Composite cabin skin and preparation method thereof

Abstract

The invention relates to the technical field of aerospace, in particular to a composite cabin skin and a preparation method thereof. The embodiment of the invention provides a preparation method of a composite cabin skin. The preparation method comprises the steps that an outer skin layer is laid on a tool; laying a core layer on the outer skin layer; wherein a plurality of pipelines are buried in the core layer; an inner skin layer is laid on the core layer. According to the method, the aircraft cabin skin plays a crucial role in weight reduction optimization, spatial layout optimization and cost control of the overall system of the aircraft besides the function of bearing the structural load, and the structure and function integration of the aircraft cabin is really realized.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a composite cabin skin and a preparation method thereof. Background Art

[0002] Device signal control and data between aircraft cabins are primarily transmitted via cables within the cabin. To prevent cable vibration while the aircraft is operating, cable covers are typically used to secure the cables to the cabin's inner surface. Furthermore, to balance the weight of the various cabins, aircraft engines often use multiple fuel tanks to supply fuel. To ensure stable fuel supply, numerous connectors are required to secure the fuel pipes to the cabin's inner walls. The number of cables and fuel pipes within the aircraft cabin takes up valuable space, and the numerous cable covers and connectors increase the cabin's overall mass, while also increasing the total assembly time for the entire aircraft. Summary of the Invention

[0003] The embodiments of the present invention provide a composite cabin skin and a preparation method thereof, which can effectively optimize the space, weight and assembly problems caused by laying cables and oil pipes in the aircraft cabin.

[0004] In a first aspect, an embodiment of the present invention provides a method for preparing a composite cabin skin, comprising:

[0005] Laying the outer skin layer on the tooling;

[0006] Laying a core layer on the outer skin layer; wherein a plurality of pipelines are buried in the core layer;

[0007] An inner skin layer is laid on the core layer.

[0008] In one possible design, laying the outer skin layer on the tooling includes:

[0009] Multiple layers of outer skin prepreg are laid on the tooling in sequence. Each layer is compacted by rolling, and each eight layers are compacted by vacuum pre-pressing.

[0010] In one possible design, laying the core layer on the outer skin layer includes:

[0011] Cut prepregs of different lengths according to the cross-section of the pipeline to be buried;

[0012] Multiple layers of core layer prepreg are laid on the outer skin layer, and are compacted by a rolling process every time a layer is laid, and are compacted by a vacuum pre-pressing process every eight layers are laid.

[0013] When the height of the multi-layer core prepreg reaches the laying height for laying the pipeline, laying and fixing the pipeline on the core prepreg;

[0014] Laying the cut prepreg on both sides of the pipeline so that the arc formed by the ends of the multiple layers of the cut prepreg wraps the pipeline;

[0015] Multiple layers of core layer prepreg are laid on the multiple layers of cut core layers until the height reaches a preset height; wherein each laid layer is compacted by a rolling process.

[0016] In a possible design, before laying the multi-layer core layer prepreg on the outer skin layer, the method further includes:

[0017] preparing a foam layer of a predetermined thickness;

[0018] Providing a pipeline in the foam layer;

[0019] Laying the foam layer on the outer skin layer;

[0020] The step of laying multiple layers of core layer prepreg on the multiple layers of cut core layers until the height reaches a preset height comprises:

[0021] Multiple layers of core layer prepreg are laid on the multiple layers of cut core layers until the height is flush with the foam layer.

[0022] In one possible design, the provision of a pipeline within the foam layer includes:

[0023] Cutting the foam layer in a direction perpendicular to the layer direction;

[0024] Processing grooves with semicircular cross-sections on two cutting surfaces;

[0025] The pipeline is placed in the two grooves and compacted tightly to obtain a foam layer with the pipeline passing through it.

[0026] In a possible design, after obtaining the foam layer with the pipelines, the method further includes:

[0027] Adhesive films are laid on the four sides of the foam layer where no pipes are passed through.

[0028] In a possible design, placing the pipeline in the two grooves and compacting them tightly to obtain a foam layer with the pipeline passing through it includes:

[0029] Laying adhesive film on the two cut surfaces including the groove;

[0030] Place the pipeline in the two grooves and compact them tightly;

[0031] Heat to firmly bond the pipe to the foam layer.

