JPH0125895Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a combustion control device for a bathtub.

Conventional devices of this kind include an ignition circuit for a burner built into the bathtub, a thermoelectric generator that is heated by the burner and generates an electromotive force, and a thermoelectric generator installed in the gas supply path to the burner and heated by the burner. An electromagnetic safety valve that is held open by the electromotive force of a thermocouple, a forced holding circuit that forcibly holds the safety valve open for a certain period of time at the initial stage of ignition, and a temperature sensing element that prevents the bath from boiling due to changes in its output. A detection circuit that detects an upward movement, a sound generation circuit that generates a sound based on the output of the detection circuit, and a current that flows in the opposite direction to the current caused by the electromotive force of the thermocouple through the safety valve using the output of the detection circuit to close the valve. It is known that the fire extinguisher is equipped with an automatic fire extinguishing circuit.

However, this device uses a battery as a power source for all of the circuits mentioned above, and the battery consumption is compensated for by charging from the thermoelectric element, so this battery does not have the ability to withstand heavy loads. It had to use nickel-cadmium (Ni-Cd) storage batteries, which had the drawback of being expensive and relatively difficult to obtain.

The purpose of the present invention is to provide a device that eliminates the drawbacks of the conventional devices described above.As shown in FIGS.
an ignition circuit 2, a thermoelectric generating element 3 that is heated by the burner 1 and generates an electromotive force, and an electromotive force of a thermocouple 5 that is interposed in the gas supply path 4 to the burner 1 and is heated by the burner 1. Electromagnetic safety valve 6 held open by
, a forced holding circuit 7 for forcibly keeping the safety valve 6 open for a certain period of time at the initial stage of ignition, a detection circuit 9 incorporating a temperature sensing element 8 and detecting the boiling of the bath by a change in its output, and the detection circuit. 9; and an automatic extinguishing circuit 11 that causes a current to flow in the safety valve 6 in a direction opposite to the current generated by the electromotive force of the thermocouple 5 to close the safety valve 6 based on the output of the detection circuit 9. In the combustion control device for a bathtub, a dry battery 12 is used as a power source for the ignition circuit 2 and the forced holding circuit 7, and the dry battery 12 is charged by the thermoelectric generating element 3 via a charging circuit 13. The thermoelectric power generation element 3 serves as a power source for the detection circuit 9, the sound generation circuit 10, and the automatic extinguishing circuit 11.
It is characterized by using

In the figure, 14 indicates a heat exchanger heated by the burner 1, 15 indicates a starter burner, 16 indicates a gas tank, and 16a indicates its operator.

As is conventionally known, the safety valve 6 is opened mechanically in conjunction with the opening operation of the operator 16a, and the thermocouple 5 is connected in series to the excitation coil 6a as shown in FIG. However, when an electromotive force of a certain value or more is generated from the thermocouple 5, the excitation coil 6a
The safety valve 6 is held open by the current flowing through the valve.

17, 18, 19, 20 in FIG. 2 are the operators 1
The first, second, and
The ignition circuit 2 is connected to a first capacitor 21 and an ignition transformer 22 which are charged by the dry battery 12 via the first and second changeover switches 17 and 18 when the gas tank 16 is closed.
The first capacitor 21 is connected to the transformer 22 by opening the operator 16a, and is discharged via the transformer 22. According to this discharge, the burner 1 is ignited by the ignition electrode 22a on the output side of the transformer 22 via the pilot burner 15.

The forced holding circuit 7 includes a second capacitor 23 that is charged by the dry battery 12 via the third changeover switch 19 when the gas tank 6 is closed, and a discharge circuit for the second capacitor 23 with the excitation coil 6a interposed. 24, and the second capacitor 23 is connected to the discharge circuit 24 by opening the operator 16a, and is discharged via the excitation coil 6a. According to this discharge, an electromotive force of a certain value or more is generated from the thermocouple 5, so that the safety valve 6 is forcibly held open for a certain period of time until the safety valve 6 is held open. I made it.

