Weaving forming method of prefabricated body and prefabricated body

Abstract

The invention relates to the technical field of textile, in particular to a weaving forming method of a prefabricated body and the prefabricated body. An upper edge plate, blade bodies and a lower edge plate are obtained through fiber weaving, then reserved fibers of one part of every two adjacent blade bodies are woven, the other part of reserved fibers are embedded into fiber layers of the upper edge plate and the lower edge plate, finally, Z-direction sewing is conducted on the joints of the blade bodies and the upper edge plate and the joints of the blade bodies and the lower edge plate, and a prefabricated body is obtained. In this way, the structural defects that an existing CMC guider blade prefabricated body is unreasonable in design and poor in fiber continuity can be effectively overcome, the structural strength of a product is guaranteed, part machining is reduced, and the integrality of a guider blade is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, and in particular to a preform weaving forming method and a preform. Background Art

[0002] The demand for high-performance aircraft engines for military and civilian aircraft is becoming increasingly urgent. There are two main ways to improve engine performance: one is to increase the compressor pressure ratio, and the other is to increase the turbine inlet gas temperature. As the turbine inlet gas temperature increases, the engine's high-temperature components need to withstand greater heat loads, and the demand for heat resistance of component materials will become increasingly higher in the future.

[0003] Usually, turbine guide vanes are designed with single-joint molding and mechanical connection assembly. The calculation of the edge plate angle is complex, the processing is difficult, and the number of parts is large. There are deficiencies in life, reliability and maintainability. In addition, the material used for multi-joint guide vanes is high-temperature alloy material, and its heat resistance is far from meeting future needs. The processing performance is poor, and the base tracking surface needs to be positioned during the processing.

[0004] Therefore, there is an urgent need to provide a preform weaving molding method and a preform to solve the above technical problems. Summary of the invention

[0005] The invention provides a preform weaving forming method and a preform, which can reduce the machining of parts and improve the overall structural strength of a turbine guide.

[0006] In a first aspect, an embodiment of the present invention provides a method for weaving a preform, wherein the preform is a preform of a turbine guide vane of an aircraft engine, and the preform comprises an upper edge plate, a blade body, and a lower edge plate connected in sequence, and the method comprises:

[0007] The fibers are woven into a blade body by a preset weaving forming method; wherein fibers are reserved at the upper and lower ends of the blade body respectively;

[0008] The fibers are woven in a layer-by-layer weaving manner to obtain an upper edge plate and a lower edge plate;

[0009] Weaving a portion of the reserved fibers in two adjacent blades with each other, and embedding another portion of the reserved fibers into the fiber layers of the upper edge plate and the lower edge plate;

[0010] The preform is obtained by performing Z-direction stitching on the connection between the blade body and the upper edge plate and the connection between the blade body and the lower edge plate using a preset stitching process.

[0011] In a second aspect, an embodiment of the present invention provides a preform, which is formed by the method mentioned in the above embodiment.

[0012] Beneficial effects:

[0013] According to the preform weaving forming method and preform provided by the embodiment of the present invention, the upper edge plate, the blade body and the lower edge plate are obtained by fiber weaving, and then a part of the reserved fibers in the two adjacent blade bodies are woven together, and the other part of the reserved fibers are embedded in the fiber layers of the upper edge plate and the lower edge plate. Finally, the connection between the blade body and the upper edge plate and the connection between the blade body and the lower edge plate are sewn in the Z direction to obtain the preform. In this way, the structural defects of the existing CMC guide vane preform, such as unreasonable design and poor fiber continuity, can be effectively overcome, which not only ensures the structural strength of the product, but also reduces the machining of parts, thereby greatly improving the integrity of the guide vane. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of a process flow of a preform weaving forming method provided by an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of the structure of a preform provided in an embodiment of the present invention;

[0017] Figure 3 A schematic diagram of a suturing process provided by an embodiment of the present invention;

[0018] Figure 4 A schematic diagram of the structure of a blade body woven using a 2.5D weaving method provided in an embodiment of the present invention.

[0019] In the figure, 1-upper edge plate, 2-blade body, 3-lower edge plate, 4-suture line. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] like Figure 1 As shown, the embodiment of the present invention provides a method for weaving a preform, wherein the preform (see Figure 2) is a preform of a turbine guide vane of an aircraft engine, the preform comprising an upper edge plate 1, a blade body 2 and a lower edge plate 3 connected in sequence, the method comprising:

[0022] Step S1, weaving the fibers into a blade body 2 by a preset weaving forming method; wherein fibers are reserved at the upper and lower ends of the blade body 2 respectively;

[0023] Step S2, weaving the fibers in a layered weaving manner to obtain an upper edge plate 1 and a lower edge plate 3;

[0024] Step S3, weaving a portion of the reserved fibers in two adjacent blades 2 with each other, and embedding another portion of the reserved fibers into the fiber layers of the upper edge plate 1 and the lower edge plate 3;

[0025] Step S4: Using a preset stitching process (e.g., using Figure 3 The connection between the blade body 2 and the upper edge plate 1 and the connection between the blade body 2 and the lower edge plate 3 are sewn in the Z direction to obtain a preform.

