Main blade folding and fixing device and helicopter

Abstract

The invention provides a main blade folding and fixing device which comprises a bottom supporting rod system connected with a longitudinal beam at the bottom of a helicopter belly; the transverse supporting rod is connected with one end of the bottom supporting rod system; one end of the blade supporting rod system is connected with the transverse supporting rod, and the other end of the blade supporting rod system is connected with a helicopter blade; meanwhile, the invention further provides a helicopter. The device provided by the invention is used for fixing the front folding blade of the helicopter, and when the helicopter is transported by a certain type of transporter, the main blade of the helicopter cannot collide with the inner wall of a cabin of the transporter under II-level limiting overload, so that the strength and rigidity design requirements are met; the whole fixing device also considers the convenience of disassembly and assembly, and is convenient for daily use and maintenance.

Description

Technical Field

[0001] The present application belongs to the technical field of helicopter functional structures, and in particular relates to a main rotor blade folding and fixing device and a helicopter. Background Art

[0002] When a helicopter is being transported by air or parked in a ship hangar, the main rotor blades of the helicopter need to be folded to reduce the lateral placement space of the fuselage. During the movement of the air transport and ship transport platform, the main rotor blades will generate inertial loads, and the folding and fixing device of the main rotor blades needs to reliably constrain the folded main rotor blades. Summary of the invention

[0003] The purpose of the present invention is: the main blade folding and fixing device provided in the present application can reliably restrain the folded main blade. When the helicopter main blade is under level II limited overload, the main blade will not hit the inner wall of the transport aircraft cabin, thereby meeting the strength and stiffness design requirements.

[0004] In a first aspect, the present application provides a main blade folding and fixing device, the device comprising:

[0005] The bottom support rod system is connected to the bottom longitudinal beam of the helicopter belly;

[0006] A transverse support rod connected to one end of the bottom support rod system;

[0007] A blade supporting rod system, one end of which is connected to the transverse supporting rod, and the other end of which is connected to the helicopter blade.

[0008] Preferably, the bottom support rod system comprises:

[0009] The first triangular support rod system is connected to the left longitudinal beam at the bottom of the helicopter belly;

[0010] The second triangular support rod system is connected to the right longitudinal beam at the bottom of the helicopter belly;

[0011] A lateral stabilizing rod system is arranged between the first triangular supporting rod system and the second triangular supporting rod system; the first triangular supporting rod system and the second triangular supporting rod system are the same.

[0012] Preferably, the first triangular support rod system comprises:

[0013] A first longitudinal rod having a joint, wherein the first longitudinal rod is connected to the left longitudinal beam at the bottom of the helicopter belly through the joint, the first longitudinal rod is parallel to the folded helicopter blades, and one end of the first longitudinal rod is connected to the transverse support rod;

[0014] First diagonal bar;

[0015] The second oblique rod; wherein the first longitudinal rod, the first oblique rod and the second oblique rod are connected end to end to form a triangular structure.

[0016] Preferably, one end of the first oblique rod is connected to the other end of the first longitudinal rod; one end of the second oblique rod is connected to the other end of the first oblique rod, and the other end of the second oblique rod is connected to one end of the first longitudinal rod.

[0017] Preferably, the first triangular support bar system further comprises:

[0018] A first vertical rod, one end of which is connected to the first longitudinal rod, and the other end of which is connected to the other end of the first oblique rod and one end of the second oblique rod.

[0019] Preferably, the lateral stabilizing bar system comprises:

[0020] lateral crossbar;

[0021] Lateral diagonal rod; wherein the lateral cross rod, the lateral diagonal rod and the first vertical rod are connected end to end to form a triangular structure.

[0022] Preferably, the blade support rod system comprises:

[0023] A first herringbone support structure, arranged on the transverse support rod;

[0024] A second herringbone supporting structure is arranged on the transverse supporting rod; wherein the first herringbone supporting structure is the same as the second herringbone supporting structure.

[0025] Preferably, the first herringbone support structure comprises:

[0026] a first blade brace, one end of which is connected to the transverse support rod;

[0027] A second blade brace, one end of the second blade brace is connected to the other end of the first blade brace, and the other end of the second blade brace is connected to the transverse support rod.

[0028] Preferably, the first blade support rod and the second blade support rod are telescopic rods, and the lengths of the telescopic rods can be adjusted; the first herringbone support structure further includes:

[0029] A clamping component is connected to the other end of the first blade support rod and one end of the second blade support rod, and the clamping component is used to clamp the folded helicopter blade.

