SU1462609A1 - Method of electric-arc welding with arc gap shorting - Google Patents

Abstract

The invention relates to the welding industry, and, in particular, to the equipment dp of elaciated arc. arc welding with short-circuits of the arc gap, and can be used in automatic and semi-automatic welding with direct current. The goal is to improve the quality of the welded joint by optimizing the welding process during short-circuiting moments. The arc is powered from a source with an increasing external characteristic. Remember that in the arc of a short circuit, during a short circuit, the arc is powered by a steeply falling external characteristic of the source. After the short note and set the initial tension. The system of automatic regularizing restores the voltage for the given feed rate of the welding cable; This reduces the spatter of the electrode metal and increases productivity. 2 Il.

Description

The invention relates to welding production, and, in particular, to equipment for electric arc welding with a melting electrode with a short circuit of an arc gap, and: can be used in automatic and semi-automatic welding with direct current.

The invention is an improvement in the quality of the welded joint by optimizing the power of the welding arc during its short circuit.

FIG. Figure 1 shows the external characteristic of the power supply; in fig. 2 is a block diagram of an apparatus for implementing the method.

On fkg. 1 ABDE points characterize the external characteristic, the power source, taking into account its fracture PE.

Lili AD is the line of the statistically optimized external characteristic of the arc with its nonworking ranges and DDj (the limited range), the BD line is the specified range of the welding modes.

to

 jMftf, l.aut) for example to the point k, 25 wires V arc voltage and, at the destabilization mode of weld- J. U ..

In the range of BD operating modes, we choose the operating point C, which corresponds to the voltage and arc current Ug, and the presence of a short pulse due to an instantaneous decrease in voltage; the working point C and the corresponding voltage J un ° with this voltage are naturally occurring. the process of short-circuiting starts and ends with the transition of a drop of liquid metal of an electrode and a weld pool and with repeated ignition of an arc at point C. Every other operating point on the BD line will be provided with an optimal welding current. LfTetanus process moments zamnsany short arc gap.

If the welder, breaking the specified welding mode (typical for semi-automatic welding), increases the wire feed speed, goes beyond point D (C due to

If it is turned out, it will return to the specified range of the BD op-ss modes.

As the npiwiepa of the practical implementation of the welding method, let us consider a block diagram of the device in FIG. 2. The device contains a multipoint DC power supply 1, in series with which it is included. Controller 2 of welded current on semiconductor elements with a pulse converter 3, output filter 4 with pact 5 in the welding arc circuit, and also control block 7 consisting of current feedback nodes 8 and voltage 9 of the arc, nodes 10, 11 forming the external optimized characteristic of the controller, to the tarator 12, the arc voltage memory unit 13 at the operating point, which includes the key 14 and the proportional-integrating controller 15, as well as the flashline modulator 16 with resistors 17 range settings are possible to weld modes.

The device works as follows,.

When welding, by adjusting the wire feed rate of the welding wire, the US selects the mode on the increasing optimized external characteristics with a working point, on the

measures C (Uac S ac S of Fig. 2), which corresponds to the output voltage. C of the regulator J- and ILc In the statistical mode, the signal is feedback from the arc current, removed from shunt 5 and multiplied by the slope factor

K-la, summed with the reference and

and

ten

compared with the real voltage of the UL arc in the accumulators of the external characteristic formation 10,11 In the case of desaturation signals through the closed key 14 S is supplied to the proportional 15 ny integrating regulator 15, Re l tor 15 with an acoustic zero error through the gyrotherm the pulse modulator 16, the output of which is connected to the pulse converter 3, fulfills the signal of dissipation

20

owl and

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The system of automatic regulation of vanip restores the welding speed that is optimal for a given feed rate.

