February 2024 Volume 6

AUTOMATION

Dual station automatic tool change station

Design of Work Piece Contacting Parts We recommend using high wear materials for the gripper fingers. We suggest you use the same material as your dies. Serrations on the fingers can be tolerated for gripping flash and perhaps on the billet but be careful when handling semi or final forged work pieces. Chamfer everything! Any edge that is going to come near a work piece or die should be chamfered. There is nothing worse than an edge-to-edge collision when a small chamfer would have allowed the robot to complete the operation. Rigging of Air Lines and Electrical Harnesses Since most hot part applications will be in harm’s way of hot scale, we need to consider how to protect the airlines and electrical harness that runs from EOAT back to the air valves that operate the EOAT. Most downtime is caused by damaged harnesses and air lines. This occurs when the lines are dragging over dies, getting caught on the robot wrist, etc. Use a cable dress out kit that includes a spring-loaded pull back to keep the lines from drooping. Also, use a flexible, high temperature cover over the lines near the wrist which can deflect scale. Use high temperature air lines and high flex (both bend and torsion) electrical cable between shoulder and wrist.

Note stacked fingers on this EOAT

What to Do for Complete Geometry Change? For certain installations, you might be faced with a complete change in the press setup. For instance, some jobs run with the billet axis vertical, and others run with the billet axis horizontal. After carefully analyzing the part geometry, it was decided two grippers would be required. Swapping the complete gripper can be handled by 1) manual changeover, or 2) automatic changeover. In the case of manual changeover, design a tooling cart that can be rolled into position at the robot’s tool maintenance station. Design the cart to receive the drop off tool and write a program to have the robot position the tool so that it engages the cart. Use one size screw to release the EOAT from the tool receiver/wrist plate. The tooling should be doweled so it can only mount one way. Quick connect air and electrical should be used. The electrical plug can be used to positively identify the tool to prevent mistakes. For automatic tool changing, use a sturdy tool rack and make sure each tool is keyed mechanically so that it only fits in one station in the rack. Automatic tool changers pass both air and electrical signals to the EOAT. Take advantage of these ports to avoid having to manually disconnect fittings. Due to die spray in the area, we suggest you place a cover over the tools in the rack to protect the precision mating surfaces of the ATC. The robot can be programmed to handle the covers during the exchange process.

FIA MAGAZINE | FEBRUARY 2024 34