Bathtub cleaning device
The cistern type bathtub cleaning device with a downstream microbubble generating unit addresses the pressure reduction issue in direct pressure devices, ensuring stable water flow and efficient microbubble generation for enhanced cleaning effectiveness and cost-effective operation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- RINNAI CORP
- Filing Date
- 2024-11-19
- Publication Date
- 2026-05-29
AI Technical Summary
In direct pressure type bathtub cleaning devices, the water pressure is reduced by the fine bubble generating unit, leading to insufficient momentum of water ejection from the injection nozzle, thereby reducing the cleaning effectiveness.
A cistern type configuration is introduced with a water reservoir open to the atmosphere, a pump to pressurize water, and a microbubble generating unit located downstream of the detergent mixing section, ensuring stable water flow and efficient microbubble generation.
The configuration maintains the cleaning effectiveness by adjusting water spray force, enhances microbubble generation, and prevents backflow of detergent-laden water, resulting in improved cleaning efficiency and long-term device performance without the need for detergent-resistant materials.
Smart Images
Figure 2026088714000001_ABST
Abstract
Description
Technical Field
[0001] The technology disclosed in this specification relates to a bathtub cleaning device.
Background Art
[0002] Patent Document 1 discloses a bathtub cleaning device including an injection nozzle provided inside a bathtub, a cleaning path having an upstream end connected to a water supply source and a downstream end connected to the injection nozzle, a detergent tank for storing detergent, a detergent mixing unit provided in a portion of the cleaning path downstream of the water supply source for mixing the detergent stored in the detergent tank with water flowing in the cleaning path, and a fine bubble generating unit provided in the cleaning path for generating fine bubbles in the water flowing in the cleaning path. The bathtub cleaning device of Patent Document 1 aims to improve the cleaning effect by generating fine bubbles in the water supplied to the bathtub. Further, the bathtub cleaning device is a bathtub cleaning device of a method (so-called direct pressure method) for supplying water to the bathtub using the water pressure from the water supply source.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In a direct pressure type bathtub cleaning device, if a fine bubble generating unit is provided in the cleaning path, the water pressure is reduced in the fine bubble generating unit, and as a result, the momentum of the water ejected from the injection nozzle may be insufficient. Consequently, the cleaning effect of the bathtub cleaning operation may be reduced. In this specification, a technology capable of suppressing a reduction in the cleaning effect of the bathtub cleaning operation in a bathtub cleaning device including a fine bubble generating unit is provided.
Means for Solving the Problems
[0005] In a first aspect of this technology, the bathtub cleaning device may include a cistern comprising: an injection nozzle provided inside the bathtub; a cleaning passage whose upstream end is connected to a water source and whose downstream end is connected to the injection nozzle; a water reservoir provided in the cleaning passage for storing water supplied from the water source in an open state to the atmosphere; and an overflow passage for discharging water that overflows from the water reservoir; a pump provided in the portion of the cleaning passage downstream of the water reservoir for pressurizing the water stored in the water reservoir toward the injection nozzle; a detergent tank for storing detergent; a detergent mixing unit provided in the portion of the cleaning passage downstream of the pump for mixing the detergent stored in the detergent tank with the water flowing through the cleaning passage; and a microbubble generating unit provided in the cleaning passage for generating microbubbles in the water flowing through the cleaning passage. The bathtub cleaning device may be configured to perform a bathtub cleaning operation in which, by driving the pump, water containing microbubbles and mixed with detergent is injected from the injection nozzle to clean the bathtub.
[0006] According to the above configuration, the bathtub cleaning device is a type of bathtub cleaning device that stores water supplied from the water source in a cistern with the water open to the atmosphere, and then pumps the water stored in the cistern into the bathtub (a so-called cistern type). In a cistern type bathtub cleaning device, the force of the water sprayed from the spray nozzle can be adjusted by adjusting the output of the pump. This prevents insufficient force of the water sprayed from the spray nozzle, thus preventing a decrease in the cleaning effect of the bathtub cleaning operation. Furthermore, according to the above configuration, the cistern is positioned upstream of the detergent mixing section in the cleaning path. This isolates the cleaning path upstream of the cistern from the cleaning path downstream of the cistern. Therefore, even if the water mixed with detergent flows back, that water is discharged into the overflow path of the cistern. This prevents the water mixed with detergent from flowing back towards the water source.
[0007] In this specification, various embodiments of the "microbubble generation unit" are conceivable. For example, one embodiment is conceivable in which dissolved gas is precipitated as microbubbles by reducing the pressure of water in which gas is dissolved. Alternatively, one embodiment is conceivable in which the bubbles are made finer by swirling or colliding water mixed with bubbles.
[0008] In a second aspect of this technology, in the first aspect described above, the microbubble generating unit may be provided in the portion of the washing passage downstream of the water reservoir.
[0009] In a configuration where the microbubble generation unit is located upstream of the water reservoir, the microbubbles generated in the microbubble generation unit are mixed with water and then temporarily stored in the water reservoir. As a result, while the water is stored in the reservoir, the microbubbles may separate from the water, potentially reducing the amount of microbubbles in the water. Consequently, the amount of microbubbles supplied to the bathtub may decrease. In contrast, with the above configuration, the microbubble generation unit is located downstream of the water reservoir, so the microbubbles generated in the microbubble generation unit are mixed with water and immediately supplied to the bathtub. This increases the amount of microbubbles supplied to the bathtub compared to a configuration where the microbubble generation unit is located upstream of the water reservoir. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0010] In a third aspect of this technology, in the second aspect described above, the microbubble generating unit may be provided in the portion of the washing passage downstream of the pump.
