Flush toilet bowl

A flush toilet bowl includes a bowl part, a rim nozzle, and a rim water spout part. The bowl part has a rim part on an upper edge of a receiving surface with a bowl shape. The rim nozzle is provided on a rear part of the bowl part and spouts flush water. The rim water spout part is provided on the rim part and spouts flush water that is spouted from the rim nozzle toward the receiving surface. The rim water spout part includes a rim water guide channel that is formed inside the rim part in such a manner that a cross-sectional area of a lower half part of the rim water guide channel is less than a cross-sectional area of an upper half part and a rim water spout port that is formed to be continuous with the rim water guide channel and in a front side region of the bowl part.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2016-237843 filed in Japan on Dec. 7, 2016.

FIELD

An embodiment of the disclosure relates to a flush toilet bowl.

BACKGROUND

Conventionally, a flush toilet bowl that is washed by flush water that is supplied from a flush water source may include a rim nozzle and a rim water spout part. A rim nozzle spouts flush water from a flush water source to a rim water spout part. A rim water spout part is provided on a rim part that is formed on an upper edge of a waste receiving surface that receives waste, and includes a rim water guide channel and a rim water spout port.

A rim water guide channel is formed inside a rim part, is formed in accordance with a shape of the rim part, and guides flush water that is spouted from a rim nozzle. Furthermore, a rim water guide channel may be formed into, for example, a longitudinally long shape in cross section, for example, in such a manner that a rim part is joined to a waste receiving surface (see, for example, Japanese Patent Application Publication No. 2014-034868). A rim water spout part is formed so as to be continuous with a rim water guide channel, is an exit opening for flush water, and spouts flush water to a waste receiving surface.

In such a flush toilet bowl, for example, abnormal noise such as explosive noise of air or mixing noise of air may be generated at a time of spout of flush water from a rim water spout part (rim water spout port). Accordingly, for example, a flush toilet bowl has been known where a plurality of small holes is formed on a rim nozzle, a space part that is defined by a wall that includes an inner wall where flush water that is spouted from the plurality of small holes on the rim nozzle collides therewith is formed on a rim water guide channel, and flush water from the plurality of small holes collides with the inner wall to fractionize air finely and thereby suppress abnormal noise that is caused by air (see, for example, Japanese Patent Application Publication No. 2008-303616).

Meanwhile, for a conventional flush toilet bowl as described above, it is possible to consider that a rim water spout port is arranged on a rim part in a region on a front side (front side region) with respect to a half of a waste receiving surface in order to cause a user to be difficult to view the rim water spout port, that is, in order to improve a design of a toilet, or in order to improve a washability of flush water on a waste receiving surface.

However, as a rim water spout port is arranged in a front side region of a waste receiving surface, a problem occurs in that a rim water guide channel is long and thereby an amount of air in the rim water guide channel increases so that abnormal noise that is caused by air is readily generated. That is, a conventional flush toilet bowl as described above has room for improvement in quietness thereof.

SUMMARY

It is an object of the present invention to at least partially solve a problem in a conventional technology.

A flush toilet bowl according to an embodiment includes a bowl part, a rim nozzle, and a rim water spout part. The bowl part is provided in such a manner that a rim part is formed on an upper edge of a receiving surface with a bowl shape. The rim nozzle is provided on a rear part of the bowl part and spouts flush water that is supplied from a flush water source. The rim water spout part is provided on the rim part, spouts flush water that is spouted from the rim nozzle, toward the receiving surface, and causes flush water to swirl on the receiving surface. The rim water spout part includes a rim water guide channel and a rim water spout port. The rim water guide channel is formed inside the rim part, is formed in such a manner that a cross-sectional area of a lower half part is less than a cross-sectional area of an upper half part in upward and downward directions, and guides flush water that is spouted from the rim nozzle. The rim water spout port is formed to be continuous with the rim water guide channel, is formed in a front side region of the bowl part, and spouts flush water that is guided by the rim water guide channel, toward the receiving surface.

DESCRIPTION OF EMBODIMENT

Hereinafter, an embodiment of a flush toilet bowl as disclosed in the present application will be described in detail, with reference to the accompanying drawings. Additionally, this invention is not limited by an embodiment as illustrated below.

General Configuration of Flush Toilet Bowl

First, a general configuration of a flush toilet bowl1according to an embodiment will be described with reference toFIG. 1toFIG. 5.FIG. 1is a perspective view of the flush toilet bowl1according to an embodiment.FIG. 2is an exploded perspective view of a toilet body2of the flush toilet bowl1according to an embodiment. Additionally,FIG. 1illustrates the flush toilet bowl1in a state where a toilet lid3and a toilet seat4(seeFIG. 3) are closed, andFIG. 2illustrates the toilet body2.

FIG. 3is a left-side cross-sectional view of the flush toilet bowl1according to an embodiment.FIG. 4is a plan view of the toilet body2of the flush toilet bowl1according to an embodiment.FIG. 5is an enlarged plan view of the toilet body2of the flush toilet bowl1according to an embodiment. Additionally,FIG. 5illustrates a planner surface of a rim part10.

