Method and apparatus for milling crankshafts

Abstract

A method of machining with a crankshaft miller to machine a workpiece into a crankshaft with pin and journal portions is disclosed in which a crankshaft workpiece is held in a chuck and is machined for at least a part of pin and journal portions of it with a cutting edge of a cutter body attached to a rotating cutter drum. In this method, such a cutter body is prepared having a diameter of its inner peripheral surface that is slightly larger than the diameter of a pin or journal portion of the workpiece to be machined. The cutter body so prepared is attached to the cutter drum via an adapter having an opening which is larger in diameter than both a diameter of the chuck and a maximum swing of the workpiece. Then, the cutter drum is positioned at a standby site in an area where the chuck is located and the workpiece is secured and held in the chuck. Then, after the workpiece is indexed or determined with respect to its phase position, the cutter drum is moved in a longitudinal direction of the workpiece to position the cutter body at a given machining site and is rotated to machine that portion with the cutting edge of the cutter body. These steps are repeated for all machinable pin and journal portions at altered machining sites. A cutter apparatus for performing the method is also disclosed.