ALGORITHM OF GENERATING THE TRACKING LOCUS OF THE TANGENT POINT FOR NC ROTARY STRETCH-BENDING FORMER

A geometric model of the movement relation in the forming process is established. A numerical solution that can calculate the locus of the tangent point of any convex curve shapeof die is deduced, and the relation curves of the location of the tangent point and the rotation angle of the rotary is obtained, which provides the precise controlling foundation for tracking the tangent point automatically. And based on the optimum target that the maximum slope of the tangent point must be minimum, a more reasonable mounting location of the die is worked out, which satisfies the constraint conditions of the movement range of the lateral pressure wheel, the maximum swing angle of the main cylinder, and the distance from the collet of the supplementary cylinder tothe center of the rotary. Meanwhile a general calculation program has been developed with VC. The result shows that the algorithm is steady, which has high efficiency and precision, and is adaptive to convex dies.