Bathtub equipment

The bathtub apparatus uses a circulation flow path and storage tank with a control device to mix water from the supply and heater, addressing thermal stimulus and temperature control issues, ensuring comfortable and stable operation.

JP7808260B2Active Publication Date: 2026-01-29TOTO LTD
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Patent Information

Application Number
JP2022027923
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-02-25
Publication Date
2026-01-29
Estimated Expiration
2042-02-25

AI Technical Summary

Technical Problem

Existing bathtub water circulation systems struggle to provide a sufficient thermal stimulus when the stored hot water is not at a high enough temperature, and external water heaters have difficulty maintaining precise temperature control due to minimum flow rate requirements, leading to potential discomfort for users.

Method used

A bathtub apparatus with a water discharge device that includes a circulation flow path, a storage tank, and a control device to adjust the temperature of discharged hot water by mixing it with water from the supply and heater, ensuring the flow rate remains above the minimum ignition level, thereby maintaining appropriate temperature control.

Benefits of technology

The system effectively adjusts the temperature of discharged hot water, providing a comfortable thermal stimulus while preventing backwashing and maintaining stable operation with standard water heaters.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

To make it possible to appropriately adjust temperature of hot water discharged from a discharge hole even in a bathtub apparatus using a general hot water supplier to supply hot water in a bathtub.SOLUTION: A bathtub apparatus (1) has: a bathtub body (2); a water absorption port (9b); a water discharge device (8) discharging hot water absorbed through the water absorption port; a circulation flow passage connecting the water absorption port and the water discharge port; a circulation pump (6) pumping hot water from the water absorption port to the water discharge port; a storage tank (12) temporarily storing water supplied from water supplier and hot water supplied by a hot water supplier (52); a water amount sensor (24a) capable of detecting a flow rate of hot water supplied by the hot water supplier (52); and a controller (16) controlling supply of hot water in the storage tank for the circulation flow passage. When flow rate of hot water detected by the water amount sensor is a prescribed flow rate or less, the controller flows water from the water supply into the storage tank as well as the hot water from the hot water supplier even when temperature of the hot water discharged from the water discharge port is raised.SELECTED DRAWING: Figure 7
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Description

[Technical Field]

[0001] The present invention relates to a bathtub apparatus, and more particularly to a bathtub apparatus equipped with a water discharge device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2019-150334 (Patent Document 1) describes a bathtub water circulation type water discharge device. This bathtub water circulation type water discharge device is configured to take in hot water from the bathtub and discharge the taken-in hot water into the bathtub from above the water surface of the bathtub. In this way, the hot water discharged from above hits the bather's shoulders and neck, providing a pleasant sensation to the bather. Furthermore, in this bathtub water circulation type water discharge device, if the temperature of the hot water detected by the detection unit is higher than a predetermined temperature, the total heat content of the hot water discharged from the water discharge port per unit time is controlled to be reduced. In other words, by reducing the flow rate of the hot water discharged from the water discharge port, the total heat content of the hot water discharged per unit time is reduced, preventing the bather from getting upset.

[0003] Furthermore, in another embodiment described in Patent Document 1, when the temperature of the hot water detected by the detection unit is higher than a predetermined temperature, tap water supplied from the water supply pipe is introduced into the circulating hot water to lower the temperature of the hot water discharged from the water discharge port. This reduces the total heat content of the hot water discharged per unit time, preventing the bather from getting upset. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-150334 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the bathtub water circulation type water discharge device described in Patent Document 1, hot water taken from inside the bathtub is directed onto the bather's shoulders and neck, providing a pleasant sensation to the bather, and by reducing the total heat quantity of the water discharged per unit time, it is possible to suppress backwashing. However, there are cases where bathers desire a thermal stimulus by having hot water poured onto their shoulders and neck. However, if the hot water stored in the bathtub is not at a sufficiently high temperature, there is a problem in that the bather cannot receive a sufficient thermal stimulus even if the hot water taken from inside the bathtub is directed onto the bather.

[0006] To provide a thermal stimulus to the bather, one possible solution is to mix high-temperature hot water supplied from an external water heater with the hot water drawn in and circulated from the bathtub, thereby raising the temperature of the hot water discharged from the water outlet. However, because the hot water discharged from the water outlet rapidly heats the bather, extremely delicate temperature control of the discharged hot water is required to provide a comfortable thermal stimulus to the bather. On the other hand, external water heaters generally cannot supply hot water at low flow rates. Specifically, external water heaters generally have the problem that the burner used to heat the water entering the water heater goes out if the flow rate of hot water supplied as instructed falls below a certain value (minimum ignition flow rate). Therefore, since it is difficult to supply only a flow rate above the minimum ignition flow rate from the external water heater, it is difficult to maintain the appropriate temperature of the hot water discharged from the water outlet.

[0007] Therefore, the present invention aims to provide a bathtub device that can appropriately adjust the temperature of hot water discharged from the water outlet, even if it is a bathtub device that supplies hot water into the bathtub using a general water heater. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a bathtub apparatus equipped with a water discharge device, which comprises a bathtub body for storing hot water, a water intake port for sucking in the hot water within the bathtub body, a water discharge device provided above the bathtub body and equipped with a water discharge port for discharging the hot water sucked in from the water intake port toward the inside of the bathtub body, a circulation flow path connecting the water intake port and the water discharge port, a circulation pump provided in the circulation flow path for pressurizing the hot water from the water intake port toward the water discharge port, a storage tank for temporarily storing water supplied from the water supply and hot water supplied from the water heater, a water volume sensor capable of detecting the flow rate of hot water supplied from the water heater, and a control device that controls the supply of hot water stored in the storage tank to the circulation flow path in order to raise the temperature of the hot water discharged from the water discharge port, and is characterized in that when the flow rate of hot water detected by the water volume sensor falls below a predetermined flow rate, the control device causes water from the water supply in addition to the hot water from the water heater to flow into the storage tank, even if the temperature of the hot water discharged from the water discharge port is to be raised.

