Adjustment device

Abstract

An adjustment device for adjusting a roll in a roll support (13) of a roll stand includes a cylinder housing (2) that can be secured to a roll support (13), and a piston (1) guided to move translationally in and across the roll support. The position of the piston (1) can be determined via a travel measurement device (9) connected to a coupling rod (6) secured directly to the piston (1). The piston (1) has a guide element (3) extending from the piston head (4) into a bore in the roll rack and in the direction toward the travel measurement device (9). The coupling rod (6) is secured to the guide element (3). To reduce the sensitivity of the adjustment device to a tipping, the guide element (3) is guided in a guide opening (14) of the cylinder housing (2). A sliding guide (7) is provided for the coupling rod (6), which can be arranged on an end of a borehole (15) in the roll rack facing the travel measurement device (9).

Claims

1. A system for adjusting a roll in a roll support, the system comprising: an adjustment device for adjusting the roll in the roll support, the adjustment device comprising: a cylinder housing fastened to the roll support and a piston in the cylinder housing, guided in the cylinder housing so as to be movable in translation in the cylinder housing; a coupling rod fastened to the piston; a travel measurement device connected to the coupling rod for and configured for determining a position of the piston; the piston including a piston base thereon located along the piston, a guide element of the piston and which extends from the piston base in the direction of the travel measurement device, and the coupling rod is fastened to the guide element; the travel measurement device is arranged on an opposite side of the roll support from the cylinder housing; a guide opening in the cylinder housing, the guide element is guided in the guide opening of the cylinder housing; a bore in and extending through the roll support; a sliding guide for slidably guiding the coupling rod through the bore in the roll support, the sliding guide is arranged within an end of the bore in the roll support facing the travel measurement device, wherein the coupling rod connects the piston and the travel measurement device and is guided at least partially through the bore in the roll support, wherein the bore is configured as a recessed bore comprised of a greater diameter at the end facing the cylinder housing than at the opposite end, wherein the guide element is a piston rod with a circular cross section, and wherein the guide element extends through the cylinder housing and into the end of the bore having the greater diameter.

2. The system as claimed in claim 1, further comprising a sliding bush arranged between the guide opening and the guide element, wherein the guide element is guided through the sliding bush.

3. The system as claimed in claim 1, further comprising a play-free threaded connection connecting the coupling rod to the guide element.

4. The system as claimed in claim 1, further comprising a bracket fastening the travel measurement device fastened on the opposite side of the roll support from the cylinder housing.

5. The system as claimed in claim 1, further comprising a covering hood configured and located for protecting the travel measurement device from the environment.

6. The system as claimed in claim 5, further comprising the bracket or the covering hood is connectable to a compressed air line which is configured to set an increased pressure, compared with the environment, in a cavity formed by the covering hood on the bracket.

7. The system as claimed in claim 1, further comprising the travel measurement device is configured for position determining via a magnetostrictive measuring method.

8. The system as claimed in claim 1, further comprising the travel measurement device is fastened to the roll support via the bracket.

9. A method for regulating positioning of the roll with respect to the roll support for the roll using the system of claim 1, the method comprising: positioning the roll with respect to the roll support during a feed movement or a return movement of the roll, and regulating the movements via position data measured continuously by the travel measurement device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to explain the invention further, reference is made in the following part of the description to the figures, from which further advantageous configurations, details and developments of the invention can be gathered. The figures should be understood as being by way of example and is intended to set out the character of the invention but not to limit it in any way, let alone describe it exhaustively. In the figures:

(2) FIG. 1 shows a schematic view of a roll stand;

(3) FIG. 2 shows a sectional illustration of a roll support; and

(4) FIG. 3 shows a sectional illustration of an adjustment device according to the invention in the operating state.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(5) FIG. 1 shows a roll stand 19, which comprises two roll supports 13 and four rolls 20, from a perspective view. The four rolls 20 are arranged above each other in a vertical direction such that the rolled stock (not shown) is being rolled and conveyed in the roll gap between the two upper rolls and the two lower rolls of the roll stand 19 in a substantially horizontal direction, as indicated by an arrow. According to the specific purpose of the roll stand 19, the mounting of more than four rolls in a roll stand, is also possible. The shaft at each of the two ends of a roll 20 is mounted via a chock 22 (shown in FIG. 2) in the opening 24 of one of the two roll supports 13 and is as such movable in a vertical direction.

