Water-washable toilet

Abstract

To provide a flush toilet that can thoroughly clean the bowl area while ensuring sufficient rim water discharge time by discharging flushing water from a single rim outlet. [Solution] The present invention relates to a flush toilet (1) that performs flushing with flushing water stored in a flushing water tank, comprising: a flushing water tank (2) that stores flushing water; a bowl portion (4) provided with a single rim outlet (4a) from which the flushing water stored in the flushing water tank is discharged; a drain trap pipe (6) connected to the lower part of the bowl portion; and a rim water channel (8) that guides flushing water from the flushing water tank to the rim outlet. The inner wall surface that forms the rim water channel, located on the outer side in the width direction of the flush toilet, is a straight inner wall surface (16a) formed in a substantially straight line when viewed from above, extending upstream from the rim outlet, and this straight inner wall surface is characterized in that, when viewed from above, it extends to the rear side of the rear end (Wr) of the water surface (W) in the bowl portion.

Description

TECHNICAL FIELD

[0001] The present invention relates to a flush toilet, and more particularly to a flush toilet that performs flushing using flushing water stored in a flushing water tank. BACKGROUND ART

[0002] WO 2005 / 085538 A (Patent Document 1) describes a flush toilet. This flush toilet performs flushing using flushing water stored in a flushing water tank, and the flushing water in the flushing water tank is discharged from one jet hole and two rim water discharge ports to flush the bowl portion. That is, in this flush toilet, the flushing water tank is provided with a jet drain valve and a rim drain valve.

[0003] Further, the flushing water discharged through the jet drain valve passes through the jet water conduit and is discharged from the jet hole. On the other hand, the flushing water discharged through the rim drain valve flows into the rim water conduit, which branches into two on the way, and the flushing water is discharged from the two rim water discharge ports respectively. The flushing water discharged from each rim water discharge port flows down while swirling on the surface of the bowl portion, and the bowl surface is flushed. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] PATENT DOCUMENT 1 International Publication No. 2005 / 085538 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] However, in the flush toilet described in Patent Document 1, flushing water is discharged from two rim outlets, resulting in a large total amount of flushing water discharged from the rim outlets. This makes it difficult to sustain rim flushing for an extended period with the limited amount of flushing water in the flushing water tank. In contrast, if a single rim outlet is provided, the total amount of flushing water discharged from the rim outlet per unit time can be reduced, making it possible to sustain rim flushing for an extended period. However, with a single rim outlet, the entire circumference of the bowl must be cleaned with the flushing water discharged from that single outlet, and there is a risk that areas that are difficult to reach with the flushing water discharged from the rim outlet may remain uncleaned.

[0006] Therefore, the present invention aims to provide a flush toilet that can thoroughly clean the bowl area while ensuring sufficient rim water discharge time by discharging flushing water from a single rim outlet. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the present invention provides a flush toilet that performs flushing with flushing water stored in a flushing water tank, comprising: a flushing water tank that stores flushing water; a bowl section provided with a single rim outlet from which the flushing water stored in the flushing water tank is discharged; a drain trap pipe connected to the lower part of the bowl section; and a rim water channel that guides flushing water from the flushing water tank to the rim outlet. The inner wall surface that forms the rim water channel, located on the outer side in the width direction of the flush toilet, is a straight inner wall surface formed in a substantially straight line when viewed from above, extending upstream from the rim outlet, and this straight inner wall surface extends to the rear side of the rear end of the water surface in the bowl section when viewed from above.

[0008] With the present invention configured in this way, a single rim outlet is provided in the bowl section, making it possible to reduce the amount of cleaning water discharged from the rim outlet, and as a result, it is possible to sustain rim water discharge for a long period of time. Furthermore, the rim water channel is equipped with a straight inner wall surface formed in a substantially straight shape, and this straight inner wall surface extends to the rear side beyond the rear end of the water surface accumulated in the bowl section. Therefore, the energy loss of the cleaning water that is discharged from the cleaning water tank by the hydrostatic pressure of the stored cleaning water and flows through the rim water channel can be minimized, and cleaning water can be discharged from the rim outlet at a high flow velocity. As a result, the surface of the bowl section can be sufficiently cleaned with cleaning water discharged from a single rim outlet.

[0009] In the present invention, preferably, the rim water channel is provided with a curved water channel on the upstream side of the straight inner wall surface, and this curved water channel is curved in a convex shape toward the outward side in the width direction of the flush toilet when viewed from above.

