Flush toilet

Abstract

To provide a flush toilet that cleans a toilet bowl with washing water supplied by the water supply pressure of tap water, and can be improved in the cleaning performance of a bowl unit.SOLUTION: A flush toilet is provided, cleaning the toilet with washing water supplied by water supply pressure. The flush toilet includes: a bowl portion 6 comprising a bowl-shaped filth receiving surface 18, a rim portion 20 formed above the filth receiving surface 18, and a shelf surface 21 formed between the filth receiving surface 18 and the rim portion 20; and one rim water spray port 10 provided in the rim portion 20 and spraying washing water toward the front along the inner peripheral surface 20a of the rim portion 20. The rim water spray port 10 is located rearward of a position X1 where the width of the filth receiving surface 18 in the left-right direction is the maximum in a plan view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flush toilet, and more particularly to a flush toilet that flushes the toilet with flush water supplied by water supply pressure from a mains water supply. [Background technology]

[0002] Conventionally, there has been known a flush toilet in which flush water supplied from a water line is discharged from a single rim spout, as described in Patent Document 1. In this flush toilet, the front end of the bowl portion is formed with a small radius of curvature, and a rim spout is provided near the front end of this bowl portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-303616 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in flush toilets such as the one described in Patent Document 1, a rim spout is provided near the front end of the bowl, so when flush water is spouted forward from the rim spout, a large amount of energy is lost as it swirls around the front end of the bowl. This weakens the momentum of the flush water swirling around the bowl, and there is a problem that the bowl cannot be sufficiently flushed with water.

[0005] Therefore, 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 in a flush toilet that uses flush water supplied by the water supply pressure of the mains. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a flush toilet that cleans the toilet bowl with flushing water supplied by the water supply pressure of a water main, and has a bowl portion equipped with a bowl-shaped waste receiving surface, a rim portion formed above the waste receiving surface, and a shelf surface formed between the waste receiving surface and the rim portion, and one spout provided in the rim portion that sprays flushing water forward along the inner surface of the rim portion, the spout being positioned rearward of the position where the left-right width of the waste receiving surface is greatest in a plan view. In the present invention configured in this way, the spout is positioned rearward of the position where the width of the waste receiving surface in the left-right direction is greatest in a plan view, making it possible to increase the distance from the spout to the front end of the bowl. This allows a larger area to be cleaned with flush water in a high-energy state before energy loss occurs at the front end of the bowl. This therefore improves the flushing performance of the bowl in a flush toilet that uses flush water supplied by the water supply pressure of the mains.

[0007] In the present invention, the waste receiving surface is preferably formed in a concave shape that is concave downward in its front region. In the present invention configured in this manner, the waste receiving surface is formed in a concave shape that is recessed downward in its front region, so that flush water can be made to flow down from the front region of the waste receiving surface.

[0008] In the present invention, the waste receiving surface is preferably formed in a convex shape that protrudes upward in an area rearward of the water discharge port. In the present invention configured in this manner, the waste receiving surface is formed in a convex shape that protrudes upward in the area rearward of the water outlet, so that in the rearward area where the force of the wash water weakens, the wash water can be placed on the convex waste receiving surface and spread throughout the rearward area.

[0009] In the present invention, the waste receiving surface is preferably formed in a convex shape that protrudes upward in a region rearward of the front region. In the present invention configured in this manner, the waste receiving surface is formed in a convex shape that protrudes upward in the area rearward of the front area, so that cleaning water can be placed on the convex waste receiving surface and spread over the entire waste receiving surface.

[0010] In addition, in the present invention, the rim portion is preferably formed so that its inner surface overhangs inwardly and upwardly, and the amount of overhang of the inner surface of the rim portion is greatest at the front end of the bowl portion. In the present invention configured in this manner, the rim portion is formed so that its inner surface overhangs inward toward the top, and the amount of overhang of the inner surface of the rim portion is greatest at the front end of the bowl portion, thereby preventing cleaning water from splashing out at the front end of the bowl portion.

