Patent Publication Number: US-11384521-B2

Title: Flush toilet

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2019-180456 filed in Japan on Sep. 30, 2019. 
     FIELD 
     A disclosed embodiment(s) relate(s) to a flush toilet. 
     BACKGROUND 
     A flush toilet has conventionally been known that causes a main stream of a washing water that swirls along a rim part to flow into a water storage part from a front side of a bowl part (see, for example, Japanese Patent No. 5553188). 
     However, in a flush toilet as described above, as a length of a bowl part in frontward and backward directions is decreased for downsizing of the flush toilet, a flow rate of a washing water may increase, so that it may not flow into a water storage part from a front side of the bowl part and a discharging performance for waste may be degraded. 
     SUMMARY 
     A flush toilet according to an embodiment includes a bowl part, a rim part, a water spout port, and a water storage part. The bowl part receives waste. The rim part is formed on a top of the bowl part. The water spout port spouts a washing water. The water storage part is formed on a bottom of the bowl part. A first region that is connected to a discharge channel and a second region that is located on a front side of the first region are formed in the water storage part. A main stream of the washing water that is spouted from the water spout port along the rim part swirls on the bowl part and flows into the first region. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a left side view of a flush toilet according to an embodiment; 
         FIG. 2  is a plan view of a toilet body according to an embodiment; 
         FIG. 3  is a III-III cross-sectional view of  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of a toilet body in a IV-IV cross section of  FIG. 3 ; 
         FIG. 5  is a V-V cross-sectional view of  FIG. 2 ; 
         FIG. 6  is a cross-sectional view of a water storage part in a VI-VI cross section of  FIG. 3 ; 
         FIG. 7  is a cross-sectional view of a water storage part in a VII-VII cross section of  FIG. 3 ; 
         FIG. 8  is a diagram where surface shapes of a first guide part and a second guide part in cross sections as indicated by A to G in  FIG. 4  are overlapped; and 
         FIG. 9  is a diagram that explains flows of a first washing water and a second washing water on a bowl part. 
     
    
    
     DESCRIPTION OF EMBODIMENT(S) 
     Hereinafter, an embodiment(s) of a flush toilet as disclosed in the present application will be explained in detail with reference to the accompanying drawing(s). Additionally, this invention is not limited by an embodiment(s) as illustrated below. Furthermore, it has to be noted that the drawing(s) is/are schematic, so that a relationship(s) among dimensions of respective elements, a ratio(s) of respective elements, or the like may be different from a reality. Among mutual drawings, parts with different relationships of mutual dimensions or ratios may also be included therein. 
     General Configuration of Flush Toilet 
     First, a general configuration of a flush toilet  1  according to an embodiment will be explained with reference to  FIG. 1 .  FIG. 1  is a left side view of the flush toilet  1  according to an embodiment. Furthermore,  FIG. 1  illustrates a wall surface  8  and a floor surface  9  in a cross section. 
     Furthermore,  FIG. 1  illustrates a three-dimensional orthogonal coordinate system that includes a Z-axis where a vertically upward direction is a positive direction, for providing a comprehensible explanation. Such an orthogonal coordinate system may also be illustrated in another figure. In such an orthogonal coordinate system, a negative direction of a Y-axis, a positive direction of the Y-axis, a positive direction of an X-axis, and a negative direction of the X-axis are defined as a front side, a back side, a right side, and a left side, respectively. Hence, in a following explanation, X-axis directions, Y-axis directions, and Z-axis directions may be leftward and rightward directions, frontward and backward directions, and upward and downward directions, respectively. 
     Furthermore, the flush toilet  1  according to an embodiment is a so-called wall-hung type flush toilet that is attached to the wall surface  8 . Additionally, a flush toilet may be a so-called floor-mounted type flush toilet that is placed on the floor surface  9 . 
     The flush toilet  1  includes a toilet body  2  and a private part washing device  3 . The flush toilet  1  according to an embodiment is a wash-down type toilet (a washdown type toilet) that washes the toilet body  2  with a washing water that is supplied from a washing water source, and discharges waste. Furthermore, the toilet body  2  is made of, for example, a ceramic. A detail of the toilet body  2  will be described later. 
     The private part washing device  3  includes a washing nozzle, a motor for driving a nozzle, a motor control device (where none of them is illustrated), and the like. The private part washing device  3  is provided on a top of the toilet body  2 , for washing a private part of a user, and washes a private part of a user with a washing water that is jetted from a washing nozzle. 
     For the flush toilet  1 , a washing water is supplied to the toilet body  2  through a water supply pipe  4   a  that is connected to a water storage tank  4 . 
     Furthermore, the flush toilet  1  discharges waste, together with a washing water, to a water discharge pipe  5 . 
     Additionally, the water storage tank  4  may be mounted on a back side of the toilet body  2  and directly supply a washing water from the water storage tank  4  to the toilet body  2 . 
     Furthermore, the flush toilet  1  includes a water supply hose  6   a  for supplying a washing water for washing a private part to the private part washing device  3  and an electric power source cable  6   b  for supplying electric power to the private part washing device  3 . 
     Toilet Body 
     Next, the toilet body  2  according to an embodiment will be explained with reference to  FIG. 2  to  FIG. 5 .  FIG. 2  is a plan view of the toilet body  2  according to an embodiment.  FIG. 3  is a III-III cross-sectional view of  FIG. 2 .  FIG. 4  is a cross-sectional view of the toilet body  2  in a IV-IV cross section of  FIG. 3 .  FIG. 5  is a V-V cross-sectional view of  FIG. 2 . 
