Device for controlling butt welding machine

摘要

A device for controlling a butt welding machine includes a pressure equalizing hydraulic slide valve connected to a manifold between the rod space of a clamping hydraulic cylinder and a reversible hydraulic slide valve coupled to both the delivery and drain manifolds of a hydraulic fluid supply system. Upon upsetting, the rod space communicates through the pressure equalizing hydraulic slide valve with the drain manifold, providing the same pressure above and beneath the piston and releasing a part of the clamping force. Provision is made for a programmed control unit or timer for energizing electromagnets adapted for switching the pressure equalizing hydraulic slide valve and a follow-up or tracking slide valve of a hydraulic drive adapted for carrying welded parts.