[0032] In one possible design, after the outer skin layer is laid, a vacuum bag is used for packaging and vacuuming;

[0033] After the inner skin is laid, a vacuum bag is used for packaging and vacuuming, and the autoclave is heated and solidified.

[0034] In one possible design, before stacking the cut prepreg on both sides of the pipeline, the process includes:

[0035] Lay unidirectional prepreg on the periphery of the pipeline to compensate for the joint gap between the cut prepreg and the pipeline;

[0036] Unidirectional prepreg is laid between the foam layer and the core layer prepreg to compensate for the joint gap between the two.

[0037] In a second aspect, an embodiment of the present invention further provides a composite cabin skin, which is prepared according to any of the preparation methods described above.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] The present invention pre-buries the pipelines for cables and oil supply into the composite cabin skin of the aircraft. The cable channels and oil supply channels in the cabin are arranged in advance before product assembly, eliminating the need for cable covers to fix the cable harnesses in the aircraft cabin and connectors to fix the oil pipes. This saves assembly time for the aircraft, reduces the weight of the aircraft, saves space inside the cabin, and realizes the structural and functional integration of the aircraft cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0041] Figure 1 This is a flow chart for preparing a composite cabin skin provided by an embodiment of the present invention.

[0042] Figure 2 It is a schematic cross-sectional view of a composite cabin skin according to the present invention.

[0043] Figure 3 This is a schematic diagram of foam segmentation of a foam layer of a composite material cabin skin core layer of the present invention.

[0044] In the picture:

[0045] 1-Inner skin layer; 2-Core layer prepreg; 3-Outer skin layer; 4-Adhesive film; 5-Foam layer; 6-Pipeline; 7-Tooling. DETAILED DESCRIPTION

[0046] 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, not all the embodiments. Based on the embodiments of 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.

[0047] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "plurality" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" described in the embodiments of the present invention are described from the perspectives shown in the accompanying drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" of another element, it can not only be directly connected "upper" or "lower" of the other element, but also indirectly connected "upper" or "lower" of the other element through an intermediate element.

[0049] like Figures 1 to 3 As shown, an embodiment of the present invention provides a method for preparing a composite cabin skin, comprising:

[0050] Laying the outer skin layer on the tooling;

[0051] A core layer is laid on the outer skin layer; wherein a plurality of pipelines are buried in the core layer;

[0052] Lay the inner skin layer on the core layer.

[0053] The present invention pre-buries the pipelines for cables and oil supply into the composite cabin skin of the aircraft. The cable channels and oil supply channels in the cabin are arranged in advance before product assembly, eliminating the need for cable covers to fix the cable harnesses in the aircraft cabin and connectors to fix the oil pipes. This saves assembly time for the aircraft, reduces the weight of the aircraft, saves space inside the cabin, and realizes the structural and functional integration of the aircraft cabin.

[0054] Specifically, the outer skin layer is first laid on the tooling used for laying, and then the core layer is laid on the outer skin layer. The core layer has a larger space and can be used to bury multiple pipelines for oil and electricity supply. Finally, the inner skin layer is laid on the core layer to obtain a core layer sandwich composite material.

[0055] It should be noted that core-layer sandwich composite materials not only offer high strength, flexural rigidity, and thermal insulation, but also significantly reduce the weight and cost of composite materials, making them widely used in the aerospace field. This application cleverly utilizes the internal space of the core layer to pre-embed piping, saving space and overall weight within the chamber without compromising the core's functionality.

[0056] In some embodiments of the present invention, laying the outer skin layer on the tooling includes:

[0057] Multiple layers of outer skin prepreg are laid on the tooling in sequence. Each layer is compacted by rolling, and each eight layers are compacted by vacuum pre-pressing.

[0058] In this embodiment, the outer skin prepreg is laid in multiple layers to obtain an outer skin with excellent mechanical properties. Before laying the outer skin, the molding tool needs to be cleaned and a release agent is applied to its upper surface.

[0059] In some embodiments of the present invention, laying a core layer on an outer skin layer comprises:

[0060] Cut prepregs of different lengths according to the cross-section of the pipeline to be buried;

[0061] Lay multiple layers of core prepreg on the outer skin layer, compacting each layer with a rolling process, and compacting each eighth layer with a vacuum pre-pressing process;

[0062] When the height of the multi-layer core prepreg reaches the laying height for laying the pipeline, the pipeline is laid and fixed on the core prepreg;

[0063] Lay the cut prepreg on both sides of the pipeline so that the arc formed by the ends of the multiple layers of cut prepreg wraps the pipeline;

[0064] Multiple layers of core prepreg are laid on top of the multiple layers of cut core layers until the height reaches a preset height; wherein each laid layer is compacted by a rolling process.

