A follow-up belt rotating device, a drop test bench and a landing gear drop test method

Abstract

The application provides a kind of servo belt rotating device, drop test bench and landing gear drop test method.The servo belt rotating device includes a first rack, a lifting device that is lifted in the first rack along the Z direction, a translation device that is laterally moved on the lifting device along the X direction, and a driving mechanism that is arranged on the translation device and is servoed with the translation device.The driving mechanism outputs rotational freedom, and an electromagnet is arranged on the power output end of the driving mechanism for clamping the wheel and making the wheel servoed.The application provides a stable and reliable connection mode by using the contact between the electromagnet and the radial side of the wheel, can accurately control the speed of the wheel, and timely withdraws before contacting the second platform, to realize high-precision drop test.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft test technology, in particular to a follow-up belt rotating device, a drop test bench and a landing gear drop test method, which are suitable for landing gear drop test. BACKGROUND

[0002] When the aircraft lands, the ground speed is large, and the wheel rapidly reaches high speed in a static state due to the impact and friction in the moment of contacting the ground, which is called wheel start-up. In order to verify the reliability of the landing gear system and the buffering characteristics of the landing gear, facilitate the adjustment of the filling parameters for the design personnel, and verify the structural strength and durability of the landing gear, the belt rotating drop test can make the test effect closer to the actual situation. During the test, the belt rotating wheel first drives the wheel to rotate through friction, and when the wheel speed reaches the target value, the landing gear is released to obtain the required test parameters.

[0003] As disclosed in the existing patent CN102072804B, a high-precision wheel pre-rotation mechanism for aircraft landing gear drop test, which drives the wheel to rotate through the contact of the friction wheel and the wheel. The friction wheel adopts a steel structure, and an outer ring is sleeved with a rubber ring that can ensure sufficient friction system. This contact type friction wheel rotating wheel method has large wear on the wheel, and the aircraft wheel is prone to overheating and tire burst during long-term test, which increases the test friction coefficient. In addition, the belt rotating method has a range requirement for the contact distance between the belt rotating wheel and the wheel. At high speed, the error is large, and the accuracy of the rotating speed cannot be guaranteed, which cannot meet the requirements of the belt rotating test with higher speed. Moreover, when adjusting the belt rotating height, it is affected by the maximum effective height, and some high drop tests cannot be performed.

[0004] As disclosed in the existing patent CN116902222A, a belt rotating device and method suitable for aircraft single-wheel double-fork landing gear drop test, which makes the wheel center on the test bench rotate along the center of the belt rotating wheel at equal distances, so that the transmission belt is kept tight to improve the wheel start-up speed accuracy and thus improve the test precision. However, in actual drop test, the tire deforms relative to the wheel, which may cause the wheel to deviate from the vertical position and slide or swing laterally. Long-term use of the limiting groove to control the landing gear wheel drop may cause damage to the landing gear.

[0005] For example, the existing patent No. CN208828133U discloses a multi-wheel multi-strut aircraft landing gear drop test with a follow-up belt rotating device. The test table belt rotating mechanism is installed on the bottom plate of the hanging basket frame. The triangular belt of the belt rotating mechanism drives the wheel to rotate quickly. After reaching the target rotating speed, the belt rotating mechanism falls freely with the landing gear, reducing the rotating speed synchronization error of the wheel and improving the test accuracy. However, when performing high drop test, the inertia force of the belt rotating mechanism on the test result needs to be considered, and the displacement change of the wheel after contacting the platform affects the belt rotating mechanism through the triangular belt.

[0006] Due to the different attitudes of the aircraft during landing, the belt rotating device needs to meet the demand of adjusting the attitude of the landing gear. In the rotating drop test of the landing gear, the vertical and horizontal speed (rotating speed) of the ground will affect the friction coefficient between the wheel and the platform. Therefore, it is necessary to improve the rotating speed accuracy of the wheel to obtain more accurate test results. SUMMARY

[0007] The purpose of the present application is to provide a follow-up belt rotating device, a drop test table and a landing gear drop test method, which can accurately control the rotating speed of the wheel and obtain more accurate test results.

