Front landing gear strut universal joint deflection angle detection device and detection method

Abstract

The application provides a front landing gear strut universal joint deflection angle detection device and detection method. The front landing gear strut universal joint deflection angle detection device comprises a handle, a pointer, a connecting shaft, a bushing, a scale disc and a pull rod, the scale disc is installed on the hinge point A through the pull rod, one end of the handle is placed in the fork ear, the bushing is sleeved on the handle and the fork ear, the connecting shaft is sleeved on the bushing, one end of the connecting shaft is connected with the actuator cylinder and extends out of one side of the bushing, the other end of the connecting shaft extends out of the other side of the bushing and is fastened through the first fastener, the pointer is installed on the handle and corresponds to the position of the scale disc. The application detects the deflection angle range of the universal joint by clockwise and counterclockwise force, so as to obtain the evidence that the stroke of the anti-swing oil liquid damping actuator cylinder is qualified.

Description

Technical Field

[0001] This invention relates to the field of aircraft nose landing gear strut testing technology, and in particular to a device and method for detecting the deflection angle of the universal joint of the nose landing gear strut. Background Technology

[0002] The universal joint of the nose landing gear strut is hinged to the upper and lower anti-torsion arms. The upper end of the upper anti-torsion arm is hinged to the outer cylinder of the strut, and the lower end of the lower anti-torsion arm is hinged to the piston rod of the strut. The three hinge axes are parallel to each other and perpendicular to the strut. The upper end of the anti-sway hydraulic damping actuator is connected to the upper anti-torsion arm, and the lower end is bolted to the universal joint to ensure that the outer cylinder and piston rod of the landing gear strut can extend and retract without relative rotation. It is essential to ensure the symmetry of the landing gear wheels relative to the landing gear strut; this symmetry is crucial for aircraft balance, landing gear heading, and proper landing gear retraction and extension.

[0003] The technical requirements stipulate that, under certain conditions, the symmetry line of the upper anti-torsion arm and the symmetry line of the universal joint should be such that, after the universal joint rotates, it can have a certain deflection angle. Whether the actual deflection angle of the universal joint meets the design requirements needs to be detected by a device and method. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for detecting the deflection angle of the universal joint of the front landing gear strut, which can effectively detect the deflection angle of the universal joint.

[0005] The technical solution of the present invention is: a device for detecting the deflection angle of a universal joint of a front landing gear strut, comprising a handle, a pointer, a connecting shaft, a bushing, a dial, and a pull rod. The dial is mounted on hinge point A via the pull rod. One end of the handle is placed in the fork lug. The bushing is fitted into the handle and the fork lug. The connecting shaft passes through the bushing, and one end of the connecting shaft extends out of the bushing and connects to the actuating cylinder. The other end of the connecting shaft extends out of the bushing and is fastened by a first fastener. The pointer is mounted on the handle and corresponds to the position of the dial.

[0006] One end of the scale of the testing device is fixed to the hinge intersection of the upper anti-torsion arm, the lower anti-torsion arm and the universal joint of the support column, and the other fixed point is on the symmetrical plane of the upper anti-torsion arm to overcome the error of the inspection angle. The detection device's pull rod connects the universal joint, dial, upper anti-torsion arm, and lower anti-torsion arm into one unit, fully presenting the working state of the front landing gear strut, making the detection of deflection angle results more accurate. The connecting shaft of the detection device connects the universal joint, handle, and actuator to simulate the installation state of an aircraft strut, restoring the real scene and making the results of the deflection angle detection more accurate.

[0007] Preferably, the upper anti-torsion arm is provided with a first symmetry line, and the dial is provided with a first center line, the first center line coinciding with the first symmetry line. Detecting the deflection angle of the universal joint at this position improves the accuracy of the detection and provides valid evidence that the actuator stroke is within acceptable limits.

[0008] Preferably, the handle includes a first head and a first rod connected to the first head. The first head has a first mounting hole extending in the X direction, and a mounting surface parallel to the X direction is provided beside the first mounting hole. The pointer is mounted on the mounting surface, the first head is located in the fork lug, and the bushing is installed in the first mounting hole. The first rod better transmits torque to the first head, causing the pointer and handle to move accordingly, thus accurately reading the deflection angle value.

