Ring-rolling mill and method for operating same

Abstract

A ring-rolling mill (1) includes a machine table (2) for accommodating the rolled material (3) and an axial stand (4) that supports at least one axial roll, preferably two axial rolls (5, 6), for rolling the end faces (7, 8) of the rolled material (3). The ring-rolling mill and a method for operation thereof facilitate rapid product change without elaborate setting-up or without conversion of the rolling mill. For that purpose at least one pressure roll, preferably two pressure rolls (9, 10), for rolling the outer circumference (11) of the rolled material (3) is further arranged on the axial stand (4). The at least one pressure roll (9, 10) is arranged so as to be translationally displaceable relative to the axial stand (4).

Claims

1.-10. (canceled)

11. A ring-rolling mill (1), comprising: a machine table (2) for accommodating rolled material (3); an axial stand (4); two axial rolls (5, 6), supported by the axial stand (4), for rolling end faces (7, 8) of the rolled material (3); two pressure rolls (9, 10), for rolling an outer circumference (11) of the rolled material (3) also arranged on the axial stand (4), wherein the two pressure rolls (9, 10) are translationally displaceable relative to the axial stand (4); and measuring means (9, 10, 16) arranged on the axial stand (4) with which an outer diameter of the rolled material (3) can be measured, the measuring means (9, 10, 16) being formed by the two pressure rolls (9, 10) and a further measuring element (16).

12. The ring-rolling mill according to claim 11, further comprising a main roll (12) and a mandrel roll (13), between which the rolled material (3) can be rolled.

13. The ring-rolling mill according to claim 11, further comprising centering rolls (14, 15) with which the rolled material (3) can be centered in relation to a machine longitudinal axis (L).

14. The ring-rolling mill according to claim 11, further comprising an open or closed-loop control with which the two pressure rolls (9, 10) can be pressed against the rolled material (3) with a specified force or in accordance with a specified translational infeed.

15. The ring-rolling mill according to claim 11, wherein the further measuring element (16) is a roller or a laser measuring device.

16. The ring-rolling mill according to claim 11, wherein a direction (T) of translational displacement of each of the two pressure rolls (9, 10) and a machine longitudinal axis (L) enclose an angle (?) between 25? and 55?, wherein the direction (T) of the translational displacement of each of the two pressure rolls (9, 10) intersects the machine longitudinal axis (L) at a first point (P1), and wherein each of the two axial rolls (5, 6) has an axis (a) that intersects the machine longitudinal axis (L) at a second point (P2), wherein the first point (P1) is closer to the axial stand (4) than the second point (P2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1a is a side view of a ring-rolling mill according to the prior art, and FIG. 1b is a top view thereof.

[0027] FIG. 2 is a schematic perspective view showing an axial stand of a ring-rolling mill in accordance with one embodiment, with which two pressure rolls are arranged displaceably in/on the axial stand.

[0028] FIG. 3 is a schematic top view of the axial stand in accordance with FIG. 2 with the representation of relevant geometric parameters.

[0029] FIG. 4 is a schematic top view of the axial stand in accordance with FIG. 2 showing a measuring arrangement for determining the external diameter of the rolled material.

DETAILED DESCRIPTION

[0030] FIG. 1 shows a solution according to the prior art. The ring-rolling mill 1 has a machine table 2 on which the rolled material 3 is placed in the form of a ring to be rolled. The radial rolling of the ring 3 is effected by a main roll 12, which interacts with a mandrel roll 13. The axial rolling of the ring 3 is effected axially by means of two axial rolls 5 and 6, which are mounted in an axial stand 4. Accordingly, the outer circumference 11 of the rolled material is rolled by the main roll 12, while the end faces 7 and 8 of the rolled material are rolled by the two axial rolls 5 and 6. Centering rolls 14 and 15 are also provided, which are arranged on centering arms 17/18 respectively and with which the rolled material 3 is centered in relation to a longitudinal machine axis L.

[0031] With a view to FIG. 2, it can be seen that, in contrast to the aforementioned previously known solution, (preferably two) pressure rolls 9 and 10 are now also arranged on the axial stand 4, which are used to roll the outer circumference 11 of the rolled material 3. It is important to note that the pressure rolls 9 and 10 can be arranged in a translationally displaceable manner relative to the axial stand 4. The translational infeed with which the pressure rolls 9/10 are moved relative to the axial stand is marked Z1 and Z2 in FIG. 2.

[0032] For this purpose, FIG. 3 illustrates which geometric ratios are particularly preferably proposed in order to achieve rolling of the rolled material 3 and thereby reduce the range of the wall thickness of the rolled material 3 in such a way that an elongation of the cross-section is obtained, which leads to an increase in the outer diameter D (see FIG. 4).

