RU2003118175A

RU2003118175A - METHOD OF COOL PIPE ROLLING AND COOL PIPE ROLLING MACHINE FOR ITS IMPLEMENTATION

Info

Publication number: RU2003118175A
Application number: RU2003118175/02A
Authority: RU
Inventors: Марат Васильевич Попов; Семён Владимирович Автономов; Георгий Вольфович Вольфович; Сергей Павлович Живцов; Алексей Маратович Попов
Original assignee: Марат Васильевич Попов; Семён Владимирович Автономов
Priority date: 2002-06-14
Filing date: 2003-06-16
Publication date: 2004-12-20

Claims

1. A method of cold rolling pipes, including a batch feed of the workpiece into the deformation zone formed by two pairs of rolls, and deformation of the fed portion sequentially by the first and second pairs of rolls during their reciprocating movement relative to the stationary mandrel, characterized in that the wall thickness calibration is carried out before the deformation of the second pair of rolls with a degree of deformation of 5-15% (μ) and a calibration coefficient of 2.0-2.5 (δ), while the workpiece is rotated both before the forward stroke and before the roll reverse .

2. Cold pipe rolling mill, comprising a bed, a cage with work rolls having gear wheels on the necks, stationary rails interacting with the wheels, a cage reciprocating movement mechanism, a rotary-feeding device, characterized in that the cage with work rolls additionally contains a second a pair of rolls having a gear wheel on the neck interacting with an additional rack configured to disengage from it, and the deformation zone formed by two pairs of rolls is made with the possibility of deformation of the workpiece on a conical mandrel, along which there are reduction zones by diameter, compression by the pipe wall thickness and diameter, the calibration zone and the overlap zone on which the metal is deformed by both pairs of rolls, while the parameters of the metal deformation zones on the mandrel are set and made on the basis of set of equalities in which the taper of the calibrating sections of the input pair of rolls and mandrel is made in accordance with the equality

where tgγ _k is a parameter characterizing the taper of the calibrating part of the stream,

tgα is a parameter characterizing the taper of the mandrel, the distance between the pairs of rolls is made in accordance with the equality

taking into account the equalities

where Lx is the stroke length of the rolls (or stand travel), mm,

lп - the length of the overlap of the crimp zones of the first and second pairs of rolls, mm,

And - the distance between the centers of the pairs of rolls, mm,

l _k1 - the length of the calibration zone of the first pair of rolls, calibrating the thickness of the pipe wall, mm,

m is the supply of the workpiece for the double course of the mill, mm,

M ₁ - drawing coefficient, or taking into account the following equalities

where l _p2 is the length of the reduction zone of the second pair of rolls, mm,

M _p2 is the drawing coefficient in the reduction zone of the second pair of rolls, and the cross section of the streams of the calibrating zone of the first pair of rolls is made in accordance with the following equality

where B is the width of the stream, mm, D is the diameter of the stream, mm.