SU1470375A1 - Centering device for short-mandrel helical-rolling mill - Google Patents

Abstract

This invention relates to pipe production. The purpose of the invention is to improve the quality of the sleeves by increasing the reliability of their centering. In the centering device of the pipe mill, the mandrel rod 4 is made faceted. Longitudinal grooves are made on its opposite faces, and longitudinal protrusions are made on the guide under the grooves; the ring 6 is rigidly connected to the split sleeve 5 has a spherical face surface on which knurling is applied. The sleeve is placed in the glass 3, mounted on the stop head 1, having a drive 2 movement. 3 il.

Description

1

The invention relates to the field of metal forming, in particular to pipe production.

The purpose of the invention is to improve the quality of the sleeves by increasing the reliability of their centering.

FIG. 1 shows the device, general, its form; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a view B in FIG. one.

The device comprises a stop head 1 with a drive 2 of its movement, a glass 3 mounted in the head rotatably, fixed at the bottom of the glass coaxially located faceted mandrel rod 4 with longitudinal grooves on the side faces, a split guide sleeve 5, on the inner surface of which made longitudinal protrusions corresponding to the grooves of the rod, rigidly fixed on the front end of the sleeve ring 6, having the shape of a sphere with a knurled. The sleeve and the ring are attached to the reference rod and placed inside the glass.

Before flashing, the mandrel on the rod 4 and the guide sleeve 5 are installed in the forward position in the deformation zone (Fig. 1), the stop of the head 1 is closed and the device is ready for operation.

When flashing, the sleeve enters the inside of the sleeve 3 by moving the front end of the ring 6 and the split guide sleeve 5 in the axial direction. The rotation of the sleeve through the mandrel and the face ring 6 nqpe- is given to a faceted rod 4, a split sleeve 5, a cup 3 and the rotating parts of the head 1 unwind.

After flashing, the stop of the head opens and the head 1 with the aid of the actuator 2 moves to the rear position by the length of the stitched sleeve. Allowing the sleeve 5 at this time is kept from axial movement by an additional stop, removes the sleeve from the glass, which is fed to the inclined table and protrudes beyond the mill. The device returns to its original position (Fig. 1) when moving the head 1 with the mandrel bar 4 and the glass 3 to the forward position by the actuator 2.

The rigid connection of the ring with the split guide bushing and the execution of the front end surface of the ring with spherical knurling eliminates the twisting of the split guide sleeve relative to the mandrel-rod, provides the necessary adhesion of the sleeve to the ring, which accelerates the unwinding of the sleeve from the end of the sleeve. As a result, the internal profile of the hole is not wound along the length of the sleeve.

Making the mandrel bar wound eliminates the twisting of the faces of the hole when the centering device is twisted and calibrates the liner, which improves the accuracy of the geometric dimensions of the hole.

The longitudinal grooves on the opposite faces of the rod, and the longitudinal protrusions on the split guide bushing ensure rigid centering of the mandrel rod and virtually eliminates its deflection under axial load, which improves the accuracy of the liner geometrical dimensions. Also connection

5th groove - the protrusion ensures simultaneous twisting of the rod and the split guide sleeve, which leads to a rapid unwinding of the glass, reducing the mismatch of the rotations of the mandrel and the centering device, which leads to the elimination of the twisting of the faces of the sleeve opening. In addition, the proposed connection of the rod with a split guide bushing makes it possible to reduce the cross-sectional area of the split guide bushing with

25 with the same critical axial force on the system, the mandrel rod, the ram, the guide bushing, which makes it possible to increase the cross section of the bottom of the glass, which senses the piercing force. All this increases the rigidity of the centering device, reduces the oscillatory processes during the firmware and increases the accuracy of the geometrical dimensions of the sleeves.

Claims (1)

Invention Formula five The centering device of the short-rolling mill of helical rolling, containing a stop head, a drive for its movement, mounted in the head with the possibility of rotation of the cup, fixed  in its bottom, a mandrel rod coaxially positioned to the glass and a guide sleeve disposed inside the cup with the possibility of axial movement with a ring enclosing the mandrel rod at the front end, characterized in that, in order to improve the quality of the sleeves by increasing the reliability of their centering, the ring is rigidly connected to a split guide bushing, the front end surface of the ring is made spherical with knurling, and the core is faceted with longitudinal grooves on the side opposite faces, under which Longitudinal projections are made on the inner surface of the split guide bushing. L A Type B Fi.g.2 Fig.Z