RU2438807C2 - Three-roll longitudinal rolling mill stand - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: three-roll stand comprises built-up foundation pivot arms arranged at 120° to accommodate rolls with bearing supports, and rolls drives and rolls balancing mechanisms fixed on foundation. Every pivot arm represents a bell crank fitted on swing axle in foundation with its one arm accommodating roll with bearing supports. Said arm stays in contact with roll radial drive. Second arm of every pivot arm stays in contact with roll balancing mechanism. Note that foundation joint is located on the plane of pivot arm swinging axes while the latter are located in bores.

EFFECT: lower production costs.

6 dwg

Description

The invention relates to the field of rolling production, and more specifically to the design of three-roll stands of longitudinal rolling mills for the production of seamless pipes and long sections of circular cross section.

Known three-roll mill stand for longitudinal rolling, see RF patent No. 79057, IPC B21B 13/10, 17/14, decl. July 22, 2008, publ. December 20, 2008

The known stand contains a detachable bed, work rolls placed on it on bearing supports, mechanisms for radial installation of rolls, interacting with bearing supports of rolls and installed in glasses placed in the bores of the bed, balancing mechanisms of rolls, each made in the form of traction passed through the cylinder rod and fixed nut, and the plane of the bed connector passes through the axis of the glasses.

The pillows of the bearing bearings of the work rolls are mounted in the flat guides of the stand bed with guaranteed mounting clearances for free movement during radial adjustment of the stand gauge.

The disadvantage of this stand design is the presence of the aforementioned mounting clearances, which during rolling lead to dynamic loads, leading to intensive wear of both the guide surfaces of the bed and the pillows of the bearing supports themselves.

This drawback leads to an increase in equipment downtime associated with the frequent replacement of worn-out equipment, lower annual mill productivity and higher production costs.

Another disadvantage is that, in order to transfer the stand, that is, replace worn rolls with new ones, it is necessary to spend, in addition to unfastening the two halves of the bed, additional time for disconnecting three electric motors and three balancing mechanisms, which also increases production costs.

Of the known three-roll stands of a longitudinal rolling mill, the closest in technical essence is the stand described in EP No. 1064107, IPC B21B 13/10, 17/04, decl. 03/02/99, publ. 07/03/2002 g.

This three-roll stand of a longitudinal rolling mill comprises a bed, swivel single-arm levers mounted at an angle of 120 ° with roller assemblies mounted on them, radial roller movement mechanisms in the form of hydraulic cylinders and roll balancing mechanisms in the form of hydraulic cylinders that select the gap between the single-arm lever and the radial hydraulic cylinder moving the roll.

A disadvantage of the known design of the three-roll mill stand of the longitudinal rolling mill is that the balancing cylinders do not select the mounting gap in the swing axis of the arm with the roll, which during rolling leads to the occurrence of dynamic shock loads in this connection, which cause progressive wear of both the axis and the one-arm lever , requires their frequent replacement and leads to significant production costs associated with the repair, maintenance of equipment and a decrease in the annual productivity of the mill.

In addition, since the stand bed is made one-piece, to replace either a worn roll, a worn single-arm lever, or the axis itself, it is necessary to press these axes both from the stand bed and from one-arm levers, which leads to an increase in costs (costs), associated with the repair and maintenance of equipment.

The objective of the present invention is to create a three-roll mill stand for longitudinal rolling, which allows to reduce production costs associated with frequent replacement of worn-out equipment, its repair, and to increase the annual productivity of the mill.

This object is achieved in that in a three-roll mill stand of a longitudinal rolling mill containing a bed, pivot arms mounted at an angle of 120 ° with rolls with bearing bearings placed thereon, radial roller movement mechanisms and roll balancing mechanisms mounted on the bed, according to the invention, each pivot arm is made two shoulders, a roller with bearings is located on one shoulder of the lever, and it is installed in contact with the mechanism of radial movement of the roll, and the second shoulder is rotatable of the lever is installed in contact with the mechanism of balancing the roll, in addition, the frame is made with a connector along the plane of the axes of swing of the rotary levers.

