Compressor apparatus

A compressor apparatus notifies a user whether compressed-air reaches a specified pressure without requiring a pressure gauge or the costs associated therewith. The compressor apparatus includes a motor M, a rotational shaft 11, a compressor main body 10 comprising a cylinder chamber 15, and a detector 7 that notifies the user that the pressure of the compressed-air supplied from the above-mentioned cylinder chamber 15 exceeds a reference pressure P. The detector 7 includes a valve main body 30 having a valve flow channel 30A having an exhaust port 33 and a switch valve 34 releasing the valve flow channel 30A to exhaust the compressed-air supplied from the exhaust port 33 when the compressed-air pressure exceeds the reference pressure P; and a detective cap 31 pushed up by the exhaust air pressure from the exhaust port 33 from the normal position Y1 to the protruding position Y2.

TECHNICAL FIELD

The present invention relates to a compressor apparatus being suitable to fill a tire with the air, being capable of notifying a user that a generated compressed-air pressure comes up to a reference pressure with high accuracy without using a pressure gauge, and being capable of filling up the tire with the air at the specified pressure previously indicated as the reference pressure.

BACKGROUND OF THE INVENTION

As a compressor apparatus to fill a tire with compressed-air, a compressor apparatus shown inFIG. 8is proposed, for example (See Patent Document 1, for example). This apparatus (a) comprisesa motor (b);a compressor main body (c) making generate compressed-air;an air-supplying means (d) letting go the generated compressed-air into a tire;a pressure gauge (e) measuring a pressure of the generated compressed-air; anda relief valve (f) as a safety valve to release an overpressure generated by the compressor main body (c).

The generated compressed-air is filled up to the tire by connecting the above-mentioned air-supplying means (d) to the tire and by driving the motor (b). At this time, a user looks at a pressure gauge (e) and recognizes that the compressed-air comes up to a specified pressure of filling the tire.

In the case of a passenger car, for example, the specified pressure of filling the tire is ordinarily in a range of from 200 to 250 kPa, and it is specified for car models. Therefore, to replenish the tire resulted in a reduction of pressure in use with the air or to fill up the punctured tire with the air, it requires the user to inflate the air while watching the pressure gauge and turns off the apparatus when the pressure reaches the specified pressure specified for car models.Patent Document 1: Japanese Laid-open Patent Publication No. 2005-344570.

DISCLOSURE OF THE INVENTION

Problem to be Solved by the Invention

Using the pressure gauge, however, it is unclear for the user to know whether the pressure reaches the specified pressure. Therefore, there are problems that an assessment of the user is apt to vary widely and that it is difficult to fill up the tire with the air at the specified pressure with high accuracy. Moreover, when filling the tire with too much air, an operation for pressure reduction needs excessive operation; it incurs increase of working hours.

It is therefore an object of the present invention to provide a compressor apparatus being capable of notifying a user that definitely whether compressed-air reaches the specified pressure or not, reducing the assessment variance of the user, and filling up the tire with the air at the specified pressure with a high degree of accuracy while eliminating a pressure gauge and reducing costs, on a basis of utilizing a conventional relief valve hitherto used, which has been as a safety valve, as a detection means.

Means for Solving the Problems

To achieve the above-mentioned object, the invention set forth in claim1of the present application is that a compressor apparatus, in a storage case, comprises a motor; a rotational shaft rotary-driven by the motor; a compressor main body comprising a rod attached to the rotational shaft via a crank, a piston disposed in the rod end, and a cylinder housing reciprocatingly the piston and forming a cylinder chamber for compressing the air between the above-mentioned piston and the cylinder; an air-supplying means having an air-supplying flow channel to supply the compressed-air from the above-mentioned cylinder chamber into the tire; and a detection means which notifies a user that a pressure of the compressed-air supplied from the above-mentioned cylinder chamber exceeds a reference pressure and prompts the user to turn off the above-mentioned motor. The above-mentioned detection means includes a valve main body having a valve flow channel comprising one end leading to the air-supplying flow channel and another end leading to an exhaust port, and an switch valve intermediating in the valve flow channel and releasing the valve flow channel to exhaust the air from the above-mentioned exhaust port when the compressed-air pressure exceeds the above-mentioned reference pressure; a detection cap disposed in the above-mentioned exhaust port and pushed up from a normal position, which is at the same level as an outer surface of the above-mentioned storage case or on the inward side of the outer surface, to a protruding position, which protrudes over the outer surface of the above-mentioned storage case, by the air pressure exhausted from the above-mentioned exhaust port; and a retaining means to keep the above-mentioned detection cap at the above-mentioned normal position when the above-mentioned compressed-air is below the reference pressure.