[0009] In this invention, hot water drawn into the bathtub body through the water intake by the circulation pump passes through the circulation flow path and is discharged into the bathtub body from the water outlet of the water discharge device located above the bathtub body. Meanwhile, water supplied from the water supply and hot water supplied from the water heater are temporarily stored in a storage tank, and the control device supplies the stored hot water to the circulation flow path to raise the temperature of the hot water discharged from the water outlet. When the hot water flow rate detected by the water volume sensor falls below a predetermined flow rate, the control device allows water from the water supply in addition to hot water from the water heater to flow into the storage tank, even if the temperature of the hot water discharged from the water outlet is to be raised.

[0010] According to the present invention, hot water supplied from the water heater flows from the storage tank into the circulation flow path, raising the temperature of the hot water discharged from the water outlet of the water discharge device and providing a thermal stimulus to the bather. However, it is difficult to control the temperature and flow rate of the hot water supplied from the water heater, and if a large amount of hot water with a high temperature is allowed to flow into the circulation flow path, the temperature of the hot water discharged from the water outlet may become too high, causing the bather to feel upset. However, with a typical water heater, there is a minimum flow rate required to maintain ignition, and it is difficult to reduce the supply rate below this minimum flow rate.

[0011] According to the present invention configured as described above, when the flow rate of hot water detected by the water volume sensor falls below a predetermined flow rate, the control device allows water from the water supply in addition to the hot water from the water heater to flow into the storage tank, even when raising the temperature of the hot water discharged from the water outlet. This allows the temperature of the hot water stored in the storage tank to be lowered below a predetermined temperature, and even in bathtub devices that use a standard water heater to supply hot water to the bathtub, the temperature of the hot water discharged from the water outlet can be appropriately adjusted. As a result, a comfortable thermal stimulus can be provided to the bather while preventing backwashing.

[0012] In the present invention, it is further preferable that the flow rate of water from the water supply flowing into the storage tank is less than the flow rate of hot water flowing into the storage tank from the water heater.

[0013] According to the present invention configured in this manner, the flow rate of water from the water supply is made less than the flow rate of hot water flowing in from the water heater, so that the flow rate of hot water supplied from the water heater is maintained above the ignition flow rate while keeping the amount of water flowing in small, thereby suppressing wasted water and appropriately controlling the temperature of the hot water discharged from the outlet.

[0014] In the present invention, preferably, the hot and cold water stored in the storage tank is flowed into a portion of the circulation flow path where negative pressure is created. According to the present invention configured in this manner, hot water supplied from the storage tank flows into a part of the circulation flow path that becomes negative pressure, thereby preventing the hot water sent to the circulation flow path from flowing back toward the storage tank, and ensuring that the hot water flows into the circulation flow path.

[0015] In the present invention, the control device preferably controls the flow rates of hot water and water flowing into the storage tank so that the total flow rate of hot water flowing into the storage tank from the water heater and water flowing into the storage tank from the water supply is greater than the flow rate of hot water and water flowing into the circulation flow path from the storage tank.

[0016] According to the present invention configured in this way, the total flow rate of the hot water flowing into the storage tank from the water heater and the water flowing into the storage tank from the mains water supply is made greater than the flow rate of the hot water flowing into the circulation flow path from the storage tank. This prevents the hot water stored in the storage tank from running out, and ensures that the temperature control of the hot water discharged from the water outlet can be reliably maintained. [Effects of the Invention]

[0017] According to the bathtub apparatus of the present invention, even in a bathtub apparatus that uses a general water heater to supply hot water into the bathtub, the temperature of the hot water discharged from the water outlet can be appropriately adjusted. [Brief explanation of the drawings]

[0018] [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] 2 is a full cross-sectional view of a bathtub apparatus according to an embodiment of the present invention taken along line II-II in FIG. 1. [Figure 3] 1 is a block diagram showing the overall configuration of a circulation device and a temperature adjustment device provided in a bathtub apparatus according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing a circulation device and a temperature adjustment device provided in a bathtub apparatus according to an embodiment of the present invention. [Figure 5]This is a front view showing the chamber and water discharge device provided in the bathtub apparatus according to an embodiment of the present invention. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 5 of the chamber and the water discharger provided in the bathtub apparatus according to the embodiment of the present invention. [Figure 7] 10 is a flowchart showing the process of thermal stimulus control executed by the bathtub apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Next, a bathtub apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the entire bathroom in which a bathtub apparatus according to an embodiment of the present invention is installed.

[0020] As shown in Figure 1, bathtub apparatus 1 according to an embodiment of the present invention comprises a bathtub main body 2, a water discharger 8 attached to the upper edge of bathtub main body 2, and a control device (control unit) 16 that controls the discharge of hot and cold water from this water discharger, and is installed in bathroom R. A remote control 18 is also attached to the wall of bathroom R, and this remote control 18 can be used to control the discharge of hot and cold water from the water discharger 8. Furthermore, in this embodiment, bathtub apparatus 1 is placed on one side of bathroom R so that it is in contact with the wall.

[0021] 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 interior wall surface of the bathroom R. The interior wall surface that forms one short side of the bathtub body 2 is configured as a backrest surface 2a, which is the interior wall surface in the short side direction of the bathtub body 2 that is formed so that the bather can lean against it. An apron 2c is removably attached to the long side of the bathtub body 2 that is not in contact with the interior wall surface of the bathroom R. Here, the backrest surface is the interior wall surface that the bather's back comes into contact with when bathing.

[0022] The water discharge device 8 is provided on the upper part of the backrest surface 2a of the bathtub main body 2, and is configured to discharge hot water toward the inside of the bathtub main body 2. In this embodiment, the water discharge device 8 has a flat, wide water outlet 8a that extends along the upper edge of the backrest surface 2a, and is configured to discharge hot water toward the shoulders of the bather leaning against the backrest surface 2a.

