Mold and method for forming a curved beam of an aircraft side stand

By designing a specialized mold and method for forming curved beams of aircraft side panel composites, and utilizing a combination of vacuum bags and autoclaves, the problem of forming curved beams of aircraft side panel composites was solved, achieving a high-efficiency and low-loss forming effect.

CN117227217BActive Publication Date: 2026-06-23TIANJIN ISTAR-SPACE TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
TIANJIN ISTAR-SPACE TECH CO LTD
Filing Date
2023-04-20
Publication Date
2026-06-23

AI Technical Summary

Technical Problem

Existing technologies struggle to efficiently form composite curved beams for aircraft side panels, especially due to their three-dimensional curvature and asymmetry at both ends, resulting in high forming difficulty and significant composite material loss.

Method used

A specially constructed mold for forming composite curved beams of aircraft side panels, including a main mold, a bottom auxiliary mold, and a top auxiliary mold, is used in conjunction with a vacuum bag and an autoclave. Through precise bending beam forming space and internal and external pressure difference forming, the mold gap is reduced, and the efficient forming of composite curved beams is achieved.

Benefits of technology

It improves the success rate of forming composite curved beams for aircraft side panels, reduces composite material loss, and increases forming efficiency, enabling the forming of two curved beams in one operation.

✦ Generated by Eureka AI based on patent content.

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Abstract

The application provides an aircraft side plate composite curved beam forming die and method, and belongs to the technical field of aircraft part manufacturing. The die comprises a main body die and a bottom auxiliary die matched with each other. The application forms a precise curved beam forming space through the aircraft side plate composite curved beam forming die, which is convenient and reliable. In addition, through the pressure difference between the inside and outside, the air pipe is completely expanded, so that the rolled pre-impregnated material layer is tightly attached to the forming space of the die. Finally, through the heat pressing tank curing forming, the composite curved beam forming difficulty is reduced compared with the conventional pipe structure forming method, the success rate is greatly improved, and the loss of composite material caused by forming failure is reduced.
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Description

Technical Field

[0001] This invention belongs to the technical field of aircraft component manufacturing, and in particular relates to a mold and method for forming curved beams of aircraft side panels. Background Technology

[0002] The horizontal stabilizer and wings of an aircraft have multiple load-bearing side panels, each with several reinforcing beams. These side panel beams are typically made of high-strength, lightweight composite materials, and to further reduce weight, they are often designed as hollow tubular structures. In short, the composite beams of the aircraft side panels are a crucial component of the aircraft's load-bearing system.

[0003] However, the composite curved beam of the aircraft side panel has a three-dimensional curvature and is asymmetrical at both ends. In addition, the wall thickness of the curved beam is also relatively large (about 4.5 mm). Therefore, it is difficult to form the composite curved beam of the aircraft side panel using conventional pipe structure machining methods, and the loss of composite material is relatively large during conventional forming. Summary of the Invention

[0004] In view of this, the present invention aims to provide a mold and method for forming curved beams of aircraft side panels, so as to alleviate the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] In a first aspect, the present invention provides a mold for forming a curved beam of composite material for an aircraft side panel, comprising:

[0007] Main body mold: horizontally set, with curvature variation in the horizontal direction, and a semi-circular top groove with an opening facing downward and extending along the length direction of the main body mold on the bottom surface, the semi-circular top groove having curvature variation in the vertical direction;

[0008] Bottom auxiliary mold: It is horizontally fixed at the bottom of the main body mold and has the same curvature change in the horizontal direction as the main body mold. The top surface has an upward-opening semi-circular bottom groove that extends along the length direction of the bottom auxiliary mold. The semi-circular bottom groove and the semi-circular top groove have the same curvature change in the vertical direction, and the two are configured to form a curved beam forming space.

[0009] In various embodiments of the above embodiments, preferably, the top surface of the main body mold is provided with an additional semi-circular bottom groove that opens upward and extends along its length direction, and the additional semi-circular bottom groove has a curvature change in the vertical direction.

[0010] The aircraft side panel composite bending beam forming mold also includes:

[0011] Top auxiliary mold: It is horizontally fixed to the top of the main mold and has the same curvature change in the horizontal direction as the main mold. The bottom surface has an additional semi-circular top groove that opens downward and extends along the length direction of the top auxiliary mold. The additional semi-circular top groove and the additional semi-circular bottom groove have the same curvature change in the vertical direction, and the two are configured to form an additional curved beam forming space.

