JPH0438165Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention uses microwave energy to heat the food to be cooked, and uses steam generated from the food in the heating chamber to increase the internal pressure of the heating chamber. This invention relates to a pressure-type microwave heating device that increases the temperature of food and heats the food to be cooked at a high temperature of 100°C or higher.

[Conventional technology]

Conventionally, this type of microwave heating apparatus has been described, for example, in the specification and drawings of Japanese Patent Application No. 76971/1982.

According to this, the food to be cooked stored in the heating chamber is heated with microwaves while the heating chamber is in communication with the outside air, and the air in the heating chamber is discharged to the outside by water vapor generated from the food to be cooked. When the steam detector detects that the atmosphere has been replaced with water vapor, a solenoid valve that shuts off the heating chamber from the outside air is activated, sealing the heating chamber filled with steam and reducing the internal pressure of the heating chamber. The food to be cooked is heated to a high temperature of 100℃ or higher.

Such high-temperature heating is suitable for shortening the cooking time of the object to be cooked, and also provides the effect of heat sterilization.

[Problem that the invention attempts to solve]

However, in the above-mentioned heating device, since the heating chamber of a certain volume is filled with steam generated from the food to be cooked, when the volume of the food to be cooked is small,
The ratio of the amount of steam generated to the volume of the food to be cooked increases, and the space volume of the heating chamber increases by the smaller capacity, so the amount of water vapor required to fill the heating chamber increases, and the amount of steam generated from the food to be cooked increases. The amount of evaporation becomes very large. As a result, problems such as overheating of the cooked food or low moisture content occur.

This invention has been made with the above-mentioned points in mind, and provides a means by which the volume within the heating chamber can be varied in accordance with the capacity of the food to be cooked.

[Means for solving problems]

This invention consists of a heating chamber whose front opening is airtightly closed by a door and in which the food to be cooked is housed, a heating source that supplies microwave energy into the heating chamber, and a ventilation pipe that communicates the heating chamber with the outside air. a steam detector for detecting a state in which the atmosphere in the heating chamber has been replaced with water vapor; and a solenoid valve provided in the ventilation pipe and actuated by the detection output of the detector to isolate the heating chamber from outside air. In the microwave heating apparatus, an adjusting body for airtightly varying the volume of the heating chamber is provided, and the adjusting body is made of a microwave-transmitting material.

[Effect]

This device is constructed as described above, and when the volume of the food to be cooked is small, by reducing the volume of the heating chamber using the regulator, the amount of evaporation from the food to be cooked will be reduced, and excess Dehydration is prevented.

〔Example〕

Next, this invention will be explained in detail with reference to FIG. 1 showing one embodiment thereof.

In the figure, 1 is a metal microwave resonant housing, 2 is a microwave-transparent partition plate that partitions the inside of the housing 1 into a stirrer chamber 3 and a heating chamber 4, and 5 is a metal microwave resonant housing provided on the upper wall of the housing 1. A magnetron is used as a heating source, and an antenna 6 protrudes into the stirrer chamber 3. 7 is a stirrer for microwave stirring provided in the stirrer chamber 3.

Reference numeral 8 denotes a door that airtightly closes the front opening of the heating chamber 4. The door 8 has a double structure, and includes an outer door 9 that closes the front opening of the heating chamber 4 and exhibits a radio wave leakage prevention function; An inner door 10 is provided as an adjustment body that moves back and forth in the chamber 4 in an airtight manner to vary the volume of the heating chamber 4 in an airtight manner.

The inner door 10 is made of a microwave transparent material, and the tip of a threaded rod 11 screwed through the outer door 9 in the front-rear direction is connected to the inner door 10, and the handle 12 at the base of the threaded rod 11 can be rotated in the forward and reverse directions. By rotating in the direction, the inner door 10 moves in the front-rear direction while maintaining an airtight space between it and the peripheral wall of the opening of the heating chamber 4, and the spatial volume of the heating chamber 4 is varied.

13 is a ventilation pipe that communicates the heating chamber 4 with the outside air; 14
1 is a solenoid valve installed in the ventilation pipe 13; 15 is a steam detector that detects the state in which the atmosphere in the heating chamber 4 has been replaced with water vapor through the ventilation pipe 13 under atmospheric pressure; 1;
Reference numeral 6 designates a barometric pressure detector disposed in the ventilation pipe 13 to detect the internal pressure of the heating chamber 4, and 17 designates a safety valve provided on the rear wall of the heating chamber 4, which is activated when the internal pressure of the heating chamber 4 increases abnormally. .

