Water-washable toilet

Abstract

To provide a flush toilet that allows overflow water from the flush water tank to be discharged into the drain socket while sufficiently reducing the risk of flush water backflowing into the flush water tank. [Solution] The present invention relates to a flush toilet (1), comprising a bowl (12), a flush water tank (42), a drain trap pipe (14), a drain socket (30) provided downstream of the drain trap pipe, an overflow channel (62) that causes flush water to overflow when the water level in the flush water tank rises above a predetermined level, and a drain channel configuration wall (64a) formed inside the drain socket upstream of a water retention valve to cause at least a portion of the flush water flowing in from the drain trap pipe to collide with and guide downward, wherein the overflow outlet of the overflow channel is formed above the lower end of the drain channel configuration wall of the drain socket.

Description

Technical Field

[0001] The present invention relates to a flush toilet, and more particularly to a flush toilet that discharges dirt with washing water.

Background Art

[0002] Japanese Patent No. 7181505 (Patent Document 1) describes a flush toilet. This flush toilet includes a bowl part, a toilet body having a drain trap pipe, a water storage tank, a water supply valve unit, a pump device, etc. Then, the washing water in the water storage tank is pressurized by the pump device and discharged from the jet discharge port, and at the same time, the washing water is discharged from the rim discharge port through the water supply valve unit to wash the bowl part. Further, an overflow bypass flow path extends from the upper part of the water storage tank, and this overflow bypass flow path is connected to the vertical pipe part of the drain socket connected to the downstream side of the drain trap pipe. Therefore, when the water level in the water storage tank exceeds a predetermined water level, the washing water is discharged into the drain socket through the overflow bypass flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the flush toilet described in Patent Document 1, the overflow bypass channel extending from the water storage tank is connected to the vertical pipe section of the drain socket. As a result, there is a risk that the flushing water that flows from the bowl through the drain trap pipe to the drain socket will flow back into the overflow bypass channel connected to the drain socket. In particular, if the cross-sectional area of ​​the overflow bypass channel is increased to enable the discharge of a large volume of overflow water from the water storage tank, there is a problem that the risk of flushing water flowing back into the overflow bypass channel from the drain socket increases. Furthermore, if a blockage occurs in the drain piping connected downstream of the drain socket, there is a problem that the risk of flushing water flowing back into the overflow bypass channel from the drain socket also increases.

[0005] Therefore, the present invention aims to provide a flush toilet that allows overflow water to be discharged from the flush water tank to the drain socket while sufficiently reducing the risk of backflow of flush water to the flush water tank. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the present invention provides a flush toilet that discharges waste using flushing water, comprising: a bowl portion for storing water and receiving waste; a flushing water tank for storing flushing water for cleaning the bowl portion; a drain trap pipe having an inlet connected to the lower part of the bowl portion and an upward pipe extending from the inlet to the top portion located above and behind; a drain socket provided on the downstream side of the drain trap pipe; an overflow channel for overflowing the flushing water in the flushing water tank when the water level in the flushing water tank rises above a predetermined water level; and a drain channel configuration wall formed inside the drain socket upstream of the water storage valve to cause at least a portion of the flushing water flowing in from the drain trap pipe to collide and guide downward, wherein the overflow outlet of the overflow channel is formed above the lower end of the drain channel configuration wall of the drain socket.

[0007] With the present invention configured in this way, since the overflow outlet of the overflow channel is formed above the lower end of the drain channel component wall of the drain socket, it is possible to prevent cleaning water flowing from the drain trap pipe into the drain socket from entering the overflow outlet.

[0008] In the present invention, preferably, a first backflow prevention wall is provided inside the drain socket below the overflow outlet and at a height above the lower end of the drain channel configuration wall, so as to prevent backflow of cleaning water to the overflow outlet.

[0009] With the present invention configured in this way, since the first backflow prevention wall is provided below the overflow outlet and at a height greater than the lower end of the drainage channel configuration wall, it is possible to prevent the cleaning water that has splashed upward inside the drain socket from reaching the overflow outlet, and the risk of cleaning water entering the overflow outlet can be further reduced.

[0010] In the present invention, preferably, the overflow outlet of the overflow channel is provided at a height equal to or greater than the lower end of the first backflow prevention wall and the drainage channel constituent wall of the drain socket.

[0011] With the present invention configured in this way, the overflow outlet of the overflow channel is provided at a height greater than or equal to the lower end of the first backflow prevention wall and the drain channel constituent wall of the drain socket, so that the risk of cleaning water flowing in from the drain trap pipeline backflowing into the overflow channel can be sufficiently reduced.

[0012] In the present invention, preferably, a second backflow prevention wall is provided inside the drain socket to prevent backflow of cleaning water to the overflow outlet. This second backflow prevention wall is provided below the first backflow prevention wall and at a height above the lower end of the drain channel configuration wall, and the first backflow prevention wall and the second backflow prevention wall are arranged so that a portion of them overlaps when viewed from above.

[0013] According to the present invention configured in this manner, a second backflow prevention wall is provided inside the drain socket below the first backflow prevention wall and at a height above the lower end of the drain channel configuration wall, and the first and second backflow prevention walls are arranged so that a portion of them overlaps when viewed from above. As a result, the path from the drain trap pipe to the overflow outlet of the cleaning water becomes very long, further reducing the risk of cleaning water entering the overflow outlet.

[0014] In the present invention, preferably, a second backflow prevention wall is provided inside the drain socket to prevent backflow of cleaning water to the overflow outlet, and this second backflow prevention wall is provided facing the overflow outlet and including the projected surface of the overflow outlet.

[0015] With the present invention configured in this way, the second backflow prevention wall provided inside the drain socket is positioned opposite the overflow outlet and includes the projection plane of the overflow outlet, thus further reducing the risk of splashing cleaning water entering the overflow outlet.

[0016] In the present invention, preferably, the present invention further includes a water-retaining on / off valve configured to open and close the pipe in the drain socket so as to accumulate cleaning water downstream of the top of the drain trap pipe, and a vent formed in the drain socket above the lower end of the drain channel configuration wall so as to discharge air that is trapped in the drain trap pipe.

[0017] According to the present invention configured in this manner, since it is equipped with an overflow channel that allows cleaning water in the cleaning water tank to overflow, by closing the water retention valve, cleaning water can be quickly supplied to the inside of the drain socket without going through the bowl section, and cleaning water can be stored in the drain socket. Furthermore, since a vent is formed in the drain socket, when the water retention valve is closed and cleaning water is stored in the drain socket, the air that has been trapped in the drain socket can be released through the vent. As a result, cleaning water can be sufficiently stored in the drain socket without being obstructed by the air that has been trapped in the drain socket. As a result, cleaning water can be stored in the drain socket without excessively raising the water level in the bowl section, and when the water retention valve is opened, a strong siphon effect can be generated in the drain trap pipeline. In addition, the drain channel configuration wall is formed so that its lower end is located below the vent, and at least a portion of the cleaning water flowing in from the drain trap pipeline is guided downward by impact, so even if a vent is provided in the drain socket, the risk of cleaning water leaking from the vent can be sufficiently reduced.

[0018] In the present invention, preferably, a valve mechanism capable of closing the vent is provided inside the drain socket, and the vent is closed by the valve mechanism when the toilet is flushed.

