JPS6321910Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an induction heating cooker, and by fixing the main components of the cooker on a single chassis to form a unit, it simplifies assembly work and conducts performance tests. The purpose is to make it easy to use and to utilize the internal space of the cooker efficiently.

The present invention is particularly suitable for a multi-port induction heating cooker equipped with a plurality of induction heating coils, a high frequency inverter for driving the coils, a power supply circuit, and the like.

FIG. 1 shows the internal structure of a two-burner induction heating cooker according to a conventional example, in which 1 is a common chassis for each heating port, and 2 and 3 are first and second inverters arranged on this chassis 1. Circuit, 4 and 5 are the same chassis 1
first and second control circuits mounted above, 6, 7;
Reference numeral 8 indicates an induction heating coil to which a high frequency current is supplied from each inverter circuit 2, 3, and 8 a fan that sends cooling air to the induction heating coils 6, 7 and switching elements constituting the inverter circuits 2, 3. A cooking appliance having such a structure has a drawback that when one heating port malfunctions, the entire chassis 1 must be removed, the malfunctioning parts must be replaced, electrical characteristics tests, etc. must be performed, making the work cumbersome. In particular, if the number of cookers increases, such as in a four-burner cooker, the chassis will become larger and the above-mentioned work will become even more extensive. In addition, you will need a shell depending on the number of cookers, that is, if it is a 2-burner cooker, you will need a shell corresponding to the size of the cooker.
There is a problem in that a unique chassis must be prepared for each, resulting in high costs.

The present invention has been developed in consideration of such circumstances, and will be described below with reference to an example in which the invention is applied to a two-burner induction heating cooker.

In FIG. 2, _B1 is a first heating unit, and _B2 is a second heating unit.The circuit configuration of the second heating unit _B2 is the same as that of the first heating unit _B1 , so a description thereof will be omitted. 9 is AC power supply, 1
0 is a cooling fan common to both heating units B ₁ and B ₂ ,
11 is a switch that drives this cooling fan 10;
12 is a power switch for the first heating unit _B1 ;
13 is a power switch for the second heating unit _B2 ;
A cooling fan switch 11 is linked to these power switches 12 and 13. 14 is a rectifier circuit;
Reference numerals 15 and 16 constitute a filter circuit with a chiyoke coil and a bypass capacitor. 17 is an induction heating coil, 18 is a transistor functioning as a switching element, 19 is a resonant capacitor, 2
0 is a freewheel diode, and these parts form a high frequency inverter circuit 21. 2
Reference numeral 2 denotes a cooking pot made of iron-based metal and placed close to the induction heating coil 17 via a top plate 23 made of a heat-resistant insulating plate such as a ceramic plate. A drive circuit 24 provides an on/off signal to the base of the transistor 18, and includes a pulse transformer, an amplification transistor, etc., which will be described later. 25 is a current detector that detects the high frequency current flowing through the induction heating coil 17;
A transformer 26 is a control power supply circuit including a power transformer and a rectifier circuit, and obtains a low DC voltage. 27
is a control circuit to which driving power is supplied from the power supply circuit 26, which controls the high frequency inverter 2 based on the high frequency detection signal input from the current transformer 25.
The transistor 18 is controlled via the drive circuit 24 so that the transistor 1 oscillates at a predetermined frequency. 28 is a thermistor that detects the temperature of the induction heating coil 17.

