JP7559611B2 - Flush toilet - Google Patents

Description

The disclosed embodiment relates to a flush toilet.

Conventionally, flush toilets are known in which flush water is discharged from a discharge section onto a waste receiving surface in a bowl section, forming a swirling flow on the waste receiving surface to flush (see, for example, Patent Document 1). In the flush toilet described above, flush water swirling on the waste receiving surface is collected toward the tip of the water storage section by a fan-shaped recess formed to expand from the water storage section, generating a push-in flow that pushes waste into the water storage section to flush.

JP 2017-172119 A

However, in conventional technology, the pushing flow that pushes waste into the water reservoir is weak, leaving room for improvement.

One aspect of the embodiment aims to provide a flush toilet that can create a strong pushing flow that pushes waste into the water reservoir.

The flush toilet according to one embodiment comprises a waste receiving surface for receiving waste, a bowl section including a shelf section formed on the upper part of the waste receiving surface, a rim section standing up from the shelf section, and a water outlet section formed on the rim section for outletting flushing water to form a swirling flow on the waste receiving surface, and a water storage section formed on the lower part of the bowl section and connected to a drainage channel, the bowl section including a recess formed in the front region of the waste receiving surface for splashing upward at least a portion of the flushing water passing through, the recess including a bottom surface section formed substantially flat and a side surface section connecting the bottom surface section and the shelf section, and characterized in that in a left-right cross-sectional view of the recess, the left-right length of the side surface section is longer than the left-right length of the bottom surface section.

This allows the formation of a relatively strong push-in flow that pushes waste into the pool. That is, the flush water that splashes up by passing through the recess has a greater potential energy than, for example, flush water that does not have a recess and does not splash up, and so can form a strong downward push-in flow when it hits the surface of the pool in the pool. In addition, the splashed-up flush water may, for example, land above the flush water flowing over the shelf, which creates a thickness in the swirling flush water, and as the relatively thick flush water flows into the pool, a stronger push-in flow can be formed. This strong push-in flow allows waste to be efficiently expelled, thereby improving the flushing performance of the flush toilet.

In addition, a recess is formed in the front region of the waste receiving surface, and the wash water passes through this recess, so the waste receiving surface, including the front region, can be reliably cleaned. In addition, because the bottom surface is formed to be approximately flat, it is possible to abruptly change the flow direction of the wash water flowing from the bottom surface to the side surface from a horizontal direction to an upward direction (in other words, a direction that splashes up), making it easier for the wash water to splash up when passing over the side surface.

In addition, by making the length of the side portion in the left-right direction longer than the length of the bottom portion in the left-right direction, it is possible to ensure a large side portion along which the swirling cleaning water flows. This makes it possible to increase the amount and speed of cleaning water flowing down the side portion (in other words, the cleaning water flowing into the recess) compared to when the length of the side portion is shorter than the length of the bottom portion, thereby forming a powerful flow of cleaning water within the recess. In this way, by forming a powerful flow of cleaning water within the recess, it is possible to make it easier for the cleaning water to splash up when it overcomes the side portion, for example, and as a result form a stronger pushing flow.

In addition, in a cross-sectional view of the recess in the left-right direction, the left-right length of the bottom surface portion is longer than the left-right length of the shelf portion.

This allows, for example, a stronger push-in flow to be formed. That is, to form a strong push-in flow, it is desirable to allow a large amount of the swirling flow flowing through the shelf to flow into the bottom of the recess. The length of the bottom is longer than that of the shelf, or conversely, the length of the shelf is shorter than that of the bottom, so the flow path width of the shelf is narrowed, and a large amount of the swirling flow flowing through the shelf can be dropped and flowed into the recess. This allows, for example, the amount of washing water flowing down the side (in other words, washing water flowing into the recess) to be increased compared to when the length of the shelf is longer than the length of the bottom and the flow path width of the shelf is wide, and therefore a powerful flow of washing water can be formed in the recess. In this way, a powerful flow of washing water is formed in the recess, and it is possible to prevent the washing water (swirling flow) from losing momentum when it goes over the side, for example, and as a result, a stronger push-in flow can be formed.

The side portion is also characterized by being formed in a convex shape that protrudes toward the center of the bowl portion.

In this way, by forming the side portion in a convex shape, it is possible to make it easier for the swirling flow that flows over the waste receiving surface or shelf portion to flow into, for example, the upper portion of the side portion. In addition, since the lower portion of the side portion is connected to the approximately flat bottom portion, it is possible to suddenly change the flow direction of the cleaning water, for example, from downward when it is flowing down the side portion to horizontal. As a result, a forceful flow of cleaning water can be formed at the bottom portion, and this forceful flow of cleaning water overcomes the side portion, making it easier for the cleaning water to splash up. Furthermore, even at the side portion that the cleaning water overcomes, the cleaning water is more likely to detach from the surface of the side portion near the apex of the convex shape, making it easier for the cleaning water to splash up.

The side surface is formed such that the vicinity of the apex of the convex shape is a point of change in the radius of curvature of the side surface, the radius of curvature of the upper portion located above the point of change and the radius of curvature of the lower portion located below the point of change are larger than the radius of curvature of the point of change, the upper portion includes an upper inclined surface that is inclined in the left-right direction of the side surface, and the lower portion includes a lower inclined surface that is inclined in the left-right direction of the side surface and is steeper than the upper inclined surface.

