SU366048A1 - DEVICE FOR THE EXCITATION AND STABILIZATION OF THE WELDING ARC - Google Patents

Description

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Devices are known for initiating and stabilizing an alternating current arc, containing capacitive energy stores and switching devices in the form of arresters or fixed contacts.

Oscillators provide perlichnoe and re-excitation of the arc. However, they have no operational reliability due to the presence of a lawsuit, even every day, requiring clean cleaning and adjustment, high level of radio interference and

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Welding pulse generators ensure the stabilization of the AC arc. They also, as oscillators, have a low reliability and are unsuitable for the primary initiation of an arc.

The proposed device is characterized in that the switching links are made on magnetic elements with a rectangular hysteresis loop (BCP). As a result, the level of radio interference created by it is sharply reduced, the reliability and service life of the device increases. In addition, we propose a device suitable for exciting and stabilizing the arc.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - the same, option.

A device (see Fig. 1) is a pulse generator consisting of a phase inverter 1, a capacitive storage device 2 with a limiting charge resistance, forming links 3, 4 and an output link 5.

Phaser 1 serves to match the phase of the output pulses of the generator with the arc power voltage. (In some cases, the phase shifter may be absent).

Capacitive storage device 2 with limiting resistance provides for the accumulation of electrical energy in each half-period of the supply voltage.

Magnetic links serve to forgive (compress in time) the pulses delivered to the welding circuit.

The device (see Fig. 2) does not have a phase shifter. It contains a power switch VK, which provides a discharge of storage capacity when the device is turned off: capacitors Ci and C2 constitute a surge protector; The fli switch allows you to vary the voltage of the output pulse; The IJz switch allows parallel or sequential connection of the device to the welding circuit. The role of the storage device is played by the capacitor C3, and the resistance Z serves to limit the current. The first forming link (type A) includes capacitors C3, Ci and a non-linear switching choke LI. Thus, the capacitor C3 enters simultaneously in both the capacitor and the nepiBiOe forming unit. The second forming unit (type B) contains the Tpi auto-transformer with BCP and capacitors Sb and Sb. The third formative element (type B) includes the autotransformer Tr2 and the capacitors St and Cg. The output z.veno contains a separator. Conditator Co, and an impulse transformer IT and interlocking conduit Xu.

The device works as follows.

After switching on the switch K, the capacitor Cz is charged from the network through the limiting resistance Z. At a certain voltage AND AND on the capacitor C3, the choke LI is saturated, as a result of which the capacitor Cz is quickly discharged through the choke LI and the capacitor C4 of tra;

The capacitor Ci is used to increase the compression ratio of the nerve link. The Tpi autotransformer boosts the voltage. At the same time, due to the Cs and Ce condists, and the presence of a core with a BCP in the autotransformer, the sludge pulse is further compressed. Similarly, the subsequent compression of the pulse by the third link, consisting of the transformer Tpz and the capacitors C and Cg, is carried out.

With a proper choice of the parameters of the circuit, the pulses with the parameters, necessary for the primary and repeated excitation (1.5-5 m / s, 3-10 kV) are obtained at the output of the device.

Terminals are used to connect the device in parallel with the gap. P (for such a B: Switch on, the switch H2 must be open, and the coupling capacitor protects the device from welding current of industrial frequency.

To successively turn on the device in the welding circuit, the switch HZ is closed, and the output terminals 8, 9 are connected to the break in the welding wire (terminal 4 is connected to the electrode holder, and terminal 8 is connected to the arc power source). The secondary winding of the pulse transformer IT piaccMiHTaiHa on the flow of welding

current and provides the introduction of high-voltage ignition pulses in series in the welding target.

The use of a pulse transformer with a core having a BCP and a saturable welding current eliminates the influence of the secondary resistance of the IT Hia IT circuit and eliminates the influence of the welding current on the operation of the circuit. Besides,

when switched on in series, the device automatically changes the mode of operation when changing the welding current. When idling, the device generates pulses, the voltage of which is sufficient for the primary

initiation of the arc. When the arc is burning, non-reduced voltage emulsions are generated, providing re-excitation of the arc. In this case, the radar level significantly decreases.

The fJi switch serves to change the voltage of the output impulses both in series and in parallel connection of the device to the welding circuit. It simultaneously changes the number of turns in

transformers Tpi, Tpz and IT, and the capacitance value of the capacitors of the second and third forming units.

Subject invention

1. A device for exciting and stabilizing an alternating current arc containing a capacitive drive and switching elements, characterized in that, with

in order to reduce the radio frequency level and increase the reliability of operation, the switching links are made on magnetic elements with saturating; mis cores.

2. Device P: O p. 1, characterized in THAT, in order to reduce radio interference

By automatically changing the voltage of the output pulses depending on the magnitude of the welding current when the device is switched on sequentially on the welding day, the device is equipped with a pulse transformer connected to its output. (rig.gr P1