JP7802269B2 - flush toilet - Google Patents

Description

The present invention relates to flush toilets, and in particular to siphon jet flush toilets in which the jet waterway is located below the top of the drain trap pipe.

Siphon jet flush toilets have been known for some time, in which flush water is discharged from a jet spout and waste is discharged by generating a siphon action within the drain trap pipe. Siphon jet flush toilets include low-silhouette toilets that are equipped with a water storage tank for storing flush water, with the bottom of this storage tank positioned lower than the top surface of the rim (see, for example, Patent Documents 1 and 2). Low-silhouette toilets have a low water storage tank, which has the advantage of providing an excellent external design for the entire toilet.

Special Publication No. 2010-531399 Japanese Patent Application Laid-Open No. 2006-291451

However, in low-profile siphon jet flush toilets, part of the water storage tank is positioned lower than the top of the rim, and the jet waterway is positioned lower than the top of the drain trap. As a result, sufficient head pressure cannot be applied to the flush water flowing through the jet waterway, and a jet of water sufficient to expel waste cannot be produced, resulting in a problem of reduced waste discharge performance.

The present invention was made to solve the above-mentioned problems, and aims to provide a siphon jet flush toilet in which the jet water conduit is located below the top of the drain trap pipe, and which is capable of jetting water sufficient to discharge waste and improving waste discharge performance.

In order to achieve the above object, the present invention provides a siphon jet flush toilet in which the jet water conduit is located below the top of the drain trap conduit, comprising a water storage tank for storing flush water, 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 for spouting flush water toward the bowl portion, a drain trap conduit including an ascending conduit provided at the bottom of the bowl portion and extending upward, a descending conduit extending downward from this ascending conduit, and a top portion located between this descending conduit and the ascending conduit and defining the seal water level, and a drain trap conduit provided at the bottom of the bowl portion. a jet spout that spouts flush water toward the inlet of the flushing machine; a jet water conduit that connects the jet spout to the water storage tank and supplies flush water from the water storage tank to the jet spout; and a drainage device that supplies or stops the flush water stored in the water storage tank to the jet water conduit, wherein the drainage device is activated and flush water in the water storage tank flows into the jet water conduit, causing a first flow rate to be spouted from the jet spout, and after spouting of this first flow rate has finished, flush water remaining in the jet water conduit flows toward the jet spout, causing a second flow rate to be spouted from the jet spout.
In the present invention configured in this way, the drainage device is driven and flush water in the storage tank flows into the jet water conduit, causing a first flow rate to be discharged from the jet water outlet, and after this first flow rate has finished, flush water remaining in the jet water conduit flows toward the jet water outlet, causing a second flow rate to be discharged from the jet water outlet, so that siphon action is generated by the first flow rate and can be continued by the second flow rate.As a result, even in a siphon jet flush toilet in which the jet water conduit is positioned below the top of the drain trap pipe, a siphon action sufficient to discharge waste can be generated and continued, thereby improving waste discharge performance.

In the present invention, the maximum instantaneous flow rate of the second flow rate is preferably set to be smaller than the maximum instantaneous flow rate of the first flow rate.
In the present invention configured as described above, the maximum instantaneous flow rate of the second flow rate is set to be smaller than the maximum instantaneous flow rate of the first flow rate, so that the siphon action can be continued by the second flow rate, which has a smaller maximum instantaneous flow rate, thereby achieving both improved waste discharge performance and water conservation.

In the present invention, the instantaneous flow rate of the second flow rate is preferably set to increase more slowly than the instantaneous flow rate of the first flow rate and reach the maximum instantaneous flow rate.
In the present invention configured in this way, the instantaneous flow rate of the second flow rate is set to increase more gradually than the instantaneous flow rate of the first flow rate before reaching the maximum instantaneous flow rate, so turbulence of the flush water spouted from the jet spouting port can be suppressed compared to when the instantaneous flow rate is increased suddenly.This allows the flush water to flow smoothly into the drain trap pipe line and continue the siphon action.

In the present invention, the flush water volume for the large flush or small flush is preferably switched by adjusting the jet water spouting time at the first flow rate.
In the present invention configured in this manner, the amount of flush water for the large flush or small flush is switched by adjusting the jet water spouting time at the first flow rate, so the amount of flush water can be switched accurately.

