Water-washable toilet

Abstract

To provide a flush toilet capable of improving the waste discharge performance by spouting enough jet water to drain waste even when the jet waterway is made compact.SOLUTION: A flush toilet includes a bowl 6, a rim spout water port 20, a drain trap pipe 8, a jet spout water port 14, a washing water source, and a jet waterway 16. The jet waterway 16 includes: an upstream flow path 16a extending forward from the washing water source; a curved flow path 16b curved from the upstream flow path 16a; and a downstream flow path 16c that extends backward from the curved flow path 16b connecting to the jet spout water port 14. In the top view, in the downstream flow path 16c of the jet waterway 16, a curved portion 40 formed eccentrically with respect to the central axis O1 of the jet spout water port 14 on the opposite side to the upstream flow path 16a. In the top view, the curved portion 40 is placed in the sealing water area.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a flush toilet, and more particularly to a siphon jet type flush toilet. [Background technology]

[0002] Siphon jet flush toilets have been known in the past, in which flush water is discharged from a jet spout and waste is discharged by generating a siphon action in the drain trap pipe, as described in Patent Document 1. In this flush toilet, the jet water conduit extends forward from the drain outlet of the water storage tank, then bends and extends rearward toward the jet spout. Furthermore, the jet water conduit is significantly eccentric with respect to the central axis of the jet spout in order to uniform the flow velocity distribution of the flush water discharged from the jet spout. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-168671 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a flush toilet such as that in Patent Document 1, the jet waterway is significantly eccentric, so a large space is required to install the jet waterway, which poses the problem of the overall size of the toilet becoming larger. On the other hand, if the jet water conduit is made compact, the flow velocity distribution of the cleaning water discharged from the jet water outlet becomes disrupted, making it impossible to discharge the jet water sufficiently to discharge the waste, which results in a problem of reduced waste discharge performance.

[0005] Therefore, the present invention was made to solve the above-mentioned problems, and aims to provide a flush toilet that can produce a jet of water sufficient to discharge waste even when the jet water channel is compact, thereby improving waste discharge performance. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a siphon jet flush toilet, comprising: a bowl portion having a bowl-shaped waste receiving surface and a rim portion formed on the upper edge; a rim spout provided on the rim portion that spouts flush water toward the bowl portion; a drain trap pipe line provided on the bottom of the bowl portion and including an ascending pipe line extending upward, a descending pipe line extending downward from the ascending pipe line, and a top portion located between the descending pipe line and the ascending pipe line and defining the seal water level; a jet spout provided on the bottom of the bowl portion that spouts flush water toward the inlet portion of the drain trap pipe line; The device has a flushing water source that supplies water, and a jet conduit that connects the flushing water source to the jet outlet and supplies flushing water from the flushing water source to the jet outlet, and the jet conduit has an upstream flow path that extends forward from the flushing water source, a curved flow path that curves from this upstream flow path, and a downstream flow path that extends rearward from this curved flow path and connects to the jet outlet, and the downstream flow path of the jet conduit has a curved portion that is eccentric to the central axis of the jet outlet on the opposite side to the upstream flow path when viewed from above, and this curved portion is located within the sealed water area when viewed from above. In the present invention configured in this way, a curved section is formed in the downstream flow path of the jet water conduit that is eccentric to the center axis of the jet water spout on the opposite side to the upstream flow path, so the flow velocity distribution of the flush water spouted from the jet water spout can be made almost uniform. Also, because the curved section is located within the water-sealing area, the jet water conduit can be made compact. As a result, even if the jet water conduit is compact, it is possible to perform jet spouting that is sufficient to discharge waste, and waste discharge performance can be improved.

[0007] In the present invention, the bent flow path is preferably disposed within the water sealing region when viewed from above. In the present invention configured in this way, the curved flow path is located within the water-sealing area, so the jet water conduit can be made compact. Also, because the curved flow path is located within the water-sealing area, the curved flow path can be kept constantly filled with water. This prevents air from accumulating within the curved flow path, making it possible to make the flow velocity distribution of flush water discharged from the jet water discharge port almost uniform.

[0008] In the present invention, preferably, a flow straightening section extending linearly toward the jet water spouting port is formed in the downstream flow path downstream of the curved section. In the present invention configured in this manner, a straightening section that extends in a straight line toward the jet water outlet is formed in the downstream flow path downstream of the curved section, so that the wash water can be straightened after flowing through the curved section, and the flow velocity distribution of the wash water ejected from the jet water outlet can be made almost uniform.

[0009] In the present invention, the jet water conduit is preferably formed by casting, which forms a solid body between the upstream flow passage and the flow straightening section of the downstream flow passage. In the present invention configured in this manner, the jet water conduit is formed by pour molding, which forms a solid body between the upstream flow path and the straightening section of the downstream flow path, so that the space between the upstream flow path and the straightening section of the downstream flow path can be made thin, and the jet water conduit can be made compact.

