Method for manufacturing a self-strengthened intermediate housing and intermediate
By covering and co-curing multiple composite prefabricated parts, the problem of high cost and complexity of the intermediate shell of traditional manufacturing self-reinforced turbines is solved, and automated manufacturing and uniform quality self-reinforced intermediate shell are realized, reducing production costs and increasing efficiency.
Patent Information
- Application Number
- CN202380042467.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-05-25
- Filing Date
- 2023-05-24
- Publication Date
- 2025-01-03
AI Technical Summary
The technology of traditional manufacturing of self-reinforced turbine intermediate housing is high and complex, and lacks automation, resulting in low production efficiency and uneven quality.
Using a covering and co-curing method, the assembly process is simplified and cost-reduced by manufacturing and positioning multiple composite preforms and curing after the inner surface is covered to form a complete self-reinforced intermediate shell.
Automatic manufacturing of self-reinforced intermediate shells is realized, reducing production costs, ensuring uniform quality, reducing manual intervention and improving production efficiency.
Smart Images
Figure CN119256147A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for the automated production of a self-reinforcing intermediate casing for a turbomachine and also to a self-reinforcing intermediate casing obtained by this method.
[0002] The invention has application in the aeronautical field, in particular in the field of manufacturing composite parts with complex geometries, such as some turbine parts. Background Art
[0003] In aircraft turbomachines such as twin-shaft turbojets, the term "intermediate casing" is generally used to denote a casing whose hub is arranged approximately between the low-pressure compressor casing and the high-pressure compressor casing. In practice, a turbojet engine generally comprises four casings, which are in the following order from upstream to downstream: the air intake casing, the fan casing, the intermediate casing and the thrust reverser casing. These four casings form the outer boundaries of the airflow (or air pulses) within the turbojet engine. Figure 1 Schematically shown in FIG. 1 is an example of such a turbojet extending along a central axis A. This turbojet 10 comprises, from upstream to downstream, an air inlet casing 11 forming the inlet of the turbojet, a fan casing 12 arranged around fan blades 15, an intermediate casing 13 connected to radial arms 16 and supporting all the rotors and stators of the turbojet, and a thrust reverser casing 14 extending to the outlet of the turbojet.
[0004] The intermediate enclosure is a generally cylindrical structure that supports the intermediate enclosure shell (ICS). The intermediate enclosure may also support one or more reinforcements that have a mechanical function. For example, some reinforcements may form radial arms and / or allow equipment (such as pipes or computers) to be fastened, or even form a firewall. An intermediate enclosure that supports the shell and / or reinforcements is called a "self-reinforcing enclosure".
[0005] Traditionally, self-reinforcing shells are one-piece machined metal parts. Shells made of composite materials have also been proposed, for example by 3D weaving and liquid resin injection molding (a method known as Resin Transfer Molding (RTM)). The shell and the reinforcement are manufactured separately and assembled by adhesion to the crankcase structure. However, these technologies for manufacturing self-reinforcing shells are costly and complex to implement, as they require a large number of operations that are largely not automated.
[0006] Therefore, there is a real need for an automated technology that can manufacture self-reinforcing housings at a lower cost. Summary of the invention
[0007] In view of the above-mentioned problem of the complexity of the technology for manufacturing a self-reinforced skin, the applicant provides an automated method for manufacturing a self-reinforced skin, in which several composite preforms are assembled and maintained by covering and co-curing the assembly.
[0008] “Co-curing” means the simultaneous curing of several composite preforms, which were manufactured separately and assembled to form a single piece that is subjected to curing.
[0009] In the following description and claims, the term "cure" will be understood to literally cure, such as for materials that must be cured (such as epoxy resins), or to consolidate, such as for thermoplastic materials that require consolidation.
[0010] "Prepreg preform" refers to a semi-finished composite element comprising fibers impregnated with resin and shaped by molding. The prepreg preform (or prepreg preform) will be simply referred to as preform in the remainder of the description.
[0011] In the following description, the concepts of inside and outside are defined according to radial positioning relative to the turbojet engine's central axis A. Thus, an inner surface is a surface that is closer to the central axis A than an outer surface of the same part.
[0012] According to a first aspect, the invention relates to a method for producing a self-reinforcing intermediate casing for a turbomachine, the method comprising the following steps:
[0013] a) producing at least one first preform by covering,
[0014] b) producing at least one second preform by covering,
[0015] c) positioning the first preform and the second preform side by side to form an assembly comprising a uniform inner surface and an undulating outer surface,
[0016] d) covering the inner surface of the component so as to consolidate the component, and
[0017] e) co-curing the consolidated assembly.
[0018] The method allows automated manufacturing of the self-reinforcing intermediate shell, which ensures cost savings and uniform quality compared to the prior art.
