SU1466896A1 - Method of friction welding of hollow part with a blank plug - Google Patents

Abstract

The invention relates to methods of friction welding of hollow parts with plugs. It m. B. used for welding hollow cylindrical parts, such as pipes, as well as holes in body parts. The goal is to simplify the design of the machine for friction welding. The blank of the plugs supplied to the welding zone is made as an element with successively alternating large and small sections, with a large section being carried out in accordance with the dimensions of the plug. The blank of the plugs is installed in the rotated cartridge, the welded surfaces are brought into contact, the heating and forging are carried out. After that, the welded parts were not unfastened, the rotational drive was switched on for a short time. There is a mechanical destruction of the workpiece in a smaller section. When implementing the method, no special clamping devices are required to fasten plugs having a small thickness. 3 il.

Description

The invention relates to the welding of metals by friction and can be used for welding hollow cylindrical parts, such as pipes, as well as holes in body parts.

The purpose of the invention is to simplify the design of a friction welding machine by eliminating special clamping devices for blanking blanks.

FIG. 1 shows a blank of friction welding plugs for a hollow cylindrical part, for example a pipe; in fig. 2 - the same, in the case of friction welding of the ends of two pipes concentrically arranged one inside the other (construction of heat exchanging equipment); in fig. 3 - scheme of welding holes in the body parts (plug is welded to the part).

Blanks for the implementation of the method are made in the form of a rod with successively alternating sections of large D and small d diameters. The length L of the section - with a diameter D - corresponds to the thickness of the plug 1, and the length / section - with a diameter d - depends on the method of manufacturing the workpiece. In the case of using a blank for welding the ends of two pipes 2 n 3 concentrically arranged one inside the other, it is made with an axial bore with diameter d equal to the conditional passage D ,, of pipe 2 of smaller diameter. The blank can also be used for welding holes in the body part 4.

Friction welding is performed as follows.

The hollow cylindrical part 5 is secured in a clamp of a non-rotating part (not shown), and the blank blanking is secured in a collet chuck 6 associated with a rotational drive, with the workpiece protruding from the cartridge by an amount equal to the sum of sections of large D and small d diameters. Enter t

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Oi O5 00 (05

the surfaces to be welded in contact, the workpiece is informed by rotation with the application of an axial heating force, and then, after braking and forging, did not break off the welded parts, the rotational drive is switched on for a short time. When this occurs, the mechanical destruction of the workpiece in a smaller section. Then, detachment and unloading of the part with Livrivia plug 1 is carried out, and the plug of the plugs is interleaved by a step equal to the sum of the lengths of sections of large D and small d diameters using known feed mechanisms. Very important for the implementation of the method is the calculation of the small diameter of the workpiece. : The method of friction welding was tested by welding samples of pipes from steel 45 with a diameter of 40 mm and a wall thickness of 2.8 with a variable cross-section rod made of steel 45; The largest diameter, mm, 8, mm, Smaller diameter, 5 mm,, 5 mm (to ensure the separation of the plug at the point of its con- tact with a smaller section, the latter can be made cone-shaped). Welding was carried out on the machine welding friction MST-2001.

The calculation of the small diameter d of the workpiece was made on the basis of the strength

M, W, r,

where .D4k is the maximum torque allowed for the equipment to be welded; Wy, is the moment of resistance of the continuous section shaft with a torsion of 0.2d-.

Since, 0-: kg / cm, where / V is the drive power of rotation, kW; n is the speed of its rotation, then for the desired cross section

.

where A is a coefficient depending on the value of the permissible torsional resistance TL.

Since for steel at 20 kg / cm, 4, then, taking into account the safety factor, we overestimate m to 90 KG / CM and by the interpolation method we find, 1.

Then the required calculated diameter is

 1D / 5

, lV.

Thus, WK resistance moment

The cross section of a small diameter d to be destroyed will be certainly less than the maximum torque / L allowed for the equipment to be welded.

5 Dt MST-2001 rotational drive power kW, rotation speed n 1000 rpm 10.6 mm.

Welding is performed under the following modes: heating force of 3.8 kgf / mm; hammering force 7.0 kgf / mm; machine welding time 12 s.

1 second after the completion of the forging, the rotational drive is switched on (in the adjustment mode). There is a mechanical destruction of a smaller billet diameter, after

5 of which, the pipe with the certified end and the blank blanking is fixed.

When implementing the method, no special clamping devices are required to fasten plugs having a small thickness.

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Claims (1)

Invention Formula The method of friction welding of a hollow part with a plug, in which the billet blank is supplied to the welding zone, each plug is separated from the billet and 2 forging, characterized in that, in order to simplify the design of the machine for friction welding by eliminating special clamping devices for blank blanking, the blank is made as an element with successively alternating Large and small sections, wherein a large section is carried out in accordance with the dimensions of the plug, and the separation of the plug from the workpiece is carried out after forging by applying a torque to the workpiece. U ////// L U77 // ////. P5 | // //// ll 1G tt If / - / / Phie.1 .2.