WO2002030587A1

WO2002030587A1 - Strip coiler entry side guides

Info

Publication number: WO2002030587A1
Application number: PCT/GB2001/004515
Authority: WO
Inventors: William Robert Laws; Geoffrey Ronald Reed
Original assignee: Encomech Engineering Developments Limited
Priority date: 2000-10-10
Filing date: 2001-10-10
Publication date: 2002-04-18
Also published as: AU2001293992A1

Abstract

An apparatus for guiding strip material (6) to a coiler, the apparatus comprising guide means (2, 4) defining a path along which the material travels from an upstream entry end towards the coiler. The guide means include an upstream portion in which a first, upstream pair of opposed guide members (2) extend along opposite sides of the material path spaced laterally further from one another at an upstream end than at a downstream end to form a converging portion of the material path, and a downstream portion in which a second, downstream pair of opposed guide members (4) extend to opposite sides of the material path to form a portion of the path downstream of the converging portion. The apparatus also includes position control means (14, 18, 20) for controlling the lateral position of the upstream and downstream pairs of guide members (2, 4), the lateral position of at least the downstream end of the downstream guide members (4) being adjustable independently of the upstream members (2).

Description

STRIP COILER ENTRY SIDE GUIDES

FIELD OF THE INVENTION

This invention relates to apparatus for guiding metal strip at the entry to a strip coiler, useful for instance when coiling metal strip from metal hot strip rolling mills. The invention further relates to an exit roller table for metal strip material, e.g. hot metal strip from a hot rolling mill, having the guide apparatus, and to metal strip handling apparatus having the exit roller and a strip coiler.

BACKGROUND OF THE INVENTION

After finish rolling, hot strip from metal hot strip rolling mills is typically transported at high speed, often up to 20 m/s, along an exit roller table to one or more 'strip coilers'. These coilers coil the strip material so that it can subsequently be more easily handled, for example transported to a different location for use as the feed stock for a cold rolling process.

It is important that the coils of sheet material produced in this way have parallel sides, since otherwise the edges of the strip are liable to be damaged during subsequent handling and processing. For this reason, it is known to direct the strip to the 'mouth' of the coiler using a guide.

The guide includes opposed guide members that contact opposite side edges of the strip to ensure its lateral position is correctly maintained. At an upstream end (entry end) of the guide, the guide elements are at a spacing greater than the strip width so that they capture the strip passed from the mill even if the strip has wandered laterally away from the centre of the exit roller table, as is often the case when the strip is cambered along its length. From the entry end, the guide tapers inwardly to terminate in a parallel sided section, in which opposed parallel portions of the side guide members are held at a spacing from one another corresponding to the width of the strip material, whereby its lateral position can be accurately maintained.

The lateral position of each side guide member is adjustable to alter the spacing between them, to accommodate strips of different widths. A coarse adjustment is achieved using hydraulic cylinders acting in unison at spaced locations along the length of each guide member, with finer adjustment typically being achieved by electrically powered screws. When making both coarse and fine adjustments, the guide elements are controlled so that the movement of each mirrors that of the other, both moving towards or away from the centre line of the coiler together by the same distance. In this way, the position of the strip is maintained with respect to the coiler centre line irrespective of its width.

Typically a coiler is required to handle strip material of thickness as great as 25mm or perhaps more. This requires the side guide members to be of a very robust construction in order that they can withstand the shock of the impact of the strip material when it is driven into the guide members. However, the coilers are also expected to be able to handle much thinner strip, perhaps strip having a thickness of 1mm or less. With this thin material a further problem is encountered, which is unwanted buckling of the material if the side forces applied by the guide members are too great. In this case, the robustness of the guides, necessary for the thicker strip, can be seen as a disadvantage because the resulting high mechanical inertia of the guide elements means their position cannot be adjusted sufficiently rapidly in response to the detection of excessive side forces applied to thin strip.

As yet, no one has proposed a guide able to effectively reconcile these two conflicting requirements for thick and thin strip.