[0011] In the present invention, the rim portion is preferably formed so that its inner peripheral surface slopes inwardly upward, and the angle of inward slope of the inner peripheral surface of the rim portion relative to the vertical direction is maximum at the front end of the bowl portion. In the present invention configured in this manner, the rim portion is formed so that its inner surface slopes inward toward the top, and the angle of inward slope of the inner surface of the rim portion relative to the vertical direction is maximum at the front end of the bowl portion, thereby preventing cleaning water from splashing out at the front end of the bowl portion. [Effects of the Invention]

[0012] According to the flush toilet of the present invention, the flushing performance of the bowl can be improved in a flush toilet that flushes the toilet with flush water supplied by the water supply pressure of the mains water supply. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a plan cross-sectional view showing a flush toilet according to an embodiment of the present invention. [Figure 2]FIG. 2 is a side cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 1 is a plan view of a flush toilet according to an embodiment of the present invention with the upper rim portion removed from the body portion. [Figure 4] FIG. 1 is a perspective view of a flush toilet according to an embodiment of the present invention with the upper rim portion removed from the body portion. [Figure 5A] FIG. 2 is a cross-sectional view taken along the line VA-VA in FIG. [Figure 5B] FIG. 2 is a cross-sectional view taken along line VB-VB in FIG. [Figure 5C] FIG. 2 is a cross-sectional view taken along the line VC-VC in FIG. [Figure 6A] FIG. 2 is a cross-sectional view taken along line VIA-VIA in FIG. [Figure 6B] FIG. 2 is a cross-sectional view taken along line VIB-VIB in FIG. [Figure 7] FIG. 2 is a diagram for explaining the flushing operation of a flush toilet according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram illustrating how the bowl portion of a flush toilet according to an embodiment of the present invention is cleaned. DETAILED DESCRIPTION OF THE INVENTION

[0014] A flush toilet according to an embodiment of the present invention will now be described with reference to the drawings. First, the basic structure of a flush toilet 1 according to an embodiment of the present invention will be explained with reference to Figures 1 and 2. Figure 1 is a plan cross-sectional view showing a flush toilet according to an embodiment of the present invention, and Figure 2 is a side cross-sectional view taken along line II-II in Figure 1. In this specification, the front side of the flush toilet as seen from the user's perspective will be referred to as the front side, the back side as the rear side, the right side as the right side, and the left side as the left side.

[0015] As shown in Figures 1 and 2, a flush toilet 1 according to an embodiment of the present invention is a siphon jet flush toilet that uses a jet of water to generate a siphon effect and discharge waste from the bowl section to the outside through the drain trap pipe. The flush toilet 1 according to the embodiment of the present invention is a siphon jet type flush toilet, but it may also be a wash-down type toilet in which waste is washed away by the flowing water caused by the difference in water level within the bowl, or a siphon type flush toilet in which siphon action is generated by the rim spout to discharge waste within the bowl to the outside through the drainage pipe.

[0016] The flush toilet 1 comprises a ceramic toilet body 2, a resin toilet seat and toilet lid (not shown) placed on the top surface of the toilet body 2, and a water storage tank 4 placed at the upper rear of the toilet body 2 and covered by a resin cover (not shown).

[0017] The toilet body 2 is formed with a bowl portion 6 for receiving waste, a drain trap pipe 8 provided at the bottom of the bowl portion 6 for discharging waste by siphon action, a rim spout 10 for rim water discharge, a rim water conduit 12 for supplying flushing water to the rim spout 10, a jet spout 14 for jet water discharge, and a jet water conduit 16 for supplying flushing water to the jet spout 14.

[0018] Bowl portion 6 has a bowl-shaped waste receiving surface 18, a rim portion 20 formed along the upper edge of bowl portion 6, and a shelf surface 21 formed between waste receiving surface 18 and rim portion 20. Bowl portion 6 also has a basin portion 22 formed in the area below waste receiving surface 18 and connected to drain trap pipe line 8. A water collecting surface W is formed inside basin portion 22.

[0019] The drain trap pipe 8 has an inlet 8a, an ascending pipe 8b extending upward from the inlet 8a, a descending pipe 8c extending downward from the ascending pipe 8b, and a top 8d located between the descending pipe 8c and the ascending pipe 8b and defining the accumulated water level. The lower end of the descending pipe 8c of the drain trap pipe 8 is connected to a drain pipe (not shown) via a drain socket (not shown).

[0020] When viewing the toilet body 2 from the front, only one rim spout 10 (spout) is formed on the rear left side of the rim portion 20. The rim spout 10 spouts flushing water forward, and this flushing water flows down onto the waste receiving surface 18 while swirling on the inner circumferential surface 20a of the rim portion 20 and the shelf surface 21, thereby cleaning the waste receiving surface 18.

