Flush toilet

Abstract

To provide a flush toilet bowl capable of improving washing performance on a bowl part and suppressing splashing out of washing water to the outside of the toilet bowl even if a water discharge port is formed to be vertically oblong.SOLUTION: As a first water discharge port 24 is formed to be vertically oblong, and a convex part 40 protruding toward an inside of a bowl part 6 is provided on an inner peripheral surface 18a of a rim part 18 on a downstream side of the first water discharge port 24 in the invention, a dirt receiving surface 16 can be washed by causing the convex part 40 to flow a portion of the washing water rotating on the inner peripheral surface 18a of the rim part 18 downward. Consequently, washing performance on the bowl part 6 can be improved and splashing out of the washing water to the outside of the toilet bowl can be suppressed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a flush toilet, and more particularly to a flush toilet that is flushed with flush water to expel waste. [Background technology]

[0002] Conventionally, as described in Patent Document 1, for example, flush toilets have been known in which flush water is discharged from a rim spout along the inner circumferential surface of the rim, forming a swirling flow in the bowl. In this flush toilet, the rim spout is made long and enlarged in order to increase the instantaneous flow rate of flush water discharged from the rim spout. A long rim spout increases its vertical width without changing its horizontal width, preventing the waste receiving surface adjacent to the rim spout from becoming smaller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-279791 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, because the vertically long rim spout has a small width, pressure loss occurs when flush water passes through the rim spout. This weakens the force of the flush water spouted from the rim spout, and there is a possibility that the bowl cannot be sufficiently cleaned. In addition, because the flush water spouted from the rim spout spreads upwards with a vertically long rim spout, there is a possibility that the flush water will splash out of the toilet bowl as it flows along the rim.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a flush toilet that can improve the flushing performance of the bowl section even if the water outlet is formed vertically, and can prevent flush water from splashing out of the toilet. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a flush toilet that flushes with flushing water and discharges waste, the bowl portion having a bowl-shaped waste receiving surface and a rim portion formed on the upper part of the waste receiving surface, a water outlet provided in the rim portion for ejecting flushing water along the inner surface of the rim portion, a water passage for directing the flushing water to the water outlet, and a drainage pipe line connected to the bottom of the bowl portion, the water outlet being formed vertically long, and the inner surface of the rim portion downstream of the water outlet is provided with a convex portion that protrudes toward the inside of the bowl portion. In the present invention configured in this way, the water outlet is formed vertically long, and a convex portion that protrudes toward the inside of the bowl portion is provided on the inner peripheral surface of the rim portion downstream of the water outlet, so that this convex portion can cause a portion of the flush water swirling around the inner peripheral surface of the rim portion to flow down and flush the waste receiving surface. This improves the flushing performance of the bowl portion. It also prevents flush water from splashing out of the toilet.

[0007] Also, in the present invention, the water spout is preferably provided forward of the front-to-rear central axis of the bowl portion, and the convex portion is provided at the front end of the inner circumferential surface of the rim portion. In the present invention configured in this manner, the water outlet is provided forward of the fore-and-aft central axis of the bowl portion, and the convex portion is provided at the front end of the inner surface of the rim portion, so that even if cleaning water flows over the front end immediately after being discharged, the cleaning water can be caused to flow down through the convex portion to clean the waste receiving surface.

[0008] In the present invention, the convex portion is preferably provided at least in a portion, in a plan view of the bowl portion, that is forward of the front-to-rear central axis of the bowl portion and where the inner surface of the rim portion is formed with the smallest radius of curvature. In the present invention configured in this manner, the convex portion is provided at least in the portion of the bowl portion that is forward of the central axis of the bowl portion in the front-to-rear direction and where the inner circumferential surface of the rim portion is formed with the smallest radius of curvature in a plan view of the bowl portion, so that when the flush water flows through the portion formed with the smallest radius of curvature, the flush water is caused to flow down by the convex portion to clean the waste receiving surface. Also, in the portion formed with the smallest radius of curvature where the flush water is most likely to splash out, the flush water is caused to flow down by the convex portion, so that the flush water can be prevented from splashing out of the toilet bowl.

[0009] In the present invention, the lower end of the convex portion is preferably inclined downward toward the flow direction of wash water swirling around the inner circumferential surface of the rim portion. In the present invention configured in this manner, the lower end of the convex portion is inclined downward toward the flow direction of the cleaning water swirling around the inner surface of the rim portion, so that a portion of the swirling cleaning water can be caused to flow down to clean the waste receiving surface.

