Method for measuring the shpericity of spherical profiles

Abstract

The invention relates to a method for measuring the sphericity or for measuring the shape deviation of spherical profiles in rolling trains that displace in the longitudinal direction thereof. According to the invention, at least three shadow edges that are adjacent to the spherical profile that is to be measured, that surrounds said spherical profile and that forms a polygon are produced and measured in a known manner, with the aid of a measuring device having at least two laser scanners that respectively comprise a light-sensitive sensor and a laser, and the corresponding tangents are calculated from said result. Said method is characterised in that a) prior to measurment, a centre (Z0) in the measuring field of the measuring device is calibrated and determined provided that said type ofcentre (Z0) has not already determined, b) perpendiculars (r1, - r6') from the centre (Z0) to the tangents (T1, bis T6' ) and also the distance from the centre (Z0) to the tangents (T1 - T6' ) is calculated, c) the corner points (A - K) of the polygon surrounding the spherical profile are calculated, a contour is determined, d) a reference circuit is determined in relation to the contour such that i) the quadratic shape deviation of the contour reaches a minimum in relation to said reference circuit, ii) said reference circuit represents the smallest possible circuit that adapts to the contour, iii) said reference circuit representing the largest possible circuit that adapts to the contour, or iv) the reference circuit together with an additional circuit that is concentric to the reference circuit surrounds the contour at a minimal radial distance, e) the diameter (Dref) of the reference circuit is calculated and the reference centre (Zp) is determined from the position in the cavitythat represents the centre point of the reference circuit and f) at least two vectors are calculated from said reference centre (Zp) to the contour and the ovality is determined from said data.

Description

technical field [0001] The invention relates to a method for roundness measurement or shape deviation measurement of a round profile advancing in the longitudinal direction in a rolling mill, wherein in a manner known per se by means of a measuring device having at least two laser scanners, Generating and measuring at least three polygon-forming projected edges abutting against and enclosing the round profile to be measured, and calculating corresponding tangents therefrom, the laser scanner each has a photosensitive sensor and a laser. Background technique [0002] In the steel industry, so-called long products / bars are rolled in special rolling mills / mill trains to obtain the desired end product. If these elongated products are to be rolled into round bars, they are usually rolled in a three-high finishing stand / stand (Gerüst) with several rolling modules (usually 3-high modules / 3-high groups). These elongated products are rolled to finished size and conveyed to a cooling...

AI Technical Summary

Problems solved by technology

In addition, the center of the circle is not determined in space, which leads to, for example, when the shape deviation is asymmetric, the determined silhouette has periodic symmetry related to the number and arrangement of tangent lines, which cannot reflect the real silhouette characteristics

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