(6) The end of each shaft of each roll in a roll stand does not necessarily have a respective chock. Referring to the exemplary roll stand depicted in FIG. 1 of the pending application (4-Hi stand), each roll has a chock at both of its ends, hence 4 chocks are arranged vertically above each other in a roll support 13 (with the roll stand comprising 8 chocks in total), of which only one chock is explicitly shown in FIG. 2. Moreover, each of the four chocks 22 in a roll support 13 are vertically movable in the respective opening 24 independently from the other chocks by some mechanism (usually hydraulic), for instance as indicated in FIGS. 3 and 4 of US 2008/0115551 A1 and in FIG. 1 of U.S. Pat. No. 6,151,943. According to the invention, there is only one measurement device per roll support for each of the uppermost and lowermost roll in the roll stand.

(7) FIG. 2 illustrates the mounting of a roll shaft in a roll support 13. The shaft at each end of a roll 20 is mounted via an axial bearing 21 in a chock 22, whereby the chock 22 can slide in a vertical direction along the inner faces 23 of an opening 24 in the roll support 13. The opening 24 can also receive the end sections of the other rolls comprised in the roll stand (not shown). The axial bearing 21 allows for rotation of the roll 20 around its axis, such that the roll 20 can be rotated either by a corresponding drive mounted to the shaft of the roll (not shown) or by the frictional forces being exerted on the surface of the roll by at least one of the adjacent rolls or by the rolled stock.

(8) In the example in FIG. 2, the shaft of a roll 20 can be moved in a vertical direction within the opening 24 of the roll support 13 by a hydraulic cylinder 1, 2 being attached to the chock 22. As such, an adjustment device, of which the hydraulic cylinder 1, 2 is part, can forcibly act on the shaft of the roll 20 which translates into a rolling force being exerted onto the adjacent roll or directly onto the rolled stock. In order to control the size and the cross section of the roll gap of the roll stand 19 during the rolling process, the vertical position of the chock 22 of each roll 20 is monitored by a travel measurement device 9 that measures the vertical position of the piston 1 of the hydraulic cylinder. Because the piston 1 is rigidly fixed to the chock 22, the vertical position sensed by the measurement device 9 corresponds to a vertical position of the corresponding roll 20 such that the resulting roll gap can be calculated from the positions of the shafts of all rolls 20 of the roll stand 19.

(9) Because the diameters of the rolls in a roll stand and their respective geometric positions are known, and all rolls are in touch with either the respective adjacent rolls and/or the rolled metal band, the roll gap can be deduced from the position measurement of said outermost rolls. Relative position measurements of adjacent bending blocks, which hold the chocks of the work rolls, as for instance shown in FIG. 3 of U.S. Pat. No. 7,174,758, are also conceivable but are subject to the elastic bending of the bending blocks when corresponding rolling and bending forces are applied thereto. In other words, measuring the position of the chocks of the uppermost and lowermost roll, which usually have the largest diameter of all rolls in a roll stand and hence the comparably largest stiffness along their rotational axis, results in the most reliable result for the roll gap during a rolling process.

(10) FIG. 3 shows a preferred embodiment of the adjustment device according to the invention. The adjustment device comprises a cylinder housing 2 and a piston 1 guided in translation therein, which jointly form a hydraulic cylinder 1, 2. As a result of a change in pressure in one of the two pressure chambers 18a, 18b of the hydraulic cylinder 1, 2, the piston 1 moves parallel to a longitudinal axis 16 of the hydraulic cylinder 1, 2 and thus carries out an adjustment movement or a return movement. In alternative variants, only one pressure chamber 18a, 18b may be provided. The piston 1 is operatively connected to an object (not illustrated) to be adjusted, wherein pressure can be exerted by the piston 1 on the object to be adjusted, on the one hand, and an actual adjustment or return movement of the object to be adjusted can be brought about, on the other hand. In the exemplary embodiment shown, the adjustment device adjusts a roll in a roll support 13 of a roll stand. The object to be adjusted is thus the roll, not illustrated, of the roll stand.