[0030] In a second aspect, the present application also provides a helicopter, comprising the main rotor blade folding and fixing device as described above.

[0031] Beneficial technical effects of this application:

[0032] In the design of the folding and fixing of the helicopter main rotor blade, this type of device is used to fix the front folding blade of the helicopter. When this type of helicopter is transported by a certain type of transport aircraft, the main rotor blade of the helicopter will not hit the inner wall of the transport aircraft cabin under the level II limited overload, meeting the strength and rigidity design requirements. At the same time, the entire fixing device also takes into account the convenience of disassembly and assembly, which is convenient for daily use and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a rod system of a fixing device provided in an embodiment of the present application;

[0034] Figure 2 A longitudinal rod force diagram provided for an embodiment of the present application;

[0035] Figure 3 A diagram of a blade clamping device provided in an embodiment of the present application;

[0036] Figure 4 A diagram of a retractable support rod provided for an embodiment of the present application;

[0037] Figure 5 A diagram of a rod system mechanics model provided in an embodiment of the present application;

[0038] Figure 6 An arc joint diagram provided for an embodiment of the present application;

[0039] Figure 7 A rear joint diagram provided for an embodiment of the present application;

[0040] Figure 8 A diagram of a bar system finite element model provided in an embodiment of the present application;

[0041] Fig. 9 A diagram showing the stiffness calculation results provided in the embodiment of the present application;

[0042] Fig.10 The first triangular rod system installation diagram provided in the embodiment of the present application;

[0043] Fig.11 The second triangular rod system installation diagram provided in the embodiment of the present application;

[0044] Fig.12 A first longitudinal rod installation diagram provided in an embodiment of the present application;

[0045] Fig.13 Installation diagram of the second and third longitudinal bars provided in the embodiment of the present application;

[0046] Fig.14 This is a fourth longitudinal rod installation diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] See also Figures 1 to 14 The blade folding fixture is generally composed of a large number of rod systems. When designing, the rod system needs to meet the design requirements of strength and stiffness at the same time. Especially in the air transport state, the end of the folded helicopter main blade is close to the inner wall of the transport aircraft. The folding fixture with poor stiffness will cause the main blade to hit the transport aircraft body, which may cause serious flight accidents. By designing a helicopter main blade folding fixture, it is ensured that under a specific main blade inertia load, the deformation of the blade end does not exceed the limit value, and the device body and connection also meet the strength design requirements.

[0048] The blade folding fixture is mainly composed of the first triangular support rod system, the second triangular support rod system, the lateral stabilizing rod system, the first herringbone support structure, the second herringbone support structure, etc. The first triangular support rod system and the second triangular support rod system are connected to the left and right longitudinal beams at the bottom of the helicopter belly through four steel joints ( Figure 1 ).

[0049] The design involves the definition of the helicopter coordinate system and load symbols. Among them, the x-axis: the helicopter's reverse heading is positive; the y-axis: the helicopter's right side along the heading is positive; the z-axis: determined by the right-hand rule, upward is positive. The forces in the x, y, and z directions are represented by Fx, Fy, and Fz; the moments in the x, y, and z directions are represented by Mx, My, and Mz.

[0050] The first longitudinal rod is arranged directly below the left longitudinal beam of the helicopter. The material of the first longitudinal rod is steel. When installed, it is inserted into the front and rear joints from front to rear in the opposite direction of the heading. The front joint provides y and z translation constraints, and the rear joint provides x, y, z translation constraints and Mx rotation constraints. Through the force transmission design of the front and rear joints, the first longitudinal rod can achieve reliable fixation ( Figure 2 ). The first longitudinal rod is relatively long. In order to provide sufficient vertical rigidity, a first diagonal rod, a second diagonal rod, and a first vertical rod are designed to be connected end to end with the first longitudinal rod to form a first triangular support rod system.

[0051] A second triangular support bar system with the same structural form is arranged directly below the right longitudinal beam at the bottom of the helicopter. The two triangular support bar systems are symmetrical about the xoz section of the helicopter coordinate system.

[0052] In order to prevent the triangular support rod system from lateral instability, a lateral stabilizing rod system is designed at the middle connection of the first longitudinal rod to form a triangular support structure. Each rod is connected to the joint in the form of a pin for easy disassembly and assembly. A transverse support rod is designed at the end of the first longitudinal rod. One side of the transverse support rod exceeds the cross section of the right longitudinal beam triangular support rod system by a certain distance to form three support points.

