Patent Publication Number: US-11020714-B2

Title: Washer liquid supply system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of Japanese Patent Application No. 2017-141268, filed on Jul. 20, 2017 in the Japan Patent Office, the entire specification, claims and drawings of which are incorporated herewith by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a system for supplying washer liquid to an object of a vehicle. 
     Description of the Related Art 
     Patent Document 1 (Japanese Examined Utility Model Application Publication No. S58-28938) disclosed ejection of a washer liquid toward the floor surface of a vehicle, the washer liquid having been prepared by mixing, in a pipe, a washer liquid supplied from a washer liquid tank and compressed air supplied from a compressor to thereby turn the mixture into an emulsion state with bubbles in it. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a washer liquid supply system, comprising: 
     a washer tank mounted on a vehicle to store washer liquid; 
     a supply section mounted on the vehicle to supply the washer liquid in the washer tank to an object of the vehicle; and 
     a bubbling section mounted on the vehicle to make the washer liquid contain bubbles, wherein the supply section supplies the washer liquid containing the bubbles to the object. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view showing a vehicle to which a washer liquid supply system according to a first embodiment of the present invention is applied; 
         FIG. 2  is a schematic view showing the washer liquid supply system according to the first embodiment of the present invention; 
         FIG. 3  is a schematic cross-sectional view showing a washer tank according to the first embodiment of the present invention; 
         FIG. 4  is an enlarged view of a part in  FIG. 3 ; 
         FIG. 5  is a schematic cross-sectional view of a keep-warm tank according to the first embodiment of the present invention; 
         FIG. 6  is a schematic external view of a connecting member according to the first embodiment of the present invention; 
         FIG. 7  is an external view of the connecting member in  FIG. 6 , in a view from direction VII; 
         FIG. 8  is a cross-sectional view taken along line VIII-VIII in  FIG. 6 ; 
         FIG. 9  is a cross-sectional view taken along line IX-IX in  FIG. 7 ; 
         FIG. 10  is a graph showing a saturated vapor pressure curve of water; 
         FIG. 11  is a schematic perspective view showing a wiper arm, a wiper blade, and a supply section; 
         FIGS. 12A to 12C  are graphs showing examples of temporal changes of the pump output and of the supply amount of washer liquid to a window panel; 
         FIG. 13  is a graph showing an example of the relation between the alcohol concentration and the target temperature of the washer liquid in the keep-warm tank; 
         FIG. 14  is a schematic view showing a washer liquid supply system according to a second embodiment of the present invention: 
         FIG. 15  is a schematic cross-sectional view showing a supply section according to the second embodiment of the present invention; 
         FIG. 16  is a schematic cross-sectional view showing a supply section according to a third embodiment of the present invention; 
         FIG. 17  is a schematic cross-sectional view showing a keep-warm tank according to a fourth embodiment of the present invention; 
         FIG. 18  is a schematic view showing a washer liquid supply system according to a fifth embodiment of the present invention; and 
         FIG. 19  is a schematic view showing a washer liquid supply system according to a sixth embodiment of the present invention. 
     
    
    
     PREFERRED EMBODIMENTS OF THE INVENTION 
     Prior to describing embodiments of the present invention, prior art is argued below. 
     In the art described in Patent Document 1, a compressor is necessary to make bubbles contained in washer liquid, and accordingly the device is in a large and complicated structure. Consequently, it is hard to mount the device on a vehicle. 
     The present invention has been developed in this situation, and an object of the present invention is to provide a washer liquid supply system in a simple structure and capable of improving the capacity of washing an object of a vehicle. 
     According to the present invention, it is possible to improve the capacity of washing an object of a vehicle, with a simple structure. 
     Hereinafter, washer liquid supply systems according to embodiments of the present invention will be described in detail, referring to the drawings and taking examples of a case that washer liquid is supplied to a window panel as an object of washing. In the description below, the same symbols will be given to the respective same elements, and overlapping description will be omitted. 
     First Embodiment 
     As shown in  FIG. 1  and  FIG. 2 , a washer liquid supply system  1 A according to a first embodiment of the present invention is a system that supplies a washer liquid W to a window shield C 1 , which is the front glass of a Vehicle C. The washer liquid W contains water, alcohol and the like to operate as an anti-freeze liquid. The washer liquid supply system  1 A includes a washer tank  10 , a pump (delivering section)  2 , a heat-retaining tank (heating section)  20 A, a connecting member  30 A, a wiper arm  3 , a wiper blade  4 , a supply section  6 A, and a control section  7 . The washer tank  10 , the heat-retaining tank  20 A, the connecting member  30 A, and the supply section  6 A are serially connected by a passage section  8  through which the washer liquid W can flow. The passage section  8  is formed by a flexible tube and the like. 
     Washer Tank 
     As shown in  FIG. 3 , the washer tank  10  is installed in a power source chamber C 2  arranged at a front part of a vehicle C, and stores the washer liquid W. The washer liquid W stored in the washer tank  10  flows through the passage section  8  (see  FIG. 1 ) to the outside of the washer tank  10  and is delivered to the supply section  6 A. The washer tank  10  is a resin member in a bottomed cylindrical shape, and is integrally provided with a bottom wall portion  11 , an upper wall portion  12 , both having a circular shape in a plan view, and a side wall portion  13 , which has an annular shape in a plan view and is extended vertically such as to connect the circumferential marginal portions of the bottom wall portion  11  and the upper wall portion  12 . The inner circumferential surface of the side wall portion  13  is provided with a groove portion  14 . 
     Groove Portion, First Inclined Portion, and Second Inclined Portion 
     The groove portion  14  is in a spiral shape with a center on the axial line of the washer tank  10  and includes a first inclined portion  14   a  and a second inclined portion  14   b . The first inclined portion  14   a  is a surface inclined the more inward in the radial direction of the washer tank  10  as a point on the surface is located the more upward. The second inclined portion  14   b  is a surface inclined the more inward in the radial direction of the washer tank  10  as a point on the surface is located the more downward. The first inclined portion  14   a  and the second inclined portion  14   b  are arranged such as to continuously and alternately appear in the height direction. In other words, the first inclined portion  14   a  on the lower side and the second inclined portion  14   b  on the upper side, which are continuous, form convex portions protruding inward in the radial direction of the washer tank  10 . Further, the first inclined portion  14   a  on the upper side and the second inclined portion  14   b  on the lower side, which are continuous, form concave portions recessed outward in the radial direction of the washer tank  10 . The convex portions and the concave portions in a cross-sectional view are in triangle shapes. Herein, at each same height on the side wall portion  13  of the washer tank  10 , an apex  14   d  of a concave portion of the groove portion  14  is provided at a part facing an apex  14   c  of a convex portion of the groove portion  14 . 
