JP7743883B2 - flush toilet - Google Patents

Description

The present invention relates to flush toilets, and in particular to flush toilets that are flushed with flush water to expel waste.

Conventionally, flush toilets that are cleaned with flush water to expel waste have been known that are equipped with a valve unit in the water supply path for flush water used for the rim spouting and jet spouting of the toilet, as disclosed in Patent Document 1, for example.
This valve unit is equipped, from upstream to downstream, with a constant flow valve, a water supply valve (a diaphragm-type main valve), a water supply channel switching valve, and a check valve (vacuum breaker). The flush water in the water supply channel is either supplied directly to the rim spout side of the toilet body by the valve unit, or the water supply channel switching valve switches the flow path to the water storage tank side and supplies water to the water storage tank, and then supplies water to the jet spout side of the toilet body.
In addition, in order to prevent backflow of cleaning water in the water supply line upstream, the entire valve unit including the check valve (vacuum breaker) is usually located above the water storage tank of the tank device.

JP 2018-80455 A

However, in the conventional flush toilet described in Patent Document 1 mentioned above, a water supply valve that controls the supply and stop of water to the water supply line and a check valve that prevents backflow in the water supply line are integrally provided within a single valve unit, which creates problems such as the flow path within the valve unit becoming more complex and the number of parts in the valve unit increasing, making the entire valve unit larger.
In addition, the stop valve that shuts off the water supply pipe connected to a water supply source such as a tap is often located below the flush toilet, and the primary water supply line from the stop valve to the valve unit above the water storage tank is also long, so it is necessary to devise a way to route and position the water supply hose that forms the primary water supply line.
However, the water supply hose that forms the primary water supply passage must be strong enough to withstand a relatively high primary water supply pressure, which limits the design freedom for the placement and routing of the water supply hose.
Therefore, in order to prevent the water supply hose from interfering with the water storage tank, it may be necessary to take measures such as reducing the tank capacity of the water storage tank.
Meanwhile, in recent years, in an effort to improve and diversify the design of flush toilets, the goal has been to design the top of the entire flush toilet as low as possible, a so-called "low silhouette." One of the key issues is how to achieve a low silhouette while still ensuring the appropriate tank capacity for the tank device that enables toilet flushing.

The present invention was made to solve the problems of the prior art mentioned above, and aims to provide a flush toilet that allows for greater freedom in tank device design and ensures sufficient tank capacity.

In order to solve the above-mentioned problems, the present invention provides a flush toilet that is flushed with flush water and discharges waste, comprising a toilet body that includes a bowl portion that receives waste, a rim portion formed on the upper edge of the bowl portion, and a drain trap portion that discharges waste within the bowl portion, and a tank device that is provided at the rear of the toilet body and supplies flush water to the toilet body, the tank device comprising a water supply channel through which flush water supplied from a water supply source flows, a valve unit that is provided downstream of a stop valve in the water supply channel and includes an on-off valve that opens and closes the water supply channel, a water storage tank body that is provided at the rear of the toilet body and above the floor surface and stores flush water supplied from the water supply channel, and a tank that supplies flush water in the water supply channel to the water storage tank body. and a water supply section, wherein the water supply passage comprises an upstream water supply pipe extending from the stopcock to the inlet of the valve unit, and a downstream water supply pipe extending from the outlet of the valve unit to the tank water supply section, and the tank water supply section comprises a water discharge section that discharges flush water supplied from the downstream water supply pipe into the water storage tank body, and a backflow prevention section that is provided upstream of the water storage tank body and prevents flush water discharged from the water discharge section into the water storage tank body from flowing back into the downstream water supply pipe, and the valve unit is provided on the outer bottom surface of the water storage tank body or below it, and the backflow prevention section is provided above the water storage tank body.
In the present invention configured in this manner, if the water supply line from the stop valve to the tank water supply section, which is required to be strong enough to withstand the relatively high water supply pressure on the primary side (upstream side), were to be made into a single water supply pipe, the length of the pipe would be long, and there would be many design constraints such as the placement and routing of the water supply pipe.
In contrast, according to the present invention, the water supply line from the stop valve to the tank water supply section can be divided into two water supply lines: an upstream water supply line extending from the stop valve to the inlet section of the valve unit, and a downstream water supply line extending from the outlet section of the valve unit to the tank water supply section, thereby improving the design freedom in terms of the placement and routing of each water supply line.
This allows for greater freedom in designing the tank device and also ensures the tank capacity of the water storage tank body.
Furthermore, since the valve unit is provided on the outer bottom surface of the water storage tank body or below it, while the backflow prevention unit is provided above the water storage tank body, the valve unit and the backflow prevention unit can be provided separately from each other.
Therefore, the internal flow path of the valve unit can be simplified, and the entire valve unit can be made smaller.
Furthermore, by providing the valve unit and the backflow prevention section separately from each other, it is possible to improve the degree of freedom in designing the arrangement of the water supply path from the valve unit to the tank water supply section.
Furthermore, since the valve unit is provided on the outer bottom surface of the water storage tank body or below it, the limited space behind the toilet body and below the water storage tank body can be effectively utilized to provide the valve unit, and the tank capacity of the water storage tank body can be made larger.
Furthermore, compared to when the valve unit is provided above the water storage tank body, the entire tank device and flush toilet can be made lower in profile and more compact.
Furthermore, since the backflow prevention section is located above the water storage tank body, it is possible to prevent flush water in the water storage tank body from flowing back into the downstream water supply pipe.

In the present invention, preferably, the valve unit is provided on the stop valve side below the outer bottom surface of the water storage tank body, the downstream water supply pipe is formed of a flexible hose member, the upstream water supply pipe is formed of a pipe member having higher rigidity than the flexible hose member, and the length of the downstream water supply pipe is set longer than the length of the upstream water supply pipe.
In this invention, the valve unit can be installed on the stop valve side below the outer bottom surface of the water storage tank body. Furthermore, the upstream water supply line extending from the stop valve to the inlet of the valve unit can be made of a pipe member with higher rigidity than a flexible hose member, and the downstream water supply line extending from the outlet of the valve unit to the tank water supply section can be made of a flexible hose member.
Therefore, for the upstream water supply pipeline extending from the stop valve to the inlet of the valve unit, a pipe member with higher rigidity than a flexible hose member is used so that it can withstand the relatively high primary (upstream) water supply pressure, and the length is set shorter than that of the downstream water supply pipeline, thereby ensuring the strength of the upstream water supply pipeline.
On the other hand, in the downstream water supply pipe extending from the outlet of the valve unit to the tank water supply section, a flexible hose member is used and set to be longer than the upstream water supply pipe, thereby improving the design freedom, such as the placement and handling of the downstream water supply pipe.
As a result, the tank capacity of the water storage tank body and surrounding space can be secured, which increases the degree of freedom in designing the entire tank device and flush toilet as a whole.

In the present invention, preferably, the connection between the outlet portion of the downstream water supply pipe and the tank water supply portion is located above the water storage tank body, and the outlet portion of the valve unit is arranged close to the outer bottom surface of the water storage tank body.
In the present invention configured in this manner, the connection between the outlet portion of the downstream water supply pipe and the tank water supply portion is located above the water storage tank body, so by arranging the outlet portion of the valve unit close to the outer bottom surface of the water storage tank body, it is possible to prevent the length of the downstream water supply pipe from becoming unnecessarily long.
Therefore, it is possible to prevent the downstream water supply pipe from unnecessarily occupying the storage area of the water tank behind the toilet body.
This allows for a wider use of the area behind the toilet body, improving the degree of freedom in designing the tank device.
In addition, since the vertical length of the downstream water supply pipe from the outlet of the valve unit to the tank water supply section can be reduced, the vertical size of the entire tank device can be reduced, and the vertical size of the entire flush toilet can also be reduced.

