Bath equipment

Abstract

To improve the detection accuracy of bathing or mixed bathing using a water level sensor at a bath tub.SOLUTION: A water level sensor 11 arranged in a circulation path 8 outputs a water level detection value in a bath tub 20 on the basis of hydraulic pressure from bath tub water 21. A controller 12 performs a second bathing-in / out determination for determining either of a bathing state or a mixed bathing state on the basis of a comparison of a water level detection value at that time point, and a reference water level in conjunction with a finish of a non-execution period of a first bathing-in / out determination using the water level detection value by the water level sensor 11. The reference water level is not updated during a period of the bathing-in state, and during the non-execution period of the first bathing-in / out determination. On the other hand, the reference water level is updated so as to reflect a change amount as far as the change amount of the water level detection value within a constant time is smaller than the bathing-in / out determination value during a period of the mixed bathing state, and larger than a reference value which is set smaller than the bathing-in / out determination value.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, bathing and exiting have been detected using the detection value of the bath water level sensor. However, since the water level sensor detects the bath water level based on the pressure applied from the bath water, when the circulation pump is operated for reheating operation or the like, the hot and cold water in the circulation path where the water level sensor is installed is pressurized, making it impossible to obtain an accurate water level detection value.

[0003] Patent Publication No. 6716049 (Patent Document 1) describes how, in order to detect bathing or leaving while the pump is operating, a bathing entry / exit determination is made after the pump operation has stopped by comparing the water level detection value before the pump started operating with the water level detection value after the pump operation has stopped.

[0004] In addition, JP 2014-199168 A (Patent Document 2) points out that the output characteristics of the water level sensor may result in large errors in determining the bathtub water level due to changes in specific gravity that accompany changes in the temperature of the water in the circulation pipe after the bathtub has been filled with water. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6716049 [Patent Document 2] JP 2014-199168 A Summary of the Invention [Problem to be solved by the invention]

[0006] Patent document 2 describes that when there is a large difference in the height at which the water level sensor and the bathtub are placed, even if the bathtub water level is constant, the water level detection value detected by the water level sensor will rise or fall in response to a decrease in the temperature of the bathtub water.

[0007] Therefore, in a situation where there is a large difference in the height of the water level sensor and the bathtub, when the bathtub water temperature has dropped and the reheating operation is performed to circulate and heat the bathtub water by operating the pump, even if the bathtub water level does not change, the water level detection value will rise or fall due to the increase in the bathtub water temperature caused by the reheating operation.

[0008] For this reason, if the bath entry / exit judgment described in Patent Document 1 is executed after the completion of the above-mentioned reheating operation, there is a concern that the entry or exit of a bath may be mistakenly detected due to an increase or decrease in the water level detection value caused by an increase in the bathtub water temperature.

[0009] The present invention has been made to solve such problems, and an object of the present invention is to improve the accuracy of detecting whether a person is entering or leaving a bath using a bathtub water level sensor. [Means for solving the problem]

[0010] In one aspect of the present invention, a bathing device including a bathtub is provided. The bathing device includes a hot water supply device, a circulation path, a water level detector that detects the water level in the bathtub based on the water pressure in the circulation path, and a control device. The circulation path is provided to circulate hot water in the bathtub between the hot water supply device and the bathtub when the circulation pump is operating. The control device controls the operation of the bathing device and detects bathing in and out of the bathtub based on the water level detected by the water level detector. The control device includes a first determination unit, a second determination unit, and a setting unit. The first determination unit detects a transition to a bathing state in which a bather is present in the bathtub when the amount of change in the water level detection value within a predetermined time in a bathing out state in which no bather is present becomes greater than a first reference value that is a predetermined positive value, and detects a transition to a bathing out state in which a bather is present in the bathtub when the amount of change in the water level detection value within a predetermined time in the bathing state becomes smaller than a second reference value that is a predetermined negative value. The second determination unit executes bathing entry / exit determination to determine whether the state is a bathing state or a leaving state in conjunction with the end of a period in which the first determination unit does not execute bathing entry / exit determination. The setting unit sets a reference water level used in the bathing entry / exit determination by the first determination unit. The second determination unit executes bathing entry / exit determination so as to determine the bathing state when a value obtained by subtracting the reference water level from the water level detection value after the end of the non-execution period is greater than a first reference value, and to determine the leaving state when the subtracted value is smaller than the first reference value. The setting unit does not update the reference water level during the bathing state and the non-execution period, and updates the reference water level based on the water level detection value when the first determination unit detects a transition from the bathing state to the leaving state and when the second determination unit determines the leaving state by the bathing entry / exit determination. The setting unit further updates the reference water level to reflect the amount of increase in the water level detection value within a specified time during the bathing exit state, when the amount of increase is smaller than the first reference value and greater than a third reference value, which is a positive value set smaller than the first reference value. Effect of the Invention

[0011] According to the present invention, by appropriately setting the reference water level used in determining whether a person is entering or leaving the bath, it is possible to improve the accuracy of detecting whether a person is entering or leaving the bath using a bathtub water level sensor. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a hot water supply system including a bath device according to an embodiment of the present invention. [Diagram 2] FIG. 13 is a conceptual diagram for explaining bathing entry / exit determination using the detection value of the water level sensor. [Diagram 3] 11 is a first flowchart for explaining bathing entry / exit determination based on a detected water level value of the bathtub. [Figure 4] 13 is a second flowchart illustrating bathing entry / exit determination based on the detected water level of the bathtub. [Diagram 5] FIG. 4 is a conceptual waveform diagram for explaining an embodiment of bathing entry / exit determination according to the flowchart of FIG. 3. [Figure 6] FIG. 5 is a conceptual waveform diagram for explaining a first embodiment of bath entry / exit determination according to the flowchart of FIG. [Figure 7] FIG. 5 is a conceptual waveform diagram for explaining a second embodiment of bath entry / exit determination according to the flowchart of FIG. [Figure 8] FIG. 1 is a conceptual diagram illustrating classifications of bathtub placement heights. [Figure 9] 11 is a conceptual diagram illustrating a change in the detected water level value depending on the height at which the bathtub is placed. FIG. [Figure 10] FIG. 11 is a conceptual waveform diagram illustrating a first example of erroneous bathing entry / exit determination caused by a reference water level. [Figure 11] FIG. 13 is a conceptual waveform diagram illustrating a second example of erroneous bathing entry / exit determination caused by the reference water level. [Figure 12] FIG. 11 is a conceptual waveform diagram illustrating the rising pattern of the bathtub water level. [Figure 13] 2 is a conceptual waveform diagram illustrating a first setting example of the reference water level used to determine bathing entry and exit in the bath device of this embodiment. FIG. [Figure 14] FIG. 13 is a conceptual waveform diagram illustrating a pattern of the bathtub water level decreasing. [Figure 15] 11 is a conceptual waveform diagram illustrating a second setting example of the reference water level used to determine bathing entry and exit in the bath device of this embodiment. FIG. [Figure 16] 4 is a first flowchart illustrating a control process for setting a reference water level in a bath apparatus according to the present embodiment. [Figure 17] 5 is a second flowchart illustrating the control process for setting a reference water level in the bath apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are designated by the same reference characters, and their description will not be repeated in principle.

[0014] (Hot water supply system configuration) FIG. 1 is a schematic diagram of a hot water supply system including a bath apparatus according to this embodiment.

[0015] 1, hot water supply system 300 includes hot water supply device 100. Hot water supply device 100 includes a hot water supply circuit 5, a reheating circuit 7, a circulation path 8, and a controller 12. Hot water supply device 100 includes a bathtub 20 installed in a bathroom 200 as a hot water supply destination, in addition to a hot water tap and the like (not shown).

[0016] The hot water supply circuit 5 is configured to include a heating mechanism (not shown) for heating the introduced low-temperature water. The heating mechanism can be configured to utilize, for example, heat from combustion of fuel such as gas or oil, and heat from exhaust heat during power generation or a heat pump. The hot water supply circuit 5 may be configured to directly discharge heated high-temperature water, or may be configured as a hot water storage type that stores heated high-temperature water.

[0017] The hot water supply circuit 5 can output hot water at a temperature set by the user by operating the heating mechanism. On the other hand, when the heating mechanism is stopped, low-temperature water is output from the hot water supply circuit 5 without being heated.