In FIG. 2, 25 indicates a DC/DC converter that boosts the electromotive force of the thermoelectric generating element 3, and the charging circuit 13
is interposedly connected to the connection circuit between the first transistor 27 which becomes conductive when a voltage higher than the Zener voltage of the Zener diode 26 is generated from the DC/DC converter 25, and the thermoelectric generating element 3 and the dry cell battery 12. and a second transformer 28 that becomes conductive when the first transistor 27 is conductive, so that the dry battery 12 is charged by the thermoelectric generating element 3 when a voltage equal to or higher than the Zener voltage is generated from the DC/DC converter 25. did.

Further, the thermoelectric generating element 3 is connected to the detection circuit 9, the sound generation circuit 10, and the automatic extinguishing circuit via the DC/DC converter 25 by a fourth changeover switch 20 that is switched in conjunction with the opening operation of the operator 16a. It is connected to circuit 11 and supplies power to these circuits 9, 10, and 11.

The detection circuit 9 includes a bridge circuit 29 incorporating a temperature sensing element 8, and a resistor 3 connected in series with the temperature sensing element 8.
A comparator 32 whose input is the voltage at the connection point 31 with 0.
and a transistor 33 whose base input is the output of the comparator 32, and the voltage at the connection point 31 corresponding to the actual bath temperature is higher than the reference voltage corresponding to the desired set temperature of the bath. In other words, when the bath is boiling, a low level output signal is generated from the comparator 32, and the transistor 33
A high level output signal is generated from the collector side.

The sound generation circuit 10 outputs a low level output signal and a high level output signal generated on the collector side of the transistor 33 of the detection circuit 9.
It consists of an inverting amplifier 34 that alternately generates a low-level output signal and a buzzer 35 that generates a sound based on the low-level output signal of the inverting amplifier 34.

The automatic extinguishing circuit 11 is connected in series to a timer 36 that generates a high level output signal after a certain period of time after the comparator 32 of the detection circuit 9 generates a low level output signal, and to the excitation coil 6a of the safety valve 6. and a thyristor 37 connected to the timer 36 and made conductive by the high level output signal of the timer 36,
When the thyristor 37 is conductive, a current in the opposite direction to the current generated by the electromotive force of the thermocouple 5 is caused to flow through the excitation coil 6a, thereby closing the safety valve 6.

In order to silence the buzzer 35 of the sounding circuit 10 in synchronization with the closing of the safety valve 6 by the automatic fire extinguishing circuit 11, the third capacitor 38 is discharged by conduction of the thyristor 37 of the automatic fire extinguishing circuit 11.
and an inverting amplifier 39 that generates a high level output signal by discharging the third capacitor 38,
According to this output signal, the input of the high level output signal from the detection circuit 9 to the sound generation circuit 10 is cut off.

The third capacitor 38 is connected to the fourth changeover switch 2
When the gas tank 16 is closed, the battery is short-circuited via the DC/DC converter 25 when the gas tank 16 is opened.

In addition, 40 in FIG. 2 indicates a display circuit composed of a light emitting diode 41 and a transistor 42 connected in parallel with the light emitting diode 41, and the display circuit 40 is connected to the third capacitor 3.
8 is charged and a low level output signal is generated from the inverting amplifier 39, the transistor 42 becomes non-conductive and the light emitting diode 41
is emitted, and due to the misfire of the burner 1, the electromotive force from the thermoelectric generating element 3 decreases, the voltage of the DC/DC converter 25 and the third capacitor 38 decreases, and the high level is output from the inverting amplifier 39. When the output signal of is generated, the light emission of the diode 41 is stopped, and whether or not the burner 1 is burning can be visually checked by the presence or absence of light emission of the light emitting diode 41.

