Forming tool and method for composite hybrid fiber honeycomb sandwich structure

Abstract

The invention relates to the technical field of aviation composite material structural part manufacturing, in particular to a forming tool and method for a composite material hybrid fiber honeycomb sandwich structure, and the method comprises the steps that an inner panel is placed on the upper end face of a glue joint tool, and a glue film is laid on the outer molded surface of the inner panel; the honeycomb core material block is placed on the outer molded surface of the inner panel through the honeycomb positioning columns, the outer panel is placed on the outer molded surface of the honeycomb core material block, the honeycomb core material block and the outer panel are integrally packaged and then placed into an autoclave to be pre-bonded, and the pre-bonding temperature T is larger than or equal to T0-15 DEG C and smaller than or equal to T0-25 DEG C; after pre-bonding is completed, the outer panel is taken down and placed on an outer panel forming tool, an adhesive film is laid on the inner molded surface of the outer panel, then the pre-bonded honeycomb core material block and the inner panel are inversely buckled on the inner molded surface of the outer panel, and after overall packaging, the honeycomb core material block and the inner panel are placed into an autoclave to be subjected to overall bonding. The forming tool and method for the composite hybrid fiber honeycomb sandwich structure aim at solving the problems that the composite hybrid fiber honeycomb sandwich structure is poor in forming quality and low in efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing aviation composite material structural parts, and in particular to a molding tool and method for a composite material hybrid fiber honeycomb sandwich structure. Background Art

[0002] Composite materials have become one of the most important aerospace structural materials today due to their high specific strength, high specific stiffness, strong designability, excellent fatigue fracture resistance, corrosion resistance, excellent dimensional stability, and ease of large-scale integral molding. In the aircraft and military aircraft industries, the amount of composite materials used has become a measure of aircraft advancement. Honeycomb sandwich composites are currently known to be the most material-efficient structural materials, offering the highest strength-to-weight ratio. Compared to solid materials, honeycomb sandwich composites use only 1% to 5% of the active material they replace.

[0003] With the development of composite sandwich structure design and manufacturing technology, the demand for integrated structural and functional design represented by smart skins is becoming increasingly apparent. The materials of the outer panels of sandwich structures are becoming more and more diversified. For example, the outer panels of sandwich structures use carbon fiber panels on one side and glass fiber panels on the other side. During the bonding process of the sandwich structure, the huge difference in thermal expansion coefficients of the two panels leads to large deformation and internal stress in the entire sandwich structure. Sometimes, this internal stress can even cause debonding between the core material of the sandwich structure and the outer panels.

[0004] Therefore, the inventors provide a molding tool and method for a composite material hybrid fiber honeycomb sandwich structure. Summary of the Invention

[0005] (1) Technical problems to be solved The embodiment of the present invention provides a molding tool and method for a composite material hybrid fiber honeycomb sandwich structure, which solves the technical problems of low molding efficiency and poor quality of the composite material hybrid fiber honeycomb sandwich structure.

[0006] (2) Technical solution A first aspect of the present invention provides a method for forming a composite hybrid fiber honeycomb sandwich structure, comprising the following steps: Laying and curing the outer panel on the outer panel forming tool; Laying and curing the inner panel on the inner panel forming tool; The inner panel after the surface polishing is placed on the upper end surface of the bonding tool, the adhesive film is spread on the inner surface of the inner panel, and then a plurality of honeycomb positioning columns are sequentially installed on the inner panel and the bonding tool; The plurality of honeycomb core blocks are placed on the inner profile of the inner panel by the honeycomb positioning column, the outer panel is placed on the upper surface of the honeycomb core block, and after overall packaging, the honeycomb core block and the inner panel are pre-bonded in the hot press tank, and the pre-bonding temperature T is T0-15℃≤T≤T0-25℃. After the pre-bonding is completed, the outer panel is removed and placed on the outer panel forming tool, the adhesive film is laid on the inner profile of the outer panel, and then the pre-bonded honeycomb core block and the inner panel are inverted on the inner profile of the outer panel, and after overall packaging, the overall bonding is carried out in the hot press tank, and the bonding temperature is T0. After the overall bonding is completed, the composite hybrid fiber honeycomb sandwich structure is taken off from the outer panel forming tool, and the packaging material is removed. T0 is the theoretical curing temperature of the adhesive film.

