JPS6115327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooking appliance that also serves as a gas leak alarm.

If you install a gas sensor that converts gas concentration into electrical output at the exhaust port of the cooker and detect the gas concentration generated from the food when it is heated, the heating status of the food can be detected electrically and Automatically detected/
It can be controlled.

In other words, this kind of gas sensor detects alcohol gas generated when drinking alcohol, steam generated when boiling leafy vegetables, and gas generated when heating fish.
Electrical resistance changes depending on CO, CO ₂ gas, etc.

Furthermore, gas sensors can detect not only the gases generated from food, but also city gas, propane gas,
It also reacts with nonflammable refrigeration gas, CO gas, etc.

Therefore, an object of the present invention is to provide a cooking appliance in which a gas sensor for cooking also functions as a gas leak alarm while not cooking.
The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows a schematic diagram of the cooking device of the present invention, which has the following configuration.

A heating device 4 and a tray 3 are provided in an oven 2 in a cooking device 1, and oven vents 6, 6' are opened on the left and right sides.

A blower motor 5 and a fan 5' are provided in the vent 6' on the right side, and are configured to be able to blow air into the oven 2.

The oven vent 6 on the left side communicates the inside of the oven 2 with outside air via an exhaust port 8 provided on the side of the cooking device 1, and a gas sensor is installed between the oven vent 6 and the exhaust port 8. 7 is provided.

Next, FIG. 2 shows the electric circuit of the cooking device of the present invention, which has the following configuration.

The AC power supply 10 is connected to one end of a switch L ₃ 11, a switch DCR ₂ 12, and a buzzer 9 as an alarm, which are connected in series via a point _P1 .

Also, from point P ₁ , cooker 1, which is opened when the door is opened,
to the _P2 point via the door switch 13 provided at the
and directly connected to the primary side of the transformer 26.

The _P2 point is connected to the _P3 point via a series-connected self-holding relay L14, a normally open cook switch 16 and one end of the switch DCR ₁ 18, which are operated at the start of cooking, and a switch _L2 15. Ru.

The switch 16 has a switch in parallel.
L ₁ 17 is connected.

Point _P3 is connected to one end of the blower motor 5 and heating device 4, which are connected in parallel.

The secondary side of the transformer is connected to _P4 through diode 25.
The _P4 point is connected to the collector of the switching transistor 23 via the relay DCR24.

Point _P4 is further connected to one end of a variable resistor 20 that determines a setting input as a reference value setting means, and one end of a resistor 19 and a gas sensor 7 connected in series.

A connection point between the resistor 19 and the gas sensor 7 is connected to a detection input terminal of a detection circuit 21 as a detection means.
The sliders of the variable resistor 20 are connected to setting input terminals of the detection circuit 21, respectively.

The output terminal of the detection circuit 21 is connected to the base of a switching transistor 23, and the emitter of the transistor 23 is grounded.

The self-holding relay L14 is a switch _L11
7. It opens and closes the switch L ₂ 15 and the switch L ₃ 11. Fig. 2 shows the demagnetized state, and the switch L ₁ 17 is "open" and the switch L ₂ 15 is also "open".
Switch L ₃ 11 is "closed".

The relay DCR 24 opens and closes the switch DCR ₁ 18 and the switch DCR ₂ 12. FIG. 2 shows the demagnetized state, and the switch DCR ₁ 18 is "closed".
Switch DCR ₂ 12 is "open".

The detection circuit 21 compares the setting input and the detection input, and if they match, the switching transistor 23
It is configured to allow current to flow through the base of.

The operation of the cooking device of the present invention having the above configuration is as follows.

That is, FIG. 2 shows the initial state, in which both the self-holding relay L14 and the relay DCR24 are demagnetized, and food heating or gas monitoring is performed in this state.

First, for food heating, place food in oven 1.
2, close the door, and press the door switch 13.
(set to "close") and press the button switch 16 to close it.

As a result, the circuits of the self-holding relay L14, the cook switch 16, and the switch DCR ₁ 18 are energized, and the self-holding relay L14 is energized.

As a result, switch L ₁ 17 is “closed” and the switch
Switch L ₂ 15 is "closed" and switch L ₃ 11 is "open".

