Static performance testing device for undercarriage

Abstract

The utility model discloses an undercarriage static performance test device which comprises a first pull plate, a second pull plate and four pull rods, and nuts are arranged at the two ends of each pull rod respectively. Two lug sets are arranged on the first pulling plate in the length direction in a spaced mode, and each lug set is provided with a positioning plug pin. A first mounting hole and four second mounting holes are formed in the first pulling plate, the four second mounting holes are formed in the outer sides of the peripheries of the two lug sets respectively, and four third mounting holes corresponding to the second mounting holes are formed in the second pulling plate; the second pulling plate is provided with a centering shaft and a fourth mounting hole, the axial center line of the fourth mounting hole and the axial center line of the centering shaft coincide, the arrangement position of the first mounting hole corresponds to that of the fourth mounting hole, and the first mounting hole and the fourth mounting hole are both provided with corresponding centering pins. The test device solves the technical problem of overstock waste caused by the fact that a set of special test device is adopted in each test in the prior art.

Description

Technical Field

[0001] The utility model belongs to the technical field of aircraft landing gear performance testing, and in particular relates to a landing gear static performance testing device. Background Art

[0002] Aircraft landing gear comes in numerous models, varieties, and small batch sizes, with increasingly shorter replacement cycles. From development to deployment, aircraft landing gear systems undergo multiple performance tests, including structural testing, drop testing, shimmy testing, retraction and extension testing, turning control testing, steering mechanism testing, and static performance testing. These tests primarily aim to: a) verify that the performance of the aircraft landing gear system meets the specified technical specifications and operational requirements, thereby obtaining basic data on the performance and usability of the new landing gear system as quickly as possible; b) verify that the limits reached by the aircraft landing gear system are consistent with its design limitations, thereby confirming its safe operation; c) verify that the compatibility, reliability, and maintainability of the aircraft landing gear system meet design requirements; d) verify that the accompanying tools, equipment, and spare parts are compatible, suitable, and complete; and e) provide a basis for the compilation of the aircraft's technical performance, operating manual, and flight manual. Currently, each test is verified using a dedicated test device, resulting in a backlog of test equipment and no longer meeting the needs of shortening the landing gear development cycle. In order to obtain accurate data on various performance indicators of the landing gear system of a new aircraft as quickly as possible, it is necessary to conduct various tests required by the aircraft design at the fastest speed during the development phase to meet the development needs of the new aircraft. Utility Model Content

[0003] In response to the current technical problems, the present invention aims to provide a landing gear static performance test device, which can solve the technical problem of backlog and waste caused by the use of a set of dedicated test devices for each test in the prior art.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A landing gear static performance test device, its structural features are: comprising a first pull plate, a second pull plate, and four pull rods, the length of the pull rods being greater than the length of the landing gear, and nuts being provided at both ends of the pull rods; the first pull plate is provided with two sets of lug groups spaced apart along the length direction, each set of lug groups is provided with a positioning pin, the positioning pin is adapted to the lug holes on the lug group and the lug holes on the outer tube lug of the landing gear, the two sets of lug groups and the corresponding positioning pins are respectively used to fix the two outer tube lugs; the first pull plate is provided with a first mounting hole and four second mounting holes, four The second mounting holes are respectively arranged on the outside of the four sides of the two groups of ear plates. The second pull plate is provided with four third mounting holes corresponding to the second mounting holes respectively. The first pull plate and the second pull plate are connected and fixed by a pull rod passing through the second mounting holes and the third mounting holes; the second pull plate is provided with a centering shaft and a fourth mounting hole. The centering shaft is used to fix the outer end of the outer tube piston rod of the landing gear. The fourth mounting hole coincides with the axial center line of the centering shaft, and the setting positions of the first mounting hole and the fourth mounting hole correspond to each other. The first mounting hole and the fourth mounting hole are both equipped with corresponding centering pins.

