JPH09105660A - Water level detector for bathtub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water level detector for bathtub which makes it possible to reduce the number of components and simplify the execution by detecting the water level in a bathtub by utilizing a thermistor necessary to detect the temperature. SOLUTION: The water level detector for bathtub comprises a thermistor 23 and temperature detecting means 24 for energizing the thermistor 23 to detect the temperature of hot water in a bathtub by the change of the resistance value of the thermistor 23. The means 24 is so constituted as to make it possible to switch between a temperature detecting mode for detecting the temperature of the hot water in the bathtub and a water level detecting mode in which the thermistor 23 is heated by applying a current and whether there is a predetermined water level of hot water in the bathtub or not is detected based on the change of the resistance value of the thermistor 23 at that time. The detector also comprises a switching means 27 for switching between the temperature detecting mode and the water level detecting mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level detecting device for a bath which is provided with a thermistor and a temperature detecting means for detecting the temperature of hot and cold water in the bath by changing the resistance value of the thermistor by energizing the thermistor.

[0002]

2. Description of the Related Art In a hot water supply device for a bath or the like, it is necessary to detect the temperature of hot and cold water in the bathtub when filling or reheating the bathtub. Conventionally, the above-mentioned thermistor is used. In general, the temperature of hot water is detected. In addition, it is necessary to detect the amount of hot water in the bathtub, that is, the water level. Conventionally, for this water level detection, the water level in the bathtub has been detected using a pressure sensor, a water level sensor, or the like.

[0003]

Therefore, when it is necessary to detect the temperature and water level of the hot water in the bathtub, conventionally, a thermistor dedicated to temperature detection and sensors dedicated to water level detection are separately required. I was there. The purpose of the present invention is
The thermistor necessary for temperature detection can also be used to detect the water level in the bathtub, thereby eliminating the previously required sensor for exclusive use of water level and the parts attached to the sensor Another object of the present invention is to provide a water level detecting device for a bathtub capable of reducing the number of points and simplifying the construction.

[0004]

In order to achieve this object, according to the invention described in claim 1, a temperature detection for detecting the temperature of hot and cold water in the bathtub by energizing the thermistor and changing the resistance value of the thermistor. The means is a temperature detection mode for detecting the temperature of hot and cold water in the bath tub, and the thermistor is energized to self-heat, and whether there is hot or cold water at a predetermined water level in the bath based on the change in the resistance value of the thermistor It is configured to be switchable to a water level detection mode that detects whether or not
Further, since the switching means for switching between the temperature detection mode and the water level detection mode is provided, the temperature detection means is set to the temperature detection mode by this switching means to detect the temperature of the hot water in the bathtub as in the conventional case. Of course, you can use this thermistor as it is by switching the temperature detection means to the water level detection mode.
The water level in the bathtub can also be detected.

That is, in this water level detection mode, the temperature detection means energizes the thermistor to cause the thermistor to self-heat. Therefore, if there is no hot water in the bathtub, or if there is hot water but the position of the thermistor is not reached, the resistance value of the thermistor will change significantly due to this high temperature due to self-heating, If there is hot and cold water at the position where the temperature of the thermistor is increased, the thermistor that self-heats will be cooled by the hot and cold water and will approach the temperature of the hot water. The water level in the bathtub is detected as a reference.

Therefore, if only the position of the thermistor is taken into consideration, the thermistor necessary for temperature detection can be used as it is, and the temperature detection means can also be used to detect the water level in the bathtub. It is possible to reduce the number of parts by eliminating the required sensors for water level detection and accessory parts, and it is possible to reduce the complexity of the construction as the number of parts is reduced.

