Poka Yoke Nest
Poka Yoke nest
The below is a poka yoke nest for a large injection moulding company. The company had some large injection molded parts that needed to be fitted with threaded inserts, star washers, seals, and part identification stickers. The parts were for a medical company and they did not want to risk parts being sent out the door without all the fittings. The fittings were small and could easily be missed.
This was a cost effective solution to insure parts could not progress down the production line without the correct fittings.
The jig had several features protruding from the base plate. These features were 3d printed and designed to fit into the geometry of the injection moulded part. This would locate the part securely and accurately. The plastic injection moulded part would be placed onto these features. Once in place the 2 cylinder on either side of the jig would extend and lock into the part, making it impossible to remove.
4 proximity inductive sensors in the base plate would look for inserts on the underside of the part. In order to detect the seal, sticker and star washers, a machine vision sensor was mounted above. Once all of the sensors were able to confirm that all the inserts were in place the cylinder would retract allowing the operator to remove the part.
If for some reason the inserts could not be fitted, a line manager would have to use a key lock to override the machine and retrieve the part. It would then be their discretion as to how the part was processed from then.
This type of poka yoke nest is a staple for Acorn. Having a nest that captures a part until a quality control criteria is met is a simple and cost effective method of quality control that is easy to incorporate into almost any production line.