RU2480315C1 - Device for electric contact welding - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention may be used in reconditioning and hardening of parts by roller electric contact welding with the help of ultrasound oscillations, as well as in roller welding of helical seams. Roller electrode loading mechanism allows creating permanent filler-to-blank hold-down force. System to excite ultrasound oscillations in workpiece comprises HF electric oscillations in workpiece and, at least, one electric oscillations-to-ultrasound oscillations converter connected to workpiece clamping mechanism to excite longitudinal oscillations therein. Said mechanism is equipped with two thrusts to clamp workpiece there between.

EFFECT: higher quality of welding.

4 cl, 1 dwg

Description

The invention relates to welding production, in particular to devices for roller contact welding with the introduction of ultrasonic vibrations, and can be used in the restoration and hardening of parts, as well as in roller welding of spiral seams.

A device for electrical contact welding is known, comprising a welding transformer, two electrodes, an electrode compression drive and an ultrasonic vibrations excitation electrode system, including an ultrasonic generator and two ultrasonic vibrations transducers connected to it, each of which is connected to its electrode (see USSR copyright certificate No. 1320031 according to class B23K 11/12 dated 06/30/1987). This device can also be used for welding filler material during the restoration or hardening of parts. The known device requires matching the frequency of the introduced ultrasonic vibrations with the frequency of the longitudinally transverse vibrations of the welded parts, which significantly complicates the configuration of the device for welding specific parts. The transmission of ultrasonic vibrations through the electrodes also imposes restrictions on the design of the electrodes and the compression drive of the electrodes. This device can also be used for welding filler material during restoration or hardening of parts, but when welding filler material, ultrasonic vibrations will be transmitted to the part through a layer of filler material, which has low acoustic characteristics, which reduces the efficiency of use of ultrasonic vibrations in electrical welding of filler materials . In addition, when ultrasonic vibrations are applied to the electrode, their efficiency decreases due to the presence of a pneumatic electrode compression system.

The objective of the invention is to develop a device for electrical contact welding with improved welding quality of filler material, which excludes the influence of the acoustic characteristics of the filler material on the process of electrical contact welding of filler material using ultrasonic vibrations.

To solve this problem, a device for electrical contact welding is proposed, which contains a mechanism for fixing the workpiece, two electrodes in contact with the workpiece, actuators for pressing the electrodes to the workpiece, a welding transformer and an ultrasonic vibration excitation system for the workpiece, which includes a generator of high-frequency electrical vibrations and at least one transducer of high-frequency electric vibrations to ultrasonic vibrations, with a mechanism for fixing the workpiece and exciting longitudinal ultrasonic vibrations in it.

In addition, the mechanism for securing the workpiece is equipped with two stops for fixing the workpiece between them, and this at least one transducer of high-frequency electric vibrations into ultrasonic vibrations is connected to at least one of these stops.

In addition, the ultrasonic vibration excitation system is equipped with yet another transducer of high-frequency electric vibrations into ultrasonic vibrations connected to another of the mentioned stops.

Preferably, roller electrodes are used in the device.

The invention improves the quality of electrical welding of filler material.

This technical effect is achieved by the fact that ultrasonic vibrations are superimposed on the fixing mechanism of the workpiece (restored) in the longitudinal direction with a constant fixed compression force. When exposed to ultrasonic vibrations on the welded surfaces, dry friction occurs. Moreover, on the surfaces to be welded, oxide films and films from adsorbed gases and liquids are destroyed. After the appearance of such a freshly formed metal surface, free of oxides and other contaminants, a direct welding of the filler material or welding of the elements to be connected takes place. The cleaning of the surfaces is greatly facilitated by the small amplitude of the vibrations of the rubbing surfaces, the reciprocating nature of these vibrations and the constancy of the effort to compress the filler material to the surface of the part.

The drawing shows a diagram of a device for electrical contact welding, illustrating the invention with respect to welding of filler material.

The device for electrical contact welding is designed to weld filler material 1 deposited on the surface of the part 2, so that the surface of the filler material is the outer surface of the workpiece. The device comprises a mechanism for fixing the workpiece, which includes two stops 3, between which the workpiece 2 is placed, roller electrodes 4 with a loading mechanism 5 for pressing the roller electrodes 4 to the outer surface of the workpiece and moving them along the workpiece. The roller electrodes 4 are connected to the welding transformer 6. The device for electrical contact welding contains a system for exciting ultrasonic vibrations in the workpiece, including a generator of high-frequency electric vibrations 7 and two transducers 8 of high-frequency electric vibrations in ultrasonic vibrations connected to the stops 3 of the mechanism for fixing the processed product and longitudinal ultrasonic vibrations exciting them.

The drawing shows that both stops 3 are equipped with transducers 8 of high-frequency electrical vibrations to ultrasonic vibrations, however, for a specialist it is clear that you can use one transducer 6, which can be mounted on either of the stops (right or left), or the mounting mechanism can only have one attachment point, for example a clamp, equipped with one transducer of high-frequency electric oscillations into ultrasonic vibrations.

In this invention, it is possible to use an electromagnetic transducer of high-frequency electrical vibrations to ultrasonic vibrations, as is done in copyright certificate No. 1320031, but you can use magnetostrictive, electrostrictive or piezoelectric transducers.

The present invention does not consider the design of the loading mechanism 5, since the design of the loading mechanism does not directly affect the welding process and any known device of this purpose can be used.

Device for electrical welding works as follows.

The filler material 1 is clamped between the part 2 and the roller electrode 4 by means of a loading mechanism. The filler material can be steel, sintered or powder polymer belts, steel wire, metal powder. Then, the rotation drive of part 2 (not shown), the generator 7 of high-frequency electric oscillations, transducers 6 of high-frequency electric oscillations to ultrasonic vibrations, a welding transformer 6 are turned on, and welding of filler material 1 to part 2 along a helical line begins. The roller electrodes 4 by means of the loading mechanism 5 are pressed against the part 2 and, due to the friction force, rotate in the direction indicated by the arrows. The advantage of this electrical contact welding circuit over analogs is that in this circuit ultrasound is applied directly to the part 2, to which the filler material 1 needs to be welded, which ensures the most efficient use of ultrasonic vibrations, as they pass through the chain: stop - part - filler material - roller electrodes, and in this case it is possible to excite in the part and, accordingly, at the boundary the surface of the part - filler material, forced ultrasonic vibrations from any pilots at an amplitude vibrations, avoiding the electrodes pneumatic compression system.

Claims (4)

1. A device for electrical contact welding of filler material to the surface of the part, comprising a mechanism for fixing the workpiece, two electrodes in contact with the workpiece, an electrode loading mechanism configured to provide a constant force to compress the filler material to the workpiece, a welding transformer and an ultrasonic excitation system oscillations in the workpiece, including a generator of high-frequency electric oscillations and, at least One transmitter high-frequency electric oscillations in the ultrasonic vibrations coupled to the mechanism for fixing the workpiece with the possibility of excitation in the product longitudinal ultrasonic oscillations. 2. The device according to claim 1, characterized in that the mechanism for securing the workpiece is equipped with two stops for securing the workpiece between them, and the transducer of high-frequency electric vibrations into ultrasonic vibrations is connected to one of these stops. 3. The device according to claim 2, characterized in that the excitation system of ultrasonic vibrations is equipped with an additional transducer of high-frequency electric vibrations into ultrasonic vibrations connected to another of the mentioned stops. 4. The device according to any one of claims 1 to 3, characterized in that it contains roller electrodes as electrodes.