Composite landing gear hybrid connection structure

Abstract

The utility model discloses a kind of composite material landing gear hybrid connection structure, it includes: composite material landing gear body, with concentrated load area and non-concentrated load area on it, assembly slot is provided in concentrated load area, filling slot is provided in non-concentrated load area, the composite material ply thickness of concentrated load area is greater than the composite material ply thickness of non-concentrated load area and there is layer loss area between the ply of two regions to transition;And co-curing metal joint, one end is inserted in the assembly slot and is connected and fixed with composite material landing gear body by structure adhesive film, co-curing metal joint is also provided with a plurality of fuselage connecting bolts for connecting with fuselage.The composite material landing gear hybrid connection structure of the utility model not only solves the problem that the existing metal structure of aircraft landing gear faces heavy weight and poor curved surface machinability, but also solves the problem that the existing composite material landing gear structure has poor impact load and concentrated load performance.

Description

Technical Field

[0001] This utility model relates to the field of aircraft landing gear technology, specifically to a composite material landing gear hybrid connection structure. Background Technology

[0002] Currently, traditional aircraft landing gear is mostly made of metal. However, metal landing gear has disadvantages such as heavy weight and poor machinability of complex curved surfaces. The heavy weight leads to increased fuel consumption, resulting in shorter flight range and poor fuel economy. The poor machinability of curved surfaces leads to high processing costs and even makes manufacturing impossible. Existing composite material landing gear structures have poor performance under impact loads and concentrated loads, requiring the use of metal structures to withstand concentrated impact loads in these areas. Utility Model Content

[0003] The purpose of this invention is to design a composite material landing gear hybrid connection structure to address the problems of existing metal structure aircraft landing gear. This structure solves the problems of large weight and poor surface machinability of existing metal structure aircraft landing gear, as well as the problems of poor performance under impact loads and concentrated loads of existing composite material landing gear structures.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution: This utility model designs a composite material landing gear hybrid connection structure, which includes the following configuration: The composite landing gear body has a concentrated load area and a non-concentrated load area. The concentrated load area is provided with an assembly groove, and the non-concentrated load area is provided with a filling groove. The composite material ply thickness in the concentrated load area is greater than that in the non-concentrated load area, and there is a layer loss area between the composite material ply for transition between the two areas. The system also includes a co-cured metal connector, one end of which is inserted into the assembly slot and connected and fixed to the composite landing gear body via a structural adhesive film (co-curing). The co-cured metal connector is further provided with several fuselage connecting bolts for connection to the fuselage. Specifically, the structural adhesive film is disposed between the co-cured metal connector and the inner wall of the assembly slot.

[0005] Furthermore, a composite material landing gear hybrid connection structure is provided in which the assembly groove and the filling groove are connected.

[0006] Furthermore, a composite material landing gear hybrid connection structure: the filling groove is filled with PMI foam and connected and fixed to the composite material landing gear body through a structural adhesive film (co-curing). Specifically, the structural adhesive film is disposed between the PMI foam and the inner wall of the filling groove.

[0007] Furthermore, a composite material landing gear hybrid connection structure is provided: the composite material landing gear body is provided with bolt holes penetrating both sides in the thickness direction, and the bolt holes are located in the concentrated load area.

[0008] Furthermore, a composite landing gear hybrid connection structure is provided: the connection structure further includes a reinforcing bolt and a nut, the reinforcing bolt being connected in the bolt hole and penetrating the co-cured metal joint and the structural adhesive film, and the nut being connected to the reinforcing bolt to reinforce and fix the connection between the composite landing gear body and the co-cured metal joint.

[0009] Furthermore, a composite material landing gear hybrid connection structure is provided: the connection structure further includes a gasket, which is sleeved on the reinforcing bolt to prevent damage to the composite material landing gear body after the reinforcing bolt and nut are tightened.

