JP7630776B2 - Flush toilet - Google Patents

Description

The present invention relates to a flush toilet, and in particular to a flush toilet that can suppress the entrainment of air when flush water is discharged, and can discharge flush water from the discharge port toward a target area in the bowl section.

Conventionally, as described in Patent Documents 1 and 2, for example, flush toilets have been known that discharge flush water from a rim spout along the inner surface of the rim portion to form a swirling flow in the bowl portion for flushing.
The flush toilet described in Patent Document 1 spouts flush water towards the bowl portion by gradually reducing the diameter of the rim water passage towards the rim spout port.
Furthermore, the flush toilet described in Patent Document 2 forms the flow path cross section of the rim water passage vertically, thereby reducing the space in which air can stagnate, and preventing air from being entrained when flush water flows through the rim water passage.

JP 2004-156308 A JP 2017-160671 A

However, in the flush toilets of Patent Documents 1 and 2 mentioned above, the rim spout is formed in a rectangular shape with approximately the same aspect ratio, so there is a possibility that air may be entrained when the flush water passes through the rim spout. If air is entrained in the flush water, the discharge direction of the flush water becomes disrupted, and there is a possibility that the flush water may not be discharged toward the target area of the bowl section.

In particular, in wash-down toilets with a larger pool surface than conventional ones, if the flush water discharged from the rim spout does not reach the target area on the pool surface, disturbances will occur on the pool surface. In this state, pushing the pool surface with flush water will not adequately remove the floating waste that is floating on the pool surface. Therefore, the above-mentioned problem is an extremely important issue that must be resolved in wash-down toilets with large pool surfaces.

The present invention has been made to solve the above-mentioned problems, and aims to provide a flush toilet that can suppress the entrainment of air when flushing water is discharged, and can discharge flushing water from the discharge port toward a target area in the bowl section.

In order to achieve the above-mentioned object, the present invention provides a flush toilet that flushes with flushing water and discharges waste, comprising a waste receiving surface that receives waste, a bowl portion having a rim portion formed on the upper part of the waste receiving surface and a jar portion formed on the lower part of the waste receiving surface within which a water collection surface is formed, a water outlet formed in the rim portion and which discharges flushing water along the inner peripheral surface of the rim portion, a water passage that guides the flushing water to the water outlet, and a drainage pipe connected to the bottom of the bowl portion, the water passage comprising a lower water passage formed in a vertically elongated rectangular shape and an upper water passage formed with a smaller width than the lower water passage and extending upward from the lower water passage, and the vertical width of the water outlet is set to be approximately the same as the vertical width of the water passage.
In the present invention thus configured, the water passage includes a lower water passage formed in a vertically long rectangular shape, and an upper water passage formed with a width smaller than that of the lower water passage and extending upward from the lower water passage, so that when flush water is supplied to the lower water passage, the lower water passage is filled with flush water, and the air that has been retained in the water passage is pushed up to the upper water passage. As a result, flush water flows through the lower water passage and air flows through the upper water passage, so that air and flush water can be separated and discharged. In addition, the vertical width of the water outlet is set to be approximately the same as the vertical width of the water passage, so that flush water is discharged from the lower region of the water outlet toward the target region of the bowl section, and air is discharged from the upper region of the water outlet. As a result, air and flush water are separated and discharged from the water outlet, so that air entrainment at the water outlet is suppressed, and flush water can be discharged from the water outlet toward the target region of the bowl section.

In the present invention, preferably, on the downstream side of the water passage, the upper surface of the lower water passage slopes downward from the upstream toward the water outlet.
In the present invention configured in this manner, on the downstream side of the water passage, the upper surface of the lower water passage slopes downward from the upstream toward the water outlet, so that a downward flow is formed by the lower water passage, and water can be discharged downward from the water outlet.

In the present invention, preferably, on the downstream side of the water passage, the upper surface of the lower water passage gradually slopes downward from the upstream side toward the water outlet.
In the present invention configured in this manner, on the downstream side of the water passage, the upper surface of the lower water passage gradually slopes downward from the upstream toward the water outlet, so that the lower water passage can straighten the flushing water while forming a downward flow.

In the present invention, preferably, on the downstream side of the water passage, the upper surface of the upper water passage extends horizontally from the upstream side toward the water outlet.
In the present invention configured in this manner, on the downstream side of the water passage, the upper surface of the upper water passage extends horizontally from the upstream toward the water outlet, so that a large space capable of accommodating air can be formed in the upper water passage, and the air and wash water can be reliably separated and discharged from the water outlet.

