Flush toilet

Abstract

To provide a water closet which can suppress residence of dirt in a pot part of a toilet bowl body so as to improve dirt discharge performance.SOLUTION: A water closet 1 has a bowl part 6 comprising a dirt receiving surface 14, and a pot part 12, and a drain trap part 8 comprising an entrance 30 connected to the lower part of the pot part and draining dirt in the bowl part. The pot part comprises a bottom wall 32 formed at the upper side and the front side of the entrance in the drain trap part, a rear wall 34 installed at the rear side of the entrance in drain trap part, and side walls 36 and 38 formed so as to surround the periphery of the bottom wall. The entrance in the drain trap part comprises a rear end 30a connected to the bottom edge of the rear wall in the pot part, and a front end 30b connected to a rear end 56c on the lateral center in the bottom wall of the pot part, and the front end 30b in the entrance of the drain trap part is installed in a position lower than the rear end 30a in the entrance of the drain trap part.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to a flushing toilet, and more particularly to a flushing toilet that is washed with washing water to discharge dirt.

Background Art

[0002] Conventionally, as a flushing toilet that is washed with washing water to discharge dirt, for example, as described in Patent Document 1, the toilet body has a bowl-shaped dirt receiving surface and a pot portion that is provided below the dirt receiving surface and forms a water storage portion with the stored water. There is known one having a bowl portion. Further, in such a conventional flushing toilet, the toilet body has a drain trap portion provided with an inlet portion connected below the pot portion, and dirt in the bowl portion can be discharged from the drain trap portion. Furthermore, the pot portion of the toilet body includes a rear wall portion extending in the left-right direction, rear side wall portions provided so as to spread outward in the left and right directions from both left and right ends of the rear wall portion, and left and right front ends of the rear side wall portions. A front side wall portion provided so as to narrow inward in the left and right directions and having their front ends joined to each other. In plan view, it generally forms a pentagonal shape. In this way, since the pot portion generally forms a pentagonal shape in plan view, a large volume can be secured in the rear region of the pot portion, so that a large amount of stored water can be secured in the water storage portion, and the water seal of the bowl portion is less likely to break.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional flushing toilet described in Patent Document 1 mentioned above, after the washing water swirling on the dirt receiving surface flows into the pot part from the front side of the pot part, a part of this washing water flows along the bottom surface of the bottom wall part of the pot part to the front side, and thus flows from the front end part side to the rear end part side of the inlet part of the drain trap part. At this time, the front end part of the inlet part of the drain trap part provided at the rear end of the left - right center in the bottom wall part of the pot part and the rear end part of the inlet part of the drain trap part provided at the lower end of the rear wall part of the pot part are provided at substantially the same height position. As a result, a part of the washing water flowing forward along the bottom surface of the bottom wall part of the pot part collides with the rear wall part of the pot part and bounces back without flowing into the inlet part of the drain trap part, and stays in the pot part. Therefore, there is a problem of reducing the dirt discharge performance (discharging force). Therefore, in recent years, there has been a problem of how to improve the dirt discharge performance by suppressing the retention of dirt in the pot part and smoothly guiding the dirt to the drain trap part.

[0005] Therefore, the present invention has been made to solve the problems of the above - described conventional technology and the problems demanded in recent years, and an object thereof is to provide a flushing toilet that can suppress the retention of dirt in the pot part of the toilet body and improve the dirt discharge performance.

Means for Solving the Problems

[0006] In order to solve the above-described problems, the present invention provides a water-washed toilet that is washed with washing water to discharge dirt, comprising a bowl-shaped dirt receiving surface, and a pot portion provided below the dirt receiving surface and forming a water storage portion with the stored water, a bowl portion having the pot portion; a drain trap portion connected to the lower part of the pot portion and having an inlet for discharging dirt in the bowl portion, the pot portion including a bottom wall formed above and in front of the inlet of the drain trap portion, a rear wall provided on the rear side of the inlet of the drain trap portion, and a side wall formed so as to surround the periphery of the bottom wall, the inlet of the drain trap portion including a rear end joined to the lower end of the rear wall of the pot portion and a front end joined to the rear end at the left-right center of the bottom wall of the pot portion. The front end of the inlet of the drain trap portion is provided at a position lower than the rear end of the inlet of the drain trap portion. In the present invention configured as described above, the washing water discharged from the water spraying portion into the bowl portion flows from the dirt receiving surface into the pot portion. At this time, the washing water flowing from the dirt receiving surface above and in front of the pot portion into the front region of the pot portion is guided from the front region of the pot portion along the bottom surface of the bottom wall of the pot portion toward the front end side of the inlet of the drain trap portion joined to the rear end at the left-right center thereof. At this time, since the front end of the inlet of the drain trap portion is provided at a position lower than the rear end of the inlet of the drain trap portion, a structure having a height difference with the front side being low and the rear side being high can be formed at the inlet of the drain trap portion. Therefore, the washing water containing dirt flowing from the front region of the pot portion to the vicinity of the front end of the inlet of the drain trap portion can smoothly pass through the rear end of the inlet of the drain trap portion without stagnating when flowing toward the drain trap portion on the rear side, and can smoothly flow into the drain trap portion. Therefore, since the dirt in the bowl portion can be smoothly guided to the drain trap portion, the dirt discharge performance (discharge force) in the water-washed toilet can be improved.

[0007] In the present invention, preferably, the bottom wall has a bottom surface that includes, in a side cross-sectional view, a first tangent line that extends in the front-rear direction along the bottom surface from the rear end of the bottom wall, and a first tangent line extension portion obtained by extending the first tangent line rearward from the rear end. The first tangent line extension portion is set to pass through a height position lower than the height position of the rear end of the inlet of the drain trap portion at the same front-rear direction position with respect to the rear end of the inlet of the drain trap portion in a side cross-sectional view. In the present invention configured as described above, the washing water containing dirt that flows from the front region in the pot portion along the bottom surface of the bottom wall to the vicinity of the front end of the inlet of the drain trap portion flows toward the drain trap portion on the rear side thereof. At this time, since the first tangent line extension portion of the first tangent line on the bottom surface of the bottom wall of the pot portion passes through a height position lower than the height position of the rear end of the inlet of the drain trap portion at the same front-rear direction position with respect to the rear end of the inlet of the drain trap portion in a side cross-sectional view, it can pass smoothly without stagnating at the rear end of the inlet of the drain trap portion and can flow smoothly into the drain trap portion. Therefore, since the dirt in the bowl portion can be smoothly guided to the drain trap portion, the dirt discharge performance (discharge force) in the flush toilet can be improved.