Furthermore,FIG. 1toFIG. 5illustrate a three-dimensional and orthogonal coordinate system that includes a Z-axis where a vertically upward direction is a positive direction, for providing a clear explanation. Such an orthogonal coordinate system may also be illustrated in another diagram. Furthermore, such an orthogonal system defines a positive direction of a Y-axis as a front side and defines a positive direction of an X-axis, a negative direction of the X-axis, and a negative direction of a Z-axis as a left side, a right side, and a top side (that may also be referred to as an “upper side”), respectively. Accordingly, directions of an X-axis, directions of a Y-axis, and directions of a Z-axis may be referred to as leftward and rightward directions, frontward and backward directions, and upward and downward directions, respectively, in the following description(s).

Furthermore, althoughFIG. 1toFIG. 5illustrate the flush toilet bowl1that is a floor-mounted type, this is not limiting, and for example, a wall-hung type may be provided. As illustrated inFIG. 1toFIG. 3, the flush toilet bowl1includes the toilet body2, the toilet lid3, the toilet seat4, and a functional part5. The toilet body (that will be referred to as a “toilet” below)2is made of, for example, a ceramic. The toilet lid3is provided rotatably in upward and downward directions and opens or closes on an upper side of the toilet2. The toilet seat4is provided on an upper side of the toilet2and rotatably in upward and downward directions.

As illustrated inFIG. 3, the functional part5is provided on a rear part of the toilet2. The functional part5includes a sanitary washing system functional part6and a water supply system functional part7. The sanitary washing system functional part6is provided on a rear part of the toilet2and has a function for washing of a private part of a user. The water supply system functional part7is provided so as to be adjacent to the sanitary washing system functional part6on a rear part of the toilet2and has a function for water supply to the toilet2.

As illustrated inFIG. 2andFIG. 3, the toilet2includes a bowl part11. The bowl part11includes a receiving surface8, a shelf surface9, and the rim part10. The receiving surface (that will be referred to as a “waste receiving surface” below)8is formed into a bowl shape and receives waste. The rim part10is formed so as to stand on the shelf surface9that is provided on an upper edge of the waste receiving surface8. As illustrated inFIG. 3, the toilet2is provided in such a manner that an entrance part12ais connected to a lower part of the bowl part11, and includes a drainage water trap pipeline12that is a water drainage path for spouting waste in the bowl part11.

As illustrated inFIG. 4, the bowl part11includes a front side region F1that is provided on a front side with respect to a center line c1that bisects a plan view thereof in frontward and backward directions and extends in leftward and rightward directions, and a back side region R1that is provided on a back side. A rim water guide channel13that is a part of a rim water spout part30that will be described later is formed inside the rim part10on one of left and right sides in the front side region F1of the bowl part11, that is, the rim part10on the right side in the front side region F1of the bowl part11when the toilet2is viewed from a front side. Furthermore, a rim water spout port14that is a part of the rim water spout part30is formed at a downstream end of the rim water guide channel13.

Furthermore, as illustrated inFIG. 4, a water guide pipe15that is a water guide channel that supplies flush water that is supplied from a (non-illustrated) water supply that is a flush water source to the rim water guide channel13is connected to an upstream side of the rim water guide channel13. Furthermore, the toilet2includes a rim nozzle40that is connected to a front end of the water guide pipe15and arranged at an entrance part13aof the rim water guide channel13. For example, the water guide pipe15is directly coupled to a water supply that is a flush water source, on an upstream side. Flush water that is supplied from the water guide pipe15into the rim water guide channel13by utilizing a water supply pressure of a water supply is guided forward in the rim water guide channel13, bends inward and backward, and is guided to the rim water spout port14on a downstream side.

Flush water that is guided to the rim water spout port14is spouted backward (which is referred to as “rim water spout”), passes through a passing water channel16that will be described later and is formed near a downstream side of the rim water spout port14, and swirls in the bowl part11, so that a swirling flow of flush water is formed in the bowl part11. Additionally, the rim water spout port14is only a water spout port that is provided on the rim part10and spouts flush water to form a swirling flow thereof in the bowl part11.

Additionally, although an example where the rim water guide channel13and the rim water spout port14that are provided for the rim water spout part30are formed inside the rim part10on a right side in the front side region F1of the bowl part11when the toilet2is viewed from a front side has been described in the flush toilet bowl1according to the present embodiment, this is not limiting, and for example, the rim water spout port14may be formed in the rim part10on a left side in the front side region F1of the bowl part11when the toilet2is viewed from a front side, so as to rim-spout water backward.

Furthermore, the rim water guide channel13and the rim water spout port14that are provided for the rim water spout part30may be formed integrally with the toilet2, for example, by processing a pottery or may be formed of a resin or the like separately from the toilet2and installed in the toilet2.

Furthermore, as illustrated inFIG. 3, a jet water spout port17is formed on a lower part of the bowl part11so as to face an entrance part12aof the drainage water trap pipeline12. The jet water spout port17spouts flush water that is pressurized by the water supply system functional part7(which is referred to as “jet water spout”). Specifically, the water supply system functional part7includes a water storage tank18that stores flush water and a pressurization pump19that pressurizes flush water that is stored in the water storage tank18, and the jet water spout port17jet-spouts such flush water.

