Important connecting structure based on expansion combination pin

Abstract

The invention relates to an important connecting structure based on expansion combination pins, which is characterized in that double lugs of a double-lug joint are respectively provided with an inner hole, a single-lug joint is also provided with an inner hole, the single-lug joint is inserted between the double lugs of the double-lug joint, and double-cone shear-resistant pins penetrate through the three inner holes of the single-lug joint and the double-lug joint; a left expansion taper sleeve and a right expansion taper sleeve are arranged on the left side and the right side of the double-taper shear pin in a sleeved mode respectively, a left lining is arranged between the left expansion taper sleeve and a left inner hole of the double-lug connector in a sleeved mode, and a right lining is arranged between the right expansion taper sleeve and a right inner hole of the double-lug connector in a sleeved mode. The shoulder of the left lining and the shoulder of the right lining abut against the two sides of a knuckle bearing arranged in an inner hole of the single-lug connector respectively. The structure is suitable for important / key connecting parts with super-large bearing capacity and impact resistance, and is convenient to disassemble frequently and convenient and reliable to disassemble.

Description

Technical Field

[0001] The invention relates to an important connection structure based on an expansion combination pin, and belongs to the field of aerospace structure design. Background Art

[0002] Large reusable aircraft in the aerospace field are restricted by factors such as transportation envelope, inspection and maintenance. Some important connection interfaces not only need to withstand various heavy loads within the entire mission profile, especially the impact load during landing, and match the deformation coordination in high and low temperature environments, but also need to have the ability to be repeatedly disassembled for easy maintenance.

[0003] Many important interfaces in the field use a single-ear and double-ear connection type, connected by a pin shaft, and the matching relationship between the hole and the shaft directly affects the load-bearing and disassembly capacity of the structure. The choice of traditional matching relationship generally uses clearance fit in situations where high loads are not required and frequent disassembly is required, while interference fit is generally used in scenarios where high loads are required. The manufacturing precision requirements are high, repeated disassembly and assembly at the shooting range are difficult, the maintenance cycle is long, and repeated disassembly will cause unnecessary wear to the hole shaft, which in turn affects the load and reduces the service life. The traditional hole-shaft matching cannot meet the interface requirements of high load and frequent disassembly proposed by new aircraft.

[0004] Therefore, it is necessary to provide an important connection structure based on expansion combination pins, which is suitable for key connection parts with ultra-large load-bearing and impact resistance, and has the ability to be frequently installed and disassembled. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies of the above-mentioned prior art and the requirements for interfaces with high load-bearing capacity and frequent disassembly proposed by new aircraft, the present invention proposes an important connection structure based on expansion combination pins, which is suitable for important / critical connection parts with ultra-large load-bearing capacity and impact resistance. The structure is convenient for frequent disassembly and the disassembly is easy and reliable.

[0007] (II) Technical solution

[0008] An important connection structure based on an expansion combination pin comprises: a double-ear joint (1), a single-ear joint (2), a double-cone shear pin (3), a left expansion cone sleeve (4), a right expansion cone sleeve (5), a left bushing (6), a right bushing (7), a left nut (8), a right nut (9), and a joint bearing (10); the two ears of the double-ear joint (1) respectively have inner holes, and the single-ear joint (2) also has an inner hole; the single-ear joint (2) is inserted between the two ears of the double-ear joint (1), and the three inner holes of the two are penetrated with the double-cone shear pin (3); A left expansion cone sleeve (4) and a right expansion cone sleeve (5) are respectively sleeved on the left and right sides of the cone shear pin (3); a left bushing (6) is sleeved between the left expansion cone sleeve (4) and the left inner hole of the double-ear joint (1); and a right bushing (7) is sleeved between the right expansion cone sleeve (5) and the left and right inner holes of the double-ear joint (1); the shoulders of the left bushing (6) and the right bushing (7) respectively abut against the two sides of the joint bearing (10) arranged in the inner hole of the single-ear joint (2); and a left nut (8) and a right nut (9) are respectively arranged at both ends of the double-cone shear pin (3).

[0009] The middle part of the double-cone shear pin (3) is the thickest and gradually becomes thinner towards the two ends, forming two symmetrical or asymmetrical pin cone surfaces (301); the two ends of the double-cone shear pin (3) have external threads (302) respectively adapted to the left nut (8) and the right nut (9), and two cotter pin holes (304) are respectively arranged at the two external threads (302); the two ends of the double-cone shear pin (3) are respectively arranged with two hexagonal mounting positioning holes (303); each cotter pin hole (304) respectively penetrates into the corresponding hexagonal mounting positioning hole (303).

[0010] The taper range of the pin taper surface (301) is 1:20 to 1:5.