[0010] According to the present invention configured in this way, the rim water channel is equipped with a curved water channel on the upstream side of the straight inner wall surface, and this curved water channel is curved convexly toward the outside in the width direction of the flush toilet, so that a flow velocity distribution can be provided to the flushing water discharged from the rim outlet. That is, when the flushing water flows through the curved water channel of the rim water channel, the flow velocity in the outer peripheral portion of the rim water channel is increased due to the convexly curved flow path toward the outside in the width direction of the flush toilet.

[0011] As a result, the flow velocity of the cleaning water is relatively high on the outer circumference of the rim outlet, and relatively low on the inner circumference. This allows the cleaning water discharged from the outer circumference of the rim outlet to swirl around inside the bowl, cleaning the parts of the bowl that are far from the rim outlet. On the other hand, the cleaning water discharged from the inner circumference of the rim outlet has a low flow velocity, so it flows downwards inside the bowl in the parts relatively close to the rim outlet. As a result, the water discharged from the rim outlet can thoroughly clean both the parts of the bowl that are close to the rim outlet and the parts that are far from the rim outlet.

[0012] In the present invention, preferably, the rim water channel is configured such that the cross-sectional area of ​​the flow path decreases toward the rim discharge port in the portion having a straight inner wall surface.

[0013] According to the present invention configured in this way, the rim water channel is configured such that the cross-sectional area of ​​the flow path decreases toward the rim outlet in the portion having a straight inner wall surface. Therefore, it is possible to increase the flow velocity of the cleaning water flowing through the rim water channel while suppressing energy loss of the cleaning water.

[0014] In the present invention, preferably, the rim water channel has an opposing inner wall surface facing the straight inner wall surface, which is formed in a top view along the shape of the bowl portion.

[0015] According to the present invention configured in this way, since the opposing inner wall surface facing the straight inner wall surface is formed along the shape of the bowl portion, a water conduit can be easily constructed in which the cross-sectional area of ​​the flow path is reduced in the portion of the straight inner wall surface.

[0016] In the present invention, preferably, a rim water inlet is provided at the upstream end of the rim water channel to allow flushing water to flow from the flushing water tank into the rim water channel, and this rim water inlet is located at an eccentric position with respect to the center in the width direction of the flush toilet bowl when viewed from above.

[0017] According to the present invention configured in this way, since the rim water inlet is located at an eccentric position with respect to the center in the width direction of the flush toilet, the rim water channel connecting the rim water inlet and the rim water outlet can be made shorter, and energy loss due to flow resistance of the water channel can be suppressed. [Effects of the Invention]

[0018] According to the flush toilet of the present invention, flushing water can be discharged from a single rim outlet, ensuring sufficient rim water discharge time while thoroughly cleaning the bowl. [Brief explanation of the drawing]

[0019] [Figure 1]It is a side cross-sectional view of a flush toilet according to an embodiment of the present invention. [Figure 2] It is a top view of the flush toilet according to the embodiment of the present invention. [Figure 3] It is a top view extracted and showing the form of the inner surface of a rim water conduit formed inside the flush toilet according to the embodiment of the present invention. [Figure 4] It is a side view extracted and showing the form of the inner surface of the rim water conduit formed inside the flush toilet according to the embodiment of the present invention. [Figure 5] In the flush toilet according to the embodiment of the present invention, it is a diagram showing an example of a simulation result of the flow velocity of flushing water flowing in the rim water conduit in a top view. [Modes for Carrying Out the Invention]

[0020] Next, the flush toilet according to the embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 is a side cross-sectional view of the flush toilet according to the embodiment of the present invention. Figure 2 is a top view of the flush toilet according to the embodiment of the present invention.

[0021] As shown in Figure 1 and Figure 2, the flush toilet 1 according to the embodiment of the present invention includes a flushing water tank 1 storing flushing water, a bowl portion 4, and a drain trap pipeline 6 extending from a lower portion of the bowl portion 4. Note that the downstream end of the drain trap pipeline 6 is connected via a drain socket to a drain pipe (none of which are shown in the drawings) provided on the floor surface of the toilet room.