SUMMARY OF THE INVENTION

The present invention is concerned generally with apparatus for guiding thick and thin strip material, in particular into a coiler and aims to address the inherent conflict discussed above. Accordingly, there is provided an apparatus for guiding metal strip material to a coiler, comprising guide means defining a path along which the material travels from an upstream entry end towards the coiler, said guide means comprising an upstream portion in which a first, upstream pair of opposed guide members extend along opposite sides of the material path spaced laterally further from one another at an upstream end than at a downstream end to form a converging portion of the material path, and a downstream portion in which a second, downstream pair of opposed guide members extend along opposite sides of the material path to form a portion of the path downstream of the converging portion, characterised by position controllers for controlling the lateral position of the upstream and downstream pairs of guide members, the lateral position of at least the downstream end of the downstream guide members being adjustable independently of the position of the upstream guide members . By decoupling the movement of the upstream and downstream guide members in this way it becomes possible to adjust the position of the downstream guide members, whilst leaving the position of the upstream guide members unchanged. Since it is adequate that the downstream guide members be of a relatively lightweight construction compared with the much heavier, robust construction of the upstream members, this in turn can allow very rapid adjustment in the position of the downstream guides, for example in response to the detection of excessive side forces on a fast moving thin strip between the guides, without sacrificing the overall robustness of the apparatus required to withstand the initial shock of a thick material entering the guide structure. The apparatus is also preferably adapted to allow at least a small degree of movement (play) between the upstream ends of the downstream guides and the adjacent downstream ends of the upstream guides. Not only does this enable rapid adjustment of the upstream ends of the downstream guides, independent of movement of the upstream guides, for instance to counter excessive side forces on the strip material, but it also allows the upstream guides to be moved laterally inwardly slightly beyond the downstream guides to provide the downstream guides greater protection from thicker strip. Likewise, for thin strip, where it may be desirable to minimise contact of the strip with the robust upstream guides, these guides can be retracted to a position just laterally outward of the downstream guides. The downstream guide members preferably extend substantially parallel to one another to define a constant width portion of the material path, the width of this portion of the path corresponding to the width of the material being coiled. The position of the downstream ends of the parallel downstream guide members, and hence the position of the downstream end of this constant width portion of the material path, can be accurately controlled to steer the sheet material into the coiler.

In a preferred form, the upstream guide members are pivotally mounted at respective pivot points at their upstream ends, the lateral position (i.e. position in the direction of the width of the material path) of their downstream ends being controlled by respective positioning means, most preferably hydraulic actuators.

The downstream guides, on the other hand, preferably have their position controlled by respective positioning means, e.g. hydraulic actuators, located one at each end (upstream and downstream) of each downstream guide member. Not only does this enable the downstream guide members to be maintained parallel to one another (when this is desired) , but it also becomes possible to adjust the angle of the path these guide members define relative to the centre line of the coiler in order to more accurately steer the material .

Although they are preferably not in mechanical contact during normal operation, it can be important that the upstream ends of the downstream guides and the downstream ends of the upstream guides are controlled to be maintained adjacent to one another and to move together. This can be achieved by appropriate control of the e.g. hydraulic actuators which position these guides. However, it is preferred not to rely solely on the control of these actuators to maintain the relationship between the adjacent ends of the upstream and downstream guides. Connectors, preferably interlocking elements with play between them, may therefore be associated with these adjacent ends to constrain them to move together while defining a limit for the relative movement (play) between them. To reduce wear on the downstream guide members, replaceable wear pads can be mounted at spaced locations along the length of each guide member in a known manner. These wear pads protrude slightly inwardly of the guides themselves, so that the pads suffer the major part of the rubbing forces applied to the guide members by the strip passing along the material path. The pads can be replaced when worn, avoiding the need to replace the complete guide member.

More preferably, however, a series of wear blocks are used in place of the pads. As with the pads, the blocks are adapted to be mounted at spaced locations along the guide member with a wear face of each block protruding slightly beyond the guide member into the material path. The blocks are provided, however, with multiple wear faces, the block being mountable on the guide in a plurality of orientations in each of which a different one of the wear faces is disposed to face the material path. In this way, when one face of the block becomes worn, it is not necessary to replace this wear element, since it is possible to reposition it to present another one of its wear faces to the material path. Only after all wear faces of the block have been used, does it need to be replaced.