[0008] In the present invention, preferably, the dirt receiving surface includes, in a side cross-sectional view, a second tangent line that extends in the front-rear direction along the dirt receiving surface, and a second tangent line extension portion obtained by extending the second tangent line rearward from the lower edge of the dirt receiving surface. The first tangent line extension portion and the second tangent line extension portion are set to be substantially parallel to each other in a side cross-sectional view. In the present invention configured as described above, the washing water discharged into the bowl portion from the water spraying portion flows into the pot portion from the dirt receiving surface. At this time, since the first tangent extension of the bottom surface on the bottom wall of the pot part and the second tangent extension of the dirt receiving surface are set to be substantially parallel to each other in a side cross-sectional view, in particular, the washing water flowing from the dirt receiving surface in front of and above the pot part into the front area inside the pot part can merge with the washing water containing dirt flowing along the bottom surface of the bottom wall to the vicinity of the front end of the inlet of the drain trap part from the front area inside the pot part. As a result, the washing water flowing from the front area inside the pot part along the bottom surface of the bottom wall toward the inlet of the drain trap part on the rear side can directly flow into the drain trap part from the inlet of the drain trap part in a state where the water potential is increased. As a result of these, since the washing water containing dirt in the bowl part can be smoothly guided from the dirt receiving surface through the pot part to the drain trap part, both the washing performance (washing power) and the dirt discharge performance (discharge power) in the water-washed toilet can be improved.

[0009] In the present invention, preferably, the drain trap part includes, in a side cross-sectional view, a protruding part provided above the rear end of its inlet and protruding forward, and a trap pipe line extending from this protruding part to the lowermost end part behind and below, and then extending from this lowermost end part behind and above, and in the trap pipe line from the protruding part to the lowermost end part of the drain trap part, the upper surface shape in its side cross-sectional view is formed in a substantially planar shape. In the present invention formed in this way, since the upper surface shape in the trap pipe line from the protruding part provided above the rear end of the inlet in the drain trap part to the lowermost end part behind and below is formed in a substantially planar shape, the washing water flowing from the front area inside the pot part along the bottom surface of the bottom wall to the rear side is smoothly guided to the downstream side along the trap pipe line from the protruding part above the rear end of the inlet of the drain trap part to the lowermost end part of the trap pipe line when flowing into the trap pipe line from the inlet of the drain trap part. At this time, the washing water flowing through the trap pipe from the protruding portion to the lowermost end portion at the rear and below smoothly flows along the upper surface having a substantially planar shape in the side cross-sectional view of the trap pipe, so that the washing water collides with the upper surface in the trap pipe from the protruding portion to the lowermost end portion at the rear and below. The pressure loss caused by this can be suppressed. As a result, the dirt in the bowl portion can be smoothly discharged from the drainage trap portion, so that the dirt discharge performance (discharge force) in the flush toilet can be improved.

[0010] In the present invention, preferably, the bowl portion further includes a joint portion that joins the upper edge of the side wall of the pot portion and the lower edge of the dirt receiving surface with a surface having a curvature, and the vertical width of the joint portion in the side cross-sectional view is set to decrease from the rear side to the front side. In the present invention formed in this way, since the vertical width of the joint portion that joins the upper edge of the side wall of the pot portion and the lower edge of the dirt receiving surface with a surface having a curvature decreases from the rear side to the front side in the side cross-sectional view, the pot portion and the dirt receiving surface can be made closer to each other in the vertical direction from the rear side to the front side. Therefore, particularly for the dirt in the front region on the dirt receiving surface, the washing water discharged from the water spraying portion onto the dirt receiving surface can be efficiently conveyed to the front region in the pot portion, so that both the washing performance (washing power) and the dirt discharge performance (discharge force) in the flush toilet can be improved.

Effect of the Invention

[0011] According to the flush toilet of the present invention, the retention of dirt in the pot portion of the toilet body can be suppressed, and the dirt discharge performance can be improved.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 4C

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, with reference to FIGS. 1 to 10, a water-washed toilet according to an embodiment of the present invention will be described. First, FIG. 1 is a schematic plan view of a water-washed toilet according to an embodiment of the present invention. FIG. 2 is a side sectional view taken along line II-II of FIG. 1. As shown in FIGS. 1 and 2, the water-washed toilet 1 according to an embodiment of the present invention includes a toilet body 2 made of pottery. This toilet body 2 includes a water guide passage 4, a bowl-shaped bowl portion 6, and a drain trap portion 8 from the upstream side to the downstream side. Thus, the water-washed toilet 1 according to an embodiment of the present invention is a so-called "siphon type water-washed toilet" that uses the siphon action to suck the dirt in the bowl portion 6 and discharge it to the outside at once from the drain trap portion 8. Note that the water-washed toilet 1 according to an embodiment of the present invention is not limited to the form of a siphon type water-washed toilet, and is also applicable to the form of a so-called "washing-down type water-washed toilet" that flushes the dirt by the flowing water action due to the water level difference in the bowl portion.

[0014] In addition, in the water-washed toilet 1 of the present embodiment shown in FIGS. 1 and 2, a toilet seat (not shown), a toilet lid (not shown), etc. are provided on the upper surface of the toilet body 2. However, since it is the same as the structure of a conventional water-washed toilet, a specific description thereof will be omitted. Furthermore, on the rear side of the toilet seat (not shown) and the toilet lid (not shown) on the upper surface of the toilet body 2, there may be provided functional parts (not shown) such as a sanitary washing part (not shown) for washing the user's private parts and a water supply system functional part related to the water supply function to the toilet body 2. However, since these are also the same as the structure of a conventional water-washed toilet, a specific description thereof will be omitted.

[0015] Next, as shown in FIG. 1, the flushing toilet 1 according to an embodiment of the present invention includes a gravity-fed water storage tank 10 which is a cleaning water source that stores the cleaning water used for toilet flushing and supplies water to the toilet body 2. Here, in the present embodiment, the cleaning water source for supplying the cleaning water to the toilet body 2 is not limited to the tank type such as the above-described gravity-fed water storage tank 10, and other forms are also applicable. That is, as the cleaning water source for supplying the cleaning water to the toilet body 2, a direct water pressure type using the water supply pressure of tap water or a flush valve type may be used, or a form in which the cleaning water is supplied using the pressure boost of a pump may also be used.

