Flush toilet

Abstract

The problem to be overcome by the present disclosure is to provide a flush toilet designed to reduce water splashing in the backflow check structure. The flush toilet includes: a toilet bowl; a drain port for discharging water into the toilet bowl; a water supply passage (3) for supplying water from a water supply source to the drain port; and a backflow check structure (4) for checking the backflow of water traveling through the water supply passage (3). The backflow check structure (4) has: an inlet port (410) communicating with the drain port; a water receiving wall (5) through which the inlet port (410) is provided in a part of the water receiving wall (5); and an outlet port (400) spaced apart from the inlet port (410) and the water receiving wall (5) and configured to guide water supplied from the water supply source toward the inlet port (410). The water receiving wall (5) is provided with a water adhesion reducing portion (9) in a part thereof located below the inlet port (410) to reduce the chance of water adhering to the lower end surface (520) of the water receiving wall (5).

Description

Technical Field

[0001] The present disclosure generally relates to a flush toilet, and more particularly, to a flush toilet provided with a backflow check structure for a water supply passage that supplies water to a toilet bowl. Background Art

[0002] Patent Document 1 discloses a flush toilet provided with a backflow check structure for a water supply passage that supplies water to a toilet bowl. The backflow check structure includes: an inlet port that communicates with a drain port provided for the toilet bowl; and an outlet port that guides water supplied from a water supply source toward the inlet port. The inlet port is arranged on a trajectory along which water flows out through the outlet port.

[0003] In the flush toilet of Patent Document 1, a part of the water flowing out through the outlet port is received by a wall surrounding the inlet port and falls along the wall. At this time, sometimes due to surface tension, a certain amount of water adheres to the lower end surface of the wall.

[0004] In this state, if the pressure of the water flowing out through the outlet port is lower than a predetermined value, the water flowing out through the outlet port collides with the water adhering to the lower end surface of the wall. This causes the adhering water to splash everywhere and reach as far as the outside of a water storage tank located below the backflow check structure.

[0005] Citation List

[0006] Patent Document

[0007] Patent Document 1: WO 2019 / 097966A1 Summary of the Invention

[0008] An object of the present disclosure is to provide a flush toilet that can reduce splashing of water in a backflow check structure.

[0009] A flush toilet according to one aspect of the present disclosure includes: a toilet bowl that receives excrement; a drain port that discharges water into the toilet bowl; a water supply passage that supplies water from a water supply source through it to the drain port; and a backflow check structure that is provided for the water supply passage and is configured to check the backflow of water traveling through the water supply passage. The backflow check structure has: an inlet port that communicates with the drain port; a water receiving wall through which the inlet port is provided in a part of the water receiving wall; and an outlet port that is spaced apart from the inlet port and the water receiving wall and is configured to guide water supplied from a water supply source toward the inlet port. The water receiving wall is provided with a water adhesion reducing portion in a part of it located below the inlet port. The water adhesion reducing portion reduces the chance of water adhering to the lower end surface of the water receiving wall. Brief Description of the Drawings

[0010] Figure 1 is a perspective view showing a flush toilet according to an exemplary embodiment of the present invention;

[0011] Figure 2 is a perspective view showing a backflow check structure of a flush toilet and a toilet bowl;

[0012] Figure 3 is a perspective view showing the backflow check structure and its surrounding parts;

[0013] Figure 4A is a cross-sectional view showing the backflow check structure and its surrounding parts taken along a vertical plane;

[0014] Figure 4B is a side view showing a main body part of the backflow check structure;

[0015] Figure 5A is a side view showing a first modification of the main body part of the backflow check structure;

[0016] Figure 5B is a side view showing a second modification of the main body part of the backflow check structure;

[0017] Figure 5C is a side view showing a third modification of the main body part of the backflow check structure; and

[0018] Figure 5D is a side view showing a fourth modification of the main body part of the backflow check structure. DETAILED DESCRIPTION

[0019] 1. Overview

[0020] Figure 1 Shows a flush toilet 1 according to an exemplary embodiment. The flush toilet 1 includes: a toilet bowl 23 that receives excrement; a drain port 253 that discharges water into the toilet bowl 23; a water supply passage 3 that supplies water from a water supply source to the drain port 253; and a backflow check structure 4 that is provided for the water supply passage 3 and is configured to check the backflow of water traveling through the water supply passage 3. The backflow check structure 4 has: an inlet port 410 that communicates with the drain port 253; a water receiving wall 5 through which the inlet port 410 is provided in a part of the water receiving wall 5; and an outlet port 400 that is spaced apart from the inlet port 410 and the water receiving wall 5 and is configured to guide water supplied from the water supply source toward the inlet port 410. As Figure 4A and Figure 4B shown, the water receiving wall 5 is provided with a water adhesion reducing portion 9 in a part thereof that is positioned below the inlet port 410. The water adhesion reducing portion 9 reduces the chance of water adhering to the lower end surface 520 of the water receiving wall 5.

