GB2218658A - A device for axially adjusting the rolls of roll stands - Google Patents

Description

2'18658 21 1 i The invention relates to a device for axially setting the

rolls of roll stands, in particular for the production of steel sections, in which hydraulically actuated rockers in the form of two-armed levers act upon lugs extending from the bearing blocks of one of the rolls. The lugs engage over the roll stand, where a cylinder-piston unit acts upon the power arm of the lever and is connected via a shear pin to the roll stand, and in which devices for adjusting and fixing the position of the bearing block in the roll stand are provided between the lugs of the bearing block and the roll stand.

The adjustment and fixing of the relative axial position of a pair of rolls, in particular rolls for producing steel sections, is of great importance to the quality and dimensional accuracy of the rolled product. In particular during the rolling of asymmetrical profiles high axial forces arise which on the one hand must be absorbed in the housing and which must also be overcome when the rolls are set, underload, in order to correct the rolled section.

Known devices for axially setting the rolls as described in the introductory clause of Claim 1 employ wedges which are transversely displaceable between the lugs of the bearing block and the roll stand and which are moved by a drive motor. These wedges change the distance between the bearing block and the roll stand and because of their self locking action simultaneously serve to fix the bearing block in the adjusted position.

A disadvantage is that these wedges cannot be adjusted while the rolls are under load but can only be adjusted in order to set the rockers in the unloaded state, i.e. when the piston-cylinder unit has no load.

f 1 1 i 2 It has-also already been proposed (DE-OS 36 28 733) to provide double acting hydraulic cylinders on the bearing blocks of the rolls which, equi-axially with the rolls. permit these to be displaced under load. The arrangement is considered disadvantageous because it is necessary to absorb the tilting of the bearing blocks, which takes place due to the deformation of the rolls, in the roll stand in the cYlinder-piston arrangement for which purpose they must be articulated between pivot pins. When the rolls are removed it is necessary to detach hoses and cables which is disadvantageous in terms of time outlay and in terms of leakages which occur when hoses are detached. Finally it is always necessary to keep available a large number of piston- cylinder units, and generally three sets of bearing blocks are kept in stock in order to avoid idle periods when the section is changed.

On the basis of the described known approaches and their disadvantages the aim of the present invention is to improve upon a device for axial setting of the type described in the introduction so that on the one hand setting under load is easily possible and on the other hand the outlay relating to the stock supply of adjusting devices and with regard to the labour required to change rolls can be minimised.

Claims (3)

The means and measures described in Claim 1 are proposed to fulfil this aim. Favourable developments are described in the sub-claim. The invention proposes a device of the type in question so that advantage consists in that it is possible to displace the rolls under load without hydraulic units attached to the bearing block. This avoids the need for additional hydraulic units; the setting device remains on the roll stand thus also obviating the need to detach hoses or terminals. A favourable connection of the hydraulic system permits the necessary high pressures and by connecting the different hydraulic devices to one another precise adjustments under load and precise holding against the forces which occur during the rolling process are assured.

1 I- 3 An exemplary embodiment of the invention is illustrated in the drawings and will be described making reference thereto:

Figure 1 illustrates the setting device corresponding to the invention in a cross-section through the roll stand and Figure 2 a is section along the line A-B in Figure 1.

In Figure 1, 1 designates the upper roll of a sectional roll stand which is mounted in the bearing block 2. The bearing block, of which only half has been shown in Figure 1. is provided on both sides with lugs 3 which engage over the roll stand 4. Between the lugs 3 and the roll stand 4 is arranged the device corresponding with the invention for the adjustment and fixing of the roll 1, which will be described further in the following making reference to Figure 2.

The device corresponding to the invention also comprises the rocker which has been referenced 5 and which, by being pivoted about the point of articulation 6 to the roll stand 4, is actuated by the piston-cylinder unit 7 which on the one hand is attached to the rocker at 8 and on the other hand is attached via a shear pin 9 at 10 to the roll stand 4.

The rocker 5 is in the form of a two-armed lever which at its end facing towards the roll 1 comprises a cup-shaped support 11 for the lug 3 of the bearing block. The lever 5 can be pivoted into the fine-line position and in this position releases the bearing block for disassembly.

With reference to Figure 2 the piston-cylinder unit by which the roll 1 can be set will be described. The plunger piston 12 of the cylinder 12a presses on the lug 3 of the bearing block and the cylinder 12a is supported at its other end against the roll stand 4. The double acting hydraulic cylinder and piston 14 is arranged laterally of the cylinder 12a of the plunger piston 12 and can be used to displace the roll 1 axially under load when this is necessary. For this purpose the piston 14 is acted upon, whereby some oil is either delivered to or withdrawn from the cylinder 12a via the connecting bore 13. The same quantity of oil is conducted to or from the opposite side of the double acting piston 14 in a manner which has not been shown in the drawing from or to the cylinder 4 chamber of the piston-cylinder unit 7 so that the latter moves in synchronism with the plunger piston 12. This ensures a precise, synchronised movement of the locating elements for the upper roll namely the lever 5 and the plunger piston 12.

The double acting piston-cylinder unit 14 provides a compact unit by means of which the plunger piston 12 may be subjected to very high pressures (up to approximately 450 bar), and at the same time allows a synchronous control of the piston-cylinder unit 7 for the adjustment of the rocker 5.

As can be seen from Figure 1, a piston-cylinder unit 15 is arranged between the piston-cylinder unit 7 and the rocker 5. This small pistoncylinder unit serves to maintain an exact amount of play between the bearing block 2 and rocker 5 even when differences occur between one bearing block and another. The piston-cylinder unit 15 withdraws or delivers a small quantity of oil 8 from or to the piston-cylinder unit 7 so that identical conditions can be maintained when small dimensional differences exist between different bearing blocks.

-4 1 1 CLAIMS 1. A device for the relative axial adjustment of the rolls of a roll stand, in particular for the production of steel sections, in which at least one of the rolls is mounted in bearing blocks which are slidable with respect to the roll stand in the axial direction of the rolls, and hydraulically actuated rockers in the form of two-armed levers bear upon lugs which extend from the bearing blocks so as to define a variable gap between the roll stand and each lug, where the piston-cylinder units act upon the power arm of the lever and are connected via a respective shear pin to the roll stand, and in which means for adjusting and fixing the position of the bearing block relative to the roll stand are arranged in the gaps between the lugs of the bearing blocks and the roll stand, and wherein the means for adjusting and fixing the position of the bearing block relative to the roll stand is a single acting plunger piston which acquires its operating pressure from a pressure convertor which is attached to the plunger piston cylinder and which is in the form of double acting piston-cylinder unit whose cylinder chambers are each connected to a respective one of the two cylinder chambers of the piston- cylinder unit which actuates the respective rocker.

2. A device as claimed in Claim 1, wherein a piston- cylinder unit which serves to set the minimum play between roll stand and the bearing block is arranged between the piston-cylinder unit which actuates the rocker and the roll stand and has its pressure chambers connected to the respective pressure chambers of the piston-cylinder unit which actuates the rocker.

3. A device substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying drawings.

Published 1989 at The Patent Office, State House, 66.'71 High Holborn. London WC1R 4TP Flarther copies maybe obtained from The Patent Office. Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Maz7 Cray, Kent, Cori. 1/87 A