This allows the swirling flow flowing through the waste receiving surface and shelf to easily flow into the upper inclined surface of the upper part, which has a large radius of curvature and is gentler than the lower inclined surface of the lower part. Also, the lower inclined surface of the lower part, which has a large radius of curvature and is steeper than the upper inclined surface of the upper part, is connected to the approximately flat bottom surface, so that the flow direction of the cleaning water can be changed more suddenly from downward to horizontal when it is flowing down the side part. Therefore, a more powerful flow of cleaning water can be formed at the bottom part, and this powerful flow of cleaning water can overcome the side part, making it easier for the cleaning water to splash up. Furthermore, even at the side part that the cleaning water overcomes, the cleaning water flows from the steep downward inclined surface to the gentle upward inclined surface, making it easier to detach from the surface of the side part near the change point, making it easier for the cleaning water to splash up.

The side surface is formed such that the vicinity of the apex of the convex shape is a point of change in the radius of curvature of the side surface, the radius of curvature of the upper portion located above the point of change and the radius of curvature of the lower portion located below the point of change are larger than the radius of curvature of the point of change, and in a cross-sectional view of the left-right direction of the recess, the vertical height of the lower portion is greater than the vertical height of the upper portion.

This allows, for example, a relatively high height (drop) to be ensured in the lower portion, allowing the wash water to drop forcefully from the lower portion to the bottom portion, thereby forming a more powerful flow of wash water at the bottom portion. Also, wash water that flows from the bottom portion into the side portion and overcomes it is less likely to reach the upper portion because the upper portion is lower in the vertical direction, making it easier for the wash water to splash up.

The side surface is formed such that the vicinity of the apex of the convex shape is a point of change in the radius of curvature of the side surface, the radius of curvature of the upper portion located above the point of change and the radius of curvature of the lower portion located below the point of change are larger than the radius of curvature of the point of change, and in a cross-sectional view of the recess in the left-right direction, the left-right length of the lower portion is shorter than the left-right length of the upper portion.

As a result, for example, the upper part of the side part is longer in the left-right direction, so it can collect more cleaning water. Also, the lower part of the side part is shorter in the left-right direction, so it is possible to ensure height (drop) in the up-down direction, and cleaning water can drop forcefully from the lower part to the bottom part, thereby forming a more powerful flow of cleaning water at the bottom part. Also, cleaning water that flows from the bottom part into the side part and overcomes it is easier to overcome the lower part because the lower part is shorter, so the cleaning water can be more easily splashed up.

The side surface is also characterized by having a side recess formed in the upper part of the convex shape, on the shelf side.

This can further improve the flushing performance of the flush toilet. That is, for example, if the swirling flow flowing along the upper part of the side part flows too quickly into the bottom part or into the pooled water part, the flushing water may not swirl sufficiently around the waste-receiving surface including the recessed part, and the flushing performance of the flush toilet may be reduced. Because the side part has a side recessed part, at least a portion of the swirling flow flowing along the upper part rides on the side recessed part and is less likely to flow too quickly into the bottom part or pooled water part. This makes it possible to sufficiently swirl the flushing water around the waste-receiving surface including the recessed part, thereby further improving the flushing performance of the flush toilet.

The bottom surface is curved so that at least a portion of it protrudes downward from the bowl portion, and the radius of curvature of the bottom surface is greater than the radius of curvature of the corner that connects the bottom surface and the side surface.

This makes it possible to ensure the flatness of the bottom surface. Therefore, in a bottom surface with a flat surface, i.e., a substantially flat bottom surface, the flow direction of the cleaning water can be suddenly changed from the horizontal direction to the upward direction, making it easier for the cleaning water to splash up.

According to one aspect of the embodiment, a strong pushing flow can be created that pushes waste into the water reservoir.

FIG. 1 is a left side view of a flush toilet according to an embodiment. FIG. 2 is a plan view of the toilet body of the flush toilet. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a perspective view of a flush toilet. FIG. 6 is an enlarged cross-sectional view of the recessed portion in the left-right direction as viewed from the front. FIG. 7 is an enlarged cross-sectional view in the left-right direction of a side surface portion of the recess as viewed from the front.

Below, an embodiment of a flush toilet disclosed in this application will be described in detail with reference to the attached drawings. Note that the invention is not limited to the embodiment shown below. It should be noted that the drawings are schematic, and the dimensional relationships of each element and the ratios of each element may differ from reality. There may also be parts in which the dimensional relationships and ratios differ between the drawings.

<Overall structure of a flush toilet>
First, the overall structure of a flush toilet 1 according to an embodiment will be described with reference to Figure 1. Figure 1 is a left side view of a flush toilet 1 according to an embodiment. Figure 1 also shows a wall surface 8 and a floor surface 9 in cross section.