[0022] Furthermore, a single rim outlet 4a is provided on the upper edge of the bowl portion 4, and a jet outlet 4b is provided on the lower part of the bowl portion 4. In this embodiment, only one rim outlet 4a is provided on the upper end, right side of the bowl portion 4, and it opens forward. In this embodiment, the jet outlet 4b opens at the bottom of the bowl portion 4, facing the inlet of the drain trap pipe 6. In addition, a shelf surface 4c is provided around the entire circumference of the upper edge of the bowl portion 4, and this shelf surface 4c has a gentler slope (closer to horizontal) than the inner surface of the bowl portion 4 on the shelf surface 4c.

[0023] During toilet flushing, flushing water stored in the flushing water tank 2 is discharged from the rim outlet 4a and the jet outlet 4b, flushing the bowl section 4. Specifically, the flushing water discharged from the rim outlet 4a flows onto the shelf surface 4c and swirls clockwise within the bowl section 4. The flushing water on the shelf surface 4c flows inward along the surface of the bowl section 4 while swirling, forming a swirling flow within the bowl section 4. The flushing water discharged from the jet outlet 4b flows into the drain trap pipe 6, which is located opposite it. As flushing water flows in from the rim outlet 4a and the jet outlet 4b, the flushing water in the bowl section 4 overflows the top 6a of the drain trap pipe 6 and flows out from the downstream end 6b of the drain trap pipe 6.

[0024] The flushing water flowing out from the downstream end 6b of the drain trap pipe 6 flows into the drain socket (not shown), where a siphon effect is induced. Due to the siphon effect, the flushing water and waste in the bowl 4 are drawn into the drain trap pipe 6, and the flushing water and waste in the bowl 4 flow out into the drain socket. The flushing water and waste that flow into the drain socket are discharged through the pipe inside the drain socket to the drain piping (not shown) on the floor of the toilet room. When the toilet is waiting to be flushed, water is stored in the bowl 4, and the water level W of this stored water is determined by the height of the top 6a of the drain trap pipe 6.

[0025] Furthermore, as shown in Figure 2, a rim drain valve 2a and a jet drain valve 2b are located inside the cleaning water tank 2, respectively. By opening these drain valves, cleaning water is discharged from the rim outlet 4a and the jet outlet 4b of the bowl section 4, respectively.

[0026] Specifically, a rim drain (not shown) is provided on the bottom of the flushing water tank 2, and this rim drain is connected to the rim outlet 4a via a rim water channel 8 formed inside the flush toilet 1. By opening the rim drain valve 2a, the flushing water in the flushing water tank 2 is discharged through the rim drain (not shown) and discharged from the rim outlet 4a. In this embodiment, the rim drain (not shown) and the rim drain valve 2a on the bottom of the flushing water tank 2 are positioned eccentrically to the right of the center in the width direction of the flush toilet 1 when viewed from above. The specific configuration of the rim water channel 8 will be described later.

[0027] Similarly, a jet drain (not shown) is provided on the bottom of the flushing water tank 2, and this jet drain is connected to the jet outlet 4b via a jet water channel 10 formed inside the flush toilet 1. By opening the jet drain valve 2b, the flushing water in the flushing water tank 2 is discharged through the jet drain (not shown) and discharged from the jet outlet 4b.

[0028] In this embodiment, the jet drain valve 2b and the jet drain outlet (not shown) are located in the center of the width direction of the flush toilet 1 when viewed from above. The jet water channel 10 extends from the jet drain outlet (not shown) towards the front of the flush toilet 1 along the center of the width direction of the flush toilet 1, then branches into two, passes through both sides of the drain trap pipe 6, and rejoins at the front of the bowl section 4, where it is connected to the jet outlet 4b.

[0029] Next, the structure of the rim water channel 8 will be described with reference to Figures 3 and 4. Figure 3 is a top view showing the shape of the inner surface of the rim water channel 8 formed inside the flush toilet bowl 1. Figure 4 is a side view showing the shape of the inner surface of the rim water channel 8 formed inside the flush toilet bowl 1.

[0030] As shown in Figures 3 and 4, the rim water channel 8 extends in the front-to-back direction of the flush toilet 1, connecting the rim water inlet 8a and the rim water outlet 4a. The rim water inlet 8a is the inlet for flushing water located at the upstream end of the rim water channel 8. Specifically, the rim water inlet 8a is a circular opening located directly below the rim drain valve 2a and the rim drain outlet (not shown) in the flushing water tank 2, and is configured to allow flushing water discharged from the rim drain outlet to flow into it. In this embodiment, the rim water inlet 8a is located eccentrically to the right of the center in the width direction of the flush toilet 1, and the rim water outlet 4a is located on the right side of the bowl portion 4. Therefore, the rim water channel 8 connecting the rim water inlet 8a and the rim water outlet 4a can be made shorter, and energy loss due to flow resistance of the water channel can be suppressed.