[0018] The hot water outlet path (not shown) of the hot water supply circuit 5 is connected to the hot water supply pipe 13a leading to the bathtub 20. The bath hot water supply valve 13 is interposed and connected to the hot water supply pipe 13a. The bath hot water supply valve 13 can be configured, for example, by a solenoid valve that can be controlled to open and close. By opening the bath hot water supply valve 13, a path can be formed through which hot water is output from the hot water supply circuit 5 to the hot water supply pipe 13a. This allows the hot water supply device 100 to include the bathtub 20 as a hot water supply destination in addition to a hot water tap, etc. In the following, the operation of supplying hot water or water to the bathtub 20 via the hot water supply pipe 13a by opening the bath hot water supply valve 13 regardless of the output temperature from the hot water supply circuit 5 is referred to as "hot water pouring". A flow rate sensor 14 is provided in the hot water supply pipe 13a, and the flow rate sensor can detect the hot water supply flow rate. The flow rate sensor 14 corresponds to one embodiment of the "flow rate detector".

[0019] The circulation path 8 is for circulating hot water 21 in the bathtub 20 (hereinafter also referred to as "bathtub water 21") within the water heater 100, and has a return pipe 8a, a forward pipe 8b, and a circulation pump 10. One end of the return pipe 8a is connected to a circulation adapter 25 in the bathtub 20, and the other end is connected to the input side of the reheating circuit 7. One end of the forward pipe 8b is connected to the output side of the reheating circuit 7, and the other end is connected to the circulation adapter 25.

[0020] By operating the circulation pump 10, a path (reheating circulation path) is formed in which bath water 21 drawn in from the circulation adapter 25 passes through the return pipe 8a, the reheating circuit 7, and the forward pipe 8b and is discharged from the circulation adapter 25. The reheating circuit 7 can be configured to include a heating mechanism (not shown) that uses the heat of combustion of fuels such as gas and oil. The reheating circuit 7 operates when the reheating circulation path is formed, heating the bath water 21 introduced from the return pipe 8a and outputting it to the forward pipe 8b. The heated bath water 21 is supplied to the bathtub 20 by the forward pipe 8b, allowing for a reheating operation that raises the temperature of the bath water 21.

[0021] A temperature sensor 9 and a water level sensor 11 are connected to the return pipe 8a. The temperature sensor 9 can detect the temperature of the bathtub water 21. The temperature sensor 9 can be configured, for example, by a thermistor.

[0022] The water level sensor 11 is configured, for example, by a pressure sensor, and detects the level of the bathtub water 21 in the bathtub 20 (hereinafter also simply referred to as the "bathtub water level") based on the water pressure of the bathtub water 21. The temperature sensor 9 and the water level sensor 11 are disposed in an area in the return pipe 8a where the bathtub water 21 enters, even when the circulation pump 10 is stopped. The water level sensor 11 corresponds to one embodiment of a "water level detector."

[0023] Return pipe 8a is further connected to hot water supply pipe 13a at connection point 8c. As a result, when hot water is poured from hot water supply device 100 while circulation pump 10 is stopped, a first hot water supply path is formed from hot water supply pipe 13a to bathtub 20 via connection point 8c and return pipe 8a, and a second hot water supply path is formed from hot water supply pipe 13a to bathtub 20 via connection point 8c, return pipe 8a, reheating circuit 7, and supply pipe 8b. This allows the bath to be filled by pouring hot water from hot water supply device 100.

[0024] In this way, hot water and cold water from water heater 100 (hot water pouring circuit) is supplied to bathtub 20 via the first and second hot water pouring paths, including circulation path 8. Bathtub 20 is provided with a drain plug 26.

[0025] The controller 12 can be configured to include, for example, a microcomputer. The controller 12 is electrically connected to the hot water supply circuit 5, the reheating circuit 7, the temperature sensor 9, the circulation pump 10, the water level sensor 11, the bath hot water supply valve 13, the flow rate sensor 14, etc. The controller 12 is connected to a power source via electrical wiring (not shown) and receives a power supply. The values ​​detected by the temperature sensor 9, the water level sensor 11, and the flow rate sensor 14 are input to the controller 12. The controller 12 corresponds to one embodiment of the "control device".

[0026] Furthermore, the controller 12 is communicatively connected to a remote control 30 and a remote control 50. Note that the communication between these devices may be in accordance with any known standard, and may be wired or wireless.

[0027] Remote control 30 is installed on the wall of bathroom 200 and is used to operate water heating apparatus 100. Remote control 30 includes a display unit 31 for displaying information, an operation unit 32 for accepting input setting operations from the user, etc., and a human detection sensor 35. Display unit 31 is typically configured with a liquid crystal panel and is configured to be able to display the bathtub water level and temperature. Operation unit 32 is typically configured with push buttons or touch buttons and is configured to be able to accept setting operations related to at least the bathtub water level and temperature.

[0028] Human detection sensor 35 is built into the case of remote control 30, and detects the presence or absence of a person in bathroom 200. Human detection sensor 35 can be typically constituted by a pyroelectric sensor.

[0029] Remote control 50 is installed outside bathroom 200 and is used to operate water heating apparatus 100. Remote control 50 is typically installed on a wall in the kitchen. Remote control 50 includes a display unit 51 for displaying information and an operation unit 52 for receiving input setting operations from a user or the like.

[0030] Display unit 51 is typically configured with a liquid crystal panel, and is configured to be able to display the hot water supply setting temperature, the bath setting temperature, etc. Operation unit 52 is typically configured with push buttons or touch buttons, and is configured to be able to accept setting operations related to the operation of water heating device 100.

[0031] Based on input setting operations by a user or the like from remote controls 30, 50, controller 12 controls the operation of water heating apparatus 100 so that water heating system 300 is operated according to user instructions.

[0032] As an example of this control, when automatic bath operation is instructed by operating remote controls 30, 50, controller 12 executes the operation of filling bathtub 20 with water. This water filling operation ends when the bath water level in bathtub 20 reaches the set water level due to hot water poured from water heater 100 and the bath water temperature detected by temperature sensor 9 reaches the bath set temperature.

[0033] In the hot water supply system 300, after the bathtub 20 has been filled with hot water, an automatic mode can be set in which the water heater 100 maintains the temperature and water level of the bathtub water 21. When the automatic mode is selected, if the bathtub water temperature detected by the temperature sensor 9 falls below a reference temperature (for example, set 2 to 3°C lower than the bathtub set temperature) set in accordance with the bathtub set temperature, a reheating operation is automatically started for heat retention control. Furthermore, if the bathtub water level detected by the water level sensor 11 falls below the set water level, a hot water addition operation is started in which hot water is additionally poured from the water heater 100 into the bathtub 20. Alternatively, the hot water addition operation or a water addition operation in which unheated water is poured from the water heater 100 into the bathtub 20 may be started in response to a user operation.

[0034] (Bath entry / exit determination process) In the bath apparatus according to this embodiment, the detection value of water level sensor 11 in bathtub 20 is used to detect whether a person enters or leaves bathtub 20.

[0035] FIG. 2 shows a conceptual diagram for explaining detection of bathing entry and exit using the detection value of the water level sensor.

[0036] 2, when the operation of filling bathtub 20 with water is completed, the bathtub water level detected by water level sensor 11 reaches the set water level. This state is initially set as the "exit bath state."

[0037] When a predetermined bathing determination condition related to a rise in the water level is met in the bathing state, a transition from the bathing state to the bathing state, i.e., bathing, is detected. On the other hand, when a predetermined bathing determination condition related to a drop in the water level is met in the bathing state, a transition from the bathing state to the bathing state, i.e., leaving the bath, is detected. For example, a bathing entry / exit determination flag is set to indicate whether the state is a bathing state or an exiting state. In this specification, the flag is set to "1" in the bathing state and "0" in the exiting state.

[0038] 3 and 4 are flowcharts illustrating bathing entry / exit determination based on the water level detection value by the water level sensor 11. The control process shown in FIGS.

[0039] 3, controller 12 determines whether water heating apparatus 100 is in bath operation in step (hereinafter simply referred to as "S") 100. In this specification, "bath operation" includes a circulation operation in which a reheating circulation path is formed by operating circulation pump 10, and a hot water pouring operation by filling the bath, adding hot water, or adding water.

[0040] The above-mentioned circulation operations can include circulation operations that do not involve combustion of the heating mechanism in the reheating circuit 7, such as the pipe cleaning operation after drainage and the air purging operation, in addition to the circulation operation during the reheating operation. The pipe cleaning operation after drainage is an operation in which the drain in the drain tank is drained via the circulation path 8, and then the circulation pump 10 is operated to pass water through the circulation path 8 to clean the pipes. The air purging operation is an operation in which the air mixed in the circulation path 8 is removed by circulating bathtub water 21 through the circulation path 8.