[0021] In the flush toilet 1 according to an exemplary embodiment having such a configuration, the water adhesion reducing unit 9 can reduce the chance of water adhering to the lower end surface 520 of the water receiving wall 5 due to surface tension when the water receiving wall 5 receives a part of the water guided from the water outlet port 400 toward the water inlet port 410. Thus, the flush toilet 1 according to this exemplary embodiment can reduce the chance of the water guided from the water outlet port 400 toward the water inlet port 410 colliding with the water adhering to the lower end surface 520 of the water receiving wall 5 and causing the water adhering to the lower end surface 520 to splash everywhere. Therefore, the flush toilet 1 according to this exemplary embodiment can reduce the splashing of water in the backflow check structure 4.

[0022] 2. Details

[0023] Next, the flush toilet 1 according to the exemplary embodiment shown in Figure 1 to FIG. 4 will be described in further detail. As Figure 1 shown, the flush toilet 1 is installed in the washroom 7. A water supply pipe 71 as a water supply source is provided on the rear wall 74 of the washroom 7. A water stop valve 72 is provided at the downstream end of the water supply pipe 71. Moreover, a drain pipe 73 leading to the sewer is provided on the floor 75 of the washroom 7.

[0024] When the flush toilet 1 is installed in the washroom 7, a connection member 6 leading to the water supply passage 3 is connected to the water stop valve 72 via a pipe 61, and a drain trap 76 of the drain pipe 232 leading to the toilet bowl 23 is connected to the drain pipe 73. Communicating the water stop valve 72 with the connection member 6 allows water to be supplied from the water supply pipe 71 (i.e., the water supply source) to the water supply passage 3 of the flush toilet 1.

[0025] The flush toilet 1 includes a toilet body 2, a water supply passage 3, and a backflow check structure 4. In Figure 1 , the direction pointing from the flush toilet 1 to the rear wall 74 of the washroom 7 and aligned with the horizontal plane is defined herein as the "backward direction", and its opposite direction is defined herein as the "forward direction". In addition, the left - right direction is defined herein with respect to a user facing backward in the front of the flush toilet 1.

[0026] The toilet body 2 is the main body of the flush toilet 1. The toilet body 2 includes a plurality of exterior parts 21, interior parts 22, a water storage tank 8 (see Figure 2 ), a toilet seat (not shown), and a toilet lid 26.

[0027] A plurality of exterior members 21 form the outer shell of the flush toilet 1. These exterior members 21 are mounted on a frame (not shown). In this embodiment, the exterior members 21 include a skirt portion 211 that supports the interior member 22 thereon, a rear lower member 213 positioned behind the skirt portion 211, and a rear upper member 212 positioned above the rear lower member 213. The toilet seat and the toilet lid 26 are mounted on the rear upper member 212 so as to be rotatable about an axis parallel to the left-right direction.

[0028] The interior member 22 is disposed inside the space surrounded by the exterior member 21 and the toilet lid 26. The interior member 22 is supported by the upper end portion of the skirt portion 211. As Figure 2 shown, the interior member 22 includes a toilet bowl 23, a drainage portion 25, and a support portion 24.

[0029] The toilet bowl 23 receives excrement (i.e., urine and feces) discharged by the user. The toilet bowl 23 is formed in a cup shape with an open upper end and a lower end portion including a drain pipe 232. The inner surface of the toilet bowl 23 (hereinafter referred to as "the toilet bowl surface 231") slopes downward toward the front end portion of the drain pipe 232. The water discharged from the drainage portion 25 swirls along the toilet bowl surface 231 about an axis parallel to the vertical direction. As Figure 1 shown, the rear end portion of the drain pipe 232 is connected to the drain pipe 73 via a drainage trap 76.

[0030] The drainage trap 76 prevents unpleasant odors from flowing back from the drain pipe 73 toward the toilet bowl, and also prevents, for example, sanitary insects from trying to enter the toilet bowl 23 from the drain pipe 73. The drainage trap 76 can be implemented as a so-called "S-shaped trap", which is an S-shaped pipe, or for example, a removable trap. The removable trap can be, for example, a flexible pipe connected to the drain pipe 232 of the toilet bowl 23. The end of the flexible pipe can switch its state by a motor, for example, from a state where the end faces upward to a state where the end faces downward, and vice versa.

[0031] The drainage portion 25 discharges water onto the toilet bowl surface 231. The drainage portion 25 is adjacent to the opening of the toilet bowl 23. The drainage portion 25 includes a drainage nozzle 251, a pair of upright walls 252, and a drainage port 253.

