Flush Toilet Apparatus

The present invention contains subject matter related to Japanese Patent Application No. 2024-056236 filed in the Japan Patent Office on Mar. 29, 2024 and Japanese Patent Application No. 2024-056327 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 relates, in particular, to a flush toilet apparatus that flushes with flush water stored in a flush water tank.

Japanese Unexamined Patent Application Publication No. 2015-168994 (PTL 1) describes a flush toilet. In this flush toilet, a drain valve included in a water storage tank apparatus is opened to eject flush water through two rim water ejection ports and a jet water ejection port that are provided in the flush toilet and to thereby flush a bowl. In this flush toilet, flush water discharged from the water storage tank apparatus first flows into a single water conduit, and the water conduit branches and allows flush water to be ejected through the two rim water ejection ports and the jet water ejection port.

In an existing general flush toilet apparatus of a tank-type, a flush water tank is provided with a single drain valve, and flush water that is discharged from the flush water tank is branched to a rim water ejection port and a jet water ejection port to perform water ejection through each of the water ejection ports. In other words, a water conduit formed in a flush toilet body branches at an intermediate portion and guides flush water to each of the rim water ejection port and the jet water ejection port.

International Publication No. 2005/085538 (PTL 2) discloses a flush toilet. This flush toilet is a tank-type flush toilet and includes a tank that stores flush water for rim water ejection and a tank that stores flush water for jet water ejection. The flush water tanks are provided with a drain valve for rim water ejection and a drain valve for jet water ejection, respectively, and these drain valves are opened to perform water ejection through each of the rim water ejection port and the jet water ejection port.

However, in the flush toilet described in PTL 1, flush water discharged from the water storage tank apparatus first flows into the single water conduit, and the water conduit branches and allows flush water to be ejected through the rim water ejection ports and the jet water ejection port. In a state before the drain valve is opened, a relatively large air layer is present in the water conduit into which flush water flows. Therefore, after the drain valve is opened in the flush toilet described in PTL 1, the air layer present in the water conduit is filled with flush water, and thereafter, flush water is ejected through the rim water ejection ports and the jet water ejection port. Accordingly, it is difficult to precisely set the time of starting ejection of flush water through the rim water ejection ports and the jet water ejection port. As a result, it becomes difficult to obtain a high flushing effect while suppressing the amount of flush water by effectively utilizing flush water.

However, in an existing flush toilet apparatus including a single drain valve, water ejection through a rim water ejection port and water ejection through a jet water ejection port are started substantially at the same time. Therefore, it cannot necessarily be said that flush water is ejected at an appropriate timing through an appropriate water ejection port, and part of flush water that is used is not sufficiently utilized for a flush. In other words, wasted water is generated due to the presence of flush water that is not sufficiently utilized for a flush.

Meanwhile, it is possible in the flush toilet described in PTL 2 to start water ejection through the rim water ejection port and the jet water ejection port at different timings since the drain valve for rim water ejection and the drain valve for jet water ejection are provided. However, it is not possible in the flush toilet described in PTL 2 to freely set the time of starting water ejection through each of the water ejection ports since the flush toilet has a structure in which each of the drain valves is pulled up by a ball chain connected to an operation lever (the ball chain serving as a common drive input member). Therefore, it is also not possible in the flush toilet described in PTL 2 to sufficiently achieve an effect of suppressing wasted water.

Further, the present inventor has found that efficient utilization of flush water is achieved by employing a form in which part of internal air remains in a jet water conduit while an enclosed state of a water flow flowing from a drain valve for jet water ejection to a jet water ejection port is maintained, instead of employing a form in which internal air is completely replaced (completely exhausted) with flush water in a jet water conduit extending from a drain valve for jet water ejection to a jet water ejection port.

Accordingly, the present invention is intended to provide a flush toilet apparatus capable of ensuring sufficient flushing performance and also achieving water saving by effectively utilizing flush water stored in a flush water tank.

The present invention has been devised on the basis of the above findings. An object of the present invention is to provide a flush toilet apparatus in which efficient utilization of flush water is achieved by employing a form in which the timing of opening each drain valve is independently controlled and in which part of internal air remains in a jet water conduit while an enclosed state of a water flow flowing from a drain valve for jet water ejection to a jet water ejection port is maintained.

To solve the above-described issues, the present invention is a flush toilet apparatus that flushes with flush water stored in a flush water tank, the flush toilet apparatus including a flush toilet body that includes a bowl and has a rim water ejection port provided in an upper portion of the bowl, a drain trap pipeline extending from a lower portion of the bowl, and a jet water ejection port provided to face an inlet of the drain trap pipeline; a flush water tank body that stores flush water for flushing the bowl of the flush toilet body; a rim drain valve that stops or allows flush water to be ejected through the rim water ejection port via a rim water conduit provided in the flush toilet body, the rim drain valve being provided at a rim-water-ejection drain port formed in the flush water tank body; and a jet drain valve that stops or allows flush water to be ejected through the jet water ejection port via a jet water conduit provided in the flush toilet body, the jet drain valve being provided at a jet-water-ejection drain port formed in the flush water tank body, in which the flush toilet apparatus has an exhaust path along which air of an air layer formed in an upstream side of the jet water conduit is discharged, in which the rim-water-ejection drain port and the jet-water-ejection drain port are each provided at a position higher than a lower end of the rim water ejection port, and in which flush water is supplied into the jet water conduit after a flush is started and before the jet drain valve is opened.