[0021] In plan view, the rim conduit 12 is formed in a tapered shape with the flow path cross section gradually becoming smaller towards the rim spout 10. A water supply hose 13 that is directly connected to the water supply is connected to the upstream side of the rim conduit 12. Flush water is supplied to the rim conduit 12 from the water supply, and is discharged from the rim spout 10 by the water supply pressure of the water supply.

[0022] Jet water outlet 14 is formed in the bottom of bowl portion 6. Jet water outlet 14 is positioned opposite inlet 8a of drain trap pipe 8 and is directed toward inlet 8a of drain trap pipe 8. Jet water outlet 14 ejects flush water toward inlet 8a of drain trap pipe 8, and this flush water flows into drain trap pipe 8, activating the siphon action.

[0023] The jet water conduit 16 extends forward from the water storage tank 4, bends, and then extends rearward. One end of the jet water conduit 16 is connected to the drain outlet 4a of the water storage tank 4, and the other end is connected to the jet water spouting outlet 14. Flush water is supplied to the jet water conduit 16 from the water storage tank 4, and the head pressure of this flush water causes the flush water to be spouted from the jet water spouting outlet 14.

[0024] The water storage tank 4 is a gravity-fed tank that stores the flush water used for jet spouting and supplies it to the jet spouting port 14. The water storage tank 4 is a small resin tank. The water storage tank 4 has a volume of approximately 3 liters, and the amount of flush water discharged from the water storage tank 4 in one flush is approximately 2 liters.

[0025] Inside the water storage tank 4 are provided a water supply device 24 that supplies flush water to the water storage tank 4, a drainage device 26 that supplies or stops the flush water stored in the water storage tank 4 to the jet water conduit 16, and a float switch 28 that detects when the flush water level in the water storage tank 4 has reached the full water level. Also provided outside the water storage tank 4 is a controller (not shown) that controls the water supply device 24 and drainage device 26 to operate or stop based on an operation signal from the user, and an operation unit (not shown) that sends out an operation signal in response to operation by the user.

[0026] The water supply device 24 comprises a constant flow valve (not shown) connected to the water supply, a rim-side solenoid valve 23 which supplies or stops the flow of flush water to the rim spout 10, and a tank-side solenoid valve 27 which supplies or stops the flow of flush water to a tank water supply port 25 located inside the water storage tank 4. The rim-side solenoid valve 23 and tank-side solenoid valve 27 are designed to be driven by commands from a controller based on operation signals from the user and water level detection signals from a float switch 28.

[0027] The drainage device 26 comprises an overflow pipe 30 that drains overflowing water from the water storage tank 4 into the toilet body 2, a drain valve 32 fixed to the lower end of the overflow pipe 30, and a toilet flushing unit 36 that opens and closes the drain valve 32 by moving the overflow pipe 30 up and down using an electric drive force. The toilet flushing unit 36 is driven by commands from a controller based on operation signals from the user.

[0028] The controller is electrically connected to the operation unit, float switch 28, rim-side solenoid valve 23, tank-side solenoid valve 27, and toilet flushing unit 36, and is capable of sending and receiving various signals. The controller receives a flush start signal for a large flush or small flush from the operation unit, and activates or stops the rim-side solenoid valve 23, tank-side solenoid valve 27, and toilet flushing unit 36 based on a pre-stored flush sequence.

[0029] The flush toilet 1 according to this embodiment of the present invention is set to have a flush water volume of approximately 4.8 liters for a large flush and approximately 3.8 liters for a small flush.

[0030] Next, the structure of the bowl portion 6 of the flush toilet 1 according to an embodiment of the present invention will be described in detail with reference to FIGS. Figure 3 is a plan view of a flush toilet according to an embodiment of the present invention with the upper rim part removed from the body, Figure 4 is a perspective view of a flush toilet according to an embodiment of the present invention with the upper rim part removed from the body, Figures 5A to 5C are cross-sectional views taken along lines VA-VA to VC-VC in Figure 1, and Figures 6A to 6B are cross-sectional views taken along lines VIA-VIA to VIB-VIB in Figure 1. Figures 5A to 5C are cross-sectional views taken along lines extending radially from the centre O of the bowl part 6.

