Flush water tank unit, and flush toilet device including the same

Abstract

To provide a flush water tank unit capable of suppressing the decrease in the instantaneous flow rate of flush water supplied to a flush toilet body immediately after a drain valve is opened.SOLUTION: A disclosed flush water tank unit (4) is a flush water tank unit for supplying washing water to a flush toilet body (2). The flush water tank unit includes: a flush water tank body (26) for storing washing water; a drain passage (26b) formed to extend downward from the bottom of the flush water tank body; an annular seat surface (26d) provided to surround the entrance of the drain passage; a drain valve (28) that is configured to drain and stop washing water from the flush water tank body when a user sits on and releases from this seat. In the bottom of the flush water tank body, a flow guide (40) that reduces the flow velocity of washing water toward the center of the drain passage is formed on the flush water tank body.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a flush water tank apparatus, and in particular to a flush water tank apparatus for supplying flush water to a flush toilet main body, and a flush toilet apparatus equipped with the same. [Background technology]

[0002] US Patent Application Publication No. 2011 / 0231988 (Patent Document 1) describes a drain valve with a valve seat with a reduced cross-sectional area. In this drain valve, the valve element of the drain valve is raised from the drain valve seat surface, which is located at the bottom of the flush water tank, causing flush water in the tank to flow into the drain passage, supplying flush water to the flush toilet main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent Application Publication No. 2011 / 0231988 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the drain valve described in Patent Document 1, when the valve disc of the drain valve is lifted from the seat surface, the flush water in the flush water tank flows in one go towards the centre of the seat surface. As a result, the flow of flush water flowing out of the flush water tank separates from the inner wall surface of the drain passage, preventing the flush water in the flush water tank from flowing smoothly into the flush toilet main body, causing a problem of a decrease in the instantaneous flow rate of flush water supplied to the flush toilet main body.

[0005] Therefore, the object of the present invention is to provide a flush water tank device that can suppress a decrease in the instantaneous flow rate of flush water supplied to the flush toilet body immediately after the drain valve is opened, and a flush toilet device equipped with the same. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention is a flush water tank device for supplying flush water to a flush toilet main body, and comprises a flush water tank main body for storing flush water, a drain passage formed so as to extend downward from the bottom surface of this flush water tank main body, an annular seat surface provided so as to surround the entrance of this drain passage, and a drain valve that drains and stops flush water from the flush water tank main body by sitting on and lifting off this seat surface, and is characterized in that a flow guide section is provided at the bottom of the flush water tank main body which reduces the flow speed of flush water within the flush water tank main body towards the centre of the drain passage.

[0007] According to the present invention configured in this way, a flow guide section is provided at the bottom of the flush water tank body that reduces the flow speed of flush water toward the center of the drain passage within the flush water tank body, thereby reducing the horizontal component of the flow speed of flush water toward the center of the drain passage. As a result, flush water flowing out of the flush water tank body is more likely to flow along the inner wall surface of the drain passage provided inside the seat surface, and it is possible to prevent the flow of flush water from separating from the inner wall surface of the drain passage. This makes it possible to increase the instantaneous flow rate of flush water flowing out of the flush water tank body, improving the flushing performance of the flush toilet body.

[0008] In the present invention, the flow guide portion is preferably a surrounding wall surface provided on the outside of the seat surface so as to surround the seat surface.

[0009] According to the present invention configured in this manner, the flow guide section is made up of an enclosing wall surface provided on the outside of the seat surface so as to surround the seat surface, so that the wash water heading toward the center of the seat surface flows over the enclosing wall surface, and the horizontal component of the flow velocity of the wash water heading toward the center of the seat surface can be reduced.

[0010] In the present invention, the upper end of the flow guide portion is preferably located above a tangent line to the inlet of the drain passage in a vertical cross section.

[0011] According to the present invention configured in this manner, the upper end of the flow guide portion is located above the tangent to the entrance of the drainage passage in the vertical cross section, so that the cleaning water heading toward the center of the seat surface must overcome the higher flow guide portion, and the horizontal component of the flow velocity heading toward the center of the seat surface can be sufficiently reduced.

[0012] In the present invention, the drain valve is preferably configured to be pulled upward from the seat surface, and when the drain valve is pulled up to its maximum, the vertical distance from the upper end of the surrounding wall surface to the drain valve is at least half the vertical distance from the seat surface to the drain valve.