In the present invention, the water discharge port is preferably disposed forward of the center line of the bowl portion in the front-to-rear direction.
In the present invention configured in this manner, the water outlet is positioned forward of the front-to-rear center line of the bowl portion, so that the distance of the water passage can be increased, and the air and cleaning water can be reliably separated and discharged from the water outlet.

In addition, in the present invention, the water outlet has a lower opening formed in a vertically long rectangular shape, and an upper opening formed to be narrower in width than the lower opening and extending upward from the lower opening.
In the present invention thus configured, the water outlet has a lower opening formed in a vertically long rectangular shape, and an upper opening formed with a smaller width than the lower opening and extending upward from the lower opening, so that flush water is discharged from the lower opening toward the target area of the bowl section, and air is discharged from the upper opening of the water outlet. As a result, air entrainment at the water outlet is suppressed, and flush water can be discharged from the water outlet toward the target area of the bowl section.

In the present invention, the width of the upper water passage begins to expand from a predetermined position upstream of the water outlet toward the water outlet, and is set so as to be approximately the same as the width of the lower water passage near the water outlet.
In the present invention configured in this manner, the width of the upper water passage begins to expand from a specified position upstream of the water outlet toward the water outlet, and is set to be approximately the same as the width of the lower water passage at a position near the water outlet, so that the water passage can be filled with water early after cleaning begins, allowing the air and cleaning water to be separated.

In addition, in the present invention, the water outlet is positioned forward of the front end of the pot portion, and the predetermined position at which the width of the upper water passage begins to expand is set to be approximately the same position as the front end of the pot portion in the fore-and-aft direction.
In the present invention configured in this manner, the water outlet is positioned forward of the front end of the basin portion, and the specified position at which the width of the upper water passage begins to expand is set to be approximately the same position in the front-to-back direction as the front end of the basin portion, so that cleaning water can be discharged from the water outlet so as to swirl around the waste receiving surface forward of the front end of the basin portion, and the cleaning water can be directed to the target area of the bowl portion.

In the present invention, the portion where the lateral width of the upper water passage is increased is provided in a straight water passage portion where the water passage extends in a substantially straight line.
In the present invention configured in this manner, the portion where the width of the upper water passage is expanded is provided in a straight portion of the water passage where the water passage extends in an approximately straight line, thereby preventing the wash water from suffering pressure loss due to the curvature of the water passage.

The flush toilet of the present invention can suppress the entrainment of air when flushing water is discharged, and flushing water can be discharged from the discharge port toward the target area in the bowl section.

FIG. 1 is a side cross-sectional view of a flush toilet according to a first embodiment of the present invention. FIG. 2 is a plan sectional view taken along line II-II in FIG. FIG. 2 is a front view of the first water outlet of the flush toilet according to the first embodiment of the present invention. 3 is a flow path cross-sectional view of the IVA-IVA cross section perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 2. 4 is a flow path cross-sectional view taken along the line IVB-IVB perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 2. 3 is a flow path cross-sectional view taken along the IVC-IVC cross section perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 2. 3 is a flow path cross-sectional view taken along the line IVD-IVD perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 2. 3 is a flow path cross-sectional view taken along the line IVE-IV perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 2. 3 is a cross-sectional view of the first water passage shown in FIG. 2 along the VV cross section. FIG. 2 is a plan cross-sectional view of the bowl portion, illustrating how flush water spouted from a first spout and a second spout in a flush toilet according to an embodiment of the present invention flows into the pooled water surface. FIG. 4 is a plan cross-sectional view of a flush toilet according to a second embodiment of the present invention. FIG. 11 is a front view of a first water outlet of a flush toilet according to a second embodiment of the present invention. 8 is a flow channel cross-sectional view taken along the line IXA-IXA perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 7. 8 is a flow path cross-sectional view taken along a cross section IXB-IXB perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 7. 9 is a flow path cross-sectional view taken along a cross section IXC-IXC perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 7. 8 is a flow path cross-sectional view taken along the line IXD-IXD perpendicular to the flow direction of the cleaning water in the first water passage shown in FIG. 7.

The flush toilet according to the first embodiment of the present invention will be described below. First, the basic structure of the flush toilet will be described with reference to Figures 1 and 2. Figure 1 is a side cross-sectional view of the flush toilet according to the first embodiment of the present invention, and Figure 2 is a plan cross-sectional view taken along line II-II in Figure 1.

