JP2023050889A - Flush toilet bowl - Google Patents

Abstract

To provide a flush toilet bowl capable of suppressing adhesion of filth and suppressing deterioration of washing performance.SOLUTION: A flush toilet bowl 1 of the present invention comprises: a bowl part 6 for receiving filth; and water discharge parts 20, 22 that discharge washing water into the bowl part to form a swirling flow; and a drain trap pipeline 8 that has a lowering pipeline 30 connected to the bowl part and extending downwardly from the bowl part and a rising pipeline 32 connected to the lowering pipeline and extending upwardly from the lowering pipeline, the lowering pipeline comprises: an inlet part 40 formed at connection with the bowl part and an outlet part 42 formed at the connection with the rising pipeline, and a reduced part 52 in which height H of a vertical cross section perpendicular to a flow line F1 of the washing water from a third virtual line L3 is smaller than that on a downstream side is formed between a first horizontal virtual line L1 and a second horizontal virtual line L2 when setting the first horizontal virtual line extending forward from the connection part on a rear side of the lowering pipeline and the bowl part, the second horizontal virtual line located below the first horizontal virtual line and extending forward from a top part of the connection part of the lowering pipeline and the rising pipeline, and the third virtual line extending along the flow line of the washing water from the top part of the lowering pipeline.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a flush toilet bowl, and more particularly to a flush toilet bowl that suppresses a decrease in waste discharge performance.

For example, as described in Patent Document 1, Patent Document 2, and Patent Document 3, a bowl portion, a water discharge portion that discharges water to the bowl portion to form a swirling flow, and a drainage pipe connected to the lower portion of the bowl portion. and flush toilets are known. In these flush toilets, the bowl portion has a filth-receiving surface and a water-storage portion which is a concave portion provided below the filth-receiving surface.

In these flush toilets, the connecting portion between the front side of the water storage portion and the inlet of the drainage pipe is formed by a convex curved surface protruding upward, and the rear side of the water storage portion and the inlet of the drainage pipe are connected. A portion is formed by a convex curved surface protruding inward. Due to the shape of the water storage portion of these flush toilets, a vertical swirl flow is formed in the water storage portion, and this swirl flow discharges heavy wastes to the drain pipe.

In particular, in the case of a so-called "rinse-off type flush toilet", in which waste is washed away by the action of running water due to the drop of water in the bowl, a swirling flow acts on the waste, etc. spreading near the entrance of the drainage pipe in the recess. In addition to this, the water pressure applied from above by the washing water has a remarkable effect of pushing waste into the drain pipe.

Japanese Patent Application Laid-Open No. 2021-25225 Japanese Patent Application Laid-Open No. 2020-7908 JP 2015-67954 A

In a conventional flush toilet, especially a wash-off type flush toilet, since a vertically swirling flow is formed in the water storage portion formed at the bottom of the bowl portion, it is necessary to form the water storage portion small. If the water storage portion becomes small, there arises a problem that the area of the bowl portion to which dirt adheres becomes large. On the other hand, if the water storage portion is made larger than the conventional one, it becomes difficult to form a flow of washing water toward the center of the water storage portion. A gap is created between the front side of the trap pipe or the upstream side of the drainage trap pipe, and the washing water flows through the gap. ) did not work well, and there was a fear that the filth could not be discharged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and is capable of suppressing the adhesion of dirt and the deterioration of cleaning performance even when the water storage portion is formed large. is intended to provide

