JPH11329709A - High frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate useless electric power consumed for a control circuit, and prevents possibility of no-load baking. SOLUTION: The heating device is provided with a relay 15, a supply circuit 18 for generating control voltage when commercial power is applied, a microcomputer 17 for setting the relay 15 in a closed state when the control voltage is generated, a door switch 14 for turning on when a door is opened, and a foodstuff detecting switch 33 for supplying the commercial power to the supply circuit 18 in the case of detecting foodstuffs in a heating chamber when the door switch 14 is in an on-state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device for controlling a power supply of a control circuit having a microcomputer and the like.

[0002]

2. Description of the Related Art FIG. 4 is a block circuit diagram of a conventional high-frequency heating device disclosed in, for example, Japanese Patent Application Laid-Open No. 8-1388851, wherein 1 is a commercial power supply, 2 is a current fuse, and 3 and 4 are doors. A pair of main door switches that turn off when the door is opened and turn on when the door is closed, and 5 is a sub door switch that connects to the contact a when the door is opened and connects to the contact b when the door is closed. Sometimes main door switch 3, 4
Current fuse 2 when the contacts of
For fusing.

A lamp 6 illuminates the heating chamber during cooking.
Is a table motor for rotating the turntable, 8 is a relay connected in series to the high-frequency generation source 11, 9 is a relay connected in series to each heater 13, and 10 is a commercial motor based on the control of a control circuit described later. Power supply 1 ON /
This is a relay that turns off. Reference numeral 12 denotes a fan motor connected in parallel to the high frequency generation source 11, reference numeral 14 denotes a door switch which turns on when the door is opened and turns off when the door is closed, and reference numeral 15 denotes a relay connected in parallel to the door switch 14. The control power is turned on / off based on the control of the circuit.

A control circuit 16 includes a microcomputer 17 (hereinafter referred to as a “microcomputer 17”) and a commercial power supply 1.
Power supply circuit 1 for converting AC voltage into stabilized DC voltage
8, a key input detection circuit 19 for outputting a cooking command to the microcomputer 17 based on an external operation, a door switch detection circuit 20 for detecting a door open / close state, and a microcomputer 17
ON / OF the relays 8, 9, 10, 15 according to the control of
F output circuit 21. The control circuit includes a display circuit, a reset circuit,
The power supply circuit 18 includes an Hz signal circuit, a quantity sensor circuit, and a temperature sensor circuit.

Next, the operation of the conventional high-frequency heating apparatus configured as described above will be described. When the door in the closed state is opened, the pair of main door switches 3 and 4 are turned off, and at the same time, the sub door switch 5 switches from the contact b to the contact a to completely disconnect the commercial power supply 1 from the load. At this time, the door switch 14 is turned on, and the commercial power supply 1 and the power supply circuit 18 of the control circuit 16 are connected. With this connection, the control circuit 1
6 starts, the door switch detection circuit 20 detects the opening of the door and outputs the information to the microcomputer 17, and when the information is input, the microcomputer 17 turns on the relay 15 and sets a certain timer time. And wait.

When the food is put into the heating chamber and the doors are closed, the pair of main door switches 3 and 4 are turned on, the sub door switch 5 is switched from the contact a to the contact b, and the door switch 14 is turned off. . On the other hand, when the microcomputer 17 detects the state through the door switch detection circuit 20, the microcomputer 17 starts counting down the previously set timer time. If a cooking command is input from the key input detection circuit 19 during that time, the countdown of the timer time is stopped, and based on the command, for example, in the case of high-frequency heating, the relay 8 and the relay 10 are connected via the output circuit 21. When it is turned on, power is supplied to the lamp 6 and the table motor 7, and power is applied to the high frequency generation source 11 and the fan motor 12. Then, when the cooking time of the high-frequency generation source 11 due to the heating cooking has elapsed, the relay 8 and the relay 10 are turned off to end the cooking, the timer time is set again, and the countdown is started.

When the timer time becomes zero due to the countdown, the relay 15 is turned off via the output circuit 21, the commercial power supply 1 and the power supply circuit 18 are disconnected, and the power supply is stopped. Also, before the timer time set at the end of cooking reaches zero, open the door and take out the food,
Then, when the door is closed again, the countdown of a fixed timer time set at the time of opening the door is started. When the measurement time reaches zero, O
The N relay 15 is turned off via the output circuit 21.

[0008]

In the above-described conventional high-frequency heating apparatus, the power is applied to the control circuit 16 by turning on the door switch 14 just by opening the door. In addition, when the food is taken out at the end of cooking and the door is closed, power is applied to the control circuit 16 until a certain timer time set when the door is opened becomes zero. The power consumed during that time was wasted, and there was a possibility of baking.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to obtain a high-frequency heating device which eliminates unnecessary power consumption and prevents the possibility of idling.

[0010]

A high-frequency heating apparatus according to the present invention comprises a power supply switching means, and a power supply circuit for generating a control voltage when commercial power is applied. Control means for closing the power supply opening / closing means, a door switch connected in parallel to the power supply opening / closing means and turned on when the door is opened, and detecting food in the heating chamber when the door switch is on. Food supply means for supplying commercial power to the power supply circuit.

The food detecting means comprises a switch which is turned on when the shaft of the table motor for rotating the food placing device is lowered by placing the food.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram of a high-frequency heating device showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of the high-frequency heating device according to the present embodiment, and FIG. It is operation | movement explanatory drawing of a food detection switch. The same or corresponding parts as those of the conventional example described with reference to FIG.

