This invention relates to a flush toilet bowl, and more particularly to a flush toilet bowl of the flush-down type, siphon type, siphon-jet type and the like.
A flush toilet bowl is disclosed in which flush water is spouted from a spout provided in the rim portion of the flush toilet bowl to generate a swirling flow for flushing the bowl (e.g., Patent Documents 1 and 2). In this type of flushing technique, adherence and persistence of soil and the like are less likely to occur on the inside of the rim of the toilet bowl, achieving good cleanability, and the entire surface of the bowl of the toilet bowl can be efficiently flushed with a small quantity of water.
In this type of flush toilet bowl, the rim portion is provided with an overhang to prevent flush water generating the swirling flow from splashing out of the toilet bowl. Minimizing such overhang of the rim portion improves cleanability and serves to prevent adherence of soil and the like more reliably.
This invention is based on the recognition of these problems, and provides a flush toilet bowl capable of minimizing the overhang of the rim portion.
According to an aspect of the invention, there is provided a flush toilet bowl including: a bowl portion including a pooling portion in communication with a drain conduit; a rim surface provided above the bowl portion; and a first slit opening configured to spout flush water supplied through a first conduit toward the bowl portion and to spout the supplied flush water in a generally tangential direction of the rim surface, thereby generating a swirling flow flowing forward near a boundary between the rim surface and the bowl portion, a slit opening shape in a cross section generally perpendicular to a flow direction of water flow spouted from the first slit opening being horizontally flattened.
An embodiment of the invention will now be described with reference to the drawings. In the drawings, similar components are labeled with like reference numerals, and the detailed description thereof is omitted as appropriate.
In front of the upper surface 12 of the flush toilet bowl 10 of this embodiment, a bowl portion 20 and a rim portion 30 provided thereabove are opened. In the rear of the upper surface 12, a water supply port 40 for introducing flush water is opened. Above the water supply port 40, for instance, a low tank, not shown, is attached so that flush water can be introduced from this low tank to the water supply port 40. Alternatively, flush water may be introduced from the waterworks through a flush valve, solenoid opening/closing valve or the like to the water supply port 40.
The bowl portion 20 has a pooling surface 24 located below the pool water level 22 and pooling flush water, and an exposed surface 26 exposed above the pool water level 22. As shown in
On the other hand, the rim portion 30 has a rim surface 32 surrounding the opening edge of the flush toilet bowl between the bowl portion 20 and the upper surface 12. A center slit opening 54 is provided near the center in the rear of the rim portion 30, and horizontally flattened slit openings 56, 56 are opened to the left and right thereof. A splitter 50 is provided in the rear of the center slit opening 54.
In this embodiment, flush water is spouted from each of the left and right flattened slit openings 56, 56. The flush water spouted forward from the slit openings 56, 56 flows forward down the exposed surface 26 of the bowl portion 20 while slightly spreading to the left and right, thereby flushing the bowl portion 20. Furthermore, the flush water spouted from the slit openings 56, 56 in a generally tangential direction of the rim surface 32 of the rim portion 30 generates a swirling flow swirling at the lower edge of the rim surface 32. This swirling flow flows forward along the boundary 28 between the rim surface 32 and the exposed surface 26.
Furthermore, in this embodiment, the slit opening shape in a cross section generally perpendicular to the flow direction of the water flow spouted from these slit openings 56, 56 is horizontally flattened. This restricts the vertical spread of the swirling flow so that flush water can be spouted in a horizontally wide range in front of the slit openings 56, 56. Furthermore, this can prevent the swirling flow swirling along the boundary 28 between the rim surface 32 and the exposed surface 26 from creeping up the rim surface 32 and splashing out of the toilet bowl, while distributing flush water over the exposed surface 26. Consequently, the overhang of the rim surface 32 for preventing the splash-out of the swirling flow can be reduced. In the specific example shown in
This reduction of the amount of overhang of the rim surface improves cleanability and serves to prevent adherence of soil and the like more reliably.
In the following, the structure of the conduit of flush water in the flush toilet bowl of this embodiment and the flow of flush water are described.