In the present invention, preferably, after the drainage device has stopped, water is discharged from the jet water discharge port at the second flow rate.
In the present invention configured in this manner, after the drainage device is stopped, a second flow rate is discharged from the jet water outlet, so that the second flow rate can be discharged from the jet water outlet using the cleaning water remaining in the jet water conduit.

In addition, in the present invention, the jet water conduit preferably has an upstream flow path extending forward from the water storage tank, a curved flow path bending from this upstream flow path, and a downstream flow path extending rearward from this curved flow path and connecting to the jet water outlet, the upstream flow path being arranged approximately parallel to the drain trap pipe, and the bottom surface on the downstream side of the upstream flow path being located below the upper end of the inlet portion of the drain trap pipe.
In the present invention configured in this manner, the upstream flow path is arranged approximately parallel to the drain trap pipe, and the bottom surface of the downstream side of the upstream flow path is located lower than the upper end of the inlet portion of the drain trap pipe.Therefore, even when the sealing water level drops and the siphon action is about to end, cleaning water continues to stagnate downstream of the upstream flow path, allowing the siphon action to continue.

In the present invention, preferably, in a region forward of the top of the drain trap pipe, the bottom surface of the upstream flow path is located below the upper end of the inlet of the drain trap pipe.
In the present invention configured in this manner, in the area forward of the top of the drain trap pipe, the bottom surface of the upstream flow path is located below the upper end of the inlet portion of the drain trap pipe, so even when the seal water level drops and the siphon action is about to end, cleaning water continues to remain in the upstream flow path, allowing the siphon action to continue.

In the present invention, the center of the jet water spouting port is preferably located at the lowest point on the central axis of the jet water conduit.
In the present invention configured in this manner, the centre of the jet water spouting outlet is positioned at the lowest point on the central axis of the jet water conduit, so wash water can be spouted from the jet water spouting outlet for a long period of time.

In the present invention, the water storage tank is preferably provided with an overflow pipe for draining overflowing water from the water storage tank, and this overflow pipe is provided at the same position as the drainage device or behind the drainage device.
In the present invention configured in this manner, the water storage tank is provided with an overflow pipe for draining overflowing water from the water storage tank, and this overflow pipe is provided at the same position as the drainage device or behind the drainage device, so that air can be replaced through the overflow pipe behind the jet water conduit, preventing the flow toward the jet water outlet from being obstructed by air replacement.

In the present invention, the jet water conduit preferably has a volume equal to or greater than one-third of the volume of the water storage tank.
In the present invention configured in this way, the jet water conduit has a volume at least one-third that of the water storage tank, so a large amount of flush water can be retained within the jet water conduit. This allows for a jet of water sufficient to discharge waste even if the water storage tank is made smaller.

In the present invention, flush water is preferably discharged from the rim discharge port after the drainage device has been stopped.
In the present invention configured in this manner, flush water is discharged from the rim spout after the drainage device is stopped, so even if the drainage device is stopped, the flush water from the rim spout is added to the flush water discharged from the jet spout, allowing the siphon action to continue for a longer period.

The flush toilet of the present invention is a siphon jet type flush toilet in which the jet water conduit is positioned below the top of the drain trap pipe, and is capable of jetting water sufficient to discharge waste, thereby providing a flush toilet that can improve waste discharge performance.

1 is a plan view showing a flush toilet according to an embodiment of the present invention. FIG. FIG. 2 is a side cross-sectional view taken along line II-II in FIG. 1. 1 is a perspective view of an entire jet conduit according to an embodiment of the present invention; FIG. FIG. 3 is a partially enlarged view of the jet spout portion of the flush toilet according to the embodiment of the present invention shown in FIG. 2. 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. 1. 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. 5. 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. 5. 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. 5. 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. 5. 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. 5. 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. 5. 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. 5. FIG. 2 is a diagram for explaining the flushing operation of a flush toilet according to an embodiment of the present invention. 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. 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.

A flush toilet 1 according to a first embodiment of the present invention will now be described.
First, the basic structure of a flush toilet 1 according to the first embodiment will be explained using FIGS. 1 and 2.
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.

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).

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

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 line 8. A water sealing surface W is formed inside this pot portion 22.

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).

The rim spout 10 is formed on the rear left side of the rim portion 20 when viewing the toilet body 2 from the front. The rim spout 10 spouts flush water forward, and this flush water flows down to the waste receiving surface 18 while swirling around the inner surface of the rim portion 20 and the shelf surface of the shelf portion 21.