In the present invention, the valve unit is preferably provided so that its outlet is located forward of the water storage tank body.
In the present invention configured in this manner, the outlet of the flow path of the valve unit is located forward of the water tank body, so the distance in the front-to-rear direction between the valve unit and the toilet body can be shortened.
This allows the downstream water supply pipe from the outlet of the bubble unit to the tank water supply section to be detoured from the front of the water storage tank body, thereby shortening the front-to-rear distance of the downstream water supply pipe.
Therefore, the path length of the downstream water supply pipe can be prevented from becoming unnecessarily long, allowing for greater utilization of the area behind the toilet body and further improving the design freedom of the tank device.

In the present invention, preferably, the valve unit has a connection portion with the downstream water supply pipe facing forward.
In the present invention configured in this manner, the connection portion of the valve unit with the downstream water supply pipe is directed forward, so that when the downstream water supply pipe is diverted from the front of the water storage tank body, the forward/backward distance of the downstream water supply pipe from the connection portion between the valve unit and the downstream water supply pipe to the tank water supply portion can also be shortened.
Therefore, the path length of the downstream water supply pipe can be prevented from becoming unnecessarily long, allowing for greater utilization of the area behind the toilet body and further improving the design freedom of the tank device.

In the present invention, preferably, the backflow prevention section comprises a small tank that is arranged to be in communication with the upper part of the water storage tank body and that allows flush water discharged from the discharge section to flow into the water storage tank body, an overflow pipe that is connected to the small tank and that allows flush water that has overflowed from the water storage tank body into the small tank to flow toward the toilet body, and a check valve that prevents flush water from flowing back from the overflow pipe into the small tank.
In the present invention configured in this manner, even if the flushing water in the water storage tank body rises into the small tank, the flushing water in the small tank can be discharged through the overflow pipe toward the toilet body, thereby preventing the flushing water in the small tank from flowing back into the downstream water supply pipe.
The check valve can also prevent flush water that has flowed out of the small tank into the overflow pipe from flowing back.

In the present invention, the valve unit preferably includes a manual operating part that enables the opening and closing of the on-off valve manually in the event of a power outage, and this manual operating part is arranged to be directed toward the side of the toilet body.
In the present invention configured in this manner, the manual operating unit that allows the opening and closing of the valve of the valve unit to be manually operated in the event of a power outage is provided so as to be directed to the side of the toilet body, making it easier for the user to see and access the manual operating unit in an emergency such as a power outage.
Therefore, the visibility and operability of the manual operation unit can be improved.
Furthermore, since the manual operating unit is directed toward the side of the toilet body, even when the downstream water supply pipe from the outlet of the bubble unit to the tank water supply unit is diverted from the front of the water storage tank body, the manual operating unit does not interfere with the downstream water supply pipe, and does not affect the forward/backward distance of the downstream water supply pipe.
Therefore, the path length of the downstream water supply pipe can be prevented from becoming unnecessarily long, allowing the area behind the toilet body to be widely utilized.
In addition, the degree of freedom in designing the tank device can be further improved by manually turning on and off the open/close valve of the valve unit in the event of a power outage.

In the present invention, preferably, the drain trap portion, when viewed in a plane, extends in the front-to-rear direction from an inlet portion connected to the bowl portion to an outlet portion rearward of the bowl portion, and the water storage tank body is arranged so as to surround the upper portion of the drain trap portion from both the left and right sides and the rear side.
In the present invention configured in this manner, the water storage tank body is positioned so that it surrounds the upper part of the drain trap section from both the left and right sides and the rear side, so that the water storage tank body can be positioned by effectively utilizing the limited space behind the toilet body.
Therefore, it is possible to ensure a larger tank capacity for the water storage tank body while achieving a low silhouette and compact size for the entire tank device and the entire flush toilet.

In the present invention, preferably, the water storage tank body has an asymmetrical shape, with a large tank body portion which is the side with the larger volume when the water storage tank body is divided in half at the center left and right, and a small tank body portion which is the side with the smaller volume when the water storage tank body is divided in half at the center left and right, and the backflow prevention portion is provided above the large tank body portion, and the valve unit is provided on the bottom surface of the small tank body portion.
In the present invention configured as described above, the water storage tank body can be made asymmetrical with the large tank body and the small tank body, and the backflow prevention unit can be provided above the large tank body of the water storage tank body. Also, the valve unit can be provided on the bottom surface of the small tank body of the water storage tank body.
This allows the limited space behind the toilet body to be used effectively, ensuring a larger tank capacity for the water storage tank body.
Additionally, it is possible to achieve a low silhouette and compact size for the entire tank device and the entire flush toilet.

In the present invention, preferably, the large tank main body comprises a rear large tank main body located rearward of the drain trap section, a front large tank main body extending forward from the rear large tank main body and located on one of the left and right sides of the drain trap section, and a lower large tank main body extending downward from the rear large tank main body, and the small tank main body comprises a rear small tank main body located rearward of the drain trap section and a front small tank main body extending forward from the rear small tank main body and located on the other of the left and right sides of the drain trap section, the front end of the front large tank main body being located forward of the front end of the front small tank main body, the bottom surfaces of the rear small tank main body and the front small tank main body being located higher than the bottom surface of the lower large tank main body, the backflow prevention section being located above the front large tank main body, and the valve unit being located on the bottom surface of the front small tank main body.
In the present invention configured in this manner, the water storage tank body can be made asymmetrical in shape depending on the rear, front, and lower large tank body portions of the large tank body portion, and the rear and front small tank body portions of the small tank body portion.
In addition, since the backflow prevention unit is provided above the large tank main body portion on the front side of the water storage tank main body, and the valve unit is provided on the bottom surface of the small tank main body portion on the front side of the water storage tank main body, the space occupied by the backflow prevention unit and the valve unit can be reduced.
Therefore, the valve unit can be provided by effectively utilizing the limited space behind the toilet body and below the water storage tank body, and a larger tank capacity can be ensured for the water storage tank body.
It is also possible to achieve a low silhouette and compact size for the entire tank device and the entire flush toilet.

The flush toilet of the present invention allows for greater freedom in tank device design while also ensuring sufficient tank capacity.

1 is a diagram showing the overall configuration of a flush toilet according to an embodiment of the present invention. 1 is a side view of a flush toilet according to an embodiment of the present invention. FIG. FIG. 2 is a partially enlarged plan view showing a portion of the tank apparatus and toilet body of a flush toilet according to an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1 is a perspective view of a flush toilet storage tank according to an embodiment of the present invention, seen from diagonally rear and above. FIG. FIG. 2 is a rear view of the water storage tank of the flush toilet according to one embodiment of the present invention. FIG. 7 is a cross-sectional view taken along line VII-VII in the valve unit of the flush toilet according to one embodiment of the present invention shown in FIG. 2, showing the solenoid valve and main valve body in a closed state (water stop state) during normal operation and during a power outage. 8 is a cross-sectional view similar to FIG. 7 of a valve unit for a flush toilet according to one embodiment of the present invention, showing the state in which the solenoid valve is normally opened to open the main valve body (water flow state). FIG. 9 is a cross-sectional view similar to FIGS. 7 and 8 of a valve unit for a flush toilet according to one embodiment of the present invention, showing the state in which the main valve body has been manually operated to open (water flow state) during a power outage.

