JPH06101385B2 - microwave - Google Patents

Description

TECHNICAL FIELD The present invention relates to a microwave oven having a novel heat retaining function.

<Prior Art> Conventionally, there is a single-function microwave oven as shown in FIG. This microwave oven 11 has a heating chamber (oven) 13 inside an outer box 12 in which food is inserted and an electromagnetically shielded door 14 is provided.
After closing, the food in the heating chamber 13 is irradiated with microwaves emitted from a built-in magnetron (not shown) to microwave the food for cooking. Further, there is known a multi-function microwave oven in which an electronic heater or a steam generator is added to the single-function microwave oven so that oven heating, grill heating, steam heating or the like can be performed.

<Problems to be Solved by the Invention> However, the above-mentioned conventional single-function or multi-function microwave oven can cook food by microwave heating or various heating, but it is no longer used after heating cooking, Since it does not have the function of actively retaining the heat of cooked food, the warmed food will soon become cold, and it will not be possible to hold baked potatoes, baked meat, cookies, bread, etc. in a warm state for a few tens of minutes. There is a drawback that. In addition, since the microwave oven is relatively large in size and takes up a lot of space, the practical use time is short. Therefore, for example, there is a demand that the heating chamber can be used also as a heat-retaining cabinet to enhance the utility value. If such a food warming function is to be realized by using an existing electric heater or a dedicated warming heater, a considerable amount of additional parts and an electric circuit for control are required, which complicates the structure and reduces the manufacturing cost. There is a problem that will rise.

Therefore, an object of the present invention is to effectively utilize microwaves generated by a magnetron, and to keep foods that have been microwave-heated once with a simple and inexpensive structure for a long time. It is to provide a microwave oven that can be expanded to increase the utility value.

<Means for Solving the Problems> In order to achieve the above object, the microwave oven of the present invention has an intermediate wall between the outer box of the microwave oven and the wall of the heating chamber, and the intermediate wall and the heating chamber are provided. A microwave waveguide is formed with the wall, and microwave switching supply means for switching and supplying the microwave emitted from the magnetron to the heating chamber and the waveguide, and provided on the outer surface of the wall of the heating chamber. The microwave absorbing heat generating body includes a microwave absorbing heat generating body having a high dielectric loss and absorbing microwaves to generate heat, and a heat insulating material provided so as to cover the outside of the microwave absorbing heat generating body. The heating chamber heats the inside of the heating chamber through the wall of the heating chamber to keep the food placed away from the wall warm.

<Operation> First, the microwave switching supply means supplies the microwave emitted from the magnetron to the heating chamber, and microwaves the food in the heating chamber. Next, the microwave switching supply means supplies the microwave to the waveguide formed by the wall of the heating chamber and the intermediate wall. Then, the microwave absorbing heat generating element provided on the wall surface of the waveguide absorbs the microwave passing through the tube to generate heat, and the heat is blocked by the heat insulating material and does not propagate to the outside, but passes through the wall. Warm the heating room. In this way, the food placed in the heating chamber away from the wall is kept warm by the heat generated by the microwave absorption heating element.

<Examples> Hereinafter, the present invention will be described in detail with reference to illustrated examples.

FIG. 1 is a vertical cross-sectional view showing an embodiment of a microwave oven of the present invention, wherein 1 is an outer box, 2 is made of stainless steel, and the like. The forming wall 4 is provided so as to surround the outside of the wall 2, and is a metal intermediate wall that forms a microwave waveguide 5 together with the wall 2.
6 is a magnetron which is provided at the end of the waveguide 5 and oscillates microwaves, and 7 is rotatably attached by pivoting one side to the edge of the opening (2a) at the center of the ceiling of the wall 2. A microwave switching supply means for supplying microwaves emitted from the magnetron 6 as shown by an arrow A to the heating chamber 3 after being reflected by an opening as shown by an arrow B and being supplied as a microwave to the waveguide 5 as shown by an arrow C. The metal damper 8 is provided in close contact with the outer surface of the wall 2 and has a high dielectric loss and absorbs microwaves to generate heat by absorbing microwaves. It is a high-temperature heat-resistant inorganic heat insulating material which covers the plate 8 and the intermediate wall (4) side of the wall 2 over substantially the entire surface.

The wall 2 of the heating chamber is not limited to stainless steel, but may be a steel plate coated with aluminum, epoxy powder, or acrylic paint. The silicon carbide plate 8 is made by sintering and firing, and adhering a plate material having a SiC content of 50% or more to the wall 2 or mixing SiC powder with an organic or inorganic binder on the outer surface of the wall 2 It is applied by applying a thickness of 2000 μm and baking and firing it together. Further, instead of the silicon carbide plate 8, a ferritic molded body such as barium ferrite or a film formed by a paint mixed with ferrite particles may be used.

