Channel inlet edge deburring for gas diffuser cases

Abstract

A method of deburring channel inlet edges inside a cavity of a gas diffuser case is disclosed. The diffuser case has a plurality of channels each having an inner surface and an inlet edge defining an inlet of the channel. The surfaces of adjacent channels co-operate to provide said inlet edge therebetween. The inlet edges of the channels are provided in an inwardly facing circular array around a central axis of the gas diffuser case. The method comprises: inserting a tool head having at least one nozzle in the cavity of the gas diffuser case; and then ejecting abrasive particles from at least one nozzle towards at least one of the channel inlet edges of the gas diffuser case to at least one of decrease a radius of at least one said edge and improve a smoothness of at least one said surface.

What is claimed is: 
     
         1 . A method of providing a diffuser case, the diffuser case having a plurality of channels each having an inner surface and an inlet edge defining an inlet of the channel, the surfaces of adjacent channels co-operating to provide one said edge therebetween, the inlet edges of the channels being provided in an inwardly facing circular array around a central axis of the diffuser case, the method comprising:
 providing a plurality of said channels in the diffuser case, the step of providing causing machining burrs to form on said edges; and then   directing a flow of abrasive particles radially outwardly towards the channel inlet edges of the diffuser case to remove the burrs and thereby deburr the inlets.   
     
     
         2 . The method according to  claim 1 , further comprising inserting a tool head having at least one nozzle in the circular array of the gas diffuser case; and wherein directing a flow of abrasive particles comprises ejecting abrasive particles from the at least one nozzle towards at least one of the channel inlet edges of the gas diffuser case to at least one of decrease a radius of at least one said edge and improve a smoothness of at least one said surface. 
     
     
         3 . The method as defined in  claim 2 , wherein ejecting abrasive particles comprises directed the at least one nozzle substantially coaxially with at least one of the channel inlet edges of the gas diffuser case. 
     
     
         4 . The method as defined in  claim 1 , further comprising wetting the abrasive particles before being directing a flow thereof. 
     
     
         5 . The method as defined in  claim 2 , further comprising, before inserting the tool head the circular array, removing burr pieces of at least some of the channel inlet edges exceeding a target profile. 
     
     
         6 . The method as defined in  claim 1 , wherein directing a flow of abrasive particles comprises ejecting the particles with a compressed carrier gas. 
     
     
         7 . The method as defined in  claim 2 , further comprising rotating the tool and wherein ejecting particles includes ejecting the particles at least partially by centrifugal effect. 
     
     
         8 . The method as defined in  claim 2 , wherein the method includes repeatedly repositioning the at least one nozzle with reference to a remaining edge to thereby deburr all channel inlet edges of the gas diffuser case.