[0006] The test device of the present invention can be used for airtightness compression tests of landing gear at multiple temperatures and static compression curve tests of landing gear on a tension and compression testing machine through appropriate combination, and the main force points are shared. The main force points of the landing gear outer tube are located on the lug holes of the two outer tube lugs, and the main force points of the piston rod are located on the inner hole and outer end face of the piston rod. When using this experimental device to conduct an airtightness compression test, the landing gear is under normal inflation pressure, and the two positioning pins are respectively passed through the lug holes of the lug group on the upper pull plate and the lug holes of the outer tube lugs to connect the outer tube and the upper pull plate into one. At this time, the installation of the landing gear's piston rod and outer tube is in the free state required by the drawings. The centering shaft on the lower pull plate is inserted into the inner hole of the landing gear's piston rod, and the four pull rods are respectively passed through the four second mounting holes of the upper pull plate and the third mounting hole of the lower pull plate. At this point, the four tie rods are parallel to each other and to the axial centerline of the landing gear outer tube. The axial centerlines of the first and second mounting holes coincide with the axial centerline of the landing gear outer tube. Nuts are tightened at each end of the four tie rods, connecting the tie rods, upper plate, and lower plate into an integrated airtight compression working state. An external force is applied to the four nuts on the outer end surface of the lower plate to perform an airtight compression test. After the airtight compression test, for the static compression curve test, centering pins are screwed into the first mounting hole of the upper plate and the second mounting hole of the lower plate. The test apparatus and landing gear are hoisted onto the tension and compression testing machine. The centering pin on the upper plate is installed in the center hole of the upper worktable of the tension and compression testing machine, and the centering pin on the lower plate is installed in the center hole of the lower worktable of the tension and compression testing machine. The center of the landing gear is now aligned with the tension and compression center of the tension and compression testing machine. The tie rods and the nuts at both ends are removed, and the stroke of the tension and compression testing machine is adjusted appropriately to restore the landing gear to normal working condition. After the landing gear is securely installed, a static compression curve test is carried out.

[0007] Preferably, each tab set includes two tabs spaced apart along the length of the first pull plate, with a gap between the two tabs greater than the width of the outer tube tab. The tabs are perpendicularly connected to the first pull plate, and the centerlines of the tab holes on the four tabs are aligned. The gap between the tabs is greater than the width of the outer tube tab, making it easier to mount the outer tube tabs on the test device and preventing damage to the outer tube tabs during testing.

[0008] Preferably, the distance between the second mounting hole and the outer ear piece in the ear piece group is greater than or equal to 20 mm.

[0009] Preferably, a gasket is provided on the outer end of the inner lug in each lug group. The gasket can be a rubber gasket, and the gasket is provided to protect the upper surface of the landing gear outer tube.

[0010] Specifically, the centering shaft is a hollow shaft, the size of which is adapted to the size of the inner hole of the outer end portion of the outer cylinder piston rod.

[0011] Preferably, a limiting portion is provided at the lower outer portion of the centering shaft, and the width of the limiting portion is greater than or equal to the diameter of the outer end portion of the outer cylinder piston rod.

[0012] Preferably, the first and second pull plates are each provided with two eyebolt mounting holes, which are spaced apart. Providing the eyebolt mounting holes facilitates the use of the eyebolts to hoist the test apparatus and landing gear during a static compression curve test, facilitating installation. The eyebolts can be removed after installation.

[0013] Preferably, the tensile strength of the materials used for the first pull plate, the positioning pin, the second pull plate, the pull rod and the nut is not less than 1680 MPa. The test device can be made of ultra-high strength steel.

[0014] Specifically, the second mounting hole is a stepped hole, the nut is a shouldered nut, and the threads of the first mounting hole and the fourth mounting hole are threaded holes.

