Wash water tank device and flush toilet device equipped with the same

Abstract

The present invention provides a flush water tank device and a flush toilet device equipped therewith, which can suppress the instability of the movement of a piston and can suppress the fluctuation of the water pressure of the flush water discharged from a first drain portion provided separately from an inlet portion. The flush water tank device of the present invention includes a drain valve water pressure drive unit, the drain valve water pressure drive unit including: a cylindrical body; a piston that moves from a first position to a second position due to the inflow of flush water into the cylindrical body; a rod that extends from the piston through a through-hole portion formed in the cylindrical body; and an elastic member provided on the piston, the cylindrical body including: an inlet portion into which flush water flows; a first drain portion that is provided separately from the inlet portion and discharges flush water; and a second drain portion that is provided separately from the first drain portion and is formed between the rod, the piston, and the through-hole portion.

Description

Technical Field

[0001] The present invention relates to a flush water tank device, and more particularly to a flush water tank device for supplying flush water to a flush toilet and a flush toilet device equipped with the same. Background Art

[0002] Patent Document 1 discloses an automatic cleaning device for a toilet. The automatic cleaning device comprises: a hydraulic cylinder that is actuated by the water pressure of the supplied water; a solenoid valve for connecting or disconnecting the supply of tap water to the hydraulic cylinder; and a float valve for opening and closing the valve seat. According to the operation of the solenoid valve, high-pressure fluid flows into the hydraulic cylinder, the piston in the hydraulic cylinder rises, and the connecting rod, connecting chain, etc. connected to the piston rise to lift the float valve, and the float valve is opened. The piston in the hydraulic cylinder is provided with a sealing member that seals between the piston and the inner wall of the hydraulic cylinder. A small hole 23a for reducing pressure is provided through the bottom of the hydraulic cylinder.

[0003] Patent Literature

[0004] Patent Document 1: Japanese Utility Model Publication No. 63-86180 Summary of the Invention

[0005] However, in the flush water tank device disclosed in Patent Document 1, if the water supply pressure fluctuates suddenly, such as by a sudden rise, while tap water is being supplied to the hydraulic cylinder, the piston may become unstable due to the impact of the sudden change in flush water pressure, as the hydraulic cylinder is provided with only a small hole 23a for reducing the pressure. This may result in malfunctioning piston operation or improper toilet flushing.

[0006] Therefore, the technical problem to be solved by the present invention is to provide a flush water tank device and a flush toilet device equipped with the same, which can suppress the unstable movement of the piston and at the same time suppress the fluctuation of the water pressure of the flush water discharged from the first drainage part set separately from the inlet part.

[0007] In order to solve the above-mentioned problem, one embodiment of the present invention is a flush water tank device for supplying flush water to a flush toilet, which is characterized by comprising: a water storage tank for storing flush water to be supplied to the flush toilet, and a drain outlet for discharging the stored flush water to the flush toilet; a drain valve for opening and closing the drain outlet to supply and stop flush water to the flush toilet; and a drain valve water pressure drive unit for driving the drain valve using the water supply pressure of the supplied tap water, the drain valve water pressure drive unit comprising: a cylindrical body for supplying tap water as flush water, a piston slidably arranged on the cylindrical body The cylinder body is provided with a first drain portion that is provided with a first position and a second position at the same time as the cleaning water flows into the cylinder body; a rod that extends from the piston through a through-hole portion formed in the cylinder body so as to connect the piston to the drain valve; and an elastic member that has a sealing function between the piston and the inner wall of the cylinder body while being provided on the piston, and the cylinder body comprises: an inlet portion, into which the cleaning water flows; a first drain portion that is provided separately from the inlet portion and discharges the cleaning water; and a second drain portion that is provided separately from the first drain portion and is formed between the rod, the piston and the through-hole portion.

[0008] According to one embodiment of the present invention thus constructed, the cylindrical body includes an inlet portion through which wash water flows; a first drain portion, disposed separately from the inlet portion, for discharging the wash water; and a second drain portion, disposed separately from the first drain portion and formed between the rod and the through-hole portion. Thus, when the flow path from the inlet portion within the cylindrical body to the first drain portion is disconnected or connected, if the wash water supply pressure to the cylindrical body undergoes a sudden change, such as a sudden rise, the second drain portion mitigates the impact of the sudden change in wash water pressure, thereby cushioning the impact on the piston from the wash water and preventing the piston from becoming unstable.

[0009] In one embodiment of the present invention, it is preferable that the first drain portion is formed in the cylindrical body.

[0010] According to one embodiment of the present invention constructed in this manner, the drain valve water pressure drive unit includes: an inlet portion formed in the cylindrical body and allowing washing water to flow in; a first drain portion provided separately from the inlet portion and discharging washing water from the cylindrical body; and a second drain portion provided separately from the first drain portion and formed between the rod, the piston, and the through-hole portion, the first drain portion being formed in the cylindrical body. Thus, in a relatively simple structure, when the flow path from the inlet portion in the cylindrical body to the first drain portion is disconnected or connected, and when the supply pressure of the washing water to the cylindrical body undergoes a sudden change, such as a sudden rise, the second drain portion cushions the impact of the sudden change in washing water pressure, thereby alleviating the impact on the piston from the washing water and preventing the piston from becoming unstable. Furthermore, when the flow path from the inlet portion of the cylindrical body to the first drain portion is disconnected, if the pressure of the wash water supplied to the cylindrical body fluctuates suddenly, such as by a sudden rise, the second drain portion mitigates the impact of the sudden change in wash water pressure, thereby suppressing fluctuations in the pressure of the wash water discharged from the first drain portion. This prevents the wash water discharged downstream of the first drain portion from becoming unstable. For example, even when the wash water is being used downstream of the first drain portion, the supply of wash water can be prevented from becoming unstable.

[0011] In one embodiment of the present invention, it is preferred that the first drain portion is formed so that the inlet of the first discharge path for discharging cleaning water from the inside of the cylindrical body to the outside of the cylindrical body is opened and closed by the rod and the through-hole portion, and the first drain portion is constructed so that when the piston is located at the first position, the inlet of the first discharge path is closed by the rod and the through-hole portion, whereby the first discharge path is in a closed state, and when the piston reaches a connecting position between the first position and the second position, the inlet of the first discharge path is opened by the rod and the through-hole portion, whereby the first discharge path is in an open state.

[0012] According to one embodiment of the present invention thus constructed, the first drain portion is configured such that when the piston is in the first position, the rod and the through-hole portion close the entrance to the first discharge path. Furthermore, when the piston reaches a connecting position between the first position and the second position, the rod and the through-hole portion open the entrance to the first discharge path, thereby placing the first discharge path in an open state. With this relatively simple structure, when the piston is in the first position, the wash water supply pressure does not leak toward the first discharge path, effectively utilizing the wash water supply pressure for piston movement. When the piston is in the connecting position between the first position and the second position, the first discharge path is opened, allowing wash water to be discharged from within the cylindrical body to the outside of the cylindrical body through the first discharge path. The piston can easily return to the first position from the second position or the connecting position.

[0013] In one embodiment of the present invention, it is preferred that the first discharge path of the first drainage portion is formed by a passage extending inside the rod from a starting position of the first discharge path of the rod to a distal end of the rod, and the starting position of the first discharge path of the rod appears at a position within the cylindrical body in a manner corresponding to the communication position of the piston.

[0014] According to one embodiment of the present invention constructed in this way, since the first discharge path of the first drainage portion is formed by a passage extending inside the rod, the flow rate of the cleaning water flowing through the passage inside the rod when the first drainage path is in an open state can be better suppressed than when the passage is formed on the outer side of the rod. At the same time, when the piston is in the first position, the water supply pressure of the cleaning water will not leak to the first discharge path side, and the water supply pressure of the cleaning water can be effectively utilized for the movement of the piston. When the piston is in the connecting position, the first discharge path is in an open state, and the cleaning water is discharged from the inside of the cylinder to the outside of the cylinder through the first discharge path, and the piston can easily return to the first position from the second position or the specified position.

[0015] In one embodiment of the present invention, it is preferred that the first discharge path of the first drainage portion is formed by a groove portion formed on the outer portion of the rod from a starting position of the first discharge path of the rod to a distal end of the rod, and the starting position of the first discharge path of the rod is a position that appears within the cylindrical body in a manner corresponding to the communication position of the piston.

[0016] According to one embodiment of the present invention constructed in this way, the first discharge path of the first drainage portion can be formed relatively simply by utilizing the groove formed on the outer portion of the rod. When the piston is located at the first position, the water supply pressure of the cleaning water will not leak to the first discharge path side, and the water supply pressure of the cleaning water can be effectively utilized for the movement of the piston. When the piston is located at the connecting position, the first discharge path is in an open state, and the cleaning water is discharged from the inside of the cylinder to the outside of the cylinder through the first discharge path. The piston can easily return to the first position from the second position or the specified position.

[0017] In one embodiment of the present invention, it is preferred that the deformation of the elastic member when the piston is located at the first position is the maximum deformation of the elastic member at each position when the piston moves from the first position to the second position.

[0018] According to one embodiment of the present invention thus constructed, the deformation of the elastic member when the piston is in the first position is the maximum deformation of the elastic member at each position of the piston between the first and second positions. Thus, when the piston is in the first position, the position at the start of water supply and most susceptible to fluctuations in the supply pressure of the wash water, the elastic member is at its maximum deformation, and the force supporting the piston is also at its maximum. This prevents the piston from tilting due to fluctuations in the supply pressure, which could lead to unstable piston movement.

[0019] In one embodiment of the present invention, it is preferable that the inner diameter of the cylindrical body at a portion corresponding to the first position of the piston is the smallest inner diameter among the inner diameters of the cylindrical body.

[0020] According to one embodiment of the present invention thus constructed, the inner diameter of the cylindrical body corresponding to the piston's first position is the smallest of the cylindrical body's inner diameters. Consequently, when the piston is in the first position, the elastic member deforms to its maximum, and the force supporting the piston is also the greatest among the forces at all positions. This relatively simple structure prevents piston tilting and unstable operation caused by fluctuations in water supply pressure.

[0021] In one embodiment of the present invention, it is preferable that the water drain valve hydraulic drive unit further includes a biasing member provided in the cylindrical body and biasing the piston toward the first position.

[0022] According to one embodiment of the present invention thus constructed, the drain valve hydraulic drive unit further includes a biasing member disposed within the cylindrical body and configured to apply a force to the piston toward the first position. This biasing member thereby provides a buffered action for the piston while simultaneously preventing instability in the piston's movement. Furthermore, even when the piston is in the first position and the biasing member is extended, reducing its stabilizing force, the elastic member's deformation is the maximum among the deformations at each position, and the force supporting the piston is also the maximum among the supporting forces at each position. Therefore, the supporting force of the elastic member compensates for the reduction in the biasing member's stabilizing force, stabilizing the piston's movement.

[0023] In one embodiment of the present invention, the second drain portion is preferably formed so that as the piston moves from the first position to the second position, a flow path cross-sectional area in the second drain portion increases and a pressure loss in the second drain portion decreases.

[0024] According to one embodiment of the present invention thus constructed, as the piston moves from the first position to the second position, the cross-sectional area of ​​the flow path within the second drain section increases, and the pressure loss in the second drain section decreases. Consequently, during the initial stage of supplying wash water into the cylindrical body, the pressure loss in the second drain section is maximized, making it difficult for the wash water supply pressure to escape toward the second drain section, and enabling the wash water supply pressure to be effectively utilized for the upward movement of the piston.

[0025] In one embodiment of the present invention, the second drain portion is preferably formed so that as the piston moves from the first position to the second position, the flow path cross-sectional area between the rod of the second drain portion and the inner wall of the through-hole portion increases, and the pressure loss of the second drain portion decreases.

[0026] According to one embodiment of the present invention thus constructed, the second drain section is configured so that as the piston moves from the first position to the second position, the cross-sectional area of ​​the flow path between the rod of the second drain section and the inner wall of the through-hole increases, thereby reducing the pressure loss in the second drain section. Thus, during the initial stage of supplying wash water to the cylindrical body with the piston in the first position, the pressure loss in the second drain section is set to a maximum, making it difficult for the wash water supply pressure to escape toward the second drain section, and enabling the wash water supply pressure to be effectively utilized for the piston's upward movement. Furthermore, when the piston reaches the second position, the pressure loss in the second drain section is set to a relatively low level, allowing the wash water in the cylindrical body to easily flow out of the second drain section, thereby mitigating the impact on the wash water in the cylindrical body.

[0027] In one embodiment of the present invention, it is preferred that the through hole portion of the cylindrical body has a dam portion, which stands upright from the surrounding portion of the through hole at the bottom of the cylindrical body toward the inner side of the cylindrical body, and when the piston is in the first position, the second drainage portion has a first flow path extending between the top of the dam portion and the piston.

[0028] According to one embodiment of the present invention thus constructed, when the piston is in the first position, the second drain section includes a first flow path extending between the top of the bank and the piston. Consequently, during the initial stage of supplying wash water into the cylindrical body with the piston in the first position, the pressure loss in the second drain section is maximized, making it difficult for the wash water supply pressure to escape toward the second drain section, and enabling the wash water supply pressure to be effectively utilized to raise the piston.

[0029] In one embodiment of the present invention, it is preferred that a clutch mechanism is further provided, which connects the drain valve and the drain valve water pressure driving part, lifts the drain valve by the drain valve water pressure driving part, and simultaneously disconnects and lowers the drain valve at a specified time, and the flow path cross-sectional area of ​​the second drain part when the clutch mechanism is disconnected becomes the largest flow path cross-sectional area among the flow path cross-sectional areas of the second drain part at each position of the piston when it moves from the first position to the second position.

[0030] According to one embodiment of the present invention thus constructed, when the clutch mechanism is disengaged, an impact is transmitted from the clutch mechanism to the piston via the rod. At this time, the flow path cross-sectional area of ​​the second drain portion becomes the largest of the flow path cross-sectional areas of the second drain portion at each position of the piston between the first and second positions. This facilitates piston movement, making it easier to dissipate the impact transmitted to the piston. This stabilizes piston movement and suppresses abnormal noise caused by the impact transmitted to the piston.

[0031] In one embodiment of the present invention, it is preferred that the central axis of the rod, the central axis of the through-hole portion, and the central axis of the cylindrical body are located on the same axis.

[0032] According to one embodiment of the present invention constructed in this manner, the central axis of the rod, the central axis of the through-hole, and the central axis of the cylindrical body are coaxial. This allows the piston within the cylindrical body to bear relatively evenly circumferential force, preventing the rod from tilting relative to the central axis of the cylindrical body during vertical movement. Furthermore, this prevents the rod from tilting even when the piston absorbs impact from the wash water.

[0033] In one embodiment of the present invention, preferably, the through-hole portion further includes a rectifying portion formed so that the diameter of the inner wall at the top thereof is substantially constant in the height direction.

[0034] According to one embodiment of the present invention thus constructed, the through-hole portion further includes a rectifying portion, wherein the diameter of the inner wall near the top is formed to be constant along the movement direction of the rod. This prevents turbulence in the flow of the washing water through the rectifying portion, discharges the washing water relatively evenly in the circumferential direction, and prevents the rod from tilting.

[0035] In one embodiment of the present invention, it is preferable that a maximum outer diameter among outer diameters of the rod is smaller than a minimum inner diameter among inner diameters of the through-hole portion.

[0036] According to one embodiment of the present invention constructed in this manner, the maximum outer diameter of the rod is smaller than the minimum inner diameter of the through-hole. This allows the rod to be inserted into the through-hole from above to assemble the drain valve hydraulic actuator. Furthermore, this prevents wash water flowing out from between the rod and the through-hole of the second drain section from colliding with the outside of the rod and causing the rod to deviate from its originally intended central axis. Furthermore, this prevents wash water from colliding with the outside of the rod from splashing and colliding with other equipment, thereby destabilizing the operation of the other equipment.

[0037] In one embodiment of the present invention, preferably, the flush water tank assembly further includes a speed reducing unit that reduces the flow rate of the flush water discharged from the second drain unit.

[0038] According to one embodiment of the present invention thus configured, the flush water tank assembly further includes a deceleration unit that decelerates the flow rate of the flush water discharged from the second drain portion. This deceleration can reduce the flow rate of the flush water discharged from the second drain portion. For example, even if the flush water discharged from the second drain portion is discharged into the storage tank from a position higher than the water surface in the storage tank, splashing of the flush water can be suppressed.

[0039] In one embodiment of the present invention, preferably, when the piston is located at the first position, the lower end of the elastic member is located above a water stop level of the water storage tank.

[0040] According to one embodiment of the present invention thus constructed, when the piston is in the first position, the lower end of the elastic member is located above the water stop level of the water storage tank. This prevents the elastic member from aging due to immersion in the cleaning water stored in the water storage tank, where it is unclear whether a user has injected chlorine solution, such as for toilet flushing, into the water storage tank. This also reduces the possibility of malfunction in the drain valve hydraulic drive unit.

[0041] In one embodiment of the present invention, it is preferable that the cylindrical body of the drain valve hydraulic driving unit is configured so that the elastic member is soaked in the washing water remaining in the cylindrical body when the piston is located at the first position.

[0042] According to one embodiment of the present invention thus constructed, the cylindrical body of the drain valve hydraulic drive unit is configured so that, when the piston is in the first position, the elastic member is immersed in the wash water remaining in the cylindrical body. This prevents the formation of scale (precipitates) from tap water on the elastic member due to repeated wetting and drying by the wash water, and also prevents the elastic member from aging due to immersion in the wash water stored in the water storage tank. This prevents the formation of scale on the elastic member and also prevents the elastic member from aging. On the other hand, if the elastic member is submerged in the wash water in the water storage tank to prevent scale formation, the elastic member must be positioned on the bottom side below the dead water level, the lower limit of the water level in the water storage tank, to ensure that it remains submerged regardless of changes in the wash water level in the water storage tank. This compromises the flexibility in the placement of the sealing member, and consequently, the piston and cylindrical body. In contrast, according to one embodiment of the present invention, the formation of scale can be suppressed, and at the same time, the occurrence of such a problem of loss of arrangement freedom can be suppressed, and the sealing member can be arranged relatively freely.

[0043] In one embodiment of the present invention, it is preferred that the piston of the water pressure driving portion of the drain valve is configured to move up and down within the cylindrical body, the first position is located at a position lower than the second position, and the cylindrical body comprises: a dam standing upward from the surrounding portion of the through hole at its bottom; and a water storage portion that can store cleaning water remaining between the dam and the inner wall of the cylindrical body, and when the piston is located at the first position, the upper end of the elastic member is located at a height lower than the top of the dam so that the elastic member is located in the water storage portion.

