RU2467848C1 - Method of contact butt welding by fusion of round cross-section parts with subsequent removal of flash - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention may be used in contact butt welding by fusion at special welding machine of drawing shops for enlargement of wire coils. Ends of parts are cut, butted and clamped in moving and fixed electrodes with hard alloy half-sleeves with cutting edges made on opposite sides. Said half-sleeves are arranged with shift of vertical plane of cutting edges by amount exceeding the width of fillet upset in butt metal yielding. Moving clamp is displaced together with part for fusion and upsetting. After upsetting to preset allowance and cutting off of welding transformer without removing upsetting force, electrode clamping force is decreased to allow slippage of welded parts. Flash heated in welding is first cut by edge of one of aforesaid sleeves while remaining flash is removed by another edge of the same clamp half-sleeve.

EFFECT: higher efficiency of welding and flash removal.

5 cl, 5 dwg

Description

The present invention relates to welding production, and in particular, to methods and devices for flash butt welding by fusion of rods or rods, performed on specialized welding machines installed in the drawing industry for enlarging wire riots.

The periodic welding of hot-rolled wire riots, which are specified in the drawing units, not only ensures their continuous operation, but also allows to increase the weight of the finished wire riots, while the duration of joining the riots should not allow the unit to stop or slow down. High productivity of welding machines in these conditions is achieved by automating the welding process and accelerating auxiliary operations, in particular, the operation of removal of weld from welded joints, which is necessary before drawing them.

There is a method of removing grata on round products from heat-strengthened aluminum alloys D16T, D18 (see, for example, the book "Flash butt welding with resistance with the formation of the connection" Sat. scientific. Tr. / USSR Academy of Sciences under the editorship of VK Lebedev - Kiev, EO Paton Electric Welding Institute, 1988, pp. 38 ... 39), in which the metal during extrusion is squeezed into grath between the working ends of the electrode forming devices and, at the final stage of the precipitation, is cut off by their edges and separated.

The disadvantage of this method of removal of burr during welding of steel products is the low resistance of the forming devices of the electrodes due to thermal softening of the edges when they come in contact with heated metal ends of the products.

There is also a known method of removing the burr after welding the workpieces of a nut tap with four semicircular knives with annular cutting edges covering the welded workpiece to the right and left of the burr in a separate filler (see the book "Flash butt welding with resistance to form a joint" Sat. scientific. Tr. / AN USSR under the editorship of Lebedev V.K. - Kiev, IEO named after E.O.Paton, 1988, pp. 80 ... 82).

The disadvantage of this method of removing the burr is the inability to maintain the temperature of the weld heated during welding due to its rapid cooling when transferring the product to the burr, therefore, either reheating or using great effort to trim and separate the burr is necessary. In addition, when removing burr in this way on cooled products from hardened steels, cold cracks may appear at the junction. Simultaneous stripping of the weld around the entire perimeter of the welded joint also leads to the formation of a ring of closed-off metal removed by shear, which can be easily removed on short parts, but cannot be removed when welding wire bundles without additional operations to separate the resulting ring.

The technical result of the invention is to increase the performance of flash butt welding of circular products by combining welding and stripping operations immediately after upsetting while maintaining the heating of the deposited metal while reducing the required effort during stripping.

The technical result is achieved by the fact that in the method of flash butt welding by fusion of products of circular cross section with subsequent removal of the burr, including trimming and joining of the ends of the products, their clamping in movable and fixed clamps by electrodes with carbide half-sleeves having cutting edges facing each other, turning on welding transformer and moving the movable clamp with the product for reflow and draft, after upsetting to a given allowance and turning off the welding transformer, without removing cages, reduce the clamping force of the electrodes of one of the clamps before the welded products begin to slip, the heated wire during welding is cut off first with the edge of one half-sleeve of the same clamp to separate the half-ring of the burr, and the remaining part of the burr is cut off with the edge of another half-sleeve of the same clamp, with the mentioned half-sleeves being installed in the clamp with the displacement of the vertical plane of the cutting edges by an amount that is greater than the width of the band, planted during the upsetting of the joint metal.

The technical result is also achieved by reducing the clamping force of the electrodes of the movable clamp, while the cut-off is first cut off with the edge of the upper half-sleeve of the movable clamp until the half ring of the upper part of the burr is separated, and the remaining part of the burr is cut off with the edge of the lower half-bush of the movable clamp installed with a vertical plane offset relative to the upper half-bush .

The technical result is also achieved by reducing the clamping force of the electrodes of the fixed clamp, while the cut is first cut off with the edge of the lower half-sleeve of the fixed clamp until the half-ring of the lower part of the burr is separated, and the remaining part of the burr is cut off with the edge of the upper half-sleeve of the fixed clamp installed with a vertical plane relative to the lower half-sleeve .

The technical result is also achieved by the fact that the rake angle of the cutting edges of the half-sleeves is carried out in a vertical plane.

The technical result is also achieved by the fact that the rake angle of the cutting edge of the half-sleeves is negative in the vertical plane.

The essence of the invention is illustrated by graphic materials (figure 1 - figure 5), where:

- figure 1 schematically shows the position of the electrodes equipped with carbide half-sleeves, after the precipitation of the welded products;

- figure 2 schematically shows the position of the electrodes equipped with carbide half-shells before stripping the edges with the edges of the half-shells of the movable clamp;

- figure 3 schematically shows the position of the electrodes equipped with carbide half-shells before stripping the edges with the edges of the half-shells of a fixed clamp;

- figure 4 shows a cross section of a half sleeve with a vertical cutting edge;

- figure 5 shows a cross section of a half sleeve with a negative rake angle of the cutting edge.