[0011] In a configuration where the microbubble generation unit is located upstream of the pump, the microbubbles generated in the microbubble generation unit flow into the pump along with the water. This can cause the pump to run dry, potentially leading to an unstable flow rate of water sprayed from the spray nozzle. In contrast, with the above configuration, the microbubble generation unit is located downstream of the pump, so water containing microbubbles does not flow into the pump. This prevents the pump from running dry, thus preventing instability in the flow rate of water sprayed from the spray nozzle. As a result, the cleaning effect of the bathtub cleaning operation can be stably achieved.
[0012] In a fourth aspect of this technology, in the third aspect described above, the microbubble generating section may be provided in the washing passage downstream of the detergent mixing section.
[0013] According to the above configuration, the microbubble generation unit is located downstream of the detergent mixing unit, so the water mixed with detergent passes through the microbubble generation unit. At this time, the water and detergent mix further. This improves the degree of mixing between the water and detergent, thereby further improving the cleaning effect of the bathtub cleaning operation.
[0014] In a fifth aspect of this technology, in the second aspect described above, the microbubble generating section may be provided in the washing passage downstream of the water reservoir and upstream of the detergent mixing section.
[0015] In a configuration where the microbubble generation unit is located upstream of the water reservoir, the microbubbles generated in the microbubble generation unit are mixed with water and then temporarily stored in the water reservoir. Therefore, while the water is stored in the reservoir, the microbubbles may separate from the water, potentially reducing the amount of microbubbles in the water. As a result, the amount of microbubbles supplied to the bathtub may decrease. In contrast, with the above configuration, the microbubble generation unit is located downstream of the water reservoir, so the microbubbles generated in the microbubble generation unit are mixed with water and immediately supplied to the bathtub. This increases the amount of microbubbles supplied to the bathtub compared to a configuration where the microbubble generation unit is located upstream of the water reservoir. This further promotes the rinsing of dirt during the bathtub cleaning operation, thus improving the cleaning effect of the bathtub cleaning operation. Furthermore, with the above configuration, since the microbubble generation unit is located upstream of the detergent mixing unit, the water mixed with detergent does not pass through the microbubble generation unit. This prevents detergent from adhering to the microbubble generating section, thus suppressing the deterioration of the microbubble generating section's performance. As a result, the cleaning effect of the bathtub cleaning operation can be maintained over the long term. Furthermore, since there is no need to use detergent-resistant materials in the microbubble generating section, the bathtub cleaning device can be manufactured at a low cost.
[0016] In a sixth aspect of this technology, in the fifth aspect described above, the microbubble generating section may be provided in the washing passage downstream of the pump and upstream of the detergent mixing section.
[0017] In a configuration where the microbubble generation unit is located upstream of the pump, the microbubbles generated in the microbubble generation unit flow into the pump along with the water. This can cause the pump to run dry, potentially leading to an unstable water flow rate from the spray nozzle. In contrast, with the above configuration, the microbubble generation unit is located downstream of the pump, so water containing microbubbles does not flow into the pump. This prevents the pump from running dry, thus preventing instability in the water flow rate from the spray nozzle. As a result, the cleaning effect of the bathtub cleaning operation can be stably achieved. Furthermore, with the above configuration, the microbubble generation unit is located upstream of the detergent mixing unit, so the water mixed with detergent does not pass through the microbubble generation unit. This prevents detergent from adhering to the microbubble generation unit, thus preventing a deterioration in the performance of the microbubble generation unit. As a result, the cleaning effect of the bathtub cleaning operation can be maintained over the long term. In addition, since there is no need to use detergent-resistant materials in the microbubble generation unit, the bathtub cleaning device can be manufactured at a low cost.
[0018] In a seventh aspect of this technology, in the fifth aspect described above, the microbubble generating section may be provided in the washing passage downstream of the water reservoir and upstream of the pump.
[0019] Since the water reservoir is open to the atmosphere, the pressure inside the reservoir is equal to atmospheric pressure. In this case, when the pump is driven, the water pressure downstream of the reservoir and upstream of the pump is reduced to below atmospheric pressure as the pump draws air. According to the above configuration, the microbubble generation unit is located downstream of the water reservoir and upstream of the pump. Therefore, for example, in a case where the microbubble generation unit reduces the pressure of the water to precipitate microbubbles, as the water passes through the microbubble generation unit, the pressure reduction of the water due to the pump's suction and the pressure reduction of the water by the microbubble generation unit combine to reduce the water pressure to a very small value. This makes it possible to increase the amount of gas precipitated from the water, that is, the amount of microbubbles generated by the microbubble generation unit. This promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0020] In an eighth aspect of this technology, in the first aspect described above, the microbubble generating section may be provided in the washing passage in a portion upstream of the detergent mixing section.
[0021] In a configuration where the microbubble generation unit is located downstream of the detergent mixing unit, the water mixed with detergent passes through the microbubble generation unit, which may cause the detergent to adhere to it. If detergent adheres to the microbubble generation unit, its performance will deteriorate, which may reduce the cleaning effectiveness of the bathtub cleaning operation. In contrast, with the above configuration, the microbubble generation unit is located upstream of the detergent mixing unit, so the water mixed with detergent does not pass through the microbubble generation unit. This prevents detergent from adhering to the microbubble generation unit, thus preventing a deterioration in its performance. As a result, the cleaning effectiveness of the bathtub cleaning operation can be maintained over the long term. Furthermore, since there is no need to use detergent-resistant materials in the microbubble generation unit, the bathtub cleaning device can be manufactured at a low cost.
[0022] In a ninth aspect of this technology, in the eighth aspect described above, the microbubble generating unit may be provided in the portion of the washing passage upstream of the pump.