As shown in
The upper conduit 46 extends above the diaphragm 44 toward the front of the flush toilet bowl, and as shown in
On the other hand, the lower conduit 48 formed below the diaphragm 44 extends on the backside of the pooling surface 24 as shown in
On the other hand, a communication port 52 is provided downstream of the splitter 50 provided in the upper conduit 46. As shown in
Furthermore, when flush water is thus smoothly introduced and fills the lower conduit 48, part of the water overflows from the lower conduit 48 through the communication port 52 into the upper conduit 46. The flush water thus overflowed flows downward from the center slit opening 54 and flushes the surface of the exposed surface 26 in the rear of the bowl portion 20. At this time, flush water is spouted from the center slit opening 54 toward the bowl portion 20 therebelow as shown by arrow E in
On the other hand, flush water spouted from the portion of the left and right slit openings 56, 56 near the center slit opening 54 flows slightly obliquely downward as shown by arrow F1 and flushes the rear of the bowl portion 20. At this time, the flow of flush water spouted from the center slit opening 54 as shown by arrow E and the flow of flush water spouted from the left and right slit openings 56, 56 as shown by arrow F1 can entirely cover and evenly flush the rear of the bowl portion 20.
Thus, flush water spouted from the left and right slit openings 56, 56 and the center slit opening 54 evenly flushes the rim surface 32 and the exposed surface 26 of the bowl portion 20, and the water flows down the bowl portion 20 to raise the water level of the bowl portion 20. Simultaneously, water containing bodily wastes is pushed into the drain port 60 of the drain conduit by the flush water spouted from the spout opening 62. By these flows, flush water containing bodily wastes fills the ascending conduit 64 (see
After the flush water is drained by siphonage, flush water spouted from the left and right slit openings 56, 56 and the spout opening 62 again raises the water level of the bowl portion 20 up to the pool water level 22.
As described above, according to this embodiment, the flow F1 spouted forward from the left and right slit openings 56, 56 and the flow E flowing down from the center slit opening 54 flush the rear and part of the front of the bowl portion 20. Furthermore, the swirling flows C, C1, C2 spouted from the slit openings 56, 56 flush the lower edge of the rim surface 32, and the flow F2 generated by the downflow of part of these swirling flows evenly flushes the front side of the bowl portion 20. That is, the flows F1, C spouted from the left and right slit openings 56, 56 and the flow E flowing down from the center slit opening 54 can evenly flush the entire surface of the bowl portion 20.
According to experiments by the inventors, even if the total quantity of water supplied to the upper conduit 46 and the lower conduit 48 is reduced to approximately 4.3 liters, the flush toilet bowl can be reliably flushed by evenly distributing flush water over the substantially entire surface of the bowl portion 20 and the rim portion 30. Furthermore, the ratio between the quantity V1 of flush water supplied to the upper conduit 46 and the quantity V2 of flush water supplied to the lower conduit 48 can be in the range of, for instance, V1:V2=3:7 to 1:4.
Furthermore, in this embodiment, the cross-sectional shape of the spouted flow of flush water spouted from the left and right slit openings 56, 56 is horizontally flattened. This serves to effectively prevent the swirling flow C1 from splashing out of the flush toilet bowl.
The expanding portion 53 of the upper conduit 46 forms a channel in which the flow direction is branched into the left and right as shown by arrows B2, each flow spouted from the slit openings 56, 56. The slit opening shape in a cross section generally perpendicular to the flow direction of this channel is horizontally flattened. For instance, supposing that each water flow formed is generally parallel to the sidewall of the splitter 50, the ratio of the width W (see
Furthermore, as the upper and lower edge of the cross section of the channel of the water flow shown by arrow B2 and the slit openings 56, 56 are close to a straight line, a tendency to restrict the vertical spread of the spouted swirling flow is observed.
Furthermore, the vertical spread of flush water on the rim surface side can be further restricted by gradually decreasing the opening width of the slit opening on the rim surface side relative to the opening width at the center to reduce the spouted amount on the rim surface side.
As shown in
More specifically,
In contrast, according to this embodiment, the overhang of the rim surface 32 can be minimized by restricting the upward spread of the swirling flow C1. That is, as described above with reference to
In this embodiment, as shown in
A communication port 52 is provided behind the center slit opening 54. Flush water overflowed from the lower conduit 48 through the communication port 52 into the upper conduit 46 and part of the flush water split to the left and right by the splitter 50 are spouted from the center slit opening 54.
