Water-washable toilet

Abstract

To improve discharge performance.SOLUTION: A water closet according to an embodiment has a bowl part, a water discharge part, a drain trap part, and a drain socket. The bowl part has a dirt receiving surface and a rim part. The water discharge part discharges washing water into the bowl part. The drain trap part is connected to a bottom of the bowl part and discharges the dirt in the bowl part. The drain socket is connected to the drain trap part on an upstream side and an exhaust port on a floor surface on a downstream side. The tubular drain socket serves as a channel for washing water discharged from the drain trap part and has an upper drain socket extending downward from the drain trap part. A channel cross-sectional area of a front region is larger than that of a rear region at the upper drain socket in plan view. Curvature of pipe shape changes at the front region and the rear region. The front region and the rear region have an inflection point at which curvature changes more largely at a connection point with each other than change in curvature of respective pipe shapes.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION The disclosed embodiments relate to a flush toilet. [Background technology]

[0002] Conventionally, flush toilets are equipped with a drain socket that connects a drain trap, which discharges waste from the bowl, to a drain outlet on the floor. There are several types of drain sockets depending on the shape of the piping, and one known example is a so-called rear-swing drain socket, in which the upstream side is connected to the drain trap, and the downstream side is swung (extended) to the rear of the toilet bowl before extending toward the front and connecting to the drain outlet (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 8,011,029 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the swing-back drain socket has the advantage that the flush water flowing from above fills the area where the flow path is bent so that it flows forward, making it easier to create a siphon effect. However, because the swing-back drain socket is prone to turbulence at the bent area, there is a risk that the difference in water pressure between the flush water flowing in the front area of ​​the drain socket and the flush water flowing in the rear area will increase, resulting in a decrease in drainage performance. As such, the prior art left room for improvement in terms of improving drainage performance.

[0005] An object of one aspect of the embodiment is to provide a flush toilet that can improve discharge performance. [Means for solving the problem]

[0006] A flush toilet according to one aspect of the embodiment comprises a bowl portion having a bowl-shaped waste receiving surface and a rim portion formed above the waste receiving surface, a water outlet provided on the rim portion and discharging flushing water into the bowl portion, a drain trap portion connected to the bottom of the bowl portion and discharging waste within the bowl portion, and a tubular drain socket connected to the drain trap portion on its upstream side and connected to a drain outlet on the floor surface on its downstream side, which serves as a flow path for flushing water discharged from the drain trap portion, the drain socket having an upper drain socket extending downward from the drain trap portion, wherein, in a plan view, the flow path cross-sectional area of ​​the front region of the upper drain socket is larger than the flow path cross-sectional area of ​​the rear region, and the front region and the rear region each have a curvature that changes, and at the connection point between them there is an inflection point where the curvature changes greater than the curvature change of the respective tubular shapes.

[0007] With this configuration, the cross-sectional area of ​​the flow path in the rear region, where the flow velocity of flush water is slow, is small, so the area where unwanted turbulence or backflow occurs within the drain socket can be narrowed. On the other hand, the cross-sectional area of ​​the flow path in the front region, where the flow velocity of flush water is fast, is large, so that when viewed as a whole, flush water flowing through the drain socket is smoothly flowing downstream, thereby improving drainage performance. Furthermore, by providing an inflection point where the curvature changes significantly at the connection between the front and rear regions of the drain socket, the area where unwanted turbulence or backflow occurs within the drain socket can be limited to a narrow area, creating a state in which the fast-flowing flush water in the front region is not obstructed. This allows a smooth flow toward downstream within the drain socket, improving drainage performance.

[0008] In addition, in the flush toilet described above, the drain socket has a front drain socket extending from rear to front, and a rear R portion connected upstream to the front drain socket and changing the flow path so that flush water flowing from above flows forward, the front drain socket has a water reservoir portion that stores some of the flush water, and the water reservoir portion is positioned below the front lower end of the drain trap portion, and the upper drain socket has an inclined portion that slopes downward to the rear from upstream to downstream, and the front side of the inclined portion is positioned below the front lower end of the drain trap portion.

[0009] With this configuration, after flushing the toilet, water droplets dripping from the lower front end of the drain trap do not fall directly into the water reservoir, but instead collide with the sloped surface of the upper drain socket, weakening their momentum before reaching the water reservoir from the lower end of the sloped surface, thereby reducing the sound of flush water dripping.

