METHOD FOR PREPARING OFFSET SHAPE

摘要

This invention relates to a method for preparing an offset shape of a cutting tool for a workpiece in a numeric controller for making a turning work. More particularly, use is made of a cutting tool having blades on both sides, each of the blades of which has a nose R and moves in both horizontal and vertical directions with respect to the rotating workpiece. When the vertical coordinate value of the work shape increases, the blade on the reference side is employed for the cutting and when the vertical coordinate value decreases, the blade on the opposite side is employed. In such a case, a cutting tool is used which further has blades on both sides, each of the blades of which has a nose R and is connected to the other at a predetermined angle theta of inclination, and which moves in both horizontal and vertical directions with respect to the rotating workpiece. When cutting is made by the reference blade when the inclination angle of the work shape in the vertical direction is smaller than the angle theta of the blade and by the blade on the opposite side when the angle of inclination of the work shape in the vertical direction is greater than the angle theta of the blade, the offset shape is prepared by use of the center of the tip of one of the blades of the cutting tool having the nose R on both sides as the control point in accordance with the final work shape. It becomes thus possible to make cutting by use of the cutting tool having blades on both sides in a machine tool using a numeric controller, and to shorten the cutting time.