Water-washable toilet

Abstract

The present invention aims to provide a flush toilet that can adequately discharge waste (especially floating waste) even with further water conservation measures. [Solution] The present invention is a siphon jet type flush toilet, comprising a bowl portion 15, a drain trap pipe 16 including an upward-extending upward pipe 16b, a jet outlet 24a that discharges flushing water toward the inlet 16a of the drain trap pipe 16, and a jet water guide channel 22 that guides the flushing water to the jet outlet. The upward pipe 16b of the drain trap pipe 16 is provided with a constriction portion 80 that narrows the flow path of flushing water in the upper flow path A1, which is located above the vertical center line CL of the drain trap pipe 16 in the cross-sectional view of the flow path, and the flow path cross-sectional area of ​​the upper flow path A1 is smaller than the flow path cross-sectional area of ​​the lower flow path A2, which is located below the center line CL.

Description

Technical Field

[0001] The present invention relates to a flushing toilet, particularly a siphon jet flushing toilet.

Background Art

[0002] Conventionally, a siphon jet flushing toilet having a jet water outlet at a position facing the inlet of a drain trap pipe is known. Such a flushing toilet uses the washing water discharged from the jet water outlet to fill the drain trap pipe with water early to generate a siphon action and to wash away dirt. However, due to the recent demand for water conservation, the amount of washing water discharged from the jet water outlet tends to be reduced, and it is desired to efficiently discharge dirt with the washing water discharged from the jet water outlet.

[0003] Therefore, the siphon jet flushing toilet described in Patent Document 1 has a guide portion formed in the rising pipe of the drain trap pipe to guide the washing water flowing back to the center of the flow path cross section. Thereby, the washing water that tries to flow back in the rising pipe of the drain trap pipe is guided to the center of the flow path cross section and is washed away by the washing water discharged from the jet water outlet.

[0004] Further, the siphon jet flushing toilet described in Patent Document 2 has a curved surface inclined downward formed on the bottom surface of the bowl portion continuous with the jet water outlet. Thereby, the washing water discharged from the jet water outlet flows into the drain trap pipe early to generate a siphon action.

[0005] Furthermore, the siphon jet flushing toilet described in Patent Document 3 is formed such that the downstream side of the jet water guide path gradually widens toward the jet water outlet. Thereby, washing water is discharged from the jet water outlet over a wide area to wash away dirt.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-72238 [Patent Document 2] Japanese Patent Publication No. 2018-3262 [Patent Document 3] Japanese Patent Publication No. 2018-3263 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the flush toilets described in Patent Documents 1 to 3, if the amount of flushing water discharged from the jet nozzle is further reduced, there is a problem in that waste (especially floating waste) cannot be sufficiently discharged.

[0008] For example, Figure 7 shows, through numerical analysis, how flushing water discharged from a jet nozzle flows through the drain trap pipe in a conventional flush toilet. In this numerical analysis, the direction of the flushing water flow is indicated by arrows; long arrows indicate regions where the flushing water velocity is high and the water pressure is strong, while short arrows indicate regions where the flushing water velocity is low and the water pressure is weak.

[0009] As shown in Figure 7, in conventional flush toilets, the main stream of flushing water discharged from the jet nozzle collides with the rising channel of the drain trap pipe, and then flows upward in the area near the bottom of the rising channel (area A in Figure 7). However, in the area near the top of the rising channel (area B in Figure 7), which is far from the main stream of flushing water, the flushing water cannot rise along the rising channel and stagnates, creating turbulence. In other words, waste (especially suspended waste) tends to accumulate in the area near the top of the rising channel (area B in Figure 7). For this reason, conventional flush toilets discharge a large volume of flushing water from the jet nozzle for a long period of time to remove the waste that has accumulated in the drain trap pipe.

[0010] However, in recent years, with the demand for water conservation, if the amount of cleaning water discharged from the jet nozzle is further reduced, a problem arises in which sewage (especially floating sewage) accumulates in the area near the top of the riser pipe (area B in Figure 7) and cannot be adequately discharged.

