JPH118057A - High frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of failure without use of a dielectric which may cause spark by holding an antenna in parallel at the bottom of a heating chamber by an antenna spacer coming in contact with the bottom of the heating chamber and an antenna shaft connected to the shaft of a motor. SOLUTION: A slit hole is formed in the center of an antenna spacer 32 made of PTFE fit to the central part of an antenna 27, and the antenna 27 is fit to the slit hole by applying pressure. The antenna 27 is held in parallel by regulating the distance from the antenna 27 to the bottom surface of a heating chamber 21 and the height of an antenna shaft to the position where the antenna 27 is fixed in the part of the antenna spacer 32. The distance between a pan receiving table 33 and the top end of the antenna is made small so that the antenna 27 does not come out from the antenna shaft. The angle change of the antenna 27 caused by wear is made almost zero, durability is enhanced, and since a dielectric such as metal component or resin does not exist in a part of the antenna shaft, where an electric field is strong, the generation of spark is prevented.

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 device provided with an antenna.

[0002]

2. Description of the Related Art Conventionally, this type of antenna-type high-frequency heating apparatus has been designed so that its characteristics can be easily controlled by changing the antenna dimensions, and the supply of radio waves into a heating chamber is simplified. However, since the temperature of the antenna shaft portion is high and the electric field is strong between the waveguide near the antenna and the opening where the heating chamber is coupled, a resin having a low dielectric constant and a high heat-resistant temperature is required for the resin receiving the antenna shaft. . Further, it has been considered that the mounting structure is difficult because discharge and spark occur due to concentration of an electric field at a mounting portion of the antenna ring for supporting the antenna shaft.

The configuration will be described below with reference to FIGS. 5 and 6. As shown in FIG. 5, a waveguide 3 for guiding a radio wave is mounted below the heating chamber 2 mounted on the main body 1, and a tip of the waveguide 3 on the machine room side oscillates a radio wave. High-frequency oscillator 4 is fixed. An antenna 5 and an antenna shaft 6 for supplying a radio wave to the heating chamber 2 are attached to an opening portion of the waveguide 3 to which the high-frequency oscillator 4 is fixed, which is connected to the heating chamber 2. Thereby, the radio wave oscillated from the high-frequency oscillator 4 passes through the waveguide 3, and the antenna shaft 6 at the opening where the waveguide 3 and the heating chamber 2 are connected,
Radio waves are supplied into the heating chamber 2 by the antenna 5.

As shown in FIG. 6, an antenna ring 7 having a ring shape made of ethylene tetrafluoride is fixed to an opening connecting the waveguide 3 and the heating chamber 2 with a rivet 8. The antenna ring 7 is held up and down between the portion of the flange 9 on the antenna shaft 6 and the antenna 5 and rotates smoothly. The antenna 5 is inserted into a threaded portion of the antenna shaft 6 inside the heating chamber 2 and fixed by a nut 10. Further, in order to prevent sparking of the antenna 5 and the antenna shaft 6, it is generally known that the whole is anodized. The D-cut portion of the shaft 12 of the motor 11 attached to the lower part of the waveguide 3 fits into the tip hole of the antenna shaft 6 attached as described above,
It is known that the antenna 5 rotates when the motor 11 is driven. In the antenna of the conventional high-frequency heating device as described above, since the temperature of the portion of the antenna shaft 6 becomes considerably high, it is generally assumed that the antenna ring 7 is made of tetrafluoroethylene having a high heat-resistant temperature. Have been.

[0005]

However, since ethylene tetrafluoride is expensive in cost, and cannot be formed in a complicated shape due to the molding method of solidifying the powder, it is necessary to add a cutting process after molding, and the processing cost is also high. It is said to be high. Furthermore, since the electric field is strong in the portion of the antenna shaft 6, the presence of a dielectric material such as a resin causes a spark. Further, in order to mount the antenna ring 7, it is common to mount the antenna ring 7 with a screw or to fix the antenna ring 7 with a resin rivet 8, but in the case of the screw type, a metal portion protrudes into the waveguide 3, so that Sparks are likely to occur due to electric field concentration at the tip of the metal powder or screw. Also, in the case of a resin rivet, since the resin rivet protrudes into the waveguide 3, there are quality problems such as melting of the resin rivet and generation of spark.

An object of the present invention is to solve the above-mentioned problems, and to provide a high-frequency heating device which has a simple structure for mounting an antenna, is low in cost, and has high reliability in quality.

[0007]

In order to solve the above problems, the present invention provides an antenna driving motor mounted at a lower portion of a heating chamber, an antenna shaft coupled to a motor shaft protruding into the waveguide. The antenna fixed to the tip of the antenna shaft rotates by the rotation of the motor shaft, and the antenna is provided with an antenna spacer for maintaining a distance from the bottom of the heating chamber, and the antenna contacts the bottom of the heating chamber. The antenna is held parallel to the bottom of the heating chamber by an antenna spacer to be connected and an antenna shaft connected to the motor shaft. According to the above invention, there is no dielectric which is an intervening member for holding the antenna axis where the electric field is strong and tends to cause a spark, and therefore, it is possible to prevent the occurrence of a defect such as a spark.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be embodied in the form described in each claim. As described in claim 1, a heating cabinet for heating food, a high-frequency oscillator for generating high-frequency radio waves, A waveguide for guiding high-frequency radio waves from the high-frequency oscillator located below the chamber to the heating chamber, an antenna axis rotated by driving a motor at the bottom of the heating chamber, and fixed to the antenna axis. An antenna, an antenna spacer mounted on the antenna, and a dish support for mounting an object to be heated mounted on the upper surface of the antenna in the heating chamber, wherein the antenna has an antenna spacer, an antenna shaft, By holding the antenna parallel to the bottom of the heating chamber by the support, there is no danger of spark generation because there is no dielectric substance for holding the antenna axis. Further, the antenna spacer can be effectively mounted by simply press-fitting the antenna into the antenna as described in claim 2, or by mounting the antenna spacer in the center portion of the antenna as described in claim 3. .

