JP2556433B2 - Combustion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device such as a gas stove.

[0002]

2. Description of the Related Art For example, in a gas stove, combustion / misfire of a burner is detected through a combustion detection sensor such as a thermocouple, and a solenoid valve provided in a gas supply path to the burner is detected by a solenoid valve in response to the detection. It is known to open and close via a drive circuit, and this type closes a solenoid valve to shut off the gas supply to the burner when a misfire is detected. I am trying.

Further, in this type of gas stove, the heating temperature of the food to be heated is detected by a temperature sensor provided so as to come into contact with the container of the food, and the detected temperature is predetermined. It is known that the solenoid valve is driven to open and close via a solenoid valve drive circuit according to whether the heating temperature of the cooked food is a predetermined reference temperature or not. When the temperature exceeds the temperature and becomes high, the solenoid valve is driven to be closed, whereby combustion of the burner is stopped and overheating is prevented.

By the way, in this type of gas stove, conventionally, a combustion detection circuit and a temperature detection circuit, which are composed of a comparator connected to a thermocouple or a temperature sensor, are provided, and by these circuits, combustion or misfire of the burner or Detecting the heating temperature of the cooked food and outputting the signal for driving the solenoid valve to open or close the solenoid valve to operate the solenoid valve drive circuit. Is common. In this case, one combustion detection circuit and one temperature detection circuit are provided.

However, in the past, burner combustion and combustion were performed by a single combustion detection circuit and temperature detection circuit as described above.
For example, if the combustion detection circuit fails, because the misfire and the heating temperature of the cooked food were detected.
There is a possibility that the electromagnetic valve cannot be driven to close even if a misfire occurs, and if the temperature detection circuit fails, even if the heating temperature of the cooked food becomes abnormally high, There is a fear that the electromagnetic valve may not be driven to be closed.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves such inconvenience, and in a combustion apparatus such as a gas stove, when a misfire occurs in the combustion section or when the heating temperature of an object to be heated becomes abnormally high. An object of the present invention is to provide a combustion device that can drive the electromagnetic valve of the fuel supply path to the combustion section to be closed as reliably as possible.

[0007]

To achieve the above object, a first aspect of the present invention is to provide an opening / closing solenoid valve provided in a fuel supply passage for supplying fuel to a combustion section, and a combustion in the combustion section. A drive signal output circuit that includes a combustion detection circuit that detects a misfire, and that outputs a signal for driving the opening and closing of the solenoid valve in response to detection of combustion and a misfire by the combustion detection circuit, and an output signal of the drive signal output circuit In a combustion apparatus including a solenoid valve drive circuit that drives the solenoid valve to open and close accordingly, a plurality of drive signal output circuits are provided, and each drive signal output circuit outputs the open / close drive signal as a binary signal of high and low levels. The solenoid valve is configured to be opened by energizing the solenoid and closed by shutting off the energization. When a plurality of switching transistors each having a high / low level open / close drive signal of the signal output circuit as a base input are connected in series to the solenoid, and at least one drive signal output circuit outputs a close drive signal for the solenoid valve. The switching transistor having the closing drive signal as a base input is turned off.

The combustion detection circuits are connected in parallel to a single combustion detection sensor provided in the combustion section,
Combustion / misfire of the combustion unit is detected by an output signal of the sensor.

A second aspect of the present invention is an opening / closing solenoid valve provided in a fuel supply passage for supplying fuel to a combustion section, and a temperature detection for detecting a heating temperature of an object to be heated due to combustion in the combustion section. A drive signal output circuit including a circuit, which outputs an opening / closing drive signal for the solenoid valve according to whether the temperature detected by the temperature detection circuit is low or high with respect to a predetermined reference temperature; and according to an output signal of the drive signal output circuit. In a combustion device including a solenoid valve drive circuit that drives the solenoid valve to open and close, a plurality of drive signal output circuits are provided, and each drive signal output circuit outputs the open / close drive signal as a binary signal of high and low levels. The solenoid valve is configured to be opened by energization of a solenoid and closed by shutting off the energization. A plurality of switching transistors each having a high-low level opening / closing drive signal of the input / output circuit as a base input are connected in series to the solenoid, and when at least one drive signal output circuit outputs a closing drive signal for the solenoid valve, It is characterized in that a switching transistor having a closing drive signal as a base input is turned off.

Each of the temperature detection circuits is connected in parallel to a single temperature sensor provided at a position in contact with the object to be heated, and detects the heating temperature of the object to be heated by the output signal of the sensor. It is characterized by

Further, a third aspect of the present invention is to provide an opening / closing solenoid valve provided in a fuel supply path for supplying fuel to a combustion section, a combustion detection circuit for detecting combustion / misfire in the combustion section, and the combustion A temperature detection circuit for detecting the heating temperature of the object to be heated due to the combustion of the part, the combustion detection circuit and the temperature detection circuit, the combustion detection circuit detects combustion and misfire, and the predetermined temperature detected by the temperature detection circuit. Outputs a signal for opening and closing the solenoid valve according to whether it is low or high with respect to a reference temperature, and at the time of detection of misfire by the combustion detection circuit or the temperature detected by the temperature detection circuit becomes a high temperature equal to or higher than the reference temperature In a combustion device including a drive signal output circuit that outputs a closing drive signal of the solenoid valve when the electromagnetic valve and an electromagnetic valve drive circuit that opens and closes the solenoid valve according to an output signal of the drive signal output circuit, Serial drive signal output circuit together are plurality, each drive signal output circuit configured to output a binary signal of high or low level of the opening and closing driving signals,
The solenoid valve is constituted by a solenoid valve that is driven to be opened by energizing a solenoid and closed by shutting off the energization, and the solenoid valve drive circuit is configured to open and close the high-low level open / close drive signal of each drive signal output circuit. A plurality of switching transistors each having a base input are connected in series to the solenoid, and when at least one drive signal output circuit outputs a close drive signal for the solenoid valve, the close drive signal is used as a base input. It is characterized in that the switching transistor is turned off.

Further, in each of the aspects of the present invention, two sets of the drive signal output circuit and the switching transistor are provided, and each switching transistor is made conductive by base inputs of high and low reverse levels. Is characterized by.

[0013]

[0014]

According to the first aspect of the present invention, any one of the plurality of drive signal output circuits including the combustion detection circuit outputs a high or low level drive signal for closing the solenoid valve. Then, among the plurality of switching transistors, the switching transistor having the closing drive signal as a base input is turned off, the power supply to the solenoid of the solenoid valve is cut off, and the solenoid valve is closed. Accordingly, even if one or more of the drive signal output circuits fails, if one drive signal output circuit is normal, the solenoid valve can be driven to be closed when misfire of the combustion unit is detected. Further, even if one or more of the switching transistors of the solenoid valve drive circuit fails, if the failure is a failure that cuts off the emitter-collector of the transistor, the solenoid is de-energized. The solenoid valve can be driven to close, and when the failure is a failure in which the emitter and collector of the transistor are short-circuited, one switching transistor and the drive signal output circuit corresponding thereto are As long as it is normal, the electromagnetic valve can be closed and driven in response to the detection of the misfire of the combustion section.

