Method for measuring the axial runout of a plane surface of a workpiece with respect to an axis of rotation, and corresponding measuring assembly

Abstract

A method for measuring the axial runout of a plane surface (22) of a workpiece (2) with respect to an axis of rotation (6) by means of a linear image sensor (19), in which a first optical scanning ofthe non-rotating workpiece is performed by translating the sensor relative to the workpiece along a direction (Z) parallel to the axis of rotation to obtain a first light intensity trend (l1) of a pixel (23) as the relative position between the workpiece and the sensor varies, and a relative position (ZR) of plane surface is determined as a function of the first light intensity trend. A second optical scanning of the workpiece is performed in the relative position of the plane surface while the workpiece rotates with respect to the axis for obtaining a second light intensity trend (I2) of thepixel as the angular position (theta) of the workpiece varies. A maximum position value and a minimum position value (Zmax, Zmin) are determined from the first light intensity trend using, as input data, light intensity values derived, or obtained by processing, by the second light intensity trend, and the axial runout is calculated as the difference between the maximum and minimum position values.

Description

technical field [0001] The invention relates to a method for measuring an axial runout or quadrature error of a planar surface of a workpiece relative to an axis of rotation, and to a corresponding measuring arrangement. [0002] In particular, the invention finds advantageous but not exclusive application in measuring assemblies for measuring dimensional shape or positional parameters of mechanical components, such as automotive engines, to which the following description makes explicit reference without loss of generality. Background technique [0003] A known measuring assembly for measuring workpieces or machine parts comprising a fixed frame, an electrically powered rotary holding mechanism mounted on the fixed frame to hold the workpiece at two axially spaced ends thereof, and rotating the workpiece about an axis, a longitudinal guide parallel to the axis, an electrically movable frame adapted to translate along the longitudinal guide and comprising a fork having two a...

AI Technical Summary

Problems solved by technology

[0012] The inspection process described above has the obvious disadvantage of a rather long cycle time, since a large number of scans need to be performed parallel to the workpiece axis, i.e. every angular position

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