SU1553226A1 - Mandrel for pilger rolling of tubes - Google Patents

Abstract

The invention relates to the field of metal forming, specifically to a tool for piligrim tube rolling. The purpose of the invention is to increase the stability of the rolling process and increase the yield by forced rotation of the pipe together with the mandrel. The mandrel for piligrim rolling tubes has a removable cone 4, made of elastic material. During cold rolling of pipes, the removable cone is made in the form of a polymer sleeve. The inner cavity of the sleeve is connected by channels in the wall with the outer surface. During warm rolling of pipes, the detachable cone is made of twisted metal wire spring with a winding direction that coincides with the thread direction of the shank 1. To facilitate reloading the mill from the side loading billet, the mandrel is provided with a ferrule 5 installed in the spring end. 4 il.

Description

FIG. J

The invention relates to the processing of metals by pressure, in particular to mandrels for piligrim tube rolling.

The purpose of the invention is to increase the stability of the rolling process and increase the yield by forced rotation of the pipe together with the mandrel.

FIG. 1 shows a mandrel with a removable cone of elastic material in the form of a polymer sleeve; in fig. 2 -

These connect the area in front of the removable cone and behind it.

During cold and warm periodic rolling of pipes, the removable cone can be made of a metal twisted wire spring with a winding direction coinciding with the thread direction of the mandrel shank 1 corresponding to the direction

c due to the moment of friction force transmitted from the mandrel through its elastic-elastic removable cone.

During cold periodic rolling of pipes, the removable cone of an elastic material can be made in the form of a polymer sleeve, for example, from oil-resistant rubber, polyurethane, caprolon, etc. materials. To stabilize friction conditions by creating a permanent lubricant drain

the mandrel with a removable cone, made 10 of the zone in front of the removable cone, is internally made of a metallic twisted wire spring; the sleeve cavity is connected by channels in

us; in fig. 3 - the same, but removable cone wall with outer surface. These openings are connected to the mandrel through an adapter and provided with a tip; in fig. 4 is a diagram for determining the angle of inclination of the generatrix of a removable 15 cone made of a twisted metal wire spring.

The mandrel consists of a threaded shank 1, a cylindrical section 2, a working cone section 3 and an additional removable cone 4 in the form of a polymeric 20 rotation of the mandrel. With this design of the sleeve or the twisted wire spring, the screw spring is wedged by friction forces in the pipe and rotates the pipe at the time of the mandrel rotation, i.e., turns it. At the time of deformation of the metal pipe

When moving the pipe along the helical one, the longitudinal displacement of its ratio takes place so that the angle of contact with the mandrel and the twisted spring, while

the edges of the pipe end with the wire turn are not spring pulled out, the friction angle is exceeded: the spring meter and the pipe is displaced with a certain amount of pressure from the mandrel side, which prevents the pipe from dropping (nedokat) from the frame.

To facilitate the recharging of pipes on mills with side loading contributes to the tip mounted at the end of the spring.

Example 1. For rolling tubes of OT4-0 alloy in the KhPTR15-30 mill using the route 35 18X1, 1.15, a cylindrical mandrel was used, equipped with a removable cone of elastic material, a polyurethane sleeve with a cone angle of maximum diameter 14.1 mm, having two longitudinal grooves, the distance between the bottom of which was 12 mm. Rolling using the proposed mandrel took place stably, with constant turning of the pipe and without loss of metal due to the formation of nedokat,

The largest diameter of the removable cone 45 also eliminated the longitudinal cracks - it is 1,005-1,020 diameters of the end of the wound, which arose during an unstable canted terminal 5.

To prevent the spring coils from being folded over and cutting into the front end coil

a arcsiM-

4P

where a is the angle of inclination of the generatrix of the cone;

d is the diameter of the wire;

p is the step of winding the spring.

The diameter of the wire is determined from the expression

d () max Dxps.) - -,

0t Uk rz

where Dvanc is the maximum diameter of the larger base;

Ј) K.Rz - diameter of the end of the working area of the mandrel;

E is the modulus of the normal elasticity of the wire material;

ag is the yield strength of the wire material.

40

barrels of the mandrel.

The mandrel for pilgrim rolling works as follows.

When rolling the first pipe, the removable cone 4 of the elastic material is deformed and passes the front end of the pipe. When the tube is rotated from the rear cartridge, the mandrel is rotated during the rolling process. Before the pipe joint approaches, the elastic-elastic removable cone creates a slight force of the front support.

As the pipe joint passes through the mandrel, the rear pipe rotates (cantus) from the rear chuck of the mill, the front pipe turns to the edge. As a result of using the proposed mandrel, the yield increased by 0.8% compared with tube rolling on conventional mandrels.

Example 2. For rolling RoCright 31/2 (with the removed front cartridge) mill along the route 42X X4.15- -25X2.15, a conic-cylindrical mandrel with a diameter at the end of the working area (in clamped) equal to

55 20.7, equipped with a removable cone made of an elastic material - a metal twisted wire spring with a winding direction that coincides with the Nati connect the area in front of the removable cone and behind it.

During cold and warm periodic rolling of pipes, the removable cone can be made of a metal twisted wire spring with a winding direction coinciding with the thread direction of the mandrel shank 1 corresponding to the direction

turning the mandrel. With this design of the screw spring, at the time of rotation of the frame, the longitudinal cracks that occurred during unstable turning back were eliminated. As a result of using the proposed mandrel, the yield increased by 0.8% compared with tube rolling on conventional mandrels.

Example 2. For rolling tubes of VT1-0 alloy at the Rokright 31/2 mill (with the removed front cartridge) using the 42X X4.15- -25X2.15 route, a conical-cylindrical mandrel with a diameter at the end of the working area (in ) equal to

20.7, fitted with a removable cone made of an elastic material - a metal twisted wire spring with a winding direction coinciding with the thread direction of the shank, with a tilt angle forming a cone, 5 °, maximum diameter, 1 mm, mm wire diameter, of 60C2 steel and pitch mm. The pipe rolling using the proposed mandrel was stable, with constant turning of the pipe and no metal loss due to the formation of under-carbonates, an increase in the yield of 1.2% compared to rolling on conventional mandrels. The use of the invention allows to increase the stability of the rolling process and increase the yield by 0.8-1.2%.

Claims (3)

1. A mandrel for piligrim rolling of tubes, comprising a threaded shank, a cylindrical section, a working conical section, and an additional removable cone having a larger base diameter, greater than the diameter of the working section end, and attached to its end with a smaller base, characterized in that in order to increase the stability of the rolling process and increase the yield by suitable forcing the pipe together with the mandrel, the removable cone is made of an elastic material. 0 five 0 s 2. The mandrel according to claim 1, characterized in that the removable cone is made in the form of a polymer sleeve, the internal cavity of which is connected by channels in the wall with the external surface. 3. The mandrel according to claim 1, characterized in that the removable cone is made of a metallic twisted wire spring with a winding direction coinciding with the thread direction of the shank, with an angle of inclination cone a.arcsin where p is the step of winding the spring; d - wire diameter, defined by the expression E i about dt. p h where Omax is the maximum diameter of the larger base; / Hrz - diameter of the end of the working area of the mandrel; E is the modulus of the normal elasticity of the wire material; 0G is the yield strength of the wire material. d (Ј MaKC-Okrz) 4. The mandrel according to claim 3, characterized in that it is provided with a tip mounted at the end of the spring. 1 2. Trumpet Rolling axis Phage. C