[0023] According to the above configuration, since the microbubble generation part is provided upstream of the pump, water containing microbubbles passes through the pump. At this time, as the water swirls or collides inside the pump, the microbubbles in the water are further refined. Thereby, the bubble diameter of the microbubbles supplied to the bathtub can be made smaller. As a result, after the water containing microbubbles is injected into the bathtub, the microbubbles remain in the water for a long time. Also, the microbubbles easily penetrate into the dirt. Thereby, the washing away of dirt during the bathtub cleaning operation is further promoted. That is, the cleaning effect of the bathtub cleaning operation can be further improved.
[0024] In the tenth aspect of the present technology, in the ninth aspect described above, the microbubble generation part may be provided in a portion of the cleaning path upstream of the water storage device.
[0025] According to the above configuration, since the microbubble generation part is provided upstream of the water storage device, the microbubbles generated in the microbubble generation part are mixed with water and then temporarily stored in the water storage device. While the water is stored in the water storage device, the microbubbles are separated from the water. At this time, the microbubbles with a large diameter are separated from the water, but the microbubbles with a small diameter remain in the water. This is because when the diameter of the microbubbles is large, the force (such as buoyancy) for separating the microbubbles from the water becomes strong. Therefore, according to the above configuration, since the microbubbles with a large diameter are removed inside the water storage device, it is possible to suppress the flow of the microbubbles with a large diameter in the portion of the cleaning path downstream of the water storage device. Thereby, it is possible to suppress the pump from idling, and it is possible to suppress the flow rate of the water injected from the injection nozzle from becoming unstable due to the idling of the pump. Thereby, the cleaning effect of the bathtub cleaning operation can be stably exhibited.
[0026] In the eleventh aspect of the present technology, in any one of the first to tenth aspects described above, the bathtub cleaning device may further include an air supply passage having an upstream end connected to the cistern and a downstream end connected to the fine bubble generation unit. The fine bubble generation unit may be configured to generate fine bubbles in the water flowing through the cleaning passage by using the air introduced from the cistern through the air supply passage.
[0027] According to the above configuration, the air inside the cistern can be introduced into the fine bubble generation unit through the air supply passage. Further, according to the above configuration, even if the water flowing through the fine bubble generation unit flows into the air supply passage, the water will flow back into the cistern. This can prevent the water flowing through the fine bubble generation unit from flowing to an unintended location (for example, a location where electrical wiring is provided).
[0028] In the twelfth aspect of the present technology, in any one of the first to eleventh aspects described above, the bubble diameter of the fine bubbles generated by the fine bubble generation unit may be less than 1 μm.
[0029] If the diameter of the fine bubbles is large, the force (such as buoyancy) for separating the fine bubbles from the water becomes stronger, so the fine bubbles are more likely to be separated from the water. Therefore, after the water containing fine bubbles (or water mixed with detergent) is sprayed into the bathtub, the fine bubbles may disappear immediately. Also, if the diameter of the fine bubbles is large, it becomes difficult for the fine bubbles to penetrate into the dirt. On the other hand, according to the above configuration, since the diameter of the fine bubbles is very small, it becomes difficult for the fine bubbles to be separated from the water. Therefore, after the water containing fine bubbles is sprayed into the bathtub, the fine bubbles remain in the water for a long time. Also, since the diameter of the fine bubbles is very small, the fine bubbles are more likely to penetrate into the dirt. This further promotes the flushing of dirt during the bathtub cleaning operation. That is, the cleaning effect of the bathtub cleaning operation can be further improved.
Brief Description of the Drawings
[0030] [Figure 1] It is a diagram schematically showing the configuration of the bathtub cleaning device 102 of Example 1. [Figure 2] This is a cross-sectional view of the microbubble generator 190 included in the bathtub cleaning device 102 of Example 1. [Figure 3] This is a flowchart of the bathtub cleaning operation performed by the controller 104 of the bathtub cleaning device 102 in Example 1. [Figure 4] This diagram schematically shows the configuration of the bathtub cleaning device 252 of Example 2. [Figure 5] This diagram schematically shows the configuration of the bathtub cleaning device 302 of Example 3. [Figure 6] This diagram schematically shows the configuration of the bathtub cleaning device 402 of Example 4. [Modes for carrying out the invention]
[0031] (Example 1: Bathtub cleaning device 102) As shown in Figure 1, the bathtub cleaning device 102 is installed between the bathtub 4, which is located in a house or the like, and the water supply source 6 (for example, a municipal water supply). The bathtub cleaning device 102 cleans the bathtub 4 using water supplied from the water supply source 6.
[0032] The bathtub cleaning device 102 includes a controller 104 that includes a CPU, ROM, RAM, etc. Various operating programs are stored in the ROM. Various signals input to the controller 104 and various data generated during the process of the CPU executing processing are temporarily stored in the RAM. The controller 104 controls each component of the bathtub cleaning device 102 by having the CPU execute processing based on the information stored in the ROM and RAM. The controller 104 is also capable of bidirectional communication with a remote control 106 installed in the kitchen or bathroom. The remote control 106 presents various information about the bathtub cleaning device 102 to the user and accepts various operations from the user to the bathtub cleaning device 102.
[0033] The bathtub cleaning device 102 further includes a cleaning passage 108, a flow control valve 110, a water supply valve 112, a cistern 114, a pump 116, a temperature sensor 118, a flow sensor 120, a check valve 122, a cleaning valve 124, a detergent tank 126, a detergent mixing unit 128, a spray nozzle 130, a drain plug 132, and a microbubble generator 190.
[0034] The upstream end of the washing channel 108 is connected to the water supply source 6 via the water supply channel 36. A heat source 38 is provided in the water supply channel 36. The heat source 38 heats the water flowing through the water supply channel 36, for example, by burning fuel gas. Therefore, water heated by the heat source 38 is supplied to the upstream end of the washing channel 108. A flow control valve 110 is provided near the upstream end of the washing channel 108. The flow control valve 110 adjusts the flow rate of water flowing through the washing channel 108 by adjusting the opening of the valve body (not shown). In addition, a water supply valve 112 is provided downstream of the flow control valve 110 in the washing channel 108. The water supply valve 112 is an on / off valve. In the washing channel 108, a cistern 114 is provided downstream of the water supply valve 112. When the water supply valve 112 is opened, water is supplied to the cistern 114.
