SU996125A1 - Apparatus for a.c. welding with arc burning stabilization - Google Patents

Description

(5) DEVICE FOR WELDING WITH VARIABLE CURRENT WITH STABILIZATION OF ARC COMBUSTION

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The invention relates to welding production, in particular to devices for welding with alternating current with arc stabilization, and can be used mainly for arc welding with a melting electrode, as well as for argon-arc welding of non-ferrous metals with a non-melting electrode.

U- About

A device for alternating-current welding with arc stabilization is known, comprising a welding transformer connected in parallel to the output of the welding transformer, a complete, j power source with a switch, and a switch control unit made in the form of zero-switch control pulse shapers. Said execution of the control unit in the known device ensures the start of the switch, allows the switch to be started at each change of polarity of the voltage on the arc, which facilitates the re-excitation of the arc at each transition of the welding current through. A disadvantage of this device is that in the event of complete arc extinction and welding transformer going to idle mode, the stabilizing pulses, due to direct connection of the nullorgan to the pulse former, are supplied at zero voltage across the arc gap and the transformer is not able to re-maintain excited arc, which reduces the stability of the arc and the quality of welding.

This disadvantage is eliminated in another known device for welding with alternating current, in which, in addition to the above-mentioned elements, a threshold element is additionally introduced, due to which the control unit of this device also provides control of the switchboard when the arc is completely interrupted. The device allows to increase to some extent the arc stability and the quality of welding. The disadvantage of the known device for alternating current welding is the lack of deep multi-dimensional monitoring of the arc gap and the appropriate programming of the arc stabilizer for various welding transformer operation modes, which makes it impossible to further improve the quality of welding and increase the stability of the AC arc, especially when cooking with floating schimis electrodes. . The purpose of the invention is to improve the quality of welding by providing an opportunity for deeper monitoring of the arc condition. The goal is achieved in that the AC welding device with arc stabilization contains a welding transformer connected in parallel to the output of the welding transformer with an additional power source with a switch and A switch control unit, made in the form of a threshold element, zero-bodies and switch control pulse shapers, an integrator and a time element are introduced the pulse delay, the threshold element and the integrator are connected in series, the input of the threshold element is connected to the output of the welding transformer, and the output of the integrator and the output of the threshold element connected to the input of the integrator are disjunctively separated from each other and conjunctively with the outputs of the zero-organs using the inverse scheme are connected to the inputs pulse shapers, to which the output of the pulse time delay element is also connected. The drawing shows the principal functional scheme of the proposed device for alternating current welding with arc stabilization. The device contains a welding transformer 1, an electrical gap, a digital product 2, null organs 3 and 4, the inputs of which are connected to the output of a welding transformer 1. The device also contains a logic node 5 for electrical connections between the elements of the device, integrator 7, pulse time delay element 54 8, pulse driver 9 and 10, and switch 11. To more fully reveal the electrical connections between the indicated elements of the device and their operation, the wires included in these elements are also included. single and semiconductor elements 12-30. The outputs of logic node 5 are designated by the positions 31 and 32.. The threshold element 6 and the integrator 7 are interconnected in series, their outputs using logic node 5 are disjunctively separated, interconnected and conjunctively with the outputs of the zero-organs 3 and A according to the inverse circuit are connected to the inputs of the formers 9 and 10 pulses, to which are also connected output element 8 time delay pulses. The input of the zero-bodies 3 and the output voltage of the welding. transformer 1. Positive pulses are removed from the outputs of the zero-organs, and the zero-organ 3 generates pulses in the positive half-period of the output voltage of the welding transformer, and the zero-organ in the negative half. The threshold element 6 generates positive square-wave pulses, which coincide with the extremum of each half-cycle of the output voltage of the welding transformer at idle. When welding or short-circuiting the electrode-product 2 circuit, the output voltage of the threshold element 6 is zero. With the help of the integrator 7, the voltage that characterizes the mode of operation of the welding transformer is generated from the output pulses of the threshold element 6, the output voltage of the integrator 7, when idling, is zero, a positive value is in welding or short-circuit. The output voltages of the zero-organs 3 and A, the threshold element 6 and the integrator 7 are fed to the four inputs of the logical node 5. The logical node 5 implements a Boolean function: on output 31, --- 6-ay-e on input 32 ui-dva-e Thus, when welding from the outputs afC and I of the logical node 