[0044] According to one embodiment of the present invention thus constructed, when the piston is in the first position, the upper end of the elastic member is located at a lower height than the top of the bank, so that the elastic member is located within the water reservoir. This relatively simple structure prevents the formation of scale (precipitates) from tap water on the elastic member due to repeated wetting and drying of the elastic member by wash water, and also prevents the elastic member from aging due to immersion in wash water stored in the water storage tank. This relatively simple structure prevents the formation of scale on the elastic member and also prevents the elastic member from aging.

[0045] In one embodiment of the present invention, preferably, when the piston is located at the first position, the top of the bank portion abuts against the lower surface of the piston.

[0046] According to one embodiment of the present invention thus constructed, when the piston is in the first position, the top of the bank abuts against the bottom of the piston, thereby preventing the washing water in the water storage portion from flowing out and facilitating the elastic member to remain immersed in the washing water.

[0047] In one embodiment of the present invention, preferably, the rod extends downward from the piston, and the bank of the cylindrical body is formed in a ring shape around the rod when viewed from above.

[0048] According to one embodiment of the present invention thus constructed, the bank of the cylindrical body is formed in a ring shape around the rod when viewed from above. When the piston is in the first position, the top of the bank abuts against the bottom of the piston. This further prevents the wash water from flowing out of the water reservoir and makes it easier to keep the elastic member immersed in the wash water.

[0049] In one embodiment of the present invention, it is preferred that the water pressure driving portion of the drain valve further includes a force-applying member, which is arranged in the cylindrical body and applies force to the piston toward the first position side. The piston includes a force-bearing portion that receives the force applied by the force-applying member, and when viewed from above, the force-bearing portion is formed on the outside of the embankment.

[0050] According to one embodiment of the present invention constructed in this way, the water pressure driving portion of the drain valve further includes a force member, which is disposed in the cylindrical body and simultaneously applies force to the piston toward the first position side. When the piston is in the first position, it is easier to maintain the top of the bank portion in contact with the lower portion of the piston. As a result, the outflow of the cleaning water in the water storage portion can be further suppressed, and the elastic member can be more easily kept in a state of being immersed in the cleaning water. In addition, the piston of the water pressure driving portion of the drain valve includes a force-bearing portion that receives the force from the force member, and when viewed from above, the force-bearing portion is formed on the outside of the bank portion. As a result, the force-bearing portion of the piston can more reliably bear the force from the force member, can further suppress the outflow of the cleaning water in the water storage portion, and can more easily keep the elastic member immersed in the cleaning water.

[0051] In one embodiment of the present invention, preferably, when the piston is located at the first position, the force receiving portion of the piston of the water pressure driving unit of the water discharge valve is located below the top of the bank.

[0052] According to one embodiment of the present invention constructed in this manner, when the piston is in the first position, the force-bearing portion of the piston of the drain valve hydraulic drive unit is located below the top of the dike. Thus, when the piston is subjected to a force from the force-applying member, the force-bearing portion, which serves as a point of application and bears the force, is located below the top of the dike, which functions as a fulcrum. Thus, when the force-bearing portion of the piston is subjected to a force, the piston is less likely to fall in a direction that deviates from the top of the dike, further stabilizing the movement of the piston. Consequently, the outflow of the cleaning water within the water storage unit can be stably suppressed, and the elastic member can be easily and stably kept immersed in the cleaning water.

[0053] In one embodiment of the present invention, it is preferred that the piston of the drain valve water pressure drive unit further includes an upper peripheral portion formed on the upper side of the elastic member, and a water passage gap for washing water to pass through is formed between the upper peripheral portion and the inner wall of the cylindrical body.

[0054] According to one embodiment of the present invention thus constructed, the piston of the drain valve hydraulic drive unit further includes an upper peripheral portion formed above the elastic member, and a water-passing gap for the flow of wash water is formed between the upper peripheral portion and the inner wall of the cylindrical body. This makes it easier to immerse the upper side of the elastic member in wash water.

[0055] In one embodiment of the present invention, it is preferable that a water passage gap between the upper outer peripheral portion and the inner wall of the cylindrical body is formed to become smaller from an upper portion toward a lower portion of the cylindrical body.

[0056] According to one embodiment of the present invention thus constructed, the water-passing gap between the upper outer peripheral portion and the inner wall of the cylindrical body is formed to decrease in size as the piston moves from the upper portion of the cylindrical body toward the lower portion. As a result, the water-passing gap between the upper outer peripheral portion and the inner wall of the cylindrical body decreases as the piston moves from the upper portion of the cylindrical body toward the lower portion. This makes it difficult for wash water on the upper side of the elastic member to flow out of the water-passing gap, making it easier for the upper side of the elastic member to be immersed in wash water.

[0057] Another embodiment of the present invention is a flush toilet apparatus comprising: the flush water tank apparatus of the present invention; and a flush toilet bowl flushed by flush water supplied from the flush water tank apparatus.

[0058] According to the present invention, it is possible to provide a flush water tank assembly and a flush toilet assembly equipped with the same, which can reduce the possibility of malfunction in a water pressure driving portion of a drain valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a perspective view showing the entire flush toilet apparatus including the flush water tank assembly according to the first embodiment of the present invention.

[0060] Figure 2 It is a cross-sectional view showing a schematic structure of a flush water tank assembly according to a first embodiment of the present invention.

[0061] Figure 3 This is a side view showing a state in which a water pressure driving portion for a drain valve, a clutch mechanism, and a drain valve of a flush water tank assembly according to a first embodiment of the present invention are arranged in a water storage tank in a standby state.

[0062] Figure 4 It is along Figure 3 The main sectional view taken along line IV-IV.

[0063] Figure 5 It is along Figure 4 A front-to-back cross-sectional view taken along line VV.

[0064] Figure 6 It is magnified Figure 5 A partial enlarged view of the vicinity of the water pressure drive unit of the drain valve of the cleaning water tank device.

[0065] Figure 7 It is along Figure 6 A cross-sectional view taken along line VII-VII.

[0066] Figure 8 It is an exploded perspective view showing the clutch mechanism of the flush water tank assembly according to the first embodiment of the present invention in an exploded manner.

[0067] Figure 9 Indicates Figure 5 The state of the piston of the drain valve hydraulic drive part on the rise on the cross section of the drain valve hydraulic drive part of the flushing water tank device.

[0068] Figure 10 Indicates Figure 5 The state when the clutch mechanism on the cross section of the drain valve water pressure drive part of the flushing water tank device is disconnected.

[0069] Figure 11 Indicates Figure 5 The piston of the drain valve hydraulic drive unit on the cross section of the drain valve hydraulic drive unit of the flushing water tank device rises to the second position.

[0070] Figure 12 Indicates Figure 5 The drain valve on the cross section of the drain valve hydraulic drive part of the flushing water tank device is lowered and the drain outlet is closed.

[0071] Figure 13 Indicates Figure 5 The piston on the cross section of the drain valve hydraulic drive portion of the flush water tank device is lowered and the rod is in contact with the movable body installed on the drain valve again.

[0072] Figure 14 It is a cross-sectional view showing a schematic structure of a flush water tank assembly according to a second embodiment of the present invention.

[0073] Figure 15 It is magnified Figure 14 A partially enlarged stereoscopic view of the water pressure drive unit of the drain valve of the cleaning water tank device.

[0074] Figure 16 It is along Figure 15 Cross-sectional view taken along line XVI-XVI.

[0075] Figure 17 Indicates Figure 14 The state in which the piston of the water pressure driving part of the drain valve in the washing water tank device is moving toward the second position.

[0076] Figure 18 Indicates Figure 14 The state when the clutch mechanism in the cleaning water tank device is disconnected.

[0077] Figure 19 Indicates Figure 14 The state in which the piston of the water pressure driving part of the drain valve in the cleaning water tank device moves to the second position.

[0078] Figure 20 Indicates Figure 14 The state in which the drain valve in the cleaning water tank device is lowered and the drain outlet is closed.

[0079] Figure 21 It is a cross-sectional view showing a schematic structure of a flush water tank assembly according to a third embodiment of the present invention.

[0080] Figure 22 It is magnified Figure 21 A partially enlarged stereoscopic view of the water pressure drive unit of the drain valve of the cleaning water tank device.

[0081] Figure 23 Viewed from the drive unit drainage channel side along the axial direction of the first rod Figure 22 Front view of the water pressure drive unit of the drain valve.

[0082] Figure 24 Yes Figure 21 A partially enlarged sectional view of the central section of the water pressure drive portion of the drain valve of the flushing water tank device.

[0083] Figure 25 Indicates Figure 21 The state in which the piston of the water pressure driving part of the drain valve in the washing water tank device is moving toward the second position.

[0084] Figure 26 Indicates Figure 21 The state when the clutch mechanism in the cleaning water tank device is disconnected.

[0085] Figure 27 Indicates Figure 21 The state in which the piston of the water pressure driving part of the drain valve in the cleaning water tank device moves to the second position.

[0086] Figure 28 Indicates Figure 21 The state in which the drain valve in the cleaning water tank device is lowered and the drain outlet is closed.

[0087] Figure 29 It is a partially enlarged perspective view showing a modified example of the water pressure driving portion of the drain valve of the flush water tank assembly according to the second embodiment of the present invention.

[0088] Explanation of symbols

[0089] 1-Flush toilet device; 4-Washing water tank device; 10-Water storage tank; 10a-Drain outlet; 12-Drain valve; 14-Drain valve hydraulic drive unit; 14a-Cylinder; 14f-Through hole; 14h-Embankment; 14i-Inner wall; 14k-Top; 14l-Inlet; 14m-First drainage section; 14n-Second drainage section; 14o-First flow path; 14p-Outer wall; 14q-Second flow path; 14s-Straightening section; 28-Piston; 30-Clutch mechanism; 32-Rod; D1-Outer diameter; D2-Inner diameter; F1-Cross-sectional area; G1-Center axis; G2-Center axis; G3-Center axis; H1-First position; H2-Second position; R1-Inner diameter; R2-Inner diameter. DETAILED DESCRIPTION

[0090] Next, a flush toilet device according to a first embodiment of the present invention will be described with reference to the accompanying drawings. From the following description, it will be apparent to those skilled in the art that numerous modifications and alternative embodiments are possible. Therefore, the following description should be construed as merely illustrative, provided to demonstrate to those skilled in the art the optimal configuration for carrying out the present invention. Details of its structure and / or function may be substantially modified or substituted without departing from the spirit of the present invention.

[0091] Figure 1 It is a perspective view showing the entire flush toilet apparatus including the flush water tank assembly according to the first embodiment of the present invention.

[0092] Figure 2 It is a cross-sectional view showing a schematic structure of a flush water tank assembly according to a first embodiment of the present invention.

[0093] like Figure 1 As shown, a flush toilet device 1 according to a first embodiment of the present invention comprises a flush toilet, i.e., a flush toilet body 2, and a flush water tank assembly 4 according to the first embodiment of the present invention, positioned behind the flush toilet body 2. The flush toilet body 2 is cleaned with flush water supplied from the flush water tank assembly 4. The flush toilet device 1 of this embodiment is configured to flush the bowl 2a of the flush toilet body 2 after a predetermined time has passed, based on operation of a wall-mounted remote control device 6 or detection of a user leaving the toilet seat by a human presence sensor 8 installed on the toilet seat after use. The flush water tank assembly 4 of this embodiment is configured to discharge flush water stored within the flush toilet body 2 in response to an instruction signal from the remote control device 6 or the human presence sensor 8, thereby flushing the bowl 2a with this flush water.

[0094] Furthermore, by the user pressing button 6a on remote control device 6, a toilet flushing operation for cleaning bowl portion 2a is executed. Furthermore, although the human body sensor 8 is located on the toilet seat in this embodiment, the present invention is not limited to this arrangement. Any location capable of detecting a user's seating, vacating their seat, or approaching, leaving, or covering their hand may be sufficient. For example, it may be located on flush toilet body 2 or flush water tank assembly 4. Furthermore, any human body sensor 8 capable of detecting a user's seating, vacating their seat, or approaching, leaving, or covering their hand may be sufficient. For example, an infrared sensor or microwave sensor may be used as human body sensor 8. Furthermore, remote control device 6 may be modified to include an operating lever or operating button device having a structure capable of mechanically controlling the opening and closing of first control valve 16 and second control valve 22, described later.

[0095] like Figure 2 As shown, the flush water tank assembly 4 includes a water storage tank 10 that stores flush water to be supplied to the flush toilet bowl 2; a drain valve 12 for opening and closing a drain outlet 10a provided in the water storage tank 10; and a drain valve hydraulic actuator 14, i.e., a drain valve lift that lifts the drain valve 12. Furthermore, the flush water tank assembly 4 internally includes a first control valve 16, a water supply control device, that controls the water supply from the tap water pipe to the drain valve hydraulic actuator 14; and a solenoid valve 18 mounted on the first control valve 16. Furthermore, the flush water tank assembly 4 internally includes a second control valve 22 for supplying flush water to the water storage tank 10; and a solenoid valve 24 mounted on the second control valve 22. Furthermore, the flush water tank assembly 4 also includes a float device 26, which serves as both a valve control device and a timer mechanism, maintaining the lifted drain valve 12 in a predetermined position.

[0096] The flush water tank assembly 4 also includes a clutch mechanism 30 that connects the drain valve 12 to a rod 32 extending from the drain valve hydraulic actuator 14. The mechanism raises the drain valve 12 by the movement of the rod 32 of the drain valve hydraulic actuator 14, and is disconnected at a predetermined time, lowering the drain valve 12. A housing 13 is formed above the drain valve 12. The housing 13 is cylindrical and has an open lower side. The housing 13 is connected to and fixed to the drain valve hydraulic actuator 14.

[0097] The water storage tank 10 is configured to store flush water to be supplied to the flush toilet body 2. A drain outlet 10a is formed at its bottom for discharging the stored flush water into the flush toilet body 2. An overflow pipe 10b is connected to the water storage tank 10, downstream of the drain outlet 10a. This overflow pipe 10b extends vertically from near the drain outlet 10a to a position above the full water level WL, or the stop level, of the flush water stored in the water storage tank 10. The stop level is the flush water level in the water storage tank 10 during standby mode, and is distinct from the dead water level, or the lower limit of the flush water in the water storage tank 10 during toilet flushing. Consequently, flush water flowing in from the upper end of the overflow pipe 10b bypasses the drain outlet 10a and flows directly into the flush toilet body 2.

[0098] The drain valve 12 is a valve body device configured to open and close the drain port 10a. The drain valve 12 is opened by being lifted upward, and the flushing water in the water tank 10 is discharged into the flush toilet body 2, thereby cleaning the bowl 2a. In addition, the drain port 10a is closed by the drain valve 12, thereby stopping the supply of flushing water to the flush toilet body 2. The drain valve 12 includes: a valve body 12b having a circular outer shape and opening and closing the drain port 10a; a valve shaft frame 12a extending upward from the valve body 12b and linked to the valve body 12b; and a support portion 12d formed in a C shape and receiving the rotating shaft 66 (see Figure 8 Drain valve 12 constitutes a direct-acting drain valve device, which causes valve shaft frame 12a to move up and down in the vertical direction, thereby causing valve body 12b to move up and down in the vertical direction, opening and closing drain outlet 10a. Furthermore, drain valve 12 is lifted by the driving force of drain valve hydraulic drive unit 14. At a predetermined moment when it reaches a predetermined height, clutch mechanism 30 is disengaged, and drain valve 12 descends due to its own weight. As drain valve 12 descends, float device 26 maintains drain valve 12 for a predetermined period of time, adjusting the time it takes for drain valve 12 to reach drain outlet 10a.

[0099] Next, refer to Figures 2 to 7 The water discharge valve hydraulic drive unit 14 will be described.

[0100] like Figure 2 、 Figure 4 and Figure 5 As shown in FIG. 1 and FIG. 2 , the drain valve water pressure drive unit 14 is configured to drive the drain valve 12 using the water supply pressure of the cleaning water supplied from the tap water pipe. Specifically, the drain valve water pressure drive unit 14 includes: a cylindrical body 14a, to which the tap water supplied from the first control valve 16 is supplied as cleaning water; a piston 28, which is slidably arranged in the cylindrical body 14a; a rod 32, which protrudes from the lower end of the cylindrical body 14a to drive the drain valve 12; a sealing member, namely a seal 20, which is provided on the piston 28 and has a sealing function between the piston 28 and the inner wall of the cylindrical body 14a; and a spring 48, which is provided in the cylindrical body 14a and is biased toward the first position H1 (refer to FIG. 1 ). Figure 6 ) side applies force to the piston 28.

[0101] A spring 48 is disposed inside the cylindrical body 14a to bias the piston 28 downward. A clutch mechanism 30 is provided at the lower end of the rod 32 to connect and disconnect the rod 32 from the valve shaft frame 12a of the drain valve 12.

[0102] The cylindrical body 14a is arranged with its axis oriented vertically, and the piston 28 is slidably received within it in the vertical direction. Furthermore, a drive unit water supply passage 34a is connected to the lower end of the cylindrical body 14a, allowing the cleaning water flowing from the first control valve 16 to flow into the cylindrical body 14a. The cleaning water flows into the cylindrical body 14a using the water pressure of the tap water supply. Therefore, the cleaning water flowing into the cylindrical body 14a lifts the piston 28 within the cylindrical body 14a against the biasing force of the spring 48. Only tap water is supplied as cleaning water to the cylindrical body 14a; cleaning water once supplied to the water storage tank 10 does not flow into the cylindrical body 14a. Furthermore, the piston 28 is not limited to moving up and down within the cylindrical body 14a; it may also move in other directions within the cylindrical body 14a (e.g., diagonally or horizontally).

[0103] On the other hand, a first drain portion 14m is provided at the upper center portion in the height direction of the cylindrical body 14a, which has an outflow hole to the drive unit drain passage 34b. The drive unit drain passage 34b is connected to the interior of the cylindrical body 14a via the first drain portion 14m. Therefore, when the washing water flows into the cylindrical body 14a from the drive unit water supply passage 34a connected to the lower part of the cylindrical body 14a, the piston 28 moves from the first position H1 (refer to Figure 6 ) That is, the lower portion of the cylindrical body 14a is lifted upward. Moreover, when the piston 28 is lifted to the second position H2 (refer to Figure 11), water flowing into cylindrical body 14a flows from first drain portion 14m through drive unit drain passage 34b and out. Specifically, when piston 28 moves to second position H2, drive unit water supply passage 34a and drive unit drain passage 34b are connected via the interior of cylindrical body 14a. Discharge portion 54 is formed at the top end of drive unit drain passage 34b, which extends from cylindrical body 14a. Thus, drive unit drain passage 34b forms a flow path extending to discharge portion 54.

