Water-washable toilet
The flush toilet's innovative drain trap section design, with a narrowing and widening flow path, enhances drainage performance by maintaining flow velocity, addressing incomplete discharge and blockage issues in conventional toilets.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOTO LTD
- Filing Date
- 2024-12-25
- Publication Date
- 2026-07-07
Smart Images
Figure 2026113106000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a flush toilet, and more particularly to a flush toilet that discharges waste using flushing water supplied from a flushing water source. [Background technology]
[0002] Conventionally, as a flush toilet that discharges waste using flushing water supplied from a flushing water source, for example, as described in Patent Document 1, a flush toilet is known in which flushing water supplied from a flushing water source is guided into the bowl section to start flushing the toilet bowl, and the waste in the bowl section is discharged from the drain trap section by the flushing water guided into the bowl section. Furthermore, in such conventional flush toilets, the drainage pipe of the drain trap section includes a descending pipe that goes down from an inlet connected to the bottom of the bowl to the rear and bottommost end, and an ascending pipe that connects to the bottommost end of the descending pipe and goes up to the rear and top. The flow path cross-section at the bottommost end is formed in a roughly inverted triangular shape, and the flow path cross-section of the ascending pipe is formed in a roughly square shape over a predetermined length, thereby improving discharge performance. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2023-32447 [Overview of the project] [Problems that the invention aims to solve]
[0004] On the other hand, with the growing need to conserve water used for flushing toilets in recent years, a challenge that has emerged is how to improve the drainage performance of the drain trap section with a small amount of water. In particular, in flush toilets with multiple flushing modes for large and small flushes, when the toilet is flushed in small flush mode, there is a problem in that, in addition to waste, paper products such as toilet paper used by the user are not completely discharged and remain in the drain trap, causing blockages. Furthermore, in order to improve the discharge performance of the drain trap section, it is conceivable that the flow velocity of the flushing water in the flow path could be increased by narrowing the vertical width of the flow path cross-section of the drain trap section, for example, by creating a region that restricts the flow path. However, because the vertical width of the flow path cross-section in the drain trap section is narrowed, if a long piece of waste reaches it, it may not be able to pass through completely, which could cause a blockage.
[0005] Therefore, the present invention was made to solve the problems that have been requested in recent years and the problems of the prior art described above, and aims to provide a flush toilet that can improve the discharge performance of the drain trap. [Means for solving the problem]
[0006] To achieve the above-mentioned objectives, the present invention provides a flush toilet that discharges waste using flushing water supplied from a flushing water source, comprising: a bowl portion including a waste receiving surface for receiving waste and a rim portion formed above the waste receiving surface; a rim discharge portion including a rim discharge port provided in the rim portion for discharging flushing water supplied from the flushing water source, and discharging water into the bowl portion only from this rim discharge port; and a drain trap portion having an inlet portion connected to the lower part of the bowl portion for discharging waste from the bowl portion, wherein the drain trap portion forms a drainage pipe that descends to the lowest end behind and below the inlet portion, and then rises to the top portion behind and above the inlet portion, and the drainage pipe is characterized in that, in the region behind the inlet portion, the maximum width of its flow path cross-section decreases from the upstream side to the region behind the lowest end in the downstream side, and then increases towards the top portion. In the present invention configured as described above, when toilet flushing is started, flushing water supplied from the flushing water source is discharged into the bowl only from the rim outlet of the rim water outlet. Along with this flushing water, the waste in the bowl that is received by the waste receiving surface is discharged into the drain pipe of the drain trap. In this case, the drainage pipe is formed such that, in the region behind its inlet, the maximum width of its flow channel cross-section decreases from the upstream side to the rearmost region of the lowest end, and then increases towards the top. In particular, in the region behind the inlet of the drainage pipe, where the maximum width of the flow channel cross-section decreases from the upstream side to the rearmost region of the lowest end, the flow velocity of the washing water can be maintained, thereby improving the discharge performance of the drainage pipe.
