Follow-up belt rotation device, drop test bench and landing gear drop test method

Abstract

The invention provides a follow-up belt rotation device, a drop test bench and an undercarriage drop test method. The follow-up belt rotating device comprises a first machine frame, a lifting device ascending and descending in the first machine frame in the Z direction, a translation device transversely moving on the lifting device in the X direction and a driving mechanism arranged on the translation device and moving along with the translation device, and the driving mechanism outputs the rotation freedom degree. The power output end of the driving mechanism is provided with an electromagnet used for clamping the airplane wheel and enabling the airplane wheel to move along with the airplane wheel. The electromagnet is in contact with the radial side face of the airplane wheel, a stable and reliable connection mode is provided, the rotating speed of the airplane wheel can be accurately controlled, the airplane wheel is withdrawn in time before being in contact with the second platform, and a high-precision drop test is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft testing, and in particular to a follow-up belt rotation device, a drop shock test bench and a landing gear drop shock test method, which are suitable for a landing gear drop shock test. Background Art

[0002] When the aircraft is landing, the touchdown speed is relatively high. At the moment when the wheels touch the ground, due to the impact and friction, the wheels quickly reach high-speed operation in a stationary state, which is called wheel spin. In order to verify the reliability of the landing gear system and the cushioning characteristics of the landing gear, and to facilitate designers to adjust the filling parameters and verify the structural strength and durability of the landing gear, the belt-rotating drop shock test can make the test results closer to the actual situation. During the test, the belt-rotating wheel is first used to drive the wheel to rotate through friction. When the wheel speed reaches the target value, the landing gear is deployed to obtain the required test parameters.

[0003] For example, the high-precision wheel pre-rotation mechanism for the aircraft landing gear drop shock test disclosed in the existing patent announcement number CN102072804B drives the wheel to rotate by contacting the friction wheel with the wheel. The friction wheel adopts a steel structure, and the outer ring is covered with a rubber ring that can ensure a sufficient friction system. This contact-type friction wheel belt rotation method causes greater wear on the wheel. Long-term testing of aircraft wheels is prone to temperature rise and tire blowout, increasing the test friction coefficient. In addition, the friction belt rotation method has a range requirement for the contact distance between the belt wheel and the wheel. When running at high speed, the error is large, the speed accuracy cannot be guaranteed, and the belt rotation test requirements at a higher speed cannot be met. In addition, when adjusting the belt rotation height, it is affected by its own maximum effective height, and some higher drop shock tests cannot be performed.

[0004] For another example, the existing patent publication number CN116902222A discloses a belt-rotating device and method suitable for a drop shock test of a single-wheel double-fork landing gear of an aircraft. On the test bench, the center of the wheel rotates equidistantly along the center of the belt-rotating wheel through a limit groove, so that the transmission belt remains taut, thereby improving the accuracy of the wheel's rotation speed and thus improving the test accuracy. However, in an actual drop shock test, the tire has a deformation relative to the wheel, which will cause the wheel to deviate from its neutral position and slide or swing sideways. Long-term use of the limit groove to control the drop of the landing gear wheel may cause damage to the landing gear.

[0005] Another example is the existing patent announcement number CN208828133U, which discloses a follow-up belt-turning device for a multi-wheel and multi-pillar aircraft landing gear drop shock test. The test bench belt-turning mechanism is installed on the bottom plate of the hanging basket frame. The V-belt of the belt-turning mechanism drives the wheels to rotate rapidly. After reaching the target speed, the belt-turning mechanism follows the landing gear to fall freely, reducing the speed synchronization error of the wheels and thus improving the test accuracy. However, when this device is used for a high drop shock test, it is necessary to consider the influence of the inertial force of the belt-turning mechanism on the test results, as well as the influence of the displacement change caused by the contact between the wheels and the platform on the belt-turning mechanism through the V-belt.

[0006] Since the aircraft has different attitudes during landing, the rotating equipment needs to meet the needs of adjusting the attitude of the landing gear. During the take-off and rotation of the landing gear, the vertical and horizontal speeds of the ground (start-up speed) will affect the friction coefficient between the wheel and the table. Therefore, it is necessary to improve the accuracy of the wheel's rotation speed to obtain more accurate test results. Summary of the invention

[0007] The object of the present invention is to provide a follow-up belt rotation device, a drop shock test bench and a landing gear drop shock test method, which can be used to accurately control the starting rotation speed of the wheel and obtain more accurate test results.