35

In the dynamics, at the beginning of a short lock and instantaneous reduction of the arc arc, the signal from the node 9

When connected to the voltage of the arc, it goes to the comparator 12, With the UPKZ K, the specified reference short-circuit voltage to the parator 2 is activated and gives the control signal Uy. the key 14 of the memory block 13 is opened. The proportional-integrating controller 15, in the absence of an error signal, becomes either a memory cell and

jj gives the conditions for remembering the arc voltage and „If Uuj, at the operating point on the static optimized external characteristic. The power supply of arcs during a short circuit occurs on the natural flow

characteristic under the voltage J. V which will be optimal for each operating point in the range of operating modes on the VO line,

At the end of the short circuit and the instantaneous increase in voltage, the key 14 is closed and the control system is closed and the control system continues to operate the lfepOTHo-pulse modulator

gg et resistor 17, by which it is possible to limit the duty cycle of the ifM pulses of welding current at a given maximum level, for example, as at point D (C,. 1 "

may - make /

SO

1 462609

measures C (Uac S ac S of Fig. 2), which corresponds to the output voltage. C of the regulator J- and ILc In the statistical mode, the feedback signal on the arc current, removed from shunt 5 and multiplied by the slope factor

K-la, summed with the reference and

and

wire V arc voltage and „„ J. U ..

is compared with the real voltage of the UL arc in the accumulators of the external characteristic formation 10,11. In case of error signals through the closed key 14 S goes to the proportional integrating regulator 15, the regulator 15 with acoustic zero error through the gyrotto pulse the modulator 16, the output of which is connected to the pulse converter 3, executes the signal mismatch

owl and

R

The automatic adjustment system restores the optimum for a given welding feed rate.

five

In the dynamics, at the beginning of a short-circuit and instantaneous reduction of arc voltage, the signal from the feedback node 9 on the arc voltage is fed to the comparator 12, With the UPKZ K the specified reference voltage, short-circuit voltage, the comparator 2 is activated and raises the control signal Uy. on the opening of the key 14 of the memory block 13. The proportional-integrating controller 15, in the absence of an error signal, becomes a memory cell and creates the conditions for storing the arc voltage and "If Uuj, at the operating point C on a static optimized external characteristic. The power supply of the arcs during a short circuit occurs on the natural supply

characteristic under the voltage J. V, which will be optimal for each operating point in the range of operating modes on the VO line,

At the end of the short circuit and the instantaneous voltage increase, the key 14 is closed and the control system is closed. The lfepOTHo-pulse modulator has a resistor 17, through which it is possible to limit the duty cycle of the welding current atM at a given maximum level, such as at point D (C 1"

may - make /

/

O

(Fig. I) A further increase in the wire feed speed, despite the mismatch Ua " -U " will result in a fracture of the optimized increasing external characteristic into the natural steeply falling arc voltage jMaKt Uun, the welding mode does not stabilize, you need to return to range possible welding modes BD.,

The welding method can replace manual metal arc welding with stick electrodes and conventional automatic and semi-automatic welding in CO with arc power from a direct current source of single-station or multi-post. With a semiconductor controller, which have external steeply dipping, low-pressure and optimized ones. specifications . Compared to these; welding methods, the proposed method, U62609

sob provides high quality

welding, labor.

performance improvement

Claims (1)

Invention Formula A arc-arc welding process with arc short-circuits, in which the welding arc is powered from a power source with an increasing static external characteristic, is due to the fact that, in order to improve the quality of the welded joint by optimizing the welding process during short chambers - Cani, remember the arc voltage before the start of the short circuit, during the short circuit the power source has a natural steeply dipping external characteristic, and at the end of the short circuit Ani arc voltage is set to voltage before the short circuit. ABOUT 9c Phage.1 I-l Editor T, Loshkareva Compiled by, Gribov Tehred A. Kravchuk Proofreader H, King Order 4673 / Circulation 498 VINILI of the State Committee for Inventory and Discovery under the State Committee on Science and Technology of the USSR 113035, Moscow, 4/5, Raushsk nab II11M | D Shi, -i 13 Uf a I , , ..J Subject