Toilet device

Abstract

To provide a toilet device capable of actualizing appropriate drive of a heat exchanger.SOLUTION: The toilet device includes the instantaneous type heat exchanger, an on-off valve for opening / closing a flow path for water flowing in the heat exchanger, a temperature sensor provided on the downstream side of the heat exchanger, and a control device for acquiring a detection temperature detected by the temperature sensor to control the heat exchanger. The control part drives the heat exchanger in the state of opening the on-off valve to calculate a variation in the detection temperature in the middle of drive of the heat exchanger, stops the drive of the heat exchanger to calculate the drop amount of the detection temperature in the middle of stopping the drive of the heat exchanger when the variation is not higher than a first value during a first time after starting the drive of the heat exchanger, and performs determination control to determine that it is possible to drive the heat exchanger when the drop amount is not lower than a second value within a second time after stopping the drive of the heat exchanger.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Aspects of the present invention generally relate to toilet devices.

Background Art

[0002] Conventionally, a toilet device may be provided with an instantaneous heat exchanger. The toilet device performs a warm water washing operation of discharging the washing water heated by the heat exchanger toward a local part of the human body such as the buttocks. When the heat exchanger is driven in a state where there is no water or water flow inside the heat exchanger, excessive heating may occur. For example, even if an on-off valve that opens and closes the water flow path flowing through the heat exchanger is open, water may not flow into the heat exchanger due to a malfunction. When the heat exchanger is driven in a state where water does not flow into the heat exchanger, dry burning may occur.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention has been made based on the recognition of such problems, and an object thereof is to provide a toilet device that can appropriately drive a heat exchanger.

Means for Solving the Problems

[0005] The first invention comprises an instantaneous heat exchanger, an on-off valve for opening and closing the water flow path flowing through the heat exchanger, a temperature sensor provided downstream of the heat exchanger, and a control unit that acquires the detected temperature detected by the temperature sensor and controls the heat exchanger. The control unit drives the heat exchanger with the on-off valve open and calculates the change amount of the detected temperature during the driving of the heat exchanger. When the change amount does not become equal to or greater than a first value within a first time from the start of driving the heat exchanger, the driving of the heat exchanger is stopped and the decrease amount of the detected temperature during the stop of driving the heat exchanger is calculated. When the decrease amount becomes equal to or greater than a second value within a second time from the stop of driving the heat exchanger, it is determined that the heat exchanger can be driven, and a toilet device characterized by performing determination control is provided.

[0006] According to this toilet device, by basing on the detected temperature of the temperature sensor provided downstream of the heat exchanger, the heat exchanger can be driven more appropriately. For example, when there is water or a water flow in the heat exchanger, it can be determined that the heat exchanger can be driven. By calculating the decrease amount of the detected temperature during the stop of driving the heat exchanger, for example, when the temperature of the water flowing into the heat exchanger is decreasing, it can be determined that the heat exchanger can be driven.

[0007] The second invention is a toilet device characterized in that, in the first invention, the second value is equal to or less than the first value.

[0008] According to this toilet device, since the second value is equal to or less than the first value, it becomes easier to detect that the temperature of the water flowing into the heat exchanger is decreasing.

[0009] The third invention is, in the first invention, further comprises a toilet seat, a seating detection sensor for detecting the user's seating on the toilet seat, and a nozzle for discharging the water flowing out from the heat exchanger. When the control unit detects the user's seating by the seating detection sensor, the determination control is started, and the toilet device is characterized in that the nozzle and the heat exchanger are made water-passing possible.

[0010] According to this toilet device, when there is water flow in the heat exchanger during the determination control, when the user sits down, the determination control and the water discharge can be performed in parallel. Thereby, for example, in the warm water washing operation, water can be immediately discharged from the nozzle, and the usability can be further improved.

[0011] A fourth invention is the toilet device according to the first invention, further comprising a nozzle for discharging the water flowing out from the heat exchanger, and when the decrease amount does not become equal to or more than the second value during the second hour from when the drive of the heat exchanger is stopped in the determination control, when the control unit receives an instruction to discharge water to the nozzle, the control unit is characterized by driving the nozzle.

[0012] According to this toilet device, by driving the nozzle, it is possible to notify the user that there is a problem in the water supply.

[0013] A fifth invention is the toilet device according to the first invention, further comprising a nozzle for discharging the water flowing out from the heat exchanger, and the control unit can perform warm water washing control for driving the heat exchanger at a first output and discharging the water heated by the heat exchanger toward the local part of the user through the nozzle, and in the determination control, the control unit is characterized by driving the heat exchanger at a second output smaller than the first output.

[0014] According to this toilet device, by reducing the output of the heat exchanger in the determination control, even if there is no water in the heat exchanger, it is possible to suppress the damage caused to the heat exchanger by dry burning in the determination control.