A flush toilet according to one embodiment of the present invention will now be described with reference to the accompanying drawings.
First, Figure 1 is a diagram showing the overall configuration of a flush toilet according to one embodiment of the present invention, and Figure 2 is a side view of the flush toilet according to one embodiment of the present invention.
As shown in Figures 1 and 2, a flush toilet 1 according to one embodiment of the present invention comprises a ceramic toilet body 2 and a tank device 4 provided behind it.
The toilet body 2 also has a bowl portion 2a that receives waste, a drain trap portion (drain trap pipe 2b) that extends from the bottom of the bowl portion 2a and discharges waste from within the bowl portion 2a, and a rim portion 2c formed on the upper edge of the bowl portion 2a.

Next, Figure 3 is a partially enlarged plan view showing a portion of the tank device and toilet body of a flush toilet according to one embodiment of the present invention, and Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3.
As shown in FIGS. 1 to 4, the tank device 4 is provided with a water supply pipe 6 (water supply passage) and a water discharge pipe 8 connected to the upstream side and downstream side thereof, respectively.
The upstream side of the water supply pipe 6 is connected to an external water supply source (not shown) such as a waterworks.
Meanwhile, the downstream side of the water supply pipe 6 is connected to a water storage tank 10 (details of which will be described later) of the tank device 4. As a result, flush water is supplied from the water supply pipe 6 to the water storage tank 10.
In addition, a stop valve 12 and a valve unit 14 are provided on the water supply pipe 6 from the upstream side to the downstream side.
Furthermore, the valve unit 14 includes a constant flow valve 16 provided in the water supply pipe 6, and an electromagnetic valve 18 that opens and closes an on-off valve (diaphragm-type main valve body 17) provided downstream of this constant flow valve 16.
The structure of the valve unit 14 will be described in detail later.

Next, as shown in Figures 1 to 4, the tank device 4 further includes a connecting unit 20 connected to the downstream side of the valve unit 14 of the water supply pipe 6, and a tank unit 22 connected downstream of this connecting unit 20 and including the water storage tank 10.
As shown in Figure 1, the water supply pipe 6 has an upstream water supply line 6a extending from the stop valve 12 to the inlet portion 14a of the valve unit 14, and a downstream water supply line 6b extending from the outlet portion 14b of the valve unit 14 to the connecting unit 20.
Furthermore, in the valve unit 14, the flow rate of the cleaning water in the water supply pipe 6 therein is adjusted to a constant value by a constant flow valve 16.
Thereafter, the solenoid valve 18 opens electromagnetically, and the flow path of the water supply pipe 6 is opened by the on-off valve (diaphragm-type main valve body 17), so that the cleaning water in the water supply pipe 6 is supplied to the tank unit 22 via the connecting unit 20.

That is, as shown in Figures 1 to 4, the connecting unit 20 is a tank water supply section that is provided upstream of the tank unit 22 and supplies cleaning water supplied from the water supply pipe 6 into the water storage tank 10 of the tank unit 22.
As shown in FIGS. 1 to 4, the connecting unit 20 specifically includes a water supply nozzle 23 (water discharge portion), a water receiving housing 24 (small tank), an overflow pipe 26, and a check valve 28.
First, the water receiving housing 24 of the connecting unit 20 has its lower opening 24 a detachably connected to the upper opening 10 a of the water storage tank 10 of the tank unit 22 .

Next, as shown in Figures 1 to 4, the water supply nozzle 23 of the connecting unit 20 is fixed to the side wall 24b of the water receiving housing 24, and its upstream end is connected to the downstream water supply pipe 6b extending from the outlet portion 14b of the valve unit 14.
On the other hand, the downstream side of the water supply nozzle 23 extends from the side wall 24b of the water receiving housing 24 to the inside, and the downstream end (tip) of the water supply nozzle 23 is directed downward to form a water supply port 23a.
That is, as shown in Figures 1, 2 and 4, the water supply port 23a of the water supply nozzle 23 is a water discharge portion that discharges cleaning water supplied from the downstream water supply pipe 6b of the water supply pipe 6 into the water receiving housing 24.
In addition, the cleaning water W1 discharged from the water supply port 23a of the water supply nozzle 23 into the water receiving housing 24 is supplied into the water storage tank 10 through the lower opening 24a of the water receiving housing 24 and the upper opening 10a of the water storage tank 10.

Next, as shown in FIGS. 1 and 4, the overflow pipe 26 of the connecting unit 20 connects the discharge pipe 8 to an overflow port 24c provided in a part of the side wall 24b of the water receiving housing 24.
The discharge pipe 8 is a connecting pipe connected at its upstream side to the pump 30 of the tank device 4 , and at its downstream side to the rim water channel 2 d inside the rim portion 2 c of the toilet body 2 .

Next, as shown in Figures 1 and 4, the check valve 28 of the connecting unit 20 is provided at the overflow port 24c, allowing the flushing water in the water receiving housing 24 to flow from the overflow port 24c into the overflow pipe 26, while preventing the flushing water in the overflow pipe 26 from flowing back into the water receiving housing 24.
In addition, the water receiving housing 24, overflow pipe 26, and check valve 28 of the connecting unit 20 are each located upstream of the water storage tank 10 and above the water storage tank 10, and also function as a backflow prevention section B (see Figure 1) that prevents the flushing water discharged from the water discharge section (water supply port 23a of the water supply nozzle 23) through the water receiving housing 24 into the water storage tank 10 from flowing back into the downstream water supply pipe 6b.

Next, as shown in FIGS. 1 and 4, the tank unit 22 includes a water storage tank 10, a pump 30, a float switch 32, a drain plug 34, a controller C, and the like.
The pump 30 is provided in a part (midway) of a water pipe 36 connected to the upstream side of the discharge pipe 8. An upstream end 36a of this water pipe 36 is connected to a downstream end 38a of a suction pipe 38 provided in the water storage tank 10.

As shown in Figures 1 and 4, when the pump 30 is operated, the flush water stored in the water storage tank 10 is sucked from the suction pipe 38 into the water supply pipe 36, and then pressure-fed to the discharge pipe 8 via the pump 30.
As a result, all of the flush water supplied from the water storage tank 10 to the discharge pipe 8 by the pump 30 is supplied into the rim conduit 2d from the inlet 2e of the rim conduit 2d.
The flush water in the rim water conduit 2d is then discharged into the bowl portion 2a from the rim water outlet 2f at the downstream end of the rim water conduit 2d, thereby flushing the toilet (so-called toilet flushing using 100% rim water discharge).
That is, each of the water supply pipe 36 and the discharge pipe 8 functions as a flush water supply pipe that supplies flush water pressure-fed from the water storage tank 10 by the pump 30 to the toilet body 2 .

The float switch 32 detects the water level in the water storage tank 10. The opening and closing operation of the solenoid valve 18 of the valve unit 14 is controlled by the controller C based on the water level in the water storage tank 10 detected by the float switch 32.
The operation of the pump 30 is also controlled by the controller C based on the water level in the water storage tank 10 detected by the float switch 32 .
For example, when the water level in the water storage tank 10 detected by the float switch 32 is below a predetermined level, the solenoid valve 18 opens, the water supply pipe 6 is opened, and the pump 30 is activated.
When the water level in the water storage tank 10 reaches a predetermined level, the electromagnetic valve 18 closes, the water supply pipe 6 is closed, and the pump 30 is stopped.
Furthermore, under the control of the controller C, the pump 30 can be driven while water is being supplied from the water supply pipe 6 to the water storage tank 10, so that flushing water can be pressurized from the water storage tank 10 to the toilet body 2, allowing water to be supplied from the water supply pipe 6 to the water storage tank 10 and flushing water to be supplied from the pump 30 to the toilet body 2 simultaneously.