     The toilet body  2  includes a bowl part  10 , a rim part  11 , a first water spout port  12  (a water spout port), a second water spout port  13  (a water spout port), and a water storage part  14 . The toilet body  2  spouts a washing water from each of the first water spout port  12  that is formed on a left side and the second water spout port  13  that is formed on a right side so as to discharge waste. Hereinafter, a washing water that is spouted from the first water spout port  12  may be referred to as a “first washing water” and a washing water that is spouted from the second water spout port  13  may be referred to as a “second washing water”. 
     The bowl part  10  is formed into a bowl shape and receives waste. The bowl part  10  includes a first guide part  20  and a second guide part  21  (a swirl part). Details of the first guide part  20  and the second guide part  21  will be described later. 
     The rim part  11  is provided on a top of the bowl part  10 . The rim part  11  includes a side wall part  11   a  that extends upward from an upper end of the bowl part  10  and an upper wall part  11   b  that extends from an upper end of the side wall part  11   a  to an inside of the bowl part  10 . The side wall part  11   a  and the upper wall part  11   b  are formed along a periphery of the bowl part  10 . The rim part  11  is formed into an overhung shape in such a manner that a first washing water does not jump out therefrom. 
     In the toilet body  2 , a passing water channel  15  where a main stream of a first washing water that is spouted from the first water spout port  12  flows is formed by the rim part  11  and the bowl part  10 . Specifically, the passing water channel  15  is formed by the side wall part  11   a  and the upper wall part  11   b  of the rim part  11  and a part of the second guide part  21  of the bowl part  10  (that will be referred to as a “bottom surface wall  21   a ” below). Additionally, the bottom surface wall  21   a  of the passing water channel  15  may be formed by the rim part  11 . The passing water channel  15  is formed so as to cause a main stream of a first washing water that is spouted from the first water spout port  12  to swirl to a back side of the bowl part  10 . 
     In the present specification, a main stream is a flow with a great force of water in the bowl part  10 , in a washing water that is spouted from a water spout port to the bowl part  10 . Furthermore, a great force of water refers to a greater magnitude of an amount of flow or a flow rate in the bowl part  10 . 
     The passing water channel  15  is formed so as to be an upward slope from a side of the first water spout port  12  toward a front end of the bowl part  10 . 
     Specifically, on the passing water channel  15 , the bottom surface wall  21   a  is formed in such a manner that a height thereof increases from a side of the first water spout port  12  toward a front end of the bowl part  10 . The bottom surface wall  21   a  is formed in such a manner that a height thereof continuously increases from a side of the first water spout port  12  toward a front end of the bowl part  10 . Furthermore, a configuration is provided in such a manner that a length of the side wall part  11   a  in upward and downward directions decreases toward a front end of the bowl part  10 . 
     An end part of the bottom surface wall  21   a  on a side of the first water spout port  12  is provided below the first water spout port  12 . An end part of the bottom surface wall  21   a  extends a water spout region where a first washing water is spouted. Hereinafter, an end part of the bottom surface wall  21   a  that is located below the first water spout port  12  may be referred to as a “region extension part  21   b  (an extension part)”. 
     Furthermore, the region extension part  21   b  is formed in such a manner that a side of the water storage part  14  is lower than a side of the rim part  11 , specifically, a side of the side wall part  11   a  of the rim part  11 . 
     Furthermore, a protrusion part  11   c  is formed on the rim part  11  on a front side of the second water sport port  13 . The protrusion part  11   c  protrudes toward an inside of the bowl part  10  so as to block the passing water channel  15 . The protrusion part  11   c  changes a direction of a main stream of a first washing water and causes the main stream of a first washing water to flow into the water storage part  14 . 
     The first water spout port  12  is formed on a top of the bowl part  10  on a left back side. The first water spout port  12  spouts, along the rim part  11 , a first washing water that is supplied through a first water transmission channel  16   a  that branches from a common water transmission channel  16 . The common water transmission channel  16  is connected to the water supply pipe  4   a  (see  FIG. 1 ) and a washing water is supplied through the water supply pipe  4   a . The first water spout port  12  spouts a first washing water along the rim part  11  from a back side toward a front side. 
     The second water spout port  13  is formed on a top of the bowl part  10  on a right back side. The second water spout port  13  spouts, to the bowl part  10 , a second washing water that is supplied through a second water transmission channel  16   b  that branches from the common water transmission channel  16 . 
     The second water spout port  13  spouts a second washing water along a back wall part  22  that is formed on a back end of the bowl part  10 . The second water spout port  13  spouts a washing water from a right side toward a left side. The back wall part  22  is formed so as to be recessed on a back side and causes a second washing water that is spouted from the second water spout port  13  to swirl. 
     Water Storage Part 
     Next, the water storage part  14  will be explained with reference to  FIG. 3 ,  FIG. 6 , and  FIG. 7 .  FIG. 6  is a cross-sectional view of the water storage part  14  in a VI-VI cross section of  FIG. 3 .  FIG. 7  is a cross-sectional view of the water storage part  14  in a VII-VII cross section of  FIG. 3 . 
     The water storage part  14  is provided below the bowl part  10 . The water storage part  14  stores a part of a washing water as a stored water. The water storage part  14  is connected to a discharge channel  17  and discharges waste, together with a washing water, to the discharge channel  17 . The discharge channel  17  is connected to the water discharge pipe  5  (see  FIG. 1 ). The water storage part  14  is formed in such a manner that a height of a front end thereof is minimum. 
     The water storage part  14  includes a front surface part  30 , a back surface part  31 , a pair of side surface parts  32 , and a bottom surface part  33 . The front surface part  30  is formed so as to protrude frontward and be curved. Furthermore, the back surface part  31  is formed so as to protrude backward and be curved. Furthermore, the bottom surface part  33  is connected to the discharge channel  17 . 