Even with the measures described above, it is possible that rapid wear of the guide members may occur, particularly at the junction between the upstream and downstream guides. In order to reduce this wear, it is proposed that additional wear elements be provided at this junction. For instance, wear rollers, with their axis of rotation arranged generally upright can be positioned at the downstream end of each upstream guide member and/or at the upstream end of each downstream guide member.

According to the invention in a second aspect, there is provided an apparatus for guiding metal strip material to a coiler, comprising guide means defining a path along which the material travels from an upstream entry end towards the coiler, said guide means comprising an upstream portion defining a converging portion of the material path, and a downstream portion defining a portion of the path downstream of the converging portion, characterised by controller means for controlling the guide means for adjustment of the width of the material path defined thereby, and wear elements projecting into the material path at the junction between the upstream and downstream portions or said guide means .

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will be more fully described below by way of non-limitative example with reference to the accompanying drawings, in which:

Fig. 1 is an oblique view of an apparatus for guiding metal strip product to the mouth of a coiler in accordance with an embodiment of the present invention;

Fig. 2 is a plan view of the coiler end of the apparatus illustrated in Fig. 1;

Fig. 3 is a view similar to that of Fig. 2, showing the manner in which strip material is guided;

Fig. 4 is a plan view, on a slightly enlarged scale, similar to that of Fig. 2 illustrating an alternative position of guide elements of the apparatus; Fig. 5 is a plan view, on a further enlarged scale, of the joint between upstream and downstream side guide members of the apparatus ;

Fig. 6 is an oblique view, on an enlarged scale, of the downstream end of the apparatus illustrated in Fig . 1 ;

Fig. 7 shows, on a further enlarged scale, a portion of one downstream guide member of Fig. 6; and

Fig. 8 shows the same view seen in Fig. 7, but with the wear blocks raised out of their seatings in the guide member .

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

In overview, the illustrated apparatus includes a series of adjustable guides 2,4 each consisting of a pair of guides 2a, 2b and 4a, 4b which serve to guide metal strip product 6 (Fig. 3) coming from a hot strip rolling mill, e.g. a finishing mill, along the downstream end of a mill exit roller table 8 to a coiler (not shown) . As seen in the Figures, the product is transported on the table 8 from left to right, the coiler being located at the right-hand, downstream end of the table 8. In Fig. 1 many of the rollers 8a of the roller table beneath the guides 2a, 2b are omitted for simplicity. The lateral positions of the guides 2a, 2b, 4a, 4b can be adjusted relative to the roller table to 'steer' the product 6 to the correct lateral position for coiling.

The coiler and the roller table 8 can be of standard construction and do not require further discussion here.

The guides 2,4 are provided in two pairs 2a, 2b and 4a, 4b, the guides of each pair being opposed to one another and disposed to opposite sides of the roller table 8. The upstream pair of guides 2a, 2b are pivotally mounted on¹ the roller table at their upstream ends 10 to be generally fixed in the lateral direction. The downstream ends 12 of these guides 2a, 2b are, however, adjustable in the lateral direction by hydraulic actuators 14. As best seen in Figs. 1 and 5, the actuators 14 act on sliding blocks 16 to which the downstream ends 12 of the upstream guides 2 are pivotally mounted at pivot 16a. In the position illustrated in Fig. 1, corresponding to a fully retracted position for the actuators 14, the upstream guides 2 are generally parallel to one another. In use, however, the downstream ends 12 of these guides are displaced inwardly, as seen in Fig. 2 for example, so that the guides 2a, 2b define an inwardly tapering path between them for the strip product 6. These upstream guides are of a relatively robust construction to withstand the forces exerted by thick strip, e.g. up to 25mm in thickness. Shorter, downstream guides 4a, 4b of a lighter construction are disposed immediately adjacent to and downstream of the upstream guides 2a, 2b, to define between them a continuance of the path for the product 6 (the guides 2a, 2b are drawn shorter in Figs. 2 to 4 for simplicity) . The lateral position of each of the downstream guides 4a, 4b is controlled by two pairs of hydraulic actuators 18,20 acting respectively at upstream and downstream ends of each guide 4a, 4b.

