Multi-box-section rotorcraft nose landing gear cabin and rotorcraft

Abstract

The invention provides a multi-box-section rotorcraft nose landing gear cabin and a rotorcraft, and belongs to the field of rotorcraft structural design. When a nose landing gear lands, a vertical load and a course load generated by a buffer strut assembly are borne and diffused through a left box section and a right box section; lateral loads are borne and diffused by the upper box section, and bending moments and torques generated in all directions are borne by all the box sections; a course load generated by the actuator cylinder is transmitted and diffused through the pommel horse type structure assembly and the upper box section, and a vertical load is transmitted through the pommel horse type structure assembly and the rear box section. While the landing gear mounting and retracting requirements are met, the large opening of the fuselage skin can be reinforced through an existing structure, the structure utilization efficiency is improved, the structure weight is reduced, landing gear load transmission can be achieved with the minimum weight cost, a front fuselage closed space can be formed, and the landing gear mounting and retracting requirements are met. And a good working environment is provided for passengers and equipment.

Description

Technical Field

[0001] The invention belongs to the field of rotorcraft structure design, and in particular relates to a front landing gear compartment of a multi-box rotorcraft and a rotorcraft. Background Art

[0002] As the requirements for rotorcraft flight speed, stealth and other performance become higher and higher, the demand for rotorcraft drag reduction is becoming more and more urgent. As one of the important sources of rotorcraft aerodynamic drag, the landing gear has to be retracted and extended during flight to reduce aerodynamic drag. Most rotorcraft landing gear do not have the retractable function. In order to meet the requirements of retracting and extending the landing gear, it is necessary to add a large opening to the fuselage and arrange the landing gear compartment at the same time. On the one hand, it is used to install and accommodate the landing gear, and on the other hand, it is used to block the internal fuselage from the external environment, providing a good internal environment for system equipment and pilots.

[0003] Traditional landing gear bays are mostly found in fixed-wing aircraft, while rotorcraft landing gear bays are relatively rare. In addition, the requirements for rotorcraft landing gear bays and fixed-wing aircraft landing gear bays are also different. Fixed-wing aircraft have a larger aircraft shape and the landing gear is mostly retracted forward, while rotorcraft are smaller in size. In order to meet the space requirements of the landing gear, the landing gear needs to be retracted backward, which will cause the load acting on the landing gear bay to increase exponentially when the landing gear lands, making it difficult to transfer the structural load. Due to the large opening of the fuselage skin, the strength and torsional stiffness of the rotorcraft fuselage structure with retractable landing gear will also be greatly affected, and the corresponding strengthening design will also lead to an increase in structural weight. Summary of the invention

[0004] In order to solve the technical problems in the prior art that the load acting on the landing gear compartment increases exponentially when the landing gear lands, the structural load transmission is difficult, the fuselage strength and torsional rigidity are low, and the structural weight is large, the present invention provides a multi-box segment rotorcraft front landing gear compartment, which is composed of five box segment structures and a saddle horse structure component. While meeting the requirements for the installation and retraction of the landing gear, the existing structure can be used to strengthen the large opening of the fuselage skin, improve the structural utilization efficiency, and reduce the structural weight. It can not only achieve the transfer of the landing gear load with the minimum weight cost, but also form a closed space in the front fuselage to provide a good working environment for the occupants and equipment. The technical solution is as follows:

[0005] In a first aspect, a front landing gear compartment of a multi-box segment rotorcraft is provided, comprising: an upper box segment 10, a front box segment 20, a left box segment 30, a rear box segment 40, a right box segment 50 and a pommel-horse type structural assembly 60. The front box segment 20 and the rear box segment 40 are respectively located at the front and rear ends of the left box segment 30 and the right box segment 50, the upper box segment 10 is located above the front box segment 20, the left box segment 30 and the right box segment 50, and the pommel-horse type structural assembly 60 is located below the upper box segment 10; the five box segments and the pommel-horse type structural assembly are fixedly connected to each other.