     The pair of side surface parts  32  is formed so as to broaden from a front side to a back side in such a manner that a distance between back ends thereof is greater than a distance between front ends thereof. That is, the water storage part  14  is formed in such a manner that a back side is larger than a front side in a plan view. 
     For the pair of side surface parts  32 , a convex surface  32   a  is formed that protrudes toward an opposed side surface part  32 . The convex surface  32   a  is formed so as to be curved in such a manner that a side surface part  32  generally protrudes toward another side surface part  32 . Additionally, the convex surface  32   a  may be formed so as to be curved in such a manner that a part of a side surface part  32  protrudes toward another side surface part  32 . The convex surface  32   a  is formed along upward and downward directions. A lower end of the convex surface  32   a  is located above the bottom surface part  33 . That is, the convex surface  32   a  is not connected to the bottom surface part  33  and a gap is formed between the convex surface  32   a  and the bottom surface part  33 . Additionally, a lower end of the convex surface  32   a  may be formed to the bottom surface part  33 . 
     Additionally, the front surface part  30  and the pair of side surface parts  32  are connected by a curved surface. Furthermore, the back surface part  31  and the pair of side surface parts  32  are connected by a curved surface. 
     In the water storage part  14 , a first region  100  that is a region on a top of the discharge channel  17  and a second region  101  that is a region on a front side of the first region  100  are formed. Partition into the first region  100  and the second region  101  is provided by a vertex of the convex surface  32   a  in a plan view. The water storage part  14  on a back side of a vertex of the convex surface  32   a  is the first region  100  and the water storage part  14  on a front side of the vertex of the convex surface  32   a  is the second region  101 . The convex surface  32   a  is formed over the first region  100  and the second region  101 . 
     In the first region  100 , a lower region  100   a  that is provided on a side of the discharge channel  17  and an upper region  100   b  above the lower region  100   a  are formed. The water storage part  14  is formed in such a manner that a change of a flow rate of a swirling flow in the upper region  100   b  is greater than that in the lower region  100   a . Specifically, a curvature of a curved surface that forms the upper region  100   b  is greater than a curvature of a curved surface that forms the lower region  100   a.    
     For example, for a curved surface that connects the back surface part  31  and the side surface part  32 , a curvature of a curved surface that forms the upper region  100   b  is greater than a curvature of a curved surface that forms the lower region  100   a . Additionally, a curvature of the back surface part  31  that forms the upper region  100   b  may be greater than a curvature of the back surface part  31  that forms the lower region  100   a.    
     Additionally, a region that transits from the upper region  100   b  to the lower region  100   a  is formed in such a manner that a curvature of a curved surface is changed continuously. 
     Furthermore, the first region  100  is formed in such a manner that a swirling flow that has a swirl radius that is greater than that in the second region  101  is generated. Specifically, a cross-sectional area of the first region  100  in a horizontal direction is greater than a cross-sectional area of the second region  101  in a horizontal direction. 
     Furthermore, the first region  100  and the second region  101  are formed in such a manner that swirling flows with different flow rates are generated in the upper region  100   b  and the second region  101 . Specifically, a curvature of a curved surface that forms the upper region  100   b  is different from a curvature of a curved surface that forms the second region  101 . For example, a curvature of the back surface part  31  that forms the upper region  100   b  is different from a curvature of the front surface part  30  that forms the second region  101 . Furthermore, a curvature of a curved surface that connects the back surface part  31  that forms the upper region  100   b  and the side surface part  32  is different from a curvature of the front surface part  30  that forms the second region  101 . 
     Furthermore, the first region  100  and the second region  101  are formed in such a manner that a swirling flow with a flow rate that is less than that in the second region  101  is generated in the lower region  100   a . Specifically, a curvature of a curved surface that forms the lower region  100   a  is less than a curvature of a curved surface that forms the second region  101 . For example, a curvature of the back surface part  31  that forms the lower region  100   a  is less than a curvature of the front surface part  30  that forms the second region  101 . 
     First Guide Part and Second Guide Part 
     Next, the first guide part  20  and the second guide part  21  will be explained with reference to  FIG. 3 ,  FIG. 4 , and  FIG. 8 .  FIG. 8  is a diagram where surface shapes of the first guide part  20  and the second guide part  21  in cross sections as indicated by A to G in  FIG. 4  are overlapped. A to G in  FIG. 8  correspond to surface shapes of the first guide part  20  and the second guide part  21  in cross sections as indicated by A to G in  FIG. 4 . 
     The first guide part  20  is formed on a top of the water storage part  14 . The second guide part  21  is formed on a top of the first guide part  20 . The second guide part  21  is formed between the first guide part  20  and the rim part  11 . The first guide part  20  and the second guide part  21  are connected by a ridge line part  23  that is formed of a curved surface. Furthermore, the ridge line part  23  is a vertex of a curved surface that connects the first guide part  20  and the second guide part  21 . 
     The first guide part  20  is formed so as to broaden from a front side toward a back side of the bowl part  10 . Specifically, the first guide part  20  is formed in such a manner that an upper end of the first guide part  20  is located outward in leftward and rightward directions from a front side toward a back side of the bowl part  10 . That is, the ridge line part  23  is formed so as to broaden from a front side toward a back side of the bowl part  10 . In other words, a distance of the ridge line part  23  from a center line O of the bowl part  10  in leftward and rightward directions increases from a front side toward a back side. 
     Furthermore, for the first guide part  20 , a length from an upper end of the water storage part  14  to an upper end of the first guide part  20  increases toward a front side of the bowl part  10 . Specifically, for the first guide part, a length of a surface from an upper end of the water storage part  14  to an upper end of the first guide part  20  increases toward a front side of the bowl part  10 . 