A protrusion 55 (see also
In the following, the result of experiments performed by the inventors is described.
Flush water was supplied from a low tank to the water supply port 40, its total quantity of water was 4.3 liters, and the maximum instantaneous flow rate was 210 liters per minute. The quantity of water supplied to the upper conduit 46 was 1.2 liters, and the quantity of water supplied to the lower conduit 48 was 3.1 liters.
At point a and point b shown in
On the other hand, it was evaluated whether the swirling flow reaches point c shown in
TABLE 1 shows the result of experiments with the instantaneous flow rate of the swirling flow flowing on the rim surface 32 being varied. Here, the distance (millimeter) from the boundary 28 to the upper end of the swirling flow C1 at points a and b is shown. For point c, “o” indicates that flush water was distributed over the exposed surface 26 of the bowl portion 20 immediately therebelow.
Here, the height H1 of the slit openings 56, 56 was 7 millimeters, and the height H2 of the center slit opening 54 was 6 millimeters.
As seen from the result of TABLE 1, for instance, even if the instantaneous flow rate of the swirling flow flowing on the rim surface 32 exceeds 100 liters per minute, the distance from the boundary 28 to the upper end of the swirling flow is 6.0 millimeters at point a, and 5.0 millimeters at point b, indicating that the upward spread of the swirling flow is sufficiently restricted. Furthermore, the swirling flow reaches point c so that the exposed surface 26 of the bowl portion 20 immediately therebelow can be evenly flushed.
Hence, it can be seen that while the distance from the boundary 28 to the upper surface 12 was 45 millimeters at point a and 55 millimeters at point b in the prototyped flush toilet bowl, these distances can be significantly reduced. For instance, if the distance from the boundary 28 to the upper surface 12 is set to e.g. approximately 10 millimeters at points a and b, the substantially entire surface of the rim surface 32 can be flushed while preventing the splash-out of the swirling flow.
Next, TABLE 2 shows the result in the case where the heights H1, H2 of the slit openings were 6 millimeters and 5 millimeters, respectively. Here, the distance (millimeter) from the boundary 28 to the upper end of the swirling flow C1 at points a and b is shown. For point c, “o” indicates that flush water was distributed over the exposed surface 26 of the bowl portion 20 immediately therebelow.
As seen from TABLE 2, by lowering the heights H1, H2 of the slit openings, the upward spread of the swirling flow flowing on the rim surface 32 can be restricted more effectively. Simultaneously, the flushing effect at point c can be maintained at a high level.
As seen from the result of TABLE 2, in the case where the heights H1, H2 of the openings are lowered, even if the distance from the boundary 28 to the upper surface 12 is set to e.g. approximately 5 millimeters at points a and b, the substantially entire surface of the rim surface 32 can be flushed while preventing the splash-out of the swirling flow.
In this embodiment, the cross-sectional shape of the water flow of flush water spouted from the left and right slit opening 56 is flattened, and thereby the upward spread of the swirling flow flowing along the boundary 28 can be restricted. However, when the swirling flows with the upward spread thus restricted come from left and right and meet on the rim surface 32 at the front end portion of the flush toilet bowl 10, part of the water may splash out of the toilet bowl because the forces of water are combined. Thus, in such cases, the rim surface 32 may be provided with an overhang in front of the flush toilet bowl.
In this case, as shown in
It is needless to say that the overhang as illustrated in
Furthermore, as shown in
The embodiment of the invention has been described with reference to specific examples. However, the invention is not limited to these specific examples. The above embodiment can be suitably modified in design by those skilled in the art, and such modifications are also encompassed within the scope of the invention as long as they fall within the spirit of the invention. For instance, the shape, size, and structure of the flush toilet bowl are not limited to those illustrated, but can be suitably modified. With regard to the material of the flush toilet bowl, it can be formed not only from ceramics, but also from, for instance, acrylic and other resins, or other various organic materials, or those with various coatings on the surface thereof.
Furthermore, the components of the above specific examples can be combined with each other as long as technically feasible, and such combinations are also encompassed within the scope of the invention as long as they fall within the spirit of the invention.
This invention can provide a flush toilet bowl capable of minimizing the overhang of the rim portion.
Number | Date | Country | Kind |
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2007-267624 | Oct 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2008/067123 | 9/22/2008 | WO | 00 | 11/24/2009 |