Patent Publication Number: US-2023151590-A1

Title: Cold water discharge apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a U.S. National Phase entry of, and claims priority to, PCT Application No. PCT/JP2020/011964, filed Mar. 18, 2020, which claims priority to Japanese Patent Application No. 2020-017716, filed Feb. 5, 2020, both of which are incorporated herein by reference in their entireties for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a cold water discharge apparatus. For example, the apparatus serves to discharge hot water to a downstream outlet port when the feed water is hot water having temperature equal to or higher than a preset temperature. The apparatus discharges cold water to a cold water discharge port when the feed water is cold water having a temperature below the preset temperature. 
     BACKGROUND OF THE INVENTION 
     A shower facility that is configured to spew out temperature-controlled hot and cold water on a user is conventionally known. For example, the shower facility according to Japanese Laid-Open Patent Publication No. H03-18332 is capable of discharging initial cold water within piping to the outside. A temperature-sensitive valve is embedded in the cold water discharge apparatus. The temperature-sensitive valve serves to switch a flow destination of the water to various discharge flow channels by expanding/contracting in response to changes in temperature. 
     In the above shower facility, a temperature-sensitive valve is provided so as to expand/contract along a pipe axis direction of a discharge flow channel, so as to prevent the apparatus from increasing in size. Further, the discharge flow channel is configured to have a narrow diameter extending along the temperature-sensitive valve in the pipe axis direction. This discharge flow channel is within a narrow gap between the temperature-sensitive valve and an outer case and passes across the middle of the temperature-sensitive valve. Because of the above configuration, the discharge flow channel, whose flow destination may be switched by the temperature-sensitive valve, is also configured to have a narrow diameter. Therefore, it is not possible to ensure a sufficient discharge flow rate of hot water and a sufficient discharge flow rate of cold water. Accordingly, there has conventionally been a need for a cold water discharge apparatus capable of ensuring an appropriate discharge rate of both hot water and the cold water, while preventing the apparatus from increasing in size. 
     SUMMARY OF THE INVENTION 
     A cold water discharge apparatus according to one embodiment of the present disclosure is configured to discharge hot water from a discharge flow channel to an outlet port when the feed water is hot water having a temperature equal to or higher than a preset temperature. The cold water discharge apparatus discharges cold water from a cold water discharge flow channel, which is branched off from the discharge flow channel, to a cold water discharge port when the feed water is cold water having a temperature below the preset temperature. A temperature-sensitive first switching valve body is provided at a branching section of the discharge flow channel and the cold water discharge flow channel. A diaphragm type second switching valve body is provided so as to extend between the discharge flow channel and the cold water discharge flow channel. The diaphragm is biased by a spring force in a direction to close the discharge flow channel. 
     The temperature-sensitive first switching valve body serves to open the cold water discharge flow channel by expanding/contracting in the pipe axis direction in response to a change in temperature of the feed water such that the feed water is cold water, while keeping the discharge flow channel constantly open. The first switching valve body closes the cold water discharge flow channel when the feed water is hot water. A diaphragm type second switching valve body can be switched between a hot water discharge mode, a cold water discharge mode, and a residual water discharge mode. 
     In the hot water discharge mode, the discharge flow channel opens due to the pressure caused by flow of hot water through the discharge flow channel, so that hot water is discharged to the outlet port. In the cold water discharge mode, the discharge flow channel closes due to the pressure caused by flow of cold water through the cold water discharge flow channel, so that cold water is discharged to the cold water discharge port. In the residual water discharge mode, the cold water discharge flow channel opens when the temperature of residual water in the first switching valve is below the preset temperature after stopping the water. Consequently, the discharge flow channel opens by being subjected to the pressure due to the gravity drop from the residual water on the downstream side of the outlet port, so that residual water is discharged through the cold water discharge flow channel. 
     With the above structure, since the first switching valve body constantly opens the discharge flow channel, the discharge flow channel can be ensured to be wide. Further, the second switching valve body can close the discharge flow channel when the feed water is cold water. In addition, the second switching valve body can open the discharge flow channel when discharging cold residual water from the cold water discharge apparatus. With this valve mechanism, it is possible to obtain a structure capable of appropriately ensuring the hot water discharge rate and the cold water discharge rate, while also preventing the cold water discharge apparatus from increasing in size. 
     Further, the cold water discharge apparatus according to one embodiment of the present disclosure may be further configured as will be described below. The branching section may be formed with a branch pipe configured to take in a portion of the feed water flowing from a supply port of the feed water to the discharge flow channel, and branch off to the cold water discharge flow channel. With the above structure, a constantly opened discharge flow channel can be ensured to be wide. 
     Further, the cold water discharge apparatus according to one embodiment of the present disclosure may further be configured as will be described below. A constant flow valve may be provided in a region downstream of a pressure chamber of the second switching valve body, the pressure chamber being in the cold water discharge flow channel. With the above structure, an appropriate pressure is applied in the pressure chamber of the second switching valve body by the constant flow valve when discharging cold water, so as to properly close the discharge flow channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view illustrating a schematic structure of a cold water discharge apparatus according to one embodiment. 
         FIG.  2    is a perspective view of the cold water discharge apparatus. 
         FIG.  3    is a partial perspective cross-sectional view illustrating an interior structure of the cold water discharge apparatus. 
         FIG.  4    is an enlarged view of a part IV in  FIG.  3   . 
