JPH0942655A - Combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustor which is excellent in safety by failure of ignition when a temperature fuse burns out by overheating. SOLUTION: A temperature fuse 42 is connected in series electrically to a water flow switch 4 which is turned ON when a water flow is detected and when the temperature fuse 42 burns out by overheating, application of voltage VCC2 is suspended on a regulator 91 even when the water flow switch 4 is turned ON. A stabilization voltage VREG as timer actuation start signal and power for actuation fails to be supplied to a suction timer circuit 6, a holding timer circuit 7 and an igniter timer circuit 51 and application of VREG as power for actuation comes to suspension to transistors 13 and 14.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a combustion device.

[0002]

2. Description of the Related Art As a combustion apparatus, for example, in a gas water heater, an electromagnetic valve is provided in a gas supply passage to a gas burner. Further, as an ignition means of a gas burner, for example, an ignition device that generates a high voltage by being energized to generate a spark discharge is known. Then, the solenoid valve and the ignition device described above,
When connected to a DC power source (for example, a dry battery) via a transistor and an ON signal is input to the transistor, the solenoid valve and the ignition device are energized.

Specifically, when a water flow switch for detecting water flow is closed, a transistor for controlling energization of an electromagnetic valve or an ignition device is operated for a predetermined time (for example, 5 seconds) based on the closing signal (ignition signal). During), a holding timer circuit and an ignition timer circuit that send an ON signal are connected. In addition, in order to prevent overheating of the heat exchanger, a thermal fuse electrically connected between the transistor and the solenoid valve may be installed near the heat exchanger.

[0004]

In the above-mentioned gas water heater, once the temperature fuse is blown, the holding current cannot flow through the solenoid valve. Therefore, until the service person finds the cause of overheating and replaces the temperature fuse, The user cannot use the gas water heater. However, since the ignition circuit can operate even in such a state and spark discharge is performed, the user may misunderstand that the gas water heater has not failed, and may repeatedly perform the ignition operation.

An object of the present invention is to provide a combustion device which is excellent in safety because the normal ignition operation is not performed when the temperature fuse is blown by overheating.

[0006]

In order to solve the above-mentioned problems,
The present invention employs the following configuration. (1) It is arranged in a gas supply path for supplying gas to the gas burner, and is arranged in a solenoid valve whose valve body opens by energization and a place heated by combustion of the gas burner, and melts at a predetermined temperature or higher. A temperature fuse, a holding circuit for forcibly energizing the solenoid valve for a predetermined time from the input of the ignition instruction signal, an ignition circuit for starting the ignition operation by the input of the ignition instruction signal, and an input of the ignition instruction signal The combustion instruction is input through the temperature fuse in a combustion device including a safety circuit that starts detection of combustion flame by the above, and energizes the solenoid valve while the combustion flame is detected.

(2) With the configuration of (1) above, the ignition instruction signal serves as electric power for operating the holding circuit and the safety circuit.

(3) An electromagnetic valve which is arranged in a gas supply passage for supplying gas to the gas burner and whose valve body opens by energization, a heat exchange passage having a heat exchange section heated by the gas burner, A water flow switch whose contacts are closed when detecting a water flow flowing through the heat exchange water passage, a temperature fuse arranged near the heat exchange section and blown out at a predetermined temperature or more, and the water flow switch and the temperature fuse through the above An operating power supply line supplied with operating power from a battery, a switch element connected between the solenoid valve, and an operating power supply line connected to the operating power supply line for a predetermined time when the operating power is supplied, an ignition signal. And an ignition circuit for performing an ignition operation while the ignition signal is being input, and an operating power supply line that is connected to the operating power supply line and is supplied with operating power, for a predetermined period of time. A holding timer circuit forcibly sending an ON signal to the switch element and the operation power supply line are connected, and when the operation power is supplied, detection of combustion flame is started, and while combustion flame is detected , A safety circuit for sending an ON signal to the switch element.

