JPH05109478A - High-frequency heating device - Google Patents

Abstract

PURPOSE:To provide a safe high-frequency heating device having little radio wave leakage quantity and advantageous cost-wise. CONSTITUTION:An enamel-finished heating chamber wall 3a is pinched by a sheath heater fitting plate 2a and a heat isolating plate tongue section 9a, and they are integrally fixed with a screw. A heat insulating plate 9 is fixed to the heating chamber wall 3a with a screw 11. Since the sheath heater 2 and the heating chamber wall 3a are electrically brought into contact with each other, a safe high-frequency heating device having little radio wave leakage quantity is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven equipped with a high frequency oscillator and a sheath heater. The present invention relates to the shape of a heat insulating plate attached so as to cover it.

[0002]

2. Description of the Related Art Conventionally, many oven ranges equipped with an electric heating device such as a sheathed heater have been put into practical use so that not only heating cooking by high frequency electromagnetic waves but also oven cooking and grill cooking can be performed. In recent years, many heating chambers with enamel finish have been put into practical use for the purpose of giving a high-class feeling and facilitating maintenance of the heating chamber.

However, even in a high-frequency heating device with a enamel finish inside the heating chamber, the means for fixing the sheath heater is
Conventionally, as shown in FIG. 8, a screw hole 22b is formed in a mounting plate 22a that connects both ends of the sheath heater 22, and is fixed by a screw 30 from the outside of the heating chamber wall 23a.

In a high-frequency heating device having an electric heating device such as a sheath heater, a heat insulating plate 29 is generally attached to cover the heating chamber wall 23a as shown in FIG. 9 for the purpose of reducing the temperature of the outer frame. Be done. Further, when the outer frame 26 is formed with the intake hole or the exhaust hole 26a, a cup containing water or the like is prevented from falling on the upper surface of the outer frame, and the water or the like is prevented from flowing from the intake hole or the exhaust hole to the electric component arrangement side. For this reason, conventionally, the cushion rubber 32 is attached to the heat insulating plate 29, or another metal fitting (not shown) is attached.

[0005]

However, the conventional example has many problems as follows.

In the high-frequency heating apparatus in which the heating chamber has a hollow finish, the sheath heater is fixed only by the screw 30 from the outside of the heating chamber. Therefore, there is a problem that the sheath heater 22 cannot electrically contact the heating chamber wall 23a sufficiently and the high frequency electromagnetic wave propagating through the sheath heater leaks from the heating chamber or the high frequency heating device. That is, when the heating chamber is enamel finish, the enamel is attached not only to the heating chamber but also to the outside of the heating chamber wall in the case of the dipping enamel processing, and in the case of the powder enamel processing, an oxide scale is generated,
An insulating layer 23c such as enamel or oxide scale is also formed on the outside of the heating chamber wall. Therefore,
The sheath heater 22 is arranged in the heating chamber 23 and the mounting plate 22 is attached.
Even if the sheath heater is fixed by screwing the screw 30 into the hole formed in a, the enamel layer 23b is interposed between the sheath heater mounting plate 22a and the heating chamber wall 23a, and the screw 3
0 and the heating chamber wall 23a also include an insulating layer 23c of enamel or oxide scale.
2 and the heating chamber wall 23a are electrically insulated from each other, and the high frequency electromagnetic wave propagating through the sheathed heater leaks out of the heating chamber or the high frequency heating device. Since leakage of high-frequency electromagnetic waves has a harmful effect on the human body as it is legally regulated, in the conventional example, a step of masking the outside of the heating chamber wall or removing oxide scale is added, which is also costly. It was supposed to be.

Further, for the purpose of preventing problems such as insulation failure and ground fault due to water flowing into the outer frame from the intake hole or the exhaust hole to the electric component side, a cushion rubber is attached to the heat insulating plate, or another metal fitting is attached. It was stuck. When attaching the cushion rubber, there was a problem that the adhesion was insufficient due to unevenness of work and adhesion of press oil, and a sufficient effect could not be obtained. When the separate metal fitting is used, a metal mold for the metal fitting is required and a means for fixing the metal fitting is required, which is disadvantageous in terms of cost.

A first object of the present invention is to provide a safer high frequency heating device with a small amount of radio wave leakage.

A second object is to provide a heat insulating plate shape which is cost-effective and has excellent quality.

