RU2422221C2 - Multiroll mill stand - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and may be used in production of straight-seam cylindrical and section tubes at continuous welding machines. Multiroll stand comprises annular foundation arranged in load bearing housing to turn from axis driven by rotational drive, working rolls with bearings and pads arranged in said foundation, and radial displacement wedge mechanisms. Stand comprises pedestal with opening and slide guides for vertical displacement, arranged on sides of said pedestal, and with annular foundation to support working rolls. Working rolls are stationary while their pads feature taper symmetric shape with their lateral inclined planes arranged to interact with radial displacement wedge mechanisms provided in rectangular openings of annular foundation. Annular foundation gearing is made up of spur gear fixed on annular foundation, gear with bearing, shaft and drive mounted on load bearing housing.

EFFECT: high quality of pipes.

2 cl, 6 dwg

Description

The invention relates to the processing of metals by pressure and can be used in the production of longitudinal seam cylindrical and shaped pipes on continuous tube welding units.

Due to the presence in the production of welded pipes of crescent, the thickness of the roll strip (billet), as well as the uneven heating and cooling of the welded billet during both welding and heat treatment of the weld, one of the most important issues in their production is the retention (stabilization) of the longitudinal weld in a vertical plane passing through the axis of the pipes.

This problem is especially relevant in the production of rectangular and square pipes, since according to state standards, the weld should be located in the middle of their sides.

Known crate pipe welding mill, see.with. USSR No. 835557, B21C 37/08, declared 07/12/1979, publ. 06/07/1981, the crate contains a frame on which, with the possibility of rotation relative to the axis of the pipe being welded, a housing with work rolls is mounted in the bearings. The rotation of the housing with rolls is carried out using a hydraulic cylinder rigidly fixed to the foundation, the rod of which is pivotally connected to a lever made on the housing.

A disadvantage of the known stand is the inability to provide, for a wide range of sizes of welded pipes, the moment necessary for each pipe size to be rotated around its axis to eliminate the constantly present weld retraction, including in different directions. This adversely affects the quality of the pipes.

Another disadvantage of the stand design is the limited turning zone of the pipe. This stand cannot be used in pipe-welding units equipped with a heat treatment line for the weld, when due to the above factors contributing to the continuous turn of the pipe, it is necessary to turn the welded pipe in one direction or another at any angle.

Of the known multi-roll stands, the closest in technical essence is the stand described in A.S. USSR No. 561578, B21B 13/02, decl. 01/03/1975, publ. 07/12/1977, the crate contains an annular bed, placed in the bearing housing with the possibility of rotation around its axis from the drive, work rolls with bearings and pillows installed in the bed, as well as wedge mechanisms for radial movement of work rolls.

The crate can be used in the manufacture of cylindrical welded straight-line pipes, however, in the manufacture of rectangular and square pipes, its use is generally impossible.

A disadvantage of the known stand design is the fact that radial compression of the workpiece requires a significant axial force to push it through the caliber, since the axis of the workpiece coincides with the axis of the rolls, which is unacceptable in the production of longitudinal joints in continuous units.

Another disadvantage of the stand is that in the production of pipes it is impossible to control the radial forces arising in the deformation zone on the rolls, especially in the production of thin-walled pipes of various sizes.

These shortcomings lead to a decrease in the quality of welded pipes.

The objective of the present invention is to create a multi-roll stand, which allows to improve the quality in the manufacture in continuous units of longitudinal seam cylindrical and shaped pipes of various sizes due to the rapid change in the position of the roll gauge with the displacement of the longitudinal weld in cross section.

The task is achieved in that a multi-roll stand containing an annular bed placed in a bearing housing with the possibility of rotation around its axis from a rotation mechanism with a drive, work rolls installed in the frame with bearing supports and pillows, as well as wedge mechanisms for radial movement of work rolls, according to the invention is equipped with a pedestal with a window, on the sides of which slide rails are made for vertical movement by means of a housing drive with an annular bed, bearing her work rolls, which are non-driveable, and the pillows of the work rolls are made of a trapezoidal symmetrical shape, the inclined side planes of which are installed in conjunction with the wedges of the radial movement mechanisms located in rectangular open windows provided in the ring frame, while the rotation mechanism of the ring frame is made in the form of a gear a cylindrical gear, the wheel of which is fixedly mounted on an annular bed, and the gear with bearings, shaft and drive are mounted on a carrier m case, in addition, a pair of wedges of each roll, farthest from the axis of the stand, is made of spring steel with through cavities and supporting platforms on sliding planes, while force sensors interacting with plates mounted on the non-inclined forked parts of these wedges are fixedly mounted inclined forked parts of said wedges.