[0023] Bathtub apparatus 1 according to an embodiment of the present invention is configured to suck in hot water stored in bathtub main body 2 through water inlet (bathtub water intake) 9b provided on bathtub main body 2 and discharge it from water outlet 8a of water discharge device 8. In other words, hot water in bathtub main body 2 is sucked in through water inlet 9b and circulated back into bathtub main body 2 through water outlet 8a of water discharge device 8. On the other hand, when raising or lowering the temperature of the hot water discharged from water outlet 8a, hot water supplied from a water heater or water supplied from the main water supply is mixed with the circulating hot water.

[0024] Next, referring to Figures 2 to 4, we will explain the configuration of the circulation device that circulates the hot water in the bathtub body 2 through the water outlet 8a of the water discharge device 8, and the temperature control device that mixes hot water or water of a predetermined temperature with the circulating hot water to adjust the temperature of the hot water discharged from the water discharge device. Fig. 2 is a full cross-sectional view of a bathtub apparatus according to an embodiment of the present invention taken along line II-II in Fig. 1. Fig. 3 is a block diagram showing the overall configuration of a circulation device and a temperature adjustment device provided in a bathtub apparatus according to an embodiment of the present invention. Fig. 4 is a perspective view showing a circulation device and a temperature adjustment device provided in a bathtub apparatus according to an embodiment of the present invention.

[0025] First, as shown in Figures 3 and 4, the circulation device that circulates hot water within the bathtub main body 2 has two water intakes 9b provided on the side wall surface 2b (Figure 2) of the bathtub main body 2, a chamber 11 into which the hot water sucked in from these water intakes 9b flows, and a circulation pump 6 that pressurizes the hot water into the chamber 11.

[0026] As shown in Figure 3, one of the two water intakes 9b is connected to chamber 11 by first pipe 4a. A circulation pump 6 is provided midway along first pipe 4a, and is configured to pump the hot water drawn in through water intake 9b into chamber 11. Furthermore, first pipe 4a branches downstream of circulation pump 6, with one end connected to chamber 11 and the other connected to bathtub water outlet 9a provided on the backrest surface 2a of bathtub main body 2. Therefore, some of the hot water pressurized by circulation pump 6 flows back into bathtub main body 2 from below the water surface inside bathtub main body 2 through bathtub water outlet 9a.

[0027] The other of the two water intakes 9b is directly connected to chamber 11 by second pipe 4b. As will be described later, hot water pressurized by circulation pump 6 flows into chamber 11 from first pipe 4a, generating negative pressure within chamber 11, which in turn draws the hot water into chamber 11 from second pipe 4b. Furthermore, third pipe 4c is connected to the top surface of chamber 11, and the hot water flowing out of chamber 11 is supplied to water discharge device 8 through third pipe 4c. Therefore, first pipe 4a, second pipe 4b, third pipe 4c and chamber 11 form a circulation flow path connected to water intake 9b and water discharge outlet 8a.

[0028] Next, the configuration of the chamber 11 will be described with reference to FIGS. 5 is a front view showing the chamber 11 and the water discharger 8 provided in the bathtub apparatus 1 of this embodiment, and FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

[0029] As shown in FIGS. 4 to 6, the chamber 11 is configured in a roughly rectangular box shape, and a first pipe line 4a and a second pipe line 4b are connected to its bottom surface. A third pipe line 4c is connected to the top surface of the chamber 11 at a position opposite the first pipe line 4a. A supply pipe line 10 for introducing hot and cold water supplied from a temperature control device (described later) is also connected to the top surface of the chamber 11. Specifically, the first pipe line 4a and the second pipe line 4b are connected side by side to the bottom surface of the chamber 11, and the third pipe line 4c is connected to the top surface of the chamber 11 at a position opposite the first pipe line 4a. The supply pipe line 10 is disposed between the first pipe line 4a and the second pipe line 4b on the top surface of the chamber 11.

[0030] As shown in Figure 4, the chamber 11 is located at a relatively low position relative to the bathtub main body 2, and is located below the surface of the hot and cold water stored in the bathtub main body 2. Therefore, during normal use of the bathtub apparatus 1, the chamber 11, the entire first pipe line 4a, the second pipe line 4b, and the lower part of the third pipe line 4c are filled with hot and cold water.

[0031] 6, a nozzle 20 is provided at the tip of the first pipe 4a connected to the bottom surface of the chamber 11, and the flow path of the hot and cold water flowing from the first pipe 4a into the chamber 11 is narrowed. This increases the flow rate of the hot and cold water pressurized by the circulation pump 6 (FIGS. 3 and 4) as it flows from the first pipe 4a through the nozzle 20 into the chamber 11. As a result, the hot and cold water that has flowed into the chamber 11 from the first pipe 4a flows forcefully into the third pipe 4c connected opposite the first pipe 4a, and the hot and cold water that has filled the chamber 11 is also drawn in and flows into the third pipe 4c.

[0032] Furthermore, the hot and cold water in chamber 11 is drawn in and flows into third pipe 4c, causing negative pressure in at least part N1 to which second pipe 4b is connected and part N2 to which supply pipe 10 is connected within chamber 11. That is, second pipe 4b and supply pipe 10 are connected to parts of the circulation flow path that become negative pressure within chamber 11. As a result, the hot and cold water in second pipe 4b and supply pipe 10 are drawn into chamber 11 by the negative pressure and flow into third pipe 4c together with the hot and cold water that has flowed in from first pipe 4a.

[0033] That is, the nozzle 20 provided in the chamber 11 and the third pipe 4c connected opposite to it act like a jet pump, causing the hot and cold water supplied from the second pipe 4b and the supply pipe 10 to flow into the third pipe 4c. The hot and cold water that flows into the third pipe 4c flows into the water discharger 8 connected to the upper end of the third pipe 4c and is discharged from its water outlet 8a toward the inside of the bathtub body 2. As shown in Figure 5, the water outlet 8a of the water discharger 8 is configured to be thin and wide, so that the hot and cold water discharged from the water outlet 8a forms a thin film that hits the bather's neck and shoulders.