As shown in Figures 1 and 2, the flush toilet 1 is a wash-down toilet in which waste is washed away by the flowing water caused by the difference in height of the water in the bowl. The flush toilet 1 comprises a ceramic toilet body 2 and a water storage tank 4 which stores flushing water for cleaning the toilet body 2. The toilet body 2 comprises a bowl portion 6 on the front side, and a common water passage 8 is formed at the upper rear portion, with an opening 7 at its upstream end communicating with the water storage tank 4. Furthermore, a drain pipe 10 is formed at the lower rear portion of the bowl portion 6 for discharging waste.
In the embodiment of the present invention, a wash-down toilet will be described, but the present invention is not limited to this, and the flush toilet of the present invention also includes a siphon type toilet that discharges waste by siphon action.

In this specification, when a user looks at the flush toilet 1 from the front, the front of the flush toilet 1 is referred to as the front, the back side as the rear, the right side as the right side, and the left side as the left side.

The above-mentioned water storage tank 4 is equipped with a drain valve 12, and when the user opens an operating lever (not shown), the drain valve 12 opens and flush water in the water storage tank 4 is supplied to the toilet body 2. In this embodiment, the amount of flush water supplied from the water storage tank 4 to the toilet body 2 is approximately 4.8 liters for a large flush and approximately 3.6 liters for a small flush.
Furthermore, in the flush toilet of the present invention, other than the water storage tank 4, the source of flush water may be one that uses direct tap water pressure or a flush valve, and flush water may also be supplied using a pump.

The bowl section 6 is provided with a bowl-shaped waste receiving surface 16, a rim section 18 formed above the waste receiving surface 16 and having an inner peripheral surface 18a exposed to the outside, and a basin section 22 formed below the waste receiving surface 16 and forming a water pooling surface 20 inside. Here, the water pooling surface 20 of the basin section 22 is approximately triangular, measuring 160 mm to 180 mm in the front-to-back direction and 125 mm to 145 mm in the width direction when viewed from above, and is formed larger (enlarged) than the water pooling surface of a conventional wash-down toilet. In addition, the basin section 22 is 200 mm to 240 mm in the front-to-back direction when viewed from above, and 150 mm to 190 mm in the width direction, forming an approximately triangular shape that is egg-shaped (an oval shape tapered at the front) larger than the water pooling surface 20.

In the rim portion 18 of the bowl portion 6, a first water outlet 24 (water outlet) for discharging flush water is formed on the front side on the left side, and a second water outlet 26 for discharging flush water is formed on the rear side on the right side. The above-mentioned common water passage 8 branches into a first water passage 28 and a second water passage 30 toward the downstream side, the first water passage 28 extends to the first water outlet 24, and the second water passage 30 extends to the second water outlet 26, so that flush water is supplied from the water storage tank 4 to the first water outlet 24 and the second water outlet 26. Here, the first water outlet 24 and the second water outlet 26 are configured to discharge flush water in a direction that forms a swirling flow that swirls in the same direction. In the case of the embodiment of the present invention, a counterclockwise swirling flow is formed.
Furthermore, the flush toilet of the present invention may have one water outlet, or may have two or more (for example, three).

Next, the first water outlet and first water passage of the flush toilet according to the first embodiment of the present invention will be described in detail with reference to Figures 2 to 5. Figure 3 is a front view of the first water outlet 24 of the flush toilet 1 according to the first embodiment of the present invention, Figures 4A to 4E are flow path cross-sectional views taken along the IVA-IVE cross section perpendicular to the flow direction of flush water in the first water passage 28 shown in Figure 2, and Figure 5 is a cross-sectional view of the V-V cross section of the first water passage 28 shown in Figure 2. In Figure 5, the dotted line indicates the upper surface 38a of the upper water passage 38 of the first water passage 28.

First, as shown in FIG. 3, the first water outlet 24 has an L-shaped cross section, and includes a lower opening 32 (encircled by a dotted line in FIG. 3) formed in a vertically elongated rectangular shape, and an upper opening 34 (encircled by a dotted line in FIG. 3) formed in a vertically elongated rectangular shape that is narrower in width than the lower opening 32 and extends upward from the left side (outside) of the upper end 32a of the lower opening 32. The upper end 32a and lower end 32b of the lower opening 32 are approximately horizontal. The upper opening 34 is formed by extending vertically upward from the left end (outer end) of the upper end 32a of the lower opening 32. The upper end 34a of the upper opening 34 is approximately horizontal. The upper opening 34 and the lower opening 32 are continuous and form a single opening.

