CS267911B1 - Welding unit for resistance welding machines - Google Patents

Abstract

The combined, at least two-point welding unit of resistance welding is intended for work in a welding press, or welding machine, for the production of welded joints by spotting one after the other, with lenses of welded joints at an extremely small distance from each other. This will achieve a better use of the basic strength of the weld material and an increase in the safety of the weld joint as a whole. The essence of the welding unit consists in the maximum possible shortening of the pitch of the welding electrodes, while preserving their straight shape. The shafts of the push rods, welding electrodes, pressure plates of the spring system and dilatation pressure springs are arranged next to each other in such a way that the shaft of one push rod is placed transversally on the inner side of the spring, along with the shaft of the other push rod, while the shaft of one push rod passes through the opening of the pressure plate at a close distance from the shaft of the second push rod. At the same time, the pressure plates and springs are positioned centrally in the same direction with respect to the axes of the rods.

Description

CS 267 911 · 11 1

BACKGROUND OF THE INVENTION The present invention relates to a welding unit for resistance welding machines and to the welding of two welding points.

Doposia! known prior art at least two-point resistance welding having associated welding units that form an integrated unit, or are assembled in frame-like unit units. Welding units full and several functions. As a result of the pressure force of the defined size, the negative effects of the continuously varying thickness of the welded material, the loss of the welding electrode length of the unsuitable setting and the fixture are suppressed, and the welding electrode is fed and supplied. The push rods of the abrasive welding units, used for the above-mentioned actions, are usually equipped with a passive force mechanism, eg a coil spring, which has considerable dimensions, as the pressure applied to the welded place must be large, the stage of the lens, so that the spring reaction plate does not allow further, by production and development of the technology, a reduction in the spacing distance of the welding electrode axes while maintaining their rigidity and dimensions. Recently, new "welding" units have emerged in research and development in which the large parts of the push rods are arranged in a new way to create additional possibilities. The requirements for further reducing the pitch of the welding electrodes persist in particular for the need for welding thin sheets of higher strengths, where even the welded joint is higher strength and lifetime claim.

The principle of the welding unit for resistance welding machines for the simultaneous welding of at least two welding points, fixed to the movable mechanism of the welding press, or the welding machine with the offset arrangement of the passive parts of the mechanism into different planes consisting of at least two welding electrodes, characterized in that one the push rod, each whole pair of push rods passes through the opening of the push plate and the inner side of the spring of the second push rod, wherein the minimum value of the axis pitch of the push rods and the welding electrodes is equal to half the sum of the diameters of the pair of push rods, the weight of the fixed mechanical wall between the pivot shafts of the pushers rods.

The main advantages of at least two-point or three-point, multi-point and multi-point resistance welding power units with extremely small spacing of the welding electrodes, with a powerful movement on a common carrier, or on multiple carriers, or presses, etc., are the ability to create at least two- or multi-point welding tools for welding the matt sheets by overlapping such that by substantially shortening the distance between the court-shaped lenses, a greater number of equally valuable weld units are realized per unit length (width) of the welded joint as has been done with prior art welding units. The team at the same time The specific welding performance and production economy is improving. The ultimate advantage will ultimately result in a higher utilization of the strength of the base material. Higher density of weld points, usually carried out on a single operation, will be carried out on several subsequent operations, while maintaining the unit load of the spot beam, allowing the production of welded joints up to the level of mechanical parameters of the base material. The new resistance welding unit also makes it possible to reduce the weld, which dimensions have been so far! limited by the strength and durability of the welded joint as a whole. The alternation of the electrodes also solves the non-rotating electrodes around their own axis.

FIG. 1 is a cross-sectional view of the overall assembly of a two-point resistive unit; FIG. 2 is a cross-sectional view of a two-point resistive welding unit in place of the pusher rods.

The two-point resistance welding unit consists of a fastening body 2, a carrier, a power electrode, or a ram 1 of the welding press. The welding unit consists

Claims (1)

2, the main body of the pressure plates 5 and the compression springs 2 are opposed to the main body axes of the push rods, whereby the pressure plates 2 against the push rods 6 are lined up in a perpendicular direction to the main body the push rod axis. This lining, together with the pushing of the pressure plates 2, allows one shaft of the push rod 6 to be placed in the opening 7 of the pressure plate 2 of the second push rod 6, thereby substantially reducing the distance of the body push rods coaxial to the welding electrodes 12 connected to the connections 10 by the supply wires. welding with a low point tool has yielded results that have higher values compared to a conventional tool. In case of static tensile stress, one spot weld with 0 5 mm, on a 1 mm thick steel plate with a tensile strength G ^ = 5 N.mm, transmits a force of around 58 N with a failure. The same oscillation, transverse and combined the stresses, including shear, as well as the non-uniform distribution of forces and strains in the stressed cross-section, transfer from about 18 to 35 N with failure. Strips 180 mm wide, welded by a classic double- or multi-point unit with a design spacing of welding electrodes of 50 mm, with individual welding points in the module 15-50-50-50-15 mm, transmits statically tensile force of 232 N with failure, and with combined strain tensile - pressure + fatigue oscillation sf = 50 Hz.s at a level of 700 to 900 kH, perpendicular to the main load forces, averages only 140 N on average. The same belts welded by a low point unit with a design spacing of welding electrodes of 25 mm with individual weld points in module 15-25-about 17 -25 ... etc.-15, together 8 point welds, carried an average static tensile force of 416 N, ie the transferred force to a single point weld dropped from about 58 to about 52 N, which is attributed to the shunt effect. However, the total static tensile force transferred increased by about 80%. With the combined loading described above, the eight-point belts only carried a force of about 248 N, i.e. the transferred force to a single point weld dropped from about 35 N max to about 31 N. However, the average weld-transmitted force increased by an average of 77 N. %. The utilization of the load-bearing capacity of the base material: the load-bearing capacity of the belt is 1 x 180 mm in the static tensile is about 900 N. The density of the weld points from the classical unit gives the weld resistance of the weld in the static tensile strength of 232 N, ergo utilization at approx. 26 while 416 N, which is about 47% utilization of the load-bearing capacity of the base material. Similar is the case of combined retraction, uneven distribution of load forces and life fatigue tests. This tool has opened the way for a higher strength of the weld joint than the joint and the way of better utilization of the materials of higher strengths and it has also allowed to further reduce the dimensions of the welding units and reduce their weight. The use of the invention lies particularly in the production of welded-on thin and high-strength steel sheet and sheet metal stampings, mainly in the automotive and transport industries, in the packaging industry, in the engineering, consumer and electrical industries. OBJECT OF THE INVENTION A welding unit for resistance welding machines for simultaneously welding at least two welding locations, mounted on a movement mechanism of a welding press, or a welding machine, with an offset arrangement of passive mechanism parts into different planes, consisting of at least two welding electrodes, characterized in that one push rod (6) of each pair of push rods (6) passes through the opening (7) of the push plate (5) and the inner CS 267 911 B1 3 of the spring side (3) of the second push rod (6), the minimum pitch value of the push rods (6 ) and the welding electrodes (12) are equal to half the sum of the diameters of the pusher rods (6) raised by the ridge of the fixed mechanical wall between the holes (8) of the shank rods (6). 1 drawing