Machine Loading Cell Made More Efficient with Robotic System
by Paula Kyle
The customer wanted to match and automate an existing Okuma machining center with a new Okuma twin spindle vertical lathe. The operations included maching 8 different bearing housings weighing approximately 40 lbs. each. Some parts required side 'A' and side 'B' machining, which accounted for 15 separate operations.
Design of a system including a Fanuc 420iL robot with machine interfacing and twin part grippers, programmed to load and unload the machines when prompted by operation sensors. The benefits of this system include eliminating the inefficient manual operation and its inherent safety problems with an automated system capable of improving output, reducing cost, and improving quality. This system featured:
- A six axis Fanuc 420iL robot with 165 lb. load capacity and integrated controller for high speed, heavy payload processes.
- Heavy duty grippers equipped with unique multi-function fingers capable of I.D. or O.D. gripping of the various parts.
- A regrip stand designed to capture all parts while the robot positions itself for the side 'B' grip and subsequent loading.
- A 4-part queuing station that allows one machine to continue operations while the other gets new inserts. (The robot will not operate while technicians are in the cell, but will resume once they leave.)
- Stainless steel chain conveyor powered in two directions with part sensors and adjustable side rails for positive control and escapement.
- Safety fence with gates and robot interface.
Description of Process:
The lathe signals the robot is ready for a part, the robot picks a part from the inbound conveyor, loads the lathe, removes part from 'A' operation, places raw casting in fixture and proceeds to load 'B' fixture with part from 'A'. Remove 'B' fixture part, replace with 'A' part and proceed to adjacent machining center where it performs 'A'/'B' operations utilizing the re-grip stand for turning the part. The robot responds to the signals from both machines resulting in a most efficient machine loading cell. The inbound/outbound conveyor responds to the needs of the robot, incrementally moving the parts. The cell is protected by the integrated safety gates which stop the motion of the robot when opened.