[0009]

[Action]

[Claim 1] An ignition instruction signal is input to each circuit through a thermal fuse. The ignition circuit starts the ignition operation. The holding circuit energizes the solenoid valve for a predetermined time,
As a result, the solenoid valve is maintained in the open state. When the gas burner ignites and the safety circuit detects combustion flame during the specified time, the safety circuit continues to energize the solenoid valve even after the specified time elapses, the solenoid valve remains open, and the gas burner continues combustion. To do.

When the thermal fuse is blown by overheating,
Even if the ignition instruction signal is output, it is not input to each circuit. Therefore, the ignition circuit does not start the ignition operation, the holding circuit does not energize the solenoid valve, the solenoid valve maintains the closed valve state, the safety circuit does not start detecting combustion flame, and the gas burner extinguishes. Hold the state.

[Claim 2] An ignition instruction signal is input to each circuit through a thermal fuse. The ignition circuit starts the ignition operation.

The holding circuit energizes the solenoid valve for a predetermined time, thereby keeping the solenoid valve open. When the gas burner ignites and the safety circuit detects combustion flame during the predetermined time, the safety circuit continues to energize the solenoid valve even after the lapse of the predetermined time, the solenoid valve maintains the open state, and the gas burner continues combustion. .

When the thermal fuse is blown by overheating,
Even if the ignition instruction signal is output, it is not input to each circuit.
Also, no operating power is supplied to the holding circuit and the safety circuit. Therefore, the ignition circuit does not start the ignition operation, the holding circuit does not energize the solenoid valve, the solenoid valve maintains the closed state,
The safety circuit does not start detecting combustion flames and the gas burner remains extinguished.

[Claim 3] When water flows through the heat exchange channel, the contact of the water flow switch is closed, and the operating power supply line is supplied with operating power from the battery through the water flow switch and the temperature fuse. It

An ignition timer circuit connected to the operating power supply line sends an ignition signal for a predetermined time, and the ignition circuit carries out an ignition operation while the ignition signal is being input. The holding timer circuit connected to the power supply line for operation is
Since the ON signal is sent to the switch element and the switch element is turned ON, the solenoid valve maintains the open state.

The safety circuit connected to the operating power supply line starts sending an ON signal to the switch element when a combustion flame is detected during a predetermined time, and the solenoid valve maintains the open state even after the lapse of the predetermined time. , The gas burner continues to burn.

When the thermal fuse is blown by overheating,
Even if water flows in the heat exchange channel and the contact of the water flow switch is closed, the operating power is not supplied to the operating power line.
Therefore, the operating power is not supplied to the switch element, the holding timer circuit, and the safety circuit. Also, the ignition timer circuit does not send the ignition signal, the ignition circuit does not perform the ignition operation,
The hold timer circuit does not send an ON signal to the switch element,
The safety circuit does not start detecting the combustion flame, the solenoid valve remains closed, and the gas burner remains extinguished.

[0018]

【The invention's effect】

[Claim 1] Since the ignition instruction signal is inputted to the holding circuit, the ignition circuit, and the safety circuit through the temperature fuse, when the temperature fuse is blown due to overheating, the ignition instruction signal is output to each circuit even if the ignition instruction signal is output. Not entered. As a result, if the temperature fuse is blown due to overheating, the ignition circuit does not start the ignition operation even if the user performs an ignition operation, the holding circuit does not energize the solenoid valve, and the safety circuit detects combustion flame. The solenoid valve remains closed and the gas burner maintains the extinguishing state.

That is, when the thermal fuse is blown, the ignition operation is not performed even if the user performs the ignition operation. Therefore, the safety is excellent and the user can be informed that the combustion device is out of order, and the repair request can be surely made.