[0006] The front landing gear 1 is located at the front end of the front landing gear compartment, and in the retracted state is located in the space surrounded by the box sections; the buffer strut assembly of the front landing gear 1 is connected to the M-shaped joint of the left box section 30 and the right box section 50; the actuator of the front landing gear 1 is connected to the pommel-horse structure assembly 60:

[0007] When the front landing gear lands, the vertical load and azimuth load generated by the buffer strut assembly are borne and diffused by the left box section 30 and the right box section 50; the lateral load is borne and diffused by the upper box section 10, and the bending moment and torque generated in all directions are borne by each box section; the azimuth load generated by the actuator is transmitted and diffused through the pommel-horse structure assembly 60 and the upper box section 10, and the vertical load is transmitted through the pommel-horse structure assembly 60 and the rear box section.

[0008] The present invention is a front landing gear compartment of a multi-box-segment rotorcraft, which is composed of a plurality of closed box-segment structures. This structural form has high stability, excellent bending and torsion bearing capabilities, and can effectively resist bending and torsional deformation caused by external loads; at the same time, the box-segment structure can distribute the external load more evenly to the entire structure, and has a plurality of load-bearing units. The load originally transmitted by a single load-bearing unit is now evenly transmitted by a plurality of load-bearing units, thereby reducing the stress level of each load-bearing unit, greatly improving the bearing capacity of the entire structure, and also improving the reliability of the system; at the same time, a plurality of box-segment structures are arranged around the landing gear installation space, and the skin opening is strengthened by the box-segment structure, so that the torsional stiffness of the entire landing gear compartment is also significantly improved, and the bearing capacity is significantly strengthened; through the configuration design of the multi-box-segment structure, the structural stiffness is improved, the stress level of the component is reduced, the cross-sectional size is reduced, and the weight efficiency is improved, thereby solving the technical problems of difficulty in transmitting the landing gear load after it becomes large and low torsional stiffness of the fuselage.

[0009] Optionally, the upper box section is composed of an upper skin 11, an upper bulkhead 12, a right outer upper longitudinal beam 13, a first bulkhead 14, a rear floor 15 and a front floor 16, and each part is riveted to form an integral structure, wherein the front floor 16 and the rear floor 15 are located at the lower part of the upper box section, and are used to separate the landing gear installation area from the internal area of ​​the fuselage; the front floor 16 and the rear floor 15 have a height difference in the vertical direction; the upper bulkhead 12 is located in the middle of the upper box section, and divides the entire upper box section into two different compartments, front and rear; The first bulkhead 14 is located at the rear of the upper box section, and its upper part is provided with an inclined surface for separating the front landing gear compartment from the cockpit; the right outer upper longitudinal beam 13 is located between the upper bulkhead 12 and the first bulkhead 14, and plays the role of supporting the upper skin 11; the upper bulkhead 12, the right outer upper longitudinal beam 13, the first bulkhead 14, the rear floor 15 and the front floor 16 are covered with the upper skin 11 on the outside, so that the entire upper box section forms a closed space for transmitting aerodynamic loads, as well as lateral loads, bending moments and torques transmitted from the landing gear.

[0010] Compared with the traditional way of transferring loads through wall panels, the overall strength and rigidity of the structure of the present invention are significantly improved; at the same time, the upper box section can also be used for the installation of system equipment, forming a comprehensive utilization of the structure and improving the utilization efficiency of the structure.

[0011] Optionally, the front box section is composed of a front floor 16, a front skin 21 and a second bulkhead 22, and the front floor 16 of the front box section and the front floor of the upper box section are common parts.

[0012] The front floor 16 of the front box section is a common part with the front floor of the upper box section, and is connected to the front skin 21 and the second bulkhead 22 by riveting; the front skin 21 is located at the front end of the second bulkhead 22, and forms a complete box section with the second bulkhead 22 and the front floor 16;

[0013] The second bulkhead 22 is an integrally machined aluminum alloy structure, and the distance tolerance between the two reinforcing ribs at the connection position between the left box section 30 and the rear box section 40 on the second bulkhead 22 is ±0.1 mm.

