RU2487771C1 - Tube cold-rolling mill stand - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed mill stand comprises stationary bed, support rails, mobile housing with vertical rolls and pads engaged with its drive, roll rack drives and fixed racks and gears fitted on axles, and pressure roll adjustment mechanisms with screw pairs. Easier access to stand components and its accurate positioning are ensured by furnishing it with the frame locked at said stationary bed by wedge joint. Frame bottom part has grooves for locking it against lengthwise displacement at support bars. Frame mid part has recess for roll and ledge for rack. Frame rear end has extending part for bearing rails. Two detachable guides are arranged on stand opposite sides, between support rails and mobile housing. Top part of every guide has surface with two ledges at its edges for reliable joint with mobile housing while bottom part has two horizontal and one vertical surfaces lined by straps to get in contact with support rails and straps of bars fitted in bed. Horizontal and vertical surfaces of every guide direct mobile housing with rolls in rolling axis.

EFFECT: higher quality of rolled tubes and expanded range of tubes, decreased overall dimensions and better operating performances.

3 dwg

Description

The invention relates to rolling production, and more specifically to the working stands of cold rolling mills of pipes with a movable power bed.

Known working stand of the cold rolling pipe mill (see AS USSR No. 1131569, class B21B 21/00, decl. 03.11.82, publ. 30.12.84), containing a fixed frame connected to the drive movable a housing with rolls, their rack-and-pinion drive with fixed rails and gears on the rolls. The bed is made with longitudinal rectangular grooves having upper and lower contact surfaces, and additional side contact strips adjacent to the grooves. The upper contact surfaces of the grooves and the side contact strips are made in the form of removable bars and are equipped with a drive transverse relative to the grooves and wedge clips.

The disadvantage of this design of the working stand is the inability to firmly fix the removable beam in the bed, forming the upper contact surface and bearing an additional contact strip, due to insufficient rigidity of the bed over the wedge clamp of the beam. The removable bars have a considerable length equal to the sum of the length of the protrusion of the movable body and the stroke length of the stand, ~ 1.5 m. In accordance with the length of the beam in the bed, a window is made for its fastening. The upper part of this window is a weak double-support beam, which serves as a support for the wedge retainer. It is not possible to tighten the wedge clips securely in the long window of the bed.

The appearance of backlash in the places of fastening of the beam will lead to a decrease in the quality of rolled pipes and premature wear of the guide surfaces.

Another disadvantage of the stand is the unreliable installation of the roll drive rail due to insufficient rigidity of the bed. The rail is installed above the window for fastening the beam on a weak double-beam beam, which is wedged by wedge clamps. Any constriction of the wedge retainer leads to the curvature of the beam, and with it the rails. The contact spot and lateral gaps in the rack mesh are broken, it quickly fails, which leads to a stop of the working stand.

Of the known working stands of the cold rolling mill, the closest in technical essence is the working stand described in A.S. USSR No. 1490778, class B21B 21/00 claimed 11.19.87, publ. 04/27/2000

This working stand of the cold rolling mill includes a fixed bed, support rails, a movable casing connected to the drive with vertical rolls, guides and pillows, their rack-and-pinion drive with fixed racks and gears on the rolls, pressure roll adjustment mechanisms with screw pairs. The fixed bed is poured into concrete. The supporting rails are made in a fixed bed. The guides are made in one piece with a movable housing.

A disadvantage of the known design of the working stand of the cold pipe rolling mill is that during the operation of the mill, the supporting surfaces under the rails break, and uneven along the length of the stand, the rails gradually tilt and lead the cage off the rolling axis. In this regard, the quality of rolled pipes decreases.

The skew of the rails is compensated by wedge gaskets, which is technologically difficult and does not allow the crate to be installed on the rolling axis with high accuracy.

The location of the support rails in a fixed bed, poured into concrete, eliminates the removal of the bed for repair work related to the machining of broken support surfaces of the bed on a milling machine.

The disadvantage of the working stand of the cold rolling mill is also the lack of the possibility of unifying the bed, poured into concrete, for installing different types of working stands in it (stand with half-disk gauges, stand with ring gauges, stand with support rolls, stands with horizontal and vertical rolls, etc. further), which narrows the technological capabilities of the mill and limits the range of rolled pipes.

In addition, due to the implementation of the guides in one piece with the movable housing, it is difficult to mount and dismantle the working stand. To remove from the bed and install the movable housing into the bed, when replacing worn slide plates and support rails, it is necessary to make openings in the bed that allow the guides of the movable housing to pass, or remove and then install the front end wall of the bed. In the first case, the dimensions of the stand increase, in the second, the operational properties of the service deteriorate.

The objective of the present invention is to create a working stand for cold pipe rolling mill, which allows to improve the quality and expand the range of rolled pipes, reduce dimensions, improve operational properties.

The task is achieved by the fact that the working stand of the cold pipe rolling mill, comprising a fixed bed, support rails, a movable housing connected to the drive with vertical rolls, guides and pillows, their rack-and-pinion drive with fixed racks and gears on the rolls, pressure roll adjustment mechanisms with screw pairs, according to the invention, is equipped with a frame fixed in a fixed frame from lateral movement by a wedge connection, including a wedge, a podlink and expansion screws, in the lower part the frame has grooves for fixing it against longitudinal movement on the support bars installed in the fixed bed, in the middle part of the frame there is a recess under the roll and ledges under the rail, and the rear end of the frame has extensions under the support rails, in addition, the guides are removable and located on opposite sides on the stand between the support rails and the movable housing, while in the upper part of each guide a plane is made with two protrusions at the edges.