[0034] Next, the temperature adjustment device provided in the bathtub apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. The temperature adjustment device is configured to allow hot water at a predetermined temperature to flow into the circulation flow path that runs from the water intake 9b of the bathtub body 2 to the water outlet 8a of the water discharger 8. This allows the temperature of the hot water discharged from the water discharger 8 to be raised or lowered, providing the bather with a warm or cold stimulus.

[0035] 3, the temperature adjustment device has a storage tank 12 that receives and temporarily stores hot water supplied from an external hot water source or water supplied from an external water source, and a pressure pump 14 that controls the flow rate of the hot water or water that flows from the storage tank 12 into the chamber 11. In this embodiment, a water heater 52 is connected as the external hot water source, and water supplied from a water supply 54 is branched at a branch point 54a and supplied to the water heater 52.

[0036] Water heater 52 heats water supplied from water supply 54 and supplies the generated hot water to storage tank 12 through hot water supply pipe 40a and hot water flow adjustment valve 56. In this embodiment, water heater 52 also serves as a hot water heater for the kitchen (not shown), and when the hot water supply temperature is set in the kitchen, hot water at that temperature is also supplied to storage tank 12. Therefore, in this embodiment, control device 16 cannot independently control the temperature of the hot water supplied from water heater 52.

[0037] Meanwhile, water supplied from a water supply 54, which is an external water supply source, is supplied to the storage tank 12 through the water supply pipe 40b and the water flow regulation valve 58. Furthermore, the hot water supply pipe 40a is provided with a check valve 41a upstream of the hot water flow regulation valve 56, and the water supply pipe 40b is provided with a check valve 41b upstream of the water flow regulation valve 58. The hot water flow adjustment valve 56 is a proportional water flow valve that controls the flow rate of hot water flowing through the hot water supply pipe 40a based on a control signal from the control device 16. The water flow regulation valve 58 is a water proportional valve that controls the flow rate of water flowing through the water supply pipe 40b based on a control signal from the control device 16.

[0038] Further, downstream of the hot water flow regulation valve 56, a hot water flow sensor 24a, which is a water volume sensor, is provided, and downstream of the cold water flow regulation valve 58, a cold water flow sensor 24b is provided. The hot water flow rate sensor 24 a is configured to detect the volumetric flow rate [L / min] of hot water flowing through the hot water supply pipe 40 a per unit time, and to output a detection signal to the control device 16 . The water flow rate sensor 24b is configured to detect the volumetric flow rate [L / min] of hot and cold water flowing through the water supply pipe 40b per unit time, and to output a detection signal to the control device 16.

[0039] Furthermore, the hot water supply pipe 40a and the cold water supply pipe 40b join at a joining point 43a provided downstream of the hot water flow rate sensor 24a and the cold water flow rate sensor 24b. A common pipe 43 is connected to the downstream side of the junction 43a and extends to the storage tank 12. A constant flow valve 28 and an inflow side temperature sensor 30 are provided in this common pipe 43 in this order from the upstream side.

[0040] The constant flow valve 28 is configured to adjust the flow rate of hot and cold water flowing through the common pipe 43 so that it does not exceed a predetermined flow rate. The inflow-side temperature sensor 30 is a thermistor configured to detect the temperature of the hot water flowing into the storage tank 12 through the common pipe 43 and output a detection signal to the control device 16.

[0041] Storage tank 12 is configured to temporarily store hot or cold water that flows into chamber 11, which is part of the circulation flow path, in order to raise or lower the temperature of the hot or cold water discharged from outlet 8a. That is, water or hot water supplied through common pipe 43 flows into storage tank 12, where it is temporarily stored, and then flows into chamber 11 through supply pipe 10. Storage tank 12 is a rectangular tank, and common pipe 43 is connected to the top of storage tank 12, while supply pipe 10 is connected to the bottom of storage tank 12. That is, common pipe 43 allows hot or cold water to flow into storage tank 12 from above the water level W0 of the water or hot water stored in storage tank 12, with a predetermined air gap between them. Therefore, water heater 52 and water supply 54 connected to storage tank 12 are isolated from their downstream sides at storage tank 12.

[0042] As shown in FIG. 3, the storage tank 12 is provided therein with a storage tank temperature sensor 32, a float switch 42, and an overflow pipe 44. The storage tank temperature sensor 32 is a thermistor configured to detect the temperature of the hot water stored in the storage tank 12 and output a detection signal to the control device 16. The float switch 42 has a stem 42a and a float 42b that can move up and down along the stem 42a. The float 42b moves up and down depending on the water level in the storage tank 12, and when the water level in the storage tank 12 reaches a predetermined level, the float switch 42 outputs a detection signal to the control device 16.

[0043] The overflow pipe 44 is an open pipe that extends upward from the bottom of the storage tank 12 into the storage tank 12, and its upper end forms an overflow section 44a. Because the overflow pipe 44 is provided, when the water level in the storage tank 12 rises above a predetermined level, the hot or cold water in the storage tank 12 flows over the overflow section 44a at the upper end into the overflow pipe 44 and is then discharged through the overflow pipe 44. The hot or cold water discharged from the storage tank 12 through the overflow pipe 44 falls onto a drain pan (not shown) provided below the bathtub body 2 and is then drained into the sewer.

[0044] Next, the storage tank 12 is connected to the chamber 11 via a supply line 10. Along the supply line 10, an outlet temperature sensor 34, a pressure pump 14, a water volume sensor 36, a check valve 38, and a solenoid valve 39 are provided, in that order from upstream to downstream. The hot or cold water flowing into the chamber 11 from the supply line 10 is mixed with the hot or cold water that has flowed into the chamber 11 from the bathtub main body 2 through the first and second lines 4a and 4b. The mixed hot or cold water passes through the third line 4c and is discharged from the water outlet 8a of the water discharger 8. Along the third line 4c, a discharge flow rate sensor 21 and a discharge water temperature sensor 22 are provided. The temperature of the hot or cold water stored in the bathtub main body 2 is detected by a bathtub temperature sensor 23.