[0014] Optionally, the left box section is composed of a rear floor 15, a front floor 16, an inclined bulkhead 31, a left outer lower longitudinal beam 32, a third bulkhead 33, a left inner longitudinal beam 34, a left lower bulkhead 35 and a left side skin 361. The inclined bulkhead 31 and the third bulkhead 33 are located at the rear end of the left box section. The inclined bulkhead 31 has a certain slope, and the slope is determined according to the movement space requirements of the system equipment; the left outer lower longitudinal beam 32 is located between the left inner longitudinal beam 34 and the left side skin 361, and the landing load of the landing gear is gradually transferred to the left outer lower longitudinal beam 32 through the diffusion of the left side skin 361; the left lower bulkhead 35 is located at the front end of the left outer lower longitudinal beam 32, dividing the left box section into two front and rear spaces; the left inner longitudinal beam 34 is located at the left box On the inner side of the section, a M-shaped landing gear support joint 341 is provided. The M-shaped landing gear support joint 341 has a joint bearing mounting hole and vertical, transverse and oblique ribs, which strengthen the landing gear mounting area. The connection point of the landing gear is close to the upper flange of the left inner longitudinal beam 34, so as to reduce the bending moment formed by the lateral load of the landing gear and reduce the structural weight. In order to avoid the landing gear door movement mechanism, a square groove is opened on the inner side of the left inner longitudinal beam 34, and the depth of the square groove is determined according to the movement envelope of the movement mechanism. The rear floor 15 and the front floor 16 are common structural members of the left box section and the upper box section, and together with the left side skin 361 form a complete closed space.

[0015] Optionally, the rear box section is composed of a third bulkhead 33, a rear lower floor 36, a right rear outer longitudinal beam 37, a right rear inner longitudinal beam 38, a fourth bulkhead 39, a left rear inner longitudinal beam 40, a left rear outer longitudinal beam 41 and a rear skin 42, and the components are fixedly connected; the right rear outer longitudinal beam 37, the right rear inner longitudinal beam 38, the left rear inner longitudinal beam 40, and the left rear outer longitudinal beam 41 serve as the main load-carrying structure of the rear box section, the right rear outer longitudinal beam 37, the right rear inner longitudinal beam 38 are butt-jointed with the right outer lower longitudinal beam 43 and the right inner longitudinal beam 45 of the right box section, and the left rear inner longitudinal beam 40 and the left rear outer longitudinal beam 41 are butt-jointed with the left inner longitudinal beam 34 and the left outer lower longitudinal beam 32 of the left box section;

[0016] The third bulkhead 33 is a common structural component of the rear box section, the left box section and the right box section; the fourth bulkhead 39 is located at the rear end face of the rear box section, and plays a certain supporting role for the rear lower floor 36; the rear lower floor 36 and the rear skin 42 are respectively laid on the upper and lower surfaces of the rear box section, so that the entire box section forms a closed space.

[0017] Optionally, the right box section is composed of the rear floor 15, the front floor 16, the oblique bulkhead 31, the third bulkhead 33, the right outer lower longitudinal beam 43, the right lower bulkhead 44, the right inner longitudinal beam 45 and the right side skin 46. The right box section has the same structure as the left box section, and the two are symmetrical relative to the center of the fuselage.

[0018] Optionally, the pommel-horse type structural assembly is composed of a right actuator support 47, a left actuator support 48, a reinforced bulkhead 49, a middle and lower bulkhead 50 and a lower connecting plate 51. The right actuator support 47 and the left actuator support 48 are arranged symmetrically on both sides, and the rear end is integrated with an actuator support joint for connecting the landing gear actuator; the front end forms a closed small box section through the belly plate surface with the reinforced bulkhead 49, the middle and lower bulkhead 50 and the lower connecting plate 51, which improves the support stiffness of the front end of the left and right actuator joints and forms another path for the vertical load transmission of the landing gear. The middle and lower bulkhead 50 is provided with vertical oblong holes, which are arranged symmetrically on the left and right sides to facilitate the passage of the landing gear door connecting rod.

[0019] Optionally, the front landing gear compartment has three platform surfaces of different heights, namely the middle front floor surface 16 of the upper box section 10, the rear floor surface 15 and the rear lower floor surface 36 in the rear box section 40. The height difference between the front floor surface 16 and the rear floor surface 15 is greater than 0; the height difference between the rear floor surface 15 and the rear lower floor surface 36 is greater than 0. The three platform surfaces isolate the interior of the fuselage from the external environment.

[0020] In a second aspect, a rotorcraft is provided, comprising a front landing gear compartment of a multi-box rotorcraft as described in any one of the first aspects, and a landing gear.