For ease of understanding, FIG. 1 also illustrates a three-dimensional Cartesian coordinate system including a Z-axis with the positive direction being the vertical upward direction. This Cartesian coordinate system may also be illustrated in other figures. In this Cartesian coordinate system, the negative direction of the Y-axis is defined as the forward direction, the positive direction of the Y-axis as the backward direction, the positive direction of the X-axis as the rightward direction, and the negative direction of the X-axis as the leftward direction. For this reason, in the following explanation, the X-axis direction may be referred to as the left-right direction, the Y-axis direction as the front-back direction, and the Z-axis direction as the up-down direction.

The flush toilet 1 according to the embodiment is a so-called wall-hung type flush toilet that is attached to a wall surface 8. However, the flush toilet 1 may also be a so-called floor-standing type flush toilet that is installed on a floor surface 9. The flush toilet 1 may also be a type that is attached to both a wall surface 8 and a floor surface 9.

The flush toilet 1 comprises a toilet body 2 and a private parts cleaning device 3. The flush toilet 1 according to the embodiment is a wash-down toilet in which the toilet body 2 is cleaned with flush water supplied from a flush water source to discharge waste. The flush toilet 1 may also be a siphon toilet. The toilet body 2 is made of ceramic, for example. Details of the toilet body 2 will be described later.

In the flush toilet 1, flush water is supplied to the toilet body 2 via a water supply pipe 4a connected to a water storage tank 4 (an example of a water supply source). The flush toilet 1 also discharges waste together with flush water into a drain pipe 5. The water storage tank 4 may be placed behind the toilet body 2, and flush water may be supplied directly from the water storage tank 4 to the toilet body 2. The flush toilet 1 is also of a low-tank type, in which flushing is performed with water stored in the water storage tank 4, but is not limited to this and may be of another type of water supply system, such as a flush valve system.

The private parts washing device 3 includes a washing nozzle, a nozzle drive motor, and a motor control device (none of which are shown). The private parts washing device 3 is provided on the top of the toilet body 2 for washing the user's private parts, and washes the user's private parts with washing water sprayed from the washing nozzle.

The flush toilet 1 also includes a water supply hose 6a that supplies cleaning water for genital cleaning to the genital cleaning device 3, and a power cable 6b that supplies power to the genital cleaning device 3. Note that, in the above description, the flush toilet 1 is equipped with the genital cleaning device 3, but this is not limited to this, and it may be configured to include only a toilet seat that does not have a genital cleaning function, or may be configured to include such a toilet seat and a cover that covers the toilet seat.

<Configuration of the toilet body>
Next, the toilet body 2 of the flush toilet 1 according to the embodiment will be described with reference to Figures 2 and 3. Figure 2 is a plan view (top view) of the toilet body 2 of the flush toilet 1 according to the embodiment. Figure 3 is a cross-sectional view taken along line III-III in Figure 2.

As shown in Figures 2 and 3, the toilet body 2 includes a bowl portion 10, a water storage portion 70, and a drain trap portion 80. The bowl portion 10 includes a waste receiving surface 20, a shelf portion 30, a rim portion 40, and a water discharge portion 50.

The waste receiving surface 20 is formed in a bowl shape capable of receiving waste. The shelf portion 30 is formed on the upper part of the waste receiving surface 20. For example, the shelf portion 30 is formed as a substantially flat surface extending outward from the periphery of the upper part of the waste receiving surface 20, and is formed in a ring shape around substantially the entire periphery of the upper part of the waste receiving surface 20. The shelf portion 30 also guides and swirls the cleaning water described below.

The shelf portion 30 is also formed so that it gradually widens from the shelf portion 30 on the side of the bottom surface (bottom surface portion 61) of the recess 60 described below toward the front, so that the front end is the widest. With this configuration, cleaning water that does not flow down into the recess 60 can be guided to the front end, as described below, so that no areas are left uncleaned. The shelf portion 30 is also formed so that the rear end is the narrowest.

The rim portion 40 is formed to stand upright from the shelf portion 30. For example, the rim portion 40 is formed to extend upward from the outer edge of the shelf portion 30. In other words, the rim portion 40 is formed above the waste receiving surface 20 via the shelf portion 30. The rim portion 40 is formed in a shape that overhangs inward to prevent cleaning water from splashing out.

The water discharge section 50 is formed in the rim section 40 and discharges wash water. Specifically, as shown in FIG. 2, the water discharge section 50 includes a main water channel 51, a first rim water channel 52a, a first water outlet 53a, a second rim water channel 52b, and a second water outlet 53b.

The main waterway 51 is connected upstream to the water storage tank 4 (see FIG. 1), and flushing water supplied from the water storage tank 4 is circulated as shown by the arrow D1. The dashed arrows in the figure indicate the flow of flushing water. In this specification, "upstream" and "downstream" refer to "upstream" and "downstream" in the flow of flushing water.

The main water channel 51 branches downstream into a first rim water channel 52a and a second rim water channel 52b. Therefore, the wash water flowing through the main water channel 51 flows toward the first rim water channel 52a and the second rim water channel 52b (see arrows D2 and D3).

The first rim water conduit 52a is formed along the rim portion 40 from the rear of the bowl portion 10 toward the left. A first water outlet 53a is provided at the downstream end of the first rim water conduit 52a, for example, formed to the left of the rim portion 40.

Therefore, the flush water that flows from the main waterway 51 to the first rim waterway 52a flows counterclockwise when viewed from above, and is then discharged from the first water outlet 53a onto the shelf portion 30 of the bowl portion 10 and the waste receiving surface 20 (see arrow D4).