[0053] The first blade support rod and the third blade support rod are the main support rods, and the second blade support rod and the fourth blade support rod are the auxiliary support rods. One end of the main support rod is connected to the blade through a blade clamp ( Figure 3 ), and the other end is placed at the intersection of the transverse support rod and the longitudinal rod. The second blade support rod intersects with the bottom of the third blade support rod and is placed at the intersection of the right longitudinal rod and the transverse support rod. The fourth blade support rod is placed at the outwardly extending end of the transverse support rod.

[0054] The propeller support rods are all retractable. Figure 4 The upper part of the propeller support rod has a large diameter, and the lower part is a detachable small diameter rod. Multiple sets of holes are opened along the axial direction of the rod where the upper and lower support rod walls overlap. Two latches are used to limit the position. According to the height of the main propeller blade, the thick and thin rods are extended and retracted, and then the latches are inserted to limit the position.

[0055] Mechanical model design of blade folding fixture ( Figure 5 ). Load transfer at the clamping point of the main blade: The loads at the clamping point of the main blade are the Y and Z direction loads Fy and Fz. There are the first blade support rod, the second blade support rod, the third blade support rod and the fourth blade support rod under each blade, forming a two-character herringbone support rod design. The auxiliary support rod only transfers axial loads. The connection points of the first blade support rod, the second blade support rod, the third blade support rod and the fourth blade support rod generate Fy and Fz to balance the force and moment;

[0056] The transverse support rod is a beam unit, extending a certain distance from the cross section of the triangular support rod system. When the inertial overload of the main blade supported above deviates to one side of the fuselage, the vertical load components of the second blade support rod and the third blade support rod can be offset, thereby reducing the vertical displacement of the end of the transverse support rod and limiting the overall deformation of the structure.

[0057] The first longitudinal rod and the second longitudinal rod are relatively long. In order to provide sufficient vertical rigidity, the rod material is steel. The first triangular support rod system and the second triangular support rod system can further improve the vertical rigidity of the structure and reduce the vertical deformation of the structure;

[0058] In order to prevent the first triangular support bar system and the second triangular support bar system from lateral instability, a lateral stabilizing bar system is provided to prevent the bar system from losing its bearing capacity due to instability.

[0059] Calculation of rod system loads and connection point loads. There are loads Fx, Fy, Fz, Mx, My, and Mz at the intersection of the ends of the first longitudinal rod and the second longitudinal rod and the transverse support rod. Fx and Mx are diffused through the fuselage connection point 2, that is, Fx2=Fx, Mx2=Mx. The end Fy and Fz are diffused through the fuselage connection points 1 and 2, that is, Fy=Fy1-Fy2, Fy*(L1+L2)=Fy1*L2, Fz=Fz1-Fz2, Fz*(L1+L2)=Fz1*L2. The end My is diffused through the Z-direction load couple of the connection points 1 and 2. The end Mz is diffused through the Y-direction load couple of the connection points 1 and 2.

[0060] Local detail load transfer design. The fuselage connection point 1 adopts a circular ring structure to connect with the fuselage joint, and the inner surface adopts a circular arc surface ( Figure 6 The first longitudinal rod and the second longitudinal rod transmit the Y-direction and Z-direction loads Fy and Fz through contact. The fuselage connection point 2 is connected to the fuselage joint using a sleeve structure with a pin ( Figure 7 ), transferring Fx, Fy, Fz, and Mx loads.

[0061] Finite element model stiffness verification ( Figure 8 )( Fig. 9 ). According to the loading design specifications, the inertial load at the center of gravity of the main blade is calculated and transferred to the blade clamping point through the blade equivalent model. The maximum deformation is obtained through the finite element calculation model. This value does not exceed the allowable value. The configuration design of the blade fixing device meets the strength and stiffness design requirements.

[0062] Installation details: Each pipe and joint are connected with quick-release pins, which is convenient for disassembly and assembly, reducing workload and improving work efficiency.

[0063] After the helicopter is parked, the pipe systems 6, 7, 8, 9 are connected through the joints 20, 25, 27 using the latches 17, 19, 24, 26, 28, 29 to form the first triangular support rod system ( Fig.10 ).

[0064] Use the pins 22, 23, 24, 26, 31, 32 to connect the pipe systems 10, 11, 12, 13 through the joints 20, 25, 30 to form a second triangular support rod system ( Fig.11 ).