[0041] During the bath operation, the water level sensor 11 cannot obtain an accurate water level detection value. Therefore, S100 is equivalent to determining whether or not the water level detection value can be obtained. The controller 12 branches the bath entry / exit determination process depending on whether or not the bath operation is in progress.

[0042] When the bath operation is not in progress (NO in S100), that is, when the water level detection value by the water level sensor 11 can be acquired, the controller 12 executes the first bath entry / exit determination in S110 to S220 shown in FIG.

[0043] On the other hand, when the bath is in operation (YES in S110), that is, when the water level detection value by the water level sensor 11 cannot be obtained, the controller 12 executes the second bath entry / exit determination in S310 to S410 shown in FIG.

[0044] (Bath entry / exit determination process when not in bath mode) First, the first bathing entry / exit determination at the timing when the water level detection value can be obtained will be described.

[0045] 3, in S110, the controller 12 reads the water level detection value X by the water level sensor 11 at the current timing as the water level detection value Xtn. Note that the water level detection value X may be the output value at each point in time by the water level sensor 11 as it is, or may be the output value from which noise (high frequency components) has been removed using a low-pass filter or the like. The water level detection value X read in S110 is held for a certain period of time for processing in the subsequent S120.

[0046] In S120, the controller 12 calculates the amount of water level change ΔXtn for the water level detection value Xtn read in S110 relative to the water level detection value Xtx a preset predetermined time Tx earlier (ΔXtn=Xtn-Xtx). When the bathtub water level rises compared to before Tx, the amount of water level change ΔXtn is positive (ΔXtn>0), and when the bathtub water level drops, the amount of water level change ΔXtn is negative (ΔXtn<0). In other words, a positive value of the amount of water level change ΔXtn indicates the "amount of rise" within the predetermined time Tx, and a negative value of the absolute value of the amount of water level change ΔXtn indicates the "amount of fall" within the predetermined time Tx.

[0047] In the present embodiment, an example will be described in which the predetermined time Tx (corresponding to the "first predetermined time") during the bathing state and the predetermined time Tx (corresponding to the "second predetermined time") during the post-bathing state are set to the same value. However, they may be set to different values.

[0048] Subsequently, the controller 12 determines, in S130, whether it is in the bathing state or the post-bathing state based on the bathing / drying determination flag. When in the post-bathing state (when the determination in S130 is YES), the controller 12 compares, in S140, the water level change amount ΔXtn calculated in S120 with the bathing determination value Xin (Xin > 0). Further, in S150, it is determined whether the state of ΔXtn > Xin continues for a preset predetermined time Tj1 (Tj1 < Tx).

[0049] The bathing determination value Xin is stored in the controller 12 in advance as the water level change amount corresponding to the increase in a predetermined volume. This bathing determination value Xin changes depending on the cross-sectional area of the bathtub 20. For example, during the construction of the hot water supply system 300 including the installation of the bathtub 20, the installer inputs the model number or size of the bathtub 20 (data that can specify the cross-sectional area), and the controller 12 can calculate and store the bathing determination value Xin using the input value.

[0050] Alternatively, it is also possible to automatically obtain it from the behavior of the water level detection value X during the bathtub filling operation that is test-executed during the bathtub trial operation at the time of construction of the hot water supply system 300. Specifically, during the bathtub trial operation, the controller 12 calculates the cross-sectional area of the bathtub 20 by executing predetermined arithmetic processing using the amount of hot water poured into the bathtub 20 calculated by integrating the detection value of the flow sensor 14 provided in the pouring pipe 13a in FIG. 1 and the change amount of the water level detection value X, and can automatically set the bathing determination value Xin from the calculated cross-sectional area.

[0051] When ΔXtn>Xin is detected (YES determination in S140), the controller 12 periodically obtains the water level detection value Xtn by S160 until Tj1 elapses (NO determination in S150), calculates the water level change amount ΔXtn, and then repeatedly executes the determination in S140. This period can be set to be equal to the period in which S120 is executed during the period when the bath draining state is maintained. That is, if ΔXtn>Xin does not continue for a predetermined time Tj1, before S150 becomes a YES determination, S140 is determined to be NO based on ΔXtn updated in S160.

[0052] When the state of ΔXtn>Xin continues for a predetermined time Tj1 (YES determination in S150), the controller 12 detects the transition from the bath draining state to the bathing state by S170. On the other hand, when the state of ΔXtn>Xin that continues for a predetermined time Tj1 is not detected (NO determination in S140), the bath draining state is maintained by S180. In this way, during the bath draining state, the determination process for detecting bathing is executed.

[0053] In contrast, when in the bathing state (NO determination in S130), the controller 12 compares the water level change amount ΔXtn calculated in S120 with the bath draining determination value Xout (Xout < 0) by S190. Further, by S200, it is determined whether the state of ΔXtn < Xout continues for a preset predetermined time Tj2 (Tj2 < Tx). The predetermined time Tj2 may be the same value as the predetermined time Tj1 or a different value from the predetermined time Tj1.

[0054] Incidentally, the bath draining determination value Xout can be set to Xout = -Xin using the bathing determination value Xin set as described above. Incidentally, it is also possible to set a manual adjustment value γ for the bathing determination value Xin and the bath draining determination value Xout. For example, the adjustment value γ can be a positive value (β > 0) or a negative value (β < 0) that can be input by the operation units 32, 52 of the remote controls 30, 50. For example, when the adjustment value γ is set, in S140, it is determined whether ΔXtn>Xin + γ.

[0055] When the controller 12 detects that ΔXtn < Xout (when the determination at S190 is YES), until a predetermined time Tj2 elapses (when the determination at S200 is NO), periodically, at S210, the controller 12 acquires the water level detection value Xtn, calculates the water level change amount ΔXtn, and then repeatedly executes the determination at S190. This period can be set to be equal to the period in which S120 is executed during the period in which the bathing state is maintained. That is, when ΔXtn < Xout does not continue for a predetermined time Tj2, before S200 becomes YES, S190 is determined to be NO based on ΔXtn updated at S210.

[0056] When the state of ΔXtn < Xout continues for a predetermined time Tj2 (when the determination at S200 is YES), the controller 12 detects, at S220, the transition from the bathing state to the out-of-bathing state. On the other hand, until a state of ΔXtn > Xout that continues for a predetermined time Tj2 is detected (when the determination at S190 is NO), the bathing state is maintained at S230. In this way, during the bathing state, the determination process for detecting getting out of the bath is executed.

[0057] FIG. 5 shows a conceptual waveform diagram for explaining an example of the first bathing entry / exit determination according to the flowchart of FIG. 3 when the bathtub is not in operation.

[0058] In the example of FIG. 5, the water level detection value X rises in response to bathing at time ta and then decreases at time tb when the bather gets out of the bath. Note that the bathtub operation (hot water supply operation or circulation operation) is not performed in either the out-of-bathing state or the bathing state.

[0059] In the out-of-bathing state, at S120 in FIG. 3, the water level change amount ΔXtn obtained by subtracting the water level detection value Xtx at Tx (seconds) before from the current water level detection value Xtn is periodically calculated and compared with the bathing determination value Xin (Xin > 0) (S140 in FIG. 3).

[0060] In FIG. 5, at time t1 after time ta, ΔXtn>Xin (S140 is determined to be YES), and during the period from time t1 to time t2 when Tj1 has elapsed, the continuously updated ΔXtn is greater than the bath entry determination value Xin. As a result, at time t2, S150 in FIG. 3 is determined to be YES, and the bath entry / exit determination flag changes from "0 (bath exit state)" to "1 (bath entry state)".

[0061] In the bath entry state after time t2, according to S120 in FIG. 3, the water level change amount ΔXtn obtained by subtracting the water level detection value Xtx at Tx (seconds) before from the current water level detection value Xtn is periodically calculated and compared with the bath exit determination value Xout (Xout<0) (S190 in FIG. 3).

[0062] In FIG. 5, at time t3 after time tb, ΔXtn<Xout (S190 is determined to be YES), and during the period from time t3 to time t4 when Tj2 has elapsed, the continuously updated ΔXtn is less than the bath exit determination value Xout. As a result, at time t4, S200 in FIG. 3 is determined to be YES, and the bath entry / exit determination flag changes from "1 (bath entry state)" to "0 (bath exit state)".