Effects of the Invention

As above stated, an apparatus according to the present invention comprises a detection means which notifies the user that the pressure of the compressed-air supplied from the cylinder chamber exceeds the reference pressure and prompts the user to turn off the motor, thereby reducing the assessment variance of the user. Therefore, the user can fill up the tire at the nearly specified pressure with a high degree of accuracy.

With respect to the above-mentioned detection means, a conventional relief valve hitherto having been used which was as a safety valve for breakage caused by overpressure as a detection means is utilized for the valve main body. And, the filling pressure of tire specified for car models is set for a reference pressure thereof. Therefore, in the above-mentioned valve main body, when the compressed-air reaches the reference pressure (the filling pressure of tire specified for car models), the compressed-air can be exhausted from the exhaust port. Furthermore, the detection cap is pushed up to the protruding position where the outer surface of the detection cap protrudes over the outer surface of the storage case owing to the above-mentioned exhaust air pressure. Therefore, this can notify the user definitely that the compressed-air exceeds the reference pressure with a smaller movement of the detection cap, that is to say, this can reduce the assessment variance of the user in bringing the motor down. Moreover, the detection means is in an easy structure, and it can eliminate the conventional pressure gauge, thereby reducing costs and downsizing the apparatus.

EXPLANATION OF THE REFERENCES

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with referent to the drawings. As illustrated inFIGS. 1 and 2, a compressor apparatus1of the present embodiment comprises a storage case2including a motor M; a rotational shaft11rotary-driven by the motor M; a compressor main body10comprising a cylinder chamber15to compress the air; an air-supplying means18supplying the compressed-air from the above-mentioned cylinder chamber15into the tire; and a detection means7which notifies a user that a pressure of the compressed-air supplied from the above-mentioned cylinder chamber15exceeds a reference pressure P and prompts the user to turn off the above-mentioned motor M.

The above-mentioned storage case2is a box object of a transversely low aspect ratio rectangle and, in this example, can be taken to upper and lower case parts2A and2B. And, as the above-mentioned motor M, variety commercially available DC motors can be used, which drive in a direct-current power supply of 12 V of an automobile. The motor M is connected to a power-supply cord19that has a power-supply plug19A being connectable to a cigar lighter socket of the car at the distal end via an on-off switch SW attached to a top surface of the above-mentioned storage case2.

As shown inFIG. 3, the above-mentioned compressor main body10comprises a rod13attached via a crank12to the rotational shaft11rotary-driven by the above-mentioned motor M; a piston14disposed in the rod end thereof; and a cylinder16housing reciprocatingly the piston14and forming a cylinder chamber15compressing the air between the above-mentioned piston14and the cylinder. Incidentally, between the motor M and the rotational shaft11, there is a well-known decelerating mechanism20comprising a gear, pulley, and the like, for example. The decelerating mechanism20slows down a rotation of the motor M as much as approximately from ⅓ to ⅛ and conveys it to the rotational shaft11.