Effect of the Invention

[0015] According to an aspect of the present invention, there is provided a toilet device capable of appropriately driving a heat exchanger.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are assigned to the same components, and detailed descriptions thereof will be omitted as appropriate. FIG. 1 is a perspective view showing a toilet device and a toilet cleaning device according to the embodiment. As shown in FIG. 1, the toilet device 2 includes a Western-style sitting toilet 4 (hereinafter simply referred to as "toilet" for convenience of explanation) and a toilet cleaning device 10. The toilet cleaning device 10 is attached on the toilet 4. The toilet cleaning device 10 may be integrally attached to the toilet 4 or detachably attached to the toilet 4.

[0018] The toilet cleaning device 10 has a main body portion 12, a toilet seat 14, and a toilet lid 16. The toilet lid 16 is provided as necessary for the toilet cleaning device 10 and can be omitted. The toilet seat 14 and the toilet lid 16 are rotatably supported with respect to the main body portion 12.

[0019] The toilet 4 has a bowl portion 4a. The bowl portion 4a is concave downward. The toilet 4 receives excreta such as urine and feces of the user in the bowl portion 4a.

[0020] The main body 12 of the sanitary cleaning device 10 is attached above a portion behind the bowl portion 4a of the toilet 4. The main body 12 has a casing 20. The toilet seat 14 and the toilet lid 16 are rotatably supported in the casing 20.

[0021] FIG. 2 is a block diagram showing the main part configuration of the sanitary cleaning device according to the embodiment. As shown in FIG. 2, the sanitary cleaning device 10 includes a cleaning water supply unit 30, a seating detection sensor 31, a human body detection sensor 32, a nozzle 34, and a control unit 42.

[0022] The seating detection sensor 31 can detect a human body existing above the toilet seat 14 immediately before the user sits on the toilet seat 14 or the user sitting on the toilet seat 14. The seating detection sensor 31 may detect not only the user sitting on the toilet seat 14 but also a user existing above the toilet seat 14. As such a seating detection sensor 31, for example, an infrared light transmitting and receiving type distance measuring sensor can be used. The seating detection sensor 31 may be a switch that is turned ON / OFF by the load when the user sits down. The seating detection sensor 31 outputs a signal indicating the detection of seating to the control unit 42 in response to the detection of the user's seating.

[0023] The human body detection sensor 32 is, for example, a pyroelectric sensor using an infrared signal, and detects an intruder who enters the room (toilet room) where the toilet device 2 is installed. The human body detection sensor 32 is connected to the control unit 42. The human body detection sensor 32 inputs the detection result to the control unit 42. The human body detection sensor 32 may be a microwave sensor such as a Doppler sensor. The human body detection sensor 32 may be able to detect a user before entering the toilet room.

[0024] The cleaning water supply unit 30 includes, for example, an on-off valve 50, a heat exchanger 51, and a temperature sensor 52. The cleaning water supply unit 30 may further include a vacuum breaker (VB) 53 and a flow rate adjustment / flow path switching valve 55 (flow path switching unit).

[0025] The on-off valve 50 is, for example, an electromagnetic valve that can be opened and closed. The on-off valve 50 switches between the supply and stoppage of the cleaning water supplied from the water supply source. The on-off valve 50 is a water supply valve that opens and closes the flow path 21 of the water flowing into the heat exchanger 51 and controls the supply of water to the heat exchanger 51. That is, when the on-off valve 50 opens, the flow path 21 of the water flowing into the heat exchanger 51 opens, and water is supplied to the heat exchanger 51. When the on-off valve 50 closes, the flow path 21 closes, and the supply of water to the heat exchanger 51 stops.

[0026] After the on-off valve 50 changes from the open state to the closed state, there may be water remaining in the heat exchanger 51 or in the portion of the flow path 21 downstream of the heat exchanger 51. When the on-off valve 50 is in the closed state, water drainage for discharging the water remaining downstream of the on-off valve 50 may be performed. That is, when the on-off valve 50 is closed, there may or may not be water in the heat exchanger 51 or in the flow path downstream of the heat exchanger 51.

[0027] For example, the heat exchanger 51 is provided downstream of the on-off valve 50. The heat exchanger 51 is, for example, an instantaneous heating type (instantaneous type) heat exchanger using a ceramic heater or the like. The instantaneous type heat exchanger generates hot water by heating while water flows inside. In the instantaneous type heat exchanger, when the heating element (heater) generates heat, the water flowing through the flow path around the heating element is heated. The heat exchanger 51 heats the cleaning water supplied from the water supply source by the heater and raises the temperature to, for example, a specified temperature. The heat exchanger 51 converts the cleaning water supplied from the water supply source into hot water at a set temperature. Hereinafter, in the present specification, the scope of "water" shall include the water (cold water) supplied from the water supply source and the hot water heated by the heat exchanger 51.

[0028] For example, the vacuum breaker 53 is provided downstream of the heat exchanger 51. The vacuum breaker 53 promotes the drainage of the portion downstream of the vacuum breaker 53 by taking in air into the flow path when there is no water flow in the flow path. The vacuum breaker 53 promotes the drainage of, for example, the nozzle 34.

[0029] The water that has passed through the heat exchanger 51 is sent to the nozzle 34. The nozzle 34 has a water discharge part 35. The water discharge part 35 has, for example, a plurality of water discharge holes 35a, 35b, and 35c. The water sent to the nozzle 34 is discharged upward from the water discharge holes of the water discharge part 35. The water discharged from the water discharge part 35 is used for, for example, local cleaning of the user sitting on the toilet seat 14.

