SU942920A1 - Single phase thyristorised power source for spot arc welding - Google Patents

Description

The invention relates to welding production, namely to power sources for arc spot welding with non-consumable electrode in inert gases. A device for arc-spot welding is known, which contains a welding power source connected in series with an electrode transferred by an electromagnet winding connected in parallel to the welding circuit 13 The disadvantage of the known device is that after the voltage input from the welding current source to the electromagnet the pull force increases dramatically , and there is a shock of the electrode on the product, which destroys the working end of the electrode. A power source is known, where an electromagnet for moving an electrode is connected to a welding circuit through a thyristor. This power source contains a welding transformer, sources of the pilot and welding arc, a smoothing filter of the pilot arc, as well as a device for interlocking the welding arc, a time controller, as well as an additional thyristor and resistance C21 are connected to the KOTOR. The known solution is intended for small-sized welding tools, where the pull force of the electromagnet does not exceed 2 N. The electromagnet control current is switched by the thyristors. After turning on the thyristors, the current is limited by the active resistance of the winding and does not exceed. 0.3 A. In welding technology it is necessary to use electromagnets, the thrust of which has a value of 20 ... 30 N, the response current - 2 ... 3 A. Increasing the current to such a value leads to an increase in the impact force of the electrode product. Repeated welding cycles are accompanied by the destruction of the electrode. 3. 9 The aim of the invention is to increase the productivity of welding by reducing the recovery time of the working end of the electrode. The goal is achieved by the fact that a single-phase thyristor power source for an arc point beam contains a welding transformer to which sources of the pilot and welding arc are connected, a smoothing filter for the pilot arc, an electromagnet, the winding of which is connected to one terminal of the power source through the thyristor, a locking device the arc current, the time controller, as well as the resistance and the additional thyristor, a time delay element is introduced, while the resistance is connected in parallel with the indicated element ix and an additional thyristor, a gate electrode connected to the auxiliary thyristor element vyder time ki, and of the complementary cathode of the thyristor is connected to the coil of the electromagnet, and its anode and the other terminal of said resistance conn cheny to terminal source welding rods do. The drawing shows a functional power supply diagram. The power source contains a welding transformer 1, a thyristor rectifier of the duty and welding arc current, consisting of thyristors 2-5 and diodes 6 and 7, a smoothing current filter of the duty arc 8-10, an arc excitation device, consisting of elements 11-15, resistance 16 and thyristor 17, electromagnet 18, type 19 electrodes of time element 20, time regulator 21, device for blocking the current of the smelting arc 2 and gas cut-off 23. In the power supply, sources of the pilot and welding arc are connected to the welding transformer 1, smoothing duty arc, mobile electrode 19, moved by an electromagnet, the winding of which is connected to one power supply terminal through the thyristor 15, the winding is connected to another terminal through the thyristor 17 and resistance 1b, connected in parallel with the time delay element 20, and the device for blocking the arc current 22 ,. Connected with time control 21. The device operates as follows. With the arrival of a signal at the input of the time controller, the gas cut-off device and the thyristors of the pilot arc are switched on. Gas welding zone is blown through and the tank 10 is charged. Then the time controller turns on the thyristor 15. A current flows through the winding of the electromagnet 18, limited by the resistance 16 and the resistance value of the winding itself. With a time delay element 20 turns on the thyristor 17. The magnitude of the current in the winding reaches its full value. After the electromagnet is triggered, the electrode touches the product. The welding circuit is short. The voltage and the pulling force of the electromagnet are reduced. Under the action of a return spring, the electrode is detached from the product, a arc is excited with a current of 15 A. Turning on the thyristor discharges the capacitance 13, locking the thyristor 15. The electromagnet winding is disconnected from the welding circuit. Arc voltage is applied to the blocking device for switching on the current of the welding arc. The signals from the time regulator are fed through the blocking device for switching on the current of the welding arc to the control of thyristors 2 and 3 The value of the current in the welding circuit is increased to the value determined by the time regulator. After the welding time has elapsed, the rectifiers of the welding arc and the pilot arc, and then the gas cut-off valve, turn off. The time of operation of the electromagnet is regulated by means of a time delay element and is 0.5 ... 0.1 s. The ratio of resistance 16, the resistance of the winding of the electromagnet and the time-delay element ensures a smooth running of the welding electrode. The use of the invention reduces the impact force of the electrode on the product, which, in turn, reduces the consumption of tungsten and the loss of working time for sharpening the working end of the electrode, thus increasing the productivity of the welding process. The expected economic effect in the calculation; per unit of product is 30 p. and with the release of such power supplies 2000 pcs. per year is 60000 r.

invention formula

Single-phase thyristor power source for arc spot welding, containing a welding transformer to which sources of the pilot and welding arc are connected, a smoothing filter for the pilot arc, an electromagnet, the winding of which is connected to one terminal of the power source through the thyristor, a device for blocking the arc current, a time regulator, as well as resistance and an additional thyristor, characterized in that, in order to increase the npo of productivity by reducing the recovery time of the working end of the electrode, not introduced an element of

time delay, while parallel to the specified element resistance and an additional thyristor are included, and the control electrode of the additional thyristor is connected to the time delay element, the cathode of the additional thyristor is connected to the electromagnet winding, and its anode and other output of the specified resistance are connected to the power arc terminal of the welding arc .

Sources of information taken into account in the examination

1. USSR author's certificate

No. cl. B 23 K 9/10, 02.01.73.

2.Zaichko V.N. Single phase tiris h

Welding

torrent power source,

production, 1977, W 8, p. 4b- 7.

Claims (1)

Claim A single-phase thyristor power source for arc spot welding, containing a welding transformer, 5 to which are connected the sources of the standby and welding arcs, a smoothing filter of the standby arc, an electromagnet, the winding of which is connected to one terminal of the power source through a thyristor, a welding current blocking device, a time controller as well as resistance and an additional thyristor, characterized in that, in order to increase the productivity of I-5 by reducing the recovery time of the working end of the electrode, a time delay element was introduced to it, while in parallel with this element resistance and an additional thyristor are connected, and the control electrode of the additional thyristor is connected to the time delay element, the cathode of the additional thyristor is connected to the electromagnet winding, and its anode and other output of the indicated resistance are connected to the power supply terminal welding arc.