In order to achieve the above object, the present invention provides a flush toilet that is flushed with cleansing water and discharges contaminants, comprising a bowl portion for receiving the contaminants, and flushing water spouted into the bowl portion to form a swirling flow. a drain trap line comprising a downcomer line connected to the bowl section and extending downwardly from the bowl section and a riser line connected to the downcomer line and extending upwardly from the downcomer line; The downcomer line has an inlet section formed at the connection with the bowl section and an outlet section formed at the connection with the riser line, the riser line having an inlet section formed at the connection with the downcomer line. and a first horizontal imaginary line extending forward from the connection portion on the rear side of the downcomer and the bowl portion, and the downcomer located below the first horizontal imaginary line. When setting a second horizontal virtual line extending forward from the top of the connecting portion of the ascending pipeline and a third virtual line extending along the flow line of the wash water from the top of the descending pipeline, the first horizontal virtual line and A reduced portion is formed between the second horizontal phantom lines, in which the height of the vertical cross section perpendicular to the flow line of the wash water from the third phantom line is smaller than that on the downstream side.
In the present invention configured as described above, the first horizontal imaginary line extending forward from the connecting portion on the rear side of the downcomer pipe and the bowl portion, and the downcomer pipe located below the first horizontal imaginary line. If a second horizontal virtual line extending forward from the top of the connecting portion of the ascending pipeline and a third virtual line extending along the streamline of the wash water from the top of the descending pipeline are set, the first horizontal virtual line and the third horizontal virtual line are set. Between the two horizontal phantom lines, there is formed a reduced portion in which the height of the vertical cross section perpendicular to the flow line of the washing water from the third phantom line is smaller than that on the downstream side. Since it is possible to prevent the wash water from passing under the dirt when it is pushed out and pressure escapes (pressure release phenomenon), it is possible to effectively utilize the flow of the wash water and suppress the deterioration of the washing performance. Furthermore, even when this reducing portion is provided in the middle of the descending pipeline, it is possible to prevent the pressure from escaping from around the waste after it has entered the descending pipeline, thereby eliminating the cause of clogging. It is possible to prevent deterioration of cleaning performance (effective use of the flow of cleaning water) while preventing this.

In the present invention, preferably, the decreasing portion is provided on the bottom surface of the front region of the bowl portion connected to the downcomer line or on the side surface on the front side of the downcomer line, and protrudes toward the center of the downcomer line. 2. The flush toilet according to claim 1, wherein the flush toilet is formed by one arcuate surface.
In the present invention configured as described above, the reducing portion is provided on the bottom surface of the front region of the bowl portion connected to the downcomer line or on the side surface on the front side of the downcomer line, and is directed toward the center of the downcomer line. Since it is formed by the first arcuate surface protruding upwardly, it is possible to prevent the pressure from escaping from below the waste while guiding the waste to the center of the descending pipe.

In the present invention, preferably, the apex of the first circular arc surface is provided between the first horizontal virtual line and the second horizontal virtual line.
In the present invention configured as described above, since the top of the first circular arc surface is provided between the first horizontal virtual line and the second horizontal virtual line, at the top of the first circular arc surface, from around the waste material It is possible to prevent the pressure from escaping, thereby effectively utilizing the flow of the washing water and preventing the suppression of the washing performance.

In the present invention, preferably, the connecting portion on the rear side of the descending pipe and the bowl portion is formed by a rear arc portion protruding toward the center of the bowl portion.
In the present invention constructed as described above, since the connecting portion on the rear side of the descending pipe and the bowl portion is formed by the rear arc portion protruding toward the center of the bowl portion, the washing water is discharged from the rear side of the waste. This can be achieved by preventing the pressure from being released, thereby making it possible to effectively utilize the flow of the cleaning water and prevent suppression of the cleaning performance.

In the present invention, preferably, the rear arc portion is provided above the first arc surface.
In the present invention configured as described above, since the rear arc portion is provided above the first arc surface, the washing water is supplied while suppressing a significant decrease in the height of the vertical cross section of the downcomer pipe. It is possible to prevent the pressure from being released.

In the present invention, the bowl preferably has a filth-receiving surface and a water-retaining portion provided below the filth-receiving surface, and the bottom of the water-retaining portion protrudes toward the center of the bowl. A second arcuate surface is provided.
In the present invention constructed as described above, the second arcuate surface protruding toward the center of the bowl portion is provided on the bottom surface of the water storage portion, so that the waste is transferred from the second arcuate surface to the first arcuate surface. It can be guided smoothly.