[0045] The outflow temperature sensor 34 is a thermistor configured to detect the temperature of the hot water flowing out from the storage tank 12 and output a detection signal to the control device 16. The pressure pump 14 is configured to control the flow rate of hot or cold water flowing from the storage tank 12 into the chamber 11 based on a control signal from the control device 16. The water volume sensor 36 is configured to detect the volumetric flow rate [L / min] of hot water or water flowing through the supply pipe 10 per unit time, and to output a detection signal to the control device 16 .

[0046] The check valve 38 is configured to prevent backflow of hot or cold water from the chamber 11 to the reservoir tank 12 through the supply line 10 . The solenoid valve 39 is opened and closed based on a control signal from the control device 16, and is configured to open when hot water or cold water is to flow into the chamber 11. When hot water or cold water is not being supplied to the chamber 11, the solenoid valve 39 is closed, and hot water or cold water will not flow into the chamber 11 from the supply pipe 10 even if negative pressure occurs in the chamber 11.

[0047] Discharge flow rate sensor 21 is a sensor configured to detect the flow rate of hot and cold water discharged from water discharger 8 through third pipe 4c and output a detection signal to control device 16. The flow rate of hot and cold water discharged from water discharger 8 can be detected (estimated), for example, from the rotation speed or voltage value of circulation pump 6. In this case, discharge flow rate sensor 21 can be omitted. The discharged water temperature sensor 22 is a thermistor configured to detect the temperature of the hot water discharged from the water discharger 8 through the third pipe 4c and output a detection signal to the control device 16.

[0048] Bathtub temperature sensor 23 is a thermistor configured to detect the temperature of the hot and cold water stored in bathtub main body 2 and output a detection signal to control device 16. The temperature of the hot and cold water stored in bathtub main body 2 can also be detected by discharge water temperature sensor 22 when hot and cold water is not flowing into chamber 11 from supply pipe 10. Therefore, discharge water temperature sensor 22 can be used as bathtub temperature sensor 23, in which case bathtub temperature sensor 23 can be omitted.

[0049] Next, the control device 16 provided in the bathtub apparatus 1 according to the embodiment of the present invention will be described. The control device 16 is configured to control the temperature adjustment device so that hot water at the bather's desired temperature is discharged from the water discharge device 8 based on the bather's operation of the remote control 18 (Figure 1). Specifically, the control device 16 is composed of a microprocessor, memory, software to operate these, an interface circuit (all not shown), and the like. The control device 16 is housed in the space behind the backrest surface 2a of the bathtub main body 2. As shown in Figure 1, the space behind the backrest surface 2a can be accessed from the washing area side of the bathroom R by removing the apron 2c of the bathtub main body 2. Therefore, maintenance such as adjustment and repair of the control device 16 can be easily performed simply by removing the apron 2c of the bathtub main body 2. In other words, by arranging the control devices 16 in a centralized location in an easily accessible space, maintenance can be improved.

[0050] First, the temperatures detected by the discharge water temperature sensor 22, bathtub temperature sensor 23, inlet temperature sensor 30, storage tank temperature sensor 32, and outlet temperature sensor 34 are input to the control device 16. In addition, a command signal from the remote control 18 and detection signals from the hot water flow rate sensor 24a, cold water flow rate sensor 24b, water volume sensor 36, and float switch 42 are also input to the control device 16.

[0051] The control device 16 sends control signals to the circulation pump 6, pressure pump 14, solenoid valve 39, hot water flow adjustment valve 56, and cold water flow adjustment valve 58 that make up the temperature adjustment device, and controls the temperature of the hot water discharged from the water discharge device 8 to be the set temperature. In other words, the control device 16 causes hot water or cold water to flow from the storage tank 12 into the hot water circulating through the circulation flow path so that the temperature detected by the discharge water temperature sensor 22 becomes the predetermined temperature. This allows hot water at a temperature higher or lower than the temperature detected by the bathtub temperature sensor 23 to be discharged from the water discharge device 8.

[0052] That is, when discharging hot water at a higher temperature than the water in the bathtub main body 2, the flow rate of the water flow adjustment valve 58 is reduced to zero, and the flow rate of the hot water flow adjustment valve 56 is set to the required flow rate, causing hot water at a higher temperature than the water in the bathtub main body 2 to be stored in the storage tank 12. Next, the solenoid valve 39 is opened and the pressure pump 14 is operated to cause the hot water in the storage tank 12 to flow into the chamber 11. As a result, the hot water in the bathtub main body 2 circulating through the circulation flow path is mixed with the hot water from the storage tank 12, and the temperature of the hot water discharged from the water discharge port 8a of the water discharge device 8 rises.

[0053] The temperature of the hot water discharged from the water outlet 8a is detected by a water discharge temperature sensor 22. If the temperature detected by the water discharge temperature sensor 22 is lower than the set temperature, the rotation speed of the pressure pump 14 is increased while the rotation speed of the circulation pump 6 is decreased, thereby increasing the proportion of hot water at a higher temperature that is mixed. If the temperature of the hot water detected by the water discharge temperature sensor 22 is higher than the set temperature, the rotation speed of the pressure pump 14 is decreased while the rotation speed of the circulation pump 6 is increased, thereby decreasing the proportion of hot water at a higher temperature that is mixed. In addition, based on the detection signals of the hot water flow rate sensor 24a, the cold water flow rate sensor 24b, and the water volume sensor 36, the control device 16 controls the hot water flow adjustment valve 56 or the cold water flow adjustment valve 58 so that the amount of hot water stored in the storage tank 12 is appropriate.

[0054] On the other hand, when discharging hot water at a temperature lower than that of the hot water in the bathtub main body 2, the flow rate of the water flow adjustment valve 58 is set to the required flow rate, and the flow rate of the hot water flow adjustment valve 56 is reduced to zero, causing water at a temperature lower than that of the hot water in the bathtub main body 2 to be stored in the storage tank 12. Next, the solenoid valve 39 is opened, and the pressure pump 14 is operated, causing the low-temperature water in the storage tank 12 to flow into the chamber 11. As a result, the low-temperature water from the storage tank 12 is mixed with the hot water in the bathtub main body 2 that is circulating through the circulation flow path, and the temperature of the hot water discharged from the water outlet 8a of the water discharge device 8 decreases.

