Hydraulic cold extrusion press

Hydraulic cold extrusion press comprising:

• a frame;
• a stationary table mounted on said frame;
• a first replaceable die part mounted on said table;
• a platen movably supported on said frame for movement toward and from said table;
• a second replaceable die part mounted on said platen for movement therewith into engagement with said first die part in a closed position and out of engagement with said first die part in an open position;
• said die parts having cooperating shapes so that when in said closed position said die parts form a die having an opening therein for receiving a workpiece with no deforming thereof;
• first piston and cylinder means mounted on said frame and connected to said piston for moving said platen and said second die part therewith between said open and closed positions;
• second working piston and cylinder means having a cylinder means mounted on said frame and a unitary piston movable toward and away from said die to perform an extruding stroke, said second piston and cylinder means comprising first and second separate working units in tandem superposed on said unitary piston;
• an extrusion mandrel supported on said unitary piston for movement therewith and extending in said platen for movement in said die opening into engagement with the workpiece for extruding the workpiece during the extruding stroke of said unitary piston;
• two stop members in spaced relationship in said platen;
• stop means on said unitary piston cooperating and engageable with said stop member for controlling the limits of travel of said unitary piston relative to said platen;
• said stop member and stop means positioning said extrusion mandrel into a starting position upon movement of said platen and second die part into said closed position;
• fluid flow conduits connecting said first and second separate working units with a source of pressurized hydraulic fluid for operating said unitary piston;
• controlled main valve means operatively associated with said second piston and cylinder means and connected to said fluid flow conduit leading to said first working unit for controlling hydraulic fluid flow to said first working unit;
• actuator means operatively connected to said controlled main valve means for adjusting said controlled main valve means, part of the pressurized hydraulic fluid being fed to said controlled main valve means and part being fed to said second working unit;
• a control device operatively connected to said actuator means for operating said actuator means in response to operating parameters of the press for controlling the extruding stroke and speed of said extrusion mandrel;
• ejector means operatively associated with said table for ejecting the workpiece;
• and
• third piston and cylinder means mounted on said frame and connected to said ejector means for operating said ejector;
• said first piston and cylinder means operating to maintain said die in said closed position during the extruding stroke of said extrusion mandrel.