An engine mounting joint structure system based on metal rubber

Abstract

The present invention discloses an engine mounting node structural system based on metal rubber, which is arranged on a main mounting plane and an auxiliary mounting plane, wherein the main mounting plane is provided with a main mounting node and two symmetrically distributed and structurally identical first and second front auxiliary fulcrums, and the auxiliary mounting plane is provided with an auxiliary mounting node. The main mounting node is a firm connection point, which limits the freedom of the engine in six directions and bears most of the weight and thrust of the engine. The front auxiliary fulcrum is provided with axial metal rubber and radial metal rubber, and the auxiliary mounting node is provided with annular metal rubber and trapezoidal cross-section metal rubber, which can effectively isolate the multi-directional broadband vibration of the engine. The engine mounting node structural system of the present invention has the advantages of simple structure, strong environmental adaptability, broadband vibration isolation and multi-directional vibration isolation, and has broad application prospects in the field of aircraft engine mounting node structural design.

Description

Technical Field

[0001] The invention belongs to the field of aerospace engine mounting node structure design, and in particular relates to an engine mounting node structure system based on metal rubber. Background Art

[0002] Aircraft engines are one of the primary excitation sources in aircraft. Their vibrations can cause vibrations in the fuselage, compromising the safety and reliability of onboard equipment. Considering vibration isolation / vibration isolation measures in the structural design of the engine mounting section is a key measure to improve cabin noise and fuselage vibration. Both the US Civil Aviation Regulations (FAR-25) and the Chinese Civil Aviation Regulations (CCAR-25) clearly stipulate that vibration isolation measures should be implemented in the engine mounting section to reduce the response caused by engine vibration.

[0003] The engine mounting node is usually a set of two mounting planes and six constrained connection structures. Of the two mounting planes of the mounting node, one plane is provided with a main mounting node, and the other plane is provided with an auxiliary mounting node. The main mounting node mainly bears the engine thrust load, weight, gyroscopic torque and inertial load of maneuvering flight, etc., and there are generally two or three of them. In order to ensure the axial positioning of the engine stator components, one of the main mounting nodes is fixedly connected to the aircraft. The auxiliary mounting node bears part of the engine's gravity, bending moment and torque, but does not bear axial loads, that is, the auxiliary mounting node bears loads other than thrust. In order to compensate for the thermal expansion of the casing when the engine is working, the auxiliary mounting node has a certain gap in the axial direction. In order to ensure the accurate axial positioning of the engine, vibration isolation measures are generally taken at the mounting nodes other than the main mounting node that is fixedly connected to the aircraft.

[0004] Current vibration isolation designs for engine mounting joints often utilize damping materials, such as rubber or metal rubber, to provide high damping across a wide frequency band. However, under high-frequency, high-amplitude vibrations, the rubber material heats up, leading to unstable isolator performance. Furthermore, rubber has poor high and low temperature resistance and is susceptible to aging, limiting its practical application in aircraft engines. Metal rubber is an elastic, highly efficient damping porous material manufactured from metal wire through a process involving wire selection, winding, stretching, braiding, and molding. When subjected to load, relative slippage between the wires creates dry friction damping, converting vibration energy into internal energy dissipation. Due to its combined high and low temperature resistance, resistance to aging, and wide-band vibration isolation capabilities, metal rubber is widely used in vibration isolator designs in the aerospace industry. However, current metal rubber mounting joints for engines only offer good vibration isolation performance in a single direction, making it difficult to achieve efficient multi-directional vibration isolation. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides an engine mounting node structure system based on metal rubber, which not only has a simple structure and strong environmental adaptability, but also has the ability of broadband vibration isolation and multi-directional vibration isolation. It can isolate the broadband vibration of the engine in multiple directions, effectively reduce the vibration level of the aircraft fuselage, and ensure the safety and reliability of airborne equipment.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A metal-rubber-based engine mounting node structure system achieves multi-directional, broadband vibration isolation for aircraft engines, thereby reducing the vibration level of the aircraft fuselage and ensuring the safety and reliability of onboard equipment. The mounting node structure is arranged on two planes: a main mounting node and an auxiliary mounting plane. The main mounting plane is equipped with a main mounting node and two symmetrically distributed and structurally identical first and second front auxiliary fulcrums. The auxiliary mounting plane is equipped with an auxiliary mounting node.

