Quality-control method for wire/rod rolling system

Abstract

Quality of a wire or rod is controlled in a rolling mill having a succession of roll stands spaced apart in a workpiece-travel direction by a method having the first step of, before rolling a wire or rod, statically measuring a sample of at least one wire or rod with typical real roll flaws and storing the flaw data in standard format in a control computer. A single cross-sectional shape or, if there is noise, an average of a plurality of averaged cross-sectional shapes are stored standardized as polar coordinates. During actual rolling of a wire or rod its actual-shape is continuously measured and actual-shape data is generated. A similarity analysis is continuously effected by comparing the flaw data in standard format with the actual-shape data of the wire or rod being rolled. When the actual cross-sectional shape data corresponds to the flaw data, an alarm is generated.

Description

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing whose sole FIGURE is a diagram illustrating the method of this invention.

Claims

1. A quality-control method for wire or rod in a computer-controlled rolling mill having a succession of roll stands spaced apart in a workpiece-travel direction, the method comprising the steps of: before rolling a wire or rod, at least one sample wire or rod with typical real roll flaws is measured statically and flaw data in standard format is stored in a control computer, a single cross-sectional shape or, if there is noise, an average of a plurality of averaged cross-sectional shapes being stored standardized as polar coordinates;during rolling of a wire or rod continuously measuring its actual-shape and generating actual-shape data corresponding thereto;continuously effecting a similarity analysis by comparing the flaw data in standard format with the actual-shape data of the wire or rod being rolled; andwhen the actual cross-sectional shape data corresponds to the flaw data, generating an alarm.

2. The quality-control method defined in claim 1, further comprising the step of: storing and standardizing the actual-shape data prior to comparing it with the flaw data.

3. The quality-control method defined in claim 1, further comprising the step of displaying a difference between the actual cross-sectional data and the flaw data.

4. The quality-control method defined in claim 1, further comprising the step of measuring the temperature of the rod or wire being rolled.

5. The quality-control method defined in claim 4 wherein the actual-shape data is corrected to correspond to a cross-sectional shape the rod or wire would have at about 20° C.

6. The quality-control method defined in claim 1 wherein the rod or wire shape is measured by lasers.

7. The quality-control method defined in claim 1 wherein at least 38 angularly generally equispaced measurements of the rod or wire radius are made to determine its cross-sectional shape.

8. The quality-control method defined in claim 7 wherein 180 such angularly generally equispaced measurements are made.

9. The quality-control method defined in claim 1 wherein the determine radius portions of the wire or rod a Fourier analysis is used.

10. The quality-control method defined in claim 9 wherein a Fast Fourier analysis is used.

11. The quality-control method defined in claim 1 wherein to determine radius portions a fitting method of the actual cross section is used.

12. The quality-control method defined in claim 1 wherein minimum and maximum diameters of the wire or rod are measured at locations along its length to develop the actual-shape data.

13. The quality-control method defined in claim 1, further comprising generating a signal representing ovalness of the rod or wire.

14. The quality-control method defined in claim 13 wherein ovalness is determined by a triangular method.

15. The quality-control method defined in claim 13 wherein ovalness is determined by a hexagonal method.

16. The quality-control method defined in claim 1 wherein the mill includes a set of calibrating roll stands and the wire or rod is measured immediately downstream therefrom.

17. The quality-control method defined in claim 1 wherein the flaw data and actual-shape data are compared by a cross correlation function.

18. The quality-control method defined in claim 1 wherein the flaw data and actual-shape data are compared by a cross covariant function.

19. The quality-control method defined in claim 1, further comprising collecting flaw data regarding underfilling and overfilling or roller offset are collected and stored.

20. The quality-control method defined in claim 1 wherein for each real flaw at least two references are assigned that are set mathematically as vectors and compared with similar references for the wire or rod.