Method and impact machine for forming a body

An impact machine for forming a body of a formable working material through impact action in a forming operation, the machine comprising:

• a machine stand;
• an upper impact unit with an upper ram;
• a lower impact unit with a lower ram;
• and
• a central unit that is essentially stationary during the forming operation,
• the central unit including a mould tool between the upper impact unit and the lower impact unit,
• the mould tool comprising a die having a through hole that together with an upper punch and a lower punch form a mould cavity for the working material,
• the upper and lower impact units being controllably raised and lowered by elevator devices relative to the central unit for setting of predetermined stroke lengths of the upper ram and of the lower ram, respectively before the forming operation, and
• said elevator devices comprising hydraulically working members having at least two upper hydraulic lifting cylinders and auxiliary, vertical piston rods that are included in an upper stand unit and carry an upper carrier for the upper impact unit, and at least two lower, hydraulic lifting cylinders and auxiliary vertical, lower impact rods, which are included in a lower stand unit and carry a lower carrier for the lower impact unit.

An impact machine for forming a body of formable working material through impact action in a forming operation, the machine comprising:

• a machine stand;
• an upper impact unit with an upper ram;
• an upper punch;
• a lower impact unit with a lower ram;
• a lower punch;
• and
• a mould cavity for the working material formed between the punches when the punches are brought towards one another,
• a stroke length of the upper ram being such that the upper ram is accelerated by motion members of the ram to a velocity such that upper parts that are movable during the forming operation and that include at least the upper ram and the upper punch obtain a first predetermined velocity,
• the upper parts having an upper part mass
• a stroke length of the lower ram being such that the lower ram is accelerated by motion members of the ram to a velocity such that lower parts that are movable during the forming operation and that include at least the lower ram and the lower punch obtain a second predetermined velocity,
• the lower parts having a lower part mass,
• the upper and lower part masses and the first and second predetermined velocities being such that the momentum of each of the downwards movable masses and the upwards movable masses become essentially equally large such that the following condition applies:
• m1×v1≅m2×v2
• where m1 is the total mass of the downwards movable masses at impact and m2 is the total mass of the upwards movable masses at impact,
• wherein the kinetic energies of the movable masses, defined as (m1v12)/2 and (m2v22)/2, are substantially transferred to the working material in the mould cavity and are of a magnitude such that the working material is plasticized and flows out and fills all parts of the mould cavity when the punches are maximally brought together for the formation of said body with desired shape, and
• wherein the rams are not integrated with the punches.

An impact machine for forming a body of a formable working material through impact action in a forming operation, the machine comprising:

• a machine stand;
• an upper impact unit with an upper ram;
• a lower impact unit with a lower ram;
• and
• a central unit that is essentially stationary during the forming operation,
• the central unit including a mould tool between the upper impact unit and the lower impact unit,
• the mould tool comprising a die having a through hole that together with an upper punch and a lower punch form a mould cavity for the working material,
• the upper and lower impact units being controllably raised and lowered by elevator devices relative to the central unit for setting of predetermined stroke lengths of the upper ram and of the lower ram, respectively before the forming operation,
• the two punches are tubular,
• a mandrel extends up into the mould cavity through the lower punch, and
• the mandrel is essentially stationary during the forming operation.