[0019] According to the present invention configured in this way, a valve mechanism capable of closing the vent is provided inside the drain socket, so that the intrusion of cleaning water into the vent can be reliably prevented. [Effects of the Invention]

[0020] According to the flush toilet of the present invention, even during a power outage, it is possible to enable the user to easily and thoroughly flush the toilet while significantly reducing the risk of leakage of flushing water from the drain channel. [Brief explanation of the drawing]

[0021] [Figure 1] This is a perspective view showing a flush toilet according to the first embodiment of the present invention. [Figure 2] The top view of the hygienic cleaning device of the water-washed toilet according to the first embodiment of the present invention, with the device removed. [Figure 3] The side cross-sectional view of the water-washed toilet according to the first embodiment of the present invention, cut along line III-III in FIG. 2. [Figure 4A] The perspective view of the functional device of the water-washed toilet according to the first embodiment of the present invention, seen from the upper left obliquely. [Figure 4B] The perspective view of the functional device of the water-washed toilet according to the first embodiment of the present invention, seen from the upper right obliquely. [Figure 5] The block diagram showing the water supply path through which the cleaning water of the water-washed toilet according to the first embodiment of the present invention flows. [Figure 6] The perspective view showing the drainage socket and the cleaning water tank taken out in the water-washed toilet according to the first embodiment of the present invention. [Figure 7] The perspective cross-sectional view showing the internal structure of the drainage socket by cutting it in the front-back direction of the water-washed toilet according to the first embodiment of the present invention. [Figure 8] The perspective cross-sectional view showing the internal structure of the drainage socket by cutting it in the width direction of the water-washed toilet according to the first embodiment of the present invention. [Figure 9] The perspective view showing the configuration for opening and closing the water storage on-off valve provided inside the drainage socket in the water-washed toilet according to the first embodiment of the present invention. [Figure 10] The cross-sectional view of the cleaning water tank showing the connection structure between the cleaning water tank and the drainage socket in the water-washed toilet according to the first embodiment of the present invention. [Figure 11] The cross-sectional view showing the state in which the cleaning water is stored in the drainage socket in order to execute the toilet cleaning during a power outage in the water-washed toilet according to the first embodiment of the present invention. [Figure 12] The perspective cross-sectional view showing the internal structure of the drainage socket by cutting it in the front-back direction of the water-washed toilet according to the second embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0022] A flush toilet according to the first embodiment of the present invention will be described below with reference to the attached drawings. First, the basic structure of a flush toilet according to the first embodiment of the present invention will be explained with reference to Figures 1 to 3. Figure 1 is a perspective view showing a flush toilet according to the first embodiment of the present invention, Figure 2 is a top view of the flush toilet according to the first embodiment of the present invention with the sanitary cleaning device removed, and Figure 3 is a side cross-sectional view taken along line III-III in Figure 2. In Figure 2, the rim water channel, jet water channel, and jet water supply pipe are indicated by dotted lines.

[0023] As shown in Figure 1, the flush toilet 1 according to the first embodiment of the present invention is a wall-mounted flush toilet whose back surface is fixed to a wall W. The flush toilet 1 comprises a ceramic flush toilet body 2, a tank device 4 for storing flushing water supplied to the flush toilet body 2, and a sanitary flushing device 6 placed on the upper surface of the flush toilet body 2. The wall W is provided with a shut-off valve 8 for supplying or stopping the flow of flushing water from a water source (not shown), such as a water supply, to the flush toilet 1. This shut-off valve 8 is connected to the flush toilet 1 via a water supply pipe 10.

[0024] As shown in Figures 2 and 3, the toilet bowl body 2 has a bowl portion 12 for receiving waste, a drain trap pipe 14 connected below the bowl portion 12 for discharging waste, and a skirt portion 16 that surrounds the bowl portion 12 and the drain trap pipe 14 from the outside. A space S is formed inside the toilet bowl body 2 between the bowl portion 12 and the drain trap pipe 14 and the skirt portion 16.

[0025] The bowl portion 12 comprises a bowl-shaped waste receiving surface 18 and a rim portion 20 formed along the upper edge of the bowl portion 12. Water is formed inside the bowl portion 12.

[0026] The rim portion 20 has a rim outlet 22 for discharging cleaning water towards the rear and a rim water channel 24 for guiding the cleaning water to the rim outlet 22. The rim outlet 22 is located near the center in the front-to-back direction on the right side of the bowl portion 12. The cleaning water discharged from the rim outlet 22 flows down the waste receiving surface 18 while swirling along the inner circumferential surface of the rim portion 20, cleaning the bowl portion 12.

[0027] Below the bowl section 12, a jet outlet 26 is formed to discharge cleaning water toward the inlet 14a of the drain trap pipe 14, and a jet water channel 28 is formed to supply cleaning water to the jet outlet 26. The jet outlet 26 is positioned opposite the inlet 14a of the drain trap pipe 14. The cleaning water discharged from the jet outlet 26 flows into the drain trap pipe 14 to activate a siphon effect.

[0028] The flush toilet 1 according to the first embodiment of the present invention is a siphon jet type flush toilet that discharges waste by generating a siphon action with a jet of water. However, the invention is not limited to this form, and other forms may include, for example, a wash-down type flush toilet that washes away waste with the flowing water action caused by the difference in water pressure, or a siphon type flush toilet that discharges waste by generating a siphon action solely with water discharged from the rim.

[0029] The drain trap pipe 14 comprises an inlet 14a connected to the bottom of the bowl section 12, an upward pipe 14b extending upward from the inlet 14a, a top 14c located at the highest point of the upward pipe 14b that defines the water level, and a rear pipe 14d extending almost horizontally backward from this top 14c. The rear pipe 14d of the drain trap pipe 14 is connected to a drain pipe (not shown) inside the wall W via a drain socket 30.

[0030] The sanitary washing device 6 comprises a main body (not shown), a washing nozzle (not shown) that is movable forward and backward from the main body, a toilet seat (not shown) that is rotatably attached to the main body, and a toilet seat cover that is rotatably attached to the main body so as to cover the toilet seat. The water supply pipe 10, which is connected to the shut-off valve 8, is connected to the main body of the sanitary washing device 6 and supplies washing water to be sprayed from the washing nozzle.

[0031] As shown in Figures 2 and 3, a space S is formed within the toilet bowl body 2 between the bowl portion 12 and the drain trap pipe 14 and the skirt portion 16. The tank device 4 is housed in the space S surrounded by the skirt portion 16 below the bowl portion 12 within the toilet bowl body 2. Functional devices for supplying flushing water stored in the tank device to the toilet bowl body are housed in the space S behind the bowl portion 12 within the toilet bowl body 2. These functional devices include, for example, a water supply valve device 32, a pump device 34, a switching valve device 36, and a control device 38. A base plate 40 is provided in the bottom opening 2a surrounded by the skirt portion 16 of the toilet bowl body 2, and the above-mentioned functional devices are supported by this base plate 40.

[0032] Next, the tank device 4, functional device, and base plate 40 housed in the space S within the toilet bowl body 2 will be explained with reference to Figures 4A and 4B. Figure 4A is a perspective view of the functional device of a flush toilet according to the first embodiment of the present invention, viewed from the upper left, and Figure 4B is a perspective view of the functional device of a flush toilet according to the first embodiment of the present invention, viewed from the upper right, at an angle. In Figure 4A, the direction of the flow of the flushing water is indicated by an arrow.

[0033] The tank device 4 includes a flush water tank 42 for storing flush water supplied to the toilet bowl body 2, a tank water supply unit 46 for allowing flush water from the tank water supply pipe 44 to flow into the flush water tank 42, a float switch 48 for detecting the water level of the flush water stored in the flush water tank 42, and a fixing member 50 for fixing the tank device 4 to the bottom surface of the toilet bowl body 2.

[0034] The flushing water tank 42 stores flushing water for cleaning the bowl portion 12. In a top view, it is formed in an L-shape, extending forward on the right side of the drain trap pipe 14, then bending and extending to the left. The flushing water tank 42 is a resin tank that stores flushing water used for rim discharge and jet discharge, and in this embodiment, the entire tank is located inside the toilet body 2. In this embodiment, the entire flushing water tank 42 is located inside the toilet body 2, but it is also acceptable for only a part of it to be located inside the toilet body 2.