[0030] The flow control and flow path switching valve 55 is provided between the vacuum breaker 53 and the nozzle 34. The flow control and flow path switching valve 55 switches the destination of the water supplied from the upstream to any one of the water discharge holes. Also, the flow control and flow path switching valve 55 changes the water discharge flow rate of the water discharged from each water discharge hole.

[0031] The temperature sensor 52 is provided downstream of the heat exchanger 51. The temperature sensor 52 is located upstream of the vacuum breaker 53 and the flow control and flow path switching valve 55. The temperature sensor 52 detects the temperature of the fluid (water or air) in the downstream portion of the flow path 21 of the heat exchanger 51. For example, the temperature sensor 52 is warmed by the heat exchanger 51 and detects the temperature of the fluid flowing out from the heat exchanger 51. The temperature sensor 52 detects the temperature of the fluid flowing from the heat exchanger 51 to the flow control and flow path switching valve 55 and the nozzle 34. The temperature sensor 52 is, for example, an outlet water temperature sensor that detects the temperature of the water immediately after flowing out from the heat exchanger 51. For the temperature sensor 52, for example, a thermistor can be used.

[0032] The nozzle 34 may be provided with a nozzle motor 36. The nozzle motor 36 drives the nozzle 34. The nozzle 34 can receive the driving force from the nozzle motor 36 and advance into the bowl part 4a of the toilet 4 or retreat inside the casing 20.

[0033] The control unit 42 controls the operations of the washing water supply unit 30, the human body detection sensor 32, and the nozzle 34. For example, the control unit 42 controls the operations of each unit according to the operation instructions input from the operation unit 44. As the control unit 42, a control circuit (such as a microcomputer) including, for example, a CPU can be used. The operation unit 44 may be a so-called remote control. The operation unit 44 may be provided on the main body unit 12 or separately from the main body unit 12. The communication between the control unit 42 and the operation unit 44 may be wired or wireless.

[0034] The control unit 42 transmits command signals to each part of the washing water supply unit 30 (the on-off valve 50, the heat exchanger 51, the flow control / flow path switching valve 55, and the nozzle motor 36) and controls the operations of each part of the washing water supply unit 30. For example, the control unit 42 controls the on-off valve 50 to control the supply of washing water. For example, the control unit 42 controls the nozzle motor 36 to move the nozzle 34 forward and backward.

[0035] In addition, the control unit 42 can perform control to drive the heat exchanger 51. That is, the control unit 42 performs control to supply drive power for generating heat to the heat exchanger 51. Thereby, the heater of the heat exchanger 51 is energized and generates heat.

[0036] The control unit 42 is connected to the temperature sensor 52 and obtains the detected temperature (detection result) detected by the temperature sensor 52. The temperature sensor 52 detects the temperature every predetermined time (for example, about every 50 to 100 milliseconds) and outputs the detection result to the control unit 42. The control unit 42 obtains the detected temperature detected every predetermined time. That is, the control unit 42 can obtain the detected temperature that changes every moment. The control unit 42 controls the heat exchanger 51 based on the detected temperature detected by the temperature sensor 52.

[0037] For example, while the user is seated on the toilet seat, the user inputs a warm water washing operation for causing the toilet device to perform a warm water washing operation to the operation unit 44. The control unit 42 receives a signal instructing the implementation of warm water washing control from the operation unit 44. The warm water washing control opens the on-off valve 50, drives the heat exchanger 51, and discharges warm water heated by the heat exchanger 51 from the nozzle 34. Further, the warm water washing control controls the flow rate adjustment / flow path switching valve 55 to switch the flow rate and flow path of the discharged water, and drives the nozzle motor 36 to advance the nozzle 34 into the bowl portion 4a. In this way, in a state where the nozzle 34 has advanced into the bowl portion 4a, a warm water washing operation of discharging warm water toward the user from the water discharge hole of the water discharge portion 35 is performed. In the warm water washing control, the control unit 42 drives the heat exchanger 51 at, for example, a first output (for example, 1200 watts).

[0038] For example, when the user sits on the toilet seat 14, the seating detection sensor 31 detects the seating of the user. The control unit 42 acquires a detection result indicating that the user has seated from the seating detection sensor 31. In this case, the control unit 42 may perform warm water preparation control. The warm water preparation control drives the heat exchanger 51 with the on-off valve 50 open, and controls the flow rate adjustment / flow path switching valve 55 to make the nozzle 34 communicate with the heat exchanger 51. As a result, warm water heated by the heat exchanger 51 flows through the downstream portion of the heat exchanger 51 and inside the nozzle 34. That is, for example, water remaining in the downstream portion of the heat exchanger 51 and inside the nozzle 34 (for example, cold water) is discharged into the bowl portion 4a (drained) and replaced with warm water heated by the heat exchanger 51. In the warm water preparation control, the nozzle 34 does not discharge water toward the user by controlling the flow rate adjustment / flow path switching valve 55. In this way, a warm water preparation operation is performed in which the heat exchanger 51 and the nozzle 34 are made to communicate with each other, the water in the flow path is drained, and warm water is introduced into the flow path (for example, the remaining water is replaced with warm water). By the warm water preparation operation, the discharge of cold water toward the user in the warm water washing operation is suppressed. Note that in this example, the hot water preparation operation is triggered by the detection of the user's seating by the seating detection sensor 31. However, the trigger for the hot water preparation operation may be any signal that can perform the hot water preparation operation before the hot water washing operation. For example, the trigger for the hot water preparation operation may be the detection of the user by the human body detection sensor 32.