[0063] Accordingly, the controller 12 executes the first bath entry / exit determination when the water level detection value X can be obtained during the non-execution of the above-described hot water injection operation and circulation operation, that is, when not in the bathtub operation. In this way, the processing of S110 to S220 (FIG. 3) by the controller 12 can constitute an embodiment of the function of the "first determination unit". Further, the bath entry determination value Xin (Xin>0) corresponds to an embodiment of the "first reference value", and the bath exit determination value Xout (Xout<0) corresponds to an embodiment of the "second reference value".

[0064] (Bath entry / exit determination process during bathtub operation) Next, with respect to the bath entry / exit determination during the bathtub operation when the water level detection value by the water level sensor 11 cannot be obtained and thus the first bath entry / exit determination by S110 to S220 (FIG. 3) cannot be executed, an explanation will be given with reference to FIG. 4.

[0065] During the bath operation (YES at S110), the controller 12 executes the second bathing entry / exit determination by S310 to S410 shown in Fig. 4. Basically, the second bathing entry / exit determination is executed each time a bath operation is started in conjunction with the end of the bath operation, and determines whether the bathing state is in or out of the bath using the water level detection value Xtn that has become reacquirable and the reference water level Xref based on the water level detection value X acquired before the start of the bath operation.

[0066] In S310, the controller 12 determines whether the bath operation for which S110 has been determined as YES involves combustion. For example, in the bath operation described above, S310 is determined as NO in the pipe cleaning operation after drainage and the air purging operation among the circulation operations. On the other hand, S310 is determined as YES in the reheating operation and the hot water pouring operation (including hot water addition operation and cold water addition operation) among the circulation operations.

[0067] When a bath operation involving combustion is being performed (YES in S310), as part of the process of setting the reference water level Xref described below, S580 accumulates the amount of hot water ΔV poured from the hot water supply circuit 5 to the bathtub 20 based on the detection value of the flow sensor 14. The accumulation by S580 is repeatedly performed until the bath operation is ended (NO in S330).

[0068] When the bathing operation ends (YES at S330), the controller 12 executes a calculation process in S590 to reflect the integrated value Σ(ΔV) of the amount of hot water poured during the bathing operation, i.e., the volume of the hot water poured, in the reference water level Xref. Specifically, a calculation is executed to increase the reference water level Xref according to the value obtained by dividing the integrated value Σ(ΔV) by the cross-sectional area of ​​the bathtub 20 used when determining the bathing determination value Xin. S590 is also part of the process of setting the reference water level Xref.

[0069] Furthermore, after the bathtub operation ends, when the detected water level value stabilizes (YES determination in S350), the controller 12 obtains the detected water level value Xtn at that timing by S355. For example, in S350, when a predetermined time Tz set in advance has elapsed since the end timing of the bathtub operation, a YES determination is made, and a NO determination is maintained until then.

[0070] When the controller 12 obtains the detected water level value Xtn after the bathtub operation ends by S355, it determines by S360 whether it is in the input state or the bath exit state. In S360, when the value obtained by subtracting the reference water level Xref from the detected water level value Xtn after the bathtub operation ends is equal to or greater than the bath entry determination value Xin (Xin > 0) (Xtn - Xref ≥ Xin), a YES determination is made. That is, when the water level in the bathtub has risen beyond the bath entry determination value Xin with respect to the reference water level Xref during the bathtub operation (YES determination in S360), the controller 12 determines by S370 that it is in the bath state and sets the bath entry / exit determination flag to "1 (bath state)". When it was in the bath exit state at the start of the bathtub operation, at this timing, the transition from the bath exit state to the bath state, that is, the bath entry is indirectly detected.

[0071] On the other hand, when Xtn - Xref < Xin, that is, when the detected water level value Xtn after the bathtub operation ends is equal to or lower than the reference water level Xref, the controller 12 makes a NO determination in S360. Then, the controller 12 determines by S380 that it is in the bath exit state and sets the bath entry / exit determination flag to "0 (bath exit state)". When it was in the bath state at the start of the bathtub operation, at this timing, the transition from the bath state to the bath exit state, that is, the bath exit is indirectly detected.

[0072] In addition, when executing a bathtub operation without combustion (NO determination in S310), the controller 12 waits for the end of the bathtub operation (YES determination in S390) and further executes the determinations in S400 and S410.

[0073] In S400, it is determined whether the bath water is being kept warm by the automatic bath operation, and in S410, it is determined based on the output of the human detection sensor 35 whether a person has currently entered the bathtub 200.

[0074] At the end of a bathing operation not involving combustion, the process proceeds to S350 only if the bath is being kept warm (YES at S400) and entry to the room is being detected (YES at S410). In this case, just like at the end of a bathing operation involving combustion described above, it is determined whether the bath is in the input state or the exit state based on the detected water level value Xtn after the end of the bathing operation.

[0075] In contrast, if at least one of the following conditions is met: the bath water is not being kept warm (NO in S400) and entry is not detected (NO in S410), the controller 12 skips the determination based on the water level detection value Xtn (S360) and determines that the bathing state is being left (S380). This prevents erroneous detection of the bathing state due to noise in the water level detection value Xtn, etc.

[0076] In this way, when the bath operation is performed, the second bath entry / exit judgment is executed after the end of the bath operation, using the water level detection value Xtn after the end of the bath operation and the reference water level Xref set before the start of the bath operation. In this way, the controller 12 can constitute one embodiment of the function of the "second judgment unit" that executes the bath entry / exit judgment in conjunction with the end of the hot water pouring operation and the circulation operation, in which the first bath entry / exit judgment (FIG. 3) is not executed by the processing of S310 to S410 (FIG. 4). In other words, the period during which the hot water pouring operation or the circulation operation is executed corresponds to one embodiment of the period during which the bath entry / exit judgment by the "first judgment unit" is not executed.

[0077] Figures 6 and 7 show conceptual waveform diagrams illustrating an example of a second bathing entry / exit determination when a bathing operation occurs, i.e., according to the flowchart of Figure 4. Figure 6 shows a first example when a bathing entry occurs during a bathing operation, while Figure 7 shows a second example when a bathing exit occurs during a bathing operation.

[0078] In the first embodiment of FIG. 6, it is assumed that a post-boiling operation, which is one of the bathtub operations, is executed between times t10 and t11. Further, at time ta between times t10 and t11, which is before the end of the post-boiling operation, the user is taking a bath. Therefore, if it is outside the bathtub operation period, as indicated by the dotted line in FIG. 6, corresponding to the bath at time ta, the bathing determination flag changes from "0" to "1". However, during the bathtub operation period, since the water level detection value by the water level sensor 11 cannot be obtained, the bathing determination is put on standby and the bathing determination flag is maintained at "0".

[0079] When the bathtub operation ends at time t11, at time t12 when the water level detection value stabilizes, S350 in FIG. 4 is determined to be YES, and the water level detection value X at that timing is set as Xtn, and the bathing determination (second bathing determination) by S360 in FIG. 4 is performed. The reference water level Xref used in this bathing determination is not updated during the bathtub operation period and during the bathing state period, as shown in FIG. 6.

[0080] Therefore, since the value at the start point of the bathtub operation is maintained for the reference water level Xref, at time t12, the water level detection value Xtn, which is the bathtub water level after bathing, is larger than (Xref + Xin). Accordingly, by the second bathing determination performed every time the bathtub operation ends, at time t12, the bathing determination flag changes from "0" to "1".

[0081] Thereafter, at the timing when the user takes a bath at time tb, the bathtub operation is not being performed and the water level detection value by the water level sensor 11 can be obtained. Therefore, similar to the explanation in FIG. 5, at time t3, ΔXtn < Xout is detected (S190 in FIG. 3 is determined to be YES). Further, at time t4 when a predetermined time Tj2 has elapsed from time t3, the bathing determination flag changes from "1" to "0". In this way, after the bathtub operation ends, it is possible to detect the user's bathing.

[0082] In the second example of Fig. 7, when the user leaves the bath at time ta, the bath operation is not being performed and the water level detection value by the water level sensor 11 can be acquired. Therefore, as explained in Fig. 5, at time t1, ΔXtn>Xin is detected (YES judgment in S140 in Fig. 3). Furthermore, at time t2, when a predetermined time Tj1 has passed since time t1, the bath entry / exit judgment flag changes from "0" to "1".