The drain plug 34 is located on the bottom of the water storage tank 10. This drain plug 34 is always closed during normal use and can be opened as needed to allow flushing water from the water storage tank 10 to be drained to the outside.

Next, the water storage tank 10 of the tank unit 22 will be described in detail with reference to FIGS.
Figure 5 is a perspective view of the flush toilet storage tank according to one embodiment of the present invention, seen from diagonally rear and above, and Figure 6 is a rear view of the flush toilet storage tank according to one embodiment of the present invention.
First, as shown in FIG. 4, the water storage tank 10 of the tank unit 22 includes a single tank body 40 and a moisture-proof material 42 that covers the outside of the tank body 40 .
3 to 6, if an imaginary vertical plane that divides the water storage tank 10 of the tank unit 22 in half at the center, left and right, is defined as a "vertical plane A1," the single tank body 40 of the water storage tank 10 and the moisture-proof material 42 on its outside have a large tank section 44 and a small tank section 46 on the left and right sides of the vertical plane A1. As a result, the water storage tank 10 is divided into two halves, left and right, by the vertical plane A1, into the large tank section 44 and the small tank section 46.

As shown in FIG. 6, the large tank section 44 is disposed on the left side of the vertical plane A1 when the tank body 40 and the dew prevention material 42 are viewed from the rear side, and the small tank section 46 is disposed on the right side of the vertical plane A1 when the tank body 40 and the dew prevention material 42 are viewed from the rear side, and the volume V1 of the large tank section 44 is set larger than the volume V2 of the small tank section 46 (V1 > V2).
As a result, the water storage tank 10 has an asymmetrical shape (generally a C-shape or U-shape in plan view in FIG. 3) due to the large tank portion 44 and the small tank portion 46.

Next, as shown in Figures 1 to 4, the drain trap pipe 2b of the toilet body 2 extends in the front-to-rear direction from the inlet portion 2g connected to the lower part of the bowl portion 2a toward the outlet portion 2h located behind the bowl portion 2a.
As shown in Figures 3 to 6, the large tank section 44 of the water storage tank 10 comprises a rear large tank section 44a that is arranged on the rear side of the drain trap pipe 2b, a front large tank section 44b that extends forward from the rear large tank section 44a and is arranged on one of the left and right sides of the drain trap pipe 2b (the right side when viewed from the front side of the toilet body 2), and a lower large tank section 44c that extends downward from the rear large tank section 44a.

Next, as shown in Figures 3 to 6, the small tank section 46 of the water storage tank 10 comprises a rear small tank section 46a arranged on the rear side of the drain trap pipe 2b, and a front small tank section 46b extending forward from the rear small tank section 46a and arranged on the other left or right side of the drain trap pipe 2b (on the left side when viewed from the front side of the toilet body 2).
That is, as shown in Figures 1, 3 and 4, the water storage tank 10 is disposed so as to surround the upper part of the drain trap pipe 2b from both the left and right sides and the rear side.

Next, as shown in Figure 4, the toilet body 2 is provided with a large tank storage section S1 and a small tank storage section S2 in the area rearward of the bowl section 2a, which store the large tank section 44 and the small tank section 46, respectively, at a position above the floor surface F1.
In other words, the large tank storage section S1 is formed in an area rearward of the bowl section 2a of the toilet body 2, on one side (to the right of the vertical plane A1 when looking at the toilet body 2 from the front) of a vertical plane A1 that divides the toilet body 2 in half at the center.
On the other hand, the small tank storage section S2 is formed in an area rearward of the bowl section 2a of the toilet body 2, on the other left or right side of the vertical plane A1 (to the left of the vertical plane A1 when looking at the toilet body 2 from the front side).

Furthermore, as shown in Figures 4 to 6, when the large tank section 44 and the small tank section 46 are installed in the large tank storage section S1 and the small tank storage section S2, respectively, the lowest position of the bottom surface of the large tank section 44 (the lowest position P1 of the bottom surface 44d of the lower large tank section 44c) is located lower than the lowest position of the bottom surface of the small tank section 46 (the lowest position P2 of the bottom surface 46c of the rear small tank section 46a and the front small tank section 46b).
Furthermore, as shown in Figures 4 to 6, when the large tank section 44 and the small tank section 46 are installed in the large tank storage section S1 and the small tank storage section S2, respectively, the highest position of the upper surface of the large tank section 44 (the highest position P3 of the upper surface 44e of the front large tank section 44b) is located above the highest position P4 of the upper surfaces 46d of the rear small tank section 46a and the front small tank section 46b of the small tank section 46, and is located below the upper surface 2i of the rim section 2c of the toilet body 2.
As shown in FIGS. 3 to 6, a position P5 of the front end 44f of the front large tank portion 44b is located forward of a position P6 of the front end 46e of the front small tank portion 46b.

4, the suction pipe 38 is provided within both the rear large tank section 44a and the lower large tank section 44c of the large tank section 44 of the tank body 40. The upstream end 36a of the water pipe 36 extending upstream (laterally) from the pump 30 is watertightly connected to the downstream end 38a of the suction pipe 38, which is part of the large tank section 44.
As shown in Figure 3, the upstream end of the discharge pipe 8 is connected to the downstream end of the water supply pipe 36 extending downstream (upward) from the pump 30, and the downstream end (outlet 8a) of the discharge pipe 8 is connected to the inlet 2e of the rim water channel 2d on the other left or right side of the vertical plane A1 of the toilet body 2 (to the left of the vertical plane A1 when viewed from the front of the toilet body 2).

Next, as shown in Figure 4, the side wall surface 44g of the large tank section 44 on the vertical plane A1 side (center side of the left and right) is positioned outside the drain trap pipe 2b within the large tank storage section S1 (to the right when looking at the drain trap pipe 2b from the front side).
Similarly, the side wall surface 46f of the small tank section 46 on the vertical plane A1 side (center side of the left and right) is positioned outside the drain trap pipe 2b within the small tank storage section S2 (on the left side when looking at the drain trap pipe 2b from the front side).
As shown in Figures 4 and 5, the drain trap pipe 2b is located in the center of the left and right sides of the toilet body 2, and the upstream end 36a of the water pipe 36 is connected to the side wall surface 44g on the left and right side of the large tank section 44 on the side of the drain trap pipe 2b.

Furthermore, as shown in FIGS. 3 and 4, the pump 30 is disposed behind the bowl portion 2a of the toilet body 2 and above the drain trap pipe 2b.
In addition, the pump 30 is positioned forward of the rear large tank section 44a and the rear small tank section 46a, and is positioned in the left-right space between the front large tank section 44b and the front small tank section 46b.
As a result, the pump 30 is provided closer to the center of the left and right of the toilet body 2 than the upstream end 36 a of the water pipe 36 and the downstream end (outlet portion 8 a ) of the water discharge pipe 8 .

Next, details such as the structure of the valve unit 14 of a flush toilet according to one embodiment of the present invention will be explained with reference to FIGS. 1, 2, 4, and 7 to 9.
FIG. 7 is a cross-sectional view taken along line VII-VII of the valve unit of the flush toilet according to the embodiment of the present invention shown in FIG.
First, as shown in Figures 1, 2, 4 and 7, the main body 48 of the valve unit 14 is located below the outer bottom surface of the water storage tank 10 of the tank device 4 (more specifically, the bottom surfaces 46c of the rear small tank portion 46a and the front small tank portion 46b of the water storage tank 10) and is fixed to an attachment member 49 (see Figure 4) fixed to the rear region R1 of the toilet body 2.
Furthermore, the main body 48 of the valve unit 14 is provided on the stop valve 12 side below the bottom surfaces 46c of the rear small tank portion 46a and the front small tank portion 46b of the water storage tank 10.