The second rim water conduit 52b is formed along the rim section 40 at the rear of the bowl section 10. The second rim water conduit 52b also has a bent portion 52b1 that bends the flow direction of the flush water midway through the flow path. Specifically, the bent portion 52b1 of the second rim water conduit 52b bends the flow direction of the flush water flowing toward the front of the bowl section 10, as shown by arrow D5, more specifically, makes a U-turn and directs it toward the rear of the bowl section 10. A second water outlet 53b is provided at the downstream end of the second rim water conduit 52b, for example, formed at the right rear of the rim section 40.

Therefore, the flush water that flows from the main waterway 51 to the second rim waterway 52b flows clockwise when viewed from above, and then the flow direction is reversed at the bent portion 52b1 to flow counterclockwise. The flush water is then discharged counterclockwise from the second water outlet 53b onto the shelf portion 30 of the bowl portion 10 and the waste receiving surface 20 (see arrow D6).

In this way, the water discharge section 50 discharges cleaning water counterclockwise from the first and second water discharge ports 53a, 53b, so that the cleaning water flows along the shelf section 30 and forms a swirling flow on the waste receiving surface 20. This swirling flow then cleans the waste receiving surface 20 of the bowl section 10, etc. The shape of the waste receiving surface 20 through which the cleaning water flows and the flow of the swirling flow will be described in detail later.

The flush water supplied to the waste receiving surface 20 of the bowl portion 10 as described above flows into the water storage portion 70 after flushing the toilet. The water storage portion 70 is formed in the lower portion of the bowl portion 10. The water storage portion 70 is formed in a substantially triangular shape when viewed from above. For example, the water storage portion 70 is formed in a tapered shape in which the length in the left-right direction (X-axis direction) decreases as it moves forward (Y-axis negative direction) when viewed from above, and the rear side is formed in a substantially arc shape. A drain trap portion 80 is connected to the lower portion (in other words, the downstream side) of the water storage portion 70. The drain trap portion 80 and the drain pipe 5 are an example of a drainage channel.

As shown in FIG. 3, the drain trap section 80 includes a descending pipe line 81, an ascending pipe line 82, and a discharge pipe line 83. The descending pipe line 81 is connected to the water reservoir section 70 and is formed to extend downward from the water reservoir section 70. The descending pipe line 81 allows the cleaning water from the bowl section 10 and the water reservoir section 70 to flow downward.

The ascending pipe 82 is connected to the descending pipe 81 and is formed to extend upward from the descending pipe 81. Specifically, the ascending pipe 82 is formed to continue from the downstream end of the descending pipe 81 and extends diagonally rearward and upward from the descending pipe 81. The ascending pipe 82 then flows the cleaning water from the descending pipe 81 upward.

The discharge pipe 83 is connected to the rising pipe 82 and extends rearward. The downstream end of the discharge pipe 83 is connected to the drain pipe 5 (see FIG. 1). Therefore, when a toilet flush is performed in the drain trap section 80 configured as described above, the flush water in the bowl section 10 and the water storage section 70 is drained through the descending pipe 81, the rising pipe 82, and the discharge pipe 83 into the drain pipe 5, and waste is discharged.

In addition, a portion of the flushing water accumulates in the water storage section 70 and the drain trap section 80, and functions as a water seal to prevent odors and other odors from the drain pipe 5 from flowing back into the bowl section 10. In FIG. 3, the surface of the flushing water accumulated in the water storage section 70, in other words the surface of the accumulated water, is indicated by the symbol 70a.

<Detailed configuration of the bowl section>
Next, we will explain the detailed configuration of the bowl portion 10 of the flush toilet 1 according to this embodiment. The bowl portion 10 according to this embodiment is configured to be able to create a strong pushing flow that pushes waste into the water collection portion 70.

The detailed description of this configuration is as follows. As shown in Figs. 2 and 3, the bowl portion 10 has a recess 60. The recess 60 is formed in the front region 21 of the waste receiving surface 20. For ease of understanding, in Fig. 2, the front region 21 is shown surrounded by a two-dot chain line. As shown in Fig. 2, the front region 21 is the region of the waste receiving surface 20 that is forward (in the negative Y-axis direction) of the front tip 71 of the water storage portion 70, and the recess 60 is formed in part or all of the front region 21.

The recess 60 will now be described with reference to Figure 4. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. Specifically, Figure 4 is a cross-sectional view in the left-right direction (X-axis direction) of the recess 60 portion of the flush toilet 1, and more specifically, a cross-sectional view in the left-right direction of the bottom surface 61 of the recess 60, which will be described later, as viewed from the front. Note that the left-right cross-section shown in Figure 4 is a cross-section at the position where the bottom surface 61 of the recess 60 is located at the very bottom (floor side) of the recess 60.

As shown in Figures 2 to 4, the recess 60 has a bottom surface portion 61 and a side surface portion 62. The bottom surface portion 61 is a portion that extends forward from near the tip portion 71 of the water storage portion 70, and is formed to be approximately flat when viewed in cross section in the left-right direction, as shown in Figure 4. The bottom surface portion 61 includes the lowest portion of the recess 60 in the up-down direction, but is not limited to this.