[0016] Next, in the flushing toilet 1 according to an embodiment of the present invention shown in FIG. 1, in a plan view of the bowl portion 6 of the toilet body 2, a central axis extending in the horizontal left-right direction so as to bisect the pot portion 12 provided at the left and right centers of the bowl portion 6 in the front-rear direction is indicated by the symbol "X". Also, in a plan view of the bowl portion 6 of the toilet body 2 shown in FIG. 1, a central axis extending in the horizontal front-rear direction so as to bisect the bowl portion 6 in the left-right direction is indicated by the symbol "Y". Furthermore, in a plan view of the bowl portion 6 of the toilet body 2 shown in FIG. 1, the intersection of the respective central axes X and Y is defined as the center O of the bowl portion 6 in the plan view, and a central axis extending in the vertical direction passing through this center O is indicated by the symbol "Z" in FIGS. 1 and 2. Also, as shown in FIG. 1, with respect to the front, rear, left, and right directions of the flushing toilet 1, they are respectively indicated by "front", "rear", "left", and "right".

[0017] Furthermore, as shown in FIGS. 1 and 2, in the flushing toilet 1 of the present embodiment, regarding the region inside the bowl portion 6, the region on the front side of the central axis X is defined as the "front region F of the bowl portion 6". Also, in the front region F of the bowl portion 6, the left region L and the right region R with respect to the central axis Y in the horizontal front-rear direction of the bowl portion 6 are respectively defined as the "left front region LF of the bowl portion 6" and the "right front region RF of the bowl portion 6". Similarly, for the region within the bowl portion 6, the region on the rear side of the central axis line X is defined as the "rear region B of the bowl portion 6". Further, in this rear region B of the bowl portion 6, the left region L and the right region R with respect to the central axis line Y in the horizontal front-rear direction of the bowl portion 6 are respectively defined as the "left rear region LB of the bowl portion 6" and the "right rear region RB of the bowl portion 6".

[0018] Next, as shown in FIG. 1, the water guide path 4 located on the upstream side of the toilet body 2 is formed on the rear side of the bowl portion 6 and is configured to guide the washing water supplied from the water storage tank 10 to the bowl portion 6. Also, as shown in FIGS. 1 and 2, the bowl portion 6 located on the downstream side of the water guide path 4 of the toilet body 2 includes a pot portion 12, a dirt receiving surface 14, a shelf portion 16, and a rim portion 18, the details of which will be described later, extending from the bottom upward. Furthermore, a first rim water discharge port 20 is provided on the front side of the rim portion 18 in the left rear region LB of the bowl portion 6, and a second rim water discharge port 22 is provided on the rear side of the rim portion 18 in the right rear region RB of the bowl portion 6.

[0019] Next, as shown in FIGS. 1 and 2, the water guide path 4 includes a common water guide path 24, a first rim water guide path 26, and a second rim water guide path 28. First, the common water guide path 24 is formed inside the toilet body 2 on the rear side of the bowl portion 6 so as to extend from the rear inlet 4a connected to the water storage tank 10 to the vicinity of the back surface side of the front bowl portion 6. Also, the first rim water guide path 26 branches from the common water guide path 24 to the left side of the bowl portion 6 in the vicinity of the back surface side of the bowl portion 6, and then extends to the first rim water discharge port 20 on the front side while bypassing the outer peripheral surface of the bowl portion 6, and is formed inside the rim portion 18 in the left rear region LB of the bowl portion 6. Thereby, the washing water supplied from the common water guide path 24 to the first rim water guide path 26 is discharged forward as the first rim water discharge from the first rim water discharge port 20 toward the shelf portion 16 on the front side thereof, and then forms a swirling flow that swirls from the left front region LF in the bowl portion 6 through the right front region RF to the right rear region RB.

[0020] Furthermore, the second rim water channel 28 branches from the common water channel 24 near the back side of the bowl portion 6 to the right side of the bowl portion 6, and then bends (U-turns) toward the second rim water outlet 22 on the left side near the right side portion of the toilet body 2, and is formed inside the rear side of the rim portion 18 in the right rear region RB of the bowl portion 6 so as to extend to the second rim water outlet 22. Thereby, the washing water supplied from the common water channel 24 to the second rim water channel 28 is discharged rearward as the second rim water discharge from the second rim water outlet 22 toward the shelf portion 16 on the rear side thereof, and then turns from the right rear region RB in the bowl portion 6 through the left rear region LB to the left front region LF, and then flows from this left front region LF into the front region in the flushing water tank portion 12. Also, a part of the second rim water discharge discharged from the second rim water outlet 22 also flows from the dirt receiving surface 14 in the region behind the flushing water tank portion 12 of the bowl portion 6 into the rear region in the flushing water tank portion 12. In addition, in the present embodiment, a form in which the shelf portion 16 of the bowl portion 6 is provided between the outer edge of the dirt receiving surface 14 and the lower end of the rim portion 18 will be described, but it is not always necessary to provide the shelf portion 16, and this shelf portion 16 may be omitted, and the first rim water discharge and the second rim water discharge discharged from the first rim water outlet 20 and the second rim water outlet 22, respectively, may be directly discharged to the upper edge portion of the dirt receiving surface 14 without passing through the shelf portion 16.

[0021] Next, with reference to FIGS. 1 to 8B, details of the flushing water tank portion 12 of the bowl portion 6 and its peripheral portion will be described. First, FIG. 3A is an enlarged side cross-sectional view of the flushing water tank portion of the toilet body, which is an enlarged view of the portion of the flushing water tank portion of the toilet body according to an embodiment of the present invention shown in FIG. 2. FIG. 3B is an enlarged side cross-sectional view of the front portion of the flushing water tank portion of the toilet body according to an embodiment of the present invention shown in FIG. 3A. Next, FIGS. 4A to 4C are cross-sectional views taken along the lines IVA - IVA, IVB - IVB, and IVC - IVC of FIG. 2, respectively. Further, FIG. 5A is a cross-sectional view taken along line VA-VA of FIG. 2, and FIG. 5B is an enlarged cross-sectional view of the pot portion of the bowl portion in the toilet body of the flushing toilet according to an embodiment of the present invention shown in FIG. 5A. Furthermore, FIG. 6A is a cross-sectional view taken along line VIA-VIA of FIG. 2, and FIG. 6B is an enlarged cross-sectional view of the pot portion of the bowl portion in the toilet body of the flushing toilet according to an embodiment of the present invention shown in FIG. 6A. Also, FIG. 7A is a cross-sectional view taken along line VIIA-VIIA of FIG. 2, and FIG. 7B is an enlarged cross-sectional view of the pot portion of the bowl portion in the toilet body of the flushing toilet according to an embodiment of the present invention shown in FIG. 7A. Furthermore, FIG. 8A is a cross-sectional view taken along line VIIIA-VIIIA of FIG. 2, and FIG. 8B is an enlarged cross-sectional view of the pot portion of the bowl portion in the toilet body of the flushing toilet according to an embodiment of the present invention shown in FIG. 8A.