The cross-sectional area of the upper opening 34 is set to about 1/6 the cross-sectional area of the lower opening 32. Both the lower opening 32 and the upper opening 34 are formed in a rectangular shape with a vertical width (H1 and h1) longer than a horizontal width (W1 and w1). The horizontal width (w1) of the upper opening 34 is set to about 1/3 the horizontal width (W1) of the lower opening 32, and the vertical width (h1) of the upper opening 34 is set to about 1/2 the vertical width (H1) of the lower opening 32.
As a result, most of the flush water is discharged from the lower opening 32, forming a front main flow F1 that swirls around the bowl portion 6 (see FIG. 6). Meanwhile, air is discharged from the upper opening 34, and a portion of the flush water is discharged and flows along the inner circumferential surface 18a of the rim portion 18.
Therefore, a front main flow F1 that swirls around the bowl portion 6 can be formed, and air within the first water passage 28 can be discharged from the first water outlet 24.

As shown in Figures 4A to 4E, the first water passage 28 has an L-shaped flow passage cross section and is continuous with the first water outlet 24. The first water passage 28 has a lower water passage 36 (part surrounded by dotted lines in Figures 4A to 4E) formed in a vertically elongated rectangular shape at the opening cross section, and an upper water passage 38 (part surrounded by dotted lines in Figures 4A to 4E) formed in a vertically elongated rectangular shape that is narrower in width than the lower water passage 36 and extends upward from the lower water passage 36. The upper water passage 38 and the lower water passage 36 are continuous and form a single water passage.

On the upstream side of the first water passage 28 (FIGS. 4A and 4B), the upper water passage 38 extends obliquely upward to the left (outside) from the left end (outer end) of the upper surface 36a of the lower water passage 36. On the downstream side of the first water passage 28 (FIGS. 4C to 4E), the upper water passage 38 extends vertically upward from the left end (outer end) of the upper surface 36a of the lower water passage 36.
As a result, on the upstream side of the first water passage 28 (FIGS. 4A and 4B), the curvature increases with the expansion of the pool surface 20, and a relatively large centrifugal force acts on the flush water, but because the upper water passage 38 extends obliquely upward, it is possible to prevent the flush water from colliding forcefully with the inner wall of the upper water passage 38. This makes it possible to prevent the flush water from colliding forcefully, becoming disturbed, and entraining air. Furthermore, on the downstream side of the first water passage 28 (FIGS. 4C to 4E), because the upper water passage 38 extends vertically upward, the flush water is guided to the lower water passage 36, and most of the flush water is discharged from the lower opening 32 of the first water outlet 24, making it possible to form a forward main flow F1 that swirls around the bowl section 6.

Downstream of the first water passage 28 (Figs. 4C-4E), the flow cross-sectional area of the upper water passage 38 is set to approximately one-sixth the flow cross-sectional area of the lower water passage 36. Both the lower water passage 36 and the upper water passage 38 are formed in a rectangular shape with a vertical width (H2-H4 and h2-h4) longer than the horizontal width (W2-W4 and w2-w4). The horizontal width (w2-w4) of the upper water passage 38 is set to approximately one-third the length of the horizontal width (W2-W4) of the lower water passage 36, and the vertical width (h2-h4) of the upper water passage 38 is set to approximately one-half the length of the vertical width (H2-H4) of the lower water passage 36.

On the downstream side of the first water passage 28 (FIGS. 4C to 4E), the width (W2 to W4) of the lower water passage 36 gradually decreases from the upstream toward the first water outlet 24. Also, as shown in FIG. 5, on the downstream side of the first water passage 28, the upper surface 36a of the lower water passage 36 gradually slopes downward from the upstream toward the first water outlet 24. Specifically, the upper surface 36a of the lower water passage 36 is inclined at an inclination angle of about 5° with respect to the horizontal direction. Also, the bottom surface 36b of the lower water passage 36 extends horizontally from the upstream toward the first water outlet 24. That is, the flow path cross-sectional area of the lower water passage 36 gradually decreases from the upstream toward the first water outlet 24.
As a result, a downward flow is formed by the lower water passage 36 and water can be discharged downward from the first water outlet 24, thereby forming a forward main flow F1 (see Figure 6).

