Water-washable toilet

Abstract

To provide a flush toilet that allows users to easily and thoroughly flush the toilet bowl even during power outages, and that can generate a stable siphon action. [Solution] The present invention relates to a flush toilet (1), comprising a bowl (12), a drain trap pipe (14), a water-retaining on / off valve (68) configured to open and close the outlet (30b) of the drain trap pipe so as to retain flushing water downstream of the top (14c) of the drain trap pipe, and an intake / exhaust control mechanism for controlling the discharge of air stagnant in the drain trap pipe. The intake / exhaust control mechanism is characterized in that, when the water-retaining on / off valve is closed and flushing water is retained in the drain trap pipe, air can be discharged from a vent inlet (64d) provided in the drain trap pipe, while when the water-retaining on / off valve is opened so as to discharge the retained water and waste in the bowl, air cannot be drawn into the drain trap pipe from the vent inlet.

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 Application Laid-Open No. 2013-227852 (Patent Document 1) describes a flush toilet. In order to enable toilet washing even during a power outage or the like, an opening / closing means is provided in the drain socket. When performing toilet washing during a power outage, washing water is supplied to the bowl portion with the opening / closing means closed to raise the water level in the bowl portion, and in this state, the opening / closing means is opened to generate a siphon action in the drain trap pipe. As a result, the washing water in the bowl portion is discharged together with the dirt through the drain trap pipe to the drain pipe, and toilet washing can be performed.

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, when flushing water is supplied to the bowl with the opening / closing mechanism closed, there is no escape route for the air trapped in the drain trap pipe, and a large amount of air remains in the drain trap pipe. Therefore, in the flush toilet described in Patent Document 1, even when flushing water is supplied to the bowl, a large air pocket is actually formed in the drain trap pipe, and it is not possible to fill the drain trap pipe to a near-full state. As a result, when the amount of flushing water necessary to generate the siphon effect flows into the bowl, the water level in the bowl becomes very high, which causes anxiety to the user. Alternatively, because the water level in the bowl becomes high, the user becomes anxious and opens the opening / closing mechanism before the necessary amount of flushing water has accumulated in the bowl, resulting in insufficient flushing. Furthermore, in the flush toilet described in Patent Document 1, since the opening / closing mechanism is opened and the siphon effect is generated with a large amount of air remaining in the drain trap pipe, the generated siphon effect is unstable, and there is also the problem that sufficient waste discharge capacity cannot be obtained.

[0005] Therefore, the present invention aims to provide a flush toilet that allows users to easily and sufficiently flush the toilet bowl even during power outages, and that can generate a stable siphon action. [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 drain trap pipe comprising an inlet connected to the lower part of the bowl portion, an ascending pipe extending from the inlet to a top portion located above and behind, and a descending pipe extending from the top portion to an outlet portion located below and behind; a water-retaining on / off valve configured to open and close the outlet portion of the drain trap pipe so as to store flushing water downstream of the top portion of the drain trap pipe; and an intake and exhaust control mechanism for controlling the discharge of air stagnant in the drain trap pipe, wherein the intake and exhaust control mechanism is characterized in that, when the water-retaining on / off valve is closed and flushing water is stored in the drain trap pipe, air can be discharged from a ventilation inlet provided in the drain trap pipe, while when the water-retaining on / off valve is opened so as to discharge the water and waste in the bowl portion, air cannot be drawn into the drain trap pipe from the ventilation inlet.

[0007] According to the present invention configured as described above, a water-retaining valve is provided to open and close the outlet of the drain trap pipe in order to accumulate cleaning water in the drain trap pipe. Therefore, in the event of a power outage, etc., by closing the water-retaining valve, allowing cleaning water to flow into the drain trap pipe, and then opening the water-retaining valve, a siphon effect can be generated within the drain trap pipe. This allows the waste and accumulated water in the bowl to be discharged. Furthermore, according to the present invention configured as described above, when the water-retaining valve is closed and cleaning water is accumulated in the drain trap pipe, the intake and exhaust control mechanism enables the discharge of air from the vent inlet provided in the drain trap pipe. Therefore, the air that has been stagnant in the drain trap pipe can be discharged through the vent inlet, and the inflow of cleaning water into the drain trap pipe is not obstructed by the stagnant air, allowing a large amount of cleaning water to flow into the drain trap pipe. As a result, a siphon effect can be generated within the drain trap pipe when the water-retaining valve is opened without excessively raising the water level in the bowl. On the other hand, when the water retention valve is opened to discharge the water and waste in the bowl, the intake and exhaust control mechanism prevents air from being drawn into the drain trap pipe from the vent inlet. Therefore, it is less likely to cause siphon disruption due to air being drawn into the drain trap pipe, and the generated siphon effect can be maintained for a relatively long time. As a result, the waste discharge performance when using the water retention valve can be improved.

[0008] Preferably, the present invention further includes an air vent pipe, one end of which is connected to an air inlet, and the other end of this air vent pipe is connected to an air outlet provided in the drainage channel downstream of the water reservoir opening / closing valve.

[0009] With the present invention configured in this way, since the other end of the air vent pipe is connected to a vent outlet provided in the drainage channel downstream of the water retention valve, air containing odors that has been stagnant in the drain trap pipeline can be discharged into the drainage channel, and odor leakage can be reliably prevented.

[0010] In the present invention, preferably, the vent outlet is located adjacent to a water-retaining on / off valve that closes the outlet of the drain trap pipe.

[0011] According to the present invention configured in this way, since the vent outlet to which the other end of the air vent pipe is connected is located adjacent to the water reservoir valve, when the water reservoir valve is opened, the cleaning water flowing through the water reservoir valve blocks the vent outlet of the air vent pipe, thereby suppressing the intake of air from the vent outlet.

[0012] In the present invention, preferably, the ventilation outlet is configured to be closed in conjunction with the opening of the water reservoir valve.

[0013] According to the present invention configured in this way, the vent outlet of the air vent pipe is configured to be closed in conjunction with the opening of the water reservoir valve, so when the water reservoir valve is opened, it is possible to prevent air from being drawn in from the vent outlet and flowing into the drain trap pipe through the vent inlet.

[0014] In the present invention, preferably, the water reservoir valve is a flapper valve, and the vent outlet is provided near the support shaft that rotatably supports the flapper valve.

[0015] With the present invention configured in this way, since the ventilation outlet is provided near the support shaft that rotatably supports the flapper valve constituting the water reservoir valve, a mechanism that opens and closes the ventilation outlet in conjunction with the opening and closing of the water reservoir valve can be easily constructed.

[0016] In the present invention, preferably, the water reservoir opening / closing valve is a flapper valve, and the vent outlet is provided in a position opposite to the opened flapper valve and is closed by the flapper valve.

[0017] According to the present invention configured in this way, the ventilation outlet is provided in a position opposite to the opened flapper valve, and the ventilation outlet is closed by the flapper valve, so that the opening of the flapper valve and the closing of the ventilation outlet can be achieved simultaneously with a simple mechanism.

[0018] In the present invention, preferably, the vent outlet is provided on the inclined wall surface of the drainage channel downstream of the water retention valve.

[0019] According to the present invention configured in this manner, since the vent outlet is provided on the inclined wall surface of the drainage channel downstream of the water retention valve, even when the vent outlet is provided on the wall surface of the drainage channel, dirt is less likely to accumulate at the vent outlet, and problems caused by clogging of the vent outlet can be suppressed.

[0020] In the present invention, preferably, the present invention further includes a cleaning water tank for storing cleaning water for cleaning the bowl section, and an overflow channel that causes the cleaning water in the cleaning water tank to overflow when the water level in the cleaning water tank rises above a predetermined water level. The overflow outlet of the overflow channel is provided to communicate with the drain trap pipe upstream of the outlet of the drain trap pipe, and the intake and exhaust control mechanism is a flapper valve that opens and closes the overflow outlet and the vent inlet, and is configured to open the vent inlet when cleaning water is flowing out from the overflow outlet.

[0021] In the present invention configured as described above, the outlet of the overflow channel that overflows the cleaning water from the cleaning water tank is provided to communicate with the drain trap pipe. Therefore, by overflowing the cleaning water from the cleaning water tank with the water retention valve closed, cleaning water can be stored in the drain trap pipe. Thus, without providing a special water supply means, cleaning water can be stored in the drain trap pipe by using the same water supply mechanism for storing cleaning water in the cleaning water tank.

[0022] Further, according to the present invention configured as described above, since the overflow outlet and the ventilation inlet are opened and closed by the flapper valve, by flowing the washing water from the overflow outlet into the drain trap pipe, the ventilation inlet can be opened simultaneously. As a result, when storing the washing water in the drain trap pipe, the air in the drain trap pipe can be automatically discharged through the ventilation inlet. Also, when the water supply to the drain trap pipe is stopped, the ventilation inlet is automatically closed, so when discharging the stored water and dirt in the bowl portion, the inhalation of air from the ventilation inlet can be blocked, and the breakage of the siphon due to the inhalation of air can be suppressed. Furthermore, when the water level in the drain trap pipe rises abnormally due to clogging of the drain pipe or the like, the overflow outlet is closed by the flapper valve, and the backflow of the washing water from the drain trap pipe to the washing water tank can be prevented. Also, in a state where no washing water is supplied from the overflow outlet, since the ventilation inlet is blocked by the flapper valve, pests and the like can be prevented from entering through the ventilation inlet from the drain pipe.