[0031] First, as shown in Figure 2, the inner peripheral surface 20a of the rim portion 20 has a lower end 20b connected to the shelf surface 21. The inner peripheral surface 20a of the rim portion 20 is also provided with an adhesive portion 20c where the rim upper portion 40 and the body portion 42, which are molded separately during the manufacture of the toilet, are adhered. This adhesive portion 20c is located near the center of the rim portion 20 in the up-down direction at the front end 6a of the bowl portion 6 (see Figure 2). The inner peripheral surface 20a of the rim portion 20 extends upward from the lower end 20b to adhesive portion 20c toward the outside of the bowl portion 6, and then extends upward from adhesive portion 20c toward the inside of the bowl portion 6 to an upper end 20d.

[0032] Next, as shown in Figure 3, the outer casing 7 of the toilet body 2 is formed so that the radius of curvature R1 in a plan view at the front end 6a of the bowl section 6 is smaller than the radius of curvature of the outer casing 7 of the toilet body 2 on the rear side. The radius of curvature R1 of the front end of the outer casing 7 of the toilet body 2 is formed with the smallest radius of curvature of the outer casing 7 of the toilet body 2. As a result, the flush toilet 1 has an external design in which the front end of the outer casing 7 of the toilet body 2 is pointed.

[0033] As shown in FIGS. 3 and 4, the lower end portion 20b of the inner peripheral surface 20a of the rim portion 20 is formed by the minimum radius of curvature R2 among the inner peripheral surface 20a of the rim portion 20 at the front end portion 6a of the bowl portion 6 in a plan view (see region S1 in FIG. 3). The left front portion 6b and the right front portion 6c on the rear side of the front end portion 6a of the bowl portion 6 are formed by a radius of curvature R3 (>R2) greater than the minimum radius of curvature R2 (see regions S2 and S3 in FIG. 3). The left side portion 6d and the right side portion 6e on the further rear side of the left front portion 6b and the right front portion 6c of the bowl portion 6 are formed by the maximum radius of curvature R4 (>R3) (see regions S4 and S5 in FIG. 3). Also, the radii of curvature R2 to R4 of the lower end portion 20b of the rim portion 20 are formed to be larger than the radius of curvature R1 of the front end portion of the outer contour 7 of the toilet body 2 (R2 to R4 > R1). Thereby, it is possible to suppress the energy loss of the washing water flowing through the inner peripheral surface 20a of the rim portion 20 at the front end portion 6a of the bowl portion 6.

[0034] As shown in FIGS. 3 and 4, above the lower end portion 20b of the inner peripheral surface 20a of the rim portion 20, an adhesive portion 20c where the upper rim portion 40 and the body portion 42, which are separately molded during toilet manufacturing, are adhered is provided. The adhesive portion 20c of the rim portion 20 is formed by a radius of curvature R5 (<R2) smaller than the radius of curvature R2 of the lower end portion 20b of the rim portion 20 at the front end portion 6a of the bowl portion 6 in a plan view. The radius of curvature R5 of the adhesive portion 20c of this rim portion 20 is formed to be approximately the same size as the radius of curvature R1 of the front end portion of the outer contour 7 of the toilet body 2 (R5 = R1). Thus, the radius of curvature R2 of the lower end portion 20b of the rim portion 20 is formed to be larger than the radius of curvature R1 of the front end portion of the outer contour 7 of the toilet body 2, so that no energy loss occurs in the washing water swirling on the inner peripheral surface 20a of the rim portion 20 at the front end portion 6a of the bowl portion 6. On the other hand, since the radius of curvature R5 of the adhesive portion 20c of the rim portion 20 is formed to be approximately the same size as the radius of curvature R1 of the front end portion of the outer contour 7 of the toilet body 2, during the manufacture of the flush toilet 1, the upper rim portion 40 and the body portion 42, which are separately molded, can be easily adhered, and thereby, the toilet body 2 can be easily manufactured.

[0035] As shown in Fig. 3, the dirt receiving surface 18 is formed such that its front end portion 18a has a radius of curvature R6. The radius of curvature R6 of the front end portion 18a of the dirt receiving surface 18 is formed to be larger than the radius of curvature R2 of the lower end portion 20b of the rim portion 20 at the front end portion 6a of the bowl portion 6 (R6 > R2). Thereby, the washing water swirling on the shelf surface 21 smoothly flows down onto the dirt receiving surface 18. In the embodiment of the present invention, the radius of curvature R6 of the front end portion 18a of the dirt receiving surface 18 is formed to be larger than the radius of curvature R2 of the lower end portion 20b of the rim portion 20 at the front end portion 6a of the bowl portion 6, but it may be formed to have the same size as the radius of curvature R2 of the lower end portion 20b of the rim portion 20.

