Flush 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] Conventionally, as described in Patent Document 1, there has been known a siphon jet type flush toilet that discharges waste by spouting flush water from a jet spout and generating a siphon effect in the drain trap pipe. In this flush toilet, the jet water conduit extends forward from the drain of the water storage tank, then bends and extends backward toward the jet water conduit. Furthermore, the jet water conduit is largely eccentric with respect to the central axis of the jet water conduit in order to make the flow velocity distribution of the flush water spouted from the jet water conduit uniform. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-168671 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a flush toilet like the one in Patent Document 1, the jet water conduit is significantly off-centered, so a large space is required to install the jet water conduit, 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 jet water sufficiently to discharge waste, resulting in a problem of reduced waste discharge performance.

[0005] Therefore, the present invention has been made to solve the above-mentioned problems, and has as its object to provide a flush toilet that can produce a jet of water sufficient to discharge waste even when the jet water passage 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 type flush toilet, comprising: a bowl portion having a bowl-shaped waste receiving surface and a rim portion formed on an upper edge thereof; a rim spout provided on the rim portion for spouting flush water toward the bowl portion; a drain trap pipe 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 a seal water level; a jet spout provided on the bottom of the bowl portion for spouting flush water toward an inlet portion of the drain trap pipe line; The jet conduit has a wash water source which supplies water, and a jet conduit which connects the wash water source to the jet outlet and supplies wash water from the wash water source to the jet outlet. The jet conduit has an upstream flow path extending forward from the wash water source, a curved flow path which curves from the upstream flow path, and a downstream flow path which extends rearward from the curved flow path and connects to the jet outlet. In a top view, the downstream flow path of the jet conduit has a curved portion which is eccentric to the opposite side to the upstream flow path with respect to the central axis of the jet outlet, and this curved portion is located within the sealed water area in a top view. In the present invention configured in this manner, a curved portion is formed in the downstream flow path of the jet water conduit, which is eccentric to the opposite side of the upstream flow path with respect to the central axis of the jet water outlet, so that the flow velocity distribution of the flush water discharged from the jet water outlet can be made almost uniform. Also, because the curved portion is disposed within the water sealing area, the jet water conduit can be made compact. As a result, even if the jet water conduit is made compact, a jet water discharge sufficient to discharge waste can be performed, and waste discharge performance can be improved.

[0007] In the present invention, the bent flow passage 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 arranged within the water-sealing area, so the jet water conduit can be made compact. Also, because the curved flow path is arranged within the water-sealing area, the curved flow path can be kept constantly full of water. This prevents air from accumulating within the curved flow path, and makes it possible to make the flow velocity distribution of the flush water discharged from the jet water outlet almost uniform.

[0008] In the present invention, preferably, a flow straightening section extending linearly toward the jet water outlet is formed in the downstream flow passage downstream of the curved section. In the present invention configured in this manner, a straightening section extending 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 to form a solid body between the upstream flow passage and the flow straightening portion of the downstream flow passage. In the present invention configured in this manner, the jet water conduit is formed by pouring to form a solid body between the upstream flow path and the straightening section of the downstream flow path. This makes it possible to make the space between the upstream flow path and the straightening section of the downstream flow path thin, thereby making the jet water conduit compact.

[0010] In the present invention, preferably, the bottom surface of the curved flow path is formed approximately 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 circumferential surface side than on the inner circumferential surface side. In the present invention configured in this manner, the bottom surface of the curved flow path is formed nearly 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 that the flow 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 flow separation on the outer circumferential surface side where a relatively large amount of wash water flows can be suppressed. This makes it possible to make the flow velocity distribution of the wash water discharged from the jet water discharge port nearly uniform. Effect of the Invention

[0011] According to the flush toilet of the present invention, even if the jet water passage 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 description of the drawings]