The side surface portions 62 are formed as inclined surfaces that extend obliquely upward from the left and right ends of the bottom surface portion 61 to the shelf portion 30, and connect the bottom surface portion 61 and the shelf portion 30. In other words, the side surface portions 62 are formed so as to be inclined outward in the up-down direction (Z-axis direction (vertical direction)).

Specifically, the side portion 62 includes a left side portion 62L and a right side portion 62R. The left side portion 62L is formed as an inclined surface that extends from the left end of the bottom portion 61 diagonally upward and to the left to the shelf portion 30. The right side portion 62R is formed as an inclined surface that extends from the right end of the bottom portion 61 diagonally upward and to the right to the shelf portion 30.

The recess 60, including the left side surface portion 62L and the right side surface portion 62R, is formed in a shape that is symmetrical about the center line E of the flush toilet 1 (see FIG. 4), i.e., a shape that is symmetrical or nearly symmetrical, but is not limited to this, and may be formed in an asymmetrical shape that does not have symmetry. In the following, when there is no need to distinguish between the left side surface portion 62L and the right side surface portion 62R, they may be referred to as "side surface portion 62".

When the toilet is flushed, flush water (swirling flow) passes through the recess 60 configured as described above. As flush water passes through the recess 60, it can splash some of the passing flush water upward, forming a powerful pushing flow that pushes waste into the water storage section 70, thereby improving the flushing ability of the flush toilet 1.

The flow of flush water will be specifically explained with reference to Figure 5. Figure 5 is a perspective view of the flush toilet 1. As shown in Figures 2, 4, and 5, the flush water (swirling flow) that flows over the waste receiving surface 20 and shelf portion 30 during toilet flushing flows down the left side surface portion 62L as shown by arrow D11. In other words, the flush water flowing over the waste receiving surface 20 etc. falls down due to the sudden drop in the left side surface portion 62L and flows into the bottom surface portion 61.

The cleaning water that flows down from the side portion 62 to the bottom portion 61 passes through the bottom portion 61 (see arrow D12). Because the bottom portion 61 is formed to be substantially flat, the flow direction of the cleaning water passing through the bottom portion 61 changes from the downward direction (more precisely, a diagonally downward right direction) when it flows down the left side portion 62L to a horizontal direction (left-right direction; more precisely, to the right).

After that, when the cleaning water flowing along the bottom surface 61 reaches the right side surface 62R, it flows diagonally upward along the right side surface 62R as shown by arrow D13. The flow direction of the cleaning water flowing along the right side surface 62R changes from the horizontal direction (to the right, to be precise) when it passed through the bottom surface 61 to an upward direction (to the diagonally upper right, to be precise).

Then, as the flush water flows over the right side surface 62R, some of the flush water splashes upward. That is, as the flush water passes through the recess 60, it splashes upward; more specifically, it splashes (jumps) above the waste receiving surface 20.

The cleaning water that has splashed up by passing through the recess 60 falls into the water storage section 70 as shown by arrow D14, in other words, lands on the water storage surface 70a (see Figure 3) in the water storage section 70.

This allows for the formation of a relatively strong push-in flow that pushes waste into the water storage section 70. That is, the wash water that splashes up by passing through the recess 60 has a larger potential energy than, for example, wash water that does not have a recess 60 and does not splash up, so that when it hits the water storage surface 70a in the water storage section 70, it can form a strong downward push-in flow. In addition, the splashed wash water can also land above the wash water flowing over the shelf section 30, for example, which creates a thickness in the swirling wash water, and the relatively thick wash water flows into the water storage section 70, forming a stronger push-in flow.

In this embodiment, waste can be efficiently expelled by the strong pushing flow described above, thereby improving the flushing ability of the flush toilet 1.

In addition, in this embodiment, a recess 60 is formed in the front region 21 of the waste receiving surface 20, and cleaning water passes through the recess 60, so that the waste receiving surface 20, including the front region 21, can be cleaned reliably.

In addition, because the bottom surface portion 61 is formed in a substantially flat shape, it is possible to abruptly change the flow direction of the cleaning water flowing from the bottom surface portion 61 to the right side surface portion 62R from a horizontal direction to an obliquely upward direction (in other words, the direction of splashing up), thereby making it easier for the cleaning water to splash up when passing over the right side surface portion 62R.

In the above description, the recess 60 is configured to splash up a portion of the washing water passing through it, but it may also splash up all of the washing water passing through it. In other words, the recess 60 may be configured to splash up at least a portion of the washing water passing through it.

Next, the recess 60 will be described in more detail with reference to Figure 6. Figure 6 is an enlarged cross-sectional view of the recess 60 in the left-right direction as viewed from the front.

As shown in FIG. 6, the recess 60 is formed such that the length B of the side surface portion 62 in the left-right direction is longer than the length A of the bottom surface portion 61 in the left-right direction in a cross-sectional view in the left-right direction (B>A).

This makes it possible to ensure a large left side surface 62L, which is an inclined surface along which swirling wash water flows. As a result, the amount and speed of wash water flowing down the left side surface 62L (in other words, wash water flowing into the recess 60) can be increased compared to when the length B of the side surface 62 is shorter than the length A of the bottom surface 61, and therefore a forceful flow of wash water can be formed within the recess 60. In this way, the formation of a forceful flow of wash water within the recess 60 makes it easier for wash water to splash up when it overcomes, for example, the right side surface 62R, resulting in a stronger pushing flow.