[0010] In the present invention, the convex portion is preferably formed so that the degree to which it protrudes inwardly of the bowl portion increases toward the downstream side. In the present invention configured in this manner, the convex portion is formed so that the degree to which it protrudes inward into the bowl portion increases the further downstream it goes, so that the cleaning water can flow downstream and clean the waste receiving surface as it swirls.

[0011] In the present invention, preferably, the lower surface of the convex portion is inclined upward toward the inside of the bowl portion. In the present invention configured in this manner, the lower surface of the convex portion is inclined upward toward the inside of the bowl portion, making it easy to clean the lower surface of the convex portion from above.

[0012] In the present invention, preferably, a horizontal surface is provided above the inner circumferential surface of the rim portion between the water spout and the convex portion. In the present invention configured in this manner, a horizontal surface is provided above the inner surface of the rim portion between the water outlet and the convex portion, so that the horizontal surface can straighten the wash water immediately after it is discharged, and the straightened wash water can be directed toward the convex portion.

[0013] Also, in the present invention, the water outlet preferably has a lower opening formed in a vertically long rectangular shape, and an upper opening formed with a smaller width than the lower opening and extending upward from the lower opening. In the present invention configured as described above, the water outlet has a lower opening formed in a vertically long rectangular shape and an upper opening formed narrower in width than the lower opening and extending upward from the lower opening, so that flush water can be discharged from the lower opening while air is exhausted from the upper opening. This prevents air from being drawn in at the water outlet, and allows the flush water from the water outlet to form a main flow for cleaning the waste receiving surface.

[0014] In the present invention, the water passage preferably has a lower water passage formed in a vertically elongated rectangular shape, and an upper water passage formed with a smaller width than the lower water passage and extending upward from the lower water passage. In the present invention thus configured, the water passage has a lower water passage formed in a vertically long rectangular shape, and an upper water passage formed narrower in width than the lower water passage and extending upward from the lower water passage, so that air flows through the upper water passage and is discharged from the upper opening, and flush water flows through the lower water passage and is discharged from the lower opening. This makes it possible to prevent air from being drawn into the water passage, and to form a main flow of flush water from the water outlet to wash the waste receiving surface.

[0015] In the present invention, preferably, on the downstream side of the water passage, the upper surface of the lower water passage slopes downward from the upstream toward the water outlet, and the upper surface of the upper water passage extends horizontally from the upstream toward the water outlet. In the present invention configured in this way, the upper surface of the lower water passage slopes downward from the upstream toward the water outlet on the downstream side of the water passage, so that a downward flow is formed by the lower water passage, and a main flow of water can be discharged downward from the water outlet. Meanwhile, the upper surface of the upper water passage extends horizontally from the upstream toward the water outlet, so that a large space capable of accommodating air is formed in the upper water passage, and the air can be reliably separated from the wash water and discharged from the water outlet. Effect of the Invention

[0016] According to the flush toilet of the present invention, even if the water outlet is formed vertically long, the flushing performance of the bowl portion can be improved and flush water can be prevented from splashing out of the toilet bowl. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a side cross-sectional view of a flush toilet according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a front view of a first water outlet of a flush toilet according to an embodiment of the present invention. [Figure 4] 3 is a flow path cross-sectional view taken along cross section A to E perpendicular to the flow direction of cleaning water in the first water passage shown in FIG. 2. [Diagram 5] 3 is a cross-sectional view of the first water passage shown in FIG. 2 along VV cross section. [Figure 6] FIG. 3 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 3 is a flow path cross-sectional view taken along cross section F to J perpendicular to the flow direction of the cleaning water in the rim portion shown in FIG. 2. [Figure 8] FIG. 2 is a plan cross-sectional view of the bowl portion, illustrating how flush water spouted from a first spout and a second spout in a flush toilet according to an embodiment of the present invention flows into the pooled water surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Below, a flush toilet according to an embodiment of the present invention will be explained. First, the basic structure of the flush toilet will be explained with reference to Figures 1 and 2. Figure 1 is a side cross-sectional view of a flush toilet according to an embodiment of the present invention, and Figure 2 is a cross-sectional view taken along line II-II in Figure 1.

[0019] As shown in Figures 1 and 2, flush toilet 1 is a wash-down toilet in which waste is washed away by the flowing water caused by the difference in height of the water inside the bowl. Flush toilet 1 comprises a ceramic toilet body 2 and a water storage tank 4 which stores flushing water for cleaning toilet body 2. Toilet body 2 comprises bowl 6 on the front side, and a common water passage 8 is formed at the upper rear part, with an opening 7 at its upstream end communicating with water storage tank 4. Furthermore, a drain pipe 10 is formed at the lower rear part of bowl 6 for discharging waste. In the embodiment of the present invention, a wash-down toilet will be described, but the present invention is not limited to this, and the flush toilet of the present invention also includes a siphon type toilet that discharges waste by siphon action.