     The first guide part  20  is asymmetric with respect to the center line O of the bowl part  10  in leftward and rightward directions. Hereinafter, an explanation may be provided in such a manner that the first guide part  20  on a left side with respect to the center line O is provided as a “first guide part  20   a ” and the first guide part  20  on a right side with respect to a center line of the bowl part  10  in leftward and rightward directions is provided as a “first guide part  20   b ”. That is, an explanation may be provided in such a manner that the first guide part  20  on a side of the first water spout port  12  is provided as a “first guide part  20   a ” and the first guide part  20  on a side of the second water spout port  13  is provided as a “first guide part  20   b”.    
     The first guide part  20   a  is formed from a back side of the first water spout port  12  to a front end of the bowl part  10 . The first guide part  20  is formed so as to cause a first washing water and a second washing water that flow downward from the region extension part  21   b  to flow into the first region  100 . 
     The first guide part  20   a  is formed in such a manner that a slope thereof increases from a back side toward a front side. Specifically, the first guide part  20   a  is formed in such a manner that a slope thereof increases from a back side toward a front side in frontward and backward directions, from a vicinity of the first water spout port  12  to a vicinity of the second region  101  of the water storage part  14 , as indicated by A to C in  FIG. 4  and  FIG. 8 . Additionally, the first guide part  20   a  may be formed in such a manner that a slope thereof increases from a back side toward a front side, from a vicinity of the first water spout port  12  to a vicinity of a front end of the second region  101 . A slope is an angle with respect to the floor surface  9  (see  FIG. 1 ). Hence, a slope increases as perpendicularity of the first guide part  20  is increased. 
     Furthermore, the first guide part  20   a  is formed in such a manner that a slope thereof deceases from a vicinity of a front end of the water storage part  14  toward a front side. 
     The first guide part  20   b  is formed from a lower side of the protrusion part  11   c  to a front end of the bowl part  10 . The first guide part  20   b  is formed in such a manner that a first washing water that flows into the first guide part  20  on a front side of the water storage part  14  (that includes the first guide part  20   a  and the first guide part  20   b ) swirls to the first region  100  and flows into the first region  100 . 
     Furthermore, the first guide part  20  is provided so as to suppress flowing of a first washing water that flows into the first guide part  20  on a front side of the water storage part  14  into the second guide part  21  above the first guide part  20   b  by the ridge line part  23 . 
     Furthermore, the first guide part  20   b  is formed in such a manner that a slope thereof increases from a front side to a back side as indicated by A to G in  FIG. 4  and  FIG. 8 . That is, a slope of the first guide part  20   b  on a front side is small. 
     Furthermore, the first guide part  20  on a front side of the water storage part  14  is formed in such a manner that a curvature of a curved surface that forms the first guide part  20 , specifically, a curved surface that forms a bottom part of the first guide part  20 , increases from a front side toward a back side, as indicated by F to G in  FIG. 4  and  FIG. 8 . 
     A slope of the second guide part  21  is less than that of the first guide part  20 . The second guide part  21  suppresses flowing of a first washing water that deviates from the passing water channel  15 , on the passing water channel  15  on a front side of the region extension part  21   b.    
     The ridge line part  23  on a right side terminates on a back side of a middle point of the water storage part  14  in frontward and backward directions. Furthermore, the ridge line part  23  on a left side has a beginning on a back side of the first water spout port  12 . A curvature of the ridge line part  23  increases from a front side toward a back side. 
     Flow of Washing Water 
     Next, a flow of a washing water in the bowl part  10  will be explained with reference to  FIG. 9 .  FIG. 9  is a diagram that explains flows of a first washing water and a second washing water in the bowl part  10 . In  FIG. 9 , a flow of a first washing water is indicated by a solid line(s) and a flow of a second washing water is indicated by a broken line(s). Additionally, a washing water as illustrated in  FIG. 9  is different from a washing water that simply flows down in the bowl part  10 , and has a certain level of a force of water. 
     A main stream of a first washing water that is spouted from the first water spout port  12  swirls on the passing water channel  15 . Specifically, a main stream of a first washing water passes through the passing water channel  15  from the first water spout port  12  and flows towards a front side, and a direction thereof is changed to a back side at a front end of the passing water channel  15  or on a front side of the water storage part  14 . A direction of a main stream of a first washing water that flows toward a back side is changed by the protrusion part  11   c  and it flows into the first region  100  of the water storage part  14 . Specifically, a main stream of a first washing water flows from a back side and a left side into the first region  100 . 
     The passing water channel  15  is formed in such a manner that a height of the bottom surface wall  21   a  increases from the first water spout port  12  toward a front end of the bowl part  10 . Hence, a kinetic energy that is possessed by a main stream of a first washing water is decreased, so that a swirl force of the main stream of a first washing water is adjusted and excessive swirling of the main stream of a first washing water is suppressed. Thereby, landing of a first washing water onto the rim part  11  or overflowing thereof is suppressed. 
     Furthermore, a part of a first washing water branches from the region extension part  21   b  and flows into the first guide part  20   a  immediately after being spouted from the first water spout port  12 , and flows into the second region  101  along the first guide part  20   a . A slope of the first guide part  20   a  increases toward a front side. Hence, a branched first washing water does not flow into the first guide part  20  on a front side of the water storage part  14  but flows into the second region  101  from a left side. 
     Furthermore, the passing water channel  15  is formed so as to be an upward slope, so that a part of a first washing water deviates from a main stream of a first washing water to the second guide part  21  in a middle of flowing through the passing water channel  15  on a front side of the region extension part  21   b . Such a first washing water that deviates to the second guide part  21  flows into the first guide part  20  on a front side of the water storage part  14 . 
