FR2640891A1 - - Google Patents

Abstract

The present invention relates to a device for rolling tubes of metallic materials according to the cold pilgrim pitch rolling process, comprising a rolling mill stand moving back and forth in the rolling direction having cylinders calibrated in s' slimming, which roll on the rolled material with an alternating direction of rotation, in which there is a cylindrical or also thinning mandrel. According to the invention, at least three annular cylinders 3a, 3b, 3c equiangularly spaced apart are mounted in a common chock 15 receiving the cylinders, rigid and closed.

Description

The present invention relates to a device for rolling tubes

  of metal materials according to the cold-pilgrim-rolling method, comprising a rolling mill cage movable back and forth in the rolling direction having calibrated slender rollers which roll on the laminated material with a sense of reciprocating rotation, in which there is a cylindrical mandrel

or thinner too.

  Cold-pilger mills are known having two annular rolls, the drive takes place so that each cylinder is driven directly by pinions fixed on the axis thereof, which meshes with racks fixed rigidly to the bench of the machine, each axis of cylinder being mounted in

separate chocks.

  Rolling mills for the cold rolling of tubes according to the method of pilger rolling are also known, in which three rolls, which are not rotated, are arranged in a staggered manner with respect to one another. Other 120 are used with constant calibration on the periphery of the cylinder, the diameter reduction of the rolled material being carried out in that oscillatingly driven rulers or support bars change the axial spacing of the rolls on the stroke. of the cage ("Stahlrohrherstellung" VEB Deutscher

  Verlag fir Grundstoffindustrie 1970, page 289).

  All of these process and device variants have the following significant disadvantages. These disadvantages are particularly evident during the rolling of materials

  very ductile, such as copper and aluminum

nium, limiting the power.

  When stretching copper in cold pilgrim mills before two cylinders, an elongation ratio of generally up to about 12 and a roll length production of up to about 160 mm per stroke of the cage. The limit for this deformation power is mostly given by the voltage states in the tube in the area of the gauge flanks. During the deformation in the bottom of the caliper under a compression tension with three axes, the periphery of the tube, which is momentarily in the zone of the flanks of the cylinders, undergoes a high tensile force in the longitudinal direction of the tube. This tensile force may exceed, during a significant elongation e - or 'a significant advance of the rolled material at each stroke of the cage, the possibility of deformation of the material of the tube. This results in narrowing of the tube wall and local ruptures of the wall. This causes problems during the subsequent pulling and the

  scrapping nieces. Other basic disadvantages

  Rates of the two-cylinder system are problems of tolerance, which result from the enlargement of the material of the tube and which can intervene likewise by limiting the cuissance. Another disadvantage of known three-roll rolling mills, which rely on their rolling forces against longitudinally movable bars, is their travel length, which is approximately equal to twice the travel of the rolling stand from a dead point to the other. This means additional kinematic loads and additional mechanics that can cause wear and tear. Consequently, the object of the present invention is to develop a device which avoids these drawbacks and, thus, makes it possible to obtain higher rolling powers, better tolerances and, finally, a better cost-effectiveness of the rolling process. pilgrim to

  cold, especially for copper-based materials.

  For this purpose, the device for rolling tubes made of metallic materials according to the method of rolling with

  cold basking shark, of the type indicated above, is

  according to the invention, in that at least three equiangularly spaced annular cylinders are mounted in a

  common chock receiving cylinders, rigid and closed.

  Preferably, the rolling angle of the rolls on the

  rolled material amounts to at least 210.

  According to another characteristic of the invention, one of the cylinders has pinions fixed on its axis, which meshes with a rack arranged in the machine bench essentially rigidly, and the remaining cylinders are rotatably connected to the first cylinder

  through bevel gears.

  Alternatively, it is proposed that at each cylinder is associated at least one pinion fixed on its axis, which meshes with a rack arranged rigidly in

the machine bench.

  Advantageously, the cylinders are adjustable by

  compared to others, to compensate for cylinder wear.

  According to another characteristic of the invention, the chock with the axes of the rolls and the rolls can be installed as a complete unit in a roll stand, which consists essentially of a guide sole and an element. coupling for the oscillating drive.

2640891.-

  The figures of the attached drawing will be bier. understand how

the invention can be realized.

  Figure 1 is a schematic cross section. of the deformation zone perpendicular to the middle of the cylinders for the movement of the cage in the direction of

  rolling, in a usual arrangement with two cylinders.

