SU567514A1

SU567514A1 - Automatic rolling mill mandrel

Info

Publication number: SU567514A1
Application number: SU7602350859A
Authority: SU
Inventors: Виктор Яковлевич Остренко; Владимир Михайлович Друян; Виктор Вольфович Перчаник; Григорий Израйлевич Милов; Юрий Геннадиевич Гуляев; Владимир Николаевич Умеренков; Владимир Яковлевич Кармазин; Михаил Петрович Онищенко
Original assignee: Днепропетровский Ордена Трудового Красного Знамени Металлургический Институт; Всесоюзный Научно-Исследовательский И Проектно-Технологический Институт Трубной Промышленности
Priority date: 1976-04-21
Filing date: 1976-04-21
Publication date: 1977-08-05

Description

Изобретение относитс к инструменту дл производства труб гор чей прокаткЦ| а именно к основному инструменту автоматических станов продольной прокатки гор чекатанных бесшовных труб.This invention relates to a tool for the production of hot rolling tubes | namely, to the main tool of automatic mills for longitudinal rolling of hot rolled seamless pipes.

Известна оправка дл прокатки трубной заготовки в круглом калибре, позвол юща : достигать значительного редуцировани трубы по диаметру и обжати по толщине стенки за один проход возрастающего вA known mandrel for rolling a pipe billet in a round caliber allows: to achieve a significant reduction of the pipe in diameter and reduction in wall thickness in one pass of increasing

направлении прокатки диаметраа соединен- ных собой коническими i перекодны ми участками ij. При этом в стане при прокатке на линии центров калибра располагают начало последнего циливдрическо- го участка оправки.the direction of rolling of diametrically connected conic i transcoding sections ij. At the same time, when rolling, the beginning of the last cylindrical section of the mandrel is located on the line of the centers of the caliber.

Така оправка не может обеспечить точности труб по стенке.Such a mandrel cannot ensure the accuracy of the pipes along the wall.

Наиболее близкой к предлагаемому изоб ретению вл етс оправка автоматического стана, состо ща из конусной части, сопр женной с торцовой поверхностью радиусом, равным 1О-6О мм, и цилиндрического по ска шириной от 17 до 45 мм и более,.сопр - женного с конической частью радиусом,Closest to the proposed invention there is a mandrel of an automatic mill consisting of a conical part, conjugated with an end surface with a radius of 10 ~ 6 mm, and a cylindrical edge with a width from 17 to 45 mm and more, concurrent with a conical part radius

равным Oj5-O,6 диаметра цилиндрического по ска 2Т.equal to Oj5-O, 6 of cylindrical diameter for 2A ska.

Недостатком оправки вл етс повышенна поперечна разностенность труб и не-.The disadvantage of the mandrel is the increased cross-spacing of the pipes and non-.

обходимость прокатки за несколько прохо дов при ее использовании. Толщина стенки в выпусках измен етс незначительно (по сравнению с первоначальной), что приводит к разностей и ости прокатываемых труб по периметру, ограничивает величину обжати по стенке заготовки и приводит к необходимости прокатывать трубу в дополнительных проходах дл обжати более толсть х участков стенки. Возникающие при дефор ацит1 напр жени в выпусках калибра по nepiivieTpy трубы вл ютс сжимаю- щими что дополнительно способствует yBen.H4omuo толщины стенки в выпусках по отношению к вершине кал бра. the need for rolling in several passes when using it. The wall thickness in the outlets varies slightly (as compared to the original), which leads to differences and spines of rolled tubes around the perimeter, limits the amount of reduction along the wall of the workpiece and leads to the need to roll the pipe in additional passages to reduce more thicknesses of the wall sections. The stresses that appear during deforming of acit1 in the nepiivieTpy caliber outlets are compressive, which additionally contributes to yBen.H4omuo wall thickness in the outlets relative to the tip of the cal.

Claims

The aim of the invention is to create tensile stresses along the perimeter of the rolled pipe in the caliber outlets at the exit of the deformation zone, reducing the transverse; production of rolled pipes and increased mill productivity. The goal is achieved by the fact that the proposed mandrel, having a truncated cone and 1 cylindrical section adjacent to its larger base, is provided with an additional, truncated cone, adjoining smaller base to the cylindrical section and having a height equal to 0.1-0.3 of the diameter of the cylindrical section, and the angle of inclination of the generatrix is 15-35. The dimensions of the additional section of the mandrel are selected taking into account the geometrical ratios in the deformation zone of the automatic mill so that in the additional section of the mandrel, which in the deformation zone is located behind the plane of the roll centers, the rolling was compressed along the sleeve wall. The friction forces arising during the reduction promote the movement of the liner in the axial direction (and at the moment of the end of the rolling and exit of the pipe from the deformation zone, they pull the pipe from the mandrel). Since the additional mandrel section increases its diameter during rolling, the sleeve due to deformation on the mandrel will also increase the diameter in this section, and the resulting tensile stresses along the pipe perimeter in the outlets, caliber reduce the wall thickness in the outlets and equalize the wall thickness of the cross section. Research Institute of the rolled stock. Since an additional section of the mandrel is located at the exit, from the deformation zone, the wall formed on it and will characterize 1.: the wall of the finished pipe. Obtaining a more accurate pipe wall will allow deformation in a smaller number of passes, since it is possible to increase the partial reduction of the wall in a single pass in the mill, which increases its productivity. Forming an additional area mates with the end surface of the mandrel radius-to prevent the occurrence of scoring and scratching on the inner surface of the pipe. FIG. 1 shows the described mandrel with an additional area; in fig. 2 - deformation center. The mandrel consists of a truncated cone 1, a cylindrical section 2, an additional truncated cone 3 with a height along the axis of the mandrel equal to 0.1-0.3 of the diameter of the cylinder, and forming an angle of inclination equal to 15-35 °. When using the mandrel rolling is as follows. The sleeve-shaped blank is set into calibrated rollers 4 with an axial plane Y Y and rolled into a pipe on the mandrel. The mandrel is fixed on the rod 5, and its additional cone 3 is extended along the rolling (axis) from the axial plane of the rolls. On a part of the mandrel 1 of the mandrel, pressure is pressed (reduced to the diameter of the sleeve), on the other part and section 2 simultaneous: reduction of its diameter. On the cone 3 is the compression on the wall of the sleeve with a simultaneous increase in the sleeve diameter and the final formation of the wall and the diameter of the finished pipe. The proposed mandrel of an automatic mill increases the rolling stock and mill productivity. The invention of the mandrel of an automatic mill, comprising a truncated cone and a cylindrical section adjacent to its larger base, is characterized in that, in order to reduce the transverse difference in pipe thickness, it is provided with an additional truncated cone adjacent a smaller base to the cylindrical section and having a height of 0 1-0.3 diameter of the cylindrical section and the angle of inclination of the generatrix equal to 15-35 °. Sources of information accepted. into account in the examination, 1. US patent, s№ 361O012, kl.72-209, U971.

2. Danilov, F. A., Gleyberg, A. Z. Balakin, V. G. Gore, rolling and pressing of pipes, Moscow, Metallurgists, 1972, p. 253.