[0007] Further, the pre-bonding temperature T is T0-20℃.

[0008] Further, the outer panel after curing and forming is processed for the first positioning hole for positioning connection with the outer skin.

[0009] Further, the inner panel after curing and forming is processed for the second positioning hole for positioning connection with the inner skin.

[0010] The second aspect of the application provides a forming tool for a composite hybrid fiber honeycomb sandwich structure, comprising an outer panel forming tool, an inner panel forming tool and a bonding tool, the outer panel and the inner panel of the composite hybrid fiber honeycomb sandwich structure have different thermal expansion coefficients, the working profile of the outer panel forming tool is matched with the first outer profile of the outer panel, the working profile of the inner panel forming tool is matched with the second inner profile of the inner panel, and the working surface of the bonding tool is matched with the second outer profile of the inner panel.

[0011] Further, the excess area of the outer panel forming tool is provided with an outer panel positioning hole drilling template.

[0012] Further, the excess area of the inner panel forming tool is provided with an inner panel positioning hole drilling template.

[0013] Further, the excess area of the bonding assembly tool is provided with a positioning hole limiting device for positioning the inner panel.

[0014] Further, the outer layer of the honeycomb positioning column is wrapped with foaming glue.

[0015] Further, the adjacent honeycomb core blocks are bonded by foaming glue.

[0016] Further, the diameter of the honeycomb positioning column is 5-10mm.

[0017] (3) Beneficial effects In conclusion, the honeycomb positioning column is used to position the honeycomb core material and the inner panel in the gluing tool in the pre-gluing process, which is accurate and reliable, and the temperature is low and the overall deformation is small; meanwhile, the honeycomb core material and the inner panel after pre-gluing are integrally glued with the outer panel in the outer panel forming tool, so that the aerodynamic shape precision of the honeycomb sandwich structure can be effectively guaranteed, and the stealth performance and assembly precision of the part are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0019] Figure 1 is a flowchart of a forming method of a composite material hybrid fiber honeycomb sandwich structure provided by the embodiments of the present application; Figure 2 is a forming structure schematic diagram of an inner panel of a composite material hybrid fiber honeycomb sandwich structure provided by the embodiments of the present application; Figure 3 is a pre-gluing structure schematic diagram of an inner panel and a honeycomb core material of a composite material hybrid fiber honeycomb sandwich structure provided by the embodiments of the present application; Figure 4 is a structure schematic diagram of an outer panel, a honeycomb core material and an inner panel of a composite material hybrid fiber honeycomb sandwich structure provided by the embodiments of the present application; Figure 5 is a structure schematic diagram of a composite material hybrid fiber honeycomb sandwich structure provided by the embodiments of the present application.

[0020] In the drawings: 1-outer panel forming tool; 2-inner panel forming tool; 3-gluing tool; 301-positioning column through hole; 4-honeycomb positioning column; 100-outer panel; 101-first outer surface; 102-first inner surface; 200-inner panel; 201-second outer surface; 202-second inner surface; 300-honeycomb core material; 301-positioning column through hole. DETAILED DESCRIPTION

[0021] The embodiments of the present application will be further described in details below with reference to the accompanying drawings and embodiments. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments, covering any modification, replacement and improvement of the parts, components and connection manners without departing from the spirit of the present application.

[0022] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in details below with reference to the accompanying drawings and embodiments.

[0023] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0024] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement" and "installation" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] The embodiment of the present application provides a forming method of a composite material hybrid fiber honeycomb sandwich structure, referring to Figure 1 The method can include the following steps: S100, laminating and curing an outer panel on an outer panel forming tool.

[0026] Specifically, the outer panel after curing and forming is processed with a first positioning hole for positioning and connecting with an outer skin, and the outer panel forming tool is machined by numerical control using INVAR alloy or Q235 steel, with a profile accuracy of ±0.1mm.