[0007] In the present invention, preferably, the drainage pipe has a reducing section in the region behind the inlet where the maximum width of the flow channel cross-section decreases from the upstream side to the downstream side up to the region behind the lowest end, and this reducing section has a constant section provided downstream thereof where the maximum vertical width of the flow channel cross-section remains constant. In the present invention configured in this way, the drainage pipe has a reducing section in the region behind its inlet where the maximum width of its flow channel cross-section decreases from the upstream side to the downstream side, up to the rearmost region of the lowest end. This reducing section is provided downstream and includes a constant section where the maximum vertical width of its flow channel cross-section remains constant. Therefore, the flow velocity of the washing water can be maintained in the reducing section where the maximum width of the flow channel cross-section of the drainage pipe decreases from the upstream side to the downstream side. Furthermore, even in a certain section where the maximum vertical width of the flow channel cross-section remains constant on the downstream side of the reduced section, the flow velocity of the washing water can be maintained, thereby further improving the discharge performance of the drainage pipeline.
[0008] In the present invention, preferably, the drainage pipe comprises a descending pipe extending downward from the inlet to the lowest end and an ascending pipe extending upward from the lowest end to the top, wherein the descending pipe comprises a first region, a second region, and a third region, which divide the area from the inlet to the lowest end into three equal parts from the upstream side to the downstream side, and the starting point where the maximum width of the flow path cross-section of the drainage pipe begins to decrease from the upstream side to the downstream side is located in the second region. In the present invention configured as described above, the starting point at which the maximum width of the flow path cross-section of the drainage pipe begins to decrease from the upstream side to the downstream side is located in the second region of the descending pipe that descends from the inlet to the lowest end of the drainage pipe. As a result, the flow velocity of the washing water can be maintained in the second region of the descending pipe, thereby improving the discharge performance of the drainage pipe.
[0009] In the present invention, preferably, the starting point is located at the center in the front-to-back direction of the second region. In the present invention configured in this way, the starting point at which the maximum width of the flow path cross-section of the drainage pipe begins to decrease from the upstream side to the downstream side is located at the center in the front-to-back direction of the second region of the drainage pipe. This allows the flow velocity of the washing water to be effectively maintained in the second region of the descending pipe, thereby further improving the discharge performance of the drainage pipe.
[0010] In the present invention, preferably, the rising pipeline comprises a fourth region, a fifth region, and a sixth region, which are provided to divide the region from the lowest end to the top into three equal parts from the upstream side to the downstream side, and the maximum width of the flow path cross-section of the drainage pipeline is smallest in the fifth region. In the present invention configured in this way, the maximum width of the flow path cross-section of the drainage pipeline is minimized in the 5th region of the 4th, 5th, and 6th regions, which are provided to divide the area from the lowest end to the top of the rising pipeline into three equal parts from the upstream side to the downstream side. Therefore, the discharge performance of the drainage pipeline can be further improved.
[0011] In the present invention, preferably, when the maximum width of the cross-section of the ascending pipe reaches the end point where the increase from the upstream side towards the top ends, the end point is provided on the downstream side of the sixth region. In the present invention configured as described above, since the end point when the increase in the maximum width of the cross-section of the ascending pipe from the upstream side towards the top ends is provided on the downstream side of the sixth region among the fourth region, the fifth region, and the sixth region which divide the region from the lowermost end to the top of the ascending pipe into three equal parts from the upstream side towards the downstream side, the discharge performance in the drain pipe can be further enhanced more effectively.
Advantages of the Invention
[0012] According to the flushing toilet of the present invention, the discharge performance of the drain trap portion can be enhanced.
Brief Description of the Drawings
[0013] [Figure 1] It is a central side cross-sectional view of a flushing toilet according to an embodiment of the present invention. [Figure 2] It is a plan cross-sectional view seen along line II-II of FIG. 1. [Figure 3] It is a cross-sectional view of a plurality of flow path cross-sections A to I of the drain pipe of the drain trap portion of a flushing toilet according to an embodiment of the present invention shown in FIG. 2. [Figure 4] It is a diagram showing an example of the result of simulating the change in the flow velocity of the flushing water passing through the lowest point in the drain pipe of the drain trap portion during toilet flushing in a flushing toilet according to an embodiment of the present invention and a conventional flushing toilet.