Moreover, in the above-mentioned crank12, one end of the above-mentioned rod13is pivotably supported via a supporting pin21. Another end of the rod13is provided with a piston14. In the present example, the above-mentioned rod13and the piston14are integrally formed as a formed body made of fiber-reinforced plastic. In this example, the piston14comprises, as shown inFIGS. 3 and 4, intake valves22including an intake bore22A extending in penetrating the piston14in the shaft center direction, a valve element22B closing the intake bore22A from a piston front-side, having a spring characteristic, and made of a elastic body such as rubber, synthetic resin, metal and the like. This piston14places in the cavity of the above-mentioned cylinder16and forms a cylinder chamber15being capable of compressing the air between the piston14and the cylinder. Incidentally, an outer circumference of the piston14is provided with a ring sealant23, thereby keeping air leakage efficiency between the cylinder16and the piston.

In this compressor main body10, when the above-mentioned piston14backs away in a direction of increasing in content of the cylinder chamber15, the above-mentioned intake valve22opens and makes inflow from the intake bore22A into the cylinder chamber15. And, when the above-mentioned piston14gets forward, the above-mentioned intake valve22is closed, the air in the above-mentioned cylinder chamber15is compressed, and the pressure is enhanced.

The above-mentioned cylinder16is jointed to an air-supplying means18having an air-supplying flow channel18A supplying the compressed-air from the cylinder chamber15into the tire.

This air-supplying means18comprises a surge tank portion26having interiorly a surge tank chamber25connected to the above-mentioned cylinder chamber15via a compressed-air inlet24. The surge tank chamber25retains the compressed-air via the small-opening-like compressed-air inlet24and dampens pulsation in pressure caused by the piston14. Incidentally, the above-mentioned compressed-air inlet24can be provided with a check valve. The above-mentioned intake valve22can be formed in the cylinder16. And, the above-mentioned surge tank portion26is provided with a nipple-like connecting section28protruding forward, for example, to connect releasably to a hose27for supplying the compressed-air. The above-mentioned air-supplying means18comprises the above-mentioned surge tank portion26and the hose27.

Thus, the compressor apparatus1according to the present invention is provided with the detection means7that notifies the user that the pressure of the compressed-air supplied from the above-mentioned cylinder chamber15exceeds the reference pressure P and prompts the user to turn off the above-mentioned motor M.

The detection means7, as shown inFIG. 5, comprises a valve main body30, a detection cap31, and a retaining means32. The above-mentioned valve main body30comprises at least a valve flow channel30A having one end leading to the above-mentioned air-supplying flow channel18A and another end leading to an exhaust port33, and a switch valve34intermediating in the valve flow channel30A and releasing the valve flow channel30A to exhaust the compressed-air supplied from the above-mentioned exhaust port33when the compressed-air pressure exceeds the above-mentioned reference pressure P.

More particularly, the valve main body30comprises a tubular housing35standing out upward from the above-mentioned surge tank portion26. In a central hole35aof the housing, a tapered cone-shaped valve seat portion35a1is formed on a lower end side thereof, and an inner threaded portion35a2is formed on an upper end side thereof. Furthermore, to the inner threaded portion35a2, an adjusting screw36is attached spirally. In the above-mentioned central hole35a, a valve shaft37to close the above-mentioned valve seat portion35a1by bringing into contact with the valve seat portion35a1. Moreover, between the above-mentioned adjusting screw36and the valve shaft37, a follow spring38forces inferiorly the above-mentioned valve shaft37is arranged. In the above-mentioned adjusting screw36, a connected hole36A having one end leading to the above-mentioned central hole35aand another end leading to and opening at exhaust port33on an upper end face of the above-mentioned adjusting screw36is formed. Therefore, the above-mentioned valve flow channel30A is formed of the above-mentioned central hole35aand the connected hole36A. And, the switch valve34is formed of the above-mentioned valve seat portion35a1and the valve shaft37.

