JP7575692B2 - Bathtub cleaning device - Google Patents

Description

The present invention relates to a bathtub cleaning device, and in particular to a bathtub cleaning device that can prevent overflow or water shortage in the hot water storage section by switching the flow rate of hot water supplied to the hot water storage section between two levels.

Conventionally, bathtub cleaning devices have employed a system in which tap water from a water source is stored in a storage tank, and the water in this storage tank is pressurized with a pump and sprayed onto the inside of the bathtub along with detergent from a spray nozzle on the side of the bathtub to clean the inside of the bathtub.

For example, in the bathtub cleaning device described in Patent Document 1, tap water from a water source is stored in an atmospheric tank, and the water in this atmospheric tank is pressurized by a pump and sprayed onto the inner surface of the bathtub together with detergent from a spray nozzle on the bathtub side to clean the inner surface of the bathtub.

In the automatic bathtub cleaning device described in Patent Document 2, a water supply pipe is connected to the cleaning nozzle from a water tank connected to a water mains, a detergent supply pipe extending from a detergent supply tank is connected to the water supply pipe, and a mixture of clean water and detergent is sprayed from the cleaning nozzle to automatically clean the inside of the bathtub.

However, in recent years, bathtub cleaning devices that do not use tap water directly but use hot water and detergent supplied from a hot water supply system are becoming more widely used.

Publication number 4-406632 Japanese Patent Application Publication No. 10-272071

Recent bathtub cleaning devices are equipped with a hot water storage section that can store hot water, a pressure pump that pressurizes the hot water from the hot water storage section and sends it to the cleaning nozzle, and the hot water supply section is equipped with a constant flow valve and an electromagnetic opening and closing valve, etc. Also, the hot water storage section is equipped with a liquid level sensor.
If the maximum water discharge rate of the pressure pump is not sufficient compared to the amount of hot water flowing into the hot water storage section, it becomes very difficult to prevent overflow or water shortages if the liquid level control in the hot water storage section is based solely on the liquid level detected by the liquid level sensor.

For example, several measures can be considered to address the above issues.
In the first measure, the amount of hot water flowing into the hot water reservoir is precisely controlled by a flow control valve or the like so that it is equal to the amount of water discharged by the pump.
The second measure is to provide a sufficient margin for the maximum water discharge volume of the pump, and to discharge an amount of water equal to the amount of hot water flowing into the hot water storage section.
In the third measure, even in an environment where the amount of water flowing into the hot water storage section is unknown, signs of overflow or drought are detected based on the detection signal from a liquid level sensor, and the amount of water flowing in is controlled using a highly responsive flow control valve, etc.

The above first to third measures require a flow rate adjustment valve capable of variably controlling the flow rate and a control means therefor, or a large pump.
The object of the present invention is to provide a bathtub cleaning device that can prevent overflow and water shortages by using a simple configuration that switches the inflow rate into the hot water storage section between two levels, large and small, without having to enlarge the pump or use a flow control valve.

The bathtub cleaning device of claim 1 is a bathtub cleaning device equipped with a hot water storage section that is provided in the middle of a hot water passage that supplies hot water to a cleaning nozzle and can store hot water supplied from the hot water passage, and a pump that can send the hot water from the hot water storage section to the cleaning nozzle, characterized in that the hot water passage that supplies hot water to the hot water storage section is provided with multiple branch passages, multiple electromagnetic opening/closing valves, and a constant flow valve, and is configured to be switchable between a first mode in which hot water is supplied to the hot water storage section at a first flow rate that is greater than the water discharge rate of the pump, and a second mode in which hot water is supplied at a second flow rate that is less than the water discharge rate.

According to the above configuration, overflow and water shortage can be prevented by switching to the first mode when the liquid level in the hot water storage section drops to a low water level, and by switching to the second mode when the liquid level in the hot water storage section rises to a high water level. The first flow rate and the second flow rate can be achieved by switching the number of constant flow rate valves that flow hot water by opening and closing multiple electromagnetic opening and closing valves.