In this case, the combustion detection circuit of each drive signal output circuit is connected in parallel to a single combustion detection sensor so that the output signal of the sensor is shared.
The device configuration can be simplified.

Further, according to the second aspect of the present invention, a signal for closing drive of the solenoid valve having a high or low level is output from any one of the plurality of drive signal output circuits including the temperature detection circuit. When output, the switching transistor having the closing drive signal as a base input, of the plurality of switching transistors, is turned off, the energization of the solenoid of the solenoid valve is cut off, and the solenoid valve is closed. .
Thus, as in the case of the first aspect, if one drive signal output circuit is normal, when the heating temperature of the object to be heated becomes higher than the reference temperature, the solenoid valve is turned on. When the solenoid valve drive circuit can be closed, and one or more of the switching transistors of the solenoid valve drive circuit fails, if the failure is a failure that cuts off between the emitter and collector of the transistor, the solenoid is connected to the solenoid. The electromagnetic valve can be driven to close by shutting off the energization of the transistor, and if the failure is a failure in which the emitter and collector of the transistor are short-circuited, one switching transistor and the corresponding drive signal As long as the output circuit is normal, the solenoid valve can be driven to close when the object to be heated is overheated.

The temperature detection circuit of each drive signal output circuit is connected in parallel to a single temperature sensor, and the output signal of the sensor is shared, thereby simplifying the device structure. You can

Further, according to the third aspect of the present invention, as in the first and second aspects, if one drive signal output circuit including the combustion detection circuit and the temperature detection circuit is normal. , When the misfire of the combustion part is detected or when the object to be heated is overheated (when the heating temperature becomes higher than the reference temperature)
Since the normal drive signal output circuit outputs a closing drive signal for the solenoid valve, the switching transistor corresponding to the drive signal output circuit can be turned off to close the solenoid valve. Even if one or more of the switching transistors of the solenoid valve drive circuit fails, if the failure is a failure that cuts off between the emitter and collector of the transistor, the solenoid is de-energized to When the solenoid valve can be driven to be closed, and if the failure is a failure in which the emitter and collector of the transistor are short-circuited, one switching transistor and the drive signal output circuit corresponding thereto are normal. As long as the misfire is detected in the combustion section or the object to be heated is overheated, the electromagnetic valve can be closed.

[0019]

In each of these aspects of the present invention,
When two sets of the drive signal output circuit and the switching transistor are provided and each switching transistor is configured to be conductive by base inputs of high and low reverse levels, both of the two sets of drive signal output circuits fail. However, the solenoid valve can be driven to close. That is,
When both of the drive signal output circuits fail, the base input of each switching transistor generally becomes the same level of high or low due to an internal short circuit of the drive signal output circuit. Therefore, if it is configured that the conduction state of each transistor is caused by the base input of the same level, both of the transistors become conduction state, the solenoid is energized, and the solenoid valve is maintained in the open state. There is a possibility. Therefore, by making each switching transistor conductive by the base inputs of high and low reverse levels, even if both of the drive signal output circuits fail as described above, the base of one of the switching transistors is connected. Is inputted with a signal of a level that brings it into a cutoff state, whereby the transistor is cut off and the energization of the solenoid is cut off, and the solenoid valve is driven to close.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory system configuration diagram of the combustion device of the present embodiment, and FIG. 2 is a circuit configuration diagram of a main part of the combustion device of FIG.

In FIG. 1, the combustion apparatus of this embodiment is, for example, a gas stove, and an opening / closing solenoid valve 3 is provided in a gas supply passage 2 (fuel supply passage) for supplying gas (fuel) to a burner 1 which is a combustion section. A gas amount adjusting valve 4 for adjusting the gas supply amount is provided. In this case, the solenoid valve 3 is driven to open by energizing the solenoid 5 and is closed to close the energization of the solenoid 5, and the gas amount adjusting valve 4 is opened by operating the operator 6 connected thereto, for example. The degree is adjusted.

Further, the gas stove of this embodiment is provided with a control unit 7 composed of various electronic circuits described later, and the control unit 7 includes a solenoid 5 of the solenoid valve 3.
And a temperature detector 8 provided at the center of the burner 1 to detect the heating temperature of the cooked food, and a combustion detector provided near the burner 1 to detect combustion / misfire of the burner 1. 9, a sparker 11 that causes a spark discharge to an ignition electrode 10 provided near the burner 1, and an ignition / fire extinguishing switch 12 for performing ignition / fire extinguishing operations of the burner 1. In this case, the control unit 7 uses the battery 13 (shown in FIG. 2) as a power source.
Furthermore, an LED lamp 14 for notifying the user of the degree of consumption of the battery 13 (voltage state of the battery 13) is connected.

The temperature detector 8 has a built-in thermistor 15 (shown in FIG. 2) which is a temperature sensor, and is used for cooking when a cooking pot or the like accommodating food is placed on the burner 1. The pan is contacted, and at this time, a signal corresponding to the heating temperature of the cooking pan or the like is output from the thermistor 15 to the control unit 7.

Further, the combustion detector 9 has a built-in thermocouple 16 (shown in FIG. 2) which is a sensor for detecting combustion, and the thermocouple 16 outputs a signal corresponding to the calorific value of the burner 1 to the control unit 7. Output to.

The control unit 7 is activated in association with the ON operation of the ignition / extinguishing switch 12, and upon activation thereof, the solenoid 5 is energized to open the solenoid valve 3 and drive the burner. 1 is supplied with gas, and spark discharge is generated in the ignition electrode 10 via the sparker 11, so that the burner 1 is ignited.

Further, as will be described later in detail, the control unit 7 detects combustion / misfire of the burner 1 by the output signal of the thermocouple 16, and also the heating temperature of the cooked food by the burner 1 and disconnection of the thermistor 15. Failure of the thermistor 1
5 output signal, burner 1 misfire detected by thermocouple 1
6, when the heating temperature of the cooked food detected through the thermistor 15 becomes higher than a predetermined reference temperature, or when the wire breakage of the thermistor 15 is detected, The solenoid valve 3 is driven to be closed via the solenoid 5.

Further, the control unit 7 monitors the voltage of the battery 13 and drives the LED lamp 14 or the solenoid valve 3 via the solenoid 5 when the voltage drops below a predetermined reference voltage. It is designed to be closed.

Next, the main circuit configuration of the control unit 7 will be described in detail with reference to FIG.

