JPH08327055A - Combustion controller - Google Patents

Abstract

PURPOSE: To simplify the structure of a combustion controller capable of effectively stopping fuel supply to a burner at the time of a malfunction for extinguishing the burner irrespective of abnormal high temperature of a material to be heated or continuously supplying fuel. CONSTITUTION: The combustion controller comprises a fuel supply switching valve 3 maintaining a valve opening state by conducting a current exceeding a set value in an operating coil 3a and closing by reducing the current, a thermocouple 4 for generating electromotive force by heating by the combustion of a burner 2, a reed switch S becoming a conductive state based on the electromotive force and a non-conductive state when the electromotive force is stopped, and a positive temperature coefficient thermistor increasing its resistance value when the temperature of the material to be heated becomes high. Further, the switch S, the thermistor 7, the coil 3a and a power source 8 are connected in a series state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects combustion state detecting means for detecting whether or not a burner is in a combustion state, and detects that the temperature of an object heated by the burner exceeds a set temperature. An overheat state detection means is provided, and the combustion state detection means detects that the burner is not in a combustion state, or the overheat state detection means causes the temperature of the heated object to exceed the set temperature. Is detected, the present invention relates to a combustion control device configured to close a valve closing type opening / closing valve provided in a fuel supply passage for the burner.

[0002]

2. Description of the Related Art A combustion control apparatus having the above-mentioned structure is used, for example, when the time of heating by combustion of a burner is too long and the temperature of an object to be heated reaches an abnormally high temperature exceeding a set temperature, or , If the burner is extinguished even though the fuel supply is continuing due to the overflow of the heated object, etc., by automatically closing the open / close valve, It is designed to ensure safety in use by avoiding the disadvantages such as continuous combustion and ignition of an object to be heated due to abnormally high temperature, and release of fuel gas (raw gas) for a long time. Is.

In this type of combustion control device, conventionally, for example, as shown in FIG. 6, as the combustion state detecting means, a thermocouple 20 for generating an electromotive force by being heated by a flame of a burner, and a thermocouple 20 A flame detection circuit 21 that amplifies the electromotive force generated by the thermocouple 20 and outputs predetermined information is provided, and as the overheat state detection means, a thermistor 22 having a negative characteristic in which the resistance value decreases as the ambient temperature increases increases. Configured to detect the temperature of the heated object,
Based on the information detected by the thermistor 22, there is provided a temperature detection circuit 23 or the like which outputs predetermined information when the temperature of the object to be heated reaches a state corresponding to the set temperature, and the output from the flame detection circuit 21 or the temperature. Based on any one of the outputs from the detection circuit 23, the drive circuit 24 turns off the transistor 25 provided in the energization path for the on-off valve actuating coil 3a to turn on the energized actuating coil 3a.
The on-off valve 3 that was maintained in the open state in a) was configured to be closed by the valve closing urging force.

In the thermoelectric conversion means such as the thermocouple, the electromotive force (voltage) generated is low (for example, in the case of a thermocouple, several tens m).
Therefore, the flame detection circuit as described above is required in order to accurately detect such a low voltage and control the switching of the transistor.

Further, since the thermistor having the negative characteristic has a characteristic that the change in the resistance value is almost linear with respect to the temperature change, it has an advantage that the temperature can be detected with relatively high accuracy.
When detecting temperature, this negative characteristic thermistor is generally used, but since this negative characteristic thermistor has a low resistance value when the temperature of the object to be heated rises,
For example, by using a comparison circuit or the like, when the output value (resistance value) of the thermistor reaches an output value corresponding to a temperature at which the temperature of the object to be heated exceeds the set temperature, the predetermined information is output in order to output predetermined information. A circuit is needed.

[0006]

However, in the above-mentioned conventional configuration, a plurality of electronic circuits such as the flame detection circuit, the temperature detection circuit and the drive circuit as described above are required, and such an electronic circuit is constructed. In addition to the disadvantage that a large number of parts are required and the configuration becomes complicated, and the number of parts is large, the production process becomes long and the cost becomes high.

The present invention has been made by paying attention to such a point, and an object thereof is to burner even if the temperature of the object to be heated becomes abnormally high or the fuel supply is continued. In a combustion control device that can accurately stop the fuel supply to the burner when there is an abnormality such as a fire extinguishing, the configuration is simplified.