[0023] In the present invention, preferably, further, there is an air vent pipe having one end connected to the ventilation inlet, and a ventilation outlet valve for opening and closing this is provided at the ventilation outlet to which the other end of the air vent pipe is connected, to block the inhalation of air into the air vent pipe.

[0024] According to the present invention configured as described above, since the other end of the air vent pipe having one end connected to the ventilation inlet is connected to the ventilation outlet, and a ventilation outlet valve for opening and closing this ventilation outlet is provided, even when water supply to the drain trap pipe is performed and the flapper valve is open, the inhalation of air from the ventilation inlet into the drain trap pipe can be blocked. As a result, even when the on-off valve for water storage is opened during the water supply to the drain trap pipe, the inhalation of air from the ventilation inlet is blocked, and the breakage of the siphon due to the inhalation of air can be prevented.

[0025] In the present invention, preferably, further, an air vent pipe having one end connected to an air inlet, and a parallel flow path portion provided on the downstream side of the outlet portion of the drain trap pipe so as to be connected to an existing drain pipe are provided. The inner pipe of the parallel flow path portion communicates with the outlet portion, and the air vent outlet to which the other end of the air vent pipe is connected is provided outside the inner pipe and inside the outer pipe of the parallel flow path portion.

[0026] According to the present invention configured as described above, since the parallel flow path portion is provided on the downstream side of the outlet portion of the drain trap pipe, the drainage of the flush toilet can be connected to the existing thick drain pipe. Further, since the air vent outlet to which the other end of the air vent pipe is connected is provided outside the inner pipe and inside the outer pipe of the parallel flow path portion, the air containing the odor remaining in the drain trap pipe can be discharged to the drain pipe, and the leakage of the odor can be reliably prevented.

Effect of the Invention

[0027] According to the flush toilet of the present invention, even during a power outage or the like, the user can easily perform sufficient toilet cleaning, and a stable siphon action can be generated.

Brief Description of the Drawings

[0028] [Figure 1] It is a perspective view showing a flush toilet according to a first embodiment of the present invention. [Figure 2] It is a top view of the flush toilet according to the first embodiment of the present invention with the sanitary cleaning device removed. [Figure 3] It is a side cross-sectional view of the flush toilet according to the first embodiment of the present invention cut along line III-III in FIG. 2. [Figure 4A] It is a perspective view of the functional device of the flush toilet according to the first embodiment of the present invention viewed obliquely from above on the left side. [Figure 4B] It is a perspective view of the functional device of the flush toilet according to the first embodiment of the present invention viewed obliquely from above on the right side. [Figure 5] It is a block diagram showing a water supply path through which the washing water of the flush toilet according to the first embodiment of the present invention flows. [Figure 6] This is a perspective view showing the drain socket and flushing water tank removed from a flush toilet according to the first embodiment of the present invention. [Figure 7] This is a perspective cross-sectional view showing the internal structure of a flush toilet according to the first embodiment of the present invention, with the drain socket cut in the front-to-back direction of the flush toilet. [Figure 8] This is a perspective cross-sectional view showing the internal structure of a flush toilet according to the first embodiment of the present invention, with the drain socket cut in the width direction of the flush toilet. [Figure 9] This is a perspective view showing a configuration for opening and closing a water-retaining valve provided inside the drain socket in a flush toilet according to the first embodiment of the present invention. [Figure 10] This is a cross-sectional view of a flushing water tank showing the connection structure between the flushing water tank and the drain socket in a flush toilet according to the first embodiment of the present invention. [Figure 11] This is a cross-sectional view showing a flush toilet according to the first embodiment of the present invention, in which flushing water is stored in the drain socket in order to perform toilet flushing during a power outage. [Figure 12] This is a perspective cross-sectional view showing the internal structure of a flush toilet according to a second embodiment of the present invention, with the drain socket cut in the front-to-back direction of the flush toilet. [Figure 13] This is a perspective cross-sectional view showing the internal structure of a flush toilet according to a second embodiment of the present invention, with the drain socket cut in the width direction of the flush toilet. [Figure 14] This is a cross-sectional view of a flush toilet according to a third embodiment of the present invention, showing the drain socket cut in the front-to-back direction of the flush toilet. [Figure 15] This is a cross-sectional view of a flush toilet according to a fourth embodiment of the present invention, showing the drain socket cut in the front-to-back direction of the flush toilet. [Modes for carrying out the invention]

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] In this embodiment, the drain trap pipe 14 consists of a ceramic inlet 14a, an upward pipe 14b, and a rear pipe 14d, which are formed as part of the toilet bowl body 2, and a downward pipe 30a, which is formed as a flow path within the drain socket 30 connected to the rear pipe 14d. That is, in this embodiment, the flow path within the resin drain socket 30 constitutes part of the drain trap pipe 14. Thus, in this embodiment, the drainage channel that discharges the waste and flushing water from the bowl portion 12 to the drainage pipe (not shown) is composed of an upward pipe 14b, a rear pipe 14d, and a drain socket 30 provided in the toilet bowl body 2.

[0037] The inlet 14a is connected to the lower part of the bowl section 12, and the rising pipe 14b extends upward from the inlet 14a, with the highest point of the rising pipe 14b being the top 14c which defines the water level. The rear pipe 14d extends almost horizontally backward from the top 14c. Furthermore, the internal flow path of the drain socket 30 connected downstream of the rear pipe 14d forms a descending pipe 30a that extends downward from the top 14c, and the lower end of this descending pipe 30a is the outlet 30b of the drain trap pipe 14. In other words, the descending pipe 30a extends from the top 14c to the outlet 30b which is located downward and backward. The downstream end of the drain socket 30 is connected to a drain pipe (not shown) inside the wall W.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] As shown in Figure 6, the drain socket 30 is connected to the highest part of the flush 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 flush water tank 42 to the overflow outlet 64c provided in the drain socket 30. Furthermore, the drain socket 30 has an inlet 30c that opens toward the front of the flush toilet 1 and a drain pipe connection 30d that opens toward the rear. Overall, the drain socket 30 has a generally crank-shaped passage, and the upper inlet 30c and the lower drain pipe connection 30d are connected by a descending pipe 30a of the drain trap pipe 14 that extends generally vertically.

[0054] The inlet portion 30c of the drain socket 30 is connected to the toilet body 2 by receiving the rear pipe 14d (Figure 3) of the drain trap pipe 14. On the other hand, the drain pipe connection portion 30d is connected to the drain pipe (not shown) by being received into the drain pipe for discharging flushing water and waste. In this embodiment, waste and flushing water in the bowl portion 12 are discharged to the drain pipe (not shown) by the drainage channel formed by the rising pipe 14b, the rear pipe 14d, and the drain socket 30 provided in the toilet body 2.

[0055] As shown in Figure 7, the drain socket 30 includes an upstream member 64 with an inlet portion 30c, a downstream member 66 with a drain pipe connection portion 30d, and a water reservoir valve 68. Here, the water reservoir valve 68 is configured to open and close the outlet portion 30b of the drain trap pipe 14. That is, a descending pipe 30a of the drain trap pipe 14 is formed inside the drain socket 30, and the outlet portion 30b at the lower end of this descending pipe 30a is opened and closed by the water reservoir valve 68.

[0056] 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. The function of the water reservoir valve 68 and the flushing procedure in the event of a power outage will be described later.

[0057] The upstream member 64 is a cylindrical member that extends generally vertically, and is provided with an inlet portion 30c 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 ventilation inlet 64d are provided on the upper part of one side of the upstream member 64.

[0058] As shown in Figure 7, the inlet portion 30c is a cylindrical part provided on the upstream member 64 so as to protrude horizontally forward, and the inside of the inlet portion 30c is in communication with the internal space of the upstream member 64. As a result, the rear pipe 14d of the drain trap pipe 14 connected to the inlet portion 30c is in communication with the internal space of the upstream member 64 (downward pipe 30a).

[0059] 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 30c. 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 30c into the upstream member 64 collide with it and are guided downward. The ventilation inlet 64d is provided above the lower end of the drainage channel wall 64a.

[0060] 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. 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 30c to reach above the second backflow prevention wall 64b.

[0061] 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.

[0062] As shown in Figure 8, the first backflow prevention wall 70a is located below the ventilation inlet 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 blocked. As a result, even if the cleaning water flowing into the upstream member 64 from the inlet 30c splashes upward, it is less likely to reach above the first backflow prevention wall 70a.

[0063] 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 the vent inlet 64d becomes very long, making it less likely for cleaning water to leak from the vent inlet 64d.

[0064] 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.

[0065] 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 section 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 section 66b has a first flow channel section 66c, which is an inner pipe communicating with the connecting portion 66a, and a second flow channel section 66d, which is an outer pipe extending parallel to the first flow channel section 66c, and has a double-pipe structure that extends generally horizontally.