The bathtub cleaning device of claim 2 is characterized in that, in the invention of claim 1, the electromagnetic opening/closing valve is provided in at least one of the multiple branch passages, and the constant flow valve is provided in at least one of the multiple branch passages.
According to the above configuration, hot water is supplied from all of the plurality of branch passages at the first flow rate, and hot water is supplied from some of the plurality of branch passages at the second flow rate.

The bathtub cleaning device of claim 3 is characterized in that, in the invention of claim 1 or 2, the hot water storage section is provided with a plurality of water supply ports each connected to the plurality of branch passages and for supplying hot water to the hot water storage section.
According to the above configuration, hot water that has flowed through multiple branch passages can be supplied to the hot water storage section from a water supply port connected to those branch passages, so that the flow rate of hot water supplied from one water supply port is reduced, thereby reducing the number of air bubbles that are generated in the hot water storage section and suppressing air entrainment in the pump.

The bathtub cleaning device of claim 4 is the invention of claim 3, characterized in that the plurality of branch passages are formed by pipe material connecting the constant flow valve and the water supply port.
According to the above configuration, since the branch passage is made of a pipe material, the configuration of the branch passage can be simplified, assembly can be simplified, and manufacturing costs can be reduced. In addition, the structure for connecting the branch passage to the hot water storage section can be simplified, which is advantageous in terms of ensuring sealing.

The bathtub cleaning device of claim 5 is characterized in that, in the invention of claim 1 or 2, the downstream ends of the multiple branch passages are connected to a junction passage, and hot water is supplied to the hot water storage section from the junction passage.
According to the above configuration, it is possible to minimize the area in which the multiple branch passages are provided, thereby increasing the degree of freedom in design.

The bathtub cleaning device of claim 6 is an invention of any one of claims 1 to 5, characterized in that the hot water storage section is equipped with a water level detection means capable of detecting at least a high water level and a low water level, and is configured to supply hot water at the second flow rate when a high water level is detected and to supply hot water at the first flow rate when a low water level is detected during pump operation.

According to the above configuration, the second flow rate is used when the water level is high, so that any further rise in the water level can be reliably prevented, and overflow can be prevented. Similarly, the first flow rate is used when the water level is low, so that any further drop in the water level can be reliably prevented, and drought can be prevented.

The bathtub cleaning device of claim 7 is the invention of claim 6, characterized in that when operation starts, hot and cold water is supplied at the second flow rate, which is the lower rate, until a high water level is detected, and then the pump operation starts. With the above configuration, it is possible to prevent the pump from sucking in air when operation starts.

The present invention provides the various effects described above.

1 is a configuration diagram of a hot water supply device, a bathtub, a bathtub cleaning device, etc. according to a first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of a cleaning unit of the bathtub cleaning device. 5 is an explanatory diagram of the operation of controlling an electromagnetic valve in the cleaning unit; FIG. FIG. 7 is a view corresponding to FIG. 3 according to a second embodiment. FIG. 11 is a diagram showing the configuration of a first switching mechanism for switching the hot and cold water flow rate in the third embodiment. FIG. 11 is a configuration diagram of a second switching mechanism according to the third embodiment. FIG. 11 is a configuration diagram of a third switching mechanism according to the third embodiment. FIG. 11 is a configuration diagram of a fourth switching mechanism according to the third embodiment. FIG. 13 is a configuration diagram of a fifth switching mechanism according to the third embodiment. FIG. 11 is a configuration diagram of a cleaning unit according to a fourth embodiment, as viewed from the front side. FIG. 11 is a plan view of the cleaning unit of FIG. 10 .

The best mode for carrying out the present invention will be described below with reference to the drawings.

As shown in Figures 1 and 2, a hot water supply device 2 for filling and reheating the bathtub 1 is connected to the bathtub 1 via a filling and reheating pipe 3. In addition, a drain plug 4 for automatically draining hot and cold water is provided at the bottom of the bathtub 1, and a cleaning nozzle 5 for cleaning the bathtub 1 by spraying detergent and hot and cold water. A lid 1a is placed over the bathtub 1.

