JPS593888A - Cooking device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention has a door switch and an auxiliary door switch that respond to the opening and closing of a door provided at the opening of a heating chamber, and the door switch is connected to a heating operation section. The present invention relates to a cooking appliance that is inserted into an energized path and that electronically controls opening and closing of the energized path to a heating operation section using the output of an auxiliary door switch.

[Technique of invention #1] Generally, a cooking device such as a microwave oven has a door switch that responds to the opening and closing of a door provided at the opening of the heating chamber, and the door opens and closes during cooking. When this occurs, power is cut off to the heating operation part and the shim magnetron to prevent leakage of radio waves and ensure safety.

Here, an example of the appearance and control circuit of a microwave oven is shown in the first section.
As shown in FIG. That is, 1 is a main body of a microwave oven, and a door 2 is provided on the front surface of the main body 1 so as to be openable and closable, and an operation panel 3 is also provided. A heating chamber (not shown) is provided in the main body 1 corresponding to the door 2,
The opening of the heating chamber is closed by a door 2.

10 is an AC power supply, and this power supply 10 includes a fuse 11 and door switches 12 and 1 that respond to the opening and closing of the door 2.
3. Relay contact 24a1 Relay contact (bidirectional contact)
25a, I) The primary side of the transformer 15 is connected via the relay contact 23a1 and the magnetron thermal 14, and the secondary side of the transformer 15 is heated via a rectifier circuit consisting of a high voltage capacitor 16 and a high voltage diode 1'7. A magnetron 18, which is an operating section, is connected. An open heater 19, which is a heating operation section, is connected to the primary side of the transformer 16 via a relay contact 24a.

and the interconnection point of door switch 12.13 and contact point 2
A short switch 2o is connected between 3h and the interconnection point of the magnetron thermal 14.

This short switch 2o is linked to the door switches 12 and 13. Further, the primary side of a transformer 21 is connected to the power source 1o via the fuse 11 and the magnetron thermal 14, and the main control section 22 is connected to the secondary side of the transformer 21. This main control section 22 is composed of a microcomputer and its peripheral circuits, and controls the cooking of the relays 24.25 and controls the output of the auxiliary door switch 26 linked to the door switch I 2.13. The relay 23 is controlled accordingly. FIG. 3 specifically shows the control portion of the relay 23 in the main control section 22. As shown in FIG. That is, an operating voltage of 5 (v) is applied to the series circuit of the auxiliary door switch 26 and the resistor 30.
) is applied, and the voltage obtained at the interconnection point between the auxiliary door switch 26 and the resistor 30 is supplied to the microcomputer 32 via the resistor 31. When the voltage input through the resistor 31 is at a high level, the microcomputer 32 supplies a high level voltage through the resistor 33 to the base of a switch, for example, an NPN transistor 34. The operating voltage 12 (V
) is applied. Note that a diode 35 for preventing back electromotive force is connected in parallel to the relay 23.

Therefore, when food is placed in the heating chamber and the door 2 is closed, the door switches 12, 13 and the auxiliary door switch 2
6 is turned on, and the short switch 2o is turned off. In this state, when you set microwave cooking and turn on the power 1o, the L/-23 and 24 operate, and the magnetron 18
Electricity is applied to the cooker and cooking begins. Therefore, when the door 2 is opened during cooking, the door switches 12, 13 are turned off, the operation of the magnetron 18 is stopped, and high frequency leakage is prevented. At this time, the short switch 2o is turned on at the same time, so if the door switch 12 is not turned off due to welding, for example, a short circuit is formed and the fuse 11 is blown, causing the fumagnetron 18 to operate. stops. At the same time, the auxiliary door switch 26 is turned off, the transistor 34 is turned off, and the operation of the relay 23 is stopped.
Even if a failure occurs in 2, 13 and the short switch 20, the operation of the magnetron 18 will be reliably stopped.

[Problems with background technology]

However, the door switches 12 and 13, the short switch 20, and the main control unit 22 all failed, and the transistor 34 remained on even though the auxiliary door switch 26 was turned off in conjunction with the opening of the door 2. In this case, the operation of the magnetron 18 cannot be stopped and high frequency leakage occurs, resulting in an extremely dangerous situation.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide a highly safe cooking device that can avoid, for example, the risk of high frequency leakage as much as possible.

[Summary of the invention]

The present invention is a cooking appliance in which a relay is controlled in accordance with the output of an auxiliary door switch, and the relay controls energization of a heating operation section, in which operating voltage is supplied to the relay via the auxiliary door switch. It is.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this case, the same parts as in FIGS. 1, 2, and 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 4, the auxiliary door switch 26 and the resistor 41
．． A relay operating voltage 12 (Vl) is applied to the series circuit of the resistors 41 and 42, and +5 (V) is supplied to the interconnection point of the resistors 41 and 42 through a diode 43 in the opposite direction. The voltage available at the interconnection point 42 is supplied to the microcomputer 32 via a resistor 44.

On the other hand, the operating voltage 12 (g) is applied to the relay 23 via the collector/emitter of the transistor 34 and the auxiliary door switch 26 .

Therefore, even though the door 2 is opened, the door switches 12 and 13 do not turn off, and the seat switch 20 does not turn off.
Even if the door 2 does not turn on, if the auxiliary door switch 26 turns off normally when the door 2 is opened, the resistor 41
．． The change in the voltage at the interconnection point 42 causes the microcomputer 32 to turn off the transistor 34, and the operation of the relay 23 is stopped. As a result, the operation of the magnetron 19 is stopped and high frequency leakage is prevented.

Incidentally, in this case, the microcomputer 32 may malfunction or the transistor 34 may fail and the transistor 34 may not turn off. At this time, the supply of operating voltage to the relay 23 is stopped by turning off the auxiliary microswitch 26, so that the operation of the relay 23 is reliably stopped, and there is no risk of high frequency leakage.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a highly safe cooking appliance that can avoid, for example, the danger of high frequency leakage as much as possible.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of the microwave oven, Fig. 2 is a configuration diagram showing an example of the control circuit of Fig. 1, Fig. 3 is a configuration diagram of the main part of Fig. 2, and Fig. 4 is an example of the control circuit of the present invention. FIG. 2 is a configuration diagram showing an example. 2...Door, 12.13...Door switch, 20.
...shi, -tosui, chi, 22...main control section, 23...
・Relay, 26...Auxiliary door switch.

Claims (1)

[Claims] In response to the opening and closing of the door installed at the opening of the heating chamber,
It has a door switch inserted into the energizing path to the heating operation section, an auxiliary door switch that operates in conjunction with this door switch, and a relay that controls the energization to the heating operation section, and this relay is connected to the output of the auxiliary door switch. What is claimed is: 1. A cooking appliance comprising: a main control section that controls the relay according to the operating voltage;