JPH07160302A - Safety device of hot water circulation processor - Google Patents

Abstract

PURPOSE:To securely prevent a heater from entering an abnormal heating state by detecting the switching function of a heater control relay before the heater causes abnormal heating. CONSTITUTION:A controller 8 performs ON-OFF control over a heater control contact Xa on the basis of the detection signal from a temperature sensor 19. Further, it is judged whether or not the controller 8 places the switching mechanism for the heater control contact Xa in normal ON-OFF operation. When it is judged that the operation is abnormal, the controller 8 turns ON a ground contact Xa1 to forcibly ground the heater 2 and turns ON a leakage prevention plug 1. Therefore, the power supply to the heater 2 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device in a hot water circulation treatment device.

[0002]

2. Description of the Related Art Heretofore, there has been proposed a hot water circulating treatment device for circulating hot water in a bath for sterilizing and purifying and further heating. In this hot water circulation treatment device, a heater is used to heat the circulating hot water, and this heater is turned on / off by a heater control relay. Then, the microcomputer or the like turns on / off the heater control relay based on a detection signal from a temperature sensor or the like to detect the temperature of the circulating hot water, whereby the circulating hot water is controlled to a predetermined temperature.

[0003]

However, if the heater control contact relay fails for some reason, there is a risk that the ON / OFF control of the heater control relay by the microcomputer may be disabled. For this reason, if the heater control relay becomes uncontrollable when it is in the ON state, the heater control relay remains in the ON state even if the microcomputer tries to control the heater control relay in the OFF state.
It remains in the state. In this state, the heating temperature of the heater rises to an abnormal temperature, and the devices around the heater receive high heat, which may cause thermal damage to those devices. Therefore, when the heating temperature of the heater becomes an abnormal temperature, the temperature may be detected by the temperature sensor, and the microcomputer or the like may stop the power supply of the heater based on the detected temperature. However, this method cannot directly and positively detect the abnormality of the heater control relay. In other words, the heater cannot be detected before the abnormal heating occurs, but only after the abnormal heating is detected, the abnormal heating of the heater cannot be predicted, and the reliability cannot be reliably prevented. there were.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and its object is to switch the function of the heater control relay before the heater causes abnormal heating. By detecting
An object of the present invention is to provide a safety device in a hot water circulation treatment device that can reliably prevent abnormal heating of a heater.

[0005]

In order to solve the above problems, the invention according to claim 1 is directed to a temperature control means for detecting the temperature of the heater, and a heater control relay based on a detection signal from the temperature detection means. ON / OFF control of the heater, judgment means for judging whether the heater control relay is normally ON / OFF operation, and forcibly turning on the heater based on the detection signal from the judgment means. The gist of the present invention is to include ground fault means for causing a ground fault and power supply stop means for detecting the ground fault by the ground fault means and stopping the power supply to the heater.

The invention according to claim 2 is a temperature detecting means for detecting the temperature of the heater, a heater control means for ON / OFF controlling the heater control relay based on a detection signal from the temperature detecting means, It is provided with a judging means for judging whether or not the heater control relay is normally ON / OFF operated, and a breaking means for cutting off a power supply path to the heater based on a detection signal from the judging means. It is what

[0007]

In the invention according to claim 1 thus constructed, the heater control relay is ON / OFF controlled based on the detection signal from the temperature detecting means. Then, the determining means determines whether or not the heater control relay is normally ON / OFF-operated, and if it is determined to be abnormal, the heater is forcibly grounded by the ground fault means. The power supply stopping means stops the power supply to the heater.
Therefore, when the switching function of the heater control relay is impaired, the heater will not cause abnormal heating.

Further, in the invention according to claim 2, the heater control relay is ON / OFF controlled based on the detection signal from the temperature detecting means. Then, by the judging means,
It is determined whether or not the heater control relay is normally ON / OFF-operated, and if it is determined to be abnormal, the power supply cutoff means cuts off the power supply path to the heater. Therefore, when the switching function of the heater control relay is impaired, the heater will not cause abnormal heating.

[0009]

【Example】

(First Embodiment) A first embodiment in which the present invention is embodied in a hot water circulation treatment device installed in a bathroom will be described below with reference to FIGS.

As shown in FIG. 1, a 100 V AC heater power source has a leakage prevention plug 1 as a power supply stopping means.
A heater 2 for heating the circulating hot water is connected via the heater 2, and the heater 2 heats the warm water circulated from the bath to the hot water circulating treatment device. The earth leakage prevention plug 1 stops the power supply to the heater 2 when a ground fault is detected.