A cleaning unit 6 that supplies detergent and hot and cold water to the cleaning nozzle 5, and a detergent tank 7 that stores detergent are arranged near the bathtub 1. The bathtub cleaning device 10 has the cleaning unit 6, detergent tank 7, and cleaning nozzle 5, which are connected by multiple pipes.

The washing unit 6 is connected to a detergent pipe 7a for supplying detergent from the detergent tank 7 and a hot water supply pipe 2a for supplying hot water from the hot water supply device 2. A level sensor is provided in the detergent tank 7, and its detection signal is supplied to the power supply communication unit 8 via a signal line 7b. In addition, the power supply communication unit 8 and the washing unit 6, which are installed on the ceiling of the bathroom, for example, are connected by a cord 8a that bundles a power cord for power supply and a communication cord.

The hot water supply device 2 is, for example, a combustion-type hot water supply device that supplies hot water heated by using the heat of combustion of fuel, but it may also be a hot water supply device having a heat pump-type heat source unit. A bathroom remote control 11 and a kitchen remote control 12 are communicatively connected to the hot water supply device 2 for starting the water filling operation and the reheating operation, setting the hot water supply temperature, etc. Also connected to the hot water supply device 2 is a cleaning remote control 13 for starting the cleaning operation by the bathtub cleaning device 10, etc.

The water heater 2 and the power communication unit 8 are connected by a cord 8b that bundles a power cord for power supply and a communication cord, and the cleaning remote control 13 can communicate with the bathtub cleaning device 10 via the water heater 2 and the power communication unit 8. The kitchen remote control 12 and the bathroom remote control 11 can also communicate with the bathtub cleaning device 10. The kitchen remote control 12 has a touch-operable display unit 12a and an audio output unit 12b. The cleaning remote control 13 has a two-digit number display unit 13a and an audio output unit 13b.

The kitchen remote control 12 and the cleaning remote control 13 are operation terminals for starting the cleaning operation of the bathtub cleaning device 10. The bathroom remote control 11 can also be used to start the cleaning operation of the bathtub cleaning device 10.

As shown in FIG. 2, the cleaning unit 6 of the bathtub cleaning device 10 includes a control unit 21 that controls the equipment related to the cleaning operation, a storage tank 22 (hot water storage section) that stores hot water, a hot water supply pipe 23 (corresponding to a part of the hot water passage) that is connected to the hot water supply pipe 2a and supplies hot water to the storage tank 22, the hot water supply pipe 23 having two branch passages 23a, 23b and a junction passage 23c (the downstream end of which is connected to the storage tank 22) where the branch passages 23a join, a filter 24 installed in the hot water supply pipe 23, an electromagnetic opening/closing valve 25a and a constant flow valve 26a installed in the branch passage 23a from the upstream side, and an electromagnetic opening/closing valve 25b and a constant flow valve 26b installed in the other branch passage 23b from the upstream side.

The storage tank 22 is provided with a float-type water level detector 22a capable of detecting low and high water levels, and the detection signal is supplied to the control unit 21. An overflow pipe 22b (see FIG. 1) is also provided extending from the storage tank 22.

The washing unit 6 further includes a discharge pipe 27 (corresponding to part of the hot and cold water passage) extending from the storage tank 22 to the washing noble 5, a pump 28, two check valves 30, a flow rate sensor 31, a thermistor 29, and an orifice 32 to which the detergent supply pipe 7a is connected, which are arranged in this order from the upstream side. An electromagnetic opening/closing valve 7c is arranged in the detergent supply pipe 7a extending from the detergent tank 7.

The control unit 21 is, for example, a microcomputer equipped with a calculation unit, a memory unit, an input/output unit, and a clock circuit, and controls the equipment related to the washing operation and the drain plug 4 based on a control program stored in the memory unit. During the washing operation, the control unit 21 opens the drain plug 4, controls the opening and closing of the electromagnetic valves 25a, 25b, 7c of the hot water supply pipe 23 and the detergent supply pipe 7a, and controls the operation of the pump 28, and stores the washing operation history including the start and end times of the washing operation, the washing course, the number of washing operations (number of automatic washings), etc.