[0036] As shown in Fig. 3, the tub portion 22 is formed such that its front end portion 22a has a radius of curvature R7. The radius of curvature R7 of the front end portion 22a of the tub portion 22 is formed to be smaller than the radius of curvature R1 of the front end portion of the outer contour 7 of the toilet body 2, the radius of curvature R2 of the lower end portion 20b of the rim portion 20, and the radius of curvature R6 of the front end portion 18a of the dirt receiving surface 18 (R7 < R1, R2, R6). Thereby, the washing water smoothly flows into the water storage surface W.

[0037] As shown in Fig. 1, the rim water outlet 10 is arranged on the rear side of the position X1 where the width in the left - right direction of the dirt receiving surface 18 of the bowl portion 6 is maximum in a plan view. Further, the rim water outlet 10 is arranged on the rear side of the position X2 where the width in the left - right direction of the water storage surface W is maximum in a plan view. Thereby, the distance from the rim water outlet 到ボウル部6の前端部6aまでの距離が比較的に長くなるようになっている。

[0038] Next, as shown in Fig. 2, the dirt receiving surface 18 is formed in a concave shape that recesses downward in its front region. Thereby, in the front region of the dirt receiving surface, the washing water is difficult to flow down because it receives a large centrifugal force, but the washing water can be made to flow down from the front region of the dirt receiving surface.

[0039] It should be noted that there is an unclear expression in the translation of line "到ボウル部6の前端部6aまでの距離が比較的に長くなるようになっている。", which might be a problem in the original text. You can check and correct it if necessary.5A to 5C, waste receiving surface 18 is formed in a convex shape that protrudes upward in an area rearward of the front area of waste receiving surface 18 (see FIGS. 5A to 5C). This allows flush water that has passed through inner circumferential surface 20a of rim portion 20 at front end 6a of bowl portion 6 to be placed on convex waste receiving surface 18 and spread over the entire waste receiving surface 18.

[0040] 5B and 5C, the waste receiving surface 18 is formed in a convex shape that protrudes upward in the area rearward of the rim spout 10 (see FIGS. 5B and 5C). This allows the flush water to ride on the convex waste receiving surface 18 and spread throughout the area rearward of the rim spout 10 in the area rearward where the force of the flush water weakens.

[0041] 2 and 5A to 5C, the angle of inclination at which waste receiving surface 18 slopes downward toward center O of bowl portion 6 (the angle of inclination downward with respect to the horizontal) is smallest in the front region of waste receiving surface 18. In other words, the angle of inclination at which waste receiving surface 18 slopes downward toward center O of the bowl portion is larger in the rear region of waste receiving surface 18 than in the front region. This allows flush water to flow smoothly from the front region of waste receiving surface 18 into the pooled water surface W.

[0042] 6A and 6B, the waste receiving surface 18 has a downwardly recessed portion 18b in its front region. The recessed portion 18b extends linearly from the front end portion 6a of the bowl portion 6 toward the pooled water surface W at the rear. This allows flush water swirling around the waste receiving surface 18 to be collected by the recessed portion 18b and flow toward the pooled water surface W.

[0043] 2 and 5A to 5C, the amount by which inner peripheral surface 20a of rim portion 20 overhangs inside bowl portion 6 (the amount by which upper end 20d of rim portion 20 protrudes inside bowl portion 6 relative to lower end 20b) is formed to be greatest at front end 6a of bowl portion 6. As a result, at front end 6a of bowl portion 6, flush water is likely to splash out of the toilet due to the large centrifugal force that is applied, but it is possible to prevent flush water from splashing out.

[0044] 2 and 5A to 5C, the angle at which inner peripheral surface 20a of rim portion 20 inclines inward into bowl portion 6 with respect to the vertical direction is maximum at front end 6a of bowl portion 6. As a result, at front end 6a of bowl portion 6, flush water is likely to splash out of the toilet due to the large centrifugal force that is applied, but it is possible to prevent flush water from splashing out.

[0045] Next, the flushing operation of the flush toilet 1 according to an embodiment of the present invention will be explained with reference to FIG. FIG. 7 is a diagram illustrating the flushing operation of a flush toilet according to an embodiment of the present invention.