[0104] like Figure 6 As shown, the cylindrical body 14a further includes: a through hole portion 14f formed at the bottom of the cylindrical body 14a on the first position side; and a water storage portion 14j that can store the cleaning water remaining between the embankment 14h described later of the through hole portion 14f and the inner wall 14i of the cylindrical body 14a.

[0105] The through-hole portion 14f includes: a bank 14h that rises upward from the surrounding portion of the through-hole formed at the bottom of the cylindrical body 14a; and a rectifying portion 14s, the inner wall of which is formed at the top so that the diameter is approximately constant along the moving direction of the rod 32 (the height direction in this embodiment). When viewed from above, the bank 14h of the cylindrical body 14a is formed in a ring shape around the rod 32. The rectifying portion 14s is formed from the top of the bank 14h to a predetermined distance below. The rectifying portion 14s forms a longitudinal wall extending in the vertical direction. The rectifying portion 14s extends approximately parallel to the outer wall of the rod 32, forming a flow path of approximately constant width between the rectifying portion 14s and the rod 32. As a result, it is possible to suppress turbulence in the flow of the cleaning water passing between the rectifying portion 14s and the rod 32.

[0106] The water storage portion 14j is formed in the cylindrical body 14a at a lower position than the top of the bank portion 14h. The water storage portion 14j is formed in a ring shape. The cylindrical body 14a is constructed so that when the lower end of the seal 20 is located at the first position H1, that is, the standby position, the seal 20 is soaked in the cleaning water of the water storage portion 14j remaining in the cylindrical body 14a after each toilet is cleaned. Here, the cleaning water remaining in the cylindrical body 14a refers to the cleaning water in the cylindrical body 14a that gradually flows out from the through-hole portion 14f after each cleaning action and remains in the cylindrical body 14a when the outflow is completed ( Figure 6(Indicated by residual water level WL3 in the figure). The residual water level WL3 of the remaining wash water is determined by the top 14k of the bank 14h, described later. Furthermore, the drive unit water supply path 34a is formed so that it is higher than the residual water level WL3 in the path from the drain valve hydraulic drive unit 14 to the vacuum breaker 36. Thus, when the outflow of wash water from the cylindrical body 14a is completed, the wash water is accumulated within the cylindrical body 14a to the residual water level WL3. When the piston 28 is in the first position H1, the upper end 20a of the seal 20 is located at a lower height than the top 14k of the bank 14h, so that the seal 20 is located within the water reservoir 14j. Furthermore, when the piston 28 (the lower end of the piston 28) is located at the first position, since the seal 20 (the lower end of the seal 20) is also approximately located at the first position, the following description will assume that the seal 20 is also located at the first position when the piston 28 is located at the first position.

[0107] like Figure 6 As shown, the cylindrical body 14a has an inlet 141, into which the washing water flows (see Figure 4 a first drain portion 14m for discharging cleaning water while being separately provided with the inlet portion 14l; and a second drain portion 14n for discharging cleaning water while being separately provided with the first drain portion 14m and being formed between the rod 32, the piston 28 and the through-hole portion 14f.

[0108] The inlet portion 141 is connected to the drive unit water supply path 34a. The inlet portion 141 is connected to the lower portion of the water storage portion 14j of the cylindrical body 14a. The inlet portion 141 forms a flow path connected to the lower side of the piston 28. The first drain portion 14m is connected to the drive unit drain path 34b, forming an outflow hole to the drive unit drain path 34b. The second drain portion 14n is connected to the space within the water storage tank 10 below the drain valve hydraulic drive unit 14. The second drain portion 14n is formed between the rod 32 and the through-hole portion 14f, and between the piston 28 and the through-hole portion 14f. The second drain portion 14n forms a second outflow path from the cylindrical body 14a. The minimum value of the flow path cross-sectional area of ​​the second drain portion 14n is smaller than the minimum value of the flow path cross-sectional area of ​​the first drain portion 14m. The minimum value of the flow path cross-sectional area of ​​the second drain portion 14n is less than or equal to half the minimum value of the flow path cross-sectional area of ​​the first drain portion 14m. The second drain portion 14n forms an auxiliary drain flow path for the first drain portion 14m.

[0109] The second drain portion 14n comprises a first flow path 14o extending transversely between the top 14k and lower portion 28c of the bank 14h when the piston 28 is in the first position H1; a second flow path 14q formed between the outer wall 14p of the bank 14h and the piston 28 and extending downwardly from the first flow path 14o in a curved manner; and a third flow path 14r extending downwardly between the rod 32 and the inner wall of the through-hole 14f when the piston 28 is in the first position H1. Furthermore, since the top 14k and lower portion 28c are substantially in contact with each other when the piston 28 is in the first position H1, the first flow path 14o has a relatively small gap. When viewed in cross-section, the second flow path 14q and the first flow path 14o form an L-shaped curved flow path. Furthermore, when viewed in cross section, a U-shaped curved flow path is formed by the second flow path 14q, the first flow path 14o, and the third flow path 14r. Furthermore, the piston 28 and the cylindrical body 14a may be formed so that when the piston 28 is in the first position H1, the top portion 14k and the bottom portion 28c do not abut against each other, forming the first flow path 14o with a relatively small gap.

[0110] The shape of the second drain portion 14n changes as the piston 28 moves up and down. Consequently, the total cross-sectional area or the minimum cross-sectional area within the second drain portion 14n changes with the movement of the piston 28. The second drain portion 14n is configured so that as the piston 28 moves from the first position H1 to the second position H2, the total cross-sectional area or the minimum cross-sectional area within the second drain portion 14n increases, thereby reducing pressure loss within the second drain portion 14n. For example, as the piston 28 moves from the first position H1 to the second position H2, the minimum cross-sectional area within the second drain portion 14n increases. For example, the minimum cross-sectional area is the minimum cross-sectional area of ​​the first flow path 14o between the top 14k of the bank 14h and the bottom 28c of the piston 28. As the piston 28 rises, the minimum cross-sectional area of ​​the first flow path 14o increases. As the piston 28 moves from the first position H1 to the second position H2, the minimum cross-sectional area of ​​the second flow path 14q increases. When the piston 28 moves from the first position H1 to the second position H2, the minimum cross-sectional area of ​​the third flow path 14r remains constant.

[0111] Furthermore, as will be described later, when the outer diameter of the lower portion of the rod 32 is formed to be smaller than the outer diameter of the upper portion of the rod 32, the second drain portion 14n is formed so that, as the piston 28 and the rod 32 ascend, the flow path cross-sectional area of ​​the third flow path 14r between the rod 32 and the inner wall of the through-hole portion 14f, for example, the total value and the minimum value of the cross-sectional area, increases, thereby reducing the pressure loss in the second drain portion 14n. At this time, the minimum value of the flow path cross-sectional area of ​​the third flow path 14r when the piston 28 is at the first position H1 ( Figure 7The flow path cross-sectional area F1 of the second drain portion 14n between the rod 32 and the inner wall of the through-hole 14f shown in FIG. 1 is smaller than the minimum flow path cross-sectional area between the rod 32 and the inner wall of the through-hole 14f when the piston 28 is at the second position H2. Furthermore, as the piston 28 rises, the minimum flow path cross-sectional area of ​​the first flow path 14o increases. As the piston 28 rises, the minimum flow path cross-sectional area of ​​the second flow path 14q increases.

[0112] The cylindrical body 14a is a substantially cylindrical member, and is formed in a conical shape such that the inner diameter of the inner wall 14i of the cylindrical body 14a decreases as it approaches the bottom. The inner diameter R1 of the cylindrical body 14a corresponding to the first position H1 of the piston 28 (see Figure 5 ) is the smallest inner diameter among the inner diameters of the cylinder. The inner diameter R1 of the cylinder 14a is smaller than the inner diameter R2 of the cylinder 14a corresponding to the second position H2 of the piston 28 (refer to Figure 11 ). The inner diameter of the cylindrical body 14a gradually decreases from the inner diameter R2 at the second position to the inner diameter R1 at the first position.

[0113] Rod 32 is a rod-shaped member connected to the bottom of piston 28. It extends downward from piston 28 to connect piston 28 to drain valve 12. It extends through through-hole 14f formed in the bottom of cylindrical body 14a, projecting downward from cylindrical body 14a. A portion of the wash water flowing into cylindrical body 14a flows out through second drain portion 14n, which forms the gap between rod 32 and through-hole 14f. Wash water flowing out of second drain portion 14n flows into water storage tank 10. Furthermore, because second drain portion 14n is relatively narrow and has high flow resistance, even when wash water is flowing out of second drain portion 14n, the pressure within cylindrical body 14a rises due to wash water flowing into cylindrical body 14a from drive unit water supply passage 34a, pushing piston 28 up against the biasing force of spring 48.

[0114] like Figure 6 As shown, the central axis G1 of the rod 32, the central axis G2 of the through-hole portion 14f, and the central axis G3 of the cylindrical body 14a are coaxial. The largest outer diameter D1 of the overall outer diameters of the rod 32 is smaller than the smallest inner diameter D2 of the overall inner diameters of the through-hole portion 14f. In this embodiment, the outer diameter of the rod 32 is substantially constant from its top to its bottom. Furthermore, the outer diameter of the lower portion of the rod 32 can be smaller than the outer diameter of the upper portion of the rod 32.

[0115] In this embodiment, the piston 28 is configured to move up and down in the cylindrical body 14a. The first position H1 of the piston 28 (see Figure 5 and Figure 6 ) is located at a position lower than the second position H2 (reference Figure 11) is located further below. The second position H2 is located above the first drain portion 14m near the center of the cylindrical body 14a, for example, a position near and above the center of the cylindrical body 14a. The piston 28 includes a force-bearing portion 28a that receives the biasing force from the spring 48, and an upper outer peripheral portion 28b formed above the seal 20.

[0116] When viewed from above, the force-bearing portion 28a is formed on the outside of the embankment 14h. The force-bearing portion 28a is formed by an annular recess. The force-bearing portion 28a abuts the lower end of the spring 48. When the piston 28 and the seal 20 are located at the first position H1, the force-bearing portion 28a is located at a position lower than the top 14k of the embankment 14h. A water-passing gap 29 is formed between the upper outer peripheral portion 28b and the inner wall 14i of the cylindrical body 14a, through which the cleaning water passes. The water-passing gap 29 is formed in an annular shape with a width that is approximately uniform over the entire circumference. Since the cylindrical body 14a is formed in a conical shape, as the piston 28 moves from the top to the bottom of the cylindrical body 14a, the water-passing gap 29 gradually becomes smaller from the top to the bottom of the cylindrical body 14a.

[0117] like Figure 6 As shown, a seal 20 is mounted on the piston 28, ensuring a watertight seal between the inner wall of the cylindrical body 14a and the piston 28. The seal 20 is a so-called U-seal, having a U-shaped cross section. The seal 20 is positioned so that the open side of the U-shape faces downward, forming an inverted U-shaped cross section. When the piston 28 is in the first position, or standby position, the lower end 20b of the seal 20 is positioned above the full water level WL of the water storage tank 10. The seal 20 is an elastic member formed of rubber. Since the seal 20 slides on the inner wall of the cylindrical body 14a together with the piston 28, it only needs to provide a certain degree of sealing function, such as preventing the leakage of wash water. However, some leakage of wash water between the seal 20 and the inner wall of the cylindrical body 14a may occur. The seal 20 may be a lip seal (e.g., L seal, V seal, etc.) whose sealing portion is formed in a lip shape, or an extrusion seal (e.g., O ring, X ring, etc.) that seals by extrusion.

[0118] Next, refer to Figure 2 The first control valve 16 and the second control valve 22 will be described.

[0119] The first control valve 16 is configured to control the water supply to the drain valve hydraulic drive unit 14 and the water supply and stop to the discharge unit 54 in response to the operation of the solenoid valve 18. Specifically, the first control valve 16 includes a main valve body 16a; a main valve port 16b opened and closed by the main valve body 16a; a pressure chamber 16c for moving the main valve body 16a; and a pilot valve 16d for switching the pressure within the pressure chamber 16c.

[0120] The main valve body 16a is configured to open and close the main valve port 16b of the first control valve 16. When the main valve port 16b is opened, tap water supplied from the water supply pipe 38 flows into the drain valve hydraulic actuator 14. A pressure chamber 16c is provided adjacent to the main valve body 16a within the housing of the first control valve 16. A portion of the tap water supplied from the water supply pipe 38 flows into the pressure chamber 16c, causing the pressure inside to rise. As the pressure in the pressure chamber 16c rises, the main valve body 16a moves toward the main valve port 16b, closing it.

[0121] The pilot valve 16d is configured to open and close a pilot valve port (not shown) provided in the pressure chamber 16c. When the pilot valve opens the pilot valve port (not shown), water in the pressure chamber 16c flows out, causing the internal pressure to drop. As the pressure in the pressure chamber 16c drops, the main valve body 16a moves away from the main valve port 16b, opening the first control valve 16. Furthermore, when the pilot valve 16d is closed, the pressure in the pressure chamber 16c rises, closing the first control valve 16.

[0122] A solenoid valve 18 attached to the pilot valve 16d moves the pilot valve 16d, opening and closing the pilot valve port (not shown). The solenoid valve 18 is electrically connected to the controller 40 and moves the pilot valve 16d based on a command signal from the controller 40. Specifically, the controller 40 receives a signal from the remote control device 6 or the human presence sensor 8 and sends an electrical signal to the solenoid valve 18, thereby causing it to operate.

[0123] A vacuum breaker 36 is provided on the drive unit water supply path 34a between the first control valve 16 and the drain valve hydraulic drive unit 14. This vacuum breaker 36 prevents water from flowing back toward the first control valve 16 when negative pressure is applied to the first control valve 16.

[0124] Next, the second control valve 22 is configured to control the supply and stop of water to the water storage tank 10 based on the operation of the solenoid valve 24. Although the second control valve 22 is connected to the water supply pipe 38 via the first control valve 16, tap water supplied from the water supply pipe 38 always flows into the second control valve 22, regardless of whether the first control valve 16 is opened or closed. The second control valve 22 includes a main valve body 22a, a pressure chamber 22b, and a pilot valve 22c. The pilot valve 22c is opened and closed by the solenoid valve 24. When the pilot valve 22c is opened by the solenoid valve 24, the main valve body 22a of the second control valve 22 is opened, allowing tap water flowing from the water supply pipe 38 to be supplied to the water storage tank 10 or the overflow pipe 10b. The solenoid valve 24 is also electrically connected to the controller 40, and the pilot valve 22c moves based on a command signal from the controller 40. Specifically, in response to operation of the remote control device 6, the controller 40 sends an electrical signal to the solenoid valve 24, thereby actuating it. Furthermore, the solenoid valve 24 may be omitted. When the solenoid valve 24 is omitted, the pilot valve 22 c is controlled by the float switch 42 as described later.

[0125] Meanwhile, a float switch 42 is connected to the pilot valve 22c. The float switch 42 is configured to control the pilot valve 22c based on the water level in the water storage tank 10, thereby opening and closing the pilot valve port (not shown). Specifically, when the water level in the water storage tank 10 reaches a predetermined level, the float switch 42 sends a signal to the pilot valve 22c, thereby closing the pilot valve port (not shown). In other words, the float switch 42 is configured to set the water level in the water storage tank 10 to the water cutoff level, i.e., the predetermined full water level WL. The float switch 42 is disposed in the water storage tank 10 and is configured to stop the water supply from the first control valve 16 to the drain valve hydraulic drive unit 14 when the water level in the water storage tank 10 rises to the full water level WL. Furthermore, the float switch 42 can be modified into a float valve mechanism. This float valve mechanism includes a float valve that moves up and down in response to the water level, and a support arm connected to the float valve float and actuating the pilot valve 22c. Consequently, when the water level in the water storage tank 10 rises to the full water level WL, the float valve mechanism's float valve float rises, and the support arm connected to the float valve float rotates upward, mechanically closing the pilot valve port of the pilot valve 22c (not shown). When the water level in the water storage tank 10 drops below the full water level WL, the float valve mechanism's float valve float descends, and the support arm connected to the float valve float rotates downward, mechanically opening the pilot valve port of the pilot valve 22c (not shown).

[0126] The water supply path 50 extending from the second control valve 22 is provided with a branching portion 50a. The water supply path 50, branching at the branching portion 50a, is configured so that water flows from one side into the water storage tank 10 and from the other side into the overflow pipe 10b. Consequently, a portion of the flush water supplied from the second control valve 22 is discharged into the flush toilet body 2 through the overflow pipe 10b, while the remaining portion is stored in the water storage tank 10.

[0127] Furthermore, a vacuum breaker 44 is provided on the water supply path 50. The vacuum breaker 44 prevents water from flowing back toward the second control valve 22 when negative pressure is applied to the second control valve 22.

[0128] Water supplied from the water main is supplied to the first control valve 16 and the second control valve 22, respectively, via a stopcock 38a located outside the water storage tank 10 and a constant flow valve 38b located downstream of the stopcock 38a and within the water storage tank 10. The stopcock 38a is provided to stop the water supply to the flush water tank assembly 4 during maintenance and is normally left open. The constant flow valve 38b is provided to allow water supplied from the water main to flow at a predetermined flow rate into the first control valve 16 and the second control valve 22, ensuring a constant flow rate regardless of the installation environment of the flush toilet assembly 1.

[0129] Controller 40 includes a built-in CPU and memory, and controls connected devices to execute the large and small cleaning modes described below, according to a predetermined control program stored in the memory. Controller 40 is electrically connected to remote control device 6, human presence sensor 8, solenoid valve 18, solenoid valve 24, and the like.

[0130] Next, the float device 26 will be described. The float device 26 is installed near the drain valve 12. The valve shaft frame 12a is lifted a predetermined distance, and the clutch mechanism 30 isolates the valve shaft frame 12a. The float device 26 then descends, closing the drain port 10a. Specifically, the float device 26 includes a float portion 26a and an engaging portion 26b that is linked to the float portion 26a. Meanwhile, a retaining claw 12g is formed at the base of the valve shaft frame 12a of the drain valve 12, which is configured to engage with the engaging portion 26b.

[0131] The engaging portion 26b is configured to engage with the retaining claw 12g of the valve shaft frame 12a, which has been separated and lowered by the clutch mechanism 30, preventing the valve shaft frame 12a and the drain valve 12 from descending and seating at the drain outlet 10a. Subsequently, as the water level within the water storage tank 10 decreases, the float portion 26a also descends. When the water level within the water storage tank 10 reaches a predetermined level, the float portion 26a rotates the engaging portion 26b, thereby disengaging the engaging portion 26b from the retaining claw 12g. This disengagement causes the valve shaft frame 12a and the drain valve 12 to descend and then seat at the drain outlet 10a. This delays the closing of the drain valve 12, allowing an appropriate amount of flushing water to be discharged from the drain outlet 10a.

[0132] Next, refer to Figures 8 to 13 The structure and function of the clutch mechanism 30 will be described.

