JP3407997B2 - Gas Combustor Safety Devices - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a gas combustor which detects the presence or absence of a flame from a burner or the like of a gas stove by using an electromotive force of a thermocouple. 2. Description of the Related Art The presence or absence of a combustion flame such as a stove burner is detected by using a thermocouple.
As disclosed in Japanese Patent No. 1320, a flame discriminating circuit detects the electromotive force of a thermocouple within a predetermined time after the burner is extinguished, and detects the presence or absence of a flame from the electromotive force of the thermocouple even after the predetermined time has elapsed. When the flame presence signal is output, if the control means for determining that the flame determination circuit is abnormal is provided, the thermocouple cools after the fire extinguishing operation so that no normal electromotive force is generated after the extinguishing operation. Set to about seconds. It is necessary to energize the microcomputer constituting the control means during the above-mentioned predetermined time, and when the control circuit or the like is driven by using a battery power source, the ignition is not performed. There is a problem that a relatively large amount of power is consumed when the battery is consumed by the container. Accordingly, an object of the present invention is to reduce power consumption by a control circuit while maintaining a safety function in a flame detection circuit using a thermocouple. SUMMARY OF THE INVENTION The present invention provides a flame detecting circuit for detecting the presence or absence of a flame by detecting an electromotive force of a thermocouple mounted on a flame hole of a burner, and detecting a blinking operation of the burner. If a re-ignition operation is performed within a predetermined time after the burner extinguishing operation, a control circuit that performs an ignition operation regardless of the output of the flame detection circuit is provided. If the electromotive force of the thermocouple drops below a preset electromotive force within a time period, the thermocouple is set to a power saving mode. When a fire extinguishing operation of the burner is detected by the control circuit, the electromotive force of the thermocouple is sequentially detected from the fire extinguishing operation. By lowering the operation clock of the microcomputer constituting the circuit to a so-called standby state,
Set the control circuit to power saving mode. As a result, the power consumption of the control circuit can be reduced, and the battery life can be extended even if the gas combustor is driven by a battery power supply. An embodiment of the present invention will be described first with reference to FIGS. 1 and 2. (1) is a gas table body with a grill,
Stoves (3) and (4) are mounted on the left and right sides of the top plate (2), and a grill (5) is built in between these stoves. (6) An operation panel mounted on the front of the gas table main body (1). The operation panel is located in front of the stove sections (3) and (4) and is slid left and right by sliding operation.
(3) Burner for hob (7) (8) and grill attached to (4)
Operation knobs (10), (11), and (12) for adjusting the heat of a grill burner (9) described later in (5) are mounted. The ignition knobs (13), (14), and (15) for blinking the stove burners (3) and (4) and the grill burner are arranged. In addition, the combustion portions of the stove burners (7) and (8) and the grill burner (9) are heated by their combustion flames (16), (16) and (16) as shown in FIG. The thermocouples (17), (17), and (17) that generate the electromotive force are provided, and a fuel passage (18) that supplies fuel to each of the burners (7), (8), (9) is provided with: Solenoid valves (19) (19) (19) set by the ignition operation of the above-mentioned ignition knobs (13) (14) (15), and gas valves (20) (20) (20) also driven by blinking operation And these gas valves are equipped with ignition switches (21) (21) (21) and cock switches (22) (22) ( 22) (22) is worn. A control circuit (23) detects the open / close state of the ignition switches (21), (21), (21) and the cock switches (22), (22), (22), etc., as shown in FIG. The thermocouple (17) is connected to the input of an arithmetic circuit (24) composed of a microcomputer.
(17) A flame detection circuit (25) that detects the electromotive force of (17) and outputs a flame presence / absence signal, and the ignition switches (21) (21) (21) and the cock switches (22) (22) ( A switch detection circuit (26) for detecting the open / close state of the battery 22) and a power supply circuit (28) for supplying power composed of dry batteries (27) and detecting power supply voltage and the like are connected, and the output is connected to the electromagnetic An electromagnetic valve drive circuit (29) for operating the valves (19), (19) and (19), and an igniter (30) for igniting the combustion portion of each of the burners (7), (8) and (9) by generating a discharge. An operating igniter drive circuit (31) is connected. The flame detecting circuit (25) sequentially detects the voltage values output from the thermocouples (17), (17) and (17) as shown in FIG. Value (for example, 3
mV) or more, a flame presence signal is output, and the arithmetic circuit (24) controls the ignition knobs (13), (14), (1)
When the fire extinguishing operation of 5) is detected from the open / closed state of the cock switches (22), (22), (22), a predetermined time (for example, 6
0)), and if the flame detection signal is output from the flame detection circuit (25) during the measurement of the predetermined time, the microcomputer enters a standby state such as lowering the operation clock of the microcomputer constituting the arithmetic circuit. Power saving mode to reduce power consumption. Therefore, as shown in the time chart of FIG. 5, the arithmetic circuit (24) operates the cocking switch (22) and the ignition switch (21) by operating the ignition knobs (13), (14) and (15). Is activated and turned on, the igniter (3) is activated by the igniter drive circuit (31).
When the stove burners (7) and (8) are ignited, this is detected by the output of the flame detection circuit (25), and the solenoid valve (19) is detected.
Is open, and the flame detection circuit
If flame signal is not output from (25), solenoid valve (19)
To stop the gas supply to the burner. The arithmetic circuit (24) includes ignition knobs (13), (14) and (15).
When the fire extinguishing operation is detected, the measurement of the predetermined time is started, and when a flameless signal is output from the flame detection circuit (25) during the measurement, the mode shifts to a power saving mode, and the flame detection circuit is activated.
(25) Ignition knob until flameless signal is output from (13) (14)
When (15) is operated and the reignition operation is performed, the ignition operation is performed by igniting the igniter (30) and ignoring the flame presence signal from the flame detection circuit (25) as in the conventional case. Do. Further, if the flame detection circuit (25) does not output the no-flame signal even after the measurement for the predetermined time, the arithmetic circuit (24) determines that the flame detection circuit (25) and the like are abnormal and ignites. Even if the operation is performed, the igniter (30) does not operate and the solenoid valve (19) (1
9) The power supply to (19) is stopped, and an alarm is issued by lighting or blinking an alarm LED (not shown). According to the structure of the present invention, the electromotive force of the thermocouple after the fire extinguishing operation is detected, and if the electromotive force falls below a predetermined electromotive force within a predetermined time, the control circuit is activated. By setting to the power saving mode, the power consumption by the control circuit can be reduced as much as possible, so that even if the gas combustor is operated by the battery power supply, the life of the battery power supply can be extended. is there.