[0022] First, as shown in FIGS. 2 and 3A, the pot portion 12 of the bowl portion 6 is provided below the dirt receiving surface 14, and forms a water storage portion W0 by the stored standing water. Here, in FIGS. 2 and 3A, the water level (sealing water level) of the standing water surface of the water storage portion W0 of the pot portion 12 of the bowl portion 6 in the standby state (sealing water state) before toilet flushing is indicated by the symbol "WL". Next, as shown in FIGS. 3A to 8B, the pot portion 12 is provided above and in front of the inlet 30 of the drain trap portion 8 and includes a bottom wall 32 that forms the bottom surface 32a of the pot portion 12. The pot portion 12 also includes a rear wall 34 (left rear wall 34a and right rear wall 34b) provided on the rear side of the inlet 30 of the drain trap portion 8. Furthermore, the pot portion 12 includes side walls 36 (rear side wall 36, rear left side wall 36a, rear right side wall 36b) provided so as to spread outward to the left and right forward from both left and right ends of the rear wall 34 (left end of the left rear wall 34a and right end of the right rear wall 34b). Further, the pot portion 12 is provided so as to narrow inward in the left and right directions from the left and right front ends of the rear side wall 36 (the front ends of the rear left side wall 36a and the rear right side wall 36b) toward the front, and includes side walls 38 (front side wall 38, front left side wall 38a, front right side wall 38b) whose front ends are joined to each other.

[0023] Next, as shown in FIGS. 3A, 3B, 5B, 6B, 7B, and 8B, the pot portion 12 further includes a lower joint portion 40 that joins the outer edge 32b of the bottom surface 32a of the bottom wall 32 and the lower edges 36c, 38c of the side walls 36, 38 with a surface having a curvature (curved surface C1). Also, in the side cross-sectional views of FIGS. 3A and 3B, and in the front cross-sectional views of FIGS. 5B, 6B, 7B, and 8B, the curvature of the curved surface C1 in the section between the lower edge 40a and the upper edge 40b of the lower joint portion 40 is set to be larger than the curvature of the tangent plane C2 including the bottom surface 32a at the lower joint point P1 that joins the lower edge 40a of the lower joint portion 40 (the lower edge 40a of the curved surface C1) and the outer edge 32b of the bottom surface 32a of the bottom wall 32. Similarly, in the side cross-sectional views of FIGS. 3A and 3B, and in the front cross-sectional views of FIGS. 5B, 6B, 7B, and 8B, the curvature of the curved surface C1 of the lower joint portion 40 is set to be larger than the curvature of the tangent plane C3 including the wall surfaces of the side walls 36, 38 at the upper joint point P2 that joins the upper edge 40b of the lower joint portion 40 (the upper edge 40b of the curved surface C1) and the lower edges 36c, 38c of the side walls 36, 38.

[0024] Next, as shown in FIGS. 3A, 3B, 5B, 6B, 7B, and 8B, the pot portion 12 further includes an upper joint portion 42 that joins the upper edges 36d, 38d of the side walls 36, 38 and the lower edge 14a of the dirt receiving surface 14 with a surface having a curvature (curved surface C4). Also, in the side cross-sectional views of FIGS. 3A and 3B and the front cross-sectional views of FIGS. 5B, 6B, 7B, and 8B, the curvature of the curved surface C4 in the section between the lower edge 42a and the upper edge 42b of the upper joint portion 42 is set to be larger than the curvature of the tangent plane C5 including the wall surfaces of the side walls 36 and 38 at the lower joint point P3 that joins the lower edge 42a (the lower edge 42a of the curved surface C4) of the upper joint portion 42 and the upper edges 36d and 38d of the side walls 36 and 38. Similarly, in the side cross-sectional views of FIGS. 3A and 3B and the front cross-sectional views of FIGS. 5B, 6B, 7B, and 8B, the curvature of the curved surface C4 of the upper joint portion 42 is set to be larger than the curvature of the tangent plane C6 including the wall surface of the dirt receiving surface 14 at the upper joint point P4 that joins the upper edge 42b (the upper edge 42b of the curved surface C4) of the upper joint portion 42 and the lower edge 14a of the dirt receiving surface 14.

[0025] Here, in the flushing toilet 1 of the present embodiment shown in FIGS. 1 to 4C, the boundary line between the bottom wall 32 of the pot portion 12 and the lower joint portion 40, which corresponds to the outer edge 32b of the bottom wall 32 of the pot portion 12 and the lower edge 40a of the lower joint portion 40, is indicated by the symbol "L1". Also, the boundary line between the lower joint portion 40 of the pot portion 12 and the side walls 36 and 38, which corresponds to the upper edge 40b of the lower joint portion 40 of the pot portion 12 and the lower edges 36c and 38c of the side walls 36 and 38, is indicated by the symbol "L2". Furthermore, the boundary line between the side walls 36 and 38 of the pot portion 12 and the upper joint portion 42, which corresponds to the upper edges 36d and 38d of the side walls 36 and 38 of the pot portion 12 and the lower edge 42a of the upper joint portion 42, is indicated by the symbol "L3". Also, the boundary line between the upper joint portion 42 of the pot portion 12 and the dirt receiving surface 14, which corresponds to the upper edge 42b of the upper joint portion 42 of the pot portion 12 and the lower edge 14a of the dirt receiving surface 14, is indicated by the symbol "L4".

[0026] Furthermore, as shown in FIGS. 3A and 3B, the vertical distance between the pot portion 12 and the dirt receiving surface 14 (the vertical distance between the boundary line L3 and the boundary line L4 shown in FIG. 3A) corresponds to the vertical width H1 from the lower edge 42a to the upper edge 42b in the side view of the upper joint portion 42, and this vertical width H1 is set to decrease from the rear side to the front side of the pot portion 12. As a result, the pot portion 12 and the dirt receiving surface 14 can be brought closer to each other in the vertical direction from the rear side to the front side.

