JPH04319288A - Heating cooker - Google Patents

Abstract

PURPOSE:To obtain a heating cooker excellent in thermoconductivity and comprising a high frequency heater and another heater of a large capacity having a simple structure. CONSTITUTION:A part or the whole of at least a bottom plate of an inner case 3 constituting a heating chamber 2 is made of a material capable of generating heat by an electromagnetic induction function. An electromagnetic induction heater is disposed under the inner case 3. As the electromagnetic induction heater, an induction heating coil 10 is used, wherein a coil 14 is press-fitted into a groove 12 formed in a coil frame 11 made of an insulating material with a partition wall 13 held therebetween. A high frequency generating circuit is commonly used as power sources of a high frequency heater and the electromagnetic induction heater. Consequently, a heat source of a large capacity having a rapid rising characteristic can be obtained, thereby enhancing heating efficiency. Since a coil insulating process is unnecessary, manufacturing work is easy and an arbitrary heating pattern can be obtained. Furthermore, a cost can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking device, and more particularly to a cooking device equipped with high-frequency heating means and electromagnetic induction heating means.

0002

[Prior Art] As shown in FIGS. 6 and 7, a heating cooker equipped with a high-frequency heating device and a heater and capable of cooking food by rotating a container containing food, known as an oven range, is well known. It is being In the figure, reference numeral 1 denotes an outer box, which has an opening in the front, and a door (not shown) is attached to the opening so that it can be opened and closed. Reference numeral 2 denotes a heating chamber, and 3a denotes an inner box forming the heating chamber 2, which is made of a material that is heat resistant and treated to reflect microwaves.

Reference numeral 4 denotes a magnetron attached to an inner box 3a on the side of the heating chamber 2. Microwaves emitted from the magnetron 4 are guided into the heating chamber 2 through openings 5, 5a provided in the inner box 3. It will be destroyed. Reference numeral 6 indicates a lower heater such as a halogen heater or sheathed heater provided at the lower part of the heating chamber 2, 7 indicates an upper heater such as a halogen heater or a heat heater provided at the upper part of the heating chamber 2, and 8 indicates an electric heating mica. Note that the turntable on which cooking containers and the like are placed and its drive device are omitted. In such a heating cooker, a cooking container or the like containing an object to be cooked is set in the heating chamber 2, and the object is cooked by the magnetron 4 and/or the heaters 6 and 7.

[0004] Furthermore, the cooking device disclosed in Japanese Patent Application Laid-open No. 2-29510 has a bread case vertically disposed in a heating chamber with an opening opening upward, and a food to be cooked in the bread case. A heating heater and magnetron, a shaft,
It consists of a rotary drive means, such as a motor, that rotates the bread case, and a blade, etc., which is attached to one end of a shaft inside the bread case and stirs the food to be cooked.

[0005] In such a heating cooker, a bread case containing food to be cooked is set in a heating chamber, and the bread case is rotated by a rotation drive means, and the bread case is heated by a heater and/or a magnetron. It is a device that heats and cooks food.

[0006]

[Problems to be Solved by the Invention] In all of the conventional heating cookers as described above, the lower heater is sandwiched between mica plates or the like, so the temperature rises slowly, and the temperature rises slowly due to heat conduction or radiant heat. The heat transfer efficiency for heating is poor. Furthermore, the rise in temperature of the heater has a negative effect on the insulation, making it impossible to use a large-capacity heater (generally up to about 600W), and even though the heating efficiency is low, the cooking device heats from outside the heating chamber. There were various problems, such as the temperature rising, which could have an adverse effect on electrical components.

The present invention has been made to solve the above-mentioned problems, and includes a high-frequency heating means and a simple structure and large-capacity heating means, which has high heat transfer efficiency and can efficiently heat the food to be cooked. The purpose is to obtain a heating cooker that can perform cooking.

[0008]

[Means for Solving the Problems] The heating cooker according to the present invention comprises at least a part or all of the bottom plate of the inner box constituting the heating chamber made of a material that generates heat by electromagnetic induction, and the lower part of the inner box This is equipped with electromagnetic induction heating means.

Further, as the electromagnetic induction heating means, an induction heating coil is used, which is formed by press-fitting a coil into a groove formed in a coil frame made of an insulating material with a partition wall in between.