[0133] like Figure 8 As shown, the clutch mechanism 30 is provided at the lower end of the rod 32 extending downward from the water pressure drive unit 14 of the drain valve, and is configured to connect and disconnect the lower end of the rod 32 and the upper end of the valve shaft frame body 12a of the drain valve 12. The clutch mechanism 30 comprises: a movable body 60 that is movable in a manner to disconnect the drain valve 12 from the water pressure drive unit 14 of the drain valve; a thin-thick portion 33 that forms the outer shape of the rod 32 thinner than the upper portion at the top end side of the rod 32; a lifting portion 35 that is further enlarged at the lower end of the thin-thick portion 33 of the rod 32; and a limiting portion 37 that hangs downward from the bottom surface of the cylindrical body 14a on the outside of the rod 32 (refer to Figure 5 ).

[0134] The movable body 60 is mounted on the valve shaft frame 12a of the drain valve 12. The movable body 60 is rotatably attached to the support portion 12d of the valve shaft frame 12a. When attached to the support portion 12d, the movable body 60 forms a movable mechanism that operates on the drain valve side. The movable body 60 is configured to switch between an engaged and disengaged position (described later) through rotation.

[0135] The movable body 60 includes: a base plate 62 extending laterally; arms 64 standing vertically from both sides of the base plate; a rotating shaft 66 serving as the center of the rotating movement of the movable body 60; and an abutment portion 68, which is abutted by the rod 32 of the drain valve water pressure drive portion 14 when the rod 32 of the drain valve water pressure drive portion 14 is about to lift the drain valve 12.

[0136] In the standby state of the clutch mechanism 30, the lifting portion 35 of the rod 32 is located below the abutment portion 68 of the movable body 60. When the rod 32 is lifted from the standby state, the movable body 60 of the clutch mechanism 30 abuts against the lifting portion 35 of the rod 32, lifting the valve shaft frame body 12a of the drain valve 12. Figure 10As shown, when the rod 32 is lifted to a predetermined height, the base plate 62 of the clutch mechanism 30 contacts the restriction portion 37, the movable body 60 rotates, and the clutch mechanism 30 is disconnected. Figure 12 、 Figure 13 As shown, after the movable body 60 and the drain valve 12 are lowered, the rod 32 is also lowered, and the clutch mechanism 30 returns to the standby state.

[0137] Next, refer to Figure 2 、 Figure 6 A series of flushing operations of the flush water tank assembly 4 and the flush toilet apparatus 1 including the same according to the first embodiment of the present invention will be described.

[0138] First, in Figure 2 In the illustrated toilet flushing standby state, the water level in the water storage tank 10 is at the predetermined full water level WL. In this state, both the first control valve 16 and the second control valve 22 are closed. Furthermore, the float device 26 is in a standby state. Next, when the user presses the flush button on the remote control device 6, the remote control device 6 transmits a toilet flushing instruction signal to the controller 40. Furthermore, in the flush toilet device 1 of this embodiment, even if a predetermined time has passed without the flush button on the remote control device 6 being pressed after the human sensor 8 detects that the user has left the seat, the toilet flushing instruction signal is transmitted to the controller 40.

[0139] like Figure 6 As shown, in the standby state, the piston 28 of the drain valve hydraulic drive unit 14 is located at the first position H1 within the cylindrical body 14a. The first position H1 of the piston 28 is the lower limit of its movable range. The piston 28 is stopped within the cylindrical body 14a. At this time, the lower end 20b of the seal 20 is located above the full water level WL of the water storage tank 10. Thus, the seal 20 is positioned in an area directly supplied with flushing water from the tap water supply, thereby preventing it from being immersed in flushing water stored in the water storage tank 10, such as chlorine solution, which may have been introduced by a user for toilet flushing. This prevents deterioration of the seal 20 due to immersion in such solution.

[0140] Meanwhile, in the standby mode, a residual water level WL3 is reached in the water reservoir 14j within the cylindrical body 14a, indicating residual wash water. With the piston 28 in the first, or standby, position, the seal 20 is immersed in the wash water remaining in the water reservoir 14j within the cylindrical body 14a and submerged. This prevents the seal 20 from drying out substantially, and also prevents the formation of scale (precipitates) from tap water on the seal 20, which would otherwise result from repeated wetting and drying by the wash water.

[0141] Furthermore, unlike the cleaning water stored in the water tank 10, for example, where it is unclear whether a user has added a certain toilet cleaning agent, since the seal 20 is immersed in the cleaning water directly supplied from the tap water, aging of the seal 20 due to chlorine in the toilet cleaning agent can be suppressed.

[0142] The deformation amount of the seal 20 when the piston 28 is in the first position H1 is the maximum deformation amount of the elastic member at each position between the piston 28 and the second position H2. The deformation amount of the seal 20 is also limited by the opening width of the opening portion of the U-shaped seal. For example, the opening width W1 of the seal 20 when the piston 28 is in the first position H1 (see Figure 6 ), which is smaller than the opening width W2 of the seal 20 when the piston 28 is located at the second position H2 (refer to Figure 11 The opening width W2 of the seal 20 is smaller than the opening width W3 (not shown) of the seal 20 in the initial state when the seal 20 is not housed in the cylindrical body 14a. In addition, as the piston 28 moves from the first position H1 to the second position H2, the opening width of the seal 20 gradually increases. In this way, the deformation amount (W3-W1) of the seal 20 when the piston 28 is in the first position H1 is greater than the deformation amount (W3-W2) of the seal 20 when the piston 28 is in the second position H2.

[0143] When the piston 28 is in the standby state at the first position H1, the spring 48 is in the most extended state, and the top 14k of the bank 14h contacts the lower surface 28c. The spring 48 biases the piston 28 toward the first position and stops contacting the top 14k.

[0144] In the standby state with the piston 28 at the first position H1, the flow path cross-sectional area within the second drain portion 14n is determined by the flow path cross-sectional area between the rod 32 and the through-hole portion 14f, and between the piston 28 and the through-hole portion 14f. The minimum flow path cross-sectional area within the second drain portion 14n is the cross-sectional area of ​​the first flow path 14o. Since the top portion 14k and the lower portion 28c are substantially in contact, the pressure loss in the second drain portion 14n is relatively large.

[0145] Next, when receiving the instruction signal to perform toilet cleaning, the controller 40 opens the electromagnetic valve 18 ( Figure 2) is actuated, causing the pilot valve 16d on the solenoid valve side to move away from the pilot valve port. This reduces the pressure within the pressure chamber 16c, causing the main valve body 16a to move away from the main valve port 16b, opening the main valve port 16b. When the first control valve 16 is opened, flush water flowing from the water supply pipe 38 is supplied to the drain valve hydraulic actuator 14 via the first control valve 16. This lifts the piston 28 of the drain valve hydraulic actuator 14, raising the drain valve 12 via the rod 32. The flush water within the water storage tank 10 is discharged from the drain port 10a into the flush toilet body 2.

[0146] When the drain valve 12 is lifted, the holding claw 12g provided on the valve shaft frame body 12a of the drain valve 12 lifts the engaging portion 26b of the float device 26 and rotates it, so that the holding claw 12g rises over the engaging portion 26b.

[0147] After piston 28 reaches its standby state, for example, when piston 28 ascends, the wash water flowing into lower chamber 14b of cylindrical body 14a, located below piston 28, is trapped in lower chamber 14b by seal 20, which performs a sealing function. This generates a force that causes piston 28 to ascend. Meanwhile, as piston 28 and seal 20 move up and down within cylindrical body 14a, some of the wash water flowing into lower chamber 14b leaks through the gap between seal 20 and inner wall 14i of cylindrical body 14a into upper chamber 14e above piston 28. At this point, the water-passing gap 29 formed between upper outer circumference 28b and inner wall 14i allows the upper side of seal 20 to be more easily immersed in wash water. Furthermore, the entire upper side of seal 20 can be immersed in wash water. Consequently, the entire seal 20, including its upper side, is immersed in wash water. Furthermore, as will be described later, even when the piston 28 descends after the clutch mechanism 30 is disengaged or in a standby state, the washing water flowing into the upper chamber 14 e easily soaks the upper side of the seal 20 through the water flow gap 29 .

[0148] Next, if Figure 10 As shown, when the drain valve 12 is further lifted, the clutch mechanism 30 is disconnected. That is, when the drain valve 12 reaches a predetermined height, the base plate 62 of the clutch mechanism 30 contacts the restriction portion 37, and the clutch mechanism 30 is disconnected.

[0149] Next, if Figure 11As shown, when the clutch mechanism 30 is disengaged, the drain valve 12 begins to descend toward the drain outlet 10a due to its own weight. The retaining claw 12g of the lowered drain valve 12 engages with the engaging portion 26b of the float assembly 26, maintaining the drain valve 12 at a predetermined height. Because the drain valve 12 is retained by the engaging portion 26b, the drain outlet 10a remains open, allowing flush water from the water storage tank 10 to continue to be discharged into the flush toilet body 2. At this time, the pilot valve 16d remains open, allowing flush water flowing from the water supply pipe 38 to be supplied to the drain valve hydraulic drive unit 14 via the first control valve 16.

[0150] When the piston 28 rises to the second position above the first drain portion 14 m , the drive unit water supply path 34 a and the drive unit drain path 34 b are connected through the interior of the cylindrical body 14 a , and the washing water is discharged from the discharge portion 54 into the water storage tank 10 .

[0151] At this time, the water-passing gap 29 between the upper outer peripheral portion 28b and the inner wall 14i is formed to become smaller as it moves from the top of the cylindrical body 14a toward the bottom. In other words, the water-passing gap 29 is formed to be larger above the cylindrical body 14a. Furthermore, when the piston 28 is located above the cylindrical body 14a, the cleaning water is more likely to leak from between the seal 20 and the inner wall 14i into the upper side chamber 14e than when it is located below the cylindrical body 14a. As a result, a portion of the cleaning water leaks from the lower side chamber 14b into the upper side chamber 14e above the seal 20. As a result, the entire seal 20, including the upper side of the seal 20, is immersed in cleaning water. Furthermore, when the piston 28 is located at the second position H2, the open width of the seal 20 is open width W2.

[0152] In the second drain section 14n, with the piston 28 in the second position H2, the top portion 14k and the bottom portion 28c separate, increasing the minimum cross-sectional area of ​​the first flow path 14o and the minimum cross-sectional area of ​​the second flow path 14q. Meanwhile, the minimum cross-sectional area of ​​the third flow path 14r remains constant. Thus, as the piston 28 ascends toward the second position H2, the top portion 14k and the bottom portion 28c separate, increasing the cross-sectional areas of the first and second flow paths 14o and 14q. This increases the total cross-sectional area or the minimum cross-sectional area within the second drain section 14n, reducing pressure loss within the second drain section 14n. Furthermore, when the piston 28 is in the second position H2, the clutch mechanism 30 is disengaged. When the clutch mechanism 30 is disengaged, the minimum value of the flow path cross-sectional area of ​​the second drain portion 14n becomes the maximum flow path cross-sectional area within the range of change from the first position H1 to the second position H2 of the piston 28. Thus, when the clutch mechanism 30 is disengaged, the pressure loss in the second drain portion 14n becomes the minimum pressure loss within the range corresponding to the pressure loss from the first position H1 to the second position H2 of the piston 28.

[0153] Next, when the water level in the storage tank 10 drops, the float switch 42, which detects the water level in the storage tank 10, opens. When the float switch 42 opens, the pilot valve 22c of the second control valve 22 opens. This allows wash water to be supplied from the second control valve 22 to the storage tank 10 via the water supply line 50. After a predetermined time has passed since the solenoid valve 18 opened, the controller 40 closes the solenoid valve 18 and the solenoid-side pilot valve 16d. When the pilot valve 16d closes, the main valve body 16a of the first control valve 16 closes. Even after the solenoid-side pilot valve 16d closes, the second control valve 22 remains open, and water supply to the storage tank 10 continues. Since the first control valve 16 is closed, the supply of wash water to the drain valve hydraulic drive unit 14 and the discharge unit 54 is stopped.

[0154] When the water level in the water storage tank 10 drops to the predetermined water level WL1, the float portion 26a of the float device 26 descends, thereby moving the engagement portion 26b. This disengages the valve shaft frame 12a from the engagement portion 26b, and the valve shaft frame 12a and the drain valve 12 begin to descend again.

[0155] As a result, the drain valve 12 is positioned at the drain port 10a, sealing the drain port 10a. After the first control valve 16 is closed and the water supply to the drain valve hydraulic drive unit 14 is stopped, the washing water in the cylindrical body 14a of the drain valve hydraulic drive unit 14 gradually flows out from the second drain portion 14n. Simultaneously, the piston 28 is pressed down by the force of the spring 48, and the rod 32 descends.

[0156] Therefore, if Figure 13 As shown, the top end 32a of the rod 32 abuts against the base plate 62, and the movable body 60 is clamped between the valve shaft frame body 12a and the rod 32 and stops, returning to the standby state before the toilet cleaning starts (see Figure 5 When piston 28 returns to its standby state at first position H1, some of the wash water leaks into upper chamber 14e above piston 28. Because water gap 29 is formed to decrease in size as it moves downward from the top of cylindrical body 14a, when piston 28 is in first position H1, wash water above seal 20 is less likely to flow downward from water gap 29. This facilitates the retention of wash water within upper chamber 14e, making it easier for the upper portion of seal 20 to be immersed in wash water. Consequently, the entire seal 20, including its upper portion, is immersed in wash water.

[0157] Since the float switch 42 remains open, the second control valve 22 remains open, and water continues to be supplied to the storage tank 10. Wash water supplied via the water supply line 50 reaches the water supply line branch 50a. Part of the wash water branched at the water supply line branch 50a flows into the overflow pipe 10b, while the remainder is stored in the storage tank 10. The wash water flowing into the overflow pipe 10b flows into the flush toilet body 2 and is used to replenish water in the bowl 2a. Meanwhile, with the drain valve 12 closed, the water level in the storage tank 10 rises due to the wash water flowing into the storage tank 10.

[0158] When the water level in the water storage tank 10 rises to the predetermined full water level WL, the float switch 42 is turned on. When the float switch 42 is turned on, the pilot valve 22c on the float switch side is closed. As a result, the pressure in the pressure chamber 22b rises due to the closed state of the pilot valve 22c, and the main valve body 22a of the second control valve 22 is closed, and the water supply is stopped. Figure 2 The machine in the water storage tank 10 is shown to have returned to a standby state.

[0159] According to the flush water tank assembly 4 according to the first embodiment of the present invention, the cylindrical body 14a includes an inlet 141 into which flush water flows; a first drain portion 14m, which is provided separately from the inlet 141 and discharges the flush water; and a second drain portion 14n, which is provided separately from the first drain portion 14m and formed between the rod 32 and the through-hole 14f. Thus, when the flush water supply pressure to the cylindrical body 14a undergoes a sudden change, such as a sudden rise, in either a disconnected or connected state between the flow path from the inlet 141 to the first drain portion 14m, the second drain portion 14n mitigates the impact of the sudden change in flush water pressure, thereby absorbing the impact of the flush water on the piston 28 and preventing the piston 28 from becoming unstable. Furthermore, when the flow path from inlet 141 in cylindrical body 14a to first drain portion 14m is disconnected, if the supply pressure of the wash water to cylindrical body 14a experiences a sudden change, such as a sudden rise, second drain portion 14n mitigates the impact of the sudden change in wash water pressure, thereby suppressing fluctuations in the wash water pressure discharged from first drain portion 14m. This prevents the wash water discharged downstream of first drain portion 14m from becoming unstable. For example, even when the wash water is being used downstream of first drain portion 14m, the supply of wash water can be prevented from becoming unstable.

[0160] Furthermore, according to the flush water tank assembly 4 of the first embodiment of the present invention, the deformation of the seal 20 when the piston 28 is in the first position H1 is the maximum deformation of the seal 20 at each position between the first position H1 and the second position H2. Thus, when the piston 28 is in the first position H1, which is the position at the start of water supply and is most susceptible to fluctuations in the flush water supply pressure, the deformation of the seal 20 is at its maximum, and the force supporting the piston 28 is also at its maximum. This prevents the piston 28 from tilting due to fluctuations in the water supply pressure, which could otherwise cause the piston 28 to become unstable.

[0161] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the inner diameter of the cylindrical body 14a corresponding to the first position H1 of the piston 28 is the smallest inner diameter of the cylindrical body 14a. Therefore, when the piston 28 is in the first position H1, the deformation of the seal 20 is at its maximum, and the force supporting the piston 28 is also at its maximum among the supporting forces at all positions. Therefore, with a relatively simple structure, it is possible to suppress tilting of the piston 28 due to fluctuations in the water supply pressure, thereby preventing unstable operation of the piston 28.

[0162] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the drain valve hydraulic drive unit 14 further includes a spring 48 disposed within the cylindrical body 14a and biasing the piston 28 toward the first position H1. Thus, the spring 48 provides a cushioning effect on the piston 28 while preventing any instability in the movement of the piston 28. Furthermore, even when the piston 28 is in the first position H1 and the spring 48 is extended, reducing its stabilizing force, the deformation of the seal 20 is the largest at any position, and the force supporting the piston 28 is also the largest at any position. Therefore, the supporting force of the seal 20 compensates for the reduction in the stabilizing force of the spring 48, stabilizing the movement of the piston 28.

[0163] Furthermore, according to the flush water tank assembly 4 of the first embodiment of the present invention, as the piston 28 moves from the first position H1 to the second position H2, the cross-sectional area of ​​the flow path within the second drain section 14n increases, thereby reducing the pressure loss in the second drain section 14n. Consequently, during the initial stage of flush water supply into the cylindrical body 14a, the pressure loss in the second drain section 14n is maximized, making it difficult for the flush water supply pressure to leak toward the second drain section 14n. This allows the flush water supply pressure to be effectively utilized to raise the piston 28.

[0164] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the second drain section 14n is configured so that as the piston 28 moves from the first position H1 to the second position H2, the cross-sectional area of ​​the flow path between the rod 32 of the second drain section 14n and the inner wall of the through-hole portion 14f increases, thereby reducing pressure loss in the second drain section 14n. Consequently, during the initial stage of flush water supply into the cylindrical body 14a, when the piston 28 is in the first position H1, the pressure loss in the second drain section 14n is maximized, making it difficult for the flush water supply pressure to escape toward the second drain section 14n. This allows the flush water supply pressure to be effectively utilized to advance the piston 28. Furthermore, when the piston 28 reaches the second position H2, the pressure loss in the second drain section 14n is relatively low, allowing flush water within the cylindrical body 14a to flow out of the second drain section 14n more easily, thus mitigating any impact on the flush water within the cylindrical body 14a.