[0021] The beneficial effects of the present invention are at least:

[0022] (1) The front landing gear compartment of this type of multi-box rotorcraft can be used for rear retractable landing gear. While meeting the requirements of landing gear installation and storage, the large structural opening is strengthened. One structure has multiple functions, and the weight efficiency is significantly improved;

[0023] (2) The front landing gear compartment of this type of multi-box rotorcraft is composed of multiple boxes, and the overall structural rigidity is good, especially the overall torsional rigidity of the front section of the fuselage has been significantly improved;

[0024] (3) Some of the boxes in the front landing gear compartment of this type of multi-box rotorcraft are also used to accommodate system equipment, thereby achieving structural integrity and meeting equipment installation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the exploded structure of the front landing gear compartment;

[0026] Figure 2 It is a schematic diagram of the three-dimensional combined structure of the front landing gear compartment and the front landing gear;

[0027] Figure 3 It is a schematic diagram of the three-dimensional structure of the upper box segment;

[0028] Figure 4 It is a schematic diagram of the three-dimensional structure of the front box segment;

[0029] Figure 5 It is a schematic diagram of the three-dimensional structure of the left box segment;

[0030] Figure 6 It is a schematic diagram of the three-dimensional structure of the rear box segment;

[0031] Figure 7 It is a schematic diagram of the three-dimensional structure of the right box segment;

[0032] Figure 8 It is a schematic diagram of the three-dimensional structure of the pommel horse type structural component;

[0033] Fig. 9 This is a schematic diagram of the longitudinal beam docking.

[0034] Among them, 1. landing gear, 10. upper box section, 20. front box section, 30. left box section, 40. rear box section, 50. right box section, 60. pommel horse structure assembly, 11. upper skin, 12. upper bulkhead, 13. right outer upper longitudinal beam, 14. first bulkhead, 15. rear floor, 16. front floor, 21. front skin, 22. second bulkhead, 31 oblique bulkhead, 32. left outer lower longitudinal beam, 33. third bulkhead, 34. left inner longitudinal beam, 35. left lower bulkhead, 361. left Side skin, 36. Rear lower floor, 37. Right rear outer longitudinal beam, 38. Right rear inner longitudinal beam, 39. Fourth bulkhead, 40. Left rear inner longitudinal beam, 41. Left rear outer longitudinal beam, 42. Rear skin, 43. Right outer lower longitudinal beam, 44. Right lower bulkhead, 45. Right inner longitudinal beam, 46. Right side skin, 47. Right actuator support, 48. Left actuator support, 49. Strengthening bulkhead, 50. Middle lower bulkhead, 51. Lower connecting plate, 52. Connecting angle, 341. M-shaped joint. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below through specific implementation modes and drawings.

[0036] The present invention provides a front landing gear compartment of a multi-box rotorcraft, such as Figure 1 As shown, it includes six parts: an upper box segment 10, a front box segment 20, a left box segment 30, a rear box segment 40, a right box segment 50 and a pommel-horse type structural component 60. The front box segment 20 and the rear box segment 40 are respectively located at the front and rear ends of the left box segment 30 and the right box segment 50, the upper box segment 10 is located above the front box segment 20, the left box segment 30 and the right box segment 50, and the pommel-horse type structural component 60 is located below the upper box segment 10; the five box segments and the pommel-horse type structural component are fixedly connected to each other.

[0037] The front landing gear 1 is located at the front end of the front landing gear compartment and is located within the space surrounded by the box segments in the retracted state and in the opened state. Figure 2 The front landing gear 1 is usually composed of components such as a buffer strut and an actuator. The buffer strut assembly is connected to the M-shaped joint of the left box section 30 and the right box section 50; the actuator of the front landing gear 1 is connected to the saddle-horse structure assembly 60. The vertical load and azimuth load generated by the buffer strut assembly are borne and diffused by the left box section 30 and the right box section 50; the lateral load is borne and diffused by the upper box section 10, and the bending moment and torque generated in all directions are borne by each box section; the azimuth load generated by the actuator is transmitted and diffused through the saddle-horse structure assembly 60 and the upper box section 10, and the vertical load is transmitted through the saddle-horse structure assembly 60 and the rear box section.