     The first guide part  20  on a front side of the water storage part  14  is formed in such a manner that a curvature of a curved surface that forms the first guide part  20  increases from a front side toward a back side. Hence, in a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , a direction of a flow of a first washing water that flows into a side of the water storage part  14  is rapidly changed by the first guide part  20  with a large curvature, so that it swirls backward along the first guide part  20   b . Therefore, in a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , flowing of a first washing water that flows into a side of the water storage part  14  into the second region  101  is suppressed, so that it swirls along the first guide part  20  and flows into the first region  100  from a right side. 
     Furthermore, in a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , a first washing water that flows into a front side greatly swirls along the first guide part  20 . In a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , a first washing water that flows into a front side swirls along the first guide part  20  with a large length, so that a kinetic energy thereof is reduced and flowing into the second guide part  21  and the passing water channel  15  is suppressed. Moreover, landing of a washing water that swirls along the first guide part  20  onto the second guide part  21  is suppressed by the ridge line part  23 . That is, recombining of a first washing water that once deviates from a main stream of a first washing water with the main stream of a first washing water is suppressed. 
     A direction of a flow of a first washing water that deviates from a main stream of a first washing water may greatly be different from that of the main stream of a first washing water, so that, as such a first washing water is combined with the main stream of a first washing water, a force of the main stream of a first washing water may be reduced and an insufficient swirl of the main stream of a first washing water may be caused. It is possible for the first guide part  20  to suppress occurrence of an insufficient swirl of a main stream of a first washing water. 
     Furthermore, in a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , when a first washing water that flows into a front side swirls and flows down, a kinetic energy thereof increases. In a first washing water that flows into the first guide part  20  on a front side of the water storage part  14 , flowing of a first washing water that flows into a front side into the second region  101  is suppressed, so that it swirls along the first guide part  20   b  and flows into the first region  100  from a right side. 
     A second washing water swirls along the back wall part  22 , subsequently flows along the first guide part  20   a  and flows into the second region  101 . Furthermore, a second washing water branches immediately after being spouted from the second water spout port  13  or in a middle of swirling along the back wall part  22 , and also flows into the first region  100 . 
     As described above, a main stream of a first washing water and a first washing water that deviates from the main stream of a first washing water flow into the first region  100  and a part of a first washing water flows into the second region  101 . Furthermore, a second washing water flows into the first region  100  and the second region  101 . 
     A washing water that flows into the first region  100  and the second region  101  forms a first swirling flow in the first region  100  and forms a second swirling flow that is different from the first swirling flow in the second region  101 . 
     Next, a first swirling flow and a second swirling flow will be explained with reference to  FIG. 6  and  FIG. 7 . 
     For the pair of side surface parts  32  of the water storage part  14 , respective convex parts  32   a  are formed as illustrated in  FIG. 6 . Hence, although a washing water that flows into the water storage part  14  while swirling in the bowl part  10  forms a flow along a wall surface(s) (the front surface part  30 , the back surface part  31 , and the side surface parts  32 ) that compose(s) the water storage part  14  in a plan view, a flow that is separated from the wall surface(s) is provided by a convex surface  32   a , so that a first swirling flow is formed in the first region  100  on a back side of a vertex of the convex surface  32   a  and a second swirling flow is formed in the second region  101  on a front side of the vertex of the convex surface  32   a.    
     Additionally, the convex surface  32   a  is formed along upward and downward directions, so that a first swirling flow is formed in a whole of the first region  100  and a second swirling flow is formed in a whole of the second region  101 . 
     In the first region  100 , waste is agitated by a first swirling flow. Furthermore, in the second region  101 , waste is agitated by a second swirling flow. Thereby, different swirling components that are a first swirling flow and a second swirling flow in a direction of a plan view are generated in the water storage part  14 , so that it is possible to improve an agitation performance for waste in a whole of the water storage part  14 . 
     Furthermore, when waste is discharged from the water storage part  14  to the discharge channel  17 , waste is pushed into the discharge channel  17  by a first swirling flow and is discharged from the discharge channel  17 . Furthermore, when waste is discharged from the water storage part  14  to the discharge channel  17 , a second swirling flow flows into the first region  100 , waste is pushed into the discharge channel  17  by the second swirling flow and is discharged from the discharge channel  17 . 
     Furthermore, a cross-sectional area of the first region  100  in a horizontal direction is greater than a cross-sectional area of the second region  101  in a horizontal direction. 
     Thereby, a first swirling flow with a large swirl radius is formed in the first region  100  and a second swirling flow with a swirl radius that is less than that of the first swirling flow is formed in the second region  101 . Hence, waste is readily agitated by a small swirling flow in the second region  101 , and further, a large swirling flow smoothly flows through the discharge channel  17  in the first region  100 , so that waste is readily discharged. 
     Furthermore, a curvature of a curved surface that forms the first region  100  and a curvature of a curved surface that forms the second region  101  are different. Specifically, a curvature of a curved surface that forms the upper region  100   b  of the first region  100  and a curvature of a curved surface that forms the second region  101  are different. 
     Thereby, swirling flows with different flow rates are formed in the upper region  100   b  and the second region  101 . 
     Furthermore, in the first region  100 , a curvature of a curved surface that forms the upper region  100   b  and a curvature of a curved surface that forms the lower region  100   a  are different. Specifically, a curvature of a curved surface that forms the upper region  100   b  is greater than a curvature of a curved surface that forms the lower region  100   a.    