Furthermore, a high frequency generating circuit is used in common as a power source for the high frequency heating means and the electromagnetic induction heating means, and the switching is performed using a changeover switch.

[0011]

[Function] When a cooking container containing food to be cooked is placed in a heating chamber and a high frequency current is supplied to the electromagnetic induction heating means, the bottom plate of the inner box rapidly generates heat due to electromagnetic induction, raising the temperature inside the heating chamber. and heat the food to cook.

Furthermore, when a high frequency current is supplied to the high frequency heating means, microwaves are output from the magnetron into the heating chamber to heat and cook the food. Note that, depending on the type of cooking and the food to be cooked, a high frequency current may be supplied to both the electromagnetic induction heating means and the high frequency heating means, and the food to be cooked may be heated by both the heat generation from the inner box and the microwave.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of an embodiment of the present invention, and FIG. 2 is an enlarged view of its essential parts. Note that the same parts as in the conventional example shown in FIGS. 6 and 7 are denoted by the same reference numerals, and explanations thereof will be omitted. In the figure,
Reference numeral 3 designates an inner box constituting the heating chamber 2, which is made of a magnetic material with high resistivity and high relative magnetic permeability, that is, a material that generates heat by electromagnetic induction, and its inner surface is treated to reflect microwaves. The inner box 3 may have all or part of the bottom plate made of a material that generates heat due to electromagnetic induction, and the other parts may be made of a material that is heat resistant and does not generate heat due to electromagnetic induction.

10 is an induction heating coil disposed under the inner box 3, 11 is a coil frame, and 14 is a coil. The coil frame 11 is made of an insulating material that is heat resistant and transmits electromagnetic waves, such as heat resistant plastic or ceramics, that is, an insulating material that does not generate heat due to electromagnetic induction.
As shown in FIGS. 3 and 4, a spiral groove 12 is provided on the upper surface with a partition wall 13 in between. In the embodiment, the width d1 of this groove 12 is approximately 90% of the diameter of the coil 14, and the width w of the partition wall 13.
was set to approximately 70% of the diameter of the coil 14, and the coil 14 was press-fitted into the groove 12 after being slightly deformed into an inertial circular shape. In addition,
The coil 14 may be secured within the groove 12 with an adhesive to withstand impacts such as being dropped.

As described above, the coils 14 of the induction heating coil 10 according to the present invention are press-fitted into the grooves 12 with the partition wall 13 in between, and since the coil frame 11 is made of an insulating material, there is no special space between the coils 14. There is no need for insulation treatment, and it forms a so-called loosely wound coil. In the example, an induction heating coil 10 having an output of 1 KW was used. In the embodiment, an example of the induction heating coil 10 is shown in which the coils 14 are spirally arranged at equal intervals, but the coils 14 may be arranged in a rectangular or other arbitrary shape, and the width w of the partition wall 13 may be partially narrowed. (close volume),
A part may be formed widely (loosely wound). Moreover, although the case where the groove 12 is provided on the upper surface of the coil frame 11 is shown, the coil frame 1
It may be provided on the lower surface of 1.

15 is the lower surface of the inner box 3 and the induction heating coil 10
This is an insulating plate disposed between the inner box 3 and the inner box 3, which is made of an insulating material that is heat resistant and transmits electromagnetic waves, and is provided in order to arrange the induction heating coil 10 close to the bottom surface of the inner box 3. However, it can be omitted. In this embodiment, the turntable on which the cooking container and the like are placed is omitted, and the cooking container and the like are placed directly on the bottom plate of the inner box 3, but the coil frame 11 and the inner box A turntable may be attached in the heating chamber 2 to a shaft passing through the bottom plate 3, and this shaft may be rotated by a motor.

FIG. 5 shows the magnetron 4 and induction heating coil 1.
0 is a circuit diagram showing an embodiment of the drive circuit, 21 is a high frequency generator including an AC-DC converter and a switching circuit;
2 is an oscillation circuit of the magnetron 4, 10 is an induction heating coil connected in parallel to the oscillation circuit 22, and 23 is a changeover switch.

