20c in Fig.6 and Fig.7 denotes a forced-feed pipe connecting portion to which the hot water forced-feed pipe 11 is connected replaceably. The arrow n indicates a hot water inflow direction. Numeral 26 denotes a decorative cover having a front end portion 26b which covers both the front end of the nozzle casing 20 and the enlarged-flange portion 1j of the nozzle mounting sleeve 1i. And a later-described throat fixing member 25 is fixed by the rear end of the decorative cover 26. On the outer peripheral surface of the decorative cover 26 which is cylindrical as a whole, there is formed an outer threaded portion 26a, which is threadedly engaged disengageably with an internal threaded portion 20j formed on the inner peripheral surface of the front end portion of the nozzle casing 20. The throat portion 59 is composed of a throat 24, a throat fixing member 25 which supports the throat 24 in a tiltable manner, and a front portion of a valve seat forming cylindrical body 21. Numeral 24a denotes a throat base having a spherical outer peripheral surface; numerals 25a and 21c denote throat supporting surfaces formed on the inner periphery of the throat fixing member 25 and that of the valve seat froming cylindrical body 21, respectively, to support the throat base 24a slidably; and numeral 24b denotes a throat tip which is cylindrical and whose outside diameter is smaller than that of the throat base 24a. The tilting angle of the throat tip 24b is manually adjustable in the vertical and horizontal directions about the base 24a. Besides, the throat 24 can be stopped at any desired tilted angle by a predetermined certain sliding resistance exerted from the the throat supporting surfaces 25a, 21c on the base 24a of the throat 24. The reference mark S denotes a space for throat tilting formed between the outer peripheral surface of the throat tip 24b and the inner peripheral surface of the decorative cover 26. The throat fixing member 25 is fitted in the front portion of the nozzle casing 20 through a positioning groove formed in the inner peripheral surface of the casing front portion, and its front face 25b is fixed to the rear end of the decorative cover 26 by means of a fixing ring 28. Further, its throat supporting surface 25a formed on the inner periphery supports the outer peripheral surface of the front portion of the throat base 24a slidably. The valve seat forming cylindrical body 21 is inserted into the central portion of the nozzle casing 20 removably from the front-end opening 1g of the nozzle casing 20 so that its rear end face is positioned in the vicinity of the forced-feed pipe connecting portion 20c, and a convex stepped portion 21b formed on the outer peripheral surface of the front portion of the cylindrical body 21 is engaged with a concave stepped portion 20i formed in the inner peripheral surface of the nozzle casing 20 to prevent a backward slide of the cylindrical body 21. The throat base 24a is fitted in the front portion of the valve seat forming cylindrical body 21 in contact with the throat supporting surface 21c formed on the inner peripheral surface of the said front portion. In this state, a forward slide of the valve seat forming cylindrical body 21 is prevented by the throat base 24a whose forward slide is prevented by the throat fixing member 25. The hot-water jet forming portion 50 is composed of a valve seat 21a which defines interiorly a hot-water jet forming path 27; a blow-off volume adjusting valve element 22 which comes into contact and moves out of contact with the valve seat 21a to adjust the degree of opening and that of closing of the hot water jet forming path 27 (that is, adjust the blow-off volume and pressure of blown-off hot water); a nozzle valve actuating motor M1 for actuating the blow-off volume adjusting valve element 22; and a rear wall forming plate 29. In Figs. 6 and 7, the numeral 21d denotes an air inflow path formed annularly along the outer peripheral surface of the valve seat forming cylindrical body 21; and numerals 21e, 21f represent air inlet openings formed on the side of an air intake pipe connecting portion 20b and on the side opposite to the connecting portion 20b, respectively, in the air inflow path 21d. The interior of the valve seat forming cylindrical body 21 and the air intake pipe connecting portion 20b are communicated with each other through the air inlet openings 21e, 21f to form the air mixing portion 70 within the cylindrical body 21. The reference mark m indicates an air inflow direction. According to the construction of the nozzle valve actuating motor M1 shown in Fig.5 and Fig.8, a cylindrical motor casing 23 is attached to the rear wall forming plate 29 removably; a cylindrical coil 23a is mounted within the motor casing 23 coaxially with the nozzle casing 20; a cylindrical magnet 23b is disposed inside the coil 23a, which magnet can be rotated forward and reverse by energizing the coil 23a; a cylindrical rotor nut 23c is mounted in the interior of the magnet 23b concentrically and integrally, which rotor nut 23c is journalled rotatably in bearings 23e; and a valve-element supporting rod 23d with the blow-off volume adjusting valve element 22 mounted on the front end thereof is extended through the rotor nut 23c so as to be slidable forward and backward axially. Further, a spiral rotor nut-side ball groove 23k is formed in the inner peripheral surface of the rotor nut 23c, while in the outer peripheral surface of the valve-element supporting rod 23d, there is formed a spiral rod-side ball groove 23m in the same direction as the rotor nut-side ball groove 23k, and a plurality of balls 23n are interposed for rolling between the opposed rotor nut-side ball groove 23k and rod-side ball groove 23m. Numeral 23g denotes a rotation preventing member for preventing the valve supporting rod 23d from rotating toghther with the rotor nut 23c, thus converting the rotating movement of the rotor nut 23c to the reciprocating linear movement of the valve-element supporting rod 23d. On the rear end of the valve-element supporting rod 23d, there is mounted a valve operation checking sensor 23f for detecting the normal operation of the nozzle valve actuating motor M1. Namely, if the sensor 23f generates an output signal, this implies that, with the activation of the motor M1, the valve-element supporting rod 23d and the valve element 22 are retracted from the reference position ( full valve-closed position ) so as to open the the hot water jet forming path 27. In other words, during the blow operation, if the valve operation checking sensor 23f generates no output signal, it implies that the nozzle valve actuating motor M1 is in trouble. The sensor 23f is composed of a position detecting Hall elelment 23i and a position detecting magnet 23j attached to the valve supporting rod 23d in a rear end position opposed to the Hall element 23i. The degree of opening of the hot water jet forming path 27 corresponds to the movement of the valve-element supporting rod 23d, which, in turn is proportional to the number of pulses (rotational angle) from the reference position ( full valve-closed position of the nozzle valve actuating motor M1). Accordingly, such degree of opening of the hot water jet forming path 27 is accurately and finely adjusted by controlling the nozzle valve actuating motor M1 by the controller C. As shown in Fig.5, an electrical connection for the nozzle valve actuating motor M1 substantially comprises an edge connector 23p and 23q, a flexible flat cable 23r and a sheath protected cable 23s. The edge connector 23p is made of a socket 23t which is connected to the flexible flat cable 23r and a plug 23u which is one end removably inserted into the socket 23t and the other end connected to the coil 23a of the nozzle valve actuating motor M1. In the nozzle valve actuating motor M1 of the above construction, the rotor nut 23c is rotated ether with the magnet 23b by energizing the coil 23a, and the valve supporting rod 23d is moved forward or backward interlockedly with the rotation of the rotor nut 23c, whereby the blow-off volume adjusting valve element 22 mounted on the front end of the valve supporting rod 23d is moved into contact with or away from the valve seat 21a to adjust the blow-off volume and pressure of hot water into the bathtub body 1. As to the degree of opening or that of closing of the blow-off volume adjusting valve element 22, the result of detection of the reference position performed by the valve operation checking sensor 23f is fed to the controller C, which, in turn, controls the energization of the coil 23a to open or close the valve element 22 to an appropriate degree, so that there can be effected a fine adjustment of the volume and pressure of the hot water to be blown off into the bathtub body 1. The nozzle valve actuating motor M1 is not specially limited if only it can move the blow-off volume adjusting valve element 22 steplessly at a very small distance to make a fine adjustment of the volume and pressure of hot water to be blown off. There may be used a piezoelectric actuator. Numeral 40 denotes a bellows-like water-proof cover formed integrally with the blow-off volume adjusting valve element 22. The rear wall of the nozzle casing 20 is enlarged so as to form a motor portion 20p which, along with a cover lid 20r, defines a motor portion storing space 20q in which a motor portion of the nozzle valve actuating motor M1 is installed. Numeral 29a and 29b denotes packings provided on the circumferential surface of the rear wall forming plate 29, while numeral 29c denotes a packing provided on the circumferential surface of the valve seat forming cylindrical body 21. Numeral 23v is a water leakage sensor which is mounted on a printed circuit 23w. Upon detecting the presence of water in the motor portion storing space 20q, the controller C stops the activation of the valve-element actuating motor M1. Due to such construction, the accident that the electricity leaks to the bather from the nozzle valve actuating motor M1 to the hot water filled in the interior of the bathtub body 1 can be prevented. Furthermore, as shown in Fig.5, the outside diameter of the motor casing 23 is made smaller than the inside diameter of a rear-end opening 20k of the nozzle casing 20. Due to such construction, the nozzle valve actuating motor M1 can be inserted into the nozzle casing 20 removably from the front-end opening of the latter. Namely, the leg-side blow-off nozzle 2 can be disassembled from the interior of the bathtub body 1. In disassembling operation, the decorative cover 26 is first removed and a nozzle mounting sleeve 1i is removed. Subsequently, the fixing ring 28, the throat fixing member 25, the throat 24 and the valve seat forming cylindrical body 21 are removed. Finally, the nozzle valve actuating motor M1 is removed together with the rear wall 29 while assuring the electrical connection due to the elongated flexible flat cable 23r, thus facilitating the maintenance of the nozzle valve actuating motor M1. Also, the back-and belly-side blow-off nozzles 3, 4 are of the same construction as that of the blow-off nozzle 2 described above to permit adjustment of the volume and pressure of hot water to be blown off. Adjustment of the blow-off nozzles 2,3,4 can be performed by the operating panel 6 or the wireless remote controller 30 as will be described later. There are two kinds of using patterns of the six leg-, back and belly-side blow-off nozzles 2, 3, 4 described above. According to one pattern, hot water is blown off from all of the six nozzles 2,3,4 at a time, while according to the other pattern, one or two kinds of nozzles are selected and used, as will be later explained with reference to Figs.36. Each use pattern can be selected by a blow-off nozzle use pattern change-over switch on the operating panel 6 or of the wireless remote controller 30. The following description is now provided about initializing (adjusting) the nozzle valve actuating motor M1 in the blow-off nozzles 2,3,4. When the power is turned ON (when the plug is inserted): 1 ○ The nozzle valve actuating motor M1 is driven in a closing direction of the blow-off volume adjusting valve element 22 for 0.5 second at a normal voltage (e.g. 12V), 50 pps. 2 ○ The nozzle valve actuating motor M1 is driven in a closing direction of the blow-off volume adjusting valve element 22 for 1.5 second at a low voltage (e.g. 4V), 200 pps. Then, in a completely closed position, the motor M1 is allowed to step out for a certain time (e.g. 2 seconds) to make initialization. 3 ○ The nozzle valve actuating motor M1 is driven at a normal voltage (e.g. 12V), 200 pps, to retreat the blow-off volume adjusting valve element 22 by 6 mm from the initialized, completely closed position. Initialization (adjustment) can be done by operating the nozzle valve actuating motor M1 like the above 1 ○ to 3 ○. The numerical values mentioned above are examples and constitute no limitation. By such initialization (adjustment) of the nozzle valve actuating motor M1, there are obtained the following effects. a) By the above operation 1 ○, it is possible to remove oil sticking to the sealing portion and ensure a subsequent smooth operation of the motor M1. b) By the above operation 2 ○, the blow-off volume adjusting valve element 22 can be brought into abutment with the valve seat 21a at a relatively low urging force, so it is possible to prevent damage, etc. of the valve element 22 and the valve seat 21a. c) By the above operation 3 ○, the blow-off volume adjusting valve element 22 is retreated and opened 6 mm from the completely closed position, thereby permitting smooth feed and drain of hot water. Further, at the time of start of a later-described blow operation, the above operations 2 ○ and 3 ○ of the nozzle valve actuating motor M1 are performed, whereby the mild blow as an initializing blow can be effected smoothly. In Fig.8a, the manner of mixing air into the hot-water flow with a conventinal blow-off nozzle 1000 is shown. As can be readily understood from the drawing, the air passes through the blow-off nozzle 1000 along the upper inner surface of thereof so that the hot water blown off from the blow-off nozzle 1000 contains a small amount of air therein resulting in the poor massaging effect. According to the blow-off nozzle 2 of the present invention, due to the provision of the hotter jet path 27 and the reciprocating valve element 22, a vigorous hot-water jet flow or the turbulent hot-water flow is produced and the air from the air intake portion 5 is sufficiently mixed to the hot-water jet flow whereby the hot water flow blown off from the blow-off nozzle 2 contains a large amount of air therein resulting in the extremely effective massaging effect including stimulating effect and relaxing effect. [II-2 ] Description of the Construction of Hot Water Suction Port The construction of a suction port fitting 350 which is attached to the suction port 1m is described hereinafter. As shown in Figs. 8c, 8d and 8e, the front end of a cylidrical sleeve 351 is connected in a watertight manner to the suction port 1m of the bathtub body 1 which is circular and is open in a lower part of the side wall of the bathtub body 1, while the rear end thereof is extended backwards substantially horizontally. Numeral 352 indicates a ring-shaped packing having the outer circumferential portion thereof snugly and water-tightly fitted in the suction port 1m along the peripheral edge of the same port 1m. Numeral 353 indicates a sleeve mounting collar which has an enlarged flange portion 354 at one end thereof and an outer male threaded portion 355 on the other end thereof. The enlarged-flange portion 354 is abutted to the front end surface of the ring-shaped packing 352 while the outer male threaded portion 355 is meshed to an inner threaded portion 356 of the cylindrical sleeve 351 so as to fixedly mount the suction port