Bathtub equipment

Abstract

To provide a bathtub device which prevents hot water from overflowing from a bathtub body as hot water increases in adjusting a temperature of the hot water to be discharged and suppresses unpleasant feeling given to a bathing person because of increased floating feeling the bathing person in the bathtub body experiences.SOLUTION: A bathtub device of the invention includes: a water discharge part 8; a circulation flow passage 4; a first pump 6 for sending hot water taken from a water intake port part in the circulation flow passage; a water supply flow passage 10 for supplying the hot water or water to adjust a temperature of the hot water in the circulation flow passage; a second pump 14 for supplying the hot water in the water supply flow passage; and a control part 16 for controlling the first pump and the second pump. The control part 16 performs the control of the first pump 6 that reduces a flow rate of the hot water flowing in the circulation flow passage so that the flow rate of the hot water flowing in the circulation flow passage 4 is smaller than the flow rate of the hot water or the water supplied from the water supply flow passage 10 in driving the second pump 14 to supply the hot water or water from the water supply flow passage to the circulation flow passage.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a bathtub apparatus, and more particularly to a bathtub apparatus that supplies hot and cold water to a bathtub. [Background technology]

[0002] A bathtub water circulation type water discharger is known, as shown in Patent Document 1. This bathtub water circulation type water discharger is configured to discharge the hot water taken in toward the neck of the bather (user) in the bathtub. This allows the bather to feel the temperature of the discharged hot water while bathing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-150334 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present invention considered supplying hot water or the like from an external supply source to the bathtub water circulation type water discharge device described in Patent Document 1 above so that the discharged water temperature could be adjusted to give the bather a feeling of refreshment and relaxation. However, when attempting to adjust the discharged water temperature by supplying hot water or the like from an external supply source, adjusting the temperature while supplying hot water from an external source to the circulating bathtub water increases the amount of hot water in the bathtub, which can cause the bathtub to overflow or cause discomfort to the bather. Furthermore, if the flow rate of circulating bathtub water is high, more hot water must be added to adjust the temperature, making the problem of hot water in the bathtub more pronounced.

[0005] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a bathtub device that can prevent the amount of hot water from increasing and overflowing the bathtub body by adjusting the temperature of the hot water being discharged, or the increased floating sensation felt by the bather in the bathtub body, causing discomfort to the bather. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a bathtub device that supplies hot water to a bathtub, comprising: a bathtub body for storing hot water; a water intake section for taking in hot water from the bathtub body; a water discharge section provided above the bathtub body and discharging the hot water absorbed from the water intake section into the bathtub body; a circulation flow path that connects the water intake section and the water discharge section; a first pump provided in the circulation flow path and transporting the hot water absorbed from the water intake section through the circulation flow path; a water supply flow path connected to the circulation flow path and supplying hot water or water from an external source to adjust the temperature of the hot water in the circulation flow path; and a control unit that controls the first pump, wherein when hot water or water is supplied from the water supply flow path to the circulation flow path, the control unit controls the first pump to reduce the flow rate of hot water flowing through the circulation flow path so that the flow rate of hot water flowing through the circulation flow path is less than the flow rate of hot water or water supplied from the water supply flow path. In one embodiment of the present invention, the bathtub apparatus is configured to supply hot water or cold water from an external source from the water supply flow path to the circulation flow path, adjusting the temperature of the hot water being discharged from the bathtub body through the water intake, circulation flow path, and discharge port. When supplying hot water or cold water from the water supply flow path to the circulation flow path, the control unit controls the first pump to reduce the flow rate of hot water or cold water flowing through the circulation flow path compared to the flow rate of hot water or cold water supplied from the water supply flow path. This prevents an increase in the discharge flow rate, preventing an increase in the hot water volume in the bathtub body that could cause the bather to overflow, or preventing the bather from feeling uncomfortable due to an increased floating sensation. In addition, by reducing the flow rate of circulating bath water, the temperature of the water in the circulation flow path can be adjusted with a smaller flow rate than that supplied from the water supply flow path, and the increase in the amount of water in the bathtub can also be reduced.

[0007] In the present invention, it is preferable that the device further comprises a storage section that is provided in the water supply flow path and stores the hot water or cold water to be supplied, the storage section being formed so as to separate the flow path between the upstream and downstream sides of the water supply flow path, and a second pump that sends the hot water in the water supply flow path toward the circulation flow path. One embodiment of the present invention configured as described above further includes a storage section provided in the water supply channel for storing the hot or cold water to be supplied, the storage section being configured to separate the upstream and downstream sides of the water supply channel, and a second pump for pumping the hot or cold water in the water supply channel toward the circulation channel. This allows the storage section to store the hot or cold water and the second pump to pump it toward the circulation channel, even if the amount of hot or cold water supplied to the water supply channel from an external supply source temporarily fluctuates due to changes in water pressure, thereby preventing temporary fluctuations in the temperature of the water being discharged. This allows for a configuration that can adjust the temperature of the hot or cold water discharged toward a bather in the bathtub to a predetermined temperature and prevents temporary fluctuations in the temperature of the hot or cold water being discharged toward a bather in the bathtub, thereby preventing discomfort to the bather.

[0008] In the present invention, the water supply passage is preferably connected to a negative pressure generating section that generates negative pressure by the flow of hot and cold water flowing through the circulation passage. In one embodiment of the present invention configured in this manner, the water supply flow path is connected to a negative pressure generating unit that generates negative pressure due to the flow of hot water and water flowing within the circulation flow path, so that the hot water or water in the water supply flow path is drawn in by the negative pressure generated by the flow of hot water and water flowing within the circulation flow path, making it less likely that the hot water or water in the water supply flow path will flow back in the water supply flow path and allowing it to be more efficiently mixed with the flow of hot water and water flowing within the circulation flow path.

[0009] In the present invention, the circulation flow path preferably includes a chamber for drawing in hot and cold water midway through the circulation flow path, and the water supply flow path is connected to a negative pressure generating unit that generates negative pressure in the chamber by the flow of hot and cold water flowing through the circulation flow path. In one embodiment of the present invention configured in this manner, the water supply flow path is connected to a negative pressure generating unit that generates negative pressure in the chamber due to the flow of hot water or water flowing through the circulation flow path, so that the hot water or water in the water supply flow path is drawn in by the negative pressure generated by the flow of hot water or water flowing through the circulation flow path, making it less likely that the hot water or water in the water supply flow path will flow back in the water supply flow path and allowing it to be more efficiently mixed with the flow of hot water or water flowing through the circulation flow path.

[0010] In the present invention, the water supply flow path is preferably connected to a negative pressure generating section in the circulation flow path upstream of the first pump, which generates negative pressure by the flow of hot and cold water flowing through the circulation flow path. In one embodiment of the present invention configured in this manner, the water supply flow path is connected to a negative pressure generating unit upstream of the first pump in the circulation flow path, which generates negative pressure due to the flow of hot water or water flowing within the circulation flow path.Therefore, the hot water or water in the water supply flow path is drawn in by the negative pressure generated by the flow of hot water or water flowing within the circulation flow path, making it less likely that the hot water or water in the water supply flow path will flow back in the water supply flow path and allowing it to be mixed more efficiently with the flow of hot water or water flowing within the circulation flow path.