[0083] Then, at time t13 while the user is taking a bath, a reheating operation, which is one of the bathing operations, is started. The reheating operation ends at time t14, but in the example of Figure 7, the user leaves the bath at time tb before the bathing operation ends at time t14.

[0084] Outside the bath operation period, the bath entry / exit judgment flag changes from "1" to "0" in response to leaving the bath at time tb, as shown by the dotted line in Figure 7. However, during the bath operation period, the water level detection value by the water level sensor 11 cannot be obtained, so the bath entry / exit judgment is put on hold and the bath entry / exit judgment flag is maintained at "1".

[0085] When the bath operation is ended at time t14, a bath entry / exit determination (second bath entry / exit determination) is made by S360 in Fig. 4 at time t15 when the water level detection value stabilizes, similar to time t12 in Fig. 6. The reference water level Xref used in the bath entry / exit determination at that time is not updated during the bathing state or during the bath operation, so the value before bathing is maintained.

[0086] As a result, at time t15, the bathtub water level after leaving the bath, the water level detection value Xtn, is smaller than (Xref+Xin). Therefore, the bath entry / exit determination flag changes from "1" to "0" at time t15 due to the second bath entry / exit determination performed each time the bath operation ends. This makes it possible to detect the user's leaving the bath after the bath operation ends.

[0087] (Problems with setting the reference water level Xref) It is understood that the accuracy of the second bath entry / exit judgment performed in conjunction with the end of the bath operation, as described in Figures 4, 6 and 7, depends on the reference water level Xref. As described above, the reference water level Xref indicates the bathtub water level in the exiting state, and is not updated during the bathing state or during the bath operation. On the other hand, from the viewpoint of improving the accuracy of the bath entry / exit judgment, it is preferable that the reference water level Xref be updated to the latest value to reflect the water level change during the exiting state. In addition, the initial value of the reference water level Xref can be set, for example, at the end of the above-mentioned filling operation of the bathtub 20, using the water level detection value of the water level sensor 11 together with the initial setting of the "exiting state".

[0088] However, as shown in Patent Document 2, if there is a large difference in the height at which the water level sensor and the bathtub are placed, a phenomenon occurs in which the water level detection value detected by the water level sensor rises or falls in response to a decrease in the temperature of the bathtub water, even if the bathtub water level is constant.

[0089] FIG. 8 shows a conceptual diagram illustrating the classification of bathtub placement heights.

[0090] Referring to Figure 8, if the placement height of the water level sensor 11 in the water heating apparatus 100 is taken as the reference height (H = 0), the placement height of the bathtub 20 can be defined as the height difference ΔH, which is the difference between the placement height of the circulation adapter 25 shown in Figure 1 and the reference height.

[0091] For example, by comparing the height difference ΔH with predetermined boundary values ​​H1, -H2, the placement height of bathtub 20 relative to water heating device 100 (water level sensor 11) placed outdoors on the ground can be stratified into "upper floor placement" corresponding to placement on the second floor or higher, "flat ground placement" corresponding to placement on the first floor, and "lower floor placement" corresponding to placement in the basement.

[0092] Fig. 9 is a conceptual diagram explaining the change in the detected water level value depending on the height at which the bathtub is placed. Fig. 9 shows the transition of the output voltage (i.e., the detected water level value) of water level sensor 11, which is made of a pressure sensor, when the temperature of the hot water retained between bathtub 20 (circulation adapter 25) and water level sensor 11 gradually decreases over time after the bath filling operation is completed.

[0093] 9, as the temperature Tbt of the stagnant hot water decreases over time, the specific gravity of the stagnant hot water gradually increases. In a case where bathtub 20 is placed at a position higher than the water level sensor (placed on an upper floor), the increase in specific gravity acts on water level sensor 11 as an increase in water pressure. Therefore, as shown by characteristic line L1, the water level detection value of water level sensor 11 gradually increases in response to the decrease in temperature.

[0094] In contrast, in cases where the bathtub 20 is placed lower than the water level sensor (placed downstairs), the increase in specific gravity acts on the water level sensor 11 as a drop in water pressure. Therefore, as shown by characteristic line L2, the water level detection value of the water level sensor 11 gradually drops in response to a drop in temperature. On the other hand, in cases where there is only a small height difference between the water level sensor 11 and the bathtub 20 (placed on flat ground), as shown by characteristic line L0, the phenomenon of the water level detection value of the water level sensor 11 rising or falling depending on the temperature of the stagnant hot water does not occur.

[0095] Fig. 10 is a conceptual waveform diagram illustrating a first example of erroneous bathing entry / exit determination caused by the reference water level. Fig. 10 shows an example of erroneous determination caused by a drop in bath water temperature during the period of bathing exit in bathtub 20 located on an upper floor.

[0096] In the example of FIG. 10, during the leaving bath state, the reheating operation is performed multiple times while the actual bath water level is maintained at X0. First, the reheating operation is performed from time tx1 to tx2. The amount of rise in bath water temperature caused by the reheating operation is assumed to be small. Between times tx1 and tx2, the water level detection value X cannot be obtained, but after the reheating operation ends and the water level detection value stabilizes, the second bathing entry / exit judgment described in FIG. 4 is performed.

[0097] As explained in Figures 6 and 7, when the reheating operation (bath operation) starts, the reference water level Xref is not updated until the second bath entry / exit judgment linked to the end of the bath operation is completed. On the other hand, the reference water level Xref becomes updateable in response to the end of the reheating operation.

[0098] If the bath water is left for a long period of time in a bathtub 20 located on an upper floor, the bath water temperature will gradually drop, and the water level detection value X by the water level sensor 11 will also gradually drop, as shown by characteristic line L2 in Figure 9. Therefore, it will be understood that if the reference water level Xref is successively updated using the water level detection value X within the updateable period, an error will occur between the reference water level Xref and the actual bath water level (X = X0).

[0099] The reheating operation starts again from time tx3 to tx4. The amount of rise in bathtub water temperature due to this reheating operation is relatively large. After the reheating operation ends, at time tx5 when the water level detection value stabilizes, the second bath entry / exit judgment is performed. At time tx5, the water level detection value X is obtained by the water level sensor 11 in a state in which the bathtub water temperature has risen to the same level as at time tx2 due to the reheating operation. In the example of FIG. 10, since the actual bathtub water level (X0) has not changed, the water level detection value X at time tx5 is equivalent to the water level detection value at time tx2, and is higher than the water level detection value immediately before time tx3 (immediately before the reheating operation begins).

[0100] If the amount of increase ΔX in the water level detection value at this time is greater than the bathing judgment value Xin, the bathing state will be erroneously judged in the second bathing entry / exit judgment linked to the end of the reheating operation at time tx5 due to a change in the detection value of the water level sensor 11, which depends on the water temperature.

[0101] In the case of the upper floor arrangement described in Fig. 8, there is a concern that the exit state may be erroneously detected due to an increase in water level detection value X by water level sensor 11 in response to a drop in temperature, as opposed to Fig. 10. There is also a concern that the water level detection value X may be affected not only by the temperature dependency that depends on the placement height of bathtub 20 as described in Fig. 9, but also by the temperature dependency of the output characteristics of water level sensor 11 itself. Since the ambient temperature of water level sensor 11 changes as slowly as the temperature of the stagnant hot water, the change in water level detection value X due to the temperature dependency of water level sensor 11 itself will also be as gradual as that shown in Fig. 8.

[0102] On the other hand, if updating of the reference water level Xref during the withdrawal state is refrained from in order to suppress the erroneous judgment in Figure 10, there is a concern that erroneous judgment as shown in Figure 11 may occur.

[0103] FIG. 11 shows a second example of erroneous bathing entry / exit determination caused by the reference water level, in which the user raises the bathtub water level with a shower before bathing.

[0104] In the example of FIG. 11, the user performs the following series of actions. First, the user enters bathroom 200 at time ty1, and from time ty1 to ty2, the user pours shower water into bathtub 20 to raise the bath water level. Then, at time ty3, the user takes a bath, and leaves the bath at time ty4. At time ty5, shortly after time ty4, the user leaves bathroom 200. Then, from time ty6 to ty7, which are after time ty5, a bath operation (e.g., reheating operation) is performed by operating remote control 50 (FIG. 1) outside bathroom 200.

[0105] As a result, human detection sensor 35 (FIG. 1) detects a "room entry state" in which the user is in bathroom 200 between times ty1 and ty5, and detects a "room exit state" from time ty5 onwards.

