Aircraft front wheel turning control system

Abstract

The invention relates to the technical field of aircraft front wheel turning control, and discloses an aircraft front wheel turning control system, which solves the problem that when the control function of the execution part of the aircraft front wheel turning control system fails, the turning angle of the front wheel support column is easy to lose control and rotate freely, so that the front wheel is easy to deflect greatly during the high-speed taxiing of the aircraft, affecting the taxiing safety of the aircraft. On the basis of satisfying the passive large-angle turning function of the tire mechanism, an active limit block is arranged to cooperate with the limit arc ring with different notch lengths, so as to limit the maximum rotation angle of the rotating drum, make the taxiing speed of the aircraft inversely proportional to the maximum rotation angle of the tire mechanism, make the maximum deflection range of the tire mechanism within the safe range at the current taxiing speed, and improve the taxiing safety of the aircraft guaranteed by the aircraft front wheel turning control system.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft front wheel turning control, in particular to an aircraft front wheel turning control system. Background Art

[0002] The turning control system of the front wheel of the aircraft consists of an input part (giving of turning signals, including through handwheels, pedals, and autopilot systems), a control part (BSCU computer - the control center of the front wheel turning system), an execution part (front wheel turning hydraulic control components, front wheel turning actuators), and a position feedback part (turning angle sensor, monitoring the angle of rotation of the front frame, forming a closed loop with the turning control of the BSCU computer).

[0003] The existing publication number "CN107867394A" discloses "an aircraft front wheel turning drive device", which includes a servo valve controlling a motor rotor to manipulate the front wheel support to turn within a range of plus or minus 65 degrees; when the servo valve control signal is cut off and the hydraulic lock is opened, the motor as a whole can rotate within a range of 360 degrees together with the front wheel support;

[0004] The above implementation is equivalent to the execution part and position feedback part in the front wheel turning control system, making the turning control of the aircraft more flexible; wherein, the turning of the front wheel strut within the range of plus or minus 65 degrees belongs to the active control part of the aircraft turning, so that the aircraft satisfies autonomous turning; the aircraft has requirements for autonomous turning angles during takeoff, landing and high-speed taxiing, and the maximum turning angle cannot exceed 6°. As the speed decreases, larger angles of turning are gradually allowed; the execution part of the above implementation lacks protection measures for the turning of the front wheel strut. On the basis that the front wheel strut has a large-angle passive turning (steering by relying on the trailer), when the execution part that controls the steering of the front wheel strut fails (such as the servo valve and hydraulic lock of the above patent), the turning angle of the front wheel strut is out of control, and the front wheel strut is prone to the risk of free rotation. Therefore, although the above implementation improves the passive steering range of the front wheel strut, it increases the risk of free rotation of the front wheel strut due to control failure during the high-speed taxiing stage of the aircraft, resulting in a large swing amplitude of the front wheel, affecting the taxiing safety of the aircraft. Summary of the invention

[0005] The purpose of the present invention is to provide an aircraft front wheel turning control system, which solves the problem that when the execution part of the control function of the aircraft front wheel turning control system fails, the turning angle of the front wheel support is prone to get out of control and free rotation, causing the front wheel to deviate significantly during high-speed taxiing of the aircraft, thereby affecting the taxiing safety of the aircraft.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solutions: an aircraft front wheel turning control system, comprising an input part, a control part, an execution part, and a position feedback part, wherein the execution part comprises a support mechanism, a tire mechanism is mounted on the lower side of the support mechanism, a turning actuator for controlling the turning of the tire mechanism is disposed on one side of the support mechanism, a rotation limiting mechanism for limiting the turning angle of the tire mechanism is mounted on the support mechanism, and the rotation limiting mechanism adapts the turning angle of the tire mechanism to the limited turning angle according to the taxiing speed of the aircraft;

[0007] The rotation limiting mechanism comprises a first cover body and a second cover body fixedly mounted on the support mechanism, a rotating drum coaxial with the support mechanism is rotatably mounted inside the first cover body and the second cover body, the turning actuator controls the rotation of the rotating drum, and further controls the steering of the tire mechanism, a plurality of limit arc rings with increasing lengths are sequentially arranged on the surface of the rotating drum along the axial downward direction, an upper and lower movable hydraulic push member is arranged inside the first cover body, a limit block movable between the plurality of limit arc rings is fixedly arranged on one side of the hydraulic push member, the limit arc ring is limited by the limit block, and its rotation angle corresponds to the rotation angle of the rotating drum;

[0008] The control part controls the limit block to move into the corresponding limit arc ring according to the taxiing speed of the aircraft to limit the maximum rotation angle of the rotating drum, so that the taxiing speed of the aircraft is inversely proportional to the maximum rotation angle of the tire mechanism.

