ROLL STAND FOR ROLLING A METAL PRODUCT

Abstract

The invention relates to a roll stand (1) for rolling a metallic product and having two work rolls supported in the roll stand by respective work roll chocks (2), wherein axial displacement means (3) is provided with which the work rolls can be displaced in direction of their longitudinal axes, wherein at least one work roll locking means (4) is provided with which the work roll chocks (2) can be locked and unlocked in the roll stand (3), wherein rotation prevention means (6) is provided with which the axial displacement means (3) can be prevented from rotation about longitudinal axes of the work roll, and wherein bending means is provided which includes a bending block (5) and with which a bending torque can be applied to the work rolls. In order to achieve a simpler design of the assembly and improved lubrication possibilities for the component to be lubricated, according to the invention, the rotation prevention means (6) and the axial displacement means (3) are fixedly connected with the bending block (5).

Description

The invention relates to a roll stand for rolling a metallic product and having two work rolls supported in the roll stand by respective work roll chocks, wherein axial displacement means is provided with which the work rolls can be displaced in direction of their longitudinal axes, wherein at least one work roll locking means is provided with which the work roll chocks can be locked and unlocked in the roll stand, wherein rotation prevention means is provided with which the axial displacement means can be prevented from rotation about longitudinal axes of the work rolls, and wherein bending means is provided which includes a bending block and with which a bending torque can be applied to the work rolls.

Such roll stand is disclosed, for example, in European Patent EP 1648 626 B1. The principle design of a such roll stand is shown in FIG. 1. The roll stand which is shown here, has two arranged one above the other work rolls which are supported in respective work roll chocks 2. For axial displacement of the work rolls, i.e., for displacement in direction of the longitudinal axis, axial displacement means 3 is provided. For applying a bending torque to the work rolls in order to influence the roll gap, there is provided, in a bending block 5 (for both the upper and lower work rolls), a bending cylinder 12. For displacement of the work rolls in the roll stand or roll housing, a releasable connection between work roll chocks 2 of the rolls and the displacement device 3 is necessary. The releasable connection is provided by work roll locking means 4. The locking or unlocking is carried out by displacement of a tongue displaceable by displacement means 8.

Thus, the roll stand 1 includes a bending and displacing system for the work rolls with work roll locking means. The axial displacement means (displacement device) is secured, in the direction of the longitudinal axis of the work roll, in front of the bending block, directly on the roll housing or on the bending block.

For work rolls to be able to be displaced along their longitudinal axes, a connection between the displacement device and the work roll chocks should be established. On one hand, this connection should be stable to enable displacement under rolling and bending forces, and on the other hand, it should be releasable to provide for roll exchange. This connection is provided by the work roll locking means 4. Upon locking, the above-mentioned tongue is pivoted, as a rule, by a hydraulically actuated lever connection, about the axis of the displacement device into a side recess in the work roll chock, providing, thus, a connection between the displacement mechanism and the chock. The purpose of the additional rotation prevention means 11 is to keep the position of the displacement device rotationally stable. With the known solution, the rotation prevention means 11 is secured on the roll housing even when the axial displacement means 3 itself is secured on the bending block.

The attachment of the rotation prevention means on the roll housing leads to various disadvantages, in particular, when the associated axial displacement means are secured on the bending block. Due to the symmetry of the roll stand, the roll stand is equipped with four of each of the above-mentioned devices (on respective inlet and outlet sides of respective upper and lower rolls), however, this is a minor disadvantage (in a seven stand finishing train) but still a relevant factor:

The attachment of the rotation prevention means to the roll housing is carried out, with a known solution, using a guide block with a loop belt and an attachment screw. For this, it is necessary to mill the roll housing at this location and, thus, during manufacturing, an expensive machining step is required.

The final assembly and adjustment of parts on the roll housing can only be done on site because of separate attachments to the displacement cylinder and the roll housing, no pre-assembly is possible. Therefore, the time of assembly is disadvantageously extended.

The installation and removal of a bending block is relatively difficult. E.g., for mounting a block in the roll housing, simultaneously, a recess in the housing and the two rotation prevention means of the respective block should be made, while the displacement device has no rotationally stable position without the rotation prevention means.