The cleaning operation will now be described.
When an operation to start the cleaning operation by bathtub cleaning device 10 is performed by operating an operating terminal such as kitchen remote control 12, control unit 21 stores hot and cold water in storage tank 22, while driving pump 28 to mix detergent with the hot and cold water supplied to cleaning nozzle 5, and sprays the detergent and hot and cold water from cleaning nozzle 5. After spraying detergent and hot and cold water for a certain period of time, hot and cold water is sprayed from cleaning nozzle 5 as a rinsing wash to wash away detergent and dirt. This spraying of detergent and hot and cold water, and spraying of hot and cold water, is repeated a predetermined number of times, and then the cleaning operation ends.

Next, with reference to Figures 3(a) to (h), we will explain the solenoid valve opening and closing control that controls the flow rate of hot and cold water supplied to the storage tank 22 via the solenoid opening and closing valves 25a, 25b and the constant flow valves 26a, 26b based on the water level detected by the water level detection sensor 22a when performing cleaning.
The constant flow valves 26a and 26b are constant flow valves that limit the flow rate to 5 L/min, and the discharge rate of the pump 28 is 6.5 L/min (constant).

This solenoid valve opening/closing control can be switched between a first mode in which hot water is supplied to the storage tank 22 at a first flow rate (10 L/min) that is greater than the discharge rate of the pump 28, and a second mode in which hot water is supplied at a second flow rate (5 L/min) that is less than the discharge rate.

Figure 3(a) shows the state immediately after the start of the washing operation, where the solenoid valve 7b for supplying detergent is open, the storage tank 22 is almost empty, and the water level is at the lowest limit. In this state, only one solenoid valve 25a is open, the pump 28 is in standby, and hot water is supplied to the storage tank 22 through the constant flow valve 26a at 5 L/min. As shown in Figure 3(b), when the water level becomes high and is detected by the water level detector 22a, the solenoid valve 25a is also closed to prevent the water level from overflowing as shown in Figure 3(c), and the pump 28 starts operating. Immediately after that, as shown in Figure 3(d), only one solenoid valve 25b is opened, and hot water is supplied through the constant flow valve 26b at 5 L/min.

Then, since the supply of hot water to the storage tank 22 is 5 L/min, while the discharge rate of the pump 28 is 6.5 L/min, the water level in the storage tank 22 gradually drops, and when the water level in the storage tank 22 drops to a low level as detected by the water level detector 22a, as shown in FIG. 3(e), in order to raise the water level, in addition to the electromagnetic on-off valve 25b, the other electromagnetic on-off valve 25a is also opened, and hot water is supplied to the storage tank 22 at 10 L/min via the constant flow valves 26a and 26b, causing the water level to rise.

The supply rate of hot and cold water is 10 L/min, while the discharge rate of pump 28 is 6.5 L/min. Therefore, the water level gradually rises, and when it reaches a high water level as shown in FIG. 3(d) and is detected by water level detector 22a, solenoid valve 25a is closed and only solenoid valve 25b is left open.

Then, since the supply of hot water to the storage tank 22 is 5 L/min, while the discharge rate of the pump 28 is 6.5 L/min, the water level in the storage tank 22 gradually drops, and when the water level in the storage tank 22 drops to a low level as detected by the water level detector 22a, as shown in FIG. 3(e), the two electromagnetic valves 25a and 25b are opened to raise the water level, and hot water is supplied to the storage tank 22 at 10 L/min, causing the water level to rise.

During cleaning, the cycle repeats as shown above in Figure 3(d) → Figure 3(e) → Figure 3(d) → Figure 3(e)... Therefore, the water level repeatedly rises and falls between the high and low water levels.