[0011] The left nut (8) and the right nut (9) have the same structure, and the effective thread length of the external thread (302) can ensure that after the left nut (8) and the right nut (9) are tightened, the thread protrudes 1 to 2 pitches from the corresponding nut, and the pitch does not contain chamfers.

[0012] The left expansion cone sleeve (4) and the right expansion cone sleeve (5) have the same structure, both are conical inner profile sleeves, both have a sleeve cone surface (401) and a longitudinal opening (402), and the taper of the sleeve cone surface (401) is the same as the taper of the matching pin cone surface (301) in the double-cone shear pin 3.

[0013] The double-ear joint (1) and the single-ear joint (2) are made of high-strength titanium alloy or precipitation-hardened stainless steel to meet the requirements of high performance and light weight; the double-cone shear pin (3), the left bushing (6) and the right bushing (7) are made of precipitation-hardened stainless steel, and the left bushing (6) and the right bushing (7) are both shouldered to improve the wear resistance and load-bearing capacity of the inner hole.

[0014] The precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, the heat treatment adopts H540, and the tensile strength is treated to be greater than or equal to 1415MPa, so that it has high strength, excellent fracture toughness and impact resistance.

[0015] The left expansion cone sleeve (4) and the right expansion cone sleeve (5) are made of precipitation hardened stainless steel; the precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, and the heat treatment adopts H595, so that its hardness is slightly lower than that of the double cone shear pin (3), the left bushing (6) and the right bushing (7), but it has better toughness. A suitable bronze alloy can also be used, and artificial failure heat treatment is performed to a tensile strength greater than or equal to 800MPa.

[0016] The spherical plain bearing (10) is a self-lubricating spherical plain bearing.

[0017] If the space is small and the impact load is large, the spherical plain bearing (10) should be a steel-on-steel lubricated radial spherical plain bearing.

[0018] (III) Beneficial effects

[0019] The present invention discloses an important connection structure based on an expansion combination pin. The structure mainly eliminates the gap between the hole and the shaft through the matching design of the expansion cone sleeve and the double-cone shear pin. Compared with the traditional straight pin, the conical shear pin is easy to disassemble and repeatedly install. Compared with the existing hole-shaft matching structure, it can meet high load-bearing requirements while achieving quick and convenient installation and disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of an important connection structure based on expansion combination pins;

[0021] Figure 2 Figure 1 A cross-sectional view of

[0022] Figure 3 Schematic diagram and cross-sectional view of double-cone shear pin;

[0023] Figure 4 Schematic diagram and cross-sectional view of two expansion cone sleeves;

[0024] Figure 5 The overall structure diagram and cross-sectional view of the two expansion cone sleeves after assembly. DETAILED DESCRIPTION

[0025] See also Figure 1-2The present invention discloses an important connection structure based on an expansion combination pin, comprising a double-ear joint 1, a single-ear joint 2, a double-cone shear pin 3, a left expansion cone sleeve 4, a right expansion cone sleeve 5, a left bushing 6, a right bushing 7, a left nut 8, a right nut 9, and a joint bearing 10; the two ears of the double-ear joint 1 respectively have inner holes, and the single-ear joint 2 also has an inner hole, the single-ear joint 2 is inserted between the two ears of the double-ear joint 1, and the three inner holes of the two are penetrated by the double-cone shear pin 3; the left expansion cone sleeve 4 and the right expansion cone sleeve 5 are respectively sleeved on the left and right sides of the double-cone shear pin 3, the left bushing 6 is sleeved between the left expansion cone sleeve 4 and the left inner hole of the double-ear joint 1, and the right bushing 7 is sleeved between the right expansion cone sleeve 5 and the left and right inner holes of the double-ear joint 1; the shoulders of the left bushing 6 and the right bushing 7 respectively abut against the two sides of the joint bearing 10 arranged in the inner hole of the single-ear joint 2; the left nut 8 and the right nut 9 are respectively arranged at both ends of the double-cone shear pin 3.

[0026] See also Figure 2-3 The middle part of the double-cone shear pin 3 is the thickest and gradually tapers toward the two ends, forming two symmetrical or asymmetrical pin cone surfaces 301; the two ends of the double-cone shear pin 3 have external threads 302 respectively adapted to the left nut 8 and the right nut 9, and two cotter pin holes 304 are respectively arranged at the two external threads 302; two hexagonal mounting positioning holes 303 are respectively arranged at the two ends of the double-cone shear pin 3; each cotter pin hole 304 respectively penetrates into the corresponding hexagonal mounting positioning hole 303.

[0027] The taper range of the pin taper surface 301 is 1:20 to 1:5.