Embodiments for Carrying Out the Invention
[0014] Hereinafter, a flushing toilet according to an embodiment of the present invention will be described with reference to the accompanying drawings. First, referring to FIGS. 1 to 3, the basic structure of the flushing toilet according to the present embodiment will be described. FIG. 1 is a central side cross-sectional view of a water-washing toilet according to an embodiment of the present invention. Further, FIG. 2 is a plan cross-sectional view taken along line II-II of FIG. 1. In this specification, with respect to the front side and the rear side of the water-washing toilet in the front-rear direction, as viewed from the user in front of the water-washing toilet, they are respectively defined as "front side" and "rear side", and with respect to the right side and the left side of the water-washing toilet in the left-right direction, they are respectively defined as "right side" and "left side".
[0015] Next, as shown in FIGS. 1 and 2, the water-washing toilet 1 is a floor-mounted water-washing toilet disposed on the floor surface F1, and is a flushing type water-washing toilet that flushes away dirt by the flowing water action due to the drop of the washing water in the bowl portion 4 of the toilet body 2. The water-washing toilet 1 further includes a toilet body 2 and a water storage tank 6 (washing water source) that stores washing water for supplying washing water for washing the toilet body 2. Furthermore, the toilet body 2 includes a bowl portion 4 on the front side, and a main water passage 8 is formed at the upper rear portion thereof, and an opening 8a provided at the upstream end thereof communicates with the water storage tank 6.
[0016] Next, as shown in FIGS. 1 and 2, the bowl portion 4 of the toilet body 2 includes a bowl-shaped dirt receiving surface 10 for receiving dirt, a rim portion 12 formed above the dirt receiving surface 10, and a pot portion 16 formed below the dirt receiving surface 10 and having a water storage surface 14 formed therein. The toilet body 2 further includes a drain trap portion 18 (details will be described later) including an inlet portion 18a connected to the lower portion of the pot portion 16 of the bowl portion 4 and a drain pipe 18b for discharging the dirt in the bowl portion 4 to the lower rear portion of the bowl portion 4.
[0017] Next, as shown in FIG. 1, the above-described water storage tank 6 includes a drain valve 20 for opening and closing a drain port 6a at the bottom thereof. For example, when the user opens an operation lever (not shown), the drain valve 20 rises and the drain port 6a is opened, and the washing water in the water storage tank 6 flows into the main water passage 8 through the opening 8a of the main water passage 8 of the toilet body 2 from the drain port 6a. The washing water in the main channel 8 is then divided and flows into two rim conduits 22 and 24 (first rim conduit 22 and second rim conduit 24), which will be described later, on their downstream side, and is then discharged from two rim outlets 26 and 28 (first rim outlet 26 and second rim outlet 28), which will be described later, at their downstream ends. In other words, the flush toilet 1 according to this embodiment is a flush toilet that performs flushing (100% flushing with rim water) using only the flushing water (rim water) supplied from each of the first rim water outlets 26 and the second rim water outlet 28.
[0018] In this embodiment, the water source for washing may be a water supply system using direct water pressure, a water supply system using a flush valve, or a system using a pump to supply washing water, in addition to the form of the water storage tank 6. Furthermore, the flush toilet 1 of this embodiment may be a siphon-type flush toilet that utilizes a siphon action to discharge waste from the bowl 4 to the outside through the drain trap 18, in addition to being a wash-down type flush toilet.
[0019] Next, as shown in Figures 1 and 2, the main water channel 8 described above extends in the front-to-back direction from the rear of the bowl portion 4 of the toilet body 2, through the center in the left-to-right direction. Furthermore, the downstream front end of the main channel 8 is equipped with a branching section 8b that branches into the first rim channel 22 and the second rim channel 24. The first rim conduit 22 extends to the first rim outlet 26 at its downstream end, and the second rim conduit 24 extends to the second rim outlet 28 at its downstream end. The cleaning water stored in the water storage tank 6 is then supplied from the main water channel 8 through the first rim water channel 22 and the second rim water channel 24, respectively, to the first rim outlet 26 and the second rim outlet 28. In other words, the first rim outlet 26 and the second rim outlet 28 each function as a first rim discharge section and a second rim discharge section, respectively, that discharge cleaning water in a direction that forms a swirling flow that rotates in the same direction. In this embodiment, the flush toilet 1 forms a counterclockwise swirling flow in a plan view.
[0020] Furthermore, as shown in Figures 1 and 2, the first rim spout 26 is located on the front left side of the rim portion 12 of the bowl portion 4 when viewed from the front. On the other hand, the second rim spout 28 is located on the rear side of the right side when viewed from the front on the rim portion 12 of the bowl portion 4. Furthermore, as shown in Figures 1 and 2, the first rim outlet 26 is located in front of the front end 14a of the water reservoir 14. On the other hand, the second rim outlet 28 is located behind the rear end 14b of the water reservoir 14.