[0009] Preferably, the pointer is mounted on the mounting surface using a two-point installation method, with one hinged and one fixed, wherein the hinge point is located close to the dial. This improves the accuracy of the pointer's mounting position and facilitates effective control of α1.

[0010] Preferably, the pointer has a second center line, and the pointer has a first scale line at the end near the dial, the first scale line and the second center line forming an angle α1.

[0011] Preferably, the dial includes a first plate, a second plate, and a third plate connected in sequence. The third plate is attached to the universal joint and connected by a pull rod. The second plate is connected to the third plate in a direction parallel to the X direction. The first plate is obliquely connected to the second plate. The first plate is mounted on the upper anti-torsion arm by a first pin.

[0012] Preferably, the first pin includes a second head, a first end cap, a second rod, and a first threaded section connected in sequence. The second rod passes through the first plate so that the first end cap abuts against the upper surface of the first plate, and the first threaded section is connected to a screw hole on the upper anti-torsion arm.

[0013] Preferably, the section of the connecting shaft assembled in the handle has a drum-shaped structure.

[0014] The present invention also provides a method for detecting the deflection angle of the universal joint of the nose landing gear strut, which uses the aforementioned device for detecting the deflection angle of the universal joint of the nose landing gear strut, and includes the following steps: Step 1: First, connect the upper anti-torsion arm and the lower anti-torsion arm into one unit using the tie rod; Step 2: Adjust the position of the dial so that the "0" position on it coincides with the first symmetry line on the upper anti-torsion arm, and fix the dial. Step 3: Place one end of the handle into the fork lug, pass the bushing through the universal joint and the handle, insert the connecting shaft into the bushing, connect the actuator to one end of the connecting shaft, and fasten the other end of the connecting shaft with the first fastener. Step four: Install the pointer on the handle and adjust it so that the first mark on the pointer is aligned with the "0" mark on the dial, then fix the pointer in place. Step 5: Check whether the angle α2 between the first symmetry line on the upper anti-torsion arm and the second symmetry line on the universal joint is within the range of 4°±10'. If yes, proceed to the next step. If no, adjust the length of the actuator cylinder until α2 is within the above range. Step 6: Set the clockwise deflection angle β1 and the counterclockwise deflection angle γ1. Step 7: Apply a certain torsional force to the handle clockwise, and detect the deflection angle β2 of the second symmetry line on the universal joint relative to the first symmetry line on the upper anti-torsion arm. Then compare β2 with β1. If β2 ≥ β1, it is qualified; if β2 < β1, it is unqualified. Step 8: Apply a certain torsional force to the handle counterclockwise and check the deflection angle γ2 of the second symmetry line on the universal joint relative to the first symmetry line on the upper anti-torsion arm. If γ2 ≥ γ1, it is qualified; if γ2 < γ1, it is unqualified.

[0015] Before detecting the deflection angle of the universal joint, the dial and pointer of the detection device can be adjusted to the "0" position, that is, coincide with the symmetrical plane of the upper torque arm. Preferably, β1=10.5°, γ2=2.5°.

[0016] Compared with related technologies, the beneficial effects of the present invention are as follows: I. This invention connects the upper anti-torsion arm, lower anti-torsion arm, universal joint, and dial of the front landing gear strut via a tie rod, so that the pin aligns the "0" position of the dial with the symmetrical plane of the upper anti-torsion arm; the pointer is connected to the universal joint via a force-applying handle, and the universal joint deflects the pointer together when subjected to force. By applying force clockwise and counterclockwise, the deflection angle range of the universal joint is detected, thereby obtaining evidence that the stroke of the anti-sway hydraulic damping actuator is qualified; II. The present invention addresses the issue that when the second symmetry line on the universal joint of the nose landing gear strut and the first symmetry line on the upper anti-torsion arm are at 4°±10′, an external force is applied to make the universal joint rotate clockwise and counterclockwise. The universal joint should rotate flexibly without jamming, and the deflection angle should be within a certain range, thereby ensuring the normal operation of the upper and lower anti-torsion arms and the balance and heading of the aircraft. Attached Figure Description