[0008] The technical solution of the present application is: a follow-up belt rotating device, comprising a first rack, a lifting device vertically moving in the first rack, a translation device horizontally moving on the lifting device along the X direction, and a driving mechanism provided on the translation device and following the translation device, the driving mechanism outputs the rotating degree of freedom, and the power output end of the driving mechanism is provided with an electromagnet for clamping the wheel and making the wheel follow.

[0009] In the above scheme, the electromagnet contacts the radial side surface of the wheel, providing a stable and reliable connection method, and accurately controlling the rotating speed of the wheel and timely withdrawing before contacting the second platform, realizing high-precision drop test.

[0010] In order to ensure the vertical movement of the lifting device and realize free fall, a lifting rack guide is provided on the first rack, and the lifting device comprises a first gear meshing with the lifting rack guide. There is no jamming in the movement process.

[0011] Preferably, the lifting device comprises a first platform and a translation rack guide arranged on the first platform, one end of the translation rack guide is T-shaped structure, the other end is provided with a rack on the lower side, the T-shaped structure of the translation rack guide is matched with a sliding block, one end of the sliding block is connected to a second gear engaged with the rack on the lower side of the other end of the translation rack guide, one end of the driving mechanism is mounted on the sliding block, and the electromagnet is arranged on the side away from the second gear. The translation rack guide integrates the T-shaped structure and the rack, which can keep the effective transmission of the driving force, and the sliding block and the electromagnet thereon can quickly exit without affecting the drop test of the wheel.

[0012] Preferably, the driving mechanism comprises a third motor mounted on the translation device, the third motor has a third motor shaft, the third motor shaft is connected with the electromagnet through elastic first and second shaft couplings. The elastic shaft couplings can better transmit motion and power to the wheel and reduce vibration and impact.

[0013] The application also provides a drop test bench, which comprises a second rack, a hanging basket that can be lifted in the Z direction in the second rack, a second platform arranged directly below the hanging basket, and the above-mentioned follow-up belt rotating device arranged beside the second rack, a first sensor for sensing position is arranged above the second platform, a second sensor for measuring force is arranged at the bottom of the second platform, and clamps are arranged on the lower surface of the hanging basket.

[0014] The operation (lifting, horizontal movement, etc.) of the follow-up belt rotating device of the application is an independent driving system, which is not integrated with the wheel driving system, effectively avoiding the impact of the wheel of the landing gear on the follow-up belt rotating device during the drop test, reducing the drop mass, and being beneficial to the adjustment of the drop work capacity of the landing gear of the small aircraft and improving the test efficiency.

[0015] Preferably, the hanging basket comprises a body and directional rollers, the second rack comprises four second support columns, four peripherally arranged support arms of the body are adapted to the inner surfaces of the second support columns in the X and Y directions, and directional rollers in contact with the second support columns are arranged on each of the support arms. The directional rollers are clamped on the second support columns 11 in a clamping manner in the X and Y directions, can keep the vertical movement of the landing gear, and ensure the accuracy of the drop force data.

[0016] In order to enhance the strength between the two support arms, protrusions extending towards the second support columns are arranged between the two support arms; the protrusions are rectangular blocks. The rectangular blocks can greatly improve the structural stability.

[0017] In order to avoid the failure of the hanging basket locking, the drop test bench further comprises a self-locking device arranged on the second rack for limiting the drop position of the hanging basket, and the self-locking device is axially telescopic to lock or unlock the hanging basket.