[0009] As a further description of the above technical solution: the support mechanism includes a support tube assembled on the lower side of the fuselage through a folding frame, a lower support rotatably connected to the tire mechanism is provided on the inner side of the support tube, and an oil-gas shock absorber for shock absorbing the lower support is also provided in the support tube, a fixed fixing ring and a rotating rotating ring are provided on the lower side of the rotating drum, a hydraulic lock is provided on one side of the rotating ring to lock the rotating drum, the output end of the turning actuator is connected to one side of the rotating ring, and a torque arm is provided on one side of the fixed ring to connect to the tire mechanism.

[0010] As a further description of the above technical solution: an annular cavity for the limit block to pass through is provided above the uppermost limit arc ring.

[0011] As a further description of the above technical solution: a hydraulic cavity is formed on the inner wall of the first cover body for the liquid pusher to slide up and down in a sealed manner, a hydraulic groove is formed on the liquid pusher close to the outer surface of the first cover body, a baffle is fixedly provided on the inner wall of the hydraulic cavity, and the baffle seal slides in the hydraulic groove formed on one side of the liquid pusher, an oil hole A and an oil hole B are formed on the inner wall of the hydraulic cavity which are connected to the outer surface of the first cover body, the oil hole A and the oil hole B are respectively located on the lowermost and uppermost sides of the inner wall of the hydraulic cavity, an electro-hydraulic valve A is formed on the outer surface of the first cover body, and the electro-hydraulic valve A is connected to the oil hole A and the oil hole B through the valve seat A.

[0012] As a further description of the above technical solution: an electro-hydraulic valve B assembled through a valve seat B is provided on the outer surface of the first cover body, and a hydraulic motor driven by the electro-hydraulic valve B is installed between the first cover body, the second cover body and the rotating drum.

[0013] As a further description of the above technical solution: a pressure mechanism that is pressurized by the weight of the aircraft fuselage is installed inside the cylinder and on the lower side of the oil-gas shock absorber, and a trigger mechanism that corrects the position of the limit block when the limit block is faulty and misaligned during the taxiing of the aircraft. The trigger mechanism corrects the position of the limit block through the pressure mechanism.

[0014] As a further description of the above technical solution: the pressure mechanism includes a cavity cover fixedly installed under the oil-gas shock absorber, and the inner side of the cavity cover is respectively provided with a first piston plate and a second piston plate from top to bottom, the upper cavity of the first piston plate stores hydraulic oil, and the cavity between the second piston plate and the first piston plate stores compressed gas, and a push claw is connected to the upper end of the lower support, and the push claw pushes the second piston plate upward to compress the compressed gas in the upper cavity, and the inner wall of the cavity for storing hydraulic oil is provided with an oil drain hole connected to the lower side of the cavity cover.

[0015] As a further description of the above technical solution: the trigger mechanism includes a connecting valve, which includes a valve body and an inner movable valve plate, the valve body surface is provided with at least two first valve holes that penetrate into the lower surface, the valve plate surface is provided with a second valve hole that is correspondingly connected to the first valve hole, the valve plate is pulled by a pull ring fixedly connected on one side so that the second valve hole is correspondingly connected to the first valve hole; the lower side of the valve body is fixedly connected to the hydraulic push member through an oil guide column assembly, the oil guide column assembly includes an oil inlet column connected to the bottom of the hydraulic groove on one side of the hydraulic push member, and an oil return column connected to the lower surface of the hydraulic push member, the oil inlet column, the oil return column and the first valve hole are correspondingly connected.

[0016] As a further description of the above technical solution: the trigger mechanism also includes a first oil pipe that is movably connected to the oil inlet column on the upper side of the connecting valve, and a second oil pipe that is movably connected to the oil return column, one end of the first oil pipe is connected to the oil drain hole, and one end of the second oil pipe is connected to the outside of the first cover body, a rotating lever is provided above the pull ring, and the lever is rotatably installed on the inner wall of the support tube through a mounting seat, a pull rope is connected between one side of the lever and the upper end of the lower support, and the pull rope limits the pulling direction of the guide wheel fixedly installed on the mounting seat through one side position, so that the lever rotates in the direction in which the valve plate slides out of the inner side of the valve body.