[0015] To facilitate the installation of the pull rod, preferably, the two third mounting holes on one side of the second pull plate in the length direction are light holes, and the two third mounting holes on the other side are U-shaped groove structures, and the openings of the two U-shaped grooves face the same direction and both face the outside of the second pull plate.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the landing gear static performance test device of the present invention can be used for landing gear static compression curve performance test and airtight compression test after disassembly and assembly, can be applied to tests at multiple temperatures, and can be used universally for tests of modified landing gears of the same series, thereby saving costs and achieving rapid response in landing gear development. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the landing gear static performance test device and the landing gear connection structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the connection structure between the test device and the landing gear during the airtightness compression test;

[0019] Figure 3 This is a schematic diagram of the connection structure between the test device and the landing gear during the static compression curve test;

[0020] Figure 4 yes Figure 1 Schematic diagram of the three-dimensional structure of the middle and upper pull plate;

[0021] Figure 5 yes Figure 1 Schematic diagram of the three-dimensional structure of the middle and lower pull-down plate;

[0022] Figure 6 yes Figure 5 Schematic diagram of the main structure.

[0023] In the figure

[0024] 1-first pull plate, 2-centering pin, 3-eye screw mounting hole, 4-positioning pin, 5-second pull plate, 6-pull rod, 7-nut, 8-ear piece group, 801-ear piece, 9-first mounting hole, 10-second mounting hole, 11-third mounting hole, 12-centering shaft, 13-fourth mounting hole, 14-limiting part, 15-outer cylinder ear piece, 16-outer cylinder piston rod, 17-gasket, 18-eye screw, 19-upper workbench of tensile and compression testing machine, 20-lower workbench of tensile and compression testing machine, 21-outer cylinder. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments may be combined unless they conflict. For ease of description, the words "upper," "lower," "left," and "right" appear below merely to indicate the directions of upper, lower, left, and right in the accompanying drawings and do not limit the structure.

[0026] like Figure 1 As shown, the static performance test device of a landing gear disclosed in this embodiment includes a first pull plate 1, a second pull plate 5, and four pull rods 6. The length of the pull rods 6 is greater than the length of the landing gear. Nuts 7 are respectively provided at both ends of the pull rods 6. The nuts 7 are shoulder nuts. Figure 4As shown, two sets of tabs 8 are spaced along the length of the lower surface of the first tension plate 1. Each tab set 8 is equipped with a positioning pin 4, which mates with the tab holes in the tab set 8 and the tab holes in the landing gear outer tube tab 15. The two tab sets 8 and their corresponding positioning pins 4 are used to secure the two outer tube tabs 15. Each tab set 8 includes two tabs 801, spaced along the length of the first tension plate 1, with a gap between them greater than the width of the outer tube tab 15. The tabs 801 are welded perpendicularly to the first tension plate 1, with the centerlines of the tab holes in the four tabs 801 aligned. A gasket 17 is glued to the outer end of the inner tab 801 in each tab set 8. This gasket 17 is a 2mm thick rubber pad that protects the upper surface of the landing gear outer tube 21. The first pull plate 1 is provided with a first mounting hole 9 and four second mounting holes 10. The four second mounting holes 10 are respectively arranged on the outer sides of the two sets of ear pieces 8. The second mounting holes 10 are stepped holes. Figure 5 As shown, the second plate 5 is provided with four third mounting holes 11 corresponding to the second mounting holes 10. The first plate 1 and the second plate 5 are connected and secured by four tie rods 6 extending through the second and third mounting holes 10 and 11. The four tie rods 6 are arranged in parallel. The two third mounting holes 11 on one side of the second plate 5 are plain holes, while the two third mounting holes 11 on the other side are U-shaped slots. The openings of the two U-shaped slots face the same direction and are both facing outward from the second plate 5. The second plate 5 is provided with a centering shaft 12 and a fourth mounting hole 13. The centering shaft 12 is used to secure the outer end of the landing gear's outer cylinder piston rod 16. The fourth mounting hole 13 coincides with the axial centerline of the centering shaft 12, and the first and fourth mounting holes 9 and 13 are located in corresponding positions. Both the first and fourth mounting holes 9 and 13 are threaded holes and are equipped with corresponding centering pins 2. The centering shaft 12 is a hollow shaft, the size of which matches the size of the inner hole of the outer end of the outer cylinder piston rod 16. Figure 6 As shown, a stopper 14 is provided on the lower outer portion of the centering shaft 12. The width of this stopper 14 is equal to the outer diameter of the outer cylinder piston rod 16. Both the first and second pull plates 1 and 5 are provided with two eyebolt mounting holes 3, spaced apart. The first pull plate 1, positioning pin 4, second pull plate 5, four tie rods 6, and nuts 7 are all made of ultra-high-strength steel 30CrMnSiNi2A, with a tensile strength of 1680 MPa, enabling testing at multiple temperatures.