Furthermore, flush water that is spouted from the jet water spout port17flows from the entrance part12aof the drainage water trap pipeline12into a rise pipeline12bon a back side of the entrance part12a, and subsequently, flows through the rise pipeline12band from a top part12cof the drainage water trap pipeline12into a fall pipeline12d.

Herein, the functional part5that is provided on the toilet2, that is, the sanitary washing system functional part6and the water supply system functional part7will be described. Additionally, the sanitary washing system functional part6and the water supply system functional part7that are provided in the functional part5have structures similar to conventional ones, and hence, such a detailed description of the functional part5will be omitted. The sanitary washing system functional part6is provided with a (non-illustrated) private part washing device that includes a (non-illustrated) nozzle device that sprays flush water toward a user that sits on the toilet seat4(seeFIG. 3) and thereby is positioned above the bowl part11.

In addition, the sanitary washing system functional part6is provided with a (non-illustrated) a water storage part that stores flush water that is supplied to a private part washing device, a (non-illustrated) heater that appropriately warms flush water in the water storage part to provide warm water, a (non-illustrated) ventilation fan, a (non-illustrated) deodorization fan, a (non-illustrated) warm air fan, a (non-illustrated) controller that controls operations of such instruments, and the like.

On the other hand, a (non-illustrated) water supply channel of the water supply system functional part7is connected to a (non-illustrated) water supply that is a water supply source, on an upstream side, and a water supply channel of the water storage tank18(seeFIG. 3) on an upstream side is provided with a (non-illustrated) constant flow valve, a (non-illustrated) electromagnetic valve, a (non-illustrated) switching valve that switches between water supply to the water storage tank18and water spout to the rim water spout port14, and the like.

In addition, the water supply system functional part7is provided with a (non-illustrated) controller that controls an opening or closing operation of an electromagnetic valve, a switching operation of a switching valve, and a rotation frequency, an operating time, or the like of the pressurization pump19(seeFIG. 3), and the like.

Furthermore, as illustrated inFIG. 5, the toilet2further includes the passing water channel16. The passing water channel16is a flow channel for flush water that is rim-spouted from the rim water spout port14and formed from a downstream end of the rim water spout port14to a back curved part of the bowl part11. The passing water channel16is formed so as to have a U-shaped cross section of a flow channel that is surrounded by an inner peripheral surface24of the rim part10, the shelf surface9that is formed below the inner peripheral surface24of the rim part10, and an overhung part25that is formed above the inner peripheral surface24of the rim part10.

Additionally, although a configuration of a so-called hybrid type flush toilet bowl that supplies flush water in the water storage tank18by utilizing a water supply pressure of a water supply for rim water spout from the rim water spout port14and controlling the pressurization pump19for jet water spout from the jet water spout port17(seeFIG. 3for both of them) has been described in the flush toilet bowl1according to the present embodiment, this is not limiting and another configuration is also applicable.

Another configuration is, for example, a configuration to switch a valve for flush water that is directly supplied from only a water supply and thereby switch between rim water spout from the rim water spout port14and jet water spout from the jet water spout port17, a configuration to switch only a pump for flush water in a water storage tank and thereby switch between rim water spout from the rim water spout port14and jet water spout from the jet water spout port17, or the like.

Rim Water Spout Part

Next, a detail of the rim water spout part30(the rim water guide channel13and the rim water spout port14) will be described with reference toFIG. 4toFIG. 6E.FIG. 6AtoFIG. 6Eillustrate five cross sections of a flow channel from an upstream side to a downstream side of the rim water guide channel13.FIG. 6Ais a cross-sectional view along A-A inFIG. 5.FIG. 6Bis a cross-sectional view along B-B inFIG. 5.FIG. 6Cis a cross-sectional view along C-C inFIG. 5.FIG. 6Dis a cross-sectional view along D-D inFIG. 5.FIG. 6Eis a cross-sectional view along E-E inFIG. 5.

As illustrated inFIG. 4andFIG. 5, the rim water guide channel13includes the entrance part13athat is connected to the water guide pipe15via the rim nozzle40, an outer part13bthat extends forward (in a negative direction of a Y-axis) from the entrance part13ainside the rim part10, a bending part13cthat bends from a downstream end of the outer part13bto an inside that is a side toward a center of the bowl part11, and an inner part13dthat extends backward (in a positive direction of the Y-axis) from the bending part13cto the rim water spout port14.

As illustrated inFIG. 6A, the outer part13b(seeFIG. 5) of the rim water guide channel13includes an outer wall part20outside the rim part10(in a positive direction of an X-axis), a lower wall part21that is integrally formed inward (in a negative direction of the X-axis) from a lower end of the outer wall part20, an inner wall part22that is opposite to the outer wall part20in a horizontal direction and has a lower end that is bonded to an upper end of the lower wall part21, and an upper wall part23that is formed integrally with an upper end of the inner wall part22and bonded to an upper end of the outer wall part20.

Bonding surfaces b1of an upper end surface of the lower wall part21and a lower end surface of the inner wall part22in the outer part13bof the rim water guide channel13form substantially horizontal surfaces. Furthermore, bonding surfaces b2of an upper surface of the outer wall part20and the upper wall part23in the rim water guide channel13form inclined surfaces that are inclined with respect to the bonding surfaces b1that are substantially horizontal surfaces. Additionally, a “substantially horizontal surface” includes not only a completely horizontal surface but also a horizontal surface enough for an upper end surface of the lower wall part21and a lower end surface of the inner wall part22, that is, both of the bonding surfaces b1to be capable of being displaced from each other in a horizontal direction (a direction of an X-axis).