fitting 350 to the side wall of the bathtub body 1 in a cantilever manner. Numeral 357 indicates a suction-pipe connecting portion of the cylindrical sleeve 351 to which one end of the hot water suction pipe 10 is connected. In the cylindrical sleeve 351, an annular filter element 358 is provided so as to prevent dust such as human hair from entering into the circulating pump P whereby the occurrence of trouble on the circulating pump P can be effectively prevented. The filter element 358 is fixedly and stably attached to the inside of the cylidrical sleeve 351 by means of a filter support 359 which has a proximal end fixedly mounted on the inner wall of the cylindrical sleeve 351. For enabling a quick and firm mounting and replacement of the filter element 358 to the filter support 359, a threaded shaft 360 is threaded into a female threaded hole 361 formed in the filter support 359 and an annnular protrusion 362 and an annular groove 363 are formed on the outer surface thereof and at the midst portion thereof while an annular groove 364 is formed in the inner surface of the filter support 359 at a position correspondent to the groove 363 and an O-ring 365 is accommodated in a space defined by two grooves 363 and 364. Furthermore, the suction port fitting 350 is also provided with a decorative cover 366 and such cover 366 has the central portion thereof connected to the head surface of the threaded shaft 360. As shown in Fig.8e, such decorative cover 366 is provided with a plurality of arcuate openings 367 for preventing the dust of considerable size from entering into the hot water circulation path D. Numeral 368 indicates a pair of auxiliary suction-pipe connecting portions of the cylindrical sleeve 351 which are usually closed by plugs or lids and opened in case the hot water suction pipe 10 must be led to the hot water suction port 1m from different direction. [II-3 ] Description of the Construction of Air Intake Portion The construction of the air intake portion 5 will be described below. As shown in Figs. 9, 9a and 9b, the air intake portion 5 is mounted on the marginal flange-like portion 1a of the bathtub body 1. The intake portion 5 is composed of a rectangular box-shaped air intake body 92 having an open top and containing a plurality of silencers 92a,92b in two rows; a cover 82 having an air intake port 82a formed outside and covering the top opening of the air intake body 92; a plural ity of air intake pipe connecting portions 83a, 83b, 83c having upper ends thereof connected to the silencers 92b and lower ends connected to the air suction pipes 12a, 12b, 12c; and a plurality of air volume adjusting valves 87a, 87b, 87c disposed in communication paths which bridge between the silencers 92b and the air intake pipe connecting portions 83a, 83b, 83c to open and close the above communication paths. Due to such construction, a finely regulated amount of air can be fed to the blow-off nozzles 2,3,4 through the air suction pipes 12a,12b and 12c. Each air volume adjusting valve 87a, 87b, 87c is composed of a cylindrical valve body 88 having an upper edge which defines an opening 88a; an air volume adjusting valve actuating motor M2 mounted to the bottom of the cylindrical valve body 88; a valve element supporting rod 89 connected to the motor M2; and a valve element 90 mounted to the front end of the rod 89 and capable of moving into and out of contact with a valve seat 88b formed at the upper edge of the valve body 88. Numeral 88d denotes a communication opening formed in the peripheral wall of the valve body 88. The air volume adjusting valve actuating motor M2 is of a linear stepping motor structure which is the same as the structure of the nozzle valve actuating motor M1, and it can be controlled by the controller C as will be described later. In this embodiment, however, there is not performed an adjustment of the air volume through the valve element 90 by driving the motor M2 during the blow operation, but there is performed the blow operation in a preset air volume. Numerals 93a,93b denote a pair of upper and lower silencer-supporting plates disposed horizontally in two rows within the air intake body 92 to support the silencers 92a,92b. A plurality of communication holes 94a,94b which are formed in silencers 92a,92b of the upper row are respectively aligned with a plurality of communication holes 94a,94b which are formed in silencers 92a,92b of the lower row. The reference mark r indicates an air inflow direction. Furthermore, as can be understood from Figs. 9, 9a and 9b, the operationg panel 6 is incorporated into the cover 82 and when an panel cover 6a is opened, a panel switching surface 6b is readily accessible thus facilitating the blow off operation together with a remote controller 30 which will be described later in details. [III-4 ] Description of Functinal Unit The construction of the functional unit 9 is hereinafter explained in view of Fig.10, Fig.11 and Fig.12. The functional unit 9 includes a rectangular box-shaped casing 60 which is made of a upper plate 60a, a bottom frame 60b, a pair of side plates 60c,60d, a front plate 60e and a rear plate 60f. In the inner space defined within the functional unit 9, a virtually horizontal shelf 61 made of three frame members 61a,61b and 61c is bridged between the side plates 60c,60d defining an upper storing space 62 and a lower storing space 63. In the upper space 62, a plurality of electric devices are disposed while, in the lower space 63, a plurality of substantially non electric devices are disposed. Namely, a leakege breaker 64 and an insulating transformer 65 are mounted on the frame member 61a, a power source transformer 66 and a noise filter 67 are mounted on the frame member 61b and the control unit C and an inverter E are mounted on the frame member 61c. On the bottom frame 60b, the circulating pump P privided with a cold-proofing heater and the filter 43 for cleaning hot water are mounted on the bottom frame 60b. Due to such construction, the electrical insulation between the electric devices and non-electric devices are reliably achieved whereby the leakege of electricity from electric devices to the hot water in the bathtub body 1 by way of non-electric devices can be compeletely prevented assuring the complete safety of the bather. Referring to other construction in the functional unit 9, a plurality of rubber connections 68 are provided at junctions of various pipings in the functional unit 9. For providing a ventulation of the functinal unit 9, a gallery 69 are provided on both side plates 60c,60d of the casing 60. [III-5 ] Description of Circulating Pump The construction of the circulating pump P will be described below. The circulating pump P has such a construction as shown in Fig.13. An upper impeller chamber 33 and a lower impeller chamber 34 are communicated with each other through a communication path 32d in a pump casing 32. The lower impeller chamber 34 is in communication with the hot water suction pipe 10 through a hot water suction path 32a formed on one side of the lower portion of the pump casing 32, also with the hot water forced-feed pipe 11 through a hot water forced-feed path 32b formed on the other side of the lower portion of the pump casing 32, and further with one end of an incoming pipe 41 of the filter 43, which will be described later, through a filtering forced-feed path 32c formed on one side of the upper impeller chamber 33. Numeral 32e denotes a suction port; numeral 32f a lower discharge port; numeral 32g an upper discharge port; z1 indicates a circulation flow direction; and z2 indicates a filtration flow direction. An impeller shaft 35 extends vertically through the centers of the upper and lower impeller chambers 33, 34, and upper and lower impellers 33a, 34a are mounted on the impeller shaft 35 coaxially within the upper and lower impeller chambers 33, 34, respectively. The impeller shaft 35 being interlocked with a drive shaft 39 of the pump driving motor M which is mounted on the pump casing 32 integrally in a watertight manner. Numeral 36 denotes a sealing member which ensures watertightness of the interior of the pump casing 32. To the upper impeller chamber 33 of the circulating pump P is connected filter 43 through the incoming pipe 41 and a return pipe 42, as shown in Fig.13a. A portion of the hot water which has been sucked into the lower impeller chamber 34 is fed to the filter 43 through the incoming pipe 41 connected to the upper discharge port 32g of the upper impeller chamber 33, then the hot water filtered by the filter 43 is fed to the hot water forced-feed pipe 11 through the return pipe 42 and joined to the hot water being fed forcibly into the pipe 11 from the lower discharge port 32f of the lower impeller chamber 34. Under the above construction, upon rotation of the upper impeller 33a, the hot water in the bathtub body 1 is sucked into the hot water suction path 32a of the lower impeller chamber 34 through the suction port 32e from the hot water suction pipe 10, then fed forcibly from the lower impeller chamber 34 to the lower discharge port 33a through the hot water forced-feed path 32b and further into the bathtub body 1 through the hot water forced-feed pipe 11. In this case, a portion of hot water which entered the lower impeller chamber 34 passes through the communication path 32d and enters the upper impeller chamber 33, then passes through the filtering forced-feed path 32c, further through the incoming pipe 41 from the upper discharge port 33a, and is fe4d to the filter 43. The hot water threrby filtered is fed into the hot water forced-feed pipe 11 through the return pipe 42. Thus, the hot water which is circulated through the hot water circulation path by means of the circulating pamp P having upper and lower impellers 33a, 34a is partially filtered by the filter 43. On the outer periphery of the circulating pump P there is provided a heater H1 for a freeze proofing pump. The heater H1 is controlled by the controller C in accordance with the result of detection of the temperature of the hot water in the hot water forced-feed pipe 11 obtained by th hot water temperature sensor T, whereby the freezing of the hot water in the circulating pump P can be prevented. The pump driving motor M is a three-phase induction type provided with a fan for cooling the motor M. Numeral 39a denotes a rotor mounted to the outer peripheral surface of the drive shaft 39 of the pump driving motor M; numeral 39b denotes a fixed magnetic pole attached to the inner peripheral surface of a motor casing 38 in an inside-outside opposed state with respect to the rotor 39a; and numeral 39c denotes a cooling fan. The inverter E, which is disposed between the pump driving motor M and an output interface 52, performs a conversion processing for the input frequency fed from a commercial AC supply, in accordance with a program stored in a memory 53 of the controller C as will be described later. More specifically, the inverter E converts the power from an AC 100V power supply into a three-phase 200V power and outputs the latter. Then, the number of revolutions of the pump driving motor M is controlled in proportion to the output frequency which has gone through the conversion processing in the inverter E to thereby control the number of revolutions of the circulating pump P, thereby permitting the volume and pressure of the hot water from the blow-off nozzles 2, 3, 4 to be changed in accordance with the aforementioned program. In this way the number of revolutions of the circulating pump P can be controlled smoothly and certainly by the inverter E. As a result, the following effects are obtained. 1 ○ By suitably combining the change in the number of revolutions of the circulating pump P made by the inverter E with the opening and closing operations of the blow-off nozzles 2, 3, 4 it is made possible to change the blow-off mode variously according to likings of bathing persons and thus it is possible to satisfy various likings of bathing persons. 2 ○ The blow strength can be changed in several steps or steplessly according to likings of bathing persons by changing the number of revolutions of the circulating pump P with the inverter E, so it is possible to give a feeling of ample satisfaction to bathing persons. 3 ○ Since the change in the number of revolutions of the circulating pump P can be done smoothly by the inverter E together with the opening or closing operation of the blow-off nozzles 2, 3, 4, it is possible to effect the change from one blow-off mode to another and further the change of the blow strength in various blow-off modes smoothly and slowly without giving any uncomfortable feeling to the person taking a bath. 4 ○ Since the circulating pump P can be given a slow leading-edge rotation by the inverter E, it is possible to prevent the occurrence of an accident such as falling-down of the bathing person, particularly a child or an old person due to sudden blow-off of hot water. 5 ○ Since the circulating pump P can be given a slow leading-edge rotation by the inverter E, it is possible to prevent the inconvenience that the pump P takes in air and races, so a smooth blow-off of hot air can be ensured by the pump P. 6 ○ Since the circulating pump P can be given a slow leading edge rotation by the inverter E, it is possible to reduce the discharge sound of air in pipes and so the reduction of noise can be attained. 7 ○ When the change of blow strength or the change of blow-off mode is performed by changing the blow-off volume and pressure as in this embodiment, wasteful electric power can be saved and so power saving can be attained. 