[0020] Here, in this specification, when a user looks at the flush toilet 1 from the front, the front of the flush toilet 1 will be described as the front, the back side as the rear, the right side as the right side, and the left side as the left side.

[0021] The above-mentioned water tank 4 is equipped with a drain valve 12, and when the user opens an operating lever (not shown), the drain valve 12 opens and flush water in the water tank 4 is supplied to the toilet body 2. Furthermore, in the flush toilet of the present invention, other than the water storage tank 4, the source of flush water may be one that uses direct tap water pressure or a flush valve, and flush water may also be supplied using a pump.

[0022] The bowl section 6 is provided with a bowl-shaped waste receiving surface 16, a rim section 18 having an inner peripheral surface 18a formed above the waste receiving surface 16 and exposed to the outside, and a basin section 22 formed below the waste receiving surface 16 and forming a water pooling surface 20 therein. Here, the water pooling surface 20 of the basin section 22 is substantially triangular, measuring 160mm to 180mm in the front-rear direction and 125mm to 145mm in the width direction when viewed from above, and is formed larger (enlarged) than the water pooling surface of a conventional wash-down toilet. The basin section 22 is also 200mm to 240mm in the front-rear direction when viewed from above, measuring 150mm to 190mm in the width direction, and forms a substantially triangular shape that is egg-shaped (an elliptical shape tapered at the front) larger than the water pooling surface 20.

[0023] In the rim portion 18 of the bowl portion 6, a first water outlet 24 (water outlet) that discharges flush water is formed at a position in front of the left side, and a second water outlet 26 that discharges flush water is formed at a position in the rear of the right side. The above-mentioned common water passage 8 branches into a first water passage 28 and a second water passage 30 toward the downstream side, the first water passage 28 extends to the first water outlet 24, and the second water passage 30 extends to the second water outlet 26, so that flush water is supplied from the water storage tank 4 to the first water outlet 24 and the second water outlet 26. Here, the first water outlet 24 discharges water toward the front of the bowl portion 6, and the first water outlet 24 and the second water outlet 26 discharge flush water in a direction that forms a swirling flow that swirls in the same direction. In the case of the embodiment of the present invention, a counterclockwise swirling flow is formed. Furthermore, the flush toilet of the present invention may have one water outlet, or it may have two or more (for example, three).

[0024] Next, the first water outlet and first water passage of a flush toilet according to an embodiment of the present invention will be described in detail with reference to Figures 2 to 5. Figure 3 is a front view of the first water outlet 24 of a flush toilet 1 according to an embodiment of the present invention, Figure 4 is a flow path cross-sectional view of cross-sections A-E perpendicular to the flow direction of flush water in the first water passage 28 shown in Figure 2, and Figure 5 is a cross-sectional view of the VV cross-section of the first water passage 28 shown in Figure 2. In Figure 5, the dotted line indicates the top surface 38a of the upper water passage 38 of the first water passage 28.

[0025] First, as shown in Fig. 3, the first water outlet 24 has an L-shaped opening cross section, and includes a lower opening 32 (part surrounded by a dotted line in Fig. 3) formed in a vertically long rectangular shape, and an upper opening 34 (part surrounded by a dotted line in Fig. 3) formed in a vertically long rectangular shape with a smaller width than the lower opening 32 and extending upward from the left side (outside) of the upper end 32a of the lower opening 32. The upper end 32a and the lower end 32b of the lower opening 32 are approximately horizontal. The upper opening 34 is formed by extending vertically upward from the left end (outer end) of the upper end 32a of the lower opening 32. The upper end 34a of the upper opening 34 is approximately horizontal. The upper opening 34 and the lower opening 32 are continuous and form a single opening.

[0026] The cross-sectional area of ​​the upper opening 34 is set to be approximately 1 / 6 the size of the cross-sectional area of ​​the lower opening 32. Both the lower opening 32 and the upper opening 34 are formed in a rectangular shape with a vertical width (H1 and h1) longer than the horizontal width (W1 and w1). The horizontal width (w1) of the upper opening 34 is set to be approximately 1 / 3 the length of the horizontal width (W1) of the lower opening 32, and the vertical width (h1) of the upper opening 34 is set to be approximately 1 / 2 the length of the vertical width (H1) of the lower opening 32. As a result, most of the flush water is discharged from the lower opening 32, forming a front main flow F1 that swirls around the bowl portion 6 (see FIG. 8). Meanwhile, air is discharged from the upper opening 34, and a portion of the flush water is discharged and flows along the inner circumferential surface 18a of the rim portion 18. Therefore, a front main flow F1 that swirls in the bowl portion 6 can be formed, and air within the first water passage 28 can be discharged from the first water outlet 24.