[0065] Use latches 18, 19, 23 to connect pipe systems 14, 15 with pipe systems 8, 12 to form a laterally stable support structure;

[0066] After the assembly is completed, the joints 20, 25 are connected to the mounting device at the frame beam under the belly using the latches 16, 21, 24;

[0067] The transverse support rods are connected to the joints 27 and 30 using the latches 29 and 32 to form a transverse blade support structure ( Fig.12 ).

[0068] Then, the first blade support rod 1 and the third blade support rod 3 are used to move the main blade of the helicopter to the correct position, and then the second blade support rod 2 and the fourth blade support rod 4 are used to fix the main blade of the helicopter, and the second blade support rod 2 and the fourth blade support rod 4 are used to fix the main blade of the helicopter to the correct position ... Fig.13 )( Fig.14 ).

[0069] Among them, the joint material is 30CrMnSiA; the pin material is 30CrMnSiA, and the radius is 4mm;

[0070] The material of tube beams 6, 7, 8, 9, 10, 11, 12, 13, and 5 is 30CrMnSiA, and the material of tube beams 1, 2, 3, 4, 13, and 14 is 2A12 aluminum material.

[0071] Each connection adopts a quick disassembly and assembly structure. A universal joint is provided between the blade clamp and the strut. The strut is provided with a length adjustment mechanism to meet the needs of quick disassembly, folding position error compensation, etc.

Claims

1. A main blade folding and fixing device, characterized in that: The device comprises: The bottom support rod system is connected to the bottom longitudinal beam of the helicopter belly; A transverse support rod connected to one end of the bottom support rod system; A blade supporting rod system, one end of which is connected to the transverse supporting rod, and the other end of which is connected to the helicopter blade.

2. The device according to claim 1, characterized in that The bottom support rod system comprises: The first triangular support rod system is connected to the left longitudinal beam at the bottom of the helicopter belly; The second triangular support rod system is connected to the right longitudinal beam at the bottom of the helicopter belly; A lateral stabilizing rod system is arranged between the first triangular supporting rod system and the second triangular supporting rod system; the first triangular supporting rod system and the second triangular supporting rod system are the same.

3. The device according to claim 2, characterized in that The first triangular support rod system comprises: A first longitudinal rod having a joint, wherein the first longitudinal rod is connected to the left longitudinal beam at the bottom of the helicopter belly through the joint, the first longitudinal rod is parallel to the folded helicopter blades, and one end of the first longitudinal rod is connected to the transverse support rod; First diagonal bar; The second oblique rod; wherein the first longitudinal rod, the first oblique rod and the second oblique rod are connected end to end to form a triangular structure.

4. The device according to claim 3, characterized in that One end of the first oblique rod is connected to the other end of the first longitudinal rod; one end of the second oblique rod is connected to the other end of the first oblique rod, and the other end of the second oblique rod is connected to one end of the first longitudinal rod.

5. The device according to claim 4, characterized in that The first triangular support bar system also includes: A first vertical rod, one end of which is connected to the first longitudinal rod, and the other end of which is connected to the other end of the first oblique rod and one end of the second oblique rod.

6. The device according to claim 5, characterized in that The lateral stabilizer bar system comprises: lateral crossbar; Lateral diagonal rod; wherein the lateral cross rod, the lateral diagonal rod and the first vertical rod are connected end to end to form a triangular structure.

7. The device according to claim 1, characterized in that The blade support rod system comprises: A first herringbone support structure, arranged on the transverse support rod; A second herringbone supporting structure is arranged on the transverse supporting rod; wherein the first herringbone supporting structure is the same as the second herringbone supporting structure.

8. The device according to claim 7, characterized in that The first herringbone support structure comprises: a first blade brace, one end of which is connected to the transverse support rod; A second blade brace, one end of the second blade brace is connected to the other end of the first blade brace, and the other end of the second blade brace is connected to the transverse support rod.

9. The device according to claim 8, characterized in that The first blade support rod and the second blade support rod are telescopic rods, and the lengths of the telescopic rods can be adjusted; the first herringbone support structure also includes: A clamping component is connected to the other end of the first blade support rod and one end of the second blade support rod, and the clamping component is used to clamp the folded helicopter blade.

10. A helicopter, characterized in that: The helicopter comprises the main blade folding and fixing device according to any one of claims 1-9.

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