[0008]

The features of the first invention are as follows:
Combustion state detecting means for detecting whether or not the burner is in a combustion state, and overheat state detecting means for detecting that the temperature of the heated object heated by the burner exceeds a set temperature, are provided. When the state detecting means detects that the burner is not in the combustion state, or when the overheated state detecting means detects that the temperature of the heated object exceeds the set temperature, fuel supply to the burner is performed. In a combustion control device configured to close a valve-closing type opening / closing valve provided in a passage, when a current exceeding a set value is passed, the opening / closing is performed against the valve-closing force. An operating coil for maintaining the valve in an open state and closing the opening / closing valve when the current decreases below the set value is provided, and the combustion state detecting means is configured to apply the combustion by the burner. When the electromotive force generated by the thermoelectric conversion means and the electromotive force generated by the thermoelectric conversion means is equal to or higher than the conduction electromotive force, the state becomes conductive, and the electromotive force is less than the non-conduction electromotive force lower than the conduction electromotive force. Then, the overheated state detection means is constituted by a temperature-sensitive variable resistance means whose resistance value becomes large when the temperature of the object to be heated becomes high. Each of the means, the variable resistance means, the operating coil and the power source are connected in series, the variable resistance means, when the temperature of the object to be heated exceeds the set temperature,
The point is that the current value supplied to the operating coil has a resistance value that is smaller than the set value.

A characteristic configuration of the second invention is to specify a configuration suitable for carrying out the first invention, wherein the switch means generates a magnetic field based on an electromotive force generated by the thermoelectric conversion means. The generating means and the contact which becomes conductive when the strength of the magnetic field generated by the magnetic field generating means becomes equal to or higher than the set value for conduction, and becomes non-conductive when the strength of the magnetic field becomes equal to or lower than the set value for non-conduction. It is in the point that is configured.

The characteristic constitution of the third invention specifies a constitution suitable for carrying out the first or second invention, and the resistance of the variable resistance means increases as the temperature of the object to be heated rises. It is composed of positive temperature coefficient thermistors.

A characteristic configuration of the fourth invention is to specify a configuration suitable for carrying out the first or second invention, wherein the variable resistance means has a temperature of the object to be heated lower than the preset temperature. If the temperature of the object to be heated exceeds the preset temperature, the switch is made non-conductive.

The characteristic configuration of the fifth invention is that the first, second, and third
Alternatively, it is intended to specify a configuration suitable for carrying out the fourth invention, and the thermoelectric conversion means is constituted by a thermocouple.

The characteristic constitution of the sixth invention specifies a constitution suitable for carrying out the first, second, third, fourth or fifth invention, and the power source is constituted by a dry battery. It is in.

The characteristic configuration of the seventh invention specifies a configuration suitable for carrying out the first, second, third, fourth, fifth or sixth invention, and ignition is performed based on an artificial operation. With starting the ignition operation for the burner by the means,
The point is that an energizing means for energizing the operating coil with a current exceeding the set value is provided from the start of the ignition operation until the set time elapses.

The characteristic constitution of the eighth invention specifies a constitution suitable for carrying out the first, second, third, fifth, sixth or seventh invention, wherein the thermoelectric conversion means is a stove. The variable resistance means is composed of a thermocouple attached to the burner, and the variable resistance means is composed of a positive temperature coefficient thermistor for detecting the temperature of the bottom of the cooker as the object to be heated.

[0016]

According to the characterizing feature of the first aspect of the invention, when the burner is burning, the thermoelectric conversion means generates an electromotive force, and when the electromotive force is equal to or higher than the electromotive force for conduction, the switch means becomes conductive. Also, when the temperature of the object to be heated is at a normal temperature not exceeding the set temperature, the variable resistance means has a low resistance value,
The current value applied to the operating coil becomes larger than the set value. Therefore, a current exceeding the set value is supplied from the power source to the operating coil, and the open / close valve is maintained in the open state.