[0039] FIG. 3 is a flowchart illustrating the operation of the toilet device according to the embodiment. For example, the control unit 42 drives the heat exchanger and performs the determination control shown in FIG. 3. The determination control determines whether the heat exchanger 51 can be driven (permitted or prohibited) after the determination control. The determination control detects, for example, the presence or absence of water or a water flow in the heat exchanger 51, determines that the heat exchanger 51 can be driven when there is water or a water flow, and determines that the heat exchanger 51 cannot be driven when there is no water or a water flow.

[0040] FIG. 4(a) is a graph illustrating the output of the heat exchanger in the determination control, and FIGS. 4(b) to 4(e) are graphs illustrating the detected temperatures of the temperature sensors in the determination control. In FIGS. 4(a) to 4(e), the horizontal axis represents time. The change in the detected temperature may be, for example, as shown in any of FIGS. 4(b) to 4(e). Note that these are for illustrative and conceptual purposes and are not necessarily the same as the actual ones.

[0041] For example, as shown in FIG. 3, the control unit 42 opens the on-off valve 50 (step S101). The control unit 42 acquires the detected temperature detected by the temperature sensor 52 (step S102). The control unit 42 starts drive control to drive the heat exchanger 51 (step S103). As a result, the heat exchanger 51 becomes on and generates heat.

[0042] When the control unit 42 starts driving the heat exchanger 51 in step S103, it drives the heat exchanger 51 at the second output (100 watts in this example) for up to the first hour at most. For example, as shown in Fig. 4(a), the heat exchanger 51 starts driving at the second output at time tm1. The heat exchanger 51 drives, for example, from time tm1 to time tm2 which is one hour after time tm1.

[0043] As shown in Fig. 3, after step S103, the control unit 42 calculates the change amount (Δt) of the detected temperature detected by the temperature sensor 52 (step S104). That is, the control unit 42 performs control to drive the heat exchanger 51 with the on-off valve 50 open, and calculates the change amount (Δt) of the detected temperature during the driving of the heat exchanger 51.

[0044] The change amount (Δt) of the detected temperature is the change amount from the detected temperature when starting to drive the heat exchanger 51 during the driving of the heat exchanger 51. For example, as shown in Fig. 4(b) etc., at the time tm1 when starting to drive the heat exchanger 51, the detected temperature of the temperature sensor 52 is TH0. The change amount (Δt) of the detected temperature is the absolute value of the difference between the latest detected temperature and the detected temperature (TH0) when starting the control to drive the heat exchanger 51. The latest detected temperature is the latest detected temperature detected by the temperature sensor 52, that is, the current detected temperature. The control unit 42 calculates the change amount (Δt) of the detected temperature for up to the first hour at most from when starting to drive the heat exchanger 51 in step S103.

[0045] Note that the detected temperature (TH0) when starting the control to drive the heat exchanger 51 is not limited to the temperature detected exactly at the same time as the start of the drive control. As long as it is the temperature detected at a timing that can be regarded as the temperature when substantially starting the drive control, the temperature detected before or after the start of the drive control may also be used. In this example, the detected temperature obtained in step S102 of Fig. 3 is used as the detected temperature (TH0) when starting the control to drive the heat exchanger 51. The detected temperature (TH0) when starting the control to drive the heat exchanger 51 may be the detected temperature detected at the same time as or immediately after the drive of the heat exchanger 51.

[0046] For example, when there is water or a water flow in the heat exchanger 51 and warm water is generated by the heat exchanger 51, the detected temperature rises from the temperature at the start of driving the heat exchanger 51. Also, for example, when there is a water flow in the heat exchanger 51, the temperature of the water flowing into the heat exchanger 51 (inlet water temperature) is not necessarily constant and may change (rise or fall) over time.

[0047] The detected temperature detected by the temperature sensor 52 downstream of the heat exchanger 51 is affected by the heat applied by the heat exchanger 51 and the inlet water temperature. For example, when there is a water flow in the heat exchanger 51 and the inlet water temperature rises, the detected temperature may rise from the temperature at the start of driving the heat exchanger 51. For example, when there is a water flow in the heat exchanger 51 and the inlet water temperature drops, the detected temperature may drop from the temperature at the start of driving the heat exchanger 51.

[0048] Therefore, as shown in FIG. 3, when the change amount (Δt) of the detected temperature becomes equal to or greater than a predetermined value (first value) within a predetermined time (first time) from when the control unit 42 starts controlling the driving of the heat exchanger 51 (step S104: Yes), the control unit 42 determines that the heat exchanger 51 can be driven (step S105). That is, the control unit 42 does not prohibit the driving of the heat exchanger 51.