     Thereby, in the upper region  100   b , a curvature of a curved surface that forms the upper region  100   b  is large, so that a change of a flow rate of a first swirling flow is large and waste is agitated. Furthermore, in the lower region  100   a , a curvature of a curved surface that forms the lower region  100   a  is small, so that a change of a flow rate of a first swirling flow is small, a flow of the first swirling flow is smooth, and waste is readily discharged to the discharge channel  17 . That is, in the first region  100 , the upper region  100   b  where a first swirling flow that mainly agitates waste is formed and the lower region  100   a  where a first swirling flow that mainly discharges waste is formed are formed. 
     Effect 
     Next, an effect of the flush toilet  1  according to an embodiment will be explained. 
     The flush toilet  1  includes the bowl part  10 , the rim part  11 , the first water spout port  12 , and the water storage part  14 . The bowl part  10  receives waste. The rim part  11  is formed on a top of the bowl part  10 . The first water spout port  12  spouts a first washing water. The water storage part  14  is formed on a bottom of the bowl part  10 . In the water storage part  14 , the first region  100  that is connected to the discharge channel  17  and the second region  101  that is located on a front side of the first region  100  are formed. A main stream of a first washing water that is spouted from the first water spout part  12  along the rim part  11  swirls in the bowl part  10  and flows into the first region  100 . 
     Thereby, the flush toilet  1  causes a main stream of a first washing water that has a strong swirl force to flow into the first region  100 , pushes waste into the discharge channel  17  while agitating it in the first region  100 , and discharges the waste. Hence, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the flush toilet  1  includes the first water spout port  12  and the second water spout port  13 . The first water spout port  12  spouts a first washing water along the rim part  11 . The second water spout port  13  is provided at a place that is different from that of the first water spout port  12  and spouts a second washing water. A main stream of a first washing water flows into the first region  100 . A second washing water flows into the second region  101 . 
     Thereby, the flush toilet  1  agitates waste by a main stream of a first washing water in the first region  100  and agitates waste by a second washing water in the second region  101 . Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. Furthermore, it is possible for the flush toilet  1  to push waste into the discharge channel  17  and discharge the waste from the discharge channel  17  by a washing water that flows from the second region  101  into the first region  100 , when waste is discharged. Hence, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the flush toilet  1  forms a first swirling flow in the first region  100  and forms a second swirling flow that is different from the first swirling flow in the second region  101 . 
     Thereby, the flush toilet  1  forms respective swirling flows in the respective regions  100 ,  101  and agitates waste by the respective swirling flows. Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste, as compared with, for example, a case where waste is agitated by one strong swirling flow in the water storage part  14 . Furthermore, it is possible for the flush toilet  1  to agitate waste by a first swirling flow and a second swirling flow near a boundary between the first region  100  and the second region  101 . Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, in the flush toilet  1 , a part of a first washing water branches from a main stream of a first washing water, is combined with a second washing water, and flows into the second region  101 . 
     Thereby, the flush toilet  1  combines a first washing water and a second washing water and forms a second swirling flow in the second region  101  by a washing water that has a strong force. Hence, it is possible for the flush toilet  1  to increase a force of a second swirling flow in the second region  101 , and it is possible to improve an agitation performance for waste in the second region  101  and improve a discharging performance for waste. Furthermore, the flush toilet  1  causes a second swirling flow that has a strong force to flow from the second region  101  into the first region  100  when waste is discharged, so that it is possible to push waste into the discharge channel  17 . Hence, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, a height of the bottom surface wall  21   a  that forms the passing water channel  15  where a first washing water flows along the rim part  11  increases from an end part on a side of the first water spout port  12  toward a front end of the bowl part  10 . 
     Thereby, the flush toilet  1  reduces a kinetic energy that is possessed by a main stream of a first washing water and suppresses a force of the main stream of a first washing water. That is, the flush toilet  1  adjusts a swirl force of a main stream of a first washing water, so that it is possible to suppress excessive swirling of the main stream of a first washing water. Hence, it is possible for the flush toilet  1  to cause a main stream of a first washing water with an adjusted force to flow into the first region  100  and it is possible to form a first swirling flow with an excellent agitation performance for waste in the first region  100 . Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, a height of the bottom surface wall  21   a  continuously increases to a front end of the bowl part  10 . 
     Thereby, it is possible for the flush toilet  1  to reduce a kinetic energy that is possessed by a main stream of a first washing water continuously and it is possible to suppress disturbing of the main stream of a first washing water. 
     Furthermore, the bowl part  10  includes the first guide part  20   a  where a part of a first washing water branches from the passing water channel  15  and flows thereon. 
     Thereby, the flush toilet  1  reduces a kinetic energy that is possessed by a main stream of a first washing water, so that it is possible to adjust a swirl force of the main stream of a first washing water. Hence, the flush toilet  1  suppresses excessive swirling of a main stream of a first washing water, so that it is possible to form a first swirling flow with an excellent agitation performance for waste in the first region  100 . Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     A slope of the first guide part  20   a  increases from a back side toward a front side. 
     Thereby, it is possible for the flush toilet  1  to suppress combining of a first washing water that branches from a main stream of a first washing water with the main stream of a first washing water. Furthermore, it is possible for the flush toilet  1  to cause a first washing water that branches from a main stream of a first washing water to flow into the second region  101 . 
     Furthermore, a length from an upper end of the water storage part  14  to an upper end of the first guide part  20   a  increases toward a front side of the bowl part  10 . 
     Thereby, the flush toilet  1  disperses a first washing water that deviates from a main stream of a first washing water in the first guide part  20  on a front side of the water storage part  14 , so that it is possible to reduce a kinetic energy that is possessed by a first washing water that flows through the first guide part  20 . Hence, it is possible for the flush toilet  1  to suppress combining of a first washing water that flows through the first guide part  20  on a front side of the water storage part  14  with a main stream of a first washing water, and it is possible to form a first swirling flow with an excellent agitation performance for waste in the first region  100 . Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, a height of an upper end of the water storage part  14  is minimum at a front end thereof. 