[0066] The first flow channel section 66c is in communication with the inside of the bowl section 12 via the drain trap pipe 14. Therefore, the parallel flow channel section 66b is provided downstream of the drain trap pipe 14, and 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.

[0067] On the other hand, the water reservoir valve 68 is installed inside the drain socket 30 to open and close the outlet portion 30b of the descending pipe 30a formed inside the drain socket 30. By closing this valve, cleaning water can be stored downstream of the top portion 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 oriented horizontally, and when it is oriented horizontally, the outlet portion 30b of the descending pipe 30a, which constitutes part of the drain trap pipe 14, is closed.

[0068] 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 30c 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 constitutes the outlet 30b of the descending pipe 30a, and the water reservoir valve 68 is seated at this outlet 30b, closing the outlet 30b. 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 (outlet 30b) of the valve seat forming member 71, closing the flow path within the drain socket 30.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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 outlet portion 30b 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] As described 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 is attached to the valve seat forming wall 70b 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.

[0083] 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.

[0084] On the other hand, as shown in Figure 8, a vent inlet 64d is provided on the upper side of the drain socket 30, alongside the overflow outlet 64c. This vent inlet 64d is located to the side of the overflow outlet 64c, higher than the center of the overflow outlet 64c. Therefore, 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 inlet 64d.

[0085] Furthermore, as shown in Figure 7, an air vent pipe 80 is connected to the vent inlet 64d. The other end of this air vent pipe 80 is connected to an air outlet 66e provided at the lower end of the downstream member 66. That is, the other end of the air vent pipe 80 extending from the vent inlet 64d is connected to an air outlet 66e provided in the drainage channel downstream of the water reservoir opening / closing valve 68. In this way, the vent inlet 64d and the air outlet 66e are in communication via the air vent pipe 80. The air discharged through the vent inlet 64d flows into the first flow path section 66c of the drain socket 30.

[0086] Furthermore, as shown in Figure 7, the vent outlet 66e is formed on the inclined wall surface 66f at the lower end of the downstream member 66, facing the water reservoir valve 68. That is, the vent outlet 66e is located below the support shaft 68a of the water reservoir valve 68, and as shown in Figure 7, when the water reservoir valve 68 is open, the back surface of the water reservoir valve 68 faces the vent outlet 66e. When the water reservoir valve 68 is open, the vent outlet 66e is closed by a packing 68b attached to the back surface of the water reservoir valve 68. In this way, since the vent outlet 66e is closed under normal conditions, air is not drawn in from the vent outlet 66e during cleaning, and the cleaning performance is not reduced.

[0087] On the other hand, in the event of a power outage, if the user pulls the water reservoir valve operating section 76a (Figure 9) to rotate the water reservoir valve 68 and seat it on the outlet section 30b, the packing 68b on the back of the water reservoir valve 68 separates from the vent outlet 66e, and the vent outlet 66e opens. In this way, the vent outlet 66e is opened and closed by the water reservoir valve 68, so in this embodiment, the water reservoir valve 68 functions as an intake and exhaust control mechanism that controls the discharge of air stagnant in the drain trap pipe 14. The vent outlet 66e is closed in conjunction with the opening of the water reservoir valve 68 and opened in conjunction with the closing of the water reservoir valve 68.

[0088] 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 rear pipe 14d of the drain trap pipe 14.

[0089] 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 inlet 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 into the drain socket 30 from the rear pipe 14d of the drain trap pipe 14 are discharged into the drain piping (not shown) through the first flow path section 66c formed in the parallel flow path section 66b.

[0090] Here, although a vent inlet 64d (Figure 8) is provided at the top of the drain socket 30, in the initial stages of normal toilet flushing, the inflow of flushing water into the drain socket 30 creates positive pressure in the space inside the drain socket 30, causing the flapper valve 78 to press against the vent inlet 64d and close it. Therefore, even after flushing water has flowed into the drain socket 30, the trapped air does not escape from the vent inlet 64d. As a result, an air pocket is formed at the top of the drain socket 30, suppressing the rise in the water level inside the drain socket 30. This suppresses the backflow of flushing water into the overflow outlet 64c and the vent inlet 64d.

[0091] Furthermore, when a siphon effect occurs, negative pressure is created inside the drain socket 30, but since the vent outlet 66e is blocked, air is not drawn into the drain socket 30 from the vent inlet 64d which is in communication with it. Therefore, the occurrence of the siphon effect in the drain socket 30 is not inhibited by the intake of air, nor is the duration of the siphon effect substantially shortened. In this way, when the water retention valve 68 is opened (separated from the outlet 30b) so that the water and waste accumulated in the bowl section 12 are discharged, the intake and exhaust control mechanism prevents air from being drawn into the drain trap pipe 14 from the vent inlet 64d.

[0092] 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.

[0093] 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.

[0094] 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).

[0095] 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.

[0096] 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.

[0097] 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).

[0098] First, in the event of a power outage, the user operates the water reservoir valve 68 by pulling the water reservoir valve operating part 76a (Figure 9) which hangs down from the bottom of the flush toilet 1. 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 closed by rotating it and seating it at the outlet 30b of the descending pipe 30a. In conjunction with the movement of the water reservoir valve 68, the packing 68b provided on the back of the water reservoir valve 68 separates from the vent outlet 66e, and the vent outlet 66e is opened.

[0099] 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.

[0100] 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 water pressure of the overflowing cleaning water.

[0101] 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 through the drain socket 30. Since the outlet 30b is closed by the water retention valve 68, the cleaning water that overflows from the cleaning water tank 42 is collected on top of the water retention valve 68 inside the drain socket 30, as shown in Figure 11. Meanwhile, the air that was trapped inside the drain socket 30 can flow into the vent inlet 64d because the vent outlet 66e is open, and is discharged downstream of the water retention valve 68 from the vent outlet 66e through the air vent pipe 80. In other words, when the water retention valve 68 is closed and cleaning water is collected in the drain trap pipeline 14, the discharge of air from the vent inlet 64d in the drain trap pipeline 14 is made possible by the intake and exhaust control mechanism. The air that flows out from the vent outlet 66e flows out into the drainage pipe from the first flow path section 66c (Figure 7).

[0102] Thus, in this embodiment, the air that has been trapped inside the drain socket 30 is discharged through the vent inlet 64d, and the storage of cleaning water in the drain socket 30 is not obstructed. In other words, if the vent inlet 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.

[0103] 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.

[0104] In contrast, the flush toilet 1 of this embodiment is provided with a ventilation inlet 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.

[0105] 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 (the descending pipe section 30a of the drain trap pipe section 14) to fall all at once, inducing a siphon effect within the drain trap pipe section 14. As a result, the flushing water and waste in the bowl section 12 are drawn into the drain trap pipe section 14 and discharged into the drainage 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.

[0106] In the example described above, the user released the water reservoir valve operating section 76a to open the water reservoir shut-off valve 68 while the water supply from the water supply valve device 32 was continuing. However, it is also possible to stop the supply of washing water by pulling the water supply operating section 76c (Figure 9) before opening the water reservoir shut-off valve 68.

[0107] 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.

[0108] According to the first embodiment of the present invention, the flush toilet 1 is equipped with a water-retaining valve 68 that opens and closes the outlet 30b of the drain trap pipe 14 so as to fill the drain trap pipe 14 with flushing water. Therefore, in the event of a power outage, etc., by closing the water-retaining valve 68 and allowing flushing water to flow into the drain trap pipe 14, and then opening the water-retaining valve 68, a siphon effect can be generated in the drain trap pipe 14. This allows the waste and accumulated water in the bowl 12 to be discharged. Furthermore, according to this embodiment, when the water-retaining valve 68 is closed and flushing water is filled into the drain trap pipe 14, the water-retaining valve 68, which is an intake and exhaust control mechanism, opens the vent outlet 66e, thereby enabling the discharge of air from the vent inlet 64d provided in the drain trap pipe 14. Therefore, the air that has been stagnating in the drain trap pipe 14 can be discharged through the vent inlet 64d, and the inflow of cleaning water into the drain trap pipe 14 is not obstructed by the stagnant air, allowing a large amount of cleaning water to flow into the drain trap pipe 14. As a result, when the water retention valve 68 is opened, a siphon effect can be generated in the drain trap pipe 14 without excessively raising the water level in the bowl section 12. On the other hand, when the water retention valve 68 is opened to discharge the water and waste in the bowl section 12, the water retention valve 68 closes the vent outlet 66e, preventing air from being drawn into the drain trap pipe 14 from the vent inlet 64d. As a result, it is less likely to cause a siphon interruption due to air being drawn into the drain trap pipe 14, and the generated siphon effect can be maintained for a relatively long time. As a result, the waste discharge performance when using the water retention valve 68 can be improved.

[0109] Furthermore, according to the flush toilet 1 of this embodiment, the other end of the air vent pipe 80 is connected to the vent outlet 66e provided in the drain channel downstream of the water retention valve 68, so that air containing odors that has been stagnating in the drain trap pipe 14 can be discharged into the drain channel, thereby reliably preventing odor leakage.