The rim conduit 12 is formed in a tapered shape, with the cross section of the flow path gradually decreasing 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 the flush water is discharged from the rim spout 10 due to the water supply pressure of the water supply.

The jet water outlet 14 is formed at the bottom of the bowl portion 6. The jet water outlet 14 is positioned 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, activating the siphon action.

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 the upstream flow path 16a, and a downstream flow path 16c extending rearward from the 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 head pressure of this flush water causes flush water to be discharged from the jet water outlet 14.

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 portion 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.

The water storage tank 4 is provided with 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 operation signals from the user, and an operation unit (not shown) that transmits operation signals in response to user operation.

The water supply device 24 includes a constant flow valve (not shown) connected to the water supply, a rim-side solenoid valve 23 that supplies or stops flush water to the rim spout 10, and a tank-side solenoid valve 27 that supplies or stops flush water to the 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 driven by commands from a controller based on user operation signals and water level detection signals from a float switch 28.

The drainage device 26 comprises an overflow pipe 30 that drains overflowing water from the 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 storage tank 4. The toilet flushing unit 36 is 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.

The controller is electrically connected to the operation unit, float switch 28, rim-side solenoid valve 23, tank-side solenoid valve 27, and toilet flush 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 flush 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.

Next, the jet water conduit 16 of the flush toilet according to this embodiment will be described in detail with reference to FIGS. 1 to 4.
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.

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, located on the right side when viewing the toilet body 2 from the front, to the jet spout 14, 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 curved flow path 16b of the jet water conduit 16 also curves (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 curved flow path 16b toward the inlet 8a of the drain trap pipe 8.

Next, as shown in FIG. 2, the jet water conduit 16 is arranged below the top 8d of the drain trap pipe 8, i.e., below the water surface W, except for a portion of area A (the area near the drain outlet 4a of the water storage 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 and horizontal width of the flow path cross section than conventional products, thereby increasing the overall volume of the jet water conduit. Specifically, the jet water conduit 16 has a volume (approximately 1 liter) that is more than one-third the volume of the water storage tank 4 (approximately 3 liters). Furthermore, the jet water conduit 16 has a volume (approximately 1 liter) that is more than half the amount of flush water (approximately 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 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 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.

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

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 point on the central axis X of the jet water conduit 16 (see Figure 2). As a result, because the center O1 of the jet water outlet 14 is located at the lowest point, flush water can be discharged from the jet water outlet 14 for a long period of time, which makes it possible to delay the intrusion of air from the jet water outlet 14 into the jet water conduit 16.

Furthermore, the upper end 14a of the jet water outlet 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 outlet 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 allows almost all of the flush water in the jet water conduit to be discharged before the siphoning action ends. Furthermore, the upper surfaces 16g, 16h, 16i and 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 toward the jet water outlet 14.

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 Figures 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 present 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 present invention shown in FIG.

First, as shown in Figure 5, the downstream flow path 16c and the curved flow path 16b of the jet water conduit 16 have a curved section 40 formed in a top view that is eccentric to the central axis O1 of the jet water outlet 14 on the opposite side to the upstream flow path 16a. The eccentricity distance D between the central axis O1 of the jet water 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 wash water discharged from the jet water outlet 14, ensuring a nearly uniform flow velocity distribution across the flow path cross section of the jet water outlet 14.

Next, as shown in FIG. 1, the curved portion 40 is located in the inner area (within the water sealing area) of the water sealing surface W when viewed from above, and the entire curved flow path 16b is also located in the inner area of the water sealing surface W. This allows the curved portion 40 and curved flow path 16b of the jet water conduit 16 to be compactly formed. Furthermore, because the curved portion 40 and curved flow path 16b are located in the inner area of the water sealing surface W, the curved portion 40 and curved flow path 16b can be kept constantly filled with water, and air retention within the curved portion 40 and curved flow path 16b can be suppressed.

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 outlet 14. The flow straightening section 42 extends approximately 25 mm in a substantially straight line toward the jet water outlet 14. This allows the flush water to be straightened after flowing through the curved section 40.

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

Here, the cleaning water F1 flowing along the inner surface of the curved flow path 16b is separated from the inner surface by centrifugal force, and stagnation S always occurs near the inner surface on the downstream side of the curved flow path 16b (see Figure 5). For this reason, even if the radius of curvature of the inner surface on the downstream side of the curved flow path 16b is reduced, the impact of energy loss is small. Therefore, because the inner surface on the downstream side of the curved flow path 16b, where stagnation S occurs, has a relatively small radius of curvature r2, it is possible to make the curved flow path 16b compact while suppressing energy loss in the cleaning water flowing through the curved flow path 16b.

