SU519299A1 - Resistance welding machine - Google Patents

Description

(54) CONTACT WELDING MACHINE

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The invention relates to the field of electric welding and can be used in electronic engineering, in instrument making and in other industries of the industry when performing spot-contact welding of parts of small thickness and diameter.

One of the main conditions for obtaining high-quality electric contact welding of parts of very small thickness and diameter (micro-objects) is the small amount of contact pressure (or contact force) that is created by the welding electrodes on the parts to be welded at the time of welding. Only with sufficiently small and stable contact forces, the deformation and disintegration of the micro-objects being welded is inadmissible.

When creating and maintaining small contact forces, electric contact force controllers are introduced into the electric welding apparatus.

Welding apparatuses are known that contain welding electrodes, a source of welding current and a contact welding force regulator.

In these devices, the welding current is switched on by means of a microswitch when a certain amount of contact force is reached, which is provided by the force controller.

The main disadvantage of the known electric contact welding machines with adjustable contact force is the inability to provide small efforts, due to the complexity and cumbersome structures of the elastic systems of regulators, as well as the fact that the microswitch is springing is part of the elastic system of the controller. Another disadvantage is the low reliability of the controls :: s due to the wear of the microswitch of the bodies and elements of the elastic system of the controller.

The aim of the invention is to improve the quality of welding microobjects.

This is achieved by the fact that the contact force regulator is made in the form of a mechanotronic converter (mechanotron), on the movable pin of which one of the welding electrodes is fixed, and the circuit of the source of welding current is electrically connected to the output chain of the mechanotron.

Claims (1)

FIG. 1 schematically shows an apparatus with a mechanotron and a pedal drive; in fig. 2 - the same, with the manual welding tool; in fig. 3 - welding tweezers with mehanotron; in fig. 4 is a circuit diagram of an apparatus with a mechanotron; in fig. 5 given output characteristic ks; aiotron. On the movable pin of the mechanotron 1 by means of the dielectric sleeve 2 and the screw 3, the movable welding electrode 4 is rigidly fixed (Fig. 1). The pin of the mechanotron is a part of a rod hardened into the membrane, on the inner end of which the movable electrodes (anodes) of the mechanotron are fastened. Another welding electrode 5 is connected by a sleeve 6 and a nut 7 to the housing 8, inside which the rod 10 moves in the guide sleeve 9, which is driven by the pedal of the welding machine (not shown). The mechanotron 1 is fastened with a screw 11 in the block 12, which is rigidly connected to the rod 10 through the platform 13. The gap between the mechanotron pin and the block is chosen sufficiently small, which limits the stroke of the mechanotron and protects the latter from accidental overloads. The spring 14, working on the slatsie, ensures the return of the rod to its original position during operation of the welding machine. The power of the mechanotron and the measurement of its signal is provided by the power supply unit 15. The device is equipped with a source of welding current 16, which is connected to electrodes 4 and 5 by means of flexible wires 17. The device with a hand tool (Fig. 2) contains a mechanotron 18, on the movable pin of which one of the welding electrodes 21 is strengthened by means of a dielectric sleeve 19 and screw 20. The mechanotron 18 is mounted in a small-sized case 22, which, when operated, is in the hand of the installer. Two screws 23 are installed in the housing 22, limiting the movement of the mechanotron pin and thereby preventing the latter from breaking in case of accidental overloads. Another welding electrode 24 is mounted directly on the welding table 25. The welding current is supplied to the electrodes 21 and 24 using flexible wires 26. During the welding process, the parts to be welded are installed on the electrode working surface 24 and then pressed by the hand tool electrode 21. The welding tweezers (Fig. 3), which allow welding of micro-objects in hard-to-reach places, consist of a mechanotron 27, on a movable pin of which, using a dielectric sleeve 28 and a screw 29, one of the welding electrodes 30 is fixed. The mechanotron is mounted in the housing 31. Another welding electrode 32 is connected to the housing by a spring hinge 33. A flat spring 36 is attached to the outer surface of the housing 31 by gaskets 34 and a screw 35, which is provided with a dielectric tip 37, which contacts the welding electrode 32. Tweezers, the installer presses down on the spring 36 and brings the electrodes 30 and 32 in contact with the parts to be welded. The welding current is supplied to the electrodes 30 and 32 by means of flexible wires 38. The proposed device with a pedal drive works as follows. On the fixed electrode 5 (Fig. 1) install the welded parts, for example, two microwires. By pushing the pedal, the rod 10 is lowered. The mechanotron 1 with the electrode 4 fixed on its pin also moves downwards. Then, electrode 4 is brought into contact with the parts to be welded. Further non-displacement of the electrode 4, which rests on the parts to be welded and the electrode 5, leads to tension in the membrane of the mech- apron and to the occurrence of contact force on the parts to be welded. The membrane of the mechanotron in this case plays the role of a sensitive dynamometric spring, the transforming force created at the end of the pin of the mechanotron, in the movement of its moving electrodes. This displacement of the electrodes causes a change in the anodic currents of the mechanotron and its output signal. The electrical circuit of the apparatus with the mecha- pron is a measuring bridge (Fig. 4), the shoulders of which are formed by the resistances of two interelectrode gaps of the mechanotron 1 and the anode loads 39, 40. The source 41 of the anode power supply is connected to one of the bridge diagonals, and the other is connected to the output anode 41. a circuit consisting of resistors 42 and 43. The output signal (output) of the mechanotron is fed to the relay coil 44, the contacts of which are included in the primary winding of the welding transformer 45 of the welding current source. The mechanotron is pre-calibrated, i.e., the dependence of its output signal on the force generated at the end of the mecha- pron probe is determined. Therefore, the contact force created on the parts to be welded during the operation of the described apparatus causes the appearance of a certain mechanotrope output signal. When this force reaches a predetermined magnitude, such an output of the mechanotron is sufficient to trigger the relay of power supply unit 15. At the same time, the relay contacts close the welding current circuit, and a current pulse passes through the parts to be welded. In this case, the simplest scheme of the welding current source without a regulator of the duration and magnitude of the current pulse is shown. In the source of welding current using a tiratron or dinistor regulator, the mechatronic circuit is connected to the grid circuit of the tyranon or emitter circuit of the dynistor. However, it avoids contact relays. Claims of resistance welding machine, containing welding electrodes, welding current source and contact cooking force regulator, characterized in that Improving the quality of welding of micro-objects, mainly microwires, the contact force regulator is made in the form of a mechanotronic force transducer (mechanotron), on the movable pin of which one of the welding electrodes is strengthened, and the source of the welding current is electrically connected to the output chain of the mechanotron. 32 31- / / „, 36fu jj 38 W n / 1b 18 20 22 g 26 28 30 Vui.S