[Brief description of the drawings] FIG. 1 is a front view showing a case example according to the present invention. FIG. 2 is a plan view of the same. FIG. 3 is a schematic configuration diagram of a main part of the same. FIG. 4 is a block diagram of a control circuit. FIG. 5 is a time chart for explaining the operation. [Explanation of symbols] 7 Burner for stove 8 Burner for stove 9 Grill burner 19 thermocouple 23 Control circuit 25 Flame detection circuit

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiya Nishimoto 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (72) Inventor Mitsuaki Tabuchi 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tori Tori Sanyo Electric Co., Ltd. (56) References JP-A-3-28627 (JP, A) JP-A-52-121818 (JP, A) JP-A-53-39839 (JP, U) JP-B-62-19654 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 5/10 320 F23N 5/24 110 F24C 3/12

Claims (1)

(57) [Claims 1] A flame detection circuit for detecting the presence or absence of a flame by detecting an electromotive force of a thermocouple mounted on a flame hole of a burner, and detecting a blinking operation of the burner. If a reignition operation is performed within a predetermined time after the burner extinguishing operation, a control circuit that performs an ignition operation regardless of the output of the flame detection circuit is provided. After that, if the electromotive force of the thermocouple falls below a preset electromotive force within the predetermined time, the thermocouple is set to a power saving mode.