         FIG.  5    is an enlarged view of a part V in  FIG.  3   . 
         FIG.  6    is a cross-sectional view corresponding to  FIG.  3    illustrating a state of each valve during cold water supply. 
         FIG.  7    is a cross-sectional view corresponding to  FIG.  3    illustrating a state of each valve during hot water supply. 
         FIG.  8    is a cross-sectional view corresponding to  FIG.  3    illustrating a state of each valve during residual water discharge. 
         FIG.  9    is a cross-sectional view corresponding to  FIG.  4    illustrating a state in which a cold water discharge function is turned off by a switching operation member. 
     
    
    
     DETAILED DESCRIPTION 
     A structure of a cold water discharge apparatus  10  according to one embodiment will be described with reference to  FIG.  1    to  FIG.  9   . In the following description, the directions, such as frontward, rearward, upward, downward leftward, and rightward, refer to the respective directions as indicated in each of the drawings. 
     As shown in  FIG.  1   , a combination faucet  1  is mounted on a wall surface W of a bathroom. A cold water discharge apparatus  10  is provided on a channel for supplying hot and cold water from the combination faucet  1  to an overhead type shower head  6 . Specifically, the cold water discharge apparatus  10  is disposed at a connecting part between a shower supply pipe  4 , which fluidly connects with the combination faucet  1  and extends upward from the combination faucet  1 , and a shower discharge pipe  5  that fluidly connects with the shower supply pipe  4  and extends upward from the shower supply pipe  4 . An upper end of the shower discharge pipe  5  is connected to the shower head  6 . 
     The combination faucet  1  is equipped with a function that allows hot and cold water supplied from behind the wall surface W of the bathroom to be mixed in the interior and to be discharged. More specifically, pipe forming channels for hot and cold water (not shown) may be provided in or behind the wall surface W of the bathroom. On the rear surface of a faucet body  2 , hot and cold water connection ports (not shown) are formed respectively. The hot and cold water connection ports of the faucet body  2  are fluidly connected with the respective pipes via a hot water supply pipe  3 A or a cold water supply pipe  3 B which are eccentric in the shape of a crank. 
     The combination faucet  1  may be equipped with a temperature control function that allows the mixing ratio of the supplied hot and cold water to be controlled internally. Further, the combination faucet  1  includes a switching function capable of switching a delivery stopping channel for the mixed hot and cold water, and an adjustment function capable of adjusting a discharge amount of hot and cold water to be discharged. 
     The adjustment of the mixing ratio of the hot and cold water may be performed by operating a substantially cylindrical temperature control handle  2 A attached to a side (for example, left side) of the faucet body  2 . Further, the switching of the channel for discharging/stopping water and adjustment of a discharge rate may be performed by operating a substantially cylindrical switching handle  2 B attached to a side (for example, right side) of the faucet body  2 . Specifically, a mixing ratio of the hot and cold water to be mixed within the faucet body  2  is adjusted to a preset temperature in accordance with a rotation position as a user rotates the temperature control handle  2 A to the desired rotation position. 
     The user may rotate the switching handle  2 B upward or downward from a predetermined water stopping position (not shown). This enables the faucet body  2  to selectively discharge hot or cold water at an amount corresponding to the amount of rotation movement of the switching handle  2 B to the shower head  6  or spout  7 , which are fluidly connected to the faucet body  2 . In the present embodiment, the hot or cold water is discharged from the shower head  6  when the switching handle  2 B is rotated upward. The hot or cold water is discharged from the spout  7  when the switching handle  2 B is rotated downward. 
     The cold water discharge device  10  is equipped with a function that allows the cold water in the piping to be discharged outside, so that the cold water remaining in the piping at the beginning of use does not spew out through the shower head  6  on the user, for instance when hot or cold water is to be discharged from the shower head  6  by operating the switching handle  2 B. Hereinafter, a specific structure of the cold water discharge apparatus  10  will be described in detail. 
     As shown in  FIG.  2   , the cold water discharge apparatus  10  is formed in substantially a box shape vertically elongated in a frontward/rearward direction. An upper end of the shower supply pipe  4  is fluidly connected to a lower end of the cold water discharge apparatus  10 , while a lower end of the shower discharge pipe  5  is connected to an upper end of the cold water discharge apparatus  10 . The upper end of the shower supply pipe  4  and the lower end of the shower discharge pipe  5  are fluidly connected to the cold water discharge apparatus  10  in a position so as to be aligned with each other on the same axis. 
     The cold water discharge apparatus  10  has an apparatus main body  11 , which may be formed as a vertically elongated box shape, as shown in  FIG.  3   . A plurality of flow channels are formed by providing a plurality of compartment walls  12  and pipes inside the apparatus main body  11 . In the following description, the main pipes provided in the cold water discharge apparatus  10  will be described with reference numerals while other pipes will be described without reference numerals. Channels or openings defined by the respective pipes will be denoted with a reference numeral to facilitate description. In each figure, each channel or opening provided in the cold water discharge apparatus  10  is indicated with a reference sign enclosed in a square. 
     As shown in  FIG.  3   , a downwardly opened supply port D 1  is formed at the lower end of the cold water discharge apparatus  10 , which is fluidly connected to the upper end of the shower supply pipe  4 . An upwardly opened outlet port D 7  is formed at the upper end of the cold water discharge apparatus  10 , which is fluidly connected to the lower end of the shower discharge pipe  5 . A rearwardly opened cold water discharge port D 4  configured to discharge cold water to the outside is formed at an upper part of a rear end of the cold water discharge apparatus  10 . 