In FIG. 2, the control unit 7 includes a thermocouple circuit 17 for generating a voltage signal according to the heat generation amount of the burner 1 by the thermocouple 16, and a burnout of the burner 1 by an output signal of the thermocouple circuit 17. First and second combustion detection circuits 18 and 19 for detecting misfire, a thermistor circuit 20 for generating a voltage signal according to the heating temperature of the cooked food by the thermistor 15, and a cooked food by an output signal of the thermistor circuit 20. First and second temperature detection circuits 21 and 22 for detecting the heating temperature of the thermistor, and a disconnection detection circuit 23 for detecting the disconnection of the thermistor 15 by the output signal of the thermistor circuit 20,
A first timer circuit 24 that receives signals from the first combustion detection circuit 18 and the first temperature detection circuit 21 and outputs a signal for opening and closing the solenoid valve 3, and a signal from the disconnection detection circuit 23 that receives the electromagnetic waves. A second timer circuit 25 that outputs a signal for opening / closing the valve 3 and two switching transistors 2
6 and 27, and a solenoid valve drive circuit 28.

Here, in accordance with the configuration of the present invention, a circuit combining the first combustion detection circuit 18, the first temperature detection circuit 21, and the first timer circuit 24, the second combustion detection circuit 19, and the second combustion detection circuit 19.
A circuit including the temperature detection circuit 22, the disconnection detection circuit 23, and the second timer circuit 25 is a drive signal output circuit 29.
a and 29b. In this embodiment, two sets of drive signal output circuits 29a and 29b are provided.

The first and second combustion detection circuits 18, 19
Have the same configuration, and these detection circuits 18, 19
Is provided with a comparator 30 for comparing the output voltage of the thermocouple circuit 17 according to the heat generation amount of the burner 1 with a reference voltage for combustion / misfire determination. And these detection circuits 1
The comparators 8 and 19 detect whether the burner 1 is in a combustion state or a misfire state by comparing the output voltage of the thermocouple circuit 17 with a reference voltage for combustion / misfire determination by the comparator 30. In response to the detection of misfire, the comparator 30 outputs a voltage signal of high and low binary levels. In the following description, a voltage signal having a level corresponding to the combustion state of the burner 1 will be referred to as a combustion detection signal, and a voltage signal having a level corresponding to the misfire state of the burner 1 will be referred to as a misfire detection signal.

The output of the first combustion detection circuit 18 is input to the first timer circuit 24, and the output of the second combustion detection circuit 19 is input to the disconnection detection circuit 23.

The first and second temperature detection circuits 21 and 22
Has the same basic configuration, and includes a comparator 31 for comparing the output voltage of the thermistor circuit 20 according to the heating temperature of the cooked food by the burner 1 with a reference voltage corresponding to a reference temperature for overheating determination. ing. Then, these detection circuits 21 and 22 detect whether the cooking temperature of the cooked food is higher or lower than the reference temperature by comparing the output voltage of the thermistor circuit 20 with the reference voltage for overheating determination by the comparator 31. The comparator 31 outputs a voltage signal of high and low binary levels according to the level of the temperature. In the following description, the voltage signal of the level corresponding to the case where the heating temperature of the cooked food is higher than the reference temperature is the overheating detection signal, and the voltage signal of the level corresponding to the case where the heating temperature is lower than the reference temperature is normally heated. It is called a detection signal.

In this case, in this embodiment, the reference temperature for overheating determination of the first temperature detection circuit 21 and the reference temperature for overheating determination of the second temperature detection circuit 22 are set to different values. In the first temperature detection circuit 21, for example, 26
The reference temperature is 0 ° C., and in the second temperature detection circuit 22, for example, 290 ° C. is the reference temperature.

The output of the first temperature detection circuit 21 is input to the first timer circuit 24, and the output of the second temperature detection circuit 22 is input to the base of the transistor 27 of the solenoid valve drive circuit 28. Further, the overheating detection signal and the normal heating detection signal which are the outputs of the second temperature detection circuit 22 are low level and high level signals, respectively, and these signals respectively drive the solenoid valve 3 to be closed as described later. It is used as a signal and an open drive signal.

The disconnection detection circuit 23 includes a thermistor 15
The thermistor circuit 20 is provided with a comparator 32 for comparing the output voltage of the thermistor circuit 20 with a reference voltage for disconnection determination.
By comparing the output voltage of the above with the reference voltage for the disconnection determination, it is detected whether or not the thermistor 15 is disconnected, and a high / low binary voltage signal is output from the comparator 32 according to the detection of the disconnection / non-disconnection. I am trying to output. In this case, the output of the second combustion detection circuit 19 is also input to the comparator 32. The comparator 32 detects the disconnection of the thermistor 15 and the second combustion detection circuit 19 when the disconnection is detected. The voltage signal of the same level is output when the misfire is detected by, and the voltage signal of the other level is output in other cases. Hereinafter, the voltage signal of the level corresponding to the disconnection of the thermistor 15 or the misfire of the burner 1 is referred to as a disconnection / misfire detection signal.

The output of the disconnection detection circuit 23 is input to the second timer circuit 25.

The first timer circuit 24 has a predetermined time constant when the misfire detection signal is output from the first combustion detection circuit 18 or the overheat detection signal is output from the first temperature detection circuit 21. Capacitor 33 to be charged and discharged
And a comparator 35 for comparing the voltage of the capacitor 33 with a reference voltage for determining output timing. As for the time constant of the time constant circuit 34, the misfire detection signal from the first combustion detection circuit 18 or the overheat detection signal from the first temperature detection circuit 21 has a predetermined time (7 seconds in this embodiment, hereinafter referred to as timer time). ) The voltage of the capacitor 33 is set to a predetermined value when continuously output.

The comparator 35 for generating the output of the first timer circuit 24 receives the misfire detection signal from the first combustion detection circuit 18 or the overheat detection signal from the first temperature detection circuit 21 as the timer time, When continuously output, this is detected by the voltage of the capacitor 33,
In response to this, the closing drive signal for the solenoid valve 3 is output, and at other times, the opening drive signal for the solenoid valve 3 is output. In this case, the output of the comparator 35 is a high / low binary level signal, the closing drive signal of the solenoid valve 3 is at a high level, and the open drive signal is at a low level.

The second timer circuit 25 has the same basic configuration as the first timer circuit 24 and includes a time constant circuit 37 having a capacitor 36 and a comparator 38. Then, the second timer circuit 25 uses the first timer circuit 2
As in the case of 4, a predetermined time in which the disconnection / misfire detection signal from the disconnection detection circuit 23 is determined by the time constant of the time constant circuit 37 (for example, 10 seconds in the present embodiment, hereinafter referred to as timer time).
The comparator 38 outputs a closing drive signal for the solenoid valve 3 when continuously output, and outputs an open drive signal for the solenoid valve 3 at other times. In this case, the comparator 38 is provided with a polarity such that the closing drive signal of the solenoid valve 3 becomes low level and the opening drive signal becomes high level, contrary to the comparator 35 of the first timer circuit 24.