[Claim 2] Since the ignition instruction signal is inputted to the holding circuit, the ignition circuit and the safety circuit through the temperature fuse, even if the ignition instruction signal is output when the temperature fuse is blown by overheating. Not input to each circuit. Moreover, the operating power is not supplied to the holding circuit and the safety circuit.

Thus, when the thermal fuse is blown by overheating, the ignition circuit does not start the ignition operation even if the user performs an ignition operation, and the holding circuit is deactivated, so that the solenoid valve is energized. However, since the safety circuit is deactivated, combustion flame detection is not started, the solenoid valve remains closed, and the gas burner maintains the extinguished state.

That is, when the thermal fuse is blown, the ignition operation is not performed even if the user performs the ignition operation. Therefore, the safety is excellent and the user can be informed that the combustion device is out of order, and the repair request can be surely made.

[Claim 3] The temperature fuse is electrically connected in series with the water flow switch, and the operating power is supplied from the battery to the operation power supply line through the water flow switch and the temperature fuse. A switch element, an ignition timer circuit, a holding timer circuit, and a safety circuit are connected to the operating power supply line. When the temperature fuse is blown due to overheating, the operating power is not supplied to the operating power line.

In this case, even if water is made to flow through the heat exchange channel to close the contacts of the water flow switch, the switch element, the ignition timer circuit, the holding timer circuit, and the safety circuit are not supplied with operating power, and thus do not operate. The ignition circuit does not perform the ignition operation (the ignition signal is not input from the ignition timer circuit).

That is, when the thermal fuse is blown, the ignition operation is not performed even if the user performs an ignition operation and causes water to flow through the heat exchange channel. Therefore, while being excellent in safety, it is possible to let the user know that the combustion device has failed,
The repair request is definitely made.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention (corresponding to claims 1 to 3) will be described with reference to FIGS. As shown in the figure, the gas instantaneous water heater A has a suction coil 11 and a holding coil 12, and an electromagnetic safety valve 1 disposed in a gas pipe 21 for supplying gas to the gas burner 2 and a transistor 13, 14, a heat exchange channel 3 having a heat exchanger 31, a water flow switch 4 that closes a contact 41 when a water flow is detected, a temperature fuse 42 that melts when an overheat is detected, and an igniter timer circuit 5.
1 and the igniter drive circuit 52 and the contact 41 are closed for a first timer time (0.4 seconds), the suction timer circuit 6 for sending an ON signal 61 and the contact 41 are closed for a second timer time (5. For 5 seconds), when the holding timer circuit 7 which sends out the ON signal 71 and the contact 41 are closed, detection of the combustion flame is started. While the combustion flame is detected, the transistor 14
And an ignition detection circuit 8 for sending an ON signal 81 to the.

Reference numeral 91 denotes a regulator. When the contact 41 is closed, the voltage V _CC2 (3V) is applied to the “IN” terminal 910 and the stabilized voltage V _CC is applied to the “OUT” terminal 911.
_REG (1.5V) is generated. Reference numeral 92 denotes a dry battery. In this embodiment, two single type 1.5V manganese dry batteries are connected in series to generate an electromotive force of voltage V _CC1 (3V). Reference numeral 9 denotes an electronic unit incorporating each circuit.

The electromagnetic safety valve 1 has a suction coil 11 (3.7 Ω) whose valve body opens when energized, and a holding coil 12 (500 Ω) which maintains the valve open state even after suction by energization. It is arranged at the uppermost stream of the pipe 21.

The gas burner 2 is installed below the heat exchanger 31, and gas is supplied by the gas pipe 21 to burn.
The gas pipe 21 is provided with an electromagnetic safety valve 1, a gas governor valve 211, a hydraulic automatic gas valve 212 connected to a water governor 323, and a capacity adjuster 213 from the upstream side.

In the combustion cylinder near the heat exchanger 31, 152
A thermal fuse 42 that melts at a temperature of not less than ° C is provided.
The thermal fuse 42 has one end electrically connected to the water flow switch 4 and the other end electrically connected to the “IN” terminal 910.