According to the present invention configured as described above, since the rim drain valve that stops or allows flush water to be ejected through the rim water ejection port and the jet drain valve that stops or allows flush water to be ejected through the jet water ejection port are included, the timing of ejecting flush water through each of the ejection ports may be precisely set, and flush water may be effectively utilized. In addition, according to the present invention configured as described above, since the exhaust path along which the air of the air layer in the jet water conduit is discharged is included and flush water is supplied into the jet water conduit after a flush is started and before the jet drain valve is opened, the air in the jet water conduit is discharged, and the water level in the jet water conduit rises. As a result, flush water may be ejected through the jet water ejection port early after the jet drain valve is opened. Consequently, it may be possible to ensure sufficient flushing performance and also achieve water saving by effectively utilizing the flush water that is stored in the flush water tank.

In the present invention, preferably, flush water is supplied into the jet water conduit by, after a flush is started and before the jet drain valve is opened, opening the rim drain valve to allow flush water to be ejected through the rim water ejection port and to thereby allow flush water to flow in through the jet water ejection port.

According to the present invention configured as described above, since flush water is supplied into the jet water conduit by, before the jet drain valve is opened, opening the rim drain valve to allow flush water to be ejected through the rim water ejection port, a water level in the jet water conduit may be caused to rise without a special configuration for supplying flush water into the jet water conduit.

In the present invention, preferably, supply of flush water into the jet water conduit causes a water level in the jet water conduit to rise, and, at a point of time when the jet drain valve is opened, a water level in the drain trap pipeline rises to be higher than a water level in the jet water conduit.

According to the present invention configured as described above, since a water level in the drain trap pipeline rises to be higher than a water level in the jet water conduit, the air remaining in the drain trap pipeline may be discharged early, and a siphon action may be started in the drain trap pipeline early after jet water ejection is started. Consequently, a siphon action may be started with a less amount of flush water, and water saving may be achieved.

In the present invention, preferably, a cross-sectional area of the jet water ejection port is larger than a cross-sectional area of the rim water ejection port.

According to the present invention configured as described above, since the cross-sectional area of the jet water ejection port is larger than the cross-sectional area of the rim water ejection port, water ejection may be performed at a large flow rate through the jet water ejection port, and a siphon action may be generated in the drain trap pipeline in a short period. Consequently, a siphon action may be started with a less amount of flush water, and water saving may be achieved.

In the present invention, preferably, ejection of flush water through the rim water ejection port forms a swirling flow on an inner wall surface of the bowl, and the swirling flow makes one or more revolutions in the bowl.

According to the present invention configured as described above, since water ejection through the rim water ejection port forms a swirling flow, and the swirling flow makes one or more revolutions in the bowl, the inner wall surface of the bowl may be thoroughly flushed while water saving is achieved.

In the present invention, preferably, the jet drain valve is opened when or after a water level in the jet water conduit rises to a highest position.

According to the present invention configured as described above, since the jet drain valve is opened when or after a water level in the jet water conduit rises to a highest position, the jet drain valve is opened after exhaustion of the air of the air layer in the jet water conduit is completed. Consequently, mixing of the air in the air layer into flush water may be suppressed, and generation of an abnormal noise at the time of jet water ejection may be suppressed.

In the present invention, preferably, one end of the exhaust path in communication with an inside of the jet water conduit is open at a position higher than a water surface that has risen in the jet water conduit due to supply of flush water into the jet water conduit.

According to the present invention, since one end of the exhaust path is open at a position higher than a water surface that has risen in the jet water conduit by supply of flush water into the jet water conduit, air may be exhausted even in a state in which the water surface in the jet water conduit has risen, and the water surface in the jet water conduit may be easily caused to rise.

In the present invention, preferably, one end of the exhaust path is open upward in a ceiling surface of the jet water conduit.

According to the present invention configured as described above, since one end of the exhaust path is open upward in the ceiling surface of the jet water conduit, even when flush water in the jet water conduit intrudes into the exhaust path, the flush water may be discharged immediately, and a stable air passage may be ensured.

In the present invention, preferably, the exhaust path is configured such that an inside of the jet water conduit is in communication outside air.

According to the present invention configured as described above, since the exhaust path is configured such that the inside of the jet water conduit is in communication with outside air, air in the jet water conduit may be easily discharged.

In the present invention, preferably, the exhaust path is configured such that an inside of the jet water conduit and an air layer in the flush water tank body are in communication with each other.

According to the present invention configured as described above, since the exhaust path is configured such that the inside of the jet water conduit and the air layer in the flush water tank body are in communication with each other, an intrusion of dust and the like into the exhaust path from outside air may be suppressed.

