JP2574589B2 - Method for manufacturing hollow blades for turbomachinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow blade for a turbomachine.

[0002]

BACKGROUND OF THE INVENTION The advantages obtained by using large chord length blades in turbomachines are particularly evident in the case of the blades of the blower rotor of a double-flow turbojet engine. These blades must meet severe service conditions, and in particular have sufficient mechanical properties to be linked to anti-vibration properties and resistance to foreign object impacts. Further, in order to obtain a sufficient speed at the blade end, it has been required to reduce the mass. This object is achieved in particular by using hollow blades.

[0003] FR-A-1 577 388 gives an example of the manufacture of a vane which is constituted by placing a tortoiseshell structure between two wall elements, these wall elements being composed in particular of a titanium alloy, It is formed into a desired profile and shape by hot pressing.

Further, according to French Patent Publication Nos. 286688 and 2304438, the application of fluid pressure and diffusion welding inside a suitable tool allows the metal to be removed from a plurality of members through a high temperature superplastic working process. Methods for manufacturing structures are known.

It is an object of the present invention to produce a component having a structure having at least three plates and, if necessary, having a controlled mass distribution with respect to the centrifugal field in the case of a rotating component. In order to achieve this, it is an object of the present invention to apply a manufacturing method which can replace a conventional method capable of obtaining a large chord-length blower blade.

[0006]

A manufacturing method which satisfies these conditions is a method of manufacturing a hollow blade for a turbomachine, particularly a blower rotor blade having a large chord length, comprising: (a) two outer metal plates and Manufacturing a primary member including at least one intermediate metal plate; (b) hot forming the primary member into a desired shape by bending and twisting; and (c) at least one intermediate member. Disposing a diffusion barrier at a non-joining position of the metal plate; and (d) assembling a member including at least one intermediate metal plate having the diffusion barrier and the two outer metal plates, and disposing the member in a tool. (E) diffusion welding the assembled members to join the parts where the diffusion barrier is not arranged, and (f) connecting the intermediate metal plate with the intermediate metal plate. Blowing a pressurized gas between the Kisotogawa metal plate, and performing an expansion and superplastic forming, comprising a method which comprises a (g) finishing stage.

[0007] Depending on the application, only one intermediate metal plate or more than one intermediate metal plate can be used.

[0008] Advantageously, the outer metal plate is obtained by hot forming from a member having a decreasing thickness.
Alternatively, it can be obtained by molding die / blowing using a hot die forging known per se or an isothermal forging method. The intermediate metal plate may be chemically processed after the primary component step of step (a) of the method, or after step (b) and before the placement of the diffusion barrier.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will be apparent from the following description of an embodiment, taken in conjunction with the accompanying drawings, in which: FIG.

In a method for manufacturing a hollow blade for a turbomachine according to a series of steps of the present invention schematically shown in FIGS.
FIG. 1 shows an example of a primary member of a blade composed of two outer metal plates 1 provided with protrusions 2 and an intermediate metal plate 7. The method of manufacturing these primary members uses techniques known per se.

FIG. 1 shows the members 1 and 7 after a bending / twisting step according to known hot forming techniques using tools (not shown).

According to a variant, the intermediate metal plate 7 may be subjected to a chemical working step before the bending / twisting step in order to obtain a predetermined mass distribution on the blades by adjusting the thickness.

In some applications, it may be advantageous to carry out the chemical machining of the intermediate metal plate 7 according to FIGS. 2 and 3A, 3B after the bending / twisting step.

In this case, chemical processing is performed to obtain a plate having a variable thickness. 3A and 3B
Shows the plate 7 after chemical processing by showing a cross-section in a direction perpendicular to the edges of the blades to be obtained or in a direction parallel to these edges. In particular, as shown in FIGS. 2 and 3A, three thickness zones 7a, 7b and 7c and / or
Alternatively, a zone of variable thickness in the vertical direction can be obtained in the intermediate metal plate 7 as shown in FIG. 3B.

These steps are performed according to known chemical processing techniques, especially by using masking, laser cutting and the like.

Thereafter, as shown in FIG.
Is attached to the intermediate metal plate 7. The application zone of the diffusion barrier is defined by a mask, which may be a rigid or flexible tool or a deposition of a suitable material known per se, which is adhesive on the surface, and cutting or peeling off the mask results in welding and masking. Configure a diffusion barrier during removal.

Next, the outer metal plate 1 and the intermediate metal plate 7, which are constituent elements of the blade 11 to be obtained, are finally joined. As shown in FIG. 5, the joining projection 2 is used. This joining step further includes preparing the assembly 11 for subsequent steps.