[0165] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, when the piston 28 is in the first position H1, the second drain portion 14n includes: a first flow path 14o extending laterally between the top portion 14k of the bank portion 14h and the piston 28; and a second flow path 14q formed between the outer wall portion 14p of the bank portion 14h and the piston 28, and extending downwardly from the first flow path 14o. Consequently, during the initial stage of flush water supply into the cylindrical body 14a with the piston 28 in the first position H1, the pressure loss in the second drain portion 14n is maximized, making it difficult for the flush water supply pressure to leak toward the second drain portion 14n, and enabling the flush water supply pressure to be effectively utilized to raise the piston 28.

[0166] Furthermore, according to the flush water tank assembly 4 of the first embodiment of the present invention, when the clutch mechanism 30 is disengaged, an impact is transmitted from the clutch mechanism 30 to the piston 28 via the rod 32. At this time, the flow path cross-sectional area of ​​the second drain portion 14n becomes the largest flow path cross-sectional area among the flow path cross-sectional areas of the second drain portion 14n at each position of the piston 28 between the first position H1 and the second position H2. Since the piston 28 can move more easily, the impact transmitted to the piston 28 is easily dissipated. This stabilizes the movement of the piston 28 and suppresses the generation of abnormal noise caused by the impact transmitted to the piston 28.

[0167] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the rod 32, the central axis G2 of the through-hole portion 14f, and the central axis G3 of the cylindrical body 14a are coaxial. This allows the piston 28 within the cylindrical body 14a to receive relatively even force in the circumferential direction, thereby preventing the rod 32 from tilting relative to the central axis G3 of the cylindrical body 14a during vertical movement. Furthermore, even when the piston 28 cushions impact from flush water, this prevents the rod 32 from tilting.

[0168] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, the through-hole portion 14f further includes a rectifying portion 14s, the diameter of the inner wall of the top portion 14k of which is formed to be constant along the moving direction of the rod 32. This prevents turbulence in the flow of flush water passing through the rectifying portion 14s, allows flush water to be discharged relatively uniformly in the circumferential direction, and prevents tilting of the rod 32.

[0169] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the maximum outer diameter of the rod 32 is smaller than the minimum inner diameter of the through-hole 14f. This allows the rod 32 to be inserted into the through-hole 14f from above, thereby assembling the drain valve hydraulic drive 14. Furthermore, flush water flowing out from between the rod 32 and the through-hole 14f of the second drain section 14n can be prevented from colliding with the outside of the rod 32 and causing the rod 32 to deviate from its originally intended central axis. Furthermore, flush water colliding with the outside of the rod 32 can be prevented from splashing and colliding with other equipment, thereby destabilizing the operation of the other equipment.

[0170] Moreover, the first embodiment of the present invention is a flush toilet device 1, which is characterized by having: a flush toilet body 2; and a flush water tank device 4, which can prevent the movement of the piston 28 from becoming unstable, and at the same time can prevent the water pressure of the flush water discharged from the first drainage part 14m set separately from the inlet part 14l from changing.

[0171] According to the flush water tank assembly 4 according to the first embodiment of the present invention, when the piston 28 is in the first position, the lower end of the seal 20 is located above the full water level WL of the storage tank 10. This prevents the seal 20 from being immersed in flush water stored in the storage tank 10, where it is unclear whether a user has injected chlorine solution, such as for toilet flushing, into the flush water, thereby preventing it from deteriorating. This also reduces the possibility of malfunctioning of the drain valve hydraulic driver 14.

[0172] Furthermore, in the flush water tank assembly 4 according to the first embodiment of the present invention, the cylindrical body 14a of the drain valve hydraulic drive unit 14 is configured so that when the piston 28 is in the first position H1, the seal 20 is immersed in the flush water remaining in the cylindrical body 14a. This prevents the formation of scale (precipitates) from tap water on the seal 20 due to repeated wetting and drying of the seal 20 by flush water, and also prevents the seal 20 from aging due to immersion in flush water stored in the water storage tank 10. This prevents the formation of scale on the seal 20 and also prevents the seal 20 from aging. On the other hand, if the seal 20 is submerged in the flush water within the water storage tank 10 to suppress scale formation, the seal 20 must be positioned on the bottom surface below the dead water level, the lower limit of the water level within the water storage tank 10, in order to maintain this position regardless of any fluctuations in the flush water level within the water storage tank 10. This compromises the flexibility in positioning the seal 20, and consequently the piston 28 and cylindrical body 14a. In contrast, the first embodiment of the present invention suppresses scale formation while also minimizing this compromise in positioning flexibility, allowing for relatively flexible positioning of the seal 20.

[0173] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, when the piston 28 is in the first position H1, the upper end of the seal 20 is located at a lower height than the top 14k of the bank 14h, so that the seal 20 is located within the water storage portion 14j. This relatively simple structure can suppress the formation of scale (precipitates) from tap water on the seal 20 due to repeated wetting and drying of the seal 20 by flush water, and can also suppress the deterioration of the seal 20 due to immersion in flush water stored in the water storage tank 10. This relatively simple structure can suppress the formation of scale on the seal 20 and also suppress the deterioration of the seal 20.

[0174] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, when the piston 28 is located at the first position H1, the top portion 14k of the bank portion 14h abuts against the lower portion 28c of the piston 28. This prevents the flush water in the water reservoir 14j from flowing out, and facilitates keeping the seal 20 immersed in the flush water.

[0175] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, the bank portion 14h of the cylindrical body 14a is formed in a ring shape around the rod 32 when viewed from above. When the piston 28 is in the first position H1, the top portion 14k of the bank portion 14h abuts against the lower portion 28c of the piston 28. This further suppresses the outflow of flush water from the water reservoir 14j and makes it easier to keep the seal 20 immersed in flush water.

[0176] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, the drain valve hydraulic drive unit 14 further includes a spring 48 disposed within the cylindrical body 14a and biasing the piston 28 toward the first position H1. When the piston 28 is in the first position H1, the top 14k of the bank 14h can be more easily maintained in contact with the bottom 28c of the piston 28. This further suppresses the outflow of flush water from the water reservoir 14j and more easily keeps the seal 20 immersed in flush water. Furthermore, the piston 28 of the drain valve hydraulic drive unit 14 includes a force-bearing portion 28a that receives the force from the spring 48. When viewed from above, the force-bearing portion 28a is formed outside the bank 14h. This allows the force-bearing portion 28a of the piston 28 to more reliably receive the force from the spring 48, further suppressing the outflow of flush water from the water reservoir 14j and more easily keeping the seal 20 immersed in flush water.

[0177] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, when the piston 28 is in the first position H1, the force-bearing portion 28a of the piston 28 of the drain valve hydraulic drive unit 14 is located below the top 14k of the bank 14h. Consequently, when the piston 28 is subjected to the force applied by the spring 48, the force-bearing portion 28a, which acts as the point of application and receives the applied force, is located below the top 14k of the bank 14h, which functions as a fulcrum. Consequently, when the force-bearing portion 28a of the piston 28 is subjected to the applied force, the piston 28 is less likely to fall in a direction deviating from the top 14k of the bank 14h, further stabilizing the movement of the piston 28. Consequently, the outflow of flush water from the water reservoir 14j can be stably suppressed, and the seal 20 can be easily and stably kept immersed in flush water.

[0178] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, the piston 28 of the drain valve hydraulic drive unit 14 further includes an upper outer peripheral portion 28b formed above the seal 20. A water-passing gap 29, through which flush water passes, is formed between the upper outer peripheral portion 28b and the inner wall of the cylindrical body 14a. This makes it easier to immerse the upper side of the seal 20 in flush water.

[0179] Furthermore, according to the flush water tank assembly 4 according to the first embodiment of the present invention, the water gap 29 between the upper outer peripheral portion 28b and the inner wall of the cylindrical body 14a is formed to become smaller as the piston 28 moves from the top of the cylindrical body 14a toward the bottom. As a result, the water gap 29 between the upper outer peripheral portion 28b and the inner wall of the cylindrical body 14a becomes smaller as the piston 28 moves from the top of the cylindrical body 14a toward the bottom. This makes it difficult for flush water on the upper side of the seal 20 to flow out of the water gap 29, making it easier for the upper side of the seal 20 to be immersed in flush water.

[0180] Furthermore, the first embodiment of the present invention is a flush toilet apparatus 1 characterized by comprising a flush toilet body 2 and a flush water tank assembly 4, and capable of reducing the possibility of malfunction of the drain valve hydraulic drive unit 14.

[0181] Furthermore, the first embodiment of the present invention is a flush toilet apparatus 1 , which is characterized by including: the flush water tank apparatus 4 of the present invention; and a flush toilet 2 flushed by flush water supplied from the flush water tank apparatus 4 .

[0182] Next, refer to Figures 14 to 20 A flush toilet device according to a second embodiment of the present invention will be described.

[0183] Since the flush toilet device 101 involved in the second embodiment has a substantially identical structure to the flush toilet device involved in the above-mentioned first embodiment, the second embodiment of the present invention will be mainly described with respect to the parts that are different from the first embodiment. For the same parts, the same reference symbols will be used in the drawings or the description, or the description of the same parts will be omitted.

[0184] A flush toilet apparatus 101 according to a second embodiment of the present invention includes a flush water tank assembly 104 according to a second embodiment of the present invention, which is positioned at the rear of the flush toilet body 2. The flush water tank assembly 104 according to this embodiment is configured to discharge flush water stored within the flush toilet body 2 in response to an instruction signal from a remote control unit 6 or a human motion sensor 8, thereby flushing the bowl 2a with this flush water.

[0185] The flush water tank assembly 104 includes a drain valve hydraulic actuator 114, a drain valve lifting unit that lifts the drain valve 12. The flush water tank assembly 104 also includes a first control valve 16, a water supply control device that controls the water supply from the tap water pipe to the drain valve hydraulic actuator 114, and a solenoid valve 18 attached to the first control valve 16. The flush water tank assembly 104 also includes a float assembly 26, which serves as both a valve control unit and a timer mechanism for maintaining the lifted drain valve 12 in a predetermined position.

[0186] The flush water tank assembly 104 further includes a clutch mechanism 130, which connects the drain valve 12 to the drain valve hydraulic drive 114. The clutch mechanism 130 utilizes the driving force of the drain valve hydraulic drive 114 to raise the drain valve 12, and is disconnected at a predetermined time to lower the drain valve 12. The clutch mechanism 130 is positioned forward of the movement direction of a second rod 133 extending laterally from the drain valve hydraulic drive 114. The clutch mechanism 130 is configured to connect and disconnect the actuating portion 133a of the second rod 133 with the driven portion 176 of the clutch mechanism 130 connected to the drain valve 12. The clutch mechanism 130 is formed separately from the housing 113 of the drain valve 12 and is positioned away from the housing 113.

[0187] The clutch mechanism 130 includes: an actuating portion 133a, located at the distal end of the second rod 133; a driven portion 176, arranged on an extension line of the moving direction of the second rod 133 extending laterally from the drain valve water pressure driving portion 114; an elastic member 178 for a driven portion, connected to the driven portion 176; a first support body 180, supporting the driven portion 176 and the elastic member 178 for a driven portion; an elastic member 182 for a supporting body, connected to the first support body 180; a second support body 184, supporting the elastic member 182 for a supporting body; and a limiting portion 186, limiting the movement of the driven portion 176 in the moving direction of the second rod 133, and at the same time moving the driven portion 176 to the side of the elastic member 178 for a driven portion.

[0188] The actuating portion 133a is formed so as to abut against the first flat surface 176a of the driven portion 176. The first flat surface 176a extends in a direction perpendicular to the direction of movement of the second rod 133. Thus, when the driven portion elastic member 178 is at its natural length, the first flat surface 176a is located in front of the actuating portion 133a. Consequently, when the second rod 133 moves toward the driven portion 176, the actuating portion 133a of the second rod 133 presses against the first flat surface 176a, causing the second rod 133 and the driven portion 176 to move laterally simultaneously. As the driven portion 176 and the first support body 180 move, the drain valve 12 is lifted by the connecting member 188, as described later. The direction of expansion and contraction of the support body elastic member 182 is lateral, for example, in the direction of movement of the second rod 133. The first support body 180 is connected to the support body elastic member 182 and moves in the direction of expansion and contraction of the support body elastic member 182.

[0189] An inclined surface 176b is formed on the opposite side of the first plane 176a of the follower 176. When the follower 176 moves toward the limiting portion 186, the inclined surface 176b contacts the limiting portion 186, and thus the inclined surface 176b is pressed toward the follower elastic member 178 and moves. As a result, the abutment between the second rod 133 and the follower 176 is released, and the connection of the clutch mechanism 130 is released. The follower 176 moves in a manner that disconnects the connection with the clutch mechanism 130. At this time, the follower elastic member 178 is in a state that is more contracted than its natural length. The expansion and contraction direction of the follower elastic member 178 is longitudinal, for example, a direction perpendicular to the moving direction of the second rod 133. The follower elastic member 178 is formed by an elastic member such as a spring.

[0190] The first support 180 and the follower 176 are moved toward the drain valve hydraulic drive unit 114 (drain valve 12) by the support elastic member 182, returning them to their original natural length. Consequently, the contact between the second rod 133 and the follower 176 is released, allowing the drain valve 12 to freely fall. The support elastic member 182 is formed of an elastic member such as a spring.

[0191] The second support 184 is fixed to the water storage tank 10. The second support 184 is connected to a restricting portion 186. The restricting portion 186 is formed so as to abut against the inclined surface 176b of the driven portion 176. The restricting portion 186 is arranged in the direction of movement of the driven portion 176. The restricting portion 186 is formed so as to move the driven portion 176 away from the second rod 133 so as to release the contact between the first flat surface 176a and the second rod 133.

[0192] The first support body 180 is connected to the upper end of the valve shaft frame body 12a of the drain valve 12 via a connecting member 188. The connecting member 188 is a metal wire, a bead chain, or the like. Thus, when the first support body 180 is pressed away from the drain valve 12 by the second rod 133, the connecting member 188 physically lifts the drain valve 12. The connecting member 188 is flexible. The connecting member 188 is disposed within a connecting member conduit 189, which is bent between the first support body 180 and the drain valve 12. The connecting member conduit 189 forms a tubular passage that guides the connecting member 188.

[0193] A housing 113 is formed above the drain valve 12, housing the drain valve 12. The housing 113 is cylindrical with an open lower side. The housing 113 is formed separately from the drain valve hydraulic actuator 114 and the clutch mechanism 130, and is also positioned away from the drain valve hydraulic actuator 114. The housing 113 is fixed to the water storage tank 10. The housing 113 is independent of the drain valve hydraulic actuator 114.

[0194] The drain valve 12 is lifted by the driving force of the drain valve hydraulic drive unit 114. When it reaches a predetermined height, the clutch mechanism 130 is disengaged at a predetermined time, and the valve descends due to its own weight. As the drain valve 12 descends, the float device 26 holds the valve 12 in place for a predetermined period of time, adjusting the time it takes for the valve 12 to rest at the drain outlet 10a.

[0195] Next, refer to Figures 14 to 20 The water discharge valve hydraulic drive unit 114 will be described.

[0196] like Figure 14 As shown in FIG. 1 , the drain valve hydraulic drive unit 114 is configured to drive the drain valve 12 using the water supply pressure of the wash water supplied from the tap water pipe. The drain valve hydraulic drive unit 114 includes a cylindrical body 114a, into which tap water supplied from the first control valve 16 is supplied as wash water; a piston 128 slidably disposed within the cylindrical body 114a; a first rod 132 extending from the piston 128 through a first through-hole 114f formed in the cylindrical body 114a; and a second rod 133 extending from the piston 128 through a second through-hole 114q formed in the cylindrical body 114a. The drain valve hydraulic drive unit 114 is formed of resin.

[0197] Furthermore, a spring 48 serving as an urging member is disposed inside the cylindrical body 114 a , and urges the piston 128 toward the first position H11 .

[0198] The cylinder 114a is formed as a horizontal cylinder. The piston 128 is received in the cylinder 114a so as to be slidable in the horizontal direction. The axis of the cylinder 114a extends in the horizontal direction.

[0199] The first through-hole portion 114f is formed in the side wall of the cylindrical body 114a on the first position side. The first through-hole portion 114f includes a bank 114h extending upward from the periphery of the through-hole formed in the side wall of the cylindrical body 114a toward the inside of the cylindrical body; and a flow straightening portion 114s, whose top inner wall has a substantially constant diameter along the direction of movement of the first rod 132. When viewed from the front, the bank 114h is formed in an annular shape around the first rod 132. The flow straightening portion 114s extends from the top of the bank 114h to a predetermined distance downstream. The flow straightening portion 114s forms a horizontally extending transverse wall. The flow straightening portion 114s extends substantially parallel to the outer wall of the first rod 132, forming a flow path of substantially constant width between the flow straightening portion 114s and the first rod 132. This prevents turbulence in the flow of wash water passing between the flow straightening portion 114s and the first rod 132.

[0200] The drain valve water pressure driving unit 114 also includes: an inlet portion 114l, which is formed in the cylindrical body 114a and into which cleaning water flows; a first drain portion 114m, which is separately provided from the inlet portion 114l and discharges cleaning water from the cylindrical body 114a; and a second drain portion 114n, which is separately provided from the first drain portion 114m and formed between the first rod 132, the piston 128 and the first through-hole portion 114f.

[0201] Inlet 114l is connected to the drive unit water supply path 34a. Inlet 114l is connected to a portion upstream of first position H11 of cylindrical body 114a. Inlet 114l forms a flow path connected to the upstream side of piston 128. Wash water flowing out of first control valve 16 flows into cylindrical body 14a through inlet 114l. Wash water flows into cylindrical body 114a using the water pressure of tap water. Therefore, the wash water flowing into cylindrical body 114a lifts piston 128 within cylindrical body 114a against the biasing force of spring 48. Only tap water is supplied as wash water to cylindrical body 114a, and wash water already supplied to water storage tank 10 does not flow into cylindrical body 114a. Furthermore, the piston 128 is not limited to moving horizontally in the cylinder 114a. The cylinder can also be arranged in an oblique or vertical direction so that the piston 128 moves in other directions (such as oblique or vertical directions) in the cylinder 114a.