[0011] In the present invention, the flow rate of hot or cold water flowing out of the storage portion is preferably the same as or less than the flow rate of hot or cold water flowing into the storage portion. In one embodiment of the present invention configured in this way, the flow rate of hot water or cold water flowing out of the storage unit is the same as or less than the flow rate of hot water or cold water flowing into the storage unit. This allows the bathtub device to store hot water or cold water in the storage unit while supplying hot water or cold water from the storage unit to the circulation flow path, making it less likely that the temperature of the hot water supplied from the storage unit to the circulation flow path will fluctuate temporarily, and making it less likely that the temperature of the hot water discharged will fluctuate temporarily.

[0012] In the present invention, preferably, the control unit controls the second pump so that the flow rate of hot water supplied to the circulation flow path when hot water supplied from a water heater as an external supply source is supplied from the water supply flow path to the circulation flow path is greater than the flow rate of water supplied to the circulation flow path when water supplied from a tap water source as an external supply source is supplied from the water supply flow path to the circulation flow path. Typically, when a bather is bathing, the temperature of the hot water stored in the bathtub body is bathing temperature (e.g., 38°C to 40°C). In contrast, the temperature of the hot water supplied from an external water heater can be set to a temperature that will not burn the bather, for example, a temperature several degrees higher than bathing temperature (e.g., 40°C to 49°C). Furthermore, the temperature of water supplied from a water supply (e.g., an external supply source) is closer to ambient temperature (e.g., 20°C to 25°C), which is more than 10 degrees lower than bathing temperature in the water pipes. The inventors of the present invention focused on the new viewpoint that the difference between the temperature of the hot water supplied from such a water heater and the temperature of the hot water in the bathtub body is smaller than the difference between the temperature of the water supplied from the water supply and the temperature of the hot water in the bathtub body. Thus, in one embodiment of the present invention, the control unit controls the second pump so that the flow rate of hot water supplied to the circulation flow path when hot water supplied from a water heater as an external supply source is supplied from the water supply flow path to the circulation flow path is greater than the flow rate of water supplied to the circulation flow path when water supplied from a mains water supply as an external supply source is supplied from the water supply flow path to the circulation flow path. This allows the flow rate of hot water or water supplied from the water supply flow path to be adjusted in accordance with the temperature difference between the temperature of the hot water in the circulation flow path and the temperature of the hot water or water being supplied, thereby more effectively regulating the temperature and reducing unnecessary water use. Furthermore, the temperature of hot water supplied from the water heater as an external supply source can be regulated by setting it to a relatively low temperature (e.g., 40°C to 49°C) rather than a relatively high temperature (e.g., 50°C to 60°C). [Effects of the Invention]

[0013] According to the bathtub device of the present invention, it is possible to prevent the amount of hot water from increasing by adjusting the temperature of the hot water being discharged, causing it to overflow from the bathtub body, or to prevent the bather from feeling uncomfortable due to an increased sense of floating felt by the bather inside the bathtub body. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing an entire bathroom in which a bathtub apparatus according to an embodiment of the present invention is installed. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] This is a side view showing the water discharge device, circulation flow path, and chamber of a bathtub apparatus according to one embodiment of the present invention, as viewed from the side of the short side of the bathtub body. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Figure 5] This is an oblique view showing the circulation flow path, water supply flow path, storage section, etc. arranged on the back side of the bathtub body of the bathtub apparatus according to one embodiment of the present invention. [Figure 6] A diagram showing the hot and cold water supply system in a bathtub apparatus according to one embodiment of the present invention. [Figure 7] 4 is a flowchart showing the operation of a bathtub apparatus according to one embodiment of the present invention. [Figure 8] A diagram showing a hot and cold water supply system in a modified example of a bathtub apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Next, a bathtub apparatus according to one embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments of the present disclosure have been described by way of example, and it will be apparent to those skilled in the art that many modifications, changes, and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention is not limited to the disclosed embodiments, and various modifications, changes, etc. can be made in form and detail without departing from the scope of the claims. Figure 1 is an oblique view showing the entire bathroom in which a bathtub device according to one embodiment of the present invention is installed, Figure 2 is a cross-sectional view taken along line II-II in Figure 1, Figure 3 is a side view showing the water discharge device, circulation flow path, and chamber of a bathtub device according to one embodiment of the present invention as viewed from the side of the short side of the bathtub body, Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3, Figure 5 is an oblique view showing the circulation flow path, water supply flow path, storage section, etc. arranged on the back side of the bathtub body of a bathtub device according to one embodiment of the present invention, and Figure 6 is a diagram showing the hot and cold water supply system in a bathtub device according to one embodiment of the present invention.

[0016] As shown in Figure 1, a bathtub apparatus 1 according to one embodiment of the present invention is a bathtub apparatus that is installed in a bathroom R and supplies hot water to the bathtub. The bathtub apparatus 1 according to one embodiment of the present invention comprises a bathtub main body 2, a water intake section (bathtub water intake) 9b that takes in hot water from the bathtub main body 2, a water discharge device 8 that is provided above the bathtub main body 2 and discharges the hot water taken in from the water intake section 9b into the bathtub main body 2, a circulation flow path 4 that connects the water intake section 9b and the water discharge device 8, a first pump (circulation pump) 6 that is provided in the circulation flow path 4 and sends the hot water taken in from the water intake section 9b through the circulation flow path 4, and an external pump connected to the circulation flow path 4 to adjust the temperature of the hot water in the circulation flow path 4. The device comprises a water supply flow path (supply pipe) 10 that supplies hot water or cold water from a supply source, a storage section (storage tank) 12 that is provided in the water supply flow path 10 and stores the hot water or cold water that is supplied, a second pump (pressurizing pump) 14 that is provided downstream of the storage section 12 in the water supply flow path 10 and sends the hot water or cold water in the storage section 12 toward the circulation flow path 4, a first temperature sensor (discharge water temperature sensor) 22 that is provided in the circulation flow path 4 and measures the temperature of the hot water in the circulation flow path 4, and a control unit 16 that controls the first pump 6 and the second pump 14.

[0017] The bathtub apparatus 1 functions as a circulation device that takes in hot water from the bathtub main body 2 through the water intake port 9b and circulates it through the water discharge device 8 into the bathtub main body 2. A remote control 18 is also attached to the wall of the bathroom R, and the bathtub apparatus 1 can be operated using this remote control 18. Furthermore, in this embodiment, the bathtub apparatus 1 is placed on one side of the bathroom R so that it is in contact with the wall. The remote control 18 is configured to accept operational inputs for bathers to adjust the temperature. The remote control 18 is electrically connected to the control unit 16 and can transmit operational input signals to the control unit 16. The remote control 18 is placed inside the bathroom R, but it may also be placed outside the bathroom R.

[0018] The bathtub body 2 is formed in a roughly rectangular box shape in a plan view and is configured to store hot and cold water inside. In this embodiment, the bathtub body 2 is positioned so that one long side and the entire two short sides on either side of it are in contact with the inner wall surface of the bathroom R. Furthermore, the inner wall surface that forms one short side of the bathtub body 2 is configured as a backrest surface 2a, which is the first inner wall surface formed for the bather to lean against. The water intake portion 9b is formed on the side wall surface 2b on the long side of the bathtub body 2.

