JPS6293893A - Cooker - Google Patents

Abstract

(57) [Summary] 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 relates to a cooking appliance having a microwave cooking function and an open cooking function.

[Technical background of the invention]

Generally, a cooking device such as a microwave oven generates high-frequency radio waves from a magnetron and supplies them into a heating chamber to carry out YK electric heating of food, so-called microwave cooking.

Some of these microwave ovens have an open cooking function in addition to the microwave cooking function.

In this open cooking, a sheathed heater installed in a heating chamber generates heat, and the temperature in the heating chamber rises based on the generated heat, thereby heating the food.

[Problems with background technology]

However, since the sheathed heater is rod-shaped, there is a problem in that food is heated unevenly during open cooking.

Furthermore, there was a problem in that the effective volume within the heating chamber was reduced due to the presence of the sheathed heater. Furthermore, there was also the problem that the sheathed heater got in the way and made it difficult to clean the inside of the heating chamber.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide a cooker that enables good open cooking without uneven heating, expands the effective volume inside the heating chamber, and also allows easy cleaning of the inside of the heating chamber. It's about pulling.

[Summary of the invention]

This invention provides a heating coil near the wall of the heating chamber, and an inverter circuit that supplies high-frequency current to the heating coil, and performs open cooking by induction heating the wall of the heating chamber by the high-frequency magnetic field of the heating coil. It is.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a heating chamber, and the food to be cooked 2 is placed in the heating chamber 1 at v, r! i.A shelf board 3 is provided for storage. A magnetron 4 is attached to the outer periphery of the side wall of the heating chamber 1, and an antenna 4a of the magnetron 4 is introduced into the heating chamber 1. Further, a heating coil 5 is disposed near the back side of the wall surface of the heating chamber 1, for example, the ceiling surface.

On the other hand, 10 is a commercial AC power supply, and an inverter circuit 20 is connected to this power supply 10. This inverter circuit 20
The control unit 40 controls the drive unit 11i11 to operate the magnetron 4 and the heating coil 5. However, the inverter circuit 20
The output is supplied to the magnetron 4 via the range side contact of the changeover switch 31 (between the enable terminal 31c and the fixed terminal 31a) and the step-up transformer 32. In addition, a switch 31 is used to change the output of the inverter circuit 20.
The heating coil 5 is supplied through the open side contact (between the movable terminal 31C and the fixed terminal 31b).

FIG. 2 shows a specific configuration of the control circuit.

First, the inverter circuit 20 includes a diode bridge 21
．． Choke coil 22. A rectifier circuit consisting of a smoothing capacitor 23, a capacitor 24 forming a series resonant circuit together with the heating coil 5 or the primary coil 32a of the step-up transformer 32 at the output end of this rectifier circuit, and a switching element such as an NPN type transistor that excites the series resonant circuit. 25 etc. Here, it is possible to select with a changeover switch 31 which of the heating coil 5 and the primary coil 32a forms the series resonant circuit.

The secondary coil 32b of the step-up transformer 32 is connected between the anode and cathode of the magnetron 4 via a half-wave voltage doubler rectifier circuit including a high-voltage capacitor 33 and a high-voltage diode 34. Then, the 7th node is grounded. Note that a predetermined heater voltage is applied to the heater (cathode) of the magnetron 4.

Next, the operation in the above configuration will be explained.

When microwave cooking is set using an operation unit (not shown), the microwave side contact (-31 cm 31a) of the changeover switch 31 is opened. In other words, the negative coil 32a and the capacitor 24 form a series resonant circuit.

The food 2 is placed in the heating chamber 1, the required cooking time is set, and the cooking is started. Then, the power supply 10 is turned on, and the resonant circuit is excited by turning on and off the transistor 25 based on the drive signal from the control section 4o. In this way, a high-frequency current of a predetermined frequency flows through the secondary coil 32a, and the voltage generated thereby is boosted and rectified by half-wave voltage doubler and applied to the magnetron 4.

Therefore, high frequency radio waves are supplied from the magnetron 4 into the heating chamber 1, and the food 2 is dielectrically heated.

After that, when the preset cooking time has passed, 1ai
o is shut off, and microwave cooking ends.

When open cooking is set using the operation unit (not shown), the open side contact (31G-31b) of the changeover switch 31 is closed. In other words, the heating coil 5 and the capacitor 24 form a series resonant circuit.

Thus, the food 2 is placed in the heating chamber 1, the required food temperature is set, and cooking is started. Then, the power supply 10 is turned on, and the resonant circuit is excited by turning on and off the transistor 25 based on the drive signal from the control section 40. In this way, a high frequency current of a predetermined frequency flows through the heating coil 5, and a high frequency magnetic field is emitted from the heating coil 5.

Therefore, the ceiling surface of the heating chamber 1 is heated by induction by the high frequency magnetic field emitted from the heating coil 5, and the temperature inside the heating chamber 1 rises. The food 2 is then heated at the temperature within the heating chamber 1.

Thereafter, when the temperature of the food 2 reaches a preset temperature, the power supply 10 is cut off and the open cooking process ends.

In this way, the ceiling surface of the heating chamber 1 is induction heated by the high frequency magnetic field of the heating coil 5, and the heating chamber 1 is heated by induction heating.
Since open cooking is performed depending on the internal temperature, the food 2 can be cooked in a good manner without uneven heating. In particular, since a conventional sheathed heater is not required, the effective volume within the heating chamber 1 can be expanded, and the interior of the heating chamber 1 can be easily cleaned.

In the above embodiment, the heating coil 5 is installed near the ceiling surface of the heating chamber 1, but it may be installed near the side wall of the heating chamber 1, for example. In addition, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without changing the objectives.

〔Effect of the invention〕

As described above, according to this invention, it is possible to perform open cooking without uneven heating, and it is also possible to expand the effective volume inside the heated seedlings, and furthermore, it is possible to easily clean the inside of the heating chamber. We can provide cooking utensils.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an example of the present invention, and FIG. 2 is a diagram showing the specific configuration of a control circuit in the same embodiment. DESCRIPTION OF SYMBOLS 1... Heating chamber, 4... Magnetron, 5... Heating coil, 20... Inverter circuit, 31... Changeover switch, 32... Step-up transformer, 40... Control part.

Claims (2)

[Claims] (1) A heating chamber, a heating coil provided near the wall of the heating chamber, and an inverter circuit that supplies a high-frequency current to the heating coil, the wall of the heating chamber being guided by the high-frequency magnetic field of the heating coil. A cooking device characterized by heating and open cooking. (2) The cooking appliance according to claim 1, wherein the inverter circuit also serves as an operating power source for a magnetron that supplies high-frequency radio waves into the heating chamber.