[0017] As a further description of the above technical solution: the position feedback part includes an angular displacement sensor for detecting the rotation angle of the drum and a carbon film displacement sensor for detecting the moving position of the limit block.

[0018] In summary, due to the adoption of the above technical scheme, the beneficial effects of the present invention are as follows: on the basis of satisfying the passive large-angle turning function of the tire mechanism, an active limit block is arranged to cooperate with the limit arc rings with different notch lengths, so as to limit the maximum rotation angle of the rotating drum, so that the aircraft taxiing speed is inversely proportional to the maximum rotation angle of the tire mechanism, so that the maximum deflection range of the tire mechanism is within a safe range at the current taxiing speed, and the taxiing safety of the aircraft guaranteed by the aircraft nose wheel turning control system is improved; and, in the case of extreme control failure of the execution part, when the limit block is misplaced before the aircraft is forced to land, the pressure mechanism utilizes the weight of the aircraft fuselage to generate hydraulic energy for the inner hydraulic oil, and cooperates with the trigger mechanism to automatically correct the position of the limit block, so that the limit block returns to the lowermost limit arc ring, so that the maximum deflection range of the rotating drum is restored to a safe range, so that when all functions of the execution part of the aircraft nose wheel turning control system fail, the safety of the forced landing can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the overall internal structure of the present invention;

[0021] Figure 3 It is a schematic diagram of the overall planar structure of the present invention;

[0022] Figure 4 For the present invention Figure 3 A is an enlarged schematic diagram;

[0023] Figure 5 It is a schematic diagram of the cross section of the first cover body and the related assembly structure of the present invention;

[0024] Figure 6 It is a schematic diagram of the structure of the outer side of the first cover body and the liquid push member of the present invention;

[0025] Figure 7 It is a schematic diagram of the inner side of the first cover body and the structure of the liquid pusher of the present invention;

[0026] Figure 8 It is a schematic diagram of the bottom surface structure of the liquid pusher of the present invention;

[0027] Fig. 9 It is a schematic diagram of the rotating drum and related assembly structure of the present invention;

[0028] Fig.10 It is a schematic diagram of the assembly position structure of the trigger mechanism and the pressure mechanism of the present invention;

[0029] Fig.11 It is a schematic diagram of the structure of the trigger mechanism of the present invention;

[0030] Fig.12This is a schematic diagram of the disassembled structure of the connecting valve of the present invention;

[0031] Fig.13 It is a schematic diagram of the hydraulic push member of the present invention moving upward in the hydraulic cavity;

[0032] Fig.14 It is a schematic diagram of the moving position of the upper end of the lower support in the support tube of the present invention.

[0033] In the figure: 10, support mechanism; 11, support cylinder; 12, oil-gas shock absorber; 13, lower support; 131, push claw; 132, extension part; 133, pressure-bearing part; 134, buffer part; 20, turning actuator; 21, torque arm; 30, tire mechanism; 40, rotation-limiting mechanism; 41, first cover body; 411, hydraulic chamber; 412, oil hole A; 413, oil hole B; 414, baffle; 415, sliding hole; 42, rotating cylinder; 421, fixed ring; 422, rotating ring; 423, hydraulic lock; 43, second cover body; 44, hydraulic push member; 441, limit block; 45, oil guide column assembly; 451, oil inlet column; 452, oil return column; 46, limit arc ring; 47 , electro-hydraulic valve A; 471, valve seat A; 48, electro-hydraulic valve B; 481, valve seat B; 50, trigger mechanism; 51, connecting valve; 511, valve body; 512, valve plate; 513, pull ring; 514, first valve hole; 515, second valve hole; 52, lever; 521, mounting seat; 53, pull rope; 531, guide wheel; 54, first oil pipe; 55, second oil pipe; 60, pressure mechanism; 61, cavity cover; 62, oil drain hole; 63, first piston plate; 64, second piston plate; 70, hydraulic motor; 71, stator; 72, rotor; 80, angular displacement sensor; 81, measuring ring; 90, carbon film displacement sensor; 91, carbon film resistor slide; 92, brush slide. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0036] Combination Figure 1-Figure 14A front wheel turning control system for an aircraft comprises an input part, a control part, an execution part and a position feedback part. The execution part comprises a support mechanism 10, a tire mechanism 30 is arranged at the lower side of the support mechanism 10, a turning actuator 20 for controlling the turning of the tire mechanism 30 is arranged at one side of the support mechanism 10, a rotation limiting mechanism 40 for limiting the turning angle of the tire mechanism 30 is arranged on the support mechanism 10, and the rotation limiting mechanism 40 adapts the turning angle of the tire mechanism 30 according to the taxiing speed of the aircraft;

