RU2333053C1 - Mandrel for cold pilger rolling - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: mandrel contains working section, detachable tip with resilient elastic bushing and threaded tailpiece. Mandrel is equipped with insert with groove installed in its threaded tailpiece. Collet grip of billet is installed in groove at axis that is fixed perpendicularly to the axis of mandrel. The front end of insert is arranged with blind threaded hole for its fixing to mandrel, and the back end is provided with threaded tailpiece for its fixing with rod.

EFFECT: invention allows to provide stable turn of short billets and pipes produced from them during the whole process of cold pilger rolling.

2 dwg

Description

The invention relates to the field of pipe production and relates to the creation of a mandrel design for cold pilgrim rolling, with the help of which short billets are rotated.

For turning workpieces of normal length, the HPT and KhTPR mills are equipped with a workpiece holding drive chuck of the workpiece, as well as front and intermediate chucks for holding and turning the pipe rolled from the workpiece. When rolling short billets at these mills, the billets and pipes exiting the deformation zone are outside the range of the said cartridges. Known mandrel designs cannot provide a stable rotation of short billets not held by cartridges and tubes rolled from them during the entire process of pilgrim rolling, which is especially necessary when rolling pipes with double feed and double rotation, when the pipe breaks off the mandrel and its rotation occurs in both extreme working stand positions. The present invention is the creation of such a design of the mandrel, with which it is possible to stable rotation of short workpieces and pipes obtained from them.

The design of the mandrel for cold pilgrim rolling is known, see V.F. Frolov, V.N. Danchenko, Ya.V. Frolov. Cold pilger tube rolling. Dnepropetrovsk, “Thresholds”, 2005, p. 170-172, containing a threaded shank and a working section.

The main disadvantage of this design of the mandrel is the inability to ensure with it the rotation of short not held by cartridges blanks during the pilgrim rolling process.

Of the known designs of mandrels for cold pilgrim rolling the closest in technical essence is the design of the mandrel described in A.S. USSR No. 1553226, cl. B21B 25/00, claimed 03/29/88, publ. 03/30/90

This mandrel contains a threaded shank, a working section and a removable tip with an elastic elastic sleeve.

The disadvantage of this design of the mandrel is the inability to ensure stable rotation during the entire process of pilgrim rolling short billets not held by cartridges and tubes rolled from them. This is due to the fact that a stable rotation of a short billet here is possible only after the front end of the short rolled billet (pipe) arrives at the holding elastic flexible sleeve located on the removable tip of the mandrel, until that moment an unstable rotation of the workpiece not held by anything occurs, leading to a deviation of the finished pipe sizes from the set.

The present invention is the creation of such a mandrel design, which ensures stable rotation of short billets and pipes obtained from them during the entire process of cold pilgrim rolling.

The object is achieved in that the mandrel for cold pilgrim rolling of billets, containing a threaded shank, a working section and a removable tip with an elastic elastic sleeve, according to the invention is equipped with an insert with a groove mounted on its threaded shank, in which is placed on an axis fixed perpendicular to the axis of the mandrel collet clamp of the workpiece, while the front end of the insert is made with a blind threaded hole, and the rear end with a threaded shank for fastening with a rod.

Such a constructive implementation of the mandrel allows you to ensure a stable rotation of short billets and pipes obtained from them during the entire process of cold pilgrim rolling. This is achieved due to the fact that first, before the rolling process, a short workpiece, sitting on the mandrel, is held by the inner diameter of the collet clamp located on the mandrel insert. During rolling during rotation of the rod, the workpiece is rotated together with the mandrel connected to the rod, while the finished pipe coming out of the deformation zone is held and rotated with the help of an elastic flexible sleeve located on the removable tip of the mandrel. When the workpiece leaves the collet clamp and, being in the deformation zone, the finished pipe is held and rotated only with the help of an elastic elastic sleeve.

To explain the invention, a specific embodiment of the invention is given below with reference to the accompanying drawings, in which: FIG. 1 shows a mandrel for cold pilgrim rolling, FIG. 2 is a view along arrow A in FIG. 1.

The mandrel for cold pilgrim rolling includes a threaded shank 1, a cylindrical section 2, a working conical section 3, a removable tip 4 placed on the removable tip 4 and secured on it with a washer 5 and nut 6, an elastic elastic sleeve 7. In addition, the mandrel is equipped with a threaded a shank 1 with an insert 8 with a groove 9, in which a collet clip 11 is placed on an axis 10 fixed perpendicular to the axis of rolling. In this case, a blind threaded hole is made at the front end of the insert 8 for connection with a threaded shank m mandrel 1, while the rear end of the insert 8 is disposed a threaded shank 12 for attachment to the rod 13.

When the front end of the short workpiece passes along the collet clamp 11 located on the mandrel insert 8, the latter is compressed and friction holds the workpiece by the inner diameter, as a result of which, when turning the rod during rolling, the short workpiece is also turned on the mandrel, which is connected to the rod. At the exit from the deformation zone, the front end of the finished pipe falls on the elastic elastic sleeve 7 located on the removable tip 4, which also holds and rotates the pipe. When the rear end of the workpiece descends from the collet clamp 11 and, while still in the deformation zone, the finished pipe is held and rotated only with the help of an elastic elastic sleeve 7.

Thus, this design of the mandrel allows you to provide a stable rotation of short billets and pipes obtained from them during the entire process of cold pilgrim rolling.

Claims (1)

A mandrel for cold pilgrim rolling of blanks containing a threaded shank, a working section and a removable tip with an elastic elastic sleeve, characterized in that it is equipped with an insert with a groove mounted on its threaded shank, in which a workpiece collet is clamped on an axis fixed perpendicular to the mandrel axis while the front end of the insert is made with a blind threaded hole, and the rear end with a threaded shank for mounting with a rod.

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