[0110] Furthermore, according to the flush toilet 1 of this embodiment, the vent outlet 66e of the air vent pipe 80 is configured to be closed in conjunction with the opening of the water reservoir valve 68. Therefore, when the water reservoir valve 68 is opened, it is possible to prevent air from being drawn in from the vent outlet 66e and flowing into the drain trap pipe 14 via the vent inlet 64d.

[0111] Furthermore, according to the flush toilet 1 of this embodiment, the ventilation outlet 66e is provided in a position opposite to the water reservoir opening / closing valve 68, which is an open flapper valve, and the ventilation outlet 66e is closed by the flapper valve, so that the opening of the flapper valve and the closing of the ventilation outlet 66e can be achieved simultaneously with a simple mechanism.

[0112] Furthermore, according to the flush toilet 1 of this embodiment, since the vent outlet 66e is provided on the inclined wall surface 66f of the drainage channel downstream of the water retention valve 68, even if the vent outlet 66e is provided on the wall surface of the drainage channel, waste is less likely to accumulate in the vent outlet 66e, and problems caused by clogging of the vent outlet 66e can be suppressed.

[0113] Furthermore, in the flush toilet 1 of this embodiment, the outlet of the overflow channel (overflow pipe 62) that overflows the flush water from the flush water tank 42 is provided to communicate with the drain trap pipe 14. Therefore, by overflowing the flush water from the flush water tank 42 with the water retention valve 68 closed, flush water can be stored in the drain trap pipe 14. Thus, without providing a special water supply means, flush water can be stored in the drain trap pipe 14 by using the same water supply mechanism for storing flush water in the flush water tank 42.

[0114] In the first embodiment described above, a flapper valve 78 was provided at a valve port 70f located at the top of the drain socket 30, and the overflow outlet 64c (valve port 70f) was opened and closed. As a modification, the present invention can also be configured such that the flapper valve 78 simultaneously opens and closes an air inlet 64d located adjacent to the overflow outlet 64c. According to this modification, when cleaning water flows out from the overflow outlet 64c, the air inlet 64d is also opened, and the flapper valve 78 also functions as an intake and exhaust control mechanism.

[0115] Next, a flush toilet according to a second embodiment of the present invention will be described with reference to Figures 12 and 13. The flush toilet of this embodiment differs from that of the first embodiment described above primarily in the position of the ventilation outlet provided in 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.

[0116] Figure 12 is a perspective cross-sectional view showing the internal structure of the drain socket 130 provided in the flush toilet of this embodiment, cut in the front-to-back direction of the flush toilet. Figure 13 is a perspective cross-sectional view showing the internal structure of the drain socket 130, cut in the width direction of the flush toilet.

[0117] In this embodiment as well, the drain socket 130 is connected to the highest part of the flush water tank 42 via an overflow pipe 62, which is an overflow passage. Furthermore, the drain socket 130 has an inlet portion 130c that opens toward the front of the toilet and a drain pipe connection portion 130d that opens toward the rear. Overall, the drain socket 130 has a generally crank-shaped passage, with the upper inlet portion 130c and the lower drain pipe connection portion 130d being connected by a generally vertical passage.

[0118] The inlet portion 130c of the drain socket 130 is connected to the toilet body 2 by receiving the rear pipe 14d (Figure 3) of the drain trap pipe 14. On the other hand, the drain pipe connection portion 130d is connected to the drain pipe (not shown) by being received into the drain pipe for discharging flushing water and waste.

[0119] Furthermore, as shown in Figure 12, the drain socket 130 includes an upstream member 164 provided with an inlet portion 130c, a downstream member 166 provided with a drain pipe connection portion 130d, and a water reservoir valve 168 configured to open and close the pipeline inside the drain socket 130. In addition, a wall forming member 170 and a valve seat forming member 171 are arranged inside the upstream member 164.

[0120] The upstream member 164 is a cylindrical member that extends generally vertically, and is provided with an inlet portion 130c that protrudes horizontally in front of the flush toilet. As shown in Figure 13, the inside of the upstream member 164 is provided with a drainage channel wall 164a, a first backflow prevention wall 170a, and a second backflow prevention wall 164b. Furthermore, an overflow outlet 164c and a ventilation inlet 164d are provided on the upper part of one side of the upstream member 164.

[0121] As shown in Figure 12, the inlet portion 130c is a cylindrical portion provided on the upstream member 164 so as to protrude horizontally forward, and the inside of the inlet portion 130c is in communication with the internal space of the upstream member 164. As a result, the rear pipe 14d of the drain trap pipe 14 connected to the inlet portion 130c is in communication with the descending pipe 130a of the drain trap pipe 14 formed inside the upstream member 164.

[0122] The drainage channel component wall 164a is a semi-dome-shaped portion formed inside the upstream member 164. The ventilation inlet 164d is located above the lower end of the drainage channel component wall 164a. As shown in Figure 13, the second backflow prevention wall 164b is a wall surface that extends substantially horizontally from the lower end of the semi-dome-shaped drainage channel constituent wall 164a.

[0123] On the other hand, as shown in Figure 12, the wall-forming member 170 is a member fitted into the upper end of the upstream member 164, and by positioning the wall-forming member 170, four wall surfaces are formed inside the upstream member 164. Specifically, the wall-forming member 170 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 170 that is generally oriented horizontally functions as the first backflow prevention wall 170a.

[0124] As shown in Figure 13, the first backflow prevention wall 170a is located below the ventilation inlet 164d and directly below the overflow outlet 164c, and by providing it, most of the horizontal cross-section of the upstream member 164 is closed. Specifically, the first backflow prevention wall 170a extends from the side wall surface of the upstream member 164 on the side where the overflow outlet 164c is provided. On the other hand, the second backflow prevention wall 164b is located below the first backflow prevention wall 170a and extends from the side wall surface on the opposite side of the upstream member 164.

[0125] Furthermore, as shown in Figure 13, the wall surface rising from the first backflow prevention wall 170a to cover the overflow outlet 164c functions as a valve seat forming wall 170b. This valve seat forming wall 170b rises from the first backflow prevention wall 170a in a direction slightly inclined with respect to the vertical. In addition, the other two wall surfaces 170c and 170d extend vertically on both sides of the valve seat forming wall 170b (Figure 12). Also, an upper end cap 170e is attached to the upper end of the upstream member 164 to close the opening at the upper end.

[0126] On the other hand, as shown in Figure 12, the downstream member 166 has a connecting portion 166a that connects to the upstream member 164 and a parallel flow channel section 166b having a double-pipe structure. The connecting portion 166a opens vertically upward and is connected to the downstream end of the upstream member 164. The parallel flow channel section 166b has a first flow channel section 166c, which is an inner pipe communicating with the connecting portion 166a, and a second flow channel section 166d, which is an outer pipe extending parallel to the first flow channel section 166c, and has a double-pipe structure that extends generally horizontally.

[0127] The first flow channel section 166c is in communication with the inside of the bowl section 12 via the connecting section 166a, the upstream member 164, and the drain trap pipe 14. Therefore, the parallel flow channel section 166b 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 166c of the parallel flow channel section 166b and is discharged into the drain pipe (not shown). On the other hand, the second flow channel section 166d is formed above the first flow channel section 166c so as to surround it.

[0128] On the other hand, the water reservoir valve 168 is installed inside the drain socket 130 to open and close the pipe inside the drain socket 130, 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 168 is a flapper valve installed at the bend of the downstream member 166, and by closing this valve, cleaning water can be stored upstream of the water reservoir valve 168. Specifically, the water reservoir valve 168 is mounted so as to be rotatable around a support shaft 168a that is oriented horizontally, and when it is oriented horizontally, the outlet portion 130b of the descending pipe 130a, which constitutes part of the drain trap pipe 14, is closed.

[0129] As shown in Figure 12, the valve seat forming member 171 is a cylindrical member fitted into the lower end of the upstream member 164. This valve seat forming member 171 forms a descending pipe 130a of the drain trap pipe 14 inside the upstream member 164. That is, the cleaning water that flows into the drain socket 130 from the inlet 130c passes through the inside of the valve seat forming member 171 and flows into the downstream member 166. The lower end of the valve seat forming member 171 functions as the outlet 130b of the descending pipe 130a on which the water reservoir valve 168 is seated. That is, when the water reservoir valve 168 is oriented in a substantially horizontal direction, the water reservoir valve 168 abuts against the lower end (outlet 130b) of the valve seat forming member 171, and the outlet 130b is closed.

[0130] Furthermore, as shown in Figure 13, an overflow outlet 164c is provided on the upper side of the drain socket 130, and an overflow pipe 62 is connected to this overflow outlet 164c. Therefore, when cleaning water overflows from the cleaning water tank 42, the cleaning water flows into the drain socket 130 through the overflow pipe 62 and the overflow outlet 164c.

