SU557833A1 - Composite Pipe Drill Rod - Google Patents

Description

one

The invention relates to the field of metal forming and can be used in pipe production.

A composite mandrel rod of a pipe rolling mill is known, which contains a replaceable tool 1 fixed to the rear end of the rod and mounted on the axis of its free end. Such a rod has a low load capacity and durability.

Closest to the proposed technical entity is a composite mandrel rod of a tube mill comprising a shank with cooling channels in the walls, a swivel head mounted on rolling bearings with a front end for attaching the mandrel 2. This device is characterized by a higher load capacity and durability. However, the bearing capacity of its rolling bearings depends on their geometric dimensions, which are limited by the transverse dimensions of the rod. This disadvantage limits the ability to use the rod in technological operations with high axial forces, for example, piercing mills.

The aim of the invention is to increase the load capacity and durability of the composite mandrel rod and expand its scope.

This goal is achieved in the proposed mandrel sterns by the fact that it is equipped with a compensating piston with a forced drive axial movement and a working piston, mounted on the rear end of the swivel head, and the internal cavity of the rod is divided into a working and compensation chambers filled with liquid and interconnected valve.

FIG. 1 shows the proposed rod with a spring acting on the shrinkage of the compensation chamber, a longitudinal section; in fig. 2 - rod with effects on

piston compensation chamber with pneumatic cylinder stock, longitudinal section.

The rod contains a rod 1, in the threaded end 2 of which a bearing 3 is installed. In the bearing there is a turning head 4 for fastening the mandrel 5 on the front channel. The part of the swivel head placed in the rod is terminated by a piston 6, which rests against the front face m in the support 7 and is placed in the working hydraulic

chamber 8. Behind the working hydraulic chamber in the shtang, a compensation hydraulic chamber 9 is made, separated from the working partition 10 with a check valve 11. A piston 12 is installed in the compensation hydraulic chamber and the axial drive is

the movement of which is made in the form of a spring 13 and a threaded shank 14, on which a nut 15 is screwed (see Fig. 1). FIG. 2, the piston 12 is connected by means of the rod 16 to the piston 17 of the pneumatic cylinder 18.

In the course of rolling or piercing the liner, the head 4, vras, and abuts against the bearing 3, the axial force of rolling from the tool through the rotary head and its piston 6 is perceived by the fluid of the working hydraulic chamber 8 of the rod 1.

In the intervals between rolling, there is no metal pressure on the tool and, therefore, there is no pressure in the hydraulic chamber 8 caused by the rolling process. Through the check valve 11, the working fluid enters the piston 12 of the spring 13 or the piston 17 of the pneumatic cylinder 18 through the check valve 11 from the compensation chamber 9 to compensate for the losses that occur during the rolling process.

Under the action of pressure during rolling, the working fluid through the channels in the pistons and the steep bars of the rod is fed to cool and lubricate the stem surfaces of the rod.

When filling the rod with working fluid, the piston of the compensation chamber is moved back by means of a nut 15 or a piston 17 of a pneumatic cylinder 18.

Claims (2)

1. Copyright certificate № 325058, cl. B 21B 25/02, 1970. 2. Copyright certificate № 437544, cl. B 21B 25/02, 1972. CIl 2 fS 77