Here, the bottom surface portion 61 is formed to be substantially flat as described above, but this "substantially flat" does not necessarily require that the upper surface 61a of the bottom surface portion 61 be straight when viewed in cross section in the left-right direction. That is, the bottom surface portion 61 may be formed to be curved so that a part or the whole of it protrudes downward from the bowl portion 10, as shown in FIG. 6. In other words, the bottom surface portion 61 may be formed to be slightly curved downward so that the apex is near the center line E in the left-right direction.

However, if the bottom surface portion 61 is excessively curved, the cleaning water may flow along the shape of the recess 60 and not separate from the surface of the recess 60, making it difficult for the cleaning water to splash up. Therefore, in the bottom surface portion 61 according to this embodiment, for example, the radius of curvature of the curved bottom surface portion 61 is made larger than the radius of curvature of the corner portion 63 that connects the bottom surface portion 61 and the side surface portion 62. The radius of curvature of the corner portion 63 is the radius of curvature of the inner circumferential surface side of the portion of the recess 60 where the bottom surface portion 61 and the side surface portion 62 are continuously connected.

This makes it possible to ensure the flatness of the bottom surface 61 even if the bottom surface 61 is curved. Therefore, in a bottom surface 61 with a flatness ensured, i.e., a substantially flat bottom surface 61, as described above, the flow direction of the cleaning water can be suddenly changed from the horizontal direction to an obliquely upward direction, making it easier for the cleaning water to splash up.

Note that, although FIG. 6 shows an example in which the bottom surface portion 61 is curved downward, this is not limiting. In other words, the bottom surface portion 61 may be formed so that the upper surface 61a is linear in cross-sectional view, without being curved downward.

Continuing with the explanation of the recess 60, the recess 60 is formed so that, in a left-right cross-sectional view, the left-right length A of the bottom surface portion 61 is longer than the left-right length C of the shelf portion 30 (A>C).

This allows, for example, a stronger push-in flow to be formed. That is, to form a strong push-in flow, it is desirable to allow a large amount of the swirling flow flowing through the shelf portion 30, etc., to flow into the bottom surface portion 61 of the recess 60. In this embodiment, the length A of the bottom surface portion 61 is formed to be longer than the length C of the shelf portion 30, or conversely, the length C of the shelf portion 30 is formed to be shorter than the length A of the bottom surface portion 61, so that the flow path width of the shelf portion 30 is narrowed, and it is possible to allow a large amount of the swirling flow flowing through the shelf portion 30 to fall and flow into the recess 60. As a result, for example, the amount of washing water flowing down the left side surface portion 62L (in other words, the washing water flowing into the recess 60) can be increased compared to when the length C of the shelf portion 30 is longer than the length A of the bottom surface portion 61 and the flow path width of the shelf portion 30 is wide, and therefore a powerful flow of washing water can be formed in the recess 60. In this way, a powerful flow of cleaning water is formed within the recess 60, which prevents the cleaning water (swirling flow) from losing momentum when passing over the right side surface portion 62R, for example, and as a result, a stronger pushing flow can be formed.

The side surface 62, which is an inclined surface, is formed in a convex shape that protrudes toward the center of the bowl portion 10. In other words, the side surface 62 is formed in a convex shape that curves so as to protrude toward the center line E of the flush toilet 1 in the left-right direction.

In this way, by forming the side portion 62 in a convex shape, for example, the upper side portion 62b of the side portion 62 (more precisely, the upper side portion 62b of the left side portion 62L) can easily flow in the swirling flow flowing through the waste receiving surface 20 and the shelf portion 30. In addition, since the lower side portion 62a of the side portion 62 (more precisely, the lower side portion 62a of the left side portion 62L) is connected to the substantially flat bottom surface portion 61, for example, the flow direction of the washing water can be suddenly changed from the downward direction (diagonally downward to the right) when it flows down the left side portion 62L to the horizontal direction (to the right). Therefore, a powerful flow of washing water can be formed at the bottom surface portion 61, and since this powerful flow of washing water overcomes the right side portion 62R, the washing water can easily splash up. Furthermore, even at the right side portion 62R, the washing water can easily detach from the surface of the right side portion 62R near the apex portion 64 of the convex shape, so that the washing water can be more easily splashed up.

The side surface portion 62 is formed so that the radius of curvature of the side surface portion 62 changes near the apex portion 64 of the convex shape. More specifically, the side surface portion 62 is formed so that the radius of curvature of the upper portion 62b located above the change point F and the radius of curvature of the lower portion 62a located below the change point F are larger than the radius of curvature of the change point F, with the vicinity of the apex portion 64 being the change point. In other words, the side surface portion 62 is formed so that the radius of curvature of the change point F is smaller than the radius of curvature of the upper portion 62b and the lower portion 62a. In other words, the side surface portion 62 is formed so that the radius of curvature of the change point F is different from the radius of curvature of the upper portion 62b and the lower portion 62a. The change point F is the innermost point of the side surface portion 62 of the convex shape.

