JPH02183993A - Composite cooker - Google Patents

Abstract

PURPOSE:To easily perform cooking such as boiling or singeing on food by inserting a microwave shielding plate provided with cut sections to prevent a closed loop between the heating coil of an induction heater and a container mounting plate. CONSTITUTION:The high-frequency magnetic field 10 is generated by a current 9 flowing in a heating coil 3. This high-frequency magnetic field 10 generates an eddy current on a container storing food such as a pot made of a conducting material and heats the container itself, and the food in the container is heated and cooked. When a shielding plate 1 made of a conducting material such as copper, aluminum or stainless steel to shield microwaves 7 is mounted on this coil 3, the high-frequency magnetic field 10 generated by the heating coil 3 tends to feed a current to this shielding plate 1. However, cut sections 2 are provided on the shielding plate 1, and the current 11 which the high-frequency magnetic field 10 tends to generate can not flow. The short-circuit current 11 by the high-frequency magnetic field 10 can be prevented by providing the out sections 2 on the shielding plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a composite cooking device having a dielectric heating device and an induction heating device driven by an inverter circuit or the like.

Conventional technology Hereinafter, a conventional composite cooking device will be explained with reference to the drawings.

FIG. 5 is a block diagram showing the circuit configuration of a conventional composite cooking device. In FIG. 5, a commercial power source 41 is converted into direct current by a rectifier 42, and converted into high frequency alternating current by an inverter circuit 43. The output of the inverter circuit 43 is switched by a changeover switch 44, and the dielectric heater 45 or the induction heater 46 is selectively driven. The dielectric heater 45 includes a step-up transformer 47 that steps up the output of the inverter circuit 43 and a magnetron 48 that is driven by the high voltage output of the step-up transformer 47. The magnetron 48 generates microwaves and dielectrically heats the food by irradiating the microwaves onto the food.The induction heater 46 generates a high-frequency magnetic field by the high-frequency current output of the inverter circuit 43. It is composed of a heating coil 49 and a heat-resistant container mounting plate 50 made of ceramic or the like on which a container such as a pot containing food is placed. heating coil 49
generates a high-frequency magnetic field, and loads 51 such as pots made of magnetic materials such as copper, aluminum, stainless steel, and pig iron.
It generates eddy current to generate heat and cook the food placed inside. FIG. 6 is a diagram showing this state.A high frequency current obtained by the inverter circuit 43 is passed through the heating coil 49, and therefore a high frequency magnetic field 52 is generated, and this high frequency magnetic field 52 is made of magnetic material. An eddy current 53 is generated in a load 51 such as a pot, and the load 51 generates heat due to the eddy current loss, and the food placed therein is heated and cooked.

FIG. 7 is a schematic sectional view showing the structure of a conventional composite cooking device. In FIG. 7, a magnetron 48 driven by an inverter circuit 43 irradiates microwaves 55 into the interior of an oven 54 surrounded by a sheet metal, dielectrically heating the food placed in a container inside the oven 54. The induction heater 46 consisting of the heating coil 49 and the container mounting plate 50 is provided on the outside of the oven 54 above the composite container.

Problems to be Solved by the Invention However, the conventional composite cooker has the following problems.
There was a problem.

Since the induction heater 46 is located outside the oven 54, when performing induction heating, the container containing the food is placed on the top of the composite cooker, and when performing dielectric heating, the container containing the food is placed on top of the composite cooker. It is necessary to place the container inside the oven 54, and if induction heating and dielectric heating are performed consecutively, manual intervention is required to move the container, and induction heating and dielectric heating are automatically alternated. It was difficult to perform automatic cooking. For this reason, it has not been possible to realize a composite cooking device that takes full advantage of the advantage of jLt heating, which allows food to be heated from the inside, and the advantage of induction heating, which allows food to be browned.

The reason why the induction heater 46 was not installed inside the oven 54 is as follows. As shown in FIG. 8, when an induction heater 63 consisting of a heating coil 61 and a container mounting plate 62 is installed inside the oven 60, the microwave 60
When cooking food by dielectric heating using the microwave oven 4, a portion of the microwave 64 passes through the container mounting plate 62 and irradiates the heating coil 61. Since the heating coil 61 is composed of an electric wire coated with an insulating material, there is a problem in that the electric wire is heated by irradiation with the microwave 64 and the insulating coating of the electric wire is naturally destroyed. For this reason, conventionally, as shown in FIG. 9, a microwave shielding plate 66 is provided with a slit 65 of such a size that the microwave 64 with a frequency of 2740 MHz (wavelength: 10.9 G1 m>) cannot pass through.
Induction heating i? It was considered to provide the induction heater 63 between the heating coil 61 of the 1763 and the container mounting plate 62 and the induction heater 63 inside the oven 60. However, with such a configuration, when performing induction heating, the microwave shielding plate 66 is affected by the high frequency magnetic field generated by the heating coil 61.
There is a problem in that an eddy current is induced in the shielding plate 66, and the shielding plate 66 is heated and generated.