[0027] As shown in Figures 4(A) to 4(E), the first water passage 28 has an L-shaped cross section and is continuous with the first water outlet 24. The first water passage 28 has a lower water passage 36 (part surrounded by a dotted line in Figure 4) formed in a vertically long rectangular shape at the opening cross section, and an upper water passage 38 (part surrounded by a dotted line in Figure 4) formed in a vertically long rectangular shape that is narrower in width than the lower water passage 36 and extends upward from the lower water passage 36. The upper water passage 38 and the lower water passage 36 are continuous and form a single water passage.

[0028] On the upstream side of the first water passage 28 (FIGS. 4(A) and 4(B)), the upper water passage 38 extends obliquely upward to the left (outside) from the left end (outer end) of the upper surface 36a of the lower water passage 36. On the downstream side of the first water passage 28 (FIGS. 4(C) to 4(E)), the upper water passage 38 extends upward in the vertical direction from the left end (outer end) of the upper surface 36a of the lower water passage 36. As a result, on the upstream side of the first water passage 28 (Figs. 4(A) and 4(B)), the curvature increases as the pooled water surface 20 expands, and a relatively large centrifugal force acts on the flush water; however, because the upper water passage 38 extends obliquely upward, the flush water is prevented from colliding forcefully with the inner wall of the upper water passage 38. This prevents the flush water from colliding forcefully, becoming disturbed, and entraining air. Furthermore, on the downstream side of the first water passage 28 (Figs. 4(C) to 4(E)), because the upper water passage 38 extends vertically upward, the flush water is guided to the lower water passage 36, and most of the flush water is discharged from the lower opening 32 of the first water outlet 24, forming a forward main flow F1 that swirls around the bowl section 6.

[0029] On the downstream side of the first water passage 28 (FIGS. 4(C) to 4(E)), the flow path cross-sectional area of ​​the upper water passage 38 is set to about one-sixth the flow path cross-sectional area of ​​the lower water passage 36. Both the lower water passage 36 and the upper water passage 38 are formed in a rectangular shape with a vertical width (H2 to H4 and h2 to h4) longer than the horizontal width (W2 to W4 and w2 to w4). The horizontal width (w2 to w4) of the upper water passage 38 is set to about one-third the length of the horizontal width (W2 to W4) of the lower water passage 36, and the vertical width (h2 to h4) of the upper water passage 38 is set to about one-half the length of the vertical width (H2 to H4) of the lower water passage 36.

[0030] On the downstream side of the first water passage 28 (FIGS. 4(C) to 4(E)), the width (W2 to W4) of the lower water passage 36 gradually decreases from the upstream toward the first water outlet 24. Also, as shown in FIG. 5, on the downstream side of the first water passage 28, the upper surface 36a of the lower water passage 36 gradually slopes downward from the upstream toward the first water outlet 24. Specifically, the upper surface 36a of the lower water passage 36 is inclined at an inclination angle of about 5° with respect to the horizontal direction. Also, the bottom surface 36b of the lower water passage 36 extends horizontally from the upstream toward the first water outlet 24. That is, the flow path cross-sectional area of ​​the lower water passage 36 gradually decreases from the upstream toward the first water outlet 24. As a result, a downward flow is formed by the lower water passage 36, and a downward forward main flow F1 can be discharged from the first water outlet 24 (see FIG. 8).

[0031] On the downstream side of the first water passage 28 (FIGS. 4(C) to 4(E)), the width (w2 to w4) of the upper water passage 38 is formed to be approximately constant from the upstream toward the first water outlet 24. Also, as shown in FIG. 5, on the downstream side of the first water passage 28, the upper surface 38a of the upper water passage 38 extends horizontally from the upstream toward the first water outlet 24. In other words, the flow path cross-sectional area of ​​the upper water passage 38 gradually increases from the upstream toward the first water outlet 24. These features allow a large space to be formed in the upper water passage 38 that can accommodate air, ensuring that the air is separated from the wash water.