[0021] Next, with reference to Figures 1 to 4, the structure of the drain trap section 18 of the flush toilet 1 of this embodiment will be described in detail. First, as shown in Figure 2, the drainage pipe 18b of the drainage trap section 18 forms a pipe that bends so as to descend to the lowest end 18c behind and below its inlet 18a, and then rise to the top 18d behind and above it.
[0022] Next, Figure 3 is a cross-sectional view of multiple flow path cross-sections A to I of the drain pipe 18b of the drain trap section 18 of the flush toilet according to this embodiment shown in Figure 2. Here, in the multiple flow path cross-sections A to I of the drain pipe 18b of the drain trap section 18 of the flush toilet 1 according to this embodiment shown in Figure 3, flow path cross-section A is the flow path cross-section at the inlet 18a of the drain pipe 18b. Flow path cross-sections B to D are each flow path cross-sections in the intermediate section between the inlet 18a and the lowest end 18c of the drain pipe 18b. Furthermore, flow path cross-section E is the flow path cross-section at the lowest end 18c of the drain pipe 18b. Furthermore, flow path cross-sections F to H are each flow path cross-sections in the intermediate section between the lowest end 18c and the top 18d of the drain pipe 18b. Furthermore, flow path cross-section I is the flow path cross-section at the top 18d of the drain pipe 18b. The maximum width of each flow path cross-section A to I shown in Figure 3 is denoted by symbols W1 to W9. Furthermore, for each channel cross-section A to H shown in Figure 3, the maximum vertical width is denoted by symbols H1 to H8, and for channel cross-section I shown in Figure 3, the maximum vertical width in the direction of the central axis (vertical direction) that bisects the left-right direction is denoted by symbol H9.
[0023] First, as shown in Figures 1 and 3, the drainage pipe 18b is formed such that, in the region behind the flow channel cross-section A of its inlet 18a (downstream region) R0, the maximum widths W3 to W7 of the flow channel cross-sections C to G decrease from the upstream side to the flow channel cross-section G of the region behind the flow channel cross-section E of the lowest end 18c, and then the maximum widths W7 to W9 of the flow channel cross-sections G to I increase from the upstream side to the flow channel cross-section I of the top 18d, from the upstream side to the downstream side. Incidentally, the maximum widths W1 to W9 [mm] of each channel cross-section A to I shown in Figure 3 are set as follows, for example: W1=70.6mm, W2=71.8mm, W3=72.2mm, W4=70.3mm, W5=69.2mm, W6=67.9mm, W7=67.0mm, W8=68.6mm, and W9=79.0mm.
[0024] Next, as shown in FIGS. 1 and 3, the drain pipe 18b has a decreasing section S1 (width decreasing section S1) in a rear region (downstream region) R0 behind the flow path cross-section A of its inlet portion 18a, where the maximum widths W3 to W7 of the respective flow path cross-sections C to G decrease from the flow path cross-section C to the flow path cross-section G in the rear region of the lowermost end portion 18c toward the downstream side. Further, this width decreasing section S1 has a constant section S2 (vertical width constant section S2) in which the maximum vertical widths H5 to H7 of the downstream flow path cross-sections E to G are constant. Incidentally, regarding the maximum vertical widths H1 to H9 [mm] of the respective flow path cross-sections A to I shown in FIG. 3, as an example, H1 = 67.5 mm, H2 = 63.0 mm, H3 = 63.6 mm, H4 = 61.4 mm, H5 = 58.0 mm, H6 = 58.0 mm, H7 = 58.1 mm, H8 = 58.4 mm, and H9 = 70.6 mm are set. Furthermore, regarding the flow path cross-sectional areas A1 to A9 [mm 2 of the respective flow path cross-sections A to I shown in FIG. 3, as an example, A1 = 3651 mm 2 , A2 = 3420 mm 2 , A3 = 3593 mm 2 , A4 = 3622 mm 2 , A5 = 3475 mm 2 , A6 = 3366 mm 2 , A7 = 3307 mm 2 , A8 = 3497 mm 2 , A9 = 5033 mm 2 are set.