     Generation of Babbles in Washer Tank 
     In this washer tank  10 , the liquid surface of the washer liquid W, which is stored inside, is moved up and down by vibration accompanying the running of the vehicle C and the like. As shown in  FIG. 4 , the washer liquid W adjacent to the liquid surface is lifted by the second inclined portion  14   b  and then bounced by the first inclined portion  14   a , to become liquid drops and drop down onto the liquid surface of the washer liquid W. Thus, bubbles are generated in the washer liquid W. 
     Pump 
     As shown in  FIG. 1  and  FIG. 2 , the pump  2  generates a flow for delivering the washer liquid W, which is stored in the washer tank  10 , to the supply section  6 A through the heat-retaining tank  20 A. In the present embodiment, the pump  2  is arranged between the washer tank  10  and the heat-retaining tank  20 A in the passage section  8 . 
     Heat-Retaining Tank 
     The heat-retaining tank  20 A is arranged between the washer tank  10  and the supply section  6 A, and temporarily stores the washer liquid W, which is delivered from the washer tank  10  to the supply section  6 A. The heat-retaining tank  20 A has a heating function to heat the washer liquid W temporarily stored in the heat-retaining tank  20 A itself, and a heat-retaining function to maintain the temperature of the heated washer liquid W. By the heating function and the heat-retaining function, the heat-retaining tank  20 A improves the washing capacity of the washer liquid W stored in the heat-retaining tank  20 A itself and makes the washer liquid W have a defrosting function. In other words, the heat-retaining tank  20 A also serves as a heating section for heating the washer liquid W. As shown in  FIG. 5 , the heat-retaining tank  20 A is provided with a tank main-body  21 , an inlet-side passage section  22 , a discharge-side passage section  23 , a deflector  24 , a heater  25 , a liquid-amount detecting section  26 A, an alcohol-concentration detecting section  27 , a liquid-temperature detecting section  28 , and a control board (control section)  29 . 
     Tank Main-Body 
     The tank main-body  21  is a resin or metal tank in which the washer liquid W is temporarily stored. The tank main-body  21  is, for example, made from a foam material, or for example, has a bilayer structure containing air, and thus has a heat-retaining function to maintain the temperature of the washer liquid W therein. 
     Inlet-Side Passage Section and Discharge-Side Passage Section 
     The inlet-side passage section  22  lets the washer liquid W, which has been delivered from the washer tank  10 , flow into the tank main-body  21 . The discharge-side passage section  23  lets the washer liquid W, which is in the tank main-body  21 , flow out to the supply section  6 A side. The respective passage sections  22  and  23  are formed by a tube or the like, and are inserted from the bottom wall portion of the tank main-body  21  into the tank main-body  21 . 
     An opening  23   a  of the discharge-side passage section  23  is arranged at a position higher than an opening  22   a  of the inlet-side passage section  22 . That is, when the liquid surface of the washer liquid W, which has been delivered into the tank main-body  21  by the pump  2 , has become higher than the opening  23   a  of the discharge-side passage section  23 , the washer liquid W in the tank main-body  21  is delivered from the discharge-side passage section  23  to the supply section  6 A side. Further, in the tank main-body  21 , a space, in consideration of the expansion of the washer liquid W, is arranged on the upper side of the opening  23   a  of the discharge-side passage section  23 . 
     Deflector 
     In the tank main-body  21 , the deflector  24  is disposed at a position higher than the opening  22   a  of the inlet-side passage section  22 , lower than the opening  23   a  of the discharge-side passage section  23 , and facing the opening  22   a  of the inlet-side passage section  22 . 
     Heater 
     The heater  25  is arranged in the tank main-body  21  as a heating section main-body for heating the washer liquid W, which is temporarily stored in the tank main-body  21 . 
     Liquid-Amount Detecting Section 
     The liquid-amount detecting section  26 A is arranged in the tank main-body  21  to detect the liquid amount of the washer liquid W temporarily stored in the tank main-body  21 . In the present embodiment, the liquid-amount detecting section  26 A is a level sensor for detecting the liquid surface of the washer liquid W temporarily stored in the tank main-body  21 . The liquid-amount detecting section  26 A outputs a detection result to the control section  7  (see  FIG. 2 ). 
     Alcohol-Concentration Detecting Section 
     The alcohol-concentration detecting section  27  is arranged in the tank main-body  21  to detect the alcohol concentration of the washer liquid W, which is temporarily stored in the tank main-body  21 . The alcohol-concentration detecting section  27  supplies a detection result to a control board  29 . In the present embodiment, the alcohol-concentration detecting section  27  detects the alcohol concentration of the washer liquid W at a position closer to the opening  23   a  of the discharge-side passage section  23  than to the opening  22   a  of the inlet-side passage section  22 . 
     Liquid-Temperature Detecting Section 
     The liquid-temperature detecting section  28  is arranged in the tank main-body  21  to detect the temperature (liquid temperature) of the washer liquid W, which is temporarily stored in the tank main-body  21 . The liquid-temperature detecting section  28  outputs a detection result to the control board  29 . 
     Control Board 
     Based on a detection result from the alcohol-concentration detecting section  27 , the control board  29  controls the heater  25  to make the liquid temperature, which is detected by the liquid-temperature detecting section  28 , close to a preset target temperature. A method of controlling the heater  25  by the control board  29  will be described later. 