[0035] The tank water supply unit 46 is located on top of the cleaning water tank 42. The upstream side of the tank water supply unit 46 is connected to the tank water supply pipe 44, and the downstream side of the tank water supply unit 46 is connected to the cleaning water tank 42. Inside the tank water supply unit 46, a flow path is formed to guide cleaning water from the tank water supply pipe 44 towards the cleaning water tank 42.

[0036] The float switch 48 is located above the flushing water tank 42. The float switch 48 is designed to turn off when the water level in the tank falls below the shut-off level (full water level). Conversely, the float switch 48 turns on when the water level in the tank rises to the shut-off level, causing the water supply valve device 32 to close.

[0037] The cleaning water tank 42 is equipped with an overflow pipe 62 for draining cleaning water outside the tank in case, for example, if the float switch 48 malfunctions and the tank continues to supply water. The overflow pipe 62 is connected to a drain socket 30, and when the cleaning water in the cleaning water tank 42 exceeds a predetermined level, the cleaning water is allowed to flow into the drain socket 30 via the overflow pipe 62.

[0038] The water supply valve device 32 includes a constant flow valve (not shown) for maintaining a constant flow rate of cleaning water, an on-off valve (not shown) located downstream of the constant flow valve for switching between supplying and shutting off cleaning water, and a solenoid valve (not shown) for driving this on-off valve. The upstream side of the water supply valve device 32 is connected to a water source (not shown) via a stopcock 8 and a water supply pipe 10, and the downstream side of the water supply valve device 32 is connected to the sanitary cleaning device 6 via a water supply pipe 52 for the sanitary cleaning device, and also to the tank device 4 via a water supply pipe 44 for the tank. When the solenoid valve opens electromagnetically, the on-off valve opens, and cleaning water from the water source is supplied to the tank device 4 via the water supply pipe 44 for the tank.

[0039] The pump device 34 is a pressurized pump that pumps the flushing water stored in the tank device 4 to the toilet bowl body 2. The upstream side of the pump device 34 is connected to the tank device 4 via an upstream connecting pipe 54, and the downstream side of the pump device 34 is connected to the switching valve device 36 via a downstream connecting pipe 56. When the pump device 34 is operated, the flushing water stored in the tank device 4 is pumped and discharged from the rim outlet 22 and the jet outlet 26, thereby flushing the toilet bowl. In the first embodiment of the present invention, the flushing toilet bowl 1 is supplied with flushing water stored in the tank device 4 to the rim outlet 22 and the jet outlet 26, but the invention is not limited to this configuration, and other configurations are also applicable, such as a configuration in which all the flushing water stored in the tank device 4 is discharged from the rim outlet 22.

[0040] The switching valve device 36 includes a switching valve body (not shown) and switches the water supply channels that supply cleaning water from the pump device 34 to the rim discharge port 22 and the jet discharge port 26, respectively. The upstream side of the switching valve device 36 is connected to the pump device 34 via a downstream connecting pipe 56, and the downstream side of the switching valve device 36 is connected to the rim water supply channel 24 via a rim water supply pipe 58 and to the jet water supply channel 28 via a jet water supply pipe 60. When the switching valve body is closed, cleaning water from the pump device 34 is supplied to the rim discharge port 22, and when the switching valve body is open, cleaning water from the pump device 34 is supplied to both the rim discharge port 22 and the jet discharge port 26.

[0041] The control device 38 is electrically connected to a remote control (not shown), a tank device 4 (float switch 48), a sanitary cleaning device 6, a water supply valve device 32, and a pump device 34, and is capable of sending and receiving various signals. When the control device 38 receives a cleaning start signal for a large or small flush from the remote control, it drives or stops the pump device 34 based on a pre-stored cleaning sequence. Specifically, when the user operates the remote control, the control device 38 drives the pump device 34 to discharge the cleaning water stored in the tank device 4 from the rim outlet 22 and the jet outlet 26. In addition, after the toilet bowl is flushed, the control device 38 opens the water supply valve device 32 to supply water to the tank, and when the float switch 48 detects that the tank is full, it closes the water supply valve device 32.

[0042] Next, with reference to Figure 5, the water supply channel through which the flushing water of the flush toilet 1 according to the first embodiment of the present invention flows will be described. Figure 5 is a block diagram showing the water supply channel through which the flushing water of a flush toilet according to the first embodiment of the present invention flows.

[0043] The water supply channel of the flush toilet 1 is configured, from upstream, with a stopcock 8, a water supply valve device 32, a tank device 4, a pump device 34, and a switching valve device 36. First, flushing water is supplied from the water source to the water supply valve device 32 via the stopcock 8 and the water supply pipe 10. The flushing water supplied to the water supply valve device 32 is supplied to the sanitary flushing device 6 via the sanitary flushing device water supply pipe 52, and also to the tank device 4 via the tank water supply pipe 44. The flushing water stored in the tank device 4 is drawn up by the pump device 34 via the upstream connecting pipe 54 and supplied to the switching valve device 36 via the downstream connecting pipe 56. The flushing water supplied to the switching valve device 36 is discharged from the rim outlet 22 via the rim water supply pipe 58 and the rim water conduit 24, and also discharged from the jet outlet 26 via the jet water supply pipe 60 and the jet water conduit 28. Furthermore, the cleaning water that overflows from the tank device 4 is discharged to the drain socket 30 via the overflow pipe 62.

[0044] Next, the configuration of the drain socket 30 and the connection structure between the drain socket 30 and the cleaning water tank 42 will be described with reference to Figures 6 to 10. Figure 6 is a perspective view showing the drain socket 30 and the flush water tank 42 removed from the toilet bowl 1. Figure 7 is a perspective cross-sectional view showing the internal structure of the drain socket 30, cut in the front-to-back direction of the toilet bowl 1. Figure 8 is a perspective cross-sectional view showing the internal structure of the drain socket 30, cut in the width direction of the toilet bowl 1. Figure 9 is a perspective view showing the configuration for opening and closing the water retention valve provided inside the drain socket 30. Figure 10 is a cross-sectional view of the flush water tank 42 showing the connection structure between the flush water tank 42 and the drain socket 30.

[0045] As shown in Figure 6, the drain socket 30 is connected to the highest part of the flushing water tank 42 via an overflow pipe 62, which is an overflow passage. In this embodiment, the overflow pipe 62 is made of a flexible hose and connects the overflow pipe connection chamber 72 of the flushing water tank 42 to the overflow outlet 64c (Figure 8) provided in the drain socket 30. Furthermore, the drain socket 30 has an inlet 30a that opens toward the front of the flushing toilet 1 and a drain pipe connection 30b that opens toward the rear. Overall, the drain socket 30 has a generally crank-shaped passage, with the upper inlet 30a and the lower drain pipe connection 30b connected by a generally vertical passage.

[0046] The inlet portion 30a of the drain socket 30 is connected to the downstream side of the drain trap pipe 14 by receiving the rear pipe 14d (Figure 3) of the drain trap pipe 14. On the other hand, the drain pipe connection portion 30b is connected to the drain pipe by being received into the drain pipe (not shown) for discharging washing water and waste. In this specification, the drain socket 30 includes any member that constitutes a flow path between the drain trap pipe 14 and the drain pipe (not shown).

[0047] As shown in Figure 7, the drain socket 30 includes an upstream member 64 with an inlet 30a, a downstream member 66 with a drain pipe connection 30b, and a water reservoir valve 68 configured to open and close the pipeline inside the drain socket 30. Furthermore, a wall forming member 70 and a valve seat forming member 71 are arranged inside the upstream member 64. The water reservoir valve 68 is a valve body that can be opened and closed by the user manually in order to enable toilet flushing in the event of a power outage, etc. The function of the water reservoir valve 68 and the flushing procedure in the event of a power outage, etc. will be described later.