[0008] The technical solution of the present invention is: a follow-up belt rotation device, including a first frame, a lifting device that is lifted and lowered in the first frame along the Z direction, a translation device that moves horizontally on the lifting device along the X direction, and a driving mechanism arranged on the translation device and following the translation device, the driving mechanism outputs rotational freedom, and an electromagnet for clamping a wheel and causing the wheel to follow is arranged on the power output end of the driving mechanism.

[0009] In the above scheme, the electromagnet is used to contact the radial side of the wheel, providing a stable and reliable connection method, and can accurately control the rotation speed of the wheel and withdraw it in time before contacting the second platform, thereby realizing a high-precision drop shock test.

[0010] In order to ensure the vertical movement of the lifting device and realize free fall, the first frame is provided with a lifting rack guide rail, and the lifting device includes a first gear meshed with the lifting rack guide rail. There is no jamming during the movement process.

[0011] Preferably, the lifting device includes a first platform and a translation rack guide rail disposed on the first platform, one end of the translation rack guide rail is a T-shaped structure, and a rack is disposed on the lower side of the other end. The T-shaped translation rack guide rail is equipped with a slider, one end of the slider is connected to a second gear meshing with the rack on the lower side of the other end of the translation rack guide rail, one end of the driving mechanism is mounted on the slider, and the electromagnet is disposed on a side away from the second gear. The translation rack guide rail integrates the T-shaped structure and the rack structure, and while maintaining the effective transmission of the motion driving force, the slider and the electromagnet thereon are quickly withdrawn without affecting the drop shock test of the wheel.

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

[0013] The present invention also provides a drop shock test bench, comprising a second frame, a hanging basket lifted and lowered in the second frame along the Z direction, a second platform arranged directly below the hanging basket, and the above-mentioned follow-up belt rotation device arranged on the side of the second frame, 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 a clamp is arranged on the lower surface of the hanging basket.

[0014] The operation (lifting, lateral movement, etc.) of the follower belt rotating device of the present invention is an independent drive system, which is not integrated with the wheel drive system, effectively avoiding the impact of the wheels of the landing gear on the follower belt rotating device during the drop shock test, while reducing the drop mass, which is beneficial to the adjustment of the drop shock work of the landing gear of small aircraft and improves the test efficiency.

[0015] Preferably, the hanging basket includes a body and directional rollers, the second frame includes four second pillars, the body is provided with arms adapted to the inner surfaces of the second pillars in the X and Y directions, and each of the arms is provided with directional rollers in contact with the second pillars. The directional rollers are clamped on the second pillars 11 in the X and Y directions in a clamping manner, which can keep the landing gear in vertical motion and ensure the accuracy of the falling force measurement data.

[0016] In order to enhance the strength between the two supporting arms, a convex block extending toward the second support column is provided between the two supporting arms; the convex block is a rectangular block, which can greatly improve the structural stability.

[0017] In order to avoid failure of the locking of the hanging basket, the drop shock test bench also includes a self-locking device arranged on the second frame for limiting the falling position of the hanging basket, and the self-locking device is axially extended to lock or unlock the hanging basket.

[0018] The present invention also provides a landing gear drop shock test method, which is performed using the above drop shock test bench and includes the following steps: Step 1: fix the upper end of the landing gear on the fixture, adjust the height of the lifting device and the position of the translation device, and adsorb the electromagnet on the wheel of the landing gear; Step 2, setting the rotation speed of the wheel; Step 3: lift the hanging basket, lifting device and landing gear to the required height for the drop shock test, start the driving mechanism to drive the electromagnet to rotate, and the wheel to rotate accordingly; when the rotation speed of the wheel reaches a preset value, control the hanging basket, lifting device and landing gear to fall freely; Step 4: When the bottom of the wheel triggers the first sensor, the electromagnet is powered off to release the wheel, the translation device is started to drive the electromagnet to move laterally to detach from the wheel; the lifting device is started to lock the electromagnet to move downward; Step 5: The basket and the landing gear continue to fall until they hit the second platform to trigger the second sensor, which measures the vertical force and horizontal force of the landing gear; the test is completed.

