METHOD OF MANUFACTURING A TURBOMACHINE COMPONENT THAT INCLUDES COOLING AIR DISCHARGE ORIFICES

Abstract

The present invention relates to a method of producing cooling fluid discharge orifices in the wall (171) of a part manufactured by the technique of lost wax casting in which a pattern of the part is produced in a wax mold, the orifices having a first portion (110E) emerging at the external surface (171ext) of the wall. The method consists in making cavities in the wax pattern that correspond to the first portions (110E) of said orifices of the part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail in relation to a non limiting embodiment illustrated in the appended drawings, in which:

FIG. 1 shows a cooled moving blade of a turbine;

FIG. 2 shows a sectional view of the wall at a cooling air discharge orifice according to the prior art;

FIG. 3 shows, in section, a casting pattern in its wax mold;

FIGS. 4 to 6 show the steps in producing flared holes according to the invention; and

FIGS. 7 and 8 show perspective views of a flared orifice according to the invention.

Claims

1. A method of producing cooling fluid discharge orifices in the wall of a part manufactured by the technique of lost wax casting in which a pattern of the part is produced in a wax mold, the orifices having a first portion emerging at the external surface of the wall, which method consists in making cavities in the wax pattern that correspond to the first portions of said orifices of the part and then in machining, in the part as cast, a second orifice portion that brings the bottom of the first orifice portion into communication with the internal surface of the wall.

2. The method as claimed in the preceding claim, wherein protuberances with a shape complementary to that of said first portions are made in the wax mold in such a way that the pattern has said cavities and the part as cast includes said preformed first portions of the orifices.

3. The method as claimed in the preceding claim, wherein the cavities corresponding to said first portions of the orifices are of flared shape.

4. The method as claimed in one of claims 1 to 3, wherein the joining regions, at least partly, provided in the cavities corresponding to said first portions of the orifices, are radiused.

5. The method as claimed in claim 2, wherein the protuberances are radiused.

6. The method as claimed in claim 4, wherein the joining region between the side walls of the cavities corresponding to said first portions of the orifices and the external surface of the pattern is radiused.

7. The method as claimed in claim 4, 5 or 6, wherein the radius or radii of curvature of the radiused surfaces is or are at least 0.1 mm preferably 0.2 mm, the radius of curvature along the profile of the radius surfaces being optionally progressive.

8. The method as claimed in claim 1, wherein the second orifice portion is of tubular shape.

9. The method as claimed in the preceding claim, wherein the machining is carried out by means of a laser beam or by EDM.

10. A turbomachine component obtained by the method of one of the preceding claims that includes cooling air discharge orifices with wall elements, of which the regions where the wall elements join together are radiused.

11. The component as claimed in the preceding claim, wherein the regions in which the first orifice portions join with the external wall of the component are radiused, the radius or radii of curvature being at least 0.1 mm.