[0037] The rotation limiting mechanism 40 includes a first cover body 41 and a second cover body 43 fixedly mounted on the support mechanism 10. A rotating drum 42 coaxial with the support mechanism 10 is rotatably mounted inside the first cover body 41 and the second cover body 43. The turning actuator 20 controls the rotation of the rotating drum 42 to further control the steering of the tire mechanism 30. A plurality of limit arc rings 46 with increasing lengths are sequentially arranged on the surface of the rotating drum 42 along the axial downward direction. An upper and lower movable hydraulic push member 44 is arranged inside the first cover body 41. A limit block 441 movable between the plurality of limit arc rings 46 is fixedly arranged on one side of the hydraulic push member 44. The limit arc ring 46 is limited by the limit block 441, and its rotation angle corresponds to the rotation angle of the rotating drum 42.

[0038] The control part controls the limit block 441 to move into the corresponding limit arc ring 46 according to the taxiing speed of the aircraft to limit the maximum rotation angle of the rotating drum 42, so that the taxiing speed of the aircraft is inversely proportional to the maximum rotation angle of the tire mechanism 30.

[0039] Specifically, compared with the existing aircraft front wheel turning control system, when the turning actuator 20 and other control structures controlling the steering of the tire mechanism 30 fail, the front wheel support column will have the risk of free rotation, resulting in a large deviation of the front wheel, especially when the tire mechanism 30 has the function of passive 360° turning, the deviation caused by the failure will only be greater, which seriously affects the safety of aircraft use; in this embodiment, the position of the limit block 441 is controlled by the hydraulic push member 44, and is moved to a suitable limit arc ring 46 according to the taxiing speed of the aircraft. Because different limit arc rings 46 have different notch lengths, the limit block 441 is not limited to the limit arc ring 46. The range of movement of the block 441 relative to the gap in the limit arc ring 46 is the range of the free rotation angle of the limit arc ring 46. During the taxiing before the aircraft takes off, its taxiing speed gradually increases, and the limit block 441 is automatically moved from top to bottom between the plurality of limit arc rings 46 by the controlled part, so that the maximum rotation angle of the tire mechanism 30 is gradually reduced. Even if the turning actuator 20 and other control structures controlling the steering of the tire mechanism 30 fail, the free rotation range of the tire mechanism 30 is also limited, so it is effectively avoided that the tire mechanism 30 has a large swing amplitude due to a fault, which affects the safety of the aircraft, and further improves the front wheel of the aircraft. Safety control of the turning control system; similarly, during the taxiing of the aircraft during landing, the speed changes from large to small, and the initial position of the limit block 441 has been moved to the limit arc ring 46 at the lowest position during takeoff, and then the position of the limit block 441 is controlled to gradually move upward, so that the rotation angle of the tire mechanism 30 controlled by the turning actuator 20 gradually increases; further, when the control of the limit block 441 fails, in the taxiing state of the aircraft during takeoff, the rotation angle of the tire mechanism 30 limited by the limit block 441 is matched with the taxiing speed of the aircraft, even if the control of the limit block 441 fails during the taxiing of the aircraft, the final stop position of the limit block 441 The limit of the maximum rotation angle of the tire mechanism 30 is matched with the current taxiing speed, so even if the tire mechanism 30 deflects, it is within the safe range, and the aircraft should be controlled to slow down and stop, and the take-off should be terminated; when the aircraft is in the landing taxiing state, when the limit block 441 fails to control, similarly, the final stop position of the limit block 441 matches the current taxiing speed, and the deflection of the tire mechanism 30 is also within the safe range, so the aircraft can finally be safely stopped; the above-mentioned aircraft front wheel turning control system, especially the tire mechanism 30, has the function of passive 360° turning, which greatly improves its safety.

[0040] The support mechanism 10 includes a support tube 11 assembled on the lower side of the fuselage through a folding frame, a lower support 13 rotatably connected to the tire mechanism 30 is provided on the inner side of the support tube 11, the lower support 13 passes through the inner side of a rotating drum 42, the rotating drum 42 rotates on the outer surface of the lower support 13, and an oil-gas shock absorber 12 for shock absorbing the lower support 13 is also provided in the support tube 11, a fixed fixing ring 421 and a rotating rotating ring 422 are provided on the lower side of the rotating drum 42, a hydraulic lock 423 is provided on one side of the rotating ring 422 for movably locking with the rotating drum 42, an output end of the turning actuator 20 is connected to one side of the rotating ring 422, when the hydraulic lock 423 locks the rotating ring 422 with the rotating drum 42, the turning actuator 20 pushes the rotating ring 422 to rotate, and can drive the rotating drum 42 to rotate, a torque arm 21 is provided on one side of the fixed ring 421 to connect with the tire mechanism 30, and the rotating rotating drum 42 drives the tire mechanism 30 through the torque arm 21 to complete the steering task.