[0010] Specifically, the composite landing gear hybrid connection structure designed in this utility model mainly includes several parts such as a composite landing gear body, a co-cured metal joint, PMI foam, structural adhesive film, reinforcing bolts, washers, nuts, and fuselage connecting bolts. The composite landing gear body consists of a concentrated load area and a non-concentrated load area. To ensure the strength of the connection area (concentrated load area), the composite landing gear body employs a locally reinforced ply (i.e., a thicker composite ply in this area) in the region connecting to the metal joint, increasing the strength of the concentrated load area. In the non-concentrated load area, a ply of normal thickness is used. A transition area is used between the normal thickness ply and the reinforced ply. Since the non-concentrated load area does not bear a large load, a filling groove is provided and filled with PMI foam, which reduces the amount of composite material used and saves costs. Meanwhile, the composite landing gear body, PMI foam, and co-cured metal joints are co-cured using an adhesive film method. After co-curing, reinforcing bolts, nuts, and washers are used to connect and strengthen the composite landing gear body, co-cured metal joints, and structural adhesive film, further avoiding the risk of structural failure and improving the connection strength between the composite landing gear body and the co-cured metal joints. In other words, by securely connecting the metal joints in the concentrated load areas of the composite landing gear body, the metal joints of this metal structure can withstand concentrated impact loads.

[0011] The beneficial effects of this utility model are: This utility model designs a composite material landing gear hybrid connection structure, in which the composite material landing gear body is made of composite material through curing and molding. This allows for the molding of large-sized complex curved surface parts, which avoids the defects of metal landing gear structures such as poor machinability, high processing costs, or even inability to process complex curved surfaces. It also avoids the problems of poor aircraft fuel economy and short flight range caused by the heavy weight of metal landing gear structures.

[0012] This invention relates to a composite material landing gear hybrid connection structure. The composite material landing gear body is co-cured with a structural adhesive film and a co-cured metal joint. The metal joint of the metal structure bears the impact load and concentrated load of the landing gear. After the composite material landing gear body and the metal joint are co-cured, secondary reinforcement is achieved using reinforcing bolts, washers, and nuts via mechanical connection, improving the reliability of the connection. Furthermore, this invention uses a unidirectional connection method between the composite material landing gear and the fuselage using fuselage connecting bolts, improving the efficiency and convenience of installation, disassembly, and maintenance, and enhancing the maintainability of the landing gear. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic diagram of the composite material landing gear body in the composite material landing gear hybrid connection structure designed for Embodiment 1 of this utility model; Figure 2 A schematic diagram of the composite material landing gear hybrid connection structure designed for Embodiment 1 of this utility model.

[0015] The markings in the image are as follows: 1-Composite landing gear body, 2-Co-cured metal joint, 3-Structural adhesive film, 4-Reinforcing bolt, 5-Nut, 6-Washer, 7-Fuselage connecting bolt, 8-PMI foam, 11-Concentrated load area, 12-Non-concentrated load area, 13-Assembly slot, 14-Filling slot, 15-Layer loss area, 16-Bolt hole. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0017] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," "right," "top," and "bottom," etc., indicating orientation or positional relationships, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein.

