JPS6059486B2 - Microwave oven with heater - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a microwave oven with a heater (commonly known as an open range) that has both the functions of an electric open oven and a microwave oven.
This invention relates to an improvement in which the lower heater is made detachable to facilitate cleaning of the inside of the refrigerator.

The lower heater of the open range uses a sheathed heater, which protects the heating wire with a sheath to improve corrosion resistance and prevent microwave leakage during microwave heating.

During cleaning, the heater is removed and the bottom of the chamber interior is wiped clean with soapy water, but at this time the soapy water may seep into the outlet and cause insulation defects, or if the lower heater is not inserted, the electronic Similarly, there was a risk of insulation failure due to water condensation accumulating inside the outlet due to the steam emitted from the food when the microwave was operated. For this reason, methods such as disconnecting the heater circuit from the power supply in conjunction with the escape operation when the heater is removed, or installing the heater socket at a relatively high position from the open bottom and mechanically blocking the socket opening are recommended. It had been taken. However, in order to disconnect the heater circuit, a double-sided cut-off switch is required, which increases the cost, and the socket is placed at a high position from the bottom of the open. However, since the outer sheath of the sheathed heater comes into contact with the sheathed heater, it has the disadvantage that safety cannot be maintained sufficiently in terms of insulation (generally, it is difficult to maintain sufficient insulation performance between the heater wire and the outer sheath of a sheathed heater).

In the present invention, a sheathed heater with sufficient insulation protection such as insulators is held in a metal cylindrical socket, a choke groove is formed on the outer periphery of the cylindrical socket to prevent microwave leakage, and The present invention aims to provide a lower heater socket that can eliminate the above-mentioned drawbacks by tilting the socket outlet forward.

The detailed structure will be explained below with reference to the drawings showing one embodiment. FIG. 1 is an example of an open range implementation circuit.

A select switch allows you to select heating means, such as a microwave oven, an electric open mode, and automatic switching from a microwave oven to an electric open mode, depending on the cooking purpose. The open switch is a switch for selectively switching between the upper and lower heaters, and for switching the power of the upper heater by half. Although these selection states will not be described in detail, FIG. 2 shows, as an example, a state in which the electrical connection is made, the upper heater is 600 W, the lower heater is 500 W, and the 2-hour time switch is set. and,
Figure 3 shows the schematic configuration of the oven. Heating storage 1
Inside, an upper heater 2 and a lower heater 3 are inserted, and a saucer 4 is placed in the middle. The lower heater 3 is held insulated from the bottom of the refrigerator by an insulator 5.

The lower heater 3 is a sheathed heater. A heater socket 6 (lower heater) is provided as close as possible to the bottom surface of the heating chamber 1. The configuration of the heater socket 6 is shown in FIG. The heater socket 6 is made of metal and has a cylindrical shape.
The socket opening 7 is placed as close as possible to the bottom of the heating chamber 1.
The cylindrical metal body 111 has a depth L larger than the diameter of the metal body 111, and a choke groove is formed along its outer periphery with the length L being approximately 1'4 of the wavelength of radio waves (microwaves) used for heating. is forming. Therefore, the diameter of the heater socket 6 is 114ti. Compared to providing a long choke groove,
In the embodiment of the present invention in which a choke groove with a length of 1' is provided in the depth direction, the diameter dimension a of the heater socket 6 can be reduced without reducing the choke effect, and the lower heater 9
It becomes possible to set the mark as close to the bottom surface as possible. Next, the lower heater 3 is a sheathed heater, in which the heater wire 8 is protected by an outer sheath 9, and an insulating material such as silica gel is filled between the heater wires 8 and 9.However, the heating wire 8 is protected by an outer sheath 9, and an insulating material such as silica gel is filled in between. It is. It is difficult to ensure insulation between the heater wire 8 and the outer sheath 9.