[0012] More preferably, the bottom auxiliary mold and the top auxiliary mold are detachably connected to the main body mold by means of a plurality of pins arranged at intervals along their length direction, which are vertically driven into the main body mold.

[0013] In various embodiments of the above examples, preferably, the main body mold has a plurality of horizontally penetrating weight-reduction holes.

[0014] Secondly, the present invention provides a method for forming an aircraft side panel composite bending beam using the aircraft side panel composite bending beam forming mold described in the above technical solution, comprising the following steps:

[0015] S1: Cover the straight steel pipe with a release film and roll a prepreg layer for manufacturing the composite material onto the outside of the release film;

[0016] S2: Fix the air duct to one end of the straight steel pipe, and pull the straight steel pipe out from the rolled prepreg layer through the other end of the straight steel pipe, and bring the air duct into the prepreg layer;

[0017] S3: Open the aircraft side panel composite curved beam forming mold, apply release agent evenly to the side wall of the curved beam forming space, then place the rolled prepreg layer with the air duct through the curved beam forming space, and finally close the mold.

[0018] S4: Use a vacuum bag to cover the aircraft side panel composite bending beam forming mold and the air duct inside it and roll the prepreg layer. The air inlet and air outlet of the air duct pass through the vacuum bag respectively, and the exit position is sealed.

[0019] S5: Place the mold into the autoclave and pressurize it, while simultaneously evacuating the vacuum bag through the air nozzle.

[0020] S6: The vacuum bag and the aircraft side panel composite bending beam forming mold inside it, as well as the rolled prepreg layer, are placed in an autoclave for curing to obtain the final aircraft side panel composite bending beam.

[0021] In various embodiments of the above examples, preferably, in step S2, the length of the air duct is greater than the length of the rolled prepreg layer, so as to facilitate subsequent vacuum bag covering.

[0022] In various embodiments of the above examples, preferably, in step S3, the rolled prepreg is tidied up before mold closing to prevent the prepreg from being pressed down during mold closing.

[0023] In various embodiments of the above examples, preferably, in step S3, the mold gap during mold closing is less than or equal to 0.01 mm.

[0024] In various embodiments of the above examples, preferably, in step S6, the curing temperature of the autoclave is 90°C and the curing pressure is 0.8 MPa.

[0025] In various embodiments of the above examples, the following steps are more preferably included:

[0026] S7: Perform flaw detection on the curved beams of the aircraft side panel composite after curing, and inspect their thickness and appearance.

[0027] Compared with existing technologies, the aircraft side panel composite bending beam forming method provided by this invention has the following advantages:

[0028] 1. This invention utilizes a mold for forming composite bending beams on aircraft side panels to create a precise bending beam forming space, which is convenient and reliable. Furthermore, by pressurizing the autoclave and simultaneously applying an external vacuum, the pressure difference between the inside and outside causes the duct to fully expand, ensuring the rolled prepreg layer adheres tightly to the forming space of the mold. Finally, the material is cured in the autoclave. Compared to conventional pipe structure forming methods, this invention reduces the difficulty of forming composite bending beams, significantly increases the success rate, and reduces composite material losses due to forming failures.

[0029] 2. The aircraft side panel composite curved beam forming mold can form two composite curved beams at once through the bottom auxiliary mold and the top auxiliary mold, which improves efficiency. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the overall structure of the aircraft side panel composite curved beam forming mold described in this invention;

[0032] Figure 2 This is a schematic diagram of the structure of the main body mold and the bottom auxiliary mold described in this invention;

[0033] Figure 3 This is a schematic diagram of the bottom auxiliary mold described in this invention;

[0034] Figure 4 This is a schematic diagram of the structure of the aircraft side panel composite curved beam described in this invention;

[0035] Figure 5 This is a schematic diagram of the structure using a vacuum bag for covering in step S5 of the present invention;

[0036] Figure 6 This is a flowchart of the steps in the method for forming the composite bending beam of the aircraft side panel according to the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1-Main mold; 101-Additional semi-circular bottom groove; 2-Bottom auxiliary mold; 201-Semi-circular bottom groove; 3-Bent beam forming space; 4-Top auxiliary mold; 5-Pin; 6-Weight reduction hole; 7-Prepreg layer; 8-Air duct; 9-Aircraft side panel composite bent beam forming mold; 10-Mold closing seam; 11-Vacuum bag; 12-Air nozzle; 13-Aircraft side panel composite bent beam; 14-Mold opening groove; 15-Additional bent beam forming space. Detailed Implementation

[0039] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0040] The present invention will now be described in detail with reference to embodiments.