[0008] The main mounting section includes a mounting lug and a W-shaped main mounting section. The mounting lug is provided with a lug mounting edge and two bending-resistant subplates. The lug mounting edge is provided with a lug pin hole and two lug bolt holes. The W-shaped main mounting section is provided with two symmetrically distributed flange mounting edges and an aircraft mounting edge. The flange mounting edge is provided with a main mounting section pin hole and two main mounting section bolt holes. The aircraft mounting edge is provided with two aircraft pin holes and four aircraft bolt holes. Circumferential positioning pins are sequentially inserted through the main mounting section pin holes and lug pin holes to achieve circumferential positioning of the W-shaped main mounting section and the mounting lug. Two main mounting section mounting bolts are sequentially inserted through the main mounting section bolt holes and lug bolt holes to achieve a secure connection between the mounting lug and the W-shaped main mounting section. The W-shaped main mounting section is axially positioned with respect to the aircraft fuselage by pin connection through the two aircraft pin holes on the aircraft mounting edge and is securely connected to the aircraft fuselage by bolt connection through the four aircraft bolt holes on the aircraft mounting edge.

[0009] The first and second front auxiliary fulcrums have identical structures. They include an outer bushing, an axial metal rubber, a radial metal rubber, an inner bushing, a bracket, and front auxiliary fulcrum bolts. The bracket is provided with a bracket bolt hole and six bracket mounting bolt holes, which secure the bracket to the engine via the six bracket mounting bolts. A front auxiliary fulcrum bolt passes through the outer bushing, axial metal rubber, radial metal rubber, inner bushing, and bracket bolt holes in sequence to secure the bracket to the aircraft fuselage.

[0010] The auxiliary mounting section comprises a core post, a circular metal rubber, a base, a trapezoidal metal rubber, an end cap, a mounting nut, a ball joint, and a fixed tail. The core post passes through the circular metal rubber, base, trapezoidal metal rubber, and end cap in sequence and is secured with the mounting nut, forming the main structure of the auxiliary mounting section. The base is provided with three base bolt holes for connecting the auxiliary mounting section to the engine; the end cap is connected to the fixed tail via a ball joint; the fixed tail is provided with two tail bolt holes for connecting the auxiliary mounting section to the aircraft fuselage.

[0011] Furthermore, the main mounting plane is provided with a main mounting node and two symmetrically distributed and structurally identical first and second front auxiliary fulcrums, thereby ensuring symmetrical load distribution, avoiding the generation of additional bending moments, and facilitating the reduction of loads transmitted to the aircraft fuselage.

[0012] Furthermore, the main mounting joint is a strong connection point that limits the freedom of the engine in six directions. The main mounting joint bears most of the weight and thrust of the engine.

[0013] Furthermore, the first front auxiliary support point and the second front auxiliary support point are provided with axial metal rubber and radial metal rubber to avoid over-constraint in assembly and effectively isolate the axial and radial multi-directional broadband vibration of the engine.

[0014] Furthermore, the auxiliary mounting section is provided with a circular metal rubber and a trapezoidal cross-section metal rubber, which is an elastic structure for isolating the broadband vibration of the engine, thereby reducing the vibration level of the aircraft fuselage;

[0015] Furthermore, the auxiliary mounting section adopts a trapezoidal cross-section metal rubber, which has a high-efficiency broadband vibration isolation capability under multi-directional loads;

[0016] Furthermore, the auxiliary mounting joint does not limit the axial freedom of the engine and is used to compensate for the thermal expansion of the engine casing when the engine is working, thereby avoiding excessive thermal stress.

[0017] Furthermore, the auxiliary mounting joint is connected to the engine and the aircraft via a ball joint, which facilitates the assembly and disassembly of the auxiliary mounting joint.

[0018] The advantages of the metal rubber-based engine mounting joint structure system of the present invention are:

[0019] (1) The engine mounting structure proposed by the present invention has a simple structural layout, is easy to assemble and disassemble, and has high reliability;

[0020] (2) The engine mounting joint structure proposed by the present invention is provided with three mounting joints on the main mounting plane, which can reduce the load on the main mounting joint and is conducive to improving the safety and reliability of the mounting joint structure system;

[0021] (3) The W-shaped main installation section proposed in the present invention adopts a symmetrically distributed flange installation edge design, which can ensure that the load is symmetrically transmitted along the center line of the main installation section, avoiding the generation of additional bending moment at the main installation section;

[0022] (4) The engine mounting structure proposed by the present invention uses metal rubber as the damping material, which has the advantages of strong environmental adaptability, strong load-bearing capacity and not easy to age;

[0023] (5) The first front auxiliary fulcrum, the second front auxiliary fulcrum and the auxiliary mounting joint proposed in the present invention all have multi-directional broadband vibration isolation capabilities, which can effectively isolate the multi-directional broadband vibration of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a right side view showing the installation of a metal rubber-based engine mounting section structure system on an engine.