Such a constructive implementation of a multi-roll stand will ensure high quality of both cylindrical and especially shaped pipes. This is achieved due to the fact that deviations of the pipe weld from the vertical plane passing through its axis and controlled by the sensor during its continuous production are eliminated without stopping the pipe welding unit by turning the welded pipe clamped by the rolls in the direction opposite to the direction of the weld from the vertical plane .

In this case, the rolls with their profile surface are installed using wedge mechanisms with the possibility of reducing the pipe in diameter up to 4% depending on its size, the magnitude of the radial forces on the rolls, which correspond to the amount of reduction and are directly proportional to the deformation of the wedges with through cavities. In case of excess of 4%, unacceptable residual deformations occur in the pipe body. The amount of deformation of the bifurcated parts of the wedges through the plate and the sensor is transmitted to the display of the cage control panel.

The drive of vertical movement of the annular bed with rolls allows you to always maintain the bottom of the pipe of any diameter at the same level, that is, the necessary condition in the pipe welding production is fulfilled: the bottom of the workpiece (strip, pipe) must be constant.

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 multi-roll stand;

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

figure 3 is the same, a section bB in figure 1;

figure 4 - the same place in figure 1;

figure 5 is the same, section GG in figure 1;

figure 6 - section DD in figure 5.

Multi-roll stand contains an annular bed 1, placed in the supporting housing 2 with the possibility of rotation around its axis from the rotation mechanism 3, which is made in the form of a gear cylindrical gear. The gear wheel 4 of the transmission together with the sliding bushings 5 is fixedly mounted on the ring frame 1, and the spur gear 6 with the rolling bearings 7, the shaft 8 and the drive 9 are mounted on the bearing housing 2. To rotate the welded pipes of large diameter around their axis, two cylindrical gears are installed with shafts, bearings and drives. Four work rolls 10 with bearing bearings 11, axles 12, pillows 13 of a symmetrical trapezoidal shape and wedge mechanisms 14 for radial movement of work rolls are mounted in an annular bed 1. The lateral inclined planes 15 of the pillows 13 interact with the wedges 16 of the radial movement mechanisms 14, which, together with the pillows 13, are placed in rectangular open windows 17 made in the ring frame 1.

A pair of wedges 18 of each roll, farthest from the axis of the stand, is made of spring steel with through cavities 19 and supporting pads 20 on the sliding planes 21, 22 and is placed on the perception side by working rolls 10 of radial forces.

At the same time, on the non-inclined forked parts of the wedges 18, force sensors 23 are fixedly fixed, interacting with the plates 24 mounted on the inclined forked parts of the wedges 18.

In addition, the multi-roll stand is equipped with a pedestal 25 with a window, a cover 26, a screw drive 27 for vertical movement, the screw 28 of which interacts with the housing 2. On the sides of the window there are slide guides 29.

Multi-roll stand operates as follows.

The welded tube 30 with a heat-treated chilled longitudinal seam and a horizontal side continuous line coated with special paint is fed by master gears (not shown) into a multi-roll stand, in which the roll gauge axis is previously aligned with the axis of the welded tube 30 using a screw drive 27 of vertical movement. Using wedges mechanisms 14 for radial movement of the sensors 23 efforts by the adjuster on the display on the control panel (not shown) are installed on a diameter that provides reduction ment of the pipe 30 by an amount up to 4%, depending on its size.

A sensor that monitors the position of the line drawn with special paint on the pipe 30, when it deviates from the nominal position in one direction or another, gives a signal to turn on the rotation mechanism 3 of the ring frame 1 with rolls 10 and turn it in the corresponding direction until the line applied to the pipe 30 will not be combined with this sensor.

The proposed multi-roll stand, in comparison with the known designs, will ensure high quality in the production of both cylindrical and shaped pipes.

Claims (2)

1. Multi-roll stand containing an annular bed placed in a bearing housing with the possibility of rotation around its axis from the rotation mechanism with drive, work rolls installed in the frame with bearing supports and pillows, as well as wedge mechanisms for radial movement of work rolls, characterized in that it equipped with a pedestal with a window, on the sides of which slide rails are made for vertical movement by means of a housing drive with an annular bed supporting work rolls that are made non-driveable, and the work roll cushions are made of a trapezoidal symmetrical shape, the inclined side planes of which are mounted in cooperation with the wedges of the radial movement mechanisms located in rectangular open windows provided for in the ring frame, while the rotation mechanism of the ring frame is made in the form of a gear cylindrical gear whose wheel is motionless mounted on an annular bed, and the gear with bearings, shaft and drive mounted on a bearing housing. 2. The multi-roll stand according to claim 1, characterized in that the pair of wedges of each roll farthest from the axis of the stand is made of spring steel with through cavities and supporting platforms on sliding planes, while force sensors are fixedly fixed on non-inclined bifurcated parts of these wedges interacting with plates mounted on inclined forked parts of said wedges.

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