Computer-Controlled Multiaxial Forging

A method of computer-controlled multiaxial forging of a workpiece, wherein a workpiece having a z-directional initial width, h0, is subject to multiple-step forging by means of a pair of forging dies moving along a first axis, z, and wherein after each forging step, the opposite dies are moved away from the workpiece and the workpiece is rotated around a second axis y, characterized by that before starting each forging step:

• finding the surfaces of the workpiece to be shaped by moving the dies by predetermined intervals, f, to the opposite surfaces of the workpiece to be shaped until a predetermined contact force, FR, FL, thereof is achieved,
• upon reaching the contact forces, storing an actual starting position, PR(i), PL(i), for each of the working surfaces of the forging dies,
• based on said actual starting positions, PR(i), PL(i), and the initial z-directional width, h0, of the workpiece, calculating and storing the z-directional width w(i) of the workpiece along the first axis z is before the actual shaping step,
• calculating a z-directional cyclical advancement dz(k) of the dies belonging to the actual forging step according to the equation:
• dz(k)=0.5*δt*{dot over (φ)}(i)*w(i)*e−{dot over (φ)}(i)*(δt*k)
• where δt is the duration of one advancement cycle [s], {dot over (φ)}(i) is the deformation rate [1/s] specified for the i-th forging step, w(i) is the z-directional width [mm] of the workpiece before carrying out the shaping operation in the i-th step, i is the number of the forging step, and k is the cycle number of advancement which is incremented after each cycle, and
• moving both dies from their actual initial positions, PR(i), PL(i), by cyclical advancements dz(k) until the deformation specified for the actual i-th forging step is achieved.