RU1790475C - Method and apparatus for controlling voltage at electric arc welding - Google Patents

Abstract

The invention relates to a welding technique. The method consists in supplying an initial voltage from a power source, the value of which corresponds to the 2 burning voltage of the arc, which is increased, by multiplying it; After that, the voltage is reduced to its original value. The device contains a diode bridge1 rectifier connected to an alternating voltage source and: a VOLTAGE arc unit. New in the device is the introduction of two chokes and two nocfleAOBateflbHO connected capacitors connected to the output of the rectifier, and the common point of the capacitors is connected through one choke to one of the rectifier inputs, one of the individual capacitor leads is directly connected, and the other through the second choke is connected to welding electrodes. 2 ill. with C

Description

The invention relates to welding technology and can be used to generate ignition voltage and stabilize the arc. .

The aim of the invention is to reduce energy loss.

In FIG. 1 shows a current-voltage characteristic for explaining the implementation of the method.

In FIG. 2 is a diagram of an apparatus implementing the method.

A method for controlling the voltage of an electric arc welding is implemented as follows. An alternating voltage is used from the power source, the value Ui (Fig. 1) of which corresponds to the voltage providing the conditions of arc burning, the alternating voltage is rectified, forming the initial constant voltage corresponding to the arc voltage. The initial voltage is then increased using the principle of multiplication and providing conditions for ignition of the arc. The multiplication factor depends on the current parameters, as well as on the current rectification scheme used. One of the optimal modes of multiplication is to increase the initial voltage by a factor of 2–2. After that, the voltage is gradually reduced to its initial value, i.e., the burning voltage of the arc, which ensures its stability. Tavi

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Thus, on the one hand, setting the value of the initial voltage corresponding to the burning voltage of the arc, on the other hand, excluding the multiplication of the voltage during combustion

-arcs, sshchigelno reduce losses er not r. weight affected by the increase in voltage necessary to ensure the ignition conditions of the arc.

An embodiment of an apparatus for controlling the voltage of an electric arc welding is proposed for multiplying by a maximum. -2-2, which contains a two-arm bridge rectifier on diodes 1,2,3,4 (Fig. 2), the bypass of which is connected to an alternating voltage source UBX. The rectifier is equipped with a voltage multiplier containing a chain of two series-connected storage capacitors 5. 6 and two chokes 7,

. 8. Conclusions. The chains of capacitors 5, 6 are connected to the rectifier output, and through the inductor 8 to the 9 volt arc unit. Each of the capacitors 5 and 6 is connected in parallel, for example, by diodes 3, 4, and between the midpoint of the chain of capacitors 5, b

..and the common point of the shoulder of the diodes 3, 4 included the inductor 7; .

The device operates as follows. : -. , .. /; ...-.-....... From the power source, an alternating voltage is applied to the input of the bridge rectifier, the value of which corresponds to the burning voltage of the arc. In idle mode (when there is no load), the voltage is rectified simultaneously with the help of diodes 1, 2 and the charge of capacitors 5, 6, each of which is charged to a voltage of 1) Vx. 2, the charge of capacitors 5, 6 is carried out

through the inductor 7, which ensures the absence of a reactive component when they are charged. Since capacitors 5, 6 are connected in series in series,

then a double voltage is formed at its terminals. In this case, the diodes 3, 4, in parallel with which the capacitors 5.6 are connected, are closed. When the electrode touches the part (ignition mode, i.e., load), the capacitors 5, b are discharged through the node 9 of the volt arc, opening the diodes 3, 4, while ensuring the transition to the bridge half-wave rectifier with voltage, the value of which decreased.

doubled and became equal to the arc burning voltage. The ripple is smoothed out using capacitors 5, 6 and chokes 7, 8, and the efficiency is

"94%. .-..-.

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Thus, the use of the voltage corresponding to the burning of the arc, its increase to the ignition voltage of the arc, achieved due to the energy accumulated about the inductor 7 and the capacitors 5, b - leads to a reduction in energy losses when implementing the inventive method of the proposed device. .-,:;.

PRI me R. A single-phase toroidel was used as a food source. a transformer whose output voltage in one of the welding modes was 21 V. After rectification, it was increased (at idle) using the principle of multiplying by 2 2. times. During arc ignition, the voltage gradually decreases to 21 V. The device used capacitors with a capacity of 0.066 F and diodes with a rated current of 250 A.

The life of the machine is about 5 kW.

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.1. A method of regulating the voltage during electric arc welding, which consists in supplying an initial voltage from a power source, raising the initial voltage to magnitude, and igniting the arc and reducing the voltage to a value of the voltage of the stable burning of the arc, which means that in order to save energy, the initial voltage value is chosen equal to the burning voltage.

2. The method according to p. 1, from l and h a to u and so that the ignition value of the arc is selected

equal to the burning voltage multiplied by a coefficient depending on the frequency and shape of the current, as well as on the current rectification scheme used,

3. An electric arc welding voltage control device comprising a diode bridge rectifier connected to an alternating voltage source, characterized in that. that, in order to save energy, two chokes and two series-connected capacitors are connected to it, connected to the rectifier leads, and the common point of the capacitor is connected through the first choke51790475 6

  ...

Sel to the common point rectified, separately, and the other through the second capacitor terminals, one - not lag, connected to the welding electrodes.

FIG 2

FIG. 1