Cutting – Processes
Patent
1997-12-03
2000-07-11
Rachuba, M.
Cutting
Processes
83 73, 83 75, B23D 1906
Patent
active
060856246
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for inspecting the edges of metal strip during production. The invention is particularly but not exclusively applicable to the production of hot rolled steel strip.
Steel strip is commonly produced by hot rolling to provide strip typically 1.5 mm to 5.5 mm thick. This strip must then be cleaned and have its edges trimmed before undergoing further processing such as cold rolling and/or coating. The edge trimming is conventionally performed by rotary cutting blades mounted above and below the strip path at either side of the desired width, the blades being rotated by pull-through of the strip.
It is important to obtain a good quality of trimmed edge if the subsequent processing is to be satisfactory. For example, a poor edge may produce small flakes of steel which become trapped between the strip and the rolls of cold rolling mills, damaging both the strip and the rolls. Poor quality edges also cannot be coated satisfactorily in processes such as powder coating.
The nature of the cut edge is determined by the setting of the rotary cutting blades. The upper blade can be adjusted vertically to give a desired degree of radial overlap with the lower blade, while the lower blade can be adjusted in and out to adjust the horizontal gap with the top blade.
It has hitherto been the practice to mount the cutting blade shafts in such a manner that these adjustments must be carried out by the manual adjustment of bolts and the like and the use of spacers and shims. Further, it has been customary to adjust the cutting blades to settings which are thought to be correct, from empirical experience with strip of the same thickness and metallurgical composition, and thereafter to edge trim whole coils of strip. Inspection has been limited to visual inspection of finished coils with the aid only of a hand lens; this can lead to a number of coils having to be scrapped or reworked if the edge quality has become unacceptable, followed by time consuming hand adjustment of the cutting blades on an empirical basis.
A principal object of the present invention is to improve on such prior art processes and apparatus.
SUMMARY OF THE INVENTION
The present invention provides a method of inspecting an edge of strip metal after the edge is trimmed by passing it between upper and lower rotary blades which remove an edge strip by partial slitting and partial shearing; the method comprising passing the trimmed strip along a predetermined path past an inspection station, forming a video image of the trimmed edge as it passes the inspection station, detecting from said image the ratio of slit to shear in the edge, and utilizing said ratio to control the trimming process.
Preferably, both edges of the strip are inspected simultaneously.
The method may further include detecting from said image(s) a measure of the straightness of the division between the cut and sheared zones, and utilizing said straightness measure(s) in controlling the trimming process.
The parameter(s) derived from the video image(s) may be used to control the trimming process by providing information to an operator in the event that the parameter or one of the parameters moves out of a predetermined range of values. Alternatively, the parameter(s) derived from the video image(s) may be used to control the trimming process by providing a feedback signal which controls the positioning of the rotary blades.
When used for the production of steel strip, the slit:shear ratio is typically maintained in the range .+-.10% for mild steel strip.
From another aspect, the invention provides apparatus for use in inspecting an edge of strip metal after the edge is trimmed by passing it between upper and lower rotary blades which remove an edge strip by partial slitting and partial shearing; the apparatus comprising an inspection station through which the strip is passed after trimming, the inspection station comprising video imaging means arranged to provide a video signal of the trimmed edge, and image processi
REFERENCES:
patent: 2346194 (1944-04-01), Sjostrom
patent: 3169432 (1965-02-01), Hoffman et al.
patent: 3203293 (1965-08-01), Lee
patent: 3286567 (1966-11-01), Wright
patent: 3292469 (1966-12-01), Vaccaro
patent: 3312135 (1967-04-01), Mraz
patent: 3730043 (1973-05-01), Zimmermann
patent: 4307637 (1981-12-01), Vanderhulst
patent: 4404634 (1983-09-01), Bautz
patent: 4475422 (1984-10-01), Lawson
patent: 4667550 (1987-05-01), Eiting
patent: 5267168 (1993-11-01), Antonissen et al.
"Improved Coil Slitting Cutter," Sheet Metal Industries, Vol. 50, No. 03, pp. 165-166, Mar. 1973.
de Magalhaes Frederico
Lever Thomas W.
Asko, Inc.
Bae Gyounghyun
Rachuba M.
LandOfFree
Edge inspection system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Edge inspection system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Edge inspection system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-530900