Such a constructive implementation of the working stand of the cold pipe rolling mill can improve the quality and expand the range of rolled pipes.

Improving the quality of rolled pipes is achieved through the use of a frame installed between the frame, poured into concrete, and the movable housing of the working stand and fixed from longitudinal and transverse movements in the frame. When the mill is operating, the surfaces on the frame under the support rails are broken, moreover, unevenly along the length of the stand, the rails gradually tilt and lead the stand away from the rolling axis. In this regard, the quality of rolled pipes decreases. To remove the uneven wear of these surfaces, the frame is removed from the mill and mounted on a milling machine, followed by machining of the respective surfaces. The resulting understatement of surfaces is compensated by the installation of flat gaskets under the support rails, exposing the working stand exactly along the axis of rolling, which ensures high quality of rolled pipes.

The expansion of the range of rolled pipes is achieved through the unification of the bed, poured into concrete for the installation of various types of casings and rolls. When rolling pipes of high accuracy from difficult to deform materials, housings are mounted on rails with vertical rolls, and a frame is used. When rolling pipes of low accuracy from easily deformable materials, housings are mounted on rollers with horizontal rolls, while the frame is dismantled.

In addition, the proposed implementation of the working stand will reduce the size and improve its operational properties. This is achieved by making the rails removable with protrusions at the edges, which provides easy access to the planks and support rails that are worn during rolling to repair or replace them.

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 cold rolling mill of pipes in section;

figure 2 is a section aa in figure 1;

figure 3 is a section bB in figure 2.

The working stand of the cold pipe rolling mill contains a fixed bed 1, support rails 2, a movable housing 4 connected to the drive 3 with vertical rolls 5 and pillows 6, gear rack drives of rolls 5 with fixed rails 7, 8 and gears 9, 10, mounted on rolls 5, and pressure adjusting mechanisms 11 of rolls 5 with screw pairs 12. The working stand is equipped with a frame 13, which is fixed in the stationary frame 1 from lateral movement by a wedge connection, including wedge 14, wedge 15 and threaded screws 16. In the lower part of the frame 13, grooves 17 are made for fixing it from longitudinal movement on the support bars 18. In the middle part of the frame 13, a recess 19 is made under the roll 5 and projections 20 under the rail 8. The rear end of the frame 13 has extensions 21 under the support rails 2. On two removable guides 22 are installed on opposite sides between the support rails 2 and the movable housing 4. A plane 23 is made in the upper part of each rail 22 with two protrusions 24, 25 at the edges, which ensure its reliable connection with the movable housing 4, and in the lower part - two horizons 26, 27 and one vertical 28 plane, lined with straps 29, 30, 31 and in contact with the support rails 2 and straps 32 of the bars 33 installed in the frame 1. Horizontal planes 26, 27 and a vertical plane 28 of each rail 22 orient the movable housing 4 with rolls 5 along the axis of rolling.

The working stand of the cold rolling mill works as follows.

When rolling pipes, the housing 4 with rolls 5 and guides 22 makes a reciprocating movement from the drive 3, while the straps 29, 31 slide along the support rails 2, and the straps 30 along the straps 32. Uneven wear of the straps 29, 30, 31, 32 and support rails 2. At the same time, the surfaces under the support rails 2 on the frame 13 are unevenly broken. The working stand gradually leaves the rolling axis. There is a need to repair or replace worn strips 29, 30, 31, 32 and support rails 2 and to remove uneven wear under the support rails 2 on the frame 13.

Removing worn strips 29, 30, 31, 32 and support rails 2 for repair or replacement is performed as follows:

- the traverse of the upper rail 7 is removed;

- the guides 22 and the drive 3 are disconnected from the housing 4;

- the housing 4 with rolls 5 is removed from the frame 1;

- with a slope, the guides 22 are removed from the bed 1 along with the slats 29, 31;

- strips 29, 30, 31, 32 are removed, they are being repaired or replaced.

Uneven wear of the surfaces under the support rails 2 on the frame 13 is removed by machining the respective surfaces. For this, the frame 13 is removed from the bed 1 and installed on a milling machine.

The resulting understatement of the surfaces on the frame 13 is compensated by installing 2 flat gaskets under the support rails, exposing the working stand exactly along the rolling axis.

The proposed design of the working stand of the cold pipe rolling mill in comparison with the known ones allows to improve the quality and expand the range of rolled pipes, reduce its dimensions and improve operational properties.

Claims (1)

The working stand of the cold pipe rolling mill, comprising a fixed bed, support rails, a movable housing connected to the drive with vertical rolls, guides and pillows, their rack-and-pinion drive with fixed racks and gears on the rolls, pressure adjustment mechanisms of the rolls with screw pairs, characterized in that it is equipped with a frame fixed in a fixed frame from lateral movement by a wedge connection, including a wedge, podshelnik and screws of a thrust, grooves are made in the lower part of the frame to fix it from longitudinal movement on the support bars installed in the fixed bed, in the middle part of the frame there is a recess under the roll and ledges under the rail, and the rear end of the frame has extensions under the support rails, while the guides are removable and are located on opposite sides of the stand between the support rails and the movable housing and in the upper part of each guide a plane is made with two protrusions at the edges.

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