     Connecting Member 
     As shown in  FIG. 1  and  FIG. 2 , the connecting member  30 A is arranged between the washer tank  10  and the supply section  6 A, and in more detail between the heat-retaining tank  20 A and the supply section  6 A. The connecting member  30 A is a bubbling section for making the washer liquid W, which flows through the connecting member  30 A, contain bubbles. As shown in  FIG. 6  through  FIG. 9 , the connecting member  30 A is a metal member in a cylindrical shape. The connecting member  30 A is provided with an inlet passage section  31 , a connecting passage section  32 , and a discharge passage section  33  in this order from the upstream side. A flexible first tube  8   a  is connected to the upstream-side end portion of the connecting member  30 A, and a flexible second tube  8   b  is connected to the downstream-side end portion of the connecting member  30 A. Herein, the first tube  8   a  forms at least a part of a first passage section, which connects the washer tank  10  (the heat-retaining tank  20 A in the present embodiment) and the connecting member  30 A. The second tube  8   b  forms at least a part of a second passage section that connects the supply section  6 A and the connecting member  30 A. 
     The inlet passage portion  31  is a passage through which the washer liquid W from the upstream side flows. The upstream end of the inlet passage section  31  is an inlet section  31   a  to which the first tube (the first passage section)  8   a  is connected. 
     The connecting passage section  32  is a passage through which the washer liquid W from the inlet passage section  31  flows. In the order from the upstream side, the connecting passage section  32  is provided with a large diameter portion  32   a , a diameter-shrinking portion  32   b  whose diameter and passage cross-sectional area become smaller as the position of the passage cross-section goes toward the downstream side, a throttle section  32   c , a diameter-expanding portion  32   d  whose diameter and the passage cross-sectional area become larger as the position of the passage cross-section goes toward the downstream side, a small diameter portion  32   e  whose passage cross-sectional area is smaller than the large diameter portion  32   a , and a diameter-shrinking portion  32   f  whose diameter and passage cross-sectional area become smaller as the position of the passage cross-section goes toward the downstream side. The passage cross-sectional area, on the upstream side, of the diameter-shrinking portion  32   b  is equal to the passage cross-sectional area of the large diameter portion  32   a . The passage cross-sectional area of the downstream-side end portion of the diameter-shrinking portion  32   b  and the passage cross-sectional area of the upstream-side end portion of the diameter-expanding portion  32   d  are equal to the passage cross-sectional area of the throttle section  32   c . The passage cross-sectional area of the downstream-side end portion of the diameter-expanding portion  32   d , and the passage cross-sectional area of the upstream-side end portion of the diameter-shrinking portion  32   f , are equal to the passage cross-sectional area of the small diameter portion  32   e . The passage cross-sectional area of the downstream-side end portion of the diameter-shrinking portion  32   f  is equal to the passage cross-sectional area of the discharge passage section  33 . The passage length of the diameter-shrinking portion  32   b  is smaller than the passage length of the diameter-expanding portion  32   d.    
     The discharge passage section  33  is a passage through which the washer liquid W from the connecting passage section  32  flows. The downstream end of the discharge passage section  33  is a discharge section  33   a  to which the second tube (the second passage section)  8   b  is connected. The passage cross-sectional area of the discharge passage section  33  is equal to the passage cross-sectional area of the inlet passage section  31 , and is smaller than the passage cross-sectional area of the large diameter portion  32   a  and the passage cross-sectional area of the small diameter portion  32   e.    
     Regarding the connecting member  30 A, the part at which the inlet passage section  31  is formed is a first fit-engagement section  34  to which the first tube  8   a  is fit-engaged (outer fitting). In other words, the inlet section  31   a  is formed at the first fit-engagement section  34 . In the connecting member  30 A, the part at which the discharge passage section  33  is formed is a second fit-engagement section  35  to which the second tube  8   b  is fit-engaged (outer fitting). In other words, the discharge section  33   a  is formed at the second fit-engagement section  35 . 
     The inlet passage section  31 , which is the passage section in the first fit-engagement section  34 , extends in a direction intersecting with the connecting passage section  32 . The discharge passage section  33 , which is the passage section in the second fit-engagement section  35 , extends colinearly with the connecting passage section  32 . That is, as shown in  FIG. 8 , in a plan view for example, a passage center line X 1  of the inlet passage section  31  intersects with a passage center line X 2  of the connecting passage section  32 . A passage center line X 3  of the discharge passage section  33  is arranged colinearly with the passage center line X 2  of the connecting passage section  32 . As shown in  FIG. 9 , in a side view for example, the passage center line X 1  of the inlet passage section  31  is shifted in parallel from the passage center line X 2  of the connecting passage section  32 . 
     Bubble Generation in Connecting Member 
     As shown in  FIG. 10 , when the state of water changes from the liquid side to the gas side of the saturated vapor pressure curve, the water generates cavitation. Further, the higher the liquid temperature of the washer liquid W, at the higher pressure the washer liquid W turns into gas, and the easier it is for the washer liquid W to generate cavitation. As shown in  FIG. 6  through  FIG. 9 , in the above-described connecting member  30 A, the throttle section  32   c  increases the flow velocity of the washer liquid W to thereby decrease the liquid pressure, deposit air, which is dissolved in the liquid, and generate bubbles in the washer liquid W. On the other hand, the diameter-expanding portion  32   d  decreases the flow velocity of the washer liquid W to thereby increase the liquid pressure, make the bubbles in the washer liquid W micro valves, and thus agitate the washer liquid W. 
     Further, when the washer liquid W flows from the inlet passage section  31  to the connecting passage section  32 , the flow turns into a swirling flow to thereby efficiently generate bubbles. 
     Wiper Arm and Wiper Blade 
     As shown in  FIG. 1  and  FIG. 2 , the root end portion of the wiper arm  3  is swingably supported at the lower end portion of the window shield C 1 . The wiper blade  4  is used to wipe the window shield C 1 . The middle portion, in the width direction, of the wiper blade  4  is supported rotatably at the tip end portion of the wiper arm  3 . 
     Supply Section 
     The supply section  6 A is a component of the object-side end portion of the washer liquid supply system  1 A, and is arranged to discharge and supply the washer liquid W, which has been delivered from the washer tank  10 , to the window shield C 1 . The supply section  6 A is installed integrally with the wiper arm  3  or the wiper blade  4 . As shown in  FIG. 11 , the supply section  6 A in the present embodiment is arranged integrally with the tip end portion of the wiper arm  3 , and has a function as a nozzle that ejects the washer liquid W in the wiping range of the wiper arm  3 . 
     Control Section 
     The control section  7  includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input-output circuit, and the like. The control section  7  controls a pump  20 , based on detection results from the liquid-amount detecting section  26 A and the alcohol-concentration detecting section  27 . 
