A large variable cross-section cylindrical honeycomb sandwich structure

Abstract

The application belongs to the technical field of helicopter structure, and discloses a large variable cross-section cylindrical honeycomb sandwich structure, which comprises four wallboards, i.e., a left wallboard, a platform wallboard, a right wallboard and a bottom wallboard, and forms a transition section overall structure of a helicopter tail beam and a fuselage after being connected, wherein the four wallboards are all plate-shaped structures with a main body of honeycomb, and are connected with each other through connecting band plates. The variable cross-section cylindrical structure meets the connection requirement of the transition area between the helicopter fuselage and the inclined beam, has light weight, high bearing capacity, can effectively weaken the vibration transmission of the tail rotor to the fuselage, realizes the structure configuration function and light weight, simplifies the processing and manufacturing difficulty, decomposes and miniaturizes the large structure, effectively improves the processing efficiency and prompts the economic benefits. The structure has good designability, and can change the structure form according to different connection structure forms.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of helicopter structure, and relates to a transition section structure design for a transition section between a tail boom and a fuselage of a helicopter, in particular to a large variable cross-section cylindrical honeycomb sandwich structure. BACKGROUND

[0002] Compared with traditional metal structures, composite materials have higher strength, rigidity, fatigue resistance and corrosion resistance, and have good shock absorption performance, flexible design, and part integration manufacturing and many other advantages. In the field of aerospace and other fields, composite material structures are widely used, and composite material structures are increasingly used to replace traditional metal structures in other fields. The large honeycomb sandwich structure is particularly suitable for structures with large stress and non-strict weight requirements.

[0003] The transition structure of the tail boom of the helicopter connecting the tail rotor and the fuselage has the characteristics of large load, high vibration level and large structure size. The traditional transition section adopts a metal frame plus skin structure or a stringer plus skin structure. The structure has a large weight, and the vibration effect of the tail rotor cannot be effectively reduced due to the large rigidity. SUMMARY

[0004] The purpose of the application is to solve the above problems. The application provides a large variable cross-section cylindrical honeycomb sandwich structure as a new transition structure scheme for the tail boom and the fuselage of the helicopter. The application meets the requirement of connection strength, has a light weight, and can effectively reduce the vibration transmission of the tail rotor.

[0005] The technical scheme of the application is as follows:

[0006] The large variable cross-section cylindrical honeycomb sandwich structure comprises four wall plates, i.e., a left wall plate, a platform wall plate, a right wall plate and a bottom wall plate. The four wall plates form a transition section overall structure between the tail boom and the fuselage of the helicopter after being connected. The four wall plates are all plate-shaped structures with a main body of honeycomb, and the four wall plates are connected to each other through connecting band plates.

[0007] Further, the four edges of the honeycomb of the four wall plates are provided with a layer of non-honeycomb laminated structure.

[0008] Further, the bottom wall plate is a trapezoidal structure. The two sides of the bottom wall plate are connected to the left wall plate and the right wall plate through two connecting band plates with an L-shaped cross section. The left wall plate and the right wall plate are curved plates. The top of the left wall plate and the right wall plate is respectively connected to two top connecting band plates. The platform wall plate is a trapezoidal structure with a larger bottom angle than the bottom wall plate. The platform wall plate is connected to the top of the left wall plate and the right wall plate through two top connecting band plates. The four wall plates form a variable cross-section cylindrical structure with a large cross section to a small cross section after being connected.

[0009] Further, at least one reinforcing frame is arranged at the same direction of the four wall plates.

[0010] Further, the reinforcing frame can be a laminated strip arranged at the same direction of the left wall plate, the platform wall plate, the right wall plate and the bottom wall plate, and four laminated strips arranged at the same section form a reinforcing frame.

[0011] Further, the reinforcing frame can be a reinforcing frame arranged inside the four wall plates, and the outer shape of the reinforcing frame is matched with the inner shape of the section of the four wall plates in the direction, and the reinforcing frame is fixed and supported on the section.

[0012] Further, the large section area is connected with the fuselage through the butt joint frame, and the small section area is connected with the diagonal beam, and a distance without the honeycomb area is reserved in the small section area.

[0013] Further, the transition area of the honeycomb and the laminated plate of the four wall plates is a bevel angle honeycomb, so that the thick honeycomb is smoothly connected with the thin laminated plate.