Furthermore, the cleaning water F2 flowing along the outer peripheral surface of the curved flow path 16b is affected by centrifugal force, resulting in a relatively larger flow rate than the cleaning water F1. The outer peripheral surface downstream 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, allowing the cleaning water F2 to flow while maintaining its flow velocity and preventing flow separation from occurring along the outer peripheral surface of the curved flow path 16b.

Furthermore, the jet water conduit 16 is formed by pour molding (double molding), which forms a solid body 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 the jet water conduit 16 compact.

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, while the bottom surface 16e of the curved flow path 16b and the bottom surface 16f of the downstream flow path 16c are formed at approximately the same height and approximately horizontal.

As shown in Figure 2, the upper surface 16g of the upstream flow path 16a, the upper surface 16h of the curved flow path 16b, and the 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.

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 circumferential surface side than on the inner circumferential surface side. This allows the flow path cross-sectional area of the curved flow path 16b to be larger on the outer circumferential surface side than on the inner circumferential surface side, making it possible to prevent the cleaning water F2 flowing along the outer circumferential surface of the curved flow path 16b from peeling off from the outer circumferential 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 circumferential surface side and the outer circumferential surface side. This allows the cleaning water to be more straightened.

As shown in Figures 6B to 6G, the cross-sections of the curved flow path 16b and the downstream flow path 16c gradually increase in width and decrease in length from the upstream side to the downstream side. This allows a flat, high-volume flow of water to be discharged from the jet water discharge port 14.

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.

Figure 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 area A, a part of the upstream flow path 16a located directly below the water storage tank 4.

Next, as shown in Figure 7(b), the water supply device is activated (the rim-side solenoid valve opens), rim spouting begins, and the flush water level gradually rises in the bowl section 6. Accordingly, the flush water level also gradually rises in the jet water conduit 16, and air that had been trapped in area A of the upstream flow path 16a is expelled from the overflow pipe 30, filling the jet water conduit 16 with water.

After this, as shown in Figure 7(c), while rim water spouting continues, the drain device 26 is activated (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 remaining in the jet water conduit 16, and a first flow rate is spouted from the jet water spout 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, 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.

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.

After that, 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 designed to allow flush water to continue to accumulate, delaying the entry of air and delaying the end of the siphon action. Rim water 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.

Next, as shown in Figure 7(f), the water supply device is activated (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 it has reached the water stop level (full level), the water supply device stops (the tank-side solenoid valve closes), and then the system returns to its original standby state as shown in Figure 7(a).

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 the inlet 8a of the drain trap pipe 8.

In this embodiment, the amount of flush water discharged from the jet water discharge port 14 is approximately 2 liters for a large flush and approximately 1.5 liters for a small flush.

During large flushing, as shown in FIG. 8A, when the drainage device 26 is first activated, jet spouting begins and a first flow rate Q1 is spouted from the jet spout port 14. At this time, the instantaneous flow rate of flush water spouted from the jet spout port 14 increases rapidly immediately after start (increase rate A) and immediately reaches the maximum instantaneous flow rate Q1max. This rapidly activates the siphon action (time T1). After this, the instantaneous flow rate decreases slightly from the maximum instantaneous flow rate Q1max and becomes approximately constant. Furthermore, 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 spout port 14 and the rim spout port 10, seal water is drawn into the drainage trap pipe 8 by siphon action. This allows a powerful siphon action to be activated and continued.

Next, as shown in Figure 8A, after the drainage device 26 is stopped (time T2), when the discharge of the first flow rate Q1 has ended, the second flow rate Q2 is discharged from the jet water spouting port 14. At this time, the instantaneous flow rate of flush water discharged 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 discharged 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, thereby achieving 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 a large amount because, in addition to the flush water discharged from the jet spout 14 and the rim spout 10, seal water is drawn into the drain trap pipe 8 by siphon action.

In a small flush, as shown in FIG. 8B, when the drain device 26 is activated, jet spouting begins and a first flow rate q1 is spouted from the jet spout port 14. At this time, the instantaneous flow rate of flush water spouted from the jet spout port 14 increases rapidly (increase rate a) immediately after start and immediately reaches the maximum instantaneous flow rate q1max. This rapidly activates the 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). Furthermore, 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 spout port 14 and the rim spout port 10, seal water is drawn into the drain trap pipe 8 by siphon action. This allows a powerful siphon action to be activated and continued.

