Flush Toilet Apparatus

The present invention contains subject matter related to Japanese Patent Application No. 2024-056326 filed in the Japan Patent Office on Mar. 29, 2024 and Japanese Patent Application No. 2024-056237 filed in the Japan Patent Office on Mar. 29, 2024, the entire contents of which are incorporated herein by reference.

The present invention relates to a flush toilet apparatus, and in particular, to a flush toilet apparatus that performs flushing by using flush water stored in a flush water tank.

Japanese Unexamined Patent Application Publication No. 2015-168994 (Patent Document 1) describes a flush toilet. In the flush toilet, when a drain valve of a water storage tank device is opened, flush water is spouted from two rim spout ports and a jet spout port provided in the flush toilet, and a bowl portion is flushed. In the flush toilet, flush water discharged from the water storage tank device first flows into a single water channel, the water channel is bifurcated, and the flush water is spouted from the two rim spout ports and the jet spout port.

In general existing tank-type flush toilets, a flush water tank has a single drain valve, flush water discharged from the flush water tank is bifurcated to a rim spout port and a jet spout port, and the flush water is spouted from each of the spout ports. That is, a water channel formed in a flush toilet body is bifurcated midway, and flush water is guided to each of the rim spout port and the jet spout port.

International Publication No. 2005/085538 (Patent Document 2) describes a flush toilet. The flush toilet is a tank-type flush toilet, and includes a tank that stores flush water for rim spouting and a tank that stores flush water for jet spouting. The flush water tanks respectively have a drain valve for rim spouting and a drain valve for jet spouting, and flush water is spouted from each of a rim spout port and a jet spout port when a corresponding one of the drain valves is opened.

However, with the flush toilet described in Patent Document 1, flush water discharged from the water storage tank device first flows into a single water channel, the water channel is bifurcated, and the flush water is spouted from the rim spout ports and the jet spout port. Therefore, spouting of flush water from the jet spout port, which is at a low position, is performed when flush water flows into the water channel, which communicates with the water storage tank device, and subsequently, spouting of water from the rim spout ports, which are at high positions, is started when the water level in the water channel rises. When the drain valve is closed, while rim spouting is stopped comparatively early because the rim spout ports are at the high positions, flush water that remains in in the water channel is continued to be spouted from the jet spout port after the water drain valve has been closed. However, flush water that is spouted from the jet spout port after a siphon action has been activated by jet spouting does not contribute to neither flushing of a waste receiving surface of the bowl portion nor refilling of the bowl portion after having been flushed, and thus the flush water is not effectively utilized. Therefore, with the flush toilet described in Patent Document 1, it is difficult to achieve water saving at a high level.

In existing flush toilet apparatuses including a single drain valve, spouting of water is started from a rim spout port and a jet spout port substantially simultaneously. Therefore, it cannot be said that flush water is spouted at an appropriate timing from an appropriate spout port, and a part of flush water to be used is not sufficiently utilized for flushing. That is, wasted water is generated due to the existence of flush water that is not sufficiently utilized for flushing.

On the other hand, with the flush toilet described in Patent Document 2, because the drain valves are respectively provided for rim spouting and jet spouting, it is possible to start spouting of water from the rim spout port and the jet spout port at different timings. However, because the flush toilet described in Patent Document 2 has a structure such that each of the drain valves is pulled up by a ball chain that is connected to an operation lever (the ball chain is a common drive input member), it is not possible to freely set a timing for spouting water from each spout port. Therefore, also with the flush toilet described in Patent Document 2, it is not possible to sufficiently achieve the effect of reducing wasted water.

Moreover, the inventors have found that it is possible to achieve efficient utilization of flush water, not by adopting a configuration (exiting configuration) with which internal air in a jet water channel extending from a drain valve for jet spouting to a jet spout port is completely replaced with flush water (completely discharged), but by adopting a configuration with which a part of internal air remains in a jet water channel while maintaining the watertightness of waterflow from a drain valve for jet spouting to a jet spout port.

The present invention has been conceived based on the above findings. Accordingly, an object of the present invention is to provide a flush toilet apparatus with which it is possible to effectively utilize flush water stored in a flush water tank and to realize water saving while ensuring sufficient flushing performance.