In the valve main body30is, as shown inFIG. 5(b), when the compressed-air pressure in the surge tank chamber25increases and exceeds the value of the reference pressure P, the compressed-air is exhausted from the exhaust port33through the valve flow channel30A by overcoming the follow spring38and by uplifting the valve shaft37. In the present invention, the above-mentioned reference pressure P is a tire-filling pressure specified for car models and can be adjusted by rotating in a spiral of the above-mentioned adjusting screw36upon request. For example, when the above-mentioned adjusting screw36is screwed up, the follow spring38is compressed, and the force of repulsion thereof presses inferiorly the switch valve34more greatly, thereby heightening the pressure pushing up the switch valve34. By contraries, when the adjusting screw36is loosened, the push-up pressure reduces. The air-filling pressure, namely a reference pressure P can be adjusted by the variation of screwing quantity of the above-mentioned adjusting screw. Incidentally, in the case of the conventional relief valve used as a safety valve, the reference pressure is a safety reference pressure determined to prevent breakage caused by the overpressure of the compressor, so that the conventional relief valve differs from the valve main body30.

The above-mentioned detection cap31is disposed in the above-mentioned exhaust port33. The detective cap31is pushed up from a normal position Y1where the outer surface31sis at the same level as an outer surface2sof the above-mentioned storage case2or is on the inward side of the outer surface2sto the protruding position Y2where the outer surface31sprotrudes over the outer surface2sof the above-mentioned storage case2by the air pressure exhausted from the exhaust port33. This can notify the user visually that the compressed-air exceeds the reference pressure P.

The above-mentioned detection cap31is a vessel-like cap and an upper end of the cylindrical body39is closed by a plate part40. In the present embodiment, the cylindrical body39has a step and comprises a large-diameter section39asurrounding the above-mentioned adjusting screw36and a small-diameter section39cextending on the upper end side thereof via a stepped section39b, for example. In the above-mentioned storage case2, a guide bore41guiding the above-mentioned detection cap31in an up-and-down slidable state is formed by inserting movably the above-mentioned cylindrical body39(the small-diameter section39c, in this example). Between the outer surface of the above-mentioned stepped section39band the storage case2, there is a spring42forcing inferiorly the above-mentioned detection cap31.

Therefore, the above-mentioned detection cap31is kept in the normal position Y1where the inner surface of the above-mentioned stepped section39babuts on an upper surface of the adjusting screw36owing to forcing by the spring42when the compressed-air is not more than the reference pressure P. According to the present embodiment, the spring42forms the above-mentioned retaining means32. When the compressed-air exceeds the reference pressure P, the pressure of the exhaust air from the exhaust port33overcomes the forcing power of the above-mentioned spring42and can push up the detection cap31to the above-mentioned protruding position Y2.

And, the above-mentioned detection cap31moves from the normal position Y1where the outer surface31sis at the same level as an outer surface2sof the above-mentioned storage case2or on the inward side of the outer surface2s, to the protruding position Y2where the outer surface31sprotrudes over the outer surface2sof the above-mentioned storage case2. Such a less displacement will allow the user know to perceive and to know a presence of movement of the detection cap31. Incidentally, to ensure letting the above-mentioned recognition more definitely, a protruding height L1from the outer surface2sof the outer surface31sin the above-mentioned protruding position Y2is preferably not less than 2.0 mm, more preferably not less than 3.0 mm. A concave depth L2of the outer surface31sfrom the outer surface2sin the normal position Y1is preferably more than 0 mm, more preferably in a range of from 0.5 to 1.5 mm. Incidentally, the compressor main body10vibrates during operation of the apparatus, so that when the above-mentioned protruding height L1is less than 2.0 mm, it becomes difficult to recognize the protruding of the detection cap31. When the detection cap31is too small, it becomes difficult for the user to recognize the movement. Therefore, a diameter D of the outer surface31sof the above-mentioned detection cap31is not less than 5.0 mm. And the user recognizes the movement of the detection cap31and stops the motor M. Therefore, it is preferable to dispose the detection cap31adjacent to the above-mentioned on-off switch SW.

In the above-mentioned valve main body30, as shown conceptually inFIG. 7, under a condition of not more than a certain pressure p1, the switch valve34keeps being closed by a force of the above-mentioned follow spring38. However, when the pressure reaches the certain pressure p1, the switch valve34opens slightly and releases the compressed-air. Thus, with increasing the pressure (p) of the compressed-air, the switch valve34opens gradually largely and becomes eventually in a fully open condition (the switch valve34opens all the way). Therefore, in the valve main body30between the pressure p1in an initial movement condition of the switch valve34and a pressure p2in the fully open condition, there is a little difference in pressure Δp (delta p).