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 spouting port 14. At this time, the instantaneous flow rate of flush water discharged 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 discharged 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, thereby achieving 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 drawn into the drain trap pipe 8 by siphon action, so a large instantaneous flow rate can be maintained.

Comparing the large and small flushes, as shown in Figures 8A and 8B, the flush water volume for the large or small flush is switched by adjusting the jet water spouting time based on the first flow rate Q1 for the large flush and the first flow rate q1 for the small flush. This allows the flush water volume to be switched accurately.

The effects of the above-described embodiment will be described below.
In a flush toilet 1 according to an embodiment of the present invention, the drainage device 26 is driven and flush water in the water storage tank 4 flows into the jet water conduit 16, causing a first flow rate Q1, q1 to be discharged from the jet water spout 14, and after the discharge of this first flow rate Q1, q1 has ended, flush water remaining in the jet water conduit 16 flows towards the jet water spout 14, causing a second flow rate Q2, q2 to be discharged from the jet water spout 14, so that a siphon action is generated by the first flow rates Q1, q1, and the siphon action can be continued by the second flow rates Q2, q2. As a result, even in a siphon jet flush toilet 1 in which the jet water conduit 16 is positioned below the top 8d of the drain trap pipe 8, a siphon action sufficient to discharge waste can be generated and continued, thereby improving waste discharge performance.

Furthermore, in a flush toilet 1 according to an embodiment of the present invention, the maximum instantaneous flow rates Q2max, q2max of the second flow rates Q2, q2 are set to be smaller than the maximum instantaneous flow rates Q1max, q1max of the first flow rates Q1, q1, so siphon action can be continued using the second flow rates Q2, q2, which have a smaller maximum instantaneous flow rate. This allows for both improved waste discharge performance and water conservation.

In a flush toilet 1 according to an embodiment of the present invention, the instantaneous flow rates of the second flow rates Q2, q2 are set to increase more gradually (increase rate b) than the instantaneous flow rates of the first flow rates Q1, q1, reaching the maximum instantaneous flow rates Q2max, q2max. This prevents turbulence in the flush water discharged from the jet spout 14 compared to when the instantaneous flow rates are increased suddenly. This allows the flush water to flow smoothly into the drain trap pipe 8, allowing the siphon action to continue.

Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the flush water volume for the large flush or small flush can be switched by adjusting the jet water spouting time at the first flow rates Q1 and q1, allowing for accurate switching of the flush water volume.

In a flush toilet 1 according to an embodiment of the present invention, after the drainage device 26 stops, the second flow rate Q2, q2 is discharged from the jet water spout 14, so the flush water remaining in the jet water conduit 16 can be used to discharge the second flow rate Q2, q2 from the jet water spout 14.

Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the upstream flow path 16a is arranged approximately parallel to the drain trap pipe 8, and the bottom surface 16d on the downstream side of the upstream flow path 16a is located below the upper end 8e of the inlet 8a of the drain trap pipe 8. Therefore, even when the seal water level drops and the siphon action is about to end, flush water continues to accumulate downstream of the upstream flow path 16a, allowing the siphon action to continue.

In a flush toilet 1 according to an embodiment of the present invention, in the area forward of the top 8d of the drain trap pipe 8, the bottom surface 16d of the upstream flow path 16a is located below the upper end 8e of the inlet 8a of the drain trap pipe 8. Therefore, even when the seal water level drops and the siphon action is about to end, flush water continues to remain in the upstream flow path 16a, allowing the siphon action to continue.

Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the center O1 of the jet water spout 14 is positioned at the lowest point of the central axis X of the jet water conduit 16, allowing flush water to be discharged from the jet water spout 14 for a long period of time.

In a flush toilet 1 according to an embodiment of the present invention, the water storage tank 4 is provided with an overflow pipe 30 for draining overflowing water from the water storage tank 4. This overflow pipe 30 is located in the same position as the drainage device 26 or further rearward than the drainage device 26, allowing air replacement via the overflow pipe 30 behind the jet water conduit 16, preventing the flow toward the jet water outlet 14 from being obstructed by air replacement.