On the downstream side of the first water passage 28 (FIGS. 4C to 4E), the width (w2 to w4) of the upper water passage 38 is formed to be approximately constant from the upstream toward the first water outlet 24. Also, as shown in FIG. 5, on the downstream side of the first water passage 28, the upper surface 38a of the upper water passage 38 extends horizontally from the upstream toward the first water outlet 24. That is, the flow path cross-sectional area of the upper water passage 38 gradually increases from the upstream toward the first water outlet 24.
As a result, a large space capable of accommodating air can be formed in the upper water passage 38, and the air can be reliably separated from the wash water.

As shown in Figure 2, the first water outlet 24 is located forward of the fore-and-aft center line of the bowl portion 6, particularly forward of the front end 22a of the pot portion 22, and the first water passage 28 extends to the first water outlet 24.
This allows the distance of the water passage to be increased, and the air can be reliably separated from the wash water and discharged from the first water outlet 24.

Next, the manner in which flush water flows into the pooled water surface in a flush toilet 1 according to the first embodiment of the present invention will be described with reference to Figure 6. Figure 6 is a plan cross-sectional view of the bowl portion 6, showing the manner in which flush water discharged from the first and second water discharge ports in a flush toilet according to the first embodiment of the present invention flows into the pooled water surface.
As shown in Figure 6, for ease of explanation, the water pooling surface 20 formed inside the pot portion 22 is divided into four areas: a first area S1 on the rear left side, a second area S2 on the rear right side, a third area S3 on the front right side, and a fourth area S4 on the front left side, by the left-right center line of the water pooling surface extending in the front-to-rear direction and the front-to-rear center line of the water pooling surface extending in the front-to-rear direction.

As shown in FIG. 6, first, the forward main flow F1 of the flushing water discharged from the first water outlet 24 flows through the forward region of the waste receiving surface 16 of the bowl portion 6, then reaches the rear region of the waste receiving surface 16 and flows into the target region, region S2 and region S1 of the pool surface 20.

Next, the rear main flow F2 of the cleaning water discharged from the second water outlet 26 flows through the rear region of the waste receiving surface 16 of the bowl portion 6, then reaches the front region of the waste receiving surface 16 and flows into regions S4 and S3 of the pool surface 20.
As is clear from FIG. 6, in the flush toilet 1 of the first embodiment of the present invention, the front main flow F1 and rear main flow F2 of the flush water flow into the pooled water surface 20 without merging.
Furthermore, the front main flow F1 and the rear main flow F2 of the flush water are each designed to flow into different regions of the boundary area divided into four regions S1, S2, S3, and S4. As a result, at the beginning of flushing, flush water flows into three or more of the four divided regions S1, S2, S3, and S4 of the pooled water surface, so that the timing of discharging floating waste can be made earlier, and further, by applying a pressing force to the entire pooled water surface 20, the pooled water surface 20 is not disturbed, so that the discharging force of floating waste can be improved.

The effects of the first embodiment described above will now be described.
First, in the flush toilet 1 according to the first embodiment of the present invention, the first water passage 28 has a lower water passage 36 formed in a vertically elongated rectangular shape, and an upper water passage 38 formed with a smaller width than the lower water passage 36 and extending upward from the lower water passage 36, so that when flush water is supplied to the lower water passage 136, the lower water passage 36 is filled with flush water, and the air that has been retained in the first water passage 28 is pushed up into the upper water passage 38. As a result, flush water flows through the lower water passage 36 and air flows through the upper water passage 38, so that the air and flush water can be separated and flowed away.
Furthermore, the vertical width (h1 and H1) of the first water outlet 24 is set to be approximately the same as the vertical width of the first water passage 28, so that flushing water is discharged from the lower region (lower opening 32) of the first water outlet 24 toward the target region of the bowl portion 6, and air is discharged from the upper region (upper opening 34) of the first water outlet 24. As a result, the air and flushing water are separated and discharged from the first water outlet 24, so that air entrainment in the first water outlet 24 is suppressed, and flushing water can be discharged from the first water outlet 24 toward the target region of the bowl portion 6.
In particular, for example, in a wash-down type flush toilet 1 having a large water collection surface, flush water can be discharged from the first water outlet 24 toward the target area (S1 and S2) of the water collection surface 20, and a pressing force can be applied to the entire water collection surface 20, so that the water collection surface 20 is not disturbed and the discharge force of floating waste can be improved.

In the flush toilet 1 according to the first embodiment of the present invention, downstream of the first water passage 28, the upper surface 36a of the lower water passage 36 is inclined downward from the upstream toward the first water outlet 24, so that a downward flow is formed by the lower water passage 36, and water can be discharged downward from the lower opening 32 of the first water outlet 24, thereby forming the forward main flow F1.