In the solenoid valve drive circuit 28, the solenoid 5 of the solenoid valve 3 is connected to the switching transistors 26 and 27.
Are connected in series, and the transistors 26, 27
When both are in the conductive state (ON state), the solenoid 5
To energize the solenoid valve 3 to open the solenoid valve 3, and when one of the transistors 26 and 27 is turned off (OFF state), the solenoid 5 is turned off to turn on the solenoid valve 3. It is designed to be closed.

In this case, the transistor 26 is of PNP type and is connected to the timer circuit 24 with the output of the first timer circuit 24 as a base input. As a result, the transistor 26 becomes conductive when the low-level signal that is the open drive signal for the solenoid valve 3 is output from the first timer circuit 24, and the high-level signal that is the close drive signal for the solenoid valve 3 is turned on. The output is cut off.

On the other hand, the transistor 27 is of NPN type, and the outputs of the second timer circuit 25 and the second temperature detection circuit 22 are used as base inputs for these circuits 2.
5, 22 are connected. As a result, the transistor 27 becomes conductive when the second timer circuit 25 or the second temperature detection circuit 22 outputs a high level signal which is an open drive signal for the solenoid valve 3, and the close drive signal for the solenoid valve 3 is generated. When a low level signal is output, the circuit is turned off.

Therefore, the transistors 26 and 27 are configured so that conduction and interruption thereof are performed by signals having mutually opposite levels.

Further, in this embodiment, between the output points of the second timer circuit 25 and the second temperature detection circuit 22 and the base of the transistor 27, the outputs of these circuits 25 and 22 are connected to the base of the transistor 27. A delay circuit 39 for interposing a voltage with a slight time delay is provided.
The delay circuit 39 is composed of a resistor 40 and a capacitor 41. The output of the second timer circuit 25 and the second temperature detection circuit 22 charges and discharges the capacitor 41 via the resistor 40, and the voltage of the capacitor 41 is increased. Is applied to the base of the transistor 27. As a result, the second timer circuit 25 and the second temperature detection circuit 22
Is applied to the base of the transistor 27 with a delay of a time constant determined by the resistance value of the resistor 40 and the capacitance of the capacitor 41. Therefore, for example, the transistor 27
In the conduction state of (the base input is high level),
When the output of the second temperature detection circuit 22 changes from high level to low level for a moment due to noise or the like, the instantaneous low level signal is not applied to the base of the transistor 27. , The conduction state of the transistor 27 is maintained.

In the present embodiment, the delay time of the output of the second timer circuit 25 and the second temperature detection circuit 22 by the delay circuit 39 is set to about several milliseconds, and the timer time of the second timer circuit 25 ( It is considered to be sufficiently shorter than 10 seconds).

By the way, in the present embodiment, while the various circuits of the control unit 7 as described above operate using the battery 13 as a power source, the power source voltage at which the battery 13 can normally operate is fixed. If the power supply voltage drops below the operable limit voltage, normal operation cannot be expected.
Therefore, when the battery 13 is exhausted and its output voltage drops to some extent, the combustion detection circuits 18, 19 and the solenoid valve drive circuit 28 do not operate normally, and the solenoid valve 3 cannot be normally driven. There is fear.

Therefore, in this embodiment, the control unit 7 sequentially monitors the voltage of the battery 13 during operation of the gas stove, and when the voltage drops to some extent, the LED lamp 14 notifies the user of this fact. Shime, or
The solenoid valve 3 is driven to close.

The structure relating to the monitoring and control of the voltage of the battery 13 will be described below.

Referring to FIG. 2, the battery 13 is turned on / off in association with the ignition / extinguishing switch 12 (see FIG. 1).
The micro switch 42 for F is connected, and the battery voltage V _D generated at the point P in the latter stage of the micro switch 42 is supplied to the compensator 30 of the combustion detection circuits 18, 19 and the solenoid valve drive circuit 28 as their power supply voltage. It has become so. Although not shown in the figure, the battery voltage V _D is also supplied to the sparker 11.

Further, in the subsequent stage of the micro switch 42,
A regulator 43, which receives the battery voltage V _D as an input and generates a constant voltage, is connected, and an output voltage V of the regulator 43 is connected.
_R (hereinafter, referred to as regulator voltage V _R ) is supplied as a voltage for generating a reference voltage in the comparator 30 and the like of the combustion detection circuits 18 and 19.

On the other hand, the control unit 7 of this embodiment compares the battery voltage V _D with a predetermined determination voltage, and blinks the LED lamp 14 in accordance with the output of the comparator 44. Drive circuit 4
6 and the LED lamp 1 according to the output of the comparator 45.
The battery voltage V _D is monitored by the voltage of the lighting drive circuit 47 that drives the lamp 4 and the capacitor 49 connected to the point P via the resistor 48, and when the battery voltage V _D becomes a predetermined value or less, A battery voltage monitoring circuit 50 for outputting a closing drive signal (low level signal) of the solenoid valve 3 is provided to the input side of the delay circuit 39 connected to the base of the transistor 27 of the solenoid valve drive circuit 28.

The battery voltage V _D is input to each of the comparators 44 and 45 via the dividing resistors 51 and 52 connected to the point P, and three comparators connected to the output side of the regulator 43. Determination voltages of different levels are input via the dividing resistors 53, 54, 55. In the present embodiment, the rated value of the battery voltage V _D in a new state of the battery 13 is set to, for example, 3V, the determination voltage in the comparator 44 is set to, for example, 2.65V, and the determination voltage in the comparator 45 is set to, for example, 1.9V. To be done. The combustion detection circuits 18 and 19, the solenoid valve drive circuit 28, and the like can operate normally until the battery voltage V _D drops to about 1.9 V, which is the determination voltage of the comparator 45. .

Each of the comparators 44 and 45 has its own
Judgment voltage and battery voltage V _DAnd the
Pond voltage V_DHigh and low binary level corresponding to the judgment voltage
The bell signals are sent to the blinking drive circuit 46 and the lighting drive, respectively.
The signal is output to the drive circuit 47. In this case, blink
The drive circuit 46 has a battery voltage V_DIs the size of the comparator 44
A signal indicating that the voltage has dropped below the constant voltage (2.65V)
The LED run when output from the comparator 44
The flash 14 is driven to blink. Also, lighting drive
The circuit 47 has a battery voltage V_DIs the judgment voltage of the comparator 45
The signal indicating that the voltage has dropped below the pressure (1.9 V) is
The LED lamp 14 when output from the palletizer 45
Is driven to light up.