An embodiment of the present invention will be described below with reference to the accompanying drawings. (Embodiment) As shown in FIG. 1, a door 23 is pivotally supported at an opening on the front surface of a main body 22 to which a heating chamber 21 is attached so as to be openable and closable. A control panel 24 for operating the heating device is mounted on the front surface of the main body 22. Heating chamber 21
A waveguide 25 is attached to the bottom of the waveguide 25. A high-frequency oscillator 26 for oscillating radio waves is provided at the tip of the waveguide 25 on the machine room side.
Has been fixed. An antenna 27 is provided at the lower part of the tip of the waveguide 25 to which the high-frequency oscillator 26 is fixed, on the side of the heating chamber 21.
And a shaft 29 of the motor 28 is mounted toward a center of an opening 30 connecting the waveguide 25 and the heating chamber 21.
The shaft 29 of the motor 28 has a D-cut shape except for a part in order to rotate the antenna 27,
The antenna 27 is rotated by coupling with a hole-shaped antenna shaft 31 having a margin corresponding to the cross section of the shaft 29 of the D-cut portion.

Next, as shown in FIG. 2, an antenna spacer 32 made of tetrafluoroethylene is attached to a central portion of the antenna 27. A slit hole 32a corresponding to the thickness and width of the antenna 27 is provided at the center of the antenna spacer 32, and has a structure for press-fitting into the antenna 27. The distance a to the bottom,
The antenna 27 is held in parallel by regulating the height b of the antenna shaft 31 up to the position where the antenna 27 is attached.
Further, a dish tray 33 mounted on the upper surface and an antenna shaft 31
The antenna 27 has a structure that does not deviate from the antenna axis 31 by reducing the distance c from the antenna 27.

FIG. 3 is a top view showing a state in which the antenna spacer 32 is mounted on the antenna 27. The position of the antenna spacer 32 is the tip f of the antenna 27 and the antenna shaft 31.
A central position between is preferred.

Next, referring to FIG.
The configuration for mounting the antenna 2 to the antenna 27 will be described.

The above-mentioned antenna spacer 32 is a plate material of about 2 mm thick made of ethylene tetrafluoride.
The C and D portions of the antenna 27 are pushed into the B portion in the directions of the outline arrows, and the protruding portion E is inserted into the square hole F of the antenna 27.
7 fixed.

[0014]

As apparent from the above description, according to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, since a dielectric substance does not intervene in the antenna shaft portion where the electric field is strong and sparks are likely to occur, it is possible to easily prevent the occurrence of sparks and to stabilize the quality.

Further, since the parallel holding of the antenna is determined by the spacer at the center of the antenna, there is almost no change in the angle of the antenna due to abrasion and the durability is excellent.

According to the second and third aspects of the present invention, it is possible to reduce both the production cost and the component cost by a simple configuration in which the antenna spacer is simply press-fitted into the central portion of the antenna.

As described above, it is possible to provide a high-frequency heating apparatus having high quality value.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is a top view of the antenna in the same embodiment.

FIG. 4 is an exploded perspective view of an antenna and an antenna spacer in the same embodiment.

FIG. 5 is a cross-sectional view of a conventional high-frequency heating device.

FIG. 6 is an enlarged sectional view of a main part of the same.

[Explanation of symbols]

 Reference Signs List 21 heating chamber 21a heating chamber bottom 25 waveguide 26 high-frequency oscillator 27 antenna 28 motor 29 axis 30 opening 31 antenna axis 32 antenna spacer 32a slit hole 33 plate support

Claims (3)

[Claims] 1. A heating chamber for heating food, a high-frequency oscillator for generating high-frequency radio waves, a waveguide for guiding high-frequency radio waves from the high-frequency oscillator located below the heating chamber to the heating chamber, An antenna shaft that is rotated by driving a motor at the bottom in the heating chamber, an antenna fixed to the antenna axis, an antenna spacer mounted on the antenna, and a heated object mounted on an upper surface of the antenna in the heating chamber A high-frequency heating apparatus, comprising: a dish tray on which an object is placed; and wherein the antenna is held parallel to a bottom of the heating chamber by supporting an antenna spacer and an antenna shaft. 2. The high-frequency heating apparatus according to claim 1, wherein a slit hole provided in the antenna spacer is press-fitted into the antenna, and the antenna spacer is mounted on the antenna. 3. The high-frequency heating device according to claim 1, wherein an antenna spacer is mounted at a central position between a tip of the antenna and an antenna axis.