RU2345851C2 - Operating mill stand of lengthwise rolling - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: operating mill stand of lengthwise rolling contains body, installed in it each 120° and having individual drive, three rollers with bearing assembly, cushions and cross bars and radial regulation mechanism of rollers. Mill body corresponds two round plates with guide ways and outfitted by located in these guide ways three cartridges, in each of it is located roller with bearing assembly, cushions and cross bars. Mechanism of rollers radial regulation is implemented in the form of three couples of screws tightening cartridges to each other and forming two equilateral triangle, each of it cooperates through ball washers with located in cartridge nuts and outfitted on its ends balance mechanism, and in the form of located in hydraulic actuator cartridges, bearing through spherical step-bearing on cross bars.

EFFECT: simplification of roll space setting, mill hardening, reduction of steel intensity and overall dimensions of mill and of all lengthwise rolling stand totally, enhanced accuracy of received products.

3 dwg

Description

The invention relates to the field of pipe production and relates to the design of stands of longitudinal rolling mills of round grade, wire and can most effectively be used in continuous mills for the production of seamless pipes.

In world practice, for the production of round cross-section varieties, wire and pipes by continuous longitudinal rolling, the stands with two rolls are most widely used.

The two-roll working stand of the longitudinal rolling mill of the P-600 series is known, manufactured by the Swedish company Centro-Morgerdshammer, see A.N. Ivoditov. Reconstruction and modernization of high-quality rolling mills. M .: Metallurgy, 1993, pp. 94, 95, containing support racks, individually driven, two rolls with bearing supports, pillows and a pillow mounting mechanism, which consists of two screws, nuts and spherical linings, and a mechanism for radial adjustment of the rolls, made in the form of four screws moving from a separate pressure mechanism.

The main disadvantage of this two-roll working stand for longitudinal rolling is that when rolling billets (rough tubes) in a two-roll caliber due to the uneven distribution of metal flow velocities and rolling forces around the circumference of the gauge, the deformation process is heterogeneous, which leads to deviations in wall thickness and pipe diameter and other products obtained.

Another disadvantage of the rolling process in a two-roll stand of a longitudinal rolling mill is the large contact surface of the metal with two rolls, resulting in increased metal pressure on the rolls, which causes a decrease in their durability.

Recently, for the production of circular cross-sections, wires and pipes, three-roll stands have been increasingly used, in longitudinal rolling, in which there are no disadvantages inherent in the longitudinal rolling process in two-roll stands, since in the three-roll caliber the deformation process is more uniform due to a more uniform distribution of metal flow rates and rolling efforts around the circumference of the caliber, which allows to increase the accuracy of the resulting pipes and other products, and the contact surface area of the metal with three rolls less, as a result of which the metal pressure on the rolls decreases and, consequently, the durability of the rolls increases.

Of the known three-roll working stands of longitudinal rolling mills, the closest in technical essence is the three-roll working stand of the longitudinal rolling mill described in US application No. 2001/0035037, class. 72-224, claimed 03/28/2001, publ. November 01, 2001. This working stand includes a housing installed in it through 120 ° and having an individual drive of three rolls with bearing bearings, pillows and traverses and a mechanism for radial adjustment of the rolls, made in the form of eccentric bushings with a drive for turning them through a bevel gear, a drive shaft and a gear disk and a connecting element rigidly fixed on it and between each other, through which the entire mechanism for adjusting the rolls is actuated.

The main drawback of the design of this stand is the complicated process of adjusting the roll distance, which is carried out here with the help of eccentric bushings with a drive to rotate them and is associated with calculating the mathematical relationship between the angle of rotation of the eccentric bushings and the change in the roll distance.

Another drawback of the construction of this stand is the presence of a bulky body that receives the rolling force, in which, in addition to tensile stresses, bending moments also arise, which work to break, as a result of which the rigidity of the stand decreases and rolling of workpieces (rough pipes) in it becomes possible only with small reductions in one pass, which leads to the installation of additional working stands, and this, in turn, increases the metal consumption and the dimensions of the mill. In addition, the low rigidity of the working stand reduces the accuracy of the resulting products.

The objective of the present invention is to provide such a design of the working stand of the longitudinal rolling mill, which allows to simplify the setting of the roll distance, increase the rigidity of the stand, reduce the metal consumption and dimensions of the stand and the entire longitudinal rolling mill as a whole, and increase the accuracy of pipes and other products obtained.