[0049] In this example, the first value is 1°C. That is, in this example, when the detected temperature changes by ±1°C or more from the time tm1, the control unit 42 determines that the heat exchanger 41 can be driven.

[0050] For example, as in the example of FIG. 4(b), the detected temperature may rise from the time tm1 when the driving of the heat exchanger 51 is started, and the change amount (Δt) of the detected temperature may become equal to or greater than the first value from the time tm1 to the time tm2 after the first time. In this case, it is considered that warm water is generated by driving the heat exchanger 51, or there is a water flow in the heat exchanger 51 and the inlet water temperature has risen. That is, it can be detected that there is water or a water flow in the heat exchanger 51.

[0051] For example, as in the example of FIG. 4(c), when the detection temperature decreases from the time tm1 when the heat exchanger is started, there may be a case where the change amount (Δt) of the detection temperature becomes equal to or greater than the first value from the time tm1 to the time tm2 one hour later. In this case, it is considered that there is a water flow in the heat exchanger 51 and the inlet water temperature has decreased. That is, it can be detected that there is water or a water flow in the heat exchanger 51.

[0052] The first value is a positive value, for example, 0.5 °C or more and 30 °C or less. The first hour is, for example, 0.5 seconds or more and 20 seconds or less. In this example, the first hour is 3 seconds, and the determination control detects the presence or absence of a water flow in the heat exchanger 51. By increasing the first hour, for example, the presence or absence of water in the heat exchanger 51 can be detected. Note that the first hour and the first value are not limited to the above, and may be appropriately determined so as to be able to detect the presence or absence of water or a water flow in the heat exchanger 51.

[0053] When the change amount (Δt) becomes equal to or greater than the first value during the first hour from the time tm1, the control unit 42 may end the determination control even before the first hour has elapsed since the time tm1. Further, when the control unit 42 determines that the heat exchanger 41 can be driven (step S105), the on state of the heat exchanger 51 may be continued even after the change amount (Δt) becomes equal to or greater than the first value (for example, after the time tm2).

[0054] For example, when there is no water or water flow that transfers heat in the heat exchanger 51, the change amount (Δt) of the detection temperature does not become equal to or greater than the first value during the first hour. Alternatively, even when water is flowing into the heat exchanger 51 but the inlet water temperature is decreasing, there is a possibility that the change amount (Δt) of the detection temperature does not become equal to or greater than the first value during the first hour. That is, since the increase in temperature due to the heating of the heat exchanger 51 and the decrease in the inlet water temperature are close, it is conceivable that even if heat is added by the heat exchanger 51, the change in the detection temperature of the downstream temperature sensor becomes small. For example, it is conceivable that the temperature increase by the heat exchanger 51 and the decrease in the inlet water temperature are balanced.

[0055] Thus, when the change amount (Δt) does not become equal to or greater than the first value during the first hour from time tm1, it is assumed that there is no water or water flow in the heat exchanger 51, or that the temperature of the water flowing into the heat exchanger is decreasing. In particular, when the incoming water temperature sensor is not provided, it is difficult to detect a decrease in the incoming water temperature.

[0056] Therefore, the control unit 42 executes, for example, steps S106 to S108 shown in FIG. 3. That is, when the change amount (Δt) of the detected temperature does not become equal to or greater than the first value during the first hour after starting the control to drive the heat exchanger 51 (step S104: No), the control unit 42 acquires the detected temperature detected by the temperature sensor 52 (step S106).

[0057] Then, the control unit 42 performs drive stop control to stop the drive of the heat exchanger 51 (step S107). That is, the control unit 42 switches from the on state in which drive power for heat generation is supplied to the heat exchanger 51 to the off state in which the supply of drive power is stopped.

[0058] For example, as shown in FIG. 4(d) or FIG. 4(e), when the change amount (Δt) of the detected temperature is less than the first value between time tm1 and time tm2, the control unit 42 switches the heat exchanger 51 from the on state to the off state at time tm2.

[0059] As shown in FIG. 3, after step S107, the control unit 42 calculates the amount of decrease in the detected temperature detected by the temperature sensor 52. That is, the control unit 42 performs control to stop the drive of the heat exchanger 51 and calculates the amount of decrease (Δtoff) in the detected temperature while the drive of the heat exchanger 51 is stopped.

[0060] The amount of decrease in the detected temperature (Δtoff) is the amount of decrease from the temperature when the drive of the heat exchanger 51 is stopped in the off state of the heat exchanger 51. For example, as shown in FIG. 4(d) etc., at the time tm2 when the drive of the heat exchanger is stopped, the detected temperature of the temperature sensor 52 is TH1. The amount of decrease in the detected temperature (Δtoff) is the absolute value of the difference between the latest detected temperature and the detected temperature (TH1) when the control to stop the drive of the heat exchanger 51 is performed, when the latest detected temperature is lower than the detected temperature (TH1) when the control to stop the drive of the heat exchanger 51 is performed. For example, the control unit 42 calculates the amount of decrease in the detected temperature (Δtoff) for the longest period of up to the second hour from when the drive of the heat exchanger 51 is stopped in step S107.