[0018] The application also provides a landing gear drop test method, which is performed by using the drop test platform, and comprises the following steps:

[0019] Step one, fixing the upper end of the landing gear on the clamp, adjusting the height of the lifting device and the position of the translation device, and adsorbing the electromagnet on the wheel of the landing gear;

[0020] Step two, setting the wheel speed value;

[0021] Step three, lifting the basket, the lifting device and the landing gear to the required height for the drop test, starting the driving mechanism to drive the electromagnet to rotate, and the wheel rotates along with the electromagnet; when the wheel speed reaches the preset value, controlling the basket, the lifting device and the landing gear to free fall;

[0022] Step four, when the bottom of the wheel triggers the first sensor, controlling the electromagnet to be powered off to release the wheel, starting the translation device to drive the electromagnet to move laterally to separate from the wheel, and starting the lifting device to lock the electromagnet to move downward;

[0023] Step five, the basket and the landing gear continue to fall until hitting the second platform to trigger the second sensor, and the second sensor measures the vertical force and the horizontal force of the landing gear; and the test is completed.

[0024] Compared with the related art, the application has the following beneficial effects:

[0025] I. By using the radial side surface contact between the electromagnet and the wheel, a stable and reliable connection mode is provided, the wheel speed can be accurately controlled, and the electromagnet can be timely withdrawn before contacting the second platform, so that a high-precision drop test is realized; and the electromagnetic interface of the follow-up belt rotating device is connected with the wheel in the radial side of the wheel, the electromagnet and the wheel fall through two independent lifting systems respectively during the drop test, and the falling speed is consistent; when contacting the ground, the electromagnet is powered off and withdrawn, so as to avoid affecting the displacement of the wheel, avoid affecting the acceleration of the wheel and the acting force on the platform;

[0026] II. By using the radial side surface contact between the electromagnet and the wheel, the impact of the lateral displacement of the wheel tire deformation on the follow-up belt rotating device is avoided, and more accurate test results can be obtained;

[0027] III. By using the radial side surface contact between the electromagnet and the wheel, compared with the mode that the friction wheel contacts the outer surface of the wheel, the wear of the wheel is reduced, the accuracy of the wheel speed control is ensured, and the requirement of the belt rotating test with larger speed is met;

[0028] Fourth, the operation (lifting, lateral movement, etc.) of the follow-up drive device of the present invention is an independent drive system, which is not integrated with the wheel drive system. This effectively avoids the impact of the landing gear wheels on the follow-up drive device during the drop test, while reducing the drop mass. This is beneficial for adjusting the drop energy of the landing gear of small aircraft and improving test efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the follower belt rotation device provided by the present invention;

[0030] Figure 2 A schematic diagram of the structure of the drop test bench provided by the present invention.

[0031] Figure 3 for Figure 2 An enlarged view of the top of the second rack in the middle;

[0032] Figure 4 This is a schematic diagram of the installation structure of the self-locking device.

[0033] In the attached diagram: 1. Second frame; 11. Second support column; 12. Second top plate; 13. Base frame; 2. Suspended basket; 21. Body; 22. Clamp; 23. Roller; 24. Support arm; 25. Protrusion; 3. Lifting device; 31. Fourth motor; 32. Fourth motor circumference; 33. Roller; 34. Chain; 4. Self-locking device; 41. Cylinder; 42. Cylinder rod; 43. Guard rod; 5. Landing gear; 51. Connecting shaft; 52. Wheel; 6. First sensor; 7. Second platform; 8. Second sensor;

[0034] 9. Follow-up rotating device; 91. First frame; 911. First support column; 912. First top plate; 92. Lifting rack and pinion guide rail; 93. Lifting device; 931. First motor; 932. First motor shaft; 933. First gear; 934. Translation rack and pinion guide rail; 935. First platform; 94. Translation device; 941. Second motor; 942. Second motor shaft; 943. Second gear; 944. Slider; 95. Drive mechanism; 951. Third motor; 952. Third motor shaft; 953. First coupling; 954. Second coupling; 96. Electromagnet. Detailed Implementation

[0035] 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.