[0202] First through-hole portion 114f is connected to drive unit drain passage 134b, and first drain portion 114m extends into drive unit drain passage 134b. The distal end of first drain portion 114m forms an outflow hole into drive unit drain passage 134b. Drive unit drain passage 134b serves as a drain pipe. First drain portion 114m is configured to open and close first discharge passage inlet 170a of first discharge passage 170, which discharges wash water from inside cylindrical body 114a to the outside of cylindrical body 114a, via first rod 132 and first through-hole portion 114f. The first drain portion 114m is configured such that when the piston 128 is in the first position H11, the first discharge path inlet 170a of the first discharge path 170 is closed via the first rod 132 and the first through-hole 114f, placing the first discharge path 170 in a closed state. Furthermore, when the piston 128 reaches a communication position between the first position H11 and the second position H12 (e.g., a predetermined position further inward than the clutch mechanism disengaged position) or moves further inward thereafter, the first discharge path inlet 170a of the first discharge path 170 is opened via the first rod 132 and the first through-hole 114f, placing the first discharge path 170 in an open state. The first drain portion 114m functions as a switching valve between the closed and open states of the first discharge path 170. The first drain portion 114m functions to form a main drainage path for wash water from the cylindrical body 114a. Furthermore, the first drain portion 114 m has a function of forming a main water supply path for flush water to the water storage tank 10 .

[0203] The first discharge path 170 of the first drain section 114m is formed by a passage extending inside the first rod 132. The first discharge path 170 is formed by the hollow internal passage of the first rod 132. The first discharge path inlet 170a of the first discharge path 170 is opened on the side surface of the first rod 132. When the piston 128 moves to the second position H12, which is further inward than the first position H11, as if pressed in, the water flowing into the cylindrical body 114a flows out from the first drain section 114m through the drive unit drain path 134b. In other words, when the piston 128 moves to the second position H12, the drive unit water supply path 34a and the drive unit drain path 134b are connected through the interior of the cylindrical body 114a.

[0204] The second drain portion 114n is formed between the first rod 132 and the first through-hole 114f, and between the piston 128 and the first through-hole 114f. The second drain portion 114n connects the pressure chamber on the inlet side of the drain valve hydraulic drive unit 114 with the space within the water storage tank 10. The second drain portion 114n forms a second drain path 172 extending from the cylindrical body 114a. When the piston 128 is in the first position H11, the second drain portion 114n opens the second drain path 172. Regardless of the position of the piston 128, the second drain path 172 remains open. Furthermore, the second drain path 172 is formed, for example, by a slight gap between the outer surface of the first rod 132 and the first through-hole 114f. However, as a modified example, a water passage for the second drain path 172 may be provided within the first rod 132. A portion of the wash water that flows into cylindrical body 114a flows out of second drain portion 114n in the gap between first rod 132 and first through-hole 114f. The wash water flowing out of second drain portion 114n flows into water storage tank 10. Furthermore, because second drain portion 114n is relatively narrow and has a high flow resistance, even when wash water is flowing out of second drain portion 114n, the pressure within cylindrical body 114a rises due to the wash water flowing into cylindrical body 114a from drive unit water supply passage 34a, counteracting the biasing force of spring 48 and lifting piston 128.

[0205] The minimum cross-sectional area of ​​second drain path 172 of second drain portion 114n is smaller than the minimum cross-sectional area of ​​first drain path 170 of first drain portion 114m. The minimum cross-sectional area of ​​second drain path 172 of second drain portion 114n is less than half the minimum cross-sectional area of ​​first drain path 170 of first drain portion 114m. Second drain portion 114n forms an auxiliary drainage flow path for first drain portion 114m. Second drain portion 114n functions as an auxiliary drainage path for wash water flowing from cylindrical body 114a.

[0206] The second drain path 172 of the second drain portion 114n includes a first flow path 114o extending along the lower portion 128c between the top portion 114k and the lower portion 128c of the bank 114h when the piston 128 is in the first position H11; and a third flow path 114r extending laterally between the first rod 132 and the inner wall of the first through-hole 114f when the piston 128 is in the first position H11. Furthermore, since the top portion 114k and the lower portion 128c are substantially in contact with each other when the piston 128 is in the first position H11, the first flow path 114o has a relatively small gap. When viewed in cross-section, the first flow path 114o and the third flow path 114r form a flow path that curves in an L-shape. Furthermore, the piston 128 and the cylindrical body 114a may be formed so that when the piston 128 is located at the first position H11, the top portion 114k and the bottom portion 128c do not abut against each other, thereby forming the first flow path 114o with a relatively small gap.

[0207] The shape of the second drain portion 114n changes as the piston 128 moves. Consequently, the total cross-sectional area or the minimum cross-sectional area within the second drain portion 114n changes as the piston 128 moves. The second drain portion 114n is configured so that as the piston 128 moves from the first position H11 to the second position H12, the total cross-sectional area or the minimum cross-sectional area of ​​the second discharge path 172 within the second drain portion 114n increases, thereby reducing pressure loss within the second drain portion 114n. For example, as the piston 128 moves from the first position H11 to the second position H12, the minimum cross-sectional area of ​​the second drain portion 114n increases. For example, the minimum cross-sectional area of ​​the second discharge path 172 is the minimum cross-sectional area between the top portion 114k and the bottom portion 128c. As the piston 128 moves toward the second position, the minimum cross-sectional area of ​​the second discharge path 172 increases. As the piston 128 moves from the first position H11 to the second position H12 , the minimum value of the flow path cross-sectional area of ​​the second discharge path 172 also increases.

[0208] Furthermore, when the outer diameter of the distal end portion of the first rod 132 is formed to be smaller than the outer diameter of the proximal end portion (piston connection portion side), the second drain portion 114n is formed so that, as the piston 128 and the first rod 132 move to the second position side, the cross-sectional area of ​​the second drain path 172 between the first rod 132 and the inner wall of the first through-hole portion 114f, for example, the total value and the minimum value of the cross-sectional area, increases, and the pressure loss of the second drain portion 114n is reduced. At this time, the minimum value of the cross-sectional area of ​​the second drain path 172 when the piston 128 is at the first position H11 (e.g., Figure 7As shown in the second drainage portion 14n, the cross-sectional area of ​​the second drainage path 172 of the second drainage portion 114n corresponding to the discharge path of the second drainage portion 14n between the first rod 32 and the inner wall of the first through-hole portion 14f is smaller than the minimum value of the flow path cross-sectional area between the first rod 132 and the inner wall of the first through-hole portion 114f when the piston 128 is located at the second position H12.

[0209] The cylindrical body 114a is a substantially cylindrical member, and is formed in a conical shape such that the inner diameter of the inner wall 114i of the cylindrical body 114a decreases as it approaches the bottom. The cylindrical body 114a in the second embodiment is arranged horizontally, and has a substantially similar structure to the cylindrical body 14a in the first embodiment, so the description thereof is omitted. The inner diameter R1 of the cylindrical body 114a corresponding to the first position H11 of the piston 128 (see Figure 5 ) is the smallest inner diameter among the inner diameters of the cylindrical body. Since the inner diameter of the cylindrical body 114a is the same as that of the first embodiment, its description is omitted.

[0210] The first rod 132 is a rod-shaped member connected to the surface on the inlet side of the piston 128. The first rod 132 extends from the piston 128 toward the pressure chamber 114g on the inlet side 1141 and extends outward through the first through-hole portion 114f of the side wall on the inlet side. The first rod 132 extends into the drive unit drainage path 134b extending from the first through-hole portion 114f. The proximal end of the first rod 132 is connected to the piston 128, and the distal end of the first rod 132 is located inside the drive unit drainage path 134b. The first rod 132 is a rod extending toward the opposite side of the second rod 133, which is a working rod for the clutch mechanism 130 and extends from the piston 128 toward the clutch mechanism 130. The rod extending from the piston 128 through the through-hole formed in the cylindrical body 114 a is not necessarily limited to being divided into the first rod 132 and the second rod 133 , but the first rod 132 and the second rod 133 may be formed as one rod.

[0211] The second rod 133 is a rod-shaped member connected to the surface of the piston 128 on the inner portion 114t side. It extends from the piston 128 to connect the piston 128 to the drain valve 12. The second rod 133 extends from the piston 128 toward the inner portion 114t, passing through a second through-hole 114q formed in the inner side wall to protrude laterally from the cylindrical body 114a. The proximal end of the second rod 133 is connected to the piston 128, while the distal end of the second rod 133 is configured to act on the driven portion 176 of the clutch mechanism 130.

[0212] like Figure 16As shown, the central axis G1 of the first rod 132, the central axis G2 of the first through-hole portion 114f, and the central axis G3 of the cylindrical body 114a are coaxial. The largest outer diameter D1 of the overall outer diameters of the first rod 132 is smaller than the smallest inner diameter D2 of the overall inner diameters of the first through-hole portion 114f. In this embodiment, the outer diameter of the first rod 132 is substantially constant from the proximal end connected to the piston to the distal end. Furthermore, the outer diameter of the distal end of the first rod 132 can be smaller than the outer diameter of the proximal end of the first rod 132.

[0213] In this embodiment, the piston 128 is configured to move laterally within the cylindrical body 114a. As the washing water flows into the cylindrical body 114a, the piston 128 moves from the first position H11 (see Figure 14 ) moves to the second position H12 (refer to Figure 19 ). The first position H11 of the piston 128 is located on the side of the inlet portion 1141, and the second position H12 is located closer to the clutch mechanism 130 than the first position H11. For example, with respect to the inlet portion 1141 of the cylindrical body 114a, the second position H12 is located on the inner side of the opposite side. The piston 128 includes: a force receiving portion 28a that receives the force from the spring 48 (refer to Figure 16 and the upper peripheral portion 28b, formed on the inner side of the seal 20. Since the structure of the piston 128 in the second embodiment is substantially the same as the structure of the piston 28 in the first embodiment, reference is made to Figure 6 and related descriptions, and descriptions of the detailed structure of the piston 128 are omitted.

[0214] Since the cylindrical body 114 a is formed in a conical shape, the water flow gap 29 gradually becomes smaller as the piston 128 moves from the second position side to the first position side of the cylindrical body 114 a .

[0215] A seal 20 is attached to the piston 128 to ensure watertightness between the inner wall of the cylinder 114a and the piston 128. The seal 20 is a so-called U-seal having a U-shaped cross section. The seal 20 is an elastic member made of rubber.

[0216] like Figure 14As shown, the flush water tank assembly 104 further includes a deceleration unit 174 that decelerates the flow rate of the flush water discharged from the second drain section 114n. The deceleration unit 174 is configured to decelerate the flow rate of the flush water discharged from the second drain section 114n. For example, the deceleration unit 174 may be a drive unit drain passage 134b formed to cover the outside of the first rod 132. The drive unit drain passage 134b extends along the outside of the first rod 132, and the flush water flowing out of the second drain section 114n is reduced in velocity along the inner wall of the drive unit drain passage 134b. Alternatively, the deceleration unit 174 may be another unit that decelerates the flow rate of the flush water discharged from the second drain section 114n. For example, the drive unit drain passage 134b may be provided with a drain passage branching portion 134c that branches to reduce the flow rate of the flush water.

[0217] Next, the first control valve 16 will be described.

[0218] The first control valve 16 is configured to control the water supply to the drain valve hydraulic drive unit 114 according to the operation of the solenoid valve 18, and to control the water supply and stop to the water storage tank 10, etc. In addition, a vacuum breaker 36 is provided on the drive unit water supply path 34a between the first control valve 16 and the drain valve hydraulic drive unit 114 (see Figure 2 ).

[0219] When the pilot valve 16 d is opened by the solenoid valve 18 , the main valve body 16 a of the first control valve 16 is opened, and the tap water flowing in from the water supply pipe 38 is supplied to the drain valve hydraulic drive unit 114 .

[0220] Furthermore, tap water supplied from the first control valve 16 to the drain valve hydraulic drive unit 114 is supplied via the first drain unit 114m and / or the second drain unit 114n via the drive unit drain passage 134b into the water storage tank 10 or the overflow pipe 10b. Furthermore, the first control valve 16 includes a pilot valve 16e, which is opened and closed by the float switch 42.

[0221] The float switch 42 is connected to the pilot valve 16e. The float switch 42 is configured to control the pilot valve 16e based on the water level in the water storage tank 10, thereby opening and closing the pilot valve port (not shown). Specifically, when the water level in the water storage tank 10 reaches a predetermined level, the float switch 42 sends a signal to the pilot valve 16e, thereby closing the pilot valve port (not shown). In other words, the float switch 42 is configured to set the water level in the water storage tank 10 to the water cutoff level, i.e., the predetermined full water level WL. The float switch 42 is disposed in the water storage tank 10 and is configured to stop the water supply from the first control valve 16 to the drain valve hydraulic drive unit 114 when the water level in the water storage tank 10 rises to the full water level WL.

[0222] Furthermore, a drain branch 134c is provided on the driver drain path 134b extending from the drain valve hydraulic driver 114. The driver drain path 134b, branching at the drain branch 134c, is configured so that water flows from one side into the water storage tank 10 and from the other side into the overflow pipe 10b. Consequently, a portion of the flush water supplied from the drain valve hydraulic driver 114 is discharged into the flush toilet body 2 through the overflow pipe 10b, while the remaining portion is stored in the water storage tank 10.

[0223] The controller 40 includes a CPU and memory, and controls the connected devices to execute the large cleaning mode and small cleaning mode described later, according to a predetermined control program stored in the memory. The controller 40 is electrically connected to the remote control device 6, the human detection sensor 8, the solenoid valve 18, and the like.

[0224] Next, the float device 26 will be described. Specifically, the float device 26 includes a float portion 26a and an engaging portion 26b linked to the float portion 26a. The valve shaft frame 12a is hoisted a predetermined distance, isolating the valve shaft frame 12a, the connecting member 188, and the clutch mechanism 130 from the drain valve hydraulic drive 114. The valve shaft frame 12a of the drain valve 12 then descends, closing the drain port 10a. The float device 26 is configured to delay this process. Meanwhile, a retaining claw 12g is formed at the base of the valve shaft frame 12a of the drain valve 12, which is designed to engage with the engaging portion 26b.

[0225] Next, refer to Figures 14 to 20 A series of flushing operations of the flush water tank assembly 104 and the flush toilet apparatus 101 including the same according to the second embodiment of the present invention will be described.

[0226] First, in Figure 14 In the illustrated toilet flushing standby state, the water level in the water storage tank 10 is at the predetermined full water level WL, and in this state, the first control valve 16 is closed. Furthermore, the float device 26 is in the standby state. Next, when the user presses the flush button on the remote control device 6, the remote control device 6 transmits a toilet flushing instruction signal to the controller 40. Furthermore, in the flush toilet device 101 of this embodiment, even if a predetermined time has passed without the flush button on the remote control device 6 being pressed after the human sensor 8 detects that the user has left the seat, the toilet flushing instruction signal is transmitted to the controller 40.

[0227] In the standby mode, the piston 128 of the drain valve hydraulic drive unit 114 is located at the first position H11 within the cylindrical body 114a. The first position H11 of the piston 128 is the position closest to the inlet within its movable range. The piston 128 is stopped within the cylindrical body 114a. At this point, the lower end 20b of the seal 20 is located above the full water level WL of the water storage tank 10. Thus, the seal 20 is positioned in an area directly supplied with flushing water from the tap water supply, preventing it from being immersed in flushing water stored in the water storage tank 10, such as chlorine solution, which may have been introduced by a user for toilet flushing. This prevents deterioration of the seal 20 due to immersion in such chemicals. Furthermore, unlike the cleaning water stored in the water tank 10, for example, where it is unclear whether a user has added a certain toilet cleaning agent, since the seal 20 is immersed in the cleaning water directly supplied from the tap water, aging of the seal 20 due to chlorine in the toilet cleaning agent can be suppressed.

[0228] The deformation of the seal 20 when the piston 128 is at the first position H11 is the maximum deformation of the elastic member at each position between the first position H11 and the second position H12 when the piston 128 moves from the first position H11 to the second position H12. Since the deformation of the seal 20 is the same as in the first embodiment, its description will be omitted.

[0229] In the standby state with the piston 128 at the first position H11, the spring 48 is in its most extended state, and the lower portion 128c of the piston 128 abuts against the top portion 114k of the bank portion 114h of the cylindrical body 114a. The spring 48 biases the piston 128 toward the first position, causing it to stop in abutment against the top portion 114k.

[0230] When the piston 128 is located at the first position H11, the first discharge path inlet 170a of the first discharge path 170 of the first drain portion 114m is closed by the first rod 132 and the first through-hole portion 114f, and the first discharge path 170 is in a closed state. When the piston 128 is located at the first position H11, the second drain portion 114n is formed between the first rod 132, the piston 128, and the first through-hole portion 114f. That is, in the standby state, the second discharge path 172 formed between the first rod 132 and the first through-hole portion 114f is in an open state. Thus, as Figure 17 As shown, when the washing water flows into cylindrical body 114a, a portion of the washing water flows out from second discharge path 172 of second drain portion 114n toward driving unit drain path 134b as indicated by arrow F11.

[0231] In the standby state with piston 128 at first position H11, the flow path cross-sectional area within second drain portion 114n is determined by the flow path cross-sectional area between first rod 132 and first through-hole 114f, and between piston 128 and first through-hole 114f. The minimum flow path cross-sectional area within second drain portion 114n is the cross-sectional area of ​​first flow path 114o. Because top portion 114k and bottom portion 128c are substantially in contact, pressure loss in second drain portion 114n is significant.

[0232] Next, when receiving the instruction signal to perform toilet cleaning, the controller 40 opens the electromagnetic valve 18 ( Figure 14 ) is actuated, causing the pilot valve 16d on the solenoid valve side to move away from the pilot valve port. This reduces the pressure within the pressure chamber 16c, causing the main valve body 16a to move away from the main valve port 16b, opening the main valve port 16b. When the first control valve 16 is opened, wash water flowing from the water supply pipe 38 is supplied to the drain valve hydraulic actuator 14 via the first control valve 16. This lifts the piston 128 of the drain valve hydraulic actuator 114, pushing the actuator 133a of the second rod 133 toward the follower 176.

[0233] When the drain valve 12 is lifted, the holding claw 12g provided on the valve shaft frame body 12a of the drain valve 12 lifts the engaging portion 26b of the float device 26 and rotates it, so that the holding claw 12g rises over the engaging portion 26b.

[0234] After the piston 128 is in the standby state, for example, when the piston 128 moves forward, the cleaning water flowing into the pressure chamber 114b of the cylinder 114a closer to the first position side than the piston 128 is mainly accumulated in the pressure chamber 114b due to the seal 20 with a sealing function, generating a force to move the piston 128 toward the second position side.

[0235] like Figure 17 As shown, when the piston 128 and the second rod 133 move toward the second position H12, the operating portion 133a contacts the first flat surface 176a of the follower portion 176, and the follower portion 176 and the first support body 180 are laterally pressed forward while causing the support body elastic member 182 to contract. This lifts the connecting member 188 connected to the first support body 180, and the drain valve 12 is lifted by the connecting member 188. As a result, the flush water in the water storage tank 10 is discharged from the drain port 10a into the flush toilet body 2 due to the lifting of the drain valve 12.