[0013] According to the present invention configured in this way, when the drain valve is raised to its maximum position, the vertical distance from the upper end of the surrounding wall to the drain valve is at least half the vertical distance from the seat surface to the drain valve, so a sufficient cross-sectional flow path area for flush water can be secured between the upper end of the surrounding wall and the drain valve, thereby avoiding a decrease in instantaneous flow rate due to the provision of the surrounding wall.

[0014] In the present invention, preferably, the surrounding wall surface surrounding the seat surface is partially cut out.

[0015] According to the present invention configured as described above, a portion of the surrounding wall surrounding the seat surface is cut out, which maintains a relatively large horizontal component of the flow velocity at the cutout portion, and the horizontal component of the flow velocity toward the center of the seat surface can be adjusted by adjusting the size of the cutout.

[0016] In the present invention, preferably, a portion of the surrounding wall surface that constitutes the flow guide portion is integrated with the wall surface that constitutes the flush water tank body.

[0017] According to the present invention configured in this manner, a portion of the surrounding wall that constitutes the flow guide section is integrated with the wall that constitutes the flush water tank body, so the present invention can also be applied to flush water tank devices in which the seat surface is provided near the wall surface of the flush water tank body.

[0018] The present invention is also a flush toilet device that is flushed with flush water, characterized by having a flush toilet main body and a flush water tank device of the present invention that is installed at the rear of the flush toilet main body so as to supply flush water to the flush toilet main body. [Effects of the Invention]

[0019] The flush water tank device of the present invention can prevent a decrease in the instantaneous flow rate of flush water supplied to the flush toilet body immediately after the drain valve is opened. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a plan view showing a flush toilet apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional side view of a flush toilet apparatus according to an embodiment of the present invention, taken along line II-II in FIG. 1. [Figure 3] FIG. 2 is an enlarged cross-sectional view showing the connection between the flush toilet main body and the flush water tank main body in a flush toilet apparatus according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing an enlarged view of the drain port portion of a flush water tank body provided in a flush water tank apparatus according to an embodiment of the present invention. FIG. [Figure 5] FIG. 2 is a top view of a flush water tank body provided in a flush water tank apparatus according to an embodiment of the present invention. [Figure 6] FIG. 10 is a top view of a flush water tank body according to a comparative example. [Figure 7] FIG. 10 is a top view of a modified flush water tank body of a flush water tank apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Next, a flush water tank apparatus according to an embodiment of the present invention, and a flush toilet apparatus equipped with the same, will be described with reference to the accompanying drawings. Fig. 1 is a plan view showing a flush toilet apparatus according to an embodiment of the present invention, and Fig. 2 is a side cross-sectional view taken along line II-II in Fig. 1.

[0022] As shown in Figures 1 and 2, the flush toilet device 1 according to an embodiment of the present invention is a siphon jet type flush toilet, and comprises a ceramic flush toilet body 2, a resin toilet seat and toilet lid (not shown) placed on the top surface of this flush toilet body 2, and a flush water tank device 4 placed at the upper rear of the flush toilet body 2 and covered by a resin cover (not shown).

[0023] The flush toilet body 2 is formed with a bowl portion 6 for receiving waste, a drain trap pipe 8 provided at the bottom of the bowl portion 6 for discharging waste by siphon action, a rim spout 10 for rim water discharge, a rim water conduit 12 for guiding flush water to the rim spout, a jet spout 14 for jet water discharge, and a jet water conduit 16 for guiding flush water to the jet spout 14.

[0024] Bowl portion 6 has a bowl-shaped waste receiving surface 18, a rim portion 20 formed along the upper edge of bowl portion 6, and a shelf portion 21 formed between waste receiving surface 18 and rim portion 20. Bowl portion 6 also has a pot portion 22 formed in the area below waste receiving surface 18 and connected to drain trap pipe line 8. A water sealing surface W is formed inside pot portion 22.

[0025] The drain trap pipeline 8 has an inlet portion 8a, an ascending pipeline 8b extending upward from the inlet portion 8a, a descending pipeline 8c extending downward from the ascending pipeline 8b, and a top portion 8d located between the descending pipeline 8c and the ascending pipeline 8b and defining the seal water level. Here, the lower end of the descending pipe 8c of the drain trap pipe 8 is connected to a drain pipe (not shown) via a drain socket (not shown).

