The cost of machine operation can be expensive, especially when machines must be manned all day long. In our current slow and unpredictable economy, many shops are looking at ways to reduce manpower and increase efficiency by automating their processes. Implementing loading and unloading systems is a way to do so, by either using stand-alone robots with grippers or grippers installed inside machines.
An example of a workpiece gripper that enables a machine tool to serve as its own robot is one manufactured by Schunk. The gripper allows the machine to pick parts from a magazine on its worktable and insert them into a workholding device for machining. Once a new part is loaded, the machine’s ATC swaps the gripper for a cutting tool, storing the gripper in the ATC magazine.
The gripper’s fingers are held open by an internal spring until the spring is overcome by the pressure of through-spindle coolant or compressed air. A bypass valve reduces the high pressure of the through-spindle coolant to an appropriate level required to actuate the gripper. Excess coolant flows out of the valve on the side of the gripper as it holds a part. Two- and three-finger models are available.
To learn about a company that uses grippers inside its internal grinding machines, read “A Simpler Way to Automatically Load Grinding Machines.” To learn about customized grippers and watch a video of a robotic cell, read “Handling Parts in a Robotic Cell.”