[0236] While the clutch mechanism 130 is disengaged, and the piston 128 moves from the first position H11 to the second position H12, the second discharge path 172 formed between the first rod 132 and the first through-hole 114f is open. As a result, as indicated by arrow F11, a portion of the wash water flowing into the cylindrical body 114a flows out of the second discharge path 172 of the second drain section 114n toward the drive unit drain path 134b. Since the amount of wash water flowing out of the second discharge path 172 is relatively small, the piston 128 is pushed forward toward the second position H12 as intended. Meanwhile, the first discharge path inlet 170a of the first discharge path 170 is closed by the first rod 132 and the first through-hole 114f, and the first discharge path 170 of the first drain section 114m is closed.

[0237] Next, if Figure 18 As shown, when the driven portion 176 further advances toward the restricting portion 186 and is stopped, the inclined surface 176b contacts the restricting portion 186, pressing the inclined surface 176b toward the driven portion elastic member 178, causing the driven portion 176 to move toward the driven portion elastic member 178. This releases the contact between the second rod 133 and the driven portion 176, and the clutch mechanism 130 is disconnected. Specifically, when the drain valve 12 is raised to a predetermined height, the driven portion 176 of the clutch mechanism 130 contacts the restricting portion 186, disengaging the clutch mechanism 130. Even after the clutch mechanism 130 is disengaged, the first drain path 170 of the first drain portion 114m remains closed until the first drain path inlet 170a is opened. As indicated by arrow F12, a portion of the wash water flows from the second drain path 172 of the second drain portion 114n toward the drive unit drain path 134b.

[0238] Next, when the clutch mechanism 130 is disengaged, the drain valve 12 begins to descend toward the drain outlet 10a due to its own weight. The retaining claw 12g of the lowered drain valve 12 engages with the engaging portion 26b of the float assembly 26, holding the drain valve 12 at a predetermined height. Because the drain valve 12 is held by the engaging portion 26b, the drain outlet 10a remains open, allowing flush water from the water storage tank 10 to continue to be discharged into the flush toilet body 2. At this time, the pilot valve 16d remains open, so flush water flowing from the water supply pipe 38 is supplied to the drain valve hydraulic drive unit 14 via the first control valve 16.

[0239] like Figure 19As shown, the piston 128 and first rod 132 are further pressed and reach the second position H12. During this process, when the piston 128 reaches its communication position (the fourth position H14 of the piston 128, which forms a communication flow path), the first discharge path inlet 170a is opened, starting from the first discharge path starting position 132a of the first rod 132, which appears within the cylindrical body 114a in a manner corresponding to the communication position of the piston 128. The fourth position H14 is located further inward of the piston than the disconnected position, where the clutch mechanism 130 is disengaged, and slightly closer to the inlet side (nearer side) than the second position H12. The distance from the connection between the first rod 132 and the piston 128 to the first discharge path starting position 132a, in other words, the distance from the first position H11 to the fourth position H14, is, for example, at least two-thirds of the movable distance of the piston 128 within the cylindrical body 114a. When first discharge path inlet 170a of first discharge path 170 is opened by first rod 132 and first through-hole 114f, first discharge path 170 of first drain section 114m is opened. Consequently, as indicated by arrow F13, wash water flows from first discharge path 170 toward drive unit drain path 134b, where it is discharged as main water from the discharge port at the downstream end of drive unit drain path 134b into water storage tank 10. At this time, as indicated by arrow F14, a portion of the wash water also flows from second discharge path 172 of second drain section 114n toward drive unit drain path 134b.

[0240] In the second drain section 114n, when the piston 128 is in the second position H12, the top portion 114k and the bottom portion 128c separate, increasing the minimum cross-sectional area of ​​the first flow path 114o. Meanwhile, the minimum cross-sectional area of ​​the third flow path 114r remains constant. Thus, as the piston 128 moves toward the second position H12, the top portion 114k and the bottom portion 128c separate, increasing the cross-sectional area of ​​the first flow path 114o, the total cross-sectional area within the second drain section 114n, or the minimum cross-sectional area, increases, and the pressure loss in the second drain section 114n decreases. Furthermore, while the piston 128 is moving toward the second position H12, the clutch mechanism 130 is disengaged. When the clutch mechanism 130 is disengaged, the minimum cross-sectional area of ​​the second drain section 114n is approximately the maximum cross-sectional area within the range of the piston 128 from the first position H11 to the second position H12. Thus, when the clutch mechanism 130 is disengaged, the pressure loss in the second drain portion 114 n becomes substantially the minimum pressure loss within the range of change corresponding to the pressure loss from the first position H11 to the second position H12 of the piston 128 .

[0241] Next, when the water level in the water storage tank 10 drops, the float switch 42, which detects the water level in the water storage tank 10, turns off. When the float switch 42 turns off, the pilot valve 16e opens. This allows wash water to be supplied from the first control valve 16 into the water storage tank 10 via the drive unit water supply path 34a and the drive unit drain path 134b. After a predetermined time has passed since the solenoid valve 18 opened, the controller 40 closes the solenoid valve 18 and the pilot valve 16d on the solenoid valve side. Meanwhile, since the pilot valve 16e is open, the first control valve 16 remains open, and water continues to be supplied to the water storage tank 10.

[0242] When the water level in the water storage tank 10 drops to the predetermined water level WL1, the float portion 26a of the float device 26 descends, thereby moving the engagement portion 26b. This disengages the valve shaft frame 12a from the engagement portion 26b, and the valve shaft frame 12a and the drain valve 12 begin to descend again.

[0243] As a result, the drain valve 12 is positioned at the drain outlet 10a, closing it. Since the float switch 42 remains off, the first control valve 16 remains open, and water continues to be supplied to the storage tank 10. Wash water supplied via the drive unit drain passage 134b reaches the drain passage branch 134c. Part of the wash water branched at the drain passage branch 134c flows into the overflow pipe 10b, while the remainder is stored in the storage tank 10. The wash water flowing into the overflow pipe 10b flows into the flush toilet body 2 and is used to replenish water in the bowl 2a. Meanwhile, while the drain valve 12 is closed, the water level in the storage tank 10 rises due to the wash water flowing into the storage tank 10.

[0244] like Figure 20 As shown, when the water level in the water storage tank 10 rises to the specified full water level WL, the float switch 42 is turned on. When the float switch 42 is turned on, the pilot valve 16e on the float switch side is closed. Consequently, since the pilot valve 16e is closed, the first control valve 16 is closed, and the water supply to the drain valve hydraulic actuator 114 is stopped. After the first control valve 16 is closed and the water supply to the drain valve hydraulic actuator 114 is stopped, the wash water within the cylindrical body 114a of the drain valve hydraulic actuator 114 gradually flows out from the first drain portion 114m and the second drain portion 114n. Simultaneously, the piston 128 is pressed downward by the force of the spring 48 and returned to the first position H11. As the piston 128 returns to the first position H11, the first discharge path inlet 170a is closed. Subsequently, as indicated by arrow F15, the wash water within the cylindrical body flows out from the second discharge path 172 to the driver drain path 134b. Therefore, in such Figure 14 The machine in the water storage tank 10 is shown to have returned to a standby state.

[0245] According to the flush water tank assembly 104 according to the second embodiment of the present invention, the drain valve hydraulic drive unit 114 includes an inlet 114l formed in the cylindrical body 114a and into which flush water flows; a first drain portion 114m provided separately from the inlet 114l and into which flush water is discharged from the cylindrical body 114a; and a second drain portion 114n provided separately from the first drain portion 114m and formed between the first rod 132 and the first through-hole 114f. Thus, when the flush water supply pressure to the cylindrical body 114a undergoes a sudden change, such as a sudden rise, in either a disconnected or connected state, the second drain portion 114n mitigates the impact of the sudden change in flush water pressure, thereby cushioning the impact on the piston 128 from the flush water and preventing the piston 128 from becoming unstable.

[0246] According to the cleaning water tank device 104 involved in the second embodiment of the present invention described above, the first drainage portion 114m is constructed so that when the piston 128 is located at the first position H11, the first discharge path inlet 170a is closed by the first rod 132 and the first through-hole portion 114f, and when the piston 128 reaches the communication position between the first position H11 and the second position H12, the first discharge path inlet 170a is opened by the first rod 132 and the first through-hole portion 114f. Through such a relatively simple structure, when the piston 128 is located at the first position, the water supply pressure of the cleaning water will not leak to the side of the first discharge path 170, and the water supply pressure of the cleaning water can be effectively utilized for the movement of the piston 128. When the piston 128 is located at the connecting position between the first position H11 and the second position H12, the first discharge path 170 is in an open state, and the cleaning water is discharged from the inside of the cylindrical body 114a to the outside of the cylindrical body 114a through the first discharge path 170, and the piston 128 can easily return to the first position H11 from the second position H12 or the connecting position.

[0247] According to the washing water tank device 104 involved in the second embodiment of the present invention described above, the first discharge path 170 of the first drainage portion 114m is formed by a path extending inside the first rod 132. Compared with when the path is formed on the outer side of the first rod 132, the flow rate of the washing water flowing through the path inside the first rod 132 when the first drainage path is in the open state can be better suppressed. When the piston 128 is in the first position H11, the water supply pressure of the washing water will not be discharged to the first discharge path 170 side, and the water supply pressure of the washing water can be effectively utilized for the movement of the piston 128. When the piston 128 is in the connecting position, the first discharge path 170 is in the open state, and the washing water is discharged from the inside of the cylindrical body 114a to the outside of the cylindrical body 114a through the first discharge path 170. The piston 128 can easily return to the first position H11 from the second position H12 or the specified position.

[0248] According to the flush water tank assembly 104 according to the second embodiment of the present invention, the flush water tank assembly 104 further includes a deceleration unit 174 that decelerates the flow rate of the flush water discharged from the second drain section 114n. This deceleration can reduce the flow rate of the flush water discharged from the second drain section 114n. For example, even if the flush water discharged from the second drain section 114n is discharged into the storage tank 10 from a position higher than the water surface in the storage tank 10, splashing of the flush water can be suppressed.

[0249] Next, refer to Figures 21 to 28 A flush toilet device according to a third embodiment of the present invention will be described.

[0250] Since the flush toilet device 201 involved in the third embodiment has a substantially identical structure to the flush toilet device involved in the second embodiment described above, the third embodiment of the present invention will mainly be described with respect to the parts that are different from the second embodiment. The same parts as those in the first and second embodiments will be described using the same reference symbols in the drawings or the description, or the description of the same parts will be omitted.

[0251] like Figure 21 As shown, a flush toilet apparatus 201 according to a third embodiment of the present invention includes a flush water tank assembly 204 according to a third embodiment of the present invention, which is positioned at the rear of the flush toilet body 2. The flush water tank assembly 204 according to this embodiment is configured to discharge flush water stored therein into the flush toilet body 2 in response to an instruction signal from a remote control unit 6 or a human motion sensor 8, thereby flushing the bowl 2a with this flush water.

[0252] The flush water tank assembly 204 includes a drain valve hydraulic actuator 214, which is a drain valve lifter that lifts the drain valve 12. Furthermore, the flush water tank assembly 204 includes a first control valve 16, which is a water supply control device, for controlling the water supply from the water pipe to the drain valve hydraulic actuator 214.

[0253] The flush water tank assembly 204 further includes a clutch mechanism 130 that connects the drain valve 12 to the drain valve hydraulic drive 214. The clutch mechanism 130 raises the drain valve 12 by the drain valve hydraulic drive 214 and is disconnected at a predetermined time to lower the drain valve 12. Since the clutch mechanism 130 of the third embodiment is the same as the clutch mechanism 130 of the second embodiment, its description will be omitted.

[0254] The drain valve 12 is lifted by the driving force of the drain valve hydraulic drive unit 214. When it reaches a predetermined height, the clutch mechanism 130 is disengaged at a predetermined time, and the valve descends due to its own weight. As the drain valve 12 descends, the float device 26 holds the valve 12 in place for a predetermined period of time, adjusting the time it takes for the valve 12 to rest at the drain outlet 10a.

[0255] Next, refer to Figures 21 to 28 The water discharge valve hydraulic drive unit 214 will be described.

[0256] like Figure 21 As shown in the figures, the drain valve hydraulic drive unit 214 is configured to drive the drain valve 12 using the water supply pressure of the washing water supplied from the tap water pipe. Since the structure of the drain valve hydraulic drive unit 214 of the third embodiment is basically the same as that of the drain valve hydraulic drive unit 114 of the second embodiment, except for the first rod 132, the same reference numerals are used in the drawings for the same parts, and the description thereof will be omitted.

[0257] The drain valve hydraulic drive unit 214 includes a first rod 232 extending from the piston 128 through a first through-hole 114f formed in the cylindrical body 114a. Since the cylindrical body 114a in the third embodiment has substantially the same structure as that in the second embodiment, its description is omitted.

[0258] The first rod 232 is a rod-shaped member connected to the surface on the inlet side of the piston 128. The first rod 232 extends from the piston 128 toward the pressure chamber 114b on the inlet side 1141 and extends outward through the first through-hole portion 114f of the side wall on the inlet side. The first rod 232 extends into the drive unit drainage path 134b extending from the first through-hole portion 114f. The proximal end of the first rod 232 is connected to the piston 128, and the distal end of the first rod 232 is located inside the drive unit drainage path 134b. The first rod 232 is a rod extending toward the opposite side of the second rod 133, which is a working rod for the clutch mechanism 130 and extends from the piston 128 toward the clutch mechanism 130. The rod extending from the piston 128 through the through-hole formed in the cylindrical body 114 a is not necessarily limited to being divided into the first rod 232 and the second rod 133 , but the first rod 232 and the second rod 133 may be formed as one rod.

[0259] like Figure 22 As shown, the drain valve water pressure driving unit 214 includes: a first drain portion 214m, which is separately provided from the inlet portion 114l and discharges cleaning water from the cylindrical body 114a; and a second drain portion 214n, which is separately provided from the first drain portion 214m and is formed between the first rod 232, the piston 128 and the first through hole portion 114f.

[0260] The first drain portion 214m extends into the drive unit drain path 134b. The distal end of the first drain portion 214m forms an outflow hole to the drive unit drain path 134b. The first drain portion 214m is formed to open and close the first discharge path inlet 270a of the first discharge path 270 that discharges the washing water from the inside of the cylindrical body 114a to the outside of the cylindrical body 114a through the first rod 232 and the first through-hole portion 114f. Figure 21 and Figure 24 As shown in FIG. 1 , the first drain portion 214m is configured such that when the piston 128 is located at the first position H11, the first discharge path inlet 270a of the first discharge path 270 is closed by the first rod 232 and the first through-hole portion 114f, and the first discharge path 270 is in a closed state. Figure 22As shown in FIG. 1 , when piston 128 reaches a communication position between first position H11 and second position H12 (e.g., a predetermined position further inward than the clutch mechanism disengagement position), or when piston 128 further moves inward after reaching the communication position, first discharge path inlet 270a of first discharge path 270 is opened via first rod 232 and first through-hole 114f, placing first discharge path 270 in an open state. First drain portion 214m functions as a switching valve between closed and open states for first discharge path 270. First drain portion 214m forms a main drainage path for wash water from cylindrical body 114a. Furthermore, first drain portion 214m forms a main water supply path for wash water to storage tank 10.

[0261] like Figure 22 As shown in FIG. 1 , the first discharge path 270 of the first drain portion 214m is formed by a groove extending from the first discharge path starting position 232a to the distal end 232b of the first rod 232 on the outer surface of the first rod 232. The groove is formed by cutting the side of the first rod 232 inward. The first discharge path starting position 232a is located at a position away from the proximal end on the piston side. The first discharge path starting position 232a is the first discharge path starting position of the first rod 232 within the cylindrical body 114a in a manner corresponding to the communication position of the piston 128 (the fourth position H14 forming the communication flow path). The first discharge path 270 forms a flow path with a fan-shaped cross-section. The first discharge path 270 is formed on the outer surface side of the first rod 232 and forms a flow path between the first rod 232 and the first through-hole portion 114f. When the groove portion of the first discharge path 270 is located closer to the inner side of the cylinder than the first through hole portion 114f as the first rod 232 moves, the groove portion of the first discharge path 270 opens laterally at a position closer to the inner side of the cylinder than the first through hole portion 114f, thereby forming a first discharge path inlet 270a of the first discharge path 270. Figure 23 As shown, when viewed from the front along the axial direction of the first rod 232 from the drive unit drain path 134b side, the first drain paths 270 are formed at four locations along the outer circumference of the first rod 232. The central angle of each sector of the cross-section of the second drain path 272 is approximately 72 degrees. The four first drain paths 270 are similarly formed from the first drain path starting position 232a to the distal end. The distance from the connection between the first rod 232 and the piston 128 to the first drain path starting position 232a, in other words, the distance from the first position H11 to the fourth position H14, is, for example, at least two-thirds of the movable distance of the piston 128 within the cylindrical body 114a.

[0262] The second drain portion 214n is formed between the first rod 232 and the first through-hole 114f, and between the piston 128 and the first through-hole 114f. The second drain portion 214n connects the pressure chamber 114b on the inlet side of the drain valve hydraulic drive unit 214 with the space within the water storage tank 10. The second drain portion 214n forms a second drain path 272 extending from the cylindrical body 114a. The second drain path 272 is formed, for example, by a slight gap between the outer surface of the first rod 232 and the first through-hole 114f. The second drain path 272 may further include a groove 272a formed by inwardly cutting away the side portion of the first rod 232 from the proximal end 232c to the distal end 232b of the first rod 232. The groove 272a of the second drain path 272 forms a flow path with a fan-shaped cross-section. Thus, when the piston 128 is in the first position H11, the second drain portion 214n opens the second drain path 272. Regardless of the position of the piston 128, the second drain path 272 remains open. A portion of the wash water flowing into the cylindrical body 114a flows out of the second drain portion 214n in the gap between the first rod 232 and the first through-hole portion 114f. The wash water flowing out of the second drain portion 214n flows into the water storage tank 10. Furthermore, because the second drain portion 214n is relatively narrow and has a high flow resistance, even when wash water is flowing out of the second drain portion 214n, the pressure within the cylindrical body 114a rises due to the wash water flowing into the cylindrical body 114a from the drive unit water supply path 34a, counteracting the biasing force of the spring 48 and lifting the piston 128.

[0263] The minimum cross-sectional area of ​​the second drain path 272 of the second drain portion 214n is smaller than the minimum cross-sectional area of ​​the first drain path 270 of the first drain portion 214m. The minimum cross-sectional area of ​​the second drain path 272 of the second drain portion 214n is less than or equal to half the minimum cross-sectional area of ​​the first drain path 270 of the first drain portion 214m. The second drain portion 214n forms an auxiliary drain flow path for the first drain portion 214m.

[0264] like Figure 23 As shown, the second discharge path 272 is formed at one location along the outer periphery of the first rod 232 when viewed from the front side of the drive unit drain path 134b along the axial direction of the first rod 232. The central angle of the sector-shaped cross section of the second discharge path 272 is approximately 72 degrees.