[0011] Therefore, the present invention was made to solve the conventional problems described above, and aims to provide a flush toilet that can sufficiently discharge waste (especially floating waste) even with further water conservation. [Means for solving the problem]

[0012] To achieve the above-mentioned objectives, the present invention provides a siphon jet type flush toilet comprising: a bowl portion having a waste receiving surface for receiving waste and a rim portion formed above the waste receiving surface; a drain trap pipe comprising an upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending upward-extending downward-extending downward-extending downward-extending upward-extending upward-extending downward

[0013] In the present invention configured as described above, the rising channel of the drain trap pipeline is provided with a constriction in the upper channel, which is located above the vertical center line of the drain trap pipeline in the cross-sectional view of the flow path, thereby narrowing the flow path through which the cleaning water flows. As a result, the cross-sectional area of ​​the upper channel is smaller than that of the lower channel, which is located below the center line, so that the accumulation of cleaning water in the drain trap pipeline is suppressed and waste can be efficiently transported within the drain trap pipeline. Therefore, even with further water conservation, waste (especially floating waste) can be sufficiently discharged.

[0014] In the present invention, preferably, the throttling portion is provided at least on the upstream side of the rising conduit. In the present invention configured in this way, the throttling section is provided at least on the upstream side of the rising pipeline, which further suppresses the accumulation of cleaning water in the drain trap pipeline and enables efficient transport of waste within the drain trap pipeline.

[0015] Furthermore, in the present invention, the throttling portion is preferably provided extending from the upstream end to the downstream end of the rising conduit. In the present invention configured in this way, the throttling section is provided from the upstream end to the downstream end of the rising pipeline, which further suppresses the accumulation of cleaning water in the drain trap pipeline and enables efficient transport of waste within the drain trap pipeline.

[0016] In the present invention, preferably, the constricted portion is provided in the cross-section of the flow path in a region outside a predetermined radius of curvature centered on the central point through which the main stream of cleaning water discharged from the jet outlet passes. In the present invention configured in this way, the constricted portion is provided in the cross-section of the flow path in an area outside a predetermined radius of curvature centered on the central point through which the main flow of cleaning water discharged from the jet outlet passes. Therefore, the area in which cleaning water stagnates can be reduced without hindering the transport of waste within the drain trap pipeline.

[0017] In the present invention, preferably, the upstream end of the rising pipe of the drain trap pipe is formed such that the cross-sectional area of the upper side flow path gradually decreases. In the present invention configured as described above, since the upstream end of the rising pipe of the drain trap pipe is formed such that the cross-sectional area of the upper side flow path gradually decreases, the washing water can be smoothly guided to the throttle portion, and the conveyance of dirt can be efficiently performed.

[0018] In the present invention, preferably, the position where the cross-sectional area of the upper side flow path is the smallest is located on the downstream side of the collision position where the main flow of the washing water discharged from the jet discharge port collides with the rising pipe. In the present invention configured as described above, since the position where the cross-sectional area of the upper side flow path is the smallest is located on the downstream side of the collision position where the main flow of the washing water discharged from the jet discharge port collides with the rising pipe, the region where the washing water on the downstream side of the collision position is most likely to stay can be reduced.

[0019] In the present invention, preferably, the top of the drain trap pipe has its upper end located on the downstream side of its lower end. In the present invention configured as described above, since the top of the drain trap pipe has its upper end located on the downstream side of its lower end, the throttle portion can be provided up to near the top.