[0035] The cistern 114 includes a water reservoir 134 for storing water. The water reservoir 134 is open to the atmosphere. The portion of the washing channel 108 upstream of the water reservoir 134 is connected to the inside of the water reservoir 134 via a water supply port 134a that opens into the inside of the water reservoir 134. The water reservoir 134 is equipped with a high-level electrode 136a and a low-level electrode 136b for detecting the water level inside. The water level detected by the high-level electrode 136a (i.e., the high water level) is higher than the water level detected by the low-level electrode 136b (i.e., the low water level). When the water level inside the water reservoir 134 falls below the low water level, the bathtub washing device 102 opens the water supply valve 112 to replenish water from the water supply source 6 to the water reservoir 134 via the water supply channel 36 and the washing channel 108. Subsequently, when the water level inside the water reservoir 134 reaches the high water level, the bathtub cleaning device 102 closes the water supply valve 112 and stops supplying water to the water reservoir 134. Thus, the water level inside the water reservoir 134 is maintained between the high and low water levels. The cistern 114 also includes an overflow passage 138 for discharging water that overflows from the water reservoir 134. The upstream end of the overflow passage 138 is connected to the inside of the water reservoir 134 via an overflow port 140 that opens into the inside of the water reservoir 134. The downstream end of the overflow passage 138 is connected to a drainage location (not shown). In the vertical direction, the lower end of the overflow port 140 is positioned above the lower end of the high water level electrode 136a (i.e., the high water level) and below the water supply port 134a. If the water level inside the reservoir 134 rises above the high water level for any reason and reaches the height of the lower end of the overflow port 140, the water in the reservoir 134 flows into the overflow port 140. The water that flows into the overflow port 140 is discharged to the drainage point via the overflow passage 138. This prevents the water overflowing from the reservoir 134 from flowing into the water supply port 134a (i.e., preventing the water in the reservoir 134 from flowing back). In other words, the cistern 114 separates the wash passage 108 upstream of the cistern 114 from the wash passage 108 downstream of the cistern 114.
[0036] In the washing channel 108, a pump 116 is provided downstream of the cistern 114 (specifically, the water reservoir 134). The pump 116 draws water stored in the water reservoir 134 through the washing channel 108 and pumps it downstream of the washing channel 108.
[0037] In the cleaning channel 108, a temperature sensor 118 is provided downstream of the pump 116. The temperature sensor 118 detects the temperature of the water flowing through the cleaning channel 108. Specifically, the temperature sensor 118 detects the temperature of the water immediately after it is pumped out by the pump 116. Also in the cleaning channel 108, a flow rate sensor 120 is provided downstream of the temperature sensor 118. The flow rate sensor 120 detects the flow rate of the water flowing through the cleaning channel 108. Specifically, the flow rate sensor 120 detects the flow rate of the water immediately after it is pumped out by the pump 116. Also in the cleaning channel 108, a check valve 122 is provided downstream of the flow rate sensor 120. The check valve 122 allows water to flow from upstream to downstream in the cleaning channel 108 and prohibits water from flowing from downstream to upstream in the cleaning channel 108. In other words, the check valve 122 prevents water from flowing backward in the cleaning channel 108. Furthermore, in the washing passage 108, a washing valve 124 is provided downstream of the check valve 122. The washing valve 124 is an on / off valve. The washing valve 124 is normally closed. The washing valve 124 is opened when water is supplied to the bathtub 4. Also, in the washing passage 108, a detergent mixing section 128 is provided downstream of the washing valve 124.
[0038] The detergent mixing unit 128 comprises a detergent passage 142, a detergent valve 144, and a mixer 146. The detergent passage 142 connects the detergent tank 126 and the mixer 146. The detergent valve 144 is located in the detergent passage 142 and opens and closes the detergent passage 142. The detergent valve 144 is normally closed. The detergent valve 144 opens when detergent is supplied from the detergent tank 126 to the washing passage 108. The mixer 146 is a venturi, which generates negative pressure when water flows inside it. The negative pressure generated by the mixer 146 draws the detergent stored in the detergent tank 126 into the mixer 146 through the detergent passage 142. The detergent drawn into the mixer 146 is mixed with the water flowing inside the mixer 146. This produces a liquid (also called a washing solution) in which water and detergent are mixed.
[0039] The downstream end of the cleaning channel 108 is connected to a spray nozzle 130. The spray nozzle 130 is located inside the bathtub 4 and is installed on the bottom wall of the bathtub 4. The spray nozzle 130 sprays water supplied from the cleaning channel 108 toward the side wall of the bathtub 4. A drain port 4a is also formed on the bottom wall of the bathtub 4 at a different location from the spray nozzle 130. A drain plug 132 is installed on the drain port 4a and opens and closes the drain port 4a. When the drain plug 132 is opened, the drain port 4a is opened and the water stored in the bathtub 4 is discharged through the drain port 4a.
[0040] In this embodiment, a microbubble generator 190 is provided in the portion of the washing passage 108 between the water reservoir 134 and the pump 116.
