JP7620214B2 - Bathtub cleaning device - Google Patents

Description

The present invention relates to a bathtub cleaning device that automatically cleans a bathtub, and in particular to a bathtub cleaning device that has a hot water storage section that stores hot water so that it can handle low water supply pressure.

Bathtub cleaning devices have been used for some time now to automatically clean bathtubs. Bathtub cleaning devices clean the bathtub by spraying cleaning liquid into the bathtub to loosen dirt adhering to the bathtub, and then spraying hot and cold water to wash it away.

For example, as shown in Patent Document 1, a bathtub cleaning device is known that opens a hot water supply valve, mixes detergent in a venturi detergent mixer with hot water flowing due to the supply pressure of clean water, opens a detergent valve, and generates cleaning liquid, which is then sprayed from a cleaning nozzle. This bathtub cleaning device is configured to spray cleaning liquid multiple times while cleaning the bathtub, and describes that the detergent valve is opened when spraying of cleaning liquid begins, and then the hot water supply valve is opened, so as not to wash away cleaning liquid that has adhered to the bathtub from the previous spray with hot water.

As shown in Patent Document 2, a bathtub cleaning device is known that uses hot and cold water flowing due to the supply pressure of clean water to perform a preliminary rinsing process in which hot and cold water is sprayed before the cleaning liquid spraying process, and at the end of the preliminary rinsing process, the detergent valve is opened to prepare cleaning liquid in the hot and cold water passage to the cleaning nozzle. This makes it possible to spray cleaning liquid immediately in the cleaning liquid spraying process.

JP 2019-146746 A JP 2018-50649 A

However, in areas or buildings where the water supply pressure is low, the bathtub cleaning devices of Patent Documents 1 and 2 above have difficulty spraying cleaning liquid and hot and cold water from the cleaning nozzle with sufficient force, and may not be able to clean adequately. To deal with cases where the water supply pressure is low, a bathtub cleaning device is known that is configured to supply hot and cold water stored in a hot and cold water storage section to the cleaning nozzle by driving a pump, and spray the cleaning liquid generated by opening the hot and cold water and detergent valves.

When stopping the spray of cleaning liquid, this type of bathtub cleaning device stops the pump and closes the detergent valve. At this time, if the detergent valve is, for example, a solenoid valve, it can close the detergent valve instantly. On the other hand, even if a stop command is issued to the pump, it will not stop instantly due to inertia. Therefore, since hot water flows with the detergent valve closed, the detergent mixing section, which is downstream of the detergent valve, becomes under negative pressure compared to the upstream side of the detergent valve. As a result, a force pulling toward the detergent mixing section acts on the valve body of the detergent valve, putting a load on the detergent valve.

On the other hand, when spraying of the cleaning liquid begins, the pump is driven and the detergent valve is opened. When the pump is driven, hot and cold water flows, creating negative pressure on the detergent mixing section side of the detergent valve, and the valve body is moved against the force pulling it towards the detergent mixing section to open the detergent valve, placing a load on the detergent valve.

The valve body of the detergent valve is often made of an elastic material such as rubber that can absorb tolerances and adhere closely to the valve seat. When cleaning the bathtub, the spraying and stopping of the cleaning liquid is repeated, so the force pulling it towards the detergent mixing section acts repeatedly on the valve body, causing it to deform, and there is a risk that the durability of the detergent valve will be compromised.

The object of the present invention is to provide a bathtub cleaning device that can reduce the load on the detergent valve when opening and closing the detergent valve.

The bathtub cleaning device of the invention of claim 1 comprises a cleaning nozzle disposed in a bathtub, a hot water storage section for storing hot and cold water, a hot water passage connecting the hot water storage section and the cleaning nozzle, a pump disposed in the hot and cold water passage, a detergent mixing section disposed in the hot and cold water passage between the pump and the cleaning nozzle, a detergent valve that opens and closes to switch between supplying and stopping detergent to the detergent mixing section, and a control section that drives the pump to control the spraying from the cleaning nozzle of cleaning liquid produced by mixing the hot and cold water sent into the hot and cold water passage toward the cleaning nozzle with the detergent in the detergent mixing section, and is characterized in that when spraying the cleaning liquid is stopped, the control section closes the detergent valve after a preset delay time has elapsed since issuing a command to stop the pump.

