RU1001569C - Method of adjusting tree-high mill of screw rolling - Google Patents

Description

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The invention relates to the processing of metals by pressure and relates to the setting up of three-roll helical rolling mills.

The closest of the known technical solutions to the present invention is a method of setting up a three-roll helical rolling mill, which includes the installation of the upper and lower work rolls on the caliber, the smallest in the dimensional gauge, when they are initially placed around the axis of rolling through 120 °, subsequent radial relative to the axis of this caliber the movement of the rolls during the transition to other calibers, and the amount of movement of all three rolls in the known method is the same.

When adjusting the speed of the rolling mill of a helical rolling according to a known method, a fixed position maintains the rolling axis coinciding with the axis of the mill and the axis of the rolled billet. Therefore, when rolling billets and rods of different diameters, its lower formers do not remain at the same level, but rise with decreasing diameter of the billet or rod and descend with its increase.

A disadvantage of the known method of setting up three-roll helical rolling mills is that, in order to carry out the rolling process of billets and rods of a wide dimensional mix, it is necessary to have complex equipment on the upstream and downstream sides of the mill, with which the billet is held on the rolling axis. Therefore, as a rule, on the exit side of the mill, complex lever tse.natory are used, and on the entrance side - chute adjustable in height. When the workpiece or rod is reduced per millimeter to hold them on the rolling axis, the solution of lever centerers is reduced or the lower gutter forming is set to a higher level.

The greatest movement of the lower forming preform, and hence the more complex equipment at the mill inlet and outlet, is required for helical rolling of large ingots, carried out in several, with large (up to 50%) total reduction. In this case, the adjustment of the gutters at the entrance and exit must be carried out after each pass, which increases the time of pauses between passes and, consequently, decreases the productivity.

If the input and output sides of the mill are set incorrectly relative to the axis of the gauge, the conditions for gripping the workpiece by rolls deteriorate, and during the rolling process, the front and rear ends of the roll significantly beat on the input and output sides of the mill, which leads to equipment breakdowns and an increase in repair time.

The aim of the invention is to simplify the design and operation of the equipment of the inlet and outlet sides of the mill by maintaining the level that forms the lower part of the roll and thereby increases productivity.

0 The goal is achieved by the fact that in the method of setting up a three-roll mill, including the installation of the upper and lower work rolls on the caliber, the smallest in the size range, at their initial

5 placed around the axis of rolling through 120 ° and subsequent radial relative to the axis of this gauge, the movement of the rolls during the transition to other calibers, the radial movement of the lower rolls is produced

0, a is 4.1-8 times smaller than the radial displacement of the upper roll. The drawing shows the deformation zone in the plane corresponding to pinching the rolls, the cross section.

5 The upper work roll 1 and the lower work rolls 2 form a specific caliber equal to the diameter of the roll 3.

Setting up the mill according to the described method is as follows. The installation of the work rolls around the axis of rolling through 120 at the smallest caliber in ethane gauge corresponds to the position of the e axis points OO, OO, OO. When switching to a larger gauge, all rolls move radially relative to the axis of the first gauge, and the lower rolls 2 move by 4.1-8 times less than the amount of movement of the upper roll 1. In this case, the lower forming rate remains at the same level, and the axis of the rolls occupy the position Oi, Oi, Oi. The axis of the caliber is shifted to position Ai.

The specific movements of the upper and lower rolls depend on the diameter of the initial and final gauges, the radius of the work rolls, the distance from the axis of intersection of the planes of movement of the axes of the rolls (point A) to the lower generator of the workpiece (point B) and are determined by the geometrical parameters of the hearth. deformations.

Let, during the adjustment period, the upper roller be moved by the value of SB, and the lower by the value of SH. Then, in order for the lower n forming roll to remain at the same level, the upper roll must be moved by an amount equal to the difference in the diameters of the final di and initial do gauges

SB di-do 2 (ri-ro).

The amount of movement of the lower roll during the adjustment period will be equal to

SH V (R + ri) 2-3 / 4 {ri-ro) 2.

where R is the radius of the roll at the beginning of the calibrating area;

Go is the radius of the gauge at a symmetrical deformation zone — the distance from the axis of intersection of the planes of movement of the axes of the rolls (point AO) to the lower generator of the workpiece (point B).

Calculations show that for existing and designed screw rolling mills

4.1 - 8.

SH

For example. In a three-roll mill, a billet with a diameter of 120 mm is rolled into a round billet with a diameter of 50 mm in seven passes.

A stack of gauges 110, 100, 90, 80, 70, 60 and 50 mm is adjusted by radial movement of the rolls. Take the diameter of the work rolls 300 mm, the radius of the smallest caliber with a symmetric deformation zone 25 mm. In order for the lower forming pacKata to remain in a constant position, the SB / 5 ratio is at a transition from a caliber of 110 mm.

Claims (1)

Invention Formula P METHOD OF SETTING A TRAHVALKOVOGA SCREW MILL OF PREFERABLE predominantly varietal profiles, including the installation of the upper and lower work rolls on the caliber, the smallest in the dimensioned assortment, with their initial placement around the rolling axis through 120 and the subsequent radial per caliber 100 mm 4.94, with a caliber of 100 mm per caliber 90 mm 4.77, with a caliber of 90 mm per caliber 80 mm 4.60, with a caliber of 80 mm per caliber of 70 mm 4.43, with a caliber of 70 mm per caliber 60 mx 4.2 and from a caliber of 60 mm to a caliber of 50 mm 4.1. When breeding rolls, from a caliber of 50 mm to a caliber of 110 mm, for subsequent rolling, it is necessary to adjust the mill with a ratio of 5c / 8n 4.5. With this setting The mill forming the bottom roll remains at the same level, which allows to simplify the design of the Equipment at the mill inlet and outlet, which can be performed, for example: in the form of massive grooves with closing lids. The setting of the mill during rolling in this case can be carried out with a constant SB / SH ratio of 4.5. In this case, the lower forming blanks will be insignificant. (0.2 ×), 7 mm. change its position in height, which does not require additional configuration of auxiliary equipment. Thus, the use of the proposed setting method allows to increase the mill capacity by reducing the time of auxiliary operations, to simplify the design and operation of equipment for the input and output sides of the mill. V; ; -: --- .; :; (56) Danilov F.A. and others. Gore cha pipe rolling, M .: Metallurgizdat, 1962, p. 404. relative to the axis of this gauge, the movement of the rolls during the transition to other calibers, characterized in that, in order to simplify the design and operation of the equipment of the input and output sides of the mill by maintaining the level of the lower generator of the roll and increasing through this productivity, the radial movement: by a value of 4.1 - 8 times less than the values of the radial displacement of the upper roll.