[0010] In the present invention, preferably, the bottom surface of the curved flow path is formed substantially horizontally, the upper surface of the curved flow path is inclined downward from the upstream side to the downstream side, and the height of the upper surface of the curved flow path is higher on the outer peripheral side than on the inner peripheral side. In the present invention configured in this way, the bottom surface of the curved flow path is formed almost horizontally, the upper surface of the curved flow path slopes downward from the upstream side to the downstream side, and the height of the upper surface of the curved flow path is higher on the outer circumferential surface side than on the inner circumferential surface side, so the flow path cross-sectional area of ​​the curved flow path is made larger on the outer circumferential surface side than on the inner circumferential surface side, and it is possible to suppress the occurrence of flow separation on the outer circumferential surface side where a relatively large amount of wash water flows. This makes it possible to make the flow velocity distribution of wash water discharged from the jet water discharge port almost uniform. [Effects of the Invention]

[0011] According to the flush toilet of the present invention, even if the jet waterway is compact, a jet of water sufficient to discharge waste can be produced, thereby providing a flush toilet that can improve waste discharge performance. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a plan view showing a flush toilet according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a side cross-sectional view taken along line II-II in FIG. [Figure 3] 1 is a perspective view of an entire jet conduit according to an embodiment of the present invention; FIG. [Figure 4] FIG. 3 is a partially enlarged view of the jet water spout portion of the flush toilet according to the embodiment of the present invention shown in FIG. 2. [Figure 5] FIG. 2 is a plan cross-sectional view of the downstream portion of the jet water conduit of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6A] FIG. 6 is a diagram showing a flow path cross section A of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6B] FIG. 6 is a diagram showing a flow path cross section B of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6C] FIG. 6 is a diagram showing a flow path cross section C of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6D]FIG. 6 is a diagram showing a flow path cross section D of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6E] FIG. 6 is a diagram showing a flow path cross section E of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6F] FIG. 6 is a diagram showing a flow path cross section F of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 6G] FIG. 6 is a diagram showing a flow path cross section G of the jet water channel of the flush toilet according to the embodiment of the present invention shown in FIG. [Figure 7] FIG. 2 is a diagram for explaining the flushing operation of a flush toilet according to an embodiment of the present invention. [Figure 8A] FIG. 10 is a diagram showing the instantaneous flow rate of flush water discharged from the jet spout during a large flush of a flush toilet according to an embodiment of the present invention, and the instantaneous flow rate of flush water flowing into the inlet of the drain trap pipe. [Figure 8B] 10 is a diagram showing the instantaneous flow rate of flush water discharged from the jet spout during a small flush of a flush toilet according to an embodiment of the present invention, and the instantaneous flow rate of flush water flowing into the inlet of the drain trap pipe. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Below, a flush toilet 1 according to a first embodiment of the present invention will be explained. First, the basic structure of a flush toilet 1 according to the first embodiment will be explained using FIGS. FIG. 1 is a plan view showing a flush toilet according to a first embodiment of the present invention, and FIG. 2 is a side cross-sectional view taken along line II-II in FIG.

[0014] As shown in Figures 1 and 2, the siphon jet flush toilet 1 according to the first embodiment comprises a ceramic toilet body 2, a resin toilet seat and toilet lid (not shown) placed on the top surface of the toilet body 2, and a water storage tank 4 placed at the upper rear of the toilet body 2 and covered by a resin cover (not shown).

[0015] The toilet body 2 is formed with a bowl portion 6 for receiving waste, a drain trap pipe 8 provided at the bottom of the bowl portion 6 for discharging waste by siphon action, a rim spout 10 for rim water discharge, a rim water conduit 12 for supplying flushing water to the rim spout 10, a jet spout 14 for jet water discharge, and a jet water conduit 16 for supplying flushing water to the jet spout 14.

[0016] Bowl portion 6 has a bowl-shaped waste receiving surface 18, a rim portion 20 formed along the upper edge of bowl portion 6, and a shelf portion 21 formed between waste receiving surface 18 and rim portion 20. Bowl portion 6 also has a pot portion 22 formed in the area below waste receiving surface 18 and connected to drain trap pipe 8. A water sealing surface W is formed inside pot portion 22.

[0017] The drain trap pipeline 8 has an inlet portion 8a, an ascending pipeline 8b extending upward from the inlet portion 8a, a descending pipeline 8c extending downward from the ascending pipeline 8b, and a top portion 8d located between the descending pipeline 8c and the ascending pipeline 8b and defining the seal water level. Here, the lower end of the descending pipe 8c of the drain trap pipe 8 is connected to a drain pipe (not shown) via a drain socket (not shown).