[0048] The upstream member 64 is a cylindrical member that extends generally vertically, and has an inlet portion 30a that protrudes horizontally in front of the flush toilet 1. As shown in Figure 8, the inside of the upstream member 64 is provided with a drainage channel configuration wall 64a, a first backflow prevention wall 70a, and a second backflow prevention wall 64b. Furthermore, an overflow outlet 64c and a vent 64d are provided on the upper part of one side of the upstream member 64.

[0049] As shown in Figure 7, the inlet portion 30a is a cylindrical portion provided on the upstream member 64 so as to protrude horizontally forward, and the inside of the inlet portion 30a is in communication with the internal space of the upstream member 64. As a result, the drain trap pipe 14 connected to the inlet portion 30a is in communication with the internal space of the upstream member 64.

[0050] The drainage channel wall 64a is a semi-dome-shaped portion formed inside the upstream member 64, and is positioned to cover approximately the upper half of the circular opening that communicates with the inlet 30a. This drainage channel wall 64a is provided on the upstream side of the water retention valve 68. Furthermore, by providing this drainage channel wall 64a, some of the sewage and washing water that flows from the drain trap pipe 14 through the inlet 30a into the upstream member 64 collide with it and are guided downward. The vent 64d is provided above the lower end of the drainage channel wall 64a.

[0051] As shown in Figure 8, the second backflow prevention wall 64b is a wall surface that extends substantially horizontally from the lower end of the semi-dome-shaped drainage channel constituent wall 64a. This second backflow prevention wall 64b extends so as to connect approximately half of the lower edge of the drainage channel constituent wall 64a with the inner wall surface of the upstream member 64. That is, the second backflow prevention wall 64b is provided at the same height as the lower end of the drainage channel constituent wall 64a. As a modification, the second backflow prevention wall 64b can also be provided at a position higher than the lower end of the drainage channel constituent wall 64a. By providing the second backflow prevention wall 64b, approximately half of the horizontal cross-section of the upstream member 64 is closed, making it difficult for the washing water flowing into the upstream member 64 from the inlet 30a to reach above the second backflow prevention wall 64b.

[0052] On the other hand, as shown in Figure 7, the wall-forming member 70 is a member fitted into the upper end of the upstream member 64, and by positioning the wall-forming member 70, four wall surfaces are formed inside the upstream member 64. Specifically, the wall-forming member 70 forms one wall surface that is generally oriented horizontally, and three wall surfaces that rise upward from this wall surface. The wall surface formed by the wall-forming member 70 that is generally oriented horizontally functions as the first backflow prevention wall 70a.

[0053] As shown in Figure 8, the first backflow prevention wall 70a is located below the vent 64d and directly below the overflow outlet 64c. By providing this wall, a large portion of the horizontal cross-section of the upstream member 64 is closed. It is preferable that the first backflow prevention wall 70a be installed at a height equal to or greater than the lower end of the drainage channel constituent wall 64a (the same height as or greater than the lower end of the drainage channel constituent wall 64a). As a result, even if the washing water flowing into the upstream member 64 from the inlet 30a splashes upward, it is less likely to reach above the first backflow prevention wall 70a. It is also preferable that the overflow outlet 64c be installed at a height equal to or greater than the first backflow prevention wall 70a and at a height equal to or greater than the lower end of the drainage channel constituent wall 64a.

[0054] Specifically, the first backflow prevention wall 70a extends from the side wall surface of the upstream member 64 on the side where the overflow outlet 64c is provided. On the other hand, the second backflow prevention wall 64b is located below the first backflow prevention wall 70a and extends from the side wall surface on the opposite side of the upstream member 64. In this way, the first backflow prevention wall 70a and the second backflow prevention wall 64b are arranged so that a portion of them overlaps when viewed from above. As a result, the path of the cleaning water flowing in from the drain trap pipe 14 to the overflow outlet 64c and vent 64d becomes very long, making it less likely for cleaning water to leak from the vent 64d.

[0055] Furthermore, as shown in Figure 8, the wall surface rising from the first backflow prevention wall 70a to cover the overflow outlet 64c functions as a valve seat forming wall 70b. This valve seat forming wall 70b rises from the first backflow prevention wall 70a in a direction slightly inclined with respect to the vertical. In addition, the other two wall surfaces 70c and 70d extend vertically on both sides of the valve seat forming wall 70b (Figure 7). Also, an upper end cap 70e is attached to the upper end of the upstream member 64 to close the opening at the upper end.

[0056] On the other hand, as shown in Figure 7, the downstream member 66 has a connecting portion 66a that connects to the upstream member 64 and a parallel flow channel portion 66b having a double-pipe structure. The connecting portion 66a opens vertically upward and is connected to the downstream end of the upstream member 64. The parallel flow channel portion 66b has a first flow channel portion 66c that communicates with the connecting portion 66a and a second flow channel portion 66d that extends parallel to the first flow channel portion 66c, and has a double-pipe structure that extends generally horizontally.

[0057] The first flow channel section 66c is in communication with the inside of the bowl section 12 via the connecting section 66a, the upstream member 64, and the drain trap pipe 14. Therefore, the parallel flow channel section 66b is provided downstream of the drain trap pipe 14, and the wastewater flowing out of the bowl section 12 flows through the first flow channel section 66c of the parallel flow channel section 66b and is discharged into the drain pipe (not shown). On the other hand, the second flow channel section 66d is formed above the first flow channel section 66c so as to surround it.

[0058] On the other hand, the water reservoir valve 68 is installed inside the drain socket 30 to open and close the pipe inside the drain socket 30, and by closing this valve, cleaning water can be stored downstream of the top 14c (Figure 2) of the drain trap pipe 14. In other words, the water reservoir valve 68 is a flapper valve installed at the bend of the downstream member 66, and by closing this valve, cleaning water can be stored upstream of the water reservoir valve 68. Specifically, the water reservoir valve 68 is mounted so as to be rotatable around a support shaft 68a that is oriented horizontally, and when it is oriented horizontally, the flow path inside the drain socket 30 is closed, and cleaning water can be stored inside the drain socket 30.

[0059] As shown in Figure 7, the valve seat forming member 71 is a cylindrical member fitted onto the lower end of the upstream member 64. This valve seat forming member 71 forms a flow path for the cleaning water at the lower part of the upstream member 64. That is, the cleaning water that flows into the drain socket 30 from the inlet 30a passes through the inside of the valve seat forming member 71 and flows into the downstream member 66. The lower end of the valve seat forming member 71 functions as a water reservoir valve seat 71a on which the water reservoir valve 68 sits. That is, when the water reservoir valve 68 is oriented in a substantially horizontal direction, the water reservoir valve 68 abuts against the lower end of the valve seat forming member 71 (water reservoir valve seat 71a), and the flow path in the drain socket 30 is closed.

[0060] Next, referring to Figure 9, we will explain the configuration for opening and closing the water reservoir valve 68 located inside the drain socket 30 in the event of a power outage or the like. Figure 9 is a perspective view showing the drain socket 30 and the power outage control mechanism connected thereto. As shown in Figure 9, a power outage operation mechanism 76 is connected to the lower side of the drain socket 30. The power outage operation mechanism 76 includes a water reservoir valve operating section 76a and an operating wire 76b attached to the water reservoir valve operating section 76a.

[0061] The water reservoir valve operating part 76a is a ring-shaped knob that hangs down from the base plate 40 attached to the bottom surface of the toilet bowl body 2. In the event of a power outage, the user can open and close the water reservoir valve 68 by pinching and pulling the water reservoir valve operating part 76a.