[0032] The drainage nozzle 251 is a nozzle for discharging the water supplied through the water supply passage 3. The drainage nozzle 251 is disposed between the pair of upright walls 252. The pair of upright walls 252 guides the water discharged from the drainage nozzle 251 so that the water swirls along the toilet bowl surface 231. The drainage port 253 discharges water onto the toilet bowl 23. In this embodiment, the drainage port 253 is an opening surrounded by the front end portion of the inner upright wall 252 of the toilet bowl 23 and a part of the opposite outer upright wall 252 of the toilet bowl 23. Alternatively, the drainage port 253 can also be an opening located at the end of the drainage nozzle 251.

[0033] The support portion 24 extends outward from the outer edge of the opening of the toilet bowl 23. The support portion 24 is supported by the upper end portion of the skirt portion 211. The toilet bowl 23 and the drainage portion 25 are fixed to the external member 21 via the support portion 24.

[0034] The water supply passage 3 guides the water supplied from the water supply source toward the drainage portion 25. The upstream end portion of the water supply passage 3 leads to the connection member 6, while the downstream end portion of the water supply passage 3 leads to the drainage nozzle 251. The water supply passage 3 is provided with a water stop valve (not shown) and a constant flow valve (not shown) so that water flows at a constant flow rate. Thus, even if the water pressure of the water supplied from the water supply source varies to some extent, the water can still be discharged into the toilet bowl 23 through the drainage port 253 at a constant flow rate.

[0035] The water supply passage 3 is provided with a backflow check structure 4. The backflow check structure 4 checks the backflow of the water traveling through the water supply passage 3. Even when the water level of the water accumulated in the toilet bowl 23 rises, for example, to immerse the drainage portion 25 in the risen water, the chance of the water accumulated in the toilet bowl 23 flowing back to the water supply source through the water supply passage 3 can be reduced.

[0036] As Figure 3 、 Figure 4A and Figure 4B shown, the backflow check structure 4 includes a water outlet pipe 40, a water inlet pipe 41, a water receiving wall 5, a splash reducing portion 42, and a covering wall 43.

[0037] The water outlet pipe 40 is a pipe communicating with the water supply source (i.e., the water supply pipe 71) and is used to guide the water supplied from the water supply source toward the water inlet pipe 41. The water outlet pipe 40 is the pipe that introduces water into the backflow check structure 4. The downstream end surface of the water outlet pipe 40 has a water outlet port 400. The water outlet port 400 is an opening through which the water traveling through the water outlet pipe 40 flows out and which guides the water supplied from the water supply source toward the water inlet port 410. The water outlet pipe 40 is supported by a support portion 80 protruding upward from the water storage tank 8. The central axis 401 of the water outlet pipe 40 is aligned with the horizontal plane and intersects at a right angle with the vertical line (in other words, the vertical plane). The inner peripheral surface 402 at one end portion of the water outlet pipe 40 adjacent to the water outlet port 400 is tapered so that its flow passage area decreases as the distance to the water outlet port 400 decreases. This enables an increase in the flow rate of the water flowing out through the water outlet port 400.

[0038] The water inlet pipe 41 is a pipe that receives the water flowing out through the water outlet port 400 and guides the water toward the drainage nozzle 251 (see Figure 2 ). The upstream end portion of the water inlet pipe 41 is connected to the water receiving wall 5. The downstream end portion of the water inlet pipe 41 leads to the drainage nozzle 251 via a hose, for example.

[0039] The upstream end face of the water inlet pipe 41 has a water inlet port 410. The water inlet port 410 is provided through a part of the water receiving wall 5. More specifically, a part of the surface of the water receiving wall 5 facing the water outlet port 400 (i.e., the right surface) is provided with the water inlet port 410.

[0040] The water inlet port 410 communicates with the drain port 253. The central axis 411 of the water inlet pipe 41 is aligned with the horizontal plane and is positioned on the extension line of the central axis 401 of the water outlet pipe 40. That is to say, the water inlet port 410 is arranged on the trajectory of the water flowing out through the water outlet port 400 with at least a predetermined water pressure. The water inlet port 410 is inclined with respect to the central axis 411 of the water inlet pipe 41. The outer peripheral surface of the water inlet port 410 around the opening is inclined downward with respect to the horizontal plane toward the water outlet port 400, so that the part thereof closest to the water outlet port 400 in the left - right direction (in other words, in the direction aligned with the trajectory of the water) is its lowest part. This makes it easier for the water inlet port 410 to receive such water even if the trajectory of the water flowing out through the water outlet port 400 draws a parabola.

[0041] The water receiving wall 5 includes an upper wall portion 50, an intermediate wall portion 51, and a lower wall portion 52. The upper wall portion 50 is parallel to the vertical plane. The intermediate wall portion 51 is continuous with the lower end of the upper wall portion 50 and slopes downward so that its lowest part is positioned at the right end (i.e., closest to the water outlet port 400). The lower wall portion 52 is continuous with the lower end of the intermediate wall portion 51 and is parallel to the vertical plane.