According to the second aspect of the present invention, there is provided a water heater having a heat exchanger for heating the water from the water supply passage by the combustion of the burner and supplying the water to the hot water supply passage, and for supplying additional hot water to the bathtub. The hot water supply passage is provided with a reheating passage connected in communication and hot water supply control means for controlling the hot water supply device, and the hot water supply control means switches the switching means to a water level detection mode before the hot water supply to the bathtub is executed. Since it is configured as described above, it is possible to detect the water level in the bathtub by the thermistor or the temperature detecting means prior to the execution of the additional heating hot water, for example, supplying hot water to an empty bathtub without hot water. It is possible to avoid such a dangerous situation.

According to the third aspect of the present invention, when it is detected that there is no hot water of a predetermined water level in the bath in the water level detection mode, the hot water supply control means is configured to activate the alarm means. Therefore, although the reheating hot water is supplied in accordance with the reheating command, it can be surely known that there is no hot water of a predetermined water level in the bathtub, and the subsequent treatment can be promptly performed.

According to the invention described in claim 4, when it is detected that there is no hot water of a predetermined water level in the bathtub in the water level detection mode, the hot water supply control means stops the additional hot water supply. Therefore, it is possible to reliably prevent the situation where hot water is supplied to an empty bathtub, and when the alarm means is activated as described above, there is no hot water of a predetermined water level and at the same time, additional hot water is supplied. You can also know the stop.

According to the fifth aspect of the invention, when it is detected in the water level detection mode that hot water of a predetermined water level is present in the bathtub, the hot water supply control means switches the switching means to the temperature detection mode. Since it is constructed, the temperature of the hot water can be detected as usual by the thermistor or the temperature detecting means. Therefore, for example, when the hot water in the bathtub is so hot that it does not need to be reheated, it is possible to perform various controls such as automatically stopping the reheating or executing completion control of the reheating. it can.

According to the sixth aspect of the invention, since the thermistor is attached to the bathtub, there is no restriction on the attachment of the thermistor as compared with the case where the thermistor is attached to, for example, a hot water supply pipe to the bathtub. In other words, if you try to detect the water level by attaching it to a hot water supply pipe, etc., it is a condition that part of the hot water supply pipe is located above the bathtub, but there is no such restriction at all, The temperature detection and the water level detection are more reliable than in the case of attachment.

According to the invention as set forth in claim 7, since the thermistor is arranged inside the bus adapter, the bus adapter not only acts as a protection member for the thermistor but is also excellent in appearance. It becomes a thing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water level detecting device for a bath according to the present invention will be described with reference to the drawings. FIG. 1 shows an outline of the whole hot water supply device for a bath, which includes a fin-tube type heat exchanger 3 for heating water supplied from a water supply passage 1 and supplying it to the hot water supply passage 2, and the heat exchanger 3. A water heater A is constituted by a gas burner 4 for heating, and the water supply passage 1 is provided with a water amount sensor 5 for detecting a water flow amount and a water supply thermistor 6 for detecting a water supply temperature.
A hot water supply thermistor 7 for detecting the hot water supply temperature is provided.

In the hot water supply passage 2, a hot water supply passage 9 for supplying hot water after heating by the heat exchanger 3 to the bathtub 8 to fill the hot water.
Are connected to each other, the other end of the water filling passage 9 is connected to the inside of the bathtub 8, a bus adapter 10 is attached to the front surface of the opening, and the hot water supply passage 2 is filled with water. A common hot water supply passage 12 having a general hot water supply tap 11 such as a calan or a shower is communicatively connected in a state where a part of the passage 9 is shared. A check valve 13 and an electromagnetic water proportional valve 1 from the upstream side are provided in the common portion of the general hot water supply passage 12 and the hot water filling passage 9.
4. A mixing thermistor 15 is provided, an interrupt sensor 16 is provided in the general hot water supply passage 12, and an electromagnetic water filling valve 17 and a vacuum breaker 18 are provided in the hot water supply passage 2.

