JPH0348412B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention detects a misfire in a combustor such as a burner using a thermoelectric element such as a thermocouple, and also detects a misfire in a combustor such as a burner using a thermoelectric element such as a thermocouple. The present invention relates to a combustion control device equipped with a forced adsorption circuit that supplies battery power during ignition.

<Prior art> A gas stove incorporating an automatic fire extinguishing mechanism that stops combustion of a burner when an object to be heated such as a pot reaches a desired set temperature has been filed, for example, in Japanese Patent Laid-Open No. 161468/1983. ing. In this case, it is necessary to constantly energize the solenoid valve coil for stopping combustion during combustion, which increases the consumption of battery power. Even if the electromagnetic coil is controlled using a relay, the power consumption of the relay is high.

<Problems to be Solved by the Invention> The present invention includes a forced adsorption circuit that drives a solenoid coil of a solenoid valve using the electromotive force of a thermoelectric element and supplies battery power to this drive coil at the time of ignition. The purpose of this invention is to reduce the power consumption of a relay that uses the battery described above to control energization of an electromagnetic coil.

<Means for Solving the Problems> In the present invention, the relay for controlling the energization of the electromagnetic coil is constructed of a latching type relay.

<Operation> As mentioned above, the relay is energized only when the relay contacts are opened and closed during ignition.

<Example> Hereinafter, an example of the present invention will first be described based on FIG. 1. Reference numeral 1 denotes a stove burner, which has a ring-shaped burner head 2 and a ventilation hole 3 provided in the center thereof.
A temperature sensor 5 for detecting the temperature of the object to be heated, such as a pot 4, is disposed inside, and the heating force is generated by being heated by the combustion flame formed in the area facing the flame hole 6 provided on the outer periphery. A pair of thermocouples 7 and 8 that generate

Reference numeral 9 denotes a gas flow path for supplying gas to the nozzle 10 provided in the burner 1, and one of the thermocouples 7 is connected upstream.
The main body 15 houses a solenoid valve 12 which is connected in series through a first relay contact piece 11', and a closure 14 which is located downstream of the solenoid valve and opens and closes by rotating the operating knob 13. At the same time, a temperature control solenoid valve 1 is located downstream of the main body and has a suction coil 17 arranged around the suction coil 16.
8 is interposed.

The adsorption coil 16 of the temperature control solenoid valve 18 is connected in series to the other thermocouple 8 via the second relay contact piece 19', and is connected in parallel to the valve hole 21 which is opened and closed by the valve body 20. A bypass 22 is provided through which weak combustion gas passes.

23 is a control circuit that receives the signal from the temperature sensor 5 and controls the first and second relay contacts 11', 19', etc., and as explained based on FIG.
The + side is grounded with a battery power supply of around 6V, and the power switch 2 is linked to the operation knob 13 above.
First and second latching relays 11 and 19 of the latching type are connected through normally open contacts 25' of 5 to drive the first and second relay contacts 11' and 19', respectively.

26 is a forced adsorption circuit for so-called instantaneous adsorption connected to the electromagnetic coil 12' of the electromagnetic valve 12, which controls a semiconductor switching element 27 connected in series to the electromagnetic coil 12', and this switching element.
It consists of a FET 28, a bipolar capacitor 29 connected to the gate of this FET and the normally closed contact 25'' of the power switch 25, and resistors 68 and 69 with relatively large resistance values that set the gate potential of the FET 28. When the power switch 25 is switched to the normally open contact 25' in conjunction with the ignition operation of step 1, the charge in the capacitor 29 turns off the FET 28 for a predetermined time, turns on the switching element 27, and energizes the electromagnetic coil 12'. .