[0026] In this embodiment, the upper edge plate 1, the blade body 2 and the lower edge plate 3 are obtained by weaving fibers, and then a part of the reserved fibers in the two adjacent blade bodies 2 are woven together, and the other part of the reserved fibers are embedded in the fiber layers of the upper edge plate 1 and the lower edge plate 3. Finally, the joints of the blade body 2 and the upper edge plate 1 and the blade body 2 and the lower edge plate 3 are sewn in the Z direction to obtain a preform. In this way, the structural defects of the unreasonable design and poor fiber continuity of the existing CMC guide vane preform can be effectively overcome, which not only ensures the structural strength of the product, but also reduces the machining of parts, and greatly improves the integrity of the guide vane.

[0027] It is worth noting that the blade root (i.e., the connection between the blade body and the upper edge plate and the blade body and the lower edge plate) in the service state is the location where the working stress is most concentrated. However, the angle between the blade body and the upper edge plate and the lower edge plate is about 90°, so the structural strength of the blade root needs to be fully guaranteed. In order to solve this technical problem, the above technical solution extends the fibers reserved at the upper and lower ends of the blade body to the upper and lower edge plates, and makes a part of the reserved fibers weave with each other and makes another part of the reserved fibers embedded in the fiber layer of the upper and lower edge plates, so as to ensure the reliable connection between the blade body and the upper and lower edge plates, thereby solving the defect of insufficient strength of the blade root caused by the prefabricated body.

[0028] In one embodiment of the invention, the fibers include silicon carbide fibers.

[0029] Compared with high-temperature alloys, ceramic-based composites can withstand higher temperatures and can significantly reduce cooling airflow. They also have high strength, high modulus, good damping performance, excellent impact resistance and long service life under high-temperature conditions. At the same time, the density of ceramic-based composites is 2.0-2.5g / cm3, which is only 1 / 4-1 / 3 of that of high-temperature alloys. It can greatly reduce the structural mass, and a simple replacement can improve the engine thrust-to-weight ratio. The silicon carbide fiber integrally woven preform, after being treated by a high-tech carbon / carbon deposition process, has the properties of friction resistance, high temperature resistance, light weight and overall high quality. Therefore, ceramic-based composites have become the most potential alternative and upgrade material for advanced engine hot-end components, and have great application potential in the hot-end stationary and rotor components of the engine. It is an emerging high-tech new material for modern development.

[0030] In one embodiment of the present invention, along the width direction of the blade body 2, the fibers reserved at the two ends of the blade body 2 are shorter than the fibers reserved in the middle, the fibers reserved at the two ends of two adjacent blade bodies 2 are used to weave each other, and the fibers reserved in the middle of the blade body 2 are used to embed into the fiber layers of the upper edge plate 1 and the lower edge plate 3. Such an arrangement can fully ensure the structural strength of the preform as a whole and achieve uniformity of the fiber volume content at different positions.

[0031] In one embodiment of the present invention, the preset weaving forming method includes a 2.5D weaving method and a 3D weaving method, which are not specifically limited herein.

[0032] In one embodiment of the present invention, the upper edge plate 1 and the lower edge plate 3 are provided with reinforcing ribs, the blade body 2 is perpendicular to the upper edge plate 1 and the lower edge plate 3 respectively, and the distance from the upper edge plate 1 to the lower edge plate 3 is not less than 20 mm.

[0033] In one embodiment of the present invention, the thickness of the leading edge of the blade airfoil 2 is variable, and the interior of the trailing edge of the blade airfoil 2 has a cavity.

[0034] In this embodiment, more warp yarn layers are locally arranged at the location where the leading edge of the blade has a larger thickness, and the weft yarn is half-wound and wrapped around to achieve uniformity of the overall volume content of the leading edge of the blade, thereby achieving one-piece shaping of the leading edge of the blade and the shape with a large difference in blade thickness; and by setting a cavity, the weight of the preform can be appropriately reduced.

[0035] like Figure 4 As shown, the cavity may be crescent-shaped, and of course may be other shapes, which are not specifically limited here.

[0036] In one embodiment of the present invention, the ply weaving patterns include 0°, 90° and ±45°.

[0037] In one embodiment of the present invention, the parameters of the preset suturing process include suturing spacing, suturing method and suturing thread specifications.