In the common portion of the general hot water supply passage 12 and the water filling passage 9, a bypass passage 19 connected to the water supply passage 1 is connected to a portion between the check valve 13 and the water proportional valve 14. ,
An electromagnetic mixing valve 20 is provided at the connection point. Further, the hot water supply passage 2 is connected to a reheating passage 21 for supplying high-temperature hot water of about 93 ° C., and the other end of the reheating passage 21 is located downstream of the hot water filling valve 17 at the vacuum breaker. It is connected to the hot water line 9 upstream of 18. That is, the additional heating passage 21 for supplying high-temperature hot water for additional heating hot water is communicatively connected to the bathtub 8 while sharing a part of the hot water filling passage 9, and the additional heating passage 21 has
An electromagnetic type reheating valve 22 is provided.

As shown in detail in FIG. 2, a thermistor 23 for detecting the hot water temperature is attached to the bath tub 8, and the thermistor 23 is inside the bus adapter 10 and in the hot water filling passage 9 and the reheating passage 21. It is arranged at a position directly above the opening to the bathtub 8. As shown in FIG. 3, the thermistor 23 is composed of a thermistor element 23a and a thin holding member 23b made of stainless steel or copper having a small heat capacity for holding the thermistor element 23a at its tip, and as shown in FIG. The hot water supply control means H mainly including a microcomputer is connected to the temperature detection means 24 included in the hot water supply control means H to energize the thermistor 23 to change the resistance value of the thermistor 23. It is configured to detect the temperature of hot water. The temperature detecting means 24 is provided with a temperature detecting circuit 25 and a water level detecting circuit 26, and further as a switching means for selectively switching between the temperature detecting circuit 25 and the water level detecting circuit 26. The mode switching circuit 27 is also provided.

When the temperature detecting means 24 is switched to the temperature detecting circuit 25 side by the mode switching circuit 27, the temperature detecting mode is set, and the thermistor 23 is energized with a small amount of current for temperature detection and the thermistor 2 is activated.
The temperature of the hot water in the bathtub 8 is detected based on the change in the resistance value of No. 3. That is, in this temperature detection mode, the resistance value of the thermistor changes with the temperature of the hot water, and as shown in (a) of FIG. 5, the higher the temperature T of the hot water, the lower the voltage V and the temperature T becomes. Since the lower the voltage, the higher the voltage V, the temperature of the hot water can be detected by the value of the A / D input voltage V.

Further, by the mode switching circuit 27,
When the temperature detection means 24 is switched to the water level detection circuit 26 side, the water level detection mode is set, and a large amount of current is supplied to the thermistor 23 to self-heat. Therefore, when there is no hot water in the bathtub 8 or when the hot water has not reached the installation position of the thermistor 23, the thermistor 23 becomes extremely hot due to self-heating and the resistance value changes significantly. Then, as shown in (b) of FIG. 5, if the voltage V becomes extremely low and there is hot water in the bathtub 8, the thermistor 23 that self-heats is cooled by the hot water to approach the temperature of the hot water, and the voltage V becomes high. Because it becomes higher, A
/ The water level of the hot water depends on the value of the input voltage V
It is possible to detect whether or not the arrangement position 3 has been reached.

Further, a fuel gas supply passage 28 for supplying a fuel gas is connected to the gas burner 4, and the fuel gas supply passage 28 is provided with an electromagnetic disconnect valve 29 for disconnecting the supply of the fuel gas. An electromagnetic proportional valve 30 with a governor and an electromagnetic safety valve 31 are provided, and the gas burner 4 further includes an igniter 3 for ignition.
2 and a flame rod 33 for detecting ignition, and a fan 34 for supplying primary air and secondary air for combustion to the gas burner 4 as well as air for cooling.

The hot water supply apparatus having such a configuration is constructed so that its operation is controlled by the hot water supply control means H, and the main remote controller Ra and the bathroom remote controller Rb for giving a control command to the hot water supply control means H are wireless or wireless. It is connected by wire. The main remote control Ra has an operation switch 35 for instructing start and stop of hot water supply, a hot water filling switch 36, a temperature setting switch 37 for setting a general hot water supply temperature, and the bathroom remote control Rb has the same operation switch 3 as well.
8, a water filling switch 39, a water filling temperature setting switch 40 for setting the water filling temperature, a reheating switch 41, an alarm lamp 42 as an alarm means, and the like are provided.