[0061] Note that the detected temperature (TH1) when the control to stop the drive of the heat exchanger 51 is performed is not limited to the temperature detected exactly at the same time as the drive stop, and may be the temperature detected at a timing that can be regarded as substantially performing the drive stop control of the heat exchanger 51, and may be the temperature detected before or after the drive stop control. In this example, the detected temperature acquired in step S106 of FIG. 3 is used as the detected temperature (TH1) when the control to stop the drive of the heat exchanger 51 is performed. The detected temperature (TH1) when the control to stop the drive of the heat exchanger 51 is performed may be the temperature detected at the same time as or immediately after the drive stop of the heat exchanger 51.

[0062] For example, when there is a water flow in the heat exchanger 51 and the inlet water temperature is decreasing, the detected temperature decreases from the temperature (TH1) when the drive of the heat exchanger 51 is stopped.

[0063] Therefore, as shown in FIG. 3, when the amount of decrease in the detected temperature (Δtoff) becomes equal to or greater than a predetermined value (second value) within a predetermined time (second hour) from when the control unit 42 performs the control to stop the drive of the heat exchanger 51 (step S108: Yes), the control unit 42 determines that the heat exchanger 51 can be driven (step S105). In this case, the control unit 42 may start driving the heat exchanger 51 again.

[0064] Note that, in this example, the second value is 1°C. That is, in this example, when the detected temperature drops by 1°C or more from time tm2, the control unit 42 determines that the heat exchanger 41 can be driven.

[0065] For example, as in the example of FIG. 4(d), the detected temperature drops from the time tm2 when the driving of the heat exchanger 51 is stopped, and there may be a case where the amount of decrease (Δtoff) in the detected temperature becomes equal to or greater than the second value from time tm2 to time tm3, which is the second hour after time tm2. In this case, it is considered that there is a water flow in the heat exchanger 51 and the inlet water temperature has dropped. That is, it can be detected that there is a water flow in the heat exchanger 51.

[0066] On the other hand, when there is no water or water flow in the heat exchanger 51, the detected temperature does not drop or the amount of decrease is small from the temperature (TH1) when the driving of the heat exchanger 51 is stopped. When the amount of decrease (Δtoff) in the detected temperature does not become equal to or greater than the second value within the second hour from the time when the control unit 42 performs the control to stop the driving of the heat exchanger 51 (step S108: No), as shown in FIG. 3, the driving of the heat exchanger 51 is prohibited. That is, for example, even if the user inputs a warm water washing operation for discharging warm water from the nozzle to the operation unit 44, the control unit 42 does not drive the heat exchanger 51.

[0067] For example, as in the example of FIG. 4(e), the detected temperature does not drop from the time tm2 when the driving of the heat exchanger 51 is stopped, and there may be a case where the amount of decrease (Δtoff) in the detected temperature does not become equal to or greater than the second value from time tm2 to time tm3, which is the second hour after time tm2. In this case, it is considered that there is no water or water flow in the heat exchanger 51. That is, it can be detected that there is no water or water flow in the heat exchanger 51. For example, when there is no water in the heat exchanger 51, after the driving of the heat exchanger 51 is stopped, the detected temperature of the temperature sensor may rise as shown in FIG. 4(e) due to natural convection of air. Therefore, in step S108, the control unit 42 determines the amount of decrease instead of the change amount of the detected temperature.

[0068] Thus, by calculating the amount of decrease in the detected temperature during the stop of the operation of the heat exchanger 51, when the temperature of the water flowing into the heat exchanger 51 has decreased, it can be determined that the heat exchanger 51 can be operated.

[0069] Note that the second value is a positive value, for example, 0.5°C or more and 30°C or less. The second time is, for example, 0.5 seconds or more and 20 seconds or less. In this example, the second time is 3 seconds. Note that the second time and the second value are not limited to the above, and may be appropriately determined so as to be able to detect the presence or absence of water or water flow in the heat exchanger 51.

[0070] When the amount of decrease (Δtoff) becomes equal to or greater than the second value during the second time from the time tm2, the control unit 42 may end the determination control even before the second time has elapsed from the time tm2. Further, when the control unit 42 determines that the heat exchanger 41 can be operated (step S105), after the amount of decrease (Δtoff) has become equal to or greater than the second value (for example, before or after the time tm3), the control unit 42 may start operating the heat exchanger 51 again.

[0071] For example, if the heat exchanger is operated when there is no water or water flow inside the heat exchanger, there is a risk of excessive heating. For example, even if the on-off valve is open, there is a possibility that water may not flow into the heat exchanger due to a malfunction. For example, if the heat exchanger is operated when no water is flowing into the heat exchanger, there is a risk of dry burning.