[0019] The water discharge device 8 is provided on the upper edge of the bathtub body 2. The water discharge device 8 is provided on the upper part of the backrest surface 2a of the bathtub body 2 and is configured to discharge hot water toward the inside of the bathtub body 2. In this embodiment, the water discharge device 8 has a flat, wide water outlet 8a extending along the upper edge of the backrest surface 2a, and is configured to discharge hot water toward the neck, shoulders, and back of a bather leaning against the backrest surface 2a. The water discharge device 8 is also configured to discharge a portion of the hot water drawn in from the water intake portion 9b through the water outlet 8a. Therefore, the hot water in the bathtub body 2 circulates, being sucked in through the water intake portion 9b and discharged through the water outlet 8a to flow into the bathtub body 2. Furthermore, a portion of the hot water drawn in from the water intake portion 9b is also discharged from the bathtub water outlet 9a provided on the backrest surface 2a of the bathtub body 2.

[0020] In addition, in this embodiment, the water outlet 8a of the water discharger 8 is formed to be flat and wide, so that the hot water discharged from the water outlet 8a is discharged as a wide, band-like water film, and lands at a position away from the backrest surface 2a on the surface of the hot water stored in the bathtub main body 2. Furthermore, in this embodiment, the water discharger 8 is configured so that the pressure strength applied by the first pump 6 can be switched between three levels: "strong," "medium," and "weak."

[0021] The circulation flow path 4 extends from the water intake 9b to the water outlet 8a of the water discharge device 8. The bathtub apparatus 1 is configured to suck in hot water from within the bathtub body 2 through the water intake 9b provided on the inner wall surface of the bathtub body 2 and discharge the hot water from the water outlet 8a of the water discharge device 8 into the bathtub body 2 via the circulation flow path 4. The circulation flow path 4 branches downstream of the first pump 6 into a flow path on the side of the bathtub water outlet 9a provided on the backrest surface 2a of the bathtub body 2, and a flow path extending to the chamber 11 side. Therefore, a portion of the hot water sucked in from the water intake 9b is discharged from the bathtub water outlet 9a provided on the backrest surface 2a of the bathtub body 2 via the circulation flow path 4.

[0022] The circulation flow path 4 includes a chamber 11 for drawing in hot and cold water from the bathtub main body 2, which is located midway along the circulation flow path, a spray-side flow path (first pipe) 4a in which the first pump 6 is located, an introduction flow path (second pipe) 4b connected to the chamber 11 and introducing hot and cold water from the bathtub main body 2 into the chamber 11, and a water discharge device-side flow path (third pipe) 4c extending from the chamber 11 toward the water discharge device 8.

[0023] A jet nozzle (nozzle) 20 is provided at the outlet of the jetting section side flow path 4a to the chamber 11. The jet nozzle 20 is arranged downstream of the first pump 6 and forms a jetting section that jets hot water supplied from the first pump 6 so that it passes through the chamber 11. The hot water jetted by the jet nozzle 20 draws hot water from within the chamber 11 by jet pump action, and the flow rate of hot water jetted from the jet nozzle 20 is added to the flow rate of hot water drawn from within the chamber 11, resulting in a larger flow rate of hot water being supplied to the water discharger side flow path 4c. The water discharger side flow path 4c extends on an extension line of the jet nozzle 20.

[0024] The first pump 6 pressurizes the hot water in the jetting section side flow path 4a toward the jet nozzle 20, and the hot water supplied from the first pump 6 is sprayed by the jet nozzle 20 so that it passes through the chamber 11. The first pump 6 is configured so that the rotation speed of the internal rotor can be changed. Therefore, the first pump 6 can change the set flow rate of the hot water delivered downstream by changing the rotation speed of the internal rotor.

[0025] Chamber 11 is located below the specified water level W1 in bathtub main body 2 (for example, the predetermined water level required when using water discharger 8), and chamber 11 is filled with hot water from bathtub main body 2. Chamber 11 forms a storage chamber that can store hot water. Therefore, when hot water sprayed by jet nozzle 20 passes through chamber 11, the hot water in chamber 11 is drawn into the sprayed hot water, forming a flow with a larger flow rate. Chamber 11 is connected to a jetting section side flow path 4a and a water discharger side flow path 4c on its upper surface opposite jetting section side flow path 4a. The pipe diameter of water discharger side flow path 4c is larger than the diameter of jet nozzle 20. Chamber 11 is also connected to water supply flow path 10. Therefore, when hot water sprayed by jet nozzle 20 draws hot water from chamber 11, the hot water in the introduction flow path and the hot water or water in the water supply flow path 10 pass through chamber 11 and are drawn into the water discharger side flow path. Such a chamber 11, jet nozzle 20 and water discharge device side flow path 4c constitute a jet pump unit, and even when attempting to supply a relatively large flow rate of hot water to the water discharge device 8, a relatively simple configuration and a relatively small structure can be used to supply a relatively large flow rate of hot water, thereby forming a bathtub device 1 that can supply a relatively large flow rate of hot water in the small, restricted space between the bathtub main body 2 and its casing (apron) 2c in the bathroom R.

[0026] Furthermore, the chamber 11 mixes the hot water drawn in from the water intake 9b and pressurized by the first pump 6 with the hot water or cold water supplied from the water supply flow path 10, and supplies the resulting mixture to the downstream flow path 4c on the water discharger side. When hot water is flowing through the circulation flow path 4, the chamber 11 is almost filled with hot water.

[0027] The first temperature sensor 22 is provided in the water discharger side flow path 4c, and is configured to measure the temperature of hot water discharged from the water discharger 8. The first temperature sensor 22 is, for example, a thermistor.

[0028] The water supply flow path 10 forms a supply path for hot and cold water to the circulation flow path 4. In the chamber 11, the water supply flow path 10 is connected to a negative pressure generating unit 11a that generates negative pressure by the flow of hot and cold water flowing through the circulation flow path 4. In the chamber 11, the ceiling portion in front of the jet nozzle 20 (the inlet portion of the water discharge device side flow path 4c) is the portion that generates positive pressure by the flow of hot and cold water. Meanwhile, in the chamber 11, the ceiling portion, side wall portion, and bottom portion other than the ceiling portion in front of the jet nozzle constitute the negative pressure generating unit 11a. The downstream end 10a of the water supply flow path 10 that is connected to the chamber 11 is located in the portion other than the ceiling portion in front of the jet nozzle 20.

[0029] Connected to the upstream side of the water supply flow path 10 are a high-temperature hot water supply pipe (hot water supply pipe) 40a which supplies hot water at a temperature higher than the temperature of the hot water stored in the bathtub main body 2, and a low-temperature hot water supply pipe (water supply pipe) 40b which supplies water at a temperature lower than the temperature of the hot water stored in the bathtub main body 2.