[0041] like Figures 1 to 4 As shown, in a first aspect, the present invention provides a mold 9 for forming a composite curved beam of an aircraft side panel, comprising:

[0042] Main body mold 1: It is set horizontally and has a curvature change in the horizontal direction. The bottom surface has a semi-circular top groove that opens downward and extends along the length direction of the main body mold 1. The semi-circular top groove has a curvature change in the vertical direction.

[0043] Bottom auxiliary mold 2: It is horizontally fixed at the bottom of the main body mold 1 and has the same curvature change in the horizontal direction as the main body mold 1. The top surface has a semi-circular bottom groove 201 that opens upward and extends along the length direction of the bottom auxiliary mold 2. The semi-circular bottom groove 201 and the semi-circular top groove have the same curvature change in the vertical direction, and the two are configured to form a curved beam forming space 3.

[0044] In various embodiments of the above embodiments, more preferably, the top surface of the main body mold 1 is provided with an additional semi-circular bottom groove 101 that opens upward and extends along its length direction, and the additional semi-circular bottom groove 101 has a curvature change in the vertical direction.

[0045] The aircraft side panel composite bending beam forming mold 9 also includes:

[0046] Top auxiliary mold 4: It is horizontally fixed to the top of the main body mold 1 and has the same curvature change in the horizontal direction as the main body mold 1. The bottom surface has an additional semi-circular top groove that opens downward and extends along the length direction of the top auxiliary mold 4. The additional semi-circular top groove and the additional semi-circular bottom groove 101 have the same curvature change in the vertical direction, and the two are configured to form an additional curved beam forming space 15.

[0047] More preferably, the bottom auxiliary mold 2 and the top auxiliary mold 4 are detachably connected to the main body mold 1 by means of a plurality of pins 5 arranged at intervals along their length direction, which are vertically driven into the main body mold 1.

[0048] In various embodiments of the above examples, preferably, the main body mold 1 has a plurality of horizontally penetrating weight-reduction holes 6.

[0049] Reference Figures 1 to 6 Secondly, the present invention provides a method for forming an aircraft side panel composite bending beam using the aircraft side panel composite bending beam forming mold 9 described above, comprising the following steps:

[0050] S1: Cover the straight steel pipe with a release film and roll a prepreg layer 7 for manufacturing the composite material outside the release film;

[0051] S2: Fix the air duct 8 to one end of the straight steel pipe, and pull the straight steel pipe out from the rolled prepreg layer 7 through the other end of the straight steel pipe, and bring the air duct 8 into the prepreg layer 7.

[0052] S3: Open the aircraft side panel composite curved beam forming mold 9, apply release agent evenly to the side wall of the curved beam forming space 3, then put the rolled prepreg layer 7 with the air duct 8 through it into the curved beam forming space 3, and finally close the mold.

[0053] S4: Use a vacuum bag 11 to cover the aircraft side panel composite bending beam forming mold 9 and the air duct 8 inside it and the rolled prepreg layer 7. The air inlet and air outlet of the air duct 8 pass through the vacuum bag 11 respectively, and the exit position is sealed.

[0054] S5: Turn on the centrifugal fan to blow air into the air duct 8 and make the rolled prepreg layer 7 expand and fit tightly against the side wall of the curved beam forming space 3, while drawing a vacuum through the air nozzle 12 of the vacuum bag 11.

[0055] S6: The vacuum bag 11 and the aircraft side panel composite bending beam forming mold 9 inside it and the rolled prepreg layer 7 are placed in a hot autoclave for curing to obtain the final aircraft side panel composite bending beam 13.

[0056] In various embodiments of the above examples, preferably, in step S2, the length of the air duct 8 is greater than the length of the rolled prepreg layer 7, so that it can be used when the vacuum bag 11 is used for subsequent covering.

[0057] In various embodiments of the above examples, preferably, in step S3, the rolled prepreg is tidied up before mold closing to prevent the prepreg from being pressed down during mold closing.

[0058] In various embodiments of the above examples, preferably, in step S3, the mold closing gap 10 during mold closing is less than or equal to 0.01 mm. Specifically, along the mold closing gap 10, the main mold 1, the top auxiliary mold 4, and the bottom auxiliary mold 2 are all provided with a plurality of mold opening grooves 14 at intervals to facilitate use during mold opening.