If the burner extinguishes due to the overflow of the object to be heated or the like while the burner is operating for combustion, the heating by the burner is stopped, so the electromotive force by the thermoelectric conversion means is stopped. Becomes less than or equal to the electromotive force for non-conduction, and the switch means becomes non-conduction. As a result, the energization of the operating coil is stopped, and the opening / closing valve is closed by the valve closing urging force.

Further, when the temperature of the object to be heated exceeds the set temperature, the resistance value of the variable resistance means becomes large, and the current value supplied to the operating coil becomes smaller than the set value. The valve closes.

As described above, since the switch means changes between the conducting state and the non-conducting state based on the electromotive force of the thermoelectric conversion means, the energization state of the operating coil is controlled to be switched based on the output of the thermoelectric conversion means. It is not necessary to use a dedicated control means for controlling the variable resistance means, and when the temperature of the object to be heated exceeds the set temperature, the variable resistance means directly reduces the current supplied to the operating coil due to the change in the resistance value. Therefore, an electronic circuit for control is unnecessary.

According to the characterizing structure of the second invention, the following function is obtained in addition to the function of the characterizing structure of the first invention. The thermoelectric conversion means is heated by burning the burner, electromotive force is generated, based on the electromotive force, for example, a magnetic field generating means such as a coil, generates a magnetic field of a strength equal to or more than the set value for conduction, The contact becomes conductive. Also, the combustion of the burner is stopped, the electromotive force by the thermoelectric conversion means becomes less than the non-conduction electromotive force, the strength of the magnetic field generated by the magnetic field generation means becomes less than the non-conduction set value, and the contacts become non-conduction. It becomes a state.

Therefore, the electromotive force generated by the thermoelectric conversion means is effective as much as possible without loss in the circuit in which the current flows by the electromotive force, without using other circuit parts other than the magnetic field generation means. Can be used.

According to the characterizing feature of the third invention, the following effect is obtained in addition to the effect of the characterizing feature of the first or second invention.
Since the variable resistance means is composed of a positive temperature coefficient thermistor,
When the temperature of the object to be heated is low, the resistance value is low and the current value supplied to the operating coil becomes larger than the set value, and the open / close valve is maintained in the open state. The resistance value increases as the temperature of the object to be heated rises, and when the temperature of the object to be heated exceeds the set temperature, the resistance value at that time decreases the current value supplied to the operating coil from the set value. Then, the on-off valve closes.

Incidentally, the positive temperature coefficient thermistor is generally, for example, as shown in FIG. 3, when the temperature rises to a certain region,
It has the characteristic that the resistance value increases rapidly. For example, in the case where the resistance value changes proportionally with temperature change, if there are individual differences in the valve closing operation current value of the operation coil, fluctuations in the power supply voltage, etc. , The temperature variation of the object to be heated when the valve closing operation is performed tends to be large, but as described above, the positive temperature coefficient thermistor having the characteristic that the resistance value rapidly increases in a narrow temperature range is used. As a result, the variation in the temperature can be suppressed to be small.

According to the characterizing feature of the fourth invention, in addition to the function of the characterizing feature of the first or second invention, there is the following effect.
The variable resistance means is composed of a temperature sensitive switch, and if the temperature of the object to be heated is lower than the set temperature, it becomes conductive and the resistance value becomes extremely small, and the current value supplied to the operating coil is the set value. And the open / close valve remains open. When the temperature of the object to be heated exceeds the set temperature, it becomes non-conductive and the resistance value becomes extremely large.
The operating coil is no longer energized and the on-off valve closes.

According to the characteristic constitution of the fifth invention, in addition to the operation of the characteristic constitution of the first, second, third or fourth invention, there is the following effect. The thermoelectric conversion means is composed of a thermocouple, and although the voltage of the electromotive force generated by the thermocouple is low, the internal resistance is low and a relatively large current can be passed. Therefore, for example, the internal resistance is high and the generated voltage is low. Compared to a configuration in which a large number of thermoelectric conversion elements and the like can be connected to obtain a required current, a smaller number of thermocouples can be used, and for example, in a low-resistance magnetic field generating means such as a coil. In the case of a configuration that supplies an electric current, it becomes possible to drive by one thermocouple.