     As shown in  FIG.  4   , the cold water discharge apparatus  10  may include a branch flow channel D 2 , which allows a flow channel to branch into upward and rearward channels, at an upper position and downstream of the supply port D 1 . Further, the cold water discharge apparatus  10  includes a cold water discharge flow channel D 3  on a rear side of the branch flow channel D 2 . As shown in  FIG.  3   , the cold water discharge flow channel D 3  is configured to connect the branch flow channel D 2  to the cold water discharge port D 4 . The cold water discharge flow channel D 3  is configured to have a shape in which the flow channel rises upward from the connection port of the flow channel branched on the rear side of the branch flow channel D 2  and bends further rearward so as to lead to the cold water discharge port D 4 . 
     As shown in  FIG.  5   , a pressure chamber D 5 , for slightly expanding the flow channel forward, is formed at the bent part of the flow channel, which is the part bent from upward to rearward of the cold water discharge flow channel D 3 . The pressure chamber D 5  is an area for exerting pressure on a diaphragm-type second switching valve body  17  from behind, as will be described later. The pressure chamber D 5  may be formed of a partition pipe  19  in the form of a round tube with a pipe axis direction oriented in the frontward/rearward direction. 
     As shown in  FIG.  3   , the cold water discharge apparatus  10  includes a discharge flow channel D 6 , which is connected to the upwardly extending flow channel of the branch flow channel D 2  and leads to the upper outlet port D 7 . A part in the middle of the flow channel of a discharge flow channel D 6  that extends to the outlet port D 7  may be closed, so as to not allow a flow therethrough, or may be opened, so as to allow a flow therethrough, by the second switching valve  17 , which will be described later. The cold water discharge port D 4  may be provided in a position lower than the outlet port D 7 . 
     As shown in  FIG.  4   , the branch flow channel D 2  may be formed using a round tubular branch pipe  13  with its pipe axis direction oriented in the frontward/rearward direction. The branch pipe  13  may include a first opening (a pipe axis opening)  13 A and a second opening (a pipe wall opening)  13 B. As shown in  FIG.  6   , the first opening  13 A is located at a rear end of the branch pipe  13  and includes an opening at a peripheral wall, which is in communication with a cold water discharge flow channel D 3 . As shown in  FIG.  7   , the second opening  13 B may be located in the center area between the front and rear of the branch pipe  13  and have an opening in communication with the discharge flow channel D 6  and an opening in communication with the supply port D 1  in the lower wall. 
     As shown in  FIG.  7   , the second opening  13 B may be located directly above the supply port D 1 . The second opening  13 B may serve as an intake port to take a portion of hot or cold water supplied from the supply port D 1  into the branch pipe  13 . More specifically, the hot or cold water flowing upward from the supply port D 1  is partly taken from the second opening  13 B and enters into the branch pipe  13 . However, the rest of the hot or cold water passes upward of the branch pipe  13  and flows toward the discharge flow channel D 6 . 
     As shown in  FIG.  4   , the cold water discharge apparatus  10  may further include a temperature-sensitive first switching valve body  14 , which is set in the branch pipe  13 . The first switching valve body  14  may have a temperature-sensitive valve mechanism that expands and contracts autonomously in the pipe axis direction in accordance with the temperature of the hot or cold water taken into the branch pipe  13 . 
     More specifically, the first switching valve body  14  may have a shaft portion  14 A extending in the form of a round rod in the pipe axis direction and an open/close valve  14 B assembled at the rear end of the shaft portion  14 A, as shown in  FIG.  4   . Further, the first switching valve body  14  has a temperature-sensitive spring  14 C, which may be made of a shaped memory alloy that exerts a spring force on the open/close valve  14 B in the rearward direction, which is a valve closing direction. Furthermore, the first switching valve body  14  has a bias spring  14 D that exerts a spring force in the forward direction to open the open/close valve  14 B, by acting on the shaft portion  14 A. 
     As shown in  FIG.  4   , the shaft portion  14 A may be axially inserted into a round tubular shaped fitting pipe  14 E, which is fitted into the branch pipe  13  from the front. With this insertion, the shaft portion  14 A is supported from the outer peripheral side by the inner peripheral surface of the fitting pipe  14 E, such that only a sliding movement in the pipe axis direction is allowed. 
     As shown in  FIG.  4   , a ring-like groove may be formed on an outer peripheral portion of the shaft portion  14 A supported by the fitting pipe  14 E. An O-ring  14 A 1  made of rubber may be inserted in the groove. The O-ring  14 A 1  serves to seal the gap between the outer peripheral surface of the shaft portion  14 A and the inner peripheral surface of the fitting pipe  14 E over its entire circumference. This prevents hot and cold water flowing into the branch flow channel D 2  from leaking forward through the gap between the outer peripheral surface of the shaft portion  14 A and the inner peripheral surface of the fitting pipe  14 E. 
     As shown in  FIG.  4   , the front end of the shaft portion  14 A may be inserted from the rear into a through hole  23 A, which may be in the form of a circular hole, of the switching operation member  20 . The switching operation member  20  is assembled at the bottom of the front end of the apparatus main body  11 . This insertion allows the front end of the shaft portion  14 A to be supported by the inner peripheral surface of the through hole  23 A of the switching operation member  20  from the outer peripheral side. The rear end of the shaft portion  14 A may be inserted from the front through a flange portion  14 F that projects in a disc shape in the radial direction. The rear end of the shaft portion  14 A is also inserted from the front through the open/close valve  14 B. The flange portion  14 F and the open/close valve  14 B are placed over one another in the thickness direction. The open/close valve  14 B comprises a hollow disc-shaped member made of rubber. 