8 ○ Since the circulating pump P can be reverse-rotated by the inverter E, it is possible to remove foreign matters such as dust from pipes. [II-6 ] Description of Filter The construction of the filter will be described below. As shown in Fig.13a, the filter 43 is composed of a filter body 43a , an acylic mesh 43b stretched in the lower portion of the filter body 43a, a filter medium 43c provided on the mesh 43b, and a baffle 43d attached to the inner surface of the upper wall of the filter body 43a. One end of the incoming pipe 41 is connected to the upper end of the filter body 43a, while one end of the return pipe 42 is connected to the lower end of the filter body 43a, and hot water is allowed to pass from above the filter body 43a downwards through the filter medium 43c, whereby the hot water can be filtered. A filter heater H2 for freeze proofing is mounted to the outer periphery of the filter 43 and it is controlled by the controller C according to the result of detection of the temperature of the hot water in the hot water forced-feed pipe 11 made by the hot water temperature sensor T, whereby the freezing of the hot water in the filter 43 can be prevented. Further, halfway of the incoming pipe 41, there is provided the motor-driven three-way valve 45, and a drain pipe 46 is connected to one end of the three-way valve 45, so that the incoming pipe 41 and the drain pipe 46 can be brought into communication with each other through the three-way valve 45. By changing over the motor-driven three-way valve 45 to make communication between the incoming pipe 41 and the drain pipe 46 and rotating the upper and lower impellers 33a, 34a of the circulating pump P, a portion of hot water is passed through the return pipe 42 and then passed from the lower portion of the filter body 43a upwards through the filter medium 43c, thereby permitting washing of the filter medium 43c. The change-over operation of the motor-driven three-way valve 45 can be done by the remote controller 30 which will be described later. [II - 7 ] Description of Controller The construction of the controller C will be described below. As shown in Fig.3, the controller C is composed of a microprocessor MPU, input/output interfaces 51, 52, a memory 53 comprising ROM and RAM, and a timer 54. In the above construction, to the input interface 51, there are connected the valve operation checking sensor 23f for detecting the degree of opening and that of closing of the blow-off volume adjusting valve 22; a valve opening checking sensor 91 for checking the opening of the air volume adjusting valve 87a,87b,87c; the pressure sensor 48 for detecting the water pressure in the hot water forced-feed pipe 11; the hot water temperature sensor T for detecting the temperature of hot water in the bathtub body 1; the operating panel 6; and the infrared ray sensor 30b for sensing a drive signal using infrared ray provided from the remote controller 30. On the other hand, to the output interface 52, there are connected later-described clock display portion 115 and hot water temperature indicating portion 116 on the operating panel 6, the pump driving motor M, the nozzle valve actuating motor M1, the air volume adjusting valve actuating motor M2, the pump heater H1, the filter heater H2 and the motor-driven three-way valve 45. The pump driving motor M is connected to the output interface 52 through the inverter E. In the memory 53, there is stored a drive sequence program for operating drive portions such as the motors M, M1, M2 and the motor-driven three-way valve 45 in accordance with output signals from the above sensors and drive signals from the operating panel 6 or from the remote controller 30. [II-8 ] Description of Operating Panel The following description is now provided with reference to Fig.9, Fig.9a and Fig.9b about the operating panel 6 which is for manually transmitting driving outputs to the controller C. The operating panel 6 is, as previously described, incorporated in the cover 5a of the air intake portion 5. As readily understood from Fig. 9b, the operating panel 6 is provided with an operations switch 100, blow operation switches such as a mild blow switch 101, a finger-pressure blow switch 102, a pulse blow switch 103, a wave blow switch 104, a cycle blow switch 105 and a program blow switch 106, hot water blow strong- and weak-side switches 107, 108, blow-off nozzle use pattern change-over switches such as a back-side blow-off nozzle use pattern switch 111, a leg-side blow-off nozzle use pattern switch 112 and a belly-side blow-off nozzle use pattern switch 113, a timer switch 114, the clock display portion 115 which also serves as a timer display portion, the hot water temperature indicating portion 116, a filter washing switch 117, a time setting switch 118 for making correction of the time displayed on the clock display portion 115, an hour setting switch 119, and a minute setting switch 120. The later-described blow operation can be started by turning ON the operation switch 100. Numeral 100a denotes a pilot lamp which goes on upon turning ON of the operation switch 100; numerals 101a, 102a, 103a, 104a, 105a and 106a denote blow operation switch indication lamps; numerals 109a, 109b, 109c, 109d and 109e denote strength level indication lamps; numerals 111a, 112a and 113a denote leg-, back- and belly-side indication lamps, respectively; numerals 121, 122 and 123 denote lamps which indicate selection patterns A, B and C in later-described pulse blow, wave blow, cycly blow and program blow; numeral 117a denotes a filter washing indication lamp; and numeral 117b denotes a filter operation indication lamp. The operating panel 6 is further provided with the infrared ray sensor 30b at one side end portion thereof as shown in Fig.9b. When any of switches provided on the remote controller 30 which will be described later is operated, an infrared ray of a predetermined wave length corresponding to the operated switch is emitted from an infrared ray radiating portion 30a provided in the remote controller 30 in accordance with a preset multi-frequency tone modulation system (MFTM). The infrared ray thus emitted is detected by the infrared ray sensor 30b and the detected signal is fed to the input interface 50 of the control unit C, whereby a desired drive unit is operated in accordance with a drive program read out from the memory 52. To the upper surface of the operating panel 6, as describe before, is attached the cover 125 which can be opened and closed and which covers the other switches and indication lamps than the timer switch 114, clock display portion 115, hot water temperature indicating portion 116, filter operation indicating lamp 117b and infrared ray sensor 30b. Further, the infrared ray sensor 30b may be disposed at a place where it is easy for the sensor to sense infrared ray other than on the operating panel 6. [II-9 ] Description of Remote Controller The following description is now provided about the remote controller 30 which is for manually transmitting driving outputs to the controller C in a bathing state separately from the operating pannel 6. As shown in Fig.14 and Fig.15a to Fig.15d, the remote controller 30 is constructed as follows. A partition wall 235 is provided within a vertically long, rectangular box-like case 231 to define in an isolated manner a substrate receiving chamber 336 for receiving therein a substrate 241 as a printed circuit board and a battery receiving chamber 237 for receiving therein a battery B in an energized state. In the upper end portion within the substrate receiving chamber 236 there is provided and infrared ray emitting portion 245 which is connected with the substrate 241, and in the upper portion of the interior of the substrate receiving chamber 236, there is provided a blow state display portion 233 in connection with the substrate 241. Further, various operating switches 234 of a membrane switch type are stuck on the lower-half surface portion of the case 231 so that they are in connection with the substrate 241. The whole of the remote controller 30 is water-tight. The case 231 is formed using an acrylonitrile-butadiene-styrene (ABS) resin to ensure rigidity, strength, impact resistance and water-tightness. Numeral 233a denotes a viewing window plate made of an acrylic resin which is transparent so that the blow state display portion 233 can be seen from the exterior. Since the operating switches 234 are membrane switches, the remote controller 30 can be made thin, light in weight and compact, the switches can be arranged freely, and sealing is ensured. Those switches are each connected to the substrate 241 through a flexible cable 234 as shown in Fig.15a. In connection with the operating switches 234, the numeral 260 denotes an operation switch; numeral 261 denotes a mild blow switch; numeral 262 denotes a finger-pressure blow switch; numeral 263 denotes a pulse blow switch; numeral 265 a wave blow switch; numeral 266 a cycle blow switch; numeral 267 a program blow switch; numerals 268 and 269 denote hot water blow strong- and weak-side switches, respectively; and numerals 274, 275 and 276 denote leg-, back- and belly-side blow-off nozzle use pattern switches, respectively. In the blow state display portion 233, the numeral 431 denotes a blow-off mode character indicating portion; numeral 432 denotes a wave blow indicating portion; numeral 432 denotes a wave blow indicating portion; numera; 433 denotes a blow-off position indicating portion; and numeral 434 denotes a strength level indicating portion. The indicating portions 431, 432, 433 and 434 each operate using liquid crystal. A concrete structure of the blow state display portion 233 and that of the operating switches 234 are the same as in the remote controller described in the foregoing Japanese Patent Application No.73367/89. The partition wall 235 is provided in an approximately one-third position from the lower end in the case 231 to form the substrate receiving chamber 236 and the battery receiving chamber 237 on the upper and lower sides, respectively, within the case 231. The chambers 236 and 237 are isolated from each other while ensuring water-tightness by means of a packing 259 provided along the side edges of the partition wall 235. The substrate receiving chamber 236 and the battery receiving chamber 237 can be isolated from each other while ensuring water-tightness by bonding the side edges of the partition wall 235 to the inner surface of the case 231 positively using an adhesive. The entire interior of the substrate receiving chamber 236 may be subjected to potting, that is, filled with a thermosetting resin, to impart impact and vibration resistance thereto and exclude the cause of moisture and corrosion. By potting using an expandable pylyurethane resin it is possible to protect the interior of the remote controller 30 and reduce the weight thereof, and it is also possible to float the remote controller 30 on the hot water surface. Further, by partially supporting the substrate 241 with an expanded polyurethane resin it is possible to protect the substrate 241 without the provision of any special substrate supporting member. In this way, even in the event the remote controller 30 should be dropped into the bath at the time of battery change, it is possible to prevent the hot water which has entered the battery receiving chamber 237 from entering the substrate receiving chamber 236. Also in the event of leakage of the battery fluid, it is possible to prevent the liquid from entering the substrate receiving chamber 236. Within the substrate receiving chamber 236 the substrate 241 connected to the blow state display portion 233 and the operating switches 234 is supported in a suspended state by means of first and second projecting support pieces 238, 239 which are projecting from a central part of a surface wall 231a of the case 231 toward a rear wall 231b thereof and a third projecting support piece 240 projecting from an upper part of the rear wall 231b toward the surface wall 231a. Between the projecting support pieces 238, 240 and the substrate 241 there are disposed first and second packings 242, 243 as shock absorbing members. The packings may be substituted by rubber springs, etc. Numeral 238′ denotes a fixing bolt. Further, an infrared ray emitting portion 245 for emitting infrared ray toward the infrared ray sensing portion 209 on the operating panel 206 is provided in the inner upper portion of the substrate receiving chamber 236. The infrared ray emitting portion 245 comprises a case 245d formed of an acrylic which permits infrared ray to pass therethrough and a total of three light emitting diodes 245a, 245b, 245c as infrared ray emitters provided in central and left and right positions within the case 245d. The central light emitting diode 45a can emit infrared ray forwards, while the left and right light emitting diodes 245b, 245c can emit infrared ray downward left- and rightwards, respectively. Further, from the infrared ray emitting portion 245 there are emitted predetermined code signals corresponding to the operating switches 234 on the basis of a preset serial code emitting signal. The infrared ray thus emitted is detected by the infrared ray sensing portion 209, then the detected signal is fed to the imput interface, a, of the controller C, and a desired driving unit is operated in accordance with a driving program read out from the memory, m. Within the battery receiving chamber 237, there can be received a battery B which serves as a power source, and a lid 247 for opening and closing is mounted to a battery opening 246 formed in the underside of the case 231. By opening and closing the lid 247, the battery B can be loaded and unloaded with respect to the battery receiving chamber 237. The lid 247 is composed of a connection plate 247a of a large width capable of closing the battery opening 246 and a fitting projection 247b projecting from the inner surface of the connection plate 247a and which is to be fitted in the battery opening 246. The connection plate 247a is mounted removably with small bolts 249 to the underside of a lid receptacle 248 which defines the battery opening 246. Numeral 250 denotes a nut provided in the lid receptacle 248. The fitting projection 247b is fitted in the batter on that a peripheral surface 247c thereof comes into contact with the inner peripheral surface of the lid receptacle 248. An O-ring mounting groove 247d is formed centrally in the peripheral surface 247c, and an O-ring 251 is mounted therein. Further, a current conducting plate 252 which turns conductive upon contact with the end face of the battery B is attached to the end face of the fitting projection 247b. Under the above construction, by inserting the fitting projection 247b of the lid 247 into the lid receptacle 248 and mounting the connection plate 247a to the lid receptacle 248, the current conducting plate 252 attached to the end face of the fitting projection 247b comes into contact with the end face of the battery B and can be turned conductive thereby. In this case, waterproofness of the interior of the battery receiving chamber 237 can be ensured by the O-ring mounted to the peripheral surface of the fitting projection 247b. Further, the upper and lower portions of the remote controller 30 constructed as above are provided with upper and lower protectors 253, 254, respectively, as shown in Figs.4 to 7 to prevent the remote controller 30 itself, the bathtub body 1, the bathroom tile, etc. from being damaged by drom shock. More specifically, the upper protector 253 is formed in the shape of a cap capable of being fittdd on the upper portion of the remote controller 30 to cover the upper portion and it is provided with infrared ray passing openings 255, 256 and 257 in positions corresponding to the central portion and right and left infrared ray emitting windows. numeral denotes a wall surface abutting portion. The lower protector 254 is formed in the shape of a cap capable of being fitted on the lower portion of the remote controller 30 to cover the lower portion. Numeral 254a denotes a wall surface abutting portion. As the material of the protectors 253 and 254 there is used one having a shock absorbing function. For example, there may be used an elastic rubbe such as nitrile butadiene rubber (NBR), an expanded polyurethane or an ethylen-propylene trimer (EPDM). Where a material of a small specific gravity such as an expanded polyurethane is used, it is possible to float the remote controller 30 on the hot water surface by adjusting the specific gravity of the same controller. Thus, by mounting the upper and lower protectors 253, 254 to the remote controller 30, even in the event of erroneous drop of the remote controller 30 onto the bathtub body 1, the bathroom tile, etc. In this embodiment, moreover, as shown in Figs.6 to 9, a magnet 280 aa mounting means is provided on the back of the remote controller 30, while a magnetic material 280′ is provided on a side wall of the bathtub body 1 or the bathroom side wall W, so that the remote controller can be attached removably to the bathroom side wall W by virtue of magnetism. The magent 280, which is in the form of a thin rectangular plate, is provided throughout the entire surface of the back of the remote controller 30 except the upper and lower portions of the controller covered with the upper and lower protectors 253, 254. Thus it is provided to enlarge the area of contact thereof with the magnetic material 280′ provided on the bathroom side wall W for example. The magnetic force of the magnet 280 can be set to a suitable magnitude so that the remote controller 30 can be mounted positively and detached easily. On the other hand, on the side wall of the bathtub body 1 or the bathroom side wall W there is provided the magnetic material 280′ which is in a thin plate, as shown in Fig.15c. The magnetic material 280′ is provided either partially plurally on the bathroom side wall W or formed widely to cover a wide area. The bathtub body 1 may be formed using the magnetic material 280′ to increase the degree of freedom for the mounting and storage of the remote controller 30. Thus, by increasing the degree of