[0030] The high-temperature hot water supply pipe 40a and the low-temperature hot water supply pipe 40b are connected to the reservoir 12 via a high-temperature solenoid valve (hot water solenoid valve) 56 and a low-temperature solenoid valve (cold water solenoid valve) 58, respectively. The high-temperature solenoid valve 56 and the low-temperature solenoid valve 58 control the start and stop of the supply of hot water or cold water. The amount of hot water or cold water flowing from each supply pipe into the reservoir 12 is controlled by a water volume proportional valve 26. Furthermore, in this embodiment, hot water at a temperature higher than the temperature of the hot water stored in the bathtub body 2, for example, hot water at a temperature set in the water heater 52, is supplied to the high-temperature hot water supply pipe 40a from the water heater 52. That is, tap water supplied from an external water supply source 54 is branched at a branch point 54a, one branch being supplied to the water heater 52 and the other branching directly into the low-temperature hot water supply pipe 40b. The tap water supplied to the water heater 52 is heated to a temperature higher than the temperature of the hot water stored in the bathtub body 2 and supplied to the high-temperature hot water supply pipe 40a. The high-temperature hot water supply pipe 40a is provided with a check valve 45 to prevent the backflow of hot water or cold water, and the low-temperature hot water supply pipe 40b is provided with a check valve 47 to prevent the backflow of cold water.

[0031] As a result, when it is desired to increase the temperature of the hot water in the circulation flow path 4 or the storage portion 12, the high-temperature side solenoid valve 56 is opened, and hot water is supplied to the storage portion 12 from the water heater 52, which serves as an external supply source. On the other hand, when it is desired to decrease the temperature of the hot water in the circulation flow path 4 or the storage portion 12, the low-temperature side solenoid valve 58 is opened, and tap water supplied from the low-temperature hot water supply pipe 40b is supplied to the storage portion 12. Note that the high-temperature side solenoid valve 56 and the low-temperature side solenoid valve 58 may be opened simultaneously, and the hot water and cold water may be mixed and supplied to the storage portion 12.

[0032] Furthermore, the temperature of the hot and cold water stored in the bathtub body 2 is measured by the first temperature sensor 22, but it may also be detected by a bathtub temperature sensor attached to the bathtub body 2. Also, although the temperature of each hot and cold water is detected, the temperature of each hot and cold water may also be estimated based on the data obtained from each sensor.

[0033] The temperatures detected by these temperature sensors are sent to the control unit 16, which adjusts the rotation speed of the second pump 14 based on these detected temperatures and causes hot water at the required high temperature to be discharged from the water discharge device 8.

[0034] The second pump 14 pumps hot water or cold water stored in the storage section 12 in the water supply flow path 10 toward the chamber 11. The second pump 14 is configured so that the rotation speed of the internal rotor can be changed. Therefore, the second pump 14 can change the set flow rate of hot water or cold water to be sent downstream by changing the rotation speed of the internal rotor.

[0035] The bathtub device 1 further includes a water volume sensor 24 for measuring the flow rate of hot water or cold water between the storage section 12 of the water supply flow path 10 and the high-temperature side solenoid valve 56 and the low-temperature side solenoid valve 58, a water volume proportional valve (flow regulating valve) 26 for controlling the flow rate of hot water or cold water, a constant flow valve 28 for limiting the maximum flow rate of water passing through the water passage regardless of water pressure, a second temperature sensor (inlet side temperature sensor) 30 for measuring the temperature of the hot water in the water supply flow path 10 leading to the storage section 12, a third temperature sensor (storage tank temperature sensor) 32 provided in the storage section 12, a fourth temperature sensor (outlet side temperature sensor) 34 for measuring the temperature of the hot water or cold water flowing out downstream from the storage section 12, a water volume sensor 36 provided downstream of the second pump 14, a check valve 38 for preventing backflow of hot water or cold water, and a solenoid valve 40 for electromagnetically opening and closing the flow path.

[0036] The water volume sensor 24, the water volume proportional valve 26, the constant flow valve 28, and the second temperature sensor 30 are provided between the storage section 12 of the water supply flow path 10 and the confluence section 43 downstream of the high-temperature side solenoid valve 56 and the low-temperature side solenoid valve 58. The confluence section 43 is the section where the high-temperature hot water supply pipe 40a and the low-temperature hot water supply pipe 40b are connected and the flows of both are joined together.

[0037] The second temperature sensor 30 is provided in the water supply flow path 10 upstream of the storage section 12, and is configured to measure the temperature of the hot water or cold water supplied to the storage section 12 from the high-temperature hot water supply pipe 40a and the low-temperature hot water supply pipe 40b. The second temperature sensor 30 is, for example, a thermistor. The third temperature sensor 32 is configured to measure the temperature of the hot water or cold water stored in the storage section 12. The third temperature sensor 32 is, for example, a thermistor.

[0038] The fourth temperature sensor 34, water volume sensor 36, check valve 38, and solenoid valve 40 are provided between the reservoir 12 and the chamber 11 of the water supply flow path 10. The fourth temperature sensor 34 measures the temperature of the hot or cold water flowing downstream from the reservoir 12. The fourth temperature sensor 34 is, for example, a thermistor. The water volume sensor 36 can measure the flow rate of the hot or cold water passing through the water supply flow path 10.

[0039] The control unit 16 is electrically connected to the first pump 6, the second pump 14, the remote control 18, the first temperature sensor 22, the water volume sensor 24, the water volume proportional valve 26, the second temperature sensor 30, the third temperature sensor 32, the fourth temperature sensor 34, the water volume sensor 36, the solenoid valve 40, the high-temperature solenoid valve 56, and the low-temperature solenoid valve 58. These electrical connections may be made entirely or partially via wireless communication, such as infrared communication. The control unit 16 incorporates a calculation device such as a CPU and a storage device such as a memory, and can control the electrically connected devices based on stored predetermined control programs, etc. For example, the control unit 16 stores in the storage device control programs for temperature adjustment preparation control, temperature adjustment control, and other control programs for supplying hot and cold water to the bathtub. Therefore, when the control unit 16 drives the second pump 14 to supply hot water or cold water from the water supply flow path 10 to the circulation flow path 4, the control program controls the first pump 6 to reduce the flow rate of hot water or cold water flowing through the circulation flow path 4 below the flow rate before the second pump 14 is driven, so that the flow rate of hot water or cold water flowing through the circulation flow path 4 is less than the flow rate of hot water or cold water supplied from the water supply flow path 10 when water is being supplied from the water supply flow path 10. Note that when the control program drives the second pump 14 to supply hot water or cold water from the water supply flow path 10 to the circulation flow path 4, the control program may also control the first pump 6 to reduce the flow rate of hot water or cold water flowing through the circulation flow path 4 below the flow rate before the second pump 14 is driven, while also controlling the supply flow rate from the second pump 14, so that the flow rate of hot water or cold water flowing through the circulation flow path 4 is less than the flow rate of hot water or cold water supplied from the water supply flow path 10 when water is being supplied from the water supply flow path 10.

[0040] Next, the reservoir 12 will be described in detail. The reservoir 12 is formed to separate the upstream and downstream sides of the water supply flow path 10. The reservoir 12 is configured to store hot or cold water up to a predetermined water level determined by the float switch 42. Therefore, an upper space 12a is formed in the upper part of the reservoir 12, and the reservoir 12 is formed so that its downstream end 10b, which forms the water supply flow path inlet, is connected to the upper space 12a. Meanwhile, the bottom surface of the reservoir 12 is connected to the water supply flow path outlet 10c.