[0038] The front landing gear compartment has three platform surfaces of different heights, namely the middle front floor surface 16 of the upper box section 10, the rear floor surface 15 and the rear lower floor surface 36 in the rear box section 40. The height difference between the front floor surface 16 and the rear floor surface 15 is 50 mm; the height difference between the rear floor surface 15 and the rear lower floor surface 36 is 185 mm. The three platform surfaces isolate the interior of the fuselage from the external environment.

[0039] See also Figure 3 The upper box section is located at the upper part of the front landing gear compartment, and is mainly composed of an upper skin 11, an upper bulkhead 12, a right outer upper longitudinal beam 13, a first bulkhead 14, a rear floor 15 and a front floor 16. Each part is riveted to form an integral structure. The front floor 16 and the rear floor 15 are located at the lower part of the upper box section, and are used to separate the landing gear installation area from the internal area of ​​the fuselage; there is a 50mm height difference between the front floor 16 and the rear floor 15 in the vertical direction, which is mainly due to the gradual reduction of the appearance forward, and is adjusted to meet the equipment installation height and the landing gear installation space requirements; the upper bulkhead 12 is located in the middle of the upper box section, dividing the entire upper box section into two different compartments, front and rear; the first bulkhead 14 is located at the rear of the upper box section, and its upper half is provided with an inclined plane for separating the front landing gear compartment and the cockpit, which is used to separate the front landing gear compartment and the cockpit. In order to maintain the appearance, the bulkhead can adopt a honeycomb sandwich structure; the right outer upper longitudinal beam 13 is located between the upper bulkhead 12 and the first bulkhead 14, and supports the upper skin 11. The structure can adopt a honeycomb sandwich structure or an aluminum panel reinforced structure. The upper skin 11 is covered on the outside of the upper bulkhead 12, the right outer upper longitudinal beam 13, the first bulkhead 14, the rear floor 15 and the front floor 16, so that the entire upper box section forms a closed space. This structure can be used to transfer aerodynamic loads, lateral loads, bending moments and torques transmitted from the landing gear. Compared with the traditional way of transferring loads through wall panels, the overall strength and rigidity of the structure are significantly improved; at the same time, this space can also be used for the installation of system equipment, forming a comprehensive utilization of the structure and improving the utilization efficiency of the structure.

[0040] See also Figure 4 The front box section is located at the front of the front landing gear compartment, and is mainly composed of the front floor 16, the front skin 21 and the second bulkhead 22. Since the front landing gear installation point is closer to the front box section, part of the landing gear load is transmitted and diffused through the front box section in the form of shear flow. In addition, in order to ensure the installation accuracy of the landing gear, the second bulkhead adopts an aluminum alloy integral machined part structure, and controls the distance tolerance between the two reinforcing ribs between the second bulkheads. Generally, the distance tolerance is controlled at ±0.1mm; the front skin 21 is located at the front end of the second bulkhead, and forms a complete box section with the second bulkhead and the front floor, and generally adopts a composite honeycomb sandwich structure; the front floor 16 and the upper box section are common parts, which are connected to the front skin 21 and the second bulkhead 22 by riveting.

[0041] See also Figure 5 The left box section is located on the left side of the front landing gear compartment, and is mainly composed of the rear floor 15, the front floor 16, the oblique bulkhead 31, the left outer lower longitudinal beam 32, the third bulkhead 33, the left inner longitudinal beam 34, the left lower bulkhead 35 and the left skin 361. The oblique bulkhead 31 and the third bulkhead 33 are located at the rear end of the left box section. The oblique bulkhead 31 needs to have a certain slope, and the slope is determined according to the movement space requirements of the system equipment; the left outer lower longitudinal beam 32 is located between the left inner longitudinal beam 34 and the left skin 361. The landing load of the landing gear will be gradually transferred to the longitudinal beam through the diffusion of the left skin 361. Therefore, the longitudinal beam has a stronger size than the left inner longitudinal beam 34; the left lower bulkhead 35 is located at the front end of the left outer lower longitudinal beam 32, dividing the left box section into two spaces, front and rear, and also supporting the box section structure; the left inner longitudinal beam 34 is located on the inner side of the left box section, and the M-shaped landing gear is integrated on it. Support joint 341, which needs to have a joint bearing mounting hole and vertical, transverse and oblique ribs to strengthen the landing gear installation area. The connection point of the landing gear needs to be close to the upper flange of the left inner longitudinal beam 34, so as to reduce the bending moment formed by the lateral load of the landing gear, thereby reducing the weight of the structure; in order to avoid the landing gear door movement mechanism, a directional groove is opened on the inner side of the left inner longitudinal beam 34, and the depth of the groove needs to be determined according to the movement envelope of the movement mechanism; the rear floor 15 and the front floor 16 are common structural members of the left box section and the upper box section, and together with the left side skin 361, a complete closed space is formed. In order to ensure the integrity of the structure, realize the diffusion of the load, and improve the rigidity of the entire box section, the left side skin 361 should avoid opening in the area between the left outer lower longitudinal beam 32 and the left inner longitudinal beam 34, so as to form a closed box section.