[0032] As shown in FIG. 2, first water outlet 24 is disposed forward of the center line of bowl portion 6 in the front-rear direction, and first water passage 28 extends to first water outlet 24. This allows the distance of the water passage to be increased, so that the air can be reliably separated from the wash water and discharged from the first water outlet 24.

[0033] Next, the inner circumferential surface of the rim part of a flush toilet according to an embodiment of the present invention will be described in detail with reference to Figures 2, 6, and 7. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 2, and Figure 7 is a flow path cross-sectional view of cross section F to J perpendicular to the flow direction of flush water in the rim part shown in Figure 2.

[0034] First, as shown in FIG. 2, in plan view, the inner circumferential surface 18a of the rim portion 18 is formed with a smallest first radius of curvature R1 at its front end 18b, a second radius of curvature R2 larger than the first radius of curvature R1 behind the first radius of curvature R1, and a maximum third radius of curvature R3 behind the second radius of curvature R2. The first water outlet 24 is provided at a front position on the left side of the bowl portion 6, at a position where the inner circumferential surface 18a of the rim portion 18 changes from the third radius of curvature R3 to the second radius of curvature R2. In addition, in the region P1 where the inner peripheral surface 18a of the rim portion 18 is formed with the smallest first radius of curvature R1, the inner peripheral surface 18a of the rim portion 18 is provided with a convex portion 40 that protrudes laterally toward the inside of the bowl portion 6 (the center of the bowl portion 6). In other words, the convex portion 40 is formed at least in the part of the inner peripheral surface 18a of the rim portion 18 where the radius of curvature is smallest. More specifically, the convex portion 40 is provided near the first water outlet 24 on the downstream side of the first water outlet 24, and is provided over the entire region P1 (the entire length in the direction in which the flush water swirls). As a result, a part of the flush water that is discharged from the first water outlet 24 and tries to swirl around the inner peripheral surface 18a of the rim portion 18 is caused to flow down to the waste receiving surface 16 by the convex portion 40.

[0035] Next, as shown in Figures 6 and 7, rim portion 18 rises upward from its lower end and has an inner surface 18a formed around the entire circumference of bowl portion 6, the inner surface 18a extending from its upper end toward the inside of bowl portion 6. 6, the protrusions 40 are provided in region P1 above the vertical central axis of the inner circumferential surface 18a of the rim portion 18. The protrusions 40 are provided over substantially the entire region above the inner circumferential surface 18a of the rim portion 18 in region P1. Furthermore, the protrusion 40 is made of ceramic and is integral with the rim portion 18, and is formed continuous with the inner peripheral surface 18a of the rim portion 18 by a smooth curve.

[0036] 6, the vertical width of the protrusion 40 is formed to gradually increase in the flow direction of flushing water swirling around the inner circumferential surface 18a of the rim portion 18. That is, the vertical width of the protrusion 40 is smaller the closer it is to the first water outlet 24, and is larger the farther it is from the first water outlet 24. Furthermore, the vertical width of the protrusions 40 is approximately half the vertical length of the inner circumferential surface 18a of the rim portion 18 at the front end 18b of the rim portion 18. This allows some of the flush water attempting to swirl at the front end 18b of the rim portion 18, which is most affected by centrifugal force, to flow down to the waste receiving surface 16 by the protrusions 40.

[0037] The lower end 40a of the convex portion 40 gradually slopes downward in the direction of flow of flushing water swirling around the inner circumferential surface 18a of the rim portion 18. The lower end 40a of the convex portion 40 slopes downward at an inclination angle of approximately 30° with respect to the horizontal direction. This allows the flushing water swirling around the inner circumferential surface 18a of the rim portion 18 to be guided downward by the lower end 40a of the convex portion 40, and to flow down to the waste receiving surface 16. Additionally, the lower end 40a of the convex portion 40 is inclined from the vicinity of the first water outlet 24 to the front end 18b of the rim portion 18, and is approximately horizontal downstream of the front end 18b of the rim portion 18. As a result, flush water swirling from the first water outlet 24 to the front end 18b of the rim portion 18, which is most affected by centrifugal force, is guided downward by the convex portion 40, and flush water that has passed the front end 18b is guided to swirl rearward.

[0038] Next, as shown in FIG. 7(F), at the position of the F cross section between the first water outlet 24 and the convex portion 40, the inner peripheral surface 18a of the rim portion 18 has a vertical surface 18c extending vertically upward from its lower end, and a horizontal surface 18d extending horizontally from the upper end of the vertical surface 18c toward the inside of the bowl portion 6. The vertical surface 18c and the horizontal surface 18d are connected perpendicularly at an inclination angle of about 90°. The vertical surface 18c and the horizontal surface 18d are connected by a small curved surface that is concave toward the outside. In other words, at the position of the F cross section between the first water outlet 24 and the convex portion 40, the convex portion 40 is not formed. Furthermore, the vertical surface 18c and the horizontal surface 18d are formed as flat surfaces, so that the flush water discharged from the first water discharge port 24 is rectified by flowing on the vertical surface 18c or the horizontal surface 18d.