     Thereby, it is possible for the flush toilet  1  to increase a length of the first guide part  20  at a center in leftward and rightward directions in the first guide part  20  on a front side of the water storage part  14 , and it is possible to reduce a kinetic energy that is possessed by a first washing water that flows through the first guide part  20 . Hence, it is possible for the flush toilet  1  to suppress combining of a first washing water that flows through the first guide part  20  on a front side of the water storage part  14  with a main stream of a first washing water, and it is possible to form a first swirling flow with an excellent agitation performance for waste in the first region  100 . Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the flush toilet  1  includes the region extension part  21   b  that extends a water spout region for a first washing water that is spouted from the first water spout port  12 . 
     Thereby, the flush toilet  1  suppresses decreasing of a water spout region of the passing water channel  15  for a first washing water, even in a case where the bottom surface wall  21   a  that forms the passing water channel  15  is formed so as to heighten from a side of the first water spout port  12  toward a front end of the rim part  11 . Hence, the flush toilet  1  suppresses retaining of a first washing water on the passing water channel  15 , so that it is possible to spout a first washing water smoothly. 
     Therefore, it is possible for the flush toilet  1  to suppress insufficient swirling of a main stream of a first washing water and it is possible to improve a discharging performance for waste. 
     Furthermore, the region extension part  21   b  is formed below the first water spout port  12 . 
     Thereby, the flush toilet  1  suppresses occurrence of unexpected retention on the passing water channel  15  where a first washing water flows, so that it is possible to suppress insufficient swirling of a main stream of a first washing water. Hence, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the region extension part  21   b  is formed on an end part of the bottom surface wall  21   a  on a side of the first water spout port  12 . 
     Thereby, it is possible for the flush toilet  1  to suppress retaining of a first washing water immediately after being spouted from the first water spout port  12 . 
     The region extension part  21   b  is sloped in such a manner that a side of the bowl part  10  is lower than a side of the rim part  11 . 
     Thereby, it is possible for the flush toilet  1  to cause a part of a first washing water that flows into the region extension part  21   b  to flow down to the first guide part  20  quickly and it is possible to suppress retaining of a first washing water on the region extension part  21   b . Hence, it is possible for the flush toilet  1  to suppress insufficient swirling of a main stream of a first washing water. Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the bowl part  10  includes the first guide part  20   b  that causes a first washing water to swirl from a left side to a right side and causes a first washing water that swirls to a right side to flow into the first region  100 . 
     Thereby, it is possible for the flush toilet  1  to cause a first washing water that deviates from a main stream of a first washing water to flow into the first region  100  and it is possible to increase a force of a first swirling flow in the first region  100 . Hence, it is possible for the flush toilet  1  to improve a discharging performance for waste. 
     Furthermore, the first guide part  20  is formed so as to broaden from a front side toward a back side. 
     Thereby, it is possible for the flush toilet  1  to cause a first washing water that deviates from a main stream of a first washing water and flows into a vicinity of a center of the first guide part  20  in leftward and rightward directions to flow into the first region while swirling along the first guide part  20 . Hence, it is possible for the flush toilet  1  to increase a force of a first swirling flow in the first region  100  and it is possible to improve a discharging performance for waste. 
     Furthermore, the bowl part  10  includes the second guide part  21  that is formed above the first guide part  23 . A first washing water that flows through the second guide part  21  is a flow that is different from a first washing water that flows through the first guide part  20 . A distance of the ridge line part  23  that connects the first guide part  20  and the second guide part  21  from the center line O of the bowl part  10  in leftward and rightward directions increases from a front side toward a back side. 
     Thereby, it is possible for the flush toilet  1  to suppress flowing of a first washing water that flows through the first guide part  20  into the second guide part  21 . That is, it is possible for the flush toilet  1  to suppress combining of a washing water that deviates from a main stream of a first washing water with the main stream of a first washing water. Hence, the flush toilet  1  suppresses disturbing of a main stream of a first washing water, so that it is possible to suppress reducing of a flow rate of the main stream of a first washing water. Therefore, it is possible for the flush toilet  1  to improve a discharging performance for waste by a first swirl force. 
     The ridge line part  23  on a right side terminates on a back side of a middle point of the water storage part  14  in frontward and backward directions. 
     Thereby, it is possible for the flush toilet  1  to cause a first washing water that swirls to a back side to flow into the first region  100 . Furthermore, it is possible for the flush toilet  1  to generate, in the first region  100 , a first swirling flow along a shape of the back surface part  31  of the water storage part  14  that forms the first region  100 . Hence, it is possible for the flush toilet  1  to agitate waste by a first swirling flow with a strong force, and it is possible to improve an agitation performance for waste in the first region  100  and improve a discharging performance for waste. 
     Furthermore, the first guide part  20  on a front side of the water storage part  14  is provided in such a manner that a curvature of a curved surface that forms the first guide part  20  increases from a front side toward a back side. 
     Thereby, the flush toilet  1  rapidly changes a direction of a first washing water that flows into a place that is close to the water storage part  14 , in the first guide part  20  on a front side of the water storage part  14 , so that it is possible to suppress flowing of a first washing water into the second region  101 . Then, it is possible for the flush toilet  1  to cause a first washing water to swirl to a right side and flow into the first region  100 . Furthermore, the flush toilet  1  suppresses rapid changing of a direction of a first washing water that flows into a front side of the bowl part  10 , in the first guide part  20  on a front side of the water storage part  14 . Hence, the flush toilet  1  suppresses flowing of a first washing water into the second region  101 , so that it is possible to cause a first washing water to swirl to a right side and flow into the first region  100 . 