According to the above configuration, the bathtub cleaning device opens the detergent valve to supply hot water to the cleaning nozzle by driving the pump, generates cleaning liquid mixed with detergent in the detergent mixing section, and sprays this cleaning liquid from the cleaning nozzle. When spraying cleaning liquid is to be stopped, the detergent valve is kept open until a preset delay time has elapsed since a command to stop the pump is issued, and then closes the detergent valve after the delay time has elapsed. By the time the delay time has elapsed, the pump rotation speed has decreased or the pump has stopped, and the negative pressure on the detergent mixing section side of the detergent valve has decreased or been eliminated, and the detergent valve is closed in a state in which the force pulling the detergent mixing section side is weakened or not working, so that the load on the detergent valve when spraying cleaning liquid is stopped can be reduced.

The bathtub cleaning device of the invention of claim 2 is the invention of claim 1, configured so that the cleaning liquid is sprayed multiple times, and the control unit, when starting at least the second or subsequent sprays of the cleaning liquid, opens the detergent valve while the pump is stopped, and issues a command to drive the pump while detergent can be supplied to the detergent mixing unit.
According to the above configuration, the detergent valve is opened without any pulling force acting on the detergent mixing section, so the load on the detergent valve when starting to spray the cleaning liquid can be reduced. Also, since the pump can be driven to mix the detergent from the start of the hot and cold water flow, it is possible to avoid washing away the cleaning liquid sprayed previously with hot and cold water.

The bathtub cleaning device of the invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the control unit issues the stop command after lowering the set rotational speed of the pump to a predetermined stop preparation rotational speed.
With the above configuration, a pump stop command is issued when the set rotational speed of the pump is reduced to the stop preparation rotational speed and the force pulling the detergent mixing section toward the detergent mixing section is weakened or not acting, and the detergent valve is closed after a set delay time has elapsed since the pump stop command. Therefore, the detergent valve can be closed reliably without any force pulling the detergent mixing section toward the detergent mixing section, thereby reducing the load on the detergent valve when spraying of the cleaning liquid is stopped.

The bathtub cleaning device of the present invention can reduce the load on the detergent valve when opening and closing it, thereby improving the durability of the detergent valve.

1 is a configuration diagram of a bathtub cleaning device according to an embodiment of the present invention. 4 is a flowchart of a bathtub cleaning operation by the bathtub cleaning device according to the embodiment. 11 is a flowchart of solenoid valve control during a bathtub cleaning operation. 13 is an example of a time chart for spraying cleaning liquid in a bathtub cleaning operation. 5 is a time chart showing a modification of the time when the cleaning liquid jet in FIG. 4 is stopped.

The following describes the form for implementing the present invention based on examples.

First, the overall configuration of the bathtub cleaning device 10 of the present invention, including the peripheral devices, will be described with reference to Figure 1. To fill and reheat the bathtub 1, the bathtub 1 and the water heater 2 are connected via a filling/reheating passage 3 and a circulation adapter 1a. In addition, at the bottom of the bathtub 1, there is provided a drain plug 4, for example an electric type, for draining hot and cold water as shown by the arrow D, and a cleaning nozzle 5 for spraying (spraying) hot and cold water and cleaning solution to clean the bathtub 1.

Near the bathtub 1 are a supply unit 6 that supplies hot water and cleaning liquid to the cleaning nozzle 5, a detergent tank 7 that stores the detergent to be supplied to the supply unit 6, and a drain switch 8 for opening and closing the drain plug 4. A hot water supply passage 2a for supplying hot water from the hot water supply device 2 is connected to the supply unit 6.

In addition, a power communication unit 9, for example, installed in the ceiling of the bathroom, is connected to the supply unit 6 so that it can supply power and communicate with it. This power communication unit 9 is equipped with a control unit 20 that controls the bathtub cleaning operation of the bathtub cleaning device 10. The bathtub cleaning device 10 is composed of a cleaning nozzle 5, a supply unit 6, a detergent tank 7, a drain switch 8, a drain plug 4, a power communication unit 9 (control unit 20), etc.

The hot water supply device 2 is a combustion-type hot water supply device that uses, for example, the heat of combustion of fuel to heat the clean water indicated by the arrow W and supply it through the hot water supply passage 2a. When hot water supply use is started by starting the bathtub cleaning operation of the bathtub cleaning device 10 or by opening the hot water tap F, the flow of hot water in the hot water supply device 2 is detected and the hot water supply operation is started. When hot water supply use is ended by ending the bathtub cleaning operation or by closing the hot water tap F, the halt of the flow of hot water in the hot water supply device 2 is detected and the hot water supply operation is ended. Note that the hot water supply device 2 may be a hot water supply device having another heat source device, such as a heat pump type heat source device.