[0026] When looking at the flush toilet body 2 from the front, the rim spout 10 is formed on the rear left side of the rim portion 20. The rim spout 10 spouts flush water forward, and this flush water swirls around the inner circumferential surface of the rim portion 20 and the shelf surface of the shelf portion 21 as it flows down to the waste receiving surface 18.

[0027] The rim water conduit 12 is formed in a tapered shape with the flow path cross section gradually becoming smaller towards the rim water outlet 10. Flush water is supplied to the rim water conduit 12 from the water mains via the flush water tank device 4, and flush water is discharged from the rim water outlet 10 due to the water supply pressure of the water mains.

[0028] Jet water outlet 14 is formed in the bottom of bowl portion 6. Jet water outlet 14 is positioned opposite inlet 8a of drain trap pipe 8 and is directed toward inlet 8a of drain trap pipe 8. Jet water outlet 14 ejects flush water toward inlet 8a of drain trap pipe 8, and this flush water flows into drain trap pipe 8, activating the siphon action.

[0029] The jet water conduit 16 comprises an upstream flow path 16a that extends forward from the flush water tank apparatus 4, a bent flow path 16b that bends from this upstream flow path, and a downstream flow path 16c that extends rearward from this bent flow path and connects to the jet spout 14. Flush water is supplied to the jet water conduit 16 from the flush water tank body 26 of the flush water tank apparatus 4, and flush water is spouted from the jet spout 14 due to the head pressure of the flush water. Thus, in this embodiment, flush water discharged from the rim spout 10 is supplied directly from the water line, and flush water discharged from the jet spout 14 is supplied from the flush water tank body 26. However, as a modified example, the present invention can also be applied to a flush toilet apparatus in which the entire amount of flush water discharged is supplied from the flush water tank.

[0030] Next, with new reference to Figures 3 to 5, the configuration of the flush water tank apparatus 4 according to an embodiment of the present invention will be described. Figure 3 is an enlarged cross-sectional view showing the connection between the flush toilet main body 2 and flush water tank main body 26 in a flush toilet apparatus 1 of this embodiment. Figure 4 is an enlarged cross-sectional view showing the drain port portion of the flush water tank main body 26 provided in the flush water tank apparatus 4 of this embodiment. Also, Figure 5 is a top view of the flush water tank main body 26 provided in the flush water tank apparatus 4 of this embodiment.

[0031] As shown in Figures 1 and 2, the flush water tank device 4 has a valve unit 24 that starts and stops the supply of flush water from the water line, a flush water tank body 26 made of resin that stores the flush water supplied via the valve unit 24, and a drain valve 28 that drains and stops the flush water from the flush water tank body 26.

[0032] The valve unit 24 has a tank water supply solenoid valve 24a, a rim water discharge solenoid valve 24b, etc., and is configured to control the supply and stop of tap water supplied from the water supply system into the flush water tank main body 26, and the discharge and stop of tap water from the rim water discharge port 10.

[0033] As shown in Figure 3, the flush water tank main body 26 is configured to store flush water for flushing the flush toilet main body, and is fixed to the flush toilet main body 2 via a base plate 30. Also, a drain valve 28 and a drain valve drive mechanism 32 are arranged inside the flush water tank main body 26. By lifting the drain valve 28 with the drain valve drive mechanism 32, the drain valve 28 opens and flush water is discharged from the flush water tank main body 26. The flush water discharged from the flush water tank main body 26 flows through an inlet 2a provided on the upper rear surface of the flush toilet main body 2, and into the jet water conduit 16 provided inside the flush toilet main body 2.

[0034] In this embodiment, the flush water tank body 26 is a small resin tank with a volume of approximately 2 liters. As shown in Figure 2, the lower part of the flush water tank body 26 is positioned below the upper surface of the rim part 20 of the flush toilet body 2, and above the top 8d of the drain trap pipe 8. This makes the flush toilet apparatus 1 a low-silhouette type toilet. Also, in this embodiment, the flush water in the flush water tank body 26 is discharged from the jet spout 14 by gravity.

[0035] As shown in Figure 3, the bottom surface of flush water tank body 26 is provided with an annular protrusion 26a that protrudes downward, and the inside of this annular protrusion 26a constitutes drain passage 26b, which is formed to extend downward from the bottom surface of flush water tank body 26. The circular opening at the bottom end of this drain passage 26b functions as a drain outlet for flush water tank body 26. The diameter of this drain outlet is formed to be approximately the same as the diameter of drain opening 30a formed in base plate 30, and drain passage 26b and drain opening 30a are smoothly connected. A groove 26c is formed on the outer peripheral surface of protrusion 26a, and an annular O-ring 34 is fitted into this groove 26c.