freedom for the mounting and storage of the remote controller 30, the user can attach the remote controller to a place permitting easy mounting and removal and so it is made possible to use the remote controller in a more easily manner. Contrary to the above, the magnetic material 280′ may be provided on the remote controller 30, while the magnet 280 may be provided on the bathroom side wall W. In this embodiment, moreover, since the upper and lower protectors 253, 254 are mounted to the remote controller 30, the magnet 280 or the magnetic material 280′ as a mounting means may be provided on those protectors. The mounting means is not limited to the magnet 280 having magnetic force. There may be used any mounting means if only it can attach the remote controller 30 to the bathroom side wall W or any other suitable place detachably, for example, a mounting means using adhesive force such as a face fastener or. In Figs.15e, 15f and 15g, a modification of the above-mentioned remote controller 30 is shown. The modification is substantially characterized in that the size or area of a blow state display portion 533 is considerably enlarged compared to the blow state display portion 233 shown in Fig. 14 so that a batther can enjoy more easily the blow states such as shown in Fig. 15h to Fig. 15m. In Fig.15h, a blow state of the mild blow is shown, wherein the blow of relatively sufficient volume and low pressure is expressed visually. In Fig.15i, a blow state of the spot blow is shown, wherein the blow of relatively small volume and high pressure is expressed visually. In Fig.15j, a blow state of the pulse blow is shown, wherein the blow operation in which the blow of a desired blow mode, e.g. the spot blow is operated periodically is expressed visually. In Fig.15k, a blow state of the cycle blow is shown, wherein the blow in which the blow positions of the blow-off nozzles are changed at a certain cycle by opening or closing each blow-off nozzle at the certain cycle in each blow-off mode is expressed visually. In Fig.15l, a blow state of the wave blow is shown, wherein the blow in which the amount of blown off is changed periodically by changing the number of revolutions of the circulating pump P is expressed visually. In Fig.15m, a blow state of the random blow is shown, wherein the blow operation in which the blow mode is randomly shifted from one blow mode to the other giving a bather always fresh feeling during bathing is expressed visually. These blow modes are further explained in detail hereinafter in view of description of blow-off modes below. Furthermore, the modification is also characterized by the reinforcement of water proofing so as to assure the use of the remote controller in the bathtub body 1. [II-10] Description of Inverter Referring to Fig.37, the inverter E comprises a rectifier circuit 938 connected to a single-phase commercial power source 937, a smoothing circuit 940 connected to the rectifier circuit 938, a switching circuit 939 connected to the smoothing circuit 940 and a motor drive unit 921, and an inverter control circuit 912 connected to the switching circuit 939. A control unit C is connected to the inverter control circuit 912 to control the output frequency of the inverter E by controlling the switching circuit 939 through the inverter control circuit 912. The rectifier circuit 938 and the smoothing circuit 940 convert the supply voltage of 100 V as of the commercial power source 937 into 200V DC. The discharge pressure and discharge rate of the circulating pump P can be freely and smoothly varied as characteristic curves Qc shown in Fig. 38 to Fig. 45 by varying the rotating speed of the circulating pump 2 by controlling the inverter 13 by the control unit C. Accordingly, the blow-off pressure and blow-off volume of the hot water blown off from the blow-off nozzles 2,3,4 are also smoothly and freely varied giving a bather a bathing feeling of versatility enhancing the comfortableness of the bather. [III] Description of Blow-off Modes The blow-off modes (mild blow, spot blow, pulse blow, wave blow, cycle blow, and program blow) obtained by this embodiment will be described below with reference to Figs.16 to 26. [III-1 ] Mild Blow The mild blow mode is a blow-off mode in which the blow-off volume of hot water from the blow-off nozzles 202,203,204 is large and the blow-off pressure thereof is low. According to this blow mode, the whole of the bather's body is wrapped in hot water mildly and softly to give the feeling of massage to the bather. More specifically, in the mold blow mode, the blow-off volume adjusting valves 222 in the blow-off nozzles 202,203,204 are opened almost fully, the number of revolutions of the circulating pump P is changed within a predetermined certain range (e.g. 1700-3000 r.p.m.), and the discharge pressure of the pump P is set to several stages (e.g. five stages) of strength levels within a preset low pressure range (e.g. 0.2-0.5 kg/ cm²) thereby permitting a large amount of hot water (e.g. 40-80 ℓ/min) to be blown off from the nozzles 202,203,204. Fig. 16 shows blow-off volume - blow-off pressure characteristic curves F1,F2,F3 which vary as the number of revolutions of the circulating pump P changes. N1,N2 N3 and N4 represent revolution performance curves of the circulating pump P, provided these performance curves are in the relation of N1 > N2 > N3 > N4 in terms of the number of revolutions. In Fig.16a, the point b on the blow-off volume - blow-off pressure characteristic curve F1 indicates the state of mold blow, assuming that the number of revolutions of the circulating pump P is near its maximum N1 (e.g. 3000 r.p.m.). Y1 represents a mild blow zone, while the points b1 and b2 indicates mild blow states set in the mild blow zone Y1. In Fig.17, there are shown blow-off nozzle characteristic curves R1, R2, and R3 obtained when the blow-off volume adjusting valves 22 are fully open, half open and quarter open. In the same figure, u1,u2 and u3 represent blow-off pressure lines, provided these pressure curves are in the relation of u1 > u2 > u3 in terms of magnitude. The point b in Fig.16a can be indicated as point b′ on the blow-off nozzle characteristic curve R1 shown in Fig.17a. In Fig.17a, Y′1 represents a mild blow zone in the blow-off characteristics, while the points b′1 and b′2 represent mild blow states set in the mild blow zone Y′1. The above mild blow operation is performed by turning ON the mild blow switch 261 of the remote controller 30. The change-over of switches at the time of changing the strength level in the mild blow mode or changing the blow-off nozzle use pattern is performed in a short time (e.g. about 1 sec). Fig.18 is a timing chart relating to the opening/closing operation of the blow-off volume adjusting valves 22 in the leg-, back- and belly-side blow-off nozzles 2,3,4 and the operation of the circulating pump P. For a certain time t₂ (e.g. 1 sec) after the lapse of a certain time t₁ (e.g. 0 sec) from the time t0 when the mild blow switch was operated, the blow-off volume adjusting valves 22 in the leg-, back-and belly-side blow-off nozzles 2,3,4 are each operated from a medium-open position d₁ (the open position before the blow-off mode change) to a preset open position d₂ (e.g. a valve-open position 6 mm retreated from a fully closed position) at a high speed (preferably the maximum speed). From just before the lapse of end time t′₁ of the preset valve opening operation of each blow-off volume adjusting valve 22, the number of revolutions V₁ (e.g. 2800 r.p.m.) before the blow-off mode change of the circulating pump P is decreased gradually so that a certain number of revolutions V₂ (e.g. 2400 r.p.m.) is reached within a certain time t′₂ (e.g 3 sec). In this embodiment, moreover, upon start of operation (upon turning ON of the operation switch 260 or 100) the blow operation is started. In the blow operation, the blow-off mode is set to the mild blow mode and the strength level is initialized to "Medium", taking into account the safety during bathing of a child or an old person, (this blow operation will hereinafter be referred to as the "child safety blow"). In this embodiment, moreover, as shown in the timing chart of Fig.19, only the blow-off volume adjusting valves 22 in the back-side blow-off nozzles 3 are once operated up to a fully closed position at the time of operation start to prevent cold water remaining in pipes after the previous use from blowing off from the back-side nozzles 3 which would cause uncomfortable feeling of the user or might endanger the user. More specifically, in Fig. 19, for a certain time t₂ (e.g. 1 sec) after the lapse of a certain time t₁ (e.g. 0 sec) from the time when the mild blow switch was operated, the blow-off volume adjusting valves 22 in the back-side nozzles 3 are each operated from a medium position (the valve-open position before the blow-off mode change) to a fully closed position at a high speed (preferably the maximum speed), and for a certain time t₄ (e.g. 1 sec) after this closed state is maintained for a certain time t₃ (e.g. 2 sec), the blow-off volume adjusting valves 22 are each operated up to a preset open position d₂ (e.g. a valve-open position 6 mm retreated from a fully closed position) at a high speed (preferably the maximum speed). As to the blow-off volume adjusting valves 22 in the leg- and belly-side blow-off nozzles 2, 4, for a certain time t₁ (e.g. 1 sec) after the lapse of a certain time t₁ (e.g. 1 sec) from the time t₀ when the mild blow switch was operated, those valves are each operated from a medium-open position d₁ (the open position before the blow-off mode change) to an almost fully open position d₂ (e.g. a valve-open position retreated 6mm from a fully closed position) at a high speed (preferably the maximum speed). The circulating pump P is operated just after the lapse of end time t′₁ of the closing or preset opening operation of each blow-off volume adjusting valve 22, and the number of revolutions thereof is increased gradually so that a certain number of revolutions V₂ (e.g. 2800 r.p.m.) is reached within a certain time t′₂ (e.g. 10 sec). The control timing for both the opening or closing operation of the blow-off volume adjusting valve 22 in each of the blow-off nozzles 2, 3, 4 and the change of the number of revolutions of the circulating pump P is determined while considering that the user will not have uncomfortable feeling and that a sudden increase in discharge pressure of the circulating pump P should be prevented. This point will be explained later in [IV-7 ]. [III-2 ] Spot Blow The spot blow mode is a blow mode in which the blow-off volume of hot water from the blow-off nozzles 2, 3, 4 is small and the blow-off pressure thereof is high and in which a hot water jet is applied vigorously to a part of the user's body, whereby the user is given a feeling of massage involving a finger-pressure feeling. More specifically, in the spot blow mode, the blow-off volume adjusting valve element 22 in each of the blow-off nozzles 2, 3, 4 is slightly opened, the number of revolutions of the circulating pump P is changed within a certain range (e.g. 2000 to 3000 r.p.m.), and the discharge pressure of the pump P can be set to several stages (e.g. five stages) of strength levels within a preset high pressure range (e.g. 0.5 to 1.0 kg/cm²). The point e on the blow-off volume - blow-off pressure characteristic curve F3 in Fig.16a indicates the state of spotblow at a minimum blow-off volume (e.g. 30ℓ/min) of hot water. In Fig.16a, moreover, Y2 represents a spot blow zone in the blow-off volume - blow-off pressure characteristics, and the points e1 and e2 each indicate the state of spotblow set within the spotblow zone Y2. The point e in Fig.16a can be expressed as point e′ on the blow-off nozzle characteristic curve R3 shown in Fig.17a. In Fig.17a, Y′2 represents a spotblow zone in the blow-off nozzle characteristics, and the points e′1 and e′2 each indicate the state of spotblow set within the spotblow zone Y′2. The above finger-pressure blow operation is performed by turning ON the spot blow switch 62 of the remote controller 30. Fig.20 is a timing chart relating to the opening/closing operation of the blow-off volume adjusting valve elements 22 in the leg-, back-and belly-side blow-off nozzles 2, 3, 4 and the operation of the circulating pump P. More specifically, in Fig. 20, for a certain time t₂ (e.g. 1 sec) after the lapse of a certain time t₁ (e.g. 0 sec) from the time t₀ when the finger-pressure blow switch was operated, each blow-off volume adjusting valve element 22 is operated from the open position d₁ before the blow-off mode change (e.g. a valve-open position retreated 6mm from a fully closed position) to a preset open position d₂ (e.g. a valve-open position 1.5 retreated from the fully closed position) at a high speed (preferably the maximum speed). Then, from just after the lapse of end time t′₁ of the preset opening operation of each blow-off volume adjusting valve element 22, the circulating pub P gradually increases its number of revolutions V₁ before the blow-off mode change ( e.g 2400 r.p.m.) so that a certain number of revolutions V₂ ( e.g. 2800 r.p.m.)is reached within a certain time t′₂ (e.g. 3 sec). [III-3 ] Pulse Blow The pulse blow mode is a blow mode in which the blow-off of hot water and stop thereof are performed in an alternate manner by opening and closing the individual blow-off nozzles 2, 3, 4 periodically to alternate the blow-off of a hot water jet and stop thereof pulsewise, thereby giving a sharp stimulation to the user. According to the pulse blow mode, in the foregoing spot blow operation the blow-off volume adjusting valve elements 22 in the blow-off nozzles 2, 3, 4 are each moved at a high speed (preferably the maximum speed) to a preset open position and a fully closed position alternately in a short time (e.g. 1 sec) at every lapse of a certain time, whereby there can be alternately created a state in which hot water is blown off and a state in which hot water is not blown off. In some case the hot water blown off contains bubbles, while in the other it does not. The change of the strength level of such pulse blow can be done by setting the blow-off volume of hot water in several stages (e.g. five stages) within a certain range (e.g. 30 to 50 ℓ/min) which can be effected by changing the number of revolutions of the circulating pump P. The above pulse blow operation is performed by turning ON the pulse blow switch 263 of the remote controller 30. Fig.21 is a timing chart relating to the opening and closing operation of the blow-off volume adjusting valve element 22 in the leg-, back- and bellyside blow-off nozzles 2, 3, 4 and the operation of the circulating pump P. More specifically, in Fig. 21, after the lapse of a certain time t₁ (e.g. 0 sec) from the time t₀ when the pulse blow switch was operated, each blow-off volume adjusting valve element 22 is operated from its open position d₁ before the blow-off mode change (e.g. a valve-open position 6 mm retreated from a fully closed position to a preset open position d₂ (e.g. a valve-open position 2 mm retreated from the fully closed position) at a high speed (preferably the maximum speed) for a certain time t₂ (e.g. 1 sec). After this open condition is maintained for a certain time t₃ (e.g. 1 Sec), the valve element 22 is closed up to the fully closed position at a high speed (preferably the maximum speed) for a certain time t₄ (e.g. 1 Sec), then after this fully closed condition is maintained for a certain time t₅ (e.g. 1 sec), the valve is opened up to the foregoing preset open position d₂ at a high speed (preferably the maximum speed) for a certain time t₆ (e.g. 1 sec). Further, after this open condition is held for a certain time t₇ (e.g. 1 sec), the valve is closed. These valve opening and closing operations are repeated periodically. After the lapse of a certain time t′₁ (e.g. 1 sec) from the time t₀ when the pulse blow switch was operated, the number of revolations V₁ before the blow-off mode change (e.g. 2400 r.p.m.) is increased gradually so as to reach certain revolutions V₂ (e.g. 2800 r.p.m.) within a certain time t′₂ (e.g. 3 sec). By changing the certain time t₃ for maintaining the preset valve-open condition there can be set different pulse blow patterns. In this embodiment, there are set three kinds of pulse blow patterns A, B and C with the certain time t₃ set to one, two and three seconds, respectively, so that there can be selected a hot water jet stimulation time for the user according to a liking of the user. [III-4 ] Wave Blow The wave blow mode is a blow mode in which the number of revolutions of the circulating pump P is changed periodically to change the blow-off volume and pressure of hot water periodically. By changing the blow-off volume and pressure with a slow period there is formed a varied flow to apply a hot water jet having the image of wave which approaches and leaves repeatedly to the user. In the wave blow mode, the blow-off volume adjusting valve elements 22 in the blow-off nozzles 2, 3, 4 are fully opened or medium-opened and the circulating pump P is turned on and off, or the number of revolutions of the pump P is changed periodically within a certain range (e.g. 1600 to 3000 r.p.m.). The change of the wave blow strength level can be done by setting the range of the number of revolutions of the circulating pump P which is to be changed periodically, in several stages (e.g. five stages) within the range of the foregoing number of revolutions. The d₁, d₂ and d₃ shown in Fig.16b represent blow-off volume blow-off pressure characteristic curves in the wave blow mode . The blow-off volume and pressure of hot water vary along the curves d₁, d₂ and d₃. The d′₁, d′₂ and d′₃ shown in Fig.17b represent blow-off nozzle characteristic curves. In the wave blow mode, the amount of bubbles can be varied greatly. The wave blow operation described above is started by turning ON the wave blow switch 265 of the remote controller 30. The hot water blow-off nozzle use pattern in the wave blow mode is the same as in the foregoing mild blow mode. Fig.22 is a timing chart relating to the opening and closing operation of the blow-off volume adjusting elements 22 in the leg-, back- and bellyside blow-off nozzles 2, 3 and 4 and the operation of the circulating pump P. More specifically, in Fig.22, after the lapse of a certain time t₁ (e.g. 1 sec) from the time t₀ when the wave blow switch was operated, each blow-off volume adjusting valve element 22 is operated at a high speed (preferably the maximum speed) for a certain time t₂ (e.g. 1 sec) from the open position d₁ before the blow-off mode change (e.g. a valve-open position retreated 6 mm from a fully closed position) up to a preset valve-open position d₂ (e.g. a valve-pen position 4 mm retreated from a fully closed position). Then, from just after the lapse of end time t₃ of the preset opening operation of each blow-off volume adjusting valve 22, the circulating pump P gradually increases its number of revolutions V₁ before the blow-off mode change (e.g. 2400 r.p.m.) so that a certain large number of revolutions V₂ (e.g. 3000 r.p.m.) is reached within a certain time t₄ (e.g. 4 sec). Thereafter, the number of revolutions thereof is gradually decreased to a smaller number of revolutions V₃ (e.g. 1800 r.p.m.) within a certain t₅ (e.g. 4 sec), then it is again increased gradually up to the above large number of revolutions V₂ within a certain time t₆ (e.g. 4 sec). In this way the number of revolutions of the circulating pump P is varied periodically. By changing the way of periodic change in the number of revolutions of the circulating pump P it is possible to set different wave blow patterns. In this embodiment, the wave blow pattern described above is designated a wave blow pattern A, and wave blow patterns which will be explained below are designated wave blow patterns B and C. Thus, there are set three kinds of patterns. According to the wave blow pattern B, as shown in the timing chart of Fig.23, from just after the lapse of end time t₃ of the preset opening operation of each blow-off volume adjusting valve 22, the number of revolutions V₁ before the blow-off mode change (e.g. 2400 r.p.m.) is increased gradually up to a large number of revolutions V₂ (e.g. 3000 r.p.m.) within a certain time t₄ (e.g. 4 sec), which large number of revolutions V₂ is maintained for a certain time t₅ (e.g. 2 sec), thereafter the number of revolutions is gradually decreased to a smaller number of revolutions V₃ (e.g. 1800 r.p.m.) within a certain time t₆ (e.g. 4 sec), which smaller number of revolutions V₃ is maintained for a certain time t₇ (e.g. 2 sec), thereafter the number of revolutions is gradually increased up to the aforesaid large number of revolutions V₂ whthin a certain time t₈ (e.g. 4 sec). In this way the number of revolutions is varied periodically. According to the wave blow pattern C, as shown in the timing chart of Fig.24, from just after the lapse of end time t₃ of the preset opening operation of each blow-off volume adjusting valve 22, the number of revolutions V₁ before the blow-off mode change (e.g. 2400 r.p.m.) is increased gradually so as to describe a downwardly convex curve up to a certain large number of revolutions V₂ (e.g. 3000 r.p.m.) within a certain time t₄ (e.g. 3 sec), thereafter the number of revolutions is gradually decreased so as to describe a downwardly convex corve to a smaller number of revolutions V₃ (e.g. 1800 rp.m.) within a certain time t₃ (e.g. 3 sec), and thereafter the number of revolutions is gradually increased so as to describe a downwardly convex curve up to the aforesaid large number of revolutions V₂ within a certain time t₆ (e.g 3 sec). In this way the number of revolutions is varied periodically. In this embodiment, since the number of revolutions of the circulating pump P is controlled by the inverter E, a periodic change in the number of revolutions of the circulating pump P is performed smoothly and positively, whereby there can be generated the wave blows A, B and C each having a pulsatory power in a faint hot water jet. Particularly, in the wave blow pattern C, the number of revolutions of the circulating pump P varies while describing a generally catenary curve, and the rate of increase and that of decrease in the number of revolutions are large in a high revolution region, while those in a low revolution region are small. Therefore, it is possible to obtain a blow-off mode having clear distinction and a finger-pressure effect for the user, in which a strong blow change occurs in a relatively short time, while a weak blow change occurs over a relatively long time. [III-5 ] Cycle Blow In the cycle blow mode, the hot water blow-off position is changed automatically and periodically, thereby permitting the user to enjoy the change in the hot water blow-off position. More specifically, in the cycle blow mode, the blow-off volume adjusting valves 22 are opened to blow off hot water for a certain time in the order of, for example, back-side blow-off nozzles 3,3 →belly-side blow-off nozzle; 4,4→leg-side blow-off nozzles 2,2. In this case, a, the blow-off mode of hot water from the blow-off nozzles 2, 3, 4 there can be used the mild blow, spotblow and wave blow modes, and further there can be adopted a blow-off mode in which the mild blow and the spotblow are changed periodically. In this embodiment, there are set three kinds of cycle blow patterns A, B and C, which will be explained below with reference to the timing charts shown in Fig.25 and 26. The cycle blow A is performed in the spotblow mode. As shown in the timing chart of Fig 25, after the lapse of a certain time t₁ (e.g. 0 sec) from the time t₀ when the cycle blow switch was operated, only the blow-off volume adjusting valves 22 in the back-side blow-off nozzles 3 are each operated from the open position d₁ before the blow-off mode change (e.g. a valve-open position 6 mm retreated from a fully closed position) up to a preset open position d₂ (e.g. a valve-open position 1.5 mm retreated from the fully closed position) at a high speed (preferably the maximum speed) for a certain time t₂ (e.g. 1 sec), while the volume adjusting valves 22 in the leg- and belly-side blow-off nozzles 2, 4 are each operated up to a fully closed position at a high speed (preferably the maximum speed) for a certain time t₂ (e.g. 1 sec). In this state, hot water is blown off in the spotblow mode from only the back-side blow-off nozzles 3, 3. After the blow-off volume adjusting valves 22 in the back-side blow-off nozzles 3 are each held in the open position d₂ for a certain time t₃ (e.g. 2 sec), they are each operated up to the fully closed position at a high speed (preferably the maximum speed) for a certain time t₆ (e.g. 1 sec). Then, after the lapse of a certain time t₅ (e.g. 0 sec), the blow-off volume adjusting valves 22 in the belly-side blow-off nozzles 4 which are closed are each operated up to the preset open position at a high speed (preferably the maximum speed) for a certain time t₆ (e.g. 1 sec), then after held in the preset open position d₂ for a certain time t₁ (e.g. 2 sec), the valves 22 are each operated up to the fully closed position at a high speed (preferably the maximum speed) for a certain time t₈. In this state, hot water is blown off in the spot blow mode from only the belly-side blow-off nozzles 4, 4. Then, after the lapse of a certain time t₉ (e.g. 0 sec), the blow-off volume adjusting valves 22 in the leg-side blow-off nozzles 2 which are closed are each operated up to the preset open position d₂ at a high speed (preferably the maximum speed) for a certain time t₁₀ (e.g. 1 sec), then after held in the preset open position d₂ for a certain time t₁₁ (e.g. 2 sec), the valves 22 are each operated up to the fully closed position at a high speed (preferably the maximum speed) for a certain time t₁₂ (e.g. 1 sec). In this state, hot water is blown off in the finger-pressure blow mode from only the leg-side blow-off nozzles 2, 2. Then, after the lapse of a certain time t₁₃ (e.g. 0 sec), the blow-off nozzle adjusting valves 22 in the back-side blow-off nozzles 3 which are closed are each operated up to the preset open position d₂ at a high speed (preferably the maximum speed) for a certain time t₁₄ (eg. 1 sec), then after held in the preset open position d₂ for a certain time t₁₅ (e.g. 2 sec), the valves 22 are each operated up to the fully closed position at a high speed (preferably the maximum speed) for a certain time t₁₆ (e.g. 1 sec). In the circulating pump P, after the lapse of a certain time t′₁ (e.g 0 sec) from the time t₀ when the cycle blow switch was operated, the number of revolutions in, before the blow-off mode change (e.g. 2800 r.p.m.) is decreased gradually to a certain number of revolutions V₂ (e.g. 2500 r.p.m.) within a certain time t′₂ (e.g. 1 sec). This number of revolutions V₂ is maintained during the blow operation. The cycle blow B is performed in the spotblow mode. According to the cycle blow pattern B, in the timing chart of the cycle blow pattern A described above the certain time t₃, t₇, t₁₁ for maintaining the preset open position d₂ of the blow-off volume adjusting valves in the blow-off nozzles 2, 3, 4 is different (e.g. 4 sec). This is the only difference. Thus, in the cycle blow patterns A and B, the blow-off volume adjusting valves 22 in the blow-off nozzles 2, 3, 4 are opened and closed at a certain period in the order of back →belly →leg →back and the number of revolutions of the circulating pump P is kept constant, so that the finger-pressure effect can be provided throughout the user's body while the spot blow position is changed. The cycle blow pattern C is performed in the wave blow mode. As shown in the timing chart. of Fig.26, there is used a preset open position d₂ which (e.g. 4 mm) is larger than that in the cycle operations A and B, and the certain time t₃, t₇, t₁₁ for maintaining the preset open position d₂ are different (e.g. 8 sec) from that in the cycle blow patterns A and B. Further, the number of revolutions of the circulating pump P is changed periodically. More specifically, in the circulating pump P, after the lapse of a certain time t′₁ (e.g. 0 sec) from the time t₀ when the cycle blow switch was operated, the number of revolutions V₁ before the blow-off mode change (eg 2400 r.pm.) is decreased gradually to a certain small number of revolutions V₃ (e.g. 1600 r.p.m.) within a certain time t′₂ (e.g 1 sec), then the number of revolutions is gradually increased to a certain laid number of solutions V₂ within a certain time t′₃ (e.g 4 sec), and thereafter the number of revolutions is gradually decreased to the certain small number of revolutions V₃ within a certain time t′₄ (e.g. 4 sec). After such certain small number of revolutions V₃ is maintained for a certain time t′₄ (e.g. 1 sec), the change of the number of revolutions (V₃ →V₂ →V₃) described above is repeated. Such changing of the number of revolutions (V₃ →V₂ →V ₃ ) is performed only during the blow →off of hot water from the blow→off nozzles 2, 3, 4, and timing is taken to maintain the certain small number of revolutions V₃ during opening or closing operation of the blow-off volume adjusting valves 22 in the blow-off nozzles 2, 3, 4 and prevent an abrupt change in the blow strength, thereby preventing the user feeling uncomfortableness. This, together with the change in the blow-off position of hot water, permits the user to enjoy a hot water jet having the image of waves peculiar to the wave blow. Although in this embodiment the change of the hot water blow-off position in the cycle blow patterns A, B and C is performed in the order of back →belly →leg →back, no special limitaion is placed in this order. There may be adopted another order (e.g. back→leg→belly →back). It is also possible to change the hot water blow-off position irregularly. [III-6 ] Program Blow The program blow mode is a blow mode in which the change of blow is diversified by suitably combining or changing with time the selection of blow-off mode, that of blow-off strength and that of blow-off position in accordance with a preset program. This blow mode permits the user to enjoy a combined blow-off mode order having unexpectedness which is not a forcing system of a fixed form. In this embodiment, moreover, a plurality of different contents of position provided in consideration of the age and sex distinction of users. Selection can be made from among program blow A which is a standard blow operation having the most general menu, program blow B which is a hard blow operation having the strongest menu, and program, blow C which is the lightest blow operation having mildness. The program blow patterns A, B and C are as shown in the program blow specification of Table 1. In Table 1, the ranks 1, 2 and 3 represent three stages of apperarnce probabilities of blow-off modes in three divided groups of the foregoing plural blow-off modes. The appearance probability of the blow-off modes belonging to rank 1 is 50%, that of the blow-off modes belonging to rank 2 is 30%, and that belonging to rank 3 is 20%. The blow strength level is set in five stages, which are weak 1, medium weak 2, medium 3, medium strong 4 and strong 5. In the program blow A , the blow strength level is set to 2-4 in order to perform a standard blow operation; in the program blow B, the blow strength level is set to 3-5 in order to perform a hard blow operation; and in the program blow C, the blow strength level is set to 1-3 in order to perform a light blow operation. As to the hot water blow-off positions (portions), there are the case where hot water is blown off from the three portions of the leg-, back- and belly-side blow-off nozzles 2, 3, 4 at a time, the case where hot water is blown off from any