Next, the control operation of the hot water supply device will be described. When the operation switch 35 of the main remote controller Ra or the operation switch 38 of the bathroom remote controller Rb is turned on, the hot water can be supplied. In this hot water-supplyable state, when the hot water tap 11 is opened and water of a set amount or more flows through the water supply passage 1, the water amount sensor 5 detects and drives the fan 34 to rotate and opens the safety valve 31. Intermittent valve 29
The valve is opened, the electromagnetic proportional valve 30 is set to the warm ignition position, the igniter 32 ignites, and the flame rod 33 confirms the ignition.

At this time, the hot water supply control means H causes the water amount sensor 5 to
On the basis of the detected water amount by the water supply thermistor 6 and the water temperature detected by the water supply thermistor 6, the required gas amount is calculated from the temperature set by the temperature setting switch 37 of the main remote controller Ra, the opening of the electromagnetic proportional valve 30 is adjusted, and the mixing valve 20 And the rotation speed of the fan 34 are also adjusted. In this way,
A part of the water from the water supply passage 1 is heated by the heat exchanger 3 and mixed with the water from the bypass passage 19, and the hot water tap 1
In addition, the opening of the electromagnetic proportional valve 30 and the opening of the mixing valve 20 are finely adjusted so that the temperature detected by the mixing thermistor 15 reaches the set temperature, and the gas burner 4 is maximized. When the temperature detected by the mixing thermistor 15 is still below the set temperature even after burning, the water proportional valve 14 is throttled to control the temperature to reach the set temperature.

When the hot water filling switch 36 of the main remote controller Ra or the hot water filling switch 39 of the bathroom remote controller Rb is turned on while the hot water can be supplied as described above, the hot water filling mode is set and hot water is supplied to the bathtub 8 to execute the hot water supply in the bathroom. From the temperature set by the hot water filling temperature setting switch 40 of the remote controller Rb, as in the case of general hot water supply, the hot water supply control means H calculates the required gas amount and adjusts the opening of the electromagnetic proportional valve 30 and the like, and the mixing thermistor. A minute adjustment is made so that the temperature detected by 15 becomes the set temperature. When the hot water tap 11 is opened during this hot water filling mode, the hot water filling valve 17 is closed based on the detection of the interrupt sensor 16, the above-mentioned general hot water supply is executed, and the hot water filling is restarted after the end of the general hot water supply.

In the state where the hot water can be supplied as described above, the bathroom remote control R
When the additional heating switch 41 of b is turned on, the additional heating mode is set. In the reheating mode, as shown in FIG. 6, the temperature detecting means 24 is switched to the water level detecting mode by turning on the operation switch 35 of the main remote controller Ra or the operation switch 38 of the bathroom remote controller Rb.
When the reheating switch 41 is turned on, it is detected whether or not there is hot water at a predetermined water level in the bathtub 8. If there is no hot water of a predetermined water level, the reheating switch 41 is turned off and the alarm lamp 42
Is turned on for a certain period of time to notify that there is no hot water at a predetermined water level in the bathtub 8. If there is hot water having a predetermined water level, the temperature detecting means 24 is switched to the temperature detecting mode to detect the temperature of the hot water in the bath 8. If the detected temperature is high enough not to require additional heating water, the additional heating switch 41 is set to OF.
If F is required and additional hot water supply is required, additional hot water supply is started.