After washing with hot water and detergent for a specified time, a rinse wash is performed for a set time in the same manner as above. In this case, however, the solenoid valve 7c is closed and the supply of detergent is cut off during washing. After washing with detergent and hot water and rinsing with hot water are repeated a specified number of times, the washing operation is ended as follows.

When the flushing operation is to be ended from the state shown in FIG. 3(f) or from the state shown in FIG. 3(e), as shown in FIG. 3(g), both electromagnetic valves 25a and 25b are switched to the closed state, water is continued to be discharged by pump 28 for a predetermined short time from the point when the water level becomes low, and pump 28 is stopped when storage tank 22 is almost empty as shown in FIG. 3(h).

Next, the operation and effect of the above-described solenoid valve opening and closing control will be described.
When the liquid level in the storage tank 22 drops to a low water level, the system switches to a first mode in which hot water is supplied at a first flow rate greater than the discharge rate, and when the liquid level in the storage tank 22 rises to a high water level, the system switches to a second mode in which hot water is supplied at a second flow rate less than the discharge rate, thereby preventing overflow and water shortages in the storage tank 22. The first flow rate and the second flow rate can be achieved by switching the number of constant flow valves (i.e., the flow rate) that allow hot water to flow out of the two constant flow valves by opening and closing the two electromagnetic on-off valves 25a, 25b.

Of the two branch passages 23a, 23b, one branch passage 23a is provided with an electromagnetic opening/closing valve 25a and a constant flow valve 26a, and the other branch passage 23b is provided with a constant flow valve 26b and a constant flow valve 26b. Therefore, when the first flow rate is reached, hot water is supplied from both of the two branch supply passages 23a, 23b, and when the second flow rate is reached, hot water is supplied from one of the branch supply passages 23a or 23b.

The downstream ends of the two branch passages 23a, 23b are connected to the junction passage 23c, and hot and cold water is supplied to the storage tank 22 from the junction passage 23c, so it is possible to minimize the area in which the two branch passages 23a, 23b are provided, allowing for greater freedom in design.

The storage tank 22 is equipped with a water level detector 22a capable of detecting at least high and low water levels, and when the pump is operating, hot water is supplied at a second flow rate that is less than the discharge rate when a high water level is detected, and hot water is supplied at a first flow rate that is greater than the discharge rate when a low water level is detected.

When the water level is high, the second flow rate is used, which reliably prevents the water level from rising any further and overflows can be prevented. Similarly, when the water level is low, the first flow rate is used, which reliably prevents the water level from falling any further and droughts can be prevented.

When the flushing operation starts, hot and cold water is supplied at the second flow rate, which is lower, until a high water level is detected, and then the pump operation starts, so that the pump can be prevented from sucking in air when the operation starts. Furthermore, since the amount of water discharged from the pump 28 is kept constant, a pump with a simple configuration can be used, and since there is no need to control the rotation speed of the pump 28, the control load on the pump 28 is low.

In this solenoid valve opening and closing control, if the solenoid valves 25a and 25b are switched from an open state to a closed state at the same time, the water hammer phenomenon will worsen. Therefore, the solenoid valves 25a and 25b are not switched from an open state to a closed state at the same time, but are switched from an open state to a closed state one by one.

As shown in FIG. 4, the storage tank 22 of the cleaning unit 6 in this embodiment is provided with a float-type water level detector 22a capable of detecting high and low water levels, as well as an electrode-type water level detector (not shown) capable of detecting the upper limit water level, which is a water level above the high water level and immediately before overflow.

The reason why this upper water level can be detected is as follows.
Since the capacity of the storage tank 22 is very small at approximately 500 cc, it is prone to overflow when the water level is raised at the start of the flushing operation, as shown in Figure 4 (b). In order to prevent overflow, an upper water level limit is made detectable.
At the start of the cleaning operation, the water level is raised to the upper limit water level as shown in FIG. 4(b), and the subsequent control shown in FIGS. 4(c) to 4(h) is the same as in the first embodiment, so a description thereof will be omitted.