Thereby, for example, in a case where the bonding surface b1on a lower end of the inner wall part22in the rim water guide channel13is bonded to the bonding surface b1on an upper end of the lower wall part21therein at a time of manufacturing of the flush toilet bowl1according to the present embodiment and simultaneously the bonding surface b2of the upper wall part23in the rim water guide channel13is bonded to the bonding surface b2on an upper end of the outer wall part20therein, the bonding surface b2of the outer wall part20and the bonding surface b2of the upper wall part23that form inclined surfaces that are both inclined with respect to a horizontal surface previously contact each other even in a case where the bonding surfaces b1that form horizontal surfaces are displaced from each other in a horizontal direction due to a manufacturing error or the like.

Accordingly, it is possible to prevent cross sections A to E (seeFIG. 5) of a flow channel from the outer part13bto the inner part13din the rim water guide channel13from being completely lost by a displacement between both of the bonding surfaces b1and it is possible to secure a water guide region of the rim water guide channel13over a whole region of the rim water guide channel13.

As illustrated inFIG. 6AtoFIG. 6B, an outer side, a lower side, an inner side, and an upper side of the rim water guide channel13are defined by a wall surface20aof the outer wall part20, a wall surface21aof the lower wall part21, a wall surface22aof the inner wall part22, and a wall surface23aof the upper wall part23, respectively.

FIG. 6Ais a cross-sectional view near the entrance part13athat is an upstream side of the rim water guide channel13(seeFIG. 5). As illustrated inFIG. 6A, the rim water guide channel13has, near the entrance part13a, a cross-sectional shape that is formed by the wall surface20aof the outer wall part20that is inclined downward toward an inside (in a negative direction of an X-axis), the wall surface21aof the lower wall part21that is gently inclined downward and toward an inside with respect to the wall surface20a, the wall surface22aof the inner wall part22that extends in upward and downward directions (directions of a Z-axis), and the wall surface23aof the upper wall part23that extends in left and right directions (directions of an X-axis).

FIG. 6Bis a cross-sectional view on a nearest downstream side of the entrance part13aof the rim water guide channel13(seeFIG. 5). As illustrated inFIG. 6B, an elongate hole that is longer in transverse directions, that is, left and right directions (directions of an X-axis), is formed on an upper part of the rim water guide channel13by an upper end part of the wall surface20aof the outer wall part20, an upper end part of the wall surface22aof the inner wall part22, and the wall surface23aof the upper wall part23.

Furthermore, an elongate hole that is continuous with an elongate hole in transverse directions and longer in longitudinal directions, that is, upward and downward directions (directions of a Z-axis), is formed below the elongate hole in transverse directions for the rim water guide channel13by the wall surface20aof the outer wall part20, the wall surface21aof the lower wall part21, and the wall surface22aof the inner wall part22.

Specifically, the rim water guide channel13is formed into a cross-sectional shape with an inversed-L-shape where an elongate hole in transverse directions and an elongate hole in longitudinal directions are combined. Accordingly, the rim water guide channel13is formed into a cross-sectional shape with a hook shape on an upper side with respect to a center (a center line) c2of the rim part10in upward and downward directions and formed into a cross-sectional shape with a liner shape on a lower side with respect to the center line c2. That is, a cross-sectional area of a lower half part of the rim part10in upward and downward directions is less than a cross-sectional area of an upper half part thereof, on a nearest downstream side of the entrance part13a(an upstream side in a whole of the rim water guide channel13) in the rim water guide channel13.

FIG. 6Cis a cross-sectional view near a center of the rim water guide channel13in a forward and backward directions (seeFIG. 5). As illustrated inFIG. 6C, an elongate hole that is longer in transverse directions, that is, leftward and rightward directions (directions of an X-axis) is formed on an upper part of the rim water guide channel13by an upper end part of the wall surface20aof the outer wall part20, an upper end part of the wall surface22aof the inner wall part22, and the wall surface23aof the upper wall part23.

Specifically, the rim water guide channel13is also formed into a cross-sectional shape with an inversed-L-shape where an elongate hole in transverse directions and an elongate hole in longitudinal directions are combined, near a center in forward and backward directions. Accordingly, the rim water guide channel13is formed into a cross-sectional shape with a hook shape on an upper side with respect to a center line c2of the rim part10in upward and downward directions and formed into a cross-sectional shape with a linear shape on a lower side with respect to the center line c2. That is, a cross-sectional area of a lower half part of the rim part10in upward and downward directions is less than a cross-sectional area of an upper half part thereof, on a nearest downstream side of the entrance part13a(an upstream side in a whole of the rim water guide channel13) in the rim water guide channel13.

