Welding process control method

FIELD: mechanical engineering; welding.

SUBSTANCE: invention can be used in welding of metal structures in different spatial positions. Welding bath is formed at flat volt-ampere curve of supply source and rising volt-ampere curve of arc. Crystallization of metal in bath is carried out at drooping volt-ampere curve of supply source and flat volt-ampere curve of arc.

EFFECT: provision of synchronization of welding wire feeding with change of external volt-ampere characteristics of supply source.

1 dwg

 

The invention relates to the field of welding and can be used when welding on process equipment, providing a pulsed supply of welding wire in the combustion zone of the arc welding of steel structures in different spatial positions.

A known method of controlling the mechanism of pulsed wire feed, including feed signal to the system control mechanism (see SU 1484526, WK 9/10, 07.06.89)/

The disadvantage of this method is the unpredictability of the process of droplet transfer of electrode metal in the weld pool and the process of arc.

A known method of controlling the welding process, including pulsed supply of welding wire and forming a weld pool (see EN 2198079 C2, VK 9/095, 9/12, 10.02.2003).

The described method, as the closest to the technical essence, adopted for the prototype. However, when implementing this method, it is impossible to synchronize the flow of welding wire to changes in the external characteristics of the power source and to control the timing of pauses and pulses.

The goal is to provide a synchronization pulse welding wire feeding with changes in the external current-voltage characteristics of the power source.

This object is achieved in that in the method of welding, comprising a pulsed supply of welding wire and the formation of swar is the offered bath, the last form on the hard volt-ampere characteristic (VAC) power source (PIS) and increasing WAH arc (L), and the crystallization of the metal of the bath is carried out on the falling WAH FE and rigid characteristic D.

The inventive method is characterized by the following distinctive features:

a) weld pool is formed on the rigid characteristic of FE and increasing WAH D;

b) crystallization of the metal of the bath is carried out on the falling WAH FE and rigid characteristic D.

Conducted research on the patent and scientific literature has allowed to draw a conclusion about the compliance of the way the criteria of patentability of inventions "novelty" and "inventive step", and prototype testing has shown positive results.

The inventive method can be implemented using the device shown in the drawing.

The presented diagram shows a system consisting of six blocks:

1 - power source of welding current.

2 - welding arc with the device switching characteristics of the power supply of the arc;

3 - the registration unit and the signal amplification short-circuit arc welding, this unit allows you to define the moment of separation of the droplets from the wire, that is, to determine the possibility of switching to the external WAH PI;

4 - unit set the duty cycle of the pulses, it is determined by the time education is Finance weld pool and the time of its crystallization;

5 - unit comparison gives permission for using current feedback to enable pause block (4) and gives the command to disable contactor;

6 is a control unit of the power contactor.

For crystallization of the weld pool, it is necessary to reduce the welding current to the minimum possible, and this requires stopping the welding wire and the transition to falling WAH FE and hard WACH Etc. But stop wire should only occur after the formation of the droplets of the metal electrode. All this imposes certain design requirements control system and the necessary synchronization of FE and feeding mechanism.

Therefore, the control scheme introduced unit 5 benchmark welding D 2 and block 3 registration short circuits connected to PI 1 and block 4 set the duty cycle and frequency of low-frequency pulses, which sends a signal to the control circuit of the power contactor KM 6. The main unit in determining the time of formation of the weld pool and its crystallization is a unit of task 4, but the time of crystallization begins only after matching the input signals from blocks 4 and 3 in block 5.

The method of welding, comprising a pulsed supply of welding wire and forming a weld pool, characterized in that the weld pool is formed on the hard volt-ampere characteristic (VAC) power source and ozrastayut WAH arc, crystallization of the metal of the bath is carried out on the falling VAC power source and rigid characteristic of the arc.



 

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