When fully retracted, the actuators 18,20 hold the downstream guides parallel with one another and, unlike the upstream guides, this parallel relationship is, under normal operating conditions, maintained as the downstream guides 4a, 4b are brought closer to one another by operation of the actuators 18,20.

All of the actuators 14,18,20 are controlled by a hydraulic servo-operated control system, the synchronisation of the actuators being electronically maintained by a central processor controlling the action of the servo system. This means that each actuator 14,18,20 can, if desired, be moved independently of the others. Closed loop control is preferred.

It is desirable that the upstream and downstream guides 2,4 of the apparatus described here are maintained generally adjacent to one another where they meet in order to provide a relatively smooth transition for the product 6 between these guides. It is also desirable, for reasons discussed below, to allow for some freedom of movement at this junction. One way to achieve this is simply to rely solely on control of the position of the actuators 14,18 which adjust the position of the downstream ends 12 of the upstream guides 2 and the upstream ends 22 of the downstream guides 4 respectively. However, whilst in practice it is intended that the control be achieved in this manner, it is desirable to provide a fail-safe mechanism which acts to maintain the proximity of the guide ends 12,22 in the event that the hydraulic control fails. One form of mechanical link which allows some freedom of movement between the upstream and downstream guides 2, but limits this movement to prevent complete separation of the guides is illustrated in Fig. 5. A recess 30 is formed in the end face of the upstream end 22 of the downstream guide 4. A projection 34 is formed on the opposed face of the sliding block 16 and engages the recess 30 to be laterally retained within it. The relative dimensions of the recess 30 and projection 34 are such that a small clearance (t) of about 8mm is present between these elements to allow a small amount of relative motion between them. In normal operation the clearance (t) will be maintained by appropriate operation of the hydraulic actuators 14,18. However, if either one of the actuators fails, the projection 34 soon engages one or other lateral side of the recess 30 such that further lateral motion of either guide causes the other guide to be carried with it . In the illustrated example, the projection and recess have a 'tongue and groove' form, but other cooperating shapes can be employed, so long as they act to restrain relative lateral movement of the guides after the clearance (t) has been taken up. It is of course possible for the projection to be formed on the downstream guide 4 and the recess in the sliding block 16 or for each of these parts to carry projections and recesses arranged to mate with corresponding formations on the other. Also illustrated in Fig. 5 are wear rollers 40.

These rollers 40, seen also in Fig. 1, are mounted at the intersection between the upstream and downstream guides 2,4, in the present example one being mounted on each of the sliding blocks 16. Each roller 40 is mounted with its rotary axis upright and projects radially beyond the guide surface 42 of the block 16. In this way, as the strip product passes from the upstream guide 2 to the downstream guide 4 it contacts the freely rotatable rollers 40, which rotate with the motion of the product, thus minimising the wear of the guides at this transition.

If desired, the rollers 40 may be arranged to be retractable relative to the guide surface 42 through which they project if, as may be the case with thin strip product, it is preferred that the product be guided by the surface of the block 16 at the transition rather than the projecting rollers 40. To reduce the wear of the downstream guides

4a, 4b, a series of wear blocks 50 (seen best in Figs. 6- 8) are employed. The blocks 50 are spaced along the length of the guides 4a, 4b, each block 50 being mounted on a location peg 52 within a respective recess 54 formed in the guide .