[0042] The intermediate part of the intermediate wall portion 51 in the front - rear direction is provided with the water inlet port 410. The inclination angle formed by the intermediate wall portion 51 with respect to the vertical plane is the same as the inclination angle formed by the outer peripheral edge portion around the opening of the water inlet port 410 with respect to the vertical plane.

[0043] As Figure 4B shown, when viewed from the right, the water receiving wall 5 has a semi - circular shape. Except for the lower end face 520, the outer peripheral portion of the water receiving wall 5 is connected to a third covering wall 432 of the covering wall 43 (described later).

[0044] The part of the water receiving wall 5 positioned below the water inlet port 410 is provided with a water adhesion reduction portion 9 for reducing the chance of water adhering to the lower end face 520 of the water receiving wall 5. In this embodiment, the water adhesion reduction portion 9 is a protruding portion 90 protruding from the lower wall portion 52 of the water receiving wall 5 toward the water outlet port 400 (i.e., to the right). The upper surface of the protruding portion 90 is an inclined surface inclined with respect to the horizontal plane.

[0045] In this embodiment, the protrusion 90 has a rectangular plate shape. The protrusion 90 is inclined such that its front end portion is positioned at the lowest level. The dimension of the protrusion 90 in the front-rear direction is larger than its dimension in the left-right direction. The upper surface of the protrusion 90 is a flat surface and is inclined toward the front end (i.e., such that its front end portion is positioned at the lowest level).

[0046] The front end portion and the rear end portion of the protrusion 90 are spaced apart from the third covering wall 432. The water received at the water receiving wall 5 travels forward along the upper surface of the protrusion 90, and most of it is guided toward the front end portion of the upper surface of the protrusion 90. This makes it easier for the water to fall from the protrusion 90 due to its own weight, thereby reducing the chance of the water adhering to the lower end surface 520 of the water receiving wall 5 due to surface tension.

[0047] The splash reducing portion 42 reduces the chance of the water splashing when the water flowing out through the water outlet port 400 enters the water inlet port 410 from adhering to the water outlet port 400. The splash reducing portion 42 is disposed between the water outlet port 400 and the water inlet port 410. The splash reducing portion 42 includes a first water intercepting plate 44 and a second water intercepting plate 45.

[0048] The first water intercepting plate 44 faces the water receiving wall 5 and the water inlet port 410, and receives the water splashing from the water receiving wall 5. The first water intercepting plate 44 is spaced apart from the water receiving wall 5. An opening 46 is provided between the lower end of the first water intercepting plate 44 and the lower end of the water receiving wall 5. The water received at either the water receiving wall 5 or the first water intercepting plate 44 falls into the water storage tank 8 through the opening 46.

[0049] The first water intercepting plate 44 is aligned with the vertical plane and intersects the central axes 401, 411 of the water outlet pipe 40 and the water inlet pipe 41, respectively (e.g., at a right angle in this embodiment). The first water intercepting plate 44 is provided with a first water through hole 440 penetrating the first water intercepting plate 44. The diameter of the first water through hole 440 is equal to or larger than the diameter of the water outlet port 400 and equal to or smaller than the water inlet port 410.

[0050] The second water intercepting plate 45 faces the water outlet port 400 and the first water intercepting plate 44. The second water intercepting plate 45 not only receives the water that has flowed out through the water outlet port 400 and has bounced back and splashed back from the first water intercepting plate 44, but also receives the water that has flowed out through the water outlet port 400, has bounced back and splashed back from the water receiving wall 5 and then has passed through the first water through hole 440 of the first water intercepting plate 44. The second water intercepting plate 45 is aligned with the vertical plane and intersects the respective central axes 411, 401 of the water inlet pipe 41 and the water outlet pipe 40 (at right angles in this embodiment). That is to say, the second water intercepting plate 45 is parallel to the first water intercepting plate 44. The second water intercepting plate 45 has a second water through hole 450 penetrating through the second water intercepting plate 45. The diameter of the second water through hole 450 is equal to or greater than the diameter of the water outlet port 400 and equal to or less than the water inlet port 410. In this embodiment, the diameter of the second water through hole 450 is equal to the diameter of the first water through hole 440. Alternatively, the diameter of the second water through hole 450 may also be greater than or less than the diameter of the first water through hole 440.

[0051] A peripheral wall portion 47 is provided around each of the first water through hole 440 and the second water through hole 450. The peripheral wall portion 47 projects from at least a part of the circumference of the first water through holes 440, 450 in at least one direction in the left - right direction (in other words, in the direction consistent with the trajectory of the water, towards the water outlet port 400 and / or towards the water inlet port 410). In this embodiment, the peripheral wall portion 47 provided for the first water through hole 440 projects to the left and right sides from the entire circumference of the first water through hole 440. On the other hand, the peripheral wall portion 47 provided for the second water through hole 450 projects only to the right from the entire circumference of the second water through hole 450.