[0017] Figure 1 A three-dimensional structural schematic diagram of the front landing gear strut universal joint deflection angle detection device provided by the present invention; Figure 2 A side view of the universal joint deflection angle detection device for the front landing gear strut provided by the present invention. Figure 3 for Figure 1 A schematic diagram of the handle in the diagram; Figure 4 for Figure 1 A schematic diagram of the pointer structure in the diagram; Figure 5 for Figure 1 A schematic diagram of the connecting shaft in the diagram; Figure 6 for Figure 1 A schematic diagram of the bushing structure; Figure 7 for Figure 1 A three-dimensional structural diagram of the dial in the image; Figure 8 for Figure 1 A side view of the dial structure; Figure 9 for Figure 1 A schematic diagram of the tie rod in the diagram; Figure 10 for Figure 1 A schematic diagram of the structure of the first pin in the middle.

[0018] In the attached diagram: 1. Handle; 11. First head; 12. First rod; 13. First mounting hole; 14. Mounting surface; 15. Second mounting hole; 16. Third mounting hole; 2. Pointer; 21. Second center line; 22. First scale line; 23. Fourth mounting hole; 24. Fifth mounting hole; 3. Connecting shaft; 31. Ear seat; 32. Second end cap; 33. Intermediate shaft; 34. Third threaded section; 4. Bushing; 41. Inner hole; 5. Dial; 51. First plate; 52. 53. Second plate; 54. Third plate; 55. Second scale line; 56. Sixth mounting hole; 57. Seventh mounting hole; 58. First center line; 6. Pull rod; 69. First shaft; 60. Second shaft; 61. Third shaft; 62. Second threaded section; 7. First fastener; 8. First pin; 81. Second head; 82. First end cap; 83. Second rod; 84. First threaded section; 9. Second pin; 17. Bolt; 18. Second fastener; 19. Knurled nut; 10. Upper anti-torsion arm; 101. First symmetry line; 20. Universal joint; 201. Fork lug; 202. Second symmetry line; 30. Lower anti-torsion arm; 40. Actuator cylinder. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0020] like Figure 1 , Figure 2 As shown, the front landing gear strut universal joint deflection angle detection device provided in this embodiment is connected between the upper anti-torsion arm 10, the universal joint 20, the lower anti-torsion arm 30, and the actuating cylinder 40. One end of the universal joint 20 is hinged to the upper anti-torsion arm 10 and the lower anti-torsion arm 30 to form a hinge point A, and the other end of the universal joint 20 is provided with a fork lug 201.

[0021] The front landing gear strut universal joint deflection angle detection device includes a handle 1, a pointer 2, a connecting shaft 3, a bushing 4, a dial 5, a pull rod 6, a first fastener 7, and a first pin 8.

[0022] like Figure 3 As shown, the handle 1 includes a first head 11 and a first rod 12 connected to the first head 11. The shape of the first head 11 is adapted to the inner cavity of the fork lug 201, and the first rod 12 is used for hand operation. The first head 11 has a first mounting hole 13 extending in the X direction, and a mounting surface 14 parallel to the X direction is provided on the side of the first mounting hole 13. The mounting surface 14 has a second mounting hole 15 and a third mounting hole 16. The second mounting hole 15 is located away from the first rod 12. The second mounting hole 15 and the third mounting hole 16 extend in the Y direction. The first mounting hole 13 is clearance-fitted with the outer diameter of the bushing 4, and the two end faces of the handle 1 are clearance-fitted with the universal joint 20.

[0023] like Figure 4 As shown, the pointer 2 has an inclined needle tip at its end, and a first scale line 22 at the tip. The first scale line 22 forms an angle α1 with the second center line 21 of the pointer 2, where α1 = 4°. The pointer 2 has a fourth mounting hole 23 and a fifth mounting hole 24. The pointer 2 is made of stainless steel 1Cr18Ni9Ti, and the first scale line 22 is a line 10mm long, 0.3mm wide, and 0.3mm deep.

