CONTROL SYSTEM OF THE DOSED ELECTRON WIRE FEED IN THE MECHANIZED ELECTRIC ARC WELDING

Abstract

The paper deals with the control problem developed in the E.O.Paton Institute for Electric
Welding by a new method of pulsed arc welding process, which uses the principle of dosed feeding of
electrode wire on the basis of information on the varying parameters of arc combustion. The electrode wire
is supplied by a high-speed computerized electric drive using a specially designed valve motor of an
optimized design.
Recently developed a new method of arc welding with pulse feed of an electrode wire is a metered feed,
which is carried out using current or voltage feedbacks of the arc process. In this case, the control pulse is
formed according to the selected (set) two levels of current or voltage and is processed by a computer
control system.
However, when implementing the control of the welding process with dosed feeding of electrode wire
and some other processes of arc mechanized and automatic welding and surfacing, problems arise for
further improving the speed of the electric drive.
In this paper, it is proposed to use a method of predictive control of arc welding with a dosed by the
parameter of the arc process by feeding the electrode wire to improve the performance of the controlled
electric drive of the feed mechanism.
The oscillograms of the welding process - surfacing with the identification of specific (characteristic)
sections of current and voltage changes, the possibility of their linearization for selecting control parameters
for the electric drive controller of the feed mechanism are considered.
A variant of the regulator structure for the electrode wire feeding system of the mechanized welding
equipment is determined using feedback signals on the parameters of the arc process.
Comparative oscillograms of the speed of impulse movement of electrode wire, as well as weld beads for
different variants of construction of the regulator of the electric drive are given. The positive effect of the
new regulator on the characteristics of the arc process is noted.
The work contains references to a number of works on the basis of which the developments described in
the article are fulfilled.
Key words: mechanized welding, dosed feed of electrode wire, transfer of electrode metal, electric drive,
electric motor, regulator and control system, efficiency.