[0010] Furthermore, in the flush toilet described above, the inflection point is, in plan view, a line that connects the end of the front region to the end of the rear region.

[0011] With this configuration, the inflection point where the curvature changes significantly is linear at the connection between the front and rear regions of the drain socket, which makes it possible to more clearly separate the front and rear regions, and to confine the area where unwanted turbulence or backflow occurs within the drain socket to a narrow area, creating a state in which the fast-flowing flush water in the front region is not obstructed. This creates a good flow toward downstream within the drain socket, improving drainage performance.

[0012] Furthermore, in the flush toilet described above, the drain socket has a front drain socket that extends from the rear to the front, and a rear R portion that is connected upstream of the front drain socket and changes the flow path so that flush water flowing from above heads forward, and there is an edge portion between the most upstream and most downstream ends of the rear R portion.

[0013] With this configuration, the water (wash water) dripping from above reaches the water pool along the edge portion, so the dripping noise of the wash water can be further suppressed. [Effects of the Invention]

[0014] According to one aspect of the embodiment, it is possible to improve discharge performance. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a side cross-sectional view showing a flush toilet according to an embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the drain socket. [Figure 3] FIG. 3 is a cross-sectional plan view showing the tubular shape of the upper drain socket. [Figure 4] FIG. 4 is an explanatory diagram (part 1) of the flow of flushing water inside the drain socket. [Figure 5] FIG. 5 is an explanatory diagram (part 2) of the flow of flushing water inside the drain socket. [Figure 6] FIG. 6 is a perspective view showing the rear R portion. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments of the flush toilet disclosed in this application will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0017] (Embodiment) <Overall configuration of a flush toilet> First, the overall structure of a flush toilet 1 according to an embodiment will be explained with reference to Figure 1. Figure 1 is a side cross-sectional view showing a flush toilet 1 according to an embodiment. Note that, to make the explanation easier to understand, Figure 1 illustrates a three-dimensional Cartesian coordinate system including a Z-axis with the positive direction being the upward vertical direction. This Cartesian coordinate system may also be illustrated in other figures.

[0018] In the following description, the positive X-axis direction in the Cartesian coordinate system may be referred to as "rightward," the negative X-axis direction as "leftward," the positive Y-axis direction as "forward," the negative Y-axis direction as "backward," the positive Z-axis direction as "upward," and the negative Z-axis direction as "downward." Note that all of the figures shown in Figure 1 and Figure 2 onwards are schematic diagrams.

[0019] As shown in Figure 1, flush toilet 1 comprises a bowl section 2, a spout section 3, a drain trap section 4, and a drain socket 5. Furthermore, flush toilet 1 is a floor-standing flush toilet. The toilet body including bowl section 2 etc. is made of ceramic, for example, but is not limited to this and could be made of resin, for example, or a combination of ceramic and resin.

[0020] Bowl portion 2 includes waste receiving surface 21 and rim portion 22. Waste receiving surface 21 is formed in a bowl shape capable of receiving waste. Rim portion 22 is formed above waste receiving surface 21 and is formed to form the upper edge of bowl portion 2. Note that in Figure 1, for the sake of simplicity, some components such as the toilet seat provided on top of bowl portion 2 and the cover that covers the toilet seat are not shown.

[0021] The water discharger 3 discharges flush water into the bowl section 2. For example, the water discharger 3 is provided on the rim section 22, and discharges flush water supplied from a water storage tank (not shown) into the bowl section 2 through a water discharge port. Note that in Figure 1, for simplicity of illustration, the water discharger 3 (water discharge port) is shown schematically by a two-dot chain line.

[0022] Flush water discharged from the water discharge section 3 generates a swirling flow, for example, on the waste receiving surface 21 of the bowl section 2, thereby cleaning the bowl section 2. After flushing the toilet, the flush water supplied to the bowl section 2 is stored in the bowl section 2 and the drain trap section 4. In FIG. 1, the flush water stored in the bowl section 2 and the drain trap section 4 is shown by a two-dot chain line, and hereinafter this flush water will be referred to as stored water W T In this way, the drain trap part 4 etc. T By filling with water, the water Tfunctions as a water seal, preventing odors and the like from flowing back into the bowl portion 2 from the drainage pipe 61 described later.

[0023] The configuration of the drain trap section 4 will be described. The drain trap section 4 is connected to the bottom 2a of the bowl section 2, and discharges waste together with flush water from within the bowl section 2. More specifically, the drain trap section 4 includes an inlet section 41, an ascending pipe line 42, and a descending pipe line 43.