[0024] like Figure 1 , Figure 2As shown, the pointer 2 is mounted on the mounting surface 14. The fourth mounting hole 23 is aligned with the second mounting hole 15 and is hinged and fixed by the second pin 9. After this point is fixed, the position of the first scale line 22 can be adjusted. After the position is adjusted, bolts 17 are installed in the fifth mounting hole 24 and the third mounting hole 16 to fix the pointer 2. The position adjustment of the first scale line 22 is a fine adjustment. In order to achieve alignment after the position adjustment, the diameter of the fifth mounting hole 24 is larger than the diameter of the third mounting hole 16.

[0025] like Figure 1 , Figure 2 As shown, the first head 11 is located in the fork lug 201. The bushing 4 is fitted into the handle 1 and the fork lug 201. Figure 6 As shown, the bushing 4 has an inner hole 41 for engaging with the shaft hole of the connecting shaft 3.

[0026] like Figure 5 As shown, the connecting shaft 3 includes a lug 31, a second end cap 32, an intermediate shaft 33, and a third threaded section 34 connected in sequence. Figure 2 , Figure 5 As shown, the connecting shaft 3 passes through the inner hole 41, and the intermediate shaft 33 is assembled in the inner hole 41. The third threaded section 34 extends out of the outer side of the bushing 4 and is fastened by the first fastener 7 (nut). After fastening, the second end cap 32 of the connecting shaft 3 presses against the end face of the bushing 4 to prevent the bushing 4 from rotating. The lug 31 is located close to the actuating cylinder 40, and the actuating cylinder 40 is hinged to the lug 31 by the second fastener 18 (bolt, washer, and nut). The intermediate shaft 33 is drum-shaped to ensure that the handle 1 transmits torque better. The bushing 4 is used to reduce wear between the handle 1 and the connecting shaft 3.

[0027] like Figure 7 , Figure 8 As shown, the dial 5 includes a first plate 51, a second plate 52, and a third plate 53 connected in sequence. The second plate 52 is connected to the third plate 53 in a direction parallel to the X-axis. The first plate 51 is obliquely connected to the second plate 52 and is mounted on the upper anti-torsion arm 10 via a first pin 8. The third plate 53 is attached to the universal joint 20 and connected via a pull rod 6. The third plate 53 has a second scale line 54. The second scale line 54 is a multi-angle scale line starting from 0. The first plate 51 has a sixth mounting hole 55, which is an oblong hole. The third plate 53 has a seventh mounting hole 56. The first pin 8 is inserted into the sixth mounting hole 55 on the first plate 51 and connected to the hole on the upper anti-torsion arm 10.

[0028] like Figure 9As shown, the pull rod 6 includes a first shaft portion 61, a second shaft portion 62, a third shaft portion 63, and a second threaded section 64 connected in sequence. The pull rod 6 passes through the dial 5, the universal joint 20, and the upper anti-torsion arm 10 at hinge point A. The second threaded section 64 extends to the outside of the universal joint 20 and is fixed by a knurled nut 19. The second shaft portion 62 has a clearance fit with the dial 5, and the third shaft portion 63 mates with holes on the universal joint 20 and the upper anti-torsion arm 10. The first shaft portion 61 is located outside the dial 5, and its end face contacts the outer surface of the third plate 53 to secure the dial 5.

[0029] like Figure 10 As shown, the first pin 8 includes a second head 81, a first end cap 82, a second rod portion 83, and a first threaded section 84 connected in sequence. Figure 1 As shown, the second rod portion 83 passes through the first plate 51, causing the first end cap 82 to press against the upper surface of the first plate 51, and the first threaded section 84 connects to the threaded hole on the upper anti-torsion arm 10. Figure 2 As shown, the upper anti-torsion arm 10 is provided with a first symmetry line 101, and the dial 5 is provided with a first center line 57, which coincides with the first symmetry line 101.

[0030] When pointer 2 is adjusted to the "0" position (that is, the first scale line 22 is aligned with the 0 on the second scale line 54), pointer 2 can move with handle 1.