[0018] When viewing the toilet body 2 from the front, the rim spout 10 is formed on the left rear side of the rim portion 20. The rim spout 10 spouts flush water forward, and this flush water swirls around the inner circumferential surface of the rim portion 20 and the shelf surface of the shelf portion 21 as it flows down to the waste receiving surface 18.

[0019] The rim conduit 12 is formed in a tapered shape, with the flow path cross section gradually becoming smaller towards the rim spout 10. A water supply hose 13 that is directly connected to the water supply is connected to the upstream side of the rim conduit 12. Flush water is supplied to the rim conduit 12 from the water supply, and is discharged from the rim spout 10 by the water supply pressure of the water supply.

[0020] Jet water outlet 14 is formed in the bottom of bowl portion 6. Jet water outlet 14 is positioned opposite inlet 8a of drain trap pipe 8 and is directed toward inlet 8a of drain trap pipe 8. Jet water outlet 14 ejects flush water toward inlet 8a of drain trap pipe 8, and this flush water flows into drain trap pipe 8, activating the siphon action.

[0021] The jet water conduit 16 comprises an upstream flow path 16a extending forward from the water storage tank 4, a curved flow path 16b bending from this upstream flow path 16a, and a downstream flow path 16c extending rearward from this curved flow path 16b and connecting to the jet water spout 14. Flush water is supplied to the jet water conduit 16 from the water storage tank 4, and the head pressure of this flush water causes flush water to be spouted from the jet water spout 14.

[0022] The water storage tank 4 is a gravity-fed tank that stores the flush water used for jet spouting and supplies it to the jet spout 14. The water storage tank 4 is a small resin tank with a volume of approximately 3 liters. The amount of flush water discharged from the water storage tank 4 during one flush is approximately 2 liters. The lower part of the water storage tank 4 is positioned below the top surface of the rim part 20 of the toilet body 2, and above the top 8d of the drain trap pipe 8. This makes the flush toilet 1 a low-silhouette type toilet. The flush water source that supplies flush water to the jet water outlet 14 is not limited to the gravity-fed water storage tank shown in this embodiment, but may also be a water storage tank equipped with a pump such as a pressure pump, jet pump, or pressure accumulator pump.

[0023] Provided within the water storage tank 4 are a water supply device 24 that supplies flush water to the water storage tank 4, a drainage device 26 that supplies or stops the flush water stored in the water storage tank 4 to the jet water conduit 16, and a float switch 28 that detects when the flush water level in the water storage tank 4 has reached the stop water level (full water level). Also provided outside the water storage tank 4 is a controller (not shown) that controls the water supply device 24 and drainage device 26 to operate or stop based on an operation signal from the user, and an operation unit (not shown) that sends out an operation signal in response to operation by the user.

[0024] The water supply device 24 comprises a constant flow valve (not shown) connected to the water supply, a rim-side solenoid valve 23 which supplies or stops the flow of flush water to the rim spout 10, and a tank-side solenoid valve 27 which supplies or stops the flow of flush water to a tank water supply port 25 located inside the water storage tank 4. The rim-side solenoid valve 23 and tank-side solenoid valve 27 are designed to be driven by commands from a controller based on operation signals from the user and water level detection signals from a float switch 28.

[0025] The drainage device 26 comprises an overflow pipe 30 that drains overflowing water from the water storage tank 4 into the toilet body 2, a drain valve 32 fixed to the lower end of the overflow pipe 30, and a toilet flushing unit 36 ​​that opens and closes the drain valve 32 by moving the overflow pipe 30 up and down using an electric drive force. In addition, a guide member 34 that guides the up and down movement of the drain valve 32 is attached to the periphery of the drain outlet 4a of the water storage tank 4. The toilet flushing unit 36 ​​is designed to be driven by commands from a controller based on operation signals from the user. The drainage device is not limited to the drainage valve shown in this embodiment, and a pressure pump, a jet pump, a pressure accumulator pump, or the like may be used instead of the drainage valve.

[0026] The controller is electrically connected to the operation unit, float switch 28, rim-side solenoid valve 23, tank-side solenoid valve 27, and toilet flushing unit 36, and is capable of sending and receiving various signals. The controller receives a flush start signal for a large flush or small flush from the operation unit, and activates or stops the rim-side solenoid valve 23, tank-side solenoid valve 27, and toilet flushing unit 36 ​​based on a pre-stored flush sequence. The flush water volume is approximately 4.8 liters for a large flush and approximately 3.8 liters for a small flush.

[0027] Next, the jet water conduit 16 of the flush toilet according to this embodiment will be described in detail with reference to Figs. FIG. 3 is a perspective view showing the entire jet water conduit according to this embodiment, and FIG. 4 is a partially enlarged view of the jet water spout portion of the flush toilet according to this embodiment shown in FIG.

