US3645122A

US3645122A - Rolling mills

Info

Publication number: US3645122A
Application number: US12951A
Authority: US
Inventors: Robert James Harlow
Original assignee: QUAY DYNAMICS Ltd
Current assignee: Brown and Root Vickers Ltd
Priority date: 1969-02-25
Filing date: 1970-02-20
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28
Also published as: GB1256907A; DE2007488A1

Abstract

Roll-deflection means for rolling mills are associated with outer and inner outboard bearings on roll extensions in that way that the outer outboard bearings are subjected to bending moments through levers and links by hydraulic units, while the inner outboard bearings act as fulcra, or vice versa.

Description

i o 1 a. ilite States tet [151 3 645 122 9 9 arlow 1 Feb. 29, 1972 [54] ROLLING MILLS [56] References Cited [72] lnventor: Robert James Harlow, Parkstone, England UNITED STATES PATENTS 73 nee: a D namlcs Bournemouth Ncuber I I g g i 3,526,1l8 9/1970 O'Brien ..72/243 3,426,567 2/l969 Smith.... ..72/245 X [22] Filed: Feb. 20, 1970 3,373,588 3/1968 Stone.... ....72/237 pp No 12 951 3,024,679 3/1962 Fox ..72/245 Primary ExaminerMilton S. Mehr 30 Foreign Application Priority Data Attorney-Hammond & Line" Feb. 25, 1969 Great Britain ..10,] 14/69 [57] ABSTRACT [52] U 72/237 Roll-deflection means for rolling mills are associated with [5]] In. cl ..iiiTbm/m) outer and inner outboard hearings on to extensions in that l 58] Fieid 245 240 way that the outer outboard bearings are subjected to bending moments through levers and links by hydraulic units, while the inner outboard bearings act as fulcra, or vice versa.

8 Claims, 4 Drawing Figures PATENTEnrEB29 I972 3.645.122

SHEET 1 0F 2 I nuenlor Reba-2' James Harlow A tlorneys PATENTEUFEBZQ I972 sum 2 BF 2 Fig.3

Inventor Ra beri James Harlaw y g J 1M A ltorneys ROLLING MILLS This invention relates to improvements in and relating to rolling mills in which means are provided for imparting to the rolling mill rolls bending moments for the purpose of compensating deflections of the rolls. These deflections are mainly, though not exclusively, the result of forces to which the rolls are subjected during rolling, and which tend to separate the rolls from each other at their center portions.

The equipment of rolling mills with means of this kind has nowadays become of great importance in view of the increased demand for rolled products, and particularly flatrolled products, with close dimensional tolerances.

In accordance with several known proposals, mill rolls, whose deflection is to be compensated, are provided for this purpose with extensions projecting beyond the conventional bearing chocks which support the rolls in the mill housings, and with special outboard bearings mounted on these extensions. It is to these outboard bearings that deflection-compensating bending moments are applied. The known means provided for this purpose generally include one or more hydraulic pressure units, the hydraulic forces produced therein being transmitted either directly or indirectly to the outboard bearings, whereby the required compensating bending moments are obtained.

In the known proposals, the fulcra for the roll deflections are situated in the centers of the bearing chocks.

These proposals were not entirely satisfactory. In most of them, the bending forces and their reactions were not balanced within the roll-deflection equipment, with the result that additional loads were imposed on structural components of the rolling mill such as its bearing chocks, screw-downs and housings. As these loads were considerably, they required strengthening of these components and thereby made the mild heavier and more expensive.

According to one known proposal, the roll-deflecting forces and their reactions are balanced within the equipment provided for that purpose, but the design evolved for this purpose was cumbersome and therefore difficult to accommodate in the space available in a rolling mill. Moreover, it complicated roll changing.

It is an object of the present invention to provide a rolling mill with novel and improved means for compensating deflections which the mill rolls undergo, the improvement aimed at by the invention consisting essentially in providing roll-deflection means which achieves a complete balance of forces and their reactions within the roll-bending means, without requiring any increase in size of other rolling mill parts and without interfering with the ready exchange of the mill rolls.