[0059] In various embodiments of the above examples, preferably, in step S6, the curing temperature of the autoclave is 90°C and the curing pressure is 0.8 MPa.

[0060] In various embodiments of the above examples, more preferably, the following steps are also included: S7: Perform flaw detection on the cured aircraft side panel composite curved beam 13, and inspect its thickness and appearance.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for forming an aircraft side panel composite bending beam using an aircraft side panel composite bending beam forming mold, characterized in that, The mold includes: Main body mold: horizontally set, with curvature variation in the horizontal direction, and a semi-circular top groove with an opening facing downward and extending along the length direction of the main body mold on the bottom surface, the semi-circular top groove having curvature variation in the vertical direction; Bottom auxiliary mold: It is horizontally fixed at the bottom of the main body mold and has the same curvature change in the horizontal direction as the main body mold. The top surface has a semi-circular bottom groove that opens upward and extends along the length direction of the bottom auxiliary mold. The semi-circular bottom groove and the semi-circular top groove have the same curvature change in the vertical direction, and the two are configured to form a curved beam forming space. The molding method includes the following steps: S1: Cover the straight steel pipe with a release film and roll a prepreg layer for manufacturing the composite material onto the outside of the release film; S2: Fix the air duct to one end of the straight steel pipe, and pull the straight steel pipe out from the rolled prepreg layer through the other end of the straight steel pipe, and bring the air duct into the prepreg layer; S3: Open the aircraft side panel composite curved beam forming mold, apply release agent evenly to the side wall of the curved beam forming space, then place the rolled prepreg layer with the air duct through the curved beam forming space, and finally close the mold. S4: Use a vacuum bag to cover the aircraft side panel composite bending beam forming mold and the air duct inside it and roll the prepreg layer. The air inlet and air outlet of the air duct pass through the vacuum bag respectively, and the exit position is sealed. S5: Place the mold into the autoclave and pressurize it, while simultaneously evacuating the vacuum bag through the air nozzle. S6: The vacuum bag and the aircraft side panel composite bending beam forming mold inside it, as well as the rolled prepreg layer, are placed in an autoclave for curing to obtain the final aircraft side panel composite bending beam.

2. The method for forming aircraft side panel composite bending beams according to claim 1, characterized in that, In step S2, the length of the air duct is greater than the length of the rolled prepreg layer so that it can be used for subsequent vacuum bag wrapping.

3. The method for forming aircraft side panel composite bending beams according to claim 1, characterized in that, In step S3, the rolled prepreg is tidied up before mold closing to prevent it from being pressed down during mold closing.

4. The method for forming a curved beam from aircraft side panel composite material according to claim 1, characterized in that, In step S3, the mold closing gap during mold closing is less than or equal to 0.01 mm.

5. The method for forming a curved beam from composite material for aircraft side panels according to claim 1, characterized in that, In step S6, the curing temperature of the autoclave is 90°C and the curing pressure is 0.8 MPa.

6. The method for forming a curved beam from aircraft side panel composite material according to claim 1, characterized in that, It also includes the following steps: S7: Perform flaw detection on the curved beams of the aircraft side panel composite after curing, and inspect their thickness and appearance.

7. The method for forming a curved beam from aircraft side panel composite material according to claim 1, characterized in that, The top surface of the main mold is provided with an additional semi-circular bottom groove that opens upward and extends along its length, and the additional semi-circular bottom groove has a curvature change in the vertical direction. The aircraft side panel composite bending beam forming mold also includes: Top auxiliary mold: It is horizontally fixed to the top of the main mold and has the same curvature change in the horizontal direction as the main mold. The bottom surface has an additional semi-circular top groove that opens downward and extends along the length direction of the top auxiliary mold. The additional semi-circular top groove and the additional semi-circular bottom groove have the same curvature change in the vertical direction, and the two are configured to form an additional curved beam forming space.

8. The method for forming a curved beam from composite material for aircraft side panels according to claim 7, characterized in that, The bottom auxiliary mold and the top auxiliary mold are detachably connected to the main mold by means of a plurality of pins arranged at intervals along their length, which are vertically driven into the main mold.

9. The method for forming a curved beam from composite material for aircraft side panels according to claim 1, characterized in that, The main body mold has multiple horizontally penetrating weight-reduction holes.