[0036] Meanwhile, a cylindrical portion 30b protruding downward is provided on the bottom surface of the base plate 30 so as to surround the drain opening 30a. An annular upper surface recess 30c is formed on the upper surface of the bottom surface of the base plate 30 so as to surround the drain opening 30a. Meanwhile, an annular lower surface recess 30d is formed on the lower surface of the bottom surface of the base plate 30 so as to surround the cylindrical portion 30b.

[0037] Furthermore, protrusion 26a protruding from the bottom surface of flush water tank body 26 is received in upper surface recess 30c formed in the upper surface of base plate 30. In this way, by fitting protrusion 26a of flush water tank body 26 into upper surface recess 30c of base plate 30, O-ring 34 arranged on the outer periphery of protrusion 26a is crushed in the radial direction of drain passage 26b, and the gap between flush water tank body 26 and base plate 30 is sealed.

[0038] Meanwhile, a gasket 36 is placed inside a circular lower surface recess 30d formed on the underside of the base plate 30. The gasket 36 is configured in an overall circular shape, and is fitted around a cylindrical portion 30b formed on the inner periphery of the lower surface recess 30d, and is received inside the lower surface recess 30d. The base plate 30 is fixed to the upper rear surface of the flush toilet body 2 with multiple bolts 38 (only one is shown in Figure 3).

[0039] As a result, the packing 36, which is located in the underside recess 30d on the underside of the base plate 30, is compressed between the base plate 30 and the flush toilet main body 2. In other words, when the flush water tank main body 26 is fixed to the flush toilet main body 2 via the base plate 30, the packing 36 is sandwiched and crushed between the underside recess 30d of the base plate 30 and the periphery of the inlet 2a on the top surface of the flush toilet main body 2. This ensures watertightness between the base plate 30 and the flush toilet main body 2.

[0040] Next, as shown in Figure 4, drain passage 26b is a passage formed to extend downward from the bottom surface of flush water tank body 26, and has a circular cross section, configured so that the flow path cross-sectional area narrows downward. Also, the inner wall surface of drain passage 26b is curved in a convex shape facing upward in the vertical cross section shown in Figure 4. Furthermore, an annular seat surface 26d (Figure 5) is provided at the inlet portion at the upper end of drain passage 26b so as to surround it. Seat surface 26d is a narrow, annular surface, and drain valve 28 seats on this seat surface 26d, and by lifting it from its seat, the drain outlet of flush water tank body 26 is opened and closed, and flush water is discharged or stopped.

[0041] That is, when flushing the bowl portion 6 of the flush toilet main body 2, the drain valve 28 is lifted by the drain valve drive mechanism 32 (Fig. 3) from the closed valve position P1 shown by the dashed line in Fig. 4 to the open valve position P2 shown by the chain line. When the drain valve 28 is in the closed valve position P1 and seated on the seat surface 26d, the discharge of flush water from the flush water tank main body 26 is stopped. Then, when the drain valve 28 is moved to the open valve position P2 and lifted off the seat surface 26d, flush water is discharged from the flush water tank main body 26.

[0042] 4 and 5, a flow guide section 40 is provided at the bottom of flush water tank body 26 so as to surround the periphery of seat surface 26d. This flow guide section 40 is a surrounding wall surface that is provided so as to rise vertically on the outside of seat surface 26d so as to surround seat surface 26d, and is formed concentrically with the circular seat surface 26d. By providing flow guide section 40 in this way, the flow speed of flush water inside flush water tank body 26 toward the center C of drain passage 26b is reduced.

[0043] 4, the surrounding wall surface that makes up flow guide section 40 is configured so that its upper end is located above tangent line L1 that contacts the inner wall surface of drain passage 26b at the entrance to the upper end of drain passage 26b. By configuring flow guide section 40 in this way, flush water that flows toward center C of drain passage 26b near the bottom surface of flush water tank body 26 hits flow guide section 40 and heads upward once, so the velocity component of the flush water heading toward center C of drain passage 26b decreases.

