SU1556835A1 - Method of surfacing cylindrical parts - Google Patents

Abstract

The invention can be used in the restoration of machine parts, in particular in the restoration of the necks of the crankshafts by welding. The purpose of the invention is to improve the quality of the cladding by reducing the heating temperature of the parts and increasing the productivity by placing and attaching the protective sheath to the parts. The parts being repaired are wound onto a surface being repaired by current or other means prior to the onset of plastic deformation, which is fixed by welding or mechanically to the part at the beginning and at the end of winding. After cooling of the protective wire sheath, tightly enveloping the surface being repaired, surfacing is carried out with the same or another wire. The shell is pressed against the part by cooling the shell before overlaying. 1 hp f-ly.

Description

The invention relates to the repair of machine parts, in particular to the welding of crankshaft journals.

The purpose of the method is to improve the quality of the cladding by reducing the heating temperature of the part and increasing the productivity by simplifying the placement and fastening of the protective sheath on the part.

The method of surfacing cylindrical parts on the protective shell is that the protective shell is placed on the restored surface, pressed against the latter and fixed at the ends, and then the surface is welded over the shell, while the protective shell is formed by winding on the part heated before plastic deformations wire, which is welded to the parts at the beginning and end of winding.

Electric wire heating is optimal, although other methods of heating are also possible, such as a gas burner flame.

The formation of a protective sheath by winding on the weld surface of the wire allows to simplify the method of surfacing and increase productivity. This method does not require additional tools for clamping the shell to the surface of the part and welding at the ends, since tight clamping of the wire shell is provided by winding the wire heated before plastic deformation and selecting the rotational speed of the part. At the beginning and end of the winding, welding current is passed through the wire, welding it at the ends to the part. In the process of winding, a current is passed through the wire, sufficient to heat the wire before the onset of plastic deformation. After cooling, the wound wire sheath is reliably crimped around the surface of the part due to internal stresses in the wire previously stretched during the winding process with tension. Shell Formation Speed (Coiling Speed)

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SP

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SP

limited only by the technical characteristics of the installation (maximum rotational speed of the part) and is quite high, which increases the performance of the surfacing.

During surfacing, heat is transferred to the part through a protective sheath made of wire, the contact between which and the part is along a helix. Efficiency of heat transfer through the line, electric wire (B) was passed through the wire, heating it up to the beginning of plastic deformation. At the beginning and end of the winding, the wire was attached to the part with welding. After cooling, the parts were made by surfacing with the same wire using a known technology. Cracks and pores in the directional metal were not observed. After surfacing, the shaft buckling increases slightly. So, at crankshafts with a beating

this reduces the heating temperature of the part and the magnitude of thermal stresses and reduces the distortion, increasing the quality of the cladding.

The beat of the middle root neck increased to 0.20 mm after surfacing of the crank neck, and the middle root beat beat. extreme at surfacing of rounding necks increases from 0.1 to 1.0 mm

The wire, from which they form obo- and more, when used as a sheet, is fastened to a part, for example, the protective sheath of a metal tape — by welding or mechanically, and then with a turn of up to 0.5 mm).

In this way, the wire is wound. Using this method, it is possible to weld the surface, and the quality of the weld is increased to 20, which increases the wire before plasticizing the life of the part by 20-30% due to comparable deformation. through her electric current. After the sheath is formed, the wire is attached to the part with a second end. Then, surfacing of the restored surface is carried out on the already formed protective sheath in the traditional way. For the formation of the sheath, the same wire can be used as for the cladding, or other, to improve the quality of the cladding 30 and to obtain special properties. Example. Restored the main and connecting rod necks of cast iron crankshafts

with known, and also improves the performance of the deposition.

Claims (2)

1. A method of surfacing cylindrical parts over a protective shell, mainly crankshafts, in which the shell is placed on a restored surface, is pressed tightly against the latter and fixed at the ends, after which the surface is welded over the shell, characterized in that, in order to improve the quality and surfacing performance, the shell is formed by winding, heated to ZMZ-53 engine overlay weld flux on the protective sheath. Surfacing root necks were carried out on the installation of the beginning of plastic deformation of the wire, U-653, the rod - 011-1-UN. Oba-and the pressing of the shell is carried out by The blade was formed by winding the wire before cooling. ZOHHGSA with a diameter of 1.6 mm on rotating 2. The method according to claim 1, wherein common detail (the speed of rotation is that the wire is heated, the passes 20 rpm). When forming the shell through it, the electric current. An electric current (B) was passed through the wire, heating it before the onset of plastic deformation. At the beginning and end of the winding, the wire was attached to the part by welding. After cooling, the parts were made by surfacing with the same wire using a known technology. Cracks and pores in the directional metal were not observed. After surfacing, the shaft buckling increases slightly. So, at crankshafts with a beating after the overlaying of the connecting rod necks, the middle root neck of the middle root neck increased to 0.20 mm of the middle root neck beat (when surfacing without a protective sheath, the middle root neck beat of the extreme root neck of the rod ends increases from 0.1 to 1.0 mm does not improve the quality of welding, which increases the service life of the part by 20-30% compared to with known, and also improves the performance of the deposition. Invention Formula t to improve the quality of the welding, which increases the service life of the part by 20-30% compared to 1. A method of surfacing cylindrical parts over a protective shell, mainly crankshafts, in which the shell is placed on a restored surface, is pressed tightly against the latter and fixed at the ends, after which the surface is welded over the shell, characterized in that, in order to improve the quality and surfacing performance, the shell is formed by winding, heated to