In the present invention, preferably, the jet water conduit is configured such that an air layer remains inside the jet water conduit even in a state in which flush water has been supplied into the jet water conduit before the jet drain valve is opened.

According to the present invention configured as described above, since an air layer remains inside the jet water conduit even in a state in which flush water has been supplied into the jet water conduit before the jet drain valve is opened, an infiltration of flush water into the exhaust path may be avoided.

In the present invention, preferably, the jet water conduit is configured such that an air pocket is formed inside the jet water conduit after the jet drain valve is opened.

According to the present invention configured as described above, since the jet water conduit is configured such that an air pocket is formed inside the jet water conduit after the jet drain valve is opened, an effective volume of the jet water conduit may be reduced, and wasted flush water may be reduced.

The present invention is a flush toilet apparatus that flushes with flush water stored in a flush water tank, the flush toilet apparatus including a flush toilet body that includes a bowl and has a drain trap pipeline extending from a lower portion of the bowl; a flush water tank that is disposed behind the flush toilet body and stores flush water for flushing the bowl of the flush toilet body; a first drain valve that switches between stop and ejection of flush water through a rim water ejection port provided in an upper edge portion of the bowl by closing and opening a first drain port provided in the flush water tank; and a second drain valve that switches between stop and ejection of flush water through a jet water ejection port provided in a lower portion of the bowl by closing and opening a second drain port provided in the flush water tank, in which the first drain valve and the second drain valve are driven based on drive inputs that differ from each other, and in which an air vent path whose one end side is open inside a jet water conduit extending from the second drain valve to the jet water ejection port and whose another end side is open in an atmospheric region is provided.

According to the present invention, since the first drain valve and the second drain valve are driven based on drive inputs that differ from each other, the timing of opening and closing the first drain port and the timing of opening and closing the second drain port may be flexibly adjusted, and an effect of suppressing wasted water may be effectively achieved.

Further, according to the present invention, since there is provided the air vent path whose one end side is open inside the jet water conduit extending from the second drain valve to the jet water ejection port and whose other end side is open in the atmospheric region, a form in which part of air remains in the jet water conduit (since an air vent function is lost after one end side of the air vent path is submerged, the air present above the one end side easily remains) may be achieved while an enclosed state of the water flow in the jet water conduit is maintained (consequently, the water head pressure in the flush water tank may be utilized for jet water ejection), and efficient utilization of flush water may be achieved.

Preferably, the one end side of the air vent path is open inside an upstream region located directly under the second drain valve or inside an intermediate region extending forward from the upstream region in plan view.

In this case, performance and design flexibility in arrangement of the air vent path may be high, and the air vent function may be desirably achieved easily.

Further, in this case, preferably a downstream region extending to the jet water ejection port is connected to the intermediate region, a water surface formed, after the second drain valve is opened and flush water reaches the jet water ejection port, in the upstream region in which the one end side of the air vent path is open or in the intermediate region by a water flow of flush water is determined depending on a position at which the one end side of the air vent path is open, and an enclosed water flow of flush water is formed from the upstream region to the jet water ejection port via the intermediate region and the downstream region.

Consequently, an enclosed state of the water flow in the jet water conduit may be maintained reliably, and the water head pressure in the flush water tank may be reliably utilized for jet water ejection.

Further, in this case, preferably, after the second drain valve is opened and flush water reaches the jet water ejection port, a flow rate of flush water that flows in the upstream region is larger than a flow rate of flush water that flows in the intermediate region, and a flow rate of flush water that flows in the intermediate region is larger than a flow rate of flush water that flows in the downstream region.

Consequently, an enclosed state of the water flow in the jet water conduit may be maintained more reliably, and the water head pressure in the flush water tank may be more reliably utilized for jet water ejection.

In addition, preferably, the air vent path is formed by a pipeline member that is formed integrally with the first drain valve and/or the second drain valve, and the other end side of the air vent path is open in an upper-side space inside the flush water tank body. Consequently, a space in which the air vent path is arranged may be absorbed by a space in which the flush water tank is arranged.

Further, in this case, preferably, the pipeline member is provided with a check valve. Consequently, generation of an undesired air backflow may be effectively avoided.

Further, in this case, preferably, the pipeline member is an overflow pipe. Consequently, the function as an air vent path and the function as an overflow pipe may be served by a single member, and cost reduction and space saving may be achieved.

Alternatively, the other end side of the air vent path may be open in a space outside the flush water tank. Preferably, the one end side of the air vent path is located above a water level of retained water. Also in this case, the air vent path is preferably provided with a check valve. Consequently, generation of an undesired air backflow may be effectively avoided.

According to the flush toilet apparatus of the present invention, it may be possible to ensure sufficient flushing performance and also achieve water saving by effectively utilizing the flush water stored in the flush water tank.

According to the present invention, since the first drain valve and the second drain valve are driven based on drive inputs that differ from each other, the timing of opening and closing the first drain port and the timing of opening and closing the second drain port may be flexibly adjusted, and an effect of suppressing wasted water may be effectively achieved.