The operation panel on the front of the microwave oven (see FIG. 15 in FIG. 3) is provided with a mode change switch (not shown) for switching the cooking mode between normal microwave heating and heat retention. , Damper 7
2 opens as shown by the arrow X in FIG. 2, and when the temperature is set to keep warm, it closes as shown by the arrow Y. Then, in the heat retention mode, a temperature control device (not shown) controls on / off of the magnetron 6 based on the detection signal of the temperature sensor so that the temperature in the heating chamber 3 becomes the preset heat retention temperature of the operation panel. Has become.

The operation of the microwave oven having the above configuration will be described below.

When the food F is placed on the turntable 10 in the heating chamber 3 of the microwave oven and the cooking mode is set to microwave heating, the damper 7 opens as indicated by arrow X, and the microwave emitted from the magnetron 6 as indicated by arrow A is generated. The food F in the heating chamber 3 is irradiated with the light reflected by the damper 7 through the opening 2a as shown by an arrow B, and is heated by microwaves. Next, when the cooking mode is set to heat retention, the damper 7 is closed as indicated by arrow Y, and the microwave passes through the waveguide 5 formed by the wall 2 and the intermediate wall 4 of the heating chamber and is indicated by arrow C. It flows like. Then,
A silicon carbide plate 8 appropriately provided in the waveguide 5 absorbs microwaves to generate heat, and the heat is blocked by the heat insulating material 9 and is not transmitted to the outside, but a wall closely contacting the silicon carbide plate 8. The inside of the heating chamber 3 is efficiently warmed through the step 2. Thus, the food heated in the microwave heating mode is brought to the set temperature by the on / off control of the magnetron 6 by the above-mentioned temperature control device by the silicon carbide plate 8 which absorbs microwaves and generates heat in the heat retention mode. It is kept warm for a desired time.

Therefore, baked fish, baked potatoes, bread, etc. can be kept warm until they are served, or several liquors can be heated at the same time and only one can be taken out and the rest can be kept warm. Therefore, it is possible to maintain heat at a suitable temperature with a narrow temperature range by gentle heating. In addition, because the microwave does not hit the food directly in the heat retention mode,
This microwave can also be used for fermentation with yeast. Further, the microwave oven of the present invention does not require an electric heater for heat retention or an electric circuit for controlling the same, and the microwave absorption heat generating element also serves as a temperature control device already installed in the heating chamber, so that the microwave oven can simply and inexpensively perform the heat retention function. As a result, the risk of failure is low and the manufacturing cost can be reduced. It is needless to say that the heat retaining mechanism expands the use of the microwave oven in a relatively large size and occupies a large space, and greatly increases the utility value.

Needless to say, the present invention is not limited to the illustrated embodiment.

<Effects of the Invention> As is apparent from the above description, the microwave oven of the present invention is
An intermediate wall is provided between the outer box of the microwave oven and the wall of the heating chamber, and a microwave waveguide is formed by the intermediate wall and the wall of the heating chamber, so that the microwave emitted from the magnetron The microwave switching and supplying means switches and supplies the heating chamber and the waveguide, and a microwave absorbing heating element that absorbs the microwave passing through the waveguide and generates heat is provided on the outer surface of the wall of the heating chamber. Since the outside of the heating element is covered with a heat insulating material, the food directly microwave-heated can be warmed to a gentle and suitable temperature via the wall of the heating chamber by the microwave absorption heating element, and at the same time, it can be kept warm. Since it does not require an electric heater or its control circuit, it also serves as an existing temperature control device and simply and inexpensively configures a heat retention mechanism, so it is possible to reduce manufacturing costs and failure rates, and use conventional microwave ovens. Greatly expanded Its value in use Te can be greatly enhance.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a microwave oven of the present invention, FIG. 2 is a detailed view of a damper portion of FIG. 1, and FIG. 3 is an external perspective view of a conventional microwave oven. 1 ... Outer box, 2 ... Heating chamber wall, 2a ... Opening part, 3 ... Heating chamber,
4 ... Intermediate wall, 5 ... Waveguide, 6 ... Magnetron, 7 ... Damper, 8 ... Silicon carbide plate, 9 ... Insulating material, F ... Food.

Claims (1)

[Claims] 1. A microwave oven in which microwaves generated by a magnetron are applied to food in a heating chamber to heat and cook the food. An intermediate wall is provided between the outer box of the microwave oven and the wall of the heating chamber. A microwave waveguide is formed by the intermediate wall and the wall of the heating chamber, and microwave switching supply means for switching and supplying the microwave emitted from the magnetron to the heating chamber and the waveguide. A microwave absorbing heating element provided on the outer surface of the wall of the heating chamber and having a high dielectric loss and absorbing microwaves to generate heat; and a heat insulating material provided so as to cover the outside of the microwave absorbing heating element A microwave oven, characterized in that the microwave absorption heating element heats the inside of the heating chamber through the wall of the heating chamber by the heat generated by the microwave absorbing heating element to keep the food placed away from the wall warm. .