[0031] Furthermore, as shown in Figure 3, the rim water channel 8 is provided with a base water channel 8b, a curved water channel 8c, and a straight water channel 8d, in that order from the upstream side. The base water conduit 8b is a water conduit connected to the rim water inlet 8a and extends from the rim water inlet 8a toward the front of the flush toilet 1. The curved water conduit 8c is a water conduit provided downstream of the base water conduit 8b and, in a top view, is curved convexly toward the outward direction in the width direction of the flush toilet 1 (downward in Figure 3).

[0032] The straight water conduit 8d is a water conduit provided downstream of the curved water conduit 8c, and extends approximately parallel to the side surface of the flush toilet 1 to the rim outlet 4a formed on the edge of the bowl 4. That is, the straight water conduit 8d extends in a direction roughly tangential to the edge of the bowl 4 at the position where the rim outlet 4a is provided, and flushing water is discharged from the rim outlet 4a in a direction tangential to the bowl 4.

[0033] Furthermore, as shown in Figure 4, the ceiling surface of the rim water conduit 8 is composed of a horizontal ceiling surface 12a that extends in a substantially horizontal direction and a downward-sloping ceiling surface 12b that is configured to become lower toward the downstream side. The horizontal ceiling surface 12a constitutes the ceiling surface of the base water conduit section 8b and the curved water conduit section 8c. The downward-sloping ceiling surface 12b constitutes the ceiling surface of the straight water conduit section 8d, and is lowest at the rim discharge port 4a. In other words, the ceiling surface of the rim water conduit 8 is configured to extend in a substantially horizontal direction upstream of the rim water conduit 8, and then gradually become lower toward the straight water conduit section 8d.

[0034] On the other hand, the bottom surface of the rim water channel 8 is highest at the raised section 14a approximately in the middle of the curved water channel 8c, and is lower on both sides. Due to this configuration, flushing water remains in the part of the rim water channel 8 upstream of the highest point of the raised section 14a even when the toilet is waiting to be flushed. That is, a water reservoir 14b with a deeper water depth is formed in the part of the rim water channel 8 upstream of the rim water inlet 8a. On the other hand, downstream of the highest point of the raised section 14a, the bottom surface of the rim water channel 8 slopes down monotonically toward the rim outlet 4a, and is lowest at the rim outlet 4a. Therefore, flushing water downstream of the highest point of the raised section 14a flows out from the rim outlet 4a, which is located at a lower position, and no flushing water remains after the toilet is flushed.

[0035] Next, as shown in Figure 3, the width of the rim water channel 8 narrows downstream from the rim water inlet 8a at the base water channel section 8b. Furthermore, the width of the rim water channel 8 is kept approximately constant throughout the curved water channel section 8c downstream of the base water channel section 8b, and at the upstream end of the straight water channel section 8d. That is, in a top view, the distance between the side walls on both sides of the rim water channel 8 is approximately constant throughout the curved water channel section 8c and at the upstream end of the straight water channel section 8d.

[0036] Furthermore, in the downstream portion of the straight water conduit 8d, the width gradually narrows toward the rim outlet 4a. That is, of the inner wall surfaces forming the straight water conduit 8d of the rim water conduit 8, the inner wall surface located on the outer side in the width direction of the flush toilet 1 (the lower side in Figure 3) is composed of a straight inner wall surface 16a that is formed in a substantially straight line when viewed from above, toward the upstream side from the rim outlet 4a. When viewed from above, this straight inner wall surface 16a extends toward the rear end Wr of the water surface W in the bowl portion 4. As a result, a sufficiently long distance of the straight water conduit 8d having the straight inner wall surface 16a can be secured at the downstream end of the rim water conduit 8, and energy loss flowing through the rim water conduit 8 can be suppressed.