[0041] As shown in Figure 2, the microbubble generator 190 comprises a casing 194, a first microbubble generator 196, and a second microbubble generator 198. The casing 194 has a substantially cylindrical shape. The casing 194 can also be considered part of the washing passage 108 (see Figure 1). An inlet 200 into which water flows is provided at the upstream end of the casing 194. An outlet 202 into which water flows out is provided at the downstream end of the casing 194. The first microbubble generator 196 is housed in the casing 194. The first microbubble generator 196 comprises a body 204 and a plurality of venturi channels 206 that penetrate the body 204. Each of the multiple Venturi channels 206 includes a narrowing channel 208 whose channel diameter decreases as it moves from upstream to downstream, and an expanding channel 210 located downstream of the narrowing channel 208, whose channel diameter increases as it moves from upstream to downstream. Between the narrowing channel 208 and the expanding channel 210, there is a throat section 209 where the channel diameter of the Venturi channel 206 is smallest. The second microbubble generator 198 is housed in a casing 194 downstream of the first microbubble generator 196. The second microbubble generator 198 includes a shaft portion 212 extending in the direction from upstream to downstream, an outer peripheral portion 214 surrounding the radially outer side of the shaft portion 212, and a plurality of blade portions 216 provided between the shaft portion 212 and the outer peripheral portion 214. A swirling channel 218 is formed between the shaft portion 212, the outer circumference portion 214, and the multiple blade portions 216.
[0042] As shown in Figure 1, the bathtub cleaning device 102 further includes an air supply passage 148. The upstream end of the air supply passage 148 is connected to the inside of the water reservoir 134 via an air inlet 150 that opens into the inside of the water reservoir 134. In the vertical direction, the lower end of the air inlet 150 is positioned above the upper end of the overflow port 140. The downstream end of the air supply passage 148 is connected to the cleaning passage 108 via a microbubble generator 190. Specifically, the downstream end of the air supply passage 148 is connected to the throat portion 209 of the venturi flow path 206 (see Figure 2).
[0043] When water flows through the microbubble generator 190 shown in Figure 2, the water first flows into the venturi channel 206 of the first microbubble generator 196. As the water passes through the narrowed-diameter channel 208 of the venturi channel 206, the pressure is reduced to below atmospheric pressure. As a result, air that was previously dissolved in the water flowing through the narrowed-diameter channel 208 precipitates out as bubbles. In addition, negative pressure (pressure below atmospheric pressure) is generated in the throat section 209 through which the water reduced in pressure in the narrowed-diameter channel 208 passes. Due to this negative pressure, air inside the water reservoir 134 (see Figure 1) is drawn into the throat section 209 from the air inlet 150 (see Figure 1) via the air supply passage 148 (see Figure 1). The air drawn into the throat section 209 mixes with the water flowing through the throat section 209 as bubbles. Therefore, the water flowing from the throat section 209 into the widened channel 210 contains not only bubbles precipitated from the water but also bubbles drawn in from the air supply channel 148. Subsequently, as the water passes through the widened channel 210, its pressure is increased to above atmospheric pressure. This causes the bubbles in the water to split and become microbubbles. In addition, the water flowing out from the venturi channel 206 flows into the swirling channel 218 of the second microbubble generator 198. As the water flows through the swirling channel 218, a swirling flow is generated, in which the water flows spirally around the shaft section 212. At this time, the microbubbles in the water become even finer due to the shear force caused by the swirling flow. In this way, microbubbles are generated in the channel where the microbubble generator 190 is installed (i.e., the washing channel 108). The diameter of the microbubbles generated by the microbubble generator 190 is less than 1 μm.
[0044] (Bathtub cleaning operation) The controller 104 causes the bathtub cleaning device 102 to clean the bathtub 4 by executing the bathtub cleaning operation shown in Figure 3. When the controller 104 receives an instruction to start cleaning the bathtub 4, for example via the remote control 106, it starts the bathtub cleaning operation.
[0045] When the bathtub cleaning operation is started, the controller 104 performs a drainage process. In the drainage process, the controller 104 opens the drain plug 132. This allows the water stored in the bathtub 4 to be discharged through the drain port 4a. The controller 104 waits for a predetermined time (for example, 10 minutes) with the drain plug 132 open, and then ends the drainage process. The waiting time in the drainage process is the time required for the bathtub 4 to be empty. When the drainage process ends, the drain plug 132 remains open. If the drain plug 132 is already open when the bathtub cleaning operation is started, the controller 104 may skip the drainage process.
[0046] After the drainage process, the controller 104 performs a pre-cleaning process. In the pre-cleaning process, the controller 104 opens the cleaning valve 124. This allows water to be supplied from the water reservoir 134 to the spray nozzle 130. The controller 104 also drives the pump 116. When the pump 116 is driven, the water stored in the water reservoir 134 is pumped by the pump 116 towards the spray nozzle 130. At this time, the controller 104 adjusts the output (i.e., rotational speed) of the pump 116 so that the flow rate detected by the flow sensor 120 is a predetermined flow rate (for example, 6 liters / minute). The water pumped to the spray nozzle 130 is sprayed from the spray nozzle 130 towards the side wall of the bathtub 4. At this time, since the detergent valve 144 is closed, water without detergent is sprayed from the spray nozzle 130. The controller 104 terminates the pre-cleaning process when the elapsed time since the start of the pre-cleaning process exceeds a predetermined time (for example, 40 seconds). When the preliminary cleaning process is complete, the controller 104 stops the pump 116 and closes the cleaning valve 124.
[0047] After the preliminary cleaning step, the controller 104 performs the cleaning step. The cleaning step includes a cleaning fluid injection step in which cleaning fluid is injected from the injection nozzle 130, and a waiting step in which the controller waits for a predetermined time.