Reference numeral 30 denotes a temperature control circuit, which includes the temperature sensor 5 made of a thermistor and resistors 31, 3 connected to it.
The output of 1 partial pressure is compared with the set value of the temperature setting volume 32, and the second latching relay 19 is activated at the output 33.
open side coil 19'', drive transistor 34
At the same time as driving the diode 3 at the output 35
6 and 37 respectively, the second latching relay 19
Closing side coil 19, drive transistor 38
Also, the attraction coil 17 and the drive transistor 3
9, and when the temperature of the heated object reaches the temperature set by the volume control 32, the open side coil 1 is activated.
9'', the drive transistor 34 is energized, the temperature control solenoid valve 18 is closed, and gas is supplied to the burner 1 through the bypass 22 for weak combustion.Then, due to this weak combustion, the temperature of the heated object becomes lower than the set temperature. When it decreases, the closing side coil 19 and the suction coil 1
7 is momentarily energized to open the valve body 20 of the temperature control solenoid valve 18 and cause the burner 1 to burn strongly.

40 is a monitor circuit for the temperature sensor 5, and includes first and second comparators 42 and 43 that compare the divided voltage outputs of the temperature sensor 5 and the resistors 31 and 31 with different reference voltages obtained by dividing the resistors 41, 41, and 41, respectively.
, an IC ₁ 44 consisting of a monostable multivibrator that outputs a high output for a predetermined time in response to the up pulses of these comparators, and an IC ₂ 4 that is the same as IC ₁ that outputs a high output for a predetermined time in response to the down pulses of the first comparator 42.
5, a first drive transistor 47 that drives the open side coil 11'' of the first latching relay 11 and the drive transistor 46 with the output of the IC _{1 44} ;
It consists of a closing side coil 11 of the first latching relay 11 and a second drive transistor 49 which drives the drive transistor 48 by the output of the IC ₂ 45.
If the temperature sensor 5 is shorted for some reason, the output of the first comparator 42 is inverted to high, and this rising pulse turns on the first drive transistor 47 for a predetermined instant to close the open side coil 1.
1'', opens the first relay contact 11', closes the solenoid valve 12, and cuts off the gas supply to the burner 1.
Stop combustion.

On the other hand, if the temperature sensor 5 is disconnected, the second
The output of the comparator 43 is reversed to high, and combustion in the burner 1 is stopped in the same manner as above at this rising pulse. Therefore, the first and second comparators 42,
The reference voltage 43 and the value of the resistance 31 are set to the output of the temperature sensor 5 in a range exceeding the general cooking temperature (about 50°C to 250°C).

Also, 50 is a forced open circuit, which connects the reference voltage by resistors 51, 51, resistor 52, and capacitor 53.
A transistor 56 that short-circuits the temperature sensor 5 is connected to the output of a third comparator 55 that compares the output of the CR timer 54 with the output of the CR timer 54.
5' for a predetermined period of time after switching to 5'.
The transistor 56 is turned on at the high output of the temperature sensor 5, and the temperature sensor 5 is forcibly short-circuited by this transistor. As a result, the first comparator 42
becomes a high output and energizes the open side coil 11'' of the first latching relay 11, and the first relay contact 1
1' is opened to cut off the power supply to the thermocouple 7 from the battery power supply 24, while the electromagnetic coil 12' is supplied with power by the forced attraction circuit 26. When the output of the third comparator 55 is reversed to low after a predetermined period of time has elapsed, the output of the first comparator 42 is also reversed to low, and the output of IC ₂ 45 due to this down pulse causes the first latching relay 11 to close. coil 11
is energized to close the first relay contact piece 11'.

57 is a battery voltage monitor circuit, with diode 5
Constant voltage reference potential 59 and resistor 60 by 8,58,
A fourth comparator 62 which compares the comparison voltage divided by 60 and 60 and has a notification LED 61 connected to its output, and the reference potential 59 and the resistors 60 and 6.
a fifth comparator which compares a comparison voltage slightly lower than the above voltage by dividing 0.60, and has an auxiliary drive transistor 64 connected to its output 63, which is a switching element that drives the open side coil 11'' of the first latching relay 11; Consisting of 66 and
A capacitor 67 having a capacity capable of driving the open-side coil 11'' at least once is connected to the auxiliary drive transistor 64, and when the battery power source drops to the first set voltage at which the control circuit 23 can operate normally, the fourth The output of comparator 62 is inverted low.
The LED 61 is turned on to notify of a decrease in battery voltage.
If the battery voltage further decreases or the battery falls out, the output of the fifth comparator 66 is inverted to low, turning on the auxiliary transistor 64, and transferring the charge in the capacitor 67 to the first The current flows through the open side coil 11'' of the latching relay 11 to open the first relay contact piece 11', and the solenoid valve 12
close to stop combustion of burner 1.