[0106] The water level detection value X by the water level sensor 11 rises due to hot water from the shower during the period from time ty1 to ty2. The rise in the bathtub water level due to the shower is gradual compared to when the user is bathing, and the amount of water level change ΔXtn (S120 in FIG. 3) during the predetermined time Tx in the first bathing entry / exit determination is smaller than the bathing determination value Xin. For this reason, bathing is not detected during the period from time ty1 to ty2, and the bathing entry / exit determination flag is maintained at "0 (exiting bath state)."

[0107] Furthermore, at time ty3, the water level detection value X rises as the user takes a bath. At this time, the amount of water level change ΔXtn (S120 in FIG. 3) is greater than the bathing determination value Xin, so bathing is detected by the first bathing entry / exit determination shown in FIG. 3. That is, in conjunction with the rise in the water level after time t3, the bathing entry / exit determination flag changes from "0 (exiting bath state)" to "1 (bathing state)."

[0108] At time ty4, the water level detection value X drops as the user leaves the bath. At this time, the amount of water level change ΔXtn (negative value) is smaller than the leaving-bathing determination value Xout (Xout<0), so leaving the bath is detected by the first bathing entry / exit determination shown in Figure 3. As a result, in conjunction with the drop in the water level after time ty4, the bathing entry / exit determination flag changes from "1 (bathing state)" to "0 (exiting state)."

[0109] On the other hand, in the period from time ty6 to ty7 after the user has left the bath, the water level detection value X cannot be obtained due to the execution of the bath operation, so at time ty8 after the end of the bath operation, a second bath entry / exit judgment (Figure 4) is executed in conjunction with the end of the bath operation.

[0110] In the example of Fig. 11, the reference water level Xref is not updated during the exit state in order to prevent erroneous judgment as explained in Fig. 10. Therefore, the reference water level Xref at time ty8 is maintained at a value corresponding to the bathtub water level X0 before time ty1.

[0111] As a result, in the second bathing entry / exit judgment at time ty8 (S360 in FIG. 4), the amount of change in the water level detection value X at time ty8 relative to the reference water level Xref is compared with the bathing judgment value Xin. Therefore, if the integrated value ΔXsw of the amount of water level rise due to showering between times ty1 and ty2 is greater than the bathing judgment value Xin, the bathing entry / exit judgment flag changes from "0" to "1" (S370 in FIG. 4) even though the person is not actually bathing. In other words, bathing is erroneously detected. There is concern that the erroneous detection shown in FIG. 11 may occur regardless of the height at which bathtub 20 is placed.

[0112] Furthermore, as a countermeasure against erroneous judgments as described in Figures 10 and 11, if the process of bathing entry / exit judgment were to be switched depending on the height at which the bathtub 20 is placed, i.e., between an upper floor placement, a flat ground placement, and a lower floor placement, there is a concern that the control would become more complicated.

[0113] (Setting process of reference water level Xref according to this embodiment) Next, a detailed explanation will be given of the setting of the reference water level Xref used for the second bathing entry / exit judgment during bath operation in the bath device of this embodiment, which takes the above-mentioned problems into consideration.

[0114] FIG. 12 shows a conceptual waveform diagram illustrating the rising pattern of the bathtub water level.

[0115] 12, the symbol XA indicates the change in the detected water level value X when the water level rises due to bathing, and the symbol XB indicates the change in the detected water level value X when the water level rises due to showering. In other words, the symbols XA and XB indicate the change in the detected water level value X when the bathtub water level actually rises.

[0116] In contrast, the symbol XC indicates a change in the detected water level value X due to a drop in temperature. As described above, the detected water level value X indicated by the symbol XC occurs mainly when the bathtub water level of the bathtub 20 located on the upper floor is detected, when the bathtub water level is not actually changing.

[0117] A conceptual diagram for explaining a first setting example of the reference water level Xref in the bath device according to the present embodiment is shown in Fig. 13. Fig. 13 shows an example of an increase in the water level detection value X over time during the exit state, and the setting of the corresponding reference water level Xref.

[0118] In the example of FIG. 13, during the period from time ta1 to ta2 and the period from time tb1 to tb2, a rise in the bathtub water level due to showering occurs, similar to symbol XB in FIG. 12, while during other periods, a rise in the water level detection value X due to a drop in temperature occurs, similar to symbol XC in FIG. 12.

[0119] In the bath apparatus of this embodiment, increases in the detected water level X similar to those indicated by symbols XA and XC are not reflected in the reference water level Xref, while increases in the detected water level X similar to those indicated by symbol XB are reflected in the reference water level Xref, thereby preventing erroneous bathing entry and exit determinations caused by errors in the reference water level Xref. In other words, the reference water level Xref is updated to reflect the amount of water level rise ΔH1 in the period from time ta1 to ta2, and the amount of water level rise ΔH2 in the period from time tb1 to tb2.

[0120] In this case, as can be seen from FIG. 12, the water level detection values ​​X for each of the symbols XA to XC can be distinguished based on the rate of increase of the water level detection value X, i.e., the amount of increase of the water level detection value X within a certain period of time.

[0121] Similarly, a drop in the bathtub water level can be dealt with as shown in FIGS.

[0122] FIG. 14 shows a conceptual waveform diagram illustrating the pattern of the drop in the bathtub water level.

[0123] 14, the symbol YA indicates the change in the detected water level value X when the water level drops as the person leaves the bath, and the symbol YB indicates the change in the detected water level value X when the water level drops due to filling a washbasin or the like or operating the drain plug 26. In other words, the symbols YA and YB indicate the change in the detected water level value X when the bathtub water level actually rises.

[0124] In contrast, the code YC indicates a change in the detected water level value X due to a drop in temperature. As described above, the detected water level value X indicated by the code YC occurs mainly when the bathtub water level of the bathtub 20 located on the lower floor is detected, when the bathtub water level is not actually changing.

[0125] A conceptual diagram for explaining a second setting example of the reference water level Xref in the bath device according to the present embodiment is shown in Fig. 15. Fig. 15 shows an example of a decrease in the water level detection value X over time during the exit state, and the corresponding setting of the reference water level Xref.

[0126] In the example of Figure 15, during the period from time tc1 to tc2 and the period from time td1 to td2, a drop in the bathtub water level occurs due to drawing water or draining water, similar to symbol YB in Figure 14, while during other periods, a drop in the water level detection value X occurs due to a drop in temperature, similar to symbol YC in Figure 14.

[0127] In this embodiment, a decrease in the detected water level X similar to the symbol YC is not reflected in the reference water level Xref, while a decrease in the detected water level X similar to the symbol YB is reflected in the reference water level Xref, thereby suppressing erroneous determination of bathing entry and exit caused by an error in the reference water level Xref. That is, the reference water level Xref is updated to reflect the amount of water level decrease ΔH3 during the period from time tc1 to tc2 and the amount of water level decrease ΔH4 during the period from time td1 to td2.

[0128] In this case, as can be seen from FIG. 14, the decrease in the water level detection value X at each of the symbols YA to YC can be distinguished based on the decrease rate of the water level detection value X, i.e., the amount of decrease in the water level detection value X within a unit time.

[0129] Figures 16 and 17 show a flow chart explaining the control process for setting the reference water level Xref in the bath apparatus according to this embodiment. The control process shown in Figures 16 and 17 is repeatedly executed by the controller 12. In the reference water level setting process of Figures 16 and 17, the bathing determination value Xin and the bathing exit determination value Xout are set in common with the bathing entry / exit determination process of Figures 3 and 4.

[0130] As shown in Fig. 16, the controller 12 determines in S500 whether or not a bathtub water level has been generated, i.e., whether or not water pressure is being applied to the water level sensor 11. The control process described below is started when the bathtub water level is generated by the bathtub 20 filling operation, and is executed repeatedly until the bathtub water level is eliminated by draining the bathtub 20. The determination in S500 is YES when the bathtub water level is higher than the position where the circulation adapter 25 is arranged and the return pipe 8a where the water level sensor 11 is arranged is filled with hot water, and is NO when not.

[0131] When the controller 12 judges YES in S500, it judges in S510 whether the bathing state is the bathing state or the leaving state based on the bathing entry / exit judgment flag, and branches the process. When the controller 12 is in the bathing state, it judges NO in S510 and advances the process to S520, thereby entering a state of waiting for a transition from the bathing state to the leaving state by execution of S220 in Fig. 3 or S380 in Fig. 4. Note that when the controller 12 judges YES in S500 during the bath filling operation, it judges NO in S510 and S520, and enters a similar waiting state until the "leaving state" is initially set in response to the end of the bath filling operation.