[0041] The reservoir 12 is provided with a float switch 42 disposed inside the reservoir 12 and an overflow pipe 44. The float switch 42 includes a stem 42a forming the rod-shaped shaft of the float switch 42 and a float portion (float) 42b that moves up and down along the stem 42a while receiving buoyancy according to the water level fluctuations in the reservoir 12. Therefore, when the float portion 42b rises along the stem 42a to the water level detection position in accordance with the water level, the float switch 42 can detect that the hot or cold water in the reservoir 12 has reached a predetermined upper water level. When the float switch 42 detects that the hot or cold water has reached the predetermined upper water level, the water level in the reservoir 12 is at least the predetermined upper water level, and the control unit 16 can determine that a predetermined amount of hot or cold water is stored in the reservoir 12. The float switch 42 is electrically connected to the control unit 16.

[0042] Overflow pipe 44 is formed to extend vertically within storage portion 12. Overflow pipe 44 opens at the top of storage portion 12 and extends from within storage portion 12 onto a drainage flow path outside storage portion 12. Thus, overflow pipe 44 is provided to prevent hot water or cold water from overflowing from storage portion 12, and when the water level within storage portion 12 exceeds the height of upper end opening 44a of overflow pipe 44, hot water or cold water flows into overflow pipe 44 and is drained into the drainage flow path.

[0043] The hot water supplied from the high-temperature hot water supply pipe 40a and the cold water supplied from the low-temperature hot water supply pipe 40b are led to the storage section 12, where they are mixed and temporarily stored. The storage section 12 is formed to a size that can store a predetermined amount of water. The predetermined amount of water, which is defined as the water storage capacity in the storage section 12 below the upper end opening 44a of the overflow pipe 44, is larger than the volume of the chamber 11. For example, the storage section 12 has a storage capacity of the predetermined amount of water in the range of approximately 0.5 L to approximately 3.0 L. The storage section 12 is also located above the chamber 11.

[0044] When attempting to store hot water or cold water in storage section 12, control section 16 controls water volume proportional valve 26, second pump 14, solenoid valve 40, etc. so that the flow rate (flow rate per unit time) of hot water or cold water flowing out downstream from storage section 12 is less than the flow rate (flow rate per unit time) of hot water or cold water flowing into storage section 12 from the upstream side of storage section 12. For example, control section 16 controls the flow rate of hot water or cold water flowing out downstream from storage section 12, which is adjusted by second pump 14, etc., to be less than the flow rate of hot water or cold water flowing into storage section 12, which is adjusted by water volume proportional valve 26, etc. Furthermore, for example, control section 16 controls the flow rate of hot water or cold water downstream from storage section 12, the outflow of which has been stopped by closing solenoid valve 40, to be less than the flow rate of hot water or cold water flowing into storage section 12, which is adjusted by water volume proportional valve 26, etc. When the amount of water stored in the reservoir 12 increases further above the predetermined water level W0, the overflow pipe 44 is used to keep the water level in the upper part of the reservoir 12 constant.

[0045] When hot water or cold water is to be supplied from the storage section 12 to the chamber 11, the control section 16 controls the water volume proportional valve 26 so that the flow rate of the hot water or cold water flowing out downstream from the storage section 12 is less than the flow rate of the hot water or cold water flowing into the storage section 12 from the upstream side of the storage section 12, or so that the flow rate of the hot water or cold water flowing out downstream from the storage section 12 is approximately the same as the flow rate of the hot water or cold water flowing into the storage section 12.

[0046] Next, the operation of the bathtub apparatus 1 according to one embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the bathtub apparatus 1 according to one embodiment of the present invention.

[0047] The flowchart shown in Fig. 7 is a flow showing the control by the control unit 16. In Fig. 7, S indicates each step. First, at the start, the control unit 16 starts the temperature adjustment preparation control and the subsequent temperature adjustment control in response to the bather's operation input on the remote control 18. Note that the control unit 16 may also start the temperature adjustment preparation control at its own discretion using a control program stored in its own storage device. At the start, the solenoid valve 40, the high-temperature solenoid valve 56, and the low-temperature solenoid valve 58 are in the closed state.

[0048] Next, in step S1, the control unit 16 determines whether the bathtub apparatus 1 is in the ON state, which means it is in a running state. For example, the control unit 16 determines whether the first pump 6 is in the ON state. If the control unit 16 determines that the bathtub apparatus 1 is not in the ON state, it proceeds to S2 to start the bathtub apparatus 1. If the control unit 16 determines that the bathtub apparatus 1 is in the ON state, it proceeds to S3 to enable relatively early adjustment of the water temperature.

[0049] In step S2, the control unit 16 starts up the bathtub apparatus 1 and turns it on. This causes the control unit 16 to start the first pump 6, which takes in hot water from the bathtub main body 2 through the water intake port 9b and pressure-pumps it downstream using the first pump 6. When the hot water sprayed by the jet nozzle 20 draws in the hot water from the chamber 11, the hot water in the inlet flow path 4b passes through the chamber 11 and is drawn into the water discharger side flow path 4c. The hot water that flows into the water discharger side flow path 4c is discharged from the water discharger 8 into the bathtub main body 2 and circulated within the bathtub main body 2. The hot water discharged from the water discharger 8 falls on the upper body, such as the neck and shoulders, of a bather sitting with their back against the backrest surface 2a in the bathtub main body 2, allowing the bather to enjoy a shoulder bath.

[0050] In step S3, the control unit 16 obtains the temperature of the hot water discharged from the water discharger 8, that is, the temperature of the circulating discharged water, from the first temperature sensor 22, and proceeds to S4.

[0051] In step S4, the control unit 16 can estimate the flow rate of hot water flowing in the circulation flow path 4 from the output of the first pump 6 or the rotation speed of the rotor, for example, the flow rate of hot water in the jetting section side flow path 4a or the flow rate of hot water in the water discharger side flow path 4c. The control unit 16 estimates, for example, the flow rate A1 [L / min] of hot water in the water discharger side flow path 4c (see Figure 6), acquires it as the circulation flow rate, and proceeds to S5. The rotation speed or output of the rotor of the first pump 6 is controlled to be constant thereafter until it is controlled in step S14. In S4, the flow rate of hot water in the circulation flow path 4 may be measured by providing a water volume sensor in the circulation flow path 4.

[0052] In step S5, the control unit 16 stores hot water or cold water in the storage unit 12 in preparation for the storage unit 12. For example, when the control unit 16 attempts to adjust the temperature of hot water to a temperature higher than the temperature of hot water to be discharged obtained in step S3, the control unit 16 opens the high-temperature side solenoid valve 56 to supply hot water at a temperature set by the water heater 52 into the storage unit 12. For example, when the control unit 16 attempts to adjust the temperature of hot water to a temperature lower than the temperature of hot water to be discharged obtained in step S3, the control unit 16 opens the low-temperature side solenoid valve 58 to supply water supplied from the water supply 54 into the storage unit 12. Note that the control unit 16 may adjust the temperature in the storage unit 12 by opening the high-temperature side solenoid valve 56 and the low-temperature side solenoid valve 58 at the same time or at different times. After storing hot water or cold water in the storage unit 12, the control unit 16 proceeds to step S6.

[0053] In step S6, control unit 16 obtains the temperature of the hot water or water in storage unit 12 using third temperature sensor 32, and proceeds to S7. In this way, a predetermined amount [L] of hot water or water is stored in storage unit 12, and the predetermined amount [L] of hot water or water is set to a predetermined temperature, so that even if the supply amount of hot water or water supplied to water supply flow path 10 from an external supply source fluctuates due to temporary fluctuations in water supply pressure, the temperature of the hot water supplied from storage unit 12 to chamber 11 and circulation flow path 4 is less likely to fluctuate temporarily.