[0044] Furthermore, in this embodiment, the surrounding wall surface constituting the flow guide section 40 is cut out at four locations on the circumference. That is, as shown in FIG. 5, the flow guide section 40 has cutouts 40a provided at equal intervals at four locations on the circumference, and the height of the surrounding wall surface is lowered in those areas. In this way, in the areas where the cutouts 40a are provided, the velocity component of the flush water moving from the periphery of the drain outlet toward the center C of the drain passage 26b is hardly reduced. Therefore, the magnitude of the average velocity component moving toward the center C of the drain passage 26b can be adjusted by changing the number and size of the cutouts 40a provided in the flow guide section 40.

[0045] 4, when the drain valve 28 is raised to the open valve position P2, which is the highest position, the vertical distance D1 from the upper end of the flow guide portion 40, which is the surrounding wall surface, to the lower surface of the drain valve 28 is equal to or greater than half of the vertical distance D2 from the seat surface 26d to the lower surface of the drain valve 28. By setting the distance from the upper end of the flow guide portion 40 to the drain valve 28 in this manner, it is possible to provide the flow guide portion 40 around the seat surface 26d while ensuring a sufficient flow path cross-sectional area between the flow guide portion 40 and the drain valve 28.

[0046] Next, the operation of the flush toilet device 1 according to an embodiment of the present invention will be explained. First, when a user performs a flushing operation on the flush toilet device 1, a controller (not shown) provided in the flush toilet device 1 sends a control signal to the rim water spouting solenoid valve 24b (Figure 1) of the valve unit 24, causing it to open. As a result, flush water supplied from the water supply passes through the rim water spouting solenoid valve 24b and the rim water conduit 12 and is discharged from the rim water outlet 10. The flush water discharged from the rim water outlet 10 forms a swirling flow above the waste receiving surface 18 of the bowl section 6, cleaning the waste receiving surface 18.

[0047] When a predetermined time has elapsed after the rim water discharge solenoid valve 24b has been opened, the controller (not shown) sends a control signal to the drain valve drive mechanism 32 (Figure 3), which activates a motor (not shown) provided in the drain valve drive mechanism 32 and raises the drain valve 28 from the seat surface 26d of the flush water tank main body 26. This opens the drain valve 28, and the flush water that had been stored in the flush water tank main body 26 flows through the drain passage 26b of the flush water tank main body 26 into the inlet 2a (Figure 3) of the flush toilet main body 2, and then passes through the jet water conduit 16 and is discharged from the jet water discharge port 14. The discharge of water from the jet water discharge port 14 induces a siphon phenomenon in the drain trap pipe 8, and the flush water and waste in the bowl section 6 are discharged through the drain trap pipe 8.

[0048] Here, when drain valve 28 is lifted up from seat surface 26d of flush water tank body 26, the flush water in flush water tank body 26 starts to flow all at once towards centre C of drain passage 26b (drain outlet). In other words, the moment drain valve 28 is lifted up, flush water in flush water tank body 26 flows from the gap between the bottom surface of drain valve 28 and seat surface 26d towards centre C of drain passage 26b, and then falls downward within drain passage 26b.

[0049] At this time, since a flow guide section 40 is provided around the periphery of the annular seat surface 26d so as to surround it, the flow toward the center C of the drain passage 26b is first directed upward so as to overcome the flow guide section 40, as shown by arrow F1 in Figure 4, and then flows downward into the drain passage 26b. The flow F1 of flush water that overcomes the flow guide section 40 and flows into the drain passage 26b then falls along the inner wall surface of the drain passage 26b. This allows the flush water in the flush water tank main body 26 to flow smoothly into the drain passage 26b at the moment the drain valve 28 is lifted from the seat surface 26d. As a result, the instantaneous flow rate of flush water flowing from the flush water tank main body 26 into the jet water conduit 16 can be increased.

[0050] In contrast, if the flow guide 40 is not provided around the seat surface 126d, as in the comparative example of flush water tank body 126 shown in Figure 6, the instant the drain valve 128 is lifted from the seat surface 126d, flush water flows toward the center of drain passage 126b at an extremely high flow rate through the gap between the bottom surface of drain valve 128 and seat surface 126d. Therefore, the flush water that flows in through the gap between drain valve 128 and seat surface 126d flows almost horizontally, as shown by arrow F3 in Figure 6. As a result, immediately after the drain valve 128 is lifted from the seat surface 126d, the flush water does not flow along the inner wall surface of drain passage 126b, narrowing the effective flow path cross-sectional area. This reduces the instantaneous flow rate immediately after the drain valve 128 is lifted. In other words, if flow guide section 40 were not provided, the horizontal component of the flush water flow would become too large, and immediately after drain valve 128 was opened, the flow of flush water would separate from the inner wall surface of drain passage 126b, creating area B where no flush water flows. As a result, flow resistance increases when the flush water flows from flush water tank body 126 into drain passage 126b, and the instantaneous flow rate decreases.