Such a constructive implementation of the three-roll stand of the longitudinal rolling mill allows to reduce production costs for equipment maintenance and increase the annual productivity of the mill.

This is achieved due to the fact that the lever on which the work roll is mounted is made two shoulders, namely, the roll itself is mounted on one shoulder, and the second shoulder is in contact with the balancing mechanism, which selects the mounting clearances both in the swing axis of the lever and in the mechanism radial movement of the roll, which during rolling eliminates dynamic (shock) loads in these joints, significantly reduces the cost of repair and maintenance of equipment, and also increases the annual productivity of the mill.

In addition, since the stand bed connector is located in a plane passing through the swing axes of the two-arm levers, the process of replacing worn rolls together with levers is greatly simplified, which also reduces the costs associated with repair and maintenance of equipment.

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

figure 1 - shows a three-roll mill stand of a longitudinal rolling mill, General view;

figure 2 is a view along arrow a in figure 1;

figure 3 - place B in figure 1 in an enlarged scale in section;

figure 4 is a section bb in figure 3;

figure 5 is a section GG in figure 3;

figure 6 is a section DD in figure 5.

The three-roll mill stand of the longitudinal rolling mill comprises a detachable bed 1, pivoting arms 2 mounted at an angle of 120 ° with rolls 3 mounted on them with bearings 4, mechanisms 5 for radial movement of the rolls 3 and mechanisms 6 for balancing the rolls 3 mounted on the bed 1.

Each of the rotary levers 2 is installed in the frame 1 on the swing axis 7 and is made two shoulders. On one shoulder “a” of this lever 2 there is a roll 3 with bearing bearings 4, and this shoulder is in contact with the mechanism 5 for radial movement of the roll 3, made in the form of pressure screws. The second shoulder "b" of each pivot arm is in contact with the balancing mechanism 6 of the roll 3, made in the form of a hydraulic cylinder.

The connector "in" of the frame 1 extends along the plane of the swing axes 7 of the swing arms 2. The swing axes 7 of the swing arms 2 are placed in the bores 8.

The crate works as follows.

Fine adjustment of the caliber of the stand "k" is carried out by the mechanism 5 of the radial movement of the rolls 3, with each two-arm lever 2, turning around axis 7, changes the caliber of the stand "k" in the right direction. The balancing mechanisms 6 constantly select the gaps in the mechanism 5 for the radial movement of the rolls 3 and the bores 8 of the split bed 1, in which the axles 7 are placed. When rolling, the metal pressure on each roll 3 is transmitted through the bearings 4 to the two-arm lever 2, axis 7, the radial mechanism 5 movement of the roll 3 and closes in the frame 1.

In this case, the balancing mechanism 6 is constantly on and selects the gaps both in the mechanism 5 for the radial movement of the rolls 3 and between the axis 7 and the bore 8 of the frame 1, which eliminates the occurrence of dynamic loads in them.

When transshipment of worn rolls 3, one part of the split bed 1 is removed, the roll assemblies with two shoulders levers 2 and axles 7 are removed and replaced with new ones. The number of operations is minimized.

The proposed three-roll mill stand for longitudinal rolling allows to reduce production costs associated with frequent replacement of worn-out equipment, its repair, and increase the annual productivity of the mill.

Claims (1)

A three-roll mill stand of a longitudinal rolling mill, comprising a bed, rotary levers mounted at an angle of 120 ° with rolls with bearings mounted on them, radial movement mechanisms for the rolls and roll balancing mechanisms fixed on the bed, characterized in that each rotary arm is made of two shoulders, on one shoulder the lever is a roll with bearing bearings, and the shoulder is installed in contact with the mechanism of radial movement of the roll, and the second shoulder of the rotary lever is installed in contact with the mechanism of balancing the roll, while the bed is made with a connector along the plane of the axes of swing of the rotary levers.

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