The hot water supply device 2 is communicatively connected to a bathroom remote control 11 and a kitchen remote control 12 for starting operations such as filling the bathtub 1 with water and reheating operation, and for setting the hot water supply temperature. The control unit 20 is also communicatively connected to a cleaning remote control 13 for starting the bathtub cleaning operation by the bathtub cleaning device 10. The hot water supply device 2 and the control unit 20 are communicatively connected to each other and obtain device status such as standby, bathtub cleaning operation, reheating operation, and combustion hot water supply from each other.

Next, the bathtub cleaning device 10 will be described.
The supply unit 6 of the bathtub cleaning device 10 has a hot water passage 14 that supplies hot water from the hot water supply passage 2a to the cleaning nozzle 5, a hot water tank 15 (hot water storage section) provided midway along the hot water passage 14 to store hot water, and a pump 16 for sending hot water from the hot water tank 15 toward the cleaning nozzle 5. A venturi 17 is interposed in the hot water passage 14 between the pump 16 and the cleaning nozzle 5 (downstream of the pump 16). The venturi 17 corresponds to a detergent mixing section that mixes detergent into the hot water sent out by the pump 16 to be supplied to the cleaning nozzle 5.

The hot water passage 14 is connected to the hot water supply passage 2a via a filter 14a, and has a parallel passage section 18 that branches and merges upstream of the hot water tank 15 and downstream of the filter 14a. In the parallel passage section 18, two branch passages 18a, 18b are connected in parallel.

The branch passage 18a is equipped with a first solenoid valve 18c for opening and closing the branch passage 18a, and a constant flow valve 18e. The branch passage 18b is equipped with a second solenoid valve 18d for opening and closing the branch passage 18b, and a constant flow valve 18f. These constant flow valves 18e and 18f each limit the flow rate to a value smaller than the discharge capacity of the pump 16, and are selected so that the total flow rate of the two is greater than the normal flow rate of the pump 16. The flow rates in the branch passages 18a and 18b are equal when the first and second solenoid valves 18c and 18d are open.

The hot and cold water passage 14 between the pump 16 and the venturi 17 is equipped with a temperature sensor 19, a flow rate sensor 14b, etc. A detergent passage 7a for supplying detergent from the detergent tank 7 is connected to the venturi 17, and detergent is supplied from the detergent passage 7a to the flowing hot and cold water by utilizing the negative pressure generated by the flow of hot and cold water in the venturi 17. This detergent passage 7a is equipped with a detergent solenoid valve 7b (detergent valve) that opens and closes to switch between supplying and stopping detergent. Although not shown in the figure, the detergent solenoid valve 7b is a typical direct acting solenoid valve that, when not energized, closes the flow path by pressing a valve body made of an elastic material against a valve seat provided in the flow path, and opens the flow path by separating the valve body from the valve seat when energized.

The control unit 20 is connected so that it can open and close the drain plug 4, open and close the first and second solenoid valves 18c and 18d, open and close the detergent solenoid valve 7b, and drive and stop the pump 16. The control unit 20 can also open and close the drain plug 4 in response to the operation of the drain switch 8. The control unit 20 is also connected to a float switch 15a that detects the water level in the hot and cold water tank 15, and a float switch 7c that detects the detergent liquid level in the detergent tank 7.

The hot water tank 15 is set to a first water level L and a second water level H that is higher than the first water level L. The first water level L corresponds to the lower limit water level of the hot water tank 15 that is preset for water level control. The second water level H corresponds to the upper limit water level of the hot water tank 15 that is preset for water level control. Of the hot water stored in the hot water tank 15, any that exceeds the upper limit water level flows from the overflow port 15b of the hot water tank 15 into the bathtub pan and is drained from a bathroom drain not shown.

The control unit 20 is, for example, a computer equipped with an arithmetic unit, a storage device, an input/output device, etc., and controls the bathtub cleaning operation for cleaning the bathtub 1, the opening and closing of the drain plug 4, etc., based on a control program stored in the storage device. For example, when the bathtub cleaning operation of the bathtub cleaning device 10 is started by operating the cleaning remote control 13, the control unit 20 executes the bathtub cleaning operation. In addition, the control unit 20 detects the operation of the drain switch 8 and drives the drain plug 4 (open → close, or close → open), and the drain plug 4 is maintained in an open or closed state until the next operation of the drain switch 8 or a command from the control unit 20 is received.