[0025] Figure 2 This is a schematic front view of the installation of a metal rubber-based engine mounting node structural system on an engine.

[0026] Figure 3 This is a schematic diagram of the mounting lug structure of the main mounting section in the engine mounting section structure system based on metal rubber.

[0027] Figure 4 It is a schematic diagram of the W-shaped main mounting section structure of the main mounting section in the metal rubber-based engine mounting section structure system.

[0028] Figure 5 It is an exploded view of the front auxiliary support point in the metal rubber-based engine mounting structure system.

[0029] Figure 6 It is a structural diagram of the front auxiliary support point in the metal rubber-based engine mounting joint structural system.

[0030] Figure 7 It is an exploded view of the auxiliary mounting section in the metal rubber-based engine mounting section structure system.

[0031] Figure 8 It is a structural diagram of the auxiliary mounting section in the metal rubber-based engine mounting section structural system.

[0032] Figure 9 This is a schematic diagram of the response of the aircraft fuselage under impact loads when the metal rubber-based engine mounting node structural system is installed.

[0033] In the figure: A. Main mounting section, B. First front auxiliary pivot point, C. Second front auxiliary pivot point, D. Auxiliary mounting section, 1. Engine, 2. Mounting lugs, 3. W-shaped main mounting section;

[0034] 21. Lug mounting edge, 22. Lug pin hole, 23. First lug bolt hole, 24. Second lug bolt hole, 25. First anti-bending sub-plate, 26. Second anti-bending sub-plate;

[0035] 31. First flange mounting edge, 32. Second flange mounting edge, 33. Main mounting section pin hole, 34. First main mounting section bolt hole, 35. Second main mounting section bolt hole, 36. Aircraft mounting edge, 37. First aircraft bolt hole, 38. Second aircraft bolt hole, 39. Third aircraft bolt hole, 310. Fourth aircraft bolt hole, 311. First aircraft pin hole, 312. Second aircraft pin hole;

[0036] 41. Outer bushing, 42. Axial metal rubber, 43. Radial metal rubber, 44. Inner bushing, 45. Bracket bolt hole, 46. Front auxiliary fulcrum bolt, 47. Bracket, 48. First bracket mounting bolt hole, 49. Second bracket mounting bolt hole, 410. Third bracket mounting bolt hole, 411. Fourth bracket mounting bolt hole, 412. Fifth bracket mounting bolt hole, 413. Sixth bracket mounting bolt hole;

[0037] 51. Core column, 52. Annular metal rubber, 53. Base, 54. Trapezoidal metal rubber, 55. End cover, 56. Mounting nut, 57. Ball joint, 58. Fixed tail end, 59. First tail end bolt hole, 510. Second tail end bolt hole, 511. First base bolt hole, 512. Second base bolt hole, 513. Third base bolt hole. DETAILED DESCRIPTION

[0038] In order to make the technical solutions and key points of the present invention clearer, the following Figures 1-8 The invention is fully described with specific examples.

[0039] like Figures 1-8 As shown, an embodiment of the present invention relates to an engine mounting node structure system based on metal rubber. The mounting node structure is not only simple in structure and highly adaptable to the environment, but also has the ability of broadband vibration isolation and multi-directional vibration isolation. It can isolate the broadband vibration of the engine in multiple directions, effectively reduce the vibration level of the aircraft fuselage, and ensure the safety and reliability of the onboard equipment.

[0040] like Figure 1 and Figure 2 As shown, the mounting section structure is provided on two planes, the main mounting plane and the auxiliary mounting plane of the engine 1. The main mounting plane is provided with a main mounting section A, as well as two symmetrically distributed and structurally identical first and second front auxiliary fulcrums B and C. The auxiliary mounting plane is provided with an auxiliary mounting section D. The main mounting section A includes a mounting lug 2 and a W-shaped main mounting section 3.

[0041] like Figure 3 As shown, the mounting lug 2 is provided with a lug mounting edge 21, as well as a first anti-bending sub-plate 25 and a second anti-bending sub-plate 26. The lug mounting edge 21 is provided with a lug pin hole 22, a first lug bolt hole 23, and a second lug bolt hole 24. The first anti-bending sub-plate 25 and the second anti-bending sub-plate 26 are used to increase the bending stiffness of the mounting lug 2.