The method of flash butt welding by fusion of products of circular cross section with subsequent removal of burrs is as follows:

- after trimming and feeding into the welding zone of the products 1, lower the upper electrodes 2 of the fixed 3 and the movable 4 clamps, while the upper and lower half-sleeves 5 of the movable clamp 4 are centered, setting the half-sleeves 5 so that the vertical plane of the cutting edge of the upper half-sleeve is offset relative to the cutting edge lower half-sleeve by an amount that is greater than the width of the belt, planted during the upsetting of the joint metal, and clamp the product 1 between the upper 2 lower 6 electrodes, respectively;

- turn on the welding transformer (not shown conditionally in the figures) at an increased voltage to compensate for the voltage drop at the contact junctions between the lower 6 current-carrying electrodes and due to an increase in the installation length, and then move the movable clamp 4 during melting and draft and weld items 1;

- after upsetting and turning off the welding transformer, without removing the upsetting force, they reduce the clamping force between the electrodes 2 and 6 of the movable clamp 4 until they begin to slip on the welded products 1, clamped in the electrodes 2 and 6 of the fixed clamp 3, and continue moving the movable clamp 4 while the cutting edges 7 of the upper half-sleeve 5 of the electrode 2 of the movable clamp 4 come closer to the weld 8 heated during welding and cut off the upper part of the burr 8, separating it in the form of a half ring, and continuing to move the movable clamp 4 further, cut off the lower second part burr cutting edge 8 7 5 bottom half sleeve electrode 6 of the movable clamp 4, the shearing force required in removing burr 8 is reduced by half;

After wear of the cutting edges 7 of the steel half-sleeves 5 of the electrodes 2 and 6 of the movable clamp 4, half-sleeves 5 of the fixed clamp 3 are brought into operation.

For this:

- after upsetting and turning off the welding transformer, without removing the upsetting force, reduce the clamping force of the electrode 2 of the fixed clamp 3 until the welded products 1 begin to slip in them and initially cut off the lower part of the weld 8 when cutting 8 with the cutting edge 7 of the lower half-sleeve 5 of the electrode 6 of the fixed clamp 3 and then, while continuing to move the welded products 1, the upper part of the burr 6 is cut off with a movable clamp 4 by the cutting edge 7 of the upper half-sleeve 5 of the electrode 2 of the fixed clamp 3.

The offset of the cutting edges relative to each other not only reduces the shear force during stripping, but also contributes to the stability of heated round products during stripping, while placing the cutting edge in the vertical plane increases the resistance of the edges, and the negative rake angle at the edges of the half-sleeves smooths and strengthens the joint, improves the surface of the stripping, prepares the joint for the subsequent seamless drawing.

Thus, the proposed method of removal of burr after flash butt welding by fusion of circular products through the use of electrodes equipped with carbide half-sleeves, with cutting edges offset relative to each other, allows:

- significantly accelerate the process of removal of burr after welding, which makes it possible to use it not only when welding wire in continuous drawing units under conditions of limiting the time allocated to docking riots before drawing;

- increase the accuracy of alignment when installing under welding ends of the products in the axial direction;

- to increase the reliability of welded joints when drawing products of circular cross section.

Claims (5)

1. The method of flash butt welding by fusion of products of circular cross section with subsequent removal of burrs, including trimming and joining of the ends of the products, their clamping in movable and fixed clamps by electrodes with carbide half-sleeves having cutting edges facing each other, turning on the welding transformer and moving the movable clamping with a product for reflow and draft, characterized in that after upsetting to a given allowance and turning off the welding transformer, without removing the upsetting force, they reduce the force pressing the electrodes of one of the clamps before the welded products begin to slip, the heated wire during welding is cut off first with the edge of one of the half-sleeves of the same clamp until the half-ring of the burr is separated, and the remaining part of the burr is cut with the edge of another half-sleeve of the same clamp, the said half-sleeves being installed in the clamp with an offset the vertical plane of the cutting edges by an amount that is greater than the width of the band, planted during the upsetting of the joint metal. 2. The method according to claim 1, characterized in that they reduce the clamping force of the electrodes of the movable clamp, wherein the beads are cut off first with the edge of the upper half-sleeve of the movable clamp until the half ring of the upper part of the burr is separated, and the remaining part of the burr is cut with the edge of the lower half-sleeve of the movable clamp installed with an offset the vertical plane of the cutting edge relative to the upper half-sleeve. 3. The method according to claim 1, characterized in that they reduce the clamping force of the electrodes of the fixed clamp, while the cut is first cut off with the edge of the lower half-sleeve of the fixed clamp until the half-ring of the lower part of the burr is separated, and the remaining part of the burr is cut off with the edge of the upper half-bush of the fixed clamp set with offset the vertical plane of the cutting edge relative to the lower half sleeve. 4. The method according to claim 1, characterized in that the rake angle of the cutting edges of the half-sleeves is carried out in a vertical plane. 5. The method according to claim 1, characterized in that the rake angle of the cutting edges of the half-sleeves is negative to the vertical plane.

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