[0042] See also Figure 6The rear box section is located at the rear of the front landing gear compartment and is the main load diffusion section of the front landing gear compartment. It is mainly composed of the third bulkhead 33, the rear lower floor 36, the right rear outer longitudinal beam 37, the right rear inner longitudinal beam 38, the fourth bulkhead 39, the left rear inner longitudinal beam 40, the left rear outer longitudinal beam 41 and the rear skin 42, and the various components are fixedly connected; the right rear outer longitudinal beam 37, the right rear inner longitudinal beam 38, the left rear inner longitudinal beam 40, and the left rear outer longitudinal beam 41 are the main load-transmitting structures of the rear box section. The right rear outer longitudinal beam 37, the right rear inner longitudinal beam 38 and the right outer lower longitudinal beam 43 of the right box section, the right inner longitudinal beam 43, and the right inner longitudinal beam 43 are connected to each other. The left rear inner longitudinal beam 40 and the left rear outer longitudinal beam 41 are connected with the left inner longitudinal beam 34 and the left outer lower longitudinal beam 32 of the left box section; the third bulkhead 33 is a common structural member of the rear box section, the left box section and the right box section. In order to diffuse the vertical load generated by the landing gear actuator and strengthen the landing gear compartment opening, it should be made of aluminum alloy machined parts; the fourth bulkhead 39 is located at the rear end face of the rear box section, which plays a certain supporting role for the rear lower floor 36; the rear lower floor 36 and the rear skin 42 are respectively laid on the upper and lower surfaces of the rear box section, so that the entire box section forms a closed space. The rear box section mainly transmits the vertical load, heading load and lateral load transmitted by the front landing gear, and also has a great effect on the bending moment and torque generated by the front landing gear. The rear skin 42 should avoid opening. Fig. 9 This is a schematic diagram of the longitudinal beam docking.

[0043] See also Figure 7 The right box section is located on the right side of the front landing gear compartment, and is mainly composed of the rear floor 15, the front floor 16, the oblique bulkhead 31, the third bulkhead 33, the right outer lower longitudinal beam 43, the right lower bulkhead 44, the right inner longitudinal beam 45 and the right side skin 46. The right box section has the same structure as the left box section, and the two are symmetrical relative to the center of the fuselage. The structure and main function of this box section are the same as those of the left box section.

[0044] See also Figure 8 The pommel-horse type structural assembly is located below the upper box section 10, in the middle of the front landing gear compartment, and is mainly composed of the right actuator support 47, the left actuator support 48, the reinforced bulkhead 49, the middle and lower bulkhead 50 and the lower connecting plate 51. The right actuator support 47 and the left actuator support 48 are arranged symmetrically on both sides, and the rear end is integrated with an actuator support joint for connecting the landing gear actuator; the front end forms a closed small box section through the belly plate surface with the reinforced bulkhead 49, the middle and lower bulkhead 50 and the lower connecting plate 51, which improves the support stiffness of the front end of the left and right actuator joints and forms another path for the vertical load transmission of the landing gear. The middle and lower bulkhead 50 is provided with vertical oblong holes, which are arranged symmetrically on the left and right sides to facilitate the passage of the landing gear door connecting rod.