     As shown in  FIG.  4   , a temperature-sensitive spring  14 C may be formed of a spring member wound in a coil shape. The rear end of the shaft portion  14 A may be inserted from the front side through the fitting pipe  14 E, and subsequently inserted into the temperature-sensitive spring  14 C and the flange portion  14 F. This allows the temperature-sensitive spring  14 C to be positioned between the fitting pipe  14 E and the flange portion  14 F. The temperature-sensitive spring  14 C pushes the flange portion  14 F rearward with the rear side of the fitting pipe  14 E acting as a base, using a resilient force (spring force). The temperature-sensitive spring  14 C has the property of changing its hardness in accordance with the temperature of the hot or cold water, upon contact with the hot or cold water taken into the branch pipe  13 . 
     More specifically, as shown in  FIG.  4   , the temperature-sensitive spring  14 C becomes stiff enough to overcome the spring force of the bias spring  14 D to allow for it to extend in the pipe axis direction when the feed water taken into the branch pipe  13  is hot water at a set temperature or higher (for example, 35° C.). As a result, the open/close valve  14 B is pressed against the rear end of the branch pipe  13 , so as to close the first opening  13 A. 
     On the other hand, as shown in  FIG.  6   , the temperature-sensitive spring  14 C becomes soft enough to be press-contracted by the spring force of the bias spring  14 D such that it contracts in the pipe axis direction when the feed water taken into the branch pipe  13  is cold water below the set temperature. As a result, the open/close valve  14 B is pulled forward away from the rear end of the branch pipe  13  due to the spring force of the bias spring  14 D, so as to open the first opening  13 A. 
     As shown in  FIG.  4   , the bias spring  14 D may also be formed of a spring member wound in a coil shape. The shaft portion  14 A is inserted through the bias spring  14 D such that the bias spring  14 D is set between the front side of the fitting pipe  14 E and a flange portion  14 G that is formed near the front end of the shaft portion  14 A. The flange portion  14 G projects in a disc shape in the radial direction. As a result, the bias spring  14 D pushes the flange portion  14 G on the front end side of the shaft portion  14 A. The bias spring  14 D pushes the shaft portion  14 A forward, with the front side of the fitting pipe  14 E as a base, using a resilient force (spring force). 
     As shown in  FIG.  3   , the cold water discharge apparatus  10  may further include a constant flow valve  15 B capable of limiting the discharge flow rate to the cold water discharge port D 4  within a certain range. The constant flow valve  15 B is in a region downstream of the pressure chamber D 5  of the cold water discharge flow channel D 3 . Due to the flow rate limitation caused by this constant flow valve  15 B, the pressure applied from the cold water discharge flow channel D 3  to the pressure chamber D 5  at the time of discharging the cold water is maintained at a certain level or more. The cold water discharge port D 4  is equipped with a rectifier  16  that regulates the discharge of cold water using a combination of nets and grid-like components to prevent scattering. 
     As shown in  FIG.  4   , the cold water discharge apparatus  10  may further include a constant flow valve  15 A capable of limiting the supply flow rate to the supply port D 1  within a certain range. The constant flow valve  15 A is positioned at the supply port D 1 , which is connected to the shower supply pipe  4 . Due to the flow rate limitation by this constant flow valve  15 A, the discharge flow rate to the shower discharge pipe  5  is maintained within a certain range. 
     As shown in  FIG.  5   , the cold water discharge apparatus  10  may be further provided with a diaphragm type second switching valve body  17  that extends between the discharge flow channel D 6  and the pressure chamber D 5  of the cold water discharge flow channel D 3 . The second switching valve body  17  may be configured to be switched into three modes, such as a cold water discharge mode M 1  shown in  FIG.  6   , a hot water discharge mode M 2  shown in  FIG.  7   , and a residual water discharge mode M 3  shown in  FIG.  8   . These modes may be switched in response to the flow channel switching operation by the first switching valve body  14 . 
     More specifically, as shown in  FIG.  6   , the second switching valve body  17  may enter the cold water discharge mode M 1 , in which the discharge flow channel D 6  is closed due to the pressure of cold water flowing through the cold water discharge flow channel D 3 , when cold water is taken into the branch pipe  13  and flows into the cold water discharge flow channel D 3 . Further, as shown in  FIG.  7   , the second switching valve body  17  may enter the hot water discharge mode M 2 , in which the discharge flow channel D 6  is opened due to the pressure of hot water flowing through the discharge flow channel D 6 , when hot water is taken into the branch pipe  13  and flows into the discharge flow channel D 6 . 
     Further, as shown in  FIG.  8   , the second switching valve body  17  may enter the residual water discharge mode M 3 , in which the discharge flow channel D 6  is opened upon being subjected to the falling pressure of the downstream residual water from the outlet port D 7  due to gravity and in which the first opening  13 A (cold water discharge flow channel D 3 ) is opened by the first switching valve body  14 , when the residual water remaining in the branch pipe  13  after stopping water has cooled down and becomes cold water below the preset temperature. As a result, the residual water downstream of the outlet port D 7 , via the first switching valve body  14 , is discharged from the cold water discharge flow channel D 3  to the cold water discharge port D 4 . 