[0028] First, as shown in Figure 1, the jet water conduit 16 is formed in an overall U-shape and connects the drain outlet 4a of the water storage tank 4, which is located on the right side when viewed from the front of the toilet body 2, to the jet spout 14, which is located in the center in the left-right direction. The upstream flow path 16a of the jet water conduit 16 extends forward from the drain outlet 4a of the water storage tank 4, approximately parallel to the drain trap pipe 8. The bent flow path 16b of the jet water conduit 16 bends (makes a U-turn) from the downstream end of the upstream flow path 16a toward the rear. Furthermore, the downstream flow path 16c of the jet water conduit 16 extends rearward from the downstream end of the bent flow path 16b toward the inlet 8a of the drain trap pipe 8.

[0029] Next, as shown in FIG. 2, jet water conduit 16 is positioned below top 8d of drain trap pipe 8, i.e., below pooled water surface W, except for a portion of area A (area near drain outlet 4a of water storage tank 4) of upstream flow path 16a located directly below water storage tank 4. Also, as shown in FIG. 3, jet water conduit 16 has a larger vertical and horizontal width of the flow path cross section compared to conventional products, which increases the overall volume of the jet water conduit. Specifically, jet water conduit 16 has a volume (approximately 1 liter) that is more than one-third the volume of water storage tank 4 (approximately 3 liters). Also, jet water conduit 16 has a volume (approximately 1 liter) that is more than half the amount of flush water (approximately 2 liters) that is discharged from water storage tank 4 in one flush. As a result, more flush water is retained in jet water conduit 16 compared to conventional products, and the head pressure of the retained flush water enables jet spouting. The present invention is not limited to toilets in which the entire jet waterway 16 is located below the top 8a of the drain trap pipe 8, but includes toilets in which a portion of the jet waterway 16 is located above the top 8a, as in this embodiment.

[0030] Furthermore, as shown in Figure 4, bottom surface 16d on the downstream side of upstream flow path 16a is located below upper end 8e of inlet portion 8a of drain trap pipe 8. Furthermore, this bottom surface 16d is located on the front side of top portion 8d of drain trap pipe 8, below upper end 8e of inlet portion 8a of drain trap pipe 8 (see Figure 2). As a result, even when the seal water level drops and siphon action is about to end, flush water continues to accumulate downstream of upstream flow path 16a, so the siphon action can continue.

[0031] Next, the centre O1 of the jet water outlet 14 is positioned at approximately the same height as the centre O2 of the inlet 8a of the drain trap pipe 8. This makes it easier for flush water spouted from the jet water outlet 14 to flow into the inlet 8a of the drain trap pipe 8. Furthermore, the centre O1 of the jet water outlet 14 is positioned at the lowest point on the central axis X of the jet water conduit 16 (see Figure 2). As a result, because the centre O1 of the jet water outlet 14 is positioned at the lowest point, flush water can be spouted from the jet water outlet 14 over a long period of time, which makes it possible to delay the entry of air from the jet water outlet 14 into the jet water conduit 16.

[0032] Furthermore, the upper end 14a of the jet water spout 14 is positioned lower than the upper end 8e of the inlet 8a of the drain trap pipe 8. This allows flush water to be discharged from the jet water spout 14 for a long period of time, allowing the siphoning action to continue. As shown in Figure 2, more than half of the jet water conduit 16 is located above the upper end 8e of the inlet 8a of the drain trap pipe 8. This makes it possible to discharge almost all of the flush water in the jet water conduit before the siphoning action ends. Furthermore, the upper surfaces 16g, 16h, 16i and the bottom surface 16d of the jet water conduit 16 are gradually inclined downward from the upstream side to the downstream side. This makes it easier for flush water to flow towards the jet water spout 14.

[0033] Next, the downstream portion of the jet water conduit 16 of the flush toilet according to this embodiment will be described in detail with reference to Figs. 1 and 4 to 6G. FIG. 5 is a plan cross-sectional view of the downstream portion of the jet water conduit of the flush toilet according to the embodiment of the invention shown in FIG. 1, and FIGS. 6A to 6G are diagrams showing flow path cross sections A to G of the jet water conduit of the flush toilet according to the embodiment of the invention shown in FIG.

[0034] First, as shown in Figure 5, in a top view, the downstream flow path 16c and the curved flow path 16b of the jet water conduit 16 are formed with a curved section 40 that is eccentric to the opposite side of the upstream flow path 16a with respect to the central axis O1 of the jet water spouting outlet 14. The eccentric distance D between the central axis O1 of the jet water spouting outlet 14 and the central axis O3 of the downstream end of the curved flow path 16b is set to approximately 9 mm. This curved section 40 adjusts the flow velocity distribution of the flush water spouted from the jet water spouting outlet 14, so that the flow velocity distribution in the flow path cross section of the jet water spouting outlet 14 becomes approximately uniform.

