Method for influencing the geometry of a rolled item in a controlled manner

Abstract

A method influences the geometry of a rolled item in a controlled manner. In the method, the rolled item is transformed from an initial condition into an intermediate or final condition by rolling with the aid of a rolling stand having at least one processing assembly. An improvement in the geometry of the rolled item, particularly during processing of asymmetric rolled items, is achieved in that the at least one processing assembly is operated in a force-controlled manner on the basis of a desired force.

Claims

1. A method for influencing a geometry of a rolled item in a controlled manner, comprising: transforming the rolled item from an initial state into an intermediate or final state by rolling the rolled item with a rolling stand having a processing facility, the processing facility being a vertical stand, the processing facility comprising first and second processing assemblies, the first and second processing assemblies being provided respectively on opposite sides of the rolled item; and operating the first processing assembly in a force-controlled manner based on a reference force; operating the second processing assembly in a position-controlled manner; identifying a midpoint between the first and second processing facilities, the midpoint being at a predetermined position; and tracking the second assembly to the first processing assembly such that the midpoint between the first and second processing assemblies always remains at the predetermined position, wherein a taper and/or a longitudinal curvature of the rolled item is measured, and the reference force for force control is determined based on the taper and/or the longitudinal curvature.

2. The method as claimed in claim 1, wherein the midpoint between the first and second processing assemblies and a separation between the first and second processing assemblies are used as a basis for closed-loop control of the first and second processing assemblies.

3. The method as claimed in claim 2, wherein the midpoint between the first and second processing assemblies is predetermined, and force control of the first processing assembly is effected by adjusting the separation between the first and second processing assemblies.

4. The method as claimed in claim 1, wherein the midpoint is offset from a centerline of the rolling stand.

5. The method as claimed in claim 1, wherein the first processing assembly is initially separated from the rolled item, and the first processing facility is moved up to the rolled item in a position-controlled manner, and then, when a reaction force acting on the first processing assembly reaches a reference force, the first processing facility is switched over to be force controlled.

6. The method as claimed in claim 1, wherein if a position of the taper and/or a direction of the longitudinal curvature of the rolled item changes, the first processing facility is switched to be position-controlled and the second processing facility is switched to be force-controlled.

7. The method as claimed in claim 1, wherein the rolled item has a longitudinal curvature, the rolled item is rolled through the rolling stand such that a longitudinal axis of the rolled item extends along a center line of the rolling stand, the midpoint between the processing facilities is offset from the center line to correct the longitudinal curvature of the rolled item.

8. A non-transitory computer readable data storage medium, storing a machine-readable computer program which when executed by a computer causes the computer to perform the method claimed in claim 1.

9. A control device for influencing a geometry of a rolled item in a controlled manner, comprising: a control device having a computer processor to: control a rolling stand to roll the rolled item and transform the rolled item from an initial state into an intermediate or final state, the rolling stand having a processing facility, the processing facility being a vertical stand, the processing facility comprising first and second processing assemblies, the first and second processing assemblies being provided respectively on opposite sides of the rolled item; and control the first processing assembly in a force-controlled manner based on a reference force; control the second processing assembly in a position-controlled manner; identify a midpoint between the first and second processing facilities, the midpoint being at a predetermined position; and control the second assembly to track the first processing assembly such that the midpoint between the first and second processing assemblies always remains at the predetermined position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:

(2) FIG. 1 schematically shows a greatly simplified first plan view of a rolling stand with two lateral processing assemblies, and

(3) FIG. 2 schematically shows a greatly simplified second plan view of a rolling stand with two lateral processing assemblies.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(4) Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

(5) FIG. 1 and FIG. 2 show a horizontal rolling stand 2, in particular a roughing stand, by which a rolled item 4, in particular a rough strip, is rolled such that the rolled item 4 is transformed from an initial state into an intermediate or finished state. The rolling stand 2 has a drive side DS and an operator side OS.

(6) In addition, two processing assemblies 6, 8 are assigned to the rolling stand 2, being positioned on either side of the rolled item 4 as shown in FIG. 2. The separation between the processing assemblies 6, 8 is designated as S in FIG. 1. Also shown in FIG. 1 is a centerline 10 of the rolling stand 2, a centerline 12 between the processing assemblies 6, 8, and a midpoint 14 between the processing assemblies 6, 8, wherein said midpoint 14 lies on the centerline 12. An offset between the two centerlines 10 and 12 is designated as Δs.

(7) In particular, the rolling stand 2 operates in reversible mode in the exemplary embodiment shown here, such that the rolled item 4 can change its rolling direction 16 many times during operation.

(8) In the situation shown in FIG. 2, the processing assemblies 6, 8 are arranged behind the rolling stand 2 in the rolling direction 16. The function of the processing assemblies 6, 8 is to restrict an asymmetrical geometry of the rolled item 4 being rolled. To this end, if a taper and/or a longitudinal curvature of the rolled item 4 is detected, provision is made for operating one of the processing assemblies 6, 8 (the processing assembly 6 in the exemplary embodiment according to FIG. 2) in a force-controlled manner, as indicated by the reference force signal F. At the same time, the second processing assembly 8 is operated in a position-controlled manner, as indicated by the position signal P. The closed-loop control of both processing assemblies 6, 8 is effected by a control device 18 which is illustrated symbolically in FIG. 2.

(9) The force-controlled processing assembly 6 counteracts the taper or the longitudinal curvature by a reference force F which is determined on the basis of the geometry of the rolled item 4. In FIG. 2, only the processing assembly 6 comes into contact with the rolled item 4, while the second processing assembly 8 is moved to a distance from the rolled item 4.

(10) However, the two processing assemblies 6, 8 are advantageously configured such that the position-controlled processing assembly 8 tracks the force-controlled processing assembly 6, while the offset Δs remains constant. A reference force F which is specified to the method or the closed-loop control device for reducing the strip curvature, but is too great and may result in an unwanted longitudinal curvature of the rolled item 4, is equalized in this way. For the implementation in terms of closed-loop control engineering, this means that the midpoint 14 is predetermined and only the separation S between the processing assemblies 6, 8 is changed in order to reach and maintain the reference force F for as long as necessary. In particular, a method for adjusting a specific longitudinal curvature as per W02009/016086 is used for processing the rolled item in this case.

(11) The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).