5, rectangular pulses are removed, similar to the signals of the null organs, which are fed to the formers 9 and 10, triggering them with a negative front. The output pulses of the drivers 9 and 10 turn on the switch 11 stabil. arc burning lysator at each transition of welding current through-zero. At idle of the welding transformer 1, the logic node 5 divides the output impulses of the threshold device 6 into two channels, and the output of the pulses of the threshold device 6 appears on the positive half-period of the output voltage of the welding transformer 1 and on the output U- on the negative . At the same time, the negative edge of the pulses at the outputs of g and a of logic device 5 falls at the moment when the output voltage of the welding transformer reaches the output voltage close to its amplitude value. Automatic shutdown of the arc stabilizer occurs as follows. The output voltage of the integrator 7 corresponding to the idle run of the welding transformer 1 is supplied to the elements 8 of the time delay of the pulses. After 1-2 seconds, the latter turns off the shapers of 9 and 10 pulses, thereby stopping the supply of stabilizing pulses to the arc gap. The implementation of the proposed device is carried out with the help of conductor and semiconductor elements. Using diodes 12 and 13, an artificial average point of the output voltage of the welding transformer 1 is obtained. The positive and negative half-periods of the output voltage of the welding transformer divided into two channels are fed to the zener diodes 1 and 15 - Resistors 16 and 17 set the current to Zener current 1 and 15, respectively. The voltage across the resistors 16 and 17 with respect to the artificial midpoint is equal to the difference between the amplitude of the output voltage of the welding transformer 1 and the voltage. stabilization stabilizers 14 and 15 The pulse voltages taken from resistors 16 and 17 through resistors 19 and 20 are applied to the zener diode 18 and are limited from above. The stabilization voltage of the zener diodes 1 and 15 is chosen so that it is greater than the output voltage of the welding transformer 1 during welding, but less than the output voltage of the welding transformer at idle, i.e. order 50-65 V. The output pulses of the threshold element 6 are fed to the input of logic node 5 and to the input of integrator 7 through diode 21. With the help of the integrating circuit 22 and 23 and the forming element 2k, these pulses are converted to the voltage required for the operation of the logical node 5 performed on the AND-OR-NOT logical elements. The absence of voltage at the output of the integrator 7 leads to cessation of the power supply to the capacitor 26. The condenser begins to discharge through resistors 27 and 28, which after a predetermined time (2-3 s) causes the transistors 29 and 30 to close and the shapers of 9 and 10 to stop working i.e. leads to the termination of the stabilizer. When the arc is re-energized and during welding, the charge of the capacitor 26 is restored through diode 25. Thus, the implementation of an alternating current welding device with arc stabilization, unlike the prototype, allows monitoring the arc condition and, thus, further enhances the quality welding. Invention device for alternating current welding with arc stabilization, comprising a welding transformer, an additional power source connected in parallel with the output of the welding transformer with a switch and a switch control unit embedded in the form of a threshold element, a switch control device characterized by that, in order to improve the quality of welding by providing the possibility of tracking the state of the electrical parameters of the arc, the integration torus and pulse time delay elements, while the threshold element and the integrator are connected in series, the input of the threshold element is connected to the output of the welding transformer, and the output of the integrator and the output of the threshold elements connected to the integrator input are disjunctively separated from each other and conjunctively with the outputs of the null organs in the inverse circuit are connected to the inputs of pulse shapers, to which the output of the element of the time delay of pulses is also podklolochen. Sources of information taken into account in the examination 1. USSR author's certificate N 60352L, cl. At 23 K 9/06, 25.07-73. 2. USSR author's certificate number 653051, cl. At 23 K 9/06, 03.10.75 (prototype).

Claims (1)

Claim A device for welding with alternating current with stabilization of the arc burning, containing a welding transformer, an additional power source connected to the output of the welding transformer connected to the commutator with a commutator and a commutator control unit, made in the form of a threshold element, null organs and pulse generators of the commutator control, characterized in that, in order to improve the quality of welding by providing the possibility of monitoring the state of the electric parameters of the arc, an integrator and elements of temporary th pulse delay, while the threshold element and the integrator are connected in series, the input of the threshold element is connected to the output of the welding transformer, and the output of the integrator and the output of the threshold elements connected to the integrator input are disjunctively separated from each other and conjunctively with the outputs of the null organs in the inversion circuit connected to the inputs of the shapers They have 996125 8 pulses, to which the output of the element of time delay of them · pulses is also connected.