[0037] On the other hand, among the inner wall surfaces of the straight water conduit section 8d, the opposing inner wall surface 16b that faces the straight inner wall surface 16a is curved in the downstream portion along the shape of the inner wall surface of the bowl section 4, and approaches the straight inner wall surface 16a toward the downstream side. That is, as shown in Figure 3, the opposing inner wall surface 16b is located on the back side of the wall section 18 that forms the bowl section 4, and the inner wall surface of the bowl section 4 and the opposing inner wall surface 16b are formed by a single wall section 18 with a substantially constant thickness. For this reason, the opposing inner wall surface 16b, which is curved to approach the straight inner wall surface 16a toward the downstream side, can be easily constructed.

[0038] Thus, in the downstream portion of the straight water conduit 8d, the ceiling gradually becomes lower (Figure 4) and the width also narrows (Figure 3) towards the rim discharge port 4a. As a result, in the straight water conduit 8d, which has a straight inner wall surface 16a, the flow path cross-sectional area of ​​the rim water conduit 8 decreases toward the rim discharge port 4a. This makes it possible to increase the flow velocity of the cleaning water that flows through the rim water conduit 8 and is discharged from the rim discharge port 4a while suppressing energy loss of the cleaning water.

[0039] Next, with reference to Figure 5, the operation of the flush toilet 1 according to an embodiment of the present invention will be explained. Figure 5 is a top view showing an example of the simulation results for the flow velocity of the cleaning water flowing through the rim water channel 8.

[0040] First, when a user of the flush toilet 1 operates the control unit (not shown) to flush the toilet, the rim drain valve 2a (Figure 2) located in the flush water tank 2 opens. As a result, the flush water stored in the flush water tank 2 flows into the rim water channel 8 through the rim drain port (not shown) and the rim water inlet 8a (Figure 4). Here, a water reservoir 14b (Figure 4) is provided at the base end water channel 8b of the rim water channel 8, and since flush water is retained in this water reservoir 14b, the air layer inside the rim water channel 8 is kept relatively small.

[0041] Therefore, once cleaning water begins to flow into the rim water inlet 8a, the upstream portion of the rim water channel 8 becomes full relatively quickly. As a result, the cleaning water discharged from the cleaning water tank 2 is less likely to be wasted in filling the space within the rim water channel 8, and the energy based on the water head of the cleaning water in the cleaning water tank 2 can be effectively utilized to forcefully discharge the cleaning water from the rim water outlet 4a. In addition, since the water reservoir 14b of the rim water channel 8 is configured to be deep, a large flow path cross-sectional area is secured at the base end water channel 8b of the rim water channel 8, which can suppress energy loss of cleaning water due to flow resistance.

[0042] The cleaning water that flows from the cleaning water tank 2 into the base water supply section 8b of the rim water supply channel 8 passes through the curved water supply section 8c and the straight water supply section 8d located downstream thereof and is discharged from the rim outlet 4a. The cleaning water discharged from the rim outlet 4a flows onto the shelf surface 4c of the bowl section 4, which is formed to be connected to the floor surface of the rim outlet 4a, and flows in a swirling motion within the bowl section 4, guided by the shelf surface 4c. That is, the cleaning water that flows onto the shelf surface 4c flows slowly toward the center of the bowl section 4, swirling on the shelf surface 4c and the surface of the bowl section 4, thereby cleaning the bowl section 4.

[0043] In this embodiment, the bowl section 4 is provided with only one rim outlet 4a. Therefore, when the rim drain valve 2a is opened, the entire amount of cleaning water that flows into the rim water channel 8 through the rim water inlet 8a is discharged from the single rim outlet 4a. As a result, the total amount of cleaning water discharged from the rim outlet 4a per unit time is kept relatively low, and the cleaning water stored in the cleaning water tank 2 can be continuously discharged for a relatively long time.

[0044] On the other hand, after the user operates the control unit (not shown) and the rim drain valve 2a is opened, the jet drain valve 2b (Figure 2) in the cleaning water tank 2 is opened after a predetermined time has elapsed. As a result, the cleaning water in the cleaning water tank 2 flows into the jet water channel 10 (Figure 2) and is discharged from the jet outlet 4b located at the bottom of the bowl section 4.

[0045] When cleaning water is discharged from the jet outlet 4b, the waste and cleaning water in the bowl section 4 flow over the top 6a of the drain trap pipe 6 and into the drain socket (not shown) from the downstream end 6b of the drain trap pipe 6. When the area around the drain socket is filled with the incoming cleaning water, a siphon effect is induced. As a result, the waste and cleaning water in the bowl section 4 are drawn into the drain trap pipe 6 and discharged through the drain trap pipe 6 and drain socket into the drain piping (not shown).