Furthermore, in the flush toilet 1 according to an embodiment of the present invention, the jet water conduit 16 has a volume that is at least one-third the capacity of the water storage tank 4, allowing a large amount of flush water to be retained within the jet water conduit 16. This makes it possible to produce a jet of water sufficient to expel waste even if the water storage tank 4 is made smaller.

In a flush toilet 1 according to an embodiment of the present invention, flush water is discharged from the rim spout 10 after the drainage device 26 is stopped. Therefore, even if the drainage device 26 is stopped, flush water from the rim spout 10 is added to the flush water discharged from the jet spout 14, allowing the siphon action to continue for a longer period of time.

The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the technical concept described in the claims.

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

Claims (10)

A siphon jet flush toilet in which the jet waterway is located below the top of the drain trap pipe,
a water storage tank for storing cleaning water;
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 for 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 jet water conduit that connects the jet water outlet and the water storage tank and supplies flush water from the water storage tank to the jet water outlet;
a drainage device that supplies or stops the flush water stored in the water storage tank to the jet waterway;
and
The drainage device is driven to cause flush water in the water storage tank to flow into the jet water conduit, thereby discharging a first flow rate from the jet water spouting outlet, and after the discharge of this first flow rate has ended, flush water remaining in the jet water conduit flows towards the jet water spouting outlet, thereby discharging a second flow rate from the jet water spouting outlet ,
A flush toilet characterized in that the instantaneous flow rate of the second flow rate is set to increase more gradually than the instantaneous flow rate of the first flow rate and reach a maximum instantaneous flow rate . A siphon jet flush toilet in which the jet waterway is located below the top of the drain trap pipe,
a water storage tank for storing cleaning water;
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 for 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 jet water conduit that connects the jet water outlet and the water storage tank and supplies flush water from the water storage tank to the jet water outlet;
a drainage device that supplies or stops the flush water stored in the water storage tank to the jet waterway;
and
The drainage device is driven to cause flush water in the water storage tank to flow into the jet water conduit, thereby discharging a first flow rate from the jet water spouting outlet, and after the discharge of this first flow rate has ended, flush water remaining in the jet water conduit flows towards the jet water spouting outlet, thereby discharging a second flow rate from the jet water spouting outlet,
A flush toilet wherein the second flow rate is discharged from the jet spout after the drainage device has stopped. A siphon jet flush toilet in which the jet waterway is located below the top of the drain trap pipe,
a water storage tank for storing cleaning water;
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 for 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 jet water conduit that connects the jet water outlet and the water storage tank and supplies flush water from the water storage tank to the jet water outlet;
a drainage device that supplies or stops the flush water stored in the water storage tank to the jet waterway;
and
The drainage device is driven to cause flush water in the water storage tank to flow into the jet water conduit, thereby discharging a first flow rate from the jet water spouting outlet, and after the discharge of this first flow rate has ended, flush water remaining in the jet water conduit flows towards the jet water spouting outlet, thereby discharging a second flow rate from the jet water spouting outlet,
A flush toilet characterized in that flush water is discharged from the rim spout after the drainage device is stopped. 4. The flush toilet according to claim 1 , wherein the maximum instantaneous flow rate of the second flow rate is set to be smaller than the maximum instantaneous flow rate of the first flow rate. The flush toilet according to any one of claims 1 to 3 , wherein the flush water volume for a large flush or a small flush is switched by adjusting the jet water spouting time at the first flow rate. the jet water conduit has an upstream flow path extending forward from the water storage tank, 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,
A flush toilet according to any one of claims 1 to 3, wherein the upstream flow path is arranged approximately parallel to the drain trap pipe, and when the upstream flow path is divided into two equal parts , the bottom surface on the downstream side is located below the upper end of the inlet of the drain trap pipe. A flush toilet as described in claim 6, wherein, in the region forward of the top of the drain trap pipe, the bottom surface of the upstream flow path is located below the upper end of the inlet of the drain trap pipe. 7. The flush toilet according to claim 6 , wherein the center of the jet spout is positioned at the lowest point on the central axis of the jet water conduit. The flush toilet according to any one of claims 1 to 3 , wherein the storage tank is provided with an overflow pipe for draining water that overflows from the storage tank, and this overflow pipe is provided in the same position as the drainage device or behind the drainage device. The flush toilet according to any one of claims 1 to 3 , wherein the jet water conduit has a volume equal to or greater than one-third of the volume of the water storage tank.