[0035] 1, the curved portion 40 is disposed in the inner region (within the water sealing region) of the water sealing surface W in top view, and the entire curved flow path 16b is also disposed in the inner region of the water sealing surface W. This allows the curved portion 40 and the curved flow path 16b of the jet water conduit 16 to be compactly formed. Furthermore, because the curved portion 40 and the curved flow path 16b are disposed in the inner region of the water sealing surface W, the curved portion 40 and the curved flow path 16b can be kept constantly filled with water, and it is possible to prevent air from accumulating in the curved portion 40 and the curved flow path 16b.

[0036] Furthermore, as shown in Figure 5, a flow straightening section 42 is formed in the downstream flow path 16c downstream of the curved section 40, extending rearward toward the jet water spout 14. The flow straightening section 42 extends in a substantially straight line for a length of about 25 mm toward the jet water spout 14. This makes it possible to straighten the flush water after it has flowed through the curved section 40.

[0037] Next, the inner peripheral surface of the curved flow path 16b is formed so that the upstream side has a curvature radius r1 and the downstream side has a curvature radius r2, and the downstream side has a curvature radius r2 that is smaller than the upstream side curvature radius r1. Also, the outer peripheral surface of the curved flow path 16b is formed so that the upstream side has a curvature radius R1 and the downstream side has a curvature radius R2, and the downstream side has a curvature radius R2 that is larger than the upstream side curvature radius R1.

[0038] Here, the cleaning water F1 flowing along the inner circumferential surface of the curved flow path 16b is separated from the inner circumferential surface by the influence of centrifugal force, and stagnation S is inevitably generated near the inner circumferential surface on the downstream side of the curved flow path 16b (see FIG. 5). For this reason, even if the radius of curvature of the inner circumferential surface on the downstream side of the curved flow path 16b is made small, the impact of energy loss is small. Therefore, the inner circumferential surface on the downstream side of the curved flow path 16b, where stagnation S occurs, has a relatively small radius of curvature r2, so that the curved flow path 16b can be made compact while suppressing energy loss in the cleaning water flowing through the curved flow path 16b.

[0039] Furthermore, the cleaning water F2 flowing along the outer peripheral surface of the curved flow path 16b is affected by centrifugal force and has a relatively larger flow rate than the cleaning water F1. The outer peripheral surface on the downstream side of the curved flow path 16b, through which a relatively large amount of cleaning water F2 flows, has a relatively large radius of curvature R2, so that the cleaning water F2 can flow while maintaining its flow velocity and the occurrence of flow separation on the outer peripheral surface of the curved flow path 16b can be suppressed.

[0040] Furthermore, the jet water conduit 16 is formed by pour molding (double molding) in which a solid body is formed between the upstream flow path 16a and the flow straightening section 42 of the downstream flow path 16c. This allows the space between the upstream flow path 16a and the flow straightening section 42 of the downstream flow path 16c to be thin, making it possible to make the jet water conduit 16 compact.

[0041] As shown in Figures 2 and 6A to 6G, the bottom surface 16d of the upstream flow path 16a of the jet water conduit 16 is formed to slope downward from the upstream side to the downstream side, and the bottom surface 16e of the curved flow path 16b and the bottom surface 16f of the downstream flow path 16c are formed to be approximately horizontal and at approximately the same height.

[0042] As shown in FIG. 2, an upper surface 16g of the upstream flow path 16a, an upper surface 16h of the curved flow path 16b, and an upper surface 16i of the downstream flow path 16c of the jet water conduit 16 are formed to slope downward from the upstream side to the downstream side.

[0043] As shown in Figures 6B to 6D, the height of the upper surface 16h of the curved flow path 16b is higher on the outer peripheral surface side than on the inner peripheral surface side. This allows the flow path cross-sectional area of ​​the curved flow path 16b to be larger on the outer peripheral surface side than on the inner peripheral surface side, making it possible to prevent the cleaning water F2 flowing along the outer peripheral surface of the curved flow path 16b from peeling off from the outer peripheral surface of the curved flow path 16b. Furthermore, as shown in Figures 6F and 6G, the height of the flow straightening section 42 of the downstream flow path 16c is formed to be approximately the same on the inner peripheral surface side and the outer peripheral surface side. This allows the cleaning water to be more smoothly straightened.

[0044] 6B to 6G, the cross section of the curved flow path 16b and the downstream flow path 16c gradually increases in width and gradually decreases in length from the upstream side to the downstream side, which makes it possible for a flattened flow of water to be discharged from the jet water spouting port 14 at a large flow rate.

[0045] Next, the flushing operation of the flush toilet 1 according to the first embodiment of the present invention will be explained using FIG. FIG. 7 is a diagram for explaining the flushing operation of the flush toilet according to the first embodiment of the present invention.

