OVERVIEW

One company has developed a process that fixtures valve bodies and similar housings having internal passages needing deburring (Mehan 1983; Brust 1997). A stream of fine abrasives is fed into the ingress above the part down onto the interior edges of the fixtured part while it is oscillated. The oscillation moves the media through the housings and ensures constant motion of the media. The free cascade (which comes out at the egress) reportedly removes burrs with or without use of abrasives and water. The process works, even though the energy at internal edges is much lower than most processes use to remove tough burrs (Meehan 1983).

Cascade finishing allows processing of parts weighing up to approximately 90 lb with few restrictions on the physical dimensions of the part. Processing involves a high-energy, rapid removal rate. It is a repeatable process that is suitable for use with stand-alone finishing equipment, as well as in-line finishing for dedicated machining centers using automated or robotic handling.

The process was developed for the Iowa Engineered Processes Corporation in 1983 (Meehan 1983), and, as noted above, its mechanism is a freely cascading stream of abrasive media flowing into the internal passages of a part. The part is rigidly fixtured and is mechanically oscillated during introduction of the media. Compounds and water are introduced with the media for improved abrasive action and cleaning. The freely cascading stream of media introduced to the internal passages of an oscillating part represents a significant improvement in...