[0025] Next, as shown in FIG. 1, the drain pipe 18b includes a descending pipe 18e that descends from its inlet portion 18a to the lowermost end portion 18c, and an ascending pipe 18f that ascends from the lowermost end portion 18c to the top portion 18d. Also, as shown in FIG. 1, the descending pipe 18e includes a first region R1, a second region R2, and a third region R3 that are provided so as to trisect the region RA from the inlet portion 18a to the lowermost end portion 18c from the upstream side to the downstream side. Furthermore, as shown in Figures 1 and 3, in the flow channel cross-sections C to G of the width reduction section S1 of the drainage pipe 12b, the starting point P1 (first center point P1 on the flow channel central axis C0) where the decrease in the maximum width W3 to W7 from the upstream side to the downstream side begins is located at the center C1 in the front-to-back direction of the second region R2.
[0026] Next, as shown in Figure 1, the rising conduit 18f is provided with a fourth region R4, a fifth region R5, and a sixth region R6, which divide the region RB into three equal parts from the upstream side to the downstream side, from the lowest end 18c to the top 18d. Furthermore, as shown in Figures 1 and 3, the maximum widths W1 to W9 of each channel cross-section A to I in the drainage pipeline 18b are minimized in the fifth region R5 of the rising pipeline 18f where channel cross-section G (for example, W7 = 67.0 mm) is located. Furthermore, as shown in Figure 1, in the ascending pipeline 18f, the endpoint P2 (second center point P2 on the flow channel central axis C0) where the maximum width W7 to W9 of the flow channel cross-section G to I increases from the upstream side toward the top 18d is located on the downstream side within the sixth region R6.
[0027] Next, Figure 4 shows an example of the results of a simulation of the change in the flow velocity of the flushing water passing through the lowest point in the drain pipe of the drain trap section during toilet flushing in both the flush toilet according to this embodiment and a conventional flush toilet. In Figure 4, the horizontal axis represents the elapsed time t [s] since the start of toilet flushing for both the flush toilet 1 of this embodiment and a conventional flush toilet, while the vertical axis represents the flow velocity V [m / s] of the flushing water passing through the lowest point in the drain pipe of the drain trap section during toilet flushing. As shown in Figure 4, in the case of the flush toilet 1 of this embodiment, when comparing it with the same duration T1 (=2.0[s]) where the time t from the start of toilet flushing is, for example, t=2.0[s] to 4.0[s], it was confirmed that the flow velocity V[m / s] of the flushing water passing through the lowest end 18c in the drain pipe 18b of the drain trap section 18 reaches a flow velocity V1=0.3[m / s] to a flow velocity V2=0.4[m / s] earlier than in the conventional flush toilet. This confirmed that the flush toilet 1 of this embodiment can improve discharge performance by increasing the flow velocity in the drain pipe 18b of the drain trap section 18.
[0028] Next, the operation of the flush toilet 1 according to this embodiment will be explained with reference to Figures 1 to 4. First, according to the flush toilet 1 of this embodiment, when toilet flushing is started, flushing water supplied from the flushing water source (water storage tank 6) is discharged into the bowl from each rim outlet 26, 28 of the rim water outlet section. Then, along with this flushing water, the waste in the bowl section 4 that is received by the waste receiving surface 10 is discharged into the drain pipe 18b of the drain trap section 18. At this time, the drainage pipe 18b is formed such that, in the region R0 behind its inlet 18a (downstream region), the maximum widths W3 to W7 of each section S1 (width reduction section S1) of its flow channel cross-sections C to G decrease from the upstream side to the flow channel cross-section G in the region behind the flow channel cross-section E at the lowest end 18c, and then the maximum widths W7 to W9 of each flow channel cross-section G to I increase from the upstream side to the flow channel cross-section I at the top 18d. As a result, the flow velocity V [m / s] of the washing water can be maintained, particularly in the region R2 to R5 where the maximum width W3 to W7 of the flow path cross-section C to G in the region R0 behind the inlet 18a of the drainage pipe 18b decreases from the upstream side to the region behind the lowest end 18c, thereby improving the discharge performance of the drainage pipe 18b.