[0062] The operating wire 76b is a wire for transmitting the operating force from the user to the water reservoir valve 68. Specifically, the operating wire 76b consists of a sheath connecting the base plate 40 and the drain socket 30, and a flexible cable (not shown) passed through this sheath. When the user pulls the water reservoir valve operating part 76a, the cable (not shown) inside the sheath is pulled, and the operating force is transmitted to the drain socket 30. The cable (not shown) passed through the operating wire 76b is connected to the support shaft 68a of the water reservoir valve 68 outside the flow path of the drain socket 30.

[0063] As a result, when the water reservoir valve operating part 76a is pulled, the operating force is transmitted by a cable (not shown) to the support shaft 68a of the water reservoir valve 68, causing the water reservoir valve 68 to rotate. When no operating force is applied to the water reservoir valve operating part 76a, the water reservoir valve 68 is in the open state as shown in Figure 7. When the user pulls the water reservoir valve operating part 76a, the water reservoir valve 68 rotates to face horizontally and seats on the water reservoir valve seat 71a at the lower end of the valve seat forming member 71, closing it. When the user releases the water reservoir valve operating part 76a, the water reservoir valve 68 returns to the open state. In this way, the water reservoir valve 68 is opened and closed by the user's operation.

[0064] Furthermore, the power outage operation mechanism 76 includes a water supply operation unit 76c and an operation wire 76d attached to the water supply operation unit 76c. The water supply control unit 76c is a loop-shaped knob that hangs down from the base plate 40 attached to the bottom surface of the toilet bowl body 2. In the event of a power outage, the user can manually operate the water supply valve device 32 (Figure 4A) by pinching and pulling the water supply control unit 76c.

[0065] The operating wire 76d is a wire for transmitting the operating force from the user to the water supply valve device 32. Specifically, the operating wire 76d consists of a sheath connecting the base plate 40 and the water supply valve device 32 (Figure 4A), and a flexible cable (not shown) passed through this sheath. When the user pulls the water supply operating part 76c, the cable (not shown) inside the sheath is pulled, and the operating force is transmitted to the water supply valve device 32. The cable (not shown) passed through the operating wire 76d is connected to a solenoid valve (not shown) built into the water supply valve device 32, which can be operated manually.

[0066] Specifically, when the user pulls the water supply operation unit 76c once, the solenoid valve (not shown) opens, and cleaning water is supplied from the water supply valve device 32 to the cleaning water tank 42 via the tank water supply pipe 44 and the tank water supply unit 46 (Figure 4A). When the user pulls the water supply operation unit 76c again, the solenoid valve (not shown) closes, and the water supply from the water supply valve device 32 to the cleaning water tank 42 stops. In the event of a power outage, the user operates the water supply operation unit 76c to allow cleaning water to flow into the cleaning water tank 42, and intentionally causes the cleaning water to overflow from the cleaning water tank 42, thereby allowing the cleaning water to flow into the drain socket 30.

[0067] Next, referring to Figure 10, we will explain the configuration for storing flushing water in the drain socket 30 in order to manually flush the toilet during a power outage or the like. First, as shown in Figure 6, an overflow pipe connection chamber 72 is provided above the rear of the cleaning water tank 42. This overflow pipe connection chamber 72 is roughly cubic in shape and is configured to communicate watertightly with the internal space of the cleaning water tank 42. An overflow pipe 62 is watertightly connected to one side of the overflow pipe connection chamber 72.

[0068] Furthermore, as shown in Figure 10, a circular outlet hole 72a is provided on one side of the overflow pipe connection chamber 72, and the overflow water that flows out from this outlet hole 72a flows into the drain socket 30 via the overflow pipe 62. That is, when the cleaning water in the cleaning water tank 42 exceeds a predetermined water level, which is the height h of the lower end of the outlet hole 72a, the cleaning water in the cleaning water tank 42 flows out as overflow water into the overflow pipe 62. In the event of a power outage, etc., the user operates the water supply operation unit 76c to supply water from the water supply valve device 32 to the cleaning water tank 42, and intentionally causes the cleaning water to overflow from the cleaning water tank 42. The overflow water from the cleaning water tank 42 flows into the drain socket 30 via the overflow pipe 62 and is stored in the drain socket 30. Note that since the cleaning water tank 42 has a sealed structure, the cleaning water will not flow out of the cleaning water tank 42 until the water level in the cleaning water tank 42 exceeds the height h.

[0069] Furthermore, a descending pipe 74 is connected to the lower side of the overflow pipe connection chamber 72, extending vertically downward from the overflow pipe connection chamber 72. This descending pipe 74 is also watertightly connected to the bottom surface of the overflow pipe connection chamber 72, and the inside of the descending pipe 74 is in communication with the inside of the overflow pipe connection chamber 72. Therefore, when the water level in the cleaning water tank 42 rises, the water level in the descending pipe 74 also rises, and when the water level in the descending pipe 74 becomes higher than the bottom surface of the overflow pipe connection chamber 72, the cleaning water in the descending pipe 74 flows into the overflow pipe connection chamber 72.

[0070] Furthermore, the lower end of the descending pipe 74 extends to near the bottom surface of the cleaning water tank 42. On the other hand, a partition wall 42a is provided on the bottom surface of the cleaning water tank 42 so as to surround the lower end of the descending pipe 74. This partition wall 42a is formed to surround a part of the space inside the cleaning water tank 42. Therefore, even if the cleaning water inside the cleaning water tank 42 is sucked out by the pump device 34, as shown in Figure 10, the cleaning water in the space surrounded by the partition wall 42a remains inside the cleaning water tank 42.

[0071] Furthermore, since the upper end of the partition wall 42a is located above the lower end of the descending pipe 74, the lower end of the descending pipe 74 is always submerged in the cleaning water remaining inside the partition wall 42a. For this reason, although the internal space of the cleaning water tank 42 is in communication with the drain socket 30 via the overflow pipe 62, odors from the drainage piping (not shown) do not leak into the cleaning water tank 42 through the drain socket 30 and the overflow pipe 62.

[0072] Next, referring again to Figures 7 and 8, the mechanism for allowing overflow water to flow into the drain socket 30 will be explained. As shown in Figure 8, an overflow outlet 64c is provided on the upper side of the drain socket 30, and an overflow pipe 62 is connected to this overflow outlet 64c. Therefore, when cleaning water overflows from the cleaning water tank 42, the cleaning water flows into the drain socket 30 through the overflow pipe 62 and the overflow outlet 64c.

[0073] As mentioned above, a valve seat forming wall 70b is provided inside the drain socket 30 so as to cover the overflow outlet 64c. A valve opening 70f (Figure 7) is provided in this valve seat forming wall 70b so as to communicate with the overflow outlet 64c. A flapper valve 78, which is a valve mechanism, is attached to the valve seat forming wall 70b so as to open and close the valve opening 70f. As shown in Figure 8, the flapper valve 78 is rotatably attached to the valve seat forming wall 70b by a support shaft 78a which is generally oriented horizontally. Since the valve seat forming wall 70b is slightly inclined with respect to the vertical, when no overflow water is flowing, the flapper valve 78 sits on the valve opening 70f by its own weight and is in a closed state. When overflow water flows from the overflow pipe 62, the flapper valve 78 is opened by the water pressure.

[0074] As shown in Figure 8, the cleaning water that flows into the drain socket 30 from the overflow pipe 62 flows over the first backflow prevention wall 70a located directly below the overflow outlet 64c, and falls through the gap between the edge of the first backflow prevention wall 70a and the inner wall surface of the upstream member 64. The cleaning water that enters the gap between the edge of the first backflow prevention wall 70a and the inner wall surface of the upstream member 64 falls over the second backflow prevention wall 64b, and then falls from the edge of the second backflow prevention wall 64b towards the water reservoir on / off valve 68. In this way, the first backflow prevention wall 70a and the second backflow prevention wall 64b lengthen the path from the overflow outlet 64c to the bottom of the drain socket 30. Therefore, backflow of sewage and cleaning water that flows into the drain socket 30 from the drain trap pipe 14 to the overflow outlet 64c can be effectively suppressed.