Between the leakage prevention plug 1 and the heater 2,
The heater control contact Xa, which is a normally open contact, is connected, and the heater 2 is controlled by turning on / off the normally open contact. Also,
A series circuit of resistors 3 and 4 is connected in parallel between the output terminals of the leakage prevention plug 1. A ground fault contact Xa, which is a normally open contact, is provided between the connection point of the resistors 3 and 4 and the ground terminal E.
1 is connected.

A resistor 6 and a parallel circuit of the light emitting diodes 9 and 10 of the photocoupler 7 are connected between the output terminals of the earth leakage prevention plug 1, and the light emitting diodes 9 and 10 positive and negative AC waves from the heater power source. The signal is transmitted to the phototransistor 11 that constitutes the photocoupler 7. The collector terminal of the phototransistor 11 is connected to the DC5V power supply terminal via the resistor 12, and is also connected to the controller 8 as the control means and the determination means. The emitter terminal of the phototransistor 11 is connected to the substrate ground. A capacitor 13 is connected between the collector terminal and the emitter terminal of the transistor 11.

When the heater control contact Xa is closed, a minute current limited by the limiting resistor 6 flows to the light emitting diodes 9 and 10 of the photocoupler 7 and a signal is transmitted to the phototransistor 11, so that the phototransistor 11 is activated. The transistor 11 is turned on. Therefore, the voltage between the collector terminal and the emitter terminal of the phototransistor 11 becomes the L voltage (about 0 V), and the L voltage is input to the controller 8. On the contrary, when the heater control contact Xa is opened, the phototransistor 11 is turned off,
When the voltage between the collector terminal and the emitter terminal of the phototransistor 11 becomes the H voltage (5V), the H voltage is input to the controller 8.

The controller 8 is connected to the base terminal of a switching transistor (hereinafter referred to as SW transistor) 15 via a resistor 14, and a resistor 16 is connected between the base terminal and the emitter terminal.
The emitter terminal of the SW transistor 15 is connected to the substrate ground. On the other hand, the collector terminal of the SW transistor 15 is connected to a DC12V power supply terminal via a drive coil 17 for controlling the opening / closing of the heater control contact Xa. Then, when the drive coil 17 is excited by the control signal from the controller 8, the heater control contact X
a is put in.

A protection diode 18 for preventing a back electromotive force generated when the drive coil 17 is turned off is connected in parallel to both terminals of the drive coil 17. In this embodiment, the heater control contact Xa and the drive coil 17 constitute a heater control relay.

Further, the controller 8 is provided with a temperature sensor 19 as a temperature detecting means arranged near the heater 2.
Are connected. Then, the controller 8 sets a predetermined voltage to S based on the circulating hot water detection temperature detected by the temperature sensor 19.
The SW transistor 15 is applied to the base terminal of the W transistor 15 to control ON, and conversely, the application of the predetermined voltage is released to control the SW transistor 15 to OFF. That is, by this control, the heater 2 is turned ON / OFF.
F is controlled, and the circulating hot water is controlled to a predetermined temperature.

Further, the controller 8 is connected to the base terminal of the SW transistor 21 via the resistor 20, and the resistor 22 is connected between the base terminal and the emitter terminal. The emitter terminal of the SW transistor 21 is connected to the substrate ground. On the other hand, SW transistor 2
The collector terminal of No. 1 is connected to a power supply terminal of DC 12V through a drive coil 23 for controlling the opening / closing of the ground fault contact Xa1. Then, when the drive coil 23 is excited by the control signal from the controller 8, the ground fault control contact Xa1 is turned on.

A protection diode 24 for preventing a counter electromotive force generated when the drive coil 23 is turned off is connected in parallel to both terminals of the drive coil 23. In this embodiment, by the ground fault contact Xa1 and the drive coil 23,
A ground fault relay as a ground fault means is configured.

When the L voltage is input from the collector terminal of the phototransistor 11 while the predetermined voltage is not applied to the base terminal of the SW transistor 15, the controller 8 applies the predetermined voltage to the SW transistor 21. Apply and turn on the ground contact Xa1. That is, although the controller 8 opens the heater control contact Xa and controls the heater 2 to be OFF,
Is operating, it is determined that the heater 2 is in an abnormal state and the heater power is forcibly grounded, and the leakage prevention plug 1 is operated to stop the power supply to the heater 2.

The controller 8 has an alarm buzzer 25.
And the display device 26 are connected, and the controller 8 is connected to the heater 2
When it is determined that the abnormal condition has occurred, the alarm buzzer 25 is turned on and the abnormal condition is displayed on the display 26.