During the bathtub cleaning operation, the control unit 20 opens the drain plug 4, and controls the opening and closing of the first and second solenoid valves 18c and 18d and the detergent solenoid valve 7b, as well as the operation of the pump 16. This bathtub cleaning operation will be explained based on the flowchart in Figure 2. In the figure, Si (i = 1, 2, ...) represents a step.

When the bathtub cleaning operation starts, in S1, the drain plug 4 is opened and the process proceeds to S2. Then, in S2, a preliminary cleaning is performed in which hot and cold water is sprayed from the cleaning nozzle 5 into the bathtub 1 for a predetermined preliminary cleaning time (e.g., 40 seconds). In the preliminary cleaning, while storing hot and cold water supplied from the water heater 2 in the hot and cold water tank 15, the pump 16 is driven so that the flow rate detected by the flow rate sensor 14b is the preset supply flow rate, and hot and cold water is sprayed from the cleaning nozzle 5 with the detergent solenoid valve 7b closed. At this time, solenoid valve control is performed for the first and second solenoid valves 18c, 18d so that the water level in the hot and cold water tank 15 is between the first water level L and the second water level H.

In solenoid valve control, for example, as shown in FIG. 3, in S11, both the first and second solenoid valves 18c, 18d are opened and the process proceeds to S12, where it is determined whether the water level in the hot and cold water tank 15 has reached the second water level H (upper limit water level). If the determination in S12 is No, the process returns to S12 with the first and second solenoid valves 18c, 18d open, and if the determination in S12 is Yes, the process proceeds to S13.

In S13, for example, the first solenoid valve 18c is left open and the second solenoid valve 18d is closed, and the process proceeds to S14, where it is determined whether the water level in the hot water tank 15 has reached (dropped to) the first water level L (lower limit water level). If the determination in S14 is No, the process returns to S14 while maintaining the open/closed state of the first and second solenoid valves 18c, 18d, and if the determination in S14 is Yes, the process returns and starts this solenoid valve control from the beginning. When stopping the pump 16, the first and second solenoid valves 18c, 18d are closed.

This solenoid valve control is also performed in the spraying of cleaning liquid after the preliminary cleaning and in the rinsing cleaning. In S13, the same solenoid valve may be closed each time, or a different solenoid valve may be closed from the previous time.

After the preliminary cleaning in S2 in Fig. 2 is completed, the process proceeds to S3, where cleaning liquid is sprayed to loosen dirt. In this cleaning liquid spray, the detergent solenoid valve 7b is opened, and cleaning liquid, which is made by mixing hot water supplied to the cleaning nozzle 5 by driving the pump 16 with detergent in the venturi 17, is sprayed from the cleaning nozzle 5 for a predetermined spray time, and then the process waits for a predetermined standby time. This spraying of cleaning liquid and standby is repeated a preset number of times (e.g., seven times).

For example, as shown in Fig. 4, in the initial (first) injection of the cleaning liquid, the set rotation speed of the stopped pump 16 is set to the set rotation speed P1 that corresponds to the preset supply flow rate R1 at time _t1, and a drive command is issued to the pump 16. Then, it is confirmed that the flow rate detected by the flow rate sensor 14b corresponds to the supply flow rate R1. Next, at time _t2 , the detergent solenoid valve 7b is opened to supply detergent to the venturi 17, and the cleaning liquid in which the detergent is mixed with hot and cold water is injected from the cleaning nozzle 5. Note that in the initial injection, the set rotation speed P1 is updated to the supply flow rate R1, and this updated set rotation speed P1 can be used as the rotation speed of the pump 16 for the next and subsequent injections.

At time _t3 , when a predetermined injection time has elapsed since time _t2 , the set rotation speed of pump 16 is set to zero and a stop command is issued to pump 16. Then, at time t4, when a preset delay time DT (e.g., 1 second) has elapsed since time _{t3 ,} detergent solenoid valve 7b is closed, and the system waits until a predetermined standby time has elapsed from time _t3, when the stop command was issued to pump 16.

