JPS6331915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency heating device such as a microwave oven, and relates to a structure for preventing leakage of radio waves from around a door.

In order to prevent radio waves from leaking from around the door, conventional high-frequency heating devices install a metal plate on the inside of the door that makes surface contact with the peripheral plate of the opening of the heating chamber. Furthermore, leakage of radio waves was prevented by providing a radio wave absorber such as ferrite around the outer periphery of the door, or by providing a periodic structure (slit seal) in the chain groove provided at the periphery of the door.

However, all of these measures to prevent radio wave leakage are subject to design issues, and there are natural limits to the dimensions allowed for the measures to prevent radio wave leakage, in that the opening of the heating chamber must be configured as large as possible, and there are limitations on design and assembly. It was extremely difficult and relatively ineffective.

The present invention includes a heating chamber provided in a main body, a door provided at an opening of the heating chamber so as to be openable and closable, and a high frequency generator that supplies high frequency waves into the heating chamber.
It consists of a sash provided around the door,
The above-mentioned drawbacks of the conventional art are solved by providing at least one protrusion on at least one of the door and the sash to locally reduce the gap between the door and the sash.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In Fig. 1, 1 is the main body of the high-frequency heating device;
A door 3 is provided at the opening of a heating chamber 2 provided in the main body 1 so as to be openable and closable. 4 is an operation panel provided on the front of the main body 1;
is provided with a timer 5 for controlling the operation of a high frequency generator (not shown), a cooking start button 6, and the like.

In FIG. 2, 7 is a metal sash located on the front of the main body 1 and provided around the door 3. Gaps D ₁ to D ₄ are provided between the sash 7 and the door 3, and the sash 7 is provided around the door 3. From the corner of No. 7, n/4 of the wavelength (λ) of the radio wave used for high-frequency heating (n = 0.12...
...) The protrusions 8 are located at the positions l ₁ to _{l 5} of the door 3 or the door 7.
There are multiple locations. The height of this protrusion is a size S ₁ that does not cause any problem in opening and closing the door 3.
~S ₆ has been prominently left. 9 is a hinge that pivotally supports the door 3.

In FIG. 3, 8 is a projection that locally reduces the gap between the door 3 and the sash 7. Reference numeral 10 denotes an inner plate provided inside the door 3, and when a high frequency wave is supplied to the heating chamber 2, the inner plate 10
An insulating coating 12 is provided to prevent sparks from coming into contact with the aperture frequency 11 of.

13 is a chiyoke groove provided on the peripheral edge of the door 3 facing the opening peripheral plate 11;
is provided with a comb-shaped periodic structure 14 shown in FIG.

By configuring the high-frequency heating device in this way, the high-frequency waves supplied into the heating chamber 2 are
The capacitor-like effect of the opening peripheral plate 11 and the insulating rim 12 provided on the inner plate 10 of the door 3 creates a conductive state for high frequencies, reducing radio wave leakage from the opening of the heating chamber 2. be able to.

Furthermore, radio waves that cannot be blocked due to the capacitor-like effect of the insulating film 12 and leak out will proceed into the chiyoke groove 13, but the shape and dimensions of the periodic structure 14 provided in the chiyoke groove 13 should be selected appropriately. This makes it possible to restrict radio waves in the X direction shown in FIG. Furthermore, if we consider that the radio waves heading toward the chiyoke groove 13 proceed in the direction in which the two-direction components of X and Z are combined, by regulating the radio waves in the X direction by the periodic structure 14 and optimally selecting the dimensions of the chiyoke groove 13, It is possible to regulate radio waves in the Z direction and enhance the attenuation effect.

Furthermore, a door 3 that comes into contact with the opening peripheral plate 11 of the heating chamber 2
By providing the insulating coating 12 on the inner plate 10 of the
There is no spark during cooking using high frequency, which prevents these parts from burning out.
Safety can be improved.