[0027] Next, as shown in FIGS. 6B, 7B, and 8B, the bottom wall 32 of the pot portion 12 is provided with a recess 44 formed so as to be recessed downward across the left and right with respect to the left and right central axis Z in a front cross-sectional view. Also, as shown in FIGS. 4A to 4C, 6B, 7B, and 8B, in the region of the bottom wall 32 of the pot portion 12 between the lower joint portion 40 and the left and right inner recesses 44, a transition region 46 is provided where the shape of the bottom wall 32 transitions from the lower joint portion 40 side toward the recess 44. This transition region 46 is formed to be convex so as to protrude upward from a planar shape toward the left and right inner sides from the lower joint portion 40 side, and then transitions to the concave shape of the recess 44. Furthermore, as shown in FIGS. 4A to 4C, the recess 44 is formed in a fan shape in a plan view such that the width in the left and right direction widens toward the inlet 30 side of the rear drain trap portion 8.

[0028] Next, as shown in FIGS. 3A, 6B, 7B, and 8B, in a side cross-sectional view, the bottom surface 44a of the recess 44 protrudes downward across the front and rear directions, and is inclined downward toward the inlet 30 side of the rear drain trap portion 8. Also, as shown in FIGS. 3A, 4A to 4C, and 5B, in the region between the lower joint portion 40 and the recess 44 in front of the recess 44, a guide portion 48 is provided which is formed in a planar shape or protrudes upward in a convex shape so as to suppress the cleaning water flowing into this region from flowing excessively into the recess 44. Furthermore, as shown in FIGS. 6B, 7B, and 8B, in a front cross-sectional view or a side cross-sectional view, the amount of depression d1 in the vertical direction from the vertex position P5 of the convexly formed portion in the transition region 46 to the lowest bottom surface position P6 of the recess 44 of the recess 44 is set to increase toward the inlet 30 side of the rear drain trap portion 8.

[0029] Next, as shown in FIGS. 3A and 4A to 4C, the recess 44 of the kettle portion 12 has a rear end 44b whose bottom surface 44a is connected to the inlet 30 of the drain trap portion 8. Further, in the side cross-sectional view of FIG. 3A, the recess 44 of the kettle portion 12 includes a first tangent line T1 extending in the front-rear direction along the bottom surface 44a from the rear end 44b thereof, and a first tangent line extension portion T2 obtained by extending the first tangent line T1 rearward from the rear end 44b. Furthermore, in the side cross-sectional view of FIG. 3A, the drain trap portion 8 forms a trap pipe line 52 that extends from the inlet 30 thereof to the lowermost end portion 50 at the rear and below, and then extends from the lowermost end portion 50 to the rear and above. Also, in the side cross-sectional view of FIG. 3A, the first tangent line extension portion T2 is set to pass through a height position lower than the height position of the rear end 30a of the inlet 30 of the drain trap portion 8 at the same front-rear direction position with respect to the rear end 30a of the inlet 30 of the drain trap portion 8. Furthermore, in the side cross-sectional view of FIG. 3A, the first tangent line extension portion T2 is located within the trap pipe line 52 so as to pass through a height position lower than the upper surface 52a within the trap pipe line 52 from the inlet 30 of the drain trap portion 8 to the lowermost end portion 50. Here, as shown in FIG. 3A, within the trap pipe line 52 from the lower end of the protruding portion 54 at the rear end 30a of the inlet 30 of the drain trap portion 8 to the lowermost end portion 50 of the drain trap portion 8, the shape of the upper surface 52a in its side cross-sectional view is formed in a substantially planar shape.

[0030] Next, the dirt receiving surface 14 includes, in the side cross-sectional view of FIG. 3A, a second tangent line T3 extending in the front-rear direction along the dirt receiving surface 14, and a second tangent line extension portion T4 obtained by extending the second tangent line T3 rearward from the lower edge 14a of the dirt receiving surface 14. And the above-described first tangent line extension portion T2 and second tangent line extension portion T4 are set to be substantially parallel to each other in the side cross-sectional view of FIG. 3A.

[0031] Next, as shown in FIGS. 4A to 4C, the rear side wall 36 of the pot portion 12 is formed such that the wall surfaces of the left and right side walls 36a and 36b in plan view are located inside the pot portion 12 as they go from top to bottom. Also, as shown in FIGS. 3A and 4A to 4C, above the rear end 30a of the inlet 30 of the drain trap portion 8 in the lower region of the rear walls 34a and 34b of the pot portion 12, a protruding portion 54 that protrudes forward is provided.

[0032] Next, as shown in FIGS. 3A and 4A to 4C, the bottom wall 32 of the pot portion 12 includes a central bottom surface 56 that includes the position of the center O in the front-rear direction of the pot portion 12, and peripheral bottom surfaces 58 formed at the left and right peripheries 56a of the central bottom surface 56. First, the central bottom surface 56 forms a recess 44 in which the central region is recessed downward from the surroundings, and is located downward as it goes toward the inlet 30 side of the rear drain trap portion 8. Also, the width of the central bottom surface 56 in the left-right direction is formed in a fan shape so as to widen from the front end 56b to the rear end 56c (corresponding to the front end 30b of the inlet 30 of the rear drain trap portion 8) of the central bottom surface 56 in the plan views of FIGS. 4A to 4C. Next, the peripheral bottom surface 58 joins the left and right peripheries 56a of the central bottom surface 56 and the lower edge 40a of the lower joint portion 40 (corresponding to the inner edge of the lower joint portion 40 in the plan views of FIGS. 4A to 4C), and substantially forms a surface that forms the transition region 46 of the bottom wall 32 of the pot portion 12. Also, as shown in FIG. 3A, the peripheral bottom surface 58 is formed at a position higher than the central bottom surface 56, and the rear end 58a thereof is joined to the protruding portion 54. Thereby, in the side cross-sectional view of FIG. 3A, the peripheral bottom surface 58 is located upward as it goes from the rear side joined to the protruding portion 54 toward the front side.