In this embodiment, the battery voltage V _D of the comparator 45 is the judgment voltage (1.
The latch circuit 56 is connected to hold the output of the comparator 45 when the signal indicating that the output voltage has dropped to 9 V) or less is output from the comparator 45. The output of the comparator 45 is input to the first timer circuit 24. In the first timer circuit 24, the battery voltage V _D from the comparator 45 is the judgment voltage (1.9) of the comparator 45.
V) Even when a signal indicating that the voltage has dropped below V is output, a closing drive signal for the solenoid valve 3 is output to the transistor 26 of the solenoid valve drive circuit 28.

It should be noted that the comparators 44 and 45 and the blinking drive circuit
The path 46 and the lighting drive circuit 47 are connected to the combustion detection circuit 18,
The battery voltage V as in the converter 30 of 19_DPower supply
It is the pressure and is the judgment voltage of the comparator 45.
Battery voltage V to 1.9V _DIs normal until
It is supposed to work.

The battery voltage monitoring circuit 50 detects the battery voltage V
_D is used as the power supply voltage, and in this case, the circuit 50 reduces the battery voltage V _D to a voltage (about 1 V in this embodiment) that is lower than 1.9 V which is the determination voltage of the comparator 45. It is supposed that it can operate normally until. Then, the battery voltage monitoring circuit 50 outputs the closing drive signal of the solenoid valve 3 to the base side of the transistor 27 of the solenoid valve drive circuit 28, for example, when the battery voltage V _D drops to 1.7 V or less. There is.

In this embodiment, when the battery voltage V _D drops to a voltage (about 1.5 V in this embodiment) lower than 1.7 V which is the judgment voltage of the battery voltage monitoring circuit 50, the transistor A transistor cutoff circuit 57 for cutting off the transistor 27 is provided at the input portion to the base of the transistor 27. The transistor cutoff circuit 57 has the delay circuit 3 at the base of the transistor 27.
The pair of dividing resistors 58 and 59 connected via a 9 is obtained by so applying via the delay circuit 39 a voltage obtained by dividing the battery voltage V _D to the base of the transistor 27, the battery voltage V _D Is about 1.5V,
The dividing resistor 5 is applied so that a voltage for turning off the transistor 27 is applied to the base of the transistor 27.
Resistance values of 8,59 are set.

Next, the operation of the gas stove of this embodiment will be described.

In the gas stove of this embodiment, when the ignition / fire extinguishing switch 12 is turned on, the micro switch 42 is turned on in synchronization with this, whereby each circuit of the control unit 7 receives the battery voltage V _D from the battery 13. Is supplied to activate each circuit.

At this time, first, the timer circuits 24 and 25 output an open drive signal for the solenoid valve 3, whereby the transistors 26 and 27 of the solenoid valve drive circuit 28 are turned on and the solenoid valve 3 is turned on. The solenoid 3 of No. 3 is energized by the battery 13 to open the solenoid valve 3. Then, when the solenoid valve 3 is driven to open, gas supply to the burner 1 is started. Further, in parallel with this, the sparker 11 is driven by the battery voltage V _D , whereby the ignition electrode 10
Ignition sparks occur at.

At this time, each combustion detection circuit 18, 19 outputs a misfire detection signal because the electromotive force of the thermocouple 16 is small until the burner 1 ignites, and the first combustion detection circuit 18
The misfire detection signal of is input to the first timer circuit 24, and the second
The misfire detection signal of the combustion detection circuit 19 is input to the second timer circuit 25 via the disconnection detection circuit 23.

When the misfire detection signal of the first combustion detection circuit 18 is continuously output for the timer time (7 seconds) of the timer circuit 24, that is, within the timer time, When the electromotive force of the thermocouple 16 does not exceed a predetermined value, the closing drive signal (high level signal) of the solenoid valve 3 is transferred to the transistor 26 of the solenoid valve drive circuit 28.
To the base of the transistor to turn off the transistor 26. As a result, the solenoid 5 of the solenoid valve 3 is de-energized, the solenoid valve 3 is closed, and the gas supply to the burner 1 is shut off.

Similarly, the second timer circuit 25 has the thermocouple 16 within the timer time (10 seconds) of the timer circuit 25.
If the electromotive force of the solenoid valve does not exceed a predetermined value, the solenoid valve drive circuit 2 outputs a close drive signal (low level signal) for the solenoid valve 3.
8 to the base of the transistor 27 to turn off the transistor 27 and close the solenoid valve 3. still,
At this time, since the output of the timer circuit 25 is applied to the base of the transistor 27 via the delay circuit 39, a slight time delay occurs, but the delay time is longer than the timer time (10 seconds) of the timer circuit 25. Since the time is sufficiently short, that is, about several milliseconds, the transistor 27 can be used almost when the timer time has elapsed.
A closing drive signal is applied to the base of the.

In this case, the timer time (7 seconds) of the first timer circuit 24 is equal to the timer time (10 seconds) of the second timer circuit 25.
Second), the solenoid valve 3 is normally driven to close according to the timer time of the first timer circuit 24. Then, for example, when the first timer circuit 24 or the first combustion detection circuit 18 corresponding thereto fails for some reason and the output of the first timer circuit 24 is maintained at the level of the opening drive signal of the solenoid valve 3, If the second timer circuit 25, the second combustion detection circuit 19 and the like are normal, the solenoid valve 3 is driven to close according to the timer time of the second timer circuit 25. Therefore, one of the drive signal output circuit 29a including the first timer circuit 24 and the first combustion detection circuit 18 and the drive signal output circuit 29b including the second timer circuit 25 and the second combustion detection circuit 19 is normal. If so, when the burner 1 does not ignite, the electromagnetic valve 3 is driven to be closed and the gas supply to the burner 1 is cut off.

Further, in this embodiment, since the signal levels for turning off the transistors 26 and 27 are different from each other, for example, the first timer circuit 24 and the second timer circuit 2 are used.
Even if both 5 are out of order, the solenoid valve 3 can be driven to be closed. That is, in general, when both the first timer circuit 24 and the second timer circuit 25 fail, the comparators 35, 38 of these timer circuits 24, 25
In many cases, the output point of is short-circuited to the ground side or the power supply side, and the output levels of both timer circuits 24 and 25 are the same level. In such a case, in the present embodiment, since the signal levels for turning off the transistors 26 and 27 are different from each other, either one of the transistors 26 and 27 is turned off, whereby the solenoid valve 3 is driven to close. It
For example, when the output levels of both timer circuits 24 and 25 become high, the transistor 26 is turned off and the solenoid valve 3 is driven to close.

In the operation at the time of ignition, the timer time of the first timer circuit 24 or the second timer circuit 25
When the burner 1 ignites within the timer time of, and the electromotive force of the thermocouple 16 becomes equal to or higher than a predetermined value, this is detected by the first combustion detection circuit 18 or the second combustion detection circuit 19, and these A combustion detection signal is output from the circuits 18 and 19. Then, in this case, the first timer circuit 24 and the second timer circuit 25 continuously output the open drive signal of the solenoid valve 3.

