JPH04309718A - Microwave oven - Google Patents

Abstract

PURPOSE:To carry out a defreezing of a frozen food under the optimum state by a method wherein the frozen food is defreezed (ice melted) under a micro- wave heating, the ice melted moisture content is changed into ultra-fine particles under an ultrasonic wave got from a piezoelectric element, discharged into surrounding air and the ultra-fine particles are sensed by a humidity sensor. CONSTITUTION:A range main body 1 is provided with a heating chamber 3, a side wall 4 of the heating chamber 3 is provided with a magnetron 5, a side wall 10 of the heating chamber 3 is provided with a discharging duct 12, a humidity sensor 13 is installed within the discharging duct 12 and a piezo-electric element 15 is disposed at a bottom plate 14 of the heating chamber 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven for heating and defrosting frozen foods using microwaves from a magnetron.

0002

[Prior Art] Conventional microwave ovens are equipped with a weight sensor in the heating chamber to measure the weight of the food, and the heating (thawing) time is set based on the weight of the food detected by this weight sensor. Microwave heating was used to finish defrosting frozen foods. In addition, the idea is to equip the heating chamber with a humidity sensor that detects moisture (steam) generated from food, and use the detection results of the humidity sensor used during normal cooking to detect and control the finished state of defrosting frozen food. It will be done.

0003

[Problem to be Solved by the Invention] In the microwave oven equipped with the above-mentioned weight sensor, the heating (thawing) time is set only based on the weight of the frozen food. The finished state was inconsistent and it was not possible to obtain the optimal thawing state.

[0004] Furthermore, in a microwave oven equipped with a humidity sensor, moisture (
The amount of steam generated is very small, and the detection level of the humidity sensor is low. When the detection level of the humidity sensor increases, the thawed food is already warm, so the humidity sensor detects the thawing of the frozen food. It could not be used to detect the finish of the paper.

[0005] The microwave oven of the present invention was developed in view of the above-mentioned problems, and uses microwave heating to thaw (thaw) frozen foods, and the thawed moisture of the frozen foods is absorbed by ultrasonic waves from a piezoelectric element. The purpose of this system is to release the ultrafine particles into the air, detect the ultrafine particles using a humidity sensor, and defrost frozen foods in an optimal state.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the microwave oven of the present invention includes a magnetron that generates microwaves to thaw frozen foods, and an ultrasonic wave to melt water from the frozen foods. It is equipped with a piezoelectric element that converts the frozen food into ultrafine particles, and a humidity sensor that detects the moisture content of the ultrafine particles generated from the frozen food using the piezoelectric element and detects the completion of thawing of the frozen food.

[0007]

[Operation] The microwave oven with the above configuration heats frozen food using microwaves from a magnetron, and converts the water in the frozen food that is melted by this heating into ultrafine particles using ultrasonic waves from a piezoelectric element. The ultrafine particles are detected by a sensor, and based on the detection results, the optimal state for thawing the frozen food is detected, and the frozen food is thawed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the microwave oven of the present invention will be described with reference to FIGS. 1 to 3. The microwave oven of the present invention includes a heating chamber 3 for heating frozen food 2 in microwave main body 1, and a magnetron 5 for generating microwaves for heating frozen food 2 on one side wall 4 of heating chamber 3. a waveguide 6 that guides the microwave from the magnetron 5 to the heating chamber 3;
has been established. An opening is provided at the connection portion of the waveguide 6 of the heating chamber 3, and the opening is closed by a waveguide cover 7 so that steam or the like in the heating chamber 3 does not leak.

A punching hole on one side wall 4 of the heating chamber 3 is provided on the blowing side through which cooling air (cooling air after cooling the magnetron 5) from the magnetron cooling fan 8 provided in the microwave main body 1 is blown. 9 is provided. Exhaust side punching hole 11 in the other side wall 10 of the heating chamber 3
and an exhaust duct 12 for discharging the exhaust from the exhaust side punching hole 11 to the range main body 1 side,
A humidity sensor 13 is provided in the exhaust duct 12 to detect steam (humidity) contained in the exhaust gas. A piezoelectric element 15 is provided outside the bottom plate 14 of the heating chamber 3 to convert moisture in the frozen food 2 into ultrafine particles using ultrasonic waves.

[0010] The operation of thawing frozen foods such as perishables in the microwave oven having the above configuration will be explained. First, when the frozen food 2 is placed in the heating chamber 3 and the thawing operation is started,
The magnetron cooling fan 8 and the piezoelectric element 15 are energized and start operating. This magnetron cooling fan 8
Air is blown from the exhaust duct 12 to clean water droplets adhering to the surface of the frozen food 2 and inside the heating chamber 3.
A humidity sensor 13 detects the humidity in the exhaust gas discharged to the
When the detected humidity reaches the first predetermined value a, it is determined that the cleaning has been completed, and the magnetron 5 is energized.

[0011] Then, the frozen food 2 is heated by the microwave from the magnetron 5, and the water melted by the heating is turned into ultrafine particles by the ultrasonic waves from the piezoelectric element 15. Thereafter, the exhaust gas containing the ultrafine particles is discharged to the exhaust duct 12, and when the humidity detected by the humidity sensor 13 reaches a second predetermined value, it is determined that defrosting is complete, and the magnetron 5, magnetron cooling fan 8, piezoelectric element 15, and the defrosting operation is completed. At this time, since the water from the frozen food 2 that has melted is immediately released into the air as ultrafine particles, there is no need to wait until the water turns into steam, and the frozen food 2 does not become warm.

0012

[Effects of the Invention] Since the microwave oven of the present invention has the above-mentioned configuration, the water that melts from frozen food is immediately released into the air as ultrafine particles, so it is possible to thaw frozen food using a humidity sensor. It is possible to achieve the optimal thawing state regardless of the shape or weight of frozen food without causing the thawed food to become warm.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a microwave oven of the present invention.

FIG. 2 is a time chart showing the operating state of each component of the microwave oven of the present invention.

FIG. 3 is a characteristic diagram showing the humidity generated in frozen food during the thawing operation of the microwave oven of the present invention.

[Explanation of symbols]

1　Microwave body 2 Frozen food 3 Heating chamber 5 Magnetron 13 Humidity sensor 15 Piezoelectric element

Claims (1)

[Claims] Claim 1: A magnetron that generates microwaves to thaw frozen food; a piezoelectric element that uses ultrasonic waves to convert the water content of the frozen food into ultrafine particles; and a piezoelectric element that generates ultrafine particles from the frozen food by the piezoelectric element. A microwave oven characterized by being equipped with a humidity sensor that detects moisture in food and detects the completion of thawing of frozen food.