[0131] As mentioned above, a valve seat forming wall 170b is provided inside the drain socket 130 so as to cover the overflow outlet 164c. A valve opening 170f (Figure 12) is provided in this valve seat forming wall 170b so as to communicate with the overflow outlet 164c. A flapper valve 178, which is an intake and exhaust control mechanism, is attached to the valve seat forming wall 170b to open and close the valve opening 170f. As shown in Figure 13, the flapper valve 178 is rotatably mounted to the valve seat forming wall 170b by a support shaft 178a which is generally oriented horizontally. Since the valve seat forming wall 170b is slightly inclined with respect to the vertical, when no overflow water is flowing, the flapper valve 178 sits on the valve opening 170f by its own weight and is in a closed state. When overflow water flows from the overflow pipe 62, the flapper valve 178 is opened by the water pressure.

[0132] As shown in Figure 13, the cleaning water that flows into the drain socket 130 from the overflow pipe 62 flows onto the first backflow prevention wall 170a located directly below the overflow outlet 164c, and falls through the gap between the edge of the first backflow prevention wall 170a and the inner wall surface of the upstream member 164. The cleaning water that enters the gap between the edge of the first backflow prevention wall 170a and the inner wall surface of the upstream member 164 falls onto the second backflow prevention wall 164b, and then falls from the edge of the second backflow prevention wall 164b towards the water reservoir opening / closing valve 168.

[0133] On the other hand, as shown in Figure 13, a vent inlet 164d is provided on the upper side of the drain socket 130, alongside the overflow outlet 164c. This vent inlet 164d is located to the side of the overflow outlet 164c, higher than the center of the overflow outlet 164c. This vent inlet 164d is opened and closed by a flapper valve 178, which is an intake and exhaust control mechanism, together with the valve opening 170f of the overflow outlet 164c. Therefore, when no overflow water is flowing, the vent inlet 164d is closed, and when overflow water flows, the vent inlet 164d is opened. In this way, the flapper valve 178 functions as an intake and exhaust control mechanism, and when overflow water flows and cleaning water flows into the drain socket 130 from the overflow outlet 164c, the air that was trapped inside the drain socket 130 is discharged from the vent inlet 164d.

[0134] Furthermore, as shown in Figure 12, an air vent pipe 180 is connected to the vent inlet 164d. The other end of this air vent pipe 180 is connected to the second flow channel section 166d of the parallel flow channel section 166b. That is, the other end of the air vent pipe 180 extending from the vent inlet 164d is connected to the vent outlet 166e which is formed to communicate with the second flow channel section 166d, and the vent inlet 164d and the vent outlet 166e are in communication via the air vent pipe 180. Therefore, the air discharged through the vent inlet 164d flows into the second flow channel section 166d of the drain socket 130.

[0135] Furthermore, a vent outlet valve 182 is provided at the vent outlet 166e, which opens and closes the vent outlet 166e. When no air is being discharged, the vent outlet 166e is closed by its own weight, and when air is pushed out from the vent inlet 164d, it is opened by the air pressure. In this way, since the vent outlet 166e is normally closed, air is not drawn in from the vent outlet 166e during cleaning, and the cleaning performance is not reduced.

[0136] Next, the operation of the flush toilet according to the second embodiment of the present invention will be described. First, when the user operates the remote control (not shown) to perform toilet flushing, the bowl portion 12 is flushed, and the waste and flushing water in the bowl portion 12 flow into the drain socket 130 through the drain trap pipe 14.

[0137] The waste and washing water that flow into the drain socket 130 are guided downward by the drain channel configuration wall 164a and fall downward within the drain socket 130. The waste and washing water that flow into the drain socket 130 induce a siphon effect within the drain socket 130. Due to the siphon effect, the waste and washing water in the bowl section 12 are drawn into the drain trap pipe 14. The waste and washing water that flow from the drain trap pipe 14 into the drain socket 130 are discharged into the drain pipe (not shown) through the first channel section 166c formed in the parallel channel section 166b.

[0138] Here, although a vent inlet 164d (Figure 13) is provided at the top of the drain socket 130, during normal toilet flushing, the vent inlet 164d is closed by the flapper valve 178. Therefore, even after flushing water flows from the drain trap pipe 14 into the drain socket 130, any stagnant air remains inside the drain socket 130. As a result, an air pocket forms at the top of the drain socket 130, suppressing a rise in the water level inside the drain socket 130. This prevents backflow of flushing water to the overflow outlet 164c and the vent inlet 164d. Furthermore, during normal toilet flushing, the water retention valve 168 is open to allow the water and waste in the bowl section 12 to be discharged, and at this time, the vent inlet 164d is closed by the flapper valve 178, which is an intake and exhaust control mechanism. Therefore, air is not drawn into the drain socket 130 from the ventilation inlet 164d, and the siphon effect in the drain socket 130 is not inhibited or substantially shortened by the drawing in of air.

[0139] On the other hand, in the event of a power outage, the user manually generates a siphon effect within the drain socket 130 to discharge the waste and cleaning water from the bowl section 12 into the drain pipe (not shown).

[0140] 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 to operate the water reservoir valve 168. That is, by pulling the water reservoir valve operating part 76a, the water reservoir valve 168 inside the drain socket 130 is rotated to close it (similar to Figure 11 in the first embodiment). In other words, the water reservoir valve 168 is rotated and seated on the outlet portion 130b at the lower end of the valve seat forming member 171, thereby closing the water reservoir valve 168.

[0141] Next, the user pulls the water supply operation part 76c (Figure 9) hanging from the bottom of the flush toilet bowl to activate the tank water supply unit 46. That is, by pulling the water supply operation part 76c, flushing water is supplied to the flushing water tank 42. When the water level in the flushing water tank 42 exceeds a predetermined level, the flushing water in the flushing water tank 42 flows into the drain socket 130 through the overflow pipe 62 and valve port 170f. The flapper valve 178 provided in the valve port 170f is opened by the water pressure of the overflowing flushing water. At the same time, the vent inlet 164d provided adjacent to the valve port 170f is also opened.

[0142] The cleaning water flowing into the drain socket 130 bypasses the first backflow prevention wall 170a and the second backflow prevention wall 164b and flows downwards through the drain socket 130. Since the outlet section 130b is closed by the water retention valve 168, the cleaning water that overflows from the cleaning water tank 42 is collected on top of the water retention valve 168 inside the drain socket 130. Meanwhile, the air that was trapped inside the drain socket 130 flows out through the vent inlet 164d because the vent inlet 164d is open. The air that flows out from the vent inlet 164d flows through the air vent pipe 180 and out to the drain piping (not shown) from the vent outlet 166e (Figure 12) provided in the second flow path section 166d. The vent outlet valve 182 provided in the vent outlet 166e is opened by the air being pushed out from the vent outlet 166e.

[0143] Thus, when accumulating cleaning water in the drain trap pipe 14, the water retention valve 168 is closed, and at this time, the flapper valve 178, which is an intake and exhaust control mechanism, opens the vent inlet 164d, allowing air to be discharged from the vent inlet 164d provided in the drain trap pipe 14. As a result, the air that had been stagnating in the drain socket 130 is discharged, and the accumulation of cleaning water in the drain socket 130 (drain trap pipe 14) is not hindered. In other words, if the vent inlet 164d is not provided and the air in the drain socket 130 cannot be discharged, an air pocket will form at the top of the drain socket 130, and a sufficient amount of cleaning water cannot be accumulated in the drain socket 130.

[0144] In contrast, the flush toilet of this embodiment is provided with a ventilation inlet 164d, which allows air that has been trapped in the drain socket 130 to be discharged. As a result, a sufficient amount of flushing water can be stored in the drain socket 130 without significantly raising the water level in the bowl 12. Therefore, the user can fill the drain socket 130 and the bowl 12 with sufficient flushing water without feeling any anxiety.

[0145] Once a sufficient amount of flushing water has accumulated, the user releases the water reservoir valve operating section 76a, opening the water reservoir on-off valve 168. This causes the flushing water accumulated above the water reservoir on-off valve 168 to fall all at once, inducing a siphon effect within the drain socket 130. 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 stop the supply of flushing water from the water supply valve device 32 to the flushing water tank 42, completing one toilet flush.

[0146] In the example described above, the user released the water reservoir valve operating section 76a to open the water reservoir valve 168 while the water supply from the water supply valve device 32 was continuing. However, before opening the water reservoir valve 168, 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 130 in this way, the flapper valve 178 closes the valve opening 170f and the vent inlet 164d. Therefore, when the user releases the water reservoir valve operating section 76a to open the water reservoir valve 168, the vent inlet 164d can be kept closed, thereby strengthening the siphon effect generated in the drain socket 130.

[0147] Furthermore, in the example described above, the water reservoir valve operating unit 76a was operated first to close the water reservoir valve 168, and then the water supply operating unit 76c was operated to start supplying cleaning water to the drain socket 130. However, it is also possible to operate the water reservoir valve operating unit 76a to close the water reservoir valve 168 after starting to supply cleaning water to the drain socket 130.

