JPH05168145A - Safety equipment for heating equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] When the safety device of the equipment has stopped operating due to an abnormality, the operation of the equipment may be stopped even if the connection terminal of the wiring of the safety device is short-circuited, and the safety device may become inoperable. Prevent dangerous driving. [Composition] The thermal fuse 14 and the current detector 19 are wired between the power supply 34 and the control circuit 28,
If the current detector 19 detects the current flowing through the control circuit 2,
A current detection signal is output to 8 to enable operation of the equipment.
The power supply line 36 for connecting the temperature fuse 14 and the current detector 19 is connected by connecting terminals 29, 30 in the middle, and the signal lines 20, 26 of the current detector 19 are also connected by the connecting terminals 22, 23. After the operation, the connection terminal 29
The control circuit 28 stops the output of the drive current of the proportional valve 12 even if the short-circuit line 37, 38 is used to temporarily short-circuit between and 30, 22 and 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a heating appliance such as a water heater, a cooker, a heater, etc., which is safely stopped when an abnormality is detected in the appliance.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a safety device of this type includes a safety device 3 (for example, a safety device 3) between a power source 1 and a control circuit 2.
The thermal fuse 3a, the bimetal switch 3b, etc. are wired, and when the device goes into an abnormal state (for example, abnormally high temperature), the wiring between the power supply 1 and the control circuit 2 is cut off (for example, the thermal fuse). The operation of the equipment was stopped by the melting of 3a or the contact of the bimetal switch 3b being turned off.

[0003]

However, in the conventional structure, both ends of the connector 5 are short-circuited as indicated by broken lines when the safety device 3 happens to operate and the serviceman happens to not prepare replacement parts. As a result, the power supply 1 and the control circuit 2 are often connected so that the equipment can be operated temporarily. If the device goes into an abnormal state again in this state, the safety device 3 will not work, and the device will continue to operate in the abnormal state, resulting in burns, a fire, or other dangerous situations. It was

Therefore, a first object of the present invention is to invalidate the emergency operation by simply short-circuiting the connection terminals of the wiring provided with the safety device.

In addition to the above-mentioned short-circuit treatment, it is also necessary to invalidate the emergency operation by short-circuiting the energization detector of the safety device.
The purpose of.

[0006]

In order to achieve the above-mentioned first object, the first means of the safety device for a heating appliance according to the present invention controls the appliance operation control means and the drive current of the control means. Output the control circuit, the power supply that supplies power to the control circuit, the intermediate wiring and terminal wiring that connect the control circuit and the power supply through the connection terminals, and detect the abnormal use of the control means Equipped with a safety device that interrupts the current of the wiring and an energization detector that is installed in the intermediate wiring to detect the presence or absence of energization, even if the safety device short-circuits the connection terminal after the energization is interrupted, the de-energization detection signal of the energization detector The control circuit stops the output of the drive current.

In order to achieve the above-mentioned second object, the second means of the present invention is a current detector as an energization detector for outputting an energization detection signal of a predetermined range to the control circuit via a specific resistance. And a signal line to be transmitted, and a connection terminal for the control circuit of the signal line, and this connection terminal and the connection terminal between the intermediate wiring and the terminal wiring are short-circuited by a short-circuit wire with a small resistance value after the cutoff of the safety device. Also, the control circuit receives a signal different from the detection signal of the current detector and stops the output of the drive current.

[0008]

With the above first means, when the safety device of the present invention detects the abnormality of the control means and shuts off the power supply to the control circuit, the safety device for the heating appliance of the present invention provides a connection between the intermediate wiring and the terminal wiring. Even if an attempt is made to short-circuit the connection terminals of the intermediate wiring to recover the interruption of the intermediate wiring by the safety device, the energization detector detects the de-energization of the intermediate wiring. The control circuit that receives this detection signal stops the drive current of the control means and can prevent an unsafe emergency operation in which the safety device does not operate normally.

Further, according to the above-mentioned second means, even if the connection terminal of the signal line is short-circuited by the short-circuit wire having a smaller resistance value in addition to the short-circuit treatment, the current detector detects the energization over the predetermined range. However, the control circuit can stop the driving current output to prevent emergency operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a heating device safety device according to the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1 shows a gas water heater as an embodiment of the present invention, in which the water supplied to the heat exchanger 10 is heated by a burner 11 to be heated. The burner 11 supplies the fuel gas with a proportional valve 12
And supply to the burner 11. The control means 13 including the heat exchanger 10, the burner 11 and the proportional valve 12 includes the burner 1
Due to the incomplete combustion of No. 1 and the like, the heat exchanger 10 is overheated to a high temperature, and the heat exchanger 10 is deteriorated and damaged due to high temperature oxidation.

The thermal fuse 14 serving as a safety device is connected to the intermediate wiring 16 at the connection portion 15, detects abnormal use of the heat exchanger 10 and melts it at a predetermined temperature to cut off the energization of the intermediate wiring 16. A current detector 19 having a diode 17 and a transistor 18 is similarly connected to the intermediate wiring 16. The signal line 20 is connected to the transistor 17, and the other end of the signal line 20 is connected to the connection terminals 22 and 23 provided on the terminal board 21 with the screw 2
4 is screwed into the screw hole 25 and connected. Connection terminal 22,
23 is fixedly connected to the signal line 26, and the other end of the signal line 26 is connected to the control circuit 28. Both ends of the intermediate wiring 16 are connected to the connection terminals 29 and 30, and the terminal wirings 31 and 32 are connected to the connection terminals 29 and 30. The other ends of the terminal wires 31 and 32 are connected to the power supply 34 and the control circuit 28. The control circuit 28 is connected by the other wiring 35 supplied with power from the power supply 34, and outputs the drive current of the proportional valve 12.

