JPH05109475A - High-frequency-heated cooking appliance - Google Patents

Abstract

PURPOSE:To improve the oscillation efficiency of a magnetron by detecting the temperature of the magnetron anode of the magnetron, controlling an impedance adjusting device by the detected temperature of the magnetron anode, and invariably keeping the temperature of the magnetron anode low. CONSTITUTION:A magnetron 3 generating microwaves heating and cooking an object 2 to be cooked is provided, and a rotary antenna 6 adjusting the load impedance in a cooking chamber 1 is provided. A thermistor 11 detecting the temperature of the magnetron anode 10 of the magnetron 3 is provided, and a controller controlling the rotary antenna 6 via the temperature detected by the thermistor 11 and keeping the temperature of the magnetron anode 10 low is provided.

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 cooker that heats and cooks food by microwaves from a magnetron, and improves the oscillation efficiency of the magnetron by adjusting the load impedance in the cooking cabinet.

[0002]

2. Description of the Related Art A conventional high-frequency heating cooker is disclosed in Japanese Examined Patent Publication Sho 62
-28553 is equipped with a magnetron for heating and cooking food, the anode current of the magnetron anode of this magnetron is detected using a voltmeter, and the magnitude of this detected anode current is displayed on the display unit. According to the magnitude of the displayed anode current, the impedance adjusting device for adjusting the load impedance in the cooking cabinet is operated by the operation unit to oscillate the magnetron with high efficiency.

[0003]

However, in the high-frequency heating cooker having the above-described structure, in the case where the cooking table has a turntable for rotating the food to perform uniform heating, the turntable The load impedance in the cooking cabinet always changes due to the rotation, that is, the rotation of the food, and therefore the anode current of the magnetron anode that fluctuates due to the load impedance also continuously changes without being stable. Is very difficult to control,
It was not possible to improve the oscillation efficiency of the magnetron.

The high frequency heating cooker of the present invention has been made in view of the above problems, and detects the temperature of the magnetron anode of the magnetron, and controls the impedance adjusting device according to the detected temperature of the magnetron anode. The object of the present invention is to improve the oscillation efficiency of the magnetron by keeping the temperature of the magnetron anode always low.

[0005]

In order to achieve the above-mentioned object, a high-frequency heating cooker of the present invention comprises a magnetron for generating microwaves for heating and cooking a food, and an impedance for adjusting load impedance in a cooking cabinet. An adjusting device, a temperature detector for detecting the temperature of the magnetron anode of the magnetron, and a controller for controlling the impedance adjusting device according to the temperature detected by the temperature detector to keep the temperature of the magnetron anode low. .

[0006]

With the above structure, the temperature of the magnetron anode, which changes relatively slowly with respect to the change of the load impedance, is detected by the temperature detector, and the impedance adjusting device is controlled by the detected temperature to keep the temperature of the magnetron anode low. , Oscillate the magnetron with high efficiency.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high frequency cooking device of the present invention will be described with reference to the drawings. In the high-frequency heating cooker of the present invention, a magnetron 3 for generating microwaves for heating and cooking the cooked food 2 is disposed on the side of the cooking chamber 1 of the cooker body, and the microwave from the magnetron 3 is used as described above. A waveguide 4 leading to the cooking cabinet 1 is provided, and the magnetron antenna 5 of the magnetron 3 is located in the waveguide 4.

On the microwave supply side of the waveguide 4, that is, on the cooking cabinet 1 side, a rotary antenna 6 which is an impedance adjusting device for adjusting the load impedance in the cooking cabinet 1 and an antenna cover 7 are arranged. An antenna drive motor 9 for driving the rotary antenna 6 via a rotary shaft 8 is arranged outside the waveguide 4.

A thermistor 11, which is a temperature detector for detecting the temperature of the magnetron anode 10, is provided in contact with the outer wall of the magnetron anode 10 of the magnetron 3, and the antenna is driven by the temperature detected by the thermistor 11. A control unit (not shown) for driving the motor 9 to control the position of the rotary antenna 6 to adjust the load impedance in the cooking cabinet 1 is provided.

A turntable 12 is provided at the bottom of the cooking cabinet 1 for heating and cooking the food 2 in a uniform state.
Is provided.

The operation of the high-frequency heating cooker having the above structure will be described.

First, when the food 2 is placed on the turntable 12 in the cooking cabinet 1 to start heating and cooking, power is supplied to the magnetron 3 and the magnetron 3 starts oscillating to generate microwaves. Microwaves are guided into the cooking chamber 1 by the waveguide 4 to heat and cook the cooked product 2. At this time, the cooked product 2 is rotated by the turntable 12 and uniformly cooked by the microwave.

Then, the thermistor 11 detects the temperature of the magnetron anode 10 of the magnetron 3, and the controller drives the antenna drive motor 9 by the detected temperature to control the position of the rotary antenna 6.

