JPH0419452B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a high frequency heating device.

Conventional technology Conventional high-frequency heating equipment generally uses a bimetal type called a thermoswitch or a fuse type as a safety protection device in the event of an abnormal temperature rise in the heating chamber or when the heated object burns. A rise prevention device was installed on the heating chamber wall and exhaust passage. On the other hand, a door switch was also installed outside the heating chamber to open and close the high-frequency oscillation circuit in response to the opening and closing of the door provided in front of the opening of the heating chamber.

Problems to be Solved by the Invention However, in such a high-frequency heating device, as shown in the circuit diagram shown in FIG. According to safety standards (by law), there are at least two door switches 5 and 6 that open and close the high-frequency oscillation circuit 1 in response to the opening and closing of the door, and even if the door switches 5 and 6 are welded, the circuit will not close. A short switch 8, which blows the fuse 7 and opens the circuit, is also required to be installed. Furthermore, an overtemperature rise prevention device 9 was provided that opens the high frequency oscillation circuit 1 and the fan motor 3 when the temperature rises abnormally in the heating chamber or when the heated object burns. After designing the exhaust route, the installation location of the overtemperature rise prevention device was determined through trial and error experiments. Even if the temperature rises abnormally in the heating chamber, or even if the object to be heated burns, the circuit is immediately started before the flame escapes from the equipment to maintain safety. was. However, when the aim is to make the equipment lighter and more compact, and when the heating chamber is composed of a single piece as shown in Japanese Patent Application No. 59-105036, the overheat prevention device is required to act more quickly. Developing a device to prevent excessive temperature rise with rapid action,
It was necessary to make the exhaust route more complicated than that in Japanese Utility Model Application No. 51-93791 (Japanese Utility Model Application No. 53-11740) at an increased cost. However, there are limits to the speed and development of a rapid-acting temperature rise prevention device, and even if one could be developed, it would be expensive, and the temperature would not be much different from the actual ambient temperature. Even if the temperature was set and the device was used normally, the overheat prevention device would be activated immediately, potentially resulting in a market complaint.

In other words, when looking at the direction of future product development (light and compact, one-piece heating chamber), it is extremely difficult to do so with conventional technology.

The present invention solves these conventional problems, and includes a door switch installed outside the heating chamber, a switch operation section that operates the door switch that penetrates the heating chamber, and a safety switch installed above the object to be heated. It is an object of the present invention to provide a high-frequency heating device which, by being configured as a device, serves as a device for preventing excessive temperature rise in the event of an abnormality in a heating chamber, and also greatly contributes to reducing product costs.

Means for Solving the Problems In order to achieve the above object, the high-frequency heating device of the present invention includes a heating chamber that stores an object to be heated, a high-frequency oscillation circuit that supplies high-frequency waves to the heating chamber, and a high-frequency oscillation circuit that cools the high-frequency oscillation circuit. a fan motor that operates the front opening of the heating chamber, a door that is pivotally supported to open and close the front opening of the heating chamber, a door switch that operates in conjunction with the opening and closing of the door, and a switch operation unit that operates the door switch. The switch operation part is made of a low dielectric loss material and is installed so as to penetrate above the heating chamber.

Function The high-frequency heating device of the present invention has a door switch mounting part provided outside the heating chamber, and a switch operation part for operating the door switch that extends through the heating chamber and is provided above the object to be heated. Therefore, since the switch unit is not exposed to high frequencies, the switch will not be destroyed by high frequencies, and high frequencies will not be added to the circuit current, causing unnecessary radiation to be emitted and This has the effect of completely eliminating noise from being imparted to the radio.

In addition, since the switch is installed in the switch mounting part on the back of the heating chamber to detect the movement of the front door of the heating chamber, it can quickly sense and respond to the appropriate movement of the door, and has the effect of creating an appropriate door switch structure. It is.

In addition, even when the temperature rises abnormally in the heating chamber,
In addition, even if the object to be heated is burnt, before the flame escapes from the equipment, the switch operation part located above the heating chamber is deformed by heat, etc., the door switch is immediately opened, and then the Since the high-frequency oscillation circuit is opened, the safety of the equipment can be maintained, and it can also serve as an overheat prevention device, eliminating the hassle, cost, and man-hours of installing a separate overheating prevention device. This has the effect of providing a safe device that is inexpensive, economical, mass-producible, and safe.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

As shown in FIG. 1, below the heating chamber 10 in the main body, there is an electrical chamber 11 for storing electrical components, and at the front opening of the heating chamber 10 there is a door 12 which is pivotally supported so as to be openable and closable. An operation panel 13 covers the front surface of the electric room 11, and includes a knob 16 of a timer 15 for controlling the heating time of the object 14 to be heated. A perspective view of the exterior is shown in Figure 2.

At the bottom of the door 12, there is a handle portion 17 formed by hollowing out a portion of the door 12.