[0148] In the flush toilet of the second embodiment of the present invention, the overflow outlet 164c and the vent inlet 164d are opened and closed by the flapper valve 178. By allowing flushing water to flow into the drain trap pipe 14 from the overflow outlet 164c, the vent inlet 164d can be opened at the same time. This allows air in the drain trap pipe 14 to be automatically discharged through the vent inlet 164d when flushing water is being stored in the drain trap pipe 14. Furthermore, when the water supply to the drain trap pipe 14 is stopped, the vent inlet 164d is automatically closed. This prevents air from being drawn in through the vent inlet 164d when draining the water and waste from the bowl 12, thereby suppressing siphon failure due to air intake. In addition, if the water level in the drain trap pipe 14 rises abnormally due to a blockage in the drain pipe, the overflow outlet 164c is closed by the flapper valve 178, preventing backflow of flushing water from the drain trap pipe 14 to the flushing water tank 42. Furthermore, when cleaning water is not supplied from the overflow outlet 164c, the vent inlet 164d is closed by the flapper valve 178, which prevents pests and other insects from entering through the vent inlet 164d from the drainage pipe.

[0149] Furthermore, in the flush toilet of this embodiment, one end of the air vent pipe 180 is connected to the vent inlet 164d, and the other end is connected to the vent outlet 166e. Since a vent outlet valve is provided to open and close this vent outlet 166e, even when water is supplied to the drain trap pipe and the flapper valve is open, it is possible to prevent air from being drawn into the drain trap pipe from the vent inlet. As a result, even when the water retention valve is opened while water is being supplied to the drain trap pipe, air is prevented from being drawn in from the vent inlet, thus preventing siphon failure due to air intake.

[0150] Furthermore, in this embodiment of the flush toilet, since a parallel flow channel 166b is provided downstream of the outlet 130b of the drain trap pipe 14, the drain of the flush toilet can be connected to an existing large drain pipe. In addition, since the vent outlet 166e, to which the other end of the air vent pipe 180 is connected, is provided inside the second flow channel 166d, which is the outer pipe of the parallel flow channel 166b, and outside the first flow channel 166c, which is the inner pipe, air containing odors that have been stagnating in the drain trap pipe 14 can be discharged into the drain pipe, thereby reliably preventing odor leakage.

[0151] Next, a flush toilet according to a third embodiment of the present invention will be described with reference to Figure 14. The flush toilet of this embodiment differs from the first embodiment described above mainly in the structure of the drain socket. Therefore, below, only the differences between the third 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 14 is a cross-sectional view of the drain socket 230 provided in the flush toilet of this embodiment, cut in the front-to-back direction of the flush toilet.

[0152] In this embodiment as well, the drain socket 230 is connected to the highest part of the flushing water tank 42 via an overflow pipe 62 (not shown in Figure 14), which is an overflow passage. Furthermore, the drain socket 230 has an inlet portion 230c that opens toward the front of the flush toilet and a drain pipe connection portion 230d that opens toward the rear. Overall, the drain socket 230 has a generally crank-shaped passage, with the upper inlet portion 230c and the lower drain pipe connection portion 230d being connected by a generally vertical passage.

[0153] The inlet portion 230c of the drain socket 230 is connected to the toilet body 2 by receiving the rear pipe 14d of the drain trap pipe 14. On the other hand, the drain pipe connection portion 230d is connected to the drain pipe by being received into the drain pipe D for discharging flushing water and waste.

[0154] Furthermore, as shown in Figure 14, the drain socket 230 includes an upstream member 264 provided with an inlet portion 230c, a downstream member 266 provided with a drain pipe connection portion 230d, and a water reservoir valve 268 configured to open and close the pipeline inside the drain socket 230. In addition, an opening is provided at the upper end of the upstream member 264, and this opening is covered by an upper end cap 270.

[0155] The upstream member 264 is a cylindrical member that extends generally vertically, and an inlet portion 230c is provided so as to protrude horizontally in front of the flush toilet. Also, as shown in Figure 14, an overflow outlet 264a is provided on the upper side of the upstream member 264, directly below the upper end cap 270, and an overflow pipe 62 is connected to this overflow outlet 264a. Therefore, when flushing water overflows from the flushing water tank 42, the flushing water flows into the drain socket 230 through the overflow pipe 62 and the overflow outlet 264a. Furthermore, a ventilation inlet 270a is provided in the upper end cap 270.

[0156] As shown in Figure 14, the inlet portion 230c is a cylindrical portion provided on the upstream member 264 so as to protrude horizontally forward, and the inside of the inlet portion 230c is in communication with the internal space of the upstream member 264. As a result, the rear pipe 14d of the drain trap pipe 14 connected to the inlet portion 230c is in communication with the descending pipe 230a of the drain trap pipe 14 formed inside the upstream member 264.

[0157] The downstream member 266 has a connecting portion 266a that connects to the upstream member 264 and a drainage channel portion 266b that connects to the drainage pipe D. The connecting portion 266a opens vertically upward and connects to the downstream end of the upstream member 264. The drainage channel portion 266b extends generally horizontally. The drainage channel portion 266b communicates with the inside of the bowl portion 12 via the connecting portion 266a, the upstream member 264, and the drainage trap pipeline 14. Therefore, the drainage channel portion 266b is located downstream of the drainage trap pipeline 14, and wastewater flowing out of the bowl portion 12 flows through the drainage channel portion 266b and is discharged into the drainage pipe D.

[0158] On the other hand, the water reservoir valve 268 is installed inside the drain socket 230 to open and close the pipe inside the drain socket 230, 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 268 is a flapper valve installed at the upstream end of the downstream member 266, and by closing this valve, cleaning water can be stored upstream of the water reservoir valve 268.

[0159] Specifically, the lower end of the upstream member 264 constitutes the outlet portion 230b of the descending pipe 230a, which forms part of the drain trap pipe 14. The water reservoir valve 268 is mounted so as to be rotatable around a support shaft 268a that is oriented horizontally. When the water reservoir valve 268 is oriented approximately horizontally, it comes into contact with the lower end (outlet portion 230b) of the upstream member 264, and the outlet portion 230b is closed.

[0160] Furthermore, a flapper valve 278 is installed to cover the overflow outlet 264a, which is provided on the upper side of the drain socket 230. The flapper valve 278 is rotatable by a pivot shaft (not shown) that is generally oriented horizontally. When no overflow water is flowing, the flapper valve 278 is closed. When overflow water flows from the overflow pipe 62, the water pressure opens the flapper valve 278. The cleaning water that flows into the drain socket 230 from the overflow pipe 62 falls towards the water reservoir opening / closing valve 268.

[0161] On the other hand, the vent inlet 270a, which is provided in the upper end cap 270 at the upper end of the drain socket 230, is located at the top of the drain socket 230. When overflow water flows from the cleaning water tank 42 and the cleaning water flows into the drain socket 230 from the overflow outlet 264a, the air that had been stagnating inside the drain socket 230 is discharged from the vent inlet 270a.

[0162] Furthermore, an air vent pipe 280 is connected to the air inlet 270a. The other end of this air vent pipe 280 is connected to an air outlet 266c located adjacent to the water reservoir valve 268, which is in a closed state at the outlet of the drain trap pipeline (as shown in Figure 14). As a result, the air discharged through the air inlet 270a flows into the drainage channel section 266b in the downstream member 266 of the drain socket 230. In addition, a check valve 280a is provided in the middle of the air vent pipe 280. This check valve 280a is configured to allow the flow of air from the air inlet 270a toward the air outlet 266c and to block the flow in the reverse direction. In this way, the check valve 280a blocks the flow of air from the air outlet 266c toward the air inlet 270a, so that air is not drawn in from the air outlet 266c during cleaning, and the cleaning performance does not deteriorate.

[0163] Next, the operation of the flush toilet according to the third embodiment of the present invention will be described. First, when the user operates the remote control (not shown) to flush the toilet, the bowl 12 is flushed, and the waste and flushing water in the bowl 12 flow into the drain socket 230 through the drain trap pipe 14. In normal toilet flushing, the water retention valve 268 is in the open position shown by the dashed line in Figure 14.

[0164] The waste and washing water that flow into the drain socket 230 fall downwards, inducing a siphon effect within the drain socket 230. Due to the siphon effect, the waste and washing water in the bowl section 12 are drawn into the drain trap pipe 14. The waste and washing water that flow from the drain trap pipe 14 into the drain socket 230 are discharged into the drain pipe D through the drain channel section 266b.

[0165] Here, although a vent inlet 270a is provided at the top of the drain socket 230, this vent inlet 270a is connected to a vent outlet 266c by an air vent pipe 280. When the water reservoir valve 268 is in the open position and cleaning water is flowing through the drain socket 230, the area around the vent outlet 266c is filled with cleaning water, so the air that was trapped inside the drain socket 230 is effectively unable to flow out through the vent outlet 266c. Therefore, even after cleaning water flows into the drain socket 230 from the drain trap pipe 14, the trapped air remains inside the drain socket 230. As a result, an air reservoir is formed at the top of the drain socket 230, suppressing the rise in the water level inside the drain socket 230. This suppresses the backflow of cleaning water to the overflow outlet 264a and the vent inlet 270a.