[0038] In one embodiment of the present invention, the suturing methods include lock stitching, chain stitching, flat stitching and single-sided stitching, and the suture thread specifications include material, number of strands and processing methods, and the processing methods include coating, twisting and treatment with a treating agent.

[0039] In addition, an embodiment of the present invention further provides a preform, which is woven into shape using the method mentioned in any of the above embodiments.

[0040] It should be noted that the preform provided in this embodiment has the same inventive concept as the above method embodiment, and therefore both have the same beneficial effects, and the beneficial effects of the preform will not be elaborated herein.

[0041] The above technical solution is introduced below through two specific embodiments.

[0042] Example 1

[0043] For a certain aircraft engine guide vane, take triple braiding as an example. The raw material is silicon carbide fiber, and the braiding method of the preform is:

[0044] (1) According to the size and shape characteristics of the blade, a 2.5D shallow cross-bend structure is designed. The warp direction is along the height direction of the blade, and the weft direction is along the circumferential direction of the blade. Since the thickness of the leading edge of the blade is relatively thick, a non-uniform layer method is used to arrange it according to the thickness change. The differential layer is planned in the middle of the leading edge of the blade. The weft yarn is continuously wrapped around the upper and lower complete layers, and half-wound at the middle differential layer position, such as Figure 4 As shown, the thickness of the leading edge of the blade is uniformly changed, thereby completing the contour weaving forming of the entire blade.

[0045] (2) The fibers reserved above and below the woven blade body are prepared by distributing more trapezoidal long-side fibers on the outer surface of the blade body and fewer short-side fibers on the inner surface as the fibers reserved above and below the blade body, and then embedding them into the upper and lower edge plate fabrics layer by layer, thereby achieving the connection between the upper and lower edge plates and the blade body.

[0046] (3) The warp yarns at the roots of the three blades are combined and woven together according to the relative positions of the three blades.

[0047] (4) According to the external dimensions and connection characteristics of the upper and lower edge plates, the 2D silicon carbide plain weave fabric is woven using the 2D weaving forming method. The cavity size of the unit layer at the blade body is accurately calculated, and the fabric layer with a crescent-shaped cavity that matches the blade body is cut on the plain weave fabric.

[0048] (5) On a contoured ply stitching die for the upper and lower edge plates with connecting ribs and with preset cavity dimensions for the blade body, a woven plain weave silicon carbide fiber cloth with a preset cavity dimension for the blade body is laid layer by layer according to the designed fiber direction (0 / 45 / -45 / 90), and at the same time, the reserved fibers of the contoured blade body prepared in step (2) are evenly distributed layer by layer in the fabrics of the upper and lower edge plates until the thickness reaches the thickness of the edge plate fabric, and the blade body is integrally connected to the upper and lower edge plates.

[0049] (6) The high-performance fiber surface is coated with organic fiber by using a coating process, and the middle area of ​​each cavity of the compacted edge plate is stitched by a stitching process with a stitching spacing of 2 mm × 2 mm, and a through stitching method is used to gradually complete the overall stitching of the blade body + upper / lower edge plate.

[0050] (7) According to the outer dimensions of the reinforcement rib, the 2.5D weaving process is used to realize the overall weaving of the reinforcement rib, and at the same time, a 1 / 4 thickness edge plate is woven at the connection between the reinforcement rib and the edge plate, and then laid on the upper and lower edge plates respectively, and the connection rib and the upper and lower edge plates are connected as a whole by a through stitching method with a stitching spacing of 2mm×2mm. Finally, a silicon carbide fiber multi-joint high-temperature guide vane preform consisting of a multi-joint blade body, an upper edge plate, a lower edge plate, and reinforcement ribs is obtained.

[0051] Example 2

[0052] For a certain aircraft engine guide vane, take triple braiding as an example. The raw material is silicon carbide fiber, and the braiding method of the preform is:

[0053] (1) According to the size and shape characteristics of the blade, a 2.5D shallow cross-connected structure weaving process is designed. The warp yarn direction is along the height direction of the blade, and the weft yarn is along the circumferential direction of the blade. The thickness of the blade is controlled by changing the number of warp yarn layers or the yarn fineness; the leading edge of the blade adopts the "half-expansion method", that is, the fabric is half-expanded along the thickness direction for weaving, and then the leading edge of the blade is closed by a core mold, and then the leading edge of the blade is sewn and woven into shape by sewing to complete the weaving of a single blade.

[0054] (2) A fiber is reserved above and below the woven blade body. More trapezoidal long-side fibers are distributed on the outer surface of the blade body, and fewer short-side fibers are distributed on the inner surface as the reserved fibers above and below the blade body. The fibers are embedded into the upper and lower edge plate fabrics layer by layer, thereby realizing the connection between the upper and lower edge plates and the blade body.