FIG. 6Dis a cross-sectional view on a downstream side with respect to a center of the rim water guide channel13in forward and backward directions (seeFIG. 5). As illustrated inFIG. 6D, the rim water guide channel13is formed into a cross-sectional shape with an elongate hole shape in longitudinal directions (directions of a Z-axis) by the wall surface20aof the outer wall part20that is a longer side, the wall surface21aof the lower wall part21that is a shorter side, the wall surface22aof the inner wall part22that is a longer side that is opposite to the wall surface20a, and the wall surface23aof the upper wall part23that is a shorter side that is opposite to the wall surface21a.

FIG. 6Eis a cross-sectional view on a nearest upstream side of the bending part13cof the rim water guide channel13(seeFIG. 5). As illustrated inFIG. 6E, the rim water guide channel13is formed into a cross-sectional shape with an elongate hole shape in longitudinal directions (directions of a Z-axis) by the wall surface20aof the outer wall part20that is a longer side, the wall surface21aof the lower wall part21that is a shorter side, the wall surface22aof the inner wall part22that is a longer side that is opposite to the wall surface20a, and the wall surface23aof the upper wall part23that is a shorter side that is opposite to the wall surface21a.

That is, an upper space where flush water is flown therein on a nearest downstream side of the entrance part13ais formed in the rim water guide channel13, and formed so as to be reduced in such a manner that a width of the upper space in left and right directions is reduced with approaching a downstream side.

Herein, as the rim water spout port14is formed on a front part of the bowl part11, that is, in the front side region F1(seeFIG. 4) like the flush toilet bowl1according to the present embodiment, a total length of the rim water guide channel13is increased and an amount of air that accumulates in the rim water guide channel13is increased as compared with a case where a water guide channel is short.

Accordingly, in a case where rim water spout is executed, a diameter of the rim water spout port14is less than that of the rim water guide channel13and the rim water spout port14executes rim water spout backward, so that the bending part13cis formed in the rim water guide channel13, and hence, a mass of air and flush water are simultaneously spouted from the rim water spout port14. Furthermore, air in the rim water guide channel13frequently accumulates on an upper part of the rim water guide channel13, and hence, is not readily agitated by flush water. Accordingly, a mass of air is directly spouted from the rim water spout port14. Thus, abnormal noise that is caused by air may be generated at a time of rim water spout.

According to an embodiment as described above, the rim water guide channel13is formed in such a manner that a cross-sectional area of a lower half part in upward and downward directions is less than a cross-sectional area of a upper half part as illustrated inFIG. 6BandFIG. 6C, so that flush water that is guided by the rim water guide channel13is readily flown into an upper part in the rim water guide channel13and air that accumulates on an upper part in the rim water guide channel13is agitated by flowing flush water. Thereby, air in the rim water guide channel13is finely fractionized, so that it is possible to suppress abnormal noise that is caused by air at a time of spout of flush water from the rim water spout port14and it is possible to improve quietness.

In particular, even in a case where the rim water spout port14is arranged in the front side region F1of the bowl part11for improvement of a design or a swirling property of flush water, it is possible to suppress abnormal noise that is caused by air and it is possible to improve quietness.

Furthermore, the rim water guide channel13is formed into a shape (an inversed-L-shape) where a cross-sectional shape thereof in upward and downward directions is provided by combining an elongate hole in longitudinal directions and an elongate hole in transverse directions, and hence, it is possible to readily form the rim water guide channel13in such a manner that a cross-sectional area of a lower half part is less than a cross-sectional area of an upper half part.

Additionally, although an embodiment as described above provides a cross-sectional shape where an elongate hole in longitudinal directions and an elongate hole in transverse directions are combined so as to provide an inversed-L-shape, this is not limiting and various cross-sectional shapes such as an inversed triangular shape may be provided. Furthermore, in a case where an elongate hole in longitudinal directions and an elongate hole in transverse directions are combined, various cross-sectional shapes such as, for example, a T-shape or a cross shape with a transverse line being on an upper side with respect to a center in upward and downward directions may be provided. In short, any shape may be allowed, as long as a cross-sectional shape of a lower half part in upward and downward directions is less than a cross-sectional shape of an upper half part.

Furthermore, according to an embodiment as described above, the rim water guide channel13includes the outer part13b, the bending part13c, and the inner part13dand the rim water spout port14is formed on a terminal end of the inner part13dand rim-spouts flush water backward, so that it is possible to reduce a volume of the rim water guide channel13as compared with a case the rim water guide channel13passes through a front end of the bowl part11, although the rim water spout port14is formed in the front side region F1of the bowl part11. Accordingly, it is possible to reduce an amount of air that accumulates in the rim water guide channel13and it is possible to further suppress abnormal noise that is caused by air.

Additionally, although a mass of air that accumulates in the rim water guide channel13is separated at the bending part13cwhere its flow (an interface with flush water) is readily destabilized to readily generate abnormal noise, air that accumulates on an upper part in the rim water guide channel13is agitated by flush water before reaching the bending part13cas described above, and hence, it is possible to suppress abnormal noise that is caused by air.

Furthermore, a guide part50(seeFIG. 8A,FIG. 8B, andFIG. 8C) is provided on the entrance part13ain the rim water guide channel13. The guide part50is a surface (where a guide part will be referred to as a “guide surface” below) that separates the entrance part13aand an upper space in the rim water guide channel13, is provided in such a manner that flush water that is spouted from the rim nozzle40(seeFIG. 4) collides therewith, and collides with flush water to cause the flush water to flow into the upper space. Additionally, a flow of flush water after flowing into an upper space due to the guide surface50will be described later by usingFIG. 8A,FIG. 8B, andFIG. 8C.