[0029] Next, according to the flush toilet 1 of this embodiment, the drain pipe 18b has a decreasing section S1 (width reduction section S1) in the region R0 behind the inlet 18a (downstream region), where the maximum width W3 to W7 of the flow path cross-section C to G decreases from the upstream region R2, R3 of the lowest end 18c to the downstream region R4, R5 of the lowest end 18c. Furthermore, this width reduction section S1 is provided downstream of it and has a constant section S2 (constant vertical section S2) where the maximum vertical width H5 to H7 of the flow path cross-section E to G remains constant. As a result, the flow velocity V [m / s] of the washing water can be maintained in the decreasing section S1 where the maximum width W3 to W7 of the flow channel cross-section C to G of the drainage pipe 18b decreases from the upstream side to the downstream side. Furthermore, in the constant section S2, where the maximum vertical width H5 to H7 of the flow channel cross-section E to G on the downstream side of the decreasing section S1 remains constant, the flow velocity V [m / s] of the washing water can be maintained, thereby further improving the discharge performance of the drainage pipe 18b.
[0030] Furthermore, according to the flush toilet 1 of this embodiment, in the flow path cross-section C to G of the width reduction section S1 of the drain pipe 12b, the starting point P1 (first center point P1 on the flow path central axis C0) at which the maximum width W3 to W7 begins to decrease from the upstream side to the downstream side is located within the second region R2 (the central point C1 in the front-to-back direction of the second region R2) of the descending pipe 18e that descends from the inlet 18a of the drain pipe 18b to the lowest end 18c. This allows the flow velocity V of the washing water to be maintained in the second region R2 of the descending pipe 18e, thereby improving the discharge performance in the drainage pipe 18b.
[0031] Next, according to the flush toilet 1 of this embodiment, the maximum widths W1 to W9 of each flow path cross-section A to I of the drain pipe 18b are minimized in the fifth region R5 of the rising pipe 18f where the flow path cross-section G (for example, W7 = 67.0 mm) is located, thus further improving the discharge performance in the drain pipe.
[0032] Furthermore, in the flush toilet 1 according to this embodiment, in the rising pipe 18f, the endpoint P2 (second center point P2 on the flow path central axis C0) where the maximum width W7 to W9 of the flow path cross-section G to I increases from the upstream side toward the top 18d is located on the downstream side within the sixth region R6, thus making it possible to further improve the discharge performance in the drain pipe 18b more effectively.
[0033] In the flush toilet 1 according to the embodiment described above, a flush toilet that performs flushing (100% flushing with rim water) is described using only flushing water (rim water) supplied from the first rim water outlet 26 and the second rim water outlet 28, which are provided on the rim portion 12. However, this embodiment is also applicable to flush toilets that use a combination of rim water discharge from the rim outlet and other types of flushing water discharge (for example, jet water discharge). [Explanation of Symbols]
[0034] 1 flush toilet 2 Toilet bowl 4 Bowl section 6. Water storage tank (water source for washing) 6a Drain 8 Leading waterway 8a opening 8b Downstream end of the main channel, branching point 10 Waste receiving surface 12 Rim section 14 Water surface 14a Front end of the reservoir surface 14b Rear end of the reservoir surface 16. Jar section 18 Drain trap section 18a Inlet of drain trap section, inlet of drain pipe, inlet of descending pipe 18b Drainage line 18c The lowest end of the drainage pipe 18d Top of the drainage pipe 18e downhill pipe 18f Ascent conduit 20 Drain valve 22. First Rim Waterway 22a Downstream end of the first rim channel, downstream end of the bottom surface of the first rim channel 22b Bottom surface of the first rim water channel 22c Inlet of the first rim conduit (upstream end of the first rim conduit) 22d The bottom surface on the upstream side of the first maximum height position on the bottom surface of the first rim water channel 24. Second Rim Waterway 24a Inlet of the second rim conduit (upstream end of the second rim conduit) 24b Bottom surface of the second rim water conduit 26. First rim outlet (rim outlet section, first rim outlet section) 26a Bottom surface of the first rim outlet 28. Second rim outlet (rim outlet section, second rim outlet section) A channel cross-section A1 Cross-sectional area of the channel section A A2 Channel cross-sectional area of channel section B A3 Channel cross-sectional area of channel section C A4 Channel cross-sectional area of channel section D A5 Channel cross-sectional area of channel section E A6 Flow channel cross-sectional area of flow channel section F A7 Flow channel cross-sectional area of flow channel section G A8 Channel cross-sectional area of channel section H A9 Flow channel cross-sectional area of flow channel section I B Channel Cross Section C channel cross