The hydraulic automatic gas valve 212 is connected to the water governor 323 by the interlocking rod 43 and opens when water flows into the heat exchange channel 3. The ability adjuster 213 is an ability adjusting knob 2
A gas corresponding to the amount of sliding of the capacity adjusting knob 214 is connected to the gas passage 14.

The heat exchange channel 3 includes the water supply pipe 32 and the heat exchanger 3.
1 and a hot water outlet pipe 33 are connected in order. Water pipe 32
Is provided with a hot water supply plug (not shown), a water filter 321, a water governor 323, and a hot water amount adjuster 325 connected to the hot water temperature adjusting knob 324. The water flow switch 4 is inserted between the dry battery 92 and the temperature fuse 42, and is connected to the water governor 323.
Is connected to an interlocking rod 43 that connects the hydraulic pressure automatic gas valve 212 with each other, and the contact 41 is closed when a water flow flows. The output side of the water flow switch 4 is the operating power supply line R.

The igniter timer circuit 51 sends an actuation signal 511 to the igniter drive circuit 52 for 5.5 seconds from the start of power supply by closing the contact 41. The igniter drive circuit 52 generates a high voltage for spark discharge while the operation signal 511 is input, and applies the high voltage for ignition to the ignition electrode 521 arranged facing the gas burner 2. Since the igniter drive circuit 52 consumes a relatively large amount of current, the voltage V _CC1 is used as operating power.

The ignition detection circuit 8 is a circuit for detecting the flame current by applying an AC voltage (about 100 V) for flame current detection to the frame rod 80 arranged facing the gas burner 2. Upon detection (detection of ignition), the ON signal 81 is sent to the transistor 14. The voltage V _CC2
Is the operating power.

The suction timer circuit 6 includes a comparator and a CR.
When the stabilized voltage V _REG is supplied as a timer operation start signal, the ON signal 61 is sent to the transistor 13 for the first timer time (0.4 seconds). The transistor 13 is arranged between the suction coil 11 and the dry cell 92, and is conductive while the ON signal 61 is being input, so that a suction current flows through the suction coil 11.

The holding timer circuit 7 includes a comparator and a CR.
When the stabilization voltage V _REG is supplied as a timer operation start signal, the ON signal 71 is sent to the transistor 14 for the second timer time (5.5 seconds).

The transistor 14 is a holding coil 12-
The electromagnetic safety valve 1 is disposed between the "OUT" terminals 911, and the electromagnetic safety valve 1 is maintained open while the ON signal 71 or the ON signal 81 is being input to conduct the holding current to the holding coil 12.

Next, the operation of the gas instantaneous water heater A is shown in FIG.
A description will be given based on the flowchart of FIG. 5 and the time chart of FIG. [Usage of appliance (see FIG. 4)] When the user opens the hot water tap (step s1), the water flow switch 4 is closed (step s2), and the voltage V _CC2 is supplied to the “IN” terminal 910 of the regulator 91. As a result, the stabilization voltage V _REG is generated at the “OUT” terminal 911.

When the supply of the regulated voltage V _REG is started, the following operation is performed in step s3. The igniter timer circuit 51 sends an actuation signal 511 to the igniter drive circuit 52, the igniter drive circuit 52 applies a high voltage to the ignition electrode 521, and spark discharge starts. The suction timer circuit 6 sends an ON signal 61 to the transistor 13, and the transistor 13 is turned on to supply a suction current to the suction coil 11, so that the electromagnetic safety valve 1 is opened. The holding timer circuit 7 is
The ON signal 71 is sent to the transistor 14, the transistor 14 becomes conductive, and the holding current flows through the holding coil 12.

In step s4, the hydraulic automatic gas valve 212 is opened and the gas burner 2 is ignited. 0.4 seconds elapse from the start of closing the water flow switch 4 (YES in step s5).
And the suction timer circuit 6 sends the ON signal 61 to the transistor 1
3, the transistor 13 is turned off and the suction current does not flow in the suction coil 11 (step s
6).