[0031] The present invention also provides a method for detecting the deflection angle of the universal joint of the nose landing gear strut, which uses the aforementioned device for detecting the deflection angle of the universal joint of the nose landing gear strut, and includes the following steps: Step 1: First, use the pull rod 6 to pass through the seventh mounting hole 56 on the dial 5 at hinge point A to connect the upper anti-torsion arm 10 and the lower anti-torsion arm 30 into one unit.

[0032] Step two, adjust the position of the dial 5 so that its "0" position coincides with the first symmetry line 101 on the upper anti-torsion arm 10 (e.g., Figure 2 (As shown). Then, insert the first pin 8 into the sixth mounting hole 55, and tighten the first threaded section 84 on the first pin 8 into the threaded hole on the upper anti-torsion arm 10, so that the end face of the first end cover 82 presses against the first plate 51, and the first center line 57 coincides with the first symmetry line 101. Tighten the knurled nut 19 on the second threaded section 64 on the pull rod 6 to completely fix the dial 5.

[0033] Step 3: Place one end of the handle 1 into the fork lug 201, pass the bushing 4 through the universal joint 20 and the handle 1, insert the connecting shaft 3 into the bushing 4, connect the actuator 40 and the lug 31 of the connecting shaft 3 through the second fastener 18, and fasten the third threaded section 34 of the connecting shaft 3 to the first fastener 7.

[0034] Step four: Install pointer 2 on the mounting surface 14 of handle 1, and adjust the first scale line 22 on pointer 2 to align with the "0" position on the second scale line 54. First insert the second pin 9, then tighten the bolt 17 to completely fix pointer 2.

[0035] Step 5: Check whether the angle α2 between the first symmetry line 101 on the upper anti-torsion arm 10 and the second symmetry line 202 on the universal joint 20 is within the range of 4°±10'. If yes, proceed to the next step; otherwise, adjust the length of the actuator cylinder 40 until α2 is within the above range. Then tighten the second fastener 18.

[0036] Step 6: Set the clockwise deflection angle β1 and the counterclockwise deflection angle γ1. For example, β1 = 10.5° and γ2 = 2.5°.

[0037] Step 7: Apply a certain torsional force of 700N clockwise to handle 1, and detect the deflection angle β2 of the second symmetry line 202 on the universal joint 20 relative to the first symmetry line 101 on the upper anti-torsion arm 10. Then compare β2 with β1. If β2≥β1, it is qualified; if β2<β1, it is unqualified.

[0038] Step 8: Apply a 700N torsional force to handle 1 counterclockwise and check the deflection angle γ2 of the second symmetry line 202 on the universal joint 20 relative to the first symmetry line 101 on the upper anti-torsion arm 10. If γ2 ≥ γ1, it is qualified; if γ2 < γ1, it is unqualified.

[0039] The inspection results are qualified, which also proves that the anti-sway oil damping actuator 40 stroke meets the technical requirements of tensile strength of 15±0.5mm and compression of 9±0.5mm.

[0040] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for detecting the deflection angle of a universal joint on a front landing gear strut, connected between an upper anti-torsion arm (10), a universal joint (20), a lower anti-torsion arm (30), and an actuating cylinder (40), wherein one end of the universal joint (20) is hinged to the upper anti-torsion arm (10) and the lower anti-torsion arm (30) to form a hinge point A, and the other end of the universal joint (20) is provided with a fork lug (201), characterized in that, The device includes a handle (1), a pointer (2), a connecting shaft (3), a bushing (4), a dial (5), and a pull rod (6). The dial (5) is mounted on hinge point A via the pull rod (6). One end of the handle (1) is placed in the fork lug (201). The bushing (4) is fitted into the handle (1) and the fork lug (201). The connecting shaft (3) is inserted into the bushing (4), with one end of the connecting shaft (3) extending out of the bushing (4) and connected to the actuator (40). The other end of the connecting shaft (3) extends out of the bushing (4) and is secured by a first fastener (7). Therefore, the pointer (2) is mounted on the handle (1) and corresponds to the position of the dial (5); the handle (1) includes a first head (11) and a first rod (12) connected to the first head (11). The first head (11) is provided with a first mounting hole (13) that passes through in the X direction. The side of the first mounting hole (13) is provided with a mounting surface (14) that is parallel to the X direction. The pointer (2) is mounted on the mounting surface (14). The first head (11) is located in the fork lug (201). The bushing (4) is installed in the first mounting hole (13).