Based on the above configuration, the operation when the temperature fuse 14 detects an abnormality due to overheating of the control means 13 will be described next.

When the thermal fuse 14 detects an abnormality and is blown, the current flowing through the intermediate wiring 16 is cut off, one of the power supply lines 36 consisting of the terminal wiring 31, the intermediate wiring 16 and the terminal wiring 32 becomes non-conductive, and the control circuit 28 becomes The power supply of the power supply 34 is cut off. Then, the control circuit 28 uses the proportional valve 1
The drive current of 2 cannot be output, the combustion of the burner 11 is stopped, and the abnormal operation is stopped. If it is determined that hot water cannot be supplied due to the operation being stopped, a repair action will be taken.

Then, as in the conventional case, the connection terminals 29, 3
0, loosen the screw 24, remove the intermediate wiring 16, and connect the connecting terminals 29, 30 with a short-circuit wire 37 such as a lead wire as shown by a broken line.
Is short-circuited, and an emergency measure is performed so that power can be supplied between the power supply 34 and the control circuit 28. By this measure, power is instantaneously supplied from the power supply 34 to the control circuit 28. However, since the intermediate wiring 15 is not energized, the current detector 19 does not input the energization detection signal to the control circuit 28. Therefore, the control circuit 28 does not output the drive signal to the proportional valve 12 and does not restart the operation.

The installation of the current detector 19 also acts as a first aid prohibition. The current detector 19 rectifies the current of the intermediate wiring 16 by the diode 17, and turns on the transistor 18 when the rectified direct current becomes a predetermined value or more. Signal line 20,
26 is applied with a voltage from the control circuit 28, and the transistor 1
When 8 is turned on, the transistor 18 is connected to the signal lines 20 and 26.
An electric current flows through. This current becomes a small current having a predetermined width due to the large resistance of the transistor 18, and the control circuit 28 outputs a drive current to the control means 13 when receiving the current of this predetermined width. And the connection terminal 2
Since the short-circuit treatment of 9, 30 is invalid, the connection terminal 22,
It can be sufficiently predicted that the short-circuiting treatment between 23 and 23 will be taken temporarily by a short-circuiting wire 38 such as a lead wire having a small resistance value.

However, even at this time, power is temporarily supplied from the power supply line 36 to the control circuit 28, but the resistance value of the short-circuit line 38 is extremely smaller than the resistance value of the transistor 18, and the signal lines 20, 26. A large current flows through.
Then, the control circuit 28 determines that this current does not match the small current having the predetermined width, stops the output of the drive current, invalidates the countermeasure, and can prevent the recurrence of the abnormality due to dangerous emergency driving.

The safety device is not limited to the temperature fuse 14, but a bimetal may be used as the temperature detector, and the same effect can be obtained even if the abnormality detection target is the power supply current, the pressure of gas or liquid, the humidity, and the like. .. Further, even if the current detector 19 is simply energized by a relay or the like, the short-circuit treatment between the connection terminals 29 and 30 can be invalidated.

[0019]

As is apparent from the above description, in the first aspect of the safety device for the heating appliance according to the present invention, the safety device detects abnormal use of the appliance and supplies power from the power supply device to the control circuit. Even if the connection between the connection terminals of the cutout device is short-circuited after being cut off, the energization detector detects the non-energization of the wiring and stops the drive current output of the control circuit, causing the cutout device to be inoperable. Driving can be prevented.

In addition, in addition to the short-circuiting treatment of the connection terminal, even if the connection terminal of the wiring of the current detector as the energization detector is further short-circuited by a short-circuit wire having a small resistance value,
The control circuit that has received a signal different from the energization detection signal of the current detector stops the output of the drive current, thereby preventing a dangerous operation in which the safety device cannot operate.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a safety device for a heating appliance according to the present invention.

FIG. 2 is a configuration diagram showing a conventional safety device for a heating appliance.

[Explanation of symbols]

 14 Thermal fuse 19 Current detector 22, 23, 29, 30 Connection terminal 28 Control circuit 37, 38 Short-circuit wire

Claims (2)

[Claims] 1. A device operation control means, a control circuit for controlling and outputting a drive current of the control means, a power supply for supplying power to the control circuit, and a connection terminal midway between the control circuit and the power supply. The safety device is equipped with the intermediate wiring and the terminal wiring that are connected with each other, the safety device that shuts off the current of the intermediate wiring by detecting abnormal use of the control means, and the energization detector that is installed in the intermediate wiring to detect the presence or absence of electricity. A safety device for a heating device, wherein the control circuit stops the output of the drive current by the non-energization detection signal of the energization detector even if the connection terminal is short-circuited after the energization is cut off. 2. A current detector as an energization detector for outputting an energization detection signal in a predetermined range to a control circuit through a specific resistance, a signal line for transmission, and a connection terminal for a control circuit for the signal line. Even if the connection terminal and the connection terminal between the intermediate wiring and the terminal wiring are short-circuited by a short-circuit wire with a small resistance value after the cutoff of the safety device, the control circuit receives a signal different from the detection signal of the current detector and the drive current The safety device for a heating device according to claim 1, wherein the output of the heating device is stopped.