Another object of the present invention is to provide a flush toilet apparatus that can achieve efficient utilization of flush water by adopting a configuration with which the timing of opening and closing each drain valve is independently controlled and a part of internal air remains in a jet water channel while maintaining the watertightness of waterflow from a drain valve for jet spouting to a jet spout port.

In order to achieve the objects described above, a flush toilet apparatus according to the present invention is a flush toilet apparatus that performs flushing by using flush water stored in a flush water tank, including: a flush toilet body including a bowl portion, a rim spout port provided in an upper part of the bowl portion, a drain trap pipe extending from a lower part of the bowl portion, and a jet spout port provided so as to face an inlet of the drain trap pipe; a flush water tank body that stores flush water for flushing the bowl portion of the flush toilet body; a rim spouting/stopping switch mechanism that spouts or stops flush water stored in the flush water tank body from the rim spout port via a rim water channel provided in the flush toilet body; and a jet spouting/stopping switch mechanism that spouts or stops flush water stored in the flush water tank body from the jet spout port via a jet water channel provided in the flush toilet body. The rim spouting/stopping switch mechanism and the jet spouting/stopping switch mechanism execute a flushing sequence including a first step of starting spouting of flush water from the rim spout port, a second step of starting spouting of flush water from the jet spout port after the first step in a state in which spouting of flush water from the rim spout port is continued and activating a siphon action in the drain trap pipe, and a third step of continuing spouting of flush water from the rim spout port after the second step while stopping spouting of flush water from the jet spout port.

With the present invention configured in this way, a flushing sequence including the first step of starting spouting of flush water from the rim spout port, the second step of starting spouting of flush water from the jet spout port after the first step and activating a siphon action, and the third step of continuing spouting of flush water from the rim spout port after the second step while stopping jet spouting is executed. As a result, because the second step is executed and a siphon action is activated at a predetermined timing after the bowl portion has been flushed due to the first step, it is possible to perform flushing of the bowl portion and discharging of bodily waste by effectively utilizing flush water. Thus, it is possible to realize water saving while ensuring sufficient flushing performance.

In the present invention, preferably, the second step is executed after a water level of standing water in the bowl portion has risen due to the first step.

With the present invention configured in this way, the second step is executed after the water level of standing water in the bowl portion has risen due to the first step. Therefore, jet spouting in the second step is executed in a state in which the bowl portion has been sufficiently flushed, the water level of standing water in the bowl portion has risen, and the water level in the drain trap pipe has also risen due to the first step. Therefore, it is possible to activate a siphon action soon after the bowl portion has been flushed, and it is possible to effectively perform flushing of the bowl portion and discharging of bodily waste with a small amount of flush water.

In the present invention, preferably, the second step is executed after flush water in the drain trap pipe has started overflowing.

With the present invention configured in this way, because the second step is executed after the water level in the drain trap pipe has risen and flush water in the drain trap pipe has started overflowing due to the first step, a siphon action occurs soon after the second step has been started, and it is possible to reduce the amount of water necessary for jet spouting and to realize water saving.

In the present invention, preferably, the first step, the second step, the third step differ from each other in a length of execution time.

With the present invention configured in this way, because the first step, the second step, and the third step differ from each other in the length of execution time, it is possible to set an execution time suitable for the function of each step, and to sufficiently utilize flush water.

In the present invention, preferably, an execution time of the third step is longer an execution time of each of the first step and an execution time of the second step.

With the present invention configured in this way, because the execution time of the third step is longer than the execution time of each of the first step and the second step, it is possible to allot a sufficient time for refilling the bowl portion after a siphon action has finished, and it is possible to utilize flush water without loss.

In the present invention, preferably, the execution time of the first step is longer than the execution time of the second step.

In general, while the effect of flushing a bowl portion is improved by spending a long time and allotting a large amount of flush water, the effect of discharging of bodily waste due to a siphon action does not change significantly even a large amount of water is used after the siphon action has been once activated. With the present invention configured in this way, because the execution time of the first step is longer than the execution time of the second step, it is possible to allot a large amount of flush water to flushing of the bowl portion, and it is possible to sufficiently utilize flush water.