In contrast, in a case that the detection means7according to the first embodiment using the spring42as the retaining means32, the above-mentioned detection cap31moves with the movement of the switch valve34. That is to say, the detection cap31repeats momentarily popping up and down, namely in-and-out movement, after reaching the above-mentioned pressure p1. The quantity and period of time of the popped-up are gradually increased. At the pressure p2under the fully open condition, the detection cap keeps being popped up in the maximum quantity. Therefore, in the first embodiment, the above-mentioned maximum quantity in popped-up is set as a protruding height L1. Furthermore, owing to the difference in pressure Δp, the assessment of the user is likely to vary widely. Then, in the case of the detection means7according to the first embodiment, a criterion for assessment is preferably defined as a point of time that the above-mentioned in-and-out movement of the above-mentioned detection cap31stops (a time point of the detection cap31maximally popped up).

Another embodiment of the detection means7(hereinafter referred to as a second embodiment) is shown inFIG. 6. In the present example, the retaining means32is formed of a magnet46that attaches to a plate part40of the above-mentioned detection cap31and is suctioned toward the above-mentioned exhaust port33. More particularly, a lower end of the detection cap31abuts on a stopper44arranged in the storage case2, for example, and there is a small gap K between the magnet46and the adjusting screw36. The small gap K is set as a distance where a suction power F between the magnet46and the adjusting screw36is substantially the same as the pressure p2at the time of the above-mentioned switch valve34being in the fully open condition. Hence, at an initial time of movement of the valve main body30, the detection cap31can stop in the normal position Y1since the above-mentioned suction power F is large. And, when the valve main body30is in a fully open condition and the pressure becomes larger than the suction power F, the above-mentioned detection cap31can move at once from the normal position Y1to the protruding position Y2.

Therefore, in the case of the second embodiment, there is no difference in pressure Δp as the case of the first embodiment. The assessment variance of the user can be reduced preferably to the first embodiment. Meanwhile,FIG. 7shows conceptually the movement of the detection cap31according to the first and second embodiments relating the movement of the switch valve34.

In the case of the second embodiment, the spring42does not affect such as the first embodiment. Thus, the protruding height L1can be kept 20 mm or more, for example, and this makes the user recognize it definitely. However, when the protruding height L1exceeds 20 mm, it is not desirable that the storage case2grows in size unnecessarily. Therefore, the upper limit of the height L1is preferably not more than 15 mm, more preferably not more than 10 mm.

In the above-mentioned magnet46, to make the suction power act stably, it is preferable to form the magnet16to have substantially the same diameter as an inner surface of the plate part40of the above-mentioned detection cap31. And, when the magnet46is too thick, the magnet gets heavy, and the detection cap31shakes up and down at the protruding position Y2; therefore, the recognition gets difficult. Thus, the thickness of the magnet46is preferably not more than 3.0 mm, more preferably not more than 2.0 mm, furthermore preferably not more than 1.5 mm. When the magnet46is too thin, the detection cap31is apt to be pushed up before the fully open condition of the above-mentioned switch valve34. Therefore, the lower limit of a thickness of the magnet46is preferably not less than 1.0 mm.

In the above-mentioned detection means7according to the present embodiment, a flow channel portion, namely the above-mentioned connected hole36A of the above-mentioned valve flow channel30A on the side of the exhaust port33, is a resonant tube45. The exhaust air from the above-mentioned exhaust port33generates a high-pitched sound of not less than 2000 Hz (a beep sound hereinafter called, for the sake of expedience). With this arrangement, it can notify the user also aurally that the compressed-air exceeds the reference pressure P, thereby enhancing the recognition effect all the more. For that purpose, a diameter (d) of the above-mentioned resonant tube45is preferably set in a range of from 1.2 to 2.5 mm. When the diameter is less than 1.2 mm, a quantity of the exhausted air becomes at a minimum, and a sound pressure of the beep sound is too low to recognize. When the diameter exceeds 2.5 mm, a hit sound by the shaft center float out from the resonant tube45loudens, and it becomes difficult to identify the beep sound. When the diameter (d) is much more larger, the beep sound gets not to be generated. And, a length of the above-mentioned resonant tube45is an important factor of for the sound pressure of the beep sound. The longer, the length J of not less than 8.0 mm is, the more favorable in the sound pressure is, thereby increasing the recognition performance.