Next, to explain its operation, the operation element 16a
When the gas tank 16 is opened by manual operation, the electromagnetic safety valve 6 is opened and the first, second, third, and fourth changeover switches 17, 18, 19, and 20 are switched, and the forced holding circuit 7 is switched on. 2nd capacitor 2
3 is discharged, thereby energizing the excitation coil 6a, the safety valve 6 is forcibly opened for a certain period of time, and gas is supplied from the gas supply path 4 to the burner 1. At this time, the first capacitor 21 of the ignition circuit 2 is also discharged, so the ignition electrode 2 on the output side of the ignition transformer 22
Burner 1 is ignited by 2a.

After the burner 1 is ignited, if an electromotive force of a certain value or more is generated from the thermocouple 5, the safety valve 6, which has been opened for a certain period of time in the forced holding circuit 7, will open even further than the electromotive force. The burner 1 continues normal combustion.

Further, after the burner 1 is ignited, if an electromotive force exceeding a certain value is generated from the thermoelectric generating element 3, the electromotive force is transmitted to the detection circuit 9, the sound generation circuit 10, and the automatic extinguishing circuit 11 via the DC/DC converter 25. And the charging circuit 13 is supplied with power, and if the charging circuit 12 is exhausted at this time, charging is performed.

Thereafter, when the temperature sensing element 8 detects that the bath is boiling, a high level output signal generated from the detection circuit 9 immediately causes the buzzer 35 of the sound generation circuit 10 to sound, and after a certain period of time has elapsed, a high level output signal is generated from the detection circuit 9. The automatic extinguishing circuit 11 is activated, the safety valve 6 is opened, and the burner 1 is extinguished. Then, in synchronization with this extinguishing, the buzzer 35 is also muted.

In order to ignite the burner 1 again, it is sufficient to return the operator 16a of the gas stove 16 to its original position and perform the above operation.

In this way, according to the present invention, the battery is used only as a power source for the compulsory holding circuit 7 and the ignition circuit 2, which are necessary only at the initial stage of ignition of this device and which have a relatively light load, and all the batteries necessary after ignition of the burner 1 are used. Since the thermoelectric power generation element 3 is used as the power source for the circuit, a battery is used as the power source for all the circuits at the initial stage of ignition and after ignition, so Niskelium cadmium, which can withstand heavy loads and is expensive and relatively difficult to obtain, is used. Compared to the conventional device that has no choice but to use a storage battery, manganese dry batteries, which are inexpensive and easily available, can be used as batteries, which is advantageous in terms of production and maintenance.

[Brief explanation of the drawing]

FIG. 1 is a partial explanatory diagram showing an example of the device of the present invention, and FIG. 2 is an overall circuit diagram showing an example of the device of the present invention. 1... Burner, 2... Ignition circuit, 3... Thermoelectric generating element, 4... Gas supply path, 5... Thermocouple, 6...
Electromagnetic safety valve, 7... Forced holding circuit, 8... Temperature sensing element, 9... Detection circuit, 10... Sound generation circuit, 11...
...Automatic extinguishing circuit, 12...Dry battery, 13...Charging circuit.

Claims (1)

[Scope of utility model registration request] Ignition circuit 2 of burner 1 installed in the bathtub,
The valve is held open by the electromotive force of a thermoelectric generating element 3 that is heated by the burner 1 and generates an electromotive force, and a thermocouple 5 that is interposed in the gas supply path 4 to the burner 1 and heated by the burner 1. An electromagnetic safety valve 6, a forced holding circuit 7 that forcibly holds the safety valve 6 open for a certain period of time at the initial stage of ignition, and a detection circuit 9 that incorporates a temperature sensing element 8 and detects the boiling of the bath based on changes in its output. A sound generation circuit 10 generates sound based on the output of the detection circuit 9.
and an automatic fire extinguishing circuit 11 that causes the safety valve 6 to flow in a direction opposite to the current generated by the electromotive force of the thermocouple 5 to close the valve according to the output of the detection circuit 9. , the ignition circuit 2
A dry battery 12 is used as a power source for the forced holding circuit 7, and the dry battery 12 is charged by the thermoelectric power generation element 3 via a charging circuit 13. 1
1. A combustion control device for a bathtub, characterized in that the thermoelectric power generation element 3 is used as a power source for a bathtub.