two of those portions, and the case where hot water is blown off from any one of those portions. Such simultaneous three-portion blow-off is indicated as (leg-back-belly); such simultaneous two-portion blow-off is indicated as (leg-back) (back-belly) (leg-belly); and such one portion blow-off is indicated as (leg) (back) (belly). The blow-off modes, blow strength levels, and hot water blow-off position, are each changed over from one to another after the lapse of a certain time (e.g. 30 sec) to give the pleasure of change to the user continuously, thereby preventing the user from becoming weary. As to the blow-off modes, consideration is made to prevent continuous appearance of the same mode, thereby ensuring the pleasure of change given to the user. In each of the program blow patterns A, B and C it is possible to set the blow time constant. In this embodiment, the program blows A, B and C are set to 4, 5 and 3 minutes, respectively. If several kinds of menus are set for each of the program blows A, B and C and any one program blow is selected, the selection of menus can be made irregularly from the selected program blow. Thus, in the program blows A, B and C, the change of blow-off mode, blow strength and blow-off portion is done irregularly in consideration of age and sex distinction, so the user can fully enjoy the unexpectedness of the contents of the change and that of the order of the change and is thereby prevented from becoming weary while taking a bath. [IV] Description of the Opetation of the Whirlpool Bath [IV-1 ] Description of Operation Procedure based on Flowcharts The operation of the whirlpool bath A described above will be explained below with reference to the flowcharts of Figs.27 to 32. First reference is here made to the main rountine shown in Fig.27. The plug of the controller C, etc. is inserted into the power source for the supply of elelctric power thereto. The nozzle valve actuating motors M1 in all of the leg-, back- and belly-side blow-off nozzles 2, 3, 4 are initialized (210). Subsequently, the whirlpool bath A turns OFF (215). In this OFF condition, the various actuators for the circulating pump P connected to the whirlpool bath A and the blow-off nozzles 2, 3, 4 are turned OFF. At this time, in the nozzles 2, 3, 4, the nozzle valve actuating motors M1 are in an initialized condition, that is, the valves are in an open condition retreated 6 mm from their fully closed positions, thereby permitting smooth supply and discharge of hot water during the supply of hot water and drain. In this OFF condition, moreover, the controller C is waiting for input, and also in this condition there can be made control by the controller C for the hot water supply operation and the freeze proofing operation in accordance with the results of detection provided from the pressure sensor 48 and the hot water temperature sensor T. Next, by the pressure sensor 48 which also serves as a level sensor there is made detection as to whether the hot water level in the bathtub body 1 has reached a blow operation permitting level (e.g. a position higher than the upper-end position of the suction port 1m provided in the bathtub body 1) (220). In the present invention, in order to ensure the blow operation, the upper-end position of the suction port 1m which is the lowest level permitting the circulation of hot water in the hot water circulation path D is used as lower-limit level permitting the blow operation, and this level is used as one condition for the start of the blow operation. This blow operation starting condition will be described In detail later. When the hot water level has not reached the blow operation permitting level (220N), warning of a decreased level is issued (225) and the operation is stopped (215). In this case, the warning of a decreased level is effected by turning on and off the indication "L" which indicates the decrease of level on the clock display portion 115 of the operating panel alternately over a period of 15 seconds and at the same time sounding a buzzer (not shown). In a bathtub provided with an automatic hot water supplying apparatus, it is possible to perform a hot water replenishing operation. When the hot water level satisfies the blow operation permitting level (220Y), there is made detection by the hot water temperature sensor T as to whether the hot water temperature in the bathtub body 1 is within a blow operation permitting range (e.g. 5 ∼ 50°C) or not (230). In this embodiment, the blow operation permitting hot water temperature range is determined in consideration of the protection of the user and of the pipes made of a synthetic resin and freeze proofing of the hot water the circulating pump P, and the said temperature range is used as one condition for the start of the blow operation. This blow operation starting condition will be described in detail later. As a result, in the case of a lower temperature than the lower limit (e.g. 5 °C) of the blow operation permitting temperature range (235Y), the freeze proofing operation is started (300). Such freeze proofing operation will be described later with reference to the subroutine shown in Fig.32. In the case of a higher temperature than the upper limit (e.g. 50°C) of the blow operation permitting temperature range (235N), there issues warning of a high temperature (400) and the operation is stopped (215). In this case, the warning of a high temperature is effected by turning on and off the indication "H" which indicates a high water temperature on the clock display portion 115 of the operating panel 6 alternately over a period of 15 seconds and at the same time sounding buzzer. In the case of a blow operation permitting hot water temperature (230Y), the blow operation can be started (500) by turning ON the operation switch 100 or 60 (415Y). The "blow operation" (500) is a generic term for the blow operations in the various blow-off modes, a timer operation in which blow operation is performed within the time preset by the user, and an automatic filter washing operation in which the filter 43 is washed automatically in parallel with the blow operation. Each blow operation, timer operation and automatic filter washing operation will be described later with reference to the subroutines shown in Figs. 28, 29 and 30. Upon turning OFF of the operation switch 100 or 260 (995Y), the operation is stopped (215). As long as the operation switch 100 or 260 is not turned OFF, the blow operation is continued. Further, by turning ON the operation switch 100 or 260 (415) it becomes possible to effect the filter washing operation just before or after the blow operation (500), and the filter washing operation can be started by turning ON the filter washing switch 117 (900). This filter washing operation will be described later with reference to the subroutine shown in Fig.31. The above blow operation will be described below with reference to the subroutine shown in Fig.28. [Blow Operation] The blow operation is programmed so that the initial blow is a child safety blow or a mild blow and the strength level is set to "Medium" (510), whereby the occurrence of accidents is prevented such as the legs of a child being carried away by the hot water jet at the time of beginning of the operation and the child falling down. In this state of child safety blow, a desired blow operation can be selected by turning ON a blow-off mode switch. More specifically, other than the mold blow operation, the spotblow operation can be started (525) by turning ON the spotblow switch 102 or 62 (520). The pulse blow operations A, B and C can be performed (535) (536) (537) by turning ON the pulse blow switch 103 or 263 (530) (531) (532). The wave blow operations A, B and C can be performed (545) (546) (547) by turning ON the wave blow switch 104 or 265 (540) (541) (542). The cycle blow operations A, B and C can be performed (555) (556) (557) by turning ON the cycle blow switch 105 or 66 (550) (551) (552). Further, by turning ON the program switch 106 or 267 (560) (561) (562) there can be performed each program blow operation (565) (566) (567). For returning to the mild blow from another blow mode, the mold blow switch 101 or 261 is again turned ON (510). All the blow operations can be stopped into OFF condition by turning OFF the operation switch 100 or 60. In this embodiment, moreover, in order to meet user's desires as far as possible, there can be performed the operation for changing the hot water blow-off position in the cases of mild blow operation, spotblow operation, pulse blow operation and wave blow operation. Further, the operation for changing the strength level of hot water to be blown off can be performed in the cases of the mild blow, finger-pressure blow, pulse blow, wave blow and cycle blow operations. Such operations for changing the hot water blow-off positioned and strength level will be described later. Next, the timer operation will be described below with reference to the subroutine shown in Fig.29. [Timer Operation] The timer operation permits the user to set a desired blow operation time and makes it possible to prevent the user from having a rush of blood to the head. The timer operation will be described below. The timer operation is started as follows. When the timer switch 114 is pushed ON (580Y) after pushing ON the operation switch 100 on sthe operating panel 6, the clock display of the clock display portion 115 which makes a digital display using a light emitting diode changes to a timer display, for example, "5" which indicates 5 minutes set as a minimum blow operation time, and thus it is possible to set "5 minutes" for the timer (585). If the timer switch 114 is turned OFF within a certain time (e.g. 2 sec) (590Y), the timer display becomes "5:00" after the lapse of 2 seconds and the timer operation is started. The numerical value of the timer display decreases every second (595). When the timer operation time has elapsed and the timer display became "0:00" (605) without turning ON the timer switch 114 during the timer operation (600N), the said timer display is turned off and off every 0.5 second for the period of 5 seconds and every 0.5 second for the period of 5 seconds and the buzzer is allowed to sound. Thereafter, upon termination of the timer operation (610), the operation is stopped and a return is made to the timer display (615). Where it is desired to set the time for the timer to any other time than the above 5 minutes, by pushing the timer switch 114 continuously for 2 seconds or more (590N) the above indication "5" is increased every 0.5 second in the unit of one minute, and since the numerical value returns to "1" after reaching a preset maximum value (e.g. "19"), it is possible to set a desired blow operation time in the range of, for example, 1 minute to 19 minutes (620). If the timer switch 114 is turned OFF when a desired value (e.g. "9") appeared (625Y), then in 2 seconds thereafter a desired timer time (e.g. "9:00") is indicated and the numerical value of this timer display decreases every second (595). If the timer switch 114 is turned ON (600) and then OFF within 2 seconds (630Y) during the timer operation, the timer operation is stopped at that time point (635) and the display returns from the timer display to the clock display. In this case, the blow operation is continued (640). If the timer switch 114 is pushed ON continuously for 2 seconds or more (630N), the timer display becomes a timer setting display corresponding to the minute indicated at that time point plus one minute, and by continuing the depression of the timer switch 114 the timer operation time can be increased every 0.5 second in the unit of one minute (620). If the timer switch 114 is turned OFF when a desired numerical value appeared (625Y), then in 2 seconds thereafter the desired time for the timer is indicated and then the value indicated decreases every second (595). The timer operation takes priorty over the blow operation and can be performed (including operation stop) regardless of the blow-off mode. In all the operation timings relating to the timer operation, such as during timer operation and during timer setting, the timer time is indicated by lighting of a light emitting diode on the clock display portion 115 of the operating panel 6. The clock display portion 115 continues to light when clock indication is not made. Therefore, the timer setting operation can be done in a simple manner. When there is no operation switch input for a certain time (e.g. 30 minutes) in the state of blow operation, the blow operation is stopped. Thus, by stopping the blow operation after the lapse of a certain time it is intended to prevent the continuance of blow operation over a long time caused by the user forgetting to stop the blow operation and thereby attain power sabing and protection of the circulating pump and pipes. Also when the blow operation is stopped by the timer as set forth above, this condition is announced by the sounding of a buzzer for 5 seconds just after the operation stop. Next, the automatic filter washing operation will be described below with reference to the subroutine shown in Fig.30. [Automatic Filter Washing Operation] In the automatic filter washing operation, the washing of the filter 43 is performed automatically in parallel with blow operation. The automatic filter washing operation is started (770) in the case of a blow operation (765Y) in which an integrated time (from the start-up of the circulating pump P) of the blow operation has elapsed a certain time (e.g. 1 hour) (760Y) and which satisfies automatic filter washing operations. The automatic filter washing conditions as referred to herein mean that the blow operation permitting hot water level and temperature should be satisfied, that the blow-off mode should be any of mild blow, finger-pressure blow, wave blow and cycle blow modes, and that the strength level should be any of strong, medium strong and medium. The automatic filter washing operation terminates upon lapse of a certain time (e.g. 1 min) of the same operation, while the blow operation continues and the integrating of time of the blow operation restarts (785). When the automatic filter washing conditions are no longer satisfied (discontinued) due to the change of the blow-off mode or of the strength level during the automatic filter washing operation (775Y) and when the number of times of retrying after discontinuance is smaller than a certain number of times (e.g. 4) (790N), the automatic filter washing operation is discontinued (795), and thereafter when a blow operation satisfying the automatic filter washing conditions is started (800Y), the automatic filter washing operation is started (770). On the other hand, when the number of times of discontinuance in the automatic filter washing operation has reached a certain number of times, the automatic filter washing operation terminates (785). This is for preventing evacuation of the bathtub body 1 caused by retrying infinitely. In the case of a blow operation not satisfying the automatic filter washing conditions despite the integrated time of the blow operation has elapsed a certain time (e.g. 1 hour) (765N), the automatic filter washing operation is started upon start of a blow operation which satisfies the automatic filter washing conditions (800Y). Nest, the filter washing operation will be described below with reference to the subroutine shown in Fig.31. [Filter Washing Operation] The filter washing operation can be performed in precedence over the blow operation by turning ON the filter washing switch 117 even before or after or during the blow operation if only after turning ON of the operation switch 100 or 260. When the filter washing switch 117 is turned ON (905Y), the filter washing operation starts (910), and if there is no abnormal condition in the discharge pressure of the circulating pump P detected by the pressure sensor 48 and