CYLINDRICAL HOLE AND FORM CENTRING AND DRILLING DEVICE

摘要

The invention relates to a device for the electrical discharge machining of at least one rectilinear cooling air passage (6) having a flared opening (8) in the wall of a hollow turbine vane (2). The inventive device comprises at least one forming electrode (10) attached to a first electrode holder and intended to produce the flared outlet opening. The forming electrode (10) comprises a first face (28a) which is provided with a groove for guiding a rectilinear electrode (7) designed to drill the rectilinear part of the air passage (6), a median portion (28) with a constant section and a pointed end portion with a section that decreases between the median portion and the point of the forming electrode.