EP0231445B1 - Method and apparatus for the horizontal adjustment of rolls in a rolling mill - Google Patents

Abstract

A method and apparatus for height or level-positioning of rolls in rolling mill frames, for adapting the upper edge of the lower working roll to the rolling plane, and for changing the rolls, expecially in four-high mills equipped with a roll changing cart which can travel in the longitudinal direction of the rolls, and equipped with interchangeable shim plates of various individual thicknesses for supporting the holding elements of the support rolls. The apparatus affords an infinitely variable and continous adaptation to the wear of the rolls. The apparatus is operated such that the level or position of the individual shim plates is carried out infinitely variable by way of a short vertical stroke. The mill preferably includes a system of movable wedges which includes two upper wedges and two lower wedges.

Description

The invention relates to a method and an apparatus for height adjustment of rolls in roll stands, for aligning the upper edge of the lower work roll with the rolling line and for changing the rolls, in particular for four-high stands, equipped with a roll changing slide which can be moved in the longitudinal direction of the rolls and has interchangeable step plates of variable thickness or height for supporting the chocks of the support rollers, as well as vertical lifting elements for supporting the chocks in the meantime.

German patent DE-C 28 06 525 describes a device for extending the rolls of roll stands and for aligning the upper edge of the lower work roll with the rolling line, equipped with a roll change slide on which several step plates of different thicknesses are arranged and by means of a displacement drive under the Chocks of the lower support roller are retractable, the step plates being arranged in a sliding frame which is movably guided on a path located on the interchangeable slide and connected to the sliding drive, the sliding drive comprising at least one spindle mounted in the interchangeable slide and driven by a motor via a transmission , furthermore with vertical lifting elements for supporting the chocks, the lifting elements being arranged on both sides of the sliding frame in the interchangeable slide. This device uses step plates of different thicknesses, however, a continuous adjustment to the roll wear is not possible.

In addition, infinitely adjustable devices are also known, the maximum possible height displacement of the chocks being carried out by means of wedges. However, these arrangements are not designed to be movable in the direction of the roller axes. Due to the necessary small wedge angle, the wedges must also be very long because of the otherwise occurring self-locking. Therefore, such devices are very expensive in terms of equipment and maintenance-unfriendly with a large space requirement.

In US-A 4 038 857 a continuous height shift of rollers in roll stands is addressed, the height shift being achieved in that a step plate designed as a stair can be continuously adjusted in height by means of wedges. Only the steps as a disadvantageously connected stair unit and the wedges are arranged in the carriage. The chocks are pulled up vertically using hydraulic cylinders and hooks. Lifting is complicated and time-consuming. In addition, the chocks have to be specially designed to accommodate the hooks and have to be kept in stock as a special, expensive reserve set. Expensive spindles for wedge adjustment are provided as horizontal lifting elements. Changing the work rolls is cumbersome and there is no easy repair and maintenance option, especially for the vertical lifting elements.

It is therefore an object of the invention to present a method and a device by means of which the disadvantages mentioned can be avoided and the difficulties can be eliminated. The roll change, in particular also the change of the work rolls, is to be simplified, while at the same time the roll gap is optimized, or a constant rolling line is maintained. In addition to a compact design, good maintenance options for the step plates and lifting elements are also to be ensured, and weakening of the roller stands is to be avoided.

The problem is solved for the method according to the invention in that in the case of several step plates of different heights, starting with the lowest step, this is raised continuously by means of a short vertical stroke until the lower step has reached the level of the next higher step, in which case the Vertical lifting elements temporarily support the chocks until the short vertical stroke has returned to its lower position and the next higher step plate has been moved under the chocks. This advantageously enables a stepless height adjustment and replacement of the work rolls with only a small space requirement. In addition, the infinitely variable height adjustment allows the upper edge of the lower work roll to be continuously adjusted to a height-constant rolling line, for example in hot strip finishing lines. A fixed roller table surface or a fixed top edge of the guide can be set as required.

In an advantageous embodiment of the invention it is provided that the short vertical stroke is generated by a horizontal stroke. This enables a compact design in which only a short vertical stroke is generated by a likewise relatively short horizontal stroke.

It is also advantageously provided that the method according to the invention is used to change the work rolls, the lower support roll with the work roll being raised by the vertical lifting elements in the roll change slide and the bottom step plate being moved under the chocks and then the support roll being lowered with the work roll, whereby the lower chock of the work rolls sits on a fixed rail and is extended. In this way, a particularly simple work roll change can be carried out without having to lift the extension rails for the roll change.