In the present invention, preferably, the first arcuate surface and the second arcuate surface are provided continuously, and the radius of curvature of the first arcuate surface is set larger than the radius of curvature of the second arcuate surface.
In the present invention configured as described above, the first arcuate surface and the second arcuate surface are provided continuously, and the radius of curvature of the first arcuate surface is set larger than the radius of curvature of the second arcuate surface. Therefore, part of the wash water flowing along the second arcuate surface of the stagnant water portion can be separated by the first arcuate surface, and the wash water and the waste can be guided to the center side of the descending pipeline, Waste can be discharged by increasing surface pressure (water pressure).

According to the flush toilet bowl of the present invention, it is possible to suppress adhesion of dirt and decrease in cleaning performance even if the water storage portion is formed large.

1 is a plan view showing a flush toilet according to an embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1; FIG. 3 is an enlarged partial cross-sectional view showing an enlarged recess and a drainage trap pipeline of FIG. 2; FIG. 3 is an enlarged partial cross-sectional view showing the recessed portion and the drainage trap pipeline in FIG. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3; FIG. 4 is a cross-sectional view taken along line BB of FIG. 3; FIG. 4 is a cross-sectional view taken along line CC of FIG. 3; FIG. 4 is a cross-sectional view taken along line DD of FIG. 3; FIG. 4 is a schematic diagram showing the flow of waste and flush water in the flush toilet according to the embodiment of the present invention; FIG. 2 is a schematic diagram showing the flow of filth, flush water, and pressure relief in a conventional flush toilet;

Hereinafter, a flush toilet according to an embodiment of the present invention will be described with reference to the drawings. First, the basic structure of a flush toilet according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a plan view showing a flush toilet according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II--II in FIG.

As shown in FIGS. 1 and 2, a flush toilet 1 according to an embodiment of the present invention includes a toilet body 2 made of ceramics. The flush toilet 1 is a so-called "wash-off type flush toilet" in which dirt is washed away by the action of running water due to the difference in water level within the bowl. The flush toilet according to this embodiment can also be applied to a siphon-type flush toilet.

A toilet body 2 of the flush toilet 1 includes a water conduit 4, a bowl-shaped bowl portion 6, and a drainage trap portion 8 from the upstream side to the downstream side. A toilet seat (not shown), a toilet lid (not shown), and the like are provided on the upper surface of the toilet body 2 .
Furthermore, the flush toilet 1 is provided with a water storage tank 10 as a flushing water source for storing flushing water and supplying it to the toilet body 2 at its rear side. In this embodiment, other than the water storage tank 10, the washing water source may be of a water supply direct pressure type or a flush valve type that directly uses the water supply pressure of tap water, or a type that supplies washing water using the compensation pressure of a pump. may be used.

A water conduit 4 is provided on the upstream side of the toilet body 2 , and the water conduit 4 guides flush water supplied from a water storage tank 10 (see FIG. 1 ) to the bowl portion 6 . The bowl portion 6 includes a dirt receiving surface 12, a rim portion 14 provided on the top of the dirt receiving surface 12, a shelf portion 16 provided between the dirt receiving surface 12 and the rim portion 14, and the dirt receiving surface 12. A recess 18 is provided below and forms a reservoir.
Further, a first rim spout 20 for spouting cleansing water to the bowl portion 6 is provided in the left front region of the rim portion 14 when the bowl portion 6 is viewed from the front, and a second rim spout 20 is provided in the right rear region. A spout 22 is provided.

The water conduit 4 includes a common water conduit 24 and a first rim water conduit 26 and a second rim water conduit 28 branching downstream from the common water conduit 24 . An inlet 4 a is formed at the upstream end of the common water conduit 24 to guide the washing water from the water storage tank 10 .
Further, the above-described first rim water outlet 20 is provided at the downstream end of the first rim water conduit 26 to guide the wash water to the first rim water outlet 20 . Similarly, the downstream end of the second rim water conduit 28 has the above-described second rim spout 28 to guide the wash water to the second rim spout 28 .

Washing water is discharged from the first rim water outlet 20 toward the shelf 16 on the front side, and washing water is discharged from the second rim water outlet 22 toward the shelf 16 on the rear side. Since wash water is spouted in the same direction from the first rim spout 20 and the second rim spout 22, a swirling flow is formed in the bowl portion 6. As shown in FIG.