According to the present invention, means for the deflection of a rolling mill roll supported by hearing chocks in the mill housings and having extensions beyond said bearing chocks, comprise inner and outer outboard bearings on said extensions, the inner outboard bearings being nearer to said bearing chocks than the outer outboard bearings, a carrier arranged longitudinally of said roll and its extensions, arms pivoted at each end of said carrier and extending longitudinally with respect to said carrier, hydraulic pressure units arranged between said carrier and the free ends of said arms, said units subjecting said arms to bending moments about their pivots, links pivoted to said arms at points outside the pivots for said arms on said carrier, said links being attached to said outer outboard bearings so as to transmit said bending moments to said outboard bearings and said roll extensions, and struts secured to said carrier at its ends and extending to said inner outboard bearings so that the reaction of the bending forces is transmitted through said struts from said carrier to said inner outboard bearings.

With this arrangement, the extensions of the roll and the roll itself are deflected about the centers of the inner outboard bearings which thus actas fulcra. Furthermore, the bending forces and their reactions are fully compensated within the roll-deflection means, so that neither these forces nor their reactions are transmitted to any outside parts of the rolling mill. The equipment is, in other words, completely self-contained.

Preferably, the links pivoted to the arms and attached to the outer outboard bearings are so connected to the latter that links and outboard bearings can slide relative to each other in the direction of the axis of the rolling mill roll to which the roll-bending equipment is applied. The struts which extend from the carrier to the inner outboard bearings preferably abut against the latter without being attached to them. Thus, the roll-deflection means, consisting of carrier, hydraulic units, arms, links and struts, can be moved relatively to the inner and outer outboard bearings and also relative to the other parts of the mill in the direction of the axis of the mill roll. In this way, the roll-deflection means can be readily moved in or out of the mill as an independent unit.

In practice, roll-deflection means are preferably provided for each of the rolls of a mill and to both its working rolls and backing rolls, so that the means are duplicated with respect to the upper and lower rolls.

The carrier of the roll-deflection equipment according to the invention is preferably supported on the mill housings by such means as hydraulic balancing cylinders which are preferably pivoted so as to allow a certain freedom of movement of the equipment relative to the rolling mill. The carrier may be box shaped, with the arms arranged inside the box.

The arms may be of triangular shape. For reasons of symmetry, an arm pivoted at one end of the carrier may be sandwiched between two arms pivoted at the opposite end of that carrier. The arrangement of pivoted arms in roll-deflection equipment for rolling mills is known in itself.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a front elevation, partly in section, of a four-high rolling mill, incorporating roll-deflection equipment according to the present invention.

FIG. 2 is a side elevation of part of the rolling mill of FIG. 1,

FIG. 3 is a part section of that rolling mill along the line 3- 3 of FIG. 1,

FIG. 4 is a section along line 4-4 of FIG. 3.

The rolling mill shown in the drawings is a horizontal mill of the four-high type having two housings 10 which are connected to each other at the top by an upper crossmember 12 and at the bottom by a lower crossmember 14. The rolling mill has further an upper backing roll 16, a lower backing roll 18, an upper working roll 20 and a lower working roll 22. The upper backing roll is supported in the housings by bearings chocks 24 and the lower backing roll by bearing chocks 26. The bearing chocks for the two working rolls are not shown for the sake of simplicity. Arranged between the upper and lower bearing

chocks

24 and 26 are means 27 for adjusting the pass opening between the two

working rolls

20 and 22. These means may include rotary and axially displacable elements such as screw spindles and motorized nuts, which may be of the kind described in the copending British Pat. application Ser. No. 1,152,518. The rolling mill is further provided at each side with prestressing units, comprising cylinders 28 and rams 30, arranged between the chocks 26 for the lowerbacking rolls and the housings 10. The bearing chocks, the roll-adjusting means and the prestressing units are all arranged in windows of the housings 10, as well known.