[0027] S200, laminating and curing an inner panel on an inner panel forming tool.

[0028] Specifically, the inner panel after curing and forming is processed with a second positioning hole for positioning and connecting with an inner skin, and the inner panel forming tool is machined by numerical control using INVAR alloy or Q235 steel, with a profile accuracy of ±0.1mm.

[0029] S300, the inner panel after the profile polishing treatment is placed on the upper end face of the bonding tool, the adhesive film is laid on the inner profile of the inner panel, and then the plurality of honeycomb positioning columns are sequentially arranged in the inner panel and the bonding tool.

[0030] Specifically, the second positioning hole for positioning and connecting with the inner skin is processed on the inner panel after curing and molding, the bonding tool is processed by numerical control using INVAR alloy or Q235 steel, and the profile precision is ±0.1mm.

[0031] S400, the plurality of honeycomb core material blocks are placed on the inner profile of the inner panel through the honeycomb positioning columns, and the outer panel is placed on the upper surface of the honeycomb core material blocks, and after overall packaging, the honeycomb core material blocks and the inner panel are pre-bonded in a hot pressing tank, and the pre-bonding temperature T is T0-15℃≤T≤T0-25℃.

[0032] Specifically, the pre-bonding temperature T is T0-20℃.

[0033] S500, after the pre-bonding is completed, the outer panel is removed and placed on the outer panel forming tool, the adhesive film is laid on the inner profile of the outer panel, and then the pre-bonded honeycomb core material blocks and the inner panel are inverted on the inner profile of the outer panel, and after overall packaging, the overall bonding is carried out in a hot pressing tank, and the bonding temperature is T0.

[0034] S600, after the overall bonding is completed, the composite hybrid fiber honeycomb sandwich structure is taken off from the outer panel forming tool, and the packaging material is removed; wherein, T0 is the theoretical curing temperature of the adhesive film.

[0035] In summary, the pre-bonding process of the honeycomb core material and the inner panel in the application is carried out on the bonding tool, the positioning is carried out by using the honeycomb positioning column, the positioning is accurate and reliable, the pre-bonding process temperature is low, the overall deformation is small, and finally the pre-bonded honeycomb core material and the inner panel are bonded with the outer panel on the outer panel forming tool, which can effectively guarantee the aerodynamic shape precision of the honeycomb sandwich structure, thereby improving the stealth performance and assembly precision of the part. In addition, more importantly, the forming method is simple in operation and high in efficiency, and can effectively improve the internal quality of the hybrid fiber honeycomb sandwich structure and reduce the overall deformation of the hybrid fiber honeycomb sandwich structure.

[0036] The embodiment of the application also provides a forming tool for a composite hybrid fiber honeycomb sandwich structure, which is used for the forming tool for the composite hybrid fiber honeycomb sandwich structure. Figures 2 to 4The tooling can include an outer panel forming tool 1, an inner panel forming tool 2, and a bonding tool 3, the outer panel 100 and the inner panel 200 of the composite hybrid fiber honeycomb sandwich structure have different thermal expansion coefficients, the working profile of the outer panel forming tool 1 is matched with the first outer profile 101 of the outer panel 100, the working profile of the inner panel forming tool 2 is matched with the second inner profile 202 of the inner panel 200, and the working surface of the bonding tool 3 is matched with the second outer profile 201 of the inner panel 200, and the bonding tool 3 is used for bonding the inner panel 200 and the honeycomb core material 300.

[0037] Specifically, the excess area of the outer panel forming tool 1 is provided with an outer panel positioning hole drilling template, and the excess area of the inner panel forming tool 2 is provided with an inner panel positioning hole drilling template, which are respectively used for positioning the first positioning hole and the second positioning hole. The excess area of the bonding assembly tool 3 is provided with a positioning hole limiting device for positioning the inner panel 200, and the bonding assembly tool 3 is further provided with a positioning column through hole 301 for positioning the honeycomb positioning column 4. The outer layer of the honeycomb positioning column 4 is wrapped with foaming glue, and the adjacent honeycomb core material blocks are bonded by foaming glue. Further, the diameter of the honeycomb positioning column 4 is 5-10mm.