[0027] The test device of this embodiment is used for airtight compression tests of landing gear at multiple temperatures and static compression curve tests of landing gear on a tension and compression testing machine. Figure 2 As shown, the airtight compression test is first carried out, which mainly includes the following test steps:

[0028] Step S1. With the landing gear under normal inflation pressure, insert two positioning pins 4 through the tab holes of the tab assembly 8 on the left and right first pull plates 1 and the tab holes of the outer tube tab 15, respectively, to integrally connect the outer tube 21 to the first pull plate 1. At this point, the outer tube piston rod 16 and outer tube 21 of the landing gear are in the free position as required by the drawings.

[0029] Step S2. Insert the centering shaft 12 of the second pull plate 5 into the inner hole of the outer end portion of the outer cylinder piston rod 16, while the outer end surface of the piston rod is close to the limiting portion 14 of the centering shaft 12;

[0030] Step S3. Pass the four tie rods 6 through the second mounting hole 10 of the first pull plate 1 and the third mounting hole 11 of the second pull plate 5 respectively; tighten the shoulder nuts on the outer end surfaces of the first pull plate 1 and the second pull plate 5 respectively to connect the tie rods 6, the first pull plate 1 and the second pull plate 5 into one body, forming Figure 2 The airtight compression working state shown in the figure; measure the extension length L1 of the pull rod 6 at the outer end of the second pull plate 5 and make a record;

[0031] Step S4. Apply external force to the four shoulder nuts on the outer end face of the second pull plate 5. This force pushes the outer cylinder piston rod 16 along the inner bore of the outer cylinder 21. Measure the distance L between the four pull rods 6 on the lower end face of the second pull plate 5 and the distance L between the two pull plates 5. When the difference between L and L1 is greater than 30% of the full travel of the outer cylinder piston rod 16, stop applying external force.

[0032] Step S5. The installed test device is placed horizontally for 8 hours or vertically for 6 hours at room temperature of 10°C to 43°C without leakage of hydraulic oil and air pressure loss. It is then kept at a low temperature of -55°C for 3 hours without leakage and sliding parts being tight. Finally, it is kept at a high temperature of 70°C or 135°C for 2 hours without sliding parts being tight. External leakage and slight moisture are allowed. The airtight compression test is completed.

[0033] like Figure 3 As shown in the figure, after the airtight compression test, the landing gear static compression curve test is carried out on the tension and compression testing machine, which mainly includes the following test steps:

[0034] Step S1. Screw the centering pin 2 into the first mounting hole 9 of the first pull plate 1 and the fourth mounting hole 13 of the second pull plate 5. Use the eyebolt 18 to hoist the test apparatus and landing gear to the tension and compression testing machine. The centering pin 2 installed on the first pull plate 1 is installed in the center hole of the upper worktable 19 of the tension and compression testing machine, and the centering pin 2 installed on the second pull plate 5 is installed in the center hole of the lower worktable 20 of the tension and compression testing machine. At this point, the center of the landing gear is aligned with the tension and compression center of the tension and compression testing machine.

[0035] Step S2. Remove the tie rod 6 and the shoulder nut, and adjust the stroke of the tension and compression testing machine appropriately to restore the landing gear to normal working condition;

[0036] Step S3. After the landing gear is securely installed, compress the landing gear buffer 10 to 20 times within the specified travel range at the required test rate. Then, conduct a static compression curve test of the oil-air buffer in both forward and reverse travels at the specified rate within the specified travel range. During the test, the buffer's movement should be smooth, flexible, and free of jamming. A computer-drawn curve that is smooth within the travel range is considered qualified. If the requirements are not met, analyze the cause, take corrective measures, and retest until qualified.