Effect of the Invention

[0020] According to the water-washing toilet of the present invention, even if further water conservation is performed, dirt (particularly, floating dirt) can be sufficiently discharged.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view of a water-washing toilet according to an embodiment of the present invention. [Figure 2] It is an overall configuration diagram of a water-washing toilet according to an embodiment of the present invention. [Figure 3]This is a block diagram showing the configuration related to the control unit of a flush toilet according to an embodiment of the present invention. [Figure 4] This is a side cross-sectional view of a flush toilet according to an embodiment of the present invention. [Figure 5A] This is a cross-sectional view along line AA in Figure 4. [Figure 5B] This is a cross-sectional view along line BB in Figure 4. [Figure 5C] This is a cross-sectional view along the CC line in Figure 4. [Figure 6] This figure shows the results of a numerical analysis of the flow velocity distribution of flushing water discharged from the jet nozzle and flowing through the drain trap pipe in a flush toilet according to an embodiment of the present invention. [Figure 7] This figure shows the results of a numerical analysis of the flow velocity distribution of flushing water discharged from the jet nozzle in a conventional flush toilet, as it flows through the drain trap pipe. [Modes for carrying out the invention]

[0022] A flush toilet according to an embodiment of the present invention will be described below with reference to the attached drawings. First, the overall configuration of a flush toilet according to an embodiment of the present invention will be explained with reference to Figures 1 to 3. Figure 1 is a perspective view of a flush toilet according to an embodiment of the present invention, Figure 2 is an overall configuration diagram of a flush toilet according to an embodiment of the present invention, and Figure 3 shows the control unit of a flush toilet according to an embodiment of the present invention. This is a diagram showing the related configurations.

[0023] As shown in Figures 1 and 2, the flush toilet 1 according to an embodiment of the present invention is a siphon jet type toilet and comprises a ceramic toilet body 2, a local cleaning device 4 positioned on the upper surface of the toilet body 2, a valve unit 6 that supplies cleaning water to the toilet body 2, a water storage tank 8 that stores cleaning water, and a pressure pump 10 that supplies the cleaning water stored in the water storage tank 8 to the toilet body 2.

[0024] The toilet bowl body 2 has a bowl section 15 comprising a bowl-shaped waste receiving surface 12 for receiving waste and a rim section 14 formed above the waste receiving surface 12, and a drain trap pipe 16 connected to the bottom of the bowl section 15 for discharging waste. A rim water channel 18 is formed inside the rim section 14, and a rim water outlet 20a is formed at the downstream end of the rim water channel 18, which is the rim water outlet section 20 for discharging water from the rim. The rim water outlet 20a is formed on the right front of the bowl section 15 when viewed from the front of the flush toilet 1, and is designed to discharge flushing water backward, forming a swirling flow along the inner circumferential surface of the rim section 14.

[0025] Furthermore, a jet water channel 22 is formed below the toilet bowl body 2, and a jet outlet 24a is formed at the jet water discharge section 24, which is the downstream end of this jet water channel 22, to discharge water in a jet. The jet outlet 24a is located below the bowl section 15 and is positioned facing the inlet 16a of the drain trap pipe 16, so as to discharge flushing water toward the inlet 16a of the drain trap pipe 16.

[0026] The drain trap pipe 16 consists of an inlet 16a, an ascending pipe 16b that rises from the inlet 16a, and a descending pipe 16c that descends from the ascending pipe 16b, with the top 16d located between the ascending pipe 16b and the descending pipe 16c. A drain socket 26 is connected to the lower end of the descending pipe 16c of the drain trap pipe 16.

[0027] As shown in Figure 1, the local cleaning device 4 comprises a main body 4a, a cleaning nozzle 4b that is movable forward and backward from the main body 4a, a toilet seat 4c that is rotatably attached to the main body 4a, and a toilet lid 4d that is rotatably attached to the main body 4a so as to cover the toilet seat 4c.

[0028] As shown in Figure 2, the valve unit 6 is equipped with a main water supply channel 30 from which flushing water is supplied from the water pipe 28, which is the source of flushing water. This main water supply channel 30 is equipped with a constant flow valve 38, a diaphragm-type solenoid valve 40, and a water supply channel switching valve 42, from the upstream side. Furthermore, the main water supply channel 30 upstream of the valve unit 6 is equipped with a stopcock 32, a strainer 34, and a branch fitting 36, from the upstream side. The main water supply channel 30 consists of a water supply hose that connects to the water pipe 28 outside the toilet.