[0042] like Figure 4 As shown, the W-shaped main mounting section 3 is provided with two symmetrically distributed and structurally identical first and second flange mounting edges 31 and 32, as well as an aircraft mounting edge 36. The W-shaped main mounting section 3 is designed with symmetrically distributed and structurally identical first and second flange mounting edges 31 and 32 to ensure that the load is symmetrically transmitted along the centerline of the main mounting section, avoiding the generation of additional bending moments at the main mounting section. The first flange mounting edge 31 is provided with a first main mounting section bolt hole 34 and a second main mounting section bolt hole 35, as well as a main mounting section pin hole 33. The aircraft mounting edge 36 is provided with a first aircraft bolt hole 37, a second aircraft bolt hole 38, a third aircraft bolt hole 39, and a fourth aircraft bolt hole 310, as well as a first aircraft pin hole 311 and a second aircraft pin hole 312. The circumferential positioning pins sequentially pass through the main mounting section pin holes 33 and the lug pin holes 22 to achieve circumferential positioning of the W-shaped main mounting section 3 and the mounting lug 2. Two main mounting section mounting bolts sequentially pass through the first main mounting section bolt hole 34 and the first lug bolt hole 23, as well as the second main mounting section bolt hole 35 and the second lug bolt hole 24, to achieve the connection and fixation between the W-shaped main mounting section 3 and the mounting lug 2. The W-shaped main mounting section is axially positioned with the aircraft fuselage by pinning through the first aircraft pin hole 311 and the second aircraft pin hole 312; and is bolted to the aircraft fuselage by bolting through the first aircraft bolt hole 37, the second aircraft bolt hole 38, the third aircraft bolt hole 39, and the fourth aircraft bolt hole 310.

[0043] The structures of the first front auxiliary support point and the second front auxiliary support point are completely identical, and the specific implementation method thereof is described by taking the first auxiliary installation section as an example. Figure 5 and Figure 6As shown, the first front auxiliary fulcrum B includes an outer bushing 41, an axial metal rubber 42, a radial metal rubber 43, an inner bushing 44, a bracket 47, and a front auxiliary fulcrum bolt 46. The bracket 47 is provided with a bracket bolt hole 45, as well as a first bracket mounting bolt hole 48, a second bracket mounting bolt hole 49, a third bracket mounting bolt hole 410, a fourth bracket mounting bolt hole 411, a fifth bracket mounting bolt hole 412, and a sixth bracket mounting bolt hole 413. Six bolts are used to secure the bracket 47 to the engine 1. A front auxiliary fulcrum bolt 46 passes through the outer bushing 41, the axial metal rubber 42, the radial metal rubber 43, the inner bushing 44, and the bracket bolt hole 45 in sequence, and is secured to the aircraft fuselage.

[0044] like Figure 7 and Figure 8 As shown, the auxiliary mounting section D includes a core column 51, a circular metal rubber 52, a base 53, a trapezoidal cross-section metal rubber 54, an end cover 55, a mounting nut 56, a ball joint 57 and a fixed tail end 58. The core column 51 passes through the circular metal rubber 52, the base 53, the trapezoidal cross-section metal rubber 54 and the end cover 55 in sequence, and is fixed by the mounting nut 56 to form the main structure of the auxiliary mounting section D. The base 53 is provided with a first base bolt hole 511, a second base bolt hole 512 and a third base bolt hole 513, and the auxiliary mounting section D is connected to the engine 1 by three bolts. The end cover 55 is connected to the fixed tail end 58 by a ball joint 57. The fixed tail end 58 is provided with a first tail end bolt hole 59 and a second tail end bolt hole 510, and the auxiliary mounting section D is connected to the aircraft fuselage by two bolts.

[0045] like Figure 2 As shown, the mounting node structure is provided with a main mounting node A on the main mounting plane, and two symmetrically distributed and structurally identical first front auxiliary fulcrums B and second front auxiliary fulcrums C. The three-point structural layout can reduce the load on the main mounting node A, which is beneficial to improving the safety and reliability of the mounting node structural system. The main mounting node A is a firm connection point that limits the freedom of the engine in six directions. The main mounting node A bears most of the weight and thrust of the engine. The first front auxiliary fulcrum B and the second front auxiliary fulcrum C are symmetrically distributed along the radial direction of the engine and have completely identical structures to ensure symmetrical load distribution and avoid additional bending moments on the engine casing. As shown Figure 5 and Figure 6 As shown, the front auxiliary support point B is provided with an axial metal rubber 42 and a radial metal rubber 43 , which can effectively isolate the axial and radial multi-directional broadband vibration of the engine 1 while avoiding over-constraint in assembly.