[0019] In addition to the features just discussed in the preceding paragraphs, the manufacturing method according to one aspect of the present invention may have one or more of the following additional features, which may be considered individually or in all technically possible combinations:
[0020] The first preform comprises a substantially U-shaped section, the upstream leg of which forms the casing flange and the downstream leg of which forms part of the reinforcement.
[0021] The second preform comprises a substantially L-shaped section, the arms of which form a reinforcement together with the downstream leg of the U-shaped section of the first preform.
[0022] - The covering of the inner surface of the assembly comprises a substantially L-shaped cross-section.
[0023] - Between the assembling step c) and the covering step d), the method comprises the step of placing a gap filler on the inner surface to fill the gap between the first preform and the second preform.
[0024] - The first preform, the second preform and the cover are substantially cylindrical.
[0025] - The first preform, the second preform and the cover are part-cylindrical.
[0026] - In addition to step a) of making the first preform and step b) of making the second preform, the method comprises the additional step of making at least one third preform which is assembled with the first preform and the second preform during assembly step c).
[0027] - Each preform comprises at least two adjacent preformed sections.
[0028] Before or after the covering step d), the method comprises a step of locally forming the ply so as to form at least one additional reinforcement.
[0029] A second aspect of the invention relates to a self-reinforcing intermediate casing for a turbomachine obtained by the above-described manufacturing method. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Other advantages and features of the present invention will become apparent from the following description shown in the accompanying drawings, in which:
[0031] Already described Figure 1 A turboshaft engine including a center casing according to the prior art is shown;
[0032] Figure 2 A portion of a self-reinforcing intermediate casing according to the invention is shown in a schematic cross-sectional view;
[0033] Figure 3 The steps of the method for producing a self-reinforcing intermediate shell according to the invention are shown in a functional view;
[0034] Figure 4Shown in simplified perspective views are different prefabricated parts which are assembled according to the manufacturing method of the invention to obtain an example of a self-reinforcing intermediate shell segment;
[0035] Figure 5 A schematic cross-sectional view shows Figure 4 Example dimensions of preforms; and
[0036] Figure 6 Another example of prefabricated parts that are assembled according to the method of the invention to obtain another example of a self-reinforcing intermediate casing is shown in a schematic cross-sectional view. DETAILED DESCRIPTION
[0037] An example of a method for automatically manufacturing a self-reinforcing intermediate shell is described in detail below with reference to the accompanying drawings. This example illustrates the features and advantages of the present invention. However, it should be noted that the present invention is not limited to this example.
[0038] In the figures, identical elements are denoted by identical reference numerals. For reasons of legibility of the figures, the size ratios between the illustrated elements are not taken into account.
[0039] exist Figure 2 An example of a self-reinforcing intermediate shell 100 is schematically shown in a cross-sectional view of FIG. The self-reinforcing intermediate shell 100 (hereinafter referred to as "shell") includes a base structure 110 supporting a shell flange 120, a main reinforcement 130, an attachment area 140 and an additional reinforcement 135. The base structure 110 is generally cylindrical in shape and can be formed as a single piece or from a plurality of assembled sections. Figure 2 An example of a segment of the base structure 110 is shown. It should be understood that several segments of substantially the same size may be manufactured separately according to the manufacturing method described below and then assembled, for example with an overlap region between each segment to ensure material continuity.
[0040] The housing 100 according to the present invention is made of several prefabricated parts assembled to each other, and the assembly is consolidated by covering the surface of the assembly. Figure 3 and Figure 4 An example of a housing manufacturing method according to the present invention is shown in FIG. Figure 3 and Figure 4 The steps of manufacturing a portion of the shell 100 are shown, in particular the steps of manufacturing the upstream portion of the shell 100 , which incorporates the shell flange 120 and the main reinforcement 130 .
[0041] According to this example, the manufacturing method 200 according to the present invention comprises:
[0042] - Step 210: Manufacturing a first preform P1 by covering,
[0043] - step 220: manufacturing a second preform P2 by covering,
[0044] - step 230: positioning and aligning the first preform P1 and the second preform P2 side by side so that the two assembled preforms form a base structure 110 having a substantially uniform inner surface Pi and an undulating outer surface,
[0045] - Step 240: Covering the inner surface of the component to consolidate the component, and
[0046] - Step 250: Curing the covered component.