[0065] In this embodiment, the core layer is formed by stacking multiple layers of core prepreg. In order to bury the pipeline in the layers of core prepreg, it is necessary to cut the core prepreg according to the cross-sectional area of ​​the pipeline to obtain cut prepregs of different lengths, that is, the length is cut according to the cross-sectional position and the cross-sectional width. The specific laying process is as follows: first lay the core prepreg to the laying height of the pipeline, and each layer of core prepreg needs to be rolled and compacted; then place the pipeline, and in order to prevent the pipeline from slipping, a positioning tool can be used to keep it fixed; lay the cut prepreg on both sides of the pipeline in sequence, so that the edge of the cut prepreg fits the outer wall of the pipeline, and lay the cut prepreg layer by layer to cover the pipeline from both sides; finally, continue to lay the core prepreg until the preset height is reached.

[0066] It should be noted that each layer of prepreg, including the core layer prepreg and the cut prepreg, needs to be rolled and compacted.

[0067] It is understandable that the pipeline is a composite material pipeline or a metal material pipeline that is resistant to high temperatures and has a certain rigidity, and the pipeline needs to be roughened before bonding.

[0068] In some embodiments of the present invention, before laying the multi-layer core prepreg on the outer skin layer, the method further includes:

[0069] preparing a foam layer of a predetermined thickness;

[0070] Pipes are laid through the foam layer;

[0071] Laying a foam layer on the outer skin layer;

[0072] Lay multiple layers of core prepreg on top of the multiple layers of cut core until the height reaches the preset height, including:

[0073] Lay multiple layers of core prepreg on top of the multiple layers of cut core until the height is flush with the foam layer.

[0074] In this embodiment, the core layer can be formed not only by stacking core prepregs, but also by a foam layer. The foam layer and the multiple core prepregs are spaced apart to further reduce the overall weight of the skin. Similarly, the foam layer can also be used to embed piping. The thickness of the foam layer is the same as the overall thickness of the core layer, and the laying height of the core prepreg is also consistent with the thickness of the foam layer, that is, the core prepreg is laid until it is flush with the upper end surface of the foam layer.

[0075] In some embodiments of the present invention, providing a pipeline in the foam layer includes:

[0076] Cut the foam layer perpendicular to the layer direction;

[0077] Processing grooves with semicircular cross-sections on two cutting surfaces;

[0078] The pipeline is placed in the two grooves and compacted tightly to obtain a foam layer with the pipeline passing through it.

[0079] In this embodiment, the foam is rigid, so the foam layer needs to be cut to pass through the pipe. Figure 3 First, the foam is machine-cut according to cutting route A to obtain two cross-sections. Then, a semicircular groove is cut on the cross-section according to cutting route B. The arc of the groove cross section matches the pipe to tighten the pipe. After the groove is obtained, the groove is clamped with two grooves and pressed tightly to obtain a foam layer with pipes.

[0080] In some embodiments of the present invention, after obtaining the foam layer with the pipelines, the method further includes:

[0081] Apply adhesive film on the four sides of the foam layer where no pipes are passed through.

[0082] In this embodiment, on the four sides of the foam layer where no pipes are provided (i.e. Figure 2 The four surfaces (upper, lower, left and right) are covered with adhesive film with a thickness of 0.2 to 0.4 mm, which is convenient for adhering and fixing the foam layer and the inner and outer skins and the multi-layer core prepreg on both sides.

[0083] In some embodiments of the present invention, the pipeline is placed in the two grooves and compacted tightly to obtain a foam layer with the pipeline, including:

[0084] Laying adhesive film on the two cut surfaces including the groove;

[0085] Place the pipes in the two grooves and compact them tightly;

[0086] Heat to firmly bond the pipe to the foam layer.

[0087] In this embodiment, in order to ensure that the groove of the foam layer and the pipeline fit firmly, an adhesive film is laid on the cut surface and subjected to heat pressing to ensure that the film is firmly adhered.