Moreover, upon dismounting of the block by turning the displacement device over after “loss of the rotation prevention means,” the displacement device itself can be damaged and personnel injured.

At the attachment points of the roll housing, the guide surfaces should be lubricated. For grease lubrication, for each rotation prevention means, approximately two open lubrication points with “loss lubrication” are required, altogether, eight open grease lubrication points for a roll stand. This leads to grease escape, which contaminates the environment and the cooling water and occasionally, to burn marks on the surface of the to-be-rolled strip.

The rotation prevention means mounted on the roll housing makes the access to media connections and conduit routing more difficult.

The object of the invention is to so improve the state-of-the-art roll stand described above that the above-mentioned drawbacks are prevented or eliminated, and advantages in manufacturing and operation of a rolling stand can be achieved. In particular, the object of the invention is to achieve a simple assembly and advantages in lubrication of the roll stand. Thus, a simpler construction of the installation and improved lubrication possibilities of the to-be-lubricated components should be achieved.

These objects are achieved by the invention characterized in that the rotation prevention means and the axial displacement means are fixedly connected with the bending block.

The rotation prevention means the, axial displacement means, and the bending block form, advantageously, an integral unit.

The connection between the rotation prevention means, the axial displacement means, and the bending block is formed, advantageously, as a screw connection.

At least two, arranged one above the other, axial displacement means are secured on the bending block.

The work roll locking means is connected with the displacement means so that they form an operative connection.

The work roll locking means advantageously includes at least one tongue movable in a direction transverse to the direction of the longitudinal axis of the work roll. Thereby, displacement means is advantageously provided which can displace the tongue.

According to further development of the invention there is provided displacement locking means located between the axial displacement means and the bending block and which can be secured there in order to prevent displacement of the axial displacement means relative to the bending block.

A media access (central) is advantageously formed on the bending block. Thereby, it can be provided that the media access communicates with entrance for medium for the work roll locking means, for the axial displacement means, and for the bending block.

Advantageously, the media access is connected with an appropriate piping. The proposed solution thereby ensures that the rotation prevention means is secured on the bending block, together with the axial displacement means (displacement device). Thereby, according to the proposed solution, an integral rotation prevention means is available for axially displaceable rolls.

A relatively simple constructive change provides a surprising number of advantages associated with manufacturing, assembly, servicing, and maintenance of a roll stand. As a result, the proposed solution is well suited for modernization and retrofitting of existing plants.

The proposed solution can be used, e.g., for flat rolling of metal strips, with the rolls being displaceable along their longitudinal axes, in particular, in hot rolling mills. It is generally also suitable for all other types of rolls.

The drawings show exemplary embodiments of the invention.

In the drawings:

FIG. 1 shows a portion of a roll stand seen in the direction of the longitudinal axis of work rolls, which represents the solution according state-of-the-art;

FIG. 2 shows a portion of a roll stand seen in the direction of the longitudinal axis of work rolls, which represents an embodiment according to the present invention;

FIG. 3 shows a perspective view of the portion of the roll stand according to the embodiment of the invention shown in FIG. 2;

FIG. 4 shows a perspective view of a section of FIG. 3 at an increased scale, which shows an arrangement of the displacement prevention means;

FIG. 5 shows a perspective view of a section of the roll stand, illustrating the media access.

A roll stand 1 shown in FIGS. 2 and 3, in principle, has the same elements which were described in connection with the discussion in the state-of-the-art (with reference to FIG. 1). As discussed, the work rolls (not shown) are arranged in respective work roll chocks 2, wherein the work roll chocks 2 are located in a roll housing 13 of the roll stand 1. For displacement of the work roll in direction of their longitudinal axis, axial displacement means 3 is provided.

The work roll locking means 4 provides a connection between the axial displacement means 3 and the roll chock. To this end, for locking purposes, a tongue 7 is driven in a corresponding recess in the roll chock 2 by (hydraulic) displacement means 8.

Further, there is provided a bending block 5 in which a bending cylinder is located in order to apply, in a known manner, a bending torque to the work rolls to influence the profile of the roll gap.