The operation described above is similarly performed when the burner 1 misfires for some reason after the combustion of the burner 1 is started.

On the other hand, at the time of heating the food by burning the burner 1, the heating temperature is detected by the first and second temperature detecting circuits 21 and 22 through the thermistor circuit 20. Then, the first temperature detection circuit 21 sends an overheating detection signal to the first timer circuit 24 when the detected heating temperature is equal to or higher than 260 ° C. which is the reference temperature for overheating determination of the circuit 21. Output. At this time, the first timer circuit 24 outputs the closing drive signal of the solenoid valve 3 to the transistor 26 when the overheat detection signal is continuously output from the first temperature detection circuit 21 for the timer time (7 seconds). Output. As a result, the transistor 26 is shut off, the solenoid valve 3 is driven to close, and the combustion of the burner 1 is stopped to prevent overheating. At this time, the heating temperature temporarily exceeds the reference temperature due to fluctuations in the combustion flame of the burner 1, etc., and the overheating detection signal from the first temperature detection circuit 21 is output for a short time (<7
However, in such a case, the continued output time of the overheat detection signal is the first timer circuit 2
Since it is shorter than the timer time of 4, the timer circuit 24 does not output the closing drive signal.

In addition, the second temperature detection circuit 22 detects, when the detected heating temperature is 290 ° C. or higher, which is higher than the reference temperature for judging overheating of the first temperature detection circuit 21,
The low-level overheat detection signal is output to the base side of the transistor 27 without passing through the second timer circuit 25. The low level overheat detection signal is sent to the delay circuit 3
It is applied to the base of the transistor 27 via 9. In this case, since the overheat detection signal is applied to the base of the transistor 27 via the delay circuit 39, it is applied to the base of the transistor 27 with a slight delay from the output point of the overheat detection signal. The delay is a few meters
It is about a second. Therefore, when the heating temperature exceeds 290 ° C., basically, a low-level signal is immediately applied to the base of the transistor 27, whereby the transistor 27 is turned off and the solenoid valve 3 operates. It is driven closed.
At this time, the second temperature detection circuit 22 may occasionally output an overheat detection signal due to noise or the like. However, such a single overheat detection signal is removed by the delay circuit 39 and the transistor is removed. It is not applied to the base of 27, and therefore the solenoid valve 3 is not driven to close.
By the operation of the temperature detection circuits 21 and 22 as described above,
For example, even if the first temperature detection circuit 21 or the first timer circuit 24 fails, if the second temperature detection circuit 22 is normal if the heating temperature becomes abnormally high, The temperature detection circuit 22 can drive the solenoid valve 3 to close, and either one of the drive signal output circuit 29a including the first temperature detection circuit 21 and the drive signal output circuit 29b including the second temperature detection circuit 22 is normal. If so, the solenoid valve 3 can be driven to be closed. Further, for example, the heating temperature is 26
When the heating temperature rapidly rises within the timer time (7 seconds) of the first timer circuit 24 after the temperature becomes 0 ° C. or higher, the second temperature detection circuit 22 drives the solenoid valve 3 to close. It is possible to prevent sudden overheating.

In addition, when the thermistor 15 is disconnected during the operation of the gas stove as described above, the disconnection is detected by the disconnection detection circuit 23. At this time, the disconnection detection circuit 23 detects the disconnection detection signal. Is output to the second timer circuit 25. Then, the second timer circuit 25
Outputs the closing drive signal of the solenoid valve 3 to the base of the transistor 27 when the disconnection detection signal is continuously output for the timer time (10 seconds). As a result, the transistor 27 is turned off and the solenoid valve 3 is driven to close. In this case, when the temperature is low when the burner 1 is ignited, or when the frozen food is cooked, the temperature rise of the thermistor 15 is slow, and the resistance value of the thermistor 15 becomes a large value of several MΩ, resulting in a disconnection In the same manner as in the above case, the disconnection detection circuit 23 may output a disconnection detection signal. However, in the present embodiment, when the disconnection detection signal continues for the timer time (10 seconds) of the second timer circuit 25, the solenoid valve 3 is driven to be closed, so that the temperature of the thermistor 15 is increased as described above. It is possible to avoid a situation in which the solenoid valve 3 is driven to be closed even though there is no disconnection when the value is low.

Next, the operation relating to the monitoring of the battery voltage V _D will be described.

When the battery 13 is exhausted during operation of the gas stove as described above and the battery voltage V _D thereof drops below 2.65 V which is the judgment voltage of the comparator 44, this is detected by the comparator 44. Then, the comparator 44 outputs a signal indicating this to the blinking drive circuit 46. At this time, the blink drive circuit 46
Causes the LED lamp 14 to blink so that the user can recognize that the battery 13 is near the end of its life. In this embodiment, since the burner 1 is ignited by the sparker 11 using the battery 13 as a power source, the battery voltage V _D is changed by the power supply to the sparker 11 during the ignition operation for the ignition. Below the judgment voltage of 44, the voltage may drop to a voltage at which the operation of the various circuits described above may become unstable, and the battery voltage V _D may rise above the judgment voltage again after the ignition operation. In such a case, the LED lamp 14 blinks only when the sparker 11 is operating, while the LED lamp 14 is turned off again after the ignition operation, and the user often overlooks the blinking of the LED lamp 14. Therefore, in this embodiment, the comparator 4
The determination voltage of 4 is set relatively high (2.65 V) so that the LED lamp 14 blinks early.

Further, the battery voltage V _D is equal to that of the comparator 4
When the voltage drops below 1.9V which is the judgment voltage of 5,
This is detected by the comparator 45, and the comparator 45 outputs a signal indicating this to the lighting drive circuit 47. At this time, the lighting drive circuit 47 drives the LED lamp 14 to light, thereby making the user recognize that the battery 13 needs to be replaced.

In this case, in this embodiment, the comparator 4
5 is the battery voltage V_DOnce drops below 1.9V,
So that its output is held by the latch circuit 56.
Therefore, when the ignition operation is performed,
Battery voltage V due to power supply _DOf the comparator 45
Below the judgment voltage (1.9V), the operation of the above-mentioned various circuits
The voltage drops to a level that may cause instability, and ignition
Battery voltage V again after making _DIs higher than the judgment voltage
Battery voltage V_DHas dropped below 1.9V
The signal shown continues to be output from the comparator 45,
Then, the LED lamp 14 is continuously turned on. This
Battery voltage V_DThe operation of the above-mentioned various circuits even for a short time
If the voltage drops to an unstable value, the user
Make sure that the battery 13 needs to be replaced.
You can The latch circuit 56 is connected to the comparator 44 side.
To hold the output of the comparator 44
May be.

At this time, the output of the comparator 45, which indicates that the battery voltage V _D has dropped below 1.9 V, is the first
It is also input to the timer circuit 24, and a closing drive signal for the solenoid valve 3 is output from the first timer circuit 24. As a result, the transistor 26 is turned off and the solenoid valve 3 is driven to close.