[0166] Furthermore, during normal toilet flushing, the water retention valve 268 is open so that the water and waste in the bowl 12 are discharged, and in this state, as described above, the area around the vent outlet 266c is filled with flushing water. Therefore, air is not substantially drawn into the drain socket 230 from the vent inlet 270a, and the siphon effect in the drain socket 230 is not inhibited or the duration of the siphon effect is not substantially shortened by the drawing in of air.

[0167] On the other hand, in the event of a power outage, the user manually generates a siphon effect within the drain socket 230 to discharge the waste and cleaning water from the bowl section 12 into the drain pipe (not shown).

[0168] 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 to operate the water reservoir valve 268. That is, by pulling the water reservoir valve operating part 76a, the water reservoir valve 268 inside the drain socket 230 is rotated to close it (shown by a solid line in Figure 14). In other words, the water reservoir valve 268 is rotated and seated at the outlet 230b of the descending pipe 230a, thereby closing the water reservoir valve 268.

[0169] Next, the user pulls the water supply operation part 76c (Figure 9) hanging from the bottom of the flush toilet bowl to activate the tank water supply unit 46. That is, by pulling the water supply operation part 76c, flushing water is supplied to the flushing water tank 42. When the water level in the flushing water tank 42 exceeds a predetermined level, the flushing water in the flushing water tank 42 flows into the drain socket 230 through the overflow pipe 62 and the overflow outlet 264a. The flapper valve 278 provided at the overflow outlet 264a is opened by the force of the overflowing flushing water.

[0170] The cleaning water that flows into the drain socket 230 flows downwards from the drain socket 230. Since the outlet 230b is closed by the water retention valve 268, the cleaning water that overflows from the cleaning water tank 42 is collected on top of the water retention valve 268 inside the drain socket 230. Meanwhile, the air that was trapped inside the drain socket 230 flows out through the vent inlet 270a. In other words, when the water retention valve 268 is closed, there is an air layer below the water retention valve 268, and the air that was trapped inside the drain socket 230 (above the water retention valve 268) can easily escape from the vent inlet 270a to the vent outlet 266c. The air that flows out from the vent outlet 266c flows out into the drainage pipe D from the drainage channel section 266b.

[0171] Thus, when cleaning water is stored in the drain trap pipe 14, the water storage valve 268 is closed, and in this state, air can be discharged from the vent outlet 266c located adjacent to the water storage valve 268. For this reason, the configuration in which the vent outlet 266c is located adjacent to the water storage valve 268, which is blocking the outlet portion 230b, functions as an intake and exhaust control mechanism. In this way, air that has been stagnating in the drain socket 230 can be discharged, and the storage of cleaning water in the drain socket 230 (drain trap pipe 14) is not hindered.

[0172] 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 268. This causes the flushing water accumulated above the water reservoir shut-off valve 268 to fall all at once, inducing a siphon effect within the drain socket 230. 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 D. Next, the user pulls the water supply operating section 76c (Figure 9) again to stop the supply of flushing water from the water supply valve device 32 to the flushing water tank 42, completing one toilet flush.

[0173] In the flush toilet of the third embodiment of the present invention, the vent outlet 266c to which the other end of the air vent pipe 280 is connected is located adjacent to the water reservoir valve 268. Therefore, when the water reservoir valve 268 is opened, the flush water flowing through the water reservoir valve 268 blocks the vent outlet 266c of the air vent pipe 280, thereby suppressing the intake of air from the vent outlet 266c.

[0174] Next, a flush toilet according to a fourth embodiment of the present invention will be described with reference to Figure 15. The flush toilet of this embodiment differs from the first embodiment described above mainly in the structure of the drain socket. Therefore, below, only the differences between the fourth 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 15 is a cross-sectional view of the drain socket 330 provided in the flush toilet of this embodiment, cut in the front-to-back direction of the flush toilet.

[0175] In this embodiment, the drain socket 330 has an inlet portion 330c that opens toward the front of the flush toilet and a drain pipe connection portion 330d that opens toward the rear. The drain socket 330 as a whole has a generally crank-shaped flow path, and the inlet portion 330c located above and the drain pipe connection portion 330d located below are connected by a generally vertical flow path.

[0176] The inlet portion 330c of the drain socket 330 is connected to the toilet body 2 by receiving the rear pipe 14d of the drain trap pipe 14. On the other hand, the drain pipe connection portion 330d is connected to the drain pipe by being received into the drain pipe D for discharging flushing water and waste.

[0177] Furthermore, as shown in Figure 15, the drain socket 330 includes an upstream member 364 provided with an inlet portion 330c, a downstream member 366 provided with a drain pipe connection portion 330d, and a water reservoir on / off valve 368 configured to open and close the pipeline inside the drain socket 330.

[0178] The upstream member 364 is a cylindrical member that extends generally vertically, and has an inlet 330c that protrudes horizontally in front of the flush toilet. Furthermore, a ventilation inlet 370 is provided at the upper end of the upstream member 364, adjacent to the inlet 330c.

[0179] The inlet portion 330c is a cylindrical part provided on the upstream member 364 so as to protrude horizontally forward, and the inside of the inlet portion 330c is in communication with the internal space of the upstream member 364. As a result, the rear pipe 14d of the drain trap pipe 14 connected to the inlet portion 330c is in communication with the descending pipe 330a of the drain trap pipe 14 formed inside the upstream member 364.

[0180] The downstream member 366 has a connecting portion 366a that connects to the upstream member 364 and a drainage channel portion 366b that connects to the drainage pipe D. The connecting portion 366a opens vertically upward and connects to the downstream end of the upstream member 364. The drainage channel portion 366b extends generally horizontally. The drainage channel portion 366b communicates with the inside of the bowl portion 12 via the connecting portion 366a, the upstream member 364, and the drainage trap pipeline 14. Therefore, the drainage channel portion 366b is located downstream of the drainage trap pipeline 14, and wastewater flowing out of the bowl portion 12 flows through the drainage channel portion 366b and is discharged into the drainage pipe D.

[0181] On the other hand, the water reservoir valve 368 is installed inside the drain socket 330 to open and close the pipe inside the drain socket 330, 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 368 is a flapper valve installed at the upstream end of the downstream member 366, and by closing this valve, cleaning water can be stored upstream of the water reservoir valve 368.

[0182] Specifically, the lower end of the upstream member 364 constitutes the outlet portion 330b of the descending pipe 330a, which forms part of the drain trap pipe 14. The water reservoir valve 368 is mounted so as to be rotatable around a support shaft 368a that is oriented horizontally. When the water reservoir valve 368 is oriented approximately horizontally, it comes into contact with the lower end (outlet portion 330b) of the upstream member 364, and the outlet portion 330b is closed.

[0183] On the other hand, an air vent pipe 380 is connected to the air inlet 370. The other end of this air vent pipe 380 forms an air outlet 380a and is attached near the pivot shaft 368a of the water reservoir valve 368. The water reservoir valve 368 is also equipped with a valve projection 368b, and when the water reservoir valve 368 is rotated around the pivot shaft 368a, the valve projection 368b also rotates with it. As shown in Figure 15, when the water reservoir valve 368 is open, the valve projection 368b comes into contact with the air outlet 380a of the air vent pipe 380, blocking it. In other words, the air outlet 380a of the air vent pipe 380 is closed in conjunction with the opening of the water reservoir valve 368. On the other hand, when the water reservoir valve 368 is rotated to face horizontally in order to close the outlet 330b of the descending pipe 330a, the valve projection 368b moves away from the vent outlet 380a, and the vent outlet 380a is opened.

[0184] Next, the operation of the flush toilet according to the fourth embodiment of the present invention will be described. First, when the user operates the remote control (not shown) to flush the toilet, the bowl 12 is flushed, and the waste and flushing water in the bowl 12 flow through the drain trap pipe 14 into the drain socket 330. In normal toilet flushing, the water retention valve 368 is in the open position shown in Figure 15.

[0185] The waste and washing water that flow into the drain socket 330 fall downwards, inducing a siphon effect within the drain socket 330. Due to the siphon effect, the waste and washing water in the bowl section 12 are drawn into the drain trap pipe 14. The waste and washing water that flow from the drain trap pipe 14 into the drain socket 330 are discharged into the drain pipe D through the drain channel section 366b.

[0186] Here, although a vent inlet 370 is provided at the top of the drain socket 330, this vent inlet 370 is connected to a vent outlet 380a by an air vent pipe 380. When the water retention valve 368 is in the open position, the vent outlet 380a is blocked by the valve projection 368b, so the air that has been trapped in the air vent pipe 380 cannot flow out from the vent outlet 380a. Therefore, even if cleaning water flows into the drain socket 330 from the drain trap pipeline 14, the cleaning water cannot effectively enter the vent inlet 370. This suppresses the backflow of cleaning water into the vent inlet 370.

[0187] Furthermore, during normal toilet flushing, the vent outlet 380a is blocked by the valve projection 368b. Therefore, virtually no air is drawn into the drain socket 330 from the vent inlet 370, and the siphon effect in the drain socket 330 is not inhibited or the duration of the siphon effect is not substantially shortened by the drawing in of air.