     Control of Increase in Initial Eject Amount 
     When a driver of the vehicle C operates an operating section (not shown), the control section  7  drives the pump  2  to thereby supply the washer liquid W to the window shield C 1 . Herein, if a state that the washer liquid W is not supplied has lasted for a long time or the like, water in the washer liquid W evaporates or alcohol in the washer liquid W volatilizes in the tank main-body  21  of the heat-retaining tank  20 A, and thus the liquid surface of the washer liquid W becomes lower than the opening  23   a  of the discharge-side passage section  23 . In this event, if it is attempted to supply the washer liquid W to the window shield C 1 , the time taken until the liquid surface of the washer liquid W reaches the opening  23   a  of the discharge-side passage section  23  becomes delay of supply of the washer liquid W to the window shield C 1  (see  FIG. 12A ). 
     Accordingly, in the initial supply of the washer liquid W, the delay of supply is reduced by increasing the output of the pump  2 . 
     In the present embodiment, based on a detection result from the liquid-amount detecting section  26 A, the control section  7  sets an increase amount for temporarily increasing the delivering amount (the delivering amount per unit time of the washer liquid W). 
     Herein, if the detection result from the liquid-amount detecting section  26 A indicates that the liquid surface level of the washer liquid W is higher than or equal to the height of the opening  23   a  of the discharge-side passage section  23 , the control section  7  sets the increase amount of the delivering amount (namely the increase amount a of the output of the pump  2 ) to zero (see  FIG. 12B ). 
     If the detection result from the liquid-amount detecting section  26 A indicates that the liquid surface level of the washer liquid W is lower than the height of the opening  23   a  of the discharge-side passage section  23 , the control section  7  sets an increase amount (see  FIG. 12C ). 
     Herein, the lower the liquid surface level of the washer liquid W from the height of the opening  23   a  is, the larger the increase amount can be set. 
     In such a manner, when a detection result from the liquid-amount detecting section  26 A indicates that the liquid surface level of the washer liquid W is lower than the height of the opening  23   a  of the discharge-side passage section  23 , the control section  7  increases the output of the pump  2  from time to (control start time of the pump  2 ), which is the initial time of supplying the washer liquid W to the window shield C 1  to predetermined time t 1  by a, compared with the output of the pump  2  at time t 1  and after. From the time t 1 , the control section  7  drives the pump  2  by a predetermined output. Herein, the predetermined time t 0 -t 1  can be set, based on the time (see  FIG. 12B ) taken from supply start of the washer liquid W until the supply amount of the washer liquid W reaches a predetermined value in a case that there is no supply delay. 
     Incidentally, the control section  7  can set the increase amount a and the increase time t 0 -t 1  such that the lower the liquid surface level of the washer liquid W from the height of the opening  23   a  is, the larger the increase amount is and the longer the increase time t 0 -t 1  is. 
     Heating Control Corresponding to Alcohol Concentration 
     When the washer liquid W stored in the tank main-body  21  of the heat-retaining tank  20 A is heated by the heater  25 , volatilization of the alcohol contained in the washer liquid W progresses, and the alcohol concentration of the washer liquid W decreases. If heating by the heater is stopped in such a state that the alcohol concentration of the washer liquid W has decreased, the washer liquid W sometimes freezes by atmospheric temperature. 
     Accordingly, the control board  29  controls the heater  25 , based on a detection result from the alcohol-concentration detecting section  27 . In detail, when the alcohol concentration detected by the alcohol-concentration detecting section  27  is lower than or equal to a preset threshold, the control board  29  stops heating by the heater  25  ( FIG. 13 ). In other words, during heating by the heater  25 , when the alcohol concentration detected by the alcohol-concentration detecting section  27  has become equal to or lower than the preset threshold, the control board  29  stops heating of the washer liquid W by the heater  25 . Even if conditions for start of heating by the heater  25  are satisfied in a stop state of the heater  25 , the control board  29  does not perform heating of the washer liquid W by the heater  25 . 
     Further, based on the detection result from the alcohol-concentration detecting section  27 , the control board  29  sets a target temperature (heating target temperature) of the washer liquid W by the heater  25 . In detail, if the alcohol concentration is higher than or equal to the threshold, the higher the alcohol concentration is, the higher the control board  29  sets the target temperature of the washer liquid W (see  FIG. 13 ). 
     As the washer tank  10  according to the first embodiment of the invention is provided with the first inclined portion  14   a , it is possible to make the washer liquid W contain bubbles by vibration of the vehicle C, without providing a special mechanism such as a compressor or the like. 
     Further, as the washer tank  10  is provided with the second inclined portion  14   b , it is possible to lift the liquid surface of the washer liquid W by the vibration of the vehicle C up to the first inclined portion  14   a  to thereby make the washer liquid W satisfactorily contain bubbles. 
     Still further, as the washer tank  10  is provided with plural first inclined portions  14   a  arrayed vertically, even if the liquid amount of the stored washer liquid W varies, it is possible to make the washer liquid W contain bubbles by the first inclined portion  14   a  at a position corresponding to the liquid surface of the washer liquid W. 
     Still further, as the washer tank  10  is provided with the first inclined portions  14   a  and the second inclined portions  14   b  formed by the groove portion  14  in a spiral shape, the washer tank  10  can be easily manufactured. 
     Yet further, in the washer tank  10 , as the first inclined portions  14   a  are formed by the groove portion  14  in a spiral shape, even if the liquid amount of the washer liquid W varies, a first inclined portion  14   a  and a second inclined portion  14   b  exist at a position corresponding to the liquid surface of the washer liquid W, which makes it possible to make the washer liquid W satisfactorily contain bubbles by the vibration of the vehicle C. 
     Further, in the washer tank  10 , the apex  14   c  of a convex portion and the apex  14   d  of a concave portion of the groove portion  14  face each other at the same height. Accordingly, it is possible to make the inner shape of the washer tank  10  the same at all height positions, and make the washer liquid W satisfactorily contain bubbles. 
     In the washer liquid supply system  1 A according to the first embodiment of the invention, as the connecting member  30 A (bubbling section) makes the washer liquid W contain bubbles, it is possible to make the washer liquid W contain bubbles by a simple structure in which the bubbling section is mounted on the vehicle C, and improve the capacity of washing the window shield C 1 . 