2 and 7, a primary water supply passage 48a and a secondary water supply passage 48b are formed inside the main body 48 of the valve unit 14. These water supply passages 48a, 48b extend generally in the front-to-rear direction from the upstream side to the downstream side.
As shown in FIGS. 2 and 7, the outlet 14b of the valve unit 14 corresponds to the downstream end of the secondary water supply passage 48b of the main body 48.
Furthermore, as shown in Figures 2 and 7, the outlet portion 14b (connection portion C1) of the valve unit 14 is directed forward and is also close to the bottom surfaces 46c of the rear small tank portion 46a and the front small tank portion 46b of the water storage tank 10.
As shown in FIG. 2, the front end of the outlet portion 14b (connection portion C1) of the valve unit 14 is located further forward than the front end 46e of the front small tank portion 46b of the water storage tank 10.

As shown in FIGS. 1 to 4 and 7, the downstream water supply pipe 6b connected to the outlet portion 14b (connection portion C1) of the valve unit 14 is formed of a flexible hose member H.
That is, the upstream end of the hose member H is connected to the outlet portion 14b (connection portion C1) of the valve unit 14, and the downstream end of the hose member H (outlet portion of the downstream water supply pipe 6b) is connected to the inlet portion (connection portion C2) of the water supply nozzle 23.
In addition, the connection portion C2 between the outlet portion of the downstream water supply pipe 6b and the inlet portion of the water supply nozzle 23 of the connecting unit 20 is located above the water storage tank 10.On the other hand, as shown in Figures 2 to 4 and 7, the upstream water supply pipe 6a connected to the inlet portion 14a of the valve unit 14 is formed of a pipe member T (see Figure 4) which is more rigid than the flexible hose member H.
In addition, the length L1 of the downstream water supply pipe 6b and hose member H from the outlet portion 14b of the valve unit 14 to the connection portion C1 of the water supply nozzle 23 is set longer than the length L2 of the upstream water supply pipe 6a and pipe member T from the stop valve 12 to the inlet portion 14a of the valve unit 14 (L1 > L2).

Next, as shown in Figures 1, 2, 4 and 7, the valve unit 14 is equipped with, in addition to the above-mentioned constant flow valve 16, diaphragm-type main valve body 17 and solenoid valve 18 provided in its main body 48, a power outage manual water supply operating device 50 and a power outage manual drainage operating device 52.
These devices 50, 52 function as manual operation units (operation units during power outages) for use as a countermeasure against power outages, enabling toilet flushing during a power outage.
Specifically, as shown in Figures 1, 2 and 7, the power outage manual water supply operating device 50 of the valve unit 14 has a handle portion 54 that is rotatably mounted on the side of the main body portion 48 of the valve unit 14 (on the left side when looking at the toilet body 2 and tank device 4 from the front side).
1, 2, and 7, the power outage manual water supply operating device 50 includes an operating shaft (spindle 56) whose outer end is fixed to the handle 54. When the handle 54 is rotated around its central axis of rotation (operating axis O1), the spindle 56 can move (slide) in the axial direction of the operating axis O1.

Next, as shown in Figure 7, under normal conditions, the diaphragm-type main valve body 17 opens and closes a communication port (water supply port 48c) that connects the primary side water supply passage 48a and the secondary side water supply passage 48b in the main body 48 of the valve unit 14 by operating the solenoid valve 18.
The solenoid valve side pilot valve element 18a of the solenoid valve 18 opens and closes the solenoid valve side pilot hole 58 of the main body 48 of the valve unit 14 which is connected to the secondary side water supply passage 48b.
Furthermore, as shown in FIG. 4, when the solenoid valve side pilot valve element 18a closes (closes) the solenoid valve side pilot hole 58, the downstream side of the pilot hole (main valve side pilot hole 62) of the main valve side pressure chamber 60 that houses the diaphragm-type main valve element 17 is closed by the tip end 56a of the spindle 56.

Next, the main body 48 of the valve unit 14 is provided with a pressure relief passage 64 that connects the solenoid valve side pilot valve chamber 18b, which houses the solenoid valve side pilot valve element 18a, with the main valve side pressure chamber 60.
Here, when the solenoid valve side pilot valve body 18 a closes (closes) the solenoid valve side pilot hole 58 , the air in the main valve side pressure chamber 60 cannot escape to the pressure relief passage 64 .
As a result, the diaphragm-type main valve body 17 is pressed toward the valve seat 66 by the pressure in the main valve side pressure chamber 60, so that the water supply port 48c is closed by the main valve body 17 (water stop state).
Furthermore, a communication passage 68 is provided in the main body 48 of the valve unit 14, extending from near the spindle 56 to the secondary water supply passage 48b. This communication passage 68 also communicates with the solenoid valve side pilot hole 58.
An O-ring 70 is provided on the outer peripheral surface of the spindle 56 near the tip 56a thereof. As a result, when the main valve body 17 is normally in a closed state, the O-ring 70 of the spindle 56 seals the main valve pressure chamber 60 and the communication passage 68 so that they do not communicate with each other.

Next, Figure 8 is a cross-sectional view similar to Figure 7 of the valve unit 14 of a flush toilet 1 according to one embodiment of the present invention, and shows the state (water flow state) in which the solenoid valve 18 is normally opened to open the main valve body 17.
As shown in FIG. 8 , when the solenoid valve 18 is actuated by a command signal (valve opening operation signal) sent from the controller C and the solenoid valve side pilot valve element 18 a opens the solenoid valve side pilot hole 58, the pressure relief passage 64 communicates with the solenoid valve side pilot hole 58.
After passing through the pressure relief passage 64 , the air in the main valve pressure chamber 60 can flow out from the solenoid valve pilot hole 58 to the communication passage 68 .
As a result, when the pressure in the main valve side pressure chamber 60 drops below the water supply pressure in the primary side water supply passage 48a, the main valve body 17 moves in the valve opening direction, and the water supply port 48c is opened.
As a result, the flush water in the primary water supply passage 48a that has passed through the constant flow valve 16 flows into the secondary water supply passage 48b from the water supply port 48c.

Then, as shown in Figure 7, when the solenoid valve side pilot valve body 18a of the solenoid valve 18 closes the solenoid valve side pilot hole 58 again in response to a command signal (valve closing operation signal) sent from the controller C, the air in the main valve side pressure chamber 60 can no longer be depressurized to the pressure relief passage 64, while the cleaning water in the primary side water supply passage 48a around the valve seat 66 passes through the bleed hole 72 in the main valve body 17 and flows into the main valve side pressure chamber 60.
This increases the pressure in the main valve side pressure chamber 60, and the diaphragm-type main valve body 17 is pressed toward the valve seat 66 by the pressure in the main valve side pressure chamber 60, so that the water supply port 48c is closed by the main valve body 17 (water stop state).