[0048] When the cleaning process begins, the controller 104 executes the cleaning fluid injection process. In the cleaning fluid injection process, the controller 104 opens the cleaning valve 124 and the detergent valve 144 and drives the pump 116. When the pump 116 is driven, the water stored in the reservoir 134 is pumped by the pump 116 towards the injection nozzle 130. At this time, the controller 104 sets the output of the pump 116 to a predetermined output. For example, the controller 104 stores the output of the pump 116 adjusted in the pre-cleaning process and sets the stored output as the output of the pump 116 in the cleaning fluid injection process. In the detergent mixing section 128, detergent is mixed with the water flowing through the cleaning passage 108 to generate cleaning fluid. The cleaning fluid is supplied to the injection nozzle 130. The cleaning fluid supplied to the injection nozzle 130 is sprayed from the injection nozzle 130 toward the side wall of the bathtub 4. The cleaning fluid sprayed from the injection nozzle 130 adheres to the wall surface of the bathtub 4. The cleaning solution adhering to the wall surface of the bathtub 4 clings to the dirt (e.g., sebum) adhering to the wall surface. The spraying time of the cleaning solution in the cleaning solution spraying process is, for example, 3 seconds.
[0049] After the cleaning solution spraying process, the controller 104 performs a standby process. During the standby process, the controller 104 stops the pump 116 and closes the cleaning valve 124 and the detergent valve 144. This stops the spraying of cleaning solution from the spray nozzle 130. In this state, the controller 104 waits for a predetermined time (for example, 40 seconds). During this time, the cleaning solution adhering to the walls of the bathtub 4 penetrates the dirt.
[0050] The controller 104 terminates the cleaning process after repeating the cleaning solution spraying process and the waiting process a predetermined number of times (for example, twice).
[0051] After the washing process, the controller 104 executes the rinsing process. In the rinsing process, the controller 104 opens the washing valve 124 and drives the pump 116. As a result, water is sprayed from the spray nozzle 130 toward the side wall of the bathtub 4, washing away the washing solution adhering to the wall surface of the bathtub 4. At this time, the detergent valve 144 is closed, so water without detergent is sprayed from the spray nozzle 130. The controller 104 adjusts the output (i.e., rotational speed) of the pump 116 so that the flow rate detected by the flow sensor 120 is a predetermined flow rate (for example, 6 liters / minute). The water spraying time in the rinsing process is, for example, 90 seconds. When the rinsing process is finished, the controller 104 stops the pump 116 and closes the washing valve 124. When the rinsing process is finished, the bathtub washing operation ends.
[0052] (Features of the bathtub cleaning device 102) When driving the pump 116, the controller 104 adjusts the output of the pump 116, for example, based on the detection result of the flow sensor 120. This allows the force of the water or cleaning solution sprayed from the spray nozzle 130 to be adjusted. Therefore, it is possible to suppress a decrease in the cleaning effect of the bathtub cleaning operation due to insufficient force of the water or cleaning solution sprayed from the spray nozzle 130.
[0053] Furthermore, the water or cleaning solution sprayed from the spray nozzle 130 contains microbubbles generated by the microbubble generator 190. The microbubbles in the water or cleaning solution penetrate the dirt (e.g., sebum) adhering to the walls of the bathtub 4, lifting the dirt away. This promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be improved.
[0054] Furthermore, the microbubble generator 190 is located downstream of the water reservoir 134, which is open to the atmosphere, and upstream of the pump 116. Therefore, when the pump 116 is driven, the water pressure flowing through the microbubble generator 190 decreases to a very small value due to the combined effect of the water pressure reduction associated with the pump 116's suction and the water pressure reduction by the microbubble generator 190. This increases the amount of gas that precipitates from the water, i.e., the amount of microbubbles generated by the microbubble generator 190. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0055] Furthermore, since the microbubble generator 190 is located downstream of the water reservoir 134, during the bathtub cleaning operation, the microbubbles generated by the microbubble generator 190 are mixed with water and immediately supplied to the bathtub 4. This increases the amount of microbubbles supplied to the bathtub 4 compared to a configuration where the microbubble generator 190 is located upstream of the water reservoir 134. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0056] Furthermore, the microbubbles generated by the microbubble generator 190 have a very small diameter, less than 1 μm. As a result, after the water containing the microbubbles is sprayed into the bathtub 4, the microbubbles remain in the water for a long time. Also, the microbubbles penetrate dirt more easily. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0057] Furthermore, since the microbubble generator 190 is located upstream of the pump 116, water containing microbubbles passes through the pump 116. During this process, the water swirls or collides inside the pump 116, further reducing the size of the microbubbles in the water. This makes the diameter of the microbubbles supplied to the bathtub 4 smaller. As a result, after the water containing microbubbles is sprayed into the bathtub 4, the microbubbles remain in the water for a longer period of time. In addition, the microbubbles penetrate dirt more easily. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0058] Furthermore, since the microbubble generator 190 is located upstream of the detergent mixing unit 128, the water mixed with detergent does not pass through the microbubble generator 190. This prevents detergent from adhering to the microbubble generator 190, thus suppressing the performance degradation of the microbubble generator 190 caused by detergent adhesion. As a result, the cleaning effect of the bathtub cleaning operation can be maintained over the long term. In addition, since there is no need to use a material with detergent resistance for the microbubble generator 190, the bathtub cleaning device 102 can be manufactured at a low cost.
[0059] Furthermore, the air supply passage 148 that introduces air into the microbubble generator 190 is connected to the inside of the water reservoir 134 via the air inlet 150. Therefore, even if water flowing through the microbubble generator 190 flows into the air supply passage 148, that water will flow into the inside of the water reservoir 134. Unlike the embodiment, if the air inlet 150 were to open to the outside of the water reservoir 134, there would be a risk that water flowing through the microbubble generator 190 would flow to unintended locations outside the water reservoir 134 (for example, locations where electrical wiring is installed). Therefore, according to the configuration of this embodiment, it is possible to suppress water flowing through the microbubble generator 190 from flowing to unintended locations (for example, locations where electrical wiring is installed).
[0060] (Example 2: Bathtub cleaning device 252) The bathtub cleaning device 252 shown in Figure 4 has substantially the same configuration as the bathtub cleaning device 102 of Example 1 (see Figure 1). Components common to both the bathtub cleaning device 252 and the bathtub cleaning device 102 are denoted by the same reference numerals, and their descriptions are omitted.