     Further, in the washer liquid supply system  1 A, as the connecting member  30 A is arranged at the passage section  8 , it is possible to improve the capacity of washing the window shield C 1 , with a simple structure. 
     Still further, in the washer liquid supply system  1 A, as the connecting member  30 A, which connects the first tube (the first passage section)  8   a  and the second tube (the second passage section)  8   b , is arranged to be the bubbling section, a component for connecting the first tube (the first passage section)  8   a  and the second tube (the second passage section)  8   b  serves also as the bubbling section. Thus, it is possible to reduce the number of components. 
     Yet further, in the washer liquid supply system  1 A, the connecting member  30 A, which is the bubbling section, is provided with the throttle section  32   c  and the diameter-expanding portion  32   d . Thus, it is possible to generate bubbles in the washer liquid W and agitate it, with a simple structure. 
     Still further, in the washer liquid supply system  1 A, as the first tube  8   a  and the second tube  8   b  are fit-engaged with the connecting member  30 A, the component for connecting the first tube  8   a  and the second tube  8   b  can also serve as the bubbling section. Thus, it is possible to reduce the number of components and simplify the structure. 
     Further, in the washer liquid supply system  1 A, as the passage center line X 1  of the inlet passage section  31  and the passage center line X 2  of the connecting passage section  32  intersect with each other, it is possible to turn the flow of the washer liquid W into a swirl flow at the diameter-shrinking portion  32   b , which is on the upstream side of the throttle section  32   c , and thereby efficiently generate bubbles. 
     Still further, in the washer liquid supply system  1 A, as the passage center line X 3  of the discharge passage section  33  and the passage center line X 2  of the connecting passage section  32  are arranged colinearly, it is possible to realize downsizing and simple forming of the connecting member  30 A. Further, in the washer liquid supply system  1 A, as the angles of the first fit-engagement section  34  and the second fit-engagement section  35  are different, the respective fit-engagement sections  34  and  35  can be easily distinguished from each other, and mistake (reversely attaching or the like) in attaching these to the respective tubes (passage sections)  8   a  and  8   b  can be pretended. 
     Yet further, in the washer liquid supply system  1 A, as the delivering amount of the washer liquid W by the pump  2  can be temporarily increased, by quickly raising the liquid surface of the washer liquid W in the heat-retaining tank  20 A, it is possible to reduce a delay in supply of the washer liquid W to the window shield C 1 . In other words, even with a structure including the heat-retaining tank  20 A, the washer liquid supply system  1 A can quickly supply the washer liquid W to the window shield C 1 . 
     Further, in the washer liquid supply system  1 A, as the increase amount of the delivering amount is set, based on a detection result from the liquid-amount detecting section  26 A, it is possible to appropriately set the increase amount so as to prevent an excess of the supply amount of the washer liquid W supplied from the supply section  6 A to the window shield C 1 . 
     Still further, in the washer liquid supply system  1 A, as the liquid-amount detecting section  26 A is a level sensor, it is possible to appropriately set the increase amount, based on the liquid surface level of the washer liquid W. 
     Yet further, in the washer liquid supply system  1 A, as the heater  25  is controlled, based on a detection result from the alcohol-concentration detecting section  27 , it is possible to prevent the alcohol concentration of the washer liquid W from excessively dropping and the washer liquid W, which has been discharged from the heat-retaining tank  20 A, from freezing. 
     Further, in the washer liquid supply system  1 A, as a threshold is used, the heater  25  is stopped before the alcohol concentration of the washer liquid W becomes to the concentration at which the washer liquid W freezes by ambient air so that the washer liquid W can be appropriately prevented from freezing. 
     Still further, in the washer liquid supply system  1 A, as the heating temperature is set, based on the alcohol concentration, for example, in a case that the alcohol concentration of the washer liquid W has been dropping, the target temperature is set low. Thus, while reducing drop of the alcohol concentration, heating by the heater  25  can be performed until just before the moment when the alcohol concentration becomes the concentration at which the washer liquid W may freeze. 
     Yet further, in the washer liquid supply system  1 A, as the alcohol concentration is detected at a position adjacent to the opening  23   a  of the discharge-side passage section  23 , it is possible to appropriately prevent the washer liquid W from freezing even in a case that the washer liquid W does not flow and stagnates between the heat-retaining tank  20 A and the supply section  6 A. 
     Second Embodiment 
     Subsequently, a washer liquid supply system according to a second embodiment of the invention will be described below, focusing on differences from the washer liquid supply system  1 A according to the first embodiment. As shown in  FIG. 14 , a washer liquid supply system  1 B according to the second embodiment of the invention is provided with a connecting member  30 B and a supply section  6 B instead of the connecting member  30 A and the supply section  6 A. The connecting member  30 B is used to connect the first tube  8   a  and the second tube  8   b  and does not have a function as a bubbling section that makes the washer liquid W contain bubbles. 
     Supply Section 
     As shown in  FIG. 15 , the supply section  6 B is provided with a pipe-side member  40 B, a nozzle-side member  50 B, and a bubbling section  60 . 
     Pipe-Side Member 
     The pipe-side member  40 B is a metal member forming the upstream-side portion of the supply section  6 B. The pipe-side member  40 B is provided with a passage section  41  allowing the washer liquid W to flow through. The passage section  41  is provided with a check valve  42 . 
     The check valve  42  is a one-way valve for preventing backflow of the washer liquid W. In other words, the check valve  42  allows the washer liquid W to flow from the passage section  8  to the nozzle-side member  50 B, and also prevents the washer liquid W from flowing from the nozzle-side member  50 B to the passage section  8  (backward flow). 
     The upstream-side end portion of the pipe-side member  40 B is arranged as a fit-engagement section  43  with which the second tube  8   b  of the passage section  8  is fit-engaged (outer fitting). Further, the pipe-side member  40 B is provided with a fitting section  44  for fitting the supply section  6 B to another unit (the wiper arm  3 , the wiper blade  4 , or the like). 
     Nozzle-Side Member 
     The nozzle-side member  50 B is a hollow cylindrical shaped metal member, which forms the downstream-side portion of the supply section  6 B. The nozzle-side member  50 B is provided with a housing section  51  and a nozzle  52 . The housing section  51  houses the bubbling section  60 . The nozzle  52  is arranged at the downstream-side end portion of the nozzle-side member  50 B, and ejects the washer liquid W, which has flowed through the bubbling section  60 , onto the window shield C 1 . 
