JPH06257761A - High frequency heating device with heater - Google Patents

Abstract

PURPOSE:To improve heating efficiency of substance to be heated and to prevent electric parts from being heated, by a method wherein cold outdoor air is prevented from flowing into a heating chamber and hot air from the heating chamber is prevented from flowing into an electric parts chamber. CONSTITUTION:It is designed that wind is generated by suction force of a self-cooling fan 34 of a circulation fan motor 31 to flow resisting an inflow of cold outdoor air into a heating chamber 21 and an outflow of hot air in the heating chamber 21 outside the chamber 21. In this instance, it is designed that a suction hole of a circulation fan 30 is positioned in the vicinity of a suction hole of the heating chamber 21 and that wind generated by the circulation fan 30 is diffused to the vicinity of the suction hole of the heating chamber 21. By this, heating efficiency can be increased and reliability can also be improved.

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 with a heater.

[0002]

2. Description of the Related Art In a conventional high-frequency heating device with a heater, it is necessary to accurately prevent the intake and exhaust directions of the heating chamber from being reversed when the heating source is a high frequency and when the heater is a heater. , Its structure was complicated and there were many problems. This will be described below with reference to the drawings.

FIG. 3 is a front sectional view of a conventional high frequency heating apparatus with a heater during high frequency heating operation. FIG. 4 is a front cross-sectional view of a conventional high-frequency heating device with a heater during a heater heating operation.

As shown in FIG. 3, a magnetron 2 which is a high-frequency heating means is coupled to the side surface of the heating chamber 1, and the object 3 to be heated is subjected to high-frequency heating by the magnetron 2 or a heater 9 provided above the heating chamber 1. It is heated by convection and radiant heating by the heat source.

FIG. 3 shows heating of an object to be heated by high frequency. Since the object to be heated 3 itself generates heat due to high frequency, a large amount of steam 19 is generated from the surface of the object to be heated 3 and dew is condensed on the inner wall of the heating chamber 1, which is not preferable. Therefore, the wind that has cooled the magnetron 2 by the cooling fan 4 is introduced into the heating chamber 1 through the air guide 5 and the air intake holes of the heating chamber right side plate 1a.
8a. The steam 19 is generated by the ventilation air 18a.
Is discharged to the atmosphere from the exhaust hole 7a of the outer box 7 through the exhaust hole of the left side plate 1b of the heating chamber and the exhaust guide 6.

On the other hand, heating by the heat source of the heater is shown in FIG.
Shown in. A heater 9 is arranged in a circulation fan chamber 8 provided above the heating chamber upper plate 1c. The circulating air 18b generated by the rotation of the circulation fan 10 is heated by the heater 9 in the circulation fan case 8 and heats the object 3 to be heated in the heating chamber 1 through the heating chamber upper plate 1c. The circulation fan 10 includes a pulley A12a, a rubber belt 13 and a pulley B12b.
It is driven by the circulation fan motor 11 via.

When the heater is heated, the object to be heated is heated from the outer surface thereof, and the heating speed is slower than that in the high frequency heating. Therefore, the generation of steam from the object to be heated 3 is small. The cooling fan 4 is stopped so that the inside of the heating chamber 1 is kept at a high temperature without being released into the atmosphere. The circulation fan motor 11 has a self-cooling fan 14,
The circulation fan motor 11 itself and other electric components are being cooled.

[0008]

However, in this structure, not only the cooling air 18c but also the ventilation air 18 described with reference to FIG. 3 is caused by the negative pressure on the suction side of the self-cooling fan 14.
The reverse ventilation air 18d that follows the path opposite to that of a is generated. The adverse effects of the reverse ventilation air 18d are as follows.

(1) Lower the temperature of the heating chamber. (2) Reduce energy efficiency.

(3) The high temperature air acts on the circulating fan motor and other electric parts to reduce the cooling performance and the life.

Conventionally, in order to prevent this adverse effect, Japanese Patent Laid-Open No.
In Japanese Patent Laid-Open No. 193517, a shutter is installed, and the opening and closing of the shutter during high frequency heating and heating of the heater prevents the passage of reverse ventilation air.

Further, in Japanese Unexamined Patent Publication No. 62-100989, the rotation control of the cooling fan is performed, and the rotation speed of the cooling fan is lowered during high frequency heating and heating of the heater to balance the negative pressure on the suction side of the self-cooling fan. It prevented the generation of reverse ventilation air.

However, in the conventional method, not only the shutter and motor rotation control parts and assembly cost are high, but also the shutter has a space in the equipment and the shutter operation noise, and the motor rotation control has noise and power line. New problems such as distorting voltage and current waveforms are also occurring.

Therefore, it is a first object of the present invention to provide a high-frequency heating device with a heater that can prevent reverse ventilation air at a low cost and reliably.

It is a second object of the present invention to provide a high-frequency heating device with a heater which prevents reverse ventilation air by utilizing the viscosity of gas.
The purpose is.

