Helicopter tailwheel locking system and tailwheel steering method

Abstract

The application discloses a helicopter tail wheel locking system and a tail wheel control method, and relates to the field of helicopter tail wheel locking systems.The system comprises a tail wheel lock, a tail wheel buffer device, an electromechanical management unit, an avionics display unit, a prompt lamp box and a switch.The electromechanical management unit is electrically connected with the switch and the tail wheel lock installed on the tail wheel buffer device.The helicopter tail wheel locking system sends a tail wheel lock control signal to the electromechanical management unit by operating the switch, and the electromechanical management unit transmits the received control signal to the tail wheel lock to drive the output shaft of the electric mechanism in the tail wheel lock to perform corresponding movement, thereby driving the mechanical lock and the lock pin in the tail wheel lock to produce linkage movement, and realizing electric locking, electric unlocking or electric locking after manual unlocking of the tail wheel lock.

Description

TECHNICAL FIELD

[0001] The present application relates to, but is not limited to, the technical field of helicopter landing gear, in particular to a helicopter tail wheel locking system and a tail wheel control method. BACKGROUND

[0002] A helicopter usually adopts a passive turning technology to realize ground turning function. In order to realize the ground turning function, the tail landing gear of the helicopter has a free orientation function, which can freely rotate left and right around its rotating shaft and follow the turning during ground movement. The free orientation function may cause the helicopter to enter a dangerous state such as tail side slip and shimmy in the case of slope landing, taxiing and the like. Therefore, in the above-mentioned cases, the tail wheel of the tail landing gear needs to be locked in the neutral position to prevent the tail landing gear from rotating. The tail wheel needs to be unlocked before the turning function is used during taxiing.

[