[0046] 7(a) shows the standby state, in which flush water has accumulated in the bowl section 6 up to the seal water level, and flush water has also accumulated in the jet water conduit 16 up to the same height as the seal water surface W. At this time, air is accumulating in a part of area A of the upstream flow path 16a located directly below the water storage tank 4.

[0047] Next, as shown in Figure 7(b), the water supply device is driven (the rim-side solenoid valve opens), rim spouting begins, and the flush water level gradually rises in the bowl section 6. In conjunction with this, the flush water level also gradually rises in the jet water conduit 16, and air that had been accumulating in area A of the upstream flow path 16a is expelled from the overflow pipe 30, causing the jet water conduit 16 to become full of water.

[0048] After this, as shown in Figure 7(c), while rim water spouting continues, the drain device 26 is driven (the drain valve 32 opens) and jet water spouting begins. At this time, the head pressure of the flush water stored in the water storage tank 4 is applied to the flush water that has accumulated in the jet water conduit 16, and a first flow rate is spouted from the jet water spouting port 14. The first flow rate is a large flow rate, and jet water spouting at the first flow rate fills the drain trap pipe 8 with water, activating the siphon action. Jet water spouting at the first flow rate continues for a predetermined time, and waste is discharged by the powerful siphon action.

[0049] Next, as shown in Figure 7(d), the drainage device 26 stops (the drainage valve 32 closes) while rim water spouting continues. Even when the drainage device 26 stops, because the overall volume of the jet water conduit 16 is large, a large amount of flush water remains within the jet water conduit 16, and the second flow rate is discharged from the jet water spout port 14 by flowing through the jet water conduit 16 while being subjected to the head pressure of the stored flush water. The second flow rate is smaller than the first flow rate, but is sufficient to continue the siphoning action. Jet water spouting at the second flow rate continues for a predetermined time, and the siphoning action continues.

[0050] Thereafter, as shown in Figure 7(e), the flush water level in the bowl section 6 drops as the seal water is discharged along with the waste due to siphon action, and air enters from the upper end of the inlet section 8a of the drain trap pipe line 8, ending the siphon action. Here, the jet water conduit 16 is formed so that flush water continues to accumulate, delaying the entry of air and delaying the end of the siphon action. Rim spouting continues, and flushing ends when flush water accumulates in the bowl section 6 up to the seal water level. At this time, flush water also accumulates in the jet water conduit 16 up to the same height as the seal water surface.

[0051] Next, as shown in Figure 7(f), the water supply device is driven (the tank-side electromagnetic valve opens) and water supply to the tank begins. When the flush water level in the water storage tank 4 rises and the float switch detects that it has reached the stop water level (full water level), the water supply device stops (the tank-side electromagnetic valve closes) and then returns to its original standby state as shown in Figure 7(a).

[0052] Next, the jet water spouting mode of a flush toilet according to an embodiment of the present invention will be described in detail with reference to Figures 8A and 8B. Figure 8A is a diagram showing the instantaneous flow rate of flush water spouted from the jet spouting port and the instantaneous flow rate of flush water flowing into the inlet of the drain trap pipe during a large flush of a flush toilet according to an embodiment of the present invention, and Figure 8B is a diagram showing the instantaneous flow rate of flush water spouted from the jet spouting port and the instantaneous flow rate of flush water flowing into the inlet of the drain trap pipe during a small flush of a flush toilet according to an embodiment of the present invention. The dashed lines in Figures 8A and 8B show the instantaneous flow rate of flush water spouted from the jet spouting port 14, and the solid lines in Figures 8A and 8B show the instantaneous flow rate of flush water flowing into inlet 8a of drain trap pipe 8.

[0053] In this embodiment, the amount of flush water spouted from the jet water spouting port 14 is approximately 2 liters for a large flush and approximately 1.5 liters for a small flush.

[0054] In a large flush, as shown in Figure 8A, first, when the drain device 26 is driven, jet spouting begins and a first flow rate Q1 is spouted from the jet water spouting port 14. At this time, the instantaneous flow rate of flush water spouted from the jet water spouting port 14 increases rapidly immediately after starting (increase rate A) and immediately reaches the maximum instantaneous flow rate Q1max. As a result, siphon action is rapidly activated (time T1). After this, the instantaneous flow rate decreases slightly from the maximum instantaneous flow rate Q1max and becomes approximately constant. Also, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 increases rapidly because, in addition to the flush water spouted from the jet water spouting port 14 and the rim water spouting port 10, seal water is drawn into the drain trap pipe 8 by siphon action. This activates a powerful siphon action, which can then be continued.