[0041] like Fig. 9 As shown, an annular cavity for the passage of a limit block 441 is provided above the uppermost limit arc ring 46. By pushing the limit block 441 into the annular cavity and then controlling the hydraulic lock 423 to disconnect the locking connection between the rotating ring 422 and the rotating drum 42, the rotating drum 42 and the tire mechanism 30 connected to the rotating drum 42 through the torque arm 21 will be in a free rotation state. At this time, the tire mechanism 30 can be controlled by the trailer to passively turn, so that the aircraft can meet the turning conditions in a narrow place (such as the deck of an aircraft carrier).

[0042] like Figure 5-Figure 7 As shown, the inner wall of the first cover body 41 is provided with a hydraulic cavity 411 for sealing and sliding the liquid push member 44 up and down, the liquid push member 44 is provided with a hydraulic groove close to the outer surface of the first cover body 41, a baffle 414 is fixedly provided on the inner wall of the hydraulic cavity 411, and the baffle 414 seals and slides in the hydraulic groove provided on one side of the liquid push member 44, and the inner wall of the hydraulic cavity 411 is provided with an oil hole A412 and an oil hole B413 connected to the outer surface of the first cover body 41, and the oil hole A412 and the oil hole B413 are respectively located at the lowermost side and the uppermost side of the inner wall of the hydraulic cavity 411, and the outer surface of the first cover body 41 is provided with an electro-hydraulic valve A47, and the electro-hydraulic valve A47 is connected with the oil hole A412 and the oil hole B413 through the valve seat A471, as shown in FIG. Figure 5As shown, one side of the electro-hydraulic valve A47 includes a P port (oil supply port), a T port (oil return port), and A and B oil ports (working oil ports), wherein the P port and the T port are connected to the external oil circuit through the oil holes on both sides of the valve seat A471, and the A and B oil ports are connected to the oil hole A412 and the oil hole B413 respectively; during operation, when oil enters the oil hole A412 and oil returns from the oil hole B413, the hydraulic oil lifts the hydraulic push member 44 at the lower side, causing the hydraulic push member 44 to move upward in the hydraulic chamber 411; on the contrary, the hydraulic oil is injected into the hydraulic groove on one side of the hydraulic push member 44, pushing the hydraulic push member 44 downward, causing it to descend in the hydraulic chamber 411, thereby realizing the position adjustment of the limit block 441 fixedly connected to one side of the hydraulic push member 44 between multiple limit arc rings 46.

[0043] like Figure 5 As shown, the outer surface of the first cover body 41 is provided with an electro-hydraulic valve B48 assembled through a valve seat B481, and a hydraulic motor 70 driven by the electro-hydraulic valve B48 is assembled between the first cover body 41, the second cover body 43 and the rotating drum 42. Specifically, the stator 71 of the hydraulic motor 70 is formed integrally on the inner wall of the first cover body 41 and the second cover body 43, and the rotor 72 of the hydraulic motor 70 is assembled on the surface of the rotating drum 42. The P port and T port of the electro-hydraulic valve B48 are connected to the external oil circuit through the valve seat B481, and the A and B oil ports of the electro-hydraulic valve B48 are connected to the hydraulic motor 70; by controlling the limit block 441 to enter the annular cavity above the limit arc ring 46 for 360° rotation, the electro-hydraulic valve B48 is started again to control the rotating drum 42 to rotate 360°. By controlling the rotation of the rotating drum 42 by the electro-hydraulic valve B48, the tire mechanism 30 can be further actively controlled to make a larger angle of steering and angle reset.