For the device for shifting the height of rolls in roll stands, for aligning the upper edge of the lower work roll to the rolling line and for changing the rolls, for carrying out the method according to the invention, the object is achieved in that the roll change slide has a wedge arrangement which can be moved by means of a lifting cylinder for the stepless height shift the individual Has step plates and the vertical lifting elements for intermediate support of the chocks are also arranged in the roller changing slide.

A further embodiment of the invention provides that the wedge arrangement consists of two upper wedges and two lower wedges, each with an upper and lower wedge forming a common contact surface and the upper in each case being positively guided in the vertical and the lower in the horizontal direction. This is a particularly reliable and reliable embodiment.

In another embodiment of the invention, it is advantageously provided that the lower wedges are rigidly connected to one another by one or more connecting elements. With this measure, there is no additional lifting element, so costs can be saved.

The contact surface of the respective upper wedge with the associated lower wedge expediently forms a wedge angle with respect to the horizontal of approximately 5 degrees. The compact design is optimized using the preferred angular arrangement.

A further embodiment of the invention advantageously provides that the lower wedges are arranged horizontally displaceably by means of a lifting cylinder, the lifting cylinder preferably being arranged between the lower wedges. Lifting cylinders are proven means of power, the arrangement between the wedges is particularly space-saving. A hydraulic clamp is expediently attached to the piston rod of the horizontal lifting cylinder and absorbs impact impulses caused by the rolling on the power means.

It is also advantageously provided that at least one upper wedge is equipped with a pressure cell and has a spacer. In this way, the rolling pressure can be controlled and a constant height of the rolling line can be maintained in a controllable manner.

Furthermore, it is provided with the invention that a plurality of step plates of different thicknesses are arranged on the roller change slide and can be moved by means of a displacement drive under the chocks of the lower support roller, the step plates being arranged in a slide frame which is movably guided on and along a track on the roller change slide is connected to the displacement drive, the displacement drive comprising at least one spindle mounted in the roller changing slide and driven by a motor via a gear. In this way, the height shift of the rollers can be set or adjusted as desired, for example continuously depending on the roller wear. Furthermore, the vertical lifting elements are expediently arranged on both sides of the sliding frame in the roller changing slide for intermediate support of the chocks.

In addition, it is provided with the invention that the lowest step plates have a thickness of about 50 mm, stationary extension rails being arranged on both sides axially parallel to the rollers on which the lower chocks of the work rolls can be moved, provided the chocks of the backup roll are on the lower step plates. This embodiment advantageously allows the work rolls to be changed without having to lift the extension rails for the roll change.

Further details, features and advantages of the invention result from the following explanation of the exemplary embodiments shown schematically in the drawings.

• Fig. 1 einen Teillängschnitt durch den erfindungsgemäßen Wechselschlitten im Bereich des linken Einbaustücks eines Walzgerüsts
• Fig. 2 einen Teillängschnitt durch den Wechselschlitten im Bereich des rechten Einbaustücks eines Walzgerüsts
• Fig. 3 einen Querschnitt aus Figur 1 gemäß der Linie A-B
• Fig. 4 einen Längsschnitt durch den erfindungsgemäßen Walzenwechselschlitten mit stufenlosem Höhenausgleich mit nur zwei Stufenplatten
• Fig. 5 schematische Darstellung des oberen Keils mit Druckmeßdose im Querschnitt

Show it:

• Fig. 1 shows a partial longitudinal section through the interchangeable slide according to the invention in the region of the left chock of a roll stand
• Fig. 2 shows a partial longitudinal section through the interchangeable slide in the area of the right chock of a roll stand
• Fig. 3 shows a cross section from Figure 1 along the line AB
• Fig. 4 shows a longitudinal section through the roll change slide according to the invention with stepless height compensation with only two step plates
• Fig. 5 shows a schematic representation of the upper wedge with pressure transducer in cross section

Figures 1 and 2 each show a section of a four-roll stand with the chocks (10, 11) of a lower backup roll (13) when rolling on a roll change slide (14) in the window openings of the roll stands (15, 16). The roller stands (15, 16) are connected by a crossmember (17), a support (18) being additionally attached to the roller stand (16). On the roller stands (15, 16), the crossmember (17) and the carrier (18), a slide rail (19) is attached at the same level on which the roller change slide (14) can be moved. A piston rod (not shown) of a displacement cylinder (not shown) attached to the carrier (18) is connected to the slide (14), so that the slide (14) can be moved out and in on the slide rail (19) from the roll stand. The top of the interchangeable slide (14) is designed as a track (20, 21) for a sliding frame (22) in which six step plates (23 - 28; 29 - 34) of different heights are arranged in a row on each side.