     Furthermore, the water storage part  14  includes the front surface part  30 , the back surface part  31 , and the pair of side surface parts  32 . The back surface part  31  is formed on a back side of the front surface part  30 . The pair of side surface parts  32  is formed between the front surface part  30  and the back surface part  31 . In the pair of side surface parts  32 , on at least one side surface part  32 , the convex surface  32   a  that protrudes toward another side surface part  32  is formed. 
     A washing water that flows into the water storage part  14  flows along the side surface part  32 , so that swirling is separated by the convex surface  32   a  of the side surface part  32 . Thereby, the flush toilet  1  forms a first swirling flow and a second swirling flow in the water storage part  14 . Hence, it is possible for the flush toilet  1  to agitate waste by each swirling flow, and it is possible to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, in the water storage part  14 , the first region  100  that is connected to the discharge channel  17  and the second region  101  that is located on a front side of the first region  100  are formed, and the convex surface  32   a  is formed over the first region  100  to the second region  101 . 
     Thereby, it is possible for the flush toilet  1  to generate a first swirling flow and a second swirling flow in the water storage part  14  without complicating a shape of the water storage part  14 . 
     Furthermore, a vertex of the convex surface  32   a  is located at a boundary between the first region  100  and the second region  101 . 
     Thereby, it is possible for the flush toilet  1  to execute partition into the first region  100  that is connected to the discharge channel  17  and the second region  101  by the convex surface  32   a  and it is possible to form a first swirling flow and a second swirling flow independently. Hence, it is possible for the flush toilet  1  to agitate waste by each swirling flow, and it is possible to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, the convex surface  32   a  is formed along upward and downward directions. 
     Thereby, it is possible for the flush toilet  1  to form a first swirling flow in a whole of the first region  100  and form a second swirling flow in a whole of the second region  101 . Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste in the respective regions  100 ,  101  and improve a discharging performance for waste. 
     Furthermore, a surface area of the first region  100  in a horizontal direction is greater than a surface area of the second region  101  in a horizontal direction. 
     Thereby, the flush toilet  1  agitates waste by a second swirling flow that has a small swirl radius in the second region  101 . Furthermore, the flush toilet  1  generates a first swirling flow that has a large swirl radius in the first region  100  that is connected to the discharge channel  17 , and discharges waste from the first region  100  by the first swirling flow. Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, the convex surface  32   a  is respectively formed on the pair of side surface parts  32 . 
     Thereby, it is possible for the flush toilet  1  to accelerate formation of a first swirling flow in the first region  100  and accelerate formation of a second swirling flow in the second region  101 . Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, a curved surface of the water storage part  14  that forms the first region  100  is provided in such a manner that a curvature of the curved surface is different in upward and downward directions. 
     Thereby, it is possible for the flush toilet  1  to form a first swirling flow that mainly agitates waste and a first swirling flow that mainly pushes waste into the discharge channel  17  and discharges the waste, in upward and downward directions of the first region  100 . Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, in the first region  100 , the upper region  100   b  and the lower region  100   a  that is formed below the upper region  100   b  are formed. A curvature of a curved surface that forms the upper region  100   b  is greater than a curvature of a curved surface that forms the lower region  100   a.    
     Thereby, the flush toilet  1  forms a first swirling flow with a large change of a flow rate in the upper region  100   b , so that it is possible to agitate waste. Furthermore, the flush toilet  1  forms a first swirling flow with a small change of a flow rate in the lower region  100   a , so that it is possible to push waste into the discharge channel  17  and discharge the waste. 
     Furthermore, a curvature of a curved surface that forms the first region  100  gradually changes from the upper region  100   b  toward the lower region  100   a.    
     Thereby, it is possible for the flush toilet  1  to reduce an energy loss at a time when a change is executed from a first swirling flow with a large change of a flow rate to a first swirling flow with a small change of a flow rate, and it is possible to improve a discharging performance for waste. 
     Furthermore, a curvature of a curved surface that forms the upper region  100   b  is different from a curvature of a curved surface that forms the second region  101 . 
     Thereby, it is possible for the flush toilet  1  to cause a first swirling flow in the upper region  100   b  and a second swirling flow in the second region  101  to swirl at different flow rates. Hence, it is possible for the flush toilet  1  to improve an agitation performance for waste and improve a discharging performance for waste. 
     Furthermore, a curvature of a curved surface that forms the lower region  100   a  is less than a curvature of a curved surface that forms the second region  101 . 
     Thereby, it is possible for the flush toilet  1  to guide a second swirling flow from the second region  101  to the lower region  100   a  smoothly and it is possible to improve a discharging performance for waste. 
     Variation Example(s) 
     A flush toilet  1  according to a variation example may connect the discharge channel  17  to a region on a front side of the water storage part  14 . Furthermore, a flush toilet  1  according to a variation example may form the convex surface  32   a  on one side surface part  32  in the pair of side surface parts  32 . 
     Furthermore, a flush toilet  1  according to a variation example may form the first water spout port  12  into a taper shape in such a manner that a first washing water is broadened, and extend a water spout region for a first washing water from the first water spout pore  12 . For example, the first water spout port  12  is formed so as to extend a water spout region for a first washing water on a upper side or a right side. 
     Furthermore, a flush toilet  1  according to a variation example may be a flush toilet that includes a part of a configuration as described above. For example, a flush toilet  1  according to a variation example may be a flush toilet that has the water storage part  14  where the convex surface  32   a  is not formed on the pair of side surface parts  32  or may be a flush toilet that has the bowl part  10  where the first guide part  20  is not formed. Furthermore, for example, a flush toilet  1  according to a variation example may be a flush toilet that has only the first water spout port  12 . 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.