[0019] Compared with the related art, the present invention has the following beneficial effects: 1. The electromagnetic magnet is in contact with the radial side of the wheel to provide a stable and reliable connection method, and the rotation speed of the wheel can be accurately controlled and withdrawn in time before contacting the second platform, so as to realize a high-precision drop shock test; and the electromagnetic interface of the follow-up belt rotating device is electrically connected to the wheel on the radial side of the wheel. When performing the drop shock test, the electromagnet and the wheel fall through two independent lifting systems respectively, and maintain a consistent falling speed. When contacting the ground, the electromagnet is powered off and withdrawn to avoid affecting the displacement of the wheel, avoiding affecting the acceleration of the wheel and the force on the platform; Second, the electromagnetic magnet is used to contact the radial side of the wheel to avoid the impact of the lateral displacement caused by the deformation of the wheel tire on the follow-up belt rotation device, so that more accurate test results can be obtained; 3. Compared with the contact between the friction wheel and the outer ring surface of the wheel, the electromagnetic magnet is used to contact the radial side of the wheel, which reduces the wear of the wheel, ensures the accuracy of the wheel speed control, and meets the requirements of the belt rotation test at a higher speed; Fourth, the operation (lifting, lateral movement, etc.) of the follower belt rotating device of the present invention is an independent drive system, which is not integrated with the wheel drive system, effectively avoiding the impact of the wheels of the landing gear on the follower belt rotating device during the drop shock test, while reducing the drop mass, which is beneficial to the adjustment of the drop shock work of the landing gear of small aircraft and improves the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of the follower belt rotating device provided by the present invention; Figure 2 A schematic diagram of the structure of the drop test bench provided by the present invention Figure 3 for Figure 2 An enlarged schematic diagram of the top of the second rack; Figure 4 It is a schematic diagram of the installation structure of the self-locking device.

[0021] In the attached drawings: 1, second frame; 11, second pillar; 12, second top plate; 13, bottom frame; 2, hanging basket; 21, body; 22, clamp; 23, roller; 24, support arm; 25, bump; 3, lifting device; 31, fourth motor; 32, fourth motor periphery; 33, roller; 34, chain; 4, self-locking device; 41, cylinder; 42, cylinder rod; 43, protection rod; 5, landing gear; 51, connecting shaft; 52, wheel; 6, first sensor; 7, second platform; 8, second sensor; 9. Follow-up belt rotation device; 91. First frame; 911. First pillar; 912. First top plate; 92. Lifting rack guide; 93. Lifting device; 931. First motor; 932. First motor shaft; 933. First gear; 934. Translation rack guide; 935. First platform; 94. Translation device; 941. Second motor; 942. Second motor shaft; 943. Second gear; 944. Slider; 95. Driving mechanism; 951. Third motor; 952. Third motor shaft; 953. First coupling; 954. Second coupling; 96. Electromagnet. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0023] like Figure 1 As shown, the follow-up belt rotating device 9 provided in this embodiment has a length direction X, a width direction Y and a height direction Z, and includes a first frame 91, a lifting rack guide rail 92, a lifting device 93, a translation device 94 and a driving mechanism 95. The first frame 91 includes four first columns 911 enclosed in a rectangular array and a first top plate 912 connected to the tops of the four first columns 911. The lifting rack guide rail 92 is arranged on the side surface where two first columns 911 are close to each other in the X direction.

[0024] The lifting device 93 includes a first motor 931 having a first motor shaft 932, a first gear 933 mounted on the first motor shaft 932, a first platform 935 provided in the first frame 91, and a translation rack guide 934 provided on the upper surface of the first platform 935. The first motor 931 is arranged around the first platform 935 so that the first gear 933 is meshed 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 a T-shaped structure, and a rack is provided at the lower side of the other end. The first gear 933 is driven by the first motor 931 to mesh and rotate on the lifting rack guide 92 to realize the lifting and lowering 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 falls freely.

[0025] The translation device 94 moves laterally relative to the translation rack guide rail 934. The translation device 94 includes a second motor 941 having a second motor shaft 942, a second gear 943 mounted on the second motor shaft 942, and a slider 944 matched to one end of the T-shaped structure of the translation rack guide rail 934. The second motor 941 is fixed to one end of the slider 944, and the second gear 943 is meshed with the rack on the translation rack guide rail 934. The second motor 941 is started to drive the second gear 943 to rotate, so that the slider 944 and the driving mechanism 95 thereon are displaced in the X direction.