[0075] On the other hand, as shown in Figure 8, a vent 64d is provided on the upper side of the drain socket 30, alongside the overflow outlet 64c. This vent 64d is located to the side of the overflow outlet 64c, higher than the center of the overflow outlet 64c. This vent 64d is opened and closed by a flapper valve 78, which is a valve mechanism, together with the valve port 70f of the overflow outlet 64c. Therefore, when no overflow water is flowing, the vent 64d is closed, and when overflow water flows, the vent 64d is opened. As a result, when overflow water flows and cleaning water enters the drain socket 30 from the overflow outlet 64c, any air that has been trapped inside the drain socket 30 is discharged through the vent 64d.

[0076] Furthermore, as shown in Figure 7, an air vent pipe 80 is connected to the vent port 64d. The other end of this air vent pipe 80 is connected to the second flow channel section 66d of the parallel flow channel section 66b. That is, the other end of the air vent pipe 80 extending from the vent port 64d is connected to a vent outlet 66e formed to communicate with the second flow channel section 66d, and the vent port 64d and the vent outlet 66e are in communication via the air vent pipe 80. Therefore, the air discharged through the vent port 64d flows into the second flow channel section 66d of the drain socket 30.

[0077] Furthermore, a vent outlet valve 82 is provided at the vent outlet 66e, which opens and closes the vent outlet 66e. When no air is being discharged, the vent outlet 66e is closed by its own weight, and when air is pushed out from the vent opening 64d, it is opened by the pressure of the air. In this way, since the vent outlet 66e is normally closed, odors from inside the drainage piping do not leak into the drain socket 30.

[0078] Next, the operation of the flush toilet 1 according to the first embodiment of the present invention will be described. First, when the user operates the remote control (not shown) to flush the toilet, the pump device 34 and the switching valve device 36 are activated, and the flushing water in the flushing water tank 42 is discharged from the rim outlet 22 and the jet outlet 26 according to a predetermined flushing sequence. As a result, the inside of the bowl 12 is flushed, and the waste and flushing water inside the bowl 12 flow into the drain socket 30 through the drain trap pipe 14.

[0079] The waste and washing water flowing into the drain socket 30 are guided downward by the drain channel component wall 64a and fall downward within the drain socket 30. At this time, any washing water that splashes up within the drain socket 30 is blocked by the second backflow prevention wall 64b and the first backflow prevention wall 70a, and does not substantially reach the overflow outlet 64c or vent 64d located at the top. The waste and washing water flowing into the drain socket 30 fill the flow path below the drain channel component wall 64a within the drain socket 30, inducing a siphon effect within the drain socket 30. Due to the siphon effect, the waste and washing water in the bowl section are drawn into the drain trap pipe 14. The waste and washing water flowing from the drain trap pipe 14 into the drain socket 30 are discharged into the drain piping (not shown) through the first flow path section 66c formed in the parallel flow path section 66b.

[0080] Here, although a vent 64d (Figure 8) is provided at the top of the drain socket 30, the vent 64d is closed by the flapper valve 78 during normal toilet flushing. Therefore, even after flushing water flows from the drain trap pipe 14 into the drain socket 30, any stagnant air remains inside the drain socket 30. As a result, an air pocket forms at the top of the drain socket 30, suppressing the rise in the water level inside the drain socket 30. This prevents backflow of flushing water to the overflow outlet 64c and the vent 64d. Furthermore, since the vent 64d is closed during normal toilet flushing, air is not drawn into the drain socket 30 from the vent 64d, and the siphon effect in the drain socket 30 is not inhibited or its duration substantially shortened by the intake of air.

[0081] Furthermore, when the toilet is flushed, the pump device 34 operates, drawing out the flushing water from the flushing water tank 42, causing the water level in the flushing water tank 42 to drop. However, the flushing water in the area enclosed by the partition wall 42a (Figure 8) inside the flushing water tank 42 remains in the tank. As a result, the lower end of the descending pipe 74 installed inside the flushing water tank 42 remains submerged, and even though the flushing water inside the flushing water tank 42 is being drawn out, odors do not enter the flushing water tank 42 from the drain socket 30 side through the overflow pipe 62.

[0082] When the toilet flushing is complete, the tank water supply unit 46 is activated, and flushing water supplied from the water supply flows into the flushing water tank 42. If the water level in the flushing water tank 42 rises above the specified level due to a malfunction of the tank water supply unit 46 or any other reason, and becomes higher than the specified level (height h of the lower end of the outlet hole 72a (Figure 10)), the flushing water flows out from the outlet hole 72a. The overflow water flows into the drain socket 30 through the overflow pipe 62 and the overflow outlet 64c (Figure 8), and is discharged into the drain piping (not shown) through the first flow path section 66c (Figure 7) of the drain socket 30. At this time, the flapper valve 78 provided at the overflow outlet 64c is opened by the force of the overflow water.

[0083] As a result, even if a malfunction occurs in the tank water supply unit 46 or the like, the flushing water will be discharged into the drainage pipe (not shown) without leaking into the toilet room. In addition, since sufficient flow path cross-sectional area is ensured in the overflow pipe 62 and overflow outlet 64c, even if a large flow rate of overflow water is generated, it can be discharged into the drainage pipe (not shown).

[0084] On the other hand, if a blockage occurs in the drainage pipe (not shown) for any reason, wastewater may flow from the drainage pipe to the drain socket 30. Even in such a case, since the overflow outlet 64c of the drain socket 30 is located at the upper end of the drain socket 30, backflow of wastewater into the overflow pipe 62 and the washing water tank 42 can be suppressed.

[0085] Next, with reference to Figure 11, the procedure for flushing a toilet during a power outage will be explained. Figure 11 is a cross-sectional view showing the state in which the water reservoir valve 68 is closed and flushing water is stored in the drain socket 30 in order to perform toilet flushing during a power outage.

[0086] During a power outage, the pump device 34 cannot be operated, making it impossible to discharge the cleaning water from the cleaning water tank through the rim outlet 22 or the jet outlet 26. Therefore, the user manually generates a siphon effect in the drain socket 30 to discharge the waste and cleaning water from the bowl section 12 into the drainage pipe (not shown).

[0087] First, in the event of a power outage, the user pulls the water reservoir valve operating part 76a (Figure 9) hanging from the bottom of the flush toilet bowl 1 to operate the water reservoir valve 68. That is, by pulling the water reservoir valve operating part 76a, the water reservoir valve 68 inside the drain socket 30 is rotated to the closed state shown in Figure 11. In other words, the water reservoir valve 68 is rotated and seated on the water reservoir valve seat 71a of the valve seat forming member 71, thereby closing the water reservoir valve 68.

[0088] Next, the user pulls the water supply operation part 76c (Figure 9) hanging from the bottom of the flush toilet 1 to activate the tank water supply unit 46. That is, by pulling the water supply operation part 76c, the solenoid valve (not shown) provided in the water supply valve device 32 (Figure 4A) is manually operated and opened. As a result, flushing water is supplied from the water supply valve device 32 to the flushing water tank 42 via the tank water supply pipe 44 and the tank water supply unit 46 (Figure 4A). When the flush toilet 1 is in standby mode, flushing water is stored in the flushing water tank 42 up to a specified level, but when water supply to the flushing water tank 42 is started, the water level in the flushing water tank 42 rises further.