[0188] On the other hand, in the event of a power outage, the user manually generates a siphon effect within the drain socket 330 to discharge the waste and cleaning water from the bowl section 12 into the drain pipe (not shown). 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 to operate the water reservoir valve 368. Specifically, by pulling the water reservoir valve operating part 76a, the water reservoir valve 368 inside the drain socket 330 is rotated to close it. In other words, the water reservoir valve 368 is rotated and seated at the outlet 330b of the descending pipe 330a, thereby closing the water reservoir valve 368.

[0189] Next, the user pulls the water supply operation part 76c (Figure 9) hanging down from the bottom of the flush toilet bowl to activate the tank water supply unit 46. In this embodiment, by pulling the water supply operation part 76c, flushing water is manually allowed to flow into the bowl section 12. When the water level in the bowl section 12 rises, the flushing water flows over the top 14c of the drain trap pipe 14 into the drain socket 330.

[0190] The cleaning water that flows into the drain socket 330 flows downwards. Since the outlet 330b is closed by the water reservoir valve 368, the incoming cleaning water is collected above the water reservoir valve 368 inside the drain socket 330. Meanwhile, the air that was trapped inside the drain socket 330 flows out through the vent inlet 370. That is, when the water reservoir valve 368 is closed, the vent outlet 380a of the air vent pipe 380 is open, so the air that was trapped inside the drain socket 330 (above the water reservoir valve 368) can easily escape from the vent inlet 370 to the vent outlet 380a.

[0191] Thus, when cleaning water is to be stored in the drain trap pipe 14, the water storage valve 368 is closed, and in this state, the vent outlet 380a, located near the pivot shaft 368a of the water storage valve 368, opens in conjunction with the closing of the water storage valve 368. For this reason, the configuration in which the vent outlet 380a is located near the pivot shaft 368a of the water storage valve 368 and is opened and closed by the valve projection 368b functions as an intake and exhaust control mechanism. In this way, air that has been stagnant in the drain socket 330 can be discharged, and the storage of cleaning water in the drain socket 330 (drain trap pipe 14) is not hindered.

[0192] 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 368. This causes the flushing water accumulated above the water reservoir shut-off valve 368 to fall all at once, inducing a siphon effect within the drain socket 330. 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 D. Next, the user pulls the water supply operating section 76c (Figure 9) again to stop the water supply from the water supply valve device 32, completing one toilet flush.

[0193] In the fourth embodiment of the flush toilet of the present invention, the vent outlet 380a of the air vent pipe 380 is configured to be closed in conjunction with the opening of the water reservoir valve 368. Therefore, when the water reservoir valve 368 is opened, it is possible to prevent air from being drawn in from the vent outlet 380a and flowing into the drain trap pipe 14 via the vent inlet 370.

[0194] Furthermore, in the flush toilet of this embodiment, since the vent outlet 380a is provided near the support shaft 368a that rotatably supports the flapper valve constituting the water reservoir valve 368, a mechanism can be easily constructed to open and close the vent outlet 380a in conjunction with the opening and closing of the water reservoir valve 368.

[0195] Although embodiments of the present invention have been described above, various modifications can be made to the embodiments described above. In particular, in the first to third embodiments described above, in the event of a power outage, etc., the cleaning water was directly overflowed from the cleaning water tank into the drain socket, thereby accumulating the cleaning water in the drain socket. In contrast, as a modification, the present invention can also be configured so that the cleaning water flows into the bowl section and the cleaning water that flows into the drain socket via the drain trap pipe is accumulated.

[0196] Furthermore, in the first and second embodiments described above, an air vent pipe was connected to the vent inlet, and the vent inlet was connected to the parallel flow path of the drain socket. However, the present invention can also be configured so that the vent inlet is connected to another location in the drain socket. In addition, the vent inlet only needs to be able to discharge air that has accumulated upstream of the water retention valve of the drain socket, and an air vent pipe does not need to be connected. [Explanation of symbols]

[0197] 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 downhill pipe 30b Exit section 30c entrance section 30d 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 Inlet 66 Downstream member 66a Connection part 66b Parallel channel section 66c First flow channel section (inner tube) 66d Second flow channel section (outer pipe) 66e Ventilation Outlet 66f Sloping wall 68. Water reservoir shut-off valve (intake / exhaust control mechanism) 68a spindle 68b Packing 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 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 78a spindle 80 Air vent pipe 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 130 Drain socket 130a downhill pipe 130b Exit section 130c entrance section 130d Drainage pipe connection 164 Upstream member 164a Drainage channel configuration wall 164b Second backflow prevention wall 164c Overflow Outlet 164d Ventilation Inlet 166 Downstream member 166a Connection 166b Parallel channel section 166c First flow channel section (inner tube) 166d Second flow channel section (outer pipe) 166e Ventilation Outlet 168 Water reservoir shut-off valve 168a spindle 170 Wall forming member 170a First backflow prevention wall 170b Valve seat forming wall 170cm wall 170d wall surface 170e Top cap 170f Benguchi 171 Valve seat forming member 178 Flapper valve (intake and exhaust control mechanism) 178a Spindle 180 Air vent pipe 182 Ventilation outlet valve 230 Drain socket 230a downhill pipe 230b Exit section 230c entrance section 230d Drainage pipe connection 264 Upstream member 264a Overflow outlet 266 Downstream member 266a Connection 266b Drainage channel section 266c Ventilation Outlet 268 Water reservoir shut-off valve 268a Spindle 270 Top cap 270a Ventilation Inlet 278 Flapper valve 280 Air vent pipe 280a Check valve 330 Drain socket 330a downcomer line 330b Exit section 330c entrance section 330d Drainage pipe connection 364 Upstream member 366 Downstream member 366a Connection 366b Drainage channel section 368 Water reservoir shut-off valve 368a spindle 368b valve protrusion 370 Ventilation Inlet 380 Air vent pipe 380a Ventilation Outlet

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 drain trap pipe comprising an inlet connected to the lower part of this bowl, an ascending pipe extending from this inlet to the top located above and behind, and a descending pipe extending from the top to the outlet located below and behind, A water-retaining valve is configured to open and close the outlet of the drain trap pipe so as to accumulate cleaning water downstream of the top of the drain trap pipe, An intake and exhaust control mechanism that controls the discharge of air trapped in the drain trap pipeline, It has, The above-described intake and exhaust control mechanism is characterized in that, when the above-described water retention valve is closed and flushing water is stored in the above-described drain trap pipe, it allows air to be discharged from the ventilation inlet provided in the above-described drain trap pipe, while when the above-described water retention valve is opened to allow the water and waste stored in the bowl to be discharged, it prevents air from being drawn into the drain trap pipe from the ventilation inlet.

2. Furthermore, the flush toilet according to claim 1, which has an air vent pipe at one end connected to the above-mentioned ventilation inlet, and the other end of the air vent pipe connected to a ventilation outlet provided in the drainage channel downstream of the above-mentioned water retention valve.

3. The flush toilet according to claim 2, wherein the above-mentioned ventilation outlet is provided in a position adjacent to the above-mentioned water-holding on / off valve that closes the above-mentioned outlet portion of the drain trap pipe.

4. The flush toilet according to claim 2, wherein the above-mentioned ventilation outlet is configured to be closed in conjunction with the opening of the above-mentioned water reservoir opening valve.

5. The flush toilet according to claim 4, wherein the above-mentioned water reservoir opening / closing valve is a flapper valve, and the above-mentioned vent outlet is provided near a support shaft that rotatably supports the above-mentioned flapper valve.

6. The above-mentioned water reservoir opening / closing valve is a flapper valve, and the above-mentioned vent outlet is provided in a position opposite to the opened flapper valve and is closed by the flapper valve, as described in claim 4.

7. The flush toilet according to claim 6, wherein the above-mentioned ventilation outlet is provided on the inclined wall surface of the drainage channel downstream of the above-mentioned water-holding valve.

8. Furthermore, a cleaning water tank for storing cleaning water to clean the bowl section, When the water level in this cleaning water tank rises above a predetermined level, an overflow channel is provided to cause the cleaning water in the cleaning water tank to overflow, It has, The overflow outlet of the overflow channel described above is provided upstream of the outlet of the drain trap pipe and is in communication with the drain trap pipe. The above intake and exhaust control mechanism is a flapper valve that opens and closes the overflow outlet and the vent inlet, and is configured such that the vent inlet is also opened when flushing water is flowing out of the overflow outlet.

9. Furthermore, the flush toilet according to claim 8, which has an air vent pipe with one end connected to the air inlet, and an air outlet to which the other end of the air vent pipe is connected, and an air outlet valve is provided which opens and closes to prevent air from being drawn into the air vent pipe.

10. Furthermore, an air vent pipe, one end of which is connected to the above-mentioned ventilation inlet, It has a parallel flow channel section provided downstream of the outlet section of the drain trap pipeline so as to connect to the existing drainage piping, The flush toilet according to claim 8, wherein the inner pipe of the parallel flow section is in communication with the outlet section, and the vent outlet to which the other end of the air vent pipe is connected is provided inside the outer pipe of the parallel flow section and outside the inner pipe.

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