An operating noise generated by the above-mentioned compressor main body10is mainly a sound ranging from 800 to 1800 Hz. Therefore, the beep sound of not less than 2000 Hz preferably improves the recognition performance. However, a too high frequency is poorly-heard; therefore, the upper limit of the beep sound is not more than 10000 Hz. In the compressor apparatus1, the generation of the beep sound makes preferably the sound pressure of the whole sound comprising the operating noise loudens by not less than 1 dB(A). The increase of loudness of less than 1 dB(A) lacks the recognition performance.

Such a resonant tube45can be applied in a case that the retaining means32is the spring42. The compressor apparatus1according to the present invention can be used not only for air filling of a tire with depressed inner pressure, but also can be used as a compressor apparatus for a puncture repairing system supplying gradually sealant and fill up the air into a punctured tire as the compressor apparatus disclosed in the Japanese Laid-open Unexamined Patent Application Publication No. 2005-344570, for example.

Although especially preferred embodiments of the present invention have been described in detail, the present invention is not limited to the illustrated embodiment, and various modifications can be made.

EMBODIMENT

Compressor apparatuses1possessing a structure shown inFIG. 2were manufactured for trial based on a specification shown Table 1. when a tire having a tire size of 195/65R15 and inflated from zero to a specified inner pressure (250 kPa), the inner pressure at operating time of a detection cap31was measured by each compressor apparatus1.

In each of the compressor apparatus1, a valve main body30was defined so that a reference pressure P was 250 kPa at a fully open condition. The detection cap31was 14 mm in outside diameter and 12 mm in inside diameter, and made of nylon resin (red color). A protruding height L1at a protruding position Y2was 7 mm. Moreover, in Embodiment 2, a magnet46was 12 mm in outside diameter and 1.0 mm in thickness.

In Embodiment 1, there was a difference in pressure by approximately 30 kPa between a pressure p1at the beginning of popping-up of a detection cap31and a pressure p2at a time point of maximum popped-up. The time point of maximum popped-up was defined as a criterion of turning off a motor, thereby eliminating the variance of the filling up pressure. And, in Embodiment 2, the beginning of popping-up and the time point of maximum popped-up come together; therefore, the user can recognize definitely that the motor turns off.

A diameter (d) of a connected hole36A in a detection means7varied based on a specification shown in Table 2, and the recognition performance with a beep sound was tested when the connected hole36A was formed as a resonant tube45. Meanwhile, the recognition performance was tested by feeling of a grader, and valuations were rated on a 4-point scale such as Very Poor—Poor—Good—Very Good. A sound pressure was measured with use of a microphone 50 cm superiorly apart from the compressor apparatus1. A length J of the connected hole36A was 8.0 mm, and an inside diameter of a central hole35aof a housing35was 8.0 mm.

TABLE 2Ex. 3Ex. 4Ex. 5Ex. 6Ex. 7Ex. 8Ex. 9Diameter (d) of Connected hole (resonant tube) [mm]1.01.21.52.02.53.03.5Sound pressure just before generating beep sound [dB(A)]87.688.389.089.589.991.593.1Sound pressure at a time point of generating beep sound87.989.491.392.092.092.2Silent[dB(A)]Difference in sound pressure [dB(A)]0.31.12.32.52.10.7—Recognition performance of beep soundVery PoorGoodVery GoodVery GoodGoodVery PoorVery Poor

As shown in Table 2, the difference in sound pressure is increased when the diameter (d) ranges from 1.2 to 2.5 mm, thereby recognizing an improvement of the recognition performance.