According to the characterizing feature of the sixth invention, the following effect is obtained in addition to the effect of the characterizing feature of the first, second, third, fourth, or fifth invention. Since a dry battery is used as the power supply, compared with the case of driving using a commercial AC power supply, for example, a voltage converting means such as a transformer and extra wiring are not required, and the structure can be simplified.

According to the characteristic constitution of the seventh invention, in addition to the operation of the characteristic constitution of the first, second, third, fourth, fifth or sixth invention, there is the following operation. When the ignition operation of the burner by the ignition means is started, a current exceeding the set value is applied to the operation coil by the energization means until the set time elapses after the ignition operation is started, and the on-off valve is opened. Since the valve open state is maintained, a predetermined time (rise time) is required from the start of heating of the thermoelectric conversion means by combustion of the burner to the generation of electromotive force sufficient to bring the switch means into the conductive state. In this case, even if the ignition operation is stopped by the time the predetermined time elapses, the ignition operation can be performed on the burner.

According to the characterizing structure of the eighth invention, the following function is provided in addition to the function of the characterizing structure of the first, second, third, fifth, sixth or seventh invention. The combustion state of the stove burner is detected by the thermocouple, and the temperature of the bottom of the cooker heated by the stove burner is detected by the positive temperature coefficient thermistor. When the stove burner is erroneously extinguished as described above, the opening / closing valve is closed, and when the bottom temperature of the cooker exceeds the set temperature, the opening / closing valve is closed.

[0029]

According to the characteristic constitution of the first invention, the temperature of the object to be heated becomes abnormally high, or the burner extinguishes even though the fuel supply is continued. Sometimes it is possible to accurately stop the fuel supply to the burner and avoid the disadvantage of continuing combustion, but with a small number of parts, a simple configuration, and a reduction in manufacturing man-hours to reduce costs. It is now possible to provide a combustion control device that enables the above.

According to the characterizing structure of the second invention, the following effect is obtained in addition to the effect of the characterizing structure of the first invention. The contact is switched to the conductive state by the magnetic field generated based on the electromotive force generated by the thermoelectric conversion means, so that, for example, an electromotive force amplifying means or the like is unnecessary as compared with the case where a semiconductor type switch means such as a transistor is used. The configuration can be simplified accordingly.

According to the characterizing structure of the third invention, the following effect is obtained in addition to the effect of the characterizing structure of the first or second invention.
By using the positive characteristic thermistor, when the temperature of the object to be heated becomes a state corresponding to the set temperature, as in the case of using the negative characteristic thermistor, a predetermined switch for opening and closing the switch means separately provided such as a transistor is opened. The current value to the operating coil can be directly reduced to a current value smaller than the set value based on the characteristic change of the positive temperature coefficient thermistor itself without using a temperature detection circuit that outputs information. Can be converted. Moreover, even though the electronic circuit as described above is not used, it is possible to accurately determine that the temperature of the object to be heated exceeds the set temperature regardless of the individual difference in the characteristics of the operating coil or the fluctuation of the power supply voltage. It becomes possible to detect.

According to the characterizing feature of the fourth invention, the following effect is obtained in addition to the effect of the characterizing feature of the first or second invention.
By using a temperature-sensitive switch, the change in the resistance value between the conducting state and the non-conducting state becomes extremely large, and the change in the current flowing to the operating coil is large. The switching to the valve closing operation of is surely performed.

According to the characterizing feature of the fifth invention, the following effect is obtained in addition to the effect of the characterizing feature of the first, second, third or fourth invention. In this type of combustion apparatus, the characteristics of a generally used thermocouple can be effectively used, and a simple configuration can be used without using a special thermoelectric conversion element.

According to the characterizing structure of the sixth invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third, fourth or fifth invention. Compared with the case of using a commercial power source, the number of parts in the power source can be reduced, and the entire device can be made with a simpler configuration.

According to the characterizing structure of the seventh invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third, fourth, fifth or sixth invention. Even when it takes a predetermined time for the thermoelectric conversion means to generate a predetermined electromotive force,
Until this time elapses, it is not necessary to continue the ignition operation by a manual operation, and the ignition operation becomes less troublesome.