In this additional hot water supply, the hot water supply control means H uses the required gas based on the amount of water detected by the water amount sensor 5 and the temperature of water detected by the water supply thermistor 6 so that the temperature detected by the hot water supply thermistor 7 will be about 93 ° C. The amount is calculated, the opening of the electromagnetic proportional valve 30 is adjusted, the rotation speed of the fan 34 is set, and the opening of the electromagnetic proportional valve 30 is finely adjusted based on the temperature detected by the hot water supply thermistor 7. When the hot-water tap 11 is opened during this hot-water supply, the interrupt of the general hot-water supply is executed based on the detection of the interrupt sensor 16, and the hot-water supply hot-water supply is restarted after the end of the general hot-water supply.

[Other Embodiment] In the above-described embodiment, the hot water supply control means (H) has a configuration in which the mode switching circuit 27 of the temperature detection means (24) is automatically switched. The circuit 27 can also be configured to be manually switched. Further, the temperature detection means 24 is switched to the water level detection mode by turning on the operation switch 35 of the main remote control Ra or the bathroom remote control Rb, but the water level detection mode is turned on by turning on the reheating switch 41. It can also be configured to switch.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an entire bath water heater.

FIG. 2 is a sectional view of the main part of the bathtub.

[Fig. 3] Enlarged view of the thermistor for temperature detection

FIG. 4 is a circuit diagram of temperature detecting means.

FIG. 5 is a graph showing the relationship between the temperature change of the thermistor and the voltage.

FIG. 6 is a flow chart showing an operation at the time of additional hot water supply.

[Explanation of symbols]

 1 Water Supply Channel 2 Hot Water Supply Channel 3 Heat Exchanger 4 Burner 8 Bathtub 10 Bus Adapter 21 Reheating Path 23 Thermistor 24 Temperature Detection Means 27 Switching Means 42 Warning Means A Water Heater H Hot Water Supply Control Means

Claims (7)

[Claims] 1. A thermistor (23) and temperature detection means (24) for detecting the temperature of hot and cold water in the bathtub (8) by energizing the thermistor (23) and changing the resistance value of the thermistor (23). A water level detecting device for a bathtub, wherein the temperature detecting means (24) detects a temperature of hot and cold water in the bath (8), and the thermistor (2).
3) energize to cause self-heating, and switches to a water level detection mode that detects whether or not there is hot water at a predetermined water level in the bathtub (8) based on the change in the resistance value of the thermistor (23) at that time. Switching means (2) configured to be possible and switching between the temperature detection mode and the water level detection mode
7) A water level detecting device for a bathtub provided. 2. A water heater (A) having a heat exchanger (3) which heats water from the water supply passage (1) by combustion of a burner (4) and supplies it to the hot water supply passage (2), and the bathtub (A). 8) is provided with a hot water supply passage (21) connected to the hot water supply passage (2) for additional hot water supply and hot water supply control means (H) for controlling the water heater (A). (H) is the switching means (2) before the hot water is supplied to the bathtub (8).
The water level detecting device for a bathtub according to claim 1, wherein 7) is switched to a water level detecting mode. 3. A bathtub (8) in the water level detection mode
The water level detecting device for a bathtub according to claim 2, wherein the hot water supply control means (H) is configured to activate an alarm means (42) when it is detected that there is no hot water of a predetermined water level inside. 4. The bathtub (8) in the water level detection mode.
The water level detecting device for a bathtub according to claim 2 or 3, wherein the hot water supply control means (H) is configured to stop the additional hot water supply when it is detected that there is no hot water of a predetermined water level inside. 5. A bathtub (8) in the water level detection mode
The water level of the bathtub according to claim 3 or 4, wherein the hot water supply control means (H) is configured to switch the switching means (27) to a temperature detection mode when it is detected that there is hot water at a predetermined water level inside. Detection device. 6. A water level detecting device for a bathtub according to claim 1, 2, 3, 4 or 5, wherein the thermistor (23) is attached to the bathtub (8). 7. A water level detecting device for a bathtub according to claim 6, wherein said thermistor (23) is arranged inside a bus adapter (10).