Apparatus for machining a workpiece to non-revolute symmetric and aspherical surface

摘要

An apparatus for machining a workpiece which has a non- revolute symmetrical and aspherical surface with a rotating grinding wheel. The apparatus comprises a workpiece supporting member supporting the workpiece and a wheel head providing the grinding wheel an outer peripheral surface of which takes a form of a part of a spherical shape. The workpiece and the grinding wheel are relatively moved by a first drive mechanism in an infeed direction, the workpiece supporting member and the wheel head are relatively moved by a second drive mechanism in a traverse feed direction perpendicular to the infeed direction, and the workpiece supporting member and the wheel head are relatively moved by a third drive mechanism in a pitch feed direction perpendicular to both of the infeed direction and the traverse feed direction. A truing device is moved by the second drive mechanism in the traverse feed direction relative to the grinding wheel, and has a truing element rotatable about an axis perpendicular to a rotational axis of the grinding wheel through a spherical center thereof. The first, second and third drive mechanisms are controlled by a control device based upon the aspherical shape data for the workpiece.