[0132] Then, when the bathing state transitions to the leaving state, that is, when the bathing entry / exit judgment flag changes from "1" to "0" (YES judgment in S520), the controller 12 updates the reference water level Xref in S800 to reflect the current water level detection value Xtn by the water level sensor 11. For example, Xref can be set to Xtn. After the reference water level Xref is updated in S800, processing returns to S500. Note that when the "leaving state" is initially set at the end of the water filling operation, YES judgment is made in S520 and processing proceeds from the above-mentioned standby state to S800, so that the reference water level Xref can be initially set.

[0133] On the other hand, if the user is in the bathing state (YES at S510), the controller 12 further branches the process at S530 depending on whether or not the bathing operation is in progress.

[0134] If the bath operation is in progress (YES in S530), the controller 12 determines in S540 whether or not the bath operation is accompanied by combustion. The determination in S540 is performed in the same manner as in S310 (FIG. 4). If the bath operation is not accompanied by combustion (NO in S540), the reference water level Xref is not updated and the process returns to S500.

[0135] When a bath operation involving combustion is being performed (when S540 returns a YES judgment), S550 waits for the completion of that bath operation. Furthermore, after the bath operation has ended (when S550 returns a YES judgment), S560 waits for the completion of the second bath entry / exit judgment (FIG. 4) linked to the end of the bath operation. For example, in the example of FIG. 7, after S550 returns a YES judgment at time t14, S560 returns a YES judgment at time t15.

[0136] When the bathing entry / exit determination is completed (YES in S560), the controller 12 determines whether the result of the bathing entry / exit determination is a bathing state or an exit state in S570. If the result of the determination is an exit state (YES in S570), the process proceeds to S800.

[0137] On the other hand, if the result of the determination is that the user is in the bathing state (NO at S570), the process returns to S500. In this case, when the transition from the bathing state to the exiting state at the end of the bathing operation is detected at S510 and S520, the process proceeds to S800.

[0138] As a result, when a bathing operation involving combustion is performed, the reference water level Xref is updated using the water level detection value Xtn in the exit state after the bathing operation is completed. On the other hand, in a bathing operation not involving combustion, the reference water level Xref is not updated even when the bathing operation is completed. In this way, the reference water level Xref is not updated in the bathing state or during the bathing operation.

[0139] If the bath operation is not in progress during the leaving bath state (NO judgment at S530), that is, if the water level detection value X can be obtained during the leaving bath state, the controller 12 proceeds to processing at S610 shown in FIG. 17 and controls the update or non-update of the reference water level Xref.

[0140] As shown in Fig. 17, in S610, the controller 12 reads the water level detection value X by the water level sensor 11 at the current timing as the water level detection value Xtn, similar to S110 in Fig. 3. Furthermore, in S620, the controller 12 calculates the water level change amount ΔXtn for the water level detection value Xtx read in S610 relative to the water level detection value Xtx a predetermined time Tx earlier, similar to S200 in Fig. 3. The processes of S610 and S620 in Fig. 17 can be common to the processes of S110 and S120 in Fig. 3.

[0141] In S630, the controller 12 branches the process depending on the polarity of the water level change amount ΔXtn calculated in S620. If ΔXtn>0, that is, if the water level detection value X is rising, then a YES determination is made in S630 and the process proceeds to S640.

[0142] In S640, the controller 12 determines whether the water level change amount ΔXtn (ΔXtn > 0) calculated in S620 is within the range of α·Xin < ΔXtn < Xin. Here, α is a predetermined coefficient with 0 < α < 1.0. That is, α·Xin is a positive value set smaller than the bathing determination value Xin and corresponds to an embodiment of the "third reference value". The coefficient α can be determined based on actual machine experiment results or the like to a value that can distinguish the rising rates of the water level detection values X at the respective symbols XB and XC in FIG. 12 using the water level change amount over a predetermined time Tx.

[0143] When α·Xin < ΔXtn < Xin (when the determination in S640 is YES), the controller 12 detects the change in the water level detection value X corresponding to the symbol XB in FIG. 12. Further, the controller 12 can determine, by S650 and S660, whether there is a flow rate in the hot water supply circuit 5 and whether the "room entry state" is detected by the human detection sensor 35.

[0144] When at least one of the conditions that there is no flow rate in the hot water supply circuit 5 (when the determination in S650 is NO) and the human detection sensor 35 detects the "room exit state" (when the determination in S660 is NO) is satisfied, even if α·Xin < ΔXtn < Xin is detected, the process proceeds to S810 and the reference water level Xref is not updated. For example, when the internal passing flow rate of the hot water supply circuit 5 is smaller than the minimum operating flow rate (MOQ), S650 is determined as YES.

[0145] By the processing of S650 and S660, it is possible to suppress the update of the reference water level Xref in the upward direction even though the bathtub water level is not actually rising. However, the processing of S650 and S660 may be omitted.

[0146] The controller 12 determines, by S680, whether the state of α·Xin < ΔXtn < Xin continues for a predetermined time Tup (Tup < Tx) set in advance, while combining the processing of S650 and S660 as necessary.

[0147] Until the specified time Tup elapses (when the determination in S680 is NO), in S690, the water level detection value Xtn is periodically acquired, the water level change amount ΔXtn is calculated, and then the determination in S640 or the determinations in S640 to S660 are repeatedly executed. The period of S690 can be set to be equal to the period in which S610 is executed during the period when the bath draining state is maintained. Further, in S670, an integration process for obtaining the water level change amount Σ(ΔX) during the specified time Tup is executed. In S670, every time the water level detection value Xtn is acquired by S690, the water level change amount ΔX with respect to the previous water level detection value Xtn is integrated. That is, when the specified time Tup elapses, the water level rise amount during the specified time Tup can be obtained using the integrated value Σ(ΔX) by S670.

[0148] Therefore, when the state of α·Xin < ΔXtn < Xin continues for the specified time Tup (when the determination in S680 is YES), in S820, the reference water level Xref is updated (Xref = Xref + Σ(ΔX)) reflecting the integrated value Σ(ΔX) obtained in S670. Further, in S830, the integrated value Σ(ΔX) in S670 is cleared (Σ(ΔX) = 0), and the process returns to S500 (FIG. 16).

[0149] On the other hand, when ΔXtn ≥ Xin, or 0 < ΔXtn ≤ α·Xin, or when the state of α·Xin < ΔXtn < Xin does not continue for the specified time Tup, the controller 12 makes a NO determination in S640 and, in S810, does not update the reference water level Xref. Also, in S810, after clearing the above-described integrated value Σ(ΔX), the process returns to S500 (FIG. 16). In this way, when ΔXtn > 0, it is possible to control the update and non-update of the reference water level Xref while reflecting the water level rise amounts ΔH1 and ΔH2 in FIG. 13 and not reflecting the change in the water level detection value due to the temperature change.

[0150] When the water level change amount ΔXtn calculated in S620 is 0 or less, that is, when the water level detection value X decreases, the controller 12 makes a YES determination in S630 and advances the process to S700.

[0151] In S700, the controller 12 determines whether the water level change amount ΔXtn (ΔXtn ≦ 0) calculated in S620 is within the range of β·Xout > ΔXtn > Xout. Here, β is a predetermined coefficient with 0 < β < 1.0. That is, β·Xout is a negative value set larger than the bath draining determination value Xout (|β·Xout| < |Xout|), corresponding to an embodiment of the "fourth reference value". The coefficient β can be determined based on the actual machine experiment results and the like to a value that can distinguish the decrease rates of the water level detection values X of the symbols YB and YC in FIG. 14 using the water level change amount in a predetermined time Tx.

[0152] When β·Xout > ΔXtn > Xout (when the determination in S700 is YES), the controller 12 detects the change in the water level detection value X corresponding to the symbol YB in FIG. 14. That is, when the water level detection value decreases (ΔXtn < 0), when |β·Xout| < |ΔXtn| < |Xout|, S700 is determined to be YES. Further, the controller 12 can determine, by S710, whether the "room entry state" is detected by the human detection sensor 35.

[0153] When the human detection sensor 35 detects the "room exit state" (when the determination in S710 is NO), even if β·Xout > ΔXtn > Xout is detected, the process proceeds to S810 and the reference water level Xref is not updated. By the process of S710, it is possible to suppress the update of the reference water level Xref in the downward direction even though the bathtub water level has not actually decreased. However, similar to the processes of S650 and S660, the process of S710 can be omitted.