Next, Figure 9 is a cross-sectional view similar to Figures 7 and 8 of the valve unit 14 of a flush toilet 1 according to one embodiment of the present invention, and shows the state (water flow state) in which the main valve body 17 has been manually opened using the power outage manual water supply operating device 50 during a power outage.
As shown in FIG. 9 , the handle portion 54 of the power outage manual water supply operating device 50 is threadedly engaged with a part of the main body portion 48 of the valve unit 14 and is fixed to one end of the spindle 56 by a fastener 74 .
During a power outage, the solenoid valve 18 does not operate, so by rotating the handle portion 54 of the power outage manual water supply operating device 50 in one direction around the operating axis O1, the spindle 56 moves axially outward from the operating axis O1 (distal to the main valve side pilot hole 62).
Then, when the spindle 56 and the O-ring 70 have moved to the point where the main valve side pressure chamber 60 and the communicating passage 68 are connected to each other, the air in the main valve side pressure chamber 60 passes through the pressure relief passage 64 and can then flow out from the solenoid valve side pilot hole 58 into the communicating passage 68.
As a result, when the pressure in the main valve side pressure chamber 60 drops below the water supply pressure in the primary side water supply passage 48a, the main valve body 17 moves in the valve opening direction, and the water supply port 48c is opened.
As a result, the flush water in the primary water supply passage 48a that has passed through the constant flow valve 16 flows into the secondary water supply passage 48b from the water supply port 48c.

As shown in Figures 7 and 9, during a power outage, the handle portion 54 of the power outage manual water supply operating device 50 is rotated in the other direction around the operating axis O1, causing the spindle 56 to move axially inward of the operating axis O1 (proximal to the main valve side pilot hole 62).
This prevents the air in the main valve side pressure chamber 60 from being depressurized into the pressure relief passage 64 and the connecting passage 68, while allowing cleaning water from the primary side water supply passage 48a around the valve seat 66 to flow into the main valve side pressure chamber 60 through the bleed hole 72 in the main valve body 17.
As a result, the pressure in the main valve pressure chamber 60 increases, and the diaphragm-type main valve element 17 is pressed toward the valve seat 66 by the pressure in the main valve pressure chamber 60 .
As a result, the water supply port 48c changes from a water-passing state (see FIG. 9) in which it is opened by the main valve body 17 to a water-stopping state (see FIG. 7) in which it is closed by the main valve body 17.
Therefore, in the event of a power outage, as shown in Figures 7 and 9, by manually operating the handle portion 54, it is possible to operate the water supply and stop operation (water supply and stop operation) to supply and stop the cleaning water in the water supply pipe 6 to the tank unit 22 via the connecting unit 20.

Here, as shown in Figures 7 to 9, the axial outer end surface 56b of the spindle 56 of the power outage manual water supply operating device 50 always protrudes outward beyond the axial outer end surface 54a of the handle portion 54, and the axial outer end portion 56b of the spindle 56 forms a protrusion that protrudes outward in the axial direction of the handle portion 54.
In particular, as shown in Figure 9, when the main valve body 17 is open during a power outage, the handle portion 54 and the spindle 56 are each in a position that is moved further outward in the axial direction than when the main valve body 17 is closed as shown in Figure 7.
As a result, as shown in Figure 9, when the main valve body 17 is open during a power outage, the axial outer end surface 56b of the spindle 56 is in contact with the inner surface of the exterior panel P, forming a contact point that interferes with the exterior panel P.
In other words, when the main valve body 17 is open during a power outage, the axial outer end surface 56b (contact portion) of the spindle 56 protrudes outward in the left-right direction beyond the mounting position P0 of the exterior panel P.

1, a drain socket 76 is provided downstream of the drain trap pipe 2b of the toilet body 2, i.e., at the outlet 2h at the rear and lower end of the drain trap pipe 2b. An opening/closing valve 78 is provided inside this drain socket 76 to open and close the flow path.
In addition, the manual drainage operating device 52 for use in the event of a power outage is equipped with an operating wire 80 that is connected to the opening/closing valve 78 of the drainage socket 76 so that it can be opened and closed, and a fixing unit 82 that holds the operating wire 80 slidably and fixes it to the toilet body 2.

Next, the end of the operating wire 80 on the drain socket side is directly or indirectly connected to a part of the on-off valve 78 .
Furthermore, a gripping ring member 84 is provided at the end of the operating wire 80 on the toilet body side (user side), so that the user can grip it.
In the event of a power outage, the user can grasp the ring member 84 and slide the operating wire 80 back and forth relative to the fixed unit 82 to open and close the on-off valve 78 of the drain socket 76.

For example, even if the operation of the solenoid valve 18 and pump 30 of the tank device 4 is stopped during a power outage, by manually rotating the handle portion 54 of the power outage manual water supply operating device 50, it is possible to open and close the opening and closing valve (main valve body 17) of the valve unit 14 and stop the water supply to the water storage tank 10.
Here, during a power outage, first, the handle portion 54 of the power outage manual water supply operating device 50 is manually rotated to open the opening/closing valve (main valve body 17) of the valve unit 14, thereby allowing water to be supplied to the water storage tank 10.
Next, the gripping ring member 84 of the power outage manual drain operating device 52 can be manually operated to close the on-off valve 78 of the drain socket 76 .
When the water level in the water storage tank 10 reaches or exceeds a predetermined level and rises into the water receiving housing 24 above the water storage tank 10, the flushing water in the housing 24 is bypassed from the overflow flow path (overflow pipe 26) to the water supply path (discharge pipe 8) downstream of the pump 30, and then supplied to the toilet body 2.
This makes it possible to seal the flow path within the drain socket 76 upstream of the opening/closing valve 78 of the drain socket 76 and within the drain trap pipe 2b of the toilet body 2, allowing water to accumulate in the bowl portion 2a of the toilet body 2.
Next, when the power outage manual drain operating device 52 is operated again to open the opening/closing valve 78 of the drain socket 76, the flushing water in the bowl portion 2a of the toilet body 2 can be reliably discharged from the drain trap pipe 2b through the drain socket 76 to the outside.
Thereafter, the handle portion 54 of the power outage manual water supply operating device 50 is manually rotated to close the opening/closing valve (main valve body 17) of the valve unit 14, thereby completing a series of water supply and drainage operations for the toilet body 2 during a power outage.

Next, the operation of the flush toilet 1 according to the embodiment of the present invention described above will be explained with reference to FIGS. 1 to 9.
Apart from the flush toilet 1 according to this embodiment, if the water supply pipe 6 from the stop valve 12 to the tank water supply section (water supply nozzle 23 of the connecting unit 20), which must be strong enough to withstand the relatively high water supply pressure on the primary side (upstream side) of the valve unit 14, were to be made into a single water supply pipe, the length of the pipe would be longer, and there would be more design constraints on the placement and routing of the water supply pipe.
In contrast, with the flush toilet 1 of this embodiment, the water supply line from the stop valve 12 to the tank water supply section (water supply nozzle 23 of the connecting unit 20) can be divided into two water supply lines: an upstream water supply line 6a extending from the stop valve 12 to the inlet 14a of the valve unit 14, and a downstream water supply line 6b extending from the outlet 14b of the valve unit 14 to the tank water supply section (water supply nozzle 23 of the connecting unit 20), thereby improving the design freedom in terms of the placement and routing of each water supply line 6a, 6b.
This allows for greater freedom in designing the tank device 4 and also ensures the tank capacity of the water storage tank 10 .
In addition, the valve unit 14 is located below the outer bottom surface of the water storage tank 10 (more specifically, the bottom surfaces 46c of the rear small tank portion 46a and the front small tank portion 46b of the water storage tank 10), while the backflow prevention portion B (the water receiving housing 24, overflow pipe 26, and check valve 28 of the connecting unit 20) is located above the water storage tank 10.
This allows the valve unit 14 and the backflow prevention section B to be provided separately from each other, which simplifies the internal flow path of the valve unit 14 and allows the entire valve unit 14 to be made smaller.
In addition, by providing the valve unit 14 and the backflow prevention section B separately from each other, it is possible to improve the design freedom, such as the arrangement of the water supply path (downstream water supply pipe 6b) from the valve unit 14 to the tank water supply section (water supply nozzle 23 of the connecting unit 20).
Furthermore, because the valve unit 14 is located below the outer bottom surface of the water storage tank 10 (more specifically, the bottom surfaces 46c of the rear small tank portion 46a and the front small tank portion 46b of the water storage tank 10), the valve unit 14 can be located by effectively utilizing the limited space in the rear region R1 of the toilet body 2 and the lower region of the water storage tank 10. This allows the water storage tank 10 to have a larger tank capacity.
Furthermore, compared to when the valve unit 14 is provided above the water storage tank 10, the entire tank device 4 and the entire flush toilet 1 can be made lower in profile and more compact.
Furthermore, since the backflow prevention section B is provided above the water storage tank 10, it is possible to prevent flush water in the water storage tank 10 from flowing back into the downstream water supply pipe 6b.