[0024] The inlet portion 41 is connected to and continues below the waste receiving surface 21 of the bowl portion 2, and allows flush water and waste from the bowl portion 2 to flow into the drain trap portion 4. The rising pipe 42 is connected to the inlet portion 41 and is formed to extend diagonally rearward and upward from the downstream end of the inlet portion 41. The descending pipe 43 is connected to the rising pipe 42 and is formed to extend downward from the downstream end of the rising pipe 42. Furthermore, the drain socket 5 is connected to the downstream end of the descending pipe 43.

[0025] Therefore, in the drain trap section 4, when the toilet is flushed, flush water and waste in the bowl section 2 are discharged into the drain socket 5 through the inlet section 41, the ascending pipe line 42 and the descending pipe line 43.

[0026] <Drainage socket configuration> Next, we will explain the drain socket 5. The drain socket 5 discharges flush water and waste from the drain trap section 4 into the drain pipe 61. For example, the upstream side of the drain socket 5 is connected to the drain trap section 4 (more precisely, the descending pipe 43 of the drain trap section 4) and the downstream side is connected to the drain outlet 62 in the floor surface F, and therefore forms a flow path that discharges flush water and the like from the drain trap section 4 into the drain pipe 61.

[0027] Furthermore, as described above, the drain socket 5 is a so-called rear-swing drain socket, in which the upstream side is connected to the drain trap section 4, and the downstream side is once swung toward the rear of the toilet bowl (negative direction of the Y axis) and then extends toward the front of the toilet bowl (positive direction of the Y axis) to connect to the drain outlet 62.

[0028] Incidentally, in the flush toilet 1 described above, when the toilet is flushed, for example, the drain socket 5 is filled with flush water, causing a siphoning action that expels waste. However, if the drain socket 5 is, for example, a swing-back drain socket, the length of the drain flow path of the drain socket 5 (for example, the length L of the drain flow path in the front-to-back direction (Y-axis direction) shown in Figure 1) tends to be relatively long. As a result, in the flush toilet 1, the siphoning action is unlikely to continue downstream of the drain socket 5, and as a result, discharge performance may decline. Note that the phenomenon of the siphoning action being unlikely to continue downstream of the drain socket 5 described above can occur in other cases as well.

[0029] Therefore, in this embodiment, a configuration is adopted that can improve the waste discharge performance. This configuration will be specifically described below with reference to Figure 2. Figure 2 is an enlarged cross-sectional view of the drain socket 5.

[0030] 1 and 2, the drain socket 5 includes an upper drain socket (vertical pipe) 51, a rear R portion 52, a front drain socket (horizontal pipe) 53, a front R portion 54, a water reservoir portion 55, and a throttle portion 56. The drain socket 5 is made of resin, but is not limited to this.

[0031] The vertical pipe 51 is a pipe that extends vertically (in the Z-axis direction) and allows flush water that has flowed in from above to flow downward. For example, as shown in FIG. 2, the vertical pipe 51 has an upstream end 51a connected to the drain trap section 4 (more precisely, the descending pipe 43 of the drain trap section 4) and a downstream end 51b connected to the rear curved section 52.

[0032] An intermediate portion 51c is formed between the upstream end 51a and the downstream end 51b. This intermediate portion 51c is formed so as to bend rearward (in the negative direction of the Y-axis), which causes the flow path in the vertical pipe 51 to swing rearward. This makes it easier for flush water to fill the area near the bent part of the vertical pipe 51 in the drain socket 5, thereby making it easier to generate a siphon effect.

[0033] The rear curved section 52 is a pipe that is located at the rear of the flush toilet 1 and changes the flow path so that flush water flowing from above is directed forward. For example, the upstream end 52a of the rear curved section 52 is connected to the vertical pipe 51 (more precisely, the downstream end 51b of the vertical pipe 51), and the downstream end 52b is connected to the horizontal pipe 53.

[0034] A curved portion 52c is formed between the upstream end 52a and the downstream end 52b. The curved portion 52c is formed to bend forward, thereby changing the flow path of the cleaning water flowing from above into a flow path going forward.

[0035] The horizontal pipe 53 is a pipe that extends in the front-to-rear direction (Y-axis direction) and directs flush water flowing from the rear to the front. For example, the upstream end 53a of the horizontal pipe 53 is connected to the rear curved portion 52 (more precisely, the downstream end 52b of the rear curved portion 52), and the downstream end 53b is connected to the front curved portion 54.