[0037] The contents described in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A landing gear static performance test device, characterized by: It comprises a first pull plate (1), a second pull plate (5), and four pull rods (6). The length of the pull rods (6) is greater than the length of the landing gear. Both ends of the pull rods (6) are respectively equipped with nuts (7). The first pull plate (1) is provided with two groups of lugs (8) spaced apart along the length direction, each group of lugs (8) is equipped with a positioning pin (4), and the positioning pin (4) is adapted to the lug holes on the lugs (8) and the lug holes on the outer tube lugs (15) of the landing gear, and the two groups of lugs (8) and the corresponding positioning pins (4) are respectively used to fix the two outer tube lugs (15); The first pull plate (1) is provided with a first mounting hole (9) and four second mounting holes (10), the four second mounting holes (10) are respectively arranged on the outer sides of the two groups of ear pieces (8), the second pull plate (5) is provided with four third mounting holes (11) respectively corresponding to the second mounting holes (10), and the first pull plate (1) and the second pull plate (5) are connected and fixed by a pull rod (6) passing through the second mounting holes (10) and the third mounting holes (11); The second pull plate (5) is provided with a centering shaft (12) and a fourth mounting hole (13). The centering shaft (12) is used to fix the outer end of the outer cylinder piston rod (16) of the landing gear. The fourth mounting hole (13) coincides with the axial center line of the centering shaft (12), and the first mounting hole (9) and the fourth mounting hole (13) are arranged at corresponding positions. The first mounting hole (9) and the fourth mounting hole (13) are both equipped with corresponding centering pins (2).

2. The landing gear static performance test device according to claim 1, characterized in that: Each ear piece group (8) comprises two ear pieces (801), the two ear pieces (801) are spaced apart along the length direction of the first pull plate (1), and a gap is provided between the two ear pieces (801) that is larger than the width of the outer tube ear piece (15); the ear pieces (801) are vertically connected to the first pull plate (1), and the center lines of the ear piece holes on the four ear pieces (801) are located on the same straight line.

3. The landing gear static performance test device according to claim 2, characterized in that: The distance between the second mounting hole (10) and the outer ear piece (801) in the ear piece group (8) is greater than or equal to 20 mm.

4. The landing gear static performance test device according to claim 2, characterized in that: A gasket (17) is provided on the outer end of the inner ear piece (801) in each ear piece group (8).

5. The landing gear static performance test device according to claim 1, characterized in that: The centering shaft (12) is a hollow shaft, the size of which is adapted to the size of the inner hole of the outer end portion of the outer cylinder piston rod (16).

6. The landing gear static performance test device according to claim 5, characterized in that: A limiting portion (14) is provided at the lower outer portion of the centering shaft (12), and the width of the limiting portion (14) is greater than or equal to the diameter of the outer end portion of the outer cylinder piston rod (16).

7. The landing gear static performance test device according to any one of claims 1 to 6, characterized in that: The first pull plate (1) and the second pull plate (5) are both provided with two eye screw mounting holes (3), and the two eye screw mounting holes (3) are spaced apart.

8. The landing gear static performance test device according to any one of claims 1 to 6, characterized in that: The tensile strength of the materials used for the first pull plate (1), the positioning pin (4), the second pull plate (5), the pull rod (6) and the nut (7) is not less than 1680 MPa.

9. The landing gear static performance test device according to any one of claims 1 to 6, characterized in that: The second mounting hole (10) is a stepped hole, the nut (7) is a shouldered nut, and the first mounting hole (9) and the fourth mounting hole (13) are both threaded holes.

10. The landing gear static performance test device according to any one of claims 1 to 6, characterized in that: The two third mounting holes (11) located on one side of the second pull plate (5) in the longitudinal direction are light holes, and the two third mounting holes (11) on the other side are U-shaped groove structures, with the openings of the two U-shaped grooves facing the same direction and both facing the outside of the second pull plate (5).

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