[0088] In some embodiments of the present invention, after the outer skin layer is laid, a vacuum bag is used for packaging and vacuuming;

[0089] After the inner skin is laid, it is packaged in a vacuum bag and vacuumed, and then heated and cured in an autoclave.

[0090] In this embodiment, during vacuum bag packaging, a release material, an isolation material, a breathable material, and a vacuum bag are placed in sequence.

[0091] In some embodiments of the present invention, before stacking the cut prepreg on both sides of the pipeline, the process includes:

[0092] Lay unidirectional prepreg on the periphery of the pipeline to compensate for the joint gap between the cut prepreg and the pipeline;

[0093] Unidirectional prepreg is laid between the foam layer and the core layer prepreg to compensate for the joint gap between the two.

[0094] In this embodiment, during the stacking process of the core layer prepreg, the gap between the core layer prepreg and the pipe is filled and compensated with unidirectional prepreg, and the gap between the core layer prepreg and the foam is filled and compensated with unidirectional prepreg, ultimately achieving the purpose of tight fitting.

[0095] An embodiment of the present invention further provides a composite cabin skin, which is prepared according to any of the above-mentioned preparation methods.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a composite cabin skin, characterized in that: include: Laying the outer skin layer on the tooling; Laying a core layer on the outer skin layer; wherein a plurality of pipelines are buried in the core layer; An inner skin layer is laid on the core layer.

2. The preparation method according to claim 1, characterized in that: The step of laying the outer skin layer on the tooling comprises: Multiple layers of outer skin prepreg are laid on the tooling in sequence. Each layer is compacted by rolling, and each eight layers are compacted by vacuum pre-pressing.

3. The preparation method according to claim 1, characterized in that: The method of laying a core layer on the outer skin layer comprises: Cutting prepregs of different lengths according to the cross-section of the pipeline to be buried; A plurality of core layer prepregs are laid on the outer skin layer, and each laid layer is compacted by a rolling process, and each laid eight layers are compacted by a vacuum pre-pressing process. When the height of the multi-layer core prepreg reaches the laying height for laying the pipeline, laying and fixing the pipeline on the core prepreg; Laying the cut prepreg on both sides of the pipeline so that the arc formed by the ends of the multiple layers of the cut prepreg wraps the pipeline; Multiple layers of core layer prepreg are laid on the multiple layers of cut core layers until the height reaches a preset height; wherein each laid layer is compacted by a rolling process.

4. The preparation method according to claim 3, characterized in that: Before laying the multi-layer core layer prepreg on the outer skin layer, the method further comprises: preparing a foam layer of a preset thickness; Placing a pipeline in the foam layer; Laying the foam layer on the outer skin layer; The step of laying multiple layers of core layer prepreg on the multiple layers of cut core layers until the height reaches a preset height comprises: Multiple layers of core layer prepreg are laid on the multiple layers of cut core layers until the height is flush with the foam layer.

5. The preparation method according to claim 4, characterized in that: The pipeline is arranged in the foam layer, comprising: Cutting the foam layer in a direction perpendicular to the layer direction; Processing grooves with semicircular cross-sections on two cutting surfaces; The pipeline is placed in the two grooves and compacted tightly to obtain a foam layer with the pipeline passing through it.

6. The preparation method according to claim 5, characterized in that: After obtaining the foam layer with pipelines, the method further comprises: Adhesive films are laid on the four surfaces of the foam layer where no pipes are passed through.

7. The preparation method according to claim 5, characterized in that: Placing the pipeline in the two grooves and compacting them tightly to obtain a foam layer with the pipeline, comprises: Laying adhesive films on two cut surfaces including the groove; Place the pipeline in the two grooves and compact them tightly; Heating makes the pipe and the foam layer bond firmly.

8. The preparation method according to claim 1, characterized in that: After the outer skin layer is laid, vacuum bag packaging is used to perform vacuuming operation; After the inner skin is laid, a vacuum bag is used for packaging and a vacuum pump is used, and the heat is increased and cured in an autoclave.

9. The preparation method according to claim 4, characterized in that: Before stacking the cut prepreg on both sides of the pipeline, the method includes: Lay unidirectional prepreg on the periphery of the pipeline to compensate for the joint gap between the cut prepreg and the pipeline; Unidirectional prepreg is laid between the foam layer and the core layer prepreg to compensate for the joint gap between the two.

10. A composite cabin skin, characterized in that: Prepared according to any one of the preparation methods described in claims 1-5.

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