Roll diameter measuring apparatus e.g. for installation in machine tool - has body and measuring head attached to it which is positioned between them with pneumatic cylinder with measuring roller adapted to measuring head

摘要

The apparatus comprises a body (10) and a measuring head (12) attached to it, which is positioned between them with an pneumatic cylinder (6). A measuring roller (13) is adapted to the measuring head. A sensor (14) determines the rotational movement of the measuring roller and another sensor (7) measures that of the workpiece is measured. The values form the sensors are processed. The measuring roller includes a two-part construction, in which there is a hard-metal ring (18) on top of an inner disc (17). The inner disc is of composite-structure carbon fibre, in which structure the ratio of the carbon fibre to the resin and the orientation of the fibres are arranged to that the coefficient of thermal expansion of the inner disc is the same as that of the ring. A turbine (24) is arranged in the measuring head, to match the speed of the measuring roller with that of the rotating workpiece (3) beforehand.