By the way, when the battery voltage V _D drops to a level (for example, about 1.8 V) at which the operations of the comparators 44 and 45 are temporarily unstable due to the operation of the sparker 11 as described above, The comparator 45 and the first timer circuit 24 do not operate as described above, and the solenoid valve 3
However, a situation may occur in which the drive is not closed by the comparator 45 or the first timer circuit 24.

In the present embodiment, however, the battery voltage monitoring circuit 50 which can normally operate up to a battery voltage V _{D of} about 1 V is provided, and the battery voltage monitoring circuit 50 is provided.
Outputs a close drive signal (low level signal) to the base of the transistor 27 when the battery voltage V _D drops below 1.7V. As a result, the transistor 27 is turned off and the solenoid valve 3 is driven to close.

Further, in this embodiment, even if the battery voltage monitoring circuit 50 should fail, if the battery voltage V _D drops to about 1.5 V, the transistor shutoff circuit 57 causes the solenoid valve 3 to operate. It can be closed. That is, when the battery voltage V _D drops to about 1.5 V, the dividing resistor 5 of the transistor cutoff circuit 57 is connected.
A low level voltage is applied to the base of the transistor 27 from the midpoint of 8, 59, whereby the transistor 27 is shut off and the solenoid valve 3 is driven to close.

[0081] Thus, in the gas stove of the present embodiment, it is possible to recognize the appropriately user of the drop of the battery voltage V _D, reliably solenoid valve 3 with a decrease of the battery voltage V _D closed Can be driven.

In the embodiment described above, the first timer circuit 24 is shared by the first combustion detection circuit 18 and the first temperature detection circuit 21, but the first combustion detection circuit 1
8 and the first temperature detection circuit 21 may include separate timer circuits. However, the circuit configuration can be simplified by sharing the first timer circuit 24 between the first combustion detection circuit 18 and the first temperature detection circuit 21 as in the present embodiment. In this case, the timer time of the first timer circuit 24 is preferably set to be relatively long from the viewpoint of performing a smooth ignition to the burner 1.
Further, from the viewpoint of preventing overheating, it is preferable to set it relatively short. In the present embodiment, the timer time is set to 7
By setting it to seconds, both conditions are satisfied.

Further, in the present embodiment, two sets of drive signal output circuits 29a and 29b including the combustion detection circuit and the temperature detection circuit are provided, but more drive signal output circuits may be provided. Of course.

Further, in this embodiment, the sparkler 11
However, the present invention can be applied to a gas stove that uses a piezoelectric element for ignition or a gas stove that uses a commercial power source as a power source. It is needless to say that the present invention can be applied to this combustion device.

In this embodiment, the solenoid valve 3 is electrically driven. However, for example, the solenoid valve 3 is mechanically opened in conjunction with an ignition / fire extinguishing switch, and the open state of the solenoid valve 3 is changed. It may be electrically maintained by energizing the solenoid 5.

Further, in this embodiment, regarding the monitoring of the battery voltage V _D , the determination voltage for the blinking drive of the LED lamp 14 and the determination voltage for the lighting drive are taken into consideration in consideration of the decrease of the battery voltage V _D by the sparker 11. However, for example, in a gas stove using a piezoelectric element for ignition or a gas stove having a separate power source for a sparker, the LED lamp 14
It is also possible to set a determination voltage different from that of this embodiment, such as setting the determination voltage for the blinking driving of No. 2 lower than that of this embodiment.

Further, in the present embodiment, the battery voltage V _D is supplied to the transistor cutoff circuit 57. However, for example, as shown by a phantom line in FIG.
The resistor 58 of No. 7 may be connected to the collector of the transistor 26 to supply the battery power supply V _D to the transistor cutoff circuit 57 via the transistor 26. By doing so, the following advantages can be obtained. Occurs.

That is, in the above-mentioned embodiment,
The battery voltage V _DPower directly
Therefore, the second timer circuit 25 fails, for example.
The output stage of the comparator 38 is kept open.
If the burner 1 misfires in such a situation
The star 26 is cut off by the first timer circuit 24.
Also the resistance of the transistor cutoff circuit 57 from the battery 13
The base current flows to the transistor 27 via 58,
The base current of the
It flows to the solenoid 5 of the solenoid valve 3. In this case, the transition
Although the base current of the star 27 is small,
In the case where the solenoid valve 3 is of low current operation type,
Is a solenoid valve generated by energizing the solenoid 5 with the base current.
3 may be kept open.

On the other hand, when the resistor 58 of the transistor cutoff circuit 57 is connected to the collector of the transistor 26 as shown by the phantom line in FIG. 2, when the transistor 26 is cut off as described above, the transistor Since the power supply to the cutoff circuit 57 is cut off, the transistor 27
The base current of the solenoid stops flowing, which causes the solenoid 5
The power supply to the solenoid valve 3 is completely cut off, and the solenoid valve 3 is reliably closed.

In this case, the transistor cutoff circuit 57
Is the battery voltage V when the transistor 26 is on.
_{When D} drops to about 1.5 V, a low level voltage is applied to the base of the transistor 27, and the transistor 27 is cut off as in the above-described embodiment.

[0091]

As is apparent from the above description, according to the first aspect of the present invention, a plurality of drive signal output circuits including the combustion detection circuit are provided, and high / low level open / close drive of each drive signal output circuit is provided. A plurality of switching transistors each having a signal as a base input are connected in series to a solenoid of a solenoid valve to form a solenoid valve drive circuit, and at least one drive signal output circuit outputs a close drive signal for the solenoid valve. At one time, the switching transistor having the closing drive signal as a base input is turned off to cut off the energization of the solenoid of the solenoid valve to drive the solenoid valve to close. Even if multiple failure occurs, if one drive signal output circuit is normal, it is possible to drive the solenoid valve to be closed, and as much as possible in case of misfire. It is possible to shut off the fuel supply to the combustion part by driving the magnetic valve to close, and at the same time, even if a failure occurs that shuts off the switching transistor that constitutes the solenoid valve drive circuit that drives the solenoid valve to open and close, The valve can be driven closed.

Then, each of the combustion detection circuits is connected in parallel to a single combustion detection sensor provided in the combustion section, and combustion / misfire of the combustion section is detected by an output signal of the sensor. This simplifies the device configuration.