[0046] Next, with reference to Figure 5, the flow of cleaning water within the rim water channel 8 will be explained. As shown in Figure 5, the flushing water that flows from the flushing water tank 2 into the rim water inlet 8a of the rim water channel 8 first flows through the base water channel 8b, slightly inward in the width direction of the toilet bowl 1 when viewed from above. Next, in the curved water channel 8c of the rim water channel 8, the flushing water flows outward in the width direction of the toilet bowl 1. This curved water channel 8c is a water channel that is curved in a convex shape toward the outside in the width direction of the toilet bowl 1 when viewed from above. Therefore, the flushing water that flows into the curved water channel 8c hits the outer side wall surface of the curved water channel 8c (the right side wall surface in Figure 5) strongly and flows along this side wall surface at a high flow velocity. That is, the flow velocity of the flushing water flowing in the curved water channel 8c is fast on the outer side in the width direction of the toilet bowl 1 when viewed from above, and relatively slow on the inner side in the width direction.

[0047] Furthermore, in the straight water supply section 8d located downstream of the curved water supply section 8c, a straight inner wall surface 16a is provided on the outer side in the width direction of the flush toilet 1. That is, the high-velocity flushing water that was flowing along the outer side wall surface in the width direction of the curved water supply section 8c now flows along the straight inner wall surface 16a of the straight water supply section 8d, which is smoothly connected to this side wall surface. Here, since the straight inner wall surface 16a is a wall surface that extends in a nearly straight line when viewed from above, the flushing water flowing along it reaches the rim outlet 4a at a high velocity with almost no flow resistance.

[0048] In addition, the opposing inner wall surface 16b, which is opposite the straight inner wall surface 16a, is curved toward the rim discharge port 4a so as to approach the straight inner wall surface 16a. As a result, the flow path cross-sectional area of ​​the rim water channel 8 narrows toward the rim discharge port 4a, thereby accelerating the cleaning water in the straight water channel section 8d and discharging it from the rim discharge port 4a at a high flow velocity.

[0049] Furthermore, as described above, the cleaning water flowing through the straight water conduit 8d has a high flow velocity on the side of the straight inner wall surface 16a and a relatively low flow velocity on the side of the opposing inner wall surface 16b. As a result, the cleaning water discharged from the rim outlet 4a also has a flow velocity distribution as shown in Figure 5, with a high flow velocity on the outer circumference side of the bowl section 4 and a low flow velocity on the inner circumference side.

[0050] As a result, the high-velocity flushing water discharged from the outer circumference of the rim outlet 4a does not easily flow down from the shelf surface 4c into the bowl section 4, but instead swirls along the shelf surface 4c for a long distance, goes around the bowl section 4, and reaches the rear of the bowl section 4 to clean the bowl surface. On the other hand, the low-velocity flushing water discharged from the inner circumference of the rim outlet 4a flows easily down from the shelf surface 4c into the bowl section 4, and after being discharged from the rim outlet 4a, it flows down into the bowl section 4 for a relatively short distance. This cleans the part of the bowl surface relatively close to the rim outlet 4a. Thus, in the flush toilet 1 of this embodiment, the entire circumference of the bowl section 4 can be cleaned with flushing water discharged from a single rim outlet 4a.

[0051] In the flush toilet 1 embodiment of the present invention, a single rim outlet 4a is provided in the bowl portion 4, which makes it possible to reduce the amount of flushing water discharged from the rim outlet 4a, and as a result, it is possible to sustain rim water discharge for a long time. Furthermore, the rim water channel 8 is equipped with a straight inner wall surface 16a formed in a substantially straight shape, and this straight inner wall surface 16a extends to the rear side of the rear end Wr (Figure 3) of the water surface W in the bowl portion 4. Therefore, the energy loss of the flushing water that is discharged from the flushing water tank 2 by the hydrostatic pressure of the stored flushing water and flows through the rim water channel 8 can be minimized, and flushing water can be discharged from the rim outlet 4a at a high flow velocity. As a result, the surface of the bowl portion 4 can be sufficiently cleaned with the flushing water discharged from the single rim outlet 4a.