The upper side portion 62b includes an upper inclined surface 62b1 that is inclined relative to the left-right direction (X-axis direction) of the side portion 62. The lower side portion 62a includes a lower inclined surface 62a1 that is inclined relative to the left-right direction of the side portion 62. The lower inclined surface 62a1 is a steeper inclined surface than the upper inclined surface 62b1. Conversely, the upper inclined surface 62b1 is a gentler inclined surface than the lower inclined surface 62a1. Specifically, the angle between the lower inclined surface 62a1 and the left-right direction (X-axis direction) is set to be larger than the angle between the upper inclined surface 62b1 and the left-right direction.

This allows the swirling flow flowing through the waste receiving surface 20 and the shelf 30 to flow easily into the upper inclined surface 62b1 (more precisely, the upper inclined surface 62b1 of the upper side portion 62b of the left side portion 62L), which has a large radius of curvature and is gentler than the lower inclined surface 62a1. Also, the lower inclined surface 62a1 (more precisely, the lower inclined surface 62a1 of the lower side portion 62a of the left side portion 62L), which has a large radius of curvature and is steeper than the upper inclined surface 62b1, is connected to the substantially flat bottom surface portion 61, so that, for example, the flow direction of the washing water can be changed more abruptly from the downward (diagonally downward to the right) direction when it flows down the left side portion 62L to the horizontal direction (to the right). Therefore, a more powerful flow of washing water can be formed at the bottom surface portion 61, and the powerful flow of washing water can overcome the right side portion 62R, making it easier for the washing water to splash up. Furthermore, on the right side surface 62R, the wash water flows from the steep downward inclination 62a1 to the gentle upward inclination 62b1, so it tends to separate from the surface of the right side surface 62R near the change point F, making it easier for the wash water to splash up.

In the above description, the upper portion 62b and the lower portion 62a are formed so that the radius of curvature is large, but the upper inclined surface 62b1 of the upper portion 62b and the lower inclined surface 62a1 of the lower portion 62a do not necessarily have to be curved (R) and may be linear.

The recess 60 is configured so that the wash water is collected in the upper portion 62b including the gentle upward inclination 62b1 of the side portion 62, and the collected wash water is dropped and poured into the bottom portion 61 at the lower portion 62a including the steep downward inclination 62a1, forming a forceful flow of wash water at the bottom portion 61. Therefore, in order to form a more forceful flow of wash water at the bottom portion 61, it is desirable to, for example, ensure the height (drop) H1 of the lower portion 62a as much as possible so that the wash water falls forcefully onto the bottom portion 61.

Therefore, in the side portion 62 according to this embodiment, the height H1 of the lower portion 62a and the height H2 of the upper portion 62b are formed to be different. In more detail, the side portion 62 is formed such that, in a cross-sectional view of the left-right direction of the recess 60, the vertical height H1 of the lower portion 62a is higher than the vertical height H2 of the upper portion 62b (H1>H2).

This allows a relatively high height (drop) to be secured in the lower portion 62a, for example, so that the cleaning water can drop forcefully from the lower portion 62a to the bottom portion 61, thereby forming a more powerful flow of cleaning water in the bottom portion 61.

In addition, the cleaning water that flows from the bottom surface portion 61 into the right side surface portion 62R is less likely to land on the upper side portion 62b of the right side surface portion 62R because the vertical height H2 of the upper side portion 62b is low, making it easier for the cleaning water to splash up.

The side portion 62 is formed so that the left-right length B1 of the lower portion 62a is different from the left-right length B2 of the upper portion 62b. In more detail, the side portion 62 is formed so that, in a left-right cross-sectional view of the recess 60, the left-right length B1 of the lower portion 62a is shorter than the left-right length B2 of the upper portion 62b (B1<B2).

As a result, for example, the upper side portion 62b of the left side portion 62L has a long left-right length B2, so it can collect more cleaning water. Also, the lower side portion 62a of the left side portion 62L has a short left-right length B2, so it is possible to ensure a sufficient vertical height (drop), and cleaning water can drop vigorously from the lower side portion 62a to the bottom portion 61, thereby forming a more powerful flow of cleaning water at the bottom portion 61.

In addition, the cleaning water that flows from the bottom surface portion 61 into the right side surface portion 62R easily overcomes the lower portion 62a of the right side surface portion 62R because the length B1 of the lower portion 62a is short, making it easier for the cleaning water to splash up.

Here, the shape of the upper portion 62b of the side surface portion 62 will be described with reference to Figure 7. Figure 7 is an enlarged cross-sectional view of the side surface portion 62 of the recess 60 in the left-right direction as viewed from the front.

As shown in FIG. 7, the side surface portion 62 has a side surface recess 65. Note that while FIG. 7 shows the side surface recess 65 of the left side surface portion 62L, a similar side surface recess 65 is also formed on the right side surface portion 62R. Also, in FIG. 7, the recess of the side surface recess 65 is exaggerated for ease of understanding.

The side recess 65 is formed in the upper part of the convex shape of the side portion 62 (i.e., the upper side portion 62b) on the shelf portion 30 side. The side recess 65 is a recess that curves so as to protrude downward (more precisely, diagonally downward).