[0026] The driving mechanism 95 includes a third motor 951 having a third motor shaft 952 and a first coupling 953 and a second coupling 954 connected to the third motor shaft 952 in sequence. The third motor 951 is mounted on the slider 944. The third motor shaft 952 faces the reverse side of the second motor 941. A plurality of electromagnets 96 are arranged on the outer surface of the second coupling 954 away from the second motor 941. The plurality of electromagnets 96 are arranged in a circle to better adsorb to the side surface of the wheel. The first coupling 953 is an elastic coupling. The third motor 951 is used to drive the plurality of electromagnets 96 to rotate, so that the wheel rotates with the belt, and better transmits motion and power to the wheel through the elastic coupling, and reduces vibration and impact.

[0027] like Figure 2 As shown, the present invention also provides a drop shock test bench, including a second frame 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 follow-up belt rotation device 9.

[0028] The second frame 1 includes four second columns 11 forming a rectangular array, a second top plate 12 connected to the tops of the four second columns 11, and a bottom frame 13 connected to the bottoms of the four second columns 11. The hanging basket 2 includes a main body 21, a clamp 22 and a directional roller 23. The main body 21 is surrounded by arms 24 adapted to the inner surfaces of the second columns 11 in the X and Y directions, and each of the arms 24 is provided with a directional roller 23 in contact with the second column 11. A protrusion 25 extending toward the second column 11 is provided between two of the arms 24. The protrusion 25 is a rectangular block. The lower surface of the main body 21 is provided with a clamp 22 adapted to the landing gear 5 for clamping the upper end of the landing gear 5, and the lower end of the landing gear 5 is mounted with a wheel 52 (such as Figure 2 as shown).

[0029] like Figure 2 , Figure 3 As shown, the lifting device 3 includes a fourth motor 31 having a fourth motor shaft 32, a roller 33 mounted on the fourth motor shaft 32, and a chain 34 rotating on the roller 3. The fourth motor 31 is mounted on the second top plate 12, and the end of the chain 34 is connected to the middle of the body 21.

[0030] The fourth motor 31 drives the roller 33 to rotate, so that the chain 34 lifts the hanging basket 2 to a predetermined height position. An electromagnet (not shown) can be set at this height position to absorb the body 21. After the fourth motor 31 is unlocked, the hanging basket 2 can be free-falling by cutting off the power of the electromagnet.

[0031] The self-locking device 4 is installed on one or two second upright posts 11 of the second frame 1. Figure 4 As shown, the self-locking device 4 includes a cylinder 42 having a cylinder rod 42, and a protection rod 73 connected to the cylinder rod 42. The cylinder 42 is installed on the outside of the second column 11, and the protection rod 73 passes through the second column 11 horizontally. Through the extension and retraction of the cylinder 42, the protection rod 73 is driven to axially extend and retract to lock (the protection rod 73 abuts against the lower surface of the body 21) or unlock the hanging basket 2. In order to ensure the stability of the movement process of the protection rod 73, a guide rail can be connected between the protection rod 73 and the second column 11.

[0032] The second platform 7 is located directly below the hanging basket 2. A first sensor 6 (such as a grating sensor) for sensing position is arranged above the second platform 7. A second sensor 8 (such as a force measuring support sensor) for measuring force is arranged at the bottom of the second platform 7.

[0033] 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 .

[0034] The present invention also provides a landing gear drop shock test method, which is performed using the above drop shock test bench and is characterized in that it includes the following steps: S1, 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.

[0035] S2, setting the rotation speed value of the wheel 52, which is the rotation speed of the third motor 951.

[0036] S3, start the cylinder 41 on the self-locking device 4 to retract, so that the protection rod 43 unlocks the hanging basket 2; at the same time, start the fourth motor 31 to lift the hanging basket 2, the lifting device 93 and the landing gear 5 to the required height for the drop shock test. Start the third motor 951 of the driving mechanism 95 to rotate, and the third motor shaft 952 drives the first coupling 953, the second coupling 954 and the electromagnet 96 to rotate in turn to drive the wheel 52 to rotate. When the rotation speed of the wheel 52 reaches the preset value, the hanging basket 2, the lifting device 93 and the landing gear 5 are controlled to fall freely.

[0037] S4, when the bottom of the wheel 52 triggers the first sensor 6, the electromagnet 96 is powered off to release the wheel 52, and the translation device 94 is started to drive the electromagnet 96 to move laterally to separate from the wheel 52. The first motor 931 of the lifting device 93 is started to lock the electromagnet 96 to move downward.

[0038] 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 horizontal force of the landing gear 5; the test is completed.

