Fuselage box section structure provided with strut type undercarriage

Abstract

The invention provides a fuselage box section structure provided with a strut type undercarriage. The fuselage box section structure comprises a front frame, a rear frame, a left beam, a right beam, an upper platform and a lower platform. Wherein the front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are riveted to form a closed box body; the directions of the front frame and the rear frame are perpendicular to the course of the aircraft and serve as bearing frames at the bottom of the aircraft; the directions of the left beam and the right beam are parallel to the course of the aircraft and serve as bearing beams at the bottom of the aircraft; the upper platform is a floor of the aircraft, and the lower platform is an external skin of the aircraft; mounting holes are formed in the upper platform and the lower platform and serve as undercarriage connectors, and the undercarriage connectors are in clearance fit with undercarriage supporting columns; and a flange plate mounting surface is arranged at the mounting hole of the lower platform and is connected with a flange plate of the undercarriage through a bolt.

Description

Technical Field

[0001] The invention relates to the field of helicopter fuselage structures, and in particular to a fuselage box section structure for installing a strut-type landing gear. Background Art

[0002] The installation of a strut-type landing gear on a helicopter fuselage requires the fuselage to provide upper and lower constraints to balance the loads in all directions.

[0003] In the past, the interface was usually provided by adding joints, which were independent of each other and each installed on the fuselage frame, which added extra weight and had low structural efficiency. Summary of the invention

[0004] The present invention provides a fuselage box-section structure for installing a strut-type landing gear. By designing a box-section structure integrated into a fuselage frame, the strut-type landing gear can be installed on the fuselage with a relatively light weight, thereby improving the structural efficiency.

[0005] The present invention provides a fuselage box section structure for installing a strut-type landing gear, comprising: a front frame, a rear frame, a left beam, a right beam, an upper platform, and a lower platform; wherein:

[0006] The front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are riveted together to form a closed box body;

[0007] The directions of the front frame and the rear frame are perpendicular to the heading of the aircraft and serve as the load-bearing frames at the bottom of the aircraft;

[0008] The directions of the left beam and the right beam are parallel to the heading of the aircraft, and serve as the load-bearing beams at the bottom of the aircraft;

[0009] The upper platform is the floor of the aircraft, and the lower platform is the outer skin of the aircraft;

[0010] Both the upper platform and the lower platform are provided with mounting holes as landing gear interfaces, and the landing gear interfaces are clearance-matched with the landing gear struts; a flange mounting surface is provided at the mounting hole of the lower platform, which is connected to the flange of the landing gear by bolts.

[0011] Optionally, maintenance holes are provided on both the left beam and the right beam.

[0012] Optionally, the position of the maintenance hole corresponds to the position of a strut of a strut-type landing gear.

[0013] Optionally, a maintenance port is provided on the upper platform.

[0014] Optionally, the maintenance port is located on the upper platform near the rear frame.

[0015] Optionally, reinforcing ribs are also provided on the left beam, the right beam, the upper platform and the lower platform.

[0016] Optionally, the mounting hole is located on the heading axis of the aircraft.

[0017] Optionally, the front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are made of aluminum alloy.

[0018] Optionally, a partition frame is provided between the front frame and the rear frame.

[0019] The present invention provides a fuselage box section structure for installing a strut-type landing gear, which is a comprehensive structure that combines upper and lower joints and is integrated with the fuselage, so that the structure not only transmits the landing gear load, but also participates in transmitting the entire aircraft load as a component of the fuselage, thereby improving the utilization rate of the load-bearing structure and saving the weight of the fuselage structure. It meets the requirements for the installation and use of the landing gear; compared with the previous independent joint solution, it saves about 20% of the weight; the upper platform is also used as a floor to meet the use of maintenance personnel; the lower platform is also used as the fuselage surface, does not protrude from the fuselage shape, and is more beautiful; the entire structure is easy to inspect and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a box-section structure mounted strut-type landing gear;

[0021] Figure 2 It is the upper axial view of the box segment structure;

[0022] Figure 3 It is the lower axial view of the box segment structure;

[0023] Figure 4 It is the disassembled view of the box segment structure;

[0024] Among them, 1-box section structure, 2-strut landing gear, 3-front frame; 4-rear frame; 5-left beam, 6-right beam, 7-upper platform, 8-lower platform, 9-partition frame, 10-upper mounting hole, 11-lower mounting hole, 12-right maintenance hole, 13-left maintenance hole, 14-upper maintenance port, 15-flange mounting surface. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 of 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.

[0026] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] The present invention will now be further described in detail with reference to the accompanying drawings and preferred embodiments, all of which are simplified schematic diagrams.

[0029] like Figure 1-4 As shown, the present invention provides a fuselage box-section structure for installing a strut-type landing gear. By designing a box-section structure integrated into a fuselage frame, the strut-type landing gear can be installed on the fuselage with a lighter weight, thereby improving the structural efficiency.