[0036] An intermediate portion 53c is formed between the upstream end portion 53a and the downstream end portion 53b. The intermediate portion 53c is formed to extend in the front-to-rear direction, and therefore flush water flowing from the rear is directed forward.

[0037] The front curved section 54 is provided downstream of the rear curved section 52, and is a pipe that changes the flow path so that flush water flowing from the rear flows downward. For example, the front curved section 54 has an upstream end 54a connected to the horizontal drawing pipe 53 (more precisely, a downstream end 53b of the horizontal drawing pipe 53), and a downstream end 54b connected to a drain outlet 62 of the drain pipe 61 via a narrowed section 56.

[0038] An ascending portion 54c and a descending portion 54d are formed between the upstream end 54a and the downstream end 54b. The ascending portion 54c is connected to the upstream end 54a and is formed to extend obliquely upward and forward from the upstream end 54a. The descending portion 54d is connected to the ascending portion 54c and is formed to extend downward from the downstream side of the ascending portion 54c. In this way, by forming the ascending portion 54c and the descending portion 54d to be curved, the front curved portion 54 changes the flow path of flush water flowing from the rear into a downward flow path.

[0039] Furthermore, in the drain socket 5, the front curved portion 54 has an ascending portion 54c formed so as to extend obliquely forward and upward, so that a water reservoir 55 is formed in the flow path from the rear curved portion 52 to the front curved portion 54. In FIG. 2, the flush water stored in the water reservoir 55 is indicated by a two-dot chain line, and such flush water will be referred to below as stored water W a It may be written as follows.

[0040] In this way, in the drain socket 5, the stored water W a For example, when flushing the toilet, the stored water W a By using this, the inside of the pipe can be filled with a relatively small amount of flushing water, thereby enabling the siphoning action to occur early.

[0041] <Configuration of upper drain socket (vertical pipe)> Next, the configuration of the upper drain socket (vertical pipe) 51 will be further described with reference to Figures 3 to 6. Figure 3 is a plan cross-sectional view showing the pipe shape of the upper drain socket (vertical pipe) 51. Note that Figure 3 shows the cross section taken along line AA in Figure 2. Figures 4 and 5 are explanatory diagrams of the flow of flush water within the drain socket 5. Note that Figures 4 and 5 show the flow of flush water using an enlarged cross section of the drain socket 5. Figure 6 is a perspective view showing the rear curved portion 52.

[0042] As shown in Figure 3, the drain socket 5 is tubular so as to serve as a flow path for flush water discharged from the drain trap section 4 (see Figure 1). As described above, the drain socket 5 has a vertical pipe 51, which is an upper drain socket, extending downward from the descending pipe line 43 of the drain trap section 4 (see Figure 1 for both).

[0043] 3, in the vertical pipe 51, the flow path cross-sectional area S1 of the front region 511 is larger than the flow path cross-sectional area S2 of the rear region 512. The front region 511 is defined by a boundary line L B The boundary line L BThe rear region 512 is the region in front of the boundary line L B It should be noted that the flush water discharged from the drain trap section 4 (downcoming pipe 43) flows at a slower rate in the rear and at a faster rate in the front.

[0044] The tubular shapes of the front region 511 and the rear region 512 do not have a constant curvature but have a varying curvature (curvature change). The front region 511 and the rear region 512 are arc-shaped in plan view. The front region 511 and the rear region 512 are tubular with both ends connected to each other, and the connecting portion has an inflection point 513 where the curvature change is greater than the change in curvature of the respective tubular shapes.

[0045] In a plan view, the inflection point 513 is a line connecting an end of the front region 511 to an opposing end of the rear region 512. Two inflection points 513 are provided: an inflection point 513 connecting one end of the front region 511 to one end of the rear region, and an inflection point 513 connecting the other end of the front region 511 to the other end of the rear region.

[0046] In this way, the inflection point 513 is linear, which makes it possible to clearly separate the front region 511 from the rear region 512. Note that the term "linear" includes the case of a substantially straight line.

[0047] 4 and 5, the vertical pipe 51 has an inclined portion 514 that slopes downward toward the rear from upstream to downstream. The front side surface of the inclined portion 514, which is an inclined surface that slopes downward toward the rear, is disposed below the front lower end portion 431 of the drain trap portion 4 (downcoming pipe line 43).