We will explain various forms of the switching mechanism that switches the hot and cold water flow rate via a branch passage, a constant flow valve, and an electromagnetic opening and closing valve provided in the hot and cold water supply pipe 23 of the washing unit 6. Note that the discharge rate of the pump 28 of the washing unit 6 is 6.5 L/min, and the other configuration of the washing unit 6 is the same as in Example 1, so the explanation will be omitted.

(a) As shown in FIG. 5, the hot water supply pipe 23 has branch passages 23a and 23b and a junction passage 23c, and an electromagnetic on-off valve 36 is interposed in the hot water supply pipe 23 upstream of the branch passages 23a and 23b. The branch passages 23a and 23b, the electromagnetic on-off valves 25a and 25b, and the constant flow valves 26a and 26b are the same as in the first embodiment.

(b) As in the second switching mechanism shown in FIG. 6, the electromagnetic valve 25a provided in the branch passage 23a of the configuration in FIG. 5 is omitted. When the electromagnetic valve 36 is opened and the electromagnetic valve 25b is closed, hot water can be supplied at 5 L/min, and when the electromagnetic valve 25b is also opened, hot water can be supplied at 10 L/min.

7, a constant flow valve 37 (flow rate: 8 L/min) and an electromagnetic on-off valve 36 are provided in the hot and cold water supply pipe 23 upstream of the branch passages 23a and 23b. A constant flow valve 26c (flow rate: 2 L/min) is provided in one branch passage 23a, and an electromagnetic on-off valve 25b is provided in the other branch passage 23b.
When the electromagnetic valve 36 is opened and the electromagnetic valve 25b is closed, hot water can be supplied at 2 L/min. When the electromagnetic valves 33 and 25b are opened, hot water can be supplied at 8 L/min.

As in the fourth switching mechanism shown in Figure 8, a constant flow valve 38 (flow rate 10 L/min) is interposed in the hot water supply pipe 23 upstream of the branch passages 23a, 23b, an electromagnetic opening/closing valve 25a and a constant flow valve 26a are interposed in one branch passage 23a, and an electromagnetic opening/closing valve 25b is interposed in the other branch passage 23b.
When the electromagnetic valve 25b is closed and the electromagnetic valve 25a is opened, hot water can be supplied at 5 L/min, and when the electromagnetic valve 25a is closed and the electromagnetic valve 25b is opened, hot water can be supplied at 10 L/min.

As in the fifth switching mechanism shown in Figure 9, three branch passages 23a, 23b, and 23d are provided in the hot water supply pipe 23, and an electromagnetic opening/closing valve 25a and a constant flow valve 26a (flow rate of 5 L/min) are provided in the branch passage 23a, an electromagnetic opening/closing valve 25b and a constant flow valve 26c (flow rate of 2 L/min) are provided in the branch passage 23b, and an electromagnetic opening/closing valve 25c and a constant flow valve 26d (flow rate of 2 L/min) are provided in the branch passage 23d.
According to this configuration, the flow rate of hot and cold water to be supplied can be switched between five levels: 2 L/min, 4 L/min, 5 L/min, 7 L/min, and 9 L/min.

Next, a washing unit 6 according to a modified embodiment will be described. However, the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.
10 and 11, electromagnetic on-off valves 25a, 25b and constant flow valves 26a, 26b are mounted in two branch passages 23a, 23b of the hot and cold water supply pipe 23 at the upper part of the inside of the casing 33 of the washing unit 6. Two reinforcing ribs 40 are formed on the inner surface of the middle part of the case 33.

A storage tank 22 is arranged on the upper right side of the casing 33, and a lid member 22c of this storage tank 22 is provided with water supply ports 42a, 42b which are connected to the two branch passages 23a, 23b respectively and for supplying hot and cold water to the storage tank 22.
The downstream portions of the branch passages 23a, 23b are formed by pipes 41a, 41b, and the downstream ends of the pipes 41a, 41b are connected to water supply ports 42a, 42b in an externally fitted manner, respectively.