The rolling mill described above is fitted with equipment for deflecting the

backing rolls

16 and 18 in such a manner that deflections of these rolls, imposed on them by the rolling load, are counteracted and compensated. For this purpose, there are provided in the rolling mill, in respect of the

upper rolls

16, 20 and the

lower rolls

18, 22, roll-deflection means 32, 132 respectively which will be presently described.

The upper backing roll 16 projects with both its ends beyond its bearing chocks 24, inner and

outer outboard bearings

36 and 38 being provided on each projecting end. These bearings as well as the bearing chocks are only diagrammatically shown in the drawings as they may be of any suitable design. Arranged on top of the rolling mill and parallel with the upper crossmember 12 is a box-shaped beam 40 acting as carrier for two substantially triangular levers arms 42' and 42" which are each pivoted at 44 to the beam 40. Each arm is forked at one end and has a triangular main portion which terminates at its narrow end in a foot 46. The two

levers

42 and 42" are so arranged with respect to each other and the beam 40 that the oblique sides of the triangles are inclined in opposite directions and the forked ends of the levers situated above the inner and

outer outboard bearings

36 and 38. Whilst the forked ends of the levers are of substantially the same width as the clear space inside the box-shaped carrier 40, their triangular portions are of reduced width so that they can be placed side by side. They are raked, as shown in FIG. 3.

The forked ends of the levers 42' and 42" project outside the box-shaped carrier 40 and are provided at their projecting ends with pivots 48 for links 50. These links have heads 51 at their lower ends and are thereby adapted to enter into T- shaped grooves 52 in the outer outboard bearings 38. The upper surface of the heads 51 has a slightly convex curvature in a plane parallel to the axis of the backing roll 16. Secured to the underside of the beam 40 and at each end thereof, is a strut 54 which extends from the beam down to the inner outboard bearing 36, resting on that hearing with a surface which has a slightly convex curvature in a plane parallel to the axis of the backing roll 16. Each strut is guided on its adjacent link 50 by means of a bush 56 which encircles the link and further by a shoe 58 which can slide in a guideway 60 provided in the top part of a housing 10.

The levers 42' and 42" are adapted to be rocked or tilted in opposite directions about their pivots 44 by means of hydraulic pressure units 62, for the purpose of applying bending moments to the backing roll 16 by means of the links 50 and the struts 54 as shown in FIG. 4. Each unit 62 consists of a cylinder 64 which is hinged at 66 to the foot 46 of one of the

levers

42 or 42" and of a ram having a rod 68 hinged at 70 to a traverse 72 mounted on top of and across the beam 40. There are further provided at either side of the beam 40 and on top of the housings 10, four hydraulic pressure units 74 for balancing the roll-deflecting means 32. These units 74 consist each of a cylinder 76, hinged at 78 to brackets 80 on top of the housings 10, and of rams having rods 82 hinged at 84 to a traverse 72. In this way, the hydraulic pressure units can follow the up-and-down movements of the backing roll 16 relative to the housings during the adjustment of that roll.

In order to ensure that the beam 40 is always squarely aligned relative to both housings 10, its longitudinal side walls are provided with vertical racks 86 which mesh with pinions 88 on a shaft 90, the latter being supported by means of the brackets 80 on the housings 10.

Substantially the same arrangement as described above with relation to the roll-deflection means 32 is provided in respect of the roll-deflection means 132 for the lower backing roll 18; accordingly the components of these latter means have the same reference numbers as the corresponding components of the roll'deflecting means 32, but augmented by 100. The only difference is in the arrangement of the pressure units 184 for balancing the means 132. These units consist of cylinders 176 secured to the lower crossmember 14, and of rams with rods 182 pivoted at 184 to the beam 140. This simplified construction is possible with regard to the lower roll deflection means 132, inasmuch as the backing roll 18 does not move relative to the housings 10 during the adjustment of the roll gap between the working rolls and 22.