For this reason, the outer skin 9 of the sheathed heater is suspended from the metal wall of the heating chamber 1 by an insulator 5 or the like.Furthermore, the end of the sheathed heater 3 is insulated from the cylindrical metal body 11 by an insulator 10. The shell 10 and the outer sheath 9 are integrally constructed to prevent deterioration of insulation performance at the end portion 12 due to moisture absorption.Furthermore, the end surfaces of the heater wire 8 and the outer sheath 9 are sealed with silicone rubber. The structure prevents moisture from being absorbed into the inside of the sheathed heater.
A pin 14 of the lower heater 3 is fixed to the insulator 10 through the insulator 10. This pin 14 is inserted into the socket metal fitting 15. The socket fitting 15 is insulated from the main metal body of the heater socket 6 by an insulator 16. In an open range, the lower heater 3 is usually heated in a microwave oven while it is attached, and the microwave inside the oven propagates outside the oven through the outer skin 9 of the sheathed heater.

As a countermeasure for this, the microwave propagation can be easily blocked by bringing the cylindrical metal body 11 into contact with the outer skin 9, but as mentioned above, in order to maintain the insulation performance of the sheathed heater, the insulator 10 is interposed. I can't do this because I am. For this purpose, the microwaves are blocked by the metal cylinder 11 and the grooves provided on its outer periphery, and the microwave components that leak slightly are blocked by the radio wave absorber 17 provided in a part of the insulator 16. Absorbs and prevents leakage outside the heating chamber. In addition to this, the radio wave absorber may be formed by mixing the insulator 16 with ferrite powder or the like. Since the cylindrical metal body 11 and the heater socket 6 are tilted forward with respect to the outlet receptacle 7, there is no fear that soapy water will infiltrate when the lower heater 3 is removed and washed with soapy water, etc. In addition, by providing the socket 7 near the bottom, there is no fear that the lower heater will float up, and since it is tilted forward with respect to the insertion direction, the lower beader will have the force to press downward even if the insertion is insufficient. works, so there is no need to worry about it rising further. Furthermore, a small hole 18 is provided near the lower socket of the heater socket 6 so that water that may have entered the heater socket 6 can be drained out of the choke groove.

In addition to the effects of the present invention described above, the following effects are also expected.

Since the lower heater can be mounted close to the bottom of the heating chamber and there is no fear of it floating up, it is possible to install a saucer 4, a turntable (not shown), etc. near the bottom, and the effective area of the heating chamber during use is increased.

If you forget to attach the lower heater and start heating in the microwave, the steam from inside the refrigerator will not enter the socket 6 and condensed water will not accumulate.
Since it can be removed between the metal parts of the socket body, no special measures are required.

Also, when the sheathed heater is installed, the metal cylinder 11 and the insulator 10
Since the sheathed heater outer skin 9 is held through the cylindrical body 1
Since the dimension L of 1 is large, it is difficult for steam to enter the socket, and the insulation performance is maintained in a good condition.
When the door 9 is opened, there is no need to turn off the lower heater 3 in conjunction with this, so compared to when the lower heater is turned off when the door is opened, heat dissipation inside the refrigerator due to opening the door during operation is prevented. It is also expected to have secondary effects, such as eliminating the need for heater start-up time, which used to take 2 to 3 minutes, and is extremely effective.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of an embodiment of an open range, Fig. 2 is a diagram showing an operating circuit during electrical open operation in Fig. 1, and Fig. 3 is a microwave oven with heater showing an embodiment of the present invention. FIG. 4 is an enlarged sectional view of the main part of the heater socket. 2... Upper heater, 3... Lower heater, 5
...Insulator, 6...Heater socket,
7... Socket opening, 8... Heater wire.

Claims (1)

[Claims] 1. The lower heater is removable, and the lower heater socket has a cylindrical shape with a depth dimension larger than the opening diameter of the socket, and the insertion direction is oriented toward the front of the socket with respect to the horizontal plane. A microwave oven with a heater characterized by being tilted. 2. The above-mentioned heater socket is constituted by a cylindrical metal body in which a choke groove having a size of approximately 1/4 of the wavelength of the radio wave used is formed along the outer periphery of a metal cylindrical socket. A microwave oven with a heater as described in Range 1. 3. Claim 1, characterized in that the inclined cylindrical metal outlet has a small hole for draining water near the socket.
Microwave oven with heater as described in section.