[0016]

In order to achieve the first object, the suction hole of the circulation fan chamber is closer to the suction hole of the heating chamber than the exhaust hole of the heating chamber. In order to achieve the second object, a part of the blow-out hole of the circulation fan chamber is arranged in the vicinity of the intake hole of the heating chamber.

[0017]

The function of the present invention is to counter the flow of the air flowing in from the exhaust hole of the heating chamber and suck the air from the intake hole of the heating chamber to further reduce the movement of the air from the heating chamber to the outside of the heating chamber.

[0018]

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

In the first embodiment, as shown in FIG. 1, a heater 29 and a circulation fan 30 are arranged in a circulation fan chamber 28 provided above the heating chamber upper plate 21c. The circulation fan 30 is driven by a circulation fan motor 31 via a pulley A 32a, a rubber belt 33 and a pulley B 32b. Circulation wind 3 generated by rotation of the circulation fan 30
8b is heated by the heater 29 in the circulation fan chamber 28 and heats the object 23 to be heated in the heating chamber 21 through the heating chamber upper plate 21c. Also, the heating chamber upper side plate 21c
Has an intake hole for the circulation fan chamber 28. The intake hole for the circulation fan chamber 28 is provided in the heating chamber 21 on the right side plate 21a of the heating chamber.
Of the heating chamber right side plate 21a due to the negative pressure generated by the rotation of the circulation fan 30.
Suppressing wind 3 by sucking air from the intake hole of the heating chamber 21 in
8e corresponds to the reverse ventilation air 38d. As a result, the reverse ventilation air 3 is discharged from the exhaust hole 27a of the outer box 27.
It is possible to prevent 8d from entering the heating chamber 21.
The strength of the deterrent wind 38e generally depends on the degree of proximity of the position of the intake hole of the circulation fan chamber 28 and the position of the intake hole of the heating chamber 21 on the heating chamber right side plate 21a. You can freely set the direction and size of the wind.

Although this can be done by design, a large number of holes are formed in the upper plate 21c in addition to the above, and the upper plate 21c is formed.
A plate in contact with c may be provided and the position of the intake hole may be changed by moving this plate, or the position of the circulation fan may be changed. By doing so, the direction and size of the circulating air 38b can be changed depending on the object to be heated.

In the second embodiment, as shown in FIG. 2, the circulating air 38b blown out from a part of the blowing holes of the circulating fan chamber 28 travels substantially parallel to the heating chamber right side plate 21a and depends on the viscosity of the gas. Air is sucked from the air intake hole of the heating chamber 21 to serve as a restraining wind 38e, which opposes the reverse ventilation wind 38d. Further, by adjusting the amount of the circulating air 38b blown out from a part of the blowout holes of the circulation fan chamber 28, the direction and size of the airflow passing through the heating chamber 21 can be freely set as in the first embodiment. .

[0022]

As described above, the following effects can be obtained in the high frequency heating device with a heater according to the present invention.

(1) It is possible to prevent cold air from entering the heating chamber from the outside and improve the energy efficiency of the heating chamber.

(2) It is possible to prevent the hot air in the heating chamber from flowing back to the machine chamber and prevent the temperature of the circulation fan motor and other parts from rising.

(3) The heat insulating effect can be enhanced with high productivity without using an expensive shutter and without using a shutter.

(4) Since the shutter is not used,
It is possible to reduce the noise without the space inside the equipment or the shutter operating noise.

[Brief description of drawings]

FIG. 1 is a front sectional view of a high-frequency heating device with a heater according to a first embodiment of the present invention.

FIG. 2 is a front sectional view of a high-frequency heating device with a heater according to another embodiment of the present invention.

FIG. 3 is a front sectional view of a conventional high-frequency heating device with a heater during high-frequency heating.

FIG. 4 is a front cross-sectional view of a conventional high-frequency heating device with a heater when the heater is heated.

[Explanation of symbols]

 21 heating chamber 22 high-frequency heating means 23 heated object 27a exhaust hole 28 circulation fan chamber 29 heater heating means 30 circulation fan 31 motor 34 self-cooling fan 38b circulation air

Claims (2)

[Claims] 1. A heating chamber having an intake hole for accommodating an object to be heated and for inhaling air for ventilation, an exhaust hole for exhausting steam or the like from the object to be heated, and the heating chamber for heating the object to be heated. A circulation fan chamber having a high-frequency heating means coupled to the heating chamber, a suction hole for sucking air from the heating chamber, a blowing hole for blowing air to the heating chamber, and a circulation fan for circulating air between the heating chamber. A heater arranged in the circulating air circulating between the heating chamber and the circulation fan chamber; a motor for driving the circulation fan; and a self-cooling fan driven by the motor. A high-frequency heating device with a heater, wherein a suction hole of the chamber is closer to an intake hole of the heating chamber than an exhaust hole of the heating chamber. 2. The high-frequency heating device with a heater according to claim 1, wherein a part of the blow-out hole of the circulation fan chamber is arranged in the vicinity of the intake hole of the heating chamber.