DIRECT CURRENT WELDING MACHINE

摘要

A direct current welding machine comprising a first set of machine frame (2, 2'), a second set of machine frame (6, 6'), a centre shaft (8), a clamping oil cylinder (3), a shearing device (4), a forging oil cylinder (7) and a medium frequency welding transformer (10), wherein a hydraulic cylinder (9) is connected onto the centre shaft (8), and the hydraulic cylinder (9) comprises a first cylinder (9-1) and a second cylinder (9-2) with the same internal diameter, a first piston (9-3), a second piston (9-4) and a shared piston rod (9-5); a first hydraulic chamber (9-1-1) is in communication with a second oil port (9-9); a second hydraulic chamber(9-1-2) is in communication with a third oil port (9-10); a third hydraulic chamber (9-2-1) is in communication with a fourth oil port (9-7); and a fourth hydraulic chamber (9-2-2) is in communication with a fifth oil port (9-8). Two shearing oil cylinders (1) both comprise a shearing cylinder body (1-7), a shearing piston (1-1), and a shearing piston rod (1-6). The fourth oil port (9-7) and the second oil port (9-9) of the hydraulic cylinder (9) are in communication with a second oil port (A2) of a three-position, four-way solenoid valve (13); and the fifth oil port (9-8) and the third oil port (9-10) are respectively in communication with a first shearing oil port (1-4) of the two shearing oil cylinders (1). The direct current welding machine can ensure the synchronism of the two shearing oil cylinders and has a simple structure.