SU61682A1 - Device for induction heating products - Google Patents

Description

The present invention relates to devices for induction heating of products by high-frequency currents, mainly during the surface hardening of steel. The invention can be implemented for other purposes.

Power systems for high-frequency surface hardening of steel are powered mainly by self-excited tube generators without intermediate circuits. The most expensive element of these installations is a heating circuit capacitor (usually mica, used for high-power radio installations).

The proposed device (it is called an inductive-capacitive vibrator by the author) eliminates a capacitor, since capacitance between turns of the secondary winding of the transformer supplying the inductor (heater) and turns of the primary winding fed by a high-frequency generator is used as the capacitance of the oscillating circuit. Structurally, this is done in that the turns of the secondary winding (coils) are located between the turns of the primary winding.

FIG. Figure 1 shows a circuit diagram of a high-frequency quenching unit with a self-excited oscillator operating with self-excitation without intermediate circuits, and an induction-capacitor vibrator; in fig. 2 shows one of the possible design options for the proposed device.

Designations in the diagram: 1 - stop choke, 2 - generator lamp, 3 - coupling capacitor, 4 - grid, 5 - primary winding of an induction-capacitive vibrator (which is the inductance of the anode circuit), 6 - secondary winding of this vibrator, consisting of a number of open rings located between the turns of the primary winding. The heating inductor 7 is connected to the terminals of the secondary winding. The dotted line 8 denotes the capacity of the primary winding, depending on the geometrical dimensions of the winding and the dielectric placed between the turns.

No. 61682 ..

Frequency / oscillations arising from the operation of the device depends3 mainly on the parameters of the vibrator: its capacitance C total. and inductance L total., which in turn consists of the sum of inductances -. a) the primary winding, b) the secondary coil, c) the inductor and d) the heated product. .

 A variant of the design of the induction-capacitive vibrator (Fig. 2), the primary winding 5 is made in the form of a cylindrical spiral of a flat copper bus bent on the edge. The start of the .9 and JO end of the winding are connected to a power generator. Between the turns of the spiral of the primary winding 5, a secondary winding 6 is placed, consisting of a series of open rings interconnected in parallel with the help of overlays //. Thus, the secondary winding is one coil. The heating inductor 7 is incident to the lining} 1. The heated product is indicated by the number 2.

The present invention can also be used for other oscillatory circuits, such as push pull.

Subject invention

Claims (2)

1. A device for induction heating of products with a high frequency current, characterized in that between the turns of the oscillating circuit coil there are one or several parallel connected incomplete turns connected to the inductor (heater and proportioned so that the capacitance between these turns and turns of said coil forms necessary for oscillatory process capacitance oscillating circuit. 2. In the device according to claim. 1, the use of coils and turns made of tapes or strips by winding them on the edge. 2 | //, ddsch C (, bsch. ig. 2 666