section C0 Central axis of the drainage pipeline C1 The central part in the longitudinal direction of the second region of the section where the width of the drainage pipe decreases. D channel cross-section E channel cross section F channel cross-section F1 Floor G channel cross-section H channel cross-section H1 Maximum vertical width of channel cross-section A H2 Maximum vertical width of channel cross-section B H3 Maximum vertical width of channel cross-section C H4 Maximum vertical width of channel cross-section D H5 Maximum vertical width of channel cross-section E H6 Maximum vertical width of channel cross-section F H7 Maximum vertical width of channel cross-section G H8 Maximum vertical width of channel cross-section H H9 Maximum vertical width of channel cross-section I I. Flow channel cross-section P1 is the first center point (starting point) on the flow path central axis C0. P2 Second center point (endpoint) on the flow path central axis C0 R0 The area behind the inlet of the drainage pipe (downstream area) R1 First area of the section where the width of the drainage pipeline decreases. R2 Second area of the section where the width of the drainage pipeline decreases. R3 Third area of the section where the width of the drainage pipeline decreases. The fourth region is formed by dividing the area from the lowest point to the top of the R4 riser pipeline into three equal parts. The fifth region is formed by dividing the area from the lowest point to the top of the R5 riser pipeline into three equal parts. The sixth region is formed by dividing the area from the lowest point to the top of the R6 riser pipeline into three equal parts. RA Downstream Pipeline: Area from the inlet to the lowest end RB Region from the lowest end to the top of the riser pipeline S1 Width reduction section (reduction section) S2 Vertical width fixed section (fixed section) W1 Maximum width of channel cross-section A W2 Maximum width of channel cross-section B W3 Maximum width of channel cross-section C W4 Maximum width of channel cross-section D W5 Maximum width of channel cross-section E W6 Maximum width of channel cross-section F W7 Maximum width of channel cross-section G W8 Maximum width of channel cross-section H W9 Maximum width of channel cross-section I
Claims
1. A flush toilet that discharges waste using flushing water supplied from a flushing water source, A bowl portion including a waste receiving surface for receiving waste and a rim portion formed above the waste receiving surface, The rim portion includes a rim spout that discharges cleaning water supplied from the cleaning water source, and the rim spout discharges water into the bowl portion only from this rim spout, The bowl section has an inlet connected to the bottom of the bowl section, and a drain trap section for discharging waste from the bowl section. The drain trap section described above forms a drainage pipe that descends to the lowest point behind and below the inlet section, and then rises to the top point behind and above it. A flush toilet characterized in that the drainage pipe is formed such that, in the region behind the inlet, the maximum width of its flow channel cross-section decreases from the upstream side to the rear region of the lowest end, and then increases towards the top.
2. The drainage pipe described above has a reducing section in the region behind the inlet where the maximum width of its flow channel cross-section decreases from the upstream side to the downstream side up to the region behind the lowest end, and this reducing section is provided on the downstream side and has a constant section where the maximum vertical width of its flow channel cross-section remains constant.
3. The drainage pipeline described above comprises a descending pipeline that goes down from the inlet to the lowest end, and an ascending pipeline that goes up from the lowest end to the top. The above-mentioned descending pipeline comprises a first region, a second region, and a third region, which are provided to divide the area from the inlet to the lowest end into three equal parts from the upstream side to the downstream side. The flush toilet according to claim 1, wherein the starting point at which the maximum width of the cross-sectional area of the drainage pipe begins to decrease from the upstream side to the downstream side is located in the second region.
4. The flush toilet according to claim 3, wherein the above starting point is located in the center of the front-to-back direction in the above second region.
5. The above-mentioned ascending pipeline comprises a fourth region, a fifth region, and a sixth region, which are provided to divide the area from the lowest end to the top into three equal parts from the upstream side to the downstream side. The flush toilet according to claim 3, wherein the maximum width of the cross-sectional area of the drainage pipe is the smallest in the fifth region.
6. The flush toilet according to claim 5, wherein the endpoint of the above-mentioned rising pipe, where the maximum width of the cross-sectional area of the flow path ends when it increases from the upstream side toward the top, is located downstream of the sixth region.