[0048] <Configuration of the water reservoir> Next, the configuration of water pool section 55 will be further described with reference to Figure 4. As shown in Figure 4, water pool section 55 has an inclined surface 551 on the bottom surface on the downstream side that slopes upward toward front end 553. Sloped surface 551 forms recess 552, where the bottom surface is recessed downward. Due to inclined surface 551, the angle of inclination of water pool section 55 gradually increases toward front end 553.

[0049] In this way, the angle of inclination of the water pool section 55 gradually increases toward the front end section 553, so that even when large pieces of waste flow downstream from the water pool section 55, stagnation of the waste due to a sudden change in the angle of inclination is suppressed.

[0050] Moreover, water pooling section 55 is located below front lower end section 431 of drain trap section 4. Note that in water pooling section 55, front end section 553 and rear end section 554 are defined by the front and rear ends of stored water Wa, and are also parts that can change depending on the amount of stored water Wa.

[0051] <Flow of cleaning water in the drain socket> Next, the flow of flush water in drain socket 5 will be described with reference to Figures 4 and 5. As shown in Figure 4 and as described above, water pool 55 is located below front lower end 431 of drain trap section 4 (downcoming conduit 43). For this reason, water droplets dripping from front lower end 431 of downcoming conduit 43 do not fall directly into water pool 55.

[0052] As shown in Figure 4, the flush water discharged from the drain trap section 4 (downward pipe 43) collides with the rear R section 52 inside the drain socket 5, and is broadly divided into a flow (flush water W1) that flows forward (horizontal pipe 53), and a flow (flush water W2) that flows upward and to the left and right sides, i.e., a turbulent flow or a backflow.

[0053] 5, the flush water W3 flowing in the front region 511 flows at a high speed and flows diagonally rearward and downward along the front side surface (inclined surface) of the inclined portion 514. That is, the flush water W3 flowing in the front region 511 flows toward the curved portion 52c (see FIG. 2) of the rear R portion 52, collides with the curved portion 52c, then changes direction of flow forward and flows into the horizontal pipe 53 located downstream.

[0054] In this way, a portion of the fast-flowing cleaning water W3 in the front region 511 flows along the front side (inclined surface) of the inclined portion 514, and the cleaning water W1 that leaves the inclined portion 514 from the lower end of the inclined portion 514 collides with the rear R portion 52 and then flows downstream while maintaining its water force.

[0055] 4, the flush water W2 flowing through the rear region 512 flows at a slow flow rate as described above, and bounces off the rear R-section 52, forming a flow that bounces upward. In this case, because the flow path cross-sectional area S2 of the rear region 512 is relatively small, the area in which unnecessary turbulence or backflow occurs within the drain socket 5 due to the flush water W2 flowing at a slow rate or flowing backward can be limited to a narrow area.

[0056] 6, an edge portion 52d is provided on the inner circumferential surface of the rear curved portion 52. The edge portion 52d is located between the most upstream end and the most downstream end of the rear curved portion 52. In this way, the presence of the edge portion 52d between the most upstream end and the most downstream end of the rear curved portion 52 allows the dripping flush water W4 to reach the water pool portion 55 along the edge portion 52d.

[0057] As explained above, according to the above embodiment, the flow path cross-sectional area S2 of the rear region 512, where the flow rate of flush water is slow, is small, so it is possible to narrow the area where unwanted turbulence or backflow occurs within the drain socket 5. On the other hand, the flow path cross-sectional area S1 of the front region 511, where the flow rate of flush water is fast, is large, so when looking at the entire flush water flowing through the drain socket 5, a good flow toward downstream is formed, thereby improving discharge performance.

[0058] Furthermore, by providing an inflection point 513 where the curvature changes significantly at the connection between the front region 511 and the rear region 512 of the drain socket 5, it is possible to confine the area where unwanted turbulence or backflow occurs within the drain socket 5 to a narrow area, thereby creating a state in which the fast-flowing flush water in the front region 511 is not impeded. This creates a good flow toward downstream within the drain socket 5, improving drainage performance.

[0059] Furthermore, because the inflection point 513 where the curvature changes significantly is linear at the connection between the front region 511 and the rear region 512 of the vertical pipe 51, the front region 511 and the rear region 512 can be more clearly separated, and the area where unwanted turbulence or backflow occurs within the drain socket 5 can be confined to a narrow area, creating a state in which the fast-flowing flush water in the front region 511 is not obstructed. This creates a good flow toward downstream within the drain socket 5, improving discharge performance.