[0052] Alternatively, as long as appropriate, the peripheral wall portion 47 provided for the first water through hole 440 may project only to the left or only to the right from the entire circumference of the first water through hole 440. Moreover, the peripheral wall portion 47 provided for the second water through hole 450 may project only to the left from the entire circumference of the second water through hole 450 or project to both the right and left sides. Alternatively, the peripheral wall portion 47 may also be provided only for a part of the circumference of the water through holes 440, 450.

[0053] The water that has bounced back and splashed back from the water receiving wall 5 towards the first water intercepting plate 44 while the water flowing out through the water outlet port 400 is entering the water inlet port 410 collides with the peripheral wall portion 47 and falls downward. Moreover, even if the water travels along the first water intercepting plate 44, the peripheral wall portion 47 prevents the water from entering the first water through hole 440. Thus, this can reduce the chance of the water flowing out through the water outlet port 400 and bouncing back from the water receiving wall 5 passing through the first water through hole 440 and flowing back towards the water outlet port 400.

[0054] The covering wall 43 reduces the chance that the water flowing out through the water outlet port 400 rebounds from the water receiving wall 5 or the splash reducing portion 42 and splashes toward the outside of the covering wall 43. The covering wall 43 includes a first covering wall 430, a second covering wall 431, and a third covering wall 432.

[0055] The first covering wall 430 connects the end (i.e., the left end) of the water outlet pipe 40 to the second water intercepting plate 45. The first covering wall 430 covers the space between the water outlet pipe 40 and the second water intercepting plate 45 in the front - rear direction and from above and to the right of the space. The second covering wall 431 connects the second water intercepting plate 45 to the end (i.e., the right end) of the peripheral wall portion 47 that protrudes rightward from the first water through - hole 440. The second covering wall 431 covers the space between the second water intercepting plate 45 and the peripheral wall portion 47 in the front - rear direction and from above and to the left of the space. The third covering wall 432 connects the first water intercepting plate 44 to the water receiving wall 5. The third covering wall 432 covers the space between the first water intercepting plate 44 and the water receiving wall 5 in the front - rear direction and from above the space.

[0056] In this embodiment, the third covering wall 432 includes a first portion 432a that protrudes leftward from the first water intercepting plate 44 and a second portion 432b that protrudes rightward from the outer peripheral portion of the water receiving wall 5.

[0057] The first covering wall 430 is integrally formed with the water outlet pipe 40. The first portion 432a of the third covering wall 432, the first water intercepting plate 44, the second covering wall 431, and the second water intercepting plate 45 are integrally formed with each other. The second portion 432b of the third covering wall 432 and the water receiving wall 5 are also integrally formed with each other.

[0058] The second portion 432b of the third covering wall 432, the first covering wall 430, and the first portion 432a of the third covering wall 432 are each provided with a mounting portion 48 that protrudes in the front - rear direction.

[0059] The front - rear mounting portions 48 are mounted on the support portion 80 that protrudes upward from the water storage tank 8. This allows the back - flow check structure 4 to be mounted above the water storage tank 8. The water storage tank 8 is supported by the frame of the toilet body 2 and is covered and hidden behind the rear upper member 212 (see Figure 1 )

[0060] The water that has rebounded from the covering wall 43, the splash reducing portion 42, or the water receiving wall 5 is received at the water storage tank 8. A drain hole 81 is provided at the bottom of the water storage tank 8, and a pipe 82, such as a tube, is connected to the drain hole 81. The pipe 82 can be connected to, for example, the toilet bowl 23. This allows the water received at the water storage tank 8 to flow into the toilet bowl 23. Alternatively, the pipe 82 can also be connected to, for example, the drain trap 76 or the drain pipe 73. Still alternatively, the water received at the water storage tank 8 can also be directly discharged onto the floor 75 of the washroom (see Figure 1)。The water storage tank 8 includes a peripheral wall 83. When viewed in a plane, the backflow check structure 4 is provided inside the peripheral wall 83, as Figure 3 shown.

[0061] The flush toilet 1 includes an overflow portion 84 provided inside the water storage tank 8 in a plan view. The overflow portion 84 has a cylindrical shape and protrudes upward from a region of the bottom surface of the water storage tank 8 that is positioned inside the peripheral wall 83. The overflow portion 84 has an overflow opening 840 at the top. The overflow opening 840 is provided at a level that is higher than the bottom surface of the water storage tank 8 but lower than the upper end of the peripheral wall 83. When the required drainage capacity cannot be satisfied only by the drain hole 81 of the water storage tank 8, the overflow opening 840 discharges the water that has traveled upward inside the peripheral wall 83.