The lowest step plates (28, 34) have a thickness of approximately 50 mm. In this way, the roll changing device (14) can be used very easily to change the work rolls alone, the lower backup roll (13) with the work roll being lifted by the vertical lifting elements (FIG. 3, numbers 70, 71) in the roll changing slide (14) the lowest step plate (28, 34) is moved under the chocks (10, 11) and then the support roller (13) is lowered with the work roller. The lower chocks of the work rolls sit on a fixed rail (not shown) and can be extended. If the backup rollers also have to be changed, they are then placed on the carriage (14). extended.

The gradation of the other step plates (23 - 27 or 29 - 33) to each other is approximately 30 mm. The step plates (23, 29; 24, 30; 25, 31; 26, 32; 27, 33; 28, 34) are each operatively connected in pairs to the hard metal pressure pieces (35, 36).

The web (20, 21) of the sliding frame (22) can be covered by hoods which are attached to the side of the roller changing slide (14) and are connected to the chocks (10, 11) by means of seals (not shown). Contamination of the step plates (23-34) in their path (20, 21) can thereby advantageously be avoided.

A spindle (40) is mounted on the roller changing slide (14) and is driven by a motor or a hydraulic motor (not shown) via worm gears and bevel gears. A guide nut (41) is screwed onto the spindle (40) and moves the sliding frame (22) horizontally via a fork (42) attached to the sliding frame (22).

A horizontal lifting cylinder (50) for actuating the movable wedge arrangement (51 - 54) for the infinitely variable height adjustment of the individual step plates (23 - 34) is also provided in the roll changing carriage (14). The wedge arrangement (51-54) essentially consists of two upper wedges (51, 52) and two lower wedges (53, 54), the upper wedge being positively guided in the vertical direction and the lower wedge in the horizontal direction. The forced guidance of the lower wedges (53, 54) is effected by wedge rails (55, 56) which can be displaced in the guide grooves (57, 58) of the roller changing slide (14). The upper wedges (51, 52) are held vertically movable in the frame of the interchangeable slide (14). The lower wedges (53, 54) are expediently connected to one another by connecting elements (59), for example one or more rods, profiled strips, rod structures, etc. A hydraulic clamp (61) is attached to the piston rod (60) of the horizontal lifting cylinder (50) to prevent impacts on the cylinder (50).

According to Figure 3, vertical lifting cylinders (70, 71) below the chocks (10, 11) are arranged as lifting elements in the roller changing slide (14) on both sides of the sliding frame (22), the pistons of which, when loaded via spacer plates (72, 73), the chocks (10 or . 11) raise. The interchangeable slide (14) is laterally supported on the lower slide rail (19), axially parallel and laterally supported on the slide strips (74, 75) which are attached to the wear strips (76, 77) of the roller stands (15, 16). The sliding frame (22) is moved laterally in the slide (14) in the slide bearings (78, 79). In the raised position, the step plates (23 - 34) required for aligning the upper edge of the lower work roll can be pushed under the hard metal pressure pieces (35, 36) on the chocks (10, 11) by the motor for the spindle (40).

FIG. 4 shows the lower part of a four-high stand, in contrast to the example chosen in FIGS. 1 and 2, only two step plates (62, 63) are provided, which are moved by means of the movable wedge arrangement (51-54), as already described above , can be moved vertically. The lifting cylinder (64) arranged between the lower wedges (53) and (54) ensures their horizontal displacement, the wedges (53, 54) being rigidly connected to one another via laterally attached cheeks (59). The lifting cylinder (64) can also be attached above and connected to the connecting elements (59), the lifting cylinder (64) being supported on its other side in each case in the frame or in a transverse connection of the roller-changing slide (14). A hydraulic clamp (66) is in turn attached to the piston rod (65) of the lifting cylinder (64) to prevent impacts on the cylinder (64). Such an arrangement, with only one step plate (62, 63) under each of the two chocks (10, 11), is particularly useful when only slight height displacements of the rollers are required. Otherwise, the step plates (62, 63) can also be exchanged for thicker ones. In this way, a virtually continuous height shift is achieved which goes beyond the vertical elevation of the wedge arrangement (51-54).

According to FIG. 5, the upper wedge (80) can expediently be equipped with a pressure cell (81) which is embedded in the recess (82) of the upper wedge (80) and on which a vertically movable spacer (83) rests.

The measures according to the invention are not limited to the exemplary embodiment shown in the drawing figures. For example, the roller changing table according to the invention or the method can, without leaving the scope of the invention, also be used in duo or six-high stands with corresponding design adaptation.