[0014] The beneficial effects of the present application are as follows:

[0015] 1. The variable section cylindrical structure meets the connection requirements of the transition area between the fuselage and the diagonal beam of the helicopter, has light weight, high bearing capacity, and can effectively reduce the vibration transmission of the tail rotor to the fuselage.

[0016] 2. On the basis of realizing the structure configuration function and light weight, the present application also simplifies the processing and manufacturing difficulty, decomposes the large structure into small size, effectively improves the processing efficiency and prompts the economic benefit.

[0017] 3. The structure of the present application has good designability, can change its structure form according to different connection structure forms, has good adaptability, and can be widely applied to large variable section structures in the aviation and aerospace industries. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a large variable section cylindrical honeycomb sandwich structure diagram of the present application;

[0019] Figure 2 is a front view of a large variable section cylindrical honeycomb sandwich structure of the present application

[0020] Figure 3 is a side wall plate structure diagram of the present application;

[0021] Figure 4 is a bottom wall plate structure diagram of the present application;

[0022] Figure 5 is a platform wall plate structure diagram of the present application;

[0023] Figure 6 A schematic view of a connecting band plate structure of the present application;

[0024] Figure 7 A schematic view of a honeycomb boundary region structure form of the present application;

[0025] Wherein, 1-left wall plate, 2-upper platform wall plate, 3-right wall plate, 4-bottom wall plate, 5-connecting band plate, 6-support frame, 51-right upper connecting band plate, 52-left upper connecting band plate, 53-left lower connecting band plate, 54-right lower connecting band plate, 1a-side wall plate honeycomb 1, 1b-side wall plate honeycomb 2, 2a-upper platform wall plate honeycomb, 4a-bottom wall plate, 7a-composite material lamination area, 8a-honeycomb. DETAILED DESCRIPTION

[0026] This part is an embodiment of the present application, which is used to explain and illustrate the technical solutions of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0027] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship as given in the drawings, which are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or the case referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include more features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0028] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be interpreted broadly, for example, it can be fixed connection, or detachable connection or integrated connection; it can be mechanical connection, or point connection; it can be direct connection, or indirect connection through intermediate medium, or the communication between the two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0029] A large variable cross-section cylindrical honeycomb sandwich structure comprises four wall plates: a left wall plate 1, a platform wall plate 2, a right wall plate 3 and a bottom wall plate 4, which are connected to form a general structure of a transition section of a helicopter tail beam and fuselage, wherein the four wall plates are all plate-shaped structures with honeycombs, and the four wall plates are connected by connecting band plates 5.

[0030] The four edges of the honeycombs of the four wall plates are all left with a non-honeycomb laminated structure, which is a reinforced plate or a metal plate.

[0031] The bottom wall plate 4 is a trapezoidal structure, and the two sides of the bottom wall plate 4 are connected to the left wall plate 1 and the right wall plate 3 by two connecting band plates 5 with an L-shaped cross section, and the left wall plate 1 and the right wall plate 3 are curved plates, and the top of the left wall plate 1 and the right wall plate 3 is respectively connected to two top connecting band plates 5, and the platform wall plate 2 is a trapezoidal structure with a larger bottom angle than the bottom wall plate 4, and the platform wall plate 2 is connected to the top of the left wall plate 1 and the right wall plate 3 by two top connecting band plates 5; the four wall plates are connected to form a large cross-section to small cross-section variable cross-section cylindrical structure.

[0032] At least one reinforcing frame is provided, which is a frame-shaped structure arranged at the same heading position of the four wall plates.

[0033] The reinforcing frame can be: laminated strips arranged at the same heading position of the left wall plate 1, the platform wall plate 2, the right wall plate 3 and the bottom wall plate 4 in the cross-sectional direction, and the four laminated strips arranged at the same cross section form a reinforcing frame.

[0034] The reinforcing frame can also be: a reinforcing frame 6 arranged inside the four wall plates, the outer shape surface of the reinforcing frame 6 matches the inner shape surface of a certain cross section of the four wall plates in the heading direction, and the reinforcing frame 6 is fixedly supported on the cross section.

[0035] The large cross-section area is the area connected to the fuselage by a butt joint frame, and the small cross-section area is the area connected to the diagonal beam, and a distance without honeycomb is reserved in the small cross-section area.

[0036] The transition area of the honeycomb and the laminated plate of the four wall plates is a bevelled corner honeycomb, which smoothly transitions between the thicker honeycomb and the thinner laminated plate.