[0047] exist Figure 3 and Figure 4 In the example of FIG. 1 , the first preform P1 corresponds to the upstream shell of the housing. Figure 4 A) has a generally U-shaped cross section, i.e. a cross section comprising a base 121 and upstream and downstream legs 122, 123, each of which extends generally vertically on either side of the base 121. The second preform P2 ( Figure 4 Drawing B) in FIG. 1 corresponds to the downstream shell of the casing and has a generally L-shaped section, i.e. a section comprising a base 131 and an arm 132 extending perpendicularly to the base 131. The legs 122 and 123 of the preform P1 may have different heights. The downstream leg 123 of the preform P1 and the arm 132 of the preform P2 preferably have the same height.
[0048] After the preforms P1 and P2 have been manufactured in steps 210 and 220, respectively, said preforms P1 and P2 are aligned with each other (step 230), i.e., they are positioned successively with respect to each other, with the downstream leg 123 of the preform P1 abutting against the arm 132 of the preform P2. This alignment or juxtaposition of the preforms P1 and P2 results in an assembly P4 comprising:
[0049] a quasi-continuous inner surface Pi formed by the bases 121 and 131 of the preforms P1 , P2 , and
[0050] An undulating outer surface, ie one comprising protrusions formed by the legs 122 , 123 of the preform P1 and the arms 132 of the preform P2 .
[0051] After the step 230 of positioning the preforms P1 and P2, a step 240 consists in covering the inner surface Pi of the assembly P4 in order to consolidate the assembly. Figure 4The cover denoted by reference numeral P3 in the drawing C of FIG. 1 not only covers this inner surface of the assembly, but also covers the upstream surface 122a of the upstream leg 122 of the preform P1. Thus, the cover P3 has an L-shaped cross section, the shape and size of the arm 124 of the cover P3 are similar to those of the upstream leg 122 of the preform P1, and the shape and size of the base 125 of the cover P3 are similar to those of the bases 121 and 131 of the juxtaposed preforms P1 and P2. Thus, the cover P3 forms the inner face 110i of the base structure 110, while the undulating outer surfaces of the juxtaposed preforms P1, P2 form the outer face 110e of the base structure 110.
[0052] Each preform P1 , P2 may be made of the same part. On the other hand, the preform P1 , P2 may comprise two or more preformed sections which are abutted against each other to form the preform. During step 240 , these different preform sections will be covered by the same cover P3 .
[0053] Just like the cover P3 , the preforms P1 , P2 may be made using various known composite covering techniques, such as the AFP (Automated Fiber Placement) technique using carbon and epoxy fibers or carbon and thermoplastic (PAEK) fibers.
[0054] Once the cover P3 has been laid up, the assembly P5 comprising the preforms P1, P2 and the cover P3 forms a single block which undergoes a thermal treatment by curing (step 250). The curing in step 250 is carried out in an oven or an autoclave according to conventional procedures in the field of manufacturing composite parts at a temperature that depends on the materials used, for example about 180° C. for epoxy resins and about 360° C. for thermoplastic materials.
[0055] According to some embodiments, the manufacturing method 200 comprises an intermediate step between step 230 and step 240: placing a backfill material called a gap filler. This gap filler is placed on the inner surface Pi at the junction of the two preforms P1 and P2 in order to fill any gap caused by the lack of material. In practice, the assembly of the preforms P1 and P2 may produce a hole, that is, a gap without material forming a groove in the inner surface Pi. Placing the gap filler makes it possible to fill this hole, thereby ensuring a smooth and regular inner surface for receiving the cover P3.
[0056] According to the size example, Figure 4The preforms P1 and P2 may each comprise twelve plies, and the cover P3 may comprise sixty plies. The assembly P5 may, for example, have a thickness of 9.72 mm for the base structure 110 and the shell flange 120, and a thickness of 3.24 mm for the main reinforcement 130, with a thickness of 0.135 mm for the material plies. Once cured, the assembly P5 forms the shell 100. Figure 5 In the example of dimensions, the base structure 110 of the housing 100 has a length of 485 mm. Figure 5 The values shown in are examples only. The preforms P1 , P2 and the covers P3 may be made from a greater or, on the contrary, a smaller number of plies, and the dimensions of these elements P1 , P2 , P3 may vary depending on the turbine concerned and the requirements.
[0057] A description of the manufacturing method 200 has been given above for an assembly P5 formed by two preforms P1, P2 and a cover P3, which assembly is designed to obtain, after curing, a shell 100 comprising a shell flange 120 and a main reinforcement 130. A person skilled in the art will understand that other shell structures can be obtained using the same method 200 by adapting the number of preforms to the desired structure. Thus, several preforms can be positioned adjacent to one another, with the cover covering the inner surface formed by all these juxtaposed preforms. Figure 6 Another example of component P5 is shown in FIG. Figure 6 In this example of assembly P5, three preforms P1, P6, P7 of substantially U-shaped section are assembled with a preform P2 of L-shaped section. As previously described, the inner surface Pi is covered by a cover P3 of L-shaped section. This example of assembly P5 enables the production, after curing, of a shell 100 having a shell flange 120, a main reinforcement 130 and two other reinforcements 135 obtained from the juxtaposed legs of preforms P6 and P7 and from the arm of preform P2 juxtaposed to the downstream leg of preform P7.
