Abstract: A stretch forming apparatus comprises a pair of jaws for pinching both ends of a work, a die placed between the pair of jaws so as to be in contact with the work, a plurality of control axis for change in positions and postures of the jaws and the die, a rotation center line setting unit for making an operator set rotation center lines for the jaws that are for partial stretch of the work by rotation of the jaws, an operation input unit for rotating the jaws by manual operation about the rotation center lines, and a control unit for synchronously controlling the plurality of control axis so that the jaws rotate in accordance with the manual operation by the operator on the operation input unit about the rotation center lines.

Abstract: A tryout of a metal mold for a mechanical press suitable for mass production is carried out with a hydraulic press in accordance with the same motion curve as that of the mechanical press so as to reduce metal mold corrections at a job site as much as possible. When trial molding is carried out, an adequate amount of oil capable of obtaining a press motion curve of the mechanical press in accumulators is accumulated so that a predetermined amount of oil can be supplied to a plurality of pressing cylinders of the hydraulic press, hydraulic oil selectively is supplied to a predetermined pressure cylinder of a plurality of pressure cylinders and hydraulic control is applied to the pressure cylinders by a servo valve so as to obtain a coincidence with a press motion curve of a mechanical press with predetermined output.