Each block 50 includes a central, tubular core piece 56, the lower end of which engages the peg 52. An elongate outer sleeve 58 of square section surrounds and is fixed to the core 56. As seen in Fig. 7, which shows one of the guides 4a only, when mounted in their respective recesses 54, the blocks 50 each present a wear face 60 to the material path defined between the two downstream guides 4a, b. These wear faces 60 project slightly inwardly of the adjacent faces 62 of the guide 4a, thus protecting the guide from the frictional forces exhibited by the fast moving strip and the resultant rapid wear. The blocks 50 mounted along the opposing guide 4b are similarly arranged to protect that guide. The upper end of each tubular core 56 is connected to a respective location crank 64, which are in themselves connected to and driven by a common shaft 66 extending parallel with the guide 4a. A similar mechanism is provided for the blocks 50 of the other guide 4b. Rotation of the shaft 66, which is driven by a hydraulic actuator 68 raises and lowers the blocks 50 on their location pegs 52. During use, this motion is used to spread the wear of the blocks caused by thin strip across a wider area each block's wear face 60. When the wear face 60 of a block becomes excessively worn, the block 50 is raised from its recess 54, as illustrated in Fig. 8, and the square section sleeve 58 rotated about the tubular core 56 so that another one of the block's four sides directed towards the material path. The block 50 is then dropped back into its recess 54. In this manner, four wear faces 60a,b,c,d can be successively presented to the material path, significantly extending the life of these wear elements before they need be replaced.

Moreover, since the axial length of the blocks 50 is, in this example, significantly greater than the thickness of the strip being transported, even allowing for the vertical reciprocation of each block 50 by the crank 64 and shaft 66 mechanism, the wear face 60 against which the strip rubs only extends to the lower half of each block. Thus, once all four of these lower wear faces 60 have been used, it is possible to invert the sleeve 58 on the core 56 to provide another four wear faces 70a,b,c,d, extending the life of each block still further .

In use, the downstream ends 12 of the upstream guides 2 are positioned by actuators 14 to converge towards one another in the direction of material travel to define a tapering path for a metal strip product 6, e.g. strip steel, from a hot rolling mill. The spacing between the guides at their downstream corresponds to the width of the product 6. As the strip product 6 enters the upstream end of the guide arrangement on the roller table 8, it contacts one or both of the converging upstream guides 2 , which direct the strip towards the correct lateral position relative to the coiler mouth (not shown) . The leading edge of the strip passes onto the downstream guides 4, which are maintained parallel at a spacing corresponding to the strip width, and is further guided toward the coiler mouth. Since the position of the downstream end of the downstream guides can be adjusted independently of the position of the junction between the upstream and downstream guides, small corrections to the lateral positioning of the strip 6 can be made by moving that end only. As seen in Fig. 4 this steering or correction of the position of the strip is achieved by setting the downstream guides 4 at a small 'steering angle' (α) to the centre line of the roller table 8, whilst maintaining the guides 4 parallel with one another . This adjustability of the downstream guides 4 independent of the upstream guides 2 also facilitates very rapid adjustment of the downstream guides 4 to counter excessive side force that might otherwise cause a thin strip to buckle. Since this adjustment is achieved without the need to move the relatively heavy upstream guides 2, the speed of response can be significantly better than the known guide arrangements in which the converging and parallel regions of the guides are formed in one part. The flexibility provided by the system in terms of adjusting the guides, in particular the possibility of adjusting all of the guides independently of each other, also allows for accurate positioning of the strip based on a centre line datum, a datum at one edge of the strip or indeed any other point across the width of the strip.

Where thicker strip product is being transported through the guides it is preferred that the downstream ends 12 of the upstream guides 2 are advanced to project slightly inwardly of the downstream guides 4 (as far as the clearance (t) in the tongue and groove joint will allow) in order to offer them greater protection from the fast moving thick strip. Conversely, when operating with thin strip, it may be advantageous to retract the downstream end 12 of the upstream guides 2 relative to the downstream guides 4, to minimise the contact between the strip and the upstream guides 2. This operation would normally take place after the head end (i.e. the leading end) of the strip has been successfully entered onto the coiler and the coiling process established.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from spirit and scope of the invention.