[0039] As shown in FIG. 7(G), at the position of cross section G in region P1 upstream of front end 18b of rim portion 18, inner peripheral surface 18a of rim portion 18 includes vertical surface 18c extending vertically upward from its lower end, horizontal surface 18d extending horizontally from the upper end of vertical surface 18c toward the inside of bowl portion 6, and protruding portion 40 provided between vertical surface 18c and horizontal surface 18d and protruding toward the inside of bowl portion 6. Protruding portion 40 is formed by a curved surface connecting between vertical surface 18c and horizontal surface 18d of rim portion 18, which rises toward the inside of bowl portion 6. In addition, lower surface 40b of protruding portion 40 is inclined upward toward the inside of bowl portion 6.

[0040] 7(H), at the position of cross section H in region P1 upstream of front end 18b of rim portion 18, the degree to which convex portion 40 protrudes inwardly into bowl portion 6 is greater than at the position of cross section G. In addition, the vertical width of convex portion 40 and the vertical width of lower surface 40b are greater than at the position of cross section G.

[0041] 7(I), at the position of cross section I of the front end 18b of the rim portion 18, the degree to which the convex portion 40 protrudes inwardly into the bowl portion 6 is greater than at the position of cross section H. In addition, the vertical width of the convex portion 40 and the vertical width of the lower surface 40b are greater than at the position of cross section H.

[0042] 7(J), at the position of cross section J in region P1 downstream of front end 18b of rim portion 18, the degree to which convex portion 40 protrudes inwardly into bowl portion 6 is substantially the same as at the position of cross section I. Furthermore, the vertical width of convex portion 40 and the vertical width of lower surface 40b are substantially the same length as at the position of cross section I.

[0043] As described above, the degree to which the convex portion 40 protrudes inwardly of the bowl portion 6 increases toward the downstream side (see Figs. 7(G)-(I)). Also, the vertical width of the convex portion 40 increases toward the downstream side (see Fig. 6). As a result, the flush water swirls toward the downstream side and thus flows downward more easily. In addition, the lower surface 40b of the convex portion 40 is inclined upward toward the inside of the bowl portion 6 (see FIGS. 7(G)-(J)). This makes it easier to clean the lower surface 40b from above compared to when the lower surface 40b of the convex portion 40 is horizontal. Also, the vertical width of the lower surface 40b of the convex portion 40 increases toward the downstream side (see FIG. 6), making cleaning even easier.

[0044] As shown in Figures 7(G) to (J), outer peripheral surface 16a of waste receiving surface 16 outside a straight line drawn vertically downward from inner peripheral edge 18e of rim portion 18 is formed so as to slope downward toward the inside of the bowl portion. The slope angle of outer peripheral surface 16a of waste receiving surface 16 is greatest at front end 18b of rim portion 18 (see Figure 7(I)). This makes it easier for flush water to flow downward at front end 18b of rim portion 18, which is most affected by centrifugal force.

[0045] Next, the manner in which flush water flows into the pooled water surface in a flush toilet 1 according to an embodiment of the present invention will be described with reference to Figure 8. Figure 8 is a plan cross-sectional view of the bowl portion 6, showing the manner in which flush water discharged from the first and second water outlets in a flush toilet according to an embodiment of the present invention flows into the pooled water surface. As shown in Figure 8, for ease of explanation, the water collection surface 20 formed inside the pot portion 22 is divided into four areas: a first area S1 on the rear left side, a second area S2 on the rear right side, a third area S3 on the front right side, and a fourth area S4 on the front left side, by a left-right center line extending in the front-to-rear direction and a front-to-rear center line extending in the left-right direction.

[0046] 8, first, part of the flush water discharged from the first water outlet 24 swirls around the inner circumferential surface 18a of the rim portion 18, while the majority flows down to the waste receiving surface 16 to form a front main flow F1. After flowing through the front region of the waste receiving surface 16 of the bowl portion 6, the front main flow F1 reaches the rear region of the waste receiving surface 16 and flows into regions S2 and S1 of the pool surface 20. This cleans the front and rear regions on the right side of the waste receiving surface 16.