In this way, by forming the side recess 65 on the side portion 62, the flushing performance of the flush toilet 1 can be further improved. That is, for example, if the swirling flow flowing through the upper portion 62b of the side portion 62 flows too quickly into the bottom portion 61 or into the water storage portion 70, the flush water will not swirl sufficiently around the waste receiving surface 20, including the recess 60, and the flushing performance of the flush toilet 1 may be reduced.

The side portion 62 in this embodiment is provided with a side recess 65, so that at least a portion of the swirling flow that flows through the upper portion 62b rides on the side recess 65 and is less likely to flow into the bottom portion 61 or the water reservoir portion 70 prematurely. This makes it possible to sufficiently swirl the flush water on the waste receiving surface 20, including the recess 60, thereby further improving the flushing performance of the flush toilet 1.

As described above, the flush toilet 1 according to the embodiment comprises a bowl section 10 having a waste receiving surface 20, a shelf section 30, a rim section 40 and a water discharge section 50, and a water pool section 70. The waste receiving surface 20 receives waste. The shelf section 30 is formed on the upper part of the waste receiving surface 20. The rim section 40 stands upright from the shelf section 30. The water discharge section 50 is formed on the rim section 40 and discharges flushing water to form a swirling flow on the waste receiving surface 20. The water pool section 70 is formed on the lower part of the bowl section 10 and is connected to a drainage channel.

The bowl portion 10 is formed in the front region 21 of the waste receiving surface 20 and has a recess 60 that causes at least a portion of the washing water passing through to splash upward. The recess 60 has a bottom surface portion 61 that is formed in a substantially flat shape, and a side surface portion 62 that connects the bottom surface portion 61 to the shelf portion 30. In addition, in a left-right cross-sectional view of the recess 60, the left-right length B of the side surface portion 62 is longer than the left-right length A of the bottom surface portion 61. This allows for the formation of a strong pushing flow that pushes waste into the water storage portion 70.

Further advantages and modifications may 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 equivalents thereof.

REFERENCE SIGNS LIST 1 Flush toilet 10 Bowl portion 20 Receiving surface 30 Shelf portion 40 Rim portion 50 Water outlet portion 60 Recessed portion 61 Bottom portion 62 Side portion 70 Water storage portion

Claims (6)

a bowl portion including a waste receiving surface for receiving waste, a shelf portion formed on an upper portion of the waste receiving surface, a rim portion erected from the shelf portion, and a water discharge portion formed on the rim portion for discharging flush water to form a swirling flow on the waste receiving surface;
a water collecting section formed in a lower portion of the bowl section and connected to a drainage channel;
The bowl portion is
A recess is formed in a front region of the waste receiving surface, and causes at least a portion of the flush water passing through the recess to splash upward,
The recessed portion is
A bottom surface portion formed in a substantially flat shape;
a side surface portion that connects the bottom surface portion and the shelf portion and is formed in a convex shape protruding toward the center of the bowl portion ,
In a cross-sectional view of the recess in the left-right direction, the length of the side surface portion in the left-right direction is longer than the length of the bottom surface portion in the left-right direction,
The side surface portion is
The vicinity of the apex of the convex shape is a change point of the radius of curvature of the side surface portion, and the radius of curvature of an upper portion located above the change point and the radius of curvature of a lower portion located below the change point are formed to be larger than the radius of curvature of the change point,
The upper portion is
An upward inclined surface inclined relative to the left-right direction of the side surface portion,
The lower portion is
The side surface includes a downward inclined surface that is inclined in the left-right direction and is steeper than the upward inclined surface.
A flush toilet characterized by: 2. The flush toilet according to claim 1, wherein, in a left-right cross-sectional view of the recess, the left-right length of the bottom portion is longer than the left-right length of the shelf portion. 3. The flush toilet according to claim 1 or 2 , wherein, in a left - right cross-sectional view of the recess, the vertical height of the lower portion is greater than the vertical height of the upper portion. 4. The flush toilet according to claim 1 , wherein, in a left-right cross-sectional view of the recess, the left-right length of the lower portion is shorter than the left-right length of the upper portion. The side surface portion is
5. The flush toilet according to any one of claims 1 to 4 , further comprising a side recess formed in the upper part of the convex shape, in a part on the shelf side. a bowl portion including a waste receiving surface for receiving waste, a shelf portion formed on an upper portion of the waste receiving surface, a rim portion erected from the shelf portion, and a water discharge portion formed on the rim portion for discharging flush water to form a swirling flow on the waste receiving surface;
a water collecting section formed in a lower portion of the bowl section and connected to a drainage channel;
The bowl portion is
A recess is formed in a front region of the waste receiving surface, and causes at least a portion of the flush water passing through the recess to splash upward,
The recessed portion is
A bottom surface portion formed in a substantially flat shape;
a side portion connecting the bottom portion and the shelf portion,
In a cross-sectional view of the recess in the left-right direction, the length of the side surface portion in the left-right direction is longer than the length of the bottom surface portion in the left-right direction,
The bottom surface portion is
At least a portion of the bowl portion is curved so as to protrude downward,
The radius of curvature of the bottom surface is greater than the radius of curvature of the corners connecting the bottom surface and the side surface.
A flush toilet characterized by:

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