(11) The cylinder housing 2 is fastened to a carrier element via corresponding fastening means, such as screw connections or welded connections, wherein the carrier element is formed in the present exemplary embodiment by the roll support 13, to be more precise by a cross member of the roll support 13. In other applications, for example in the case of hydraulic presses, the carrier element is formed by a part corresponding to the cross member of the roll support 13. In this embodiment, the cylinder housing 2 is arranged on the underside of the roll support 13, wherein the underside faces the roll in the operating state of the roll stand.

(12) The adjustment device further comprises a travel measurement device 9 by means of which the position of the piston 1 relative to the cylinder housing 2, or to the roll support 13, can be determined. The travel measurement device 9 is in this case arranged on the opposite side of the roll support 13 from the cylinder housing 2, i.e. in this case on the top side. To make the movement of the piston 1 measurable, the travel measurement device 9 is directly connected to the piston 1 via a coupling rod 6, such that the coupling rod 6 directly follows the movement of the piston 1 and passes on the position of the piston 1 to the travel measurement device 9, or the travel measurement device 9 measures the movement of the coupling rod 6.

(13) On the side facing the roll support 13, or on the side facing the travel measurement device 9, i.e. the top side, the piston 1 has a piston base 4, to which, inter alia, pressure can be applied in order to achieve an adjustment movement. In the center of the piston base 4, the piston 1 has a guide element 3 which extends, parallel to the longitudinal axis 16, away from the piston base 4, in the direction of the travel measurement device, i.e. upward. The guide element 3 and the piston 1 can in this case be configured either in one piece, for example as a cast part or turned part, or in two or more pieces, such that the guide element 3 and piston 1 are manufactured separately, wherein the guide element 3 is fastened to the piston 1, for instance welded or screwed thereto, prior to the assembly of the adjustment device. In the variant embodiment illustrated, the guide element 3, just like the piston 1 and the bore of the cylinder housing 2, is configured as a cylinder and has a circular cross-sectional area with respect to the longitudinal axis 16. The diameter of the guide element 3 is in this case about 35% of the diameter of the piston 1, wherein values between 10% and 45%, in particular between 20% and 40%, are conceivable.

(14) The guide element 3 is guided in a guide opening 14 in the cylinder housing 2 and projects upwardly through this guide opening 14 out of the cylinder housing 2. Since, as a result of the interaction of the guide element 3 and guide opening 14, the piston 1 is additionally guided and supported with respect to radially acting forces, tipping of the piston 1 relative to the cylinder housing 2 is prevented. Tipping can occur for example in the event of uneven loading by the object to be adjusted, in this case the roll, wherein the piston 1 and cylinder housing 2 no longer form a common longitudinal axis 16 in the event of tipping, but enclose an angle, between 0.5° and 10°, with one another. In order to further improve guiding, a sliding bush 5, in which the guide element 3 is guided in a sliding manner, is arranged in the guide opening 14. The sliding bush 5 is in this case advantageously manufactured from plastics material in order to reduce friction effects, and at the same time serves to seal off the first pressure chamber 18a, wherein it is also conceivable to attach additional sealing means, for instance sealing rings.

(15) The guide element 3 additionally also serves for fastening the coupling rod 6, which is fastened to that side of the guide element 3 that faces away from the piston base 4, i.e. to the top side. In this case, a number of different fastening methods may be used, for example clamping connections, force-fitting or form-fitting connections. In the present exemplary embodiment, the coupling rod 6 is connected to the guide element 3 via a play-free threaded connection, wherein the coupling rod 6 has a threaded portion configured as a threaded pin and the guide element 3 has a corresponding threaded bore Other variants are conceivable, for example a variant in which the threaded portion is formed by the guide element 3 and the threaded bore by the coupling rod 6, or a variant in which fastening takes place via a number of play-free screws. Since the threaded connection does not have any axial play, i.e. no relative movement in the axial direction occurs between the coupling rod 6 and piston 1 in the event of a movement of the piston 1, the travel of the piston 1 is detectable by the travel measurement device 9 without measuring errors.

(16) To make it possible to connect the travel measurement device 9 arranged on the top side of the roll support 13 and the piston 1, or guide element 3, located on the opposite side of the roll support 13 together via the coupling rod 6, the roll support 13 has a bore 15 in which the coupling rod 6 is partially guided. At the end facing the cylinder housing 2, i.e. the lower end, the diameter of the bore 15 is larger than at the opposite, upper, end, and so that part of the guide element 3 that projects out of the cylinder housing 2 can be received in that portion of the bore 15 that has the larger diameter. The axial extent of the portion is in this case at least great enough for the guide element 3 to be received entirely in the bore 15 in the upper end position of the piston 1. In the upper portion, the bore 15 has a smaller diameter such that the coupling rod 6 can pass through. In other words, the bore 15 is thus embodied as a recessed bore.