The upstream ends of the pipes 41a and 41b are located on the left and right, and the water supply ports 42a and 42b are located on the right and left, so the pipe 41a is formed to be approximately twice as long as the pipe 41b. The lengths of the pipes 41a and 41b are made different to prevent confusion between the pipes 41a and 41b during assembly. The pipes 41a and 41b are made of a single piece of synthetic resin molded product to make them as compact as possible.

A discharge port (not shown) is formed in the center of the bottom plate of the storage tank 22, and a pump 28 is connected to this discharge port, with a discharge pipe 27 extending from the discharge portion of this pump 28. This pump 28 discharges hot water drawn in from the discharge port through the discharge pipe 27 to the cleaning nozzle 5.

This discharge pipe 27 is fitted with two check valves 30, a flow rate sensor 31, a thermistor 29 and an orifice 32. The orifice 32 is formed in a synthetic resin block 39, which is formed with a detergent passage to which the detergent supply pipe 7a is connected, and this detergent passage is connected to the orifice 32 by a small diameter passage. The synthetic resin block 39 is also fitted with an electromagnetic on-off valve 7c capable of opening and closing the detergent passage. The orifice 32 is connected to a mid-way point of the discharge pipe 27 (corresponding to a part of the hot water passage) which extends to the washing nozzle 5. The harness extending from the equipment inside the case 33 is led to the outside through a screw-in type cylindrical metal fitting 35.

Next, the storage tank 22 will be described.
The storage tank 22 has a lid member 22c (top plate) fixed to the upper end of the tank body with bolts or screws. The storage tank 22 has water supply ports 42a, 42b through which hot and cold water flows in from pipes 41a, 41b, a discharge port for discharging hot and cold water to the pump 28, and partition plates 44a, 44b that divide the space within the storage tank 22 to allow hot and cold water to pass through.

The partition plates 44a, 44b are formed to extend vertically upward from the bottom surface of the storage tank 22 between the water supply ports 42a, 42b and the discharge port in a plan view. The storage tank 22 is provided with the overflow port 22b, and the upper ends of the partition plates 44a, 44b are located a distance a (e.g., about 10 to 15 mm) above the lower end of the overflow port 22b.

The discharge port is provided near the center of the bottom plate of the storage tank 22, and the water supply ports 42a, 42b are provided on the lid member 22c (top plate) of the storage tank 22 at positions spaced apart on either side of the discharge port in a plan view, and the partition plates 44a, 44b are provided between each of the water supply ports 42a, 42b and the discharge port.

The storage tank 22 is equipped with a water level detector 34 that detects the level of the hot and cold water stored therein. The mounting plate 34a of the water level detector 34 is fixed to the lid member 22c, a cylinder 34b extends downward from the mounting plate 34a, and a cylinder 34c with a smaller diameter than the cylinder 34b extends downward from the lower end of the cylinder 34b, and an annular float 34d is attached to the cylinder 34c so that it can rise and fall.

The operation and effects of the above-mentioned cleaning unit 6 will now be described.
Since the hot water that has flowed through the two branch passages 23a, 23b can be supplied to the storage tank 22 from the water supply ports 42a, 42b connected to the branch passages 23a, 23b, the flow rate of the hot water supplied from one water supply port 42a, 42b is reduced, thereby reducing the amount of air bubbles generated in the storage tank 22 and suppressing air entrainment in the pump 28.

The two branch passages 23a, 23b are made of pipes that connect the constant flow valves 26a, 26b to the water supply ports 42a, 42b, simplifying the structure of the branch passages 23a, 23b, simplifying assembly, and reducing manufacturing costs. In addition, the structure for connecting the branch passages 23a, 23b to the storage tank 22 is simplified, which is advantageous in ensuring sealing performance.

