SU703176A1 - Stand for manufacturing welded straight-seam tubes - Google Patents

Description

(54) MILL FOR MANUFACTURE OF WELDED STRAIGHT PIPES

The invention relates to pipe welded production, in particular to the production of electric arc welded pipes by arc welding on continuous electric pipe welders,

 A mill is known for producing welded pipe welded pipes containing a formed stand with open gauges and a stand with closed caches formed by lower and upper rolls with a split washer, as well as a welding device

In the manufacture of pipes in a long-standing mill, the tube billet enters the welding device with a significant gap between the edges, since the disc washer holds the edges of the tube billet parallel and at a distance from the vertical section of the bone passing through the axis. molding mill. Occurring in the welding unit of the preformings of the pipe billet, before contact of the edges, internal stresses are generated by the pipe billet S, which elastically expands, ie, spring the pipe billet. If for. the transit time of the weld rolls, which create extra effort, counterbalance these internal stresses, the weld seam did not have enough time to cool down, possible hot cracks in the weld metal, or even destruction of the weld seam.

Thus, the phenomenon of springiness limits the speed of passage of the billet through the welding machine.

0 device, i.e. the speed of operation and, consequently, the efficiency of the all-electric welded unit, negatively the quality of the welded joint.

five

The purpose of the invention is to improve the quality of pipes and productivity of the mill by deforming tubular billet to the contact of edges in the last forming stand with simultaneous

0 by holding the edges in a vertical plane.

To do this, the rolls are made along the molding process of the forming stand made of an elastic material, for example

5 polyurethane.

FIG. 1 shows a mill for the production of welded straight pipes, general view; in fig. 2 - rolls and washer of the last washer as the forming stand was formed; in fig. 3 plot tube stock placed in the last forming stand. , V -. . - The mill contains horizontal stands 1 mounted on the frame, vertical stands 2 and a welding device (not shown in the drawing). The caliber of the last molding stand was made in the form of the upper and lower rolls, mounted on axles 3 with the help of dowels 4 and fixed by remote from lateral movements. sleeves 5. The upper roller consists of side sections b, working sections 7 and a split washer 8. The lower roller consists of similar side sections b and working section 9. Working sections of the roll are made of elastic material, for example polyurethane, the strip 10 passes successively through horizontal and vertical forming stands of the mill; Polbsa is gradually graduating from stand to stand into pipe billet 11 .; The pipe billet, which has a radius greater than the radius of the gauge at the entrance to the rolls, elastically deforms the working sections of the BepxHiero and the lower rolls, respectively. As a result, an extended contact zone 12 of an elastic material with the workpiece is formed, located on both sides of the plane 13 of the axes of the rolls. As the edges of the pipe billet are advanced with a cut washer along the contact 12 from its entrance and until it reaches the end zone. of cycle 14, each post-ice-tight uchaytok.trubnyj billet exposes with the bend, at the moment when the descent of the puck washer, the deformed elastic material of the working sections of the rolls continues to adhere to the surface of the tubular billet. The accumulated deformation energy is sufficient for him to, in order to unload, form the pipe billet, in particular, to carry out its round billet. beaten to full contact edges. Cutting the washer will allow you to keep the edges in the vertical plane passing through the axis of the tube-forming mill.

Claims (1)

703176 A laboratory tube electric welding mill 10-60, consisting of five horizontal molding stands and four vertical forming stands installed between them, was used. Forming a billet tube 33x0.8; 1x0; 2.0; 2.2 mm of steel grade Х18Н10Т, In the last one along the horizontal-forming stand, the rolls were made of elastic material. The width of the washer was 3 mm, diameter - 33 mm caliber. Regardless of the size of the billet molding was carried out at a speed of 2; 4 8 and 10 m / min. At the same time, in the entire range of speeds, the shape of the unit was obtained with a pipe billet of a strictly cylindrical shape without a gap between the edges. The use of bridges of elastic material in the last stand of the mill allows you to set the springing of the billet while holding the edges in a vertical plane, which ensures high quality welded iiJBa And increases the productivity of the mill. Claims of the invention: A DLI plant for the manufacture of welded straight welded pipes, comprising forming with open gauges and cages with closed gauges formed by upper and upper rollers with a split washer, as well as a welding device, which joins the seam; by the fact that, in order to improve the quality of the pipes and the mill's productivity by deforming the tube billet before the edges in the last forming die touch together while simultaneously holding the edges fi of the vertical plane, the rolls in the latter along the molding, the forming stands are made of elastic Matter; .. Sources of information taken into account during the examination 1. USSR author's certificate No. 212966, cl. B 21 C 37/06, 19i66, rJ // 12 Fig.Z,