According to such a configuration, flush water is flown into an upper part in the rim water guide channel13more readily and air that accumulates on an upper part in the rim water guide channel13is agitated more reliably, so that it is possible to further suppress abnormal noise that is caused by air.

By returning toFIG. 4andFIG. 5, the rim water spout port14is formed on a front end of the inner part13dof the rim water guide channel13. The rim water spout port14rim-spouts backward flush water that is guided to the rim water spout channel13. Flush water that is rim-spouted from the rim water spout port14flows through the passing water channel16and becomes a swirling flow that flows while swirling on the waste receiving surface8.

Furthermore, the rim water spout port14is formed in such a manner that an upper end of the rim water spout port14is positioned on a lower half part of the rim part10in upward and downward directions. According to such a configuration, it is possible to reduce a volume of the rim water guide channel13just in front of the rim water spout port14. Accordingly, it is possible to reduce an amount of air that accumulates in the rim water guide channel13and it is possible to further suppress abnormal noise that is caused by air.

Additionally, although the rim water spout port14is comparatively small so that air is not readily spouted from the rim water spout port14and abnormal noise is readily generated, air that accumulates on an upper part in the rim water guide channel13is agitated before reaching the bending part13cso that it is possible to suppress abnormal noise that is caused by air.

Furthermore, the rim water spout port14may be formed in such a manner that a cross section of an opening of the rim water spout port14has a triangular shape with a vertex in an upward direction. According to such a configuration, it is possible to reduce a region of the overhung part25(seeFIG. 5) that is positioned above the passing water channel16(seeFIG. 5) on a downstream side of the rim water spout port14.

Rim Nozzle

Next, the rim nozzle40will be described with reference toFIG. 7AtoFIG. 7D.FIG. 7Ais a perspective view of the rim nozzle40.FIG. 7Bis a plan view of the rim nozzle40.FIG. 7Cis a cross-sectional view along F-F inFIG. 7B.FIG. 7Dis an illustration diagram of a water spout surface43aof the rim nozzle40. The rim nozzle40spouts flush water that is supplied from a (non-illustrated) water supply that is a flush water source and flows in the water guide pipe15(seeFIG. 5) into the rim water guide channel13(seeFIG. 5). The rim nozzle40is provided on the entrance part13aof the rim water guide channel13.

As illustrated inFIG. 7AtoFIG. 7C, the rim nozzle40includes a nozzle body41, a connection part42, and a water spout part43. The nozzle body41is formed into, for example, a cylindrical shape. The nozzle body41forms a passing water channel for flush water in the rim nozzle40. The connection part42is formed into, for example, a cylindrical shape and connected to a front end of the water guide pipe15so that the rim nozzle40is connected to the water guide pipe15. The connection part42is provided on one end side of the nozzle body41and is provided so as to form a space that continuously extends from the nozzle body41.

As illustrated inFIG. 7C, the connection part42has a central axis line c32that is inclined at a predetermined angle with respect to a central axis (a central axis line) c31of the nozzle body41(a passing water channel in the rim nozzle40). That is, the connection part42is provided on the nozzle body41to be inclined at a predetermined angle.

As illustrated inFIG. 7AtoFIG. 7C, the water spout part43(that is also referred to as a “nozzle cap water spout part”) is mounted on the other end side of the nozzle body41so as to be coaxial with the central axis line c31of the nozzle body41. Additionally, the water spout part43is arranged on the entrance part13a(seeFIG. 8A) of the rim water guide channel13in a state where the rim nozzle40is mounted on the rim water guide channel13.

The water spout part43includes the water spout surface43a. The water spout surface43ais a front end surface of the water spout part43and spouts flush water toward an inside of the rim water guide channel13. A plurality of small holes43bthat spout flush water is formed on the water spout surface43a. For example, nine small holes43bare formed thereon. In a case where nine small holes43bare formed, for example, one small hole43b(that is also referred to as a “center small hole”) is formed at, for example, a center of the water spout surface43aand remaining eight small holes43bare formed around the center small hole43b. Additionally, eight small holes43baround one center small hole43bare formed so as to have, for example, an angle of 45 degrees on a concentric circle of the center small hole43b.

According to such a configuration, flush water is spouted from the plurality of small holes43b, so that the flush water is divided into a plurality of streams in the rim water guide channel13(seeFIG. 8A), air that accumulates in the rim water guide channel13is readily involved with such a plurality of water streams, and air is agitated by the flush water. Thereby, air in the rim water guide channel13is finely fractionated. Accordingly, a mass of air is spouted from the rim water spout port14at a time of rim water spout, so that it is possible to suppress generation of abnormal noise such as explosive noise of air or mixing noise of air.

Furthermore, a groove may be formed on the water spout surface43aso as to connect a small hole43bwith a small hole43b. Furthermore, a groove may be formed, for example, so as to extend radially from a center small hole43band connect each small hole43bwith the center small hole43b. Such a groove is formed, so that it is possible to drain water that is attached to a small hole43bby surface tension thereof outside the water spout part43and it is possible to prevent freezing in a cold region or the like.