[0051] On the other hand, in the flush toilet device 1 of this embodiment shown in Figure 4, when the drain valve 28 is opened, the flow of flush water heading towards the centre C of the drain passage 26b is temporarily directed upward by the flow guide section 40, so the horizontal component of the flow of flush water is reduced appropriately. For this reason, the flow of flush water flowing into the drain passage 26b does not separate from the inner wall surface of the drain passage 26b, and the flush water can flow smoothly along the inner wall surface of the drain passage 26b, making it possible to increase the instantaneous flow rate.

[0052] Furthermore, as shown in Figure 4, in the flush toilet device 1 of this embodiment, a flow guide section 40 is provided on the bottom surface of the flush water tank body 26, and a cutout section 40a is provided in this flow guide section 40. In the area where this cutout section 40a is provided, as shown by arrow F2 in Figure 4, the flow of flush water from the periphery of the flow guide section 40 towards the centre C of the drainage passage 26b is not directed upward, but flows almost horizontally into the inside of the flow guide section 40. For this reason, after passing through cutout section 40a, the flush water heads towards the centre C of the drainage passage 26b at a relatively high flow rate, and then merges with the flush water that has passed over the flow guide section 40, and flows into the drainage passage 126b.

[0053] In this way, the horizontal component of the flow velocity of the flush water increases in the portion where the notch 40a is provided in the flow guide portion 40, while the horizontal component of the flow velocity of the flush water decreases in the portion where the flush water passes over the flow guide portion 40. Therefore, the average flow velocity of the flush water toward the center C of the drain passage 26b can be adjusted by the size and number of the notch 40a provided in the flow guide portion 40. In this embodiment, the size and number of the notch 40a provided in the flow guide portion 40 are set so that the flow velocity of the flush water toward the center C of the drain passage 26b is as high as possible within the range where separation does not occur on the inner wall surface of the drain passage 126b.

[0054] In this way, after the drain valve 28 is raised from the seat surface 26d and flush water is discharged from the jet water spouting port 14, a predetermined time later the controller (not shown) sends a control signal to the rim water spouting solenoid valve 24b to close it. This stops rim water spouting from the rim water spouting port 10 and completes one toilet flush.

[0055] According to the flush toilet apparatus 1 of the embodiment of the present invention, a flow guide 40 is provided at the bottom of the flush water tank body 26, which reduces the flow speed of flush water heading towards the centre C of the drain passage 26b inside the flush water tank body 26, and therefore the horizontal component of the flow speed of flush water heading towards the centre C of the drain passage 26b is reduced. As a result, flush water flowing out of the flush water tank body 26 is more likely to flow along the inner wall surface of the drain passage 26b, which is provided on the inside of the seat surface 26d, and it is possible to prevent the flow of flush water from separating from the inner wall surface of the drain passage 26b. This makes it possible to increase the instantaneous flow rate of flush water flowing out of the flush water tank body 26, and improve the flushing performance of the flush toilet body 2.

[0056] Furthermore, according to the flush toilet device 1 of this embodiment, the flow guide section 40 is made up of an enclosing wall surface provided on the outside of the seat surface 26d so as to surround the seat surface 26d, so that flush water heading toward the center C of the seat surface 26d flows over the enclosing wall surface, reducing the horizontal component of the flow velocity of flush water heading toward the center of the seat surface 26d.

[0057] Furthermore, with the flush toilet device 1 of this embodiment, the upper end of the flow guide section 40 is located above the tangent line L1 (Figure 4) of the entrance of the drainage passage 26b in the vertical cross section, so the flush water heading toward the center C of the seat surface 26d must overcome the higher flow guide section 40, and the horizontal component of the flow velocity heading toward the center C of the seat surface 26d can be sufficiently reduced.

[0058] Furthermore, with the flush toilet device 1 of this embodiment, when the drain valve 28 is raised to its maximum, the vertical distance D1 (Figure 4) from the top of the surrounding wall surface (flow guide portion 40) to the drain valve 28 is more than half the vertical distance D2 from the seat surface 26d to the drain valve 28, so a sufficient cross-sectional flow path area for flush water can be secured between the top of the surrounding wall surface and the drain valve 28. For this reason, it is possible to avoid a decrease in instantaneous flow rate due to the provision of the surrounding wall surface.