Further, the wash water spouted from the first rim spout 20 flows into the recess 18 described above while swirling. The wash water spouted from the second rim spout 22 flows into the front area of the recess 18 after swirling around the recess 18 , and the wash water spouted from the first rim spout 20 and the second rim spout 20 The wash water spouted from the spout 22 merges within the recess 18 to form a vertical swirl flow within the recess 18 .

As shown in FIG. 2, a drain trap line 8 is connected to the recess 18 of the bowl portion 6 . The drain trap line 8 includes a downcomer line 30 extending downwardly from the recess 18 and a riser line 32 connected to the downstream end of the downcomer line 30 . The downstream side of the ascending pipeline 32 extends to a discharge port (not shown) to which an external discharge pipe (not shown) is connected.
Here, the concave portion 18 forms a water storage portion with water that is stored. Before flushing the toilet bowl, water is accumulated up to the sealing water level WL in the recess 18. - 特許庁

Next, referring to FIG. 3, the recess 18 of the bowl portion 6 and the drain trap line 8 will be described in detail. FIG. 3 is an enlarged partial cross-sectional view showing the recessed portion 18 and the drain trap pipe line 8 of FIG.
As shown in FIG. 3, the front region of the recess 18 is provided with a bottom surface 34 that gently slopes downward toward the rear. A rear arc portion 36 projecting forward in an arc shape is provided in the rear region of the recess 18 .

First, the bottom surface 34 of the recess 18 includes a front side arc surface 34a which is a second arc surface having a large curvature radius R1 (R1=200 mm) extending from P1 to P2 on the front side, and the front side arc surface 34a. A rear arc surface 34b, which is an arc-shaped first arc surface having a small curvature radius R2 (R2=30 mm) extending from P2 to P3 on the rear side continuously formed on the rear side from 34a. Here, the radius of curvature R1 of the front circular arc surface 34a is preferably in the range of 180 mm to 230 mm. Furthermore, the radius of curvature R2 of the rear arc surface 34b is preferably in the range of 20 mm to 40 mm.
Here, if the radius of curvature R1 is too small, the area of the near-horizontal portion of the front portion of the concave portion 18, which is the water storage portion, expands, so that dirt remains on top of it and becomes difficult to be guided into the drain trap pipe line 8. On the other hand, if the radius of curvature R1 is too large, the volume of the recessed portion 18, which is the water storage portion, increases, and dirt is easily diffused during cleaning, degrading the discharge performance. is almost lost, the vertical swirling flow forming force is weakened, and the discharge performance is deteriorated.
On the other hand, if the radius of curvature R2 is too small, it becomes angular and the appearance deteriorates. It becomes impossible to suppress the decrease in pressure release.

A rear arc portion 36 of the concave portion 17 is formed by an arc having a radius of curvature R3 (R3=8 mm). This radius of curvature R3 is preferably in the range of 6 mm to 12 mm. The rear arc portion 36 has a lower end position indicated by P4. Here, if the radius of curvature R3 is too large, a large step is formed at the rear and front of the recess 18, and the rear flow cannot be sufficiently delivered to the front, causing turbulence and weakening the vertical swirling flow forming force. Also, the height difference between the front and rear of the recess 18 deteriorates the appearance.

Next, the downcomer line 30 has an inlet 40 which is its upstream end. This is the portion determined by the line connecting the lower end position P3 of the rear area of 34 . Downcomer line 30 has an outlet 42 at its downstream end.
The riser line 32 has an inlet 44 at its upstream end and an outlet 46 (see FIG. 2) at its downstream end.

Next, referring to FIG. 4, the positional relationship between the rear region 34b of the bottom surface 34 of the recess 18 and the inlet 40 of the descending pipeline 30 will be described. FIG. 4 is an enlarged partial cross-sectional view showing the recessed portion and the drainage trap pipeline in an enlarged manner and describing the first to third phantom lines.