Although the slit 65 is provided for the purpose of not reducing this eddy current, the slit 65 alone has not been able to completely prevent the eddy current.

For this reason, the induction heaters 46 and 63 could only be provided inside the oven 5460.

The present invention solves the above-mentioned problems, and aims to provide a composite cooking device in which the induction heater is removed from the inside of the oven, and the dielectric heater and induction heater can be used without any trouble. It is.

Means for Solving the Problems In order to solve the above problems, the present invention provides an inverter circuit that replaces the DC power obtained by rectifying a commercial power source, a source, a battery, etc. with a high-frequency AC power source, A dielectric heater comprising a step-up transformer for boosting the output of the inverter circuit, a magnetron driven by the output of the step-up transformer, a heating coil for generating a high-frequency magnetic field, and a container for placing food. An induction heater having a heat-resistant and insulating capacity 3U placing plate, and an oven for storing food to be dielectrically heated and cooked by the induction heater, and the induction heater is provided inside the oven. , a shielding plate made of a conductive material that shields microwaves is provided between the heating coil and the container mounting plate of the induction heater, and the shielding plate is protected against short-circuit current by a high-frequency magnetic field generated by the heating coil. A cut portion is provided to prevent this from occurring, so that the closed loop does not have a round shape.

Effect With the above configuration, a shielding plate that shields My20 waves between the heating coil of the induction heater and the container mounting plate enables a configuration in which the induction heater is provided inside the oven for dielectric heating of food. When performing dielectric heating, this shielding plate shields the microwaves that pass through the container mounting plate of the induction heater, preventing the heating coil from being irradiated with microwaves, and thus preventing the insulation coating of the heating coil from being irradiated. In addition to preventing thermal damage, the cuts in the shield plate prevent eddy currents from flowing, which eliminates the generation of eddy currents caused by the high-frequency magnetic field created by the heating coil when the induction heater is used, thereby preventing fires. do not have.

Example An embodiment of the present invention will be described below with reference to the drawings.

Since the operation and circuit configuration of the composite cooking device of the present invention are the same as those of the conventional one, the explanation will be omitted and the different points will be mainly explained.

FIG. 1 shows the outside of a shielding plate for microwave shielding of a composite cooker which is an embodiment of the present invention. It is a diagram. FIG. 2 is a schematic sectional view of the composite cooking device showing where in the composite cooking device the shielding plate shown in FIG. 1 is disposed. In FIG. 2, an induction heater 8 consists of a heating coil 3 that generates a high-frequency magnetic field and a heat-resistant and insulating container mounting plate 4 made of ceramic or other material on which containers containing food are placed.
The microwave oven 6 is installed inside one of the ovens 6 for storing foods in order to cook the foods by dielectric heating using the microwaves 7 generated by the oven. A shielding plate 1 for shielding microwaves is provided between the heating coil 3 and the container mounting plate 4, and blocks microwaves 7 passing through the container mounting plate 4. The shielding plate 1 is provided with a cut portion 2 as shown in FIG. 1, and the cut portion 2 makes the shielding plate 1 into a shape that does not have a closed loop through which a short-circuit current due to the high-frequency magnetic field generated by the heating coil 3 flows. This prevents the plate 1 from being heated.

The operation of the above configuration will be explained. The relationship between the high frequency magnetic field generated by the heating coil 3 and the current flowing through the shield plate 1 due to this high frequency magnetic field will be explained with reference to FIG. FIG. 3 shows a state in which the shielding plate 1 is placed on the heating coil 3. The upper half of FIG. 3 shows the shielding plate 1, and the lower half shows the heating coil 3. In FIG. 3, a high frequency magnetic field 10 is generated in the direction shown in FIG. 3 by a current 9 flowing through the heating=1 coil 3. This high frequency magnetic field 10 generates an eddy current in a container containing food, such as a pot made of a conductive material, causing the container itself to generate heat, heating and burying the food in the container. When a shielding plate 1 made of a conductive material such as copper, aluminum, or stainless steel is placed on top of this heating coil 3 to shield the microwave 7, the high-frequency magnetic field 1o generated by the heating coil 3 is transmitted to the shielding plate 1. The current 11 is also applied to the current 11. However, the shielding plate 1 is provided with a cut portion 2, and the high-frequency magnetic field 10 is oriented as shown in FIG.
The current 11 that is intended to be created cannot form a closed loop because of the cut portion 2, and the short circuit current 11 will not flow.

In this way, the cut portion 2 is attached to the shielding plate 1 for microwave shielding.
By providing this, it is possible to prevent short circuit current 11 caused by high frequency magnetic field 10, so that shielding plate 1 will not heat up and burn.

