Cross-rolling unit and method for setting the roll pass of a cross-rolling unit

Abstract

A cross-rolling unit and a method for setting the roll pass of a cross-rolling unit, having at least two rolls and a roll housing, in which at least one of the rolls is mounted such that its position can be adjusted in order to change the roll pass, allow the roll pass to be adjusted by means of a roll-positioning apparatus even during rolling, which roll-positioning apparatus is characterized by a housing-connected part and a roller-mill-connected part, which can be moved relative to the housing-connected part during rolling, which parts can be repositioned relative to each other, and/or which roll-positioning apparatus characterized by a drive which is dimensioned in such a way that rolling forces can be applied.

Claims

1. A cross-rolling unit (10) having at least two rolls (30) and having a roll housing (27) in which at least one of the rolls (30) is mounted such that its position is adjustable in order to change the roll pass, wherein a roll-positioning apparatus (22) comprises a housing-connected part and a part connected to a roller mill (21) which is movable relative to the housing-connected part during rolling, both of which are adjustable relative to each other, wherein the roll-positioning apparatus (22) comprises at least one movable hydraulic cylinder operable at more than 50,000 hPa and controllable by quick-acting switching valves, and wherein a drive of the roll-positioning apparatus (22) is configured to apply rolling forces.

2. The cross-rolling unit (10) according to claim 1, wherein the at least one movable hydraulic cylinder is movable at more than 30 mm/s.

3. The cross-rolling unit (10) according to claim 1, wherein two roll-positioning apparatuses (22) are provided for at least one of the rolls (30).

4. The cross-rolling unit (10) according to claim 1, further comprising a multi-variable control (70) which comprises at least two input variables and at least one output variable.

5. The cross-rolling unit (10) according to claim 4, wherein the at least two input variables and the at least one output variable are both determined by the roll-positioning apparatus (22) and/or are transmitted to the roll-positioning apparatus (22), and/or wherein the at least two input variables comprise workpiece infeed speed (71), workpiece outfeed speed (72), wall thickness (73), eccentricity (74), outside diameter (75), ovality (76), rolling force (77) and/or mandrel holding force (78), and/or wherein the at least one output variable comprises dynamic position adjustment (81) of at least one of the rolls (20), adjustment of a rolling center (82) by adjusting all rolls (20), dynamic adjustment of a mandrel position (83) and/or adjustment of a spread angle (80).

6. The cross-rolling unit (10) according to claim 1, wherein the at least one movable hydraulic cylinder has a stroke height less than 150 mm.

7. The cross-rolling unit (10) according to claim 6, wherein the stroke height of the at least one hydraulic cylinder is less than 100 mm.

8. The cross-rolling unit (10) according to claim 6, wherein a mandrel position of a mandrel (30) is adjustable parallel to a workpiece during rolling by means of a mandrel position adjustment apparatus (31).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, objectives and properties of the present invention are described by means of the following description of exemplary embodiments which are also shown in particular in the accompanying drawing. In the drawing:

(2) FIG. 1 shows a schematic top view of two cross-rolling units of a cross-rolling unit;

(3) FIG. 2 shows a schematic side view of a first cross-rolling unit;

(4) FIG. 3 shows a schematic side view of a second cross-rolling unit;

(5) FIG. 4 shows a schematic front view of a third cross-rolling unit;

(6) FIG. 5 shows a schematic side view of the third cross-rolling unit;

(7) FIG. 6 shows a schematic front view of a fourth cross-rolling unit;

(8) FIG. 7 shows a schematic side view of the fourth cross-rolling unit;

(9) FIG. 8 shows a schematic side view of a workpiece passing through a cross-rolling unit with mandrel, with measured and manipulated variables; and

(10) FIG. 9 shows a schematic illustration of the multi-variable control with input and output variables.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) The cross-rolling units 10 shown in the figures each comprise at least two rolls 20 (see FIGS. 1 to 3) or three rolls 20 (see FIGS. 4 to 7), which are supported in roller mills 21, which in turn are mounted on a roll housing 27 such that they can be set via a roll-positioning apparatus 22.

