A lot of strange things can happen when feeding pliable parts from a feeder bowl. When slightly warped or twisted parts bypass the mechanical tooling used to ensure correct part orientation, assembly errors can happen. When a machine shuts down and an operator must clear a jam or reorient parts, productivity is lost.
Error-proofing with vision sensors is a simple, cost-effective way for manufacturers to prevent defects and downtime caused by incorrectly oriented components. One of our customers, Miniature Precision Components (MPC) in Prairie du Chien, WI, is a case in point.
In MPC’s system, a vibratory bowl feeds O-rings into an automated oil cap assembly cell. A sealing bead on one side of each O-ring must face the right way or the finished oil cap will not function as intended. So the feeder bowl includes mechanical tooling designed to prevent inverted O-rings from entering the rotary dial assembly station. However, when O-rings that aren’t perfectly flat occasionally make it past the knife-edge tooling and get loaded upside down in the dial fixture, the machine shuts down.
According to MPC, having an operator flip these seals manually and restart the machine was costing them $20,000 a year in lost production. And if they hadn’t solved the problem with a low-cost vision sensor, that cost may have increased to $120,000 a year at full production volumes.
A fix to detect inverted O-rings can cost as little as $1,000 and be installed and running in less than an hour. For more information, you can read the full storyhere.
How have you used vision sensors in automated assembly applications? I’d love to hear your experiences.
John Lewis is market development manager at Cognex. Formerly a technical editor for an engineering magazine, he has been writing about motion control, factory automation, machine vision and other technology topics since 1996. He has published hundreds of articles in dozens of trade journals and holds a B.S. degree in chemical engineering from the University of Massachusetts, Lowell.
Editor’s note: “Cognex on Machine Vision” is one of a new series of guest spots by industry experts that will appear regularly on ASSEMBLY’s blog page. Check back frequently to read more commentaries from John, as well as contributions on automated assembly systems, leak testing, robotics and ergonomics.