In the drive circuit as described above, the power supply current supplied to the high frequency generation circuit 21 is converted into a high frequency current. Now, when the changeover switch 23 is turned to the a side, the high frequency current is supplied to the oscillation circuit 22, which oscillates and emits microwaves from the magnetron 4 into the heating chamber 4. Furthermore, when the changeover switch 23 is turned to the b side, a high frequency current flows through the induction heating coil 10, causing the inner box 3 disposed close to the induction heating coil 10 to generate heat due to electromagnetic induction. In addition, as shown by the broken line, a third contact c is provided to connect the oscillation circuit 22 and the induction heating coil 10.
, both the magnetron 4 and the induction heating coil can be operated at the same time by turning the changeover switch 23 to the c side.

Next, the operation of the present invention constructed as described above will be explained. First, the food to be cooked is placed in a cooking container and placed into the heating chamber 2 through the opening, either directly or placed on a turntable, and the door is closed. When using this heating cooker as an oven range, set the selector switch 23 (see Figure 5) to the b side and set the induction heating coil 10 to 20 to 50KH.
A high frequency current of about z is applied. Magnetic flux is generated by the excitation of the induction heating coil 10, and alternating eddy currents are generated in the bottom plate of the inner box 3 due to electromagnetic induction, and the bottom plate rapidly generates heat, raising the temperature of the heating chamber 2 by radiation and air convection. to heat and cook the food in the cooking container. Note that the cooking time can be further shortened by energizing the upper heater 7 as needed and heating the food by its radiant heat or air convection.

Next, when using it as a microwave oven,
When the changeover switch 23 is turned to the a side, the magnetron 4 outputs microwaves into the heating chamber 2 to heat and cook the food. In this case, the upper heater 7 is energized to promote heating, or depending on the type of food to be cooked, the selector switch is set to the c side so that both the magnetron 4 and the induction heating coil 10 heat the food. Good too.

[0021]

Effects of the Invention As is clear from the above description, the present invention comprises at least a part of the bottom plate of the inner box constituting the heating chamber made of a material that generates heat by electromagnetic induction, and By installing an electromagnetic induction heating means, it is possible to obtain a large-capacity heat source that starts up quickly compared to conventional heater heating, and also increases heating efficiency by directly generating heat from the bottom plate of the inner box. can be significantly improved.

[0022] Furthermore, by using an induction heating coil in which the coil is press-fitted into a groove formed in a coil frame made of an insulating material with a partition wall in between, the coils are insulated by the partition wall, so special insulation treatment is not necessary. There is no need for this method, production is extremely easy, and since the insulation between the coils is ensured, a large-capacity induction heating coil can be obtained. Furthermore, by changing the shape of the grooves, any desired heating pattern can be obtained.

Furthermore, since the high-frequency heating means and the electromagnetic induction heating means use a common high-frequency power source and are switched using a changeover switch, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is an enlarged view of the main part of FIG. 1;

FIG. 3 is a plan view of an embodiment of an induction heating coil.

FIG. 4 is a partially enlarged sectional view of FIG. 3;

FIG. 5 is a circuit diagram of an embodiment of a drive circuit for a magnetron and an induction heating coil.

FIG. 6 is a schematic diagram of an example of a conventional heating cooker.

FIG. 7 is an enlarged view of the main part of FIG. 6;

[Explanation of symbols]

2 Heating chamber 3 Inner box 4 Magnetron 7 Upper heater 10 Induction heating coil 11 Coil frame 12 groove 13 Partition wall 14 Coil 15 Insulating board 21 High frequency generator 22 Oscillator 23 Selector switch

Claims (3)

[Claims] 1. An inner box constituting a heating chamber, a heating means disposed under the inner box, and a high-frequency heating means attached to a side wall of the inner box; In the heating cooker for cooking by accommodating a container for cooking, at least a part or the entire bottom plate of the inner box is made of a material that generates heat by electromagnetic induction, and an electromagnetic induction heating means is used as the heating means. A heating cooker characterized by: 2. The electromagnetic induction heating means is an induction heating coil formed by press-fitting a coil into a groove formed in a coil frame made of an insulating material with a partition wall in between. Heating cooker. 3. An oscillation circuit of the high-frequency heating means connected to the output side of the high-frequency generator via a changeover switch, and an electromagnetic induction heating means connected in parallel between the oscillation circuit and the changeover switch. 2. The cooking device according to claim 1, wherein the output of the high frequency generator is supplied to either or both of an oscillation circuit and an electromagnetic induction heating means by switching the changeover switch.