Even if a stop command is issued to the pump 16, the pump 16 does not stop instantly due to inertia, so the timing for closing the detergent solenoid valve 7b is delayed by a delay time DT after the stop command is issued to the pump 16. As a result, the supply flow rate of hot and cold water supplied to the cleaning nozzle 5 becomes lower than the supply flow rate R1 or becomes zero, so the negative pressure generated in the venturi 17 is weakened or eliminated. Therefore, the detergent solenoid valve 7b can be closed when the force pulling the valve body of the detergent solenoid valve 7b toward the venturi 17 side due to the negative pressure is weakened or does not work. The initial injection time may be longer than the second and subsequent injection times, taking into account the fact that the hot and cold water from the venturi 17 to the cleaning nozzle 5 is pushed out by the cleaning liquid.

At time _t5 when the standby time has elapsed, detergent solenoid valve 7b is opened for the second injection, and then at time _t6 , the set rotation speed of pump 16, which has been stopped, is set to set rotation speed P1 and a drive command is issued to pump 16 to inject cleaning liquid. The time between time _t5 and time _t6 is short (for example, about 0.2 seconds) relative to the specified injection time. Since detergent solenoid valve 7b capable of supplying detergent is opened before pump 16 is driven, negative pressure is not generated in venturi 17, and detergent solenoid valve 7b can be opened without a force acting on the venturi 17 side to pull in the valve body of detergent solenoid valve 7b.

At time _t7 , when a predetermined injection time has elapsed since time _t5 , similar to the first injection, the set rotation speed of the pump 16 is set to zero and a stop command is issued to the pump 16. Then, at time _t8 , when the delay time DT has elapsed since time _t7 , the detergent solenoid valve 7b is closed with the supply flow rate of hot and cold water supplied to the washing nozzle 5 reduced or zero, and the system waits until a predetermined standby time has elapsed.

The bathtub cleaning device 10 repeats the same operation as the second injection described above until the injection just before the final injection. At this time, the supply flow rate of hot and cold water supplied to the cleaning nozzle 5 is reduced or zero, so the negative pressure in the venturi 17 is weakened or not generated. Therefore, the detergent solenoid valve 7b is opened and closed when the force pulling the valve body of the detergent solenoid valve 7b toward the venturi 17 is weak or not acting, reducing the load on the detergent solenoid valve 7b. Note that the injection time from the second injection onwards may be measured starting from the time when the drive command for the pump 16 is issued.

For the final spray, the detergent solenoid valve 7b is kept closed, and at time _t9 , the set rotation speed of the pump 16, which has been stopped, is set to set rotation speed P1 and a drive command is issued to the pump 16. This pushes out and sprays the cleaning liquid remaining in the hot and cold water passage 14 between the venturi 17 and the cleaning nozzle 5 with hot and cold water, until all the cleaning liquid is used up. Then, at time _t10 , when a predetermined spray time has elapsed since time _t9 , the set rotation speed of the pump 16 is set to zero and a stop command is issued to the pump 16, and spraying of the cleaning liquid ends after a predetermined standby time has elapsed since time _t10 . The spray time, standby time, delay time, supply flow rate, etc. of the hot and cold water and cleaning liquid can be set as appropriate according to the capacity, etc. of the bathtub cleaning device 10.

After spraying the cleaning liquid in S3, the process proceeds to S4, where a rinse is performed. In the rinse, like the pre-wash in S2, hot and cold water is sprayed for a specified rinse time (e.g., 60 seconds) with the detergent solenoid valve 7b closed to wash away dirt. After the rinse in S4 is completed, the process proceeds to S5, where the first and second solenoid valves 18c and 18d are closed and the pump 16 is driven until the hot and cold water tank 15 is empty to drain the tank, after which the bathtub cleaning operation ends.

When stopping the pump 16 during the spraying of the cleaning liquid, for example, as shown in Fig. 5, the set rotation speed P1 of the pump 16 can be reduced to a predetermined stop preparation rotation speed P2 at time _tn , and then the set rotation speed of the pump 16 can be set to zero at time _tn+1 to issue a stop command to the pump 16. The stop preparation rotation speed P2 is set to a rotation speed at which the negative pressure generated in the venturi 17 is weaker than that generated in the case of the set rotation speed P1, or a small supply flow rate R2 at which no negative pressure is generated. Since a stop command is issued to the pump 16 at time _tn+1 when the supply flow rate has been reduced to R2, when the detergent solenoid valve 7b is closed at time _tn+2, which is the delay time DT after time tn ₊₁ , the supply flow rate is more reliably reduced or zero than in the case of Fig. 4, and no force pulling the detergent solenoid valve 7b toward the venturi 17 acts on the detergent solenoid valve 7b.