[0028] The left nut 8 and the right nut 9 have the same structure, and the effective thread length of the external thread 302 can ensure that after the left nut 8 and the right nut 9 are tightened, the thread protrudes from the corresponding nut by 1 to 2 pitches, and the pitch does not contain chamfers.

[0029] See also Figure 4-5 The left expansion cone sleeve 4 and the right expansion cone sleeve 5 have the same structure, both are conical inner profile sleeves, both have a sleeve cone surface 401 and a longitudinal opening 402, and the taper of the sleeve cone surface 401 is the same as the taper of the matching pin cone surface 301 in the double-cone shear pin 3.

[0030] The double-ear joint 1 and the single-ear joint 2 are made of high-strength titanium alloy or precipitation-hardened stainless steel to meet the requirements of high performance and lightweight.

[0031] The double-cone shear pin 3, the left bushing 6 and the right bushing 7 are made of precipitation-hardened stainless steel. Both the left bushing 6 and the right bushing 7 are shouldered to improve the wear resistance and load-bearing capacity of the inner hole.

[0032] The precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, the heat treatment adopts H540, and the tensile strength is treated to be greater than or equal to 1415MPa, so that it has high strength, excellent fracture toughness and impact resistance.

[0033] The left expansion cone sleeve 14 and the right expansion cone sleeve 5 are made of precipitation hardened stainless steel.

[0034] The precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, and the heat treatment is H595, so that its hardness is slightly lower than that of the double cone shear pin 3, the left bushing 6 and the right bushing 7, but it has better toughness. A suitable bronze alloy can also be used, and artificial failure heat treatment is performed to a tensile strength greater than or equal to 800MPa.

[0035] The left nut 8 and the right nut 9 are made of the same material, which matches the double-cone shear pin 3 to prevent sticking.

[0036] For example, if the double-taper shear pin 3 is made of 0Cr13Ni8Mo2Al, the matching nut can be made of high-temperature alloy GH4169, heat-treated to 1200MPa or more, to achieve thread strength matching with the double-taper shear pin 3; at the same time, surface treatment should be carried out as needed, such as anodizing for titanium alloy parts, and passivation for precipitation-hardened stainless steel and high-temperature alloy parts; this set of connection structure is suitable for key connection parts with ultra-large load-bearing and impact-resistant properties, and can also effectively prevent corrosion and avoid the risk of hydrogen embrittlement.

[0037] The inner hole of the double-ear joint 1 is respectively fitted with the left bushing 6 and the right bushing 7 by an interference fit of H7 / s6 to ensure that no rotational wear occurs between the two.

[0038] See also Figure 2 The axial distance between the left expansion cone sleeve 4 and the right expansion cone sleeve 5 is L1. The L1 gap size is based on the maximum gap and taper of the double-cone shear pin 3 and the left expansion cone sleeve 4 and the right expansion cone sleeve 5. At the same time, the length tolerance of the two expansion cone sleeves is controlled within the range of -0.2 to 0 mm.

[0039] The axial distance between the outer side surface of the left ear of the double-ear joint 1 and the right side surface of the left nut 8 is L2, and the axial distance between the outer side surface of the right ear of the double-ear joint 1 and the left side surface of the right nut 8 is L3. The negative tolerance of the dimensions of L2 and L3 is controlled by assembly to a maximum of 0.5 mm to ensure that a small gap is still left in L1 after actual assembly to avoid premature contact between the two expansion cone sleeves, which may cause a clearance fit of the pin shaft of the double-cone shear pin 3.

[0040] The spherical plain bearing 10 is a self-lubricating spherical plain bearing.

[0041] If the space is small and the impact load is large, the spherical plain bearing 10 should be a steel-on-steel lubricated radial spherical plain bearing.

[0042] The spherical bearing 10 and the inner hole of the single-ear joint 2 are interference fit, and the size tolerance of the inner hole is M7; a boss is set at one end of the single-ear joint 2, and a groove rolled and closed by a steel ball or roller is set at the other end to fix the spherical bearing 10.

[0043] The working principle of an important connection structure based on an expansion combination pin of the present invention is as follows: during the tightening process of the left nut 8 and the right nut 9, the sleeve cone surface 401 is squeezed onto the pin cone surface 301 of the double cone shear pin 3. Based on the longitudinal opening 402, and the two expansion cone sleeves are lower in hardness than the double cone shear pin 3 and the two bushings, expansion deformation occurs, thereby eliminating the gap between the hole and the shaft. Compared with the traditional hole-shaft matching, the present invention can ensure sufficient extrusion area and more uniform force. During the installation of the expansion cone sleeve, the middle surface of the longitudinal opening 402 should be placed in the vertical plane (XOZ plane) of the main load direction (Y direction), thereby avoiding the extrusion area from being affected and being more conducive to load transmission. At the same time, the present invention is easy to install and disassemble, and has excellent reusability. After the expansion cone sleeve is pushed out during each disassembly process, there is enough gap between the hole and the shaft to facilitate the disassembly of the joint, simplifying installation and maintenance.