[0089] Then, when the water level in the cleaning water tank 42 exceeds the height h (Figure 10) of the lower end of the outlet hole 72a, the cleaning water in the cleaning water tank 42 flows into the drain socket 30 through the outlet hole 72a, the overflow pipe 62, and the valve opening 70f. In this way, during a power outage, cleaning water is intentionally made to overflow from the cleaning water tank 42 and flow into the drain socket 30. The flapper valve 78 provided at the valve opening 70f is opened by the force of the overflowing cleaning water. At the same time, the vent 64d provided adjacent to the valve opening 70f is also opened.

[0090] The cleaning water flowing into the drain socket 30 bypasses the first backflow prevention wall 70a and the second backflow prevention wall 64b and flows downwards into the drain socket 30. Since the water reservoir valve seat 71a is closed by the water reservoir valve 68, the cleaning water that overflows from the cleaning water tank 42 is collected on the water reservoir valve 68 inside the drain socket 30, as shown in Figure 11. Meanwhile, the air that was trapped inside the drain socket 30 flows out through the vent port 64d because the vent port 64d is open. The air that flows out from the vent port 64d flows through the air vent pipe 80 and out into the drain piping from the vent outlet 66e (Figure 7) provided in the second flow path section 66d. The vent outlet valve 82 provided in the vent outlet 66e is opened by the air being pushed out from the vent outlet 66e.

[0091] Thus, since the drain socket 30 is provided with a vent 64d, any air trapped inside the drain socket 30 is discharged, and the storage of cleaning water in the drain socket 30 is not hindered. In other words, if the vent 64d is not provided and the air inside the drain socket 30 cannot be discharged, an air pocket will form at the top of the drain socket 30, and a sufficient amount of cleaning water cannot be stored inside the drain socket 30. In this case, the cleaning water that flows into the drain socket 30 will flow through the drain trap pipe 14 and into the bowl section 12, causing the water level in the bowl section 12 to rise significantly.

[0092] When the water level in the bowl section 12 rises significantly, the user may become anxious that the cleaning water will overflow from the bowl section 12 and release the water reservoir valve operating section 76a before sufficient cleaning water (overflow water) has accumulated in the drain socket 30 and the bowl section 12. In this way, if the water reservoir valve operating section 76a is released before sufficient cleaning water has accumulated, and the water reservoir on / off valve 68 is opened, a sufficient siphon action cannot be induced in the drain socket 30. As a result, the cleaning water and waste in the bowl section 12 cannot be discharged into the drainage pipe.

[0093] In contrast, the flush toilet 1 of this embodiment is provided with a vent 64d, which allows air that has been trapped in the drain socket 30 to be discharged. As a result, a sufficient amount of flushing water can be stored in the drain socket 30 without significantly raising the water level in the bowl 12. Therefore, the user can fill the drain socket 30 and the bowl 12 with sufficient flushing water without feeling any anxiety.

[0094] Once a sufficient amount of flushing water has accumulated, the user releases the water reservoir valve operating section 76a, opening the water reservoir shut-off valve 68. This causes the flushing water accumulated above the water reservoir shut-off valve 68 to fall all at once, inducing a siphon effect within the drain socket 30. As a result, the flushing water and waste in the bowl section 12 are drawn into the drain trap pipe 14 and discharged into the drain pipe (not shown). Next, the user pulls the water supply operating section 76c (Figure 9) again to close the solenoid valve (not shown) provided in the water supply valve device 32 (Figure 4A). This stops the supply of flushing water from the water supply valve device 32 to the flushing water tank 42, completing one toilet flush.

[0095] In the example described above, the user released the water reservoir valve operating section 76a to open the water reservoir valve 68 while the water supply from the water supply valve device 32 was continuing. However, before opening the water reservoir valve 68, the user may pull the water supply operating section 76c (Figure 9) to stop the supply of cleaning water. By stopping the supply of cleaning water to the drain socket 30 in this way, the flapper valve 78 closes the valve opening 70f and the vent opening 64d. Therefore, when the user releases the water reservoir valve operating section 76a to open the water reservoir valve 68, the vent opening 64d can be kept closed, making the siphon effect generated in the drain socket 30 stronger.

[0096] Furthermore, in the example described above, the water reservoir valve operating unit 76a was operated first to close the water reservoir valve 68, and then the water supply operating unit 76c was operated to start supplying cleaning water to the drain socket 30. However, after starting to supply cleaning water to the drain socket 30, the water reservoir valve operating unit 76a may also be operated to close the water reservoir valve 68.

[0097] In the flush toilet 1 of the first embodiment of the present invention, the overflow outlet 64c of the overflow pipe 62, which is an overflow passage, is formed above the lower end of the drain passage component wall 64a of the drain socket 30, so that flush water flowing from the drain trap pipe 14 into the drain socket 30 can be prevented from entering the overflow outlet 64c.

[0098] Furthermore, according to the flush toilet 1 of this embodiment, since the first backflow prevention wall 70a is provided below the overflow outlet 64c and at a height above the lower end of the drainage channel configuration wall 64a, it is possible to prevent flush water that has splashed upward inside the drain socket 30 from reaching the vent 64d, and the risk of flush water entering the overflow outlet 64c can be further reduced.

[0099] Furthermore, according to the flush toilet 1 of this embodiment, the overflow outlet 64c of the overflow pipe 62, which is the overflow passage, is provided at a height greater than or equal to the lower end of the first backflow prevention wall 70a and the drain passage constituent wall 64a of the drain socket 30, so the risk of flush water flowing in from the drain trap pipe 14 backflowing into the overflow pipe 62 can be sufficiently reduced.

[0100] Furthermore, according to the flush toilet 1 of this embodiment, a second backflow prevention wall 64b is provided inside the drain socket 30 below the first backflow prevention wall 70a and at a height above the lower end of the drain channel constituent wall 64a, and the first backflow prevention wall 70a and the second backflow prevention wall 64b are arranged so that a portion of them overlaps when viewed from above. As a result, the path of the flush water flowing in from the drain trap pipe 14 to the overflow outlet 64c becomes very long, and the risk of flush water entering the overflow outlet 64c can be further reduced.

[0101] Furthermore, according to the flush toilet 1 of this embodiment, a flapper valve 78, which is a valve mechanism capable of closing the vent 64d, is provided inside the drain socket 30, so that flushing water can be reliably prevented from entering the vent 64d.

[0102] Next, a flush toilet according to a second embodiment of the present invention will be described with reference to Figure 12. The flush toilet of this embodiment differs from the first embodiment described above mainly in the structure of the backflow prevention wall provided inside the drain socket. Therefore, below, only the differences between the second embodiment of the present invention and the first embodiment described above will be explained, and similar configurations, operations, and effects will not be described. Figure 12 is a perspective cross-sectional view showing the drain socket provided in the flush toilet of this embodiment. Note that Figure 12 is shown with the upper end cap (not shown) attached to the upper end of the drain socket removed.

[0103] As shown in Figure 12, the drain socket 90 provided in the flush toilet of this embodiment has an inlet portion 90a connected to the drain trap pipe 14 and a drain pipe connection portion 90b connected to the drain pipe. Inside the drain socket 90, a water reservoir valve 92 is arranged which is configured to open and close the pipe inside the drain socket 90.

[0104] Furthermore, the drain socket 90 is provided with a semi-dome-shaped drainage channel wall 94a that collides with and guides at least a portion of the cleaning water flowing in from the drain trap pipe 14 downwards. In addition, an overflow outlet 94b is provided on one side wall surface of the upper part of the drain socket 90, which allows overflow water from the cleaning water tank to flow into the drain socket 90.