[0154] The controller 12 determines, by S730, whether the state of β·Xout > ΔXtn > Xout continues for a preset predetermined time Tdw (Tdw < Tx), while combining the process of S710 as necessary.

[0155] Until the predetermined time Tdw has elapsed (when S730 is judged as NO), S740 periodically acquires the water level detection value Xtn and calculates the water level change amount ΔXtn, and then S700 or S700 and S710 are repeatedly judged. The cycle of S740 can be set to be equal to the cycle of S610, as in S690.

[0156] Furthermore, S720 executes an accumulation process similar to S670. That is, in S720, every time a water level detection value Xtn is acquired by S740, the water level change amount ΔX relative to the previous water level detection value Xtn is accumulated. That is, when a predetermined time Tdw has elapsed, the water level change amount (negative value) during the predetermined time Tdw is calculated using the accumulated value Σ(ΔX) by S730. The absolute value of Σ(ΔX) at this time corresponds to the amount of water level drop.

[0157] When the state of β·Xout>ΔXtn>Xout continues for a predetermined time Tdw, the controller 12 updates the reference water level Xref (Xref=Xref+Σ(ΔX)) by using the negative integrated value Σ(ΔX) calculated by S720 in S820. Furthermore, the integrated value Σ(ΔX) calculated by S670 is cleared by S830 (Σ(ΔX)=0), and the process returns to S500 (FIG. 16).

[0158] On the other hand, when ΔXtn≦Xout, or β·Xout≦ΔXtn≦0, or when the state of β·Xout>ΔXtn>Xout does not continue for the predetermined time Tdw, the controller 12 judges S700 as NO, and does not update the reference water level Xref in S810. As described above, in S810, the integrated value Σ(ΔX) is also cleared, and then the process returns to S500 (FIG. 16).

[0159] In this way, when ΔXtn<0, the update or non-update of the reference water level Xref can be controlled so as to reflect the amounts of water level drop ΔH3 and ΔH4 in Fig. 15 while not reflecting changes in the detected water level value in response to temperature changes. As described above, one embodiment of the "setting unit" can be configured by the processing of S500 to S830 shown in Fig. 16 and Fig. 17 and S580, S590 in Fig. 4 by the controller 12.

[0160] In this way, the bath device according to the present embodiment can prevent erroneous detection of the bathing state or the exiting state in the bathing entry / exit determination executed in conjunction with the end of the bathing operation by reflecting the amount of water level change within a certain range within a unit time during the exiting state in the reference water level Xref in a limited manner. As a result, the accuracy of bathing entry / exit detection using the bathtub water level sensor can be improved.

[0161] Furthermore, because it is possible to update the reference water level Xref by eliminating changes in the detected water level value corresponding to temperature changes that appear depending on the height of the bathtub 20, the control process for bathing entry / exit determination can be standardized regardless of the height of the bathtub 20, that is, between an upper floor placement, a flat ground placement, and a lower floor placement. Therefore, the accuracy of bathing entry / exit detection using the bathtub water level sensor can be improved without complicating the control.

[0162] In addition, in Figure 17, an example is described in which both the water level rise amount and the water level fall amount are reflected in the reference water level, but only one of the water level rise amount and the water level fall amount may be reflected in the reference water level, for example, by omitting the processing of S700 to S730 in Figure 7, so that only the water level rise amount is reflected.

[0163] In this embodiment, the execution period of the bath operation (including the pouring operation and the circulation operation) is shown as a representative example of the first bath entry / exit judgment (S110-S220: FIG. 3), i.e., the "non-execution period" of the bath entry / exit judgment by the "first judgment unit". However, in this embodiment, a similar non-execution period may be provided separately from the execution period of the bath operation. In other words, the second bath entry / exit judgment (S310-S380: FIG. 4) according to this embodiment, which reflects the control of updating and non-updating the reference water level Xref, i.e., the bath entry / exit judgment by the "second judgment unit", can be executed appropriately in conjunction with the end of an arbitrarily set non-execution period of the bath entry / exit judgment by the "first judgment unit".

[0164] 3, 4, 16, and 17 are described as being executed by controller 12, but the subject that executes the control process is not limited to this. For example, the control process can be executed by a microcomputer (not shown) stored in remote control 30 or 50, and the location of the device corresponding to the "control device" is not specified. The function of the "control device" can also be realized by a device external to hot water supply system 300.

[0165] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0166] 5 hot water circuit, 7 reheating circuit, 8 circulation path, 8a return pipe, 8b supply pipe, 8c connection point, 9 temperature sensor, 10 circulation pump, 11 water level sensor, 12 controller, 13 hot water supply valve, 13a hot water supply pipe, 14 flow sensor, 20 bathtub, 21 bathtub water, 25 circulation adapter, 26 drain plug, 30, 50 remote control, 31, 51 display unit, 32, 52 operation unit, 35 human detection sensor, 100 hot water supply device, 200 bathroom, 300 hot water system, X, Xtn water level detection value, Xin bathing entry judgment value, Xout bathing exit judgment value, Xref reference water level.

Claims

1. A bathing device including a bathtub, A water heater; a circulation path for circulating hot and cold water in the bathtub between the hot water supply device and the bathtub when a circulation pump is operated; a water level detector that detects the water level in the bathtub based on the water pressure in the circulation path; a control device for controlling the operation of the bathing device and detecting bathing in and out of the bathtub based on the water level detected by the water level detector; The control device includes: a first determination unit which detects a transition to a bathing state in which a bather is present in the bathtub when an amount of change in the water level detection value within a first predetermined time period in a bathing leaving state in which no bather is present in the bathtub becomes greater than a first reference value which is a predetermined positive value, and which detects a transition to the bathing leaving state when an amount of change in the water level detection value within a second predetermined time period in the bathing state becomes smaller than a second reference value which is a predetermined negative value; a second determination unit that executes a bathing entry / exit determination to determine whether the bathing state is the bathing state or the leaving state in conjunction with the end of a period in which the first determination unit does not execute the bathing entry / exit determination; a setting unit that sets a reference water level used in the bathing entry / exit determination by the second determination unit, the second determination unit executes the bathing / leaving determination so as to determine that the bathing state is present when a value obtained by subtracting the reference water level from the water level detection value after the non-execution period is greater than the first reference value, and to determine that the bathing state is present when the subtracted value is smaller than the first reference value; the setting unit does not update the reference water level during the bathing state and the non-execution period, and updates the reference water level based on the water level detection value when the first determination unit detects a transition from the bathing state to the leaving bathing state and when the second determination unit determines that the bathing state is the leaving bathing state through the bathing entry / exit determination, The bath device further includes a setting unit that updates the reference water level to reflect the amount of increase in the water level detection value within the first specified time during the bathing exit state, when the amount of increase in the water level detection value within the first specified time is smaller than the first reference value and greater than a third reference value, which is a positive value set smaller than the first reference value.

2. A bath apparatus as described in claim 1, wherein the third reference value is set to be greater than the amount of increase in the water level detection value within the first specified time period caused by a change in the output of the water level detector due to a temperature drop at a constant water level in the bathtub.

3. The bath apparatus of claim 1 or 2, wherein the setting unit further updates the reference water level to reflect the amount of decrease in the water level detection value within the second specified time during the bathing exit state when the amount of decrease in the water level detection value within the second specified time is smaller than the absolute value of the second reference value and greater than the absolute value of a fourth reference value, which is a negative value set greater than the second reference value.

4. A bath apparatus as described in claim 3, wherein the absolute value of the fourth reference value is set to be greater than the amount of decrease in the water level detection value within the second specified time caused by a change in the output of the water level detector due to a decrease in temperature at a constant water level in the bathtub.

5. The bathtub further includes a human detector provided in the bathroom, A bath device as described in any one of claims 1 to 4, wherein the setting unit does not update the reference water level during a period in the bathing exit state when the human detector does not detect a person in the bathroom.

6. A bath device as described in any one of claims 1 to 5, wherein the setting unit does not update the reference water level when there is no flow in the water heating device, even if the amount of increase in the water level detection value within the first specified time is smaller than the first reference value and greater than the third reference value during the bathing exit state.

7. The control device controls the hot water supply operation from the hot water supply device to the bathtub using the circulation path and the circulation operation by operating the circulation pump according to the operation mode of the bath device, A bath apparatus according to any one of claims 1 to 6, wherein the non-execution period includes an execution period of the pouring operation or the circulation operation.

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