[0059] Furthermore, according to the flush toilet device 1 of this embodiment, a portion of the surrounding wall surface (flow guide section 40) that surrounds the seat surface is cut out (Figs. 4 and 5). As a result, a relatively large horizontal component of the flow velocity is maintained in the cutout section (cutout section 40a), and the horizontal component of the flow velocity toward the center of seat surface 26d can be adjusted by adjusting the size of the cutout.

[0060] Although the embodiment of the present invention has been described above, various modifications can be made to the above-described embodiment.

[0061] For example, in the embodiment described above, the surrounding wall surface that makes up the flow guide portion was configured separate from the side wall surface of the flush water tank body, but as shown in Fig. 7, part of the surrounding wall surface can also be integrated with the side wall surface of the flush water tank body. That is, in the modified example shown in Fig. 7, a surrounding wall surface 52 is provided as a flow guide portion so as to surround the periphery of the seat surface 50a of the flush water tank body 50. This surrounding wall surface 52 is provided concentrically with the annular seat surface 50a, and part of it is integrated with one of the side wall surfaces 50b of the flush water tank body 50. In this way, even when part of the surrounding wall surface 52 is integrated with the side wall surface 50b of the flush water tank body 50, the surrounding wall surface 52 can reduce the horizontal component of the flow velocity toward the center C of the seat surface 50a, and the instantaneous flow rate of flush water flowing through the drain passage 50c can be increased. [Explanation of symbols]

[0062] 1 Flush toilet device 2 Flush toilet body 2a Inlet 4. Cleaning water tank device 6 Bowl section 8 Drain trap pipe 8a Entrance 8b Ascending pipe 8c descending pipe 8d top 10 Rim Spout 12 Rim Waterway 14 Jet outlet 16 Jet Waterway 16a Upstream channel 16b Bent flow path 16c Downstream channel 18 Waste receiving surface 20 Rim 21 Shelf 22 Pressure Points 24 Valve unit 24a Tank water supply solenoid valve 24b Rim water outlet solenoid valve 26 Cleaning water tank body 26a Protrusion 26b Drain passage 26c groove 26d seat surface 28 Drain valve 30 base plate 30a drainage opening 30b Cylindrical part 30c Top recess 30d Bottom recess 32 Drain valve drive mechanism 34 O-ring 36 Gasket 38 volts 40 Flow guide section (enclosure wall) 40a Notch 50 Cleaning water tank body 50a seat surface 50b Side wall 50c drainage passage 52 Siege Wall 126 Cleaning water tank body 126b Drain passage 126d seat surface 128 Drain valve

Claims

1. A flush water tank device for supplying flush water to a flush toilet body, A flush water tank body that stores flush water; a drain passage formed to extend downward from the bottom surface of the flush water tank body; an annular seat surface provided to surround the inlet of the drainage passage; a drain valve that drains flush water from the flush water tank body and stops the discharge by sitting on and lifting off the seat surface; and A flush water tank device characterized in that a flow guide portion is provided at the bottom of the flush water tank body to reduce the flow rate of flush water toward the center of the drainage passage within the flush water tank body.

2. 2. The flush water tank apparatus according to claim 1, wherein the flow guide portion is a surrounding wall surface provided on the outside of the seat surface so as to surround the seat surface.

3. 3. A flush water tank apparatus according to claim 2, wherein the upper end of the flow guide portion is located above a tangent line at the inlet of the drain passage in a vertical cross section.

4. A flush water tank device as described in claim 2, wherein the drain valve is configured to be pulled upward from the seat surface, and when the drain valve is pulled up to its maximum, the vertical distance from the upper end of the surrounding wall surface to the drain valve is more than half the vertical distance from the seat surface to the drain valve.

5. 3. The flush water tank device according to claim 2, wherein the surrounding wall surface surrounding the seat surface is partially cut out.

6. 3. A flush water tank apparatus according to claim 2, wherein a portion of the surrounding wall surface that constitutes the flow guide portion is integrated with the wall surface that constitutes the flush water tank body.

7. A flush toilet device that is flushed with flush water, A flush toilet body, a flush water tank device according to any one of claims 1 to 6, which is provided at the rear of the flush toilet main body so as to supply flush water to the flush toilet main body; A flush toilet apparatus comprising:

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