[0105] Furthermore, a first backflow prevention wall 96 and a second backflow prevention wall 98 are provided inside the drain socket 90. The first backflow prevention wall 96 is a wall surface that extends substantially horizontally to connect the lower end of the drainage channel configuration wall 94a with the inner wall surface of the drain socket 90. In this embodiment, the first backflow prevention wall 96 is configured to block approximately half of one side of the drain socket 90 in the width direction.

[0106] The second backflow prevention wall 98 is a wall surface that extends upward from the upper surface of the drainage channel constituent wall 94a and is generally oriented vertically. The second backflow prevention wall 98 extends in the front-rear direction from the center of the width direction of the drainage socket 90 and is formed up to the upper end of the drainage socket 90.

[0107] The overflow outlet 94b, which allows overflow water to flow in from the overflow channel, is positioned above the first backflow prevention wall 96 and opposite the second backflow prevention wall 98. That is, the horizontal projection plane 94c of the overflow outlet 94b is included in the second backflow prevention wall 98. Therefore, almost all of the cleaning water that flows into the drain socket 90 from the overflow outlet 94b collides with the second backflow prevention wall 98 above the first backflow prevention wall 96. The cleaning water then bypasses the rear end edge 98a of the second backflow prevention wall 98 and falls downward from the edge 96a of the first backflow prevention wall 96.

[0108] As described above, in this embodiment, a first backflow prevention wall 96 and a second backflow prevention wall 98 are provided inside the drain socket 90, and the path from the inlet 90a to the overflow outlet 94b is lengthened. As a result, backflow of cleaning water and waste that flows in from the drain trap pipe 14 to the overflow outlet 94b is suppressed. In addition, since the second backflow prevention wall 98 is provided facing the overflow outlet 94b, it is possible to suppress cleaning water splashing inside the drain socket 90 from entering the overflow outlet 94b.

[0109] In the first embodiment described above, a flapper valve 78 was provided to open and close the overflow outlet 64c and the vent 64d. In contrast, in this embodiment, the flapper valve (not shown), which is a valve mechanism, is provided near the wash water tank. Since this flapper valve opens and closes the valve port and vent (not shown) of the overflow water, in this embodiment, the overflow outlet 64c also functions as a vent (not shown).

[0110] According to the flush toilet of the second embodiment of the present invention, the second backflow prevention wall 98 provided inside the drain socket 90 is provided facing the overflow outlet 64c and including the projection plane of the overflow outlet 94b, so that the risk of flush water splashing inside the drain socket 90 entering the overflow outlet 64c can be further reduced.

[0111] Although embodiments of the present invention have been described above, various modifications can be made to the embodiments described above. In particular, in the embodiments described above, in the event of a power outage, etc., cleaning water was accumulated in the drain socket by directly overflowing cleaning water from the cleaning water tank into the drain socket. In contrast, as a modification, the present invention can also be configured so that cleaning water flows into the bowl section and the cleaning water that flows into the drain socket via the drain trap pipe is accumulated.

[0112] Furthermore, in the embodiments described above, an air vent pipe was connected to the vent, and the vent was connected to the parallel flow path of the drain socket. However, the present invention can also be configured so that the vent is connected to another location in the drain socket. In addition, the vent only needs to be able to discharge air that has accumulated upstream of the water reservoir valve of the drain socket, and an air vent pipe does not need to be connected. [Explanation of symbols]

[0113] 1 flush toilet 2 Flush toilet body 2a Bottom opening 4 Tank equipment 6. Sanitary cleaning equipment 8. Shut-off valve 10 Water supply pipe 12 Bowl section 14 Drain trap pipe 14a Entrance 14b Ascent conduit 14c top 14d Rear conduit 16 Skirt section 18 Waste receiving surface 20 Rim section 22 Rim spout 24 Rim water conduit 26 Jet nozzle 28. Jet water conduit 30 Drain sockets 30a Entrance 30b Drainage pipe connection 32 Water supply valve device 34 Pumping equipment 36. Switching valve device 38 Control device 40 base plate 42 Washing water tank 42a Partition wall 44 Water supply pipe for tank 46 Tank water supply unit 48 Float switch 50 Fixing member 52 Water supply pipe for sanitary cleaning equipment 54 Upstream connecting pipe 56 Downstream connecting pipe 58 Rim water supply pipe 60 Water supply pipe for jet 62 Overflow pipe (overflow channel) 64 Upstream member 64a Drainage channel configuration wall 64b Second backflow prevention wall 64c Overflow Outlet 64d Ventilation 66 Downstream member 66a Connection part 66b Parallel channel section 66c First channel section 66d Second channel section 66e Ventilation Outlet 68 Water reservoir shut-off valve 68a spindle 70 Wall forming member 70a First backflow prevention wall 70b Valve seat forming wall 70c wall 70d wall surface 70e Top cap 70f valve opening 71 Valve seat forming member 71a Water reservoir valve seat 72 Overflow pipe connection chamber 72a Outflow hole 74 Downcomer 76 Power outage operation mechanism 76a Water sump valve operation part 76b Operating wire 76c Water supply operation section 76d Operating wire 78. Flapper valve (valve mechanism) 78a spindle 80 Air vent pipe 82 Ventilation outlet valve 90 Drain socket 90a Entrance 90b Drainage pipe connection 92 Water reservoir shut-off valve 94a Drainage channel configuration wall 94b Overflow exit 94c projection surface 96 First backflow prevention wall 96a Edge 98 Second backflow prevention wall 98a Rear edge

Claims

1. A flush toilet that uses flushing water to discharge waste, It has a bowl section that collects water and also receives waste, A cleaning water tank for storing cleaning water to clean this bowl section, A drain trap pipe comprising an inlet connected to the lower part of the bowl section, and an upward pipe extending from this inlet to the top located above and behind, A drain socket is provided on the downstream side of this drain trap pipe, When the water level in the above-mentioned cleaning water tank rises above a predetermined level, an overflow channel is provided to cause the cleaning water in the above-mentioned cleaning water tank to overflow, The drainage channel configuration wall is formed inside the drain socket upstream of the water reservoir opening valve, so as to cause at least a portion of the cleaning water flowing in from the drain trap pipeline to collide and be guided downward, A flush toilet characterized in that the overflow outlet of the overflow channel described above is formed above the lower end of the drainage channel component wall of the drain socket described above.

2. The flush toilet according to claim 1, wherein a first backflow prevention wall is provided inside the drain socket to prevent backflow of flushing water to the overflow outlet, below the overflow outlet and at a height greater than or equal to the lower end of the drainage channel configuration wall.

3. The flush toilet according to claim 2, wherein the overflow outlet of the overflow channel is provided at a height greater than or equal to the lower end of the first backflow prevention wall and the drain channel constituent wall of the drain socket.

4. A second backflow prevention wall is provided inside the drain socket to prevent backflow of flushing water to the overflow outlet, and this second backflow prevention wall is provided below the first backflow prevention wall and at a height above the lower end of the drain channel configuration wall, and the first backflow prevention wall and the second backflow prevention wall are arranged so that a portion of them overlap when viewed from above, as described in claim 2.

5. The flush toilet according to claim 2, wherein a second backflow prevention wall is provided inside the drain socket to prevent backflow of flushing water to the overflow outlet, and this second backflow prevention wall is provided facing the overflow outlet and including the projected surface of the overflow outlet.

6. Furthermore, a water-retaining valve is configured to open and close the pipe within the drain socket so as to accumulate cleaning water downstream of the top of the drain trap pipe, To discharge the air trapped in the drain trap pipeline, a vent is formed in the drain socket above the lower end of the drain channel configuration wall, A flush toilet according to claim 1, having the following features.

7. The toilet according to claim 6, wherein a valve mechanism capable of closing the vent is provided inside the drain socket, and the vent is closed by the valve mechanism when the toilet is flushed.

Images