Claims

1. An apparatus for guiding metal strip material (6) to a coiler, comprising guide means (2, 4) defining a path along which the material travels from an upstream entry end towards the coiler, said guide means comprising an upstream portion in which a first, upstream pair of opposed guide members (2a, 2b) extend along opposite sides of the material path spaced laterally further from one another at an upstream end than at a downstream end to form a converging portion of the material path, and a downstream portion in which a second, downstream pair of opposed guide members (4a, 4b) extend along opposite sides of the material path to form a portion of the path downstream of the converging portion, characterised by position controllers (14, 18, 20) for controlling the lateral position of the upstream and downstream pairs of guide members, the lateral position of at least the downstream end of the downstream guide members (4a, 4b) being adjustable independently of the position of the upstream guide members (2a, 2b) .

2. An apparatus according to claim 1, wherein the upstream ends of the downstream guide members (4a, 4b) are movable relative to the adjacent downstream ends (12) of the upstream guide members (2a, 2b) .

3. An apparatus according to claim 1 or claim 2, wherein the downstream guide members (4a, 4b) extend substantially parallel to one another to define a constant width portion of the material path, the width of this portion of the path corresponding to the width of the material being coiled.

4. An apparatus according to any one of the preceding claims, wherein the upstream guide members (2a, 2b) are pivotally mounted at respective pivot positions at their upstream ends, the lateral position of their downstream ends (12) being controlled by respective positioning controllers.

5. An apparatus according to any one of the preceding claims, wherein the positions of the downstream guide members (4a, 4b) are controlled by respective position controllers (18, 20) at both ends of each downstream guide member (4a, 4b) .

6. An apparatus according to any one of the preceding claims, wherein the upstream ends of said downstream guide members (4a, 4b) and the respective downstream ends (12) of said upstream guide members (2a, 2b) are controlled to be maintained substantially adjacent one another and to move together.

7. An apparatus according to claim 6, comprising connectors (16) connecting said upstream ends of said downstream guide members (4a, 4b) and the respective downstream ends (12) of said upstream guide members (2a, 2b) so as to constrain them to move substantially together with a restricted amount of play for relative movement between them.

8. An apparatus according to any one of the preceding claims, comprising wear elements (14) projecting into the material path at the junction between the upstream and downstream guide members (2, 4) .

9. An apparatus according to claim 8 , wherein said wear members comprise rollers (40) having their axes of rotation arranged upright and positioned at the downstream end of each upstream guide member (2a, 2b) and/or at ^' the upstream end of each downstream guide member (4a, 4b) .

10. An apparatus according to claim 8 or 9, wherein said wear members (40) are retractable out of said material path.

11. An apparatus according to any one of the preceding claims, comprising a plurality of wear elements (50) spaced apart along the length of at least one of the downstream guide members .

12. An apparatus according to claim 11, wherein said wear elements (50) are wear blocks, each block having multiple wear faces (60a, b, c, d) and being mountable on the guide apparatus in a plurality of orientations in each of which orientations a different one of the wear faces is disposed to face the material path.

13. An apparatus according to claim 12 , wherein each said block (50) is moveable between at least some of said plurality of orientations by rotation about a generally vertical axis of the block.

14. An apparatus according to claim 12 or 13 , wherein each said block (50) is movable between at least some of said plurality of orientations by inverting the block.

15. An apparatus for guiding metal strip material to a coiler, comprising guide means (2, 4) defining a path along which the material travels from an upstream entry end towards the coiler, said guide means comprising an upstream portion (2) defining a converging portion of the material path, and a downstream portion (4) defining a portion of the path downstream of the converging portion, characterised by controller means (14, 18, 20) for controlling the guide means for adjustment of the width of the material path defined thereby, and wear elements (40) projecting into the material path at the junction between the upstream and downstream portions or said guide means .

16. An apparatus according to claim 16, wherein said wear members (40) comprise rollers with their axes of rotation arranged generally upright.

17. An apparatus according to claim 15 or 16, wherein said wear members (40) are retractable out of said material path.

18. An exit roller table for metal strip material having a guide apparatus according to any one of the preceding claims .

19. Metal strip handling apparatus comprising an exit roller table according to claim 18 and a coiler arranged to receive metal strip from said guide apparatus .