     As shown in  FIG.  5   , the second switching valve body  17  may be positioned within the partition pipe  19 , which may be in the form of a round tube. The partition pipe  19  defines the pressure chamber D 5  of the cold water discharge flow channel D 3 . Specifically, the second switching valve body  17  may include a disc-shaped pressure receiving plate  17 A with a surface oriented to the pipe axis direction. The second switching valve body  17  may also include a shaft portion  17 B extending in the pipe axis direction passing through the center of the pressure receiving plate  17 A. The second switching valve body  17  may further include a diaphragm valve  17 C joined to the front surface of the pressure receiving plate  17 A in an overlapping manner. Still further, the second switching valve body  17  may have a pressure control spring  17 D that exerts a spring force on the pressure receiving plate  17 A in the forward direction, which is the valve closing direction. 
     As shown in  FIG.  5   , the pressure receiving plate  17 A may have an extending portion that projects rearward from the outer peripheral edge thereof in a cylindrical shape. The pressure receiving plate  17 A may be set so as to be loosely fitted in the piping of the partition pipe  19 . As a result, the pressure receiving plate  17 A may be supported from the outer peripheral side by the partition pipe  19 , such that only a sliding movement in the pipe axis direction is allowed. 
     As shown in  FIG.  5   , the diaphragm valve  17 C may be made of a rubber thin film member. A peripheral edge of the diaphragm valve  17 C, which protrudes from the outer peripheral edge of the pressure receiving plate  17 A over the entire circumference, may contact the inner peripheral wall of the partition pipe  19  over the entire circumference. As a result, the diaphragm valve  17 C completely partitions the discharge flow channel D 6  and the pressure chamber D 5 . 
     As shown in  FIG.  5   , the pressure control spring  17 D may include a spring member wound in a coil shape. The shaft portion  17 B is inserted through the front end of the pressure control spring  17 D. The pressure control spring  17 D may be set between the pressure receiving plate  17 A and a spring support  19 A fixed to the partition pipe  19 . As a result, the pressure control spring  17 D pushes the pressure receiving plate  17 A forward, with the spring support  19 A as a base, using the resilient force (spring force). Due to the spring force, the diaphragm valve  17 C is pushed forward by the pressure receiving plate  17 A. The diaphragm valve  17 C is pushed from behind into a downstream opening  18 B of a discharge relay pipe  18  provided in front thereof, so as to close the downstream opening  18 B. 
     As shown in  FIG.  6   , the diaphragm valve  17 C keeps the downstream opening  18 B of the discharge relay pipe  18  closed (in the cold water discharge mode M 1 ), even when cold water is taken into the branch pipe  13  and streams into the cold water discharge flow channel D 3 . The reason for this is that the diaphragm valve  17 C is pressed forward due to the pressure of the cold water being applied to the pressure receiving plate  17 A facing the pressure chamber D 5  as the cold water flows through the cold water discharge flow channel D 3 . At this moment, the diaphragm valve  17 C is subjected to the proper forward pressing force due to the flow rate limitation of the constant flow valve  15 B provided in a downstream region of the cold water discharge flow channel D 3 . 
     On the other hand, as shown in  FIG.  7   , the diaphragm valve  17 C may be pushed rearward against the spring force of the pressure control spring  17 D due to the pressure of the hot water when it is allowed to flow through the discharge flow channel D 6 . The diaphragm valve  17 C is thereby pushed rearward, away from the downstream opening  18 B of the discharge relay pipe  18 , to open the downstream opening  18 B. As a result, the second switching valve body  17  enters the hot water discharge mode M 2 , in which the diaphragm valve  17 C opens the discharge flow channel D 6  to discharge hot water to the outlet port D 7 . 
     As shown in  FIG.  5   , the discharge relay pipe  18  may be formed by a round tubular pipe with its pipe axis direction oriented to the frontward/rearward direction. The discharge relay pipe  18  may have a round tubular shape which is slightly smaller than the partition pipe  19 . The discharge relay pipe  18  is arranged with the rear end slightly entered in the partition pipe  19  from the front. 
     As shown in  FIG.  7   , hot water is taken into the piping from the upstream opening  18 A on the front end of the discharge relay pipe  18  when the hot water flows from the supply port D 1  into the discharge flow channel D 6 . The discharge relay pipe  18  then allows the hot water to flow downstream from the downstream opening  18 B at its rear end when the feed water is hot water (and when the pressure of cold water from the cold water discharge flow channel D 3  is insufficiently applied to the pressure chamber D 5 ). 
     In other words, the pressure from the cold water discharge flow channel D 3  is not sufficiently applied to the pressure chamber D 5  when the feed water is hot water. Therefore, the diaphragm valve  17 C can open, as the hot water flowing through the discharge relay pipe  18  presses the diaphragm valve  17 C rearward. This allows the hot water to flow downstream from the downstream opening  18 B. The hot water flowing out of the downstream opening  18 B flows so as to bounce forward through the gap between the rear end of the discharge relay pipe  18  and the front end of the partition pipe  19  enclosing the rear end of the discharge relay pipe  18 , with the open diaphragm valve  17 C acting as a wall. The hot water is then discharged into the downstream outlet port D 7 . 