[0054] In step S7, control unit 16 determines whether preparation of storage unit 12 is complete. For example, if float switch 42 does not detect that the water level of hot water or cold water in storage unit 12 has reached a predetermined upper water level, control unit 16 determines that preparation of storage unit 12 is not complete and returns to step S5. For example, control unit 16 determines that preparation of storage unit 12 is complete by detecting with float switch 42 that the water level of hot water or cold water in storage unit 12 has reached a predetermined upper water level and by measuring with third temperature sensor 32 that the temperature of hot water or cold water in storage unit 12 has reached a desired temperature, and proceeds to step S8.

[0055] In step S8, control unit 16 starts temperature adjustment control of the hot water discharged from bathtub apparatus 1 into the bathtub, and then proceeds to step S9.

[0056] In step S9, the control unit 16 determines whether or not an instruction to end the temperature adjustment control has been received by the bather operating the remote control 18. The control unit 16 may also execute the instruction to end the temperature adjustment control at its own discretion, such as when a predetermined time has elapsed, according to a control program stored in its own storage device. If the control unit 16 receives an instruction to end the temperature adjustment control, it proceeds to END to prevent the wasteful consumption of hot water and other fluids for temperature adjustment. If the control unit 16 does not receive an instruction to end the temperature adjustment control, it proceeds to S10 to continue the temperature adjustment control of the hot water being discharged.

[0057] In step S10, the control unit 16 acquires the target temperature of water discharged from the water discharger 8 and the current temperature of water discharged from the water discharger 8, and then proceeds to S11.

[0058] In step S11, the control unit 16 calculates the water supply flow rate A3 [L / min] (see Figure 6) of hot water, etc. to be supplied from the water supply flow path 10, for example, from the difference between the target water supply temperature and the current water supply temperature, and the flow rate of hot water on the circulation flow path 4 side, and proceeds to S12.

[0059] In step S12, the control unit 16 determines whether the water supply flow rate A3 calculated in S11 is equal to or greater than 0. If the water supply flow rate A3 calculated in S11 is not equal to or greater than 0, the control unit 16 determines that there is no further need to supply hot water or other water from the water supply flow path 10, and proceeds to END to terminate the temperature adjustment control. If the water supply flow rate calculated in S11 is equal to or greater than 0, the control unit 16 determines that there is still a need to supply hot water or other water from the water supply flow path 10, and proceeds to S13.

[0060] In step S13, control unit 16 determines whether or not the water supply flow rate A3 calculated in S11 is equal to or greater than the water supply flow rate (circulation flow rate) A1 in circulation flow path 4 obtained in S4. If water supply flow rate A3 calculated in S11 is equal to or greater than the water supply flow rate (circulation flow rate) A1 in circulation flow path 4 obtained in S4, i.e., if the water supply flow rate A1 in circulation flow path 4 is less than the water supply flow rate A3 calculated in S11, control unit 16 determines that driving second pump 14 to supply the calculated water supply flow rate A3 will enable water supply such that the water supply flow rate through circulation flow path 4 is less than the water supply flow rate from water supply flow path 10, and proceeds to S15. If the water supply flow rate A3 calculated in S11 is less than the flow rate (circulation flow rate) A1 of hot water in the circulation flow path 4 obtained in S4, i.e., if the circulation flow rate A1 of hot water in the circulation flow path 4 is greater than the water supply flow rate A3 calculated in S11, the control unit 16 proceeds to S14 so that the flow rate of hot water flowing through the circulation flow path 4 can be less than the flow rate of hot water or cold water supplied from the water supply flow path 10.

[0061] In step S14, the control unit 16 executes control of the first pump 6 to reduce the circulation flow rate A1 of the hot water flowing through the circulation channel 4 so that the circulation flow rate of the hot water in the circulation channel 4 is less than the flow rate of the hot water or water supplied from the water supply channel 10. Then, it proceeds to S15. The circulation flow rate of the hot water flowing through the circulation channel 4 is decreased from the circulation flow rate A1 of the hot water flowing through the circulation channel 4 to the reduced circulation flow rate A4 [L / min]. For example, the reduced circulation flow rate A4 is set as a relatively large flow rate that satisfies the relationship A1 < A3 by comparing the circulation flow rate A1 before driving the second pump 14 with the water supply flow rate A3. For example, the maximum flow rate A1 is set as the reduced circulation flow rate A4. For example, the circulation flow rate A1 before driving the second pump 14 is about 30 [L / min], the water supply flow rate A3 is a value within the range of about 12 [L / min] to about 15 [L / min], and the reduced circulation flow rate A4 is about 10 [L / min]. As a modification, while reducing the circulation flow rate of the hot water flowing through the circulation channel 4, the flow rate of the hot water or water supplied from the water supply channel 10 may be slightly increased, and a relationship may be realized such that the circulation flow rate of the hot water in the circulation channel 4 is less than the flow rate of the hot water or water supplied from the water supply channel 10 through the cooperation of the first pump 6 and the second pump 14.

[0062] In step S15, the control unit 16 opens the solenoid valve 40, and further, the control unit 16 drives the second pump 14 to supply hot water or cold water from the water supply flow path 10 to the circulation flow path 4. After executing S15, the control unit proceeds to S16. Therefore, if the control unit reaches S15 without going through S13 to S14, when driving the second pump 14 to supply hot water or cold water from the water supply flow path 10 to the circulation flow path 4, the control unit 16 supplies water from the water supply flow path 10 to the circulation flow path 4 so that the flow rate of hot water or cold water flowing through the circulation flow path 4 is less than the flow rate of hot water or cold water supplied from the water supply flow path 10, and then proceeds to S16. Furthermore, when the process advances from S14 to S15, the control unit 16 controls the first pump 6 to reduce the circulation flow rate A1 of hot water flowing through the circulation flow path 4 so that the flow rate of hot water flowing through the circulation flow path 4 is less than the flow rate of hot water or cold water supplied from the water supply flow path 10 when driving the second pump 14 to supply hot water or cold water from the water supply flow path 10 to the circulation flow path 4. As a result, water is supplied from the water supply flow path 10 to the circulation flow path 4 in a state where the flow rate of hot water flowing through the circulation flow path 4 is less than the flow rate of hot water or cold water supplied from the water supply flow path 10. Therefore, even when hot water or cold water is supplied from the water supply flow path 10 to the circulation flow path 4 to adjust the temperature of the hot water being discharged, the circulation flow rate can be reduced and an increase in the discharge flow rate can be suppressed, preventing the hot water in the bathtub body 2 from increasing and overflowing the bathtub body 2 or preventing the bather from feeling uncomfortable due to an increased floating sensation felt by the bather in the bathtub body 2. For example, the ratio of the water supply flow rate A3 to the circulation flow rate A1 or the reduced circulation flow rate A4 is set to a ratio within the range of 1.2:1 to 1.5:1. Here, since hot water or cold water is temporarily stored in storage section 12 up to a predetermined amount [L], even if the supply amount of hot water or cold water supplied to water supply flow path 10 from an external supply source fluctuates due to a temporary fluctuation in water supply pressure, the temperature of the hot water supplied from storage section 12 to chamber 11 and circulation flow path 4 is less likely to fluctuate temporarily.