[0062] The water that has entered the overflow opening 840 is allowed to flow onto the floor 75 (see Figure 1 ). Alternatively, the water that has entered the overflow opening 840 can also be made to flow into, for example, the toilet bowl 23, the drain trap 76, or the drain pipe 73.

[0063] 3. Advantages

[0064] When water is supplied to the toilet bowl 23, the flush toilet 1 according to the above exemplary embodiment operates as follows.

[0065] Specifically, when water is supplied from the water supply pipe 71, which is a water supply source, to the water outlet pipe 40, the water is guided toward the water inlet port 410 through the water outlet port 400 of the water outlet pipe 40.

[0066] The water flowing out through the water outlet port 400 passes through the water through-holes 450, 440 of the water intercepting plates 45, 44 and enters the water inlet port 410. At the same time, a part of the water flowing out through the water outlet port 400 can be received at the water receiving wall 5.

[0067] The water received at the water receiving wall 5 travels downward along the surface of the water receiving wall 5 (specifically, its right-facing surface) and reaches the upper surface of the protrusion 90. Then, the water travels along the upper surface of the protrusion 90 and flows forward to be mostly guided toward the front end portion of the upper surface of the protrusion 90. Then the water falls due to its own weight. Thus, the water falling from the front end portion of the upper surface of the protrusion 90 is received by the water storage tank 8 and then discharged through the drain hole 81.

[0068] Thus, the flush toilet 1 according to this embodiment can reduce the chance of water adhering to the lower end surface 520 of the water receiving wall 5 due to surface tension. Therefore, the flush toilet 1 according to this embodiment reduces the occurrence frequency of the above problem that the water flowing out through the water outlet port 400 collides with the water adhering to the lower end surface 520 when the pressure is lower than a predetermined value and causes the adhering water to splash toward the outside of the peripheral wall 83 of the water storage tank 8.

[0069] In addition, in the flush toilet 1 according to this embodiment, the protruding portion 90 protrudes from the lower wall portion 52, which is the lower part of the water receiving wall 5, toward the water outlet port 400. Thus, the protruding portion 90 serves as an eave. This allows the protruding portion 90 to reduce the chance of the water flowing out through the water outlet port 400 reaching the lower end surface 520 of the water receiving wall 5.

[0070] Furthermore, in the flush toilet 1 according to this embodiment, the protruding portion 90 is provided to cover the entire lower wall portion 52 of the water receiving wall 5 except for its front and rear end portions. Thus, it also makes it easier to prevent the water traveling along the surface of the water receiving wall 5 from reaching the lower end surface 520.

[0071] 4. Variations

[0072] Next, variations of the flush toilet 1 according to the above exemplary embodiment will be described in turn. Note that the various variations to be described below can be appropriately combined and employed.

[0073] The water adhesion reducing portion 9 only needs to be configured to reduce the adhesion of water to the lower end surface 520 of the water receiving wall 5 due to surface tension, and does not have to have Figure 4B the structure shown.

[0074] Alternatively, as in Figure 5A the first variation shown, the water adhesion reducing portion 9 may include a protruding portion 90, the upper surface of which includes two surfaces inclined with respect to the horizontal plane. In the first variation, the upper surface of the protruding portion 90 has a vertex at a point in the front-rear direction. The upper surface of the protruding portion 90 includes a surface inclined downward toward the front end as a part located in front of the vertex and a surface inclined downward toward the rear end as the other part located behind the vertex.

[0075] Alternatively, as in Figure 5B the second variation shown, the water adhesion reducing portion 9 may also include two protruding portions 91, 92, each protruding from the lower wall portion 52 toward the water outlet port 400. These two protruding portions 91, 92 are arranged to be spaced apart from each other in the front-rear direction. The upper surface of the front protruding portion 91 is an inclined surface inclined downward toward the rear end with respect to the horizontal plane. The upper surface of the rear protruding portion 92 is an inclined surface inclined downward toward the front end with respect to the horizontal plane. The second variation makes it easier for the water adhering to the surface of the water receiving wall 5 to travel along the respective upper surfaces of the two protruding portions 91, 92, and most of it is guided toward the gap between the two protruding portions 91, 92 and falls through the gap.

[0076] Alternatively, as in Figure 5CIn the third modification shown, the water adhesion reducing portion 9 may also be the lower end surface 520 of the water receiving wall 5 that is inclined with respect to the horizontal plane. In the third modification, the lower end surface 520 of the water receiving wall 5 is inclined such that its front end portion is positioned at the lowest level. This makes it easier for the water that has been received at the water receiving wall 5 and has reached the lower end surface 520 of the water receiving wall 5 to flow forward along the lower end surface 520, and most of the water is guided toward the front end portion of the lower end surface 520 and falls from this front end portion.