[0047] Next, part of the flush water discharged from the second water discharge port 26 swirls around the inner circumferential surface 18a of the rim portion 18, while the majority flows down to the waste receiving surface 16 to form a rear main flow F2. After flowing through the rear region of the waste receiving surface 16 of the bowl portion 6, the rear main flow F2 reaches the front region of the waste receiving surface 16 and flows into regions S4 and S3 of the pool surface 20. This cleans the rear and front regions on the left side of the waste receiving surface 16. As is clear from Figure 8, in the flush toilet 1 of the embodiment of the present invention, the front main flow F1 and rear main flow F2 of the flush water do not merge, but rather evenly cleanse the entire waste receiving surface 16 and flow into the pooled water surface 20. This makes it possible to improve the flushing performance of the bowl section 6. Furthermore, the front main flow F1 and the rear main flow F2 of the flush water are each designed to flow into different regions of the boundary area divided into four regions S1, S2, S3, and S4. As a result, at the beginning of flushing, flush water flows into three or more of the four divided regions S1, S2, S3, and S4 of the pooled water surface, so that the timing of discharging floating waste can be accelerated, and further, by applying a pressing force to the entire pooled water surface 20, the pooled water surface 20 is not disturbed, so that the discharging force of floating waste can be improved.

[0048] The effects of the above-described embodiment will now be described. In the flush toilet 1 according to the embodiment of the present invention, the first water outlet 24 is formed vertically long, and a convex portion 40 that protrudes toward the inside of the bowl portion 6 is provided on the inner circumferential surface 18a of the rim portion 18 downstream of the first water outlet 24, so that this convex portion 40 can cause a portion of the flush water swirling around the inner circumferential surface 18a of the rim portion 18 to flow down and clean the waste receiving surface 16. This can improve the flushing performance of the bowl portion 6. It can also prevent flush water from splashing out of the toilet.

[0049] Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the first water outlet 24 is provided forward of the front-to-rear central axis of the bowl portion 6, and the convex portion 40 is provided at the front end 18b of the inner circumferential surface 18a of the rim portion 18, so that even if the flush water flows through the front end 18b, which is most affected by centrifugal force immediately after being discharged, the flush water can be made to flow down by the convex portion 40 to clean the waste receiving surface 16.

[0050] In a flush toilet 1 according to an embodiment of the present invention, the convex portion 40 is provided at least in the portion forward of the central axis in the front-to-rear direction of the bowl portion 6 in a plan view of the bowl portion 6, where the inner circumferential surface 18a of the rim portion 18 is formed with the minimum radius of curvature R1, and so when flowing through the portion formed with the minimum radius of curvature R1, the flush water is caused to flow down by the convex portion 40 to clean the waste receiving surface 16. Also, because the flush water is caused to flow down by the convex portion 40 in the portion formed with the minimum radius of curvature R1 where the flush water is likely to splash out, it is possible to prevent the flush water from splashing out of the toilet bowl.

[0051] Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the lower end 40a of the convex portion 40 is inclined downwards towards the direction of flow of flush water swirling around the inner circumferential surface 18a of the rim portion 18, so that some of the swirling flush water can be caused to flow downward to clean the waste receiving surface 16.

[0052] In a flush toilet 1 according to an embodiment of the present invention, the convex portion 40 is formed so that the degree to which it protrudes inward into the bowl portion 6 increases the further downstream it goes, so that the flush water can flow downstream in a swirling motion and clean the waste receiving surface 16.

[0053] Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the underside 40b of the convex portion 40 is inclined upward toward the inside of the bowl portion, making it easy to clean the underside 40b of the convex portion 40 from above.

[0054] In a flush toilet 1 according to an embodiment of the present invention, a horizontal surface 18d is provided above the inner circumferential surface 18a of the rim portion 18 between the first water outlet 24 and the convex portion 40, so that the flush water immediately after discharge can be rectified by the horizontal surface 18d, and the rectified flush water can be made to flow toward the convex portion 40.

[0055] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the first water outlet 24 has a lower opening 32 formed in a vertically elongated rectangular shape, and an upper opening 34 formed with a smaller width than the lower opening 32 and extending upward from the lower opening 32, so that flush water can be discharged from the lower opening 32 while air is exhausted from the upper opening 34. This prevents air from being drawn in at the first water outlet 24, and the flush water from the first water outlet 24 can form a main flow F1 to clean the waste receiving surface 16.

