Patent ID: 6398096
Filing Date: 2002-06-04
Classification: B21D,Y10T

Abstract:
A hydraulic drive mechanism to actuate a tool for joining at least two workpieces of ductile material, comprisinga punch drive for actuating a punch to exert a joining force, said punch drive comprising a piston cylinder assembly including a piston with a piston rod and a cylinder with first and second work chambers, the first work chamber being pressurized via a first fluid connection to move said punch from an inoperative position to an operative position and the second work chamber being pressurized via a second fluid connection to return said punch from said operative position to said inoperative postion, and a clamp drive for actuating a clamp means providing a clamping force for clamping said at least two workpieces during the joining operation against an upsetting die, said clamp drive comprising a piston cylinder assembly including a pressure chamber which is pressurized for generating said clamping force, the piston cylinder assembly of said clamp drive being carried by said piston rod of said punch drive, and said pressure chamber of said clamp drive communicating with said second work chamber of said punch drive via a flow passage such that pressure from said second work chamber of said punch drive is transmitted to said pressure chamber of said clamp drive in order to generate said clamping force.