[0036] like Figure 1As shown, the belt driving device 9 provided by the embodiment has a length direction X, a width direction Y and a height direction Z, and comprises a first frame 91, a lifting rack guide 92, a lifting device 93, a translation device 94 and a driving mechanism 95. The first frame 91 comprises four first columns 911 arranged in a rectangular array and a first top plate 912 connected to the top of the four first columns 911. The lifting rack guide 92 is arranged on the side surface of the two first columns 911 close to each other in the X direction.

[0037] The lifting device 93 comprises a first motor 931 with a first motor shaft 932, a first gear 933 mounted on the first motor shaft 932, a first platform 935 arranged in the first frame 91, and a translation rack guide 934 arranged on the upper surface of the first platform 935. The first motor 931 is arranged around the first platform 935, and the first gear 933 is engaged with the lifting rack guide 92 at the corresponding position. The translation rack guide 934 extends along the X direction in the middle of the first platform 935. One end of the translation rack guide 934 is in a T-shaped structure, and the other end is provided with a rack on the lower side. The first gear 933 is driven to rotate on the lifting rack guide 92 by the first motor 931, so as to realize the lifting of the lifting device 93 in the height direction Z. At the same time, the height position of the lifting device 93 is self-locked by the first motor 931, and when the first motor 931 is unlocked, the lifting device 93 is free falling.

[0038] The translation device 94 is transverse to the translation rack guide 934. The translation device 94 comprises a second motor 941 with a second motor shaft 942, a second gear 943 mounted on the second motor shaft 942, and a slider 944 matched with the T-shaped structure end of the translation rack guide 934. The second motor 941 is fixed to one end of the slider 944, and the second gear 943 is engaged with the rack on the translation rack guide 934. The second motor 941 is started to drive the second gear 943 to rotate, so as to displace the slider 944 and the driving mechanism 95 thereon in the X direction.

[0039] The driving mechanism 95 includes a third motor 951 with a third motor shaft 952, a first coupling 953 and a second coupling 954 connected to the third motor shaft 952 in sequence. The third motor 951 is installed on the sliding block 944. The third motor shaft 952 is towards the reverse side of the second motor 941. A plurality of electromagnets 96 are arranged on the outer surface of the side away from the second motor 941 of the second coupling 954. The plurality of electromagnets 96 are circumferentially arranged to better adsorb the side surface of the wheel. The first coupling 953 is a elastic coupling. The third motor 951 is used to drive the plurality of electromagnets 96 to rotate, so that the wheel follows the belt and better transmits motion and power to the wheel through the elastic coupling, and reduces vibration and impact.

[0040] As shown in Figure 2 , the application also provides a drop test bench, which includes a second rack 1, a hanging basket 2, a lifting device 3, a self-locking device 4, a first sensor 6, a second platform 7, a second sensor 8 and a following belt device 9.

[0041] The second rack 1 includes four second columns 11 forming a rectangular array, a second top plate 12 connected to the top of the four second columns 11, and a bottom frame 13 connected to the bottom of the four second columns 11. The hanging basket 2 includes a body 21, a clamp 22 and a directional roller 23. The body 21 is provided with a support arm 24 adapted to the inner surface of the second column 11 in the X and Y directions around the body 21, and the directional roller 23 in contact with the second column 11 is arranged on each support arm 24. The protrusion 25 extending towards the second column 11 is arranged between two support arms 24. The protrusion 25 is a rectangular block. The lower surface of the body 21 is provided with the clamp 22 adapted to the landing gear 5, so as to clamp the upper end of the landing gear 5, and the lower end of the landing gear 5 is installed with the wheel 52 through the connecting shaft 51 (as shown in Figure 2 ).

[0042] As shown in Figure 2 , Figure 3 , the lifting device 3 includes a fourth motor 31 with a fourth motor shaft 32, a roller 33 installed on the fourth motor shaft 32, and a chain 34 wound on the roller 33. The fourth motor 31 is installed on the second top plate 12, and the end of the chain 34 is connected to the middle of the body 21.

