APPARATUS AND METHOD TO MEASURE THE DIMENSIONAL AND FORM DEVIATION OF CRANKPINS AT THE PLACE OF GRINDING

摘要

An apparatus and a relevant method for checking a crankpin ( 18 ) of a crankshaft ( 34 ) positioned on a numerical control grinding machine where it is worked includes a gauging head ( 39 ) with a Vee-shaped reference device ( 20 ) and a feeler ( 17 ), axially movable along a translation direction, that touches the crankpin surface, and an articulated support device ( 5,9,12 ) connected to the grinding-wheel slide ( 1 ), carrying the guaging head and allowing the reference device ( 20 ) to keep contact with the crankpin during its orbital motion around the main rotation axis ( 0 ) of the crankshaft. Rough values corresponding to a transducer ( 41 ) signals provided at predetermined angular positions of the crankshaft are stored and are processed also to compensate alterations caused both by contact between the sides of the Vee-shaped reference device and the surface of the crankpin to be checked, and by variations of the angular arrangement of the Vee-shaped reference device in the course of orbital rotations of the pin.