[0046] 7(a) shows the standby state, in which flush water has accumulated in the bowl section 6 up to the initial water level of the pooled water surface W, and flush water has also accumulated in the jet water conduit 16 up to the same height as the initial water level of the pooled water surface W. At this time, air is accumulating in area A upstream of the jet water conduit 16, located directly below the water storage tank 4.

[0047] Next, as shown in Figure 7(b), the water supply device is driven (the rim-side solenoid valve opens) and flush water is discharged from the rim outlet 10 (rim water discharge begins). The flush water discharged from the rim outlet 10 swirls around the bowl section 6 and flows into the pooled water surface W. The water level in the pooled water surface W gradually rises, and the flush water level also gradually rises in the jet water conduit 16. As a result, the air that had been trapped in area A is expelled from the overflow pipe 30 and the jet water conduit 16 becomes full of water.

[0048] After this, as shown in Figure 7(c), while flush water is being discharged from the rim spout 10, the drain device 26 is driven (the drain valve 32 opens), and flush water is discharged from the jet spout 14 (jet spouting begins). At this time, the head pressure of the flush water stored in the water storage tank 4 is applied to the flush water that has accumulated in the jet water conduit 16, and a first flow rate is discharged from the jet spout 14. The first flow rate is a large flow rate, and jet water discharge at the first flow rate fills the drain trap pipe 8, activating the siphon action. Jet water discharge at the first flow rate continues for a predetermined time, and waste is discharged by the powerful siphon action.

[0049] Next, as shown in Figure 7(d), the drainage device 26 stops (the drainage valve 32 closes) while flush water is being discharged from the rim spout 10. Even when the drainage device 26 stops, because the overall volume of the jet water conduit 16 is large, a large amount of flush water remains within the jet water conduit 16, and as the water flows through the jet water conduit 16 under the head pressure of the stored flush water, it is discharged from the jet water spout 14 at a second flow rate. The second flow rate is smaller than the first flow rate, but is sufficient to continue the siphoning action. Jet water is discharged at the second flow rate continuously for a predetermined time, and the siphoning action continues.

[0050] Thereafter, as shown in Figure 7(e), the siphon action causes the accumulated water to be discharged together with the waste, causing the water level at the accumulated water surface W to drop, and air enters from the upper end of the inlet 8a of the drain trap pipe 8, ending the siphon action. Here, the jet water conduit 16 is formed so that flush water continues to accumulate, delaying the entry of air and delaying the end of the siphon action. Flush water continues to be discharged from the rim outlet 10, and flushing ends when the flush water accumulates in the bowl section 6 up to the initial water level at the accumulated water surface W. At this time, flush water has also accumulated in the jet water conduit 16 up to the same height as the accumulated water surface W.

[0051] Next, as shown in Figure 7(f), the water supply device is driven (the tank-side electromagnetic valve opens) and water supply to the tank begins. When the flush water level in the water storage tank 4 rises and the float switch detects that it has reached the water stop level (full water level), the water supply device stops (the tank-side electromagnetic valve closes), and then the initial state is restored as shown in Figure 7(a).

[0052] Next, referring to FIG. 8, the manner in which the bowl portion 6 of the flush toilet 1 according to this embodiment of the present invention is flushed will be described. FIG. 8 is a diagram illustrating how the bowl portion of a flush toilet according to an embodiment of the present invention is cleaned.

[0053] As shown in Figure 8, most of the flush water discharged from the rim spout 10 swirls on the inner circumferential surface 20a of the rim portion 20 and on the shelf surface 21 (F1). Because the radius of curvature R2 of the inner circumferential surface 20a of the rim portion 20 is large at the front end 6a of the bowl portion 6, energy loss of the flush water flowing along the inner circumferential surface 20a of the rim portion 20 is suppressed.

[0054] A portion of the flush water swirling on shelf surface 21 flows down from shelf surface 21 onto waste receiving surface 18, and swirls on waste receiving surface 18. Because waste receiving surface 18 has a convex shape that protrudes upward in a region rearward of the front region of waste receiving surface 18, a portion of the flush water swirling on waste receiving surface 18 is guided to the rear region (F2). Furthermore, because waste receiving surface 18 has a concave shape that recesses downward in the front region of waste receiving surface 18, a portion of the flush water swirling on waste receiving surface 18 is guided from concave waste receiving surface 18 to pooled water surface W (F3). The flush water guided to pooled water surface W flows smoothly into pooled water surface W because the radius of curvature of front end 22a of basin portion 22 is small.