Herein, the rim nozzle40is formed so as to spout flush water upward in the rim water guide channel13. Specifically, as illustrated inFIG. 7C, a central axis line c33of the water spout surface43a(a small hole43b) in the rim nozzle40is inclined upward with respect to the central axis line c31of the nozzle body41. Additionally, “spouting flush water upward” indicates that a main stream of flush water is directed upward.

Thus, according to an embodiment as described above, the rim nozzle40is formed so as to spout flush water upward in the rim water guide channel13, so that flush water that is guided by the rim water guide channel13is readily flown into an upper part in the rim water guide channel13and air that accumulates on an upper part in the rim water guide channel13is agitated by flowing flush water. Thereby, air in the rim water guide channel13is finely fractionized, so that it is possible to suppress abnormal noise that is caused by air at a time of spout of flush water from the rim water spout port14and it is possible to improve quietness.

In particular, even in a case where the rim water spout port14is arranged in the front side region F1of the bowl part11for improvement of a design or a swirling property of flush water, it is possible to suppress abnormal noise that is caused by air and it is possible to improve quietness.

Furthermore, as illustrated inFIG. 7D, the water spout surface43ais a surface inclined at a predetermined angle α, so that the central axis line c33of the water spout surface43ain the rim nozzle40is inclined with respect to the central axis line c31of the nozzle body41.

According to such a configuration, it is possible to readily form the rim nozzle40so as to spout flush water upward. Thereby, flush water that is guided by the rim water guide channel13is readily flown into an upper part in the rim water guide channel13and air that accumulates on an upper part in the rim water guide channel13is agitated by flowing flush water, so that it is possible to suppress abnormal noise that is caused by air.

Furthermore, it is possible to spout flush water upward by only exchanging a single body of the rim nozzle40. Accordingly, it is possible to improve versatility. Furthermore, it is possible to attain space saving as compared with, for example, a case where the rim nozzle40is wholly inclined upward.

State of Flow of Flush Water in Rim Water Guide Channel

Next, a state of a flow of flush water in the rim water guide channel13at a time of rim water spout will be described with reference toFIG. 8AtoFIG. 8C.FIG. 8AtoFIG. 8Care diagrams illustrating a state of a flow of flush water in the rim water guide channel13. Additionally,FIG. 8Aillustrates a case where the rim water guide channel13of the rim part10is viewed from a diagonal upside on a right side,FIG. 8Billustrates a case where the rim water guide channel13is viewed from a right side, andFIG. 8Cillustrates a case where the rim water guide channel13is viewed from a diagonal upside on a back side.

As illustrated inFIG. 8AtoFIG. 8C, flush water W that is guided from the water guide pipe15and spouted from the plurality of small holes43bof the water spout surface43aof the rim nozzle40collides with the guide surface (the guide part)50on the entrance part13aof the rim water guide channel13so as to become a rising flow W1that rises and flows into an upper space. Flush water that flows into an upper space becomes a falling flow W2that sequentially falls from the upper space of the rim water guide channel13with a width that is gradually reduced in left and right directions, in the middle of flowing to a downstream side while agitating air that accumulates on an upper part in the rim water guide channel13, and flows so as to fall onto the lower wall part21of the rim water guide channel13.

That is, flush water in the rim water guide channel13rises immediately after being spouted from the rim nozzle40, flows through an upper part in the rim water guide channel13to agitate air, and flows to a downstream side so as to fall sequentially. Flush water is spouted (rim-spouted) from the rim water spout port14(seeFIG. 5) on a downstream side of the rim water guide channel13.

Furthermore, as illustrated inFIG. 8AtoFIG. 8C, the rim nozzle40is formed so as to spout flush water toward a side wall surface (for example, the wall surface22aof the inner wall part22) of the rim water guide channel13. According to such a configuration, the rim nozzle40is formed so as to spout flush water upward in the rim water guide channel13and toward a side wall surface (for example, the wall surface22aof the inner wall part22) of the rim water guide channel13, so that flush water that is guided by the rim water guide channel13is readily flown into an upper part in the rim water guide channel13and it is possible to guide flush water along the side wall surface (for example, the wall surface22aof the inner wall part22) of the rim water guide channel13. Thereby, air that accumulates on an upper part in the rim water guide channel13is agitated more reliably and it is possible to further suppress abnormal noise that is caused by air.

State of Flush Water and Air in Rim Water Guide Channel

Next, a state of flush water and air in the rim water guide channel13at a time of rim water spout will be described with reference toFIG. 9AtoFIG. 10B.FIG. 9AandFIG. 9Bare diagrams illustrating a state of flush water and air in the rim water guide channel13in a comparative example.FIG. 10AandFIG. 10Bare diagrams illustrating a state of flush water and air in the rim water guide channel13in an embodiment.

Additionally,FIG. 9AtoFIG. 10Bschematically illustrate a case where the rim water guide channel13is viewed from a right side. Furthermore,FIG. 9AandFIG. 10Aillustrate a state of flush water and air at a point of time when flush water reaches the bending part13c(seeFIG. 5) of the rim water guide channel13, andFIG. 9BandFIG. 10Billustrate a state of flush water and air at a point of time when rim water spout from the rim water spout port14(seeFIG. 5) is started.