FIG. 6 shows the placement of the vanes 11 on the tool 14 including a pressurized gas inlet 15 and a suitable sealing device. According to the example shown, the seal inside and outside of the tool is obtained by a separate packing 16 and the seal between the inside of the blade and the inside of the tool is 1 in FIG.
As shown in FIG. 3, it is ensured by peripheral welding of the members. The sealing of the tool to the outside and the inside of the vane to the inside of the tool, depending on the tool used, can be ensured by packing formed directly by creep and welding-diffusion on the periphery of the member. In this case, the packing portion is removed at the time of finishing by processing. The welding-diffusion process is performed in a furnace. In an example applied to a titanium alloy member, the step is 930
C. and uses an inert gas such as argon to pressurize the member as indicated by arrow 17. According to one production example, the applied pressure is 4 MPa. The welds 18 between the intermediate metal plate 7 and the outer metal plate 1 may be arranged alternately on both sides as shown in FIG.

Next, the gas collecting device, which has been arranged before, and the chemical working process of the intermediate metal plate 7 and the tool 1
By using the gas inlet pre-formed at the time of disposing the blades 11 on the blade 4, the blades 11 are connected to a special tool 14 for performing the blowing under argon pressure and the superplastic working process.
To be placed. During this process, the blades 11 are
Take the final inner shape as shown in

Thereafter, finishing of the blade 11 is performed by a technique known per se such as finishing, in particular, processing including cutting of the peripheral portion and removal of the adhered portion, finishing of the leading and trailing edges of the blade 11 and finishing of the blade leg. Obtain the final shape. Note that the leading and trailing edges of the blade may have a shape close to the final shape before finishing.

The method for manufacturing a hollow blade for a turbomachine described above can be applied to a blade including various modifications within the scope of the present invention. In particular, instead of a single intermediate metal plate 7, a plurality of intermediate metal plates can be used. At least one of these plates has a continuous surface, similar to the plate 7 corresponding to the embodiment described above with reference to FIGS. Furthermore, it is also possible to use one or more intermediate auxiliary plates, for example with a cut-out in the center, to reinforce the edges of the blades obtained in particular.

According to another variant, two intermediate metal plates are used to obtain a blade structure as shown in the sectional view of FIG.
And 20 may be combined. Depending on the application, another structure as shown in FIG. 9 may be used. In each case, after bonding the various plates by welding-diffusion and subjecting the assembly to a bending / twisting step, gas pressure blowing and superplastic working steps are applied according to the invention.

The method described above can optionally use different materials for the intermediate metal plate and the outer metal plate, in particular the material of the outer metal plate needs to have the same superplastic workability as the material of the intermediate metal plate. There is no.

[Brief description of the drawings]

FIG. 1 is a perspective view of a component member of a blade according to a manufacturing method of the present invention.

FIG. 2 is a perspective view of an intermediate metal plate having a variable thickness.

FIG. 3A is an example of a partial detailed view of the plate shown in FIG. 2;

FIG. 3B is another example of a partial detailed view of the plate shown in FIG. 2;

FIG. 4 is a perspective view of an intermediate metal plate provided with a diffusion barrier.

FIG. 5 is a perspective view of a finally joined oblique member.

FIG. 6 is an explanatory diagram of a member welding-diffusion process.

FIG. 7 is an explanatory view of a blowing of a reinforcing material inside the member and a superplastic working step.

FIG. 8 is a sectional view of a modified example of a blade.

FIG. 9 is a sectional view of another modified example of the blade.

[Explanation of symbols]

 1 outer metal plate 7 intermediate metal plate 14 tool

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // B23K 20/00 310 B23K 20/00 310L (72) Inventor Bernard Philippe Coronil Soye France, 77176 Sabigny le Temple, Are Dou Paul-Cro 3 (72) Inventor Danilo Barrera France, 92310 Sable, Lille de Fontonner 32

Claims (6)

(57) [Claims] 1. A method of manufacturing a hollow blade for a turbomachine, in particular, a blower rotor blade having a large chord length, comprising: (a) a primary member including two outer metal plates and at least one intermediate metal plate; Manufacturing; and (b) desirably bending and twisting the primary member.
A step of hot molding into the shape of, (c) at least one non-bonding of the intermediate metal plate
Placing a diffusion barrier at a location; and (d) at least one intermediate metal having said diffusion barrier.
Member comprising a metal plate and the two outer metal plates
Assembling and disposing in a tool; and (e) diffusion welding the assembled member to form the diffusion burr.
A step of joining the site where Ya is not arranged together, and performing blow, inflation and superplastic forming pressurized gas between the outer metal plate and (f) said intermediate metal plate, (g) A finishing step. 2. After the production step (a), at least one
2. The method of claim 1, further comprising the step of chemically processing said intermediate metal plate. To 3. After fabrication step (b), the so as to obtain a plate of variable thickness to bending and twisting the intermediate metal plate, to claim 1 or 2, characterized in that it comprises a chemically processed to step The described method. 4. The method according to claim 1, wherein the primary member comprises two outer metal plates and a plurality of intermediate metal plates. 5. The intermediate metal plate, the method according to claim 4, characterized in that it comprises at least one intermediate plate having at least one intermediate plate and the central cut-out portion having a continuous surface. 6. The number of intermediate metal plates is two, and the two intermediate metal plates are joined to the outer metal plate by diffusion welding, and then gas pressure blowing and superplastic 5. The method according to claim 4, wherein the processing is performed.