[0058] In some embodiments not shown in the figures, the casing 100 obtained by the manufacturing method 200 may include a downstream casing flange, ie a casing flange located at the end of the base structure 110 opposite to where the upstream casing flange 120 is located.
[0059] In some embodiments, intermediate elements or additional reinforcements are made on the base structure 110 by locally adding plies. For example, Figure 2 The reinforcement 135 can be made of continuous plies at selected locations. Figure 6The explained way of manufacturing the reinforcement 135 can be obtained by applying several plies successively one above the other at selected positions. Similarly, intermediate elements (such as fastener positions 140) can be produced by locally applying several plies one above the other. These plies can be placed on the external face 110e of the assembly P5 or on the internal face 110i of the assembly P5. These plies are cured at the same time as all other elements of the assembly P5. Therefore, regardless of the number of preforms and / or plies added, the same curing step 240 is performed during the manufacturing method 200.
[0060] Regardless of the embodiment, the manufacturing method 200 provides the advantage of being cheaper than current manufacturing techniques because the manufacturing method is automated, requires only a single curing step, and no longer requires human intervention to adhere the components together. The automation of the method also ensures a consistent level of quality.
[0061] The above-mentioned figures show a cross section of a housing 100. It will be appreciated that the housing can be manufactured in its entirety using the method according to the invention. Thus, a substantially cylindrical housing or any other structure extending 360° can be produced in a single piece using this method. On the other hand, the housing or structure can be made in a plurality of sections, for example two half-shells or structures extending over 180° or even less. The sections of the housing or structure manufactured using the method according to the invention are then partially cylindrical. The manufacturing method according to the invention also enables the manufacture of housings or structures having complex geometries, such as double or triple curvature geometries; in this case, the shape and cross section of the prefabricated parts to be assembled are determined according to the geometry of the housing.
[0062] Although described through multiple examples, alternatives and embodiments, the manufacturing method according to the present invention and the shell obtained by the method include various alternatives, modifications and improvements, which will be obvious to those skilled in the art and should be understood to be within the scope of the present invention.
Claims
1. A method (200) for manufacturing a self-reinforcing intermediate casing (100) for a turbine, the method comprising the following steps which are performed successively: a) producing (210) at least one first preform (P1) by covering, b) producing (220) at least one second preform (P2) by covering, c) positioning (230) said first preform (P1) and said second preform (P2) side by side to form an assembly (P4) comprising a uniform inner surface (Pi) and an undulating outer surface (110e), d) covering (240) said inner surface (Pi) of said component in order to consolidate said component, and e) co-curing (250) the consolidated assembly.
2. The method according to claim 1, characterized in that The first preform (P1) comprises a generally U-shaped section, the upstream leg (122) of which forms a shell flange (120) and the downstream leg (123) of which forms part of a reinforcement (130).
3. The method according to claim 2, characterized in that The second preform (P2) comprises a substantially L-shaped section, the arm (132) of which forms, together with the downstream leg (123) of the U-shaped section of the first preform, the reinforcement (130).
4. The method according to any one of claims 1 to 3, characterized in that The cover (P3) of the inner surface of the assembly (P4) comprises a generally L-shaped cross section.
5. The method according to any one of claims 1 to 4, characterized in that Between the assembling step c) and the covering step d), the method comprises the step of placing a gap filler on the inner surface (Pi) to fill the gap between the first preform and the second preform.
6. The method according to any one of claims 1 to 5, characterized in that The first preform (P1), the second preform (P2) and the cover (P3) are substantially cylindrical.
7. The method according to any one of claims 1 to 5, characterized in that The first preform (P1), the second preform (P2) and the cover (P3) are partially cylindrical.
8. The method according to any one of claims 1 to 7, characterized in that In addition to step a) of manufacturing the first preform and step b) of manufacturing the second preform, the method comprises the additional step of manufacturing at least one third preform (P6, P7) which is assembled with the first preform and the second preform during assembly step c).
9. The method according to any one of claims 1 to 8, characterized in that Each preform (P1, P2) comprises at least two adjacent preformed sections.
10. The method according to any one of claims 1 to 9, characterized in that Before or after the covering step d), the method comprises a step of locally forming the ply so as to form at least one additional reinforcement (135).
11. A self-reinforcing intermediate casing (100) for a turbine, characterized in that: The self-reinforcing intermediate shell is obtained by a manufacturing method (200) according to any one of claims 1 to 10.