According to the second aspect of the present invention, a plurality of drive signal output circuits including a temperature detection circuit are provided, and
A solenoid valve drive circuit is configured by connecting a plurality of switching transistors, whose base inputs are high-low level open / close drive signals of each drive signal output circuit, to a solenoid valve drive circuit, and at least one drive signal output circuit When the closing drive signal of the solenoid valve is output, the switching transistor whose base input is the closing drive signal is turned off.
Then, the solenoid of the solenoid valve is de-energized and the solenoid valve is driven to close, so that even if one or more of the drive signal output circuits fails, one drive signal output circuit can operate normally. If so, the solenoid valve can be driven to close, and when the heating temperature of the object to be heated becomes abnormally high, the solenoid valve can be driven to close as reliably as possible to shut off the fuel supply to the combustion section. However, it is possible to prevent overheating of the object to be heated, and at the same time, the solenoid valve is driven to close even when a failure occurs that shuts off the switching transistor that constitutes the solenoid valve drive circuit that drives the solenoid valve to open and close. be able to.

Then, each temperature detection circuit is connected in parallel to a single temperature sensor provided at a position in contact with the object to be heated,
By detecting the heating temperature of the object to be heated by the output signal of the sensor, the device configuration can be simplified.

According to the third aspect of the present invention, a drive signal output circuit including both a temperature detection circuit and a combustion detection circuit is provided, and when a misfire is detected by the combustion detection circuit or by the temperature detection circuit. When the detected temperature becomes higher than the reference temperature, each drive signal output circuit is configured to output a closing drive signal for the solenoid valve, and the solenoid valve drive circuit is configured as in the first aspect and the second aspect. With the same configuration, it is possible to shut off the fuel supply to the combustion unit by driving the solenoid valve to be closed as reliably as possible in a state where it is preferable to shut off the fuel supply to the combustion unit due to misfire or overheating. At the same time, the solenoid valve can be driven to close even when a failure occurs such that the switching transistor forming the solenoid valve drive circuit is cut off.

[0096]

Further, in the present invention of each aspect, two sets of the drive signal output circuit and the switching transistor are provided, and the respective switching transistors are made conductive by base inputs of high and low reverse levels. When a failure occurs such that the output point of each drive signal output circuit is short-circuited to the power supply side or the ground side, one of the switching transistors of the solenoid valve drive circuit can be shut off, which closes the solenoid valve. Can be driven.

[Brief description of drawings]

FIG. 1 is an explanatory system configuration diagram of an example of a combustion apparatus of the present invention.

FIG. 2 is a circuit configuration diagram of a main part of the combustion apparatus of FIG.

[Explanation of symbols]

1 ... Burner (combustion part), 2 ... Gas supply path (fuel supply path), 3 ... Solenoid valve, 5 ... Solenoid, 15 ... Thermistor (temperature sensor), 16 ... Thermocouple (combustion detection sensor),
18, 19 ... Combustion detection circuit, 21, 22 ... Temperature detection circuit, 26, 27 ... Switching transistor, 29a,
29b ... Drive signal output circuit.

Claims (6)

(57) [Claims] 1. An on-off solenoid valve provided in a fuel supply path for supplying fuel to a combustion section, and a combustion detection circuit for detecting combustion / misfire in the combustion section. Detection of combustion / misfire by the combustion detection circuit In a combustion apparatus including a drive signal output circuit that outputs a signal for opening and closing the solenoid valve according to, and an electromagnetic valve drive circuit that opens and closes the solenoid valve according to an output signal of the drive signal output circuit, A plurality of drive signal output circuits are provided, each drive signal output circuit is configured to output the opening / closing drive signal by a binary signal of high and low levels, and the solenoid valve is driven to open by energizing a solenoid. And a solenoid valve that is driven to be closed by shutting off the energization. The solenoid valve drive circuit receives high-low level open / close drive signals from the drive signal output circuits as base inputs. A plurality of switching transistors are connected in series to the solenoid, and when at least one drive signal output circuit outputs a closing drive signal for the solenoid valve, a switching transistor having the closing drive signal as a base input is turned off. A combustion device characterized by being configured. 2. A combustion detection circuit of each drive signal output circuit is connected in parallel to a single combustion detection sensor provided in the combustion section, and a combustion / misfire of the combustion section is detected by an output signal of the sensor. The combustion device according to claim 1, wherein the combustion device is detected. 3. An on-off solenoid valve provided in a fuel supply path for supplying fuel to a combustion section, and a temperature detection circuit for detecting a heating temperature of an object to be heated due to combustion in the combustion section, the temperature detection circuit comprising: A drive signal output circuit that outputs an opening / closing drive signal for the solenoid valve according to whether the detected temperature is low or high with respect to a predetermined reference temperature, and a solenoid valve that opens / closes the solenoid valve according to the output signal of the drive signal output circuit. In a combustion apparatus including a drive circuit, a plurality of the drive signal output circuits are provided, and each drive signal output circuit is configured to output the opening / closing drive signal by a binary signal of high and low levels, and the solenoid valve is , A solenoid valve that is driven to open by energizing the solenoid and closed by shutting off the energization. The solenoid valve drive circuit is configured to open and close high and low levels of each drive signal output circuit. A plurality of switching transistors each having a motion signal as a base input are connected in series to the solenoid, and when at least one drive signal output circuit outputs a close drive signal for the solenoid valve, the close drive signal is input as a base. And a switching transistor that is configured to be turned off. 4. The temperature detection circuit of each drive signal output circuit is connected in parallel to a single temperature sensor provided at a position in contact with the object to be heated, and the object to be heated is output by the output signal of the sensor. The combustion device according to claim 3, wherein a heating temperature is detected. 5. An on-off solenoid valve provided in a fuel supply path for supplying fuel to a combustion section, a combustion detection circuit for detecting combustion / misfire in the combustion section, and heating of an object to be heated by combustion in the combustion section. A temperature detection circuit for detecting a temperature; and a combustion detection circuit and a temperature detection circuit, which detect combustion / misfire by the combustion detection circuit and whether the temperature detected by the temperature detection circuit is low or high with respect to a predetermined reference temperature. A solenoid valve closing drive for outputting an opening / closing drive signal of the solenoid valve and for detecting a misfire by the combustion detection circuit or when the temperature detected by the temperature detection circuit becomes higher than the reference temperature. In a combustion device including a drive signal output circuit that outputs a signal and a solenoid valve drive circuit that opens and closes the solenoid valve according to an output signal of the drive signal output circuit, the drive signal output circuit includes a plurality of drive signal output circuits. Each of the drive signal output circuits is configured to output the open / close drive signal as a binary signal of high and low levels, and the solenoid valve is driven to open by energizing the solenoid and closed by shutting off the energization. The solenoid valve drive circuit comprises a plurality of switching transistors connected in series to the solenoid, each switching transistor having a high-low level opening / closing drive signal of each drive signal output circuit as a base input. The combustion device is configured such that, when one drive signal output circuit outputs a close drive signal for the solenoid valve, a switching transistor whose base input is the close drive signal is turned off. 6. A drive signal output circuit and two sets of switching transistors are provided, and each of the switching transistors is made conductive by base inputs of high and low reverse levels. The combustion device according to any one of 1.