[0037] Another embodiment of the present application will be described below with reference to the accompanying drawings.

[0038] The application provides a large variable cross-section cylindrical honeycomb sandwich structure, which comprises left and right wall plates, an upper platform wall plate, a bottom wall plate, a support frame and connecting band plates. The left and right wall plates, the upper platform wall plate and the bottom wall plate are composed of the honeycomb sandwich structure and are variable cross-section, the left and right wall plates, the upper platform wall plate and the bottom wall plate form a variable cross-section cylindrical structure, every two of the wall plates are connected by the band plates through riveting or bolt connection, the support frame is arranged in the cylindrical structure and is riveted and fixed with the reserved laminated area of the left and right wall plates, the upper platform wall plate and the bottom wall plate to strengthen the strength and rigidity of the cylindrical structure. The left and right wall plates are the honeycomb sandwich curved surface structure, which can provide greater load capacity and has a good aerodynamic shape; the upper platform wall plate and the bottom wall plate are horizontal structures, which can provide better equipment installation conditions. The honeycomb sandwich structure of the left and right wall plates, the upper platform wall plate and the bottom wall plate leaves sufficient laminated structure without honeycomb on four sides to reserve the riveting or bolt connection area to avoid the mechanical connection structure from damaging the fragile honeycomb area structure.

[0039] The key point of the application is that the large variable cross-section cylindrical honeycomb sandwich structure is composed of four independent large honeycomb sandwich structures to form a variable cross-section cylindrical large bearing structure, which simplifies the complex variable cross-section structure and effectively solves the connection problem between the large cross-section area of the helicopter fuselage and the small opening cross-section of the diagonal beam. The structure form has strong adaptability, the honeycomb sandwich structure can be designed to adapt to the transition connection of various special-shaped areas, the internal space of the cylindrical structure is large, the support frame can be arranged flexibly according to the load condition to strengthen the overall structural strength and rigidity, and a large number of functional equipment can also be arranged.

[0040] As shown in Figure 1 , Figure 2 , the main structure of the application is composed of the left wall plate 1, the upper platform wall plate 2, the right wall plate 3, the bottom wall plate 4, the four connecting band plates 5 and the support frame 6. The left wall plate 1 is connected with the upper platform wall plate 2 through the left upper band plate 53 and is connected with the bottom wall plate 4 through the left lower connecting band plate 53. Similarly, the right wall plate 3 is connected with the upper platform wall plate 2 through the right upper connecting band plate 51 and is connected with the bottom wall plate 4 through the right lower connecting band plate 54. In this way, the wall plates composed of four honeycomb sandwich structures are connected into a cylindrical structure, and the strength and rigidity thereof are strengthened by the support frame 6. Here, the strengthening is not limited to one reinforcing frame. More support frames can also be arranged according to the load size.

[0041] As shown in Figure 1 , the large cross-section area is connected with the fuselage through the butt joint frame, the small cross-section area is connected with the diagonal beam, and one end of the small cross-section area is reserved without the honeycomb area to facilitate the mechanical connection with the butt joint.

[0042] The left wall plate 1 and the right wall plate 3 are similar and symmetrical variable cross-section curved honeycomb sandwich structures, and in the application, the left and right wall plates are collectively referred to as side wall plates, and the side wall plate structure is as shown in Figure 3 The side wall plate honeycomb sandwich structure is curved in shape, so that the stress is more uniform when the cylindrical integrated structure is formed, and the side wall plate has two honeycomb areas, i.e., a honeycomb 1a and a honeycomb 1b, as shown in Figure 3 The honeycomb area can only be used to improve the stiffness and cannot bear excessive load, and if more support frames are arranged, the side wall plate also needs to disconnect the honeycomb connecting area of the support frame, and the peripheral area needs to be mechanically connected to other structures, so the honeycomb area cannot be arranged.

[0043] The bottom wall plate 4 and the upper platform wall plate 2 are as shown in Figure 4 、 Figure 5 The bottom wall plate 4 and the upper platform wall plate 2 are large in one cross-section and small in the other cross-section, and the entire large variable cross-section cylindrical structure is realized by variable cross-section of the bottom wall plate, and the bottom wall plate 4 and the upper platform wall plate 2 can be adaptively changed according to the required change rate of the entire cylindrical structure, and by controlling the change rate from the large cross-section to the small cross-section of the bottom wall plate 4 and the upper platform wall plate 2, the change rate between the two ports of the entire large variable cross-section cylindrical honeycomb sandwich structure can be controlled. The bottom wall plate 4 and the upper platform wall plate 2 are both horizontally flat structures, and both can reserve mounting interfaces on the upper surface to accommodate airborne functional equipment; if the entire large variable cross-section cylindrical honeycomb sandwich structure needs more support frames, the honeycomb area 4a of the bottom wall plate 4 and the honeycomb area 2a of the upper platform wall plate 2 can be disconnected to reserve support frame connecting areas.