[0055] When the temperature of hot water detected by discharge water temperature sensor 22 is higher than the set temperature, the rotation speed of pressure pump 14 is increased while the rotation speed of circulation pump 6 is decreased, thereby increasing the proportion of low-temperature water that is mixed. When the temperature of hot water detected by discharge water temperature sensor 22 is lower than the set temperature, the rotation speed of pressure pump 14 is decreased while the rotation speed of circulation pump 6 is increased, thereby decreasing the proportion of low-temperature water that is mixed.

[0056] Next, the thermal stimulus control by the control device 16 will be specifically described with reference to FIG. The bathtub apparatus 1 of this embodiment is configured to be able to execute thermal stimulus control in order to provide a comfortable thermal stimulus to the bather in the bathtub main body 2 when the bather wants to warm up. Figure 7 is a flowchart showing the process of thermal stimulus control executed by the bathtub apparatus 1 according to this embodiment of the present invention. The flowchart shown in Figure 7 is executed by operating the remote control 18 when the bather wants to warm up.

[0057] First, in step S1 of Figure 7, it is determined whether circulating water is being discharged from the water discharger 8 at the time the bather operates the remote control 18. That is, when circulating water is being discharged, the solenoid valve 39 is closed and the circulation pump 6 is operated. In this state, hot water in the bathtub body 2 is sucked in through the water intake 9b, discharged from the water outlet 8a of the water discharger 8, and circulated back into the bathtub body 2. Meanwhile, because the solenoid valve 39 is closed, hot water in the storage tank 12 does not flow into the circulation flow path. Thus, when the bather operates the remote control 18 while circulating water is being discharged, the processing of the flowchart shown in Figure 7 proceeds to step S3.

[0058] On the other hand, if the bather operates the remote control 18 while circulating water discharge is not being performed, the process proceeds to step S2, where circulating water discharge is started. That is, the circulation pump 6 is operated with the solenoid valve 39 closed, and the hot water in the bathtub main body 2 is discharged from the water discharge port 8a of the water discharger 8 to circulate. In this way, even if the bather operates the remote control 18 to warm up, the water discharger 8 will not initially discharge hot water that is warmer than the hot water in the bathtub main body 2, but rather the circulating water discharge will be started first.

[0059] Next, in step S3, the temperature of the hot water being discharged from the water discharger 8, detected by the discharge water temperature sensor 22, is acquired by the control device 16. Furthermore, in step S4, the flow rate of the hot water being discharged from the water discharger 8, detected by the discharge flow rate sensor 21, is acquired by the control device 16.

[0060] Next, in step S5, storage tank 12 is prepared. Specifically, control device 16 sends a control signal to hot water flow adjustment valve 56 to set it to the required flow rate, and causes hot water generated in water heater 52 to flow into storage tank 12. As described above, in this embodiment, water heater 52 is also used as a water heater for use in the kitchen (not shown), so hot water at a temperature set in the kitchen may be supplied to storage tank 12, and control device 16 does not control the set temperature of water heater 52.

[0061] Furthermore, in step S6, the temperature of the hot water stored in storage tank 12, detected by storage tank temperature sensor 32, is acquired by control device 16. If storage tank 12 is empty when hot water supply from water heater 52 begins, the temperature of the hot water stored in storage tank 12 will be approximately equal to the temperature of the hot water supplied from water heater 52. However, if low-temperature hot water or water remains in storage tank 12 when hot water supply from water heater 52 begins, the temperature of the hot water in storage tank 12 will be lower than the temperature of the hot water supplied from water heater 52.

[0062] In this way, if low-temperature hot water or the like remains in the storage tank 12, hot water continues to flow in from the water heater 52, and the low-temperature hot water mixed with the low-temperature hot water or the like in the storage tank 12 overflows through the overflow pipe 44. This increases the temperature of the hot water stored in the storage tank 12. Note that, because the storage tank 12 has a relatively small volume, the temperature of the hot water in the storage tank 12 rises in a relatively short time even if low-temperature hot water or the like remains in the storage tank 12.

[0063] Next, in step S7, it is determined whether preparation of storage tank 12 is complete. That is, in step S7, it is determined whether a sufficient amount of hot water at a sufficiently high temperature is stored in storage tank 12. As described above, the temperature of the hot water in storage tank 12 is detected by storage tank temperature sensor 32. Also, whether a sufficient amount of hot water is stored in storage tank 12 is detected by float switch 42. If preparation of storage tank 12 is not complete, the process returns to step S5, and the process of steps S5 → S6 → S7 → S5 is repeated until preparation is complete.

[0064] When the preparation of the storage tank 12 is completed, the temperature adjustment process of steps S8 to S18 is executed. In step S9, it is determined whether an instruction signal to end the temperature adjustment process has been input. If an instruction signal to end the temperature adjustment process has been input, one iteration of the process in the flowchart shown in Figure 7 is completed. Specifically, when the bather operates remote control 18 to end the thermal stimulus by the discharge of warm water, an instruction signal to end the temperature adjustment process is input to control device 16.

[0065] If an instruction signal to end the temperature adjustment process has not been input, the process proceeds to step S10, where the control unit 16 acquires the target water discharge temperature from the water discharge device 8 and the current water discharge temperature from the water discharge device 8, and then proceeds to S11.

[0066] In step S11, the control unit 16 calculates the required flow rate of hot water, etc. to be supplied from the water supply flow path 10, for example, based on the difference between the target water discharge temperature and the current water discharge temperature, and the flow rate of hot water on the circulation flow path 4 side, and then proceeds to S12.