[0060] Furthermore, because some of the fast-flowing flush water W3 in the front region 511 flows along the front side surface (inclined surface) of the sloped portion 514, the flush water W3 that leaves the sloped portion 514 from its lower end hits the rear R-section 52 and then flows downstream while maintaining its water force. This creates a good flow heading downstream within the drain socket 5, improving drainage performance. Furthermore, the water pool 55 is located below the front lower end 431 of the drain trap portion 4 (downcoming conduit 43), so that after the toilet is flushed, water droplets dripping from the front lower end 431 of the drain trap portion 4 (downcoming conduit 43) do not fall directly into the water pool 55, but instead hit the sloped surface of the sloped portion 514 of the vertical pipe 51 once, weakening their falling momentum before reaching the water pool 55 from the lower end of the sloped portion 514, thereby suppressing the sound of dripping flush water.

[0061] Furthermore, because edge portion 52d exists between the most upstream and most downstream ends of rear curved portion 52, flush water W4 dripping from above flows along edge portion 52d and reaches water pool 55. This further reduces the dripping noise of flush water W4.

[0062] In the above embodiment, the inflection point 513 at the connection portion of the two regions 511, 512 is linear so as to clearly separate the front region 511 and the rear region 512 of the vertical pipe 51 and to make the pipe shape smooth, but for example, the inflection point 513 may be dot-shaped. When the inflection point 513 is dot-shaped, for example, the pipe outer shapes of the two regions 511, 512 may be formed so that the shape where the front region 511 and the rear region 512 are connected is pot-shaped in a plan view.

[0063] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0064] 1 flush toilet 2 Bowl section 3. Water outlet 4 Drain trap section 5 drain socket 21 Waste receiving surface 22 Rim 51 Upper drain socket (vertical pipe) 52 Rear R section 53 Front drain socket (horizontal pipe) 54 Front R section 55 Water reservoir 56 Constriction section 61 Drainage piping 62 Drain port 431 Lower front end 511 Anterior area 512 Posterior area 513 Inflection Point 514 Slope F Floor S1 Flow path cross-sectional area S2 Channel cross-sectional area W1 Cleaning water W2 cleaning water W3 Cleaning water W a Stored water W T standing water

Claims

1. a bowl portion having a bowl-shaped waste receiving surface and a rim portion formed above the waste receiving surface; a water discharge portion provided in the rim portion and discharging flush water into the bowl portion; a drain trap portion connected to the bottom of the bowl portion and configured to discharge waste from the bowl portion; a tubular drain socket having an upstream side connected to the drain trap section and a downstream side connected to a drain outlet on the floor surface, which serves as a flow path for flushing water discharged from the drain trap section, and having an upper drain socket extending downward from the drain trap section; Equipped with The upper drain socket is In a plan view, the flow path cross-sectional area of ​​the front region is larger than the flow path cross-sectional area of ​​the rear region, The front region and the rear region are The curvature of each tube shape changes, and at the connecting portion there is an inflection point where the curvature changes more than the curvature change of each tube shape. A flush toilet characterized by:

2. The drain socket is the upper drain socket; a front drain socket extending from rear to front; a rear R portion that is connected to the upper drain socket downstream of the upper drain socket and connected to the front drain socket upstream of the front drain socket, and that changes the flow path so that flush water flowing from above flows forward; and The front drain socket is A water reservoir for storing a portion of the cleaning water is provided. The water reservoir portion is The drain trap portion is disposed below a front lower end portion of a lower end portion of a descending pipe, which is a pipe connected to the drain socket in the drain trap portion, the front lower end portion being a front end side in the front-to-rear direction, The upper drain socket is It has an inclined portion that slopes downward toward the rear from upstream to downstream, The inclined portion is The front side surface is disposed below the front lower end portion of the drain trap portion.

2. The flush toilet according to claim 1.

3. The inflection point is In a plan view, the linear shape connects the end of the front region to the end of the rear region.

3. The flush toilet according to claim 1 or 2.

4. The drain socket is a front drain socket extending from rear to front; a rear R portion that is connected upstream of the front drain socket and changes the flow path so that flush water flowing from above flows forward; and An edge portion is present on the inner peripheral surface of the rear R portion between the most upstream end and the most downstream end of the rear R portion. A flush toilet according to any one of claims 1 to 3.

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