[0055] The following describes the effects and advantages of the flush toilet 1 according to the embodiment of the present invention described above. In a flush toilet 1 according to an embodiment of the present invention, the rim spout 10 is positioned rearward of the position X1 where the width in the left-right direction of the waste receiving surface 18 is greatest in a plan view, making it possible to increase the distance from the rim spout 10 to the front end 6a of the bowl section 6. This allows a larger area to be cleaned with flush water in a high-energy state before energy loss occurs at the front end 6a of the bowl section 6. This makes it possible to improve the flushing performance of the bowl section 6 in a flush toilet 1 that flushes the toilet with flush water supplied by the water supply pressure of the mains water supply.

[0056] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the waste receiving surface 18 is formed in a concave shape that is recessed downward in its front region, so that flush water can be made to flow down from the front region of the waste receiving surface 18.

[0057] In the flush toilet 1 according to an embodiment of the present invention, the waste receiving surface 18 is formed in a convex shape that protrudes upward in the area rearward of the rim spout 10, so that in the rearward area where the force of the flush water weakens, the flush water can be placed on the convex waste receiving surface 18 and spread throughout the rearward area.

[0058] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the waste receiving surface 18 is formed in a convex shape that protrudes upward in the area rearward of the front area, so that flushing water can be placed on the convex waste receiving surface 18 and spread over the entire waste receiving surface 18.

[0059] In the flush toilet 1 according to an embodiment of the present invention, the rim portion 20 is formed so that its inner surface 20a overhangs inward and upward, and the amount of overhang of the inner surface 20a of the rim portion 20 is formed so that it is greatest at the front end 6a of the bowl portion 6, thereby preventing flush water from splashing out at the front end 6a of the bowl portion 6.

[0060] Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the rim portion 20 is formed so that its inner peripheral surface 20a slopes inward as it moves upward, and the angle of inward slope of the inner peripheral surface 20a of this rim portion 20 relative to the vertical is greatest at the front end 6a of the bowl portion 6, thereby preventing flush water from splashing out at the front end a of the bowl portion 6.

[0061] The present invention is not limited to the above-described embodiments, and various changes and modifications are possible within the scope of the technical concept described in the claims. [Explanation of symbols]

[0062] 1: Flush toilet 2: Toilet bowl body 4: Water tank 6: Bowl section 6a: Front end of bowl 6b: Front left part of bowl 6c: Right front part of bowl 6d: Left side of bowl 6e: Right side of the bowl 7: Outer casing of the toilet bowl 8: Drain trap pipe 8a: Inlet of drain trap pipe 10: Rim spout 14: Jet spout 18: Waste receiving surface 18a: Front end of waste receiving surface 18b: Recessed portion of waste receiving surface 20: Rim 20a: Inner surface of rim 20b: Lower end of rim 20c: Rim adhesive 20d: Upper end of rim 21: Shelf surface 22: Pressure point 22a: Front end of the acupoint 40: Upper rim 42: Torso

Claims

1. A flush toilet that uses flush water supplied by the water supply pressure of the mains water supply, a bowl portion including a bowl-shaped waste receiving surface, a rim portion formed above the waste receiving surface, and a shelf surface formed between the waste receiving surface and the rim portion; one water outlet provided in the rim portion and which discharges flush water forward along the inner circumferential surface of the rim portion; and A flush toilet characterized in that the water outlet is located rearward of the position at which the width of the waste receiving surface in the left-right direction is greatest in a plan view.

2. 2. The flush toilet according to claim 1, wherein the waste receiving surface is formed in a concave shape that is recessed downward in its front region.

3. The flush toilet according to claim 2, wherein the waste receiving surface is formed in a convex shape that protrudes upward in an area rearward of the spout.

4. 4. The flush toilet according to claim 2 or 3, wherein the waste receiving surface is formed in a convex shape that protrudes upward in an area rearward of the front area.

5. The rim portion is formed so that its inner peripheral surface overhangs inwardly and upwardly, 2. The flush toilet according to claim 1, wherein the amount of overhang of the inner peripheral surface of the rim portion is greatest at the front end of the bowl portion.

6. The rim portion is formed so that its inner peripheral surface slopes upward and inward, 2. The flush toilet according to claim 1, wherein the angle of inward inclination of the inner peripheral surface of the rim relative to the vertical is greatest at the front end of the bowl.

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