[0018] Example 1

[0019] like Figures 1-2 As shown, this embodiment 1 designs a composite material landing gear hybrid connection structure, which includes the following configuration: The composite landing gear body 1 has a concentrated load area 11 and a non-concentrated load area 12. The concentrated load area 11 is provided with an assembly groove 13, and the non-concentrated load area (12) is provided with a filling groove 14. The assembly groove 13 and the filling groove 14 are connected. The filling groove 14 is filled with PMI foam 8 and co-cured with the composite landing gear body 1 through a structural adhesive film 3 (connected and fixed). The composite material ply thickness of the concentrated load area 11 is greater than that of the non-concentrated load area 12, and there is a layer loss area 15 between the two areas for transition. The composite landing gear body 1 is also provided with bolt holes 16 penetrating both sides in the thickness direction, and the bolt holes 16 are located in the concentrated load area 11, that is, the bolt holes 16 penetrate the area with a larger ply thickness. The co-cured metal connector 2 has one end inserted into the assembly groove 13 and co-cured with the composite material landing gear body 1 through the structural adhesive film 3 (connected and fixed). The co-cured metal connector 2 is also provided with a number of fuselage connecting bolts 7 for connecting with the fuselage. It also includes a reinforcing bolt 4, a nut 5, and a washer 6. The reinforcing bolt 4 is connected to the bolt hole 16 and passes through the co-cured metal joint 2 and the structural adhesive film 3. The nut 5 is connected to the reinforcing bolt 4 to fix the connection between the composite landing gear body 1 and the co-cured metal joint 2. The washer 6 is sleeved on the reinforcing bolt 4 to prevent the reinforcing bolt 4 and nut 5 from damaging the composite landing gear body 1 after the composite landing gear body 1, the co-cured metal joint 2, and the structural adhesive film 3 are tightened.

[0020] Specifically, in Embodiment 1, the metal joint 2 primarily bears the impact load and concentrated load of the landing gear. Therefore, to ensure the strength of the connection area between the composite landing gear body 1 and the metal joint 2, a locally reinforced ply design is adopted for this connection area to form a region that can withstand concentrated loads. A thicker composite ply is used in the concentrated load area 11, while a normal thickness ply design is used in the non-concentrated load area 12. A layer-dropping area serves as a transition between the normal thickness ply and the reinforced ply. Thanks to the ply design of the concentrated load area 11 and the non-concentrated load area 12 in the composite landing gear body 1, the strength requirements of the connection area between the composite landing gear body 1 and the metal joint 2 are met, effectively coping with the impact load and concentrated load of the landing gear, while also achieving the goal of low-cost manufacturing of the non-concentrated load area 12.

[0021] Therefore, the composite material landing gear hybrid connection structure of this utility model has many advantages, such as light weight, low cost, good performance under impact load and concentrated load, and superior machinability of complex curved surfaces compared to metal structures.

[0022] The above-described preferred embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of this utility model. Any obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A composite material landing gear hybrid connection structure, characterized in that, The connection structure includes the following settings: The composite landing gear body (1) has a concentrated load area (11) and a non-concentrated load area (12). The concentrated load area (11) is provided with an assembly groove (13), and the non-concentrated load area (12) is provided with a filling groove (14). The composite material ply thickness of the concentrated load area (11) is greater than that of the composite material ply thickness of the non-concentrated load area (12), and there is a ply loss area (15) between the two areas for transition. And a co-cured metal connector (2), one end of which is inserted into the assembly slot (13) and connected and fixed to the composite landing gear body (1) through the structural adhesive film (3). The co-cured metal connector (2) is also provided with several fuselage connecting bolts (7) for connecting to the fuselage.

2. The composite material landing gear hybrid connection structure according to claim 1, characterized in that, The assembly slot (13) is connected to the filling slot (14).

3. A composite material landing gear hybrid connection structure according to claim 1 or 2, characterized in that, The filling groove (14) is filled with PMI foam (8) and is connected and fixed to the composite material landing gear body (1) through the structural adhesive film (3).

4. The composite material landing gear hybrid connection structure according to claim 1, characterized in that, The composite landing gear body (1) is also provided with bolt holes (16) that penetrate both sides in the thickness direction, and the bolt holes (16) are located in the concentrated load area (11).

5. The composite material landing gear hybrid connection structure according to claim 4, characterized in that, The connection structure also includes a reinforcing bolt (4) and a nut (5), wherein the reinforcing bolt (4) is connected in the bolt hole (16) and passes through the co-cured metal joint (2) and the structural adhesive film (3), and the nut (5) is connected to the reinforcing bolt (4) for fixing the connection between the composite landing gear body (1) and the co-cured metal joint (2).

6. The composite material landing gear hybrid connection structure according to claim 5, characterized in that, The connection structure also includes a gasket (6), which is fitted onto the reinforcing bolt (4).

Images