[0052] Furthermore, according to the flush toilet 1 of this embodiment, the rim water channel 8 is equipped with a curved water channel 8c on the upstream side of the straight inner wall surface 16a, and this curved water channel 8c is curved convexly toward the outside in the width direction of the flush toilet 1, so that a flow velocity distribution can be given to the flushing water discharged from the rim outlet 4a (Figure 5). That is, when the flushing water flows through the curved water channel 8c of the rim water channel 8, the flow velocity increases in the outer peripheral portion of the rim water channel 8 due to the convexly curved flow path toward the outside in the width direction of the flush toilet 1. As a result, both the part of the bowl 4 close to the rim outlet 4a and the part far from the rim outlet 4a can be sufficiently cleaned by water discharged from a single rim outlet 4a.

[0053] Furthermore, in the flush toilet 1 of this embodiment, the rim water channel 8 is configured such that the cross-sectional area of ​​the flow path decreases toward the rim water outlet 4a in the portion having a straight inner wall surface 16a, thereby increasing the flow velocity of the flushing water flowing through the rim water channel 8 while suppressing energy loss of the flushing water.

[0054] Furthermore, in the flush toilet 1 of this embodiment, since the opposing inner wall surface 16b facing the straight inner wall surface 16a is formed by a single wall portion 18 that follows the shape of the bowl portion 4, a water channel in which the cross-sectional area of ​​the flow path is reduced in the portion of the straight inner wall surface 16a can be easily constructed.

[0055] Furthermore, according to the flush toilet 1 of this embodiment, since the rim water inlet 8a is provided at an eccentric position with respect to the center in the width direction of the flush toilet 1, the rim water channel 8 connecting the rim water inlet 8a and the rim water outlet 4a can be made shorter, and energy loss due to flow resistance of the water channel can be suppressed.

[0056] Although embodiments of the present invention have been described above, various modifications can be made to the embodiments described above. In particular, in the embodiments described above, the bowl portion was provided with a jet nozzle in addition to a single rim nozzle, but the present invention can also be applied to flush toilets that do not have a jet nozzle. Furthermore, the flush toilet in the embodiments described above was a so-called "one-piece" type flush toilet in which the flushing water tank was formed integrally, but the flushing water tank may be configured as a separate part. Moreover, in the embodiments described above, the rim nozzle was provided on the right side of the bowl portion, but the present invention can also be applied to flush toilets in which the rim nozzle is provided at a different position. [Explanation of Symbols]

[0057] 1 flush toilet 2. Washing water tank 2a Drain valve for rim 2b Drain valve for jet 4 Bowl section 4a Rim outlet 4b Jet nozzle 4c shelf surface 6. Drain trap pipe 6a Top 6b Downstream end 8 Rim water conduit 8a Rim water inlet 8b Base water intake section 8c Curved water conduit 8d Straight water conduit 10. Jet water conduit 12a Horizontal ceiling surface 12b descending ceiling surface 14a Ridge 14b Water reservoir 16a Straight inner wall surface 16b Opposing inner wall surface 18 Wall

Claims

1. A flush toilet that performs flushing using flushing water stored in a flushing water tank, A washing water tank that stores washing water, This bowl section is provided with a single rim outlet from which the cleaning water stored in the cleaning water tank is discharged, The drain trap pipe connected to the bottom of this bowl section, A rim water channel that guides cleaning water from the above-mentioned cleaning water tank to the above-mentioned rim outlet, It has, Of the inner wall surfaces forming the rim water channel, the inner wall surface located on the outer side in the width direction of the flush toilet is a straight inner wall surface formed in a substantially straight line when viewed from above, extending upstream from the rim water outlet. This flush toilet is characterized in that, when viewed from above, the straight inner wall surface extends to the rear of the rear end of the water surface in the bowl.

2. The flush toilet according to claim 1, wherein the rim water channel is provided with a curved water channel on the upstream side of the straight inner wall surface, and the curved water channel is curved in a convex shape toward the outward side in the width direction of the flush toilet when viewed from above.

3. The flush toilet according to claim 1, wherein the rim water channel is configured such that, in the portion having the straight inner wall surface, the cross-sectional area of ​​the flow path decreases toward the rim water outlet.

4. The flush toilet according to claim 3, wherein the rim water channel has an opposing inner wall surface facing the straight inner wall surface, and in a top view, is formed in accordance with the shape of the bowl portion.

5. The flush toilet according to claim 1, wherein a rim water inlet is provided at the upstream end of the rim water channel for allowing flushing water to flow from the flushing water tank into the rim water channel, and this rim water inlet is provided at an eccentric position with respect to the center in the width direction of the flush toilet when viewed from above.

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