According to the characterizing structure of the eighth invention, the following effects are obtained in addition to the effects of the characterizing structure of the first, second, third, fifth, sixth or seventh invention. In a stove with a relatively simple configuration of the entire device, the temperature of the object to be heated becomes abnormally high, or when the burner extinguishes while the fuel supply continues, By simplifying the circuit configuration for accurately stopping the fuel supply to the burner, it becomes possible to complete the entire device with a simpler configuration.

[0037]

Embodiments Embodiments will be described below with reference to the drawings. FIG. 1 shows an electric circuit configuration of a gas stove as an example of a combustion control device according to the present invention. In this gas stove, fuel (gas) is supplied to a burner 2 through a fuel supply passage 1 and the burner 2 burns the fuel. An object to be heated (not shown) (for example, a cooking device such as a pan) is configured by the burner 2.
Is configured to heat.

In the fuel supply passage 1, there is a valve open state in which the fuel supply passage 1 is opened to enable fuel supply to the burner 2.
The on-off valve 3 which can be switched to a closed state in which the fuel supply passage 1 is shut off and the fuel supply to the burner 2 is stopped, and which is energized to a closed state by an energizing means such as a spring not shown. It is equipped. This on-off valve 3 is based on human operation,
It is configured so that it can be operated in a valve open state against the urging force of the urging means, and when the operation force is released, the urging force restores the valve closed state. Further, the opening / closing valve 3 is provided with an operating coil 3a for maintaining the valve open state by being energized by electromagnetic force. That is,
The open / close valve 3 is maintained in the open state while a current equal to or more than a set value is being supplied to the operating coil 3a, and the fuel supply to the burner 2 is continuously maintained.

The gas stove has a combustion state detecting means A for detecting whether or not the burner 2 is in a combustion state.
And an overheat state detecting means B for detecting that the temperature of the heated object heated by the burner 2 exceeds the set temperature, and the combustion state detecting means A detects that the burner 2 is not in the combustion state. Alternatively, when the overheat state detecting means B detects that the temperature of the object to be heated exceeds the set temperature, the opening / closing valve 3 is closed.

The combustion state detecting means A has a thermocouple 4 (an example of thermoelectric conversion means) for generating an electromotive force by heating due to combustion of the burner 2, and an electromotive force generated by the thermocouple 4 is equal to or more than a conduction electromotive force. Then, a magnetic field having a strength equal to or higher than the setting value for conduction is generated, and the strength of the magnetic field generated when the electromotive force is equal to or lower than the electromotive force for non-conduction lower than the setting value for conduction is equal to or lower than the setting value for non-conduction. And a coil 5 (an example of a magnetic field generating means) that is in a conductive state when a magnetic field having a strength greater than or equal to the set value for conduction is generated in the coil 5, and a non-conductive state when the strength of the magnetic field is less than or equal to the set value for non-conduction Reed switch 6
(An example of a contact). Therefore, in the coil 5 and the reed switch 6, when the electromotive force generated by the thermocouple 4 is equal to or higher than the conduction electromotive force, the coil 5 and the reed switch 6 are brought into the conducting state, and when the electromotive force is lower than the conduction electromotive force and is equal to or lower than the non-conduction electromotive force, the non-conduction is set. The switch means S that is in the conductive state is configured.

As shown in FIG. 2, the reed switch 6 is constructed by enclosing a pair of reed pieces 6a, 6b made of a ferromagnetic material inside a glass tube 6c together with an inert gas in a state of facing each other. The inner ends of the tubes of the pieces 6a and 6b are arranged in a slightly separated state in a natural state (a state in which no magnetic field is applied from the outside). And the coil 5
On the outer side of the reed switch 6, the lead pieces 6a,
The longitudinal direction of 6b and the axial direction of the coil are substantially aligned.

Therefore, when the coil 5 is energized to generate a magnetic field having a strength equal to or higher than the set value for conduction inside the coil 5, as shown by a line M in FIG. The N pole is induced at the end and the S pole is induced at the end of the other lead piece 6b.
a and 6b are attracted by the magnetic attraction force and come into contact with each other to switch to the conducting state, the energization to the coil 5 is stopped, and the strength of the generated magnetic field is set to the non-conducting set value lower than the conducting set value. Then, magnetism is not induced, and each lead piece 6a,
6b is configured to be in an original state, that is, a state in which it is slightly separated by elastic force, and is in a non-conductive state.