18 is a dew condensation prevention heater that heats the wall surface of the heating chamber 4 excluding the door 8 and the partition wall 2; 19 is the heating chamber 4;
The food to be cooked is housed in the container and placed on the saucer 20.

Then, the food to be cooked 19 is housed in the heating chamber 4,
After locking the door 8, the inner door 10 is moved rearward by operating the handle 12, and the space volume of the heating chamber 4 is adjusted to the minimum value corresponding to the capacity of the food 19 to be cooked.

Next, the electromagnetic valve 14 is opened, the heating chamber 4 is communicated with the atmosphere only through the ventilation pipe 13, and heater heating and microwave heating are performed.

The microwave oscillated by the magnetron 5 passes through the partition plate 2 while being stirred by the stirrer 7, and heats the food to be cooked 19 in the heating chamber 4. Here, since the inner door 10 that reduces the volume of the heating chamber 4 is made of a microwave-transmitting material, the effect of microwaves on the food 19 is reduced by the change in the spatial volume of the heating chamber 4 due to the inner door 10. There will be no problem at all.

And the microwave-heated food 19
emits water vapor at the same time as the temperature rises, and this releases water vapor inside the heating chamber 4, that is, the area behind the inner door 10 inside the heating chamber 4 (hereinafter, this area is particularly referred to as the high-pressure heating section).
The high-pressure heating section of the heating chamber 4 is filled with air while being discharged to the outside through the ventilation pipe 13.

When the high-pressure heating section is filled with steam, steam is ejected from the vent pipe 13, and this is detected by the steam detector 15. After this detection, a certain period of time (time for the food to be cooked 19 to reach 100°C evenly); Normal pressure heating is performed in a state filled with steam, and the temperature of the food to be cooked 19 is evenly raised to 100°C.

After the certain period of time has elapsed, the solenoid valve 14 is activated and closed, and the heating chamber 4 is isolated from the outside air. As the microwave heating progresses, the high-pressure heating section of the heating chamber 4 becomes high-pressure and high-temperature. Cooked food 19
is heated under such conditions.

When this high-pressure heating section rises to the specified pressure, the oscillation of the magnetron 5 is stopped by the operation of the barometric pressure detector 16 that detects this, and at the same time, the pressure of the high-pressure heating section gradually decreases until it reaches a constant pressure. , the magnetron 5 is detected by the atmospheric pressure detector 16.
oscillation is restarted, and this process is repeated for the heating treatment time T of the food to be cooked 19.

When the heating time T expires, the electromagnetic valve 14 is opened, the water vapor in the high-pressure heating section is discharged to the outside through the ventilation pipe 13, and the pressure in the heating chamber 4 returns to normal pressure.

[Effect of idea]

As described above, according to the microwave heating device of this invention, the volume of the heating chamber is adjusted to the minimum level by varying the volume of the heating chamber using the adjusting body according to the capacity of the food to be cooked stored in the heating chamber. It is possible to reduce the amount of water vapor generated from the food to be cooked and prevent excessive dehydration.It is possible to prevent abnormal heating of the food to be cooked and a decrease in the moisture content, and also to quickly fill the heating chamber with steam. By doing so, the effect of shortening the heating time can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view showing one embodiment of the microwave heating device of this invention. 4... Heating chamber, 5... Magnetron, 8... Door, 10... Inner door (control body), 13... Ventilation pipe, 14... Solenoid valve, 15... Steam detector, 19
...Items to be cooked.

Claims (1)

[Claims for Utility Model Registration] A heating chamber whose front opening is airtightly closed by a door and in which food to be cooked is stored; a heating source that supplies microwave energy into the heating chamber; and a heating chamber that supplies microwave energy to the heating chamber; A vent pipe that communicates with the heating chamber, a steam detector that detects a state in which the atmosphere in the heating chamber has been replaced with water vapor, and a steam detector that is installed in the vent pipe and is activated by the detection output of the detector to isolate the heating chamber from outside air. A microwave heating device comprising a solenoid valve, the microwave heating device comprising: an adjustment body that airtightly varies the volume of the heating chamber; and the adjustment body is made of a microwave transparent material.