Next, an example in which the above embodiment is partially modified will be described.
(1) The discharge rate of the pump is not limited to 6.5 L/min, but can be set to various discharge rates around this amount.
The flow rate of the constant flow valve is not limited to 2L/min, 5L/min, 8L/min, etc.
As long as it is possible to selectively realize a first flow rate that is greater than the discharge rate of the pump and a second flow rate that is less than the discharge rate of the pump, any appropriate flow rate can be set.

(2) By setting the second flow rate, which is smaller than the pump's discharge rate, to a value close to the discharge rate, the rate at which the water level drops from the high water level to the low water level can be slowed down, and the frequency of switching of the electromagnetic opening/closing valve can be reduced.
(3) In place of the constant flow valve, an orifice having stable flow characteristics may be used.
(4) When starting the flushing operation, instead of starting the pump operation after a high water level is detected, the pump operation can be started a predetermined time after a low water level is detected.

(5) The bathtub cleaning device 10 in the above embodiment has been described as using hot water supplied from the hot water supply device 2 for cleaning, but it can also be configured to use water supplied from a water source. In that case, a constant flow valve is required that can provide the desired flow rate even when the water pressure of the mains is low, such as on the upper floors of an apartment building. If only one constant flow valve is installed, a constant flow valve with a high flow rate will be used, and the minimum required water pressure will be high, at around 0.15 MPa.
However, in the present invention, two constant flow valves 26a, 26b with a relatively small flow rate are employed, so that operation is possible even with a minimum water pressure that is significantly lower than about 0.15 MPa.

(6) In addition, a person skilled in the art could implement the above-mentioned embodiments in various modified forms without departing from the spirit of the present invention, and the present invention also includes such modified forms.

1 Bathtub 2 Hot water supply device 5 Cleaning nozzle 6 Cleaning unit 7 Detergent tank 10 Bathtub cleaning device 11 Bathroom remote control 13 Cleaning remote control 22 Storage tank (hot water storage section)
23 Hot water supply pipe (hot water passage)
23a, 23b, 23d Branch passage 23c Junction passage 25a, 25b, 36 Electromagnetic opening and closing valves 26a, 26b, 26c, 26d Constant flow valve 27 Water discharge piping (hot water passage)
28 Pump 41a, 41b Pipe material 42a, 42b Water supply port

Claims (7)

A bathtub cleaning device including a hot water reservoir that is provided in the middle of a hot water passage that supplies hot water to a cleaning nozzle and that can store hot water supplied from the hot water passage, and a pump that can deliver the hot water from the hot water reservoir to the cleaning nozzle,
a hot water passage for supplying hot water to the hot water storage section, the hot water passage being provided with a plurality of branch passages, a plurality of electromagnetic opening/closing valves, and a constant flow rate valve;
This bathtub cleaning device is configured to be switchable between a first mode in which hot water is supplied to the hot water storage section at a first flow rate that is greater than the water discharge rate of the pump, and a second mode in which hot water is supplied at a second flow rate that is less than the water discharge rate. The bathtub cleaning device according to claim 1, characterized in that the electromagnetic opening and closing valve is provided in at least one of the plurality of branch passages, and the constant flow valve is provided in at least one of the plurality of branch passages. The bathtub cleaning device according to claim 1 or 2, characterized in that the hot water storage section is provided with a plurality of water supply ports each connected to the plurality of branch passages and for supplying hot water to the hot water storage section. The bathtub cleaning device according to claim 3, characterized in that the multiple branch passages are made of pipe material connecting the constant flow valve and the water supply port. The bathtub cleaning device according to claim 1 or 2, characterized in that the downstream ends of the multiple branch passages are connected to a junction passage, and hot water is supplied to the hot water storage section from the junction passage. The hot water storage section is provided with a water level detection means capable of detecting at least a high water level and a low water level,
A bathtub cleaning device as described in any one of claims 1 to 5, characterized in that, during pump operation, hot water is supplied at the second flow rate when a high water level is detected, and hot water is supplied at the first flow rate when a low water level is detected. The bathtub cleaning device according to claim 6, characterized in that when operation is started, hot and cold water is supplied at the second flow rate until a high water level is detected, and then pump operation is started.