When 5.5 seconds have passed from the start of closing the water flow switch 4 (YES in step s7), the holding timer circuit 7
Does not send the ON signal 71 to the transistor 14,
The igniter timer circuit 51 does not send the operation signal 511 to the igniter drive circuit 52, and the spark discharge is stopped (step s8).

As shown in FIG. 6A, in the case of "normal", the ignition detection circuit 8 has already detected the flame current and the ON signal 8 has been detected.
Since 1 is being sent to the transistor 14 (YES in step s9), the electromagnetic safety valve 1 is kept held. Voltage V
_CC1 is 1.8V or higher (YE in step s10)
S) If the flame current is detected, hot water supply is continued until the device is stopped.

When the flame current is not detected (non-ignition; (b) of FIG. 6), when the flame current is no longer detected (misfire; FIG. 6)
(C)} or when the voltage V _CC1 becomes less than 1.8 V (voltage drop; (d) in FIG. 6), the confirmation lamp 93 is continuously lit and the ignition detection circuit 8 turns on the transistor 81 of the ON signal 81. The transmission to 14 is stopped (step s11). As a result, the electromagnetic safety valve 1 is closed.

When the user notices an abnormality and closes the hot water supply valve (step s12), water stops flowing, so the automatic water pressure gas valve 212 is closed (step s13), the water flow switch 4 is turned off, and the confirmation lamp 93 is turned on. The light is turned off (step s14).

[Stopping Use of Equipment (See FIG. 5)] When the user closes the hot water supply valve to stop the use (step S1),
Since the water stops flowing, the automatic water pressure gas valve 212 is closed (step S2) and the gas burner 2 is extinguished (step S3).
Then, the water flow switch 4 is turned off (step S4), and the electromagnetic safety valve 1 is closed (step S5).

[When the thermal fuse 42 is blown] (e) of FIG.
As shown in, when the user opens the hot water tap, water flows and the water flow switch 4 closes, but since the temperature fuse 42 is blown, the voltage V _CC2 is applied to the “IN” terminal 910 of the regulator 91. As a result, the stabilization voltage V _REG is not output to the “OUT” terminal 911.

Therefore, the transistor 14, the suction timer circuit 6, the hold timer circuit 7, and the igniter timer circuit 51 are not supplied with the stabilized voltage V _REG , and the ignition detection circuit 8 is not supplied with the voltage V _CC2 . Then, the suction timer circuit 6
Does not send the ON signal 61 to the transistor 13, the igniter timer circuit 51 does not send the ignition signal 511, the hold timer circuit 7 does not send the ON signal 71 to the transistor 14, and the ignition detection circuit 8 detects combustion flame. The electromagnetic safety valve 1 maintains the closed state, and the gas burner 2 maintains the extinguished state.

The gas instantaneous water heater A has the advantages [a] to [d] due to the following constitutions and operations. Thermal fuse 4
2 has one end electrically connected to the water flow switch 4 and the other end electrically connected to the "IN" terminal 910 of the regulator 91 (series electric connection with the water flow switch 4).

When the temperature fuse 42 is blown, the user performs an ignition operation (opens the hot water supply tap to let water flow in the heat exchange channel 3).
Even if the contact 41 of the water flow switch 4 is closed by performing the above, the transistor 14, the suction timer circuit 6, the holding timer circuit 7,
The stabilized voltage V _REG is not supplied to the igniter timer circuit 51, and the voltage V _CC2 is not supplied to the ignition detection circuit 8.