Further, the overheat state detecting means B is constituted by a positive temperature coefficient thermistor 7 as an example of a temperature sensitive type variable resistance means whose resistance value becomes large when the temperature of the object to be heated becomes high. The reed switch 6, the positive temperature coefficient thermistor 7, the operating coil 3a, and the dry battery 8 as an example of a power source are connected in series to form a closed valve L1 for valve maintenance.

The positive temperature coefficient thermistor 7 has a resistance value such that when the temperature of the object to be heated exceeds a set temperature (for example, about 200 ° C.), the current value supplied to the actuating coil 3a decreases below the set value. Is configured to be. In other words, this positive temperature coefficient thermistor 7 is, as shown in FIG.
For example, it is arranged so as to come into contact with the bottom of a cooking pot, and when the temperature of the object to be heated exceeds the set temperature (about 200 ° C.), the resistance value suddenly increases. The current applied to the valve is sharply reduced to a current value smaller than the set value for maintaining the open state of the on-off valve 3.

The closed circuit L1 for maintaining the valve is switched to a conductive (ON) state by an ignition operation and is maintained in that state, and is switched to a non-conductive (OFF) state by a fire extinguishing operation and maintained in that state. A changeover switch 9 is provided. An ignition circuit L2 is provided in parallel with the closed valve maintaining circuit L1. The ignition circuit L2 is in a conduction (ON) state only while the ignition operation is being performed, and the ignition operation is performed. A self-reset type ignition switch 10 that returns to a non-conduction (OFF) state when stopped, and electricity is supplied as the ignition switch 10 is turned on, and an igniter 11 causes the burner 2 to perform an ignition operation. An ignition transformer 12 is provided. The ignition transformer 12 and the igniter 11 constitute the ignition means TE.

Further, when the changeover switch 9 is changed over from the OFF state to the ON state, the clocking is started 2
Two timer circuits 13 and 14 are provided. The first timer circuit 13 turns on the first transistor 15 for about 5 seconds from the time when the changeover switch 9 is switched to the ON state, and forcibly opens the valve different from the closed valve L1 for maintaining the valve opening. The closed circuit L3 is electrically connected, and regardless of the state of the reed switch 6, the operating coil 3a is energized for about 5 seconds to forcefully maintain the open / close valve 3 in the open state. It is configured. The first timer circuit 13 and the first transistor 15 allow the energizing means TU.
Will be configured. In addition, the second timer circuit 14
Is configured to turn on the second transistor 17 from the time when the changeover switch 9 is switched to the ON state until the time set by the time setter 16 (for example, 2 hours) elapses. When the continuous combustion time exceeds the time set by the time setter 16, the energization of the operating coil 3a is stopped and the combustion of the burner 2 is forcibly stopped.

Next, the operation of the combustion control device having the above structure will be described. When the ignition operation is started by a manual operation, the on-off valve 3 is operated in the open state against the urging force of the urging means, and the changeover switch 9 is OF.
The ignition switch 10 is turned ON while the F state is switched to the ON state. Then, the fuel supply to the burner 2 is started and the ignition by the igniter 11 is started to ignite the burner 2. Further, even if the first timer circuit 13 is activated in response to the changeover of the changeover switch 9 from the OFF state to the ON state and the ignition operation is stopped immediately after the burner 2 is ignited, it takes about 5 seconds. During the passage of, the energization of the operating coil 3a is maintained, and the on-off valve 3 is maintained in the open state. Therefore, after the heating of the burner 2 is started, it takes about several seconds until the electromotive force for conduction is generated in the thermocouple 4, but the ignition operation is performed until the electromotive force for conduction is generated in the thermocouple 4. Need not be continued, and the operation is less troublesome.

After that, when the thermocouple 4 generates an electromotive force higher than the conduction electromotive force due to the heating by the combustion of the burner 2,
A current flows through the coil 5 based on the electromotive force, and a magnetic field having a strength equal to or higher than the conduction set value is generated. As a result, the reed switch 6 is turned on and the first transistor 15 is turned off.
Even after the FF state, the energization of the operating coil 3a continues, the on-off valve 3 is maintained in the open state, and the combustion of the burner 2 is continued.