(12) The rolls 20 can rotate about roll axes 25 and have rolling surfaces 26 which successively come into contact with an elongated workpiece 32 shown in more detail only in FIG. 8.

(13) Here, the workpiece 32 runs substantially along a rolling centerline 11, which roughly represents the material center of gravity of the material passing through and, more precisely, represents the axis from an infeed roller table, which is not shown, through the center of the rolling unit to an outfeed roller table, which is not shown.

(14) In this case, the roll axes 25 are aligned substantially parallel to the rolling centerline 11, with a slight angle of inclination between 5 and 8 being provided in the present exemplary embodiment. In deviating embodiments, other angles of inclination can of course also be provided here, possibly also with respect to the horizontal.

(15) The rolls 20 themselves have a relatively complex rolling surface 26, which in turn leads to a relatively complex roll pass and in particular also to a different load on the respective roller mills 21 of a roll 20. This means that the roll axes 25 can also be inclined relative to the horizontal, which can possibly also be provided without load in cross-rolling units 10.

(16) The roll-positioning apparatus 22 of the exemplary embodiments shown in FIGS. 1 and 2 are connected to the roll housing 27 via longitudinal beams that serve as engagement points 24 such that via the engagement points 24 or via the connection between the engagement points 24 and the roll housing 27, which can be referred to as engagement means 23, the rolling forces are transferred into the roll housing 27, which leads to a corresponding spring-back of the roll housing 27 which, as a consequence of the non-uniform loading of the rolls 20 and the roller mills 21 already indicated above, can ultimately lead to a corresponding non-uniform loading of the roll housing 27.

(17) In the exemplary embodiments illustrated in FIGS. 4 to 7, a solid roll housing 27 is provided in which, in the exemplary embodiment according to FIGS. 4 and 5, a thread to a roll-positioning apparatus 22 is provided and, in the exemplary embodiment according to FIGS. 6 and 7, a hydraulic cylinder and piston arrangement is provided, which can be used to set the rolls 20 and can be defined as an engagement means 23. It is understood that in deviating embodiments, possibly also in the exemplary embodiments according to FIGS. 6 and 7, threads can be provided as roll-positioning apparatuses in the exemplary embodiment, while in the exemplary embodiment illustrated in FIGS. 4 and 5, hydraulic roll-positioning apparatuses 22 can also be used 6 instead of the threads.

(18) In the arrangements according to FIGS. 2 to 5, each roller mill 21 is mounted on the roll stand 27 such that it can be set by means of two roll-positioning apparatuses 22. As a result, it is in particular possible to also set the angle of roll axes 25 with respect to the rolling center line 11, or it is also possible to react to non-uniform load changes.

(19) The exemplary embodiments according to FIGS. 6 and 7, on the other hand, have only one roll-positioning apparatus 22 per roller mill 21, which is easier to implement in terms of design.

(20) It is understood that also in the exemplary embodiments according to FIGS. 2 to 5, in each case only one roll-positioning apparatus and/or one hydraulic roll-positioning apparatus 22 can be provided, while in the exemplary embodiment according to FIGS. 6 and 7, it is also possible to provide two roll-positioning apparatuses 22 or mechanical roll-positioning apparatuses 22, if necessary. It is also possible to combine mechanical and hydraulic roll-positioning apparatus 22, if necessary. Likewise, other roll-positioning apparatuses 22, such as piezoelectric or pneumatic setting means, can be provided.

(21) As can be seen directly from the figures, the rolling surface 26 of the rolls 20 has a component of movement perpendicular to the rolling centerline 11 of the cross-rolling unit 10 during rolling. Accordingly, it generally follows from this that the rolling surface 26 of the rolls have a component of movement perpendicular to the direction of movement of the workpiece 32 through the cross-rolling unit 10 during rolling. Also, the axes 25 of the two rolls 20 have a component parallel to the rolling centerline 11 of the cross-rolling unit 10, as is immediately apparent from the figures.