[A] Even if the user performs an ignition operation when the thermal fuse 42 is blown, the suction current does not flow and the raw gas is not released, which is safe. [A] If the user performs an ignition operation when the temperature fuse 42 is blown, a spark discharge (creeping sound) does not occur, the confirmation lamp 93 does not light up, and the operation and display at the normal time are not performed. It is easy to see that the gas water heater is out of order. [C] When the thermal fuse 42 is blown, the user notices a failure and stops using the battery, so that the battery can be prevented from being consumed and a repair request can be made quickly.

[D] The igniter drive circuit 52 and the power source (a large current flows) for operating the transistor 13 do not pass through the temperature fuse 42 or the water flow switch 4, so that the contact 4
It is possible to prevent the fusing of No. 1 and the contact failure and the fusing of the thermal fuse 42 due to a large current. In the above embodiment, the electromagnetic valve has the suction coil and the holding coil separately, but one coil may serve both the suction and the holding. Further, in the above embodiment, the water heater is shown as the combustion device, but it may be applied to other combustion devices such as a fan heater.

[Brief description of drawings]

FIG. 1 is an external view of a gas instantaneous water heater according to one embodiment of the present invention.

FIG. 2 is a configuration diagram of the gas instantaneous water heater.

FIG. 3 is an electrical connection diagram of the gas instantaneous water heater.

FIG. 4 is a flowchart showing the operation of the gas instantaneous water heater.

FIG. 5 is a flowchart showing the operation of the gas instantaneous water heater.

FIG. 6 is a time chart showing the operation of the gas instantaneous water heater.

[Explanation of symbols]

A Gas Instantaneous water heater (combustion device) 1 Electromagnetic safety valve (solenoid valve) 2 Gas burner 3 Heat exchange channel 4 Water flow switch 6 Suction timer circuit 7 Holding timer circuit 8 Ignition detection circuit (safety circuit) 14 Transistor (switch element) 21 Gas Pipe (gas supply path) 31 Heat exchanger (heat exchange part) 41 Contact 42 Temperature fuse 51 Igniter timer circuit (ignition timer circuit) 52 Igniter drive circuit (ignition circuit) 61 ON signal 71 ON signal 92 Dry cell 511 Operation signal (ignition) Signal) V _CC2 voltage (ignition instruction signal, operating power) V _REG stabilization voltage (ignition instruction signal, operating power)

Claims (3)

[Claims] 1. A solenoid valve, which is disposed in a gas supply path for supplying gas to a gas burner and has a valve body which opens when energized, and a location which is heated by combustion of the gas burner, and which has a predetermined temperature or higher. A temperature fuse that blows, a holding circuit that forcibly energizes the solenoid valve for a predetermined time from the input of an ignition instruction signal, an ignition circuit that starts an ignition operation by the input of an ignition instruction signal, and an ignition instruction signal In a combustion device including a safety circuit that starts detection of combustion flame by input of, and while the combustion flame is detected, the ignition instruction signal is input through the temperature fuse. And a combustion device. 2. The combustion device according to claim 1, wherein the ignition instruction signal serves as electric power for operating the holding circuit and the safety circuit. 3. A solenoid valve arranged in a gas supply passage for supplying gas to the gas burner, the valve body of which is opened by energization, a heat exchange passage having a heat exchange section heated by the gas burner, A water flow switch whose contacts are closed when it detects a water flow flowing through the water passage, a temperature fuse arranged in the vicinity of the heat exchange section and blown out at a predetermined temperature or higher, and the battery via the water flow switch and the temperature fuse. An operating power supply line supplied with operating power from a switch element connected between the solenoid valve and the operating power supply line, and an operating power is supplied for a predetermined time, an ignition signal is output. An ignition timer circuit for sending out, an ignition circuit for performing an ignition operation while the ignition signal is input, and an operating power connected to the operating power supply line, and operating power is supplied, during the predetermined time, A holding timer circuit that forcibly sends an ON signal to the switch element, and is connected to the operating power supply line, starts detecting combustion flame when operating power is supplied, and detects combustion flame while it is being detected. And a safety circuit that sends an ON signal to the switch element.