When the controller 8 determines that the heater 2 is abnormal, power is supplied to not only the heater 2 but also other load devices such as a pump for circulating hot water and a UV lamp for sterilizing hot water. Be stopped.

Next, the operation of the hot water circulation treatment device configured as described above will be described with reference to the flow charts of FIGS. 2 shows the operation of the entire hot water circulation processing device, and FIG. 3 shows the self-check operation for the heater control contact Xa.

First, the operation of the entire hot water circulation processing device will be described. As shown in FIG. 2, initial setting such as temperature setting of circulating hot water is performed in a state where power is supplied to the hot water circulating device in step 1 (hereinafter, step is abbreviated as S). S2
At S3, a self-check is made as to whether or not the heater control switch Xa is functioning normally (hereinafter referred to as a heater relay self-check routine).
When it is detected that is abnormal, the process proceeds to S4, the load devices other than the heater are stopped, and then the process proceeds to S5. In S5, the controller 8 displays the display unit 26 to notify the user of the abnormality. Further, in S6, the controller 8 turns on the alarm buzzer 25 for 30 seconds to notify the user of the abnormality. Further, in S7, the controller 8 turns on the ground contact Xa1 to forcibly cause the heater power supply to ground,
Go to S8. Then, in S8, the operation of the leakage prevention plug 1 stops the supply of power to the heater 2.

If it is detected in S3 that the controller 8 is normal, the process proceeds to S9. In S9, when the user turns on the manual operation switch for operating the hot water circulation processing device, in S10 the controller 8 turns on the hot water circulation pump, which is a load device other than the heater, the UV lamp, etc. Start operation of the device.

Subsequently, when the measured value t of the temperature of the circulating water measured by the temperature sensor 19 in S11 is higher than the set temperature T set in S1 by the user (t ≧ T).
Shifts to S12. In S12, the controller 8 opens the heater control contact Xa and turns off the heater 2,
The water temperature of the circulating hot water is T = t. Then S
At 13, the controller 8 executes a heater relay self-check routine. When it is detected that the controller 8 is abnormal in S14, the process proceeds to S4 and the above-described operations of S4 to S8 are repeated.

On the other hand, if the measured value t is lower than the set temperature T in S11 (T> t), the process proceeds to S15. S
At 15, the controller 8 turns on the heater control contact Xa to turn on the heater 2 so that the water temperature of the circulating hot water becomes T = t, and the process proceeds to S16. If the manual operation switch is ON in S16, the operations from S11 are repeated.
When the user turns off the manual operation switch, the heater 2 is turned off in S17.

Then, in S18, the controller 8 executes a heater relay self-check routine. When it is detected that the controller 8 is abnormal in S19, the process proceeds to S4 and the operations of S4 to S8 described above are repeated. On the other hand, S
If the controller 8 detects that the controller 8 is normal in 19, the process proceeds to S20. Controller 8 at S20
Stops the operation of load devices other than the heater 2. After that, the series of processes described in and after S9 is repeated.

Next, the heater relay self-check routine described in S2, S14 and S19 will be described in detail. As shown in FIG. 3, when the controller 8 detects the L voltage during the OFF control of the heater control contact Xa in S21, the process proceeds to S22. Then, in S22, the controller 8 determines that the switching function of the heater control contact Xa is abnormal and sets an error flag. In addition, S21
When the controller 8 detects the H voltage during OFF control of the heater control contact Xa, the controller 8 determines that the switching function of the heater control contact Xa is normal.

As described above, in the hot water circulation processing device in the first embodiment, the controller 8 self-checks the switching function of the heater control contact Xa. For this reason, even when the heater control contact Xa is actually in the ON state due to fusion or the like during the OFF control of the heater control contact Xa, the controller 8 causes the heater 2 to abnormally heat up. It is possible to detect the abnormality of the heater control contact Xa before the above condition and stop the power supply to the heater 2 and other load devices. As a result, the heater 2 is prevented from abnormally heating to prevent
It is possible to prevent thermal damage to other devices arranged around the device and to notify the user of an abnormal situation by the alarm buzzer 25 and the display 26.

(Second Embodiment) Next, a second embodiment will be described with reference to FIGS. However, the same components as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof is omitted.
The drive coil 23, the ground contact Xa1, and the resistors 3 and 4 described in the first embodiment are omitted.

As shown in FIG. 4, a heater control contact Xa and a safety switch Xb, which is a normally closed contact, are connected between the leakage prevention plug 1 and the heater. Also, the S
The collector terminal of the W transistor 21 is D via a drive coil 27 for controlling opening / closing of the safety switch Xb.
It is connected to the power supply terminal of C12V. Then, the drive coil 27 is excited by the control signal from the controller 8, and the safety switch Xb is opened. In the second embodiment, the safety switch Xb and the drive coil 27 constitute a power cutoff relay as a cutoff means for cutting off the power supply to the heater 2.