(22) In the exemplary embodiment illustrated in FIG. 2, the displacement 40 between the two roller mills 21 of both rollers 20 is measured by arranging a distance measuring system 41 in each case between roll reference points 50 on the roller mills 21 and reference datums 60 arranged on the respective roller mill 21, wherein the measurement can easily also be carried out during rolling. Here, specifically, the roll reference point 50 of a first roller mill 21 can be designated as the reference datum 60 of the second roller mill 21 using the same distance measurement system 41.

(23) It is understood that in a deviating embodiment, it is also possible to use only a single distance measuring system 41, which then is only provided between two roller mills 21 or references 50, 60 which are provided in each case at one of the two rolls 20, possibly resulting in the fact, however, that as a consequence, it is possible to make only a somewhat more inaccurate statement about the respective roll pass.

(24) In this exemplary embodiment, the respective ends of the distance measuring system 41 are directly attached to the roller mills 21, so that the roller mills 21 themselves serve as roller datum points 51 or reference datum points 61. Accordingly, the roller mills 21 also serve as respective references for measuring the displacement 40 to the respective other roller mill 21.

(25) It is understood that in the exemplary embodiment according to FIG. 2, separate assemblies can also serve as roller datum points 51 or reference datum points 61, as illustrated by way of example in the exemplary embodiment according to FIG. 3. Other assemblies, such as assemblies provided between the roll-positioning apparatus 22 and the roller mills 21 or the longitudinal beams or housing beams can also be used accordingly or corresponding separate assemblies can serve as supports for the roller datum points 51 or reference datum points 61.

(26) In the embodiment shown in FIG. 3, lugs are provided in each case as roller datum point 51 and reference datum point 61, respectively, wherein the lugs for the roller datum point 51 are arranged on the roller mills 21 and the lugs for the reference datum points 61 are arranged on a separate reference frame 62.

(27) The reference frame 62 is decoupled from the roll housing 27 so that it provides a reference or reference datum 61 independently of the respective rolling forces. The latter is also the case in the exemplary embodiment according to FIGS. 4 and 5, wherein here the roller datum points 51 or the roller datums 50 are provided on the roller mills 21 which, however, in deviating embodiments can also be provided on other assemblies, as is the case in the exemplary embodiment according to FIGS. 6 and 7, which also uses a reference frame 62.

(28) It is understood that in a deviating embodiment of the exemplary embodiments shown in FIGS. 3, 6 and 7, separate lugs for providing the roller datum points 51 or the reference datum frame 61 can also be dispensed with if this is structurally feasible, in particular with regard to space, wherein, if necessary, the inclined arrangement of the rolls 20 with the resulting shifted arrangement of the roller mills 21 can be used in order to be able to couple the distance measuring system 41 without separate lugs.

(29) Also, in the exemplary embodiments shown in FIGS. 3 to 7, a distance measurement, if necessary, can be carried out between the rollers 20 or the roller mills 21 themselves, as is illustrated by way of example by means of the exemplary embodiment shown in FIG. 2.

(30) In the exemplary embodiment example shown in FIG. 3, the displacement 40 of only one roller mill 21 of each roller 20 is measured accordingly, wherein it is understood that, as shown in dashed lines, a further reference frame 62 can also be provided for the measurement of the respective other roller mills 21 of each roller 20 in order to be able to make even more precise statements about the roll pass. Likewise, in the exemplary embodiments according to FIGS. 4 to 7, individual distance measuring systems 41 can also be dispensed with, if necessary, while foregoing corresponding measuring accuracy.

(31) As is immediately apparent in the exemplary embodiments according to FIGS. 3 to 7, the displacement 40 between the roller mills of the rollers 20 and a reference provided outside the engagement means 23 is measured. For this purpose, the reference datum 61 is arranged outside the engagement point 24 of the roll-positioning apparatus 22 of the roller mill 21, which engagement point engages on the roll housing 27.

