Patent ID: 6698267
Filing Date: 2004-03-02
Classification: B21J,B22F,B30B

Abstract:
A method of forming a body of a formable working material in an impact machine, the impact machine comprising an upper impact unit with an upper ram, an upper punch, a lower impact unit with a lower ram, a lower punch, an upper impact body, a lower impact body, and a mould cavity for the working material between the punches when the punches are brought towards one another, the method comprising:moving downwards movable masses and upwards movable masses towards one another, the downward movable masses obtaining a downwards directed velocity and the upwards movable masses obtaining an upwards directed velocity, wherein downwards movable masses comprise at least the mass of the upper ram and the mass of the upper punch, wherein the upwards movable masses comprise at least the masse of the lower ram and the mass of the lower punch, wherein the upper punch and the lower punch are pressed at a static pressure from above and below, respectively, against the working material in the mould cavity prior to the impact by a downwards directed force exerted on the upper impact body and by an upwards directed force exerted on the lower impact body, respectively, wherein the movable parts have such masses and velocities so that the momentums of the downwards movable masses and the momentums of the upwards movable masses become essentially equal and the following condition applies: m1Ã—v1â‰…m2Ã—v2 where m1 is the total mass of the downwards movable masses and m2 is the total mass of the upwards movable masses at impact, and wherein the kinetic energies of the movable masses, defined as (m1v12)/2 and (m2v22)/2, are essentially transferred to the working material in the mould cavity and are of a magnitude such that the working material is plasticized and flows out to fill all parts of the mould cavity when the punches are maximally brought together for the formation of said body with desired shape.