SU941055A1 - Apparatus for multiarc welding - Google Patents

Description

(54) DEVICE FOR MULTI-YEAR WELDING

one

The invention relates to the field of welding production, in particular, to devices for multi-arc welding. A device for multi-arc welding is known, comprising a main DC source, welding electrodes and power sources of the pilot arc 1 connected to the welding electrodes.

A disadvantage of the known device is the inability to separate control of each arc, which reduces the quality of welding.

A device for multi-arc welding is known, comprising a main DC source, welding electrodes, power switching circuits by the number of electrodes made of thyristors connected between the main DC source and the corresponding welding electrodes, and power sources of the pilot arc connected to the welding electrodes. 2. The device provides the possibility of separate control of each arc, which allows to improve the quality of welding to some extent.

A disadvantage of this device is the presence of electromagnetic interaction between the arcs, causing their deviation from the welded joint, which is not

gives opportunities for further improvement of welding quality.

The aim of the invention is to improve the quality of multi-arc welding.

This is achieved by the fact that the device for multi-arc welding, containing the main source of direct current, welding electrodes, power switching circuits by the number of electrodes, is made of 10 thyristors connected between the main source of direct current and the corresponding welding electrodes. . Electrodes power supply on duty

15 arcs, a transformer is introduced with the number of windings equal to the number of electrodes, while the transformer windings are wound on its core in one direction, with equal numbers of turns and included

20 between the corresponding welding electrodes and thyristors of power switching circuits.

The drawing is principled

25 Wiring diagram for multi-arc welding.

A device for multi-arc welding contains the main source 1 of direct current, thyristors 2, 3, transformer 4

30 with two windings having the same number of coils wound in the same direction and included in the chains of welding arcs, auxiliary sources 5, 6 connected in parallel to the arc gaps and used for casting arc arcs, electrodes 7, 8 and welding item 9. Switching on thyristors 2, 3 and sources 1, 5, 6 are produced by a control unit (not shown in the diagram).

The device works as follows.

The source 1 is set to the operating current between the non-consumable electrodes 7, 8 and part 9, duty arcs are energized from the auxiliary sources 5, 6. After the welding wire is supplied, the thyristor 3 is turned on and the main arc from the main source is ignited between the electrode 7 and the part 9 1 n power source on duty. Then the thyristor 2 is turned on and a main arc also occurs between the electrode 8 and the workpiece 9. Through the winding of the transformer 4 connected to the thyristor 2 and the electrode 8, a current begins to flow, causing a decrease in the current in the circuit of the electrode 7, which, in turn, contributes to a further increase in the current in the circuit of the electrode 8. The redistribution of arc currents occurs as a result of inductive coupling windings of the transformer 4. When the current flowing through the thyristor 3 becomes mena1: from the current of the pilot arc, a reverse voltage will be applied to the thyristor 3 and it will turn on. From this moment on, a arc will be burning between electrode 7 and part 9, and a main arc between electrode 8 and part 9. After 25 ms, the thyristor 3 is turned on and the reverse redistribution of arc currents occurs. Due to the alternate switching on of the thyristors 2, 3, the arcs are energized by a pulsed current with a pulse duration equal to the pause duration. The current of each arc is the sum of the standby current and the average current equal to half the amplitude value of the current per pulse.

The device can be used to power three or more arcs. For this, the main source I is set to a current exceeding the average arc current as many times as the arcs are powered from source 1, the number of windings corresponding to the number of arcs is placed on the core of the transformer 2 and the required number of thyristors is set.

0 Introduction to a device for multi-arc welding of a transformer with specifically wound windings, the number of which is equal to the number of welding electrodes, made it possible to exclude electromagnetic

5 interaction between the arcs and due to this increase the quality of welding.

Claims (2)

1. Japanese Patent No. 53-32353, cl. 12 V 5 10B, onublnk. 09/07/78. 2. Handbook of converter equipment, ed. I. M. Chimlenko, Kiev, “Technique 1978, p. 182 (prototype).