2. The nose landing gear strut universal joint deflection angle detection device according to claim 1, characterized in that, The upper anti-torsion arm (10) is provided with a first symmetry line (101), and the dial (5) is provided with a first center line (57), which coincides with the first symmetry line (101).

3. The nose landing gear strut universal joint deflection angle detection device according to claim 1, characterized in that, The pointer (2) is mounted on the mounting surface (14) by a two-point installation method of one hinge and one fixed, wherein the hinge point is set close to the dial (5).

4. The nose landing gear strut universal joint deflection angle detection device according to claim 1, characterized in that, The pointer (2) is provided with a second center line (21), and the pointer (2) is provided with a first scale line (22) at the end near the dial (5). The first scale line (22) and the second center line (21) form an angle α1.

5. The nose landing gear strut universal joint deflection angle detection device according to claim 1, characterized in that, The dial (5) includes a first plate (51), a second plate (52) and a third plate (53) connected in sequence. The third plate (53) is attached to the universal joint (20) and connected by a pull rod (6). The second plate (52) is connected to the third plate (53) in a direction parallel to the X direction. The first plate (51) is obliquely connected to the second plate (52). The first plate (51) is installed on the upper anti-torsion arm (10) by a first pin (8).

6. The nose landing gear strut universal joint deflection angle detection device according to claim 5, characterized in that, The first pin (8) includes a second head (81), a first end cap (82), a second rod (83) and a first threaded section (84) connected in sequence. The second rod (83) passes through the first plate (51) so that the first end cap (82) abuts against the upper surface of the first plate (51). The first threaded section (84) is connected to the screw hole on the upper anti-torsion arm (10).

7. The nose landing gear strut universal joint deflection angle detection device according to claim 1, characterized in that, The section of the connecting shaft (3) assembled in the handle (1) has a drum-shaped structure.

8. A method for detecting the deflection angle of the universal joint of the nose landing gear strut, comprising using the nose landing gear strut universal joint deflection angle detection device as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: First, connect the upper anti-torsion arm (10) and the lower anti-torsion arm (30) into one unit by passing the pull rod (6) through the dial (5); Step 2: Adjust the position of the dial (5) so that the "0" position on it coincides with the first symmetry line (101) on the upper anti-torsion arm (10), and fix the dial (5). Step 3: Place one end of the handle (1) into the fork lug (201), pass the bushing (4) through the universal joint (20) and the handle (1), insert the connecting shaft (3) into the bushing (4), connect the actuator (40) to one end of the connecting shaft (3), and fasten the other end of the connecting shaft (3) with the first fastener (7); Step 4: Install the pointer (2) on the handle (1) and adjust the pointer (2) so that the first scale line (22) on it is aligned with the "0" position of the scale (5), and then fix the pointer (2). Step 5: Check whether the angle α2 between the first symmetry line (101) on the upper anti-torsion arm (10) and the second symmetry line (202) on the universal joint (20) is within the range of 4°±10'. If yes, proceed to the next step. If no, adjust the length of the actuator (40) until α2 is within the above range. Step 6: Set the clockwise deflection angle β1 and the counterclockwise deflection angle γ1. Step 7: Apply a certain torsional force to the handle (1) clockwise, detect the deflection angle β2 of the second symmetry line (202) on the universal joint (20) relative to the first symmetry line (101) on the upper anti-torsion arm (10), and then compare β2 with β1. If β2≥β1, it is qualified; if β2<β1, it is unqualified. Step 8: Apply a certain torsional force to the handle (1) counterclockwise and detect the deflection angle γ2 of the second symmetry line (202) on the universal joint (20) relative to the first symmetry line (101) on the upper anti-torsion arm (10). If γ2 ≥ γ1, it is qualified; if γ2 < γ1, it is unqualified.

9. The method for detecting the deflection angle of the universal joint of the nose landing gear strut according to claim 8, characterized in that, β1=10.5°, γ2=2.5°.

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