Patent ID: 9039487
Filing Date: 2015-05-26
Classification: B24C

Abstract:
1. A blasting method, comprising the steps of: providing an upper housing member having a space inside and an opening communicating with said space at a bottom face located at a lower extent of the upper housing; positioning said upper housing member above a workpiece, so as to arrange the opening of the upper housing member facing toward a surface of said workpiece, and to make a predetermined clearance between the bottom face of the upper housing member and the surface of said workpiece; providing a blast gun having an ejection hole with an elongated rectangular cross sectional shape, with the rectangular cross sectional shape having an opening width measured on a width direction line and an opening length measured on a length direction line transverse to the width direction line, in the upper housing member so that said ejection hole is disposed proximity to said surface of said workpiece to be processed through said opening of said upper housing member, and the ejecting direction of said blast gun is approximately vertical to said workpiece; providing rectifying plates in said upper housing at locations that are adjacent to each of the two opposed sides of said blast gun that are located on the width direction line, with plural rectifying plates being adjacent to each of the opposed sides of said blast gun and all of the plural rectifying plates being symmetrically inclined at a same angle relative to vertical for deflecting a flow of abrasives along a surface of said workpiece so that said flow of said abrasives are moved away from said surface of said workpiece; moving said workpiece by a carrier means relatively with respect to the blast gun with keeping a clearance between the bottom face of the upper housing member and the surface of said workpiece; ejecting a mixed fluid of a compressed gas and abrasives in an elongated rectangular shape according to a cross sectional shape of said ejection hole to said surface of said workpiece to be processed from an ejection hole of said blast gun; and providing suctioning means to create negative pressure within the space in the upper housing member, including providing suctioning means ducts at each of two opposed sides of the blast gun, with the two opposed sides being located on the width direction line of the ejection hole, to make the space negative pressure for recovering cut scraps of said workpiece and abrasives from said surface of said workpiece through the opening and the space of said upper housing member.