     Bubbling Section 
     The bubbling section  60  is provided integrally with the supply section  6 B to make the washer liquid W contain bubbles. In the present embodiment, the bubbling section  60  is built-in the nozzle-side member  50 B. That is, the bubbling section  60  is arranged on a coupling plane Y 1  between the pipe-side member  40 B and the nozzle-side member  50 B, and in more detail, between the nozzle  52  and the coupling plane Y 1 , which is between the pipe-side member  40 B and the nozzle-side member  50 B. The bubbling section  60  is provided with a diameter-shrinking portion  61  whose diameter and the passage cross-sectional area become smaller as the point on the cross-section goes from the upstream side toward the downstream side, a throttle section  62 , and a diameter-expanding portion  63  whose diameter and the passage cross-sectional area become larger as the point on the cross-section goes toward the downstream side. The passage cross-sectional area of the downstream-side end portion of the shrinking portion  61  and the passage cross-sectional area of the upstream-side end portion of the diameter-expanding portion  63  are equal to the passage cross-sectional area of the throttle section  62 . The relations between the passage cross-sectional area and the passage length of the shrinking portion  61 , the throttle section  62 , and the diameter-expanding portion  63  may be similar to the relations between the passage cross-sectional area and the passage length of the diameter-shrinking portion  32   b , the throttle section  32   c , and the diameter-expanding portion  32   d  of the connecting member  30 A. Further, the bubbling section  60  may be provided with, on the upstream side of the shrinking portion  61 , a large diameter portion similar to the large diameter portion  32   a , and/or provided with, on the downstream side of the diameter-expanding portion  63 , a small diameter portion similar to the mall diameter portion  32   e.    
     The coupling plane Y 1  is a plane on which the downstream-side end portion of the pipe-side member  40 B and the upstream-side end portions, of the nozzle-side member  50 B and the bubbling section  60 , contact with each other. In other words, the upstream-side end portion of the bubbling section  60  is disposed on the same plane as the upstream-side end portion of the nozzle-side member  50 B on the coupling plane Y 1 , and is in contact with the downstream-side end portion of the pipe-side member  40 B on the coupling plane Y 1 . A coupling plane Y 2  is a plane on which the pipe-side member  40 B and the upstream-side end portion of the check valve  42  contact with each other. A coupling plane Y 3  is a plane on which the nozzle-side member  50 B and the downstream-side end portion of the bubbling section  60  contact with each other. 
     Generation of Bubbles in Nozzle-Side Member 
     In the nozzle-side member  50 B, the throttle section  62  increases the flow velocity of the washer liquid W, and thereby decreases the liquid pressure to deposit air dissolved in the liquid and thus generate bubbles in the washer liquid W. The diameter-expanding portion  63  decreases the flow velocity of the washer liquid W and thereby increases the liquid pressure to agitate the washer liquid W, making the bubbles in the washer liquid W be micro bubbles. 
     As the washer liquid supply system  1 B according to the second embodiment of the invention can make the washer liquid W contain bubbles immediately before supplying the washer liquid W, it is thereby possible to suppress vanishing of bubbles during delivering the washer liquid W and appropriately exercise a washing capacity. 
     Further, in the washer liquid supply system  1 B, as the bubbling section  60  is arranged on the coupling plane Y 1  between the pipe-side member  40 B and the nozzle-side member  50 B, the bubbling section  60  can be formed as a separate component to improve the productivity. 
     Still further, in the washer liquid supply system  1 B, as the bubbling section  60  is arranged on the coupling plane Y 1 , the fitting workability can be improved. 
     Further, in the washer liquid supply system  1 B, the bubbling section  60  is built in the nozzle-side member  50 B, and the check valve  42  is built in the pipe-side member  40 B. Accordingly, for the washer liquid supply system  1 A, after the bubbling section  60  and the check valve  42  are attached to respective separate members, the pipe-side member  40 B and the nozzle-side member  50 B can be attached so that the attaching work can be improved. 
     Still further, in the washer liquid supply system  1 B, as the supply section  6 B is arranged on the wiper arm  3  or the wiper blade  4 , it is possible to shorten the distance from a position where bubbles are generated to the window shield C 1 , and thereby reduce vanishing of bubbles. 
     Yet further, in the washer liquid supply system  1 B, as the heat-retaining tank  20 A is arranged on the upstream side with respect to the bubbling section  60 , it is possible to increase the amount of generating the bubbles and improve the washing capacity, by making the heated washer liquid W contain bubbles. 
     Third Embodiment 
     Subsequently, a washer liquid supply system according to a third embodiment of the invention will be described below, focusing on differences from the washer liquid supply system  1 B according to the second embodiment. As shown in  FIG. 16 , a washer liquid supply system  1 C according to the third embodiment of the invention is provided with a supply section  6 C instead of the supply section  6 B. 
     Supply Section 
     The supply section  6 C is provided with a pipe-side member  40 C and a nozzle-side member  50 C instead of the pipe-side member  40 B and the nozzle-side member  50 B. 
     Pipe-Side Member 
     The pipe-side member  40 C is not provided with a check valve  42  nor a fitting section  44 . 
     Nozzle-Side Member 
     The nozzle-side member  50 C is provided with a fitting section  54  for fitting the supply section  6 C to other units (the wiper arm  3 , the wiper blade  4 , or the like). 
     Herein, a coupling plane Y 4  is a plane on which the downstream-side end portion of the pipe-side member  40 C, and the upstream-side end portions of the nozzle-side member  50 C and the bubbling section  60 , contact with each other. In other words, the upstream-side end portion of the bubbling section  60  is disposed on the same plane as the upstream-side end portion of the nozzle-side member  50 C on the coupling plane Y 4 , and is in contact with the downstream-side end portion of the pipe-side member  40 C on the coupling plane Y 4 . A coupling plane Y 5  is a plane on which the nozzle-side member  50 C and the downstream-side end portion of the bubbling section  60  contact with each other. 
     In addition to preventing back flow by the check valve  42 , the supply section  6 C according to the third embodiment of the invention has an effect similar to the supply section  6 B according to the second embodiment. 