Next, the operation of the hot water circulation treatment device configured as described above will be described with reference to the flowchart of FIG. Note that FIG. 5 shows the operation of the entire hot water circulation processing device, and the description of the same operation as that of the first embodiment is omitted. The operations of S6 to S8 described in the first embodiment are omitted, and instead, S30 and S31 described later are added.

In S2, it is self-checked whether the heater control switch Xa is functioning normally, and S
When it is detected that the controller 8 is abnormal in 3
After shifting to S4 and stopping the load devices other than the heater by shifting to S4, the process shifts to S5. In S5, the controller 8 displays the display unit 26 to inform the user of the abnormality of the heater 2. Then, in S30, the controller 8 causes the safety switch X
Open b. Then, the power supply path to the heater 2 is cut off and only the heater 2 is stopped without operating the leakage prevention plug 1 in S31. That is, a pump for circulating hot water, which is another load device, and UV for sterilizing hot water.
Power supply to lamps etc. will be continued.

As described above, in the hot water circulation processing apparatus according to the second embodiment, when the controller 8 detects an abnormality in the switching function of the heater control contact Xa, the heater 2 is heated before the heater 2 enters the abnormal heating state. The power supply to 2 can be stopped. As a result, the heater 2
It is possible to prevent abnormal heating from occurring in advance and prevent thermal damage to other devices arranged around the heater 2, and inform the user of an abnormal situation by the alarm buzzer 25 and the display 26. can do.

The present invention is not limited to the above embodiment, and may be appropriately modified as follows without departing from the spirit of the present invention. (1) In the first embodiment, the ground fault contact Xa1 and the drive coil 2
I tried to operate the leakage prevention plug using 3
The ground contact Xa1 and the drive coil 23 may be omitted and replaced with a semiconductor switch such as a triac.

(2) In the second embodiment, the safety switch Xb and the drive coil 27 are used to cut off the power supply to the heater 2. However, the safety switch Xb and the drive coil 27 are omitted and a triac or the like is omitted. You may change to the semiconductor switch of.

[0037]

As described in detail above, according to the first aspect of the invention, the switching function of the heater control relay is detected before the heater causes abnormal heating, so that the power supply stopping means supplies the heat to the heater. Since the power supply can be stopped, it is possible to reliably prevent abnormal heating of the heater.

According to the second aspect of the invention, by detecting the switching function of the heater control relay before the heater causes abnormal heating, the power supply cutoff means can cut off the power supply path to the heater. Therefore, there is an excellent effect that the abnormal heating of the heater can be surely prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram for detecting an abnormality of a heater control relay in a first embodiment embodying the present invention.

FIG. 2 is a flowchart showing the operation of the entire hot water circulation processing device in the first embodiment.

FIG. 3 is a flowchart showing a self-check operation of the heater control contact Xa in the first embodiment.

FIG. 4 is a circuit diagram for detecting an abnormality of a heater control relay in the second embodiment.

FIG. 5 is a flowchart showing the operation of the entire hot water circulation processing device in the second embodiment.

[Explanation of symbols]

1 ... Leakage prevention plug (power supply stopping means), 2 ... Heater, 8 ... Controller (heater control means, determination means),
17 ... Drive coil, Xa ... Heater control contact (17 and Xa
A heater control relay is configured by. ), 19
... Temperature sensor (temperature detecting means), 23 ... Drive coil, X
a1 ... Ground fault contact (23 and Xa1 constitute ground fault means), 27 ... Drive coil, Xb ... Safety switch (27 and Xb constitute breaking means)

Claims (2)

[Claims] 1. A temperature detecting means for detecting a temperature of a heater, a heater control means for controlling ON / OFF of a heater control relay based on a detection signal from the temperature detecting means, and a normal ON / OFF state of the heater control relay. Judgment means for judging whether or not it is operating, ground fault means for forcibly grounding the heater on the basis of a detection signal from the judgment means, and ground fault detection by the ground fault means, A safety device in a hot water circulation processing device, comprising: a power supply stopping means for stopping power supply to a heater. 2. A temperature detecting means for detecting the temperature of the heater, a heater control means for controlling ON / OFF of the heater control relay based on a detection signal from the temperature detecting means, and the heater control relay being normally ON / OFF. A safety device in a hot water circulation processing device, comprising: a judgment means for judging whether or not it is operating, and a cutoff means for cutting off a power supply path to the heater based on a detection signal from the judgment means. .