[0010]

In order to achieve the first object, in the present invention, a heating chamber in which a tongue portion having a screw hole is formed in a heat insulating plate and a hollow finish is made by the tongue portion and the sheath heater mounting plate. The wall is sandwiched, and the sheath heater mounting plate, the heating chamber wall, and the tongue of the heat insulating plate are integrally fixed by screws, and the heat insulating plate is fixed by the screw to the flange of the heating chamber wall.

Further, in order to achieve the second object, a ring-shaped convex portion is formed on the heat insulating plate at a position facing the intake hole or the exhaust hole formed in the outer frame, and the side on which the electric component is not arranged is formed. Then, the ring-shaped convex portion was divided, and the heat insulating plate was provided with a sloping inclined surface on the side where the electric component was not arranged.

[0012]

[Function] The tongue portion formed on the heat insulating plate and the heating chamber wall which is enamel finished by the sheath heater mounting plate are sandwiched, and the sheath heater mounting plate, the heating chamber wall and the tongue portion of the heat insulating plate are integrally fixed with screws, Even if there is enamel or oxide scale on the surface of the heating chamber wall, the sheathed heater can be attached to the mounting plate-
It can be electrically connected to the heating chamber wall more reliably through a route such as screw-insulating plate tongue-insulating plate-screw-heating chamber wall, and it is possible to reduce the amount of radio waves propagating through the sheath heater and leaking from the heating chamber. .. Further, the step of removing the insulating layer is unnecessary, which is advantageous in terms of cost.

Further, a ring-shaped convex portion is formed on the heat insulating plate at a position facing the intake hole or the exhaust hole formed in the outer frame. This convex portion is divided on the side where the electric parts are not arranged, and by forming an inclined surface on the heat insulating plate, a cup containing water falls on the outer frame and the water is sucked into the intake hole or the exhaust hole. Even if it flows into the high-frequency heating device from the above, the water is stored in the convex part on the heat-resistant plate and flows down to the side where the electric parts are not arranged from the inclined surface, so problems such as insulation failure and ground fault can be solved. .. Further, by forming the convex portion integrally with the heat insulating plate, not only the quality is improved, but also the cost is advantageous.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is a high frequency oscillator, 2 is an electric heating device such as a sheath heater, 3 is a heating chamber, 4 is a door, 5 is an operation panel, and 6 is an outer frame.

Hereinafter, description will be given with reference to FIGS. The heating chamber 3 is composed of a heating chamber wall 3a, and when a enamel finish is performed, a enamel steel plate is mainly used. The heating chamber side of the heating chamber wall 3a is provided with a enamel 3b, and the outside of the heating chamber wall is provided with an insulating layer 3c of enamel in the case of dipping enamel processing, and an insulating layer 3c of oxide scale in the case of powder enamel processing. It is formed.

The sheath heater 2 has a mounting plate 2 near the terminals.
a is attached, and a screw hole 2b is machined in the attachment plate 2a. Sheath heater 2 installed from inside heating chamber 3
Is arranged so that the terminal portion 2c is exposed to the outside of the heating chamber. A heat insulating plate 9 is attached above the heating chamber, and the sheath heater 2
The outer frame 6 is prevented from reaching a high temperature when electricity is applied to the. The heat insulating plate 9 has a tongue portion 9a and a hole 9b formed in the tongue portion. Further, the heat insulating plate 9 is provided with a mounting hole 9c for fixing to the heating chamber wall flange portion 3d. Next, a method of mounting each component will be described. In the present invention, the heating chamber wall 3a is sandwiched between the sheath heater mounting plate 2a and the tongue portion 9a of the heat insulating plate and is integrally fixed by the screw 10. The heat insulating plate 9 is further fixed to the heating chamber flange portion with screws 11. Therefore, even if the hollow 3b and the insulating layer 3c are present on the surface of the heating chamber wall 3a, the sheath heater 2 has the sheath heater mounting plate 2a-the screw 10-the heat insulating plate tongue 9a-the heat insulating plate 9-the screw 11
-Electrical contact with the heating chamber wall 3a in the course of the heating chamber wall 3a, and since the sheathed heater and the heating chamber wall are held at the same potential, leakage of high frequency electromagnetic waves to the outside can be reduced.

