KR920017758A - Resistance welding method and arrangement for implementation of this method - Google Patents

Abstract

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Description

Resistance welding method and arrangement for implementation of this method

Since this is an open matter, no full text was included.

1 shows a connection diagram of a resistance seal welder having an arrangement according to the invention for adjusting the welding current,

FIG. 2 shows a detailed view of the part of the arrangement according to the invention indicated on line II-II in FIG. 1,

FIG. 3 shows a detailed view of a regulator represented by one block in FIG.

Claims (36)

In a resistance welding method in which pulsations in periodic half-waves are in particular alternating current and have an inrush current generated from the primary alternating voltage and regulated by its pulse wavelength modulation, the primary alternating voltage during the pulse wavelength modulation is A method in which a ping frequency is subdivided into individual half-waves, the frequency of which is multiple of the welding current frequency in order to create a special welding current shape. The method according to claim 1, wherein 20 times the frequency of the welding current is selected as the chipping frequency. The method according to claim 1 or 2, wherein the welding current is controlled in half wave based on the rated value-actual value comparison by affecting the duty ratio according to the pulse wavelength modulation. 4. A method according to claim 3, wherein each half wave of the primary alternating voltage is subdivided n times, n rated values of actual welding current-actual comparisons are made, and the duty ratio is affected n times. The method according to any one of claims 1 to 4, wherein the shape of the welding current can be selected in advance by the rating table. It has a DC intermediate circuit (14c) and generates a first alternating voltage (Up) and transmits it to the welding transformer (16), which is connected to the welding electrodes (10) and (12) of the resistance welder. In an arrangement for carrying out the method as claimed in any one of claims 1 to 5 having one static frequency converter 14 having such a damper 14b as an output stage, An arrangement characterized by such a control device by means of which the chopper can be controlled for multiple chopping of each half wave of the primary variable voltage. In the arrangement according to claim 6 for the implementation of the method as claimed in claim 3, the control device comprises a bumper of the frequency converter 14 for controlling the welding current I by pulse wavelength modulation in front of the first alternating current. 14b) having a regulator 18 having a welding current reference element, and the welding current reference element of the regulator 18 for each of the coiling intervals for comparison with the respective current actual values detected at each of the coiling intervals. And a storage device (52) comprising current ratings corresponding to the shape of the welding current. 8. The amplifier 14b of the frequency converter 14 comprises transistors T ₁ -T _{4 as} circuit elements and free-wheel diodes F ₁ -F ₄ parallel to the circuit elements. Arrangement comprising a bridge circuit having a. An arrangement according to claim 7 or 8, characterized in that a rating table selectable via the input section (W _tab ) is available in the storage device (52) for each desired form of welding current. 10. An arrangement according to claim 9, wherein the lower table is selectable via an adjustable welding frequency input for each welding frequency fs in each rating table in the storage unit (52). 10. An arrangement according to claim 9, wherein a rating table corresponding to the desired shape of the welding current is available for each welding frequency in the storage device (52). The regulator 18 is characterized by the respective current ratings in the table in the arrangement claimed in any one of claims 9 to 11 comprising a PID control circuit 50 having a feed forward loop 60. And a change to the following current rating value is stored and supplied to the output of the PID control circuit 50 as a feed-word value. 13. The storage device according to any of claims 7 to 12, wherein the storage device 52 has a multiplier 54 connected thereto, which multiplier is input via an adjustable current rating input Isoll of the regulator 18. An array characterized by multiplying the facial expression by a selectable factor. 14. Arrangement according to claim 13, characterized in that the multiplier (54) has further inputs which can be input from the welding machine control system (19), in which other factors are manually or superimposed via the input. A resistance welder having the arrangement claimed in any one of claims 6-14. A method for resistance welding with a pulsating current in periodic half waves, more particularly with an alternating current, wherein the welding current deviates from sinusoidal phenomena. 17. The welding current of claim 16, wherein the welding current initially increases to sinusoidal shape after zero crossing, decreases before the sinusoidal peak is reached, and then increases again and then mainly sinusoidal towards zero crossing. Decreasing. 17. The welding current of claim 16, wherein the welding current adopts a process of increasing first, initially at sinusoidal shape, and then repeatedly decreasing after zero crossing, and thereafter decreasing mainly at sinusoidal direction towards zero crossing. Characterized in that the method. 19. The method of claim 18, wherein the welding current follows a process of decreasing and increasing twice, mainly between sinusoidal sections. The method of claim 16, wherein the process of welding current initially increases steeply, then slowly decreases, and then steeply decreases. 17. The method of claim 16, wherein the welding current increases substantially linearly from zero crossings, repeatedly decreases and again increases in the region of peak waves of half wave and then decreases substantially linearly toward zero crossings. 22. The method of claim 21, wherein the process of welding current decreases and increases twice between generally straight sections. 17. The method of claim 16, wherein the welding current follows a triangular process. The method of claim 16, wherein the welding current follows the course of the formulation. 25. The method of claim 24, wherein a change in current of another formulation occurs between shoulders of the course of the longer formulation. The method of claim 24, wherein the current variation of the plurality of similar formulations occurs between shoulders of the course of the longer formulation. The method of claim 16, wherein the welding current initially increases substantially linearly, then decreases substantially linearly and continues to increase, and then decreases substantially linearly again. 28. The method of claim 27, wherein the reduction in current in the halfwave occurs primarily at zero value of the current. 28. The method of claim 27, wherein the reduction in current in the halfwave occurs below zero of the current. 18. The method of claim 17, wherein the reduction in current in half wave occurs to zero. 18. The method of claim 17, wherein the reduction in current in the halfwave occurs below the zero value of the current. 27. The method of claim 26, wherein the current variation of the formulation shape has a higher horizontal section than the interval of said plurality of next or each subsequent variation of variation. 33. The method of any one of claims 16 to 32, wherein the welding frequency is 500 Hz or 250 Hz. 34. Use of the method as claimed in any one of claims 16 to 33 in seam roll welding of lineages. 34. Use of the method as claimed in any one of claims 16 to 33 in spot welding. 34. Use of the method as claimed in any one of claims 16 to 33 in sheet metal blank welding. ※ Note: The disclosure is based on the initial application.