[0063] In step S16, the control unit 16 returns from the temperature regulation loop end of S16 to the temperature regulation loop start of S8 to continue the process in order to carry out the hot and cold water temperature regulation control.

[0064] When the control unit 16 proceeds to the end, it closes the solenoid valve 40, closes the high-temperature side solenoid valve 56 and the low-temperature side solenoid valve 58, stops the second pump 14, and ends the series of control processes.

[0065] Next, referring to Figure 6, we will explain the effect of changing the flow rate of water supply in a bathtub device 1 according to one embodiment of the present invention when hot water supplied from a water heater 52 is supplied to the circulation flow path 4 and when water supplied from a water supply system 54 is supplied to the circulation flow path 4. When a bather is bathing in the bathtub body 2, the temperature of the hot water stored in the bathtub body 2 is generally bathing temperature (e.g., 38°C to 40°C). In contrast, the temperature of the hot water supplied from the water heater 52, which serves as an external supply source, is set to a temperature that will not burn the bather, for example, a temperature several degrees higher than bathing temperature (e.g., 40°C to 49°C). The temperature of the water supplied from the water supply 54, which serves as an external supply source, is closer to ambient temperature, which is 10 degrees or more lower than bathing temperature (e.g., 20°C to 25°C). The inventors of the present invention have focused on a new viewpoint: the difference between the temperature of the hot water supplied from the water heater 52 and the temperature of the hot water in the bathtub body 2 is smaller than the difference between the temperature of the water supplied from the water supply 54 and the temperature of the hot water in the bathtub body 2. In one embodiment of the present invention, the control unit 16 controls the second pump 14 so that the flow rate B1 [L / min] of hot water supplied to the circulation flow path 4 when hot water supplied from the water heater 52 as an external supply source (for example, only hot water supplied from the water heater 52) is supplied from the water supply flow path 10 to the circulation flow path 4 is greater than the flow rate B2 [L / min] of water supplied to the circulation flow path 4 when water supplied from the water supply system 54 as an external supply source (for example, only water supplied from the water supply system 54) is supplied from the water supply flow path 10 to the circulation flow path 4. As a result, when adjusting the temperature of the hot water in the circulation flow path 4, i.e., the temperature of the hot water discharged from the water discharger 8, the flow rate of the hot water or water supplied from the water supply flow path 10 can be adjusted according to the temperature difference between the temperature of the hot water in the circulation flow path and the temperature of the hot water or water being supplied, thereby enabling more effective temperature adjustment. Also, it is possible to prevent more hot water or water than necessary being supplied from the water supply flow path 10 (wasteful water use). Furthermore, the temperature of the hot water supplied from the water heater 52 as an external supply source can be set to a relatively low temperature (e.g., 40°C to 49°C) rather than a relatively high temperature (e.g., 50°C to 60°C), so that the flow rate of the hot water supplied from the water heater 52 is greater than the flow rate of the water supplied from the water supply 54, thereby adjusting the temperature of the hot water discharged from the water discharger 8.

[0066] In one embodiment of the present invention configured as described above, bathtub apparatus 1 supplies hot water or water supplied from an external source from water supply flow path 10 to circulation flow path 4, adjusting the temperature of the hot water being discharged from inside bathtub main body 2 through water intake 9b, circulation flow path 4, and water discharge port 8a and returning to bathtub main body 2. When supplying hot water or water from water supply flow path 10 to circulation flow path 4, control unit 16 controls first pump 6 to reduce the flow rate of hot water flowing through circulation flow path 4 compared to the flow rate of hot water or water supplied from water supply flow path 10. Therefore, even when supplying hot water or water from water supply flow path 10 to circulation flow path 4 to adjust the temperature of the discharged hot water, an increase in the discharge flow rate can be suppressed, preventing an increase in the hot water volume in bathtub main body 2 that could cause the bathtub main body 2 to overflow, or preventing an increased floating sensation felt by a bather in bathtub main body 2, which could cause discomfort to the bather. In addition, by suppressing the flow rate of circulating bath water, the temperature of the water in the circulation flow path 4 can be adjusted with a smaller flow rate of water than that supplied from the water supply flow path 10, and the increase in the amount of water in the bathtub can also be suppressed.

[0067] In one embodiment of the present invention configured as described above, the system further includes a storage section 12 provided in the water supply flow path 10 for storing the hot or cold water to be supplied, the storage section 12 being configured to separate the upstream and downstream sides of the water supply flow path 10, and a second pump 14 for sending the hot or cold water in the water supply flow path 10 toward the circulation flow path 4. As a result, even if the amount of hot or cold water supplied to the water supply flow path 10 from an external supply source temporarily fluctuates due to changes in water pressure or the like, the hot or cold water is stored in the storage section 12 and sent from the storage section 12 toward the circulation flow path 4 by the second pump 14, making it difficult for the temperature of the hot or cold water to fluctuate temporarily. This realizes a configuration that can adjust the temperature of the hot or cold water to be discharged toward a bather in the bathtub to a predetermined temperature, and also prevents the temperature of the hot or cold water to be discharged toward a bather in the bathtub from fluctuating temporarily, causing discomfort to the bather.

[0068] In one embodiment of the present invention configured in this manner, the water supply flow path 10 is connected to a negative pressure generating unit 4d that generates negative pressure due to the flow of hot water and water flowing within the circulation flow path 4, so that the hot water or water in the water supply flow path 10 is drawn in by the negative pressure generated by the flow of hot water and water flowing within the circulation flow path 4, making it less likely that the hot water or water in the water supply flow path 10 will flow back in the water supply flow path 10 and allowing it to be mixed more efficiently with the flow of hot water and water flowing within the circulation flow path 4.

[0069] In one embodiment of the present invention configured in this manner, the water supply flow path 10 is connected to a negative pressure generating unit 4d that generates negative pressure in the chamber 11 due to the flow of hot water or water flowing through the circulation flow path 4, so that the hot water or water in the water supply flow path 10 is pulled by the negative pressure generated by the flow of hot water or water flowing through the circulation flow path 4, making it less likely that the hot water or water in the water supply flow path 10 will flow back in the water supply flow path 10 and allowing it to be mixed more efficiently with the flow of hot water or water flowing through the circulation flow path 4.

[0070] In one embodiment of the present invention configured in this manner, the water supply flow path 10 is connected to a negative pressure generating unit 4d upstream of the first pump in the circulation flow path 4, which generates negative pressure due to the flow of hot water or water flowing within the circulation flow path 4.Therefore, the hot water or water in the water supply flow path 10 is drawn in by the negative pressure generated by the flow of hot water or water flowing within the circulation flow path 4, making it less likely that the hot water or water in the water supply flow path 10 will flow back in the water supply flow path 10 and allowing it to be mixed more efficiently with the flow of hot water or water flowing within the circulation flow path 4.

[0071] In one embodiment of the present invention configured in this manner, the flow rate of hot water or cold water flowing out of storage section 12 is the same as or less than the flow rate of hot water or cold water flowing into storage section 12. This allows bathtub apparatus 1 to store hot water or cold water in storage section 12 while supplying hot water or cold water from storage section 12 to circulation flow path 4, making it less likely that the temperature of the hot water supplied from storage section 12 to circulation flow path 4 will fluctuate temporarily, and making it less likely that the temperature of the hot water discharged will fluctuate temporarily.