As illustrated inFIG. 9AandFIG. 9B, flush water that is spouted from a rim nozzle140linearly flows to a downstream side in a comparative example. In such a case, a large amount of air remains on an upstream side to a downstream side, even at a point of time when an interface102between flush water100and air101stagnates and the flush water100reaches the bending part13c(seeFIG. 5). Accordingly, as rim water spout is started, the flush water100and the air101are spouted from the rim water spout port14(seeFIG. 5), so that abnormal noise that is caused by the air101is readily generated.

On the other hand, as illustrated inFIG. 10AandFIG. 10B, in an embodiment, flush water that is spouted from the rim nozzle40is flown into an upper part of the rim water guide channel13(seeFIG. 5) by the guide surface (the guide part)50and flows through an upper part of the rim water guide channel13because a cross-sectional area of a lower half part of the rim water guide channel13is less than a cross-sectional area of an upper half part thereof. Furthermore, the rim nozzle40spouts flush water upward, so that flush water also flows through an upper part of the rim water guide channel13.

Flush water that flows through an upper part of the rim water guide channel13flows to a downstream side while agitating air that accumulated on an upper part thereof, so that air is finely fractionized and mixed into flush water and air is spouted from the rim water spout port14without providing a mass thereof and together with flush water.

Thus, flush water flows through an upper part in the rim water guide channel13, so that air that accumulates on an upper part in the rim water guide channel13is agitated by flowing flush water. Thereby, air in the rim water guide channel13is finely fractionized, so that it is possible to suppress abnormal noise that is caused by air at a time of spout of flush water from the rim water spout port14and it is possible to improve quietness.

According to an aspect of an embodiment, it is possible to suppress abnormal noise that is caused by air and improve quietness.

Configuration (1) is a flush toilet bowl, including a bowl part that is provided in such a manner that a rim part is formed on an upper edge of a receiving surface with a bowl shape, a rim nozzle that is provided on a rear part of the bowl part and spouts flush water that is supplied from a flush water source, and a rim water spout part that is provided on the rim part, spouts flush water that is spouted from the rim nozzle, toward the receiving surface, and causes flush water to swirl on the receiving surface, wherein the rim water spout part includes a rim water guide channel that is formed inside the rim part, is formed in such a manner that a cross-sectional area of a lower half part of the rim water guide channel is less than a cross-sectional area of an upper half part in upward and downward directions, and guides flush water that is spouted from the rim nozzle, and a rim water spout port that is formed to be continuous with the rim water guide channel, is formed in a front side region of the bowl part, and spouts flush water that is guided by the rim water guide channel, toward the receiving surface.

According to Configuration (1), a rim water guide channel is formed in such a manner that a cross-sectional area of a lower half part of the rim water guide channel is less than a cross-sectional area of an upper half part in upward and downward directions, so that flush water that is guided by the rim water guide channel is readily flown into an upper part in the rim water guide channel and air that accumulates on the upper part in the rim water guide channel is agitated by flowing flush water. Thereby, air in the rim water guide channel is finely fractionized, so that it is possible to suppress abnormal noise that is caused by air at a time of spout of flush water from a rim water spout port and it is possible to improve quietness.

Configuration (2) is the flush toilet bowl according to Configuration (1), wherein the rim water guide channel includes a guide part that guides flush water that is spouted from the rim nozzle upward at an entrance part for flush water of the rim water guide channel.

According to Configuration (2), flush water is flown into an upper part in a rim water guide channel more readily and air that accumulates on the upper part in the rim water guide channel is agitated more reliably, so that it is possible to further suppress abnormal noise that is caused by air.

Configuration (3) is the flush toilet bowl according to Configuration (1) or (2), wherein the rim water guide channel includes an outer part that extends forward through an inside of the rim part, a bending part that bends from a terminal of the outer part toward an inner side that is a side of the receiving surface, and an inner part that extends backward from the bending part, and the rim water spout port is formed at a terminal of the inner part and spouts flush water backward.

According to Configuration (3), while a rim water spout port is formed in a front side region of a bowl part, it is possible to cause a volume of a rim water guide channel to be less than a case where the rim water guide channel extends through a front edge of the bowl part. Accordingly, it is possible to reduce an amount of air that accumulates in the rim water guide channel and it is possible to further suppress abnormal noise that is caused by air.

Configuration (4) is the flush toilet bowl according to any one of Configurations (1) to (3), wherein the rim water spout port is formed in such a manner that an upper end of the rim water spout port is positioned at a lower half part of a rim part in upward and downward directions.

According to Configuration (4), it is possible to reduce a volume of a rim water guide channel just in front of a rim water spout port. Accordingly, it is possible to reduce an amount of air that accumulates in the rim water guide channel and it is possible to further suppress abnormal noise that is caused by air.

Configuration (5) is the flush toilet bowl according to any one of Configurations (1) to (4), wherein the rim water guide channel is formed into a shape where a cross-sectional shape in upward and downward directions is provided by combining a longitudinal elongate hole and a transverse elongate hole.

According to Configuration (5), it is possible to readily form a rim water guide channel where a cross-sectional area of a lower half part is less than a cross-sectional area of an upper half part in upward and downward directions.