The task is achieved by the fact that in the working stand of the longitudinal rolling mill, comprising a housing installed in it through 120 ° and having an individual drive three rolls with bearing supports, pillows and traverses and a mechanism for radial adjustment of the rolls, according to the invention, the casing body is made of two round plates with guides and is equipped with three cassettes located in these guides, in each of which there is a roll with bearing bearings, pillows and a traverse, and a mechanism for radial adjustment of the rolls flax in the form of three pairs of tightening cassettes between themselves and forming two equilateral triangles of screws, each of which interacts through spherical washers with nuts placed in the cassette and is equipped with balancing mechanisms at its ends, and in the form of hydraulic cylinders located in cassettes, supported through traverses on spacers .

Such a constructive implementation of the three-roll working stand of the longitudinal rolling mill makes it possible to simplify the adjustment of the roll distance by moving cassettes with rolls, pillows and traverses placed therein by means of screw pairs.

In addition, for more precise adjustment of the roll distance, the stand design provides for additional adjustment of the rolls using the hydraulic cylinders installed in the cartridges.

Another advantage of the stand is its lightweight, small-sized design and increased rigidity, achieved by performing the stand body in the form of two lightweight plates, in which there are three cassettes with rolls, pulled together by the receiving force of rolling three pairs of screws.

The increased rigidity provides large reductions in the stand in one pass, which allows the use of a small number of stands on the longitudinal rolling mill and thereby reduce its metal consumption and dimensions.

The increased rigidity of the cage also allows to obtain products of high accuracy.

Another advantage of the design of this stand is its quick disassembly and assembly in the mill line.

To explain the invention, a specific embodiment of the invention is provided below with reference to the accompanying drawings, in which:

figure 1 shows the working stand of the longitudinal rolling mill in section,

figure 2 is the same, a view along arrow A in figure 1,

figure 3 is the same, a section bB in figure 2.

The working stand of the longitudinal rolling mill comprises a housing made in the form of two round plates 1 with guides 2 in which three cassettes 3 are placed. Each cassette 3 has a roll 4 with bearing bearings 5, pillows 6 and a connecting pillow 6 with a traverse 7. Three rolls 4 together with cassettes 3 are installed in the guides 2 of the plate 1 through 120 ° and have an individual drive. Cassettes 3 are pulled together by three pairs of screws 8, forming two equilateral triangles between each other and with the help of which the roll distance is adjusted. Each screw 8 interacts through spherical washers 9 with nuts 10 located in the cassette 3, and is equipped with balancing mechanisms 11 at its ends. For additional adjustment of the rolls 4, hydraulic cylinders 12 located in the cassettes 3 are used, which rely on the yokes 7 through the spherical thrust bearings 13.

When rolling in a working stand of a longitudinal rolling mill, the workpiece (rough tube) passes through a gauge formed by three rolls. The force arising during rolling is perceived by the bearing bearings 5 of the rolls 4 and transmitted through the pillows 6 and the beam 7 to the cassettes 3, which tend to diverge from the rolling axis. The displacement of the cassettes 3 is prevented by the pulling cassettes with each other three pairs of screws 8.

The adjustment of the roll distance in the stand is as follows:

- first, by synchronous rotation of three pairs of screws 8 simultaneously, cassettes 3 with rollers 4, their bearing supports 5, pillows 6 and traverses 7 are displaced by screws in three directions to the required distance,

- then, to adjust the caliber, already in the process of rolling, the rolls 4 are moved individually or simultaneously using the hydraulic cylinders 12 installed in the cassettes 3, which, through the spherical thrust bearings 13, act on the cross beams 7 and, accordingly, on the rolls 4.

Transshipment of rolls in the stand is as follows:

- cassettes 3 are screwed apart by an amount greater than Δ when the rolls 4, pillows 6 and crosshead 7 can be removed from the cassettes.

The proposed design of the working stand of the longitudinal rolling mill in comparison with the known ones makes it possible to simplify the setting of the roll distance, increase the rigidity of the stand, reduce the metal consumption and dimensions of the stand and the entire longitudinal rolling mill as a whole, and increase the accuracy of the products obtained.

This design of the working stand also allows you to quickly disassemble and assemble it in the mill line.

Claims (1)

The working stand of the longitudinal rolling mill, comprising a housing installed in it through 120 ° and having an individual drive, three rolls with bearing bearings, pillows and traverses and a mechanism for radial adjustment of the rolls, characterized in that the housing of the stand is made of two round plates with guides and equipped with placed in these guides by three cassettes, in each of which there is a roll with bearing bearings, pillows and a traverse, and the mechanism of radial adjustment of the rolls is made in the form of three pairs of tightening cartridges I am waiting for myself and the screws forming two equilateral triangles, each of which interacts through spherical washers with the nuts placed in the cassette and has balancing mechanisms at the ends, and in the form of hydraulic cylinders located in the cassettes, supported through the spherical thrust bearings on the yokes.

Images