[0045] The upper box section 10, the front box section 20, the left box section 30 and the right box section 50 all have common structural parts, namely the front floor 16 and the rear floor 15. The above four box sections can be connected through the common structural parts. Since there is a 50mm step difference between the front floor 16 and the rear floor 15, the left inner longitudinal beam 34 and the right inner longitudinal beam 45 retain a 50mm step difference at the joint position of the two floors, and longitudinal ribs and oblique ribs need to be designed at this position to ensure the continuity of the longitudinal beam structure and realize the load transfer of the landing gear. A 185mm height step difference is retained between the upper box section 10 and the rear box section 40. In order to ensure the transfer of load, a connecting angle 52 through hole is set on the third bulkhead 33, and the connecting angle 52 is used to achieve the docking of the front and rear beams. This type of connection has direct load transfer and has obvious weight advantages.

[0046] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A front landing gear compartment of a multi-box rotorcraft, characterized in that: include: The invention relates to an upper box section (10), a front box section (20), a left box section (30), a rear box section (40), a right box section (50) and a pommel-horse type structural component (60). The front box section (20) and the rear box section (40) are respectively located at the front and rear ends of the left box section (30) and the right box section (50). The upper box section (10) is located above the front box section (20), the left box section (30) and the right box section (50). The pommel-horse type structural component (60) is located below the upper box section (10). The five box sections and the pommel-horse type structural component are fixedly connected to each other. The front landing gear (1) is located at the front end of the front landing gear compartment and is located within the space surrounded by the box sections in a retracted state; the buffer support assembly of the front landing gear (1) is connected to the M-shaped joints of the left box section (30) and the right box section (50); the actuator of the front landing gear (1) is connected to the saddle horse type structure assembly (60); When the front landing gear lands, the vertical load and the azimuth load generated by the buffer strut assembly are borne and diffused by the left box section (30) and the right box section (50); the lateral load is borne and diffused by the upper box section (10), and the bending moment and torque generated in various directions are borne by each box section; the azimuth load generated by the actuator is transmitted and diffused by the saddle horse type structure assembly (60) and the upper box section (10), and the vertical load is transmitted by the saddle horse type structure assembly (60) and the rear box section.

2. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The upper box section is composed of an upper skin (11), an upper bulkhead (12), a right outer upper longitudinal beam (13), a first bulkhead (14), a rear floor (15) and a front floor (16), and the various parts are riveted to form an integral structure, wherein the front floor (16) and the rear floor (15) are located at the lower part of the upper box section, and are used to separate the landing gear installation area from the internal area of ​​the fuselage; there is a height difference between the front floor (16) and the rear floor (15) in the vertical direction; the upper bulkhead (12) is located in the middle of the upper box section, and divides the entire upper box section into two different compartments, front and rear; the first bulkhead (14) is located at the rear of the upper box section, and its upper half is provided with an inclined surface for separating the front landing gear compartment from the cockpit; The right outer upper longitudinal beam (13) is located between the upper bulkhead (12) and the first bulkhead (14), and plays a role in supporting the upper skin (11); the upper bulkhead (12), the right outer upper longitudinal beam (13), the first bulkhead (14), the rear floor (15) and the front floor (16) are covered with the upper skin (11) on the outside, so that the entire upper box section forms a closed space for transmitting aerodynamic loads, as well as lateral loads, bending moments and torques transmitted from the landing gear.

3. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The front box section is composed of a front floor (16), a front skin (21) and a second bulkhead (22). The front floor (16) of the front box section and the front floor of the upper box section are common parts. The front floor (16) of the front box section and the front floor of the upper box section are common parts, and are connected to the front skin (21) and the second bulkhead (22) by riveting; the front skin (21) is located at the front end of the second bulkhead (22), and forms a complete box section with the second bulkhead (22) and the front floor (16); The second bulkhead (22) adopts an aluminum alloy integral machined component structure, and the distance tolerance between two reinforcing ribs at the connection position of the left box section (30) and the rear box section (40) on the second bulkhead (22) is ±0.1 mm.

4. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The left box section is composed of a rear floor (15), a front floor (16), an inclined bulkhead (31), a left outer lower longitudinal beam (32), a third bulkhead (33), a left inner longitudinal beam (34), a left lower bulkhead (35) and a left side skin (361). The inclined bulkhead (31) and the third bulkhead (33) are located at the rear end of the left box section. The inclined bulkhead (31) has a certain slope, which is determined according to the movement space requirements of the system equipment. The left outer lower longitudinal beam (32) is located between the left inner longitudinal beam (34) and the left side skin (361). The landing load of the landing gear is gradually transferred to the left outer lower longitudinal beam (32) through the diffusion of the left side skin (361). The left lower bulkhead (35) is located at the front end of the left outer lower longitudinal beam (32), dividing the left box section into two spaces, front and rear. The longitudinal beam (34) is located on the inner side of the left box section, and a M-shaped landing gear support joint (341) is provided on the longitudinal beam. The M-shaped landing gear support joint (341) has a joint bearing mounting hole and vertical, horizontal and oblique ribs, which play a role in strengthening the landing gear mounting area. The connection point of the landing gear is close to the upper flange of the left inner longitudinal beam (34) to reduce the bending moment formed by the lateral load of the landing gear and reduce the structural weight. In order to avoid the landing gear door movement mechanism, a square groove is opened on the inner side of the left inner longitudinal beam (34), and the depth of the square groove is determined according to the movement envelope of the movement mechanism. The rear floor (15) and the front floor (16) are common structural members of the left box section and the upper box section, and together with the left side skin (361) form a complete closed space.

5. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The rear box section is composed of a third bulkhead (33), a rear lower floor (36), a right rear outer longitudinal beam (37), a right rear inner longitudinal beam (38), a fourth bulkhead (39), a left rear inner longitudinal beam (40), a left rear outer longitudinal beam (41) and a rear skin (42), and the components are fixedly connected; the right rear outer longitudinal beam (37), the right rear inner longitudinal beam (38), the left rear inner longitudinal beam (40) and the left rear outer longitudinal beam (41) serve as the main load-transmitting structure of the rear box section; the right rear outer longitudinal beam (37) and the right rear inner longitudinal beam (38) are butt-jointed with the right outer lower longitudinal beam (43) and the right inner longitudinal beam (45) of the right box section; the left rear inner longitudinal beam (40) and the left rear outer longitudinal beam (41) are butt-jointed with the left inner longitudinal beam (34) and the left outer lower longitudinal beam (32) of the left box section; The third bulkhead (33) is a common structural member of the rear box section, the left box section and the right box section; the fourth bulkhead (39) is located at the rear end surface of the rear box section, and plays a certain supporting role for the rear lower floor (36); the rear lower floor (36) and the rear skin (42) are respectively laid on the upper and lower surfaces of the rear box section, so that the entire box section forms a closed space.

6. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The right box section is composed of a rear floor (15), a front floor (16), an inclined bulkhead (31), a third bulkhead (33), a right outer lower longitudinal beam (43), a right lower bulkhead (44), a right inner longitudinal beam (45) and a right side skin (46); the right box section has the same structure as the left box section, and the two are symmetrical relative to the center of the fuselage.

7. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The pommel-horse type structural assembly is composed of a right actuator support (47), a left actuator support (48), a reinforced bulkhead (49), a middle and lower bulkhead (50) and a lower connecting plate (51). The right actuator support (47) and the left actuator support (48) are arranged symmetrically on both sides, and an actuator support joint is integrated at the rear end for connecting the landing gear actuator; the front end forms a closed small box section through the belly plate surface with the reinforced bulkhead (49), the middle and lower bulkhead (50) and the lower connecting plate (51), forming another path for the vertical load transmission of the landing gear; the middle and lower bulkhead (50) is provided with a vertical oblong hole, which is arranged symmetrically on the left and right.

8. The front landing gear compartment of a multi-box rotorcraft according to claim 1, characterized in that: The front landing gear compartment has three platform surfaces of different heights, namely a middle front floor surface (16) of the upper box section (10), a rear floor surface (15) and a rear lower floor surface (36) in the rear box section (40). The height difference between the front floor surface (16) and the rear floor surface (15) is greater than 0; the height difference between the rear floor surface (15) and the rear lower floor surface (36) is greater than 0. The three platform surfaces isolate the interior of the fuselage from the external environment.

9. A rotorcraft, characterized in that: It comprises a front landing gear compartment of a multi-box rotorcraft as described in any one of claims 1 to 8, and a landing gear.

Images