[0077] Alternatively, as Figure 5D shown in the fourth modification, the water adhesion reducing portion 9 may also be a waterproof surface 93 provided on the water receiving wall 5. In the fourth modification, the surface of the lower wall portion 52 of the water receiving wall 5 (specifically, its right-facing surface) is the waterproof surface 93. Additionally, the lower end surface 520 of the water receiving wall 5 may also be the waterproof surface 93. The waterproof surface 93 can be formed by any suitable known method. For example, the waterproof surface 93 can be formed by providing microscopic unevenness on the surface of the lower wall portion 52. Alternatively, the waterproof surface 93 can also be formed by applying a waterproof coating to the surface of the lower wall portion 52 or fixing a waterproof sheet to the surface of the lower wall portion 52.

[0078] Optionally, the water adhesion reducing portion 9 according to Figure 4B the exemplary embodiment shown and the water adhesion reducing portion 9 according to Figures 5A to 5D the first to fourth modifications shown can be appropriately combined and employed.

[0079] The protrusions 90, 91, 92 only need to have an upper surface that is inclined with respect to the horizontal plane and do not have to have a plate shape.

[0080] Furthermore, as long as the protrusions 90, 91, 92 have an upper surface that is inclined with respect to the horizontal plane, the upper surface of the protrusion 90 does not have to be inclined downward toward the front end or the rear end, but can also be inclined downward to the right end (specifically, inclined such that the portion closest to the water outlet port 400 is positioned at the lowest level). Similarly, the lower end surface 520 of the water receiving wall 5 does not have to be inclined downward toward the front end, but can also be inclined downward toward the rear end, the right end, or the left end.

[0081] In addition, the upper surfaces of the protrusions 90, 91, 92 do not have to be flat surfaces, but can also be surfaces with height differences. The upper surfaces of the protrusions 90, 91, 92 only need to have such a shape that causes the water adhering to the upper surfaces of the protrusions 90, 91, 92 to travel downward and flow toward the lower end portions of the upper surfaces of the protrusions 90, 91, 92. Similarly, the lower end surface 520 of the water receiving wall 5 does not have to be a flat surface, but can also be a surface with height differences.

[0082] In the above exemplary embodiment, the openings surrounded by the outer peripheral edges of the water inlet port 410 and the openings surrounded by the outer peripheral edges of the water outlet port 400 are arranged such that their respective central axes are aligned with each other. However, this is merely an example and should not be construed as restrictive. Alternatively, if the water flowing out through the water outlet port 400 draws a parabola, the water inlet port 410 can be positioned on the parabola.

[0083] 5. Restatement

[0084] As can be seen from the foregoing description of the exemplary embodiment and its variations, the flush toilet (1) according to the first aspect has the following configuration:

[0085] Specifically, the flush toilet (1) according to the first aspect includes: a toilet bowl (23) for receiving excrement; a drain port (253) for discharging water into the toilet bowl (23); and a water supply passage (3) for supplying water from a water supply source to the drain port (253) therethrough. The flush toilet (1) according to the first aspect further includes a backflow check structure (4) provided for the water supply passage (3) and configured to check the backflow of water traveling through the water supply passage (3). The backflow check structure (4) has: a water inlet port (410) communicating with the drain port (253); a water receiving wall (5) through which the water inlet port (410) is provided in a part of the water receiving wall (5); and a water outlet port (400) for guiding the water supplied from the water supply source toward the water inlet port (410). The water outlet port (400) is spaced apart from the water inlet port (410) and the water receiving wall (5). A water adhesion reducing portion (9) is provided in a part of the water receiving wall (5) positioned below the water inlet port (410). The water adhesion reducing portion (9) reduces the chance of water adhering to the lower end surface (520) of the water receiving wall (5).

[0086] In the flush toilet (1) according to the first aspect having such a configuration, the water adhesion reducing portion (9) can reduce the chance of water adhering to the lower end surface (520) of the water receiving wall (5) when the water receiving wall (5) receives a part of the water flowing out through the water outlet port (400). Thus, the flush toilet (1) according to the first aspect can reduce the chance of the water flowing out through the water outlet port (400) colliding with the water adhering to the lower end surface (520) of the water receiving wall (5) and splashing the adhered water everywhere. Therefore, the flush toilet (1) according to the first aspect can reduce the splashing of water in the backflow check structure (4).

[0087] As can be seen from the foregoing description of the exemplary embodiment and its variations, the flush toilet (1) according to the second aspect has the following additional configuration, which can be implemented in combination with the configuration of the flush toilet (1) according to the first aspect:

[0088] Specifically, in the flush toilet (1) according to the second aspect, the water adhesion reduction part (9) is a protruding part (90) protruding from the water receiving wall (5) toward the water outlet port (400). The upper surface of the protruding part (90) is an inclined surface inclined with respect to the horizontal plane.