[0038] It should be clear that each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment focuses on the difference from other embodiments. The present application is not limited to the specific steps and structures described above and shown in the drawings. Moreover, for the sake of brevity, detailed description of known methods and techniques is omitted.

[0039] The above is only an embodiment of the present application, and is not limited to the present application. The present application can have various modifications and changes for those skilled in the art without departing from the scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for forming a composite material hybrid fiber honeycomb sandwich structure, characterized in that: The method comprises the following steps: Laying and curing the outer panel on the outer panel forming tool; Laying and curing the inner panel on the inner panel forming tool; The inner panel after the surface polishing is placed on the upper end surface of the bonding tool, the adhesive film is spread on the inner surface of the inner panel, and then a plurality of honeycomb positioning columns are sequentially installed on the inner panel and the bonding tool; Multiple honeycomb core material blocks are placed on the inner surface of the inner panel by the honeycomb positioning column, and the outer panel is placed on the upper surface of the honeycomb core material block. After the whole is packaged, it is placed in an autoclave to pre-bond the honeycomb core material block and the inner panel. The pre-bonding temperature T is T0-15°C≤T≤T0-25°C; After the pre-bonding is completed, the outer panel is removed and placed on the outer panel forming tooling, and the inner surface of the outer panel is covered with adhesive film. Then, the pre-bonded honeycomb core material block and the inner panel are inverted on the inner surface of the outer panel. After the whole is packaged, it is placed in the autoclave for overall bonding, and the bonding temperature is T0; After the overall bonding is completed, the composite material hybrid fiber honeycomb sandwich structure is removed from the outer panel forming tool and the packaging material is removed; wherein, T0 is the theoretical curing temperature of the film.

2. The method for forming a composite hybrid fiber honeycomb sandwich structure according to claim 1, characterized in that: The pre-bonding temperature T is T0-20°C.

3. The method for forming a composite hybrid fiber honeycomb sandwich structure according to claim 1, characterized in that: The outer panel after solidification is processed with a first positioning hole for positioning and connecting with the outer skin.

4. The method for forming a composite hybrid fiber honeycomb sandwich structure according to claim 1, characterized in that: After solidification and molding, the inner panel is processed with a second positioning hole for positioning and connecting with the inner skin.

5. A molding tool used in the molding method of the composite material hybrid fiber honeycomb sandwich structure according to claim 1, characterized in that: The invention comprises an outer panel forming tool (1), an inner panel forming tool (2) and a bonding tool (3); the outer panel (100) and the inner panel (200) of the composite material mixed fiber honeycomb sandwich structure have different thermal expansion coefficients; the working surface of the outer panel forming tool (1) is adapted to the first outer surface (101) of the outer panel (100); the working surface of the inner panel forming tool (2) is adapted to the second inner surface (202) of the inner panel (200); the working surface of the bonding tool (3) is adapted to the second outer surface (201) of the inner panel (200); and the bonding tool (3) is used for bonding the inner panel (200) to the honeycomb core material (300).

6. The forming tool for the composite material hybrid fiber honeycomb sandwich structure according to claim 5, characterized in that: The margin area of ​​the outer panel forming tool (1) is provided with an outer panel positioning hole drilling template.

7. The forming tool for the composite material hybrid fiber honeycomb sandwich structure according to claim 5, characterized in that: The margin area of ​​the inner panel forming tool (2) is provided with an inner panel positioning hole drilling template.

8. The forming tool for the composite material hybrid fiber honeycomb sandwich structure according to claim 5, characterized in that: The margin area of ​​the adhesive assembly tool (3) is provided with a positioning hole limiting device for positioning the inner panel (200).

9. The molding tool for composite hybrid fiber honeycomb sandwich structure according to claim 5, characterized in that: The outer layer of the honeycomb positioning column (4) is wrapped with foam glue.

10. The forming tool for composite hybrid fiber honeycomb sandwich structure according to claim 5, characterized in that: Adjacent honeycomb core material blocks are bonded together by using foam adhesive.

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