Here, a first horizontal imaginary line L1 extending horizontally forward from the lower end position P4, which is the connecting portion 48 of the descending pipeline 30 and the rear arc portion 36 of the recess 18, is drawn. A second horizontal imaginary line L2 extending horizontally forward from the top 50a of the connecting portion 50 between the descending pipeline 30 and the ascending pipeline 32 is drawn. Draw a third imaginary line L3 extending along the streamline F1 of the wash water flowing through (which is also the axis of the downcomer line 30).

As shown in FIG. 4, the top position P6 of the rear region 34b of the bottom surface 34 of the recess 18 is located between the first horizontal virtual line L1 and the second horizontal virtual line L3. It has become. Furthermore, in the present embodiment, the entire rear area 34b (the area from P2 to P3) is similarly positioned between the first virtual line L1 and the second virtual line L3.

Here, X1 shown in FIG. 4 indicates a cross-sectional shape of a region corresponding to the rear side region 34b in the conventional flush toilets described in Patent Documents 1 to 3, and X2 similarly indicates a conventional flush toilet. It shows a cross-sectional shape corresponding to the rear arc portion 36 of the flush toilet.
The rear region 34b of the bottom surface 34 of the recess 18 in this embodiment has a greater amount of upward protrusion than in the conventional flush toilet. Also, the radius of curvature R3 of the rear arc portion 36 is smaller than the radius of curvature of the conventional flush toilet, and the amount of forward protrusion is large.

Next, the cross-sectional shape of the downcomer line 30 and the vicinity of the inlet 40 of the downcomer line 30 will be described with reference to FIGS. 3 and 5A to 5D. 5A is a cross-sectional view along line AA of FIG. 3, FIG. 5B is a cross-sectional view along line BB of FIG. 3, and FIG. 5C is line CC of FIG. 5D is a cross-sectional view taken along line DD of FIG. 3. FIG. 5A and 5B indicate the portion of the imaginary pipeline formed by the imaginary line L3.

Lines AA, BB, CC, and DB shown in FIG. to show vertical cross-sections perpendicular to each other.
First, FIG. 5A shows the cross-sectional shape of a vertical cross section passing through the top position P6 of the rear arc surface 34b of the bottom surface 34 of the recess 18. As shown in FIG. Here, the height of this vertical section is H1, which is smaller than heights H2, H3, and H4, which will be described later.

FIG. 5B shows the cross-sectional shape of a vertical cross section passing through the position P3 of the connecting portion with the bottom surface 34 of the recess 18 on the front side of the downcomer line 30 . Here, the height of this vertical section is H2.
FIG. 5C shows the cross-sectional shape of a vertical cross section passing through the position P4 of the lower end of the rear arc portion 36 of the recess 18 on the rear side of the descending pipeline 30 . Here, the height of this vertical section is H3.
FIG. 5D shows the profile of a vertical section through P7 on the downstream side of inlet 40 of downcomer line 30. FIG. Here, the height of this vertical section is H4.

Here, the height of each vertical section has a relationship of "H1<H2=H3=H4". Note that each of H2, H3, and H4 may be larger than the value of H1, and may not be the same value. The shape of each vertical cross section is formed in substantially the same triangular shape except that the height is different. The maximum lateral change of the flow path, which causes clogging, etc., is suppressed. In other words, the cross-sectional area of FIG. 5A is the smallest between virtual lines L1 and L2.

In the above-described embodiment, the height H1 in the vertical section passing through the top position P6 of the rear arcuate surface 34b of the bottom surface 34 of the recess 18 is smaller than the height of other vertical sections located downstream. , this position P6 forms a reduced portion 52 of the height of the vertical section. This reduced portion 52 (position P6) is formed on the bottom surface 34 of the recess 18 on the upstream side of the inlet portion 40 of the descending pipeline 8 .
Here, in the present embodiment, as shown in FIG. 4, the position P6 of the apex is provided below the midpoint of the halves of the heights of the imaginary horizontal line L1 and the imaginary horizontal line L2. preferable. By providing the reducing portion 52 below the center point of the imaginary horizontal line L1 and the imaginary horizontal line L2, the pressure around the waste W after the waste W enters (or is conveyed close to) the downcomer pipe 30 is reduced. can be prevented from escaping, it is possible to further reduce the cleaning performance (effectively utilize the flow of cleaning water) while preventing the cause of clogging pressure release phenomenon.