Since the power switch 25 is connected to the normally closed contact 25'' when combustion is stopped, the battery power source 24 has a large resistance value for the forced adsorption circuit 26, so that, for example, the resistors 31, 31, Resistors 41, 41, 41, 51, 51, 6 for setting reference voltages of comparators 42, 43, 55, 62, 66
The normally closed contact 25'' side of the capacitor 29 is negatively charged through a resistor with a relatively low resistance such as 0, 60, 60, etc.
By pressing and turning and then releasing the push operation, the battery power supply 24 is energized to the electromagnetic coil 12' in the forced adsorption circuit 26, and at the same time, the forced release circuit 5 is turned on.
0, the power supply to the thermocouple 7 of the battery power source 24 is cut off to prevent battery wastage, and even if the operation knob 13 is released, the solenoid valve 12 is kept open and the closure 14 is kept open. The burner 1 is supplied with fuel via the fuel tank. Then, the burner 1 is ignited using an appropriate ignition means (not shown).

On the other hand, the first relay contact piece 11' is opened by the control shot of the temperature sensor 5 by the forced opening circuit 50, and is closed by the monitor circuit 40 when the third comparator 55 is reversed after a predetermined period of time has elapsed, resulting in steady combustion. to go into. At this time, temperature sensor 5
If so, the output of the first comparator 42 will not be reversed and the first relay contact 11' will remain open, so when the power supply from the forced adsorption circuit 26 is stopped, the solenoid valve 12 will be closed.

Further, if the temperature sensor 5 is open at the above time, the output of the second comparator 43 is reversed to high, energizing the open side coil 11'' of the first latching relay 11, and the first relay contact 11' is opened to stop combustion of burner 1.

<Effects of the Invention> As described above, in the structure of the present invention, in which a so-called forced adsorption circuit for instantaneous adsorption of a solenoid valve used as a safety device is provided, the solenoid valve can be relay-controlled with low power consumption. This is effective when controlling burner combustion using battery power instead of using a commercial power source such as a table stove. In addition, when the temperature sensor is abnormal, the burner combustion can be stopped by controlling the relay, and if the temperature sensor is provided with a function to detect abnormal temperature of the heated object, this function can be fully utilized.

Furthermore, by closing the solenoid valve to stop combustion before the relay becomes uncontrollable due to a drop in battery voltage such as when the battery falls off, the solenoid valve can always be safely controlled.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the present invention, and FIG. 2 is an electric circuit diagram. 5... Temperature sensor, 7, 8... Thermocouple, 11
...First latching relay, 11'...First relay contact, 11''...Open side coil, 12'...Electromagnetic coil, 24...Battery power supply, 26...Forced adsorption circuit, 40...Monitor Circuit, 64...Auxiliary drive transistor, 67...Capacitor.

Claims (1)

[Claims] 1. A thermoelectric element is connected in series to an electromagnetic coil via a relay contact, and a battery power source is connected in series to the electromagnetic coil via a switching element, and the switching element is controlled at the time of ignition to activate the electromagnetic coil. A combustion control device comprising: a forced adsorption circuit that supplies battery power to a coil; and a forced open circuit that opens the relay contact for a predetermined time during ignition; and the relay contact is a latching type relay. 2. The device according to claim 1, comprising a monitor circuit that detects disconnection of a temperature sensor that detects the temperature of the heated object and energizes the open side coil of the latching relay when such disconnection occurs. Combustion control device. 3 When the battery voltage drops below a predetermined voltage,
2. The combustion control device according to claim 1, further comprising a switching element for energizing the open coil of the latching relay, and a capacitor connected to the switching element for driving the open coil.