in the hot water temperature in the bathtub body 1 detected by the hot water temperature sensor T, that is, if the pressure and hot water temperature are blow operation permitting pressure and temperature (915N), the filter washing operation is continued for a certain time (e.g. 5 min) and after the lapse of the certain time the operation stops (215). In the filter washing operation, the number of revolutions of the circulating pump P is set to, for example, 3000 r.p.m, and the blow-off nozzle adjusting valves 22 in the leg- and back-side blow-off nozzles 2, 3 are slightly opened, for example, 0.5 mm backward from their fully closed positions, with only the blow-off volume adjusting valves 22 in the back-side blow-off nozzles 4 being fully closed. If the pressure and water temperature are not normal (915V), there is made detection as to whether the water temperature is lower than the lower limit (e.g. 5 °C) of the blow operation permitting temperature range, and if the answer is affirmative (925Y), the freeze proofing operation is started (320), while if the answer is negative, that is, if the hot water temperature is higher than the upper limit (e.g. 50 °C) of the said temperature range (925N), the operation stops (215). Next, the freeze proofing operation with be described below with reference to the subroutine shown in Fig. 32. [Freeze Proofing Operation] The freeze proofing operation is performed to prevent freezing of the water in the circulating pump P and in the hot water circulation path D. It is performed in precedence over the blow operation, and when the water temperature becomes lower than the lower limit (e.g. 5 °C) of the blow operation permitting temperature range during the blow operation, the blow operation is stopped forcibly and the freeze proofing operation is started. First, the hot water temperature in the hot water circulation path D is detected by the hot water temperature sensor T, and if the detected temperature is lower than the lower limit (e.g. 5 °C) of the blow operation permitting temperature range (310Y), the water level in the bathtub body 1 is detected by the pressure sensor 48 which also serves as a level sensor. If the detected level is a blow operation permitting level (e.g. a level higher than the upper end of the suction port 1m) (315Y), the freeze proofing operation is started (320). In the freeze proofing operation, the circulating pump P is rotated at a low speed (e.g. 1000 r.p.m.) by inverter control to circulate water through the hot water circulation path D. In this case, if the water temperature is lower than the lower limit (e.g. 5 °C) of the blow operation permitting temperature range of lower than the temperature which is the said lower-limit temperature plus the temperature (e.g. 2-3 °C) corresponding to the hysteresis in the hot water temperature sensor T (325N) and if the water level in the bathtub body 1 is the blow operation permitting level (330V), the feeeze proofing operation is continued. During the freeze proofing operation, the indication "C" indicating a low water temperature is turned on and off every second on the clock display portion 115 of the operating panel 6. If by additional supply of hot water the water temperature rises to the lower limit of the blow operation permitting temperature range or higher or to the temperature which is the said lower-limit temperature plus the temperature corresponding to the hysteresis in the hot water temperature sensor T or higher (325Y), the operation stops (215). Main operations in the operation procedure of the whirlpool bath described above will be further explained below. [IV-2 ] Description of Conditions for Starting Blow Operation The blow operation in the foregoing operation procedure is started only when preset water level and temperature conditions in the bathtub body 1 are satisfied. More specifically, as shown in Fig.33, the water level condition is determined on the basis of the suction port 1m and the belly-side blow-off nozzles 4 both provided in the bathtub body 1. A water level higher than the upper end of the opening of each belly-side blow-off nozzle 4 is designated water level A; a water level between the upper end of the opening of each belly-side blow-off nozzle 4 and the upper end of the suction port 1m is designated water level B; and a water level lower than the upper end of the suction level 1m is designated water level C. When the water level is A or B, the blow operation is started, while when the water level is C, the blow operation is not started. Further, when the water level changed from A or B to C during blow operation, the blow operation is stopped. In this case, even if the water level is returned to B or A from C by additional supply of hot water for example, the blow operation is held OFF, and by again turning ON the operation switch the level-drop stop can be cancelled, thereby attaining sureness and safety of operation. In this connection, in the clock display portion 115 of the operating panel 6, the indication "L" indicating a level drop is turned on and off for 15 seconds alternately every second by means of a light emitting diode, and at the same time warning is given by sounding of a buzzer. Detection of the water levels A, B and C is performed in such a manner as shown in Fig. 34. In consideration of waving of the hot water surface when the user enters or leaves the bathtub, the output voltage of the pressure sensor 48 which serves as a level sensor is provided with hysteresis to prevent hunting, whereby the controlling operation of the controller C can be done smoothly through the pressure sensor 48. In Fig.34, Soc represents a threshold value from a water level lower than the level C to the level C; Scb represents a threshold value from the level C to the level B; Sba represents a threshold value from the level B to the level A; Sab represents a threshold value from the level A to the level B; Sbc represents a threshold value from the level B to the level C; and Sco represents a threshold value from the level C to a lower water level side. Hysteresis is provided between the threshold values Soc and Sco, between the threshold values Scb and Sbc, and between the threshold values Sba and Sab. The water temperature condition is determined on the basis of a water temperature taking into account the protection of the user and of the pipes made of a synthetic resin, e.g. 50 °C, and a water temperature taking into account the prevention of freezing of the water in the circulation pump P, e.g. 5 °C. The water temperature higher than 50 °C is designated the water temperature A; the water temperature in the range of 5 °C to 50°C is designated the water temperature B; and the water temperature lower than 5 °C is designated the water temperature C. The blow operation is performed at the water temperature B and not performed at the water temperature A or C. When the water temperature changes from B to A or C during the blow operation, the operation is stopped. In this case, even if the water temperature is returned to B from A by additional supply of water for example, the blow operation is kept OFF, and only by again turning ON the operation switch the stop of the operation caused by the rise of the temperature can be cancelled to ensure the sureness and safety of operation. In this case, the indication "H" indicating a high water temperature is turned on and off alternately every second for 15 seconds by means of a light emitting diode on the closk display portion 115 of the operating panel 6, and at the same time a buzzer will sound to give warning. The water temperatures A, B and C are detected in such a manner as shown in Fig.35. In consideration of waving of the hot water surface when the user enters or leaves the bathtub, the resistance value of the hot water temperature sensor T is provided with hysteresis to prevent hunting, whereby the controlling operation of the controller C can be done smoothly. In Fig.35, S′oc represents a threshold value from a temperature lower than the water temperature C to the temperature C; S′cb represents a threshold value from the temperature C to B; S′ba represents a threshold value from the temperature B to A; S′ab represents a threshold value from the temperature A to B; S′bc represents a threshold value from the temperature B to C.; and S′co represents a threshold value from the temperature C to a lower temperature side. Hysteresis is provided between the threshold values S′oc and S′co, between S′cb and S′bc, and between S′ba and S′ab. [IV-3 ] Description of State Transition of Blow-off Modes The state transition of blow-off modes in the operation procedure described above is as shown in Table 2. In Table 2. an operation stop condition and blow-off modes are enumerated in the vertical direction and state numbers are enumerated in the corresponding right-hand positions, while in the lateral direction there are enumerated operating switches (operation switch, mild switch, spotblow switch, pulse blow switch, wave blow switch, cycle blow switch, program blow switch) as well as display portions (mild blow, spotblow, pulse blow, wave blow, cycle blow, program blow, selection pattern A, B, C, display portions) which are indicated by light emitting diodes on the operating panel 6. Table 2 shows the transition from a blow-off mode before turning ON of each operating switch to a blow-off mode after turning ON thereof. In the cases of pulse blow, wave blow, cycle blow and program blow each having the selection patterns A, B and C as sub modes, between blow-off modes of the same kind, newly added sub modes are sure to shift in a preset order, for example, in the order from high to low frequency of use (A→B →C →A in this embodiment). Between blow-off modes of different kinds, a shift is made surely to a preset sub mode, for example, a sub mode of a high frequency of use (the sub mode A in this embodiment). Description will now be made more concretely with reference to Table 2. Upon turning ON of the operation switch 100, a shift is made from operation stop (state No. "0") to mild blow (state No. "1"). In this state, if the pulse blow switch 263 or 103 is turned ON, a shift is made from mild blow to pulse blow A (state No. "3A"). If in this state the finger-pressure blow switch 262 or 102 is turned ON, a shift is made from pulse blow A to spotblow (state No. "2") If in the state of pulse blow A the pulse blow switch 263 or 103 is turned ON for transition to a blow-off mode of the same kind, a shift is made to pulse blow B (state No. "3B"). Further, if the wave blow switch 265 or 104 is turned ON for transition from the state of pulse blow A to a blow-off mode of a differend kind, a shift is made to wave blow A (state No. "4A"), while if the cycle blow switch 266 or 105 is turned ON, a shift is made to cycle blow A (state No. "5A"), or if the program blow switch 267 or 106 is turned ON, a shift is made to program blow A (state No. "6A"). Thus, since the blow-off mode is set to the mild blow mode at the beginning of operation, even when the user is a child or an old person, it is possible to prevent the user from being carried away his legs by the hot water jet and falling down and also prevent the user from feeling uncomfortableness due to an excessive blow strength. Moreover, since the sub blow-off modes are sure to shift in a preset order, it is easy for the user to understand a sub mode transition pattern and easy to operate. The mark "ON" in Table 2 indicates lighting of the display portion of the blow-off mode being adopted. For example, in the case of pulse blow A, the letter "A" lights in both the pulse blow display portion 138 and the selection pattern display portion (142). In the case of program blow patterns A, B and C, the program blow display portion 141 and the selection pattern display portion 145 light up, while the mild blow, finger-pressure blow, pulse blow and wave blow display portions 136, 137, 138, 139 go on and off. In Table 2, the mark "-" represents non-change and the mark "." represents an OFF condition. In the state transition of blow-off modes described above, the blow strength level does not change even if the blow-off mode is changed. Thus, it is possible to maintain the body feeling strength level in the blow-off mode before change, so it is not necessary to perform a strength level changing operation, that is, it is possible to prevent the user from feeling uncomfortableness at the time of change of the blow-off mode. It is also possible to change the strength level to a medium level with change in the blow-off mode. Further, the hot water blow-off position is not changed even if the blow-off mode is changed. Thus, it is possible to maintain the hot water blow-off position in the blow-off mode before change, so it is not necessary to perform a blow-off position changing operation, that is, it is possible to prevent the user from feeling uncomfortableness at the time of change of the blow-off mode. As to the hot water blow-off position, it is also possible to open all the blow-off nozzles 2, 3, 4 with change in the blow-off mode, allowing the user to feel the blow-off mode after change all over hid body, and thereafter make a change to desired blow-off positions matching the blow-off mode. [IV-4 ] Description of State Transition of Hot Water Blow-off Positions The hot water blow-off position changing operation in the operation procedure based on flowcharts of [IV-1] will be described below with reference to the explanatory view of Fig.36. In this embodiment, the hot water blow-off position can be changed so as to apply a hot water jet to the user's whole body or a part of the body according to the user's liking. More specifically, a six-hole operation is initialized (950) in which hot water is blown off from the six, leg-, back- and belly-side blow-off nozzles 2,2,3,3,4,4 simultaneously. From the six-hole operation (950) in which all of the ON-OFF type pattern switches for the leg-, back- and belly-side blow-off nozzles are ON, a change can be made into a four-hole operation (955)(956)(957) in which two blow-off nozzles are OFF, by pushing OFF any switch (951) (952)(953). By pushing ON and OFF-state switch out of the pattern switches for the leg-, back- and belly-side blow-off nozzles (951)(952)(953) it is possible to make a return from the four-hole operation (955)(956)(957) to the six-hole operation (950). It is also possible to change from the four-hole operation (955) (956)(957) into a two-hole operation (967)(968)(969) in which additional two blow-off nozzles are OFF, by pushing Off an ON-state switch out of the pattern switches for the leg-, back- and belly-side blow-off nozzles (960)-(965). Further, it is possible to make a return from the two-hole operation (967)(968)(969) to the four-hole operation (955)(956)(957) by pushing ON and OFF-state switch out of the pattern switches for the leg-, back- and belly-side blow-off nozzles (960)-(965). Table 3 shows the state transition of hot water blow-off positions described above, in which operation stop and blow-off positions (back, belly, leg, back-belly, belly-leg, back-leg, back-belly-leg) are enumerated in the vertical direction and state numbers are enumerated in the corresponding right-hand positions, while in the lateral direction there are enumerated operating switches (operation switch as well as back-, belly- and leg-side switches) and pilot lamps (back-, belly- and leg-side pilot lamps) which are turned ON by light emitting diodes on the operating panel 6. An explanation will now be made concretely with reference to Table 3. If the operation switch 100 is turned ON, a change is made from operation stop (state No. "0") to a six-hole operation (950) (state No. "111") in which hot water is blown off from the six, leg-, back- and belly-side blow-off nozzles 2,2,3,3,4,4 simulataneously, and if in this state the back-side nozzle pattern switch 274 or 111 is pushed