Next, a mounting part 19 for mounting the door switch 18 is provided at the rear of the heating chamber 10, and a switch operating part 2 is provided to transmit the reaction of the door 12 and to actuate the door switch 18.
0 is provided so as to pass through the heating chamber 10 and be above the object to be heated 14, and to slide using the hole 10b of the front plate 10a and the hole 10d of the rear plate 10c as guides. Therefore, when the door 12 is closed, the switch operating section 20 is pushed by the door 12, the door switch 18 is pushed, and the circuit is turned on.

Also, when the door 12 starts to open, the door switch 18
The door switch 18 is turned OFF by the pushing force of a contact spring or the like (not shown) inside the door. Since the switch operating section 20 is located inside the heating chamber 10, it may be made of polypropylene or the like with low dielectric loss.

Then, the switch operation unit 20 will be activated by radio waves.
will not heat up, stretch, or deform. In addition, since the door switch 18 is not installed inside the heating chamber 10, it is not exposed to high frequencies, so the door switch 18 is not damaged by high frequencies, and the high frequencies are attached to the circuit wires, resulting in unnecessary radiation from the TV. , there is no interference with the radio.

Furthermore, since the switch operating section 20 is located above the object to be heated 14 in the heating chamber 10, even if the temperature of the object to be heated 14 rises abnormally while heating the object 14 in the heating chamber 10, Even if the object to be heated 14 is burnt, before the flame 21 escapes from the device, the switch operation part 20 is deformed and damaged as shown by the dotted line in FIG. 1 due to heat, etc., and the door switch 18 is opened. Then, since the high frequency oscillation circuit is opened, the safety of the equipment can be maintained, and it can also serve as an overheat prevention device, eliminating the hassle, cost, and man-hours of installing a separate overheating prevention device. This makes it possible to provide safe equipment that is inexpensive, economical, and mass-producible. An example of the circuit diagram is shown in FIG. The cooling fan motor 2 of the high frequency oscillation circuit 1, the motor 3 and switch 4 of the heating time control timer 15, and the door switches 5 and 18 that open and close the high frequency oscillation circuit 1 in response to the opening and closing of the door are required according to safety standards (by law). top) at least 2
Even if the door switches 5 and 18 are welded due to individual abnormality,
Shoot the circuit and blow fuse 7,
A short switch 8 that opens the circuit is also required to be installed. Furthermore, the door switch 18 acts as an over-temperature rise prevention device that opens the high-frequency oscillation circuit 1 and the fan motor 3 when there is an abnormal temperature rise in the heating chamber 10 or when the object to be heated burns. Become a device.

Effects of the Invention As described above, according to the high frequency heating device of the present invention, the following effects can be obtained.

(1) Since the door switch is installed outside the heating chamber, it is not exposed to high frequencies, so the door switch is not damaged by high frequencies, and high frequencies are not transmitted from the door switch to the circuit wires connected to each circuit. Since there is no radiation, there is no unnecessary radiation and no interference with television or radio.

(2) Since the door is installed at the front of the heating chamber and the door switch is installed at the rear, it responds very sensitively to the movement of the door, making it a highly sensitive door switch with good immediate decision making, which prevents radio wave leakage from around the door. The circuit can be turned off even at extremely low levels, making it an extremely safe device.

(3) When the temperature of the heated object in the heating chamber rises abnormally or the heated object burns, the switch operation part deforms and falls off, turning the door switch OFF and eventually disconnecting the high frequency oscillation circuit and fan motor. It can be opened and closed, making it a safe device, and
There is no need to separately provide a temperature rise prevention device, and since it is unnecessary, it contributes to lower costs and assembly man-hours, and allows for efficient economical design. Therefore, it is possible to provide a device with a safety circuit that is indispensable for future product development, such as a lightweight, compact, single-piece heating chamber, and is suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a high-frequency heating device that is an embodiment of the present invention, FIG. 2 is an external perspective view of the same device, and FIG.
The figure is a circuit diagram of the same device, and FIG. 4 is a circuit diagram of a conventional high-frequency heating device. 1... High frequency oscillation circuit, 2... Cooling fan motor, 10... Heating chamber, 11... Electrical room, 12...
Door, 13... Operation panel, 14... Heated object,
15...Timer, 16...Timer knob, 1
7...Handle part, 18...Door switch, 19
...Door switch mounting part, 10a...Front plate, 10
b...Hole part, 10c...Rear plate, 10d...Hole part,
20...Switch operation part, 21...Flame.

Claims (1)

[Claims] 1. A heating chamber that stores an object to be heated, a high frequency oscillation circuit that supplies high frequency waves to the heating chamber, a cooling fan motor that cools the high frequency oscillation circuit, and a front opening of the heating chamber that is pivotally supported to be openable and closable. A door, a door switch that operates in conjunction with the opening and closing of the door, and a switch operation section that responds to the door switch, the door switch being installed outside the heating chamber, and the switch operation section being made of a low dielectric loss material. A high-frequency heating device is formed so as to penetrate above the heating chamber.