Further, according to the present invention, the ring-shaped convex portion 9d is formed on the heat insulating plate 9 at a position facing the intake hole or the exhaust hole 6a formed in the outer frame 6, and the side on which the electric component is not arranged. An inclined surface 9c gradually decreasing to S is formed so as to divide the convex portion 9d. In FIG. 6, 7 is an electric heating device, and a sheathed heater is used in this embodiment, but the same effect can be obtained by using a halogen heater or a quartz tube heater. According to this structure, the cup 12 filled with water falls on the outer frame 6 and the intake hole or the exhaust hole 6a
Even if water or the like intrudes into the high-frequency heating device from the inside, the water or the like is collected in the ring-shaped convex portion 9d and flows from the inclined surface 9e to the side S where the electric component is not disposed, and the high-frequency oscillator 1 or the high voltage It is possible to solve the problem that the electrical parts such as the transformer 8 have poor insulation or are grounded.

As described above, according to the high frequency heating apparatus of the present invention, if the object to be heated is put in the heating chamber 3, the door 4 is closed, the cooking means is selected on the operation panel 5, and the cooking is started, the cooking is safely performed. It can be performed.

[0020]

As described above, the following effects can be obtained in the high frequency heating apparatus according to the first aspect. (1) Even in a high-frequency heating device in which the wall of the heating chamber is enamel finished, the wall of the heating chamber is sandwiched between the sheath heater mounting plate and the tongue of the heat insulating plate mounted above the heating chamber, and they are integrally fixed with screws. Since the heat insulating plate is fixed to the wall of the heating chamber with screws, the sheath heater and the wall of the heating chamber are in electrical contact with each other, and it is possible to greatly reduce high frequency electromagnetic waves from propagating through the sheath heater and leaking to the outside. It becomes a safer high frequency heating device. Further, the step of removing the masking and the insulating layer is unnecessary, which is advantageous in terms of cost.

In the second aspect, the following effects can be obtained. (2) By forming a ring-shaped convex portion on the heat insulating plate facing the intake hole or the exhaust hole formed in the outer frame, and further providing a gradually decreasing inclined surface on the side where the electric component is not arranged. Water and the like spilled on the outer frame will also flow to the side where the electric component is not arranged, and it is possible to eliminate problems such as insulation failure and ground fault of the electric component. Further, since the convex portion and the inclined surface are formed of the heat insulating plate, not only the reliability is improved but also the cost is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of the present invention.

FIG. 2 is a perspective view showing a main part.

FIG. 3A is a perspective view showing the shape of a heat insulating plate and screws of the present invention. FIG. 3B is a perspective view showing the shape of a sheath heater.

FIG. 4 is a sectional view of the high-frequency heating device of the present invention.

5A is a plan view showing the shape of a heat insulating plate of the present invention, and FIG. 5B is a sectional view taken along the line A-A ′.

FIG. 6 is a sectional view for explaining the effect of the present invention.

FIG. 7 is an external view of the high-frequency heating device of the present invention.

FIG. 8 is a cross-sectional view showing a conventional sheath heater mounting method.

FIG. 9 is a cross-sectional view showing a conventional heat insulating plate configuration.

[Explanation of symbols]

 1 High Frequency Oscillator 2 Heater Heater 2a Mounting Plate 3 Heating Chamber 3a Heating Chamber Wall 3b Hollow 3c Insulating Layer 3d Heating Chamber Wall Flange 6 Outer Frame 6a Intake or Exhaust Hole 7 Electric Heater 9 Heat Insulating Plate 9a Tongue 9c Mounting Hole 9d Convex Part 9e Sloping surface S Non-electrical component placement side

Claims (2)

[Claims] 1. A heating chamber for housing and heating an object to be heated, a high-frequency oscillator for oscillating high-frequency electromagnetic waves, an electric heating device for heating the object to be heated, and a heat insulating plate for covering the upper wall of the heating chamber. A enamel finish is applied to the heating chamber, a mounting plate is fixed to the electric heating device, and the heating chamber wall is sandwiched and fixed between the mounting plate and the tongue portion formed on the heat insulating plate, and the heat insulating plate is fixed to the heating chamber. A high frequency heating device configured to be fixed to the wall flange. 2. A heating chamber for housing and heating an object to be heated, a high-frequency oscillator for oscillating high-frequency electromagnetic waves, an electric heating device for heating the object to be heated, and a heat insulating plate covering an upper wall of the heating chamber. An outer frame having intake or exhaust holes formed above the heat insulating plate is provided, and a ring-shaped convex portion is formed on the heat insulating plate at a position facing the intake or exhaust holes formed in the outer frame, and electric parts are arranged. The high-frequency heating device in which the ring-shaped convex portion is divided on the non-exposed side, and the heat insulating plate is provided with an inclined surface that gradually lowers on the side on which no electric component is arranged.