[0033] Next, as shown in FIGS. 4A to 4C, the protruding portion 54 is provided at the lower end of the rear wall 34 of the pot portion 12 and is provided over the entire left-right width direction at the rear end 30a of the inlet 30 of the drain trap portion 8. Further, as shown in FIGS. 4A to 4C, the protruding portion 54 has a front end 54a in a plan view thereof formed in a convexly curved shape facing rearward.

[0034] Next, as shown in FIG. 3A, the inlet 30 of the drain trap portion 8 includes a rear end 30a joined to the lower end of the rear wall 34 of the pot portion 12, and a front end 30b joined to the left and right central rear end 56c on the central bottom surface 56 of the bottom wall 32 of the pot portion 12. Also, as shown in FIG. 3A, the front end 30b of the inlet 30 of the drain trap portion 8 is provided at a position lower than the rear end 30a of the inlet 30 of the drain trap portion 8.

[0035] Next, with reference to FIGS. 1 to 10, the flow of the washing water in the bowl portion 6 during toilet washing in the flushing toilet 1 according to an embodiment of the present invention will be described. FIG. 9 is a schematic plan view schematically illustrating the flow of the washing water in a state where the washing water discharged from the second rim water outlet in the bowl portion of the flushing toilet according to an embodiment of the present invention swirls from the rear side to the front side of the bowl portion and then flows into the pot portion from the front side. Further, FIG. 10 is a schematic side cross-sectional view schematically illustrating the flow of the washing water in a state where the washing water discharged from the second rim water outlet in the bowl portion of the flushing toilet according to an embodiment of the present invention swirls from the rear side to the front side of the bowl portion and then flows into the pot portion from the front side. First, as shown in FIG. 9, in the flushing toilet 1 of the present embodiment, when toilet washing is started, the washing water W in the water storage tank 10 is supplied from the inlet 4a of the water guiding path 4 of the toilet main body 2 to the common water guiding path 24. The washing water W in this common water guiding path 24 branches into the first rim water guiding path 26 and the second rim water guiding path 28 as the first washing water W1 and the second washing water W2, respectively.

[0036] Next, as shown in FIGS. 9 and 10, the first washing water W1 in the first rim water guiding path 26 is discharged forward as the first rim water discharge W1 from the downstream first rim water outlet 20. This first rim water discharge W1 forms a swirling flow f1 that swirls from the left front region LF in the bowl portion 6 through the right front region RF to the right rear region RB. On the one hand, as shown in FIGS. 9 and 10, the second washing water W2 in the second rim water channel 28 is discharged as the second rim discharge water W2 from the second rim discharge port 22. This second rim discharge water W2 forms a flow f2 that swirls from the right rear region RB in the bowl portion 6 through the left rear region LB to the left front region LF and then flows into the front region in the kettle portion 12 from this left front region LF. Also, a part of the second rim discharge water W2 discharged from the second rim discharge port 22 flows into the rear region in the kettle portion 12 from the dirt receiving surface 14 in the region behind the kettle portion 12 of the bowl portion 6.

[0037] Next, as shown in FIGS. 9 and 10, in the washing water W3 that has flowed into the kettle portion 12, it is collected on the concave portion 44 side (left and right center side) of the bottom wall 32 of the kettle portion 12, thereby forming a flow f3 of the washing water that converges from the bottom wall 32 of the kettle portion 12 toward the inlet 30 of the drain trap portion 8, and forming a flow that strongly pushes the dirt into the drain trap portion 8. Also, a part of the washing water W3 guided below the kettle portion 12 further collides with the protruding portion 54 provided above the rear end 30a of the inlet 30 of the drain trap portion 8 in the lower region of the rear walls 34a and 34b of the kettle portion 12 from above. As a result, the washing water W3 after the collision bounces back upward, forward, etc., so that the flow f3 of the washing water W3 is changed to a flow f4 that generally flows upward. And the flow f4 of the washing water forms a flow that swirls in the vertical direction (hereinafter referred to as "vertical swirling flow f4"). After the dirt in the kettle portion 12 is stirred together with the washing water that has flowed into the kettle portion 12 and the stored water in the water storage portion W0, it is discharged from the inlet 30 of the drain trap portion 8 into the drain trap portion 8.

[0038] On the other hand, the washing water W3 that has flowed from the dirt receiving surface 14 in front of the kettle portion 12 along the front side wall 38 (particularly, refer to the front right side wall 38b in FIGS. 9 and 10) of the kettle portion 12 to the rear side wall 36 (particularly, refer to the rear right side wall 36b in FIGS. 9 and 10) collides with the wall surface of the rear side wall 36b, and then is guided downward and rearward along the wall surface of this rear side wall 36b, and flows into the vicinity of the lower ends of the rear walls 34a and 34b of the kettle portion 12 and the rear end 30a of the inlet 30 of the drain trap portion 8. Of the washing water W3 that has flowed near the lower end of the rear wall 34 (34a, 34b) of the pot portion 12 and the rear end 30a of the inlet 30 of the drain trap portion 8 and has a vector of the flow that goes downward without going backward, the washing water W3 flows into the drain trap portion 8 from the inlet 30 of the drain trap portion 8 while maintaining the vector of the flow f3.

[0039] According to the flushing toilet 1 according to one embodiment of the present invention described above, a part of the washing water W1, W2 discharged into the bowl portion 6 from each of the first rim water discharge port 20 and the second rim water discharge port 22 which are water discharge portions swirls on the dirt receiving surface 14 up to the front side of the pot portion 12 and then flows into the pot portion 12 from the front side of the pot portion 12 (refer to the flows f1 of the washing water W1, W3 in FIGS. 9 and 10). And the washing water W3 that has flowed from the dirt receiving surface 14 above and in front of the pot portion 12 into the front region in the pot portion 12 is guided from the front region in the pot portion 12 along the bottom surface 32a (the bottom surface 44a of the concave portion 44) of the bottom wall 32 of the pot portion 12 toward the front end 30b side of the inlet 30 of the drain trap portion 8 joined to the rear end 44b at the center left and right thereof. At this time, as shown in FIG. 3A, since the front end 30b of the inlet 30 of the drain trap portion 8 is provided at a position lower than the rear end 30a of the inlet 30 of the drain trap portion 8, it is possible to have a structure in which the front side is low and the rear side is high at the inlet 30 of the drain trap portion 8. Therefore, the washing water W3 containing dirt flowing from the front region in the pot portion 12 toward the vicinity of the front end 30b of the inlet 30 of the drain trap portion 8 can smoothly pass through without stagnating at the rear end 30a of the inlet 30 of the drain trap portion 8 when flowing toward the drain trap portion 8 on the rear side thereof, and can smoothly flow into the drain trap portion 8. Therefore, since the dirt in the bowl portion 6 can be smoothly guided to the drain trap portion 8, the dirt discharge performance (discharge force) in the flushing toilet 1 can be improved.