Next, with the flush toilet 1 according to this embodiment, the valve unit 14 can be installed on the stop valve 12 side, below the outer bottom surface of the water storage tank 10 .
Furthermore, the upstream water supply pipe 6a extending from the stop valve 12 to the inlet 14a of the valve unit 14 could be formed using a pipe member T with higher rigidity than the flexible hose member H. In addition, the downstream water supply pipe 6b extending from the outlet 14b of the valve unit 14 to the tank water supply section (connection portion C2 of the water supply nozzle 23) could be formed using the flexible hose member H.
Therefore, for the upstream water supply pipe 6a extending from the stop valve 12 to the inlet 14a of the valve unit 14, a pipe member T with higher rigidity than the flexible hose member H is used so that it can withstand the relatively high primary (upstream) water supply pressure, and the length is set shorter than the downstream water supply pipe 6b, thereby ensuring the strength of the upstream water supply pipe 6a.
On the other hand, in the downstream water supply pipe 6b extending from the outlet portion 14b of the valve unit 14 to the tank water supply portion (water supply nozzle 23 of the connecting unit 20), a flexible hose member H is used and set to be longer than the length of the upstream water supply pipe 6a, thereby improving the design freedom, such as the placement and handling of the hose member H (downstream water supply pipe 6b).
As a result, the tank capacity and surrounding space of the water storage tank 10 can be secured, which increases the degree of freedom in designing the tank device 4 as a whole and the flush toilet 1 as a whole.

Next, in the flush toilet 1 according to this embodiment, the connection C2 between the outlet of the downstream water supply pipe 6b and the tank water supply section (the inlet of the water supply nozzle 23 of the connecting unit 20) is located above the water storage tank 10.
In addition, by arranging the outlet portion 14b of the valve unit 14 close to the outer bottom surface of the water storage tank 10, the length of the hose member H (downstream water supply pipe 6b) can be prevented from becoming unnecessarily long.
Therefore, unnecessary occupation of the hose member H (downstream water supply pipe 6b) in the storage area R1 of the water storage tank 10 at the rear of the toilet body 2 can be suppressed.
Therefore, the rear region R1 of the toilet body 2 can be widely utilized, and the degree of freedom in designing the tank device 4 can be improved.
In addition, the vertical length of the hose member H (downstream water supply pipe 6b) from the outlet portion 14b (connection portion C1) of the valve unit 14 to the inlet portion (connection portion C2) of the water supply nozzle 23 can be reduced.
Therefore, the vertical size of the entire tank device 4 can be reduced, and the vertical size of the entire flush toilet 1 can also be reduced.

Next, with the flush toilet 1 according to this embodiment, the front end of the outlet 14 b of the flow path of the valve unit 14 is located further forward than the front end 46 e of the storage tank 10 .
This allows the distance between the valve unit 14 and the toilet body 2 in the front-to-rear direction to be shortened.
Therefore, when the hose member H (downstream water supply pipe 6b) from the outlet portion 14b (connection portion C1) of the valve unit 14 to the inlet portion (connection portion C2) of the water supply nozzle 23 is routed from the front of the water storage tank 10, the front-to-rear distance of the hose member H (downstream water supply pipe 6b) can also be shortened.
Therefore, the path length L1 of the hose member H (downstream water supply pipe 6b) can be prevented from becoming unnecessarily long, allowing for greater utilization of the rear region R1 of the toilet body 2 and further improving the design freedom of the tank device 4.

Next, with the flush toilet 1 of this embodiment, the connection C1 between the outlet 14b of the valve unit 14 and the hose member H (downstream water supply pipe 6b) is directed forward. This makes it possible to shorten the front-to-rear distance of the hose member H (downstream water supply pipe 6b) from the connection C1 between the outlet 14b of the valve unit 14 and the hose member H (downstream water supply pipe 6b) to the inlet (connection C2) of the water supply nozzle 23 when the hose member H (downstream water supply pipe 6b) is routed around from the front of the water storage tank 10.
Therefore, the path length L1 of the hose member H (downstream water supply pipe 6b) can be prevented from becoming unnecessarily long, allowing for greater utilization of the rear region R1 of the toilet body 2 and further improving the design freedom of the tank device 4.

Next, with the flush toilet 1 of this embodiment, even if the flush water in the storage tank 10 rises up into the small tank (water receiving housing 24), the flush water in the water receiving housing 24 can be made to flow out from the overflow pipe 26 toward the toilet body 2. This makes it possible to prevent the flush water in the water receiving housing 24 from flowing back into the hose member H (downstream water supply pipe 6b).
The check valve 28 also prevents flush water that has flowed out from the water receiving housing 24 into the overflow pipe 26 from flowing back.

Next, the flush toilet 1 according to this embodiment is provided with a power outage manual water supply operating device 50 that allows the opening and closing of the on-off valve (diaphragm-type main valve body 17) of the valve unit 14 to be manually operated during a power outage.
The manual operation portion (handle portion 54 ) of the power outage manual water supply operating device 50 is arranged to be directed toward the side of the toilet body 2 .
This makes it easier for the user to see and access the handle portion 54 of the manual water supply operating device 50 in the event of an emergency such as a power outage.
Therefore, the visibility and operability of the handle portion 54 of the manual water supply operating device 50 during a power outage can be improved.
Furthermore, since the handle portion 54 of the manual water supply operating device 50 for use in case of a power outage is directed toward the side of the toilet body 2, even when the hose member H (downstream water supply pipe 6b) from the outlet portion 14b of the valve unit 14 to the inlet portion (connection portion C2) of the water supply nozzle 23 is diverted from the front of the water storage tank 10, the handle portion 54 of the manual water supply operating device 50 for use in case of a power outage does not interfere with the hose member H (downstream water supply pipe 6b), and does not affect the forward/backward distance of the hose member H (downstream water supply pipe 6b).
Therefore, the path length L1 of the hose member H (downstream water supply pipe 6b) can be prevented from becoming unnecessarily long, allowing the area R1 behind the toilet body 2 to be widely utilized.
In addition, the design freedom of the tank device 4 can be further improved by manually stopping the water supply by opening and closing the valve (diaphragm-type main valve body 17) of the valve unit 14 in the event of a power outage.

Next, with the flush toilet 1 according to this embodiment, the water storage tank 10 is positioned above the drain trap pipe 2b so as to surround it from both the left and right sides and the rear side.
This allows the water storage tank 10 to be placed by effectively utilizing the limited space in the rear region R1 of the toilet body 2.
Therefore, it is possible to ensure a larger tank capacity for the water storage tank 10 while achieving a low silhouette and compact size for the entire tank device 4 and the entire flush toilet 1 .