Designing the axial displacement means in form of a hydraulic cylinder requires, as a rule, that the axial displacement means has a round outer shape. To avoid an undesired rotation, it should be supported against another component, without a possibility of rotation relative thereto. According to the invention, the axial displacement means is supported against rotation by being supported against the bending block. To this end, there is provided a screw connection unit formed of the above-mentioned elements, roll locking means 4, axial displacement means 3, and bending block 5. The unit can be pre-assembled at the plant and then transported to an assembly site.

The above-mentioned connection of the locking means 4 with the bending block 5 by the screw connection 6, advantageously, is carried out simultaneously for both upper and lower rolls, with the bending block 5 being already equipped with respective cylinders 12 for the upper and lower work rolls.

To avoid open lubrication points, the bearing locations are combined. FIGS. 2 and 3 show that the bearing spots are already closed, preferably, with a round guide, so that for each roll housing, there are only 4 points for 1 closed bearing spot. Use of a sealed round guide means insures that the bearing spots are maintenance-free and, thus, 4 multiply by 2, that is 8 loss lubrication points are eliminated.

For an integral unit formed of axial displacement means (displacement device), rotation preventing means, and bending block, displacement locking means 9 is provided, as shown in FIG. 4. The displacement locking means 9 secures the displacement device in a predetermined position relative to the bending block. In this way, damage or injury from moving parts can be prevented.

A further advantageous embodiment or effect of the proposed solution is illustrated in FIG. 5. It shows that an improved access of the medium connection, which results from elimination of the attachments to the roll housing, becomes possible. Further, thereby, a hard connection of all of the tubular junctions becomes possible. Potential leak points are reduced, and the piping system of the roll housing can be substantially simplified.

Thus, the entire stand is substantially simplified, whereby substantial advantages in manufacturing and on-site assembly, and particularly, in maintenance of the roll stand are achieved.

LIST OF REFERENCE NUMERALS

• • 1 Roll stand
  • 2 Work roll chock
  • 3 Axial displacement means
  • 4 Work roll locking means
  • 5 Bending block
  • 6 Rotation prevention means
  • 7 Tongue
  • 8 Displacement means
  • 9 Displacement prevention means
  • 10 Media access
  • 11 Means for securing rotation prevention means to a roll housing
  • 12 Bending cylinder
  • 13 Roll housing

Claims

1. Roll stand (1) for rolling a metallic product and having two work rolls supported in the roll stand by respective work roll chocks; wherein axial displacement means (3) is provided with which the work rolls can be displaced in direction of their longitudinal axes,wherein at least one work roll locking means (4) is provided with which the work roll chocks (2) can be locked and unlocked in the roll stand (3),wherein rotation prevention means (6) are provided with which the axial displacement means (3) can be prevented from rotation about longitudinal axes of the work roll, andwherein bending means is provided which includes a bending block (5) and with which a bending torque can be applied to the work rolls,characterized in thatthe work roll locking means (4), the rotation prevention means (6) and the axial displacement means (3) are fixedly connected with the bending block (5).

2. Roll stand according to claim 1, characterized in that the rotation prevention means (6), the axial displacement means (3), and the bending block (5) form an integral unit.

3. Roll stand according to claim 1, characterized in that connection of the work roll locking means (4), the axial displacement means (3), and the bending block (5) is formed as a screw connection.

4. Roll stand according to claim 1, characterized in that two arranged one above the other axial displacement means (3) are secured on the bending block (5).

5. Roll stand according to claim 1, characterized in that a releasable displacement locking means (9) is provided which is located between the axial displacement means (3) and the bending block (5) and can be secured there in order to prevent displacement of the axial displacement means relative to the bending block (5).

6. Roll stand according to claim 1, characterized in that a media access (10) is provided on the bending block (5).

7. Roll stand according to claim 6, characterized in that the media access (10) communicates with entrance for medium for the work roll locking means (4), for the axial displacement means (3), and for the bending block (5).

8. Roll stand according to claim 6, characterized in that the medium access (10) is connected with piping.

9. Roll stand according to claim 7, characterized in that the medium access (10) is connected with piping.