     Fourth Embodiment 
     Subsequently, a washer liquid supply system according to a fourth embodiment of the present invention will be described, focusing on differences from the washer liquid supply system  1 A according to the first embodiment. As shown in  FIG. 17 , a washer liquid supply system  1 D according to the fourth embodiment of the invention is provided with a heat-retaining tank  20 D instead of the heat-retaining tank  20 A. 
     Heat-Retaining Tank and Liquid Amount Detecting Section 
     The heat-retaining tank  20 D is provided with a liquid-amount detecting section  26 D instead of the liquid-amount detecting section  26 A. The liquid-amount detecting section  26 D is a weight sensor for detecting the weight of the washer liquid W temporarily stored in the tank main-body  21 . The liquid-amount detecting section  26 D outputs a detection result to the control section  7  (see  FIG. 2 ). 
     The control section  7  stores in advance the relation between the weight of the washer liquid W detected by the liquid-amount detecting section  26 D and the level of the liquid surface of the washer liquid W, as a mathematical expression, a table, or the like. The control section  7  uses this relation to convert the weight of the washer liquid W detected by the liquid-amount detecting section  26 D into the level of the liquid surface of the washer liquid W. 
     In more detail, the control section  7  stores in advance the relation between the weight of the washer liquid W detected by the liquid-amount detecting section  26 D, the alcohol concentration detected by the alcohol-concentration detecting section  27 , and the level of the liquid surface of the washer liquid W as a mathematical expression, a table, or the like. The control section  7  uses this relation to convert the weight of the washer liquid W detected by the liquid-amount detecting section  26 D into the level of the liquid surface of the washer liquid W. 
     In the washer liquid supply system  1 D according to the fourth embodiment of the invention, as the liquid-amount detecting section  26 A is a weight sensor and the control section  7  converts a weight into a level, it is possible to appropriately set an increase amount, based on the liquid surface level of the washer liquid W. 
     Further, in the washer liquid supply system  1 D, as the deflector  24  disturbs the flow of the washer liquid W, it is possible to inhibit the washer liquid W, which is from the inlet-side passage section  22 , from flowing to the discharge-side passage section  23 , without being heated. 
     Still further, in the washer liquid supply system  1 D, by the use of the deflector  24 , it is possible to detect the weight of the washer liquid W with a simple structure. 
     Further, in the washer liquid supply system  1 D, by the use of a detection result from the alcohol-concentration detecting section  27 , it is possible to appropriately obtain the level of the liquid surface of the washer liquid W. Further, in the washer liquid supply system  1 D, as the alcohol-concentration detecting section  27  is arranged at a position closer to the opening  23   a  of the discharge-side passage section  23  than to the opening  22   a  of the inlet-side passage section  22 , it is possible to appropriately detect the alcohol concentration. 
     Fifth Embodiment 
     Subsequently, a washer liquid supply system according to a fifth embodiment of the invention will be described, focusing on differences from the washer liquid supply system  1 A according to the first embodiment. As shown in  FIG. 18 , a washer liquid supply system  1 E according to the fifth embodiment of the invention is provided with a bypass passage section  8 E, a switching section  9 E, and an ambient temperature detecting section  101 . 
     Bypass Passage Section 
     The bypass passage section  8 E is a passage section that connects a point between the pump  2  and the heat-retaining tank  20 A and a point between the heat-retaining tank  20 A and the connecting member  30 A in such a manner that the washer liquid W can flow therethrough. That is, the bypass passage section  8 E bypasses the heat-retaining tank  20 A. 
     Switching Section 
     The switching section  9 E is, in the passage section  8 , arranged at a part that connects a point, which is between the pump  2  and the heat-retaining tank  20 A, and the bypass passage section  8 E. The switching section  9 E switches the flow direction of the washer liquid W, based on control by the control section  7 . The switching section  9 E is provided with a solenoid valve and the like to be able to switch between the following states: 
     A first state that permits the washer liquid W, which has been delivered from the pump  2 , to flow to the heat-retaining tank  20 A, and prohibits the washer liquid W from flowing to the bypass passage section  8 E; 
     A second state that permits the washer liquid W, which has been delivered from the pump  2 , to flow to the heat-retaining tank  20 A, and permits the washer liquid W to flow to the bypass passage section  8 E; and A third state that prohibits the washer liquid W, which has been delivered from the pump  2 , from flowing to the heat-retaining tank  20 A, and permits the washer liquid W to flow to the bypass passage section  8 E. 
     Ambient Temperature Detecting Section 
     The ambient temperature detecting section  101  is a temperature sensor for detecting the temperature in the surroundings of the vehicle C (see  FIG. 1 ), namely the ambient temperature. The ambient temperature detecting section  101  outputs a detection result to the control section  7 . 
     Control of Switching Section Based on Ambient Temperature 
     If a detection result from the ambient temperature detecting section  101  is higher than or equal to a preset certain temperature (30° C. degree for example), the control section  7  sets the switching section  9 E to the third state. 
     Control of Switching Section Based on Liquid Amount in Heat-Retaining Tank 
     On the other hand, when a detection result from the ambient temperature detecting section  101  is lower than the above-described certain temperature and when a detection result from the liquid-amount detecting section  26 A indicates that the level of the liquid surface of the washer liquid W is lower than the opening  23   a  of the discharge-side passage section  23 , the control section  7  sets the switching section  9 E to the second state in an initial stage of supplying the washer liquid W. Further, when a certain time has elapsed after setting the switching section  9 E to the second state, the control section  7  sets the switching section  9 E to the first state. 
     The control section  7  may be arranged such as to make the output of the pump  2 , which is output during when the switching section  9 E is set to the second state, larger than the output of the pump  2 , which is output during when the switching section  9 E is set to the first state. 
     Further, when a detection result from the ambient temperature detecting section  101  is lower than the above-described certain temperature and if a detection result from the liquid-amount detecting section  26 A indicates that the level of the liquid surface of the washer liquid W is higher than or equal to the height of the opening  23   a  of the discharge-side passage section  23 , the control section  7  sets the switching section  9 E to the first state during supplying the washer liquid W. 
     Herein, the lower level of the liquid surface of the washer liquid W from the opening  23   a  of the discharge-side passage section  23  is, the longer the control section  7  can set the time of setting the switching section  9 E to the second state. 