Claims (15)

1. Method for the vertical redisposition of rolls in roll stands for equalising the upper edge of the lower working roll with the rolling line and for the exchanging of the rolls, in particular in four-high roll stands, equipped with a roll changing carriage, which is movable in longitudinal direction of the rolls and displays exchangeable stepped plates (23 to 28) of variable thickness or height for the support of the chocks (10, 11) of the backing rolls, as well as vertical lifting elements (70, 71) for the meantime support of the chocks (10, 11), characterised thereby, that in the case of several stepped plates of different height and starting with the lowest step, this is raised steplessly each time by means of a lifting element (50, 64) of short vertical stroke until the lower step has reached the level of the next higher step, for which the vertical lifting elements (70, 71) then meantime take over the support of the chocks (10, 11) until the lifting element (50, 64) of short vertical stroke has travelled back to its lower setting and the next higher step plate has been moved below the chocks (10,11).

2. Method according to claim 1, characterised thereby, that the short vertical stroke is produced by an horizontal stroke.

3. Method according to claim 1 or 2, characterised thereby, that it is used for the exchanging of the working rolls, wherein the lower backing roll is raised with the working roll by the vertical lifting elements in the roll changing carriage and the lowermost step plate is moved below the chocks and the backing roll is then lowered with the working roll, while the lower chock of the working rolls sets down on a fixed rail and is moved out.

4. Apparatus for the vertical redisposition of rolls in roll stands for equalising the upper edge of the lower working roll with the rolling line and for the exchanging of the rolls, in particular in four-high roll stands, equipped with a roll changing carriage, which is movable in longitudinal direction of the rolls and displays exchangeable stepped plates of variable thickness or height for the support of the chocks of the backing rolls, as well as vertical lifting elements for the meantime support of the chocks, for the performance of the method according to one of the preceding claims, characterised thereby, that the roll changing carriage (14) displays a wedge arrangement (51 to 54; 80), which is movable by means of lifting cylinders (50, 64), for the stepless vertical redispositon of the indivdual stepped plates (23 to 34; 62, 63) and the vertical lifting elements (70, 71) for the meantime support of the chocks (10, 11) are likewise arranged in the roll changing carriage (14).

5. Apparatus according to claim 4, characterised thereby, that the wedge arrangement consists of two upper wedges (51, 52) and two lower wedges (53, 54), wherein an upper wedge (51 or 52) and a lower wedge (53 or 54) each time form a common contact surface and the upper wedge is constrainedly guided each time in vertical direction and the lower wedge is constrainedly guided each time in horizontal direction.

6. Apparatus according to claim 4, characterised thereby, that the lower wedges (53, 54) stand in rigid effective connection each with the other through one or more connecting elements (59).

7. Apparatus according to claim 5 or 6, characterised thereby, that the contact surface of the respective upper wedge (51 or 52) forms a wedge angle of about 5 degrees relative to the horizontal with the associated lower wedge (53 or 54).

8. Apparatus according to one of the claims 4 to 7, characterised thereby, that the lower wedges (53, 54) are arranged to be horizontally displaceable by means of a stroke cylinder (50, 64).

9. Apparatus according to claim 8, characterised thereby, that the stroke cylinder (64) is arranged between the lower wedges (53, 54).

10. Apparatus according to one of the claims 4 to 8, characterised thereby, that an hydraulic clamp (61, 66) is mounted at the piston rod (60, 65) of the horizontal stroke cylinder (50, 64).

11. Apparatus according to one of the claims 4 to 10, characterised thereby, that at least an upper wedge (80, 51 or 52) is equipped with a pressure- measuring cell (81) and possesses a spacer member (83).

12. Apparatus according to one of the claims 4 to 11, characterised thereby, that several stepped plates (23 to 34) of different thickness are arranged on the roll changing carriage (14) and movable by means of a displacing drive (40 to 42) to below the chocks (10, 11) of the lower backing roll (13), wherein the stepped plates (23 to 34) are arranged in a displacing frame (22), which guided to be movable on a track (20, 21) situated on the roll changing carriage (14) and connected with the displacing drive (40 to 42), wherein the displacing drive (40 to 42) comprises at least one spindle (40), which is borne in the roll changing carriage (14) and driven by a motor by way of gears.

13. Apparatus according to one of the claims 4 to 12, characterised thereby, that the vertical lifting elements (70, 71) for the meantime support of the chocks (10, 11) are arranged in the roll changing carriage (14) at both sides of the displacing frame (22).

14. Apparatus according to claim 12 or 13, characterised thereby, that the difference in step height between the individual stepped plates (23 to 27 or 29 to 33) amounts to about 30 millimetres.

15. Apparatus according to one of the claims 4 to 14, characterised thereby, that the lowest stepped plates (28, 34; 62, 63) display a thickness of about 50 millimetres, wherein stationary move-out rails, on which the lower chocks of the working rolls are movable in so far as the chocks (10, 11) of the backing roll (13) rest on the lower stepped plates (18, 34; 62, 63), are arranged between the roll stands (15, 16) at both sides of and parallelly with the axes of the rolls.

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