[0046] like Figure 7 and Figure 8As shown, the auxiliary mounting node D is supported by a circular metal rubber 52 and a trapezoidal cross-section metal rubber 54. The entire structure is an elastic component that can isolate the broadband vibration of the engine 1. The trapezoidal cross-section metal rubber 54 has a high-efficiency broadband vibration isolation capability under multi-directional loads and can isolate the multi-directional vibration loads of the engine 1. The auxiliary mounting node D connects the engine 1 and the aircraft via a ball joint 57, facilitating the assembly and disassembly of the auxiliary mounting node D. The auxiliary mounting node D does not limit the axial freedom of the engine and is used to compensate for the thermal expansion of the engine casing during operation to avoid excessive thermal stress.

[0047] like Figure 9 As shown, the dashed line represents the aircraft's vibration displacement response curve under a 50g-11ms impact load in the X-direction, the dashed line represents the aircraft's vibration displacement response curve under a 50g-11ms impact load in the Y-direction, and the dotted line represents the aircraft's vibration displacement response curve under a 50g-11ms impact load in the Z-direction. The impact loads are broadband in the frequency domain. Under impact loads in all three directions, the aircraft's vibration displacement is relatively small in magnitude and decays rapidly. This demonstrates the advantages of the metal-rubber-based engine mounting structure system for multi-directional broadband vibration isolation.

[0048] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A metal rubber-based engine mounting joint structure system, characterized by: Set on the main installation plane and the auxiliary installation plane, wherein the main installation plane is provided with a main installation node and two symmetrically distributed and structurally identical first and second front auxiliary support points, and the auxiliary installation plane is provided with an auxiliary installation node; The main mounting section includes a mounting lug and a W-shaped main mounting section. The W-shaped main mounting section is circumferentially positioned by a circumferential positioning pin and the mounting lug, and is connected and fixed by two main mounting section mounting bolts and the mounting lug. The W-shaped main mounting section is axially positioned with the aircraft fuselage by pinning through two aircraft pin holes, and is connected and fixed to the aircraft fuselage by bolting through four aircraft bolt holes. The structures of the first front auxiliary fulcrum and the second front auxiliary fulcrum are completely identical; the first front auxiliary fulcrum and the second front auxiliary fulcrum include an outer bushing, an axial metal rubber, a radial metal rubber, an inner bushing, a bracket and a front auxiliary fulcrum bolt; the bracket is connected and fixed to the engine through six bracket mounting bolts; the front auxiliary fulcrum bolts pass through the outer bushing, axial metal rubber, radial metal rubber, inner bushing and bracket bolt holes in sequence, and are connected and fixed to the aircraft fuselage.

2. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: The auxiliary mounting section includes a core column, a circular metal rubber, a base, a trapezoidal cross-section metal rubber, an end cover, a mounting nut, a ball joint and a fixed tail end; the core column passes through the circular metal rubber, the base, the trapezoidal cross-section metal rubber and the end cover in sequence, and is fixed by a mounting nut to form the main structure of the auxiliary mounting section; three base bolt holes are provided on the base for connecting and fixing the auxiliary mounting section to the engine; the end cover is connected to the fixed tail end through a ball joint; the fixed tail end is provided with two tail end bolt holes for connecting and fixing the auxiliary mounting section to the aircraft fuselage.

3. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: A main mounting node and two symmetrically distributed and structurally identical first and second front auxiliary fulcrums are set on the main mounting plane to ensure symmetrical load distribution, avoid the generation of additional bending moment, and help reduce the load transmitted to the aircraft fuselage.

4. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: The main mounting node is a strong connection point that limits the freedom of the engine in six directions and bears most of the weight and thrust of the engine.

5. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: The first front auxiliary support point and the second front auxiliary support point are provided with axial metal rubber and radial metal rubber to avoid over-constraint in assembly and effectively isolate the axial and radial multi-directional broadband vibration of the engine.

6. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: The auxiliary installation joint is connected to the engine and the aircraft via a ball joint, which facilitates the assembly and disassembly of the auxiliary installation joint.

7. The metal rubber-based engine mounting joint structure system according to claim 1, characterized in that: The auxiliary mounting section is provided with an annular metal rubber and a trapezoidal cross-section metal rubber, which are used to isolate the multi-directional broadband vibration of the engine, thereby reducing the vibration level of the aircraft fuselage.

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