The operation and effects of the bathtub cleaning device 10 will now be described.
The bathtub cleaning device 10 opens the detergent solenoid valve 7b (detergent valve) to mix the hot water supplied to the cleaning nozzle 5 by the drive of the pump 16 with the detergent in the venturi 17 (detergent mixing section) to generate cleaning liquid, and sprays this cleaning liquid from the cleaning nozzle 5. When spraying the cleaning liquid is to be stopped, the detergent solenoid valve 7b is kept open until a preset delay time DT has elapsed since a command to stop the pump 16 is issued, and the detergent solenoid valve 7b is closed after the delay time DT has elapsed. The rotation speed of the pump 16 decreases or the pump 16 stops before the delay time DT has elapsed, and the supply flow rate decreases or becomes zero, so that the negative pressure on the venturi 17 side of the detergent solenoid valve 7b is reduced or eliminated. Therefore, the detergent solenoid valve 7b is closed in a state in which the force pulling the detergent toward the venturi 17 side is weakened or does not act after the delay time DT has elapsed, so that the load on the detergent solenoid valve 7b when spraying the cleaning liquid is stopped can be reduced.

In addition, when the spraying of the cleaning liquid starts, the detergent solenoid valve 7b is opened without any pulling force acting on the venturi 17 side, so the load on the detergent solenoid valve 7b when spraying of the cleaning liquid starts can be reduced. Moreover, the pump 16 can be driven to mix the detergent from the time when the hot water starts to flow, so it is possible to prevent the previously sprayed cleaning liquid from being washed away by the hot water.

In addition, the set rotational speed of the pump 16 can be lowered to the stop preparation rotational speed P2 to issue a stop command for the pump 16 in a state in which the force pulling toward the venturi 17 is weakened or not acting, and the detergent solenoid valve 7b can be closed after the set delay time DT has elapsed. Therefore, since the detergent solenoid valve 7b can be closed reliably in a state in which no force pulling toward the venturi 17 is acting, the load on the detergent solenoid valve 7b when spraying of the cleaning liquid is stopped can be reduced.

The supply flow rate may be checked in a preliminary wash, and the detergent solenoid valve 7b may be opened from the first wash for the washing liquid injection, and then a drive command may be issued to the pump 16. Also, the detergent solenoid valve 7b may be opened for the final wash for the washing liquid injection, and the washing liquid generated may be injected, and the remaining washing liquid may be used up in a rinse wash, and then rinsed away with hot water. In addition, those skilled in the art may implement the above embodiment in various modified forms without departing from the spirit of the present invention, and the present invention includes such modified forms.

1: Bathtub 1a: Circulation adapter 2: Hot water supply device 2a: Hot water supply passage 3: Hot water filling/reheating passage 4: Drain plug 5: Cleaning nozzle 6: Supply unit 7: Detergent tank 7a: Detergent passage 7b: Detergent solenoid valve (detergent valve)
7c: detergent float switch 8: drain switch 9: power supply communication unit 10: bathtub cleaning device 11: bathroom remote control 12: kitchen remote control 13: cleaning remote control 14: hot and cold water passage 14a: filter 14b: flow rate sensor (flow rate detection means)
15: Hot water tank (hot water storage section)
15a: float switch 15b: overflow port 16: pump 17: venturi (detergent mixing section)
18: Parallel passages 18a, 18b: Branch passage 18c: First solenoid valve 18d: Second solenoid valve 18e, 18f: Constant flow valve 19: Temperature sensor 20: Control unit

Claims (3)

a control unit that drives the pump to drive the water passage and controls the spraying from the cleaning nozzle of cleaning liquid produced by mixing detergent in the detergent mixing unit with hot and cold water sent into the hot and cold water passage toward the cleaning nozzle;
A bathtub cleaning device characterized in that, when stopping the spray of the cleaning liquid, the control unit closes the detergent valve after a predetermined delay time has elapsed since issuing a command to stop the pump. The cleaning liquid is sprayed multiple times,
The bathtub cleaning device described in claim 1, characterized in that, when starting at least the second or subsequent spraying of the cleaning liquid, the control unit opens the detergent valve while the pump is stopped, and issues a command to drive the pump while detergent can be supplied to the detergent mixing unit. The bathtub cleaning device according to claim 1 or 2, characterized in that the control unit issues the stop command after lowering the set rotation speed of the pump to a predetermined stop preparation rotation speed.