[0044] The connecting belt plate 5 is as shown in Figure 6 It is a laminated composite structure, which is not limited to a laminated composite structure, and can also be other metal material structural parts. The connecting belt plate 5 is completely fitted according to the shape of the side wall plate and the upper bottom wall plate connected thereto, and can be connected to the left side wall plate 1, the upper platform wall plate 2, the right side wall plate 3 and the bottom wall plate to form an integrated structure by gluing, riveting or other mechanical connection methods.

[0045] The honeycomb arrangement of the left side wall plate 1, the upper platform wall plate 2, the right side wall plate 3 and the bottom wall plate 4 honeycomb sandwich structure is as shown in Figure 7 The 7a is a laminated area, and the 8a is a honeycomb area. The honeycomb in the transition area between the honeycomb area and the laminated area needs to have a 30° bevel angle, so that the load is smoothly transitioned. This place is not limited to a 30° bevel angle, and other bevel angles are also within the protection scope of the application. The honeycomb area and the connecting structure area need to have a distance of at least 10 mm to avoid the honeycomb sliding error and to prevent the honeycomb from being squeezed and damaged.

[0046] The above merely describes specific embodiments of the present application, and the detailed description of the present application is not exhaustive of the conventional technology. However, the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. The protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A large-scale variable cross-section cylindrical honeycomb sandwich structure, characterized in that, It includes four wall panels: left wall panel (1), platform wall panel (2), right wall panel (3) and bottom wall panel (4). The four wall panels are connected to form the overall structure of the transition section between the helicopter tail beam and the fuselage. The four wall panels are all plate-shaped structures with honeycomb as the main body. The four wall panels are connected to each other by connecting strips (5). The honeycomb structure on all four sides of the four wall panels has a non-honeycomb laminated structure. The bottom wall panel (4) has a trapezoidal structure. The two sides of the bottom wall panel (4) are connected to the left wall panel (1) and the right wall panel (3) by two L-shaped connecting strips (5). The left wall panel (1) and the right wall panel (3) are curved panels. The top of the left wall panel (1) and the right wall panel (3) are respectively connected by two top connecting strips (5). The platform wall panel (2) has a trapezoidal structure with a trapezoidal base angle larger than that of the bottom wall panel (4). The platform wall panel (2) is connected to the top of the left wall panel (1) and the right wall panel (3) by two top connecting strips (5). After the four wall panels are connected, a variable cross-section cylindrical structure from a large cross-section to a small cross-section is formed.

2. The large variable cross-section cylindrical honeycomb sandwich structure according to claim 1, characterized in that, At least one reinforcing frame is provided, which is a frame structure located at the same heading position of the four wall panels.

3. A large variable cross-section cylindrical honeycomb sandwich structure according to claim 2, characterized in that, The reinforcing frame consists of laminated strips in the same direction on the left wall panel (1), platform wall panel (2), right wall panel (3) and bottom wall panel (4), and four laminated strips in the same cross section form a reinforcing frame.

4. A large variable cross-section cylindrical honeycomb sandwich structure according to claim 2, characterized in that, The reinforcing frame is a reinforcing frame (6) located inside the four wall panels. The outer surface of the reinforcing frame (6) matches the inner surface of a certain section in the flight direction of the four wall panels. The reinforcing frame (6) is fixedly supported on the section.

5. A large variable cross-section cylindrical honeycomb sandwich structure according to claim 1, characterized in that, Its large cross-section area is the area connected to the fuselage through the docking frame, and its small cross-section area is the area connected to the inclined beam. A distance without honeycomb area is reserved in the small cross-section area.

6. A large variable cross-section cylindrical honeycomb sandwich structure according to claim 1, characterized in that, The transition area between the honeycomb and laminated structures of the four wall panels is a beveled honeycomb, which allows for a smooth transition between the thicker honeycomb and the thinner laminated structure.

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