[0029] Furthermore, a rim-side water supply channel 44 for supplying cleaning water to the rim outlet 20a and a tank-side water supply channel 46 for supplying cleaning water to the water storage tank 8 are connected to the downstream side of the water supply channel switching valve 42. A rim water conduit 18 is connected to the downstream end of the rim-side water supply channel 44, so that cleaning water is supplied to the rim outlet 20a by the water supply pressure of the waterworks.

[0030] The constant flow valve 38 is used to restrict the flow rate of the cleaning water that flows in via the stopcock 32, strainer 34, and branch fitting 36 to below a predetermined flow rate. The cleaning water that has passed through the constant flow valve 38 flows into the electromagnetic valve 40, and the cleaning water that has passed through the electromagnetic valve 40 is supplied by the water supply channel switching valve 42 to the rim outlet 20a from the rim-side water supply channel 44, which is on the rim side, or to the water storage tank 8 from the tank-side water supply channel 46, which is on the tank side.

[0031] The water supply channel switching valve 42 is a switching valve that can supply cleaning water to both the rim-side water supply channel 44 and the tank-side water supply channel 46 at the same time, and can arbitrarily change the ratio of the amount and flow rate of water supplied to the rim side and the tank side. The water supply channel switching valve 42 is equipped with a rotor (not shown) for changing the ratio of the amount and flow rate of water supplied to the rim side and the tank side, and this rotor is driven to a desired position by a motor (not shown).

[0032] A pump-side water supply channel 48 is connected to the lower part of the water storage tank 8, and a pressurizing pump 10 equipped with a pump chamber is connected to the downstream end of this pump-side water supply channel 48. Furthermore, the pressurizing pump 10 and the jet water conduit 22 are connected by a jet-side water supply channel 50, and the pressurizing pump 10 pressurizes the cleaning water stored in the water storage tank 8 and supplies it to the jet outlet 24a.

[0033] The pressurizing pump 10 is configured to pressurize the cleaning water stored in the water storage tank 8 and discharge it from the jet outlet 24a at a predetermined flow rate. The pressurizing pump 10 is connected to the pump-side water supply channel 48 on its upstream side and to the jet-side water supply channel 50 on its downstream side. The pressurizing pump 10 comprises a casing 10a, an impeller 10b which is a vane that is rotatable in both forward and reverse directions within the casing, and a motor 10c which rotates the impeller 10b. It is a centrifugal pump that uses the centrifugal force generated by the rotation of the impeller 10b to pressurize the cleaning water in the water storage tank 8.

[0034] A vacuum breaker 52, which acts as a check valve, is provided in the rim-side water supply channel 44, and a vacuum breaker 54, which acts as a check valve, is also provided in the tank-side water supply channel 46. These vacuum breakers prevent backflow from the rim outlet 20a and the water storage tank 8. Furthermore, the wash water that overflows from the atmospheric vent of the vacuum breaker 52 in the rim-side water supply channel 44 flows into the water storage tank 8 through the return pipe 55.

[0035] The water storage tank 8 is a sealed type water storage tank, and a ball-type check valve 56 is provided at the connection between the tank-side water supply channel 46 and the water storage tank 8, and a ball-type check valve 58 is also provided at the connection between the return pipe 55 and the water storage tank 8. These ball-type check valves prevent backflow of the cleaning water even when the water storage tank 8 is full, exceeding the upper limit of the overflow channel.

[0036] A drain valve 62 is provided at the bottom of the water storage tank 8. This drain valve 62 is located below the pressure pump 10, and by opening the drain valve 62 during maintenance, the cleaning water inside the water storage tank 8 and the pressure pump 10 can be drained.

