SU871857A1 - Support strip of roller mill for die rolling of tubes - Google Patents

Description

The invention relates to a pipe mill technological tool and can be used in the manufacture of pipes on roller rolling mills. The known support bar of a roller mill consisting of a base plate and cheeks with a profiled surface, each of which has reduction zones for reducing and calibrating H and calibrating the feed rotation pipe, is located in front of the reduction zone, with the curve of one radius 1} outlined. The closest in technical description to the present invention is the support plate of a roller mill, containing a base and a working profile surface composed of re-emission, compression, calibration, and saucer company located before redutsirova audio zone and after calibration zone, this generatrix profile 1fi reduction zone is formed from the beginning to the end with variably smart shayuscheys conicity, i.e. can be made in the form of several linear sections, the angle of inclination of which to the end of this zone decreases, or along the entire length of this zone as a convex. The disadvantage of the specified support strips is that if they are used for rolling in double feed mode, even with relatively small values of feeds in the deformation zone, the ends of the pipes are joined. This disadvantage is due to the fact that at the beginning of the squeezing zone during the return run of the cage, the axial forces reach a maximum value and the linear displacement of the metal is both in the exit direction of the finished pipe and in the entry direction of the workpiece. This leads to the joining of blanks in the deformation zone, and thus the appearance of defects on the surface of the plank, which reduces its service life. The purpose of the invention is to increase the life of the plank. The goal is achieved by the fact that 387 in the base plate of a roller mill of periodic rolling of tubes, containing a base and a profile working surface, an erected contiguous reduction zone and a reduction zone conjoined between them, the profile of which in its tail part has a tapering variable by the end, the calibration zone and the fly-back sheds located in front of the reduction zone and after the calibration zone, forming the profile of the reduction zone from its beginning, are 13–18% of its extension; However, the circumferential concave arc of the tail section adjoins the forming profile, the radius of which is located in a vertical plane passing through the beginning of the crimping zone, and is determined by the Kob.I W5 relationship (- the extension of the initial part of the crimping area with the forming profile in the form of a concave arc / f is the angle between the horizontal and the tangent AB, drawn to the concave arc of the circle at the point of its conjugation with the beginning of the tail part of the reduction zone. Making the profile at the beginning of the crimping zone in the form of a concave arc reduces the reduction at the beginning of it and distributes them to the tail part, thereby reducing the axial forces and the probability of joining the pipes, and therefore prevent the occurrence of defects on the surface of the strip. FIG. 1 shows the plank of a rolling mill for periodic truo rolling, general view; in fig. 2 - the same, side view. The device comprises a base 1 and parallelly arranged guide shelves 2..,., .. „gdnP 0.10, b-a) | P | +2

rAeDft, D.j.p - diameters of the workpiece and the finished pipe;

m - blank feed; o is the total stretch ratio; wall thickness of the workpiece and

finished pipe;

. O, 3-0.4 m - rolling roller radius;

section length

working cone;

the radius of the roller on the bottom of the stream; pipe strength; yield strength of the workpiece; minimal contact surface of the workpiece ends.

Claims (2)

1 photo of the initial part of the reduction zone. Each shelf has a profiled working surface composed of interconnected reduction zones ρ reduction t Qg, calibrations, feed / turn apertures 8 / J, located before and after the reduction zone. calibration zones. The end sections of the EX are adjacent to the sheds. The forming profile of the reduction zone from its beginning on the length Rob. Of different 13-18% of its length, is made in the form of a concave circular arc of radius R. Meltingly, forming the profile of the tail part of the reduction zone can be formed with the end of this arc or a convex arc or a thrust-seven straight line segments, arranged at an angle to the horizontal, decreasing towards the end of the tail part of the crimping zone1, i.e. The forming profile of the tail part of the crimping zone is made with its cone's variable decreasing by the end. The radius R of the concave arc of the circumference of the initial part of the crimping zone is located in the vertical plane passing through the beginning of the crimping zone to defined by the COS dependence) de c - the length of the initial section of the crimp with the generatrix in the form of a concave arc of a circle; - the angle between the horizontal and the tangent drawn to the concave arc at the point of its conjugation with the beginning of the tail part of the reduction zone. The angle can be determined by the formula. Mr. B) tLZ () KkeoBh.n. 58 Planck works as follows. When rollers are rolled up (not shown in fig.1n2), the working surface of the shelves of the support bar in the in-turn feeding-turning l located in front of the reduction zone is used to feed and rotate the pipe in the rezutsirovanny area, the pipe is deformed across the diameter in the reduction zone - deformation but wall thickness , in the calibration zone - calibration, in the shed of feedings and rotation C, located behind the calibration zone, - the second feed and turn of the pipe. When the roller rolls back, the deformation of the pipe occurs in the reverse order. When using the considered strip rolled billet size 2Oh1,2 mm tube 18xO, 45 mm. The material of the workpiece is steel Х18Н1ОТ, in which 65 is 45.0 kg / mm –ac5 in the pipe 95 kg / mm; the radius of the roller stream along the bottom is 74 mm; contact surface area F 50 mm. Pipe rolling is carried out with double submission of the workpiece, the magnitude of which is 5 mm + 5 mm 1 O mm, the total stretching ratio, j, 3, a, tc 1.2. On these strips, a rolled batch of pipes in the amount of 2 O thou. M. The proposed bearing plank of the roller mill reduces axial forces by reducing the compression at the beginning of the crimping zone; reduce the likelihood of pipe joining due to a decrease in axial forces and a redistribution of magnitude with a decrease in the beginning and an increase in its middle; Increase the durability of the plank by reducing the likelihood of joints that cause defects on the working surface of the slats. 76 Claims Supporting plate of a rolling mill for periodic rolling of tubes comprising a base and a profile working surface composed of interconnected reduction zones and reduction zones, forming a profile of which in its tail part has a tapering variable by the end, calibration zones and feed sheds and rotation, located in front of the reduction zone and after the calibration zone, characterized in that, in order to increase its service life, the profile of the reduction zone from its beginning over the length of 1318% The extension is made in the form of a circular concave arc which is smoothly mated to the tail section of the tail section, the radius of which is located in a vertical plane passing through the beginning of the crimping zone and is determined by the dependence p. o5 on the COS (the length of the initial section of the reduction zone forming the profile in the form of a concave arc of a circle - the angle between the horizontal and the tangent drawn to the concave arc of a circle at a point, its conjugation with the beginning of the tail part of the compression zone. Sources of information taken into account during experimentation 1. USSR author's certificate No. 68О774, cl. B 21 B 21 / OO. 1977. 2. Khaustov GI, et al. Ways to increase the productivity of the KPTR 15-ZO mill. Metallurgical and mining industry, № 2, 1977, p. 24-26. 1 Phi1.2