[0044] like Figure 3-Figure 4 , Figure 9-12 As shown, the lower side of the oil-gas shock absorber 12 in the support tube 11 is equipped with a pressure mechanism 60 that is pressurized by the weight of the aircraft fuselage, and a trigger mechanism 50 that corrects the position of the limit block 441 when the position of the limit block 441 is faulty and offset during the taxiing of the aircraft. The trigger mechanism 50 corrects the position of the limit block 441 through the pressure mechanism 60;

[0045] The pressure-applying mechanism 60 includes a cavity cover 61 fixedly mounted below the oil-gas shock absorber 12, and a first piston plate 63 and a second piston plate 64 are respectively provided on the inner side of the cavity cover 61 from top to bottom. The upper cavity of the first piston plate 63 stores hydraulic oil, and the cavity between the second piston plate 64 and the first piston plate 63 stores compressed gas. A push claw 131 connected to the upper end of the lower support 13 pushes the second piston plate 64 upward to compress the compressed gas in the upper cavity, so that the compressed gas pushes the first piston plate 63, so that the hydraulic oil stored in the upper cavity has hydraulic energy, and the inner wall of the cavity for storing hydraulic oil is provided with an oil drain hole 62 connected to the lower side of the cavity cover 61.

[0046] The trigger mechanism 50 includes a connecting valve 51, which includes a valve body 511 and a valve plate 512 movable inside. The surface of the valve body 511 is provided with at least two first valve holes 514 penetrating to the lower surface. The surface of the valve plate 512 is provided with a second valve hole 515 correspondingly connected to the first valve hole 514. The valve plate 512 is pulled by a pull ring 513 fixedly connected to one side, so that the second valve hole 515 is correspondingly connected to the first valve hole 514. The lower side of the valve body 511 is fixedly connected to the hydraulic push member 44 through an oil guide column assembly 45. The oil guide column assembly 45 includes an oil inlet column 451 connected to the bottom of the hydraulic groove on one side of the hydraulic push member 44, and an oil return column 452 connected to the lower surface of the hydraulic push member 44. Figure 6 , Figure 8 As shown, the oil inlet column 451, the oil return column 452 and the first valve hole 514 are connected to each other, and a sliding hole 415 for sealing and sliding of the oil inlet column 451 and the oil return column 452 is opened on the surface of the baffle 414. When the hydraulic push member 44 moves up and down, the connecting valve 51 will also move up and down accordingly.

[0047] The trigger mechanism 50 also includes a first oil pipe 54 disposed on the upper side of the connecting valve 51 and movably connected to the oil inlet column 451, and a second oil pipe 55 movably connected to the oil return column 452. One end of the first oil pipe 54 is connected to the oil drain hole 62, and one end of the second oil pipe 55 is connected to the outside of the first cover body 41. A rotating lever 52 is disposed above the pull ring 513. The lever 52 is rotatably mounted on the inner wall of the support tube 11 through a mounting seat 521. The mounting seat 521 and the lever 52 are rotatably connected through a torsion spring. , so that the lower end of the lever 52 is kept above the pull ring 513. When the lower end of the lever 52 moves to the second limit arc ring 46 from bottom to top in the limit block 441, the pull ring 513 will be sleeved on the outer surface of the lever 52. A pull rope 53 is connected between one side of the lever 52 and the upper end of the lower support 13. The pull rope 53 limits the pulling direction of the guide wheel 531 fixedly installed on one side relative to the mounting seat 521, so that the lever 52 rotates in the direction in which the valve plate 512 slides out from the inner side of the valve body 511.

[0048] Specifically, Fig.14 As shown, the upper end of the lower support 13 moves between three positions in the support tube 11, namely: the aircraft is in the air, the fuselage pressure does not act on the oil-gas shock absorber 12, the working end of the oil-gas shock absorber 12 extends, and the upper end of the lower support 13 is located at the extension part 132. In this state, the pull rope 53 is not subjected to force and is relaxed; the aircraft is on the ground and taxiing, in which state, the pull rope 53 is stretched straight, and the push claw 131 squeezes the second piston plate 64 to compress the upper compressed gas; in the process of the aircraft landing from the air, the downward inertia of the fuselage gravity will force the working end of the oil-gas shock absorber 12 to be further compressed, so that the upper end of the lower support 13 is located at the buffer part 134, and then the working end of the oil-gas shock absorber 12 returns to the pressure-bearing part 133. In this process, the pull rope 53 will pull the lever 52 to swing once;