In the present invention, preferably, the first step, the second step, and the third step differ from each other in an instantaneous flow rate of flush water spouted from the rim spout port.

With the present invention configured in this way, because the first step, the second step, and the third step differ from each other in the instantaneous flow rate of flush water spouted from the rim spout port, it is possible to set a flow rate suitable for the function of each step, and it is possible to sufficiently utilize flush water.

In the present invention, preferably, an instantaneous flow rate of flush water spouted from the rim spout port in the third step is lower than an instantaneous flow rate of flush water spouted from the rim spout port in each of the first step and the second step.

With the present invention configured in this way, the instantaneous flow rate of flush water spouted from the rim spout port in the third step is lower than that in each of the first step and the second step. Therefore, flush water spouted from the rim spout port in the third step does not swirl significantly in the bowl portion, and flows down toward the inlet of the drain trap pipe rapidly. As a result, it is possible to assist in discharging of bodily waste due to a siphon action activated by rim spouting in the second step. Moreover, because it is not necessary to perform high-flow-rate rim flushing for inducing a siphon action after the siphon action has occurred, it is possible to contribute to water saving by reducing flow rate after the siphon action has occurred.

A flush toilet apparatus according to the present invention is a flush toilet apparatus that performs flushing by using flush water stored in a flush water tank, including: a flush toilet body including a bowl portion and a drain trap pipe extending from a lower part of the bowl portion; a flush water tank that is disposed on a back side of the flush toilet body and stores flush water for flushing the bowl portion of the flush toilet body; a first drain valve that switches between spouting and stopping of flush water from a rim spout port provided in an upper edge part of the bowl portion by opening and closing a first drain port provided in the flush water tank; and a second drain valve that switches between spouting and stopping of flush water from a jet spout port provided on a front side of the lower part of the bowl portion by opening and closing a second drain port provided in the flush water tank. The first drain valve and the second drain valve are configured to be driven based on drive inputs that differ from each other. A jet water channel extending from the second drain valve to the jet spout port includes an upstream region that is positioned directly below the second drain valve, an intermediate region that extends forward from the upstream region in plan view, and a downstream region that extends sideward from a front side region of the intermediate region below a water level of standing water, circumvents the lower part of the bowl portion and/or the drain trap pipe, and reaches the jet spout port. A maximum value of an area of a vertical cross section of the intermediate region perpendicular to a front-back direction is larger than a maximum value of an area of a vertical cross section of the upstream region perpendicular to the front-back direction. The maximum value of the area of the vertical cross section of the intermediate region perpendicular to the front-back direction is larger than a maximum value of an area of a vertical cross section of the downstream region perpendicular to a passage direction.

With the present invention, because the first drain valve and the second drain valve are driven based on drive inputs that differ from each other, it is possible to flexibly set the timing of opening and closing the first drain port and the timing of opening and closing the second drain port, and it is possible to effectively achieve the effect of reducing wasted water.

Moreover, with the present invention, by adopting a dimensional relationship such that the maximum value of the area of the vertical cross section of the intermediate region perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the upstream region perpendicular to the front-back direction and is larger than the maximum value of the area of the vertical cross section of the downstream region perpendicular to the passage direction, it is possible to realize a configuration such that a part of internal air remains in the intermediate region while maintaining the watertightness of waterflow in the jet water channel (thus it is possible to utilize the hydraulic head pressure in the flush water tank for jet spouting), and it is possible to achieve efficient utilization of flush water (in particular, efficient utilization of hydraulic head pressure).

Preferably, after spouting of water from the jet spout port has been started, a flow rate of flush water flowing in the upstream region is higher than a flow rate of flush water flowing in the intermediate region, and the flow rate of flush water flowing in the intermediate region is higher than a flow rate of flush water flowing in the downstream region.

With this configuration, it is possible to more reliably maintain the watertightness of waterflow of flush water in the jet water channel, and it is possible to more reliably utilize the hydraulic head pressure in the flush water tank for jet spouting.

Further in this case, preferably, the maximum value of the area of the vertical cross section of the upstream region perpendicular to the front-back direction is larger than the maximum value of the area of the vertical cross section of the downstream region perpendicular to the passage direction.