[0056] In the flush toilet 1 according to the embodiment of the present invention, the first water passage 28 has a lower water passage 36 formed in a vertically elongated rectangular shape, and an upper water passage 38 formed with a smaller width than the lower water passage 36 and extending upward from the lower water passage 36, so that air flows through the upper water passage 38 and is discharged from the upper opening 34, and flush water flows through the lower water passage 36 and is discharged from the lower opening 32. This prevents air from being drawn in the first water passage 28, and flush water from the first water outlet 24 can form a main flow F1 to clean the waste receiving surface 16.

[0057] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the upper surface 36a of the lower water passage 36 slopes downward from the upstream toward the first water outlet 24 on the downstream side of the first water passage 28, so that a downward flow is formed by the lower water passage 36, and a downward main flow F1 can be discharged from the first water outlet 24. Meanwhile, the upper surface 38a of the upper water passage 38 extends horizontally from the upstream toward the first water outlet 24, so that a large space capable of accommodating air is formed in the upper water passage 38, so that the air can be reliably separated from the flush water and discharged from the first water outlet 24.

[0058] The present invention is not limited to the above-described embodiment, and various changes and modifications are possible within the scope of the technical idea described in the claims. [Explanation of symbols]

[0059] 1 flush toilet 6 Bowl section 8 Common Waterway 10 Drain line 16 Waste receiving surface 16a Outer surface of waste receiving surface 18 Rim 18a Inner surface of rim 18b Front end of rim 18c Vertical surface of rim 18d Horizontal surface of the rim 18e Inner edge of rim 22 Pressure Point Section 24 First outlet 28 1st waterway 32 Lower opening of first outlet 32a Upper end of lower opening 32b Lower end of the lower opening 34 Upper opening of first outlet 34a Upper end of upper opening 36 Lower channel of the first channel 36a Upper surface of the lower channel 36b Underside of the lower channel 38 Upper channel of the first channel 38a Top of the upper waterway 40 Convex 40a Lower end of convex part 40b Lower surface of convex portion R1 First radius of curvature R2 Second radius of curvature R3 Third radius of curvature P1 Area formed by the first radius of curvature F1 Main flow discharged from the first outlet

Claims

1. A flush toilet that uses flush water to flush waste, A bowl portion including a bowl-shaped waste receiving surface and a rim portion formed on an upper portion of the waste receiving surface and having an inner peripheral surface around which flush water swirls; a water outlet provided in the rim portion and configured to discharge wash water along an inner peripheral surface of the rim portion; a water passage for guiding flush water to the water outlet; a drain line connected to the bottom of the bowl portion, The water outlet is formed vertically, The inner peripheral surface of the rim portion has, on the downstream side of the spout, a vertical surface extending vertically, a horizontal surface extending horizontally from an upper end of the vertical surface toward the inside of the bowl portion, and a curved surface connecting the vertical surface and the horizontal surface, A flush toilet characterized in that the curved surface connecting the vertical surface and the horizontal surface is formed by a convex protrusion that protrudes toward the inside of the bowl portion downstream of the spout, and is formed by a concave shape that is recessed toward the outside of the bowl portion between the spout and the convex portion.

2. A flush toilet as described in claim 1, wherein, in a plan view of the bowl portion, the spout is located forward of the fore-and-aft central axis of the bowl portion, and the convex portion is located at the front end of the bowl portion.

3. 2. The flush toilet according to claim 1, wherein the convex portion is provided at least in a portion of the bowl portion that is forward of a central axis of the bowl portion in the front-to-rear direction and where the inner circumferential surface of the rim portion is formed with a minimum radius of curvature, when viewed in plan view.

4. 4. The flush toilet according to claim 1, wherein the lower end of the convex portion is inclined downwardly towards the flow direction of flush water swirling around the inner circumferential surface of the rim portion.

5. 5. The flush toilet according to claim 4, wherein the convex portion is formed so that the degree to which it protrudes inwardly from the bowl portion increases downstream.

6. 6. The flush toilet according to claim 5, wherein the lower surface of the convex portion is inclined upward toward the inside of the bowl portion.

7. 2. The flush toilet according to claim 1, wherein the water outlet has a lower opening formed in a vertically elongated rectangular shape, and an upper opening formed with a smaller width than the lower opening and extending upward from the lower opening.

8. 8. The flush toilet according to claim 7, wherein the water passage comprises a lower water passage formed in a vertically elongated rectangular shape, and an upper water passage formed with a smaller width than the lower water passage and extending upward from the lower water passage.

9. 9. The flush toilet according to claim 8, wherein, on the downstream side of the water passage, the upper surface of the lower water passage slopes downward from the upstream toward the spout, and the upper surface of the upper water passage extends horizontally from the upstream toward the spout.

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