     As shown in  FIG.  3   , the cold water discharge apparatus  10  may further include a switching operation member  20  at the bottom of the front end. The switching operation member  20  can be operated externally by the user to switch the cold water discharge function to an inactive state. As shown in  FIG.  4   , the switching operation member  20  may include a round tubular shaped connecting pipe  21  with its pipe axis direction oriented in the frontward/rearward direction. The switching operation member  20  may also include an operation handle  22  in a cylindrical container shape rotatably connected to the connecting pipe  21 . The switching operation member may further include a cylindrical slider  23 , which is slidable in the pipe axis direction within the connecting pipe  21  by operation of the operation handle  22 . 
     As shown in  FIG.  4   , the rear end of the connecting pipe  21  is connected to the front end of the branch pipe  13 . The connecting pipe  21  projects forward from the apparatus main body  11 . The operation handle  22  may be provided in such an orientation that the bottom of the cylindrical container is oriented in the forward direction, to face where the user stands. Inside the cylinder of the operation handle  22 , a feed screw shaft  22 A projects in a round rod shape, rearward from the center of the bottom surface. The operation handle  22  may be set on the connecting pipe  21 , so as to allow the feed screw shaft  22 A to be inserted from the front into the connecting pipe  21 . As a result, the operation handle  22  covers the connecting pipe  21  from the outer peripheral side. 
     As shown in  FIG.  4   , by the above-described assembly, the feed screw shaft  22 A may be rotatably supported by the inner peripheral surface of the connecting pipe  21 . Thereby, the operation handle  22  can be operated to rotate around and with respect to the connecting pipe  21 . 
     As shown in  FIG.  4   , the slider  23  may be set within the connecting pipe  21  and may be supported from its outer peripheral side so that only a sliding movement in the pipe axial direction is allowed with respect to the connecting pipe  21 . Spiral female threads are formed on the inner peripheral surface of the cylindrical portion of the slider  23 . The slider  23  is screwed to male threads of the feed screw shaft  22 A, which is also inserted into the connecting pipe  21 . As a result, the feed screw shaft  22 A causes the slider  23  to move in the pipe axis direction as the operation handle  22  is operated to rotate. 
     Specifically, as shown in  FIG.  9   , the feed screw shaft  22 A feeds the slider  23  rearward in the connecting pipe  21  due to the rotation of the operation handle  22  in a counterclockwise direction. As a result, the rear end face of the slider  23  is pressed against the front surface of the flange portion  14 G of the first switching valve body  14 . Subsequently, the slider  23  pushes the shaft portion  14 A of the first switching valve body  14  rearward, such that the open/close valve  14 B is pressed against the rear end of the branch pipe  13  so as to close the first opening  13 A. 
     As shown in  FIG.  9   , this allows the first switching valve body  14  to restrict the expansion of the temperature-sensitive spring  14 C in the pipe axis direction. As a result, the first switching valve body  14  ensures the first opening  13 A is always closed, independent of the temperature of the water taken into the branch pipe  13 . In other words, the first switching valve body  14  does not open the first opening  13 A. Accordingly, the first switching valve body  14  does not allow cold water to flow to the cold water discharge flow channel D 3 , even if cold water flows into the branch pipe  13 . Therefore, similar to that shown in  FIG.  7   , water flows through the discharge flow channel D 6  and constantly pushes and opens the diaphragm valve  17 C so as to be discharged to the outlet port D 7 . 
     Further, as shown in  FIG.  4   , the slider  23  is fed forward in the connecting pipe  21  in response to the feed screw shaft  22 A being rotated by rotating the operation handle  22  in a clockwise direction. The rear end face of the slider  23  is thereby pulled forward and away from the flange portion  14 G of the first switching valve body  14 . As a result, the first switching valve body  14  is returned to a state in which the temperature-sensitive spring  14 C can expand and contract in the pipe axis direction in accordance with the temperature of the hot and cold water taken into the branch pipe  13 . 
     As shown in  FIG.  4   , the operation handle  22  is configured to be restricted to rotate in the clockwise direction to a position where the slider  23  abuts against a stepped portion  22 B of the screw shaft  22 A from behind. This prevented the screw shaft  22 A from rotating when the operation handle  22  is attempted to be further rotated in the clockwise direction. A projection  22 C formed on the outer peripheral surface of the operation handle  22  moves to be directly above the operation handle  22  when the operation handle  22  is rotated to the position where the clockwise rotation is restricted. 
     As shown in  FIG.  9   , by rotating the operation handle  22  in the counterclockwise direction, the slider  23  pushes the shaft portion  14 A of the first switching valve body  14  rearward to close the first opening  13 A. This causes the counterclockwise rotation to be restricted. The projection  22 C formed on the outer peripheral surface of the operation handle  22  moves to be directly below the operation handle  22  by rotating the operation handle  22  to the position where the counterclockwise rotation is restricted. In other words, the operation handle  22  can be rotated within a 180° range, between the positions where the projection  22 C is located directly above or below the operation handle  22 . The cold water discharge function can be switched between an active state and an inactive state by rotating the operating handle  22 . 
     The flow of the cold water discharge will be described with reference to  FIG.  6   . More specifically, the flow of the cold water discharge will be described when the feed water to be supplied to the cold water discharge apparatus  10  is below the preset temperature (for example, at 35° C.). In this case, the cold water is discharged to the cold water discharge port D 4 , as indicated by pale bold arrows in  FIG.  6   . The pale bold arrows are to schematically indicate the flow of the cold water discharge. The cold water may actually flow through the respective flow channels or openings through which the above-described arrows pass. 