When the temperature of the object to be heated reaches an abnormally high temperature exceeding the set temperature while the burner 2 is burning to heat the object to be heated, the resistance value of the positive temperature coefficient thermistor 7 is increased. Rapidly increases, and the value of the current supplied to the operating coil 3a becomes extremely small. As a result, the opening / closing valve 3 is switched to the closed state by the urging force of the urging means, and the combustion of the burner 2 is stopped.

If the burner 2 extinguishes when the burner 2 burns to heat the object to be heated and the boiling water or boiling water of the object to be heated overflows, the thermocouple 4 Since the heating for is stopped, the electromotive force generated in the thermocouple 4 becomes less than the non-conduction electromotive force, and the strength of the magnetic field generated in the coil 5 becomes less than the non-conduction set value, The reed switch 6 is turned off. As a result, the on-off valve 3 is switched to the closed state by the urging force of the urging means,
Since the fuel supply to the burner 2 is stopped, the fuel is prevented from being discharged for a long time.

When the time (2 hours) set by the time setter 16 has passed without abnormal heating of the object to be heated or extinguishing of the burner 2 as described above, the second transistor 17 is turned off. Then, the combustion of the burner 2 is stopped. Therefore, for example, even if the burner 2 is erroneously continued to burn by forgetting the fire extinguishing operation, the combustion will be automatically stopped when the set time (2 hours) has elapsed, and The safety of is secured. Moreover, by changing and setting the set time in advance according to the purpose of use (cooking menu etc.) by the time setting device 16,
Since the user can set the heating time, disadvantages such as excessive heating are less likely to occur, and convenience in use is improved.

[Other Embodiments] (1) In the above embodiment, the energizing means TU for energizing the operating coil 3a during a set time period from the start of ignition operation.
As an example, a configuration in which the transistor 15 is operated in the timer circuit 13 is illustrated. However, as shown in FIG. 4, the dry battery 8 is not operated in a non-operating state by the switching operation of the changeover switch 18 which is changed over in accordance with the point extinguishing operation. It is also possible to employ a configuration in which a capacitor 19 that is charged by the above-described capacitor and discharges the charging charge to the operating coil 3a in accordance with the ignition operation is provided, and the operating coil 3a is energized for a set time by discharging the charging charge of the capacitor 19.

According to this structure, compared with the case where the transistor is driven by the timer circuit, there is no disadvantage that the current continues to flow in the operating coil 3a due to the ON failure of the transistor, and the reliability is improved. It will be done.

(2) In the above embodiment, when the combustion time of the burner 2 has passed the time set by the time setter 16,
The circuit for stopping the combustion of the burner 2 is provided, and the energizing means for energizing the operating coil 3a for a set time in accordance with the ignition operation is provided. However, as shown in FIG.
A configuration without such a circuit may be used.

(3) In the above embodiment, the reed switch and this reed switch are turned ON / OF as the switch means.
Although the case where it is configured by a coil that generates a magnetic field for F is exemplified, for example, the configuration is configured by sealing a light emitting diode and a phototransistor that becomes conductive when the light emitting diode emits light with resin. The photocoupler and a plurality of thermocouples connected in series are used to cause the light emitting diode to emit light by the electromotive force of the plurality of thermocouples heated by the burner, and a photodiode which becomes conductive based on the light emission is used. A configuration provided in the valve-opening maintenance closed circuit L1 or a configuration in which semiconductor contacts such as switching transistors provided in the valve-opening maintenance closed circuit L1 are turned on / off by electromotive force in the plurality of thermocouples. May be As described above, by using the semiconductor type switch means having no mechanical contact, the durability can be improved.

(4) In the above embodiment, the case where a positive temperature coefficient thermistor is used as the variable resistance means has been exemplified, but in addition, a resistance temperature detector whose resistance value increases as the temperature rises may be used. Further, for example, using a temperature sensitive switch such as a bimetal, which is conductive when the temperature of the object to be heated is lower than the set temperature, and is non-conductive when the temperature of the object to be heated exceeds the set temperature. Good.

(5) In the above embodiment, the thermocouple 4 is used as the thermoelectric conversion means, but other thermoelectric conversion elements such as a pyroelectric element may be used.