[0072] Typically, when a bather is bathing, the temperature of the hot water stored in the bathtub main body 2 is bathing temperature (e.g., 38°C to 40°C). In contrast, the temperature of the hot water supplied from an external water heater can be set to a temperature that will not burn the bather, for example, a temperature several degrees higher than bathing temperature (e.g., 40°C to 49°C). Furthermore, the temperature of water supplied from a water supply (e.g., an external supply source) is closer to ambient temperature, which is 10 degrees or more lower than bathing temperature in the water pipes (e.g., 20°C to 25°C). The inventors of the present invention focused on the new viewpoint that the difference between the temperature of the hot water supplied from such a water heater and the temperature of the hot water in the bathtub main body 2 is smaller than the difference between the temperature of water supplied from the water supply and the temperature of the hot water in the bathtub main body 2. Thus, in one embodiment of the present invention, control unit 16 controls second pump 14 so that the flow rate of hot water supplied to circulation flow path 4 when hot water supplied from a water heater as an external supply source is supplied from water supply flow path 10 to circulation flow path 4 is greater than the flow rate of water supplied to circulation flow path 4 when water supplied from a mains water supply as an external supply source is supplied from water supply flow path 10 to circulation flow path 4. As a result, when adjusting the temperature of hot water discharged from water discharger 8, the flow rate of hot water or water supplied from water supply flow path 10 is adjusted according to the temperature difference between the temperature of hot water in circulation flow path 4 and the temperature of the hot water or water being supplied, thereby making it possible to more effectively adjust the temperature and reduce unnecessary water use. Also, the temperature of hot water supplied from a water heater as an external supply source can be adjusted by setting it to a relatively low temperature (e.g., 40°C to 49°C) rather than a relatively high temperature (e.g., 50°C to 60°C).

[0073] The embodiments for carrying out the present invention are not limited to those described above, and other modified examples may also be applied. In this embodiment, as shown in FIG. 6 , the water supply flow path 10 is connected to the chamber 11. However, as shown in FIG. 8 , instead of connecting the downstream end of the water supply flow path 10 to the chamber 11, the downstream end of the water supply flow path 10 may be connected to the jetting portion-side flow path 4a of the circulation flow path 4 upstream of the first pump 6. Therefore, the water supply flow path 10 may be connected to a negative pressure generator 4d in the jetting portion-side flow path 4a of the circulation flow path 4 upstream of the first pump 6, which generates negative pressure due to the flow of hot and cold water flowing in the jetting portion-side flow path 4a of the circulation flow path 4. In this case, the negative pressure generator 4d is formed on the inner wall of the jetting portion-side flow path 4a upstream of the first pump 6. As a result, the hot and cold water or water in the water supply flow path 10 is pulled by the negative pressure generated by the flow of hot and cold water flowing in the jetting portion-side flow path 4a, making it difficult for the hot and cold water or water in the water supply flow path 10 to flow back in the water supply flow path 10 and allowing it to more efficiently mix with the flow of hot and cold water flowing in the jetting portion-side flow path 4a.

[0074] 6, the water supply passage 10 is connected to the chamber 11. However, in another modification, the chamber 11 may be omitted, and the water supply passage 10 may be connected to a negative pressure generator 4d that generates negative pressure by the flow of hot water through the jetting-side passage 4a of the circulation passage 4. Thus, the water supply passage 10 can be connected to a negative pressure generator 4d at any part of the circulation passage 4.

[0075] Furthermore, in an embodiment of the present invention, when switching the hot water discharged from the water discharge device 8 from hot water with a higher temperature to hot water with a lower temperature than the hot water in the bathtub main body 2, or vice versa, it is necessary to replace the hot water in the storage tank 12 from hot water with hot water with a lower temperature, or vice versa. In this case, as another variation, the flow rate of hot water flowing into the storage tank 12 can be made less than the flow rate of hot water flowing out of the storage tank 12 for a predetermined time before switching the hot water temperature, thereby reducing the amount of hot water stored in the storage tank 12 at the time of switching. This allows the temperature of the hot water discharged from the water discharge device 8 to be switched quickly. [Explanation of symbols]

[0076] 1: Bathtub equipment 2: Bathtub body 4: Circulation channel 4d: Negative pressure generating section 6: First pump 8a: Outlet 9: Water intake section (bathtub intake) 9b: Water intake part 10: Water supply channel 11: Chamber 11a: Negative pressure generating section 12: Storage section 14: Second pump 16: Control section 52: Water heater 54: Waterworks

Claims

1. A bathtub device that supplies hot and cold water to a bathtub, A bathtub body for storing hot water; A water intake section for taking in hot water from the bathtub body; A water discharge section is provided above the bathtub body and discharges hot water absorbed from the water intake section into the bathtub body; a circulation flow path that connects the water intake portion and the water discharge portion; a first pump that is provided in the circulation flow path and that sends hot and cold water sucked from the water intake port through the circulation flow path; a water supply flow path connected to the circulation flow path and supplying hot or cold water from an external supply source so as to adjust the temperature of the hot or cold water in the circulation flow path; a control unit that controls the first pump, The control unit controls the first pump to reduce the flow rate of hot water sucked in from the water intake section when supplying hot water or water from the water supply flow path to the circulation flow path in order to adjust the temperature of the hot water discharged from the water discharge section, and makes the flow rate of hot water sucked in from the water intake section less than the flow rate of hot water or water supplied from the water supply flow path, so that the temperature of the hot water discharged from the water discharge section can be changed by supplying a small amount of water to the circulation flow path.This bathtub device is characterized by this.

2. Furthermore, a storage section is provided in the water supply flow path and stores hot water or cold water to be supplied, the storage section being formed so as to separate the flow path between the upstream side and the downstream side of the water supply flow path; The bathtub apparatus according to claim 1, further comprising a second pump that sends hot and cold water in the water supply passage toward the circulation passage.

3. 3. The bathtub apparatus according to claim 1, wherein the water supply passage is connected to a negative pressure generating unit that generates negative pressure by the flow of hot and cold water flowing through the circulation passage.

4. A bathtub device as described in claim 1 or 2, wherein the circulation flow path has a chamber for drawing in hot and cold water midway through the circulation flow path, and the water supply flow path is connected to a negative pressure generating unit that generates negative pressure in the chamber by the flow of hot and cold water flowing through the circulation flow path.

5. The bathtub apparatus according to claim 1 or 2, wherein the water supply flow path is connected to a negative pressure generating unit in the circulation flow path upstream of the first pump, which generates negative pressure by the flow of hot and cold water flowing through the circulation flow path.

6. 6. The bathtub apparatus according to claim 2, wherein the flow rate of hot or cold water flowing out of the storage section is the same as or less than the flow rate of hot or cold water flowing into the storage section.

7. The bathtub device described in claim 2, wherein the control unit controls the second pump so that the flow rate of hot water supplied to the circulation flow path when hot water supplied from a water heater as an external supply source is supplied from the water supply flow path to the circulation flow path is greater than the flow rate of water supplied to the circulation flow path when water supplied from a tap water source as an external supply source is supplied from the water supply flow path to the circulation flow path.

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