JPH05234671A - High frequency heating device - Google Patents

Abstract

PURPOSE:To increase the quantity of draft without changing the torque of a fan motor, and thereby facilitate cooling a magnetron by allowing both an inlet port and an exhaust port provided for a cooking chamber to be of a choke structure in the cooking chamber in which the magnetron generating microwaves is built. CONSTITUTION:Microwaves are generated by a magnetron with a power supply transformer 5 so as to be irradiated to a cooking chamber 2 through a wave guide 8, and air is supplied to a high frequency wave generating means '7 by a fan-4 to cool the magnetron. Air which has cooled the means 7 is led to the cooking chamber 2 through an inlet port 9 so as to be exhausted outside out of an exhaust port 10. A light is provided for a place close to the inlet port 9, and the inlet port 9 is made to concurrently function as a natural lighting port too. In this constitution, the inlet port 9 is constrained to remain as of a choke structure, and microwaves are made to come in a folded section 13 provided for the wall surface 11 even when microwaves come in in the inlet port 9 of the cooking chamber 2, so that the interference of microwaves is overwhelmed with one another by reflecting the aforesaid microwaves coming in.

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 equipped with a magnetron. The high-frequency heating device also includes a combination of different heat sources such as an electric heater and a gas flame, such as a toaster range, an oven range, and a gas convection range.

[0002]

2. Description of the Related Art A magnetron generates heat at the same time as it radiates microwaves, and unless it is properly cooled, the magnetron itself may become hot and may be destroyed. For this reason, the high-frequency heating device equipped with the magnetron is provided with a fan, an intake hole, and an exhaust hole to cool the magnetron and ventilate the inside. Also, in order to illuminate the cooking chamber, the intake hole and the exhaust hole have a lighting function,
There are also lighting holes.

Conventionally, the intake hole, the exhaust hole, and the lighting hole are generally formed by providing a large number of circular punched holes on the wall surface of the cooking chamber having a thickness of 0.5 to 0.9 mm. This circular hole cannot be larger than 3 mm in diameter for the reason described later.

[0004]

In the high frequency heating device,
5cm of microwave leakage due to the Electrical Appliance and Material Control Law
Must be less than 1 mw / cm ² measured at the distance. For this reason, in the conventional high-frequency heating device, it is necessary that the diameter of the circular punched hole for the intake hole, the exhaust hole, and the lighting hole is 3 mm or less. To increase the lighting amount and the ventilation amount, a light source with high illuminance should be used. It had to be used and the motor torque of the blower fan had to be increased.

[0005]

SUMMARY OF THE INVENTION According to the present invention, all of a plurality of holes provided in the wall surface of a cooking chamber, such as a ventilation hole or a lighting hole, or a part where microwave leakage is particularly problematic is punched out. It is proposed that the hole is called a choke structure and the circumference of the hole is bent to the outside or the inside.

[0006]

1 is a perspective explanatory view of a high frequency heating apparatus (1) which is one of the embodiments using the present invention. This high-frequency heating device (1) has a cooking chamber (2) inside, and a door (3) for loading and unloading the object to be heated is provided on the front surface thereof so that the cooking chamber (2) can be opened and closed. It has a structure.

In the high frequency heating device (1), in addition to the cooking chamber (2) and the door (3), a blower fan (4), a power transformer (5), a light (6), a high frequency generator (7). ), And a wave director (8).

The high frequency generator (7) having a magnetron generates microwaves when the magnetron is energized from the power transformer (5), and the generated microwaves pass through the wave director (8) to the cooking chamber (2). Is irradiated. The blower fan (4) blows air to the high frequency generator (7) to cool the magnetron. The air that has cooled the high-frequency generator (7) enters the cooking chamber (2) through the intake hole (9) and is exhausted to the outside through the exhaust hole (10). A light (6) which is a light source for illuminating the cooking chamber (2) is provided near the intake hole (9), and the intake hole (9) also functions as a daylighting hole to illuminate the cooking chamber (2). There is.

The intake hole (9) has a structure called a choke structure as shown in FIG. 2 which is a partial sectional view. In the present embodiment, the wall surface (11) of the cooking chamber (2)
If the thickness is 0.5 to 0.9 mm, in order to make the diameter of the hole (12) 4 to 9.2 mm, the length of the bent portion (13) around the hole (12) is 1 It was confirmed by measuring the radio wave leakage that it was achieved by setting the distance to 0.2 to 2 mm. That is, even when microwaves having a frequency of 2450 MHz are incident on the inside of the intake hole (9), the microwaves collide with each other by being reflected by the surrounding bent portion (13), so that the microwaves interfere with each other and cancel each other. The electric field strength of the microwave leaking into the equipment is below the value specified by the Electrical Appliance and Material Control Law.

In order to make the hole a choke structure having a desired length, assuming that the desired length is L and the diameter of the hole is d, a punching hole having a diameter of d-2L is made in advance by a press machine, and then the diameter of d is used. This is done by punching the center of the hole with a press machine having a punching die.

In the above embodiment, the intake hole (9) having the function of a lighting hole has a choke structure. However, such as an exhaust hole, an intake hole and a lighting hole, such as at the left and right of the cooking chamber. As long as the holes are provided on the wall surface, any of the holes may have a choke structure, and the holes having the choke structure may have a diameter larger than at least a hole for punching.

In the embodiment, the electric appliance control method is given as an example.
Similar regulations are also applied to foreign countries and are set as international standards, and the present invention can be applied not only to domestic products but also to export products.

[0013]

Since the present invention is configured as described above, it has the following effects.

By making the intake hole and the exhaust hole a choke structure, the diameter of the hole can be made 3 mm or more, the amount of ventilation can be increased without changing the torque of the blower fan motor, and the magnetron can be cooled easily.

Further, by making the lighting hole a choke structure, the diameter of the hole can be 3 mm or more, and the amount of lighting can be improved.

[Brief description of drawings]

FIG. 1 is an overall perspective explanatory view of a high-frequency heating apparatus having an intake hole and an exhaust hole having a daylighting function according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of an intake hole of an embodiment according to the present invention.

[Explanation of symbols]

 (2) Cooking room (4) Blower fan (6) Light (7) High frequency generator with magnetron (9) Intake hole (10) Exhaust hole (11) Side of cooking room (12) Hole (13) Bent part

Claims (1)

[Claims] 1. A high frequency heating apparatus including a magnetron, wherein a part or all of a plurality of holes provided on a wall surface of a cooking chamber has a choke structure.