By controlling the position of the rotating antenna 6 and adjusting the load impedance in the cooking cabinet 1, the magnetron anode 10 is kept at a low temperature so as not to rise, and the magnetron 3 is highly efficiently operated. Oscillate.

As described above, by maintaining the temperature of the magnetron anode 10 at a low temperature, the magnetron 3 oscillates with high efficiency. Generally, the input energy to the magnetron 3 is the microwave energy oscillated from the magnetron 3. It is represented by the sum of thermal energies indicated by the temperature of the magnetron anode 10, and when the input energy is constant, the higher the temperature of the magnetron anode 10, the smaller the microwave energy oscillated and the lower the oscillation efficiency.
On the contrary, when the temperature of the magnetron anode 10 is low, the microwave energy to be oscillated becomes large and the oscillation efficiency becomes high.

Then, the load impedance is the cooking cabinet 1
It changes depending on the amount and position of the cooked food 2 inside, and the oscillation efficiency and the magnetron anode 1 change as the load impedance changes.
The temperature of 0 also fluctuates.

Therefore, the temperature of the magnetron anode 10 is detected as described above, and the rotating antenna 6 is detected by this temperature.
The load impedance in the cooking cabinet 1 is controlled by controlling the position of 1 to maintain the temperature of the magnetron anode 10 at a low temperature, so that the magnetron 3 can always oscillate with high efficiency.

For example, as a result of conducting an experiment in which 300 cc of water is put in the cooking cabinet 1 and heated for 60 seconds, when the rotary antenna 6 is heated at the position A shown by the solid line in FIG. 3, the shaded area shown in FIG. It becomes a load impedance like
With heating in this state, as shown in Table 1, the temperature of the magnetron anode 10 was 200 ° C., and the water temperature increased only by 40 ° C.

However, if the rotary antenna 6 is heated at the position B shown by the broken line in FIG.
The load impedance inside becomes the load impedance shown by the shaded area in FIG. 5, and as shown in Table 1, the temperature of the magnetron anode 10 becomes 150 ° C. and the water temperature rises by 52 ° C.

[0020]

[Table 1]

As is clear from the above experiment, the lower the temperature of the magnetron anode 10, the larger the temperature rise of the water temperature,
It can be seen that the magnetron 3 oscillates with high efficiency.

Therefore, the oscillation efficiency of the magnetron 3 can be improved by detecting the temperature of the magnetron anode 10 with the thermistor 11 and controlling the position of the rotary antenna 6 so that the temperature of the magnetron anode 10 does not rise. The cooked food 2 can be cooked in a short time.

Another embodiment of the high-frequency heating cooker according to the present invention will be described with reference to FIG.

In this high frequency heating cooker, a waveguide 4 for guiding microwaves from the magnetron 3 is provided above the cooking cabinet 1 of the cooker main body, and a stub 13 as an impedance adjusting device is provided in the waveguide 4. By providing this stub 13 and operating it according to the temperature of the magnetron anode 10 detected by the thermistor 11, the load impedance in the cooking cabinet 1 is adjusted and the temperature of the magnetron anode 10 is kept at a low temperature.

[0025]

The high-frequency heating cooker of the present invention detects the temperature of the magnetron anode and controls the impedance adjusting device to maintain the temperature of the magnetron anode at a low temperature, so that the oscillation efficiency of the magnetron is improved. Can be improved, the cooking time for cooking can be shortened, and power can be saved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a high-frequency heating cooker according to the present invention.

FIG. 2 is a partially cutaway enlarged view showing a magnetron of the high-frequency heating cooker of the present invention.

FIG. 3 is a side view showing the position of the rotary antenna of the high-frequency heating cooker according to the present invention.

FIG. 4 shows a rotary antenna of the high frequency heating cooker of the present invention,
It is a characteristic view which shows the load impedance in the cooking cabinet at the time of a position.

FIG. 5 shows a rotary antenna B of the high-frequency heating cooker according to the present invention.
It is a characteristic view which shows the load impedance in the cooking cabinet at the time of a position.

FIG. 6 is a schematic sectional view showing another embodiment of the high-frequency heating cooker according to the present invention.

[Explanation of symbols]

 1 Cooking Cabinet 2 Cooking Material 3 Magnetron 4 Waveguide 5 Magnetron Antenna 6 Rotating Antenna 7 Antenna Cover 8 Rotating Axis 9 Antenna Drive Motor 10 Magnetron Anode 11 Thermistor 12 Turntable 13 Stub

Claims (1)

What is claimed is: 1. A high-frequency heating cooker for heating and cooking food by microwaves from a magnetron, an impedance adjusting device for adjusting a load impedance in a cooking cabinet, and a temperature detecting device for detecting a temperature of a magnetron anode of the magnetron. A high-frequency heating cooker, comprising: a heater and a controller that controls the impedance adjusting device according to the temperature detected by the temperature detector to keep the temperature of the magnetron anode low. 1.