[0055] Next, as shown in Figure 8A, after the drainage device 26 is stopped (time T2), when the spouting of the first flow rate Q1 has ended, the second flow rate Q2 is spouted from the jet water spouting port 14. At this time, the instantaneous flow rate of flush water spouted from the jet water spouting port 14 increases more gradually (increase rate B) compared to the increase rate A of the first flow rate Q1, and reaches the maximum instantaneous flow rate Q2max. This makes it possible to prevent the flush water spouted from the jet water spouting port 14 from becoming turbulent. Furthermore, the maximum instantaneous flow rate Q2max of the second flow rate Q2 is set to be smaller than the maximum instantaneous flow rate Q1max of the first flow rate Q1. This allows the siphon action to continue with the second flow rate Q2, which is smaller than the first flow rate Q1, making it possible to achieve both improved waste discharge performance and water conservation. Furthermore, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 is made up of flush water discharged from the jet spout 14 and the rim spout 10, as well as seal water being drawn into the drain trap pipe 8 by siphon action, so a large instantaneous flow rate can be maintained.

[0056] In a small flush, as shown in Figure 8B, first, when the drain device 26 is driven, jet spouting begins and a first flow rate q1 is spouted from the jet water spouting port 14. At this time, the instantaneous flow rate of flush water spouted from the jet water spouting port 14 increases rapidly (increase rate a) immediately after start, and immediately reaches the maximum instantaneous flow rate q1max. This rapidly activates siphon action (time t1). After this, the instantaneous flow rate decreases slightly from the maximum instantaneous flow rate q1max, and then decreases rapidly when the drain device 26 stops (time t2). Also, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 increases rapidly because, in addition to the flush water spouted from the jet water spouting port 14 and the rim water spouting port 10, seal water is drawn into the drain trap pipe 8 by siphon action. This activates a powerful siphon action, which can be continued.

[0057] Next, as shown in Figure 8B, after the drainage device 26 is stopped (time t2), when the spouting of the first flow rate q1 has ended, the second flow rate q2 is spouted from the jet water spouting port 14. At this time, the instantaneous flow rate of flush water spouted from the jet water spouting port 14 increases more gradually (increase rate b) compared to the increase rate a of the first flow rate q1, and reaches the maximum instantaneous flow rate q2max. This makes it possible to prevent the flush water spouted from the jet water spouting port 14 from becoming turbulent. Furthermore, the maximum instantaneous flow rate q2max of the second flow rate q2 is set to be smaller than the maximum instantaneous flow rate q1max of the first flow rate q1. This allows the siphon action to continue with the second flow rate q2, which is smaller than the first flow rate q1, making it possible to achieve both improved waste discharge performance and water conservation. Furthermore, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 is made up of flush water discharged from the jet spout 14 and the rim spout 10, as well as seal water being drawn into the drain trap pipe 8 by siphon action, so a large instantaneous flow rate can be maintained.

[0058] Comparing the large flush and small flush, as shown in Figures 8A and 8B, the flush water volume for the large flush or small flush is switched by adjusting the jet water spouting time at the first large flush flow rate Q1 and the first small flush flow rate q1. This allows the flush water volume to be switched appropriately.

[0059] The effects of the above-described embodiment will be described below. In a flush toilet 1 according to an embodiment of the present invention, a curved section 40 is formed in the downstream flow path 16c of the jet water conduit 16, which is eccentric to the opposite side of the upstream flow path relative to the central axis O1 of the jet water spout 14, making it possible to make the flow velocity distribution of the flush water spouted from the jet water spout 14 approximately uniform. Furthermore, because the curved section 40 is located within the water-sealed area, the jet water conduit 16 can be made compact. As a result, even if the jet water conduit 16 is made compact, it is still possible to perform jet spouting sufficient to discharge waste, improving waste discharge performance.

[0060] Furthermore, in a flush toilet 1 according to an embodiment of the present invention, the curved flow path 16b is located within the water-sealed area, allowing the jet water conduit 16 to be made compact. Furthermore, because the curved flow path 16b is located within the water-sealed area, the curved flow path 16b can be kept constantly filled with water. This prevents air from accumulating within the curved flow path 16b, making it possible to make the flow velocity distribution of the flush water discharged from the jet water spout 14 approximately uniform.

[0061] In a flush toilet 1 according to an embodiment of the present invention, a straightening section 42 that extends in a straight line toward the jet water outlet 14 is formed in the downstream flow path 16c downstream of the curved section 40, so that the flush water can be straightened after flowing through the curved section 40, and the flow velocity distribution of the flush water discharged from the jet water outlet 14 can be made approximately uniform.

[0062] Furthermore, in a flush toilet 1 according to an embodiment of the present invention, the jet water conduit 16 is formed by pour molding, which forms a solid molded body between the upstream flow path 16a and the rectification section 42 of the downstream flow path 16c, so the space between the upstream flow path 16a and the rectification section 42 of the downstream flow path 16c can be made thin, allowing the jet water conduit 16 to be made compact.