[0049] The above implementation is applied in the front wheel turning control system of an aircraft. When the control structure of the execution part fails completely, such as the turning actuator 20, the electro-hydraulic valve A47, and the electro-hydraulic valve B48 are all out of control, and the limit block 441 is not inside the lowermost limit arc ring 46, the rotating drum 42 has a risk of large swing amplitude. This implementation is achieved by: first, the pull ring 513 is automatically sleeved on the surface of the lever 52 (such as Fig.13 As shown in the figure, because the limit block 441 is only located inside the lowermost limit arc ring 46, the pull ring 513 and the lever 52 are not sleeved, and they are in the sleeved state in other cases). When the aircraft lands, the weight inertia of the fuselage causes the pull rope 53 to pull the lever 52 to swing, and the swinging lever 52 pulls the valve plate 512 out of the valve body 511 through the pull ring 513, so that the first valve hole 514 is connected with the corresponding second valve hole 515. Then, the hydraulic oil in the chamber cover 61 in the pressurized state is injected into the hydraulic push member 4 through the first oil pipe 54 and the oil inlet column 451. 4, the hydraulic groove on one side of the hydraulic push member 44 is pushed down, and at the same time, the hydraulic oil on the lower side of the hydraulic push member 44 is discharged through the oil return column 452 and the second oil pipe 55 to prevent the hydraulic oil from blocking the hydraulic push member 44 from descending. In this way, the limit block 441 is in a downward moving state, and returns to the lowermost limit arc ring 46 during the swing of the drum 42 with the tire mechanism 30, thereby re-limiting the maximum swing range of the drum 42 and restoring it to a safe range. When the execution parts of the aircraft's front wheel turning control system all fail, the safety of forced landing can be guaranteed.

[0050] like Figure 2-Figure 4 , Figure 9-10 As shown, the position feedback part includes an angular displacement sensor 80 for detecting the rotation angle of the rotating drum 42 and a carbon film displacement sensor 90 for detecting the moving position of the limit block 441. The angular displacement sensor 80 detects the rotation angle of the rotating drum 42 by detecting the measuring ring 81 at the upper end of the rotating drum 42, so as to form a closed loop with the rotation angle control of the tire mechanism 30; the carbon film displacement sensor 90 includes a carbon film resistor slide 91 fixed on the inner wall of the support tube 11, and a brush slide 92 arranged on one side of the connecting valve 51 and slidingly attached to the carbon film resistor slide 91. The carbon film resistor slide 91 measures the sliding height of the brush slide 92, so as to detect the position of the connecting valve 51, so as to further control the position feedback of the limit block 441 moving in the corresponding limit arc ring 46 to form a closed loop.

[0051] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An aircraft front wheel turning control system, comprising an input part, a control part, an execution part, and a position feedback part, characterized in that: The execution part comprises a support mechanism (10), and the lower side of the support mechanism (10) is equipped with: a tire mechanism (30); a turning actuator (20) for controlling the turning of the tire mechanism (30); and a rotation limiting mechanism (40) for limiting the turning angle of the tire mechanism (30); The rotation limiting mechanism (40) comprises a first cover body (41) and a second cover body (43) fixedly mounted on the support mechanism (10); a rotating cylinder (42) coaxial with the support mechanism (10) is rotatably mounted inside the first cover body (41) and the second cover body (43); a plurality of limit arc rings (46) with increasing lengths are sequentially arranged on the surface of the rotating cylinder (42) along the axial downward direction; an upper and lower movable hydraulic push member (44) is arranged inside the first cover body (41); a limit block (441) movable between the plurality of limit arc rings (46) is fixedly arranged on one side of the hydraulic push member (44); The control part controls the limit block (441) to move into the corresponding limit arc ring (46) according to the taxiing speed of the aircraft to limit the maximum rotation angle of the rotating drum (42), so that the taxiing speed of the aircraft is inversely proportional to the maximum rotation angle of the tire mechanism (30).

2. The aircraft nose wheel turning control system according to claim 1, characterized in that: The support mechanism (10) comprises a support tube (11) which is assembled on the lower side of the fuselage through a folding frame, a lower support tube (13) which is rotatably connected to a tire mechanism (30) is provided inside the support tube (11), and a gas-oil shock absorber (12) which is used to reduce the shock of the lower support tube (13) is also provided inside the support tube (11), a fixed ring (421) and a rotating ring (422) are provided on the lower side of the rotating cylinder (42), a hydraulic lock (423) is provided on one side of the rotating ring (422) and is movably locked with the rotating cylinder (42), an output end of the turning actuator (20) is connected to one side of the rotating ring (422), and a torque arm (21) is provided on one side of the fixed ring (421) and is connected to the tire mechanism (30).

3. The aircraft front wheel turning control system according to claim 2, characterized in that: An annular cavity for the limiting block (441) to pass through is provided above the uppermost limiting arc ring (46).