In addition, in the flush toilet 1 according to the first embodiment of the present invention, downstream of the first water passage 28, the upper surface 36a of the lower water passage 36 gradually slopes downward from the upstream toward the first water outlet 24, so that the lower water passage 36 can straighten the flush water while forming a downward flow.

In the flush toilet 1 according to the first embodiment of the present invention, downstream of the first water passage 28, the upper surface 38a of the upper water passage 38 extends horizontally from the upstream toward the first water outlet 24, so that a large space capable of accommodating air can be formed in the upper water passage 38, and the air and flush water can be reliably separated and discharged from the first water outlet 24.

In addition, in the flush toilet 1 according to the first embodiment of the present invention, the first water outlet 24 is positioned forward of the center line of the bowl portion 6 in the front-to-rear direction, so the distance of the first water passage 28 can be increased, and the air and flush water can be reliably separated and discharged from the first water outlet 24.

In the flush toilet 1 according to the first embodiment of the present invention, the first water outlet 24 has a lower opening 32 formed in a vertically elongated rectangular shape, and an upper opening 34 formed with a smaller width than the lower opening 32 and extending upward from the lower opening 32, so that flush water is discharged from the lower opening 32 of the first water outlet 24 toward the target area of the bowl portion 6, and air is discharged from the upper opening 34 of the first water outlet 24. As a result, air is separated from the flush water and discharged from the first water outlet 24, so that air entrainment in the first water outlet 24 is suppressed, and flush water can be discharged from the first water outlet 24 toward the target area of the bowl portion 6.

Next, a flush toilet 100 according to a second embodiment of the present invention will be described with reference to Figures 7 to 9D. Except for the shape of the first water outlet and the downstream side of the first water passage, the basic configuration is the same as the flush toilet 1 according to the first embodiment of the present invention described above. Below, only the differences from the flush toilet 1 according to the first embodiment will be described, and a description of the similar configurations, actions, and effects will be omitted.

Figure 7 is a plan cross-sectional view of a flush toilet according to a second embodiment of the present invention, and corresponds to Figure 2 of the first embodiment. Figure 8 is a front view of the first water outlet of a flush toilet according to the second embodiment of the present invention, and Figures 9A to 9D are cross-sectional views of the flow path at cross sections IXA to IXD perpendicular to the flow direction of flush water in the first water passage shown in Figure 7. In the flush toilet 100 according to the second embodiment of the present invention shown in Figures 7 to 9D, the same parts as those in the flush toilet 1 according to the first embodiment of the present invention described above are given the same reference numerals. In Figure 7, the dotted line indicates the right end (inner end) 138c of the upper surface 138a of the upper water passage 138 of the first water passage 128.

As shown in FIG. 8, the first water outlet 124 has an opening cross section formed in a vertically long rectangular shape (rectangular shape). Specifically, the first water outlet 124 is set so that the vertical width (H101) of its opening is approximately the same as the vertical width (H105) of the first water passage. In addition, the first water outlet 124 is set so that the horizontal width (W101) of its opening is approximately the same as the horizontal width (W105) of the first water passage. In addition, the upper end 124a and the lower end 124b of the first water outlet 124 are approximately horizontal and are set to be approximately the same length. The left and right side ends 124c of the first water outlet 124 are approximately vertical and are set to be approximately the same length. The vertical width (H101) of the first water outlet 124 is set to be approximately three times the horizontal width (W101) of the first water outlet 124.

The opening cross-sectional area of the first water outlet 124 is set to be larger than each flow path cross-sectional area of the first water passage 128. As a result, most of the flush water is discharged from the lower region of the first water outlet 124, forming a forward main flow F1 that swirls around the bowl section 6. In addition, air is discharged from the upper region of the first water outlet 124, and the air in the first water passage 128 is discharged.

As shown in FIG. 9A, in the IXA cross section, the first water passage 128 has an L-shaped flow passage cross section, as in the first embodiment described above. The first water passage 128 has a lower water passage 136 (part surrounded by a dotted line in FIG. 9A) formed in a vertically elongated rectangular shape, and an upper water passage 138 (part surrounded by a dotted line in FIG. 9A) formed in a vertically elongated rectangular shape that is narrower in width than the lower water passage 136 and extends upward from the lower water passage 136. The upper surface 138a of the upper water passage 138 and the upper surface 136a and lower surface 136b of the lower water passage 136 are approximately horizontal. In addition, the sides of the upper water passage 138 and the lower water passage 136 are approximately vertical.