[0265] like Figure 22As shown, the bank 114h extends to the first position H11 in the portion corresponding to the second discharge path 272, but is formed to a shorter length in the portion corresponding to the first discharge path 270. Even with this bank 114h and the first rod 232, the second discharge path 272 of the second drainage portion 214n includes: a first flow path 114o extending transversely to the lower portion 128c between the top 114k of the bank 114h and the lower portion 128c when the piston 128 is in the first position H11; and a third flow path 114r extending transversely between the first rod 232 and the inner wall of the first through-hole 114f when the piston 128 is in the first position H11. The third flow path 114r forms a flow path between the outer surface of the first rod 232, excluding the groove 272a, and the inner wall of the first through-hole 114f. The third flow path 114r may further include a groove portion 272a and a flow path between the groove portion 272a and the inner wall of the first through-hole portion 114f.

[0266] The shape of the second drain portion 214n changes as the piston 128 moves. Consequently, the total cross-sectional area or the minimum cross-sectional area within the second drain portion 214n changes with the movement of the piston 128. The second drain portion 214n is designed so that as the piston 128 moves from the first position H11 to the second position H12, the total cross-sectional area or the minimum cross-sectional area of ​​the second discharge path 272 within the second drain portion 214n increases, thereby reducing pressure loss within the second drain portion 214n. For example, as the piston 128 moves from the first position H11 to the second position H12, the minimum cross-sectional area of ​​the second drain portion 214n increases. For example, the minimum cross-sectional area of ​​the second drain portion 272 is the minimum cross-sectional area between the top portion 114k of the bank 114h and the bottom portion 128c of the piston 128. As the piston 128 moves from the first position H11 to the second position H12, the minimum cross-sectional area of ​​the second discharge path 272 increases.

[0267] Furthermore, when the outer diameter of the distal end portion of the first rod 232 is formed to be smaller than the outer diameter of the proximal end portion, the second drain portion 214n is formed so that, as the piston 128 and the first rod 232 move to the second position side, the cross-sectional area of ​​the second drain path 272 between the first rod 232 and the inner wall of the first through-hole portion 114f, for example, the total value and the minimum value of the cross-sectional area, increases, and the pressure loss of the second drain portion 214n is reduced. At this time, the minimum value of the cross-sectional area of ​​the second drain path 272 when the piston 128 is at the first position H11 (e.g., Figure 7As shown in the second drainage portion 14n, the cross-sectional area of ​​the second discharge path 272 of the second drainage portion 214n, such as the discharge path corresponding to the first rod 32 and the inner wall of the first through-hole portion 14f, is smaller than the minimum value of the flow path cross-sectional area between the first rod 232 and the inner wall of the first through-hole portion 114f when the piston 128 is located at the second position H12.

[0268] Next, refer to Figures 21 to 28 The following describes a series of flushing operations of the flush water tank assembly 204 and the flush toilet apparatus 201 equipped therewith according to the third embodiment of the present invention. Since the flushing operations of the flush water tank assembly 204 and the like in the third embodiment are substantially the same as those of the flush water tank assembly 104 and the like in the second embodiment, only the first drain section 214m and the second drain section 214n will be described. Any overlapping descriptions will be made with those of the second embodiment and omitted.

[0269] like Figure 21 and Figure 24 As shown, when the piston 128 is located at the first position H11, the first discharge path inlet 270a of the first discharge path 270 of the first drainage portion 214m is closed by the first rod 232 and the first through-hole portion 114f, and the first discharge path 270 is in a closed state. When the piston 128 is located at the first position H11, the first discharge path inlet 270a of the first discharge path 270 of the first rod 232 is located at a position closer to the drive portion drainage path 134b side than the top 114k of the embankment 114h. When the piston 128 is located at the first position H11, the second drainage portion 214n is formed between the first rod 232, the piston 128 and the first through-hole portion 114f. That is, in the standby state, the second discharge path 272 formed between the first rod 232 and the first through-hole portion 114f is in an open state. Thus, as Figure 25 As shown, when the washing water flows into the cylindrical body 114a, as shown by arrow F21, a portion of the washing water flows out from the second discharge path 27 of the second drain portion 214n to the driving unit drain path 134b side.

[0270] Next, when a signal indicating that the toilet should be flushed is received and the first control valve 16 is opened, flush water flowing from the water supply pipe 38 is supplied to the drain valve hydraulic drive unit 214 via the first control valve 16. As a result, the piston 128 of the drain valve hydraulic drive unit 214 is lifted, and the operating portion 133a of the second rod 133 is pushed toward the driven portion 176.

[0271] like Figure 25As shown, when the piston 128 and the second rod 133 move toward the second position H12, the operating portion 133a contacts the first flat surface 176a of the follower portion 176, and the follower portion 176 and the first support body 180 are pressed forward while causing the support body elastic member 182 to contract. This lifts the connecting member 188 connected to the first support body 180, and the drain valve 12 is lifted by the connecting member 188. As a result, the flush water in the water storage tank 10 is discharged from the drain port 10a into the flush toilet body 2 due to the lifting of the drain valve 12.

[0272] While the clutch mechanism 130 is disengaged, and the piston 128 moves from the first position H11 to the second position H12, the second discharge path 272 formed between the first rod 232 and the first through-hole 114f is open. As a result, as indicated by arrow F21, a portion of the wash water flowing into the cylindrical body 114a flows out of the second discharge path 272 of the second drain section 214n toward the drive unit drain path 134b. Since the amount of wash water flowing out of the second discharge path 272 is relatively small, the piston 128 is pushed forward toward the second position H12 as intended. Meanwhile, the first discharge path inlet 270a of the first discharge path 270 is closed by the first rod 232 and the first through-hole 114f, and the first discharge path 270 of the first drain section 214m is closed.

[0273] Next, if Figure 26 As shown, when the driven portion 176 further advances toward the restricting portion 186 and is stopped, the contact between the second rod 133 and the driven portion 176 is released, and the clutch mechanism 130 is disconnected. Specifically, when the drain valve 12 is raised to a predetermined height, the driven portion 176 of the clutch mechanism 130 contacts the restricting portion 186, disengaging the clutch mechanism 130. Even after the clutch mechanism 130 is disengaged, the first discharge path 270 of the first drain portion 214m remains closed until the first discharge path inlet 270a is opened. As indicated by arrow F22, a portion of the wash water flows from the second discharge path 272 of the second drain portion 214n toward the drive unit drain path 134b.

[0274] like Figure 27As shown, the piston 128 and the first rod 232 are pushed forward and reach the second position H12. During this process, when the piston 128 advances to its connecting position (the fourth position H14 of the piston 128, which forms the connecting flow path), the first discharge path inlet 270a is opened, starting from the first discharge path starting position 232a of the first rod 23, which appears within the cylindrical body 114a in a manner corresponding to the connecting position of the piston 128. The fourth position H14 is located closer to the piston than the disconnected position, where the clutch mechanism 130 is disconnected, and slightly closer to the inlet side (near side) than the second position H12. When the first discharge path inlet 270a of the first discharge path 270 is opened by the first rod 232 and the first through-hole portion 114f, the first discharge path 270 of the first drainage portion 214m is in an open state. As a result, as indicated by arrow F23, the wash water is discharged from the first discharge path 27 to the drive unit drain path 134b, and the wash water is discharged as the main water supply from the discharge portion at the downstream end of the drive unit drain path 134b into the water storage tank 10. At this time, as indicated by arrow F24, a portion of the wash water also flows out from the second discharge path 272 of the second drain portion 214n to the drive unit drain path 134b side.

[0275] Meanwhile, because pilot valve 16e is open, first control valve 16 remains open, continuing to supply water to water storage tank 10. Furthermore, when the water level in water storage tank 10 drops to predetermined water level WL1, float portion 26a of float device 26 descends, thereby moving engagement portion 26b. This disengages valve shaft frame 12a from engagement portion 26, allowing valve shaft frame 12a and drain valve 12 to resume descending.

[0276] As a result, the drain valve 12 is positioned at the drain outlet 10a, closing it. Since the float switch 42 remains off, the first control valve 16 remains open, and water continues to be supplied to the storage tank 10. Wash water supplied via the drive unit drain passage 134b reaches the drain passage branch 134c. Part of the wash water branched at the drain passage branch 134c flows into the overflow pipe 10b, while the remainder is stored in the storage tank 10. The wash water flowing into the overflow pipe 10b flows into the flush toilet body 2 and is used to replenish water in the bowl 2a. Meanwhile, while the drain valve 12 is closed, the water level in the storage tank 10 rises due to the wash water flowing into the storage tank 10.

[0277] like Figure 28As shown, after the first control valve 16 is closed and the water supply to the drain valve hydraulic drive unit 214 is stopped, the cleaning water in the cylindrical body 114a of the drain valve hydraulic drive unit 214 gradually flows out from the first drain portion 214m and the second drain portion 214n. At the same time, the piston 128 is pressed down by the force of the spring 48 and returns to the first position H11. As the piston 128 returns to the first position H11, the first discharge path inlet 270a is closed, and then, as shown by arrow F25, the cleaning water in the cylindrical body flows out from the second discharge path 272 to the drive unit drain path 134b side. As a result, the cleaning water in the cylindrical body is in a state as shown in FIG. Figure 21 The machine in the water storage tank 10 is shown to have returned to a standby state.

[0278] According to the flush water tank assembly 204 according to the third embodiment of the present invention, the drain valve hydraulic drive unit 114 includes: an inlet 114l formed in the cylindrical body 114a into which flush water flows; a first drain portion 214m provided separately from the inlet 114l and into which flush water is discharged from the cylindrical body 114a; and a second drain portion 214n provided separately from the first drain portion 214m and formed between the first rod 232 and the first through-hole portion 114f. Thus, when the flush water supply pressure to the cylindrical body 114a undergoes a sudden change, such as a sudden rise, in either a disconnected or connected state between the inlet 114l and the first drain portion 214m, the second drain portion 214n mitigates the impact of the sudden change in flush water pressure, thereby cushioning the impact on the piston 128 from the flush water and preventing the piston 128 from becoming unstable.

[0279] According to the cleaning water tank device 204 involved in the third embodiment of the present invention mentioned above, the first discharge path 270 of the first drainage portion 214m can be formed relatively simply by utilizing the groove formed on the outer portion of the first rod 232. When the piston 128 is located at the first position H11, the water supply pressure of the cleaning water will not leak to the side of the first discharge path 270, and the water supply pressure of the cleaning water can be effectively utilized for the movement of the piston 128. When the piston 128 is located at the connecting position, the first discharge path 270 is in an open state, and the cleaning water is discharged from the inside of the cylindrical body 114a to the outside of the cylindrical body through the first discharge path 270, and the piston 128 can easily return to the first position H11 from the second position H12 or the specified position.

[0280] Furthermore, in the water pressure driving unit 214 of the drain valve according to the second embodiment of the present invention, the second drain path 172 is described as being formed by a slight gap between the outer surface of the first rod 132 and the first through hole 114f as an example, but the present invention is not limited to this method. As a modified example, Figure 29As shown, the second drain path 172 of the second drain portion 114n can also form an internal passage 172c extending from the second drain path inlet 172b inside the first rod 132. The second drain path inlet 172b opens on the side of the first rod 132. The inclusion of the internal passage 172c in the second drain path 172 can further stabilize the discharge volume. This internal passage 172c can also be connected to the first drain path 170 of the second embodiment. The minimum cross-sectional area of ​​the flow path between the second drain path inlet 172b and the internal passage 172c is smaller than the minimum cross-sectional area of ​​the flow path between the first drain path inlet 170a and the internal passage of the first drain path 170.

Claims

1. A flush water tank device for supplying flush water to a flush toilet, characterized by: A water storage tank is provided for storing flush water to be supplied to the flush toilet and is provided with a drain port for discharging the stored flush water to the flush toilet; A drain valve, opening and closing the drain port, and supplying and stopping the flushing water to the flush toilet; and a water pressure driving unit for a drain valve, which drives the drain valve using the water pressure of the supplied tap water. The water pressure driving unit of the drain valve includes: a cylindrical body, the tap water is supplied as washing water, a piston slidably disposed within the cylindrical body and moving from a first position to a second position in response to the inflow of washing water into the cylindrical body; a rod extending from the piston through a through-hole formed in the cylindrical body; an elastic member, which, while being provided on the piston, has a sealing function between the piston and the inner wall of the cylinder; an inlet portion, into which cleaning water flows while being formed in the cylindrical body; a first drain portion, disposed separately from the inlet portion and configured to discharge the washing water from the cylindrical body; and a second drain portion that is provided separately from the first drain portion and is formed between the rod, the piston, and the through-hole portion.

2. The flushing water tank device according to claim 1, characterized in that: The first drain portion is formed in the cylindrical body.

3. The flushing water tank device according to claim 1, characterized in that: The first drain portion is formed such that an inlet of a first discharge path for discharging washing water from the cylindrical body to the outside of the cylindrical body is opened and closed by the rod and the through hole. The first drainage portion is configured such that, when the piston is located at the first position, the entrance of the first discharge path is closed by the rod and the through-hole portion, thereby the first discharge path is in a closed state; and when the piston reaches a communication position between the first position and the second position, the entrance of the first discharge path is opened by the rod and the through-hole portion, thereby the first discharge path is in an open state.

4. The flushing water tank device according to claim 3, characterized in that: The first discharge path of the first drain portion is formed by a passage extending inside the rod from a first discharge path starting position of the rod to a distal end of the rod, and the first discharge path starting position of the rod is a position appearing in the cylindrical body in a manner corresponding to the communication position of the piston.

5. The flushing water tank device according to claim 3, characterized in that: The first discharge path of the first drainage portion is formed by a groove portion formed on the outer surface of the rod from the first discharge path starting position of the rod to the distal end of the rod, and the first discharge path starting position of the rod appears at a position within the cylindrical body in a manner corresponding to the communication position of the piston.

6. The flushing water tank device according to any one of claims 1 to 5, wherein The amount of deformation of the elastic member when the piston is located at the first position is the maximum amount of deformation of the elastic member at each position when the piston moves from the first position to the second position.

7. The flushing water tank device according to claim 6, characterized in that: The inner diameter of the cylindrical body at a portion corresponding to the first position of the piston is the smallest inner diameter among the inner diameters of the cylindrical body.

8. The flushing water tank device according to claim 6, characterized in that: The water discharge valve hydraulic drive unit further includes a biasing member that is provided in the cylindrical body and biases the piston toward the first position.

9. The flushing water tank device according to claim 1, characterized in that: The second drain portion is formed so that, as the piston moves from the first position to the second position, a flow path cross-sectional area in the second drain portion increases and a pressure loss in the second drain portion decreases.

10. The flushing water tank device according to claim 9, characterized in that: The second drain portion is formed so that as the piston moves from the first position to the second position, a flow path cross-sectional area between the rod of the second drain portion and the inner wall of the through-hole portion increases, thereby reducing pressure loss in the second drain portion.

11. The flushing water tank device according to claim 9, characterized in that: The through hole portion of the cylindrical body includes a bank portion that rises from a portion surrounding the through hole at the bottom of the cylindrical body toward the inside of the cylindrical body. The second drain portion includes a first flow path extending between a top portion of the bank and the piston when the piston is located at the first position.

12. The flushing water tank device according to claim 9, characterized in that: The device further comprises a clutch mechanism that connects the drain valve and the drain valve hydraulic drive unit, lifts the drain valve by the drain valve hydraulic drive unit, and disconnects at a predetermined time to lower the drain valve. The flow path cross-sectional area of ​​the second drain portion when the clutch mechanism is disengaged is the largest flow path cross-sectional area among the flow path cross-sectional areas of the second drain portion at each position of the piston between the first position and the second position.

13. The flushing water tank device according to claim 1, characterized in that: The central axis of the rod, the central axis of the through-hole portion, and the central axis of the cylindrical body are located on the same axis.

14. The flush water tank device according to claim 1, wherein the through hole portion further comprises a rectifying portion formed so that the diameter of the inner wall of the top portion is constant along the moving direction of the rod.

15. The flush water tank device according to claim 1, wherein a maximum outer diameter among outer diameters of the rod is smaller than a minimum inner diameter among inner diameters of the through hole portion.

16. The flushing water tank device according to claim 1, characterized in that: The flush water tank assembly further includes a speed reducing unit that reduces the flow rate of the flush water discharged from the second drain unit.

17. The flush water tank device according to claim 1, wherein when the piston is located at the first position, the lower end of the elastic member is located above a water stop level of the water storage tank.

18. The flushing water tank device according to claim 17, characterized in that: The cylindrical body of the water pressure driving portion of the drain valve is configured so that the elastic member is soaked in the washing water remaining in the cylindrical body when the piston is located at the first position.

19. The flushing water tank device according to claim 18, characterized in that: The piston of the water pressure driving unit of the drain valve is configured to move up and down within the cylindrical body. The first position is located below the second position. The cylindrical body comprises: a bank portion erected upward from the peripheral portion of the through hole at the bottom thereof; and a water storage portion capable of storing the cleaning water remaining between the bank portion and the inner wall of the cylindrical body. When the piston is located at the first position, the upper end of the elastic member is located at a height position lower than the top of the bank portion so that the elastic member is located in the water storage portion.

20. The flushing water tank device according to claim 19, characterized in that: When the piston is located at the first position, the top of the bank abuts against the lower surface of the piston.

21. The flushing water tank device according to claim 20, characterized in that: The rod extends downward from the piston. The bank of the cylindrical body is formed in a ring shape around the rod when viewed from above.

22. The flushing water tank device according to claim 20, characterized in that: The water pressure driving unit of the drain valve further includes a biasing member, which is disposed in the cylindrical body and applies a force to the piston toward the first position. The piston includes a force receiving portion that receives the biasing force from the biasing member, and the force receiving portion is formed outside the bank portion in a plan view.

23. The flushing water tank device according to claim 22, wherein When the piston is located at the first position, the force receiving portion of the piston of the water pressure driving unit of the water discharge valve is located below the top of the bank.

24. The flushing water tank device according to claim 19, wherein: The piston of the water pressure driving unit of the drain valve further includes an upper outer peripheral portion formed on the upper side of the elastic member, and a water flow gap for washing water to flow is formed between the upper outer peripheral portion and the inner wall of the cylindrical body.

25. The flushing water tank device according to claim 24, characterized in that: The water flow gap between the upper outer peripheral portion and the inner wall of the cylindrical body is formed so as to become smaller from the upper side toward the lower side of the cylindrical body.

26. A flush toilet device, characterized by: The cleaning water tank device comprises: a cleaning water tank device according to any one of claims 1 to 25; The flush toilet is cleaned by the flush water supplied from the flush water tank device.

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