Claims

1. An important connection structure based on expansion combination pins, characterized in that: The invention comprises a double-ear joint (1), a single-ear joint (2), a double-cone shear pin (3), a left expansion cone sleeve (4), a right expansion cone sleeve (5), a left bushing (6), a right bushing (7), a left nut (8), a right nut (9), and a joint bearing (10); the two ears of the double-ear joint (1) respectively have inner holes, and the single-ear joint (2) also has an inner hole; the single-ear joint (2) is inserted between the two ears of the double-ear joint (1), and the three inner holes of the two are penetrated with the double-cone shear pin (3); the double-cone shear pin (3) is connected to the left A left expansion cone sleeve (4) and a right expansion cone sleeve (5) are respectively sleeved on the left and right sides; a left bushing (6) is sleeved between the left expansion cone sleeve (4) and the left inner hole of the double-ear joint (1); a right bushing (7) is sleeved between the right expansion cone sleeve (5) and the right inner hole of the double-ear joint (1); the shoulders of the left bushing (6) and the right bushing (7) respectively abut against the two sides of a joint bearing (10) arranged in the inner hole of the single-ear joint (2); and a left nut (8) and a right nut (9) are respectively arranged at both ends of the double-cone shear pin (3).

2. The important connection structure based on the expansion combination pin according to claim 1 is characterized in that: The middle part of the double-cone shear pin (3) is the thickest and gradually becomes thinner towards the two ends, forming two symmetrical or asymmetrical pin cone surfaces (301); the two ends of the double-cone shear pin (3) have external threads (302) respectively adapted to the left nut (8) and the right nut (9), and two cotter pin holes (304) are respectively arranged at the two external threads (302); the two ends of the double-cone shear pin (3) are respectively arranged with two hexagonal mounting positioning holes (303); each cotter pin hole (304) respectively penetrates into the corresponding hexagonal mounting positioning hole (303).

3. The important connection structure based on the expansion combination pin according to claim 2 is characterized in that: The taper range of the pin taper surface (301) is 1:20 to 1:

5.

4. The important connection structure based on the expansion combination pin according to claim 2, characterized in that: The left nut (8) and the right nut (9) have the same structure, and the effective thread length of the external thread (302) can ensure that after the left nut (8) and the right nut (9) are tightened, the thread protrudes 1 to 2 pitches from the corresponding nut, and the pitch does not contain chamfers.

5. The important connection structure based on the expansion combination pin according to claim 2, characterized in that: The left expansion cone sleeve (4) and the right expansion cone sleeve (5) have the same structure, both are conical inner profile sleeves, both have a sleeve cone surface (401) and a longitudinal opening (402), and the taper of the sleeve cone surface (401) is the same as the taper of the matching pin cone surface (301) in the double-cone shear pin 3.

6. The important connection structure based on the expansion combination pin according to claim 1, characterized in that: The double-ear joint (1) and the single-ear joint (2) are made of high-strength titanium alloy or precipitation-hardened stainless steel to meet the requirements of high performance and light weight; the double-cone shear pin (3), the left bushing (6) and the right bushing (7) are made of precipitation-hardened stainless steel, and the left bushing (6) and the right bushing (7) are both shouldered to improve the wear resistance and load-bearing capacity of the inner hole.

7. The important connection structure based on the expansion combination pin according to claim 6 is characterized in that: The precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, the heat treatment adopts H540, and the tensile strength is treated to be greater than or equal to 1415MPa, so that it has high strength, excellent fracture toughness and impact resistance.

8. The important connection structure based on the expansion combination pin according to claim 7 is characterized in that: The left expansion cone sleeve (4) and the right expansion cone sleeve (5) are made of precipitation hardened stainless steel; the precipitation hardened stainless steel is 0Cr13Ni8Mo2Al, and the heat treatment adopts H595, so that its hardness is slightly lower than that of the double cone shear pin (3), the left bushing (6) and the right bushing (7), but it has better toughness. A suitable bronze alloy can also be used, and artificial failure heat treatment is performed to a tensile strength greater than or equal to 800MPa.

9. The important connection structure based on the expansion combination pin according to claim 1, characterized in that: The spherical plain bearing (10) is a self-lubricating spherical plain bearing.

10. The important connection structure based on the expansion combination pin according to claim 1, characterized in that: If the space is small and the impact load is large, the spherical plain bearing (10) should be a steel-on-steel lubricated radial spherical plain bearing.

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