Apparatus and method for machining a hollow generally cylindrical workpiece

摘要

A fixture for holding a brake drum or other similarly shaped workpiece for machining. The fixture includes a body having a body cavity and a clamping assembly disposed therein. The clamping assembly includes a positioning plate having a plurality of positioning posts secured thereto. The positioning posts are received within fastener apertures formed in the brake drum mounting face for locating the drum within the fixture so that the drum axis is coaxially aligned with the fixture axis for proper machining. The clamping assembly further includes a clamping plate and clamping flange for clamping the mounting face of the brake drum during machining to simulate the compressive forces applied to the drum as it is mounted to a vehicle during operation. The fixture further includes first and second pluralities of chucking assemblies for gripping the body of the brake drum along respective first and second spaced apart planes thereby reducing distortions caused by the cutting tool during machining.