Runout carriages 94 are arranged below the lower beam 146), the wheels )6 of these carriages being adapted to be moved along rails, not shown, on which the lower roll-deflection means 132 can be moved out of the mill after the beam 140 has been lowered by a sufficient distance.

When a rolled article passes through the gap between the working rolls 20 and 22 of the rolling mill and is reduced in thickness thereby, the load imposed on the rolls tends to bend these two rolls as well as the two backing rolls 16 and 18, so

that the article would have convex instead of flat surfacesT counteract this tendency, oppositely directed bending moments are applied to the rolls by the roll-deflecting means 32 and 132. The left-hand end of the upper backing roll 16 is therefore subjected, as shown in FIG. 4, to a clockwise bending moment and its right-hand end to an anticlockwise bending moment.

The counteracting bending moments are imparted to

upper rolls

16 and 20 by the pressure units 62 through the

levers

42 and 42" and the links 50, the struts 54 taking the reactions. Further counteracting bending moments are imparted to the lower rolls 18 and 22 by the corresponding parts of the rolldeflecting means 132. It will thus be seen that the forces and reactions of the roll-deflecting bending moments imposed on the rolls by means 32 and 132 are entirely taken by their components and are not transmitted to other parts of the rolling mill such as the bearing chocks 24 and 26 or housings 10.

The convex curvature of surfaces on the heads 51 and on the struts 54 enables the

outboard bearings

36 and 38 and the roll extensions to deflect freely without imposing any additional strain on them.

The invention has been described here with relation to a rolling mill whose roll-deflecting means are utilized for bending the mill rolls so that the middle portions of opposite rolls approach each other. It is understood that the invention can also be utilized in a mill in which the middle portions of opposite rolls are to be separated from each other by the rolldeflecting means. In this case, the direction of the bending moments applied to the levers is reversed and the links and struts exchange their positions with regard to the outer and inner outboard bearings.

With the above-described design of roll-deflection means, it is possible to obtain a relatively large bending force from a relatively small hydraulic force. This is achieved by arranging the pivots for the links and those for the levers close to each other and by placing the hydraulic pressure units at a considerable distance from the pivots.

What we claim is:

1. In a rolling mill, having housings, rolls, bearing chocks for supporting said rolls in said housings, said rolls having extensions beyond said bearing chocks and inner and outer outboard bearings on said roll extensions, the arrangement of deflecting means for one of said rolls, said roll-deflecting means comprising a carrier arranged longitudinally of said roll and its extensions, arms pivoted at each end of said carrier and extending longitudinally with respect to said carrier, hydraulic pressure units arranged between said carrier and the free ends of said arms, said units subjecting said arms to bending moments about their pivots, links pivoted to said arms at points outside the pivots for said arms on said carrier, said links being attached to said outer outboard bearings so as to transmit said bending moments to said outboard bearings and said roll extensions, and struts secured to said carrier at its ends and extending to said inner outboard bearings so that the reaction of the bending forces is transmitted through said struts from said carrier to said inner outboard bearings.

2. A rolling mill according to claim 1, in which said rolldeflecting means are applied to a working roll of said mill.

3. A rolling mill according to claim 1, in which said rolldeflecting means are applied to a backing roll of said mill.

4. A rolling mill according to claim 1, in which the links pivoted to the arms and attached to the outer outboard bearings are so connected to the latter that links and outboard bearings can slide relative to each other in the direction of the axis of the rolling mill roll to which the roll-bending equipment is applied.

5. A rolling mill according to claim 1, in which the struts which extend from the carrier to the inner outboard bearings abut against the latter without being attached to them.

6. A rolling mill according to claim 1, in which the carrier is supported on the mill housings by hydraulic balancing cylinders.

7. A rolling mill according to claim 1, in which the carrier is box shaped, with the arms arranged inside the box.

8. A rolling mill according to claim 1, in which the arms are in the form of triangular levers.

Claims

2. A rolling mill according to claim 1, in which said roll-deflecting means are applied to a working roll of said mill.

3. A rolling mill according to claim 1, in which said roll-deflecting means are applied to a backing roll of said mill.