[0072] On the other hand, according to the embodiment, by relying on the detected temperature of the temperature sensor 52 provided downstream of the heat exchanger 51, the heat exchanger 51 can be operated more appropriately. For example, when there is water or water flow in the heat exchanger 51, it can be determined that the heat exchanger 51 can be operated. Also, when there is no water or water flow in the heat exchanger 51, it can be determined that the heat exchanger 51 cannot be operated, and thereafter, the operation of the heat exchanger 51 can be suppressed. Thereby, excessive heating of the heat exchanger 51 can be suppressed. For example, in the warm water washing operation, it is possible to suppress the discharge of high-temperature washing water.

[0073] For example, in a conventional toilet device, a flow rate sensor and an inlet water temperature sensor may be provided. The flow rate sensor detects the flow rate of water flowing through the heat exchanger. The inlet water temperature sensor is provided upstream of the heat exchanger and detects the temperature of the water flowing into the heat exchanger. For example, in such a conventional toilet device, based on the detection result of the flow rate sensor, the presence or absence of water flow inside the heat exchanger is detected.

[0074] On the other hand, in the toilet device according to the embodiment, it is possible to determine whether or not to drive the heat exchanger 51 according to the presence or absence of water or water flow inside the heat exchanger 51 without using a flow rate sensor or an inlet water temperature sensor. Since it is not necessary to provide a flow rate sensor or an inlet water temperature sensor, the manufacturing cost can be suppressed. For example, an inexpensive toilet device can be provided.

[0075] Also, in the determination control, when the change amount (Δt) of the detected temperature during the first hour does not become equal to or greater than the first value due to a decrease in the inlet water temperature, the decrease amount (Δtoff) of the detected temperature during the stop of the drive of the heat exchanger 51 may become equal to or greater than the first value.

[0076] For example, the second value may be equal to or less than the first value. Thereby, when the change amount of the detected temperature does not become equal to or greater than the first value during the first hour in the determination control, it becomes easier to detect that the temperature of the water flowing into the heat exchanger is decreasing. For example, the accuracy of the determination is improved.

[0077] The output of the heat exchanger 51 in the determination control may be smaller than the output of the heat exchanger 51 in the normal operation (for example, the warm water washing operation). For example, as described above, the control unit can perform warm water washing control in which the heat exchanger 51 is driven at a first output (for example, 1200 watts) and the water warmed by the heat exchanger 51 is discharged from the nozzle 43 toward the local part of the user. In the determination control, the control unit 42 drives the heat exchanger 51 at a second output (for example, 100 watts) smaller than the first output. By reducing the output of the heat exchanger 51 in the determination control, even if there is no water in the heat exchanger 51, it is possible to suppress the damage caused to the heat exchanger 51 by dry burning in the determination control.

[0078] As described above, in the determination control, when step S108 is No, it is considered that there is no water or water flow in the heat exchanger 51. In this case, even if the drive of the heat exchanger 51 is stopped, the user may not notice that there is a problem with the water supply.

[0079] Therefore, in the determination control, when the decrease amount (Δtoff) does not become equal to or greater than the second value during the second hour after the drive of the heat exchanger 51 is stopped (step S108: No), if the user inputs a cleaning operation for discharging water to the nozzle 34, the control unit 42 drives the nozzle. For example, the nozzle 34 is advanced and retracted with respect to the bowl portion 4a. In this way, even when the drive of the heat exchanger 51 is stopped, by driving the nozzle 34, it is possible to notify the user that there is a problem with the water supply due to some factor.

[0080] Further, for example, the determination control described with reference to FIG. 3 is executed when the user sits on the toilet seat. Thereby, when the user inputs a warm water washing operation to the operation unit 44 after sitting down, the heat exchanger 51 can be appropriately driven. For example, dry firing can be suppressed.

[0081] For example, when the control unit 42 detects the user's sitting by the sitting detection sensor 31, it starts the determination control. Further, the control unit 42 controls the flow rate adjustment / flow path switching valve 55 to make the water discharge hole of the nozzle 34 and the heat exchanger 51 communicate with water during the determination control. Thereby, when there is a water flow in the heat exchanger 51 during the determination control, the water flowing out from the heat exchanger 51 is discharged from the nozzle 34. That is, the determination control and the water drainage for warm water preparation can be performed in parallel and simultaneously.

[0082] It is also conceivable to perform determination control during the execution of the warm water washing operation. However, in this case, if the driving of the heat exchanger is stopped during the execution of the determination control or the output of the heat exchanger is low, there is a possibility that the water cannot be sufficiently warmed during the execution of the determination control. For this reason, if water is discharged toward the user during the execution of the determination control, there is a possibility that the unwarmed water will be discharged toward the user. Further, it is also conceivable to perform the determination control and the waste water discharge in parallel immediately before discharging water toward the user in the warm water washing operation. In this case, however, the timing of the water discharge toward the user will be delayed.

[0083] On the other hand, in the embodiment, as described above, when there is a water flow in the heat exchanger during the determination control, the determination control and the waste water discharge can be performed in parallel when the user sits down. Thereby, for example, in the warm water washing operation, water can be immediately discharged from the nozzle, and the usability can be further improved. However, in the embodiment, the determination control may be executed before or after the warm water preparation (waste water discharge).