[0067] Next, in step S12, it is determined whether the required flow rate calculated in step S11 is greater than zero. If the calculated required flow rate is zero, one iteration of the process in the flowchart shown in Figure 7 is terminated. For example, if the temperature of the hot water drawn in through the water inlet 9b and circulating is equal to the set temperature acquired in step S10, there is no need to allow hot water to flow in from the storage tank 12, and the required flow rate of hot water to flow in from the storage tank 12 is zero (for example, if the thermal stimulus is continued for a long period of time, the temperature of the hot water in the bathtub body 2 will rise, and this state may occur). On the other hand, if the required flow rate calculated in step S11 is greater than zero, the control device 16 sends a control signal to the hot water flow adjustment valve 56 so that the required flow rate of hot water flows from the hot water heater 52 into the storage tank 12. Furthermore, the hot water flow rate sensor 24a detects the flow rate of the hot water supplied from the hot water heater 52 and passing through the hot water flow adjustment valve 56, and the processing in the flowchart shown in Figure 7 proceeds to step S13.

[0068] In step S13, it is determined whether the flow rate detected by the hot water flow sensor 24a is greater than a predetermined flow rate. In other words, in a typical gas water heater, if the flow rate of hot water to be supplied falls below a predetermined minimum ignition flow rate, the gas cannot be maintained in an ignited state and the flow rate cannot be further reduced. In step S13, it is determined whether the flow rate supplied from the water heater 52 is greater than the minimum ignition flow rate to allow the required flow rate to flow from the storage tank 12 and maintain a stable ignition state. In this embodiment, the minimum ignition flow rate of the water heater 52 is approximately 3.5 L / min, and the predetermined flow rate at which the water heater 52 can maintain a stable ignition state is set to approximately 4.0 L / min. If the flow rate detected by the hot water flow sensor 24a is greater than the predetermined flow rate, the process in the flowchart proceeds to step S14.

[0069] In step S14, control device 16 sends a control signal to flow adjustment valve 26 to set the hot water supply flow rate of hot water flowing from water heater 52 to storage tank 12 to a flow rate slightly higher than the required flow rate calculated in step S11. This hot water supply flow rate is sufficiently higher than the minimum ignition flow rate, so water heater 52 can maintain ignition. Furthermore, in step S16, control device 16 sends a control signal to pressure pump 14 to cause hot water at the required flow rate calculated in step S11 to flow into the circulation flow path. That is, control device 16 operates pressure pump 14 so that the flow rate detected by water volume sensor 36 becomes the required flow rate calculated in step S11. As a result, the temperature of the hot water discharged from water discharge device 8 becomes the set temperature.

[0070] In addition, the flow rate of hot water flowing from the water heater 52 into the storage tank 12 is set to be slightly higher than the required flow rate out of the storage tank 12. Therefore, even if there is a detection error in the hot water flow adjustment valve 56 or the hot water flow sensor 24a, it is possible to prevent the hot water in the storage tank 12 from running out.

[0071] On the other hand, if it is determined in step S13 that the flow rate detected by the hot water flow rate sensor 24a is equal to or less than the predetermined flow rate, the process proceeds to step S15. In step S15, the control device 16 sends a control signal to the hot water flow adjustment valve 56 to set the hot water supply flow rate of the hot water flowing from the hot water heater 52 into the storage tank 12 to a predetermined flow rate that is higher than the minimum ignition flow rate of the hot water heater 52. This allows the hot water heater 52 to maintain ignition.

[0072] Furthermore, in step S15, the control device 16 sends a control signal to the water flow control valve 58 to allow tap water to flow from the water supply 54 into the storage tank 12. The water supply flow rate for flowing tap water from the water supply 54 into the storage tank 12 is determined so that when a predetermined flow rate of hot water flows in from the water heater 52, the temperature of the hot water in the storage tank 12 is a predetermined temperature higher than the temperature of the hot water in the bathtub body. In other words, if the temperature of the hot water supplied from the water heater 52 is high and the temperature of the hot water in the storage tank 12 becomes very high, the flow rate of hot water that must be flowed from the storage tank 12 into the circulation flow path to achieve the set temperature becomes extremely low. If the flow rate of hot water flowing from the storage tank 12 into the circulation flow path becomes extremely low, the flow rate from the water heater 52 that is stored in the storage tank 12 must also be throttled. If the flow rate falls below the predetermined value, the water heater will be turned off, and hot water will no longer be supplied, making it impossible to maintain the temperature rise of the hot water discharged from the water discharge device 8. For this reason, tap water is flowed into the storage tank 12 from the water supply 54 at a predetermined flow rate, and the temperature of the hot water in the storage tank 12 is lowered to an appropriate temperature.

[0073] This prevents the flow rate of hot water flowing into the circulation flow path from storage tank 12 from becoming extremely low. In this way, when the temperature of the hot water supplied from water heater 52 is high and the flow rate of hot water detected by hot water flow sensor 24a falls below a predetermined flow rate, control device 16 causes water from water supply 54 to flow into the storage tank in addition to the hot water from water heater 52, even in a situation where the temperature of the hot water discharged from outlet 8a should be increased.

[0074] Next, in step S17, the control device 16 recalculates the required flow rate necessary to raise the temperature of the hot water discharged from the water discharge device 8 to the set temperature, based on the temperature of the hot water stored in the storage tank 12. Here, the recalculated required flow rate is greater than the required flow rate calculated in step S11, because the temperature of the hot water in the storage tank 12 has dropped due to the water supply from the water supply 54 being performed in step S15. Furthermore, in step S17, the hot water at the recalculated required flow rate flows from the storage tank 12 into the circulation flow path. As a result, the temperature of the hot water discharged from the water discharge device 8 is set to the set temperature.

[0075] In this way, when the flow rate detected by the hot water flow sensor 24a is below the predetermined flow rate required to maintain ignition of the water heater, the control device 16 supplies tap water from the water supply 54 to the storage tank 12 even when raising the temperature of the hot water discharged from the water discharge device 8, and after reducing the temperature difference between the temperature of the hot water in the storage tank 12 and the temperature of the hot water in the bathtub body 2 to below the predetermined temperature difference, causes the hot water in the storage tank 12 to flow into the circulation flow path.

[0076] The total flow rate of the hot water supply flow rate (=predetermined flow rate) and the cold water supply flow rate flowing into the storage tank 12 is greater than the required flow rate (=flow rate flowing into the circulation flow path) recalculated in step S17. As a result, the water level in the storage tank 12 rises, and when this rises above the height of the overflow portion 44a of the overflow pipe 44, the hot water in the storage tank 12 is discharged through the overflow pipe 44.