With this configuration, it is possible to more reliably maintain the watertightness of waterflow of flush water in the jet water channel, and it is possible to more reliably utilize the hydraulic head pressure in the flush water tank for jet spouting.

Further in this case, preferably, the intermediate region is not filled with water from a time when the second drain valve is opened to a time when the second drain valve is closed.

With this configuration, it is possible to reliably achieve efficient utilization of flush water.

Preferably, the flush water tank is positioned above the rim spout port.

With this configuration, it is possible to utilize the hydraulic head pressure of the flush water tank also for rim spouting.

The flush water tank may be integrated with the flush toilet body, or may be separate from the flush toilet body.

With the flush toilet apparatus according to the present invention, it is possible to effectively utilize flush water stored in a flush water tank and to realize water saving while ensuring sufficient flushing performance.

With the present invention, it is possible to achieve an effect of reducing wasted water because the first drain valve and the second drain valve are driven so that the timing of opening and closing the first drain valve and the timing of opening and closing the second drain valve are different from each other.

Next, referring to the drawings, flush toilet apparatuses according to embodiments of the present invention will be described.

is a top view illustrating the schematic configuration of a flush toilet apparatus according to a first embodiment of the present invention.is a side cross-sectional view illustrating the schematic configuration of the flush toilet apparatus according to the first embodiment of the present invention.is a block diagram illustrating a flush water supply system of the flush toilet apparatus according to the first embodiment of the present invention.is a front cross-sectional view illustrating the internal configuration of a flush water tank body of the flush toilet apparatus according to the first embodiment of the present invention.

As illustrated in, a flush toilet apparatusaccording to the first embodiment of the present invention is composed of a flush toilet bodyand a flush water tank bodydisposed on a back part of the flush toilet body. The flush toilet apparatusaccording to the present embodiment is configured so that flushing is performed when a lever handleprovided on the flush water tank bodyis operated after use. In, illustrations of a drain valve and the like included in the flush water tank bodyare omitted.

The flush toilet bodyincludes a bowl portionand a drain trap pipeextending from a lower part of the bowl portion. A rim spout portis provided in an upper edge part of the bowl portion, and a jet spout portis provided in a lower part of the bowl portion. When toilet flushing is performed, flush water is spouted from each of the rim spout portand the jet spout portat a predetermined timing, a waste receiving surface of the bowl portionis flushed, and bodily waste and flush water in the bowl portionare discharged to the drain trap pipe. The bodily waste and flush water discharged to the drain trap pipeare discharged to a sewage pipe (not shown) through a drain socket (not shown). In the present embodiment, the cross-sectional area the jet spout portis larger than the cross-sectional area of the rim spout port. If a plurality of rim spout portsare provided, the spout ports are configured so that the cross-sectional area of the jet spout portis larger than the sum of the cross-sectional areas of the rim spout ports

As illustrated in, flush water is supplied to the flush water tank bodyfrom a water supply sourcesuch as waterworks, and the supplied flush water is stored in the flush water tank body. A rim drain valveand a jet drain valveare contained in the flush water tank bodyso that flush water is spouted or stopped from a drain port provided in a bottom part of the flush water tank body.

In the present embodiment, flush water discharged by opening the rim drain valveis spouted from the rim spout portthrough a rim water channelformed in the flush toilet body. Flush water discharged by opening the jet drain valveis spouted from the jet spout portthrough a jet water channelformed in the flush toilet body.

Next, referring to, the internal structure of the flush water tank bodywill be described.

As illustrated in, an inner tankis disposed in the flush water tank body. The flush water tank bodyincludes: the rim drain valvethat is a rim spouting/stopping switch mechanism disposed in the flush water tank bodyand outside of the inner tank; the jet drain valvethat is a jet spouting/stopping switch mechanism disposed in the inner tank; a ball tapthat is a feed valve; and a hydraulic drive mechanism.

The flush water tank bodyand the inner tankare containers that are configured to store flush water to be supplied to the flush toilet body. In the present embodiment, the flush water tank bodyis made of ceramics, and the inner tank, which is disposed in the flush water tank body, is made of a resin. In the present specification, “flush water stored in the flush water tank body” includes flush water stored in the inner tank, in addition to flush water stored in the flush water tank body(and outside the inner tank).