Therefore, the heating device 4 and the blower motor 5 are energized and the food in the oven 2 starts heating, but even if the cook switch 16 is opened, the switch does not turn off.
Since L ₁ 17 is closed, the self-holding relay L14 continues to be energized.

As the food in the oven 2 is heated, gas is generated from the food, and the amount of gas generated increases in proportion to the heating temperature.

As a result, the gas concentration of the air flowing out from the oven vent 6 increases, which is detected by the gas sensor 7 as a change in resistance value.

As a result, the voltage input to the detection input terminal of the detection circuit 21 changes.

The variable resistor 20 is operated according to the heated food, a reference value is determined, and a voltage corresponding to a predetermined gas generation amount is applied to the setting input of the detection circuit 21, so that the input is detected by the gas sensor 7. When the detection circuit 21 matches the setting input, that is, the reference value
causes a current to flow through the base of the switching transistor 23.

As a result, relay DCR24 is energized, switch DCR ₁ 18 is "open" and switch DCR ₂ 12 is "closed".

Since the switch DCR ₁ 18 is opened, the self-holding relay L 14 is demagnetized so that the switch L ₁ 17 is "open", the switch L ₂ 15 is "open", and the switch L ₃ 1 is "open".
1 is "closed".

Therefore, the switch L ₃ 11, the switch DCR ₂ 12, and the buzzer 9 are energized, the buzzer 9 sounds, announcing the end of heating, and the heating device 4 and blower motor 5 are de-energized to end the heating.

The above has been about the effect of food heating, but next we will explain the effect of gas monitoring.

In this case, since the push switch 16 is not connected, the self-holding relay L14 remains demagnetized.

On the other hand, the detection circuit 21 remains in operation, and the gas sensor 7 monitors the gas concentration of the outside air through the exterior gap of the cooking appliance, the intake port, and the exhaust port 8.

That is, when a gas leak occurs in the outside air, for example, in the kitchen, the resistance value of the gas sensor 7 changes, and the voltage value input to the detection circuit 21 changes.

When the amount of gas leak reaches a predetermined amount (determined by the position of variable resistor 20), current is passed through the output terminal of detection circuit 21, and relay DCR24 is energized.

As a result, the switch DCR ₁ 18 becomes "open", the switch DCR ₂ 12 becomes "closed", and the switch L ₃ 1
1. The switch DCR ₂ 12 and buzzer 9 circuits are energized.

That is, the buzzer 9 will sound, giving a warning of gas leakage.

The cooking device that also serves as a gas leak alarm according to the present invention has the following effects in the above configuration and operation.

(1) Since gas leaks are monitored when the cooker is not used for heating food, the cost is lower than installing a separate gas leak alarm.

(2) Since the cooker is installed in the kitchen, gas leakage can be prevented in the kitchen where the risk of gas leakage is greatest.

(3) For electric and gas combination cookers, gas leakage from the cooker itself can be monitored.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the cooking device of the present invention, and FIG. 2 is an electric circuit diagram of the same cooking device. 1: Cooker, 2: Oven, 3: Tray, 4:
Heating device, 5: Blower motor, 5': Fan,
6: Oven vent, 6': Oven vent,
7: Gas sensor, 8: Exhaust port, 9: Buzzer, 1
0: AC power supply, 11: Switch L ₃ , 12: Switch DCR ₂ , 13: Door switch, 14: Self-holding relay L, 15: Switch L ₂ , 16: Switch switch, 17: Switch L ₁ , 18: Switch
DCR ₁ , 19: Resistor, 20: Variable resistor, 21: Detection circuit, 23: Switching transistor, 2
4: Relay DCR, 25: Diode, 26: Transformer.

Claims (1)

[Claims] 1 Using a gas sensor whose electrical resistance changes depending on the concentration of gas or steam, the heating status of food can be detected electrically.
In a cooker that is automatically detected and controlled, there is a reference value setting means that sets a reference value according to the type of heated food or gas, and a resistance value of a gas sensor installed in the exhaust path that is set in advance. A detection means for detecting that the reference value of the reference value setting means coincides with the reference value is provided, and an alarm that is activated by the detection output of the detection means and serves as a cooking completion alarm and a gas leak alarm,
A cooking appliance characterized in that a gas sensor and a detection means are kept in an operating state at all times, even when cooking is not being heated.