3 and 4 show two circuits having such a circuit configuration.
A specific wiring diagram of the induction heating cooker is shown, in which the first heating unit _B1 is placed on the right side of the figure, and the second heating unit _B2 is placed on the left side. Reference numeral 10 denotes a cooling fan disposed between both units B ₁ and B ₂ , that is, in the center of the cooking appliance, and is commonly used for cooling both units B ₁ and B ₂ , and one or both units rotates during heating operation. Reference numeral 29 is an exhaust port provided at a position from which air is blown out by the cooling fan 10, and 30 is a mounting bracket for fixing the cooling fan 10, which is formed of an aluminum plate or the like having good thermal conductivity. 14 is this mounting bracket 30
With the rectifier circuit fixed to the surface, the fitting 30 acts as a cooling medium. 31 is a power transformer that obtains control voltages for the first and second heating units B ₁ and B ₂ ;
Reference numeral 32 is a chiyoke coil constituting a filter circuit. The first heating unit _B1 consists of a circuit board and other parts mounted on a single chassis 33 supported on the bottom surface of the cooking device case. That is 3
Reference numeral 4 denotes a control circuit board fixed to the chassis 33 by fixing members 35, 35, and a pulse transformer 3 constituting the drive circuit 24 of the switching transistor 18.
6 and transistor 37, current transformer 2
5. Furthermore, various electric components 38, 38, etc., such as ICs, are connected by wiring. Reference numeral 39 denotes an inverter circuit board, which is fixed to the chassis 33 with fixing members 40, 40, and has a switching transistor 18, a resonant capacitor 19, and a freewheel diode 20 attached thereto. 21 is a heat sink of the transistor 18. 16 is a bypass capacitor fixed to the inverter circuit board 39; 28
is a thermistor similarly arranged on this base 39 and detects the temperature of the induction heating coil 17. Although these components do not constitute the high frequency inverter circuit 21, they are fixed here in order to arrange the components at a high density. These components can also be attached to the control circuit board 34. 41,41
is a connecting wire that supplies high frequency current to the induction heating coil 17, and is connected via a current transformer 25.

The second heating unit _B2 is the same as the first heating unit _B1 .
The first heating unit _B1 is arranged in a direction rotated by 180 degrees around the fan 10. With this arrangement, if in the first heating unit _B1 the parts that require cooling are placed near the fan 10, that is, on the left side in the figure, then in the second heating unit _B2 , These parts are located on the right side in the figure, so that the cooling action can be performed uniformly and efficiently in both units B ₁ and B ₂ .

In this way, the present invention is such that the first and second heating units each have the electrical components, circuit board, and heat dissipation plate that make up one heating unit arranged on a single independent chassis, and there is no cooling between the two chassis. Because the fans are arranged, each chassis can be assembled and the parts can be shared.Furthermore, each chassis can be assembled with respect to the cooling fan so that the parts on both chassis that require cooling can effectively receive the wind from the cooling fan. The arrangement of the upper parts and the board can be made symmetrical, the cooling effect can be made uniform in both heating units, and cooling can be effectively achieved with a single cooling fan.
In addition, since each heating unit can be tested for characteristics or disassembled and repaired by removing one unit at a time, operation becomes easier. Furthermore, each unit can have the same wiring structure, and the length and position of the connecting wires connecting each component are equalized, so high frequency noise due to the magnetic field emitted by the induction heating coil can be kept to a constant value for each unit. The values can be kept to a minimum. Particularly, connection lines between structural components of a high-frequency inverter circuit tend to generate noise, and the noise reduction effect by mounting such components in a fixed arrangement on a predetermined circuit board is significant.

[Brief explanation of the drawing]

Fig. 1 is a top view showing the structure of a conventional example, Fig. 2 is a circuit diagram for explaining an embodiment of the present invention, Fig. 3 is a top view of the same example, and Fig. 4 is a cross section taken along line A-A' in Fig. 3. It is a diagram. B ₁ , B ₂ ...first and second heating units, 10...
...Cooling fan, 17...Induction heating coil, 33...
...Chassis, 34...Control circuit board, 39...Inverter circuit board.

Claims (1)

[Scope of utility model registration request] In an induction heating cooker including first and second induction heating coils and a high frequency inverter that supplies high frequency current to each of these coils, a first heating unit corresponding to the first induction heating coil, and a second induction heating A second heating unit corresponding to the coil and each of the heating units each have a chassis, and each chassis has an inverter circuit board on which electrical components constituting the high frequency inverter are attached, and an oscillation circuit board of the high frequency inverter. A control circuit board is attached with electrical components for controlling the high-frequency inverter, and a heat sink is attached to cool the switching elements constituting the high-frequency inverter. A cooling fan is provided between the two heating units, and the second heating unit The unit is an induction heating cooker in which the first heating unit is arranged in a direction rotated by 180 degrees around the cooling fan.