Next, with the flush toilet 1 according to this embodiment, the storage tank 10 can be made asymmetrical in shape, with the large tank main body (large tank 44) and the small tank main body (small tank 46).
Furthermore, the backflow prevention section B (the water receiving housing 24 of the connecting unit 20, the overflow pipe 26, and the check valve 28) can be provided above the water storage tank 10.
Furthermore, the valve unit 14 can be provided on the bottom surface 46 c of the small tank portion 46 of the water storage tank 10 .
As a result, the limited space in the rear region R1 of the toilet body 2 can be effectively utilized, and the tank capacity of the water storage tank 10 can be increased.
Additionally, the tank device 4 as a whole and the flush toilet 1 as a whole can be made low-profile and compact.

Next, according to the flush toilet 1 of this embodiment, the water storage tank 10 can be made asymmetrical in shape depending on the rear large tank section 44a, front large tank section 44b, and lower large tank section 44c of the large tank section 44, and the rear small tank section 46a and front small tank section 46b of the small tank section 46.
In addition, backflow prevention section B (water receiving housing 24, overflow pipe 26, check valve 28 of connecting unit 20) is provided above the front large tank section 44b of the water storage tank 10, and valve unit 14 is provided on the bottom surface 46c of the front small tank section 46b of the water storage tank 10.
As a result, the spaces occupied by the backflow prevention section B and the valve unit 14 can be reduced.
Therefore, the limited space in the rear region R1 of the toilet body 2 and below the water tank 10 can be effectively utilized to provide the valve unit 14, and the tank capacity of the water tank 10 can be increased.
It is also possible to achieve a low silhouette and compact size for the entire tank device 4 and the entire flush toilet 1.

1 Flush toilet 2 Toilet body 2a Bowl portion 2b Drain trap pipe (drain trap portion)
2c Rim portion 2d Rim water conduit 2e Inlet of rim water conduit 2f Rim water outlet 2g Inlet portion of drain trap pipe 2h Outlet portion of drain trap pipe 2i Upper surface of rim portion 4 Tank device 6 Water supply pipe (water supply conduit)
6a: Upstream water supply pipe 6b: Downstream water supply pipe 8: Outlet of discharge pipe 8a: Outlet portion of discharge pipe 10: Water storage tank (water storage tank body)
10a Upper opening 10b Outer upper surface of water storage tank 12 Stop valve 14 Valve unit 14a Inlet portion of valve unit 14b Outlet portion of valve unit 16 Constant flow valve 17 Diaphragm type main valve body (on-off valve)
18 Solenoid valve 20 Connection unit (tank water supply section)
22 Tank unit 23 Water supply nozzle (tank water supply part, water discharge part)
23a Water inlet (tank water supply, water outlet)
24 Water receiving housing (tank water supply section, backflow prevention section, small tank)
24a Lower opening 24b Side wall 24c Overflow port 26 Overflow pipe (tank water supply part, backflow prevention part)
28. Check valve (tank water supply section, backflow prevention section)
30 Pump 32 Float switch 32a Detector 34 Drain plug 36 Water pipe (outer water pipe)
36a: Upstream end of water pipe 38: Suction pipe 38a: Downstream end of suction pipe 40: Tank body 40a: Bottom surface of tank body 42: Dew prevention material 42a: Outer upper surface of dew prevention material 44: Large tank section (large tank body section)
44a Rear large tank section (rear large tank main body)
44b Front large tank section (front large tank main body)
44c Lower large tank section (lower large tank main body section)
44d Bottom surface of lower large tank portion 44e Top surface of front large tank portion 44f Front end of front large tank portion 44g Side wall surface of large tank portion 46 Small tank portion (small tank main body portion)
46a Rear small tank section (rear small tank main body section)
46b Front small tank section (front small tank main body section)
46c Bottom surfaces of rear small tank section and front small tank section 46d Top surface of rear small tank section 46e Front end of front small tank section 46f Side wall surface of small tank section 48 Main body section of valve unit 48a Primary water supply path of main body section of valve unit 48b Secondary water supply path of main body section of valve unit 48c Water supply port 49 Mounting member 50 Manual water supply operation device for use in case of power outage (manual operation section)
52 Manual drainage operation device for power outages 54 Handle section (manual operation section)
54a: outer end surface in the axial direction of the handle portion 56: spindle (operating shaft portion)
DESCRIPTION OF SYMBOLS 56a Tip portion of spindle 56b Axial outer end portion, outer end face of spindle 58 Solenoid valve side pilot hole 60 Main valve side pressure chamber 62 Main valve side pilot hole 64 Pressure relief passage 66 Valve seat 68 Communication passage 70 O-ring 72 Bleed hole 74 Fastener 76 Drain socket 78 On-off valve 80 Operation wire 82 Fixing unit 84 Gripping ring member A1 Vertical surface dividing the water storage tank into two at the center, left and right B Backflow prevention unit C Controller C1 Connection portion between outlet portion of valve unit and downstream water supply pipe C2 Connection portion between outlet portion of downstream water supply pipe and water supply nozzle D Pump drive unit F1 Floor surface H Hose member L1 Length of downstream water supply pipe and hose member L2 Length of upstream water supply pipe and pipe member O1 Operation axis of handle operation unit P Exterior panel P0 Exterior panel installation position
P1: Lowest position of the bottom of the large tank (lower large tank) P2: Lowest position of the bottom of the small tank (rear small tank and front small tank) P3: Highest position of the top of the large tank (front large tank) P4: Highest position of the top of the small tank (rear small tank) P5: Front end position of the front large tank P6: Front end position of the front small tank R1: Rear area of the toilet body, storage area for the water tank S1: Large tank storage area of the toilet body S2: Small tank storage area of the toilet body T: Pipe member V1: Volume of the large tank V2: Volume of the small tank W1: Flushing water

Claims (4)

A flush toilet that is flushed with flush water to discharge waste,
a toilet body including a bowl portion for receiving waste, a rim portion formed on the upper edge of the bowl portion, and a drain trap portion for discharging waste within the bowl portion;
a tank device provided behind the toilet body and supplying flush water to the toilet body,
The tank device includes a water supply passage through which flush water supplied from a water supply source flows;
a valve unit including an on-off valve provided downstream of the stop valve of the water supply passage for opening and closing the water supply passage;
a water storage tank body provided behind the toilet body and above the floor surface, for storing flush water supplied from the water supply channel;
a tank water supply unit that supplies flush water in the water supply channel to the water storage tank body,
the water supply passage includes an upstream water supply pipe extending from the stopcock to the inlet of the valve unit, and a downstream water supply pipe extending from the outlet of the valve unit to the tank water supply section;
The tank water supply section includes a water discharge section that discharges flush water supplied from the downstream water supply pipe into the water storage tank body, and a backflow prevention section that prevents backflow into the valve unit,
A flush toilet characterized in that the backflow prevention section is provided at a distance from the valve unit and is provided above the rim section, while the valve unit is arranged on the outside of the storage tank body so as to be located above the lowest point on the bottom surface of the storage tank body and inside the outermost surface of the flush toilet . A flush toilet according to claim 1, wherein the outlet of the valve unit is located close to the outer bottom surface of the water storage tank body. A flush toilet according to claim 1 or 2, wherein the valve unit is equipped with a manual operating unit that allows the on-off valve to be manually opened and closed during a power outage, and this manual operating unit is arranged to face the side of the toilet body. The drain trap portion extends in a front-rear direction from an inlet portion connected to the bowl portion to an outlet portion rearward of the bowl portion in a plan view,
2. The flush toilet according to claim 1, wherein the water storage tank body is disposed above the drain trap portion so as to surround a portion of it.