Downstream of the IXA cross section, as shown in Figures 9B to 9D, the width (w103 to w104) of the upper water passage 138 gradually increases from the upstream toward the first water outlet 124. The vertical width (h103 and h104) of the upper water passage 138 is formed to be approximately constant from the upstream toward the first water outlet 124. The width (W103 to W105) and the vertical width (H103 and H104) of the lower water passage 136 are formed to be approximately constant from the upstream toward the first water outlet 124. In this way, in the first water passage 128 downstream of the IXA cross section, the flow path cross-sectional area of the first water passage 128 gradually increases from the position of the IXA cross section toward the first water outlet 124.

As shown in FIG. 9D, in the IXD cross section, the first water passage 128 is formed with a vertically elongated rectangular (rectangular) flow passage cross section. Specifically, the upper surface 128a and the lower surface 128b of the first water passage 128 are approximately horizontal and are set to be approximately the same length. The left and right side surfaces 128c of the first water passage 128 are approximately vertical and are set to be approximately the same length. The first water passage 128 downstream of the IXD cross section is formed with a flow passage cross section having a substantially constant shape and area, and is continuously connected to the first water outlet 124.

As shown in FIG. 7, the width (or flow channel cross-sectional area) of the upper water passage 138 starts to expand in the front-rear direction from a predetermined position (position of IXA cross section) that is the same as or near the front end 22a of the pot portion toward the first water outlet 124 (see dotted line 138c in FIG. 7). In other words, the predetermined position where the width of the upper water passage 138 starts to expand is set to a position that is the same as or near the front end 22a of the pot portion. Specifically, the predetermined position where the width of the upper water passage 138 starts to expand is set to a position about 35 mm upstream of the first water outlet 124. In this way, since the predetermined position where the width of the upper water passage 138 starts to expand is set to a position about 35 mm upstream of the first water outlet 124, the first water passage 128 can be filled with water and the washing water can be separated from the air sooner after the start of the flush, compared to when it is set to a position near the first water outlet 124.

As shown in Fig. 7, a straight water passage section 128d extending in a substantially straight line is formed at the downstream end of the first water passage 128, and the width (or flow passage cross-sectional area) of the upper water passage 138 increases toward the first water outlet 124 at the straight water passage section 128d. The right end (inner end) 138c of the upper surface 138a of the upper water passage 138 is inclined toward the inside of the bowl section 6 toward the front in a plan view (see dotted line 138c in Fig. 7). In this way, the portion where the width (or flow passage cross-sectional area) of the upper water passage 138 increases is provided at the straight water passage section 128d, so that the flush water can be prevented from suffering pressure loss due to the curvature of the water passage.
It should be noted that the straight water passage portion in the present invention is not limited to one that extends completely straight, but includes one that is slightly curved as long as it does not affect normal toilet flushing.

The effects of the second embodiment described above will now be described.
First, in the flush toilet 100 according to the second embodiment of the present invention, the first water passage 128 has a lower water passage 136 formed in a vertically elongated rectangular shape, and an upper water passage 138 formed with a smaller width than the lower water passage 136 and extending upward from the lower water passage 136, so that when flush water is supplied to the lower water passage 136, the lower water passage 136 is filled with flush water, and air that has been retained in the first water passage 128 is pushed up into the upper water passage 138. As a result, flush water flows through the lower water passage 136 and air flows through the upper water passage 138, allowing the air and flush water to be separated and flowed away. Furthermore, the vertical width (H101) of first water outlet 124 is set to be approximately the same as the vertical width of first water passage 128, and is formed in a vertically long rectangular shape, so that flushing water is discharged from the lower region of first water outlet 124 toward the target region of bowl portion 6, and air is discharged from the upper region of first water outlet 124. As a result, air entrainment in first water outlet 124 is suppressed, and flushing water can be discharged from first water outlet 124 toward the target region of bowl portion 6.
In particular, for example, in a wash-down type flush toilet 100 having a large water collection surface, flush water can be discharged from the first water outlet 124 toward the target area (S1 and S2) of the water collection surface 20, and a pressing force can be applied to the entire water collection surface 20, so that the water collection surface 20 is not disturbed and the discharge force of floating waste can be improved.