However, other forms are also applicable in this embodiment. The decreasing portion 52, in which the height of the vertical cross section perpendicular to the flow line of the cleansing water from the third virtual line L3 is smaller than that of the downstream side, is formed by the first horizontal virtual line L1 and the second horizontal virtual line L2. It may be in the middle of the descending pipeline 8 as long as it is located between L2.

Next, the operation of the flush toilet 1 according to the embodiment of the present invention described above will be described with reference to FIGS. 6A and 6B. FIG. 6A is a schematic diagram showing the flow of sewage and flush water in a flush toilet according to an embodiment of the present invention, and FIG. 6B is a schematic diagram showing the flow of sewage and flush water and pressure release phenomenon in a conventional flush toilet. .

First, as shown in FIG. 6B, in the conventional flush toilet 60, if the recessed portion 62, which is the water storage portion, is formed larger than the conventional one, it becomes difficult for flush water to flow toward the center of the water storage portion 62. Since cleaning is performed while the dirt is scattered in the pooled water portion 62, a gap C is generated between the dirt W and the like and the front side surface of the drainage trap conduit 64 or the upstream side surface of the drainage trap conduit 64. A so-called "pressure relief phenomenon" occurs in which the cleaning water FW flows through the gap C, and the water pressure (surface pressure) PB is not applied well to the dirt W, and there is a fear that the dirt cannot be discharged.

On the other hand, as shown in FIG. 6A, according to the flush toilet 1 according to the present embodiment, the first horizontal plane extending forward from the connecting portion 48 (position P4) on the rear side of the descending pipe 30 and the bowl portion 8 is provided. A virtual line L1, a second horizontal virtual line L2 located below the first horizontal virtual line L2 and extending forward from the top portion 50a of the connection portion 50 between the downcomer pipe 30 and the upcomb pipe 32, and the downcomer pipe 30. When a third imaginary line L3 extending along the streamline F1 of the cleansing water is set from the top portion 30a of the wash water, the line of the cleansing water Since the height H of the vertical cross section perpendicular to the flow line F1 is formed in the reduced portion 52, the height H is smaller than that on the downstream side. It is possible to prevent the pressure from escaping (pressure release phenomenon), and to apply a large water pressure (surface pressure) PA to the filth W. Therefore, according to the flush toilet 1 according to the present embodiment, it is possible to effectively utilize the flow of flushing water and suppress deterioration in flushing performance. Furthermore, even when the reducing portion 52 is provided in the middle of the descending pipeline 30, it is possible to prevent the pressure around the waste W from escaping after the waste W has entered the descending pipeline 30. , while preventing the cause of clogging, it is possible to lower the cleaning performance (effectively utilize the flow of cleaning water).

Next, according to the flush toilet 1 according to the present embodiment, the decreasing portion 52 is located on the bottom surface 34 of the front area of the recess 18 of the bowl portion 6 connected to the downcomer duct 30 or the front side surface of the downcomer 30 . , which corresponds to the rear arc surface 34b, which is the first arc surface protruding toward the center of the descending pipeline 30). It is possible to prevent pressure from escaping from below the dirt.

Next, according to the flush toilet 1 according to the present embodiment, the top of the rear arcuate surface 34b, which is the first arcuate surface, is provided between the first horizontal virtual line L1 and the second horizontal virtual line L2. Therefore, it is possible to prevent the pressure from escaping around the dirt at the top of the rear arcuate surface 34b, thereby effectively utilizing the flow of the washing water and preventing the suppression of the washing performance.

Next, according to the flush toilet 1 according to the present embodiment, the connecting portion 48 on the rear side of the descending pipe 30 and the bowl portion 6 is formed by the rear arc portion 36 projecting toward the center of the bowl portion 6. , it is possible to prevent the pressure of the washing water from escaping from the rear side of the dirt W, thereby effectively utilizing the flow of the washing water and preventing the suppression of the washing performance.