Also, there is a gap formed between the metal door 3 and the metal sash 7 provided on the outer periphery of this door 3.
From the corner of sash 7 to D ₁ to _{D 4} , λ/4×n
By providing protrusions 8 on the sash 7 or the door 3 at positions l ₁ to _{l 5} , the gap between the sash 7 and the door 3 is locally reduced, which acts almost like a capacitor and reduces leakage radio waves. The electric field level decreases due to accumulation or shot state, and leakage of waves to the outside of the main body 1 can be suppressed.

Furthermore, if the material of the protrusion 8 is a material with dielectric loss, such as a polymeric material, it can absorb leakage radio waves and serve as an insulating paper for a capacitor, thereby reducing radio waves leaking out of the main body 1. . In addition, when the protrusions are made of polymeric material such as plastic material,
This is because it is made of the same material as the sash so that it can be formed all at once.

FIG. 5 shows the characteristics of the amount of radio waves leaking from the gap between the door 3 and the opening peripheral plate 11, where the broken line characteristic A is the characteristic of the high-frequency heating device of this embodiment, and the characteristic B is the characteristic of the conventional high-frequency heating device. It is.

In this way, the high-frequency heating device of this embodiment has extremely low leakage of radio waves, so it is highly safe and has a high radio wave sealing effect even when the door 3 is slightly open.
For example, even if the power circuit of the high frequency generator is not cut off when the handle provided on the door 3 is grasped, the switch 15 of the power circuit of the high frequency generator may be installed on the door 3 as shown in FIG. with pin 16
It becomes possible to have an ON-OFF configuration. Therefore, as the door 3 is opened and closed, the switch 15 of the power supply circuit of the high-frequency generator can be turned ON and OFF using the pin 16, which simplifies the configuration of the handle and switch 16, making assembly work easier, and providing an easy-to-use high-frequency generator. A heating device can be provided at low cost.

In this embodiment, the insulating coating 12 is used as the inner plate 10 of the door 3.
However, the same effect can be obtained by providing the periodic structure 14 in the opening peripheral plate 11 of the heating chamber 2. Also, although the shape of the periodic structure 14 provided in the chiyoke groove 13 is comb-shaped, it is limited to the comb-shape. The shape of the door 3 and the groove 1
It may be selected optimally depending on the dimensions of the third grade.

As is clear from the above description, according to the high frequency heating device of the present invention, the gap formed between the door provided at the opening of the heating chamber so as to be openable and closable, and the sash provided around the door can be reduced. To provide a safe and easy-to-use high-frequency heating device at a low cost by preventing radio waves from leaking from the gap between the sash and the door by providing projections that locally reduce the size in several places on at least one of the sash or the door. Can be done. Although closing all the gaps between the door and the sash with a dielectric material is effective in preventing leakage of radio waves, it becomes impossible to open and close the door. A configuration in which a dielectric material is provided to reduce the gap between the door and the sash over the entire circumference can also be considered, but this is similar to the configuration in which the door is made larger and the gap is made smaller. The present application is thought to disturb radio waves and prevent leakage of radio waves by providing a protrusion that locally reduces the gap between the door and the sash.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a high-frequency heating device showing an embodiment of the present invention, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a side sectional view taken along line A-A' in FIG. 4 is a perspective view of the door shown in FIG. 3, FIG. 5 is a characteristic diagram showing the amount of radio wave leakage, and FIG. 6 is a side view showing a switch of the power supply circuit of the high frequency generator. 2... Heating chamber, 3... Door, 7... Satsushi, 8
……protrusion.

Claims (1)

[Scope of Claims] 1. A heating chamber provided in the main body, a door provided in an opening in the heating chamber so as to be openable and closable, a high frequency generator that supplies high frequency waves into the heating chamber, and a periphery of the door. a sash provided in the sash, and a protrusion that locally reduces the gap between the door and the sash is provided on at least one of the door or the sash.
High frequency heating equipment installed in more than one location. 2. The high-frequency heating device according to claim 1, wherein the protrusion is provided at a position that is an integral multiple of 1/4 of the wavelength (λ) of the radio wave used for dielectric heating from the corner of the sash.