In addition, in the flush toilet 1 according to the second embodiment of the present invention, the width of the upper water passage 138 begins to expand from a predetermined position upstream of the first water outlet 124 (position of IXA cross section) toward the first water outlet 124, and is set to be approximately the same as the width (W105) of the lower water passage 136 in the vicinity of the first water outlet 124 (position of IXD cross section), so that the water passage can be filled with water early after flushing begins, and air and flush water can be separated. In addition, the width of the upper water passage 138 is set to be approximately the same as the width (W105) of the lower water passage 136 in the vicinity of the first water outlet 124 (position of IXD cross section), so that the cleaning ability of the upper surface 138a of the upper water passage 138 can be improved compared to the first embodiment described above.

In the flush toilet 1 according to the second embodiment of the present invention, the first water outlet 124 is positioned forward of the front end 22a of the basin portion 22, and the predetermined position (position of cross section IXA) at which the width of the upper water passage 138 begins to expand is set to be approximately the same position in the front-to-rear direction as the front end 22a of the basin portion 22, so that flush water can be discharged from the first water outlet 124 so as to swirl around the waste receiving surface 16 forward of the front end 22a of the basin portion 22 (see the front main flow F1 in Figure 6), and the flush water can be directed to the target area of the bowl portion 6.

In addition, in the flush toilet 1 according to the second embodiment of the present invention, the portion where the width of the upper water passage 138 is enlarged (the position of cross section IXA to cross section IXD) is provided in the straight water passage portion 128d where the water passage extends in a substantially straight line, so that the flush water is prevented from experiencing pressure loss due to the curvature of the water passage.

The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the technical ideas described in the claims.

1 Flush toilet according to a first embodiment of the present invention 6 Bowl portion 8 Common water passage 10 Drainage pipe 16 Waste receiving surface 18 Rim portion 18a Inner peripheral surface of rim portion 22 Bowl portion 22a Front end of bowl portion 24 First water outlet 28 First water passage 32 Lower opening 32a of first water outlet Upper end 32b of lower opening Lower end 34 of lower opening Upper opening 34a of first water outlet Upper end 36 of upper opening Lower water passage 36a of first water passage Upper surface 36b of lower water passage Lower surface 38 of lower water passage Upper water passage 38a of first water passage Upper surface 100 of upper water passage Flush toilet according to a second embodiment of the present invention 124 First water outlet 128 First water passage 128d Straight water passage portion 136 of first water passage Lower water passage 138 of first water passage Upper channel of the first channel

Claims (9)

A flush toilet that uses flush water to flush waste,
A waste receiving surface for receiving waste;
A rim portion formed on an upper portion of the waste receiving surface;
a bowl portion including a pot portion formed below the waste receiving surface and having a water collecting surface formed therein;
a water outlet formed in the rim portion for discharging wash water along an inner peripheral surface of the rim portion;
a water passage for guiding flush water to the water outlet;
a drain line connected to the bottom of the bowl portion,
The water passage includes a lower water passage formed in a vertically long rectangular shape, and an upper water passage formed to have a smaller width than the lower water passage and extending upward from the lower water passage,
A flush toilet characterized in that the vertical width of the water outlet is set to be approximately the same as the vertical width of the water passage in the vicinity of the water outlet . The flush toilet according to claim 1, wherein the upper surface of the lower water passage is inclined downward from the upstream side toward the water outlet on the downstream side of the water passage. The flush toilet according to claim 2, wherein, on the downstream side of the water passage, the upper surface of the lower water passage gradually slopes downward from the upstream side toward the water outlet. A flush toilet according to claim 2 or 3, in which, on the downstream side of the water passage, the upper surface of the upper water passage extends horizontally from the upstream side toward the water outlet. The flush toilet according to claim 1, wherein the water outlet is disposed forward of the center line of the bowl portion in the front-to-rear direction. The flush toilet according to claim 1, wherein the water outlet has a lower opening formed in a vertically elongated rectangular shape, and an upper opening formed with a smaller width than the lower opening and extending upward from the lower opening. The flush toilet according to claim 1, in which the width of the upper water passage starts to expand from a predetermined position upstream of the spout toward the spout, and is set to be approximately the same as the width of the lower water passage at a position near the spout. The water outlet is disposed forward of the front end of the pot portion,
8. The flush toilet according to claim 7, wherein the predetermined position where the lateral width of the upper water passage begins to increase is set to be substantially the same position as the front end of the basin portion in the front-to-rear direction. The flush toilet according to claim 7 or 8, wherein the portion where the width of the upper water passage is increased is provided in a straight portion of the water passage where the water passage extends in a substantially straight line.

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