(32) In present embodiments, resistance sensors, capacitive sensors, and/or inductive sensors are used as distance measuring systems 41 or for distance measurement. Alternatively, optical range finders, ultrasonic sensors, or radar sensors can be used accordingly.

(33) Accordingly, a contacting or also contactless measurement can be carried out.

(34) In the exemplary embodiment shown in FIG. 8, a piercing process of a workpiece 32 by means of a mandrel 30 and two rolls 20 is schematically illustrated. A corresponding procedure can be applied in particular in interaction with the other cross-rolling units 10 presented herein.

(35) It is understood that, alternatively, hollow blocks with a mandrel 30 as an internal tool can also be rolled with corresponding cross-rolling units 10. Also, if necessary, internal tools or mandrels 30 can be dispensed with, regardless of whether a block or a hollow block is being cross-rolled as a workpiece 32.

(36) Also shown as examples in FIGS. 8 and 9 are manipulated and measured variables which, among other manipulated and measured variables, can advantageously be used as input variables and output variables, respectively, for a multi-variable control 70 in all embodiments shown herein. It is understood that is also possible, if necessary, to use only individual measured and manipulated variables and that individual ones of these measured and manipulated variables can be omitted, or that further measured and manipulated variables as well as variables derived therefrom can be used for the multi-variable control 70.

(37) For example, the workpiece infeed speed 71, the workpiece outfeed speed 72, the wall thickness 73, the eccentricity 74, the outside diameter 75, the ovality 76, the rolling force 77 and the mandrel holding force 78 can serve as measured variables and are shown schematically in FIG. 8. These measured variables and further measured variables as well as variables derived from the measured variables can then serve as input variables of the multi-variable control 70, as shown as an example in FIG. 9.

(38) Also schematically shown by way of example as manipulated variables in FIGS. 8 and 9 are an adjustment 80 of the spread angle, a dynamic positioning adjustment 81 of the rolls 20 used here as top and bottom rolls, a dynamic adjustment of the rolling center 82 by synchronously adjusting the rolls used as top and bottom rolls, and the dynamic adjustment 83 of the mandrel position.

(39) In concrete terms, these manipulated variables can be implemented, if necessary, by individual output variables to the respective roll-positioning apparatuses 22 and a mandrel-positioning apparatus 31 holding the mandrel 30, whereas in the present exemplary embodiment, these manipulated variables each jointly activate the associated actuators, i.e., the roll-positioning apparatuses 22 and the mandrel position adjusting apparatus 31, respectively, in order to ensure synchronous movement of the rolls 20, for example.

(40) It is understood that the adjustment 80 of the spreading angle is done, for example, by a corresponding adjustment of the mandrel 30 perpendicular to the rolling center line 11 using the mandrel position adjustment device 31, or else by the dynamic adjustment of the rolling center 82.

(41) Apart from that, the mandrel position adjustment apparatus 31 can also adjust the axial position of the mandrel 30, i.e. the position thereof with respect to the rolls 20 as viewed along the rolling centerline 11, which can also be used as a manipulated variable, if necessary.

(42) All manipulated variables shown in these exemplary embodiment can be adjusted, in particular during rolling.

REFERENCE LIST

(43) 10 cross-rolling apparatus 11 rolling center line 20 roll 21 roller mill 22 roll-positioning apparatus 23 engagement means 24 engagement point 25 roll axes 26 roll surface 27 roll housing 30 mandrel 31 mandrel position adjusting apparatus 32 workpiece 40 displacement (shown as example) 41 distance measuring system 50 roll datum (designated as an example) 51 roll datum point (designated as an example) 60 reference datum (designated as an example) 61 reference datum point (designated as an example) 62 reference frame 70 multi-variable control 71 workpiece infeed speed 72 workpiece outfeed speed 73 wall thickness 74 eccentricity 75 outer diameter 76 ovality 77 rolling force 78 mandrel holding force 80 adjustment of spread angle 81 dynamic positioning adjustment, individually 82 dynamic adjustment of rolling center 83 dynamic adjustment of mandrel position