[0055] (3) The warp yarns at the roots of the three blades are combined and woven together according to the relative positions of the three blades.

[0056] (4) According to the external dimensions and connection characteristics of the upper and lower edge plates, the 2D silicon carbide plain weave fabric is woven using the 2D weaving forming method. The cavity size of the unit layer at the blade body is accurately calculated, and the fabric layer with a crescent-shaped cavity that matches the blade body is cut on the plain weave fabric.

[0057] (5) On a contoured ply stitching die for the upper and lower edge plates with connecting ribs and with preset cavity dimensions for the blade body, a woven plain weave silicon carbide fiber cloth with a preset cavity dimension for the blade body is laid layer by layer according to the designed fiber direction (0 / 45 / -45 / 90), and at the same time, the reserved fibers of the contoured blade body prepared in step (2) are evenly distributed layer by layer in the upper and lower edge plate fabrics until the thickness reaches the edge plate fabric thickness, and the blade body is integrally connected to the upper and lower edge plates.

[0058] (6) Lay the contour-cut 2D silicon carbide plain weave fabric on the preset connection rib position of the laid edge plate until the thickness of the connection rib fabric is reached. The thickness is controlled by the laying pressure to ensure the accuracy of the contour after the laying is completed.

[0059] (7) The twisting method is used to improve the silicon carbide fiber bundle braiding forming suture line. The suture line is used to suture the middle area of ​​each cavity of the compacted edge plate by suture technology, with a suture spacing of 2mm×2mm, and a through suture method to gradually complete the overall suture of the blade body + upper / lower edge plate. Then, the suture spacing is 2mm×2mm, and the through suture method is used to complete the overall connection of the connecting ribs and the upper and lower edge plates to improve the Z-direction interlayer performance. Finally, a silicon carbide fiber multi-joint high-temperature guide vane preform consisting of a multi-joint blade body, an upper edge plate, a lower edge plate, and a reinforcing rib is obtained.

[0060] It should be noted that, in this article, relational terms such as primary and secondary are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical factors in the process, method, article or device including the elements.

[0061] Finally, it should be noted that the above is only a preferred embodiment of the present invention, which is only used to illustrate the technical solution of the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for weaving a preform, characterized in that: The preform is a preform of a turbine guide vane of an aircraft engine, and the preform comprises an upper edge plate (1), a blade body (2) and a lower edge plate (3) which are connected in sequence. The method comprises: The fibers are woven in a preset weaving and forming manner to obtain a blade body (2); wherein fibers are reserved at the upper and lower ends of the blade body (2); The fibers are respectively woven in a layered weaving manner to obtain an upper edge plate (1) and a lower edge plate (3); Weaving a portion of the reserved fibers in two adjacent blade bodies (2) with each other, and embedding another portion of the reserved fibers into the fiber layers of the upper edge plate (1) and the lower edge plate (3); The prefabricated body is obtained by performing Z-direction sewing on the connection between the blade body (2) and the upper edge plate (1) and the connection between the blade body (2) and the lower edge plate (3) using a preset sewing process.

2. The method according to claim 1, characterized in that Along the width direction of the blade body (2), the fibers reserved at the two end positions of the blade body (2) are shorter than the fibers reserved at the middle position; the fibers reserved at the two end positions of two adjacent blade bodies (2) are used to weave together, and the fibers reserved at the middle position of the blade body (2) are used to embed into the fiber layers of the upper edge plate (1) and the lower edge plate (3).

3. The method according to claim 2, characterized in that The fibers include silicon carbide fibers.

4. The method according to claim 2, characterized in that: The preset weaving forming methods include 2.5D weaving method and 3D weaving method.

5. The method according to claim 2, characterized in that: The upper edge plate (1) and the lower edge plate (3) are provided with reinforcing ribs, the blade body (2) is perpendicular to the upper edge plate (1) and the lower edge plate (3) respectively, and the distance between the upper edge plate (1) and the lower edge plate (3) is not less than 20 mm.

6. The method according to claim 2, characterized in that The thickness of the leading edge of the blade airfoil (2) is variable, and the interior of the trailing edge of the blade airfoil (2) has a cavity.

7. The method according to claim 2, characterized in that The ply weaving modes include 0°, 90° and ±45°.

8. The method according to any one of claims 2 to 7, characterized in that: The parameters of the preset suturing process include suturing spacing, suturing method and suturing thread specifications.

9. The method according to claim 8, characterized in that The suturing methods include lock stitching, chain stitching, flat stitching and single-side stitching. The suture thread specifications include material, number of strands and processing methods. The processing methods include coating, twisting and treatment with a treating agent.

10. A preform, characterized in that: The method according to any one of claims 1 to 9 is used for weaving.

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