[0037] An upper float switch 64 and a lower float switch 66 are located inside the water storage tank 8. The upper float switch 64 switches to the ON state when the water level in the water storage tank 8 reaches a predetermined position L2 that is slightly lower than the maximum water level L3 during normal use, and the control unit 74 detects this and closes the electromagnetic valve 40. The lower float switch 66 switches to the ON state when the water level in the water storage tank 8 drops to the minimum water level L1 during normal use, and the control unit 74 detects this and stops the pressurizing pump 10.

[0038] Furthermore, an overflow channel 60 for draining excess cleaning water is provided inside the water storage tank 8. The upper end of this overflow channel 60 opens into the water storage tank 8, and its lower end is connected to the jet-side water supply channel 50. A flapper valve 67, which is a check valve, is installed in this overflow channel 60 to prevent backflow from the jet outlet 24a.

[0039] As shown in Figures 1 and 2, the flush toilet 1 includes a seating sensor 68 for detecting the user's sitting motion, a line sensor 70 for detecting the type and amount of waste after the user's excretion, and a control unit 74 that controls the pressurizing pump 10 based on the detection results detected by the line sensor 70.

[0040] The seating sensor 68 is located on the underside of the left rear of the toilet seat 4c of the local washing device 4. The seating sensor 68 is a load sensor that detects the user's weight. The seating sensor 68 is configured to detect changes in weight when the user is seated on the toilet seat 4c, and to detect the start and end of defecation by the user.

[0041] The line sensor 70 is mounted on the main body 4a of the local cleaning device 4, facing into the bowl section 15, and is configured to detect the type and amount of waste that falls into the bowl section 15. The line sensor 70 consists of multiple light-receiving elements arranged in a straight line, and is configured to acquire one-dimensional data (linear still images) over time at predetermined time intervals. The acquired one-dimensional data is arranged in a time series by the control unit 74 to generate a single two-dimensional image, which is used to determine the type and amount of waste.

[0042] As shown in Figure 3, the control unit 74 is electrically connected to the upper float switch 64, the lower float switch 66, the seat sensor 68, the line sensor 70, the toilet flush switch 76, the electromagnetic switch 40, the water supply channel switching valve 42, and the pressure pump 10, and is configured to communicate with various devices. When the toilet flush switch 76 is pressed, the control unit 74 sequentially operates the electromagnetic switch 40, the water supply channel switching valve 42, and the pressure pump 10, so that flushing water is first discharged from the rim outlet 20a, then flushing water is discharged from the jet outlet 24a while flushing water is being discharged from the rim outlet 20a, and finally flushing water is discharged from the rim outlet 20a.

[0043] The control unit 74 is configured to generate a single two-dimensional image by arranging multiple one-dimensional data acquired from the line sensor 70 in a time series, and to determine the type and amount of waste that has fallen into the bowl section 15. Furthermore, for each toilet flush, the control unit 74 is configured to control the pressurizing pump 10 based on the determination result of the type and amount of waste, and to change the instantaneous flow rate and discharge time of the flushing water discharged from the jet nozzle 24a.

[0044] Next, the drain trap pipe 16 of the flush toilet 1 according to an embodiment of the present invention will be described in detail with reference to Figures 4 and 5A to 5C. Figure 4 is a side cross-sectional view of a flush toilet according to an embodiment of the present invention, and Figures 5A to 5C are cross-sectional views taken along lines AA to CC in Figure 4. The dashed lines in Figures 5A to 5C represent imaginary lines that depict approximately perfect circles with radii of curvature R1 and R2.

[0045] As shown in Figures 4 and 5A to 5C, the rising pipe 16b of the drain trap pipe 16 is provided with a constriction 80 in the upper flow path A1, which is located above the vertical center line CL of the drain trap pipe 16 (the center line that bisects the interior of the drain trap pipe 16 inside the outer edge in the vertical direction) in the flow path cross-section (cross-section perpendicular to the direction in which the cleaning water flows). As a result, the flow path cross-sectional area of ​​the upper flow path A1, which is located above the center line CL, is smaller than the flow path cross-sectional area of ​​the lower flow path A2, which is located below the center line CL.