4. The aircraft nose wheel turning control system according to claim 3, characterized in that: The inner wall of the first cover body (41) is provided with a hydraulic cavity (411) for sealing and sliding the liquid pusher (44) up and down. The liquid pusher (44) is provided with a hydraulic groove near the outer surface of the first cover body (41). A baffle (414) is fixedly provided on the inner wall of the hydraulic cavity (411). The baffle (414) seals and slides in the hydraulic groove provided on one side of the liquid pusher (44). The inner wall of the hydraulic cavity (411) is provided with an oil hole A (412) and an oil hole B (413) which are connected to the outer surface of the first cover body (41). The oil hole A (412) and the oil hole B (413) are respectively located at the lowermost side and the uppermost side of the inner wall of the hydraulic cavity (411). The outer surface of the first cover body (41) is provided with an electro-hydraulic valve A (47). The electro-hydraulic valve A (47) is connected with the oil hole A (412) and the oil hole B (413) through a valve seat A (471).

5. The aircraft nose wheel turning control system according to claim 4, characterized in that: An electro-hydraulic valve B (48) assembled through a valve seat B (481) is provided on the outer surface of the first cover body (41), and a hydraulic motor (70) driven by the electro-hydraulic valve B (48) is installed between the first cover body (41), the second cover body (43) and the rotating drum (42).

6. The aircraft nose wheel turning control system according to claim 2, characterized in that: A pressure mechanism (60) for applying pressure by the weight of the aircraft fuselage is installed inside the support tube (11) and under the oil-gas shock absorber (12), and a trigger mechanism (50) for correcting the position of the limit block (441) when the limit block (441) is faulty and deviated during the taxiing of the aircraft. The trigger mechanism (50) corrects the position of the limit block (441) through the pressure mechanism (60).

7. An aircraft front wheel turning control system according to claim 6, characterized in that: The pressure mechanism (60) includes a chamber cover (61) fixedly mounted below the oil-gas shock absorber (12), and the inner side of the chamber cover (61) is provided with a first piston plate (63) and a second piston plate (64) from top to bottom, respectively. The upper cavity of the first piston plate (63) stores hydraulic oil, and the cavity between the second piston plate (64) and the first piston plate (63) stores compressed gas; a push claw (131) connected to the upper end of the lower support (13), the push claw (131) pushes the second piston plate (64) upward to compress the compressed gas in the upper cavity, and the inner wall of the cavity for storing hydraulic oil is provided with an oil drain hole (62) connected to the lower side of the chamber cover (61).

8. The aircraft nose wheel turning control system according to claim 7, characterized in that: The trigger mechanism (50) comprises a connecting valve (51), the connecting valve (51) comprising a valve body (511) and a valve plate (512) movable inside, the surface of the valve body (511) is provided with at least two first valve holes (514) penetrating to the lower surface, the surface of the valve plate (512) is provided with second valve holes (515) corresponding to and communicating with the first valve holes (514), the valve plate (512) is pulled by a pull ring (513) fixedly connected to one side, so that The second valve hole (515) is correspondingly connected to the first valve hole (514); the lower side of the valve body (511) is fixedly connected to the hydraulic push member (44) through an oil guide column assembly (45); the oil guide column assembly (45) comprises an oil inlet column (451) connected to the bottom of the hydraulic groove on one side of the hydraulic push member (44), and an oil return column (452) connected to the lower surface of the hydraulic push member (44); the oil inlet column (451), the oil return column (452) and the first valve hole (514) are correspondingly connected.

9. An aircraft front wheel turning control system according to claim 8, characterized in that: The trigger mechanism (50) further comprises a first oil pipe (54) arranged on the upper side of the connecting valve (51) and movably connected to the oil inlet column (451), and a second oil pipe (55) movably connected to the oil return column (452); one end of the first oil pipe (54) is connected to the oil discharge hole (62); one end of the second oil pipe (55) is connected to the outside of the first cover body (41); a rotatable lever (52) is arranged above the pull ring (513); the lever (52) is rotatably mounted on the inner wall of the support tube (11) through a mounting seat (521); a pull rope (53) is connected between one side of the lever (52) and the upper end of the lower support (13); the pull rope (53) limits the pulling direction of the guide wheel (531) fixedly mounted on one side relative to the mounting seat (521), so that the lever (52) is rotated in the direction in which the valve plate (512) slides out from the inner side of the valve body (511).

10. The aircraft nose wheel turning control system according to claim 1, characterized in that: The position feedback part comprises an angular displacement sensor (80) for detecting the rotation angle of the rotating drum (42) and a carbon film displacement sensor (90) for detecting the moving position of the limit block (441).

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