[0084] The embodiment may include the following configuration. (Configuration 1) An instantaneous heat exchanger, An on-off valve that opens and closes a flow path of water flowing through the heat exchanger, A temperature sensor provided downstream of the heat exchanger, A control unit that acquires a detected temperature detected by the temperature sensor and controls the heat exchanger, and the control unit drives the heat exchanger with the on-off valve open and calculates a change amount of the detected temperature during the driving of the heat exchanger, when the change amount does not become equal to or greater than a first value within a first hour from when the driving of the heat exchanger is started, the driving of the heat exchanger is stopped and a decrease amount of the detected temperature during the stop of the driving of the heat exchanger is calculated, A toilet device characterized in that determination control is performed to determine that the heat exchanger can be driven when the decrease amount becomes equal to or greater than a second value within a second hour from when the driving of the heat exchanger is stopped. (Configuration 2) The toilet device according to Configuration 1, wherein the second value is equal to or less than the first value. (Configuration 3) A toilet seat, A seating detection sensor that detects the user's seating on the toilet seat, A nozzle that discharges the water flowing out from the heat exchanger, further comprising: When the control unit detects the user's seating by the seating detection sensor, the control unit starts the determination control and enables water to flow through the nozzle and the heat exchanger. The toilet device according to Configuration 1 or 2, characterized in that. (Configuration 4) further comprising a nozzle that discharges the water flowing out from the heat exchanger, In the determination control, when the amount of decrease does not become equal to or more than the second value during the second time from when the driving of the heat exchanger is stopped, when the control unit receives an instruction to discharge water to the nozzle, the control unit drives the nozzle. The toilet device according to any one of Configurations 1 to 3, characterized in that. (Configuration 5) further comprising a nozzle that discharges the water flowing out from the heat exchanger, The control unit can perform warm water washing control in which the water heated by the heat exchanger is discharged from the nozzle toward the user's local area by driving the heat exchanger with a first output, In the determination control, the control unit drives the heat exchanger with a second output smaller than the first output. The toilet device according to any one of Configurations 1 to 4, characterized in that.

[0085] The embodiments of the present invention have been described above. However, the present invention is not limited to these descriptions. Regarding the above-described embodiments, those in which those skilled in the art make appropriate design changes are also included in the scope of the present invention as long as they have the features of the present invention. For example, the shape, dimensions, material, arrangement, installation form, etc. of each element are not limited to those illustrated and can be changed as appropriate. In addition, each element included in each of the above-described embodiments can be combined as far as technically possible, and combinations thereof are also included in the scope of the present invention as long as they include the features of the present invention.

Explanation of Signs

[0086] 2: Toilet device 4: Western-style toilet bowl 4a: Bowl part 10: Hygienic washing device 12: Main body part 14: Toilet seat 16: Toilet lid 20: Casing 21: Flow path 30: Washing water supply part 31: Seating detection sensor 32: Human body detection sensor 34: Nozzle 35: Water discharge part 35a, 35b, 35c: Water discharge holes 36: Nozzle motor 41: Heat exchanger 42: Control part 43: Nozzle 44: Operation part 50: On-off valve 51: Heat exchanger 52: Temperature sensor 53: Vacuum breaker 55: Flow regulation / flow path switching valve

Claims

1. An instantaneous heat exchanger, a switching valve for opening and closing a water flow path through which water flows through the heat exchanger, a temperature sensor provided downstream of the heat exchanger, a control unit that acquires a detected temperature detected by the temperature sensor and controls the heat exchanger, comprising: the control unit, drives the heat exchanger with the switching valve open and calculates a change amount of the detected temperature during driving of the heat exchanger, when the change amount does not become equal to or greater than a first value during a first time period from when driving of the heat exchanger is started, stops driving of the heat exchanger and calculates a decrease amount of the detected temperature during stoppage of driving of the heat exchanger, when the decrease amount becomes equal to or greater than a second value within a second time period from when driving of the heat exchanger is stopped, determines that driving of the heat exchanger is possible, and performs determination control. A toilet device characterized by this.

2. The toilet device according to claim 1, wherein the second value is equal to or less than the first value.

3. A toilet seat, a seating detection sensor that detects a user's seating on the toilet seat, a nozzle that discharges water flowing out from the heat exchanger, further comprising: the control unit starts the determination control when detecting a user's seating by the seating detection sensor, and enables water to flow through the nozzle and the heat exchanger. The toilet device according to claim 1, characterized by this.

4. further comprising a nozzle that discharges water flowing out from the heat exchanger, when the decrease amount does not become equal to or greater than the second value during the second time period from when driving of the heat exchanger is stopped in the determination control, the control unit drives the nozzle when receiving an instruction to discharge water to the nozzle. The toilet device according to claim 1, characterized by this.

5. further comprising a nozzle that discharges water flowing out from the heat exchanger, the control unit can perform warm water washing control in which water heated by the heat exchanger is discharged to the nozzle toward a user's local area by driving the heat exchanger at a first output, in the determination control, the control unit drives the heat exchanger at a second output smaller than the first output. The toilet device according to claim 1, characterized by this.

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