[0061] The bathtub cleaning device 252 differs from the bathtub cleaning device 102 in that the microbubble generator 190 is installed in the portion of the cleaning passage 108 between the cleaning valve 124 and the detergent mixing section 128.
[0062] In this embodiment, since the microbubble generator 190 is located downstream of the water reservoir 134, the microbubbles generated by the microbubble generator 190 are mixed with water and immediately supplied to the bathtub 4 during the bathtub cleaning operation. As a result, the amount of microbubbles supplied to the bathtub 4 increases compared to a configuration in which the microbubble generator 190 is located upstream of the water reservoir 134. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0063] Furthermore, since the microbubble generator 190 is located downstream of the pump 116, water containing microbubbles does not flow into the pump 116. This prevents the pump 116 from running dry, thus preventing the flow rate of water sprayed from the spray nozzle 130 from becoming unstable due to the pump 116 running dry. As a result, the cleaning effect of the bathtub cleaning operation can be stably achieved.
[0064] Furthermore, since the microbubble generator 190 is located upstream of the detergent mixing unit 128, the water mixed with detergent does not pass through the microbubble generator 190. This prevents detergent from adhering to the microbubble generator 190, thus suppressing the performance degradation of the microbubble generator 190 caused by detergent adhesion. As a result, the cleaning effect of the bathtub cleaning operation can be maintained over the long term. In addition, since there is no need to use a material with detergent resistance for the microbubble generator 190, the bathtub cleaning device 252 can be manufactured at a low cost.
[0065] (Example 3: Bathtub cleaning device 302) The bathtub cleaning device 302 shown in Figure 5 has substantially the same configuration as the bathtub cleaning device 102 of Example 1 (see Figure 1). Components common to both the bathtub cleaning device 302 and the bathtub cleaning device 102 are denoted by the same reference numerals, and their descriptions are omitted.
[0066] The bathtub cleaning device 302 differs from the bathtub cleaning device 102 in that the microbubble generator 190 is installed in the portion of the cleaning passage 108 between the detergent mixing section 128 and the spray nozzle 130.
[0067] In this embodiment, the microbubble generator 190 is located downstream of the detergent mixing unit 128, so that the water mixed with detergent (i.e., the cleaning solution) passes through the microbubble generator 190. At this time, the water swirls or collides, further mixing the water and detergent. This improves the degree of mixing between the water and detergent, thereby further improving the cleaning effect of the bathtub cleaning operation.
[0068] Furthermore, since the microbubble generator 190 is located downstream of the pump 116, water containing microbubbles does not flow into the pump 116. This prevents the pump 116 from running dry, thus preventing the flow rate of water sprayed from the spray nozzle 130 from becoming unstable due to the pump 116 running dry. As a result, the cleaning effect of the bathtub cleaning operation can be stably achieved.
[0069] Furthermore, since the microbubble generator 190 is located downstream of the water reservoir 134, the microbubbles generated by the microbubble generator 190 are immediately supplied to the bathtub 4 after being mixed with water. This increases the amount of microbubbles supplied to the bathtub 4 compared to a configuration where the microbubble generator 190 is located upstream of the water reservoir 134. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0070] (Example 4: Bathtub cleaning device 402) The bathtub cleaning device 402 shown in Figure 6 has substantially the same configuration as the bathtub cleaning device 102 of Example 1 (see Figure 1). Components common to both the bathtub cleaning device 402 and the bathtub cleaning device 102 are denoted by the same reference numerals, and their descriptions are omitted.
[0071] The bathtub cleaning device 402 differs from the bathtub cleaning device 102 in that the microbubble generator 190 is installed in the portion of the cleaning passage 108 between the water supply valve 112 and the water reservoir 134.
[0072] In this embodiment, the microbubble generator 190 is located upstream of the water reservoir 134. As a result, the microbubbles generated by the microbubble generator 190 are mixed with water and then temporarily stored in the water reservoir 134. While the water is stored in the water reservoir 134, the microbubbles are separated from the water. At this time, larger diameter microbubbles are separated from the water, but smaller diameter microbubbles remain in the water. This is because the larger the diameter of the microbubbles, the stronger the force (buoyancy, etc.) that separates the microbubbles from the water. Therefore, in this embodiment, since larger diameter microbubbles are removed inside the water reservoir 134, it is possible to suppress the flow of large diameter microbubbles into the part of the cleaning passage 108 downstream of the water reservoir 134. This suppresses the pump 116 from running dry, and thus prevents the flow rate of water sprayed from the spray nozzle 130 from becoming unstable due to the pump 116 running dry. This allows the cleaning effect of the bathtub cleaning operation to be stably achieved.
[0073] Furthermore, since the microbubble generator 190 is located upstream of the pump 116, water containing microbubbles passes through the pump 116. During this process, the water swirls or collides inside the pump 116, further reducing the size of the microbubbles in the water. This makes the diameter of the microbubbles supplied to the bathtub 4 smaller. As a result, after the water containing microbubbles is sprayed into the bathtub 4, the microbubbles remain in the water for a longer period of time. In addition, the microbubbles penetrate dirt more easily. This further promotes the rinsing of dirt during the bathtub cleaning operation. In other words, the cleaning effect of the bathtub cleaning operation can be further improved.
[0074] Furthermore, since the microbubble generator 190 is located upstream of the detergent mixing unit 128, the water mixed with detergent does not pass through the microbubble generator 190. This prevents detergent from adhering to the microbubble generator 190, thus suppressing the performance degradation of the microbubble generator 190 due to detergent adhesion. As a result, the cleaning effect of the bathtub cleaning operation can be maintained over the long term. In addition, since there is no need to use a material with detergent resistance for the microbubble generator 190, the bathtub cleaning device 402 can be manufactured at a low cost.