(17) The travel measurement device 9 is joined to the roll support 13 via a bracket 8, wherein the bracket 8 receives that portion of the coupling rod 6 that projects out of the bore 15 and is thus arranged coaxially with the bore 15 and therefore also with the piston 1, guide element 3 and cylinder housing 2. The bracket 8 also forms a receptacle for the travel measurement device 9, wherein the travel measurement device 9 is likewise arranged concentrically with the longitudinal axis 16 and is in operative contact with the coupling rod 6, or is connected directly to the coupling rod 6. In the present exemplary embodiment, only one housing of the travel measurement device 9 is illustrated. The housing is not in section, such that measuring elements which are arranged in the interior of the housing and are movable relative to one another cannot be seen. The housing of the travel measurement device 9 is in this case fastened, preferably screwed, to the bracket 8. The coupling rod 6 projects in this case into the housing of the travel measurement device 9 and is connected to one of the measuring elements. The position of the piston 1 is in this case determined via the detection of the relative movement of the two measuring elements. It is also conceivable in this case for the coupling rod 6 not to project into the housing of the travel measurement device 9 but for the measuring element joined to the coupling rod 6 to interact with the measuring element arranged in the housing of the travel measurement device 9.

(18) The travel measurement device 9 can in this case be configured to determine a position of the piston 1, or of the coupling rod 6, by means of a magnetostrictive measuring method which works on the basis of a physical principle known per se. In this case, a permanent magnet of the travel measurement device 9 is generally connected to the coupling rod, while at least one fixed base of the travel measurement device 9 is arranged in the housing of the travel measurement device 9. The magnetostrictive measuring method is suitable in particular on account of its insensitivity to environmental influences, such as temperature or shaking, and the high precision of the measured values. In alternative variant embodiments of the invention, however, it is also possible for other measuring methods, for example magnetoresistive, optical or electronic measuring methods, to be used, without departing from the scope of the invention.

(19) The position, detected by the travel measurement device 9, of the piston 1 is passed on to a control unit, not illustrated, of the adjustment device, or of the roll stand, via a connecting line 11. In this control unit, the adjustment movement of the piston 1 is regulated in a corresponding manner, in order in particular to exactly set the rolling gap.

(20) In order to fix and to guide the coupling rod 6 in the radial direction, a sliding guide 7, which is preferably likewise manufactured from plastics material, is attached to the upper end of the bore 15. The sliding guide 7 has, in the present exemplary embodiment, a collar that extends in the radial direction, in order to be supported on the roll support 13.

(21) In order to protect the sensitive electronics of the travel measurement device 9, a covering hood 12 is fastened to the bracket 8, which protects the travel measurement device 9 from the environment and prevents penetration of foreign bodies, for instance dirt particles or liquids. The bracket 8 and covering hood 12 in this case form a cavity in which the travel measurement device 9 and the upper end of the coupling rod 6 are arranged. For even further protection, the cavity formed, which is sealed off from the environment, is able to be connected to a compressed air line via a port 10 in order to form a positive pressure in the cavity by feeding compressed air, such that, even in the case of minor leaks, no foreign bodies can penetrate into the cavity. The positive pressure compared with atmospheric pressure is in this case generally between 0.5 bar and 1 bar. In order for it to be possible to guide the connecting line 11 out of the cavity, a cable feedthrough 17 is provided in the bracket 8, said cable feedthrough 17 being sealed off for example via a PG screw connection. The port 10 and the cable feedthrough 17 can be attached both to the bracket 8 and to the covering hood 12.

LIST OF REFERENCE SIGNS

(22) 1 Piston 2 Cylinder housing 3 Guide element 4 Piston base 5 Sliding bush 6 Coupling rod 7 Sliding guide 8 Bracket 9 Travel measurement device 10 Port 11 Connecting line 12 Covering hood 13 Roll support 14 Guide opening 15 Bore 16 Longitudinal axis 17 Cable feedthrough 18a First pressure chamber 18b Second pressure chamber