     As shown in  FIG.  6   , firstly, the temperature-sensitive first switching valve body  14  opens the first opening  13 A on the rear end side of the branch pipe  13 . This occurs when the cold water (for example, below 35° C.) flows through the supply port D 1  to the branch flow channel D 2 . As a result, the cold water flows from the first opening  13 A to the cold water discharge flow channel D 3 . This water is then discharged through the cold water discharge port D 4 . 
     As shown in  FIG.  6   , the cold water streaming to the cold water discharge channel D 3  also flows into the pressure chamber D 5  and pushes the diaphragm valve  17 C of the second switching valve body  17  from behind. Consequently, the second switching valve body  17  closes the downstream opening  18 B of the discharge relay pipe  18 . As a result, the cold water discharge apparatus  10  enters the cold water discharge mode M 1 . 
     As shown in  FIG.  6   , on the other hand, the cold water flowing from the supply port D 1 , over the branch flow channel D 2 , and into the discharge flow channel D 6  is stopped by the discharge relay pipe  18 , which is closed by the diaphragm valve  17 C. As a result, the cold water is prevented from being discharged to the outlet port D 7 . 
     The flow of the hot water discharge will be described with reference to  FIG.  7   . More specifically, the flow of the hot water discharge will be described when the feed water to be supplied to the cold water discharge apparatus  10  is at the preset temperature or higher (for example, at or above 35° C.). In this case, the hot water is discharged to the outlet port D 7 , as indicated by solid bold arrows in  FIG.  7   . The solid bold arrows are also to schematically indicate the flow of the hot water discharge. The hot water may actually flow through the respective flow channels or openings within the respective piping through which the above-described arrows pass. 
     As shown in  FIG.  7   , firstly, the temperature-sensitive first switching valve body  14  closes the first opening  13 A on the rear end side of the branch pipe  13 . This occurs when the hot water (for example, 35° C. or higher) flows through the supply port D 1  into the branch flow channel D 2 . As a result, the hot water flowing over the branch flow channel D 2  to the discharge flow channel D 6  exerts pressure on the diaphragm valve  17 C from the front and pushes the diaphragm valve  17 C to move rearward against the spring force. 
     As a result, the second switching valve body  17  opens the downstream opening  18 B of the discharge relay pipe  18 . Accordingly, the cold water discharge apparatus  10  enters the hot water discharge mode M 2 . Consequently, the hot water flowing through the discharge flow channel D 6  is discharged through the discharge rely pipe  18  to the outlet port D 7 . 
     The flow of the residual water discharge will be described with reference to  FIG.  8   . More specifically, the flow of the residual water discharge will be described when the residual water remaining in the branch pipe  13  after stopping the water has cooled down and becomes cold water below the preset temperature (for example, 35° C.). In this case, the cooled residual water flows, as indicated by the pale bold arrows in  FIG.  8   . This residual water is discharged to the cold water discharge port D 4 . The pale bold arrows are to schematically indicate the flow of the discharge of the residual water. The residual water may actually flow through the respective flow channels or openings within the respective piping through which the above-described arrows pass. 
     As shown in  FIG.  8   , firstly, the temperature-sensitive first switching valve body  14  opens the first opening  13 A on the rear end side of the branch pipe  13 . This occurs when the residual water remaining in the branch pipe  13  after stopping the water has cooled down and becomes cold water. As a result, the residual water within the discharge flow channel D 6  flows through the first opening  13 A and into the cold water discharge flow channel D 3 , due to the action of gravity. Further, the residual water remaining downstream of the outlet port D 7  exerts pressure on the diaphragm valve  17 C from the front, due to the pressure caused by the gravity drop. This pressure pushes the diaphragm valve  17 C to move rearward against the spring force. 
     As a result, the second switching valve body  17  opens the downstream opening  18 B. This allows the cold water discharge apparatus  10  to enter the residual water discharge mode M 3 . Consequently, the residual water within the discharge flow channel D 6  and the residual water downstream of the outlet port D 7  flow through the first opening  13 A and into the cold water discharge flow channel D 3 , due to the action of gravity. These sources of residual water are discharged through the cold water discharge port D 4  to the outside. Therefore, even if the residual water remaining in the shower discharge pipe  5  and shower head  6  in  FIG.  1    cools down over time to be cold water, it will not be spewed out on the user at the next use. 
     In summary, the cold water discharge apparatus  10  according to the first embodiment may be configured as follows. In the following, the reference numerals in parentheses are the reference numerals corresponding to the respective structures described in the above embodiments. 
     As shown in  FIG.  3   , the cold water discharge apparatus ( 10 ) serves to discharge hot water from the discharge flow channel (D 6 ) to the outlet port (D 7 ) when the feed water is hot water having a temperature equal to or higher than the preset temperature. The cold water discharge apparatus ( 10 ) serves to discharge cold water from the cold water discharge flow channel (D 3 ), which branches off from the discharge flow channel (D 6 ), to a cold water discharge port (D 4 ) when the feed water is cold water having a temperature below the preset temperature. A temperature-sensitive first switching valve body ( 14 ) is provided at a branching section of the discharge flow channel (D 6 ) and the cold water discharge flow channel (D 3 ). A diaphragm type second switching valve body ( 17 ) is provided so as to extend over the discharge flow channel (D 6 ) and the cold water discharge flow channel (D 3 ). The diaphragm is biased by a spring force in a direction to close the discharge flow channel (D 6 ). 
