Patent ID: 6935927
Filing Date: 2005-08-30
Classification: B24C

Abstract:
1. A blasting method for a junction between a large-diameter main bore in an article and a small-diameter branch bore branching off at an angle from the main bore in the article, comprising the steps of: inserting a pillar-shaped rod from a first open end of the main bore with the leading end of the rod close to the junction without blocking the branch bore; jetting a wet slurry made of a mixture of abrasives arid water from a blasting gun into the main bore from a second open end thereof; colliding the wet slurry with the leading end of the rod to redirect the wet slurry toward the branch bore to drive the abrasives against the junction for removal of burrs located inside the article at the junction; and providing an outer peripheral wall of the rod with a helical groove to produce a swirling motion in the blast of the wet slurry jetted into the main bore.