Next, according to the flush toilet 1 according to the present embodiment, the rear arc portion 36 is provided above the rear arc surface 34b, which is the first arc portion. It is possible to prevent the pressure of the wash water from being released while suppressing a large decrease in height.

Next, according to the flush toilet 1 according to the present embodiment, the bottom surface 34 of the recessed portion 18, which is the water storage portion, is provided with the front side arcuate surface 34a, which is the second arcuate surface protruding toward the center of the bowl portion 6. Therefore, the waste W can be smoothly guided from the front arcuate surface 34a to the rear arcuate surface 34b, which is the first arcuate surface.

Next, according to the flush toilet 1 according to the present embodiment, the rear arcuate surface 34b and the front arcuate surface 34a are provided continuously, and the arc surface on the rear side is larger than the curvature radius R1 of the front arcuate surface 34a. Since the radius of curvature R2 of 34b is set larger, part of the wash water flowing along the front arcuate surface 34a of the concave portion 14, which is the water storage portion, is separated by the rear arcuate surface 34b, and the downcomer pipe Washing water and dirt can be guided to the center side of the channel 30, and surface pressure (water pressure) can be increased to discharge the dirt.

1 flush toilet bowl 2 toilet bowl body 6 bowl portion 8 drainage trap pipe 18 concave portion (water storage portion)
30 Descending pipeline 32 Ascending pipeline 34 Bottom surface 34a Front arcuate surface (second arcuate surface)
34b rear arc surface (first arc surface)
40, 44 inlets 42, 46 outlets 48, 50 connecting portion 50 decreasing portion L1 first horizontal virtual line L2 second horizontal virtual line L2 third virtual line F1 flow lines H1 to H4 of washing water height of vertical section

Claims (7)

A flush toilet that is washed with flush water and discharges waste,
a bowl portion for receiving dirt;
a water discharger that discharges wash water into the bowl to form a swirling flow;
a drain trap line including a downcomer line connected to and extending downwardly from the bowl section and a riser line connected to the downcomer line and extending upwardly from the downcomer line;
said downcomer line having an inlet formed at a connection with said bowl and an outlet formed at a connection with said riser,
The ascending pipeline has an inlet formed at the connection with the descending pipeline and an outlet formed downstream,
A first horizontal imaginary line extending forward from a connecting portion on the rear side of the descending pipeline and the bowl portion, and a connecting portion of the descending pipeline and the ascending pipeline located below the first horizontal imaginary line. When setting a second horizontal virtual line extending forward from the top and a third virtual line extending along the streamline of the wash water from the top of the descending pipeline, the first horizontal virtual line and the second horizontal virtual line A flush toilet, characterized in that a reduced portion is formed in the interval, in which the height of a vertical cross section perpendicular to the flow line of flush water from the third imaginary line is smaller than that on the downstream side. The reduced portion is provided on the bottom surface of the front region of the bowl portion connected to the downcomer line or on the side surface on the front side of the downcomer line, and is a first circular arc surface protruding toward the center of the downcomer line. The flush toilet bowl according to claim 1, wherein the flush toilet is formed by: 3. The flush toilet according to claim 1, wherein the top of the first circular arc surface is provided between the first horizontal virtual line and the second horizontal virtual line. 4. A flush toilet according to any one of claims 1 to 3, wherein the connecting portion on the rear side of the descending conduit and the bowl portion is formed by a rear circular arc portion projecting toward the center of the bowl portion. 5. The flush toilet according to claim 4, wherein the rear arc portion is provided above the first arc surface. The bowl portion has a filth receiving surface and a water storage portion provided below the filth receiving surface, and the bottom surface of the water storage portion has a second arcuate surface protruding toward the center of the bowl portion. 6. A flush toilet according to any one of claims 1 to 5, wherein a flush toilet is provided. 7. The first arc surface and the second arc surface are provided continuously, and the radius of curvature of the first arc surface is set larger than the radius of curvature of the second arc surface. The described flush toilet.

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