[0030] The present invention provides a fuselage box section structure for installing a strut-type landing gear, comprising: a front frame, a rear frame, a left beam, a right beam, an upper platform, and a lower platform; wherein:

[0031] The front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are riveted together to form a closed box body;

[0032] The directions of the front frame and the rear frame are perpendicular to the heading of the aircraft and serve as the load-bearing frames at the bottom of the aircraft;

[0033] The directions of the left beam and the right beam are parallel to the heading of the aircraft, and serve as the load-bearing beams at the bottom of the aircraft;

[0034] The upper platform is the floor of the aircraft, and the lower platform is the outer skin of the aircraft;

[0035] Both the upper platform and the lower platform are provided with mounting holes as landing gear interfaces, and the landing gear interfaces are clearance-matched with the landing gear struts; a flange mounting surface is provided at the mounting hole of the lower platform, which is connected to the flange of the landing gear by bolts.

[0036] Optionally, maintenance holes are provided on both the left beam and the right beam.

[0037] Optionally, the position of the maintenance hole corresponds to the position of a strut of a strut-type landing gear.

[0038] Optionally, a maintenance port is provided on the upper platform.

[0039] Optionally, the maintenance port is located on the upper platform near the rear frame.

[0040] Optionally, reinforcing ribs are also provided on the left beam, the right beam, the upper platform and the lower platform.

[0041] Optionally, the mounting hole is located on the heading axis of the aircraft.

[0042] Optionally, the front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are made of aluminum alloy.

[0043] Optionally, a partition frame is provided between the front frame and the rear frame.

[0044] The design scheme of the present invention specifically includes the following aspects:

[0045] The present invention determines the installation position of the strut-type landing gear 2 according to the overall layout of the helicopter, designs frames in front and rear of this position, designs beams on the left and right sides, and designs the upper and lower parts in the form of platform plates. The landing gear interface is designed on the upper and lower platforms. The front frame 3, the rear frame 4, the left beam 5, the right beam 6, the upper platform 7, and the lower platform 8 are riveted to form a box-segment structure 1, which can withstand various directional loads transmitted from the landing gear. The left and right beams are aligned with the longitudinal beams of the fuselage and are located on the force transmission path of the entire aircraft, and can transmit the load of the entire aircraft. The layout of the front and rear frames comprehensively considers the requirements of other systems on the aircraft, and a bulkhead 9 can be added depending on the frame spacing.

[0046] The landing gear interface is located on the upper platform 7 and the lower platform 8. The upper platform 7 is provided with an upper mounting hole 10, and the lower platform 8 is provided with a lower mounting hole 11. Both platforms are fitted with the landing gear strut clearance through the circular holes. The lower platform 8 also provides a flange mounting surface 15, which is connected to the flange of the landing gear by bolts. The bending moment generated by the lateral load and heading load of the landing gear and the eccentric bending moment generated by the vertical load are balanced by the upper platform 7 and the lower platform 8. The upper platform 7 is only used to bear the in-plane load caused by the balanced bending moment; in addition to bearing the in-plane load, the lower platform 8 also needs to bear the vertical load and the torque generated by the in-plane load. The platform load is transmitted to the frame and beam through rivets, and then diffused to the fuselage.

[0047] Because the box section structure is relatively closed, and the tail wheel lock and mounting bolts of the landing gear require maintenance, an upper maintenance opening 14 is opened on the upper platform 7, a left maintenance hole 13 is opened on the left beam 5, and a right maintenance hole 12 is opened on the right beam 6 as maintenance channels. The openings are designed according to ergonomic design principles.

[0048] The upper platform 7 of the box-section structure can be used as a floor for people to step on; the lower platform 8 can be used as the fuselage surface, eliminating the fuselage skin and saving weight; the frame and beam web can be wall-mounted to install system equipment, so that this section of the structure can play a variety of functions.

[0049] The various parts constituting the box-section structure are simple in structure and are made of aluminum alloy plates, which have low cost and good processability.

Claims

1. A fuselage box section structure for installing a strut-type landing gear, characterized in that: include: Front frame, rear frame, left beam, right beam, upper platform, lower platform; among them,; The front frame, the rear frame, the left beam, the right beam, the upper platform and the lower platform are riveted together to form a closed box body; The directions of the front frame and the rear frame are perpendicular to the heading of the aircraft and serve as the load-bearing frames at the bottom of the aircraft; The directions of the left beam and the right beam are parallel to the heading of the aircraft, and serve as the load-bearing beams at the bottom of the aircraft; The upper platform is the floor of the aircraft, and the lower platform is the outer skin of the aircraft; Both the upper platform and the lower platform are provided with mounting holes as landing gear interfaces, and the landing gear interfaces are clearance-matched with the landing gear struts; a flange mounting surface is provided at the mounting hole of the lower platform, which is connected to the flange of the landing gear by bolts.

2. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: Maintenance holes are provided on both the left and right beams.

3. The fuselage box section structure for mounting a strut-type landing gear according to claim 2, characterized in that: The position of the maintenance hole corresponds to the position of the strut of the strut-type landing gear.

4. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: A maintenance port is provided on the upper platform.

5. The fuselage box section structure for mounting a strut-type landing gear according to claim 4, characterized in that: The maintenance port is located on the upper platform close to the rear frame.

6. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: Reinforcement ribs are also arranged on the left beam, the right beam, the upper platform and the lower platform.

7. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: The mounting hole is located on the heading axis of the aircraft.

8. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: The front frame, rear frame, left beam, right beam, upper platform and lower platform are made of aluminum alloy.

9. The fuselage box section structure for mounting a strut-type landing gear according to claim 1, characterized in that: A partition frame is also arranged between the front frame and the rear frame.

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