[0089] In the flush toilet (1) according to the second aspect having such a structure, the inclined upper surface of the protruding part (90) protruding from the water receiving wall (5) toward the water outlet port (400) allows most of the water received at the water receiving wall (5) to be guided toward the lower end part of the upper surface of the protruding part (90). Thus, the flush toilet (1) according to the second aspect makes it easier for the water received at the water receiving wall (5) to fall.

[0090] As can be seen from the foregoing description of the exemplary embodiments and their variations, the flush toilet (1) according to the third aspect has the following additional structure, which can be implemented in combination with the structure of the flush toilet (1) according to the second aspect:

[0091] Specifically, in the flush toilet (1) according to the third aspect, the backflow check structure (4) further includes a covering wall (43) provided to surround the water receiving wall (5). The protruding part (90) is spaced apart from the covering wall (43).

[0092] In the flush toilet (1) according to the third aspect having such a structure, the covering wall (43) can prevent the water that has been guided from the water outlet port (400) toward the water inlet port (410) and has collided with the water receiving wall (5) from splashing toward the outside of the water receiving wall (5). In addition, the flush toilet (1) according to the third aspect also allows the water traveling downward from the upper surface of the protruding part (90) to fall through the gap between the protruding part (90) and the covering wall (43). That is, the covering wall (43) does not impede the fall of water from the protruding part (90).

[0093] As can be seen from the foregoing description of the exemplary embodiments and their variations, the flush toilet (1) according to the fourth aspect has the following additional structure, which can be implemented in combination with the structure of the flush toilet (1) according to any one of the first to third aspects:

[0094] Specifically, in the flush toilet (1) according to the fourth aspect, the water adhesion reduction part (9) is the lower end surface (520) of the water receiving wall (5). The lower end surface (520) is inclined with respect to the horizontal plane.

[0095] The flush toilet (1) according to the fourth aspect having such a structure causes the water that has been received at the water receiving wall (5) and has reached the lower end surface (520) of the water receiving wall (5) to be guided mostly downward along the inclined lower end surface (520) and to fall smoothly.

[0096] As can be seen from the foregoing description of the exemplary embodiments and their variations, the flush toilet (1) according to the fifth aspect has the following additional configurations, which can be implemented in combination with the configuration of the flush toilet (1) according to any one of the first to fourth aspects:

[0097] Specifically, in the flush toilet (1) according to the fifth aspect, the water adhesion reduction portion (9) is a waterproof surface (93) provided on the water receiving wall (5).

[0098] In the flush toilet (1) according to the fifth aspect having such a configuration, the waterproof surface (93) makes the water received at the water receiving wall (5) more likely to fall.

[0099] Note that the embodiments described above with reference to the accompanying drawings are only exemplary embodiments among the various embodiments of the present disclosure and should not be construed as restrictive. On the contrary, without departing from the scope of the present disclosure, the exemplary embodiments can be easily modified in various ways as appropriate depending on design choices or any other factors.

[0100] List of Reference Numerals

[0101] 1 Flush toilet

[0102] 23 Toilet bowl

[0103] 253 Drain port

[0104] 3 Water supply passage

[0105] 4 Backflow check structure

[0106] 400 Water outlet port

[0107] 410 Water inlet port

[0108] 5 Water receiving wall

[0109] 520 Lower end surface

[0110] 43 Covering wall

[0111] 9 Water adhesion reduction portion

[0112] 90 Protrusion

[0113] 93 Waterproof surface

Claims

1. Flushing toilet, comprising: A toilet bowl configured to receive excrement; A drain port configured to discharge water into the toilet bowl; A water supply passage configured to supply water from a water supply source to the drain port therethrough; And A backflow check structure provided for the water supply passage and configured to check the backflow of water traveling through the water supply passage, The backflow check structure having: An inlet port communicating with the drain port; A water receiving wall, the inlet port being provided through the water receiving wall in a part of the water receiving wall; And An outlet port spaced from the inlet port and the water receiving wall and configured to guide water supplied from the water supply source toward the inlet port, The water receiving wall is provided with a water adhesion reduction portion in a part thereof positioned below the inlet port, and the water adhesion reduction portion is configured to reduce the chance of water adhering to the lower end surface of the water receiving wall.

2. The flushing toilet according to claim 1, wherein The water adhesion reduction portion is a protruding portion protruding from the water receiving wall toward the outlet port, and The upper surface of the protruding portion is an inclined surface inclined with respect to the horizontal plane.

3. The flushing toilet according to claim 2, wherein The backflow check structure further includes a covering wall provided to surround the water receiving wall, and The protruding portion is spaced from the covering wall.

4. The flushing toilet according to any one of claims 1 to 3, wherein The water adhesion reduction portion is the lower end surface of the water receiving wall, and the lower end surface is inclined with respect to the horizontal plane.

5. The flushing toilet according to any one of claims 1 to 3, wherein The water adhesion reduction portion is a waterproof surface provided on the water receiving wall.

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