[0040] Further, according to the flushing toilet 1 of the present embodiment, the washing water W3 containing dirt that flows from the front region in the pot portion 12 along the bottom surface 32a (bottom surface 44a of the recess 44) of the bottom wall 32 to the vicinity of the front end 30b of the inlet 30 of the drainage trap portion 8 flows toward the drainage trap portion 8 on the rear side thereof. At this time, the first tangent extension T2 of the first tangent T1 on the bottom surface 32a (bottom surface 44a of the recess 44) of the bottom wall 32 of the pot portion 12 passes through a height position lower than the height position of the rear end 30a of the inlet 30 of the drainage trap portion 8 at the same front-rear direction position with respect to the rear end 30a of the inlet 30 of the drainage trap portion 8 in the side cross-sectional view of FIG. 3A. Thereby, the washing water W3 smoothly passes through the rear end 30a of the inlet 30 of the drainage trap portion 8 without stagnating and can smoothly flow into the drainage trap portion 8. Therefore, since the dirt in the bowl portion 6 can be smoothly guided to the drainage trap portion 8, the dirt discharge performance (discharging power) in the flushing toilet 1 can be improved.

[0041] Furthermore, according to the flushing toilet 1 of the present embodiment, a part of the washing waters W1 and W2 discharged into the bowl portion 6 from the first rim water discharge port 20 and the second rim water discharge port 22 which are water discharge portions swirls on the dirt receiving surface 14 to the front side of the pot portion 12 and then flows from the dirt receiving surface 14 on the front side of the pot portion 12 into the pot portion 12 (see the flows f1 and f2 of the washing waters W1 and W2 in FIGS. 9 and 10). At this time, the first tangent extension T2 on the bottom surface 32a (bottom surface 44a of the recess 44) of the bottom wall 32 of the pot portion 12 and the second tangent extension T4 on the dirt receiving surface 14 are set to be substantially parallel to each other in the side cross-sectional view of FIG. 3A. Thereby, in particular, the washing water W1 flowing from the dirt receiving surface 14 in front of and above the pot portion 12 into the front region in the pot portion 12 can merge with the washing water W3 containing dirt flowing along the bottom surface 32a (bottom surface 44a of the recess 44) of the bottom wall 32 from the front region in the pot portion 12 to the vicinity of the front end 30b of the inlet 30 of the drainage trap portion 8. As a result, the washing water W3 flowing from the front region in the pot portion 12 along the bottom surface 32a of the bottom wall 32 (the bottom surface 44a of the recess 44) toward the inlet 30 of the drain trap portion 8 on the rear side can directly flow into the trap pipe 52 from the inlet 30 of the drain trap portion 8 in a state where the water flow has increased. As a result, the washing water containing dirt in the bowl portion 6 can be smoothly guided from the dirt receiving surface 14 through the pot portion 12 to the drain trap portion 8, so that both the washing performance (washing power) and the dirt discharge performance (discharge power) in the water-washed toilet 1 can be improved.

[0042] Further, according to the water-washed toilet 1 according to the present embodiment, from the protruding portion 54 provided above the rear end 30a of the inlet 30 in the drain trap portion 8 to the lowermost end portion 50 at the rear and below thereof, the shape of the upper surface 52a in the trap pipe 52 is formed in a substantially planar shape. As a result, when the washing water W3 flowing rearward along the bottom surface 32a of the bottom wall 32 (the bottom surface 44a of the recess 44) from the front region in the pot portion 12 flows into the trap pipe 52 from the inlet 30 of the drain trap portion 8, it is smoothly guided downstream along the trap pipe 52 from the protruding portion 54 above the rear end 30a of the inlet 30 of the drain trap portion 8 to the lowermost end portion 50 of the trap pipe 52. At this time, the washing water W3 flowing through the trap pipe 52 from the protruding portion 54 to the lowermost end portion 50 at the rear and below thereof flows smoothly along the substantially planar upper surface 52a in the side cross-sectional view of the trap pipe 52 shown in FIGS. 3A and 10, so that the pressure loss caused by the washing water W3 colliding with the upper surface 52a in the trap pipe 52 from the protruding portion 54 to the lowermost end portion 50 at the rear and below thereof can be suppressed. As a result, the dirt in the bowl portion 6 can be smoothly discharged from the drain trap portion 8, so that the dirt discharge performance (discharge power) in the water-washed toilet 1 can be improved.

[0043] Furthermore, according to the flushing toilet 1 of the present embodiment, as shown in FIG. 3A, in a side cross-sectional view of the joint portion 42 that joins the upper edges 36d, 38d of the side walls 36, 38 of the pot portion 12 and the lower edge 14a of the dirt receiving surface 14 with a surface C1 having a curvature, the vertical width H1 is set to decrease from the rear side to the front side. As a result, the pot portion 12 and the dirt receiving surface 14 can be brought closer to each other in the vertical direction from the rear side to the front side. Therefore, in particular, with respect to the dirt in the front region on the dirt receiving surface 14, a part of the washing water W1, W2 discharged onto the dirt receiving surface 14 from each of the first rim water discharge ports 20 and the second rim water discharge ports 22, which are water discharge portions, can be efficiently conveyed to the front region in the pot portion 12. Thus, both the washing performance (washing power) and the dirt discharge performance (discharge power) in the flushing toilet 1 can be improved.