[0063] In a flush toilet 1 according to an embodiment of the present invention, the bottom surface 16e of the curved flow path 16b is formed almost horizontally, the top surface 16h of the curved flow path 16b slopes downward from the upstream side to the downstream side, and the height of the top surface 16h of the curved flow path 16b is higher on the outer circumferential surface side than on the inner circumferential surface side, so that the cross-sectional area of ​​the curved flow path 16b is larger on the outer circumferential surface side than on the inner circumferential surface side, and it is possible to prevent flow separation from occurring on the outer circumferential surface side, where a relatively large amount of flush water flows. This makes it possible to make the flow velocity distribution of the flush water discharged from the jet water spout 14 almost uniform.

[0064] The present invention is not limited to the above-described embodiments, and various changes and modifications are possible within the scope of the technical concept described in the claims. [Explanation of symbols]

[0065] 1: Flush toilet 2: Toilet bowl body 4: Water tank 6: Bowl section 8: Drain trap pipe 8a: Inlet of drain trap pipe 8b: Drain trap pipe riser 8c: Downstream pipe of drain trap pipe 8d: Top of drain trap pipe 8e: Upper end of the inlet of the drain trap pipe 10: Rim spout 14: Jet spout 14a: Upper end of jet outlet 16: Jet waterway 16a: Upstream flow path of jet channel 16b: Curved flow path of jet waterway 16c: Downstream flow path of the jet channel 16d: Bottom surface of the upstream channel of the jet waterway 16e: Bottom of the bent channel of the jet waterway 16f: Bottom surface of the downstream channel of the jet channel 16g: Upper surface of the upstream channel of the jet waterway 16h: Upper surface of the curved channel of the jet waterway 16i: Upper surface of the downstream channel of the jet channel 18: Waste receiving surface 20: Rim 26: Drainage device 30: Overflow pipe 32: Drain valve 40: Curved section 42: Rectifier D: Eccentricity distance F1: Cleaning water on the inner surface F2: Cleaning water on the outer surface O1: Center of jet outlet O2: Center of the inlet of the drain trap pipe O3: Center of the downstream end of the curved channel X: Central axis of the jet waterway Q1, q1: First flow rate Q1max, q1max: Maximum instantaneous flow rate of the first flow rate A, a: Increase rate of the first flow rate Q2, q2: Second flow rate Q2max, q2max: Maximum instantaneous flow rate of the second flow rate B, b: Increase rate of the second flow rate R1: Radius of curvature on the upstream side of the outer surface R2: Radius of curvature on the downstream side of the outer surface r1: Radius of curvature on the upstream side of the inner surface r2: Radius of curvature on the downstream side of the inner surface W: Water sealing surface

Claims

1. A siphon jet flush toilet, a bowl portion having a bowl-shaped waste receiving surface and a rim portion formed on an upper edge thereof; a rim spout provided in the rim portion and spouting flush water toward the bowl portion; a drain trap pipe provided at the bottom of the bowl portion and including an ascending pipe extending upward, a descending pipe extending downward from the ascending pipe, and a top portion located between the descending pipe and the ascending pipe and defining a seal water level; a jet spout provided at the bottom of the bowl portion and spouting flush water toward the inlet of the drain trap pipe; a wash water source that supplies wash water to the jet outlet; a jet water conduit that connects the flush water source and the jet water spouting port and supplies flush water from the flush water source to the jet water spouting port; and the jet water conduit has an upstream flow path extending forward from the wash water source, a curved flow path bending from the upstream flow path, and a downstream flow path extending rearward from the curved flow path and connecting to the jet water spouting port, In the downstream flow path of the jet water conduit, a curved portion is formed in which the inner and outer circumferential surfaces of the downstream flow path are eccentric to the opposite side of the upstream flow path with respect to the central axis of the jet water spouting port in a top view, A flush toilet characterized in that the curved portion and the bent flow path are entirely located within the water sealing area when viewed from above.

2. A flush toilet as described in claim 1, wherein the inner surface of the curved flow path is formed so that, when viewed from above, the radius of curvature on the downstream side is smaller than the radius of curvature on the upstream side, and the outer surface of the curved flow path is formed so that, when viewed from above, the radius of curvature on the downstream side is larger than the radius of curvature on the upstream side.

3. 3. The flush toilet according to claim 1, wherein a flow straightening section extending linearly toward the jet spout is formed in the downstream flow path downstream of the curved section.

4. 4. The flush toilet according to claim 3, wherein the jet water conduit is formed by pour molding, which forms a solid molded body between the upstream flow path and the flow straightening section of the downstream flow path.

5. The bottom surface of the curved flow path is formed substantially horizontally, 2. The flush toilet according to claim 1, wherein the upper surface of the curved flow path slopes downward from the upstream side to the downstream side, and the height of the upper surface of the curved flow path is higher on the outer circumferential side than on the inner circumferential side.

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