[0043] The roller 33 is driven to rotate by the fourth motor 31, so that the chain 34 lifts the hanging basket 2 to a predetermined height position. The electromagnet (not shown) can be arranged at the height position to adsorb the body 21. After the fourth motor 31 is unlocked, the free fall of the hanging basket 2 is realized by de-energizing the electromagnet.

[0044] The self-locking device 4 is installed on one or both of the second columns 11 of the second rack 1. As shown inFigure 4 As shown, the self-locking device 4 comprises a cylinder 42 with a cylinder rod 42 and a guard rod 73 connected to the cylinder rod 42. The cylinder 42 is installed outside the second stand 11, and the guard rod 73 horizontally passes through the second stand 11. The extension and contraction of the cylinder 42 drives the axial extension and contraction of the guard rod 73 to lock (the guard rod 73 abuts against the lower surface of the body 21) or unlock the basket 2. To ensure the smoothness of the movement of the guard rod 73, a guide rail can be connected between the guard rod 73 and the second stand 11.

[0045] The second platform 7 is located directly below the basket 2, and a first sensor 6 (such as a grating sensor) for sensing position is arranged above the second platform 7, and a second sensor 8 (such as a force pillar sensor) for measuring force is arranged at the bottom of the second platform 7.

[0046] The follow-up belt rotating device 9 is arranged beside the second frame 1, and the electromagnet 96 corresponds to the position of the wheel 52.

[0047] The application also provides a landing gear drop test method, which is performed by using the drop test platform, and comprises the following steps.

[0048] S1, the upper end of the landing gear 5 is fixed to the clamp 22, the height of the lifting device 93 and the position of the translation device 94 are adjusted, and the electromagnet 96 is adsorbed to the wheel 52 of the landing gear 5.

[0049] S2, the rotating speed value of the wheel 52 is set, and the rotating speed value is the rotating speed of the third motor 951.

[0050] S3, the cylinder 41 of the self-locking device 4 is retracted to unlock the basket 2 by the guard rod 43, and meanwhile, the fourth motor 31 is started to lift the basket 2, the lifting device 93 and the landing gear 5 to the required height for the drop test. The third motor 951 of the driving mechanism 95 is started to rotate, and the third motor shaft 952 drives the first coupling 953, the second coupling 954 and the electromagnet 96 in sequence to rotate, so as to drive the wheel 52 to rotate follow-up. When the rotating speed of the wheel 52 reaches the preset value, the basket 2, the lifting device 93 and the landing gear 5 are controlled to free fall.

[0051] S4, when the bottom of the wheel 52 triggers the first sensor 6, the electromagnet 96 is controlled to be powered off to release the wheel 52, the translation device 94 is started to drive the electromagnet 96 to move laterally to be separated from the wheel 52, and the first motor 931 of the lifting device 93 is started to lock the electromagnet 96 to move downward.

[0052] S5, the basket 2 and the landing gear 5 continue to fall under the action of the lifting device 3 until they hit the second platform 7 to trigger the second sensor 8, and the second sensor 8 measures the vertical force and the horizontal force of the landing gear 5; the test is completed.

[0053] The above-mentioned actions are uniformly arranged by the controller. The translation device 94 is timely withdrawn before the wheel 52 contacts the second platform 7, avoiding the impact and damage of the tire deformation and displacement of the wheel 52 on the follow-up belt rotation device 9. At the same time, the first grating sensor 6 is arranged close to the second platform 7, reducing the error of the wheel 52 rotation speed after the driving mechanism 95 is withdrawn, so that the speed of the wheel 52 when contacting the second platform 7 can reach the expected requirement as much as possible.

[0054] After the test is completed, the controller controls the basket 2 to be lifted, and controls the self-locking device 4 to lock the basket 2.