     As shown in  FIG.  3   , the temperature-sensitive first switching valve body ( 14 ) serves to open the cold water discharge flow channel (D 3 ) by expanding/contracting in the pipe axis direction, in response to a change in temperature of the feed water, when the feed water is cold water. Even if the cold water discharge flow channel (D 3 ) is open, the discharge flow channel (D 6 ) is also kept constantly open. The first switching valve body ( 14 ) closes the cold water discharge flow channel (D 3 ) when the feed water is hot water. A diaphragm type second switching valve body ( 17 ) can be switched between a hot water discharge mode (M 2 ), a cold water discharge mode (M 1 ), and a residual water discharge mode (M 3 ). 
     As shown in  FIG.  7   , in the hot water discharge mode (M 2 ), the discharge flow channel (D 6 ) opens due to the pressure caused by flow of the hot water through the discharge flow channel (D 6 ), so that the hot water is discharged to the outlet port (D 7 ). As shown in  FIG.  6   , in the cold water discharge mode (M 1 ), the discharge flow channel (D 6 ) closes due to the pressure caused by the flow of the cold water through the cold water discharge flow channel (D 3 ), so that the cold water is discharged to the cold water discharge port (D 4 ). As shown in  FIG.  8   , in the residual water discharge mode (M 3 ), the cold water discharge flow channel (D 3 ) opens when the temperature of the residual water in the first switching valve ( 14 ) after stopping the water is below the preset temperature. Consequently, the discharge flow channel (D 6 ) opens by being subjected to pressure due to the gravity drop from the residual water on the downstream side of the outlet port (D 7 ). As a result, the residual water is discharged through the cold water discharge flow channel (D 3 ). 
     With the above structure, since the first switching valve body ( 14 ) allows the discharge flow channel (D 6 ) to be constantly open, a wide discharge flow channel (D 6 ) can be ensured. Further, although the configuration allows the discharge flow channel (D 6 ) to be closed by the second switching valve body ( 17 ) when the feed water is cold water, the discharge flow channel (D 6 ) can be rationally opened when discharging the cooled residual water within the cold water discharge apparatus ( 10 ). With this rationalization of the valve mechanism, it is possible to obtain a structure capable of appropriately ensuring the hot water discharge rate and the cold water discharge rate, while preventing the cold water discharge apparatus ( 10 ) from increasing in size. 
     As shown in  FIG.  4   , the branching section comprises a branch pipe ( 13 ) that takes a portion of the feed water flowing from the feed water supply port (D 1 ) into the discharge flow channel (D 6 ) and allows it to be branched to the cold water discharge flow channel (D 3 ). With the above-structure, a constantly opened discharge flow channel (D 6 ) can be ensured to be wide. 
     As shown in  FIG.  5   , the constant flow valve ( 15 B) may be provided in an area downstream of the pressure chamber (D 5 ) of the second switching valve body ( 17 ) and in the cold water discharge flow channel (D 3 ). With the above-structure, the discharge flow channel (D 6 ) can be appropriately closed by appropriately exerting pressure on the pressure chamber (D 5 ) side of the second switching valve body ( 17 ) by the constant flow valve ( 15 B) when discharging cold water. 
     Although the above has been described with reference to one embodiment, the present disclosure may be carried out in various forms, examples of which will be described below as alternatives to the above-described embodiment. 
     The cold water discharge apparatus according to the present disclosure shall not be limited to the one provided on a channel for supplying hot or cold water configured to connect a combination faucet to an overhead type shower head. For example, the cold water discharge apparatus may be the one provided on a channel for supplying hot or cold water configured to connect a combination faucet to a handheld type shower head or a spout. Further, the cold water discharge apparatus may be connected to a combination faucet that is installed in a location other than a wall surface of a bathroom, such as a kitchen or sink. 
     The temperature-sensitive first switching valve body may be configured to be provided with an expansion and contraction direction (the pipe axis direction) oriented in the height direction after the cold water discharge apparatus is installed. The diaphragm-type second switching valve body may similarly be configured with a movable direction oriented in the height direction after the cold water discharge apparatus is installed. The expansion and contraction direction of the first switching valve body and the movable direction of the second switching valve body need not necessarily be parallel to each other, but may be arranged in an orientation in a mutually twisted relationship. 
     The discharge flow channel may be configured to be fluidly connected to the branch flow channel provided with the first switching valve body in the pipe axis direction. Further, the cold water discharge flow channel may be configured to be fluidly connected to the branch flow channel provided with the first switching valve body in a direction orthogonal to the pipe axis direction. Moreover, it may be configured such that the entire feed water supplied from the supply port flows to the discharge flow channel through the first switching valve body. 
     The supply port and the outlet port may be arranged not in line with each other. The supply port, the outlet port, and the cold water discharge port may be provided so as to open in any direction, irrespective of how the cold water discharge apparatus is installed. 
     The temperature-sensitive spring of the first switching valve body may comprise a wax-type thermoelement alternative to a spring member made of a shape memory alloy wound in a coil shape. The switching temperature of the hot water discharge and the cold water discharge by the first switching valve body can be freely set by adjusting the balance of the spring force between the temperature-sensitive spring and the bias spring, and may be set at a temperature below 35° C. or higher than 35° C.