(6) In the above embodiment, the case where the dry battery is used as the power source is exemplified, but the power may be supplied by using the commercial AC power source.

(7) In the above embodiment, the case where the gas stove is used is illustrated, but the present invention is not limited to the gas stove, and may be applied to a combustion control device such as a hot water supply device or a fan heater.

It should be noted that reference numerals are added to the claims to facilitate the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram.

FIG. 2 is a sectional view of a reed switch.

[Figure 3] Characteristic diagram of the thermistor

FIG. 4 is a circuit configuration diagram of another embodiment.

FIG. 5 is a circuit configuration diagram of another embodiment.

FIG. 6 is a circuit configuration diagram showing a conventional example.

[Explanation of symbols]

 2 burner 3 on-off valve 3a actuating coil 4 thermoelectric conversion means 5 magnetic field generating means 6 contacts 7 variable resistance means 8 power supply A combustion state detection means B overheat state detection means S switch means TE ignition means TU energization means

Claims (8)

[Claims] 1. A combustion state detecting means (A) for detecting whether or not the burner (2) is in a combustion state, and the burner (2).
An overheat state detecting means (B) for detecting that the temperature of an object to be heated exceeds a set temperature, and the burner (2) is not in a combustion state by the combustion state detecting means (A). Is detected, or the overheated state detecting means (B) detects that the temperature of the object to be heated exceeds the set temperature, the fuel supply path to the burner (2) is provided. A combustion control device configured to close a valve-closing type opening / closing valve (3), wherein the opening / closing is performed against a valve-closing force by applying a current exceeding a set value. An operating coil (3a) is provided for maintaining the valve (3) in an open state and closing the on-off valve (3) when the current decreases below the set value, the combustion state detecting means ( A) is due to combustion of the burner (2) Thermoelectric conversion means (4) for generating electromotive force by heating, and when the electromotive force generated by the thermoelectric conversion means (4) becomes equal to or higher than the electromotive force for conduction, the electroconductive state is established, and the electromotive force is lower than the electromotive force for conduction. A switch means (S) that becomes non-conductive when the electromotive force for non-conduction is less than or equal to the electromotive force for non-conduction. The overheated state detection means (B) has a high resistance value when the temperature of the object to be heated becomes high. The variable resistance means (7) is of a temperature type, and the switch means (S), the variable resistance means (7), the actuating coil (3a) and the power source (8) are connected in series. When the temperature of the object to be heated exceeds the set temperature, the variable resistance means (7) has a resistance value such that the current value supplied to the operating coil (3a) decreases below the set value. Combustion control device. 2. The switch means (S) generates a magnetic field based on an electromotive force generated by the thermoelectric conversion means (4), and a magnetic field generation means (5). 2. A contact (6) which is in a conducting state when the strength of the magnetic field is greater than or equal to the setting value for conduction and which is in a non-conducting state when the strength of the magnetic field is less than or equal to the setting value for non-conduction. Combustion control device. 3. The combustion control device according to claim 1, wherein the variable resistance means (7) is composed of a positive temperature coefficient thermistor whose resistance increases as the temperature of the object to be heated increases. 4. The variable resistance means (7) becomes conductive when the temperature of the object to be heated is lower than the set temperature, and becomes non-conductive when the temperature of the object to be heated exceeds the set temperature. 2. A temperature-sensitive switch consisting of
Or the combustion control device according to 2. 5. The combustion control device according to claim 1, 2, 3 or 4, wherein the thermoelectric conversion means (4) is composed of a thermocouple. 6. The combustion control device according to claim 1, wherein the power source (8) is composed of a dry battery. 7. Ignition means (TE) based on human operation
Along with the start of the ignition operation for the burner (2) by the above, a current exceeding the set value is passed through the operating coil (3a) until the set time elapses after the ignition operation is started. The combustion control device according to claim 1, 2, 3, 4, 5, or 6, further comprising energizing means (TU). 8. The thermoelectric conversion means (4) is composed of a thermocouple attached to a stove burner, and the variable resistance means (7) detects the temperature of the bottom of the cooker as the object to be heated. Claims 1 and 2, which are composed of a thermistor,
The combustion control device according to 3, 5, 6 or 7.