[0039] The above actions are coordinated by the controller. The translation device 94 is withdrawn in time before the wheel 52 contacts the second platform 7 to avoid the deformation and displacement of the tire of the wheel 52 causing impact and damage to the follow-up belt rotation device 9. At the same time, the first grating sensor 6 is arranged close to the second platform 7 to reduce the error of the rotation speed of the wheel 52 after the drive 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.

[0040] After the test is finished, the controller controls the hanging basket 2 to lift and controls the self-locking device 4 to lock the hanging basket 2.

[0041] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A follow-up belt rotation device, characterized in that: The invention comprises a first frame (91), a lifting device (93) which is lifted and lowered in the first frame (91) along the Z direction, a translation device (94) which is laterally moved on the lifting device (93) along the X direction, and a driving mechanism (95) which is arranged on the translation device (94) and moves with the translation device (94), wherein the driving mechanism (95) outputs a rotational degree of freedom, and an electromagnet (96) for clamping a wheel and making the wheel move with the driving mechanism (95) is arranged on a power output end.

2. The follow-up belt rotation device according to claim 1, characterized in that: The first frame (91) is provided with a lifting rack guide rail (92), and the lifting device (93) comprises a first gear (933) meshing with the lifting rack guide rail (92).

3. The follow-up belt rotation device according to claim 1, characterized in that: The lifting device (93) comprises a first platform (935) and a translation rack guide rail (934) arranged on the first platform (935); one end of the translation rack guide rail (934) is a T-shaped structure, and a rack is arranged on the lower side of the other end; the translation rack guide rail (934) of the T-shaped structure is matched with a slider (944); one end of the slider (944) is connected to a second gear (943) meshing with the rack on the lower side of the other end of the translation rack guide rail (934); one end of the driving mechanism (95) is mounted on the slider (944); and the electromagnet (96) is arranged on a side away from the second gear (943).

4. The follow-up belt rotation device according to claim 1, characterized in that: 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 to the electromagnet (96) in sequence through a first elastic coupling (953) and a second coupling (954).

5. A drop shock test bench, characterized in that: The invention comprises a second frame (1), a hanging basket (2) which is lifted and lowered in the second frame (1) along the Z direction, a second platform (7) arranged directly below the hanging basket (2), and a follow-up belt rotation device as claimed in any one of claims 1 to 4 arranged beside the second frame (1), wherein a first sensor (6) for sensing position is arranged above the second platform (7), a second sensor (8) for measuring force is arranged at the bottom of the second platform (7), and a clamp (22) is arranged on the lower surface of the hanging basket (2).

6. The drop test bench according to claim 5, characterized in that: The hanging basket (2) comprises a main body (21) and directional rollers (23); the second frame (1) comprises four second pillars (11); arms (24) adapted to the inner surfaces of the second pillars (11) in the X and Y directions are arranged around the main body (21); and each of the arms (24) is provided with a directional roller (23) in contact with the second pillar (11).

7. The drop test bench according to claim 6, characterized in that: A convex block (25) extending in the direction of the second support column (11) is provided between the two support arms (24); the convex block (25) is a rectangular block.

8. The drop test bench according to claim 5, characterized in that: It also comprises a self-locking device (4) arranged on the second frame (1) for limiting the falling position of the hanging basket (2), wherein the self-locking device (4) is axially retracted to lock or unlock the hanging basket (2).

9. A landing gear drop test method, performed using the drop test bench as claimed in any one of claims 5 to 7, characterized in that: The steps include: Step 1, fixing the upper end of the landing gear (5) on the fixture (22), adjusting the height of the lifting device (93) and the position of the translation device (94), and adsorbing the electromagnet (96) on the wheel (52) of the landing gear (5); Step 2, setting the rotation speed value of the wheel (52); Step 3, lifting the hanging basket (2), the lifting device (93) and the landing gear (5) to a height required for the drop shock test, starting the driving mechanism (95) to drive the electromagnet (96) to rotate, and the wheel (52) to rotate accordingly; when the rotation speed of the wheel (52) reaches a preset value, controlling the hanging basket (2), the lifting device (93) and the landing gear (5) to fall freely; Step 4: 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 separate from the wheel (52); the lifting device (93) is started to lock the electromagnet (96) to move downward; Step 5, the basket (2) and the landing gear (5) continue to fall until they hit the second platform (7) to trigger the second sensor (8), and the second sensor (8) measures the vertical force and horizontal force of the landing gear (5); Complete the experiment.

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