[0055] The above-mentioned is only an embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and the drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A servo-belt turning device characterized by, The device comprises a first rack (91), a lifting device (93) which is lifted in the Z direction in the first rack (91), a translation device (94) which is horizontally moved in the X direction on the lifting device (93), and a driving mechanism (95) which is arranged on the translation device (94) and follows the translation device (94), wherein the driving mechanism (95) outputs a rotational degree of freedom, and an electromagnet (96) for clamping and following a wheel is arranged on the power output end of the driving mechanism (95); the lifting device (93) comprises a first platform (935) and a translation rack guide (934) arranged on the first platform (935), one end of the translation rack guide (934) is in a T-shaped structure, the other end is provided with a rack on the lower side, a slider (944) is matched with the translation rack guide (934) in the T-shaped structure, one end of the slider (944) is connected to a second gear (943) which is engaged with the rack on the lower side of the other end of the translation rack guide (934), one end of the driving mechanism (95) is mounted on the slider (944), and the electromagnet (96) is arranged on the side away from the second gear (943); the driving mechanism (95) comprises a third motor (951) mounted on the translation device (94), the third motor (951) has a third motor shaft (952), the third motor shaft (952) is connected with the electromagnet (96) through elastic first and second couplings (953) and (954) in sequence.

2. The driven belt transfer device of claim 1, wherein, The first rack (91) is provided with a lifting rack guide (92), and the lifting device (93) comprises a first gear (933) which is engaged with the lifting rack guide (92).

3. A drop test rig characterised in that, The device comprises a second rack (1), a hanging basket (2) which is lifted in the Z direction in the second rack (1), a second platform (7) which is arranged directly below the hanging basket (2), and a following belt rotating device as claimed in claim 1 or 2 which is arranged on the side of the second rack (1), a first sensor (6) for sensing position is arranged above the second platform (7), a second sensor (8) for measuring force is arranged on the bottom of the second platform (7), and a clamp (22) is arranged on the lower surface of the hanging basket (2).

4. The drop test rig of claim 3, wherein, The hanging basket (2) comprises a body (21) and a directional roller (23), the second rack (1) comprises four second support columns (11), the periphery of the body (21) is provided with support arms (24) which are adapted to the inner surfaces of the second support columns (11) in the X and Y directions, and the directional roller (23) which contacts the second support column (11) is arranged on each support arm (24).

5. The drop test rig of claim 4, wherein, A protrusion (25) which extends to the direction of the second support column (11) is arranged between two support arms (24); the protrusion (25) is a rectangular block.

6. The drop test station of claim 3, wherein, A self-locking device (4) for limiting the falling position of the hanging basket (2) is further arranged on the second rack (1), and the self-locking device (4) is axially telescopic to lock or unlock the hanging basket (2).

7. A landing gear drop test method using the drop test rig according to any one of claims 3 to 6, characterized in that, The device comprises the following steps: Step one, fix the upper end of the landing gear (5) on the fixture (22), adjust the height of the lifting device (93) and the position of the translation device (94), and adsorb the electromagnet (96) on the wheel (52) of the landing gear (5); Step two, set the wheel (52) speed value; Step three, lift the basket (2), lifting device (93) and landing gear (5) to the required height of the drop test, start the driving mechanism (95) to drive the electromagnet (96) to rotate, and the wheel (52) rotates with the driving mechanism (95); when the wheel (52) reaches the preset speed, control the basket (2), lifting device (93) and landing gear (5) to free fall; Step four, when the bottom of the wheel (52) triggers the first sensor (6), control the electromagnet (96) to release the wheel (52) to release the wheel (52); start the translation device (94) to drive the electromagnet (96) to move laterally to separate from the wheel (52); start the lifting device (93) to lock the electromagnet (96) to move downward; Step five, the basket (2) and landing gear (5) continue to fall until they hit the second platform (7) to trigger the second sensor (8), which measures the vertical force and horizontal force of the landing gear (5); Complete the test.

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