[0012] [Figure 1] FIG. 1 is a plan view showing a flush toilet according to an embodiment of the present invention. [Diagram 2] 2 is a side cross-sectional view taken along line II-II in FIG. 1. [Diagram 3] FIG. 2 is a perspective view of an overall jet conduit according to an embodiment of the present invention; [Figure 4] FIG. 3 is a partial enlarged view showing the jet water spout portion of the flush toilet according to the embodiment of the present invention shown in FIG. 2. [Diagram 5] 2 is a plan cross-sectional view of the downstream portion of the jet water channel of the flush toilet according to the embodiment of the invention shown in FIG. 1. [Figure 6A] 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 invention shown in FIG. 5. FIG. [Figure 6B] 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 invention shown in FIG. 5. FIG. [Figure 6C] 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 invention shown in FIG. 5. FIG. [Figure 6D]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 invention shown in FIG. 5. FIG. [Figure 6E] 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 invention shown in FIG. 5. FIG. [Figure 6F] 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 invention shown in FIG. 5. FIG. [Figure 6G] 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 invention shown in FIG. 5. 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] 1 is a diagram showing the instantaneous flow rate of flush water spouted from a jet spouting port 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 an inlet of a drain trap pipe. FIG. [Figure 8B] 1 is a diagram showing the instantaneous flow rate of flush water discharged from a 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 an inlet of a drain trap pipe. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 with reference to 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 type flush toilet 1 according to the first embodiment comprises a ceramic toilet body 2, a plastic 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 plastic 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 water outlet 10 for rim water spouting, a rim water conduit 12 for supplying flushing water to the rim water outlet 10, a jet water outlet 14 for jet water spouting, and a jet water conduit 16 for supplying flushing water to the jet water outlet 14.

[0016] The bowl portion 6 comprises a bowl-shaped waste receiving surface 18, a rim portion 20 formed along the upper edge of the bowl portion 6, and a shelf portion 21 formed between the waste receiving surface 18 and the rim portion 20. The bowl portion 6 also comprises a pot portion 22 formed in the area below the waste receiving surface 18 and connected to the drain trap pipe 8. A water sealing surface W is formed inside the 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 determining 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 looking at the toilet body 2 from the front, the rim spout 10 is formed on the rear left side of the rim portion 20. The rim spout 10 spouts flushing water forward, and this flushing 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 water conduit 12 is formed in a tapered shape with the flow path cross section gradually becoming smaller towards the rim water outlet 10. A water supply hose 13 that is directly connected to a water supply is connected to the upstream side of the rim water conduit 12. Flush water is supplied to the rim water conduit 12 from the water supply, and the flush water is discharged from the rim water outlet 10 by the water supply pressure of the water supply.

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

[0021] The jet water conduit 16 is equipped with 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 outlet 14. Flush water is supplied to the jet water conduit 16 from the water storage tank 4, and the flush water is spouted from the jet water outlet 14 by the head pressure of this flush water.

[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 in one flush is approximately 2 liters. The lower part of the water storage tank 4 is positioned below the upper 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. In addition, the wash water source that supplies wash water to the jet water outlet 14 is not limited to the gravity-fed water storage tank shown in this embodiment, but may be a water storage tank equipped with a pump such as a pressure pump, a jet pump, or an 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 transmits 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 a water supply, a rim-side solenoid valve 23 which supplies or stops flush water to the rim spout 10, and a tank-side solenoid valve 27 which supplies or stops flush water to a tank water supply port 25 located in the water storage tank 4. The rim-side solenoid valve 23 and the tank-side solenoid valve 27 are 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 driving 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 an operation signal 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 drives 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 amount of flush water 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 the present 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 showing the jet water spout portion of the flush toilet according to this embodiment shown in FIG.

[0028] First, as shown in Fig. 1, the jet water conduit 16 is formed in a U-shape as a whole, and connects the drain outlet 4a of the water storage tank 4, which is located on the right side when the toilet body 2 is viewed from the front, to the jet water outlet 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, almost 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 backward 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, the jet water conduit 16 is arranged below the top 8d of the drain trap pipe 8, that is, below the water surface W, except for a part of region A (region near the drain port 4a of the water tank 4) of the upstream flow path 16a located directly below the water storage tank 4. Also, as shown in FIG. 3, the jet water conduit 16 has a larger vertical width and horizontal width of the flow path cross section than the conventional product, and therefore the overall volume of the jet water conduit is larger. Specifically, the jet water conduit 16 has a volume (about 1 liter) that is more than one-third the volume of the water storage tank 4 (about 3 liters). Also, the jet water conduit 16 has a volume (about 1 liter) that is more than half the amount of flush water (about 2 liters) discharged from the water storage tank 4 in one flush. As a result, more flush water is retained in the jet water conduit 16 than in the conventional product, and the head pressure of the retained flush water enables the jet water to be discharged. The present invention is not limited to toilets in which the entire jet water conduit 16 is located below the top 8a of the drain trap pipe 8, but includes toilets in which a portion of the jet water conduit 16 is located above the top 8a, as in this embodiment.

