JP3032186U - Output transformer separated induction heating device - Google Patents

Abstract

(57) [Abstract] [Purpose] In an induction heating device, a heating coil, an output transformer, and a resonant capacitor are used as a portable heating unit that is separated from a high-frequency power source and can be extended by a lightweight and flexible cable. provide. [Structure] An output transformer 36 and a heating coil 2 are combined into a heating unit 1 which is separated from a high frequency power supply main body 35. Then, a light and flexible cable 39 is provided between them.
Connect with. The resonance capacitor 21 is inserted in series on the primary coil side and placed in the heating unit 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to heating a metal work by a high frequency induction heating method.

[0002]

[Prior art]

 In the conventional induction heating device, the output transformer is generally incorporated in the induction heating device main body, and the heating coil is also on the main body side, so that the work and the selection of the work are limited.

[0003]

[Problems to be solved by the device]

If the heating coil part can be extended from the induction heating device body with a flexible and lightweight cable, the degree of freedom in selecting the work will be expanded. Therefore, consider incorporating the output transformer and heating coil together to form a heating unit, and extending the space between the primary side of the output transformer and the induction heating device body. When the numbers of turns of the primary and secondary coils of the output transformer are n ₁ and n ₂ , generally n ₁ > n _2, so that the current on the primary side is smaller and the loss is smaller than that on the secondary side. However, when the oscillating frequency becomes higher, the power transmission is hindered by the inductance distributed in the cable. Therefore, if the oscillation frequency is suppressed to about 25 kHz, the above problem can be avoided. On the other hand, lowering the oscillation frequency increases the capacitance of the resonant capacitor, which increases the size and weight of the heating unit.

[0004]

[Means for Solving the Problems]

 Until now, the resonance capacitor was inserted in the secondary side of the output transformer, but if this insertion position is moved to the primary side, the capacitance and volume of the resonance capacitor can be reduced as shown below.

[0005]

[Action]

As shown in FIGS. 4a and 4b, when a resonance capacitor is inserted in series on the primary side or the secondary side of the output transformer 36, the capacitance of the capacitor at resonance and the voltage at both ends are respectively C ₁ , V _C1. , Or C ₂ and V _C2 , the relational expression shown in FIG. 4c is established. Here, Q is the Q value of resonance. By the way, assuming that the volume occupied by the capacitor having the capacitance C and the withstand voltage V is W, the following relationship is approximately established: W = CV (4) The required withstand voltage and its volume of C ₁ and C ₂ are respectively V _C1P (Peak value of V _C1 ), W ₁ , and V _C2P , W ₂ , from formulas (1), (2), (3) and (4) From this, since normally n ₁ > n ₂ , the volume can be reduced to n ₂ / n ₁ by moving the position where the resonance capacitor is inserted from the secondary side of the output transformer 36 to the primary side. However, it should be noted that the voltage V ₁ across the primary coil of the output transformer 36 becomes Q times V _{0 due to} the resonant voltage appearing across the inductance of the heating coil 2. Therefore, in order to obtain the same output, the cross-sectional area of the core of the output transformer 36 must be Q times.

[0006]

【Example】

A manufacturing example of the heating unit 1 designed based on the above description is shown in FIGS. The heating unit 1 comprises a heating coil 2, an output transformer 36 and a resonance capacitor 21. The coil 10 of the output transformer was sandwich-wound in five layers on the middle leg of the ferrite core 9 in order to improve the degree of coupling between the primary and secondary coils. The primary coil was divided into the first layer, the third layer, and the fifth layer with 59T, and the secondary coil was a copper plate (t0.5), and the second layer and the fourth layer were wound with 1T each. At the beginning and the end of the winding of the secondary coil, lead plates (strip copper plates, t1.5) 11, 12, 13, and 14 are soldered, respectively, and in order to cool the coil 10 and the lead plate, The water jackets 17, 18, 19, 20 were soldered on top of the plates 11, 12, 13, 14. The lead plates 11 and 14 are connected to the electrodes 3 and 4, and the lead plates 12 and 13 are connected to the electrodes 4 and 3 via the relay plates 16 and 15, respectively. These secondary coils are connected in parallel at electrodes 3 and 4 to form a 1T primary coil. One of the terminals of the primary coil is connected to the main connector 24, and the other is connected to the main connector 24 via the resonance capacitor 21. The resonance capacitor 21 is attached to a terminal plate (copper plate) 22 in consideration of the heat radiation effect, so that the capacitance of the capacitor can be increased or decreased. The circulation route of the cooling water is as follows: hose connector 6 (water supply port) -electrode 3-hose port 8-water jackets 17, 18, 19, 20-hose port 7-electrode 4-heating coil 2- Electrode 3-hose connector 5 (drainage port). FIG. 3 shows the overall configuration of an output heating type induction heating device according to the present invention. The specifications of the high frequency power supply 35 are as follows. DC power supply voltage V _DC = 280 V) Oscillation frequency = 25 kHz, oscillation output = 3 kW _o The size of the high frequency power supply is 203 × 275 × 490 mm, which is a compact size. The cable 39 that supplies a high-frequency current from the high-frequency power source 35 to the heating unit 1 has a light weight of 2 mm ² × 4 × 5 m and is flexible. The capacitance of the resonance capacitor 21 was set to about 0.15 μF so that the resonance coil 21 would be in a resonance state under the condition that the heating coil 2 had a work.

[0007]

[Effect of device]

 When applying high frequency induction heating to soldering or brazing of iron materials, it is appropriate to set the oscillation frequency to around 25 kHz in consideration of the depth of current penetration. In this case, the output transformer and the heating coil can be used as a heating unit and can be extended from the high frequency power supply main body with a lightweight and flexible cable. At this time, by inserting the resonant capacitor into the primary side of the output transformer, the space occupied by the resonant capacitor can be reduced, and the heating unit can be prevented from increasing in size. Therefore, the heating system of the present invention is useful for automating the heating work using the robot and incorporating various automation devices accompanied by the heating work, and for increasing the flexibility of the heating work and expanding the work range.

[Brief description of drawings]

FIG. 1 is a plan view of a heating unit according to an embodiment of the present invention.

FIG. 2 is a front view of a heating unit according to an embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment of the present invention.

FIG. 4 is a schematic diagram of a circuit. (A) High frequency power supply and heating unit (resonant capacitor; primary side). (B) Heating unit (resonant capacitor; secondary side). (C) Relational expression

[Explanation of symbols]

 1: Heating unit 2: Heating coil 3, 4: Electrode 5, 6: Hose connector 7, 8: Hose port 9: Ferrite core 10: Coil 11, 12, 13, 14: Lead plate 15, 16: Relay plate 17, 18, 19, 20: Water jacket 21, 38: Resonant capacitor 22: Terminal board 23, 27: Temperature sensor connector 24, 26: Main connector 25: Temperature sensor 28: Start / Stop switch 29: Abnormality indicator light 30: Reset switch 31: Output adjustment 32: Power switch 33: Power indicator light 34: Output ammeter 35: High frequency power supply 36: Output transformer 37: Work 39: Cable

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[Procedure amendment]

[Submission date] July 3, 1996

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

Claims (1)

[Scope of utility model registration request] 1. An output transformer is separated from the main body of the induction heating device, and is independent as a heating unit together with a heating coil,
A resonant capacitor is inserted in the primary side of the output transformer in order to reduce the size.