These applications are material-handling operations in which the robot is used to service a production machine by transferring parts to and/or from the machine.
There are three cases that fit into this application category:
Machine load/unload – The robot loads a raw work part into the process and unloads a finished part. A machining operation is an example of this case.
Machine loading – The robot must load the raw work part or materials into the machine but the part is ejected from the machine by some other means.
In a pressworking operation, the robot may be programmed to load sheet metal blanks into the press, but the finished parts are allowed to drop out of the press by gravity.
Machine unloading – The machine produces finished parts from raw materials that are loaded directly into the machine without robot assistance.
The robot unloads the part from the machine. Examples in this category include die casting and plastic modeling applications.
The application is best typified by a robot-centered workcell which consists of the production machine, the robot, and some form of parts delivery system.
To increase the productivity of the cell and the utilization of the robot, the cell may include more than a single production machine.
This is desirable when the automatic machine cycle is relatively long, hence causing the robot to be idle a high proportion of the time.
Some cells are designed so that each machine performs the same identical operation.
Other cells are designed as flexible automated systems in which different parts follow a different sequence of operations at different machines in the cell.
In either case, the robot is used to perform the parts handling function for the machines in the cell.
Robots have been successfully applied to accomplish the loading and/or unloading function in the following production operations:
- Die casting
- Plastic molding
- Forging and related operations
- Machining operations
- Stamping press operations