FIGS. 4(a) and 4(b) are schematic diagrams showing the structure of a shielding plate in which safety measures are taken, which are other embodiments of the present invention. The shielding plate 21 shown in FIG. 4fa) has a cut portion 22.
is provided in two places and is divided into a first pattern 23 and a second pattern 24, and a DC power supply 25 and a resistor 2 are connected between the first pattern 23 and the second pattern 24.
6.27 is connected to the resistor 27, and a control circuit 28 of the inverter circuit is connected to both ends of the resistor 27. 1st pattern 2
3 and the second pattern 24 are each made of a conductive material, so if either one of the two cut portions 22 is electrically connected for some reason, the DC power source 25 and the first A closed loop consisting of the pattern 23, the second pattern 24, and the resistors 26 and 27 is formed, and the resistor 2
A voltage is generated across 7. This voltage is used as a detection signal to detect an abnormal state in which the first pattern 23 and the second pattern 24 are electrically connected for some reason, and this detection signal is sent to the control circuit of the inverter circuit. 2
8 and if an abnormality is detected, the operation of the inverter circuit is immediately stopped. Here, even if only one of the two cut portions 22 is electrically connected, a closed loop consisting of the first pattern 23 and the second pattern 24 is not formed, but as shown in FIG. In the shielding plate 1 having only one cant portion 2, if the cut portion 2 is electrically connected, a closed loop will be formed and a short MI current will flow due to the high frequency magnetic field created by the heating coil 3, causing an instantaneous There is a very high risk that the shielding plate 1 will heat up and ignite, resulting in a fire.

For this reason, as shown in FIG. 4, a plurality of cut portions 22 are provided on the shielding plate 21, and if one of the cut portions 22 is electrically connected, the operation of the inverter circuit is immediately stopped. This is an extremely effective measure for safety.

The first part is completely separated on both sides as shown in Figure 4(a).
In the case of the shielding plate 21 consisting of the pattern 23 and the second pattern 24, the distribution of microwaves generated from the magnetron and irradiated into the oven chamber is uneven, and the first pattern 23 and the second pattern 24 are uneven. In order to solve this problem, as shown in FIG. The second patterns 34 may be arranged so that the distance from each other is uniform, so that the first pattern 33
It is possible to prevent a potential difference from occurring between the pattern 34 and the second pattern 34.

Effects of the Invention As described above, the composite cooker of the present invention has a shielding plate for shielding microwaves, which has a cut part between the heating coil of the induction heater and the container mounting plate to prevent a closed loop from forming. By inserting the induction heater, it is possible to use the induction heater and the dielectric heater without any trouble by incorporating the induction heater into the oven chamber that stores the container containing the food. Using an induction heater, you can easily do things like boiling or browning food, which devices are not good at, inside the oven, making it possible to do a wider range of cooking.

[Brief explanation of the drawing]

Fig. 1 is an external view of a shielding plate of a composite cooking device which is an embodiment of the present invention, Fig. 2 is a schematic sectional view showing the structure of the compound cooking appliance, and Fig. 3 is a diagram showing the shielding plate of the compound cooking appliance. Partial plan views showing the shielding plate and the heating coil for explaining the relationship with the magnetic field created by the heating coil, FIGS. Figure 5 is a block diagram showing the circuit configuration of the combined cooker, and Figure 6 is a block diagram showing the circuit configuration of the combined cooker. Principle diagrams explaining how current is generated, Figures 7 and 8
Each figure is a schematic sectional view of a conventional composite cooking device, and FIG. 9 is an external view of a conventional microwave shielding plate. 1, 21.31... Shielding plate, 2, 22.32...
Cup 1 part, 3... Heating coil, 4... Container placement plate, 5... Macui Tsukasa Ron, 6... Oven, 7...
・Microwave, 8... Induction heater, 10... High frequency magnetic field, 41... Power source for music, 42... Rectifier, 43...
...Inverter circuit, 45...Dielectric heater, 47...
・Boss Le Trans. Agent Yoshihiro Morimoto 2I-22-22-Cut sound p Renka 4th figure 1θ tθ-6, high) A fiber absorption 5th 41-Misakidensan, 4z--Rectification (43- , -47 par 7r: l) also, 4 ter...induction 47 --- Shoulder 1 mo trans 2nd figure Me figure 1/D figure

Claims (1)

[Claims] 1. An inverter circuit that exchanges the DC power obtained by rectifying a commercial power source or the DC power obtained from a battery with a high-frequency AC power source, a step-up transformer that boosts the output of the inverter circuit, and is driven by the output of this step-up transformer. an induction heater having a heating coil that generates a high-frequency magnetic field and a heat-resistant and insulating container mounting plate for placing a container containing food; an oven for storing food to be cooked by induction heating using a container, the induction heater is provided inside the oven, and microwaves are shielded between the heating coil of the induction heater and the container mounting plate. The composite cooking device is provided with a shielding plate made of a conductive material, and the shielding plate is shaped to have no closed loop by providing a cut part so that short circuit current is not generated due to the high frequency magnetic field generated by the heating coil.