RU2428267C2 - Longitudinal rolling mill three-roll stand - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, particularly, to production of seamless tubes and bars. Proposed stand comprises foundation, three encased rolls arranged through 120° and roll case turn drive. Said foundation is made up of two semi-foundations, rigidly jointed together. Roll cases are hinged with support pins arranged in one of said semi-foundations, roll case drive is made up of hydraulic cylinders mounted in another semi-foundation. Note here that angle between plane passing through support pin and working roll axes and semi-foundations joint plane exceeds that of roll bite.

EFFECT: regulated rolls opening and closing speeds.

3 dwg

Description

The invention relates to the field of rolling production and relates to the improvement of the design of a three-roll mill stand for longitudinal rolling for the production of seamless pipes and long sections of circular cross section.

Known three-roll mill stand for longitudinal rolling, see US patent No. 5144827, class. B21B 13/00, claimed 07/11/91, publ. 09.09.92, containing the bed, placed in the bed through 120 ° on the eccentric shafts, three work rolls and a worm drive turning the eccentric shafts to adjust the caliber of the stand.

The main drawback of the design of this three-roll mill stand for longitudinal rolling is the impossibility of rolling products with thinned ends, since it is impossible to reduce and breed work rolls during the rolling process, and this, in turn, limits its technological capabilities. This is because the rotary drive of the eccentric bushings is made using a worm gear with low efficiency, quickly wearing out, and its use as a power is unreliable during operation.

Another drawback of the three-roll stand design under consideration, limiting its technological capabilities, is the insufficient speed of the eccentric mechanism with a worm drive, which leads to an increase in the end waste of products, a decrease in the yield and productivity of the entire unit under conditions of high rolling speeds.

Of the known three-roll stands of longitudinal rolling mills, the closest in technical essence is the three-roll stand of the longitudinal rolling mill described in German Patent No. 10015340, cl. B21B 13/10, claimed 03/28/2000, publ. October 11, 2001. This cage contains a bed, three work rolls installed in it through eccentric bushings through 120 ° in the housings, and a rotation drive for these eccentric bushings for adjusting the caliber of the cage. The rotary drive of the eccentric bushings is equipped with a bevel gear and is located on the front side of the stand frame.

The main drawback of the design of this stand is the impossibility of rolling products with thinned ends, since it is impossible to reduce and breed work rolls during the rolling process, and this limits its technological capabilities. This is because in the adjustment of the stand gauge there is no mechanical power or other drive, and the conical drive used is suitable only for radial adjustment of the stand gauge between passes.

The objective of the present invention is to expand the technological capabilities of a three-roll mill stand for longitudinal rolling.

The problem is achieved in that in a three-roll mill stand of a longitudinal rolling mill containing a bed, three work rolls and 120 rotational drives of the housings located in it in the housings through 120 °, according to the invention, the bed is made of two semi-rigidly fixed to each other, the roll casings are hinged with with support pins located in one of the half-beds, and the drive of rotation of the hinged housing of the rolls is made in the form of power hydraulic cylinders mounted in another half-frame, while the angle between the plane, going through the axis of the support pin and the corresponding work roll, and the plane of the connector of the half-shell is greater than the angle of metal capture by the roll.

Such a constructive implementation of a three-roll mill stand for longitudinal rolling allows you to expand its technological capabilities.

Firstly, in the proposed stand, it is possible to manufacture products with thinned ends due to the possibility of adjusting the caliber of the stand during the rolling process. This is achieved by turning each articulated housing together with the work roll located therein around the support pin using two power cylinders.

Secondly, in this stand it is possible to obtain products with the required length of the thinned ends at high rolling speeds. This is achieved due to the possibility of moving the articulated housings with work rolls in an adjustable wide range of speeds from the power cylinders.

In addition, the design of a three-roll mill stand for longitudinal rolling allows a stable task of the metal in the rolls from either side of the bed. The stable task of the metal is achieved due to the fact that the angle α between the plane passing through the axis of the support pin and the corresponding work roll and the plane of the half-joint is larger than the angle β of metal capture. When this condition is met, the power cylinders prevent the gripping force Q from turning the hinged bodies with rolls around the support pins counterclockwise and hold the rolls in the desired position.

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

figure 1 shows a General view of the crate with the uninstalled,

figure 2 - section aa in figure 1,

figure 3 is a section bB in figure 1

The three-roll stand of the longitudinal rolling mill contains a bed consisting of two half-stands 1 and 2, fixed between each other by threaded couplers 3, three work rolls 4 with drive shafts 5, which are placed in hinged housings 6, balancing devices 7 in the form of springs and six power hydraulic cylinders 8 located in the peninsula 2.

The hinged body 6 with the work rolls 4 can be rotated from the power hydraulic cylinders 8 around the support pins 9, which are installed in the half-frame 1. The plane passing through the axis of the support pin 9 and the corresponding work roll 4, is inclined to the plane of the connector “a” half-frame 1 and 2 at an angle α, which is greater than the angle β of capture of the metal by the roll.

When rolling in the proposed three-roll stand, the rolling force from each work roll 4 through the hinge body 6 and the support pin 9 is transmitted to the half-beds 1 and 2, fastened with threaded ties 3, which ensures high rigidity of the caliber of the stand d _to .

In the manufacture of products with thinned ends during the rolling process, a change in the caliber of the stand d _k is required, with a decrease in d _k , hydraulic fluid is pumped into hydraulic cylinders 8, and with an increase in d _k , hydraulic fluid is displaced from hydraulic cylinders 8.

The required length of the thinned ends of the rolled products is obtained due to the adjustment during the rolling of the speeds of information and breeding of the work rolls 4 according to technological requirements.

The proposed design of a three-roll mill stand for longitudinal rolling compared with the known allows to expand its technological capabilities.

Claims (1)

A three-roll mill stand of a longitudinal rolling mill, comprising a bed, three work rolls housed in the housings through 120 ° and a rotation drive of these housings, characterized in that the bed is made of two half-beds rigidly fixed to each other, the roll housings are hinged with support pins located in one of the half-beds, and the drive of rotation of the hinged casings of the rolls is made in the form of power hydraulic cylinders mounted in another half-shelf, with the angle between the plane passing through the axis of the support pin and the corresponding stvuyuschego work roll and the plane of the connector polustanin more metal roll nip angle.

Images