  FIG. 2 is a curve showing the distribution of longitudinal tensions over half of the periphery of the

tube, according to Figure 1.

  Figure 3 is a schematic cross section of the

  zone of deformation for a three-cylinder arrangement.

  FIG. 4 is a curve showing the distribution of the longitudinal tensions on 120a of the periphery of the tube,

  according to the layout of Figure 2.

  Ficure 5 shows a roll stand of the invention.

  Referring in particular to Figure 1, the laminated material 1 is between the fixed mandrel 2 and the annular rollers 3a and 3b rolling on the rolled material. In order for the rolls, without leaning against the sizing flanks 5, to surround the rolled material which is rotated and advanced to at least one of the two dead points of the roll stand, a "clearance" is required which results in distribution of deformations and, thus, tensions which has no symmetry of revolution. The main voltage appears in the direction of the longitudinal axis of the tube. It is a compression tension in the contact areas between the rolled material and the mandrel, becoming a tensile force on the flanks, because in this area no reduction in wall thickness and no noticeable reduction in diameter are not made. The difference in voltage between the bottom of the gauge 6 and the zone of the spacing of the cylinders 7 is given essentially by the size and shape of the necessary clearance, which, in turn, depends, inter alia, on the value of the deformation. instantaneous and advance of the magnifying glass, that is to say that the greater the deformation and power, the greater is said play, as well as the tensile force in the

  zone of the spacing between the cylinders.

  The schematic distribution of the longitudinal forces on half of the periphery of the tube is represented on the

  Figure 2. The positions 0 and 180 characterize the space-

  between the cylinders 7 (in FIG. 1) and the position at 90 the gauge base 6 (in FIG. 1). The symmetry

  stresses is related to a rotation angle of the tube of 90.

  Fig. 3 shows the cross-section of the deformation zone for a three-roll arrangement, in which, by construction, the clearance can be much smaller and the tube is surrounded more closely than is possible for a two-way arrangement. cylinders. The

  cylinders are designated 3a, 3b and 3c.

  The situation for the three-cylinder system, shown in Figure 3, is much more appropriate. Because the angular extent of a cylinder is only about 120, the rolling can be performed for the same deformation and the same advance of the magnifying glass, with a much smaller clearance, so that the force distribution is improved and the maximum tensile force is significantly reduced, which

  higher rolling rates (Figure 4).

  1 Figure 5 shows a rolling mill cage showing the

  features of the invention. The two drive gears

  8 meshes with the fixed racks 9 and thus directly rotate the horizontal cylinder axis 10, mounted on bearings at 4, with the annular cylinder 3a. The other two axes of the cylinders 12 and 13 with their annular rolls 3b, 3c are driven through the pairs of bevel gears 11,14. The axes of the cylinders 10, 12 and 13 are mounted at 4 in a common error, which, in turn, is fixed at

  cage sole 16, which is driven through the

  connecting rods and slides into the cuides 17.

Claims (5)

  1 - Device for rolling tubes made of metallic materials according to the method of rolling pilgrim   cold, having a rolling mill cage in va-and-   comes into the rolling direction having tapered cylinders which roll on the rolled material with a reciprocating direction, in which there is a cylindrical or tapered mandrel, characterized in that at least three cylinders annular (3a, 3b, 3c) equiangularly spaced are mounted in-a common chock (15) receiving cylinders, rigid and closed. 2 Device according to claim 1, characterized in that the rolling angle of the rolls (3a, 3b, 3c) on the rolled material (1) is at least 2100.  3 - Device according to claim 1, characterized in that one of the cylinders (3a) has pinions (8) fixed on its axis (10), which meshes with a rack (9) arranged in the machine bench essentially rigid, and in that the remaining cylinders (3b, 3c) are rotatably connected to the first cylinder (3a) via bevel gears (11,14).   4 - Device according to claim 1, characterized in that, with each cylinder (3a, 3b, 3c) is associated with at least one pinion (8) fixed on its axis (10,12,13), which meshes with a rack (9) arranged so rigid in the machine bench.   1 - Device according to claim 1, characterized in that the cylinders (3a, 3b, 3c) are adjustable relative to each other, to compensate cylinder wear.   6 - Device according to claim 1, characterized in that the chock (15) with the axes of the cylinders (10,12,13) and the cylinders (3a, 3b, 3c) can be installed as a complete unit in a roll stand, which consists essentially of a sole   guide (16) and a coupling element for the input; oscillation.