[0077] When the processing of step S16 or S17 is completed, the processing in the flowchart returns to step S9, and the processing of steps S9 to S16 or S9 to S17 is repeatedly executed until an instruction to end the temperature adjustment processing is input (step S9 → return) or the required flow rate becomes zero (step S12 → return).

[0078] According to the embodiment of the bathtub apparatus 1 of the present invention, water supplied from the water supply 54 or hot water supplied from the water heater 52 flows into the circulation flow path via the supply pipe 10, thereby raising the temperature of the hot water discharged from the water outlet 8a of the water discharger 8 and providing a thermal stimulus to the bather. Furthermore, according to the embodiment of the bathtub apparatus 1, when the flow rate of hot water detected by the water volume sensor falls below a predetermined flow rate, the control device 16 allows water from the water supply to flow into the storage tank 12 in addition to the hot water from the water heater 52, even if the temperature of the hot water discharged from the water outlet 8a is to be raised. This allows the temperature of the hot water stored in the storage tank 12 to be lowered below the predetermined temperature, making it easy to adjust the temperature of the hot water discharged from the water outlet 8a to an appropriate temperature. As a result, a comfortable thermal stimulus can be provided to the bather while preventing backwashing.

[0079] Furthermore, according to the bathtub device 1 of this embodiment, the flow rate of water from the water supply 54 is made less than the flow rate of hot water flowing in from the water heater 52, so that the flow rate of hot water supplied from the water heater 52 is maintained above the ignition flow rate while keeping the amount of water flowing in small, thereby suppressing wasted water while appropriately controlling the temperature of the hot water discharged from the outlet 8a.

[0080] Furthermore, according to the bathtub device 1 of this embodiment, the hot water supplied from the supply pipe 10 flows into a part of the circulation flow path that becomes negative pressure, thereby preventing the hot water sent to the circulation flow path from flowing back into the supply pipe, and ensuring that the hot water flows into the circulation flow path.

[0081] Furthermore, with the bathtub apparatus 1 of this embodiment, the total flow rate of the hot water flowing into the storage tank 12 from the water heater 52 and the water flowing into the storage tank 12 from the mains water supply is set to be greater than the flow rate of the hot water flowing into the circulation flow path from the storage tank 12. This prevents the hot water stored in the storage tank 12 from running out, and ensures that the temperature of the hot water discharged from the outlet 8a can be reliably controlled.

[0082] Although the above describes an embodiment of the present invention, various modifications can be made to the above-described embodiment. In the embodiment of the present invention, when switching the hot water discharged from the water discharge device 8 from a hot water temperature higher than that of the hot water in the bathtub main body 2 to a cold water temperature lower than that of 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 a hot water temperature higher to a cold water temperature lower than that of the hot water in the storage tank 12, or vice versa. In this case, it is desirable to reduce the flow rate of hot water flowing into the storage tank 12 compared to 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]

[0083] 1 Bathtub equipment 2 Bathtub body 2a Backrest 2b Side wall 2c Apron 4a 1st pipeline 4b 2nd pipeline 4c 3rd pipeline 6 Circulation Pump 8. Water discharge device 8a Outlet 9a Bathtub outlet 9b Water intake 10 Supply line 11 Chamber 12 Storage Tank 14 Pressure pump 16 Control device 18 Remote Control 20 nozzles 21 Discharge flow rate sensor 22 Water discharge temperature sensor 23 Bathtub temperature sensor 24a Hot water flow sensor (water volume sensor) 24b Water flow sensor 28 Constant flow valve 30 Inlet temperature sensor 32 Storage tank temperature sensor 34 Outlet temperature sensor 36 Water volume sensor 38 Check valve 39 Solenoid valve 40a hot water pipe 40b Water supply pipe 41a Check valve 41b Check valve 42 Float switch 42a stem 42b Float 43 Common pipe 43a Confluence 44 Overflow pipe 44a Overflow section 52 Water heater 54 Water Supply 54a Branch 56 Hot water flow adjustment valve 58 Water flow control valve

Claims

1. A bathtub device equipped with a water discharge device, A bathtub body that stores hot water, A water intake port for sucking in hot water from the bathtub body, A water discharge device is provided above the bathtub body and has a water discharge port that discharges hot water drawn in from the water inlet toward the inside of the bathtub body; a circulation flow path connecting the water intake and the water discharge; a circulation pump provided in the circulation flow path for pumping hot water from the water inlet toward the water outlet; a storage tank for temporarily storing water supplied from the waterworks and hot water supplied from the water heater; a water volume sensor capable of detecting the flow rate of hot water supplied from the water heater; a control device that controls the supply of hot water stored in the storage tank to the circulation flow path in order to increase the temperature of the hot water discharged from the water outlet; A bathtub device characterized in that when the flow rate of hot water supplied from the water heater and detected by the water volume sensor falls below a predetermined flow rate set higher than the minimum ignition flow rate of the water heater, the control device causes water from the tap water to flow into the storage tank in addition to the hot water from the water heater, even if it increases the temperature of the hot water discharged from the outlet, and sets the flow rate of hot water flowing from the water heater into the storage tank to a flow rate higher than the minimum ignition flow rate of the water heater.

2. 2. The bathtub apparatus according to claim 1, further comprising a structure in which the flow rate of water from the water supply flowing into the storage tank is less than the flow rate of hot water flowing into the storage tank from the water heater.

3. 3. The bathtub apparatus according to claim 1, wherein the hot and cold water stored in the storage tank flows into a portion of the circulation flow path that is under negative pressure.

4. A bathtub device as described in any one of claims 1 to 3, wherein the control device controls the flow rate of hot water and water flowing into the storage tank so that the total flow rate of hot water flowing into the storage tank from the water heater and water flowing into the storage tank from the water supply is greater than the flow rate of hot water and water flowing into the circulation flow path from the storage tank.

Citation Information

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