[0046] The inner circumferential surface of the riser pipe 16b of the drain trap pipe 16 is formed with a predetermined radius of curvature R1 centered on the center point O1 of the drain trap pipe 16, except for the portion where the constricted section 80 is provided in the flow path cross-section. In contrast, the inner circumferential surface of the riser pipe 16b in the portion where the constricted section 80 is provided (the inner circumferential surface 80a of the constricted section 80) is formed with a predetermined radius of curvature R2 centered on the center point O2 through which the main flow of cleaning water discharged from the jet outlet 24a passes in the flow path cross-section. Here, the main flow of cleaning water discharged from the jet outlet 24a refers to, for example, the bundle of cleaning water discharged from the jet outlet 24a that flows along the bottom surface of the riser pipe 16b after colliding with it. Furthermore, the center point O2 through which the main flow of cleaning water discharged from the jet outlet 24a passes is located below the center point O1 of the drain trap pipe 16, and the positions of each center point are arranged at different locations.

[0047] The predetermined radius of curvature R2 that constitutes the inner circumferential surface 80a of the constricted section 80 is set to be larger than the predetermined radius of curvature R1 that constitutes the inner circumferential surface of the riser pipe 16b other than the inner circumferential surface 80a of the constricted section 80. The inner circumferential surface 80a of the constricted section 80 with the predetermined radius of curvature R2 is connected to the inner circumferential surface of the riser pipe 16b with the predetermined radius of curvature R1 in the upper flow path A1. In other words, the constricted section 80 is provided in the upper flow path A1 and is located in the region outside the predetermined radius of curvature R2 (and inside the predetermined radius of curvature R1) centered on the center point O2. As a result, the area in which the cleaning water stagnates is reduced without hindering the transport of waste in the drain trap pipe. In addition, the cleaning water discharged from the jet outlet 24a flows evenly throughout the entire interior of the riser pipe 16b.

[0048] The restrictor section 80 is provided extending from the upstream end 16e to the downstream end 16f of the riser pipe 16b. This creates a region within the riser pipe 16 where cleaning water is more likely to accumulate. In this embodiment, the restrictor section 80 is provided extending from the upstream end 16e to the downstream end 16f of the riser pipe 16b, but it is not limited to this configuration; it is sufficient if it is provided at least on the upstream side of the riser pipe 16b.

[0049] The position where the cross-sectional area of ​​the upper flow path A1 is smallest (the cross-sectional position of line AA in Figure 4) is located downstream (rear) of the collision point P where the main stream of cleaning water discharged from the jet outlet 24a collides with the rising pipeline 16b. This reduces the area downstream of the collision point P where cleaning water is most likely to accumulate. Furthermore, a flow straightening section 22a (a flow path with a substantially constant cross-sectional area and extending in a straight line) is provided downstream of the jet water conduit 22 to straighten the direction of the cleaning water flow. The collision point P is the position where the imaginary line L, which is the central axis of the flow straightening section 22a extended from the jet outlet 24a, intersects with the rising pipeline 16b (see Figure 4).

[0050] The upstream end 16e of the rising pipe 16b of the drain trap pipe 16 is formed such that the cross-sectional area of ​​the upper flow path A1 gradually decreases. This allows the washing water and waste to be guided smoothly to the constriction section 80 compared to the case where the cross-sectional area of ​​the upper flow path A1 narrows abruptly, and enables efficient transport of waste.

[0051] The upper end 16g of the top 16d of the drain trap pipe 16 (the highest part of the upper surface of the rising pipe 16b) is located downstream (rearward) of the lower end 16h of the top 16d of the drain trap pipe (the lowest part of the bottom surface of the rising pipe 16b). As a result, the constricted section 80 is provided up to the vicinity of the top 16d (directly above the lower end 16h of the top 16d).