Explanation of Reference Numerals

[0044] 1 Flushing toilet 2 Toilet body 4 Water guide path 4a Entrance of the water guide path 6 Bowl portion 8 Drain trap portion 10 Water storage tank (washing water source) 12 Pot portion 14 Dirt receiving surface 14a Lower edge of the dirt receiving surface 16 Shelf portion 18 Rim portion 20 First rim water discharge port (water discharge portion) 22 Second rim water discharge port (water discharge portion) 24 Common water guide path 26 First rim water guide path 28 Second rim water guide path 30 Entrance of the drain trap portion 30a Rear end of the entrance of the drain trap portion 30b Front end of the entrance of the drain trap portion 32 Bottom wall of the pot portion 32a Bottom surface of the bottom wall of the pot portion 32b Outer edge of the bottom wall of the pot portion 34 Rear wall of the pot portion Left rear wall of the 34a pot part Right rear wall of the 34b pot part Rear side wall of the 36 pot part (side wall of the pot part) Rear left side wall of the 36a pot part (side wall of the pot part) Rear right side wall of the 36b pot part (side wall of the pot part) Lower edge of the rear side wall of the 36c pot part (lower edge of the side wall of the pot part) Upper edge of the rear side wall of the 36d pot part Front side wall of the 38 pot part (side wall of the pot part) Front left side wall of the 38a pot part (side wall of the pot part) Front right side wall of the 38b pot part (side wall of the pot part) Lower edge of the front side wall of the 38c pot part (lower edge of the side wall of the pot part) Upper edge of the rear side wall of the 38d pot part Lower joint part (joint part of the pot part) Lower edge of the 40a lower joint part Upper edge of the 40b lower joint part Upper joint part Lower edge and inner edge of the 42a upper joint part Upper edge of the 42b upper joint part Concave part of the bottom wall of the pot part Bottom surface of the 44a concave part Rear end of the 44b concave part Transition region of the bottom wall of the pot part Guide part Lowest end part of the drain trap part Trap pipeline Upper surface of the trap pipeline from the inlet of the drain trap part to the lowest end part Protrusion part Front end at the protrusion part Central bottom surface of the bottom wall of the pot part Periphery of the 56a central bottom surface Front end of the 56b central bottom surface Rear end of the 56c central bottom surface Peripheral bottom surface of the bottom wall of the pot part Rear end of the 58a peripheral bottom surface Rear region of the B bowl part Bending surface of the 71C1 lower joint part (surface having the curvature of the joint part) C2 contact plane C3 contact plane Bending surface of the C4 upper joint (surface having the curvature of the joint) C5 contact plane C6 contact plane Vertical recess amount from the vertex position of the convexly formed portion in the transition region to the lowest bottom surface position of the recess Front region of the F bowl portion Flow of cleaning water f1 Flow of cleaning water f2 Flow of cleaning water f3 Flow of cleaning water f4 (vertical swirling flow) Vertical width in the side view of the upper joint H1 Left region of the L bowl portion Left rear region of the LB bowl portion Left front region of the LF bowl portion Boundary line L1 between the bottom wall of the kettle portion and the lower joint Boundary line L2 between the lower joint and the side wall of the kettle portion Boundary line L3 between the side wall and the upper joint of the kettle portion Boundary line L4 between the upper joint and the dirt receiving surface of the kettle portion Center of the O bowl portion, center in the front - rear direction of the kettle portion Lower joint point P1 joining the lower edge of the lower joint and the outer edge of the bottom surface of the bottom wall Upper joint point P2 joining the upper edge of the lower joint and the lower edge of the side wall Lower joint point P3 joining the lower edge of the upper joint and the upper edge of the side wall Upper joint point P4 joining the upper edge of the upper joint and the lower edge of the dirt receiving surface Vertex position P5 of the convexly formed portion in the transition region of the bottom wall of the kettle portion Lowest bottom surface position P6 of the recess of the kettle portion Right region of the R bowl portion Right rear region of the RB bowl portion Right front region of the RF bowl portion Tip of the T kettle portion (front end of the kettle portion) First tangent line T1 extending in the front - rear direction along the bottom surface from the rear end of the recess of the kettle portion First tangent line extension T2 The second tangent line extending in the front-rear direction along the bottom surface from the rear end of the concave portion of the T3 pot part T4 Second tangent line extension W Washing water W0 Water storage part W1 First washing water, first rim water discharge W2 Second washing water, second rim water discharge W3 Washing water inside the pot part WL Water sealing level X Central axis in the horizontal left-right direction of the bowl part Y Central axis in the horizontal front-rear direction of the bowl part Z Vertical central axis passing through the center of the bowl part

Claims

1. A water-washed toilet that is washed with washing water to discharge dirt, comprising: a bowl portion having a bowl-shaped dirt receiving surface and a pot portion provided below the dirt receiving surface to form a water storage portion by the stored water; a drain trap portion having an inlet connected below the pot portion and discharging dirt in the bowl portion; the pot portion includes a bottom wall formed above and in front of the inlet of the drain trap portion, a rear wall provided on the rear side of the inlet of the drain trap portion, and a side wall formed so as to surround the periphery of the bottom wall; the inlet of the drain trap portion includes a rear end joined to the lower end of the rear wall of the pot portion and provided with a protruding portion protruding forward, and a front end joined to the rear end at the left-right center on the bottom surface of the concave portion of the bottom wall of the pot portion; the front end of the inlet of the drain trap portion is provided at a position lower than the rear end of the inlet of the drain trap portion in a side cross-sectional view; the bowl portion further includes a joint portion that joins the upper edge of the side wall of the pot portion and the lower edge of the dirt receiving surface with a surface having a curvature, and the vertical width of the joint portion in a side cross-sectional view is set to decrease from the rear side toward the front side. A water-washed toilet characterized by this.

2. The bottom wall has a bottom surface that, in a side cross-sectional view, includes a first tangent line extending in the front-rear direction along the bottom surface from the rear end of the bottom wall, and a first tangent line extension portion obtained by extending the first tangent line from the rear end to the rear side; The water-washed toilet according to claim 1, wherein the first tangent line extension portion is set to pass through a height position lower than the height position of the rear end of the inlet of the drain trap portion at the same front-rear direction position with respect to the rear end of the inlet of the drain trap portion in a side cross-sectional view.

3. The dirt receiving surface, in a side cross-sectional view, includes a second tangent line extending in the front-rear direction along the dirt receiving surface, and a second tangent line extension portion obtained by extending the second tangent line from the lower edge of the dirt receiving surface to the rear side; The water-washed toilet according to claim 2, wherein the first tangent line extension portion and the second tangent line extension portion are set to be substantially parallel to each other in a side cross-sectional view.

4. The drain trap portion, in a side cross-sectional view, includes the protruding portion provided above the rear end of the inlet and protruding forward, and a trap pipe line that extends from the protruding portion to the lowermost end portion at the rear and below, and then extends from the lowermost end portion to the rear and above.

4. The flush toilet according to claim 1, wherein the trap pipe from the protruding portion of the drain trap portion to the lowest end has an upper surface that is formed in a substantially linear shape in a side cross-sectional view.

Images