     Heating Control Corresponding to Alcohol Concentration 
     The lower the ambient temperature detected by the ambient temperature detecting section  101  is, the higher the control section  7  sets the threshold (see  FIG. 13 ). 
     In the washer liquid supply system  1 E according to the fifth embodiment of the present invention, the washer liquid W temporarily flows through both the heat-retaining tank  20 A and the bypass passage section  8 E. Accordingly, even in a state that a delay in supplying the washer liquid W to the window shield C 1  could occur, the delay in supplying the washer liquid W can be prevented by the use of the bypass passage section  8 E. That is, the washer liquid supply system  1 E can quickly supply the washer liquid W to the window shield C 1  even in a structure including the heat-retaining tank  20 A. 
     Further, by utilizing a detection result from the liquid-amount detecting section  26 A, in a state that a delay in supplying the washer liquid W could occur, the washer liquid supply system  1 E can prevent a delay in supplying the washer liquid W, by the use of the bypass passage section  8 E; and in a state that a delay in supplying the washer liquid W does not occur, the washer liquid supply system  1 E can appropriately exercise the washing capacity, by supplying the washer liquid W having been heated. 
     If the ambient temperature is high, the washer liquid supply system  1 E can prevent a delay in supplying the washer liquid W, by using the bypass passage section  8 E, and can appropriately exercise a washing capacity, by supplying the washer liquid W at a comparatively high temperature. 
     Further, as the washer liquid supply system  1 E changes the threshold, corresponding to the ambient temperature, if the ambient temperature is low, the washer liquid supply system  1 E sets the threshold high to maintain the alcohol concentration high so that the washer liquid W can be appropriately prevented from freezing. If the ambient temperature is high, the washer liquid supply system  1 E sets the threshold low so that, even in a case of a comparatively low alcohol concentration, the washer liquid supply system  1 E continues to heat the washer liquid W by the heater  25  so that the washing capacity by the washer liquid W can be appropriately exercised. 
     Sixth Embodiment 
     Subsequently, a washer liquid supply system according to a sixth embodiment of the present invention will be described below, focusing on differences from the washer liquid supply system  1 A according to the first embodiment. As shown in  FIG. 19 , a washer liquid supply system  1 F according to the sixth embodiment of the invention is provided with a return passage section  8 F and a switching section  9 F. 
     Return Passage Section 
     The return passage section  8 F is a passage section, of a passage section  8 , that connects a point between the heat-retaining tank  20 A and the supply section  6 A (the connecting member  30 A in the present embodiment), and the washer tank  10 , such that the washer liquid W can flow therethrough. That is, the return passage section  8 F returns the washer liquid W, which has been discharged from the heat-retaining tank  20 A, back to the washer tank  10 . 
     Switching Section 
     The switching section  9 F is arranged at a connecting part connecting a point, which is between the heat-retaining tank  20 A of the passage section  8  and the supply section  6 A (the connecting member  30 A in the present embodiment), and the return passage section  8 F, and switches the flow direction of the washer liquid W, based on control by the control section  7 . The switching section  9 F includes a solenoid valve and the like to be able to switch the following states: 
     A first state that permits the washer liquid W from the heat-retaining tank  20 A to flow to the supply section  6 A, and prohibits the washer liquid W from flowing to the return passage section  8 F; and 
     A second state that prohibits the washer liquid W, which has been delivered from the heat-retaining tank  20 A, from flowing to the supply section  6 A, and permits the washer liquid W to flow to the return passage section  8 F. 
     Control of Switching Section, Based on Alcohol Concentration 
     If alcohol concentration detected by the alcohol-concentration detecting section  27  is lower than or equal to the threshold, the control section  7  drives the pump  2  and makes the switching section  9 F to the second state. In this state, the washer liquid W with a dropped alcohol concentration in the tank main-body  21  of the heat-retaining tank  20 A is returned, by the pump  2 , through the switching section  9 F and the return passage section  8 F to the washer tank  10 . The washer liquid W, with a comparatively high alcohol concentration, in the washer tank  10  is delivered by the pump  2  into the tank main-body  21  of the heat-retaining tank  20 A. 
     As the washer liquid supply system  1 F according to the sixth embodiment of the present invention replaces the washer liquid W in the heat-retaining tank  20 A if the alcohol concentration has dropped, it is possible to prevent the washer liquid W, whose alcohol concentration has dropped, from being delivered to the supply section  6 A. 
     Embodiments of the present invention have been described above, however, the invention is not limited thereto, and can be changed and modified, as appropriate, within a range without departing from the spirit of the invention. For example, an object to be supplied with the washer liquid W is not limited to the window shield C 1  and may be, for example, a cover of a headlight of the vehicle C. Further, the washer liquid supply systems  1 A to  1 F according to the respective embodiments can be combined, as appropriate. 
     Further, in the connecting member  30 A, the method of making the washer liquid W contains bubbles is not limited to the above described. 
     Still further, the method of making the washer liquid W contain bubbles in the bubbling section  60  is not limited to the above-described. For example, a washer liquid supply system may be provided with a compressor mounted on the vehicle C so that the bubbling section  60  mixes air, which has been compressed by this compressor, with the washer liquid W to thereby make the washer liquid W contain bubbles. 
     Yet further, the shapes of the coupling planes Y 1  and Y 4  are not limited to be a linear shape in a side view. 
     Further, arrangement may be made such that a check valve is built in a nozzle-side member, and a bubbling section is built in a pipe-side member. 
     Still further, the washer liquid supply system  1 D may be provided with an inclination detecting section for detecting the inclination of the vehicle C. With this structure, by further using a detection result from the inclination detecting section, the control section  7  can determine whether the level of the liquid surface of the washer liquid W is at a height that is higher than or equal to the opening  23   a  of the discharge-side passage section  23 . Further, the control of the increase of the initial discharge amount can be applied, not only to the above-described heat-retaining tank  20 A and heat-retaining tank  20 D, but also to a heat-retaining tank having a structure which may generate a delay in discharge, for example, a structure in which the inside of the tank main-body  21  has a plural-chamber structure or a structure in which a reserve chamber is provided between the inlet-side passage section  22  and the discharge-side passage section  23 . 
     Further, the heat-retaining tanks  20 A and  20 D may have a structure without the control board  29 . In this structure, a different control section  7  or the like provided on the vehicle C can control the heater  25 .