[0052] Next, with reference to Figure 6, the flow (operation) of flushing water in the drain trap pipe of a flush toilet according to an embodiment of the present invention will be explained. Figure 6 shows the results of a numerical analysis of the flow velocity distribution of flushing water discharged from the jet nozzle and flowing through the drain trap pipe in a flush toilet according to an embodiment of the present invention. In this numerical analysis result, the direction of the flushing water flow is indicated by arrows, with long arrows indicating regions where the flushing water flow velocity is high and the water pressure is strong, and short arrows indicating regions where the flushing water flow velocity is low and the water pressure is weak.

[0053] First, when the toilet flushing switch 76 is pressed by the user, the pressure pump 10 is activated, and flushing water stored in the water storage tank 8 is supplied to the jet water supply channel 22 via the jet side water supply channel 50. The flushing water supplied to the jet water supply channel 22 passes through the flow straightening section 22a located downstream of the jet water supply channel 22 and is discharged from the jet outlet 24a. At this time, as the flushing water passes through the flow straightening section 22a, a main flow (a bundled flow) is formed in which the direction of the flushing water flow is straightened.

[0054] The main stream F1 of the cleaning water discharged from the jet outlet 24a collides with the bottom surface of the rising pipe 16b of the drain trap pipe 16 at the collision point P. After colliding with the rising pipe 16b, the main stream F2 of the cleaning water flows upward along the bottom surface of the rising pipe 16b in the region near the bottom surface of the rising pipe 16b (region C in Figure 6). At this time, the main stream F2 of the cleaning water flows through the lower flow path A2 of the rising pipe 16b.

[0055] On the other hand, the upper flow path A1 of the rising pipe 16b of the drain trap pipe 16 is provided with a constriction section 80 that narrows the flow path for the flushing water. As a result, compared to conventional flush toilets (see Figure 7), the area near the upper surface of the rising pipe 16b (area D in Figure 6) is reduced, and the area where flushing water stagnates is reduced. This suppresses the stagnation of flushing water and the generation of turbulence in area D, which is far from the main flow F2 of flushing water flowing through area C. In addition, the main flow F2 of flushing water flowing through area C draws in the surrounding flushing water, so compared to conventional flush toilets (see Figure 7), a flow F3 that rises along the rising pipe 16b is formed in area D. Therefore, the flushing water discharged from the jet outlet 24a efficiently transports waste within the drain trap pipe 16.

[0056] Next, the effects and advantages of the flush toilet 1 according to the embodiment of the present invention described above will be explained. First, in the flush toilet 1 according to an embodiment of the present invention, the rising pipe 16b of the drain trap pipe 16 is provided with a constriction section 80 that narrows the flow path of flushing water in the upper flow path A1, which is located above the vertical center line CL of the drain trap pipe 16 in the cross-sectional view of the flow path. Since the flow path cross-sectional area of ​​the upper flow path A1 is smaller than the flow path cross-sectional area of ​​the lower flow path A2, which is located below the center line CL, the stagnation of flushing water in the drain trap pipe 16 is suppressed, and waste can be efficiently transported within the drain trap pipe 16. Therefore, even with further water conservation, waste (especially floating waste) can be sufficiently discharged.

[0057] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the throttling section 80 is provided at least on the upstream side of the rising pipe 16b, which further suppresses the accumulation of flushing water in the drain trap pipe 16 and enables efficient transport of waste within the drain trap pipe 16.

[0058] In the flush toilet 1 according to an embodiment of the present invention, the constriction section 80 is provided extending from the upstream end 16e to the downstream end 16f of the rising pipe 16b, thereby further suppressing the accumulation of flushing water in the drain trap pipe 16 and enabling efficient transport of waste within the drain trap pipe 16.

[0059] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the constriction portion 80 is provided in the flow path cross-section in an area outside a predetermined radius of curvature R2 centered on the central point O2 through which the main flow of flushing water discharged from the jet outlet 24a passes. Therefore, the area in which flushing water stagnates can be reduced without hindering the transport of waste within the drain trap pipe 16.