OFF, a shift is made to a four-hole operation (955) of the leg- and belly-side blow-off nozzles 2,2,4,4 and the state number becomes "011". In the above four-hole operation state No. "011"), both leg-side pilot lamp 112a and belly-side pilot lamp 113a go on. Thus, the six-hole operation is initialized at the start of operation, and by turning ON and OFF the leg-, back- and belly-side blow-off nozzle use pattern switches there can be made an easy change from the six-hole operation to the four- or two-hole operation, or from the two-hole operation to the four- or six-hole operation. In Table 3, the mark "-" represents non-change and the mark "." represents an OFF condition. In the state transition of hot water blow-off positions described above, the strength level does not change as long as the blow operation does not stop even if the hot water blow-off positions are changed. Thus, since it is possible to maintain the strength level in the blow-off positions before change, it is not necessary to perform a strength level changing operation, that is, it is possible to prevent the user from feeling uncomfortableness at the time of change of the blow-off positions. [IV-5 ] Description of State Transition of Strength Level in Blow Operation The strength level in the operation procedure based on flowcharts of [IV-1 ] is set to five stages of "strong," "medium strong," " medium," "medium weak" and "weak" for each blow-off mode, and different strengths are set in consideration of the contents of the blow-off modes; that is, different blow-off modes lead to different below strengths even at the same strength level indication "medium". The state transition of such strength level is as shown in Table 4. In Table 4, operation stop and five-stages of strength levels (strong, medium strong, medium, medium weak, weak) as well as program blow patterns A, B, C are enumerated in the vertical direction, and state numbers are enumerated in the corresponding right-hand positions, while in the lateral direction there are enumerated operating switches (operation switch as well as hot water blow strong- and weak-side switches) and strength level indicating lamps (level strong, medium strong, medium, medium weak and weak indicting lamps) using light emitting diodes. The strength level is set so taht when the hot water blow strong-side switch 68 or 107 is pushed and then released, a shift is made in a direction in which the strength is enhanced one stage, while when the hot water blow weak-side switch 69 or 108 is pushed and then released, a shift is made in a direction in which the strength is weakened one stage. For example, if the operation switch 100 is turned ON, a shift is made from operation stop (stage No. "0") to the strength level "medium" (state No. "3"), and if in this state the hot water blow strong-side switch 68 or 107 is pushed and then released, a shift is made from " medium" to the strength level "medium strong" (state No. "4"), then if the same switch 68 or 107 is again pushed and then released, a shift is made to the strength level "strong" (state No. "5"). Further, if in the strength level "medium" the hot water blow weak-side switch 69 or 108 is pushed and then released, a shift is made to the strength level "medium weak" (state No. "2"), and if the same switch 69 or 108 is again pushed and then released, a shift is made to the strength level "weak" (state No. "1"). In the program blow patterns A, B and C, since the strength level is programmed boforehand, it cannot be changed even upon operation of the hot water blow strong- and weak-side switches 68, 69, or 107, 108. In Table 4, the mark "ON" indicates lighting of the strength level indicating lamp in operation. The mark "ON/OFF" indicates that the strength level indicating lamp goes ON and OFF when the program blow pattern A, B or C incapable of changing the strength level is in operation. Further, "-" indicates non-change and "." indicates an OFF condition. Thus, since the strength level is set to "medium" at the start of blow operation, there is no fear of a too strong hot water jet causing the user to feel uncomfortableness, and also when the user is a child or an old person, it is possible to prevent the user from being carried away by the hot water jet and falling down. Further, for both increase and decrease the strength level is changed step by step, so it is possible to prevent a sudden change in the user's body feeling and also possible to prevent the pipes from being damaged by water hammer due to sudden rise of the water pressure in the pipes. [IV-6 ] Description of Priority of Main Operations The priority of main operations in the operation procedure based on flowcharts of [IV-1 ] is as shown in Table 5. Thus the stop at a high water temperature is given the top priority to ensure safety, and also as to the other operations the order of priority is provided among them, thereby permitting the protection of the user and of the constituent members and permitting optimum control to effect an efficient operation. [IV-7 ] Control Timing between Opening/Closing of Blow-off Volume Adjusting Valves and Change of the Number of Revolutions of Circulating Pump The following Tables 6 and 7 show the control timing between opening and closing operations of the leg-, back- and belly-side blow-off nozzles 2, 3, 4 and the change of the number of revolutions of the circulating pump P. In the case where it is necessary to increase the number of revolutions of the circulating pump P at the time of changing the blow-off mode as shown in Table 6, the opening or closing operation of the blow-off nozzles 2, 3, 4 is performed prior to changing the number of revolutions of the pump P, while when it is necessary to decrease the number of revolutions of the circulating pump P, the change of the number of revolutions of the pump P is performed prior to the opening or closing operation of the blow-off nozzles 2, 3, 4. When the number of hot water jets is to be decreased at the time of changing the number of such jets as shown in Table 7, the number of revolutions of the circulating pump P is decreased prior to the closing operation of the blow-off nozzles 2, 3, 4, while when the number of hot water jets is to be increased, the opening operation of the nozzles 2, 3, 4 is performed prior to changing the number of revolutions of the pump P. Thus, at the time of changing the blow-off mode and the number of hot water jets, the control timing for the opening or closing operation of the blow-off nozzles 2, 3, 4 and that for the change of the number of revolutions of the circulating pump P are made different, whereby not only it is possible to prevent the user from feeling u ncomfortableness due to a change of the blow strength but also an abrupt change in the discharge pressure of the circulating pump P can be prevented, thereby preventing the damage of pipes caused by water hammer, etc. [IV-8 ] Electricity insulation against high frequency components of inverter produced current. Hereinafter, preferred embodiments of electricity insulation means applicable for protecting the transfer of high frequency components of inverter-produced current to the hot water in said bathtub body 1 is explained in view of attached drawings. (a) As shown in Figs. 46,47 and 48, an isolating transformer 1140 is interposed between the inverter E and a commercially available power source 937. Fig.49 is a graph showing the frequency distribution of the leakage high-frequency voltage, and Fig.50 is a graph showing the variation of the leakage high-frequency current with time, when the isolating transformer 1140 is provided. As can be readily understood, the leakage high-frequency voltage and leakage high-frequency current of the high-frequency components shown in Figs. 49 and 50 are far less than those shown in Fig. 51 and 52 in the conventional bathtub unit respectively. Thus, the present invention prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (b) As shown in Fig.10 to Fig.12, the circulating pump P and the inverter E are accommodated in the functional unit 9 and an electric insulation is provided between the circulating pump P and the inverter E as well as between the inverter E and the casing 60 of the functional unit 9. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (c) As shown in Fig.53,54 and 55, an isolating transformer 1140 is interposed between the inverter E and a commercially available power source 937 and a motor casing 938 of the circulating pump P is connected to an intermediate point n of the commercially available power source 937. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (d) A motor portion 1038 and a pump portion 32 of the circulating pump P are integrally constructed and the motor portion 1038 and the pump portion 32 are electrically insulated from each other. Namely, as shown in Fig. 9, an insulating plate 1033 formed of a synthetic resin is interposed between the motor casing 32 and the pump casing 38 to prevent a high-frequency current that flows from a field core 1024 to the motor casing 38 from leaking through the pump casing 32 into the water contained in the bathtub 1. The impeller integrally having the upper impeller 33a and the lower impeller 34a is formed of an insulating synthetic resin. The lower end of the rotor shaft 35 of the motor unit M is fitted in the core 1035 of the upper boss 1034 of the impeller. Thus, the pump unit 32 is insulated electrically from the motor unit 38. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (e) As shown in Fig.10 to Fig. 12, the inverter E is electrically insulated from the casing 60 of the functional unit 9 which accommodates said inverter E therein and a capacity coupling between the inverter E and the casing 60 of the functional unit 9. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (f) As shown in Fig. 10, a functional unit 9 is disposed remote from the bathtub body 1 and, in the functional unit 9, the circulating pump P is disposed at the center of the unit 9, the filter 43 is disposed beside the circulating pump 9, and above these elements, a motor portion and electric parts such as the control unit C and the inverter E are disposed. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility. (g) As shown in Fig. 57, a line filter 1143 is interposed between the inverter E and a commercially available power source 937. In the circuit shown in Fig.56, numeral 1145 indicate a pair of lead lines, numerals 1146 and 1147 indicate condensers, numeral 1148 indicates a casing of filter 1143. Due to such construction, the present invention also prevents effectively the bathing person being struck by electricity even if the motor M is grounded imperfectly by any possibility.

Claims: A whirlpool bath with an inverter-controlled circulating pump comprising: a) a bathtub body (1), b) a circulating pump (P) driven by a power-operated motor and mounted exteriorly on said bathtub body (1), c) a hot water circulation path (D) disposed between said bathtub body (1) and said circulating pump (P), said hot water circulation path (D) comprising a hot water suction path (10) and a hot water forced-feed path (11), said hot water forced-feed path having at least one terminal end which is open into said bathtub body (1), d) at least one blow-off nozzle (2)(3)(4) which is mounted on said terminal end of said hot water forced-feed path (11), e) an air intake portion (5) connected to said hot water forced-feed path (11) to permit blowing of bubbling hot water into said bathtub body from said blow-off nozzles, f) a control unit (C) provided with an inverter (E) interposed between a drive circuit of said power-operated motor (M) of said circulating pump (P) and a power source, whereby the operation of said circulating pump (P) is controlled such that the revolution of said motor (M) is readily and smoothly varied by way of a frequency modulation effected by said inverter (E) to provide varying blow-off strength of hot water, and the improvement being characterized in that said whirlpool bath is further provided with an electrically isolating transformer (1140) interposed between said inverter (E) and a commercially available power source (937) and that a motor casing (938) of said circulating pump (P) is connected to an intermediate point (n) of said commercially available power source (937). A whirlpool bath with an inverter-controlled circulating pump according to claim 1, wherein said blow-off nozzle is further provided with valve means (22) for gradually regulating the blow-off amount and blow-off pressure and said blow-off nozzle (2)(3)(4), and said control unit is capable of simultaneously regulating said valve means (22) of said blow-off nozzle (2)(3)(4) and said circulating pump (P) receiving signals transmitted from an operating panel (6) thus providing following blow-off modes; a) a blow-off mode in which said valve means (22) of said blow-off nozzle (2)(3)(4) is positioned at a position which enable a full opening of said blow-off nozzle (2)(3)(4) and the revolution of said circulating pump (P) is increased from a medium speed level to high speed level thus providing a blow in which the amount of said hot water blown off from said blow-off nozzles (2) (3)(4) is large and the blow-off pressure thereof is low; b) a blow-off mode in which said revolution of said circulating pump (P) is held at said high speed level and said valve means (22) of said blow-off nozzle (2)(3)(4) is regulated such that the amount of hot water blown off from said blow-off nozzles (2)(3)(4) is small and the blow-off pressure thereof is high; c) a blow-off mode in which said revolution of said circulating pump (P) is held at said high speed level and said valve means (22) of said blow-off nozzle (2)(3)(4) moves between a fully-nozzle-open position and a fully-nozzle-closed position to perform blow-off of hot water and stop thereof in an alternate manner; and d) a blow-off mode in which said valve means (22) of said blow-off nozzle (2)(3)(4) is positioned at a position which enable a full or half opening of said blow-off nozzle (2)(3)(4) and the revolution of said circulating pump (P) is periodically changed thus providing a blow in which the amount of said hot water to be blown off is charged periodically. A whirlpool bath with an inverter-controlled circulating pump according to claim 1, wherein said circulating pump (P) and said inverter (E) are accommodated in a functional unit (60) and an electricity insulation is provided between said circulating pump (P) and said inverter (E) as well as between said inverter (E) and said functional unit (60). A whirlpool bath with an inverter-controlled circulating pump according to claim 1, wherein a motor portion and a pump portion of said circulating pump (P) are integrally constructed and said motor portion and said pump portion are electrically insulated from each other. A whirlpool bath with an inverter-controlled circulating pump according to claim 1, wherein said inverter (E) is electrically insulated from a functional unit (60) which accomodates said inverter (E) therein and a capacity coupling between said inverter (E) and said functional unit (60) is minimized. A whirlpool bath with an inverter-controlled circulating pump according to claim 1, wherein a functional unit (60) is disposed remote from said bathtub body (1) and, in said functional unit (60), said circulating pump (P) is disposed at the center of said unit (60), a filter is disposed beside said circulating pump, and above these elements, a motor portion and electric parts such as said control unit (C) and said inverter (E) are disposed.

Inventors: HARAGA HISATO, HASHIDA MITUAKI, INATOMI YASUTOSHI, MORIYAMA KENJI, OBATA TAKASHI, UCHIYAMA KOICHI, HARAGA, HISATO, HASHIDA, MITUAKI, INATOMI, YASUTOSHI, MORIYAMA, KENJI, OBATA, TAKASHI, UCHIYAMA,KOICHI
Applicants: TOTO LTD, TOTO LTD.
Application year: 1989
Main classification: A61H33
IPC codes: A61H33