[0033] As can be seen in FIG. 3 (top view), the axial stand 4 supports the axial rolls 5/6 along with the two pressure rolls 9 and 10, which in each case are displaced in a translational direction T relative to the axial stand 4 (this is effected by means of actuators, which are not shown). The direction of the axis a of the axial rolls 5, 6 coincides with the longitudinal machine axis L in the top view.

[0034] In the top view, the direction T encloses an angle a with the machine longitudinal axis L, which is approximately 35? in the exemplary embodiment. Preferred values for the angle a are between 25? and 55?. The intersection point between the direction T and the longitudinal machine axis L is shown as the first point P1 in FIG. 3.

[0035] If the axis a of the axial rolls 5/6 is intersected with the longitudinal machine axis L, a second point P2 is obtained.

[0036] Thereby, it is preferably provided that the first point PI is closer to the axial stand 4 than the second point P2.

[0037] Thus, the arrangement of the pressure rolls 9, 10 is provided outside the machine longitudinal axis L. The angle a between the direction T and the machine longitudinal axis L is a substantial parameter upon the rolling of the ring. A further relevant parameter is the relative position between the first point Pl and the second point P2 in relation to the axial stand 4. If this is effected as described and as shown in FIG. 3, the continuous feeding of the pressure rolls 9, 10 can be effected in the direction T against the ring cross-section. As a result, the wall thickness of the rolled material can be reduced, with the result that elongation of the cross-section leads to an increase in diameter.

[0038] The rolling of the ring is interrupted as soon as a desired outer diameter D of the rolled material 3 is reached. Reference is made to FIG. 4 for the relevant measurement.

[0039] It can be seen here that, due to the concept, the two pressure rolls 9 and 10 are in contact with the outer circumference 11 of the rolled material 3 during the rolling process and, as a result of the known geometry of the pressure rolls 9, 10, a first measuring point M1 and a second measuring point M2 are therefore constantly known during the rolling process. FIG. 4 also shows that there is a further measuring element 16, here in the form of a measuring roller, with which a third measuring point M3 can be recorded. Knowing the three measuring points M1, M2 and M3, the outer diameter D of the (circular) rolled material can thus be easily determined.

[0040] If a raw part of the rolled material 3 is to be rolled from an initial diameter to an enlarged outside diameter D, the geometric arrangement described, based on the aforementioned range for the angle a and for the relative position of the two points P1 and P2 with respect to the axial stand 4, allows an increasing ring diameter to be achieved with an infeed Z1/Z2 (see FIG. 2) and thus with decreasing x-values for the two pressure rolls 9, 10 (see the coordinate system in FIGS. 3 and 4); thus, the wall thickness of the ring is reduced and ring growth can take place.

[0041] If the geometric ratios explained were not observed, there would be no growth in the outer diameter D with an infeed Z1/Z2 in the direction shown in FIG. 2, i.e. with decreasing x-values for the two pressure rolls 9 and 10. Therefore, the geometric relationships/parameters described above are of particular importance in the event that the specified ring growth is desired/required. Accordingly, the pressure rolls 9, 10 thereby can be fed continuously in the direction of the infeed Z1, Z2, while at the same time the outer diameter D of the rolled material 3 increases.

[0042] This applies in particular to the preferred procedure, according to which the main roll 12 and the mandrel roll 13 are not engaged, i.e. do not contact the rolled material.

[0043] As a function of the size of the ring-rolling mill, the pressure rolls can be arranged on the side walls of the axial stand, or alternatively between the side walls or outside them.

List of Reference Signs

[0044] 1 Ring-rolling mill [0045] 2 Machine table [0046] 3 Rolled material (ring) [0047] 4 Axial stand [0048] 5 Axial roll [0049] 6 Axial roll [0050] 7 End face of the rolled material [0051] 8 End face of the rolled material [0052] 9 Pressure roll [0053] 10 Pressure roll [0054] 11 Outer circumference of the rolled material [0055] 12 Main roll [0056] 13 Mandrel roll [0057] 14 Centering roll [0058] 15 Centering roll [0059] 16 Measuring element [0060] 17 Centering arm [0061] 18 Centering arm [0062] L Longitudinal machine axis [0063] T Direction of the translational displacement of the pressure roll [0064] Z1 Translational infeed [0065] Z2 Translational infeed [0066] ? Angle [0067] a Axis of the axial roll [0068] P1 First point [0069] P2 Second point [0070] D Outer diameter of the rolled material [0071] M1 Measuring point [0072] M2 Measuring point [0073] M3 Measuring point