[0060] In the flush toilet 1 according to an embodiment of the present invention, the upstream end 16e of the rising pipe 16b of the drain trap pipe 16 is formed such that the cross-sectional area of ​​the flow path A1 of the upper flow path gradually decreases, so that the flushing water can be smoothly guided to the restricting section 80 and waste can be transported efficiently.

[0061] Furthermore, in the flush toilet 1 according to the embodiment of the present invention, the position where the cross-sectional area of ​​the upper flow path A1 is smallest is located downstream of the collision point P where the main stream of flushing water discharged from the jet outlet 24a collides with the rising pipe 16b. Therefore, the region downstream of the collision point P where flushing water is most likely to stagnate can be reduced.

[0062] In the flush toilet 1 according to an embodiment of the present invention, the top portion 16d of the drain trap pipe 16 has an upper end portion 16g located downstream of the lower end portion 16h, so the constricted portion 80 can be provided up to the vicinity of the top portion 16d.

[0063] The present invention is not limited to the embodiments described above, and various modifications and variations are possible within the scope of the technical idea described in the claims. [Explanation of symbols]

[0064] 1: Flush toilet 12: Waste receiving surface 14: Rim section 15: Bowl Section 16: Drain trap pipe 16a: Inlet of drain trap pipe 16b: Rising pipe for drain trap piping 16c: Downward pipe for drain traps 16d: Top of the drain trap pipe 16e: Upstream end of the riser pipeline 16f: Downstream end of the ascending pipeline 16g: Upper end of the top 16h: Lower end of the top 22: Jet water conduit 22a: Flow straightening section of the jet conduit 24: Jet water outlet 24a: Jet nozzle 80: Aperture section 80a: Inner surface of the aperture A1: Upper channel of the rising pipeline A2: Downward channel of the descending pipeline CL: Centerline of the drain trap pipe O1: Center point of the drain trap pipe. O2: The central point through which the main stream of cleaning water discharged from the jet nozzle passes. P: Collision position R1: Radius of curvature of the inner surface of the drain trap pipe. R2: Radius of curvature of the inner surface of the aperture.

Claims

1. It is a siphon jet type flush toilet, A bowl portion comprising a waste receiving surface for receiving waste, and a rim portion formed above the waste receiving surface, A drain trap pipe includes a rising pipe located below the bowl section and extending upward, a descending pipe extending downward from the rising pipe, and a top section located between the descending pipe and the rising pipe. A jet outlet is provided below the bowl section and discharges cleaning water toward the entrance of the drain trap pipe, A jet water channel that guides the cleaning water to the jet outlet, It has, A flush toilet characterized in that, in the upward channel of the drain trap pipe described above, a constriction is provided in the upper channel, which is located above the vertical center line of the drain trap pipe in the cross-sectional view of the flow path, and the flow path cross-sectional area of ​​the upper channel is smaller than the flow path cross-sectional area of ​​the lower channel, which is located below the center line.

2. The toilet flush according to claim 1, wherein the constricted portion is provided at least on the upstream side of the rising pipe.

3. The flush toilet according to claim 2, wherein the constricted portion is provided extending from the upstream end to the downstream end of the riser pipe.

4. The flush toilet according to any one of claims 1 to 3, wherein the constricted portion is provided in the cross-section of the flow path in a region outside a predetermined radius of curvature centered on the central point through which the main flow of the flushing water discharged from the jet outlet passes.

5. The flush toilet according to claim 1, wherein the upstream end of the rising pipe of the drain trap pipe is formed such that the cross-sectional area of ​​the flow path of the upper side flow path gradually decreases.

6. The flush toilet according to claim 1, wherein the position where the cross-sectional area of ​​the upper flow path is smallest is located downstream of the collision point where the main stream of flushing water discharged from the jet outlet collides with the rising pipe.

7. The flush toilet according to claim 1, wherein the top of the drain trap pipe has an upper end that is located downstream of the lower end.

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