[0075] (modified version) A heat source 38 is not required in the water supply channel 36. In this case, water from the water source 6 may be supplied to the washing channel 108 without being heated.
[0076] The microbubble generator 190 may be installed in a part of the cleaning passage 108 that is different from any of the parts in Examples 1-4. For example, the microbubble generator 190 may be installed in the part of the cleaning passage 108 between the check valve 122 and the cleaning valve 124.
[0077] The microbubble generator 190 may be replaced with a microbubble generator of a different form. For example, the microbubble generator 190 may be replaced with one comprising a pressurizer (e.g., a pressurized tank) that pressurizes the liquid to dissolve air into the liquid, and a vacuum generator (e.g., a venturi) that reduces the pressure of the liquid to precipitate microbubbles.
[0078] The upstream end of the air intake passage 148 may be connected to the overflow passage 138. That is, the air intake port 150 may open into the interior of the overflow passage 138.
[0079] The bathtub cleaning devices 102, 252, 302, and 402 do not need to be equipped with an air supply passage 148. Even in this case, the microbubble generator 190 can generate microbubbles based on the air dissolved in the water flowing through the cleaning passage 108, or the mixed air.
[0080] The bubble diameter of the microbubbles generated by the microbubble generator 190 may be 1 μm or larger. The bubble diameter of the microbubbles may be, for example, 1 μm or more and less than 100 μm.
[0081] The output of the pump 116 during bathtub cleaning operation may be set without relying on the detection results of the flow sensor 120. For example, the output of the pump 116 may be set to a value selected by the installer who installs the bathtub cleaning device 102 from among a predetermined set value. In this case, the installer may select the set value based on the length of the piping that constitutes the cleaning path 108, etc.
[0082] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]
[0083] 2: Bathtub cleaning device, 4: Bathtub, 4a: Drain, 6: Water source, 36: Water supply channel, 38: Heat source unit, 102: Bathtub cleaning device, 104: Controller, 106: Remote control, 108: Cleaning channel, 110: Flow control valve, 112: Water supply valve, 114: Cistern, 116: Pump, 118: Temperature sensor, 120: Flow sensor, 122: Check valve, 124: Cleaning valve, 126: Detergent tank, 128: Detergent mixing unit, 130: Spray nozzle, 132: Drain plug, 134: Water reservoir, 134a: Water supply port, 136a: High water level electrode, 136b: Low water level electrode, 138: Over - Flow path, 140: Overflow port, 142: Detergent path, 144: Detergent valve, 146: Mixer, 148: Air supply path, 150: Air supply port, 190: Microbubble generator, 194: Casing, 196: First microbubble generator, 198: Second microbubble generator, 200: Inlet, 202: Outlet, 204: Body, 206: Venturi flow path, 208: Reduced diameter flow path, 209: Throat, 210: Expanded diameter flow path, 212: Shaft, 214: Outer circumference, 216: Blade, 218: Swirling flow path, 252: Bathtub cleaning device, 302: Bathtub cleaning device, 402: Bathtub cleaning device
Claims
1. A spray nozzle installed inside the bathtub, A washing path is connected to a water source at its upstream end and to the injection nozzle at its downstream end, A cistern including a water reservoir provided in the washing passage for storing water supplied from the water source in an open state to the atmosphere, and an overflow passage for discharging water that overflows from the water reservoir, A pump is provided in the portion of the washing passage downstream of the water reservoir, which pumps the water stored in the water reservoir toward the injection nozzle. A detergent tank for storing detergent, A detergent mixing unit is provided in the portion of the washing passage downstream of the pump, and mixes the detergent stored in the detergent tank with the water flowing through the washing passage. A bathtub cleaning device comprising a microbubble generating unit provided in the cleaning passage for generating microbubbles in the water flowing through the cleaning passage, The bathtub cleaning device is configured to perform a bathtub cleaning operation by driving the pump, which sprays water containing fine bubbles and mixed with detergent from the spray nozzle to clean the bathtub.
2. The bathtub cleaning device according to claim 1, wherein the microbubble generating unit is provided in the portion of the cleaning passage downstream of the water reservoir.
3. The bathtub cleaning device according to claim 2, wherein the microbubble generating unit is provided in the portion of the cleaning passage downstream of the pump.
4. The bathtub cleaning device according to claim 3, wherein the microbubble generating section is provided in the portion of the cleaning passage downstream of the detergent mixing section.
5. The bathtub cleaning device according to claim 2, wherein the microbubble generating section is provided in the portion of the cleaning passage downstream of the water reservoir and upstream of the detergent mixing section.
6. The bathtub cleaning device according to claim 5, wherein the microbubble generating unit is provided in the portion of the cleaning passage downstream of the pump and upstream of the detergent mixing unit.
7. The bathtub cleaning device according to claim 5, wherein the microbubble generating unit is provided in the portion of the cleaning passage downstream of the water reservoir and upstream of the pump.
8. The bathtub cleaning device according to claim 1, wherein the microbubble generating section is provided in the portion of the cleaning passage upstream of the detergent mixing section.
9. The bathtub cleaning device according to claim 8, wherein the microbubble generating unit is provided in the portion of the cleaning passage upstream of the pump.
10. The bathtub cleaning device according to claim 9, wherein the microbubble generating unit is provided in the portion of the cleaning passage upstream of the water reservoir.
11. The bathtub cleaning device further includes an air supply passage whose upstream end is connected to the cistern and whose downstream end is connected to the microbubble generating section. The bathtub cleaning device according to claim 1, wherein the microbubble generating unit is configured to generate microbubbles in the water flowing through the cleaning passage using air introduced from the cistern through the air supply passage.
12. The bathtub cleaning device according to any one of claims 1 to 11, wherein the diameter of the microbubbles generated by the microbubble generating unit is less than 1 μm.