In FIG. 1, reference numeral 31 denotes a plug for connecting to a commercial power supply through an outlet (not shown), and reference numeral 32 denotes a state in which a pair of main door switches 3 and 4 are turned off, that is, a door 35 of the apparatus is opened. The auxiliary door switch which is turned on when the door 25 is opened and the current fuse 2 is blown when the contacts of the main door switches 3 and 4 are not turned off when the door 25 is opened.

Reference numeral 33 denotes a food detection switch, which is attached to a switch fixing plate 40 provided at the bottom of the housing 34 of the present apparatus, for example, and is linked with the vertical operation of the shaft 39 of the table motor 7 to operate the door switch. The power supply circuit 14 is connected or disconnected between the power supply circuit 14 or the power supply opening / closing relay 15. Specifically, when the shaft 39 is in the position as shown in FIG.
9 turns on when it falls as shown in FIG. The shaft 39 penetrates through the bottom of the heating chamber 36 and is attached to the food placing device 37. When the food 38 is placed on the food placing device 37, the shaft 39 is lowered together with the food placing device 37, and the food 38 is moved. When removed, it rises to a predetermined position.

When a power supply circuit 18 generates a control voltage by turning on a food detection switch 33, a microcomputer 17 provided in a control circuit 16 of the present apparatus activates a power supply opening / closing relay 15 connected in parallel with the door switch 14. It is turned on via the output circuit 21.

In the high-frequency heating apparatus of the present embodiment configured as described above, when the plug 31 is connected to the outlet and the closed door 35 is opened, the pair of main door switches 3 and 4 are turned off, and at the same time, The sub door switch 32 and the door switch 14 are turned on. Here, when the food 38 is placed on the food placing device 37 in the heating chamber 36 and the door 35 is closed, when the food 38 is placed, the shaft 39 moves down together with the food placing device 37 and the food detecting switch 33 is turned on. ON
The commercial power supply 1 is applied to the power supply circuit 18 to start up the power supply of the control circuit 16. At this time, the microcomputer 17 starts up and turns on the power supply opening / closing relay 15 via the output circuit 21.
When the door 35 is closed, the pair of main door switches 3, 4
Is turned on, the sub door switch 32 and the door switch 14 are turned off.

At this time, the door switch detection circuit 20 detects the closed state of the door 35 and outputs the information to the microcomputer 17. When the information is input, the microcomputer 17 outputs the information from the key input detection circuit 19. When a cooking command is input, control according to the command is started. For example, in the case of high-frequency heating, the relay 8 and the relay 10 are turned on through the output circuit 21, and the high-frequency generation source 11 and the fan motor 12
And a power supply to the lamp 6 and the table motor 7.

After the elapse of the cooking time of the heating cooking, the microcomputer 17 turns off the relays 8 and 10 through the output circuit 21 and the relay 1 for opening and closing the power supply.
5 is turned off to cut off the power supply to the power supply circuit 18.
When the food 35 is taken out by opening the door 35 at the end of cooking, when the door 35 is opened, a pair of main door switches 3,
4 is turned off, the sub door switch 32 and the door switch 14 are turned on, and when the food 38 is taken out, the shaft 39 is raised.
F. When the door 35 is closed after the food 38 is taken out, the pair of main door switches 3 and 4 are turned on, and at the same time, the sub door switch 32 and the door switch 14 are turned off.

As described above, in the present embodiment, the food detection switch 33 for applying power to the control circuit 16 only when the food 38 is placed on the food placing device 37 is provided.
Power is applied to the control circuit when the door is opened, and when the door is opened and closed at the end of cooking, the power is not shut off until a certain time elapses.
6 has the effect of reducing power consumption.

Further, as described above, if the food 38 is not placed on the food placing device 37, no power is applied to the control circuit 16, so that there is no possibility of idling and there is an effect of improving safety.

[0021]

As described above, according to the present invention, when the food detecting means detects food in the heating chamber when the door switch is in the ON state in conjunction with the opening of the door, the power supply circuit of the control means is provided. Since the commercial power is supplied, there is an effect that the power consumed by the control means during the time until the food is stored in the heating chamber and the time from when the food is removed from the heating chamber to when the apparatus is stopped can be reduced. Further, as described above, if the food detecting means does not detect the food, no commercial power is applied to the power supply circuit of the control means, so that there is no possibility of burning and the safety is improved.

Since the food detecting means comprises a switch which is turned on when the shaft of the table motor for rotating the food placing device is lowered by placing the food, the power consumption of the control means can be reduced with a simple configuration. This has the effect of being economical for the user.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the high-frequency heating device according to the present embodiment.

FIG. 3 is an operation explanatory diagram of a food detection switch which is a main part of the embodiment.

FIG. 4 is a block circuit diagram of a conventional high-frequency heating device disclosed in, for example, Japanese Patent Application Laid-Open No. 8-138851.

[Explanation of symbols]

3,4 Main door switch, 6 lamp, 7 Table motor, 8,9,10 Relay, 11 High frequency source, 1
2 fan motor, 13 heating heater, 14 door switch, 15 power supply opening / closing relay, 16 control circuit, 32
Secondary door switch, 33 food detection switch.

Claims (2)

[Claims] A power supply circuit for generating a control voltage when a commercial power is applied; and a control means for closing the power supply circuit when the control voltage is generated. And connected in parallel to the power opening / closing means, and ON when the door is opened
A high frequency heating apparatus comprising: a door switch that performs a power supply operation; and a food detection unit that supplies commercial power to the power supply circuit when food is detected in the heating chamber when the door switch is in an ON state. 2. The high frequency heating apparatus according to claim 1, wherein said food detecting means comprises a switch which is turned on when a shaft of a table motor for rotating the food placing device is lowered by placing the food. apparatus.