[0030] Furthermore, as shown in Fig. 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 below upper end 8e of inlet portion 8a of drain trap pipe 8 on the front side of top portion 8d of drain trap pipe 8 (see Fig. 2). As a result, even if the seal water level drops and the siphoning action is about to end, flush water continues to accumulate on the downstream side of upstream flow path 16a, so that the siphoning action can be continued.

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

[0032] Furthermore, the upper end 14a of the jet water outlet 14 is disposed below 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 outlet 14 for a long time, so that the siphoning action can be continued. As shown in FIG. 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 allows almost all flush water in the jet water conduit to be discharged before the siphoning action ends. In addition, 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 allows flush water to flow easily toward the jet water outlet 14.

[0033] Next, the downstream portion of the jet water conduit 16 of the flush toilet according to the present 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 passage 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 passage of the flush toilet according to the embodiment of the invention shown in FIG.

[0034] First, as shown in Fig. 5, in the downstream flow passage 16c and the bent flow passage 16b of the jet water conduit 16, a curved section 40 is formed which is eccentric to the opposite side of the upstream flow passage 16a with respect to the central axis O1 of the jet water outlet 14 in a top view. The eccentric distance D between the central axis O1 of the jet water outlet 14 and the central axis O3 of the downstream end of the bent flow passage 16b is set to about 9 mm. This curved section 40 adjusts the flow velocity distribution of the wash water discharged from the jet water outlet 14, so that the flow velocity distribution in the flow passage cross section of the jet water outlet 14 becomes almost 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. In addition, 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 full of water, and it is possible to prevent air from accumulating in the curved portion 40 and the curved flow path 16b.

[0036] 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 outlet 14. The flow straightening section 42 extends in a substantially straight line toward the jet water outlet 14 with a length of about 25 mm. This makes it possible to straighten the wash water after it has flowed through the curved section 40.

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

[0038] Here, the cleaning water F1 flowing along the inner peripheral surface of the curved flow path 16b is separated from the inner peripheral surface by the effect of centrifugal force, and stagnation S always occurs near the inner peripheral surface on the downstream side of the curved flow path 16b (see FIG. 5). Therefore, even if the radius of curvature of the inner peripheral surface on the downstream side of the curved flow path 16b is made small, the effect of energy loss is small. Therefore, since the inner peripheral surface on the downstream side of the curved flow path 16b, where the stagnation S occurs, has a relatively small radius of curvature r2, it is possible to make the curved flow path 16b compact while suppressing the occurrence of energy loss in the cleaning water flowing through the curved flow path 16b.

[0039] Furthermore, the cleaning water F2 flowing along the outer circumferential surface of the curved flow path 16b is affected by centrifugal force and has a relatively large flow rate compared to the cleaning water F1. The outer circumferential 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 separation of the flow can be suppressed on the outer circumferential surface of the curved flow path 16b.

[0040] Furthermore, the jet water conduit 16 is formed by pour molding (double molding) which forms a solid body between the upstream flow passage 16a and the flow straightening section 42 of the downstream flow passage 16c. This allows the space between the upstream flow passage 16a and the flow straightening section 42 of the downstream flow passage 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, a bottom surface 16d of the upstream flow passage 16a of the jet water conduit 16 is formed to slope downward from the upstream side to the downstream side, and a bottom surface 16e of the curved flow passage 16b and a bottom surface 16f of the downstream flow passage 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 passage 16a, an upper surface 16h of the curved flow passage 16b, and an upper surface 16i of the downstream flow passage 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 outer peripheral surface side to be larger than the inner peripheral surface side in the flow path cross-sectional area of ​​the curved flow path 16b, and makes 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. Also, as shown in Figures 6F and 6G, the height of the flow straightening section 42 of the downstream side flow path 16c is formed to be approximately the same on the inner peripheral surface side and the outer peripheral surface side. This makes it possible to straighten the flow of the cleaning water more.

[0044] As shown in Figures 6B to 6G, the cross section of the curved flow path 16b and the downstream side flow path 16c gradually increases in width and gradually decreases in length from the upstream side to the downstream side, which allows 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 bowl section 6 up to the seal water level, and flush water has also accumulated in jet conduit 16 up to the same height as seal surface W. At this time, air is retained in region A, a part of upstream flow path 16a located directly below 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 the air that had been retained in part of area A of the upstream flow path 16a is discharged 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 retained in the jet water conduit 16, and the first flow rate is spouted from the jet water spouting port 14. The first flow rate is a large flow rate, and the 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), while rim water spouting continues, the drainage device 26 stops (the drainage valve 32 closes). 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 in the jet water conduit 16, and the second flow rate is spouted from the jet water spouting port 14 by flowing through the jet water conduit 16 while receiving 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 siphon action. Jet water spouting at the second flow rate continues for a predetermined time, and the siphon action continues.

[0050] After that, as shown in Fig. 7(e), the flush water level in the bowl section 6 drops as the seal water is discharged together with the waste by the siphoning action, and air enters from the upper end of the inlet section 8a of the drain trap pipe line 8, ending the siphoning action. Here, the jet water conduit 16 is formed so that flush water continues to accumulate, so that the entry of air can be delayed and the end of the siphoning action can be delayed. The 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 Fig. 7(f), the water supply device is driven (the tank side solenoid 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 the flush water level has reached the stop water level (full water level), the water supply device stops (the tank side solenoid valve closes) and then returns to the original standby state as shown in Fig. 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. Fig. 8A is a diagram showing the instantaneous flow rate of flush water spouted from the jet spouting port 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, and Fig. 8B is a diagram showing the instantaneous flow rate of flush water spouted from the jet spouting port 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. The dashed lines in Fig. 8A and Fig. 8B show the instantaneous flow rate of flush water spouted from the jet spouting port 14, and the solid lines in Fig. 8A and Fig. 8B show the instantaneous flow rate of flush water flowing into inlet 8a of the 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 the large flush, as shown in FIG. 8A, first, when the drain device 26 is driven, jet spouting is started and the 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 starting, and immediately reaches the maximum instantaneous flow rate Q1max. This causes the siphoning action to be rapidly started (time T1). After this, the instantaneous flow rate decreases slightly from the maximum instantaneous flow rate Q1max and becomes almost 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, sealing water is drawn into the drain trap pipe 8 by the siphoning action. This allows a strong siphoning action to be started and continued.

[0055] Next, as shown in Figure 8A, after the drainage device 26 is stopped (time T2), when the discharge of the first flow rate Q1 ends, the second flow rate Q2 is discharged from the jet water outlet 14. At this time, the instantaneous flow rate of flush water discharged from the jet water outlet 14 increases more gently (increase rate B) compared with 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 discharged from the jet water outlet 14 from becoming turbulent. Also, 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, and allows both improved waste discharge performance and water conservation to be achieved. Also, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 can be maintained at a large instantaneous flow rate because, in addition to flush water discharged from the jet water outlet 14 and the rim water outlet 10, sealing water is drawn into the drain trap pipe 8 by the siphon action.

[0056] In the small flush, as shown in FIG. 8B, first, when the drainage device 26 is driven, jet spouting is started 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 starting, and immediately reaches the maximum instantaneous flow rate q1max. This causes the siphoning action to be rapidly activated (time t1). After this, the instantaneous flow rate decreases slightly from the maximum instantaneous flow rate q1max, and then decreases rapidly when the drainage device 26 stops (time t2). Also, the instantaneous flow rate of flush water flowing into the inlet 8a of the drainage 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, sealing water is drawn into the drainage trap pipe 8 by the siphoning action. This allows a strong siphoning action to be activated and continued.

[0057] Next, as shown in Figure 8B, after the drainage device 26 is stopped (time t2), when the discharge of the first flow rate q1 ends, the second flow rate q2 is discharged from the jet water outlet 14. At this time, the instantaneous flow rate of flush water discharged from the jet water outlet 14 increases more gently (increase rate b) compared with 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 discharged from the jet water outlet 14 from becoming turbulent. Also, 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, and allows both improved waste discharge performance and water conservation to be achieved. Also, the instantaneous flow rate of flush water flowing into the inlet 8a of the drain trap pipe 8 can be maintained at a large instantaneous flow rate because, in addition to flush water discharged from the jet water outlet 14 and the rim water outlet 10, sealing water is drawn into the drain trap pipe 8 by the siphon action.

[0058] Comparing the large and small flushes, as shown in Figures 8A and 8B, the amount of flush water for the large or small flush is switched by adjusting the jet water spouting time at the first flow rate Q1 for the large flush and the first flow rate q1 for the small flush. This makes it possible to switch the amount of flush water 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 with respect to the central axis O1 of the jet water spout 14, so that the flow velocity distribution of the flush water spouted from the jet water spout 14 can be made approximately uniform. Also, because the curved section 40 is disposed within the sealed water area, the jet water conduit 16 can be made compact. As a result, even if the jet water conduit 16 is made compact, jet water spouting sufficient to discharge waste can be performed, and waste discharge performance can be improved.

[0060] Furthermore, in a flush toilet 1 according to an embodiment of the present invention, the curved flow path 16b is arranged within the water-sealing area, allowing the jet water conduit 16 to be made compact. Also, because the curved flow path 16b is arranged within the water-sealing area, the curved flow path 16b can be kept constantly full of 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 spouted from the jet water spouting port 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 towards 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 body between the upstream flow path 16a and the straightening section 42 of the downstream flow path 16c, so that the space between the upstream flow path 16a and the straightening section 42 of the downstream flow path 16c can be made thin, making the jet water conduit 16 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 nearly 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, making it possible to prevent flow separation 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 spouted from the jet water spouting port 14 nearly uniform.

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

[0065] 1: Flush toilet 2: Toilet 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 line 8e: Upper end of the inlet of the drain trap pipe 10: Rim spout 14: Jet water outlet 14a: Top of the jet outlet 16: Jet Waterway 16a: Upstream channel of the jet channel 16b: Curved channel 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 conduit 16h: Top surface of the bent channel of the jet waterway 16i: Top surface of the downstream channel of the jet conduit 18: Waste receiving surface 20: Rim section 26: Drainage device 30: Overflow pipe 32: Drain valve 40: Curved section 42: Rectifier D: Eccentricity distance F1: Cleaning water for the inner surface F2: Washing water on the outer surface O1: Center of jet outlet O2: Center of the drain trap pipe inlet O3: Center of downstream end of bent channel X: Central axis of the jet channel 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 periphery R2: Radius of curvature on the downstream side of the outer periphery r1: Radius of curvature on the upstream side of the inner periphery r2: Radius of curvature on the downstream side of the inner circumferential surface W: Water sealing surface

Claims

1. A siphon jet type 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 upwardly extending riser pipe, a downwardly extending faller pipe from the riser pipe, and a top portion located between the faller pipe and the riser pipe and defining a seal water level; a jet water outlet provided at the bottom of the bowl portion and configured to discharge flush water toward an inlet of the drain trap pipe; a wash water source for supplying wash water to the jet outlet; a jet water conduit that connects the wash water source and the jet water outlet and supplies wash water from the wash water source to the jet water outlet; having the jet water conduit has an upstream flow passage extending forward from the wash water source, a bent flow passage bending from the upstream flow passage, and a downstream flow passage extending rearward from the bent flow passage and connecting to the jet water outlet, a curved portion is formed in the downstream flow path of the jet water conduit, the curved portion being eccentric to a side opposite to the upstream flow path with respect to a central axis of the jet water spouting port in a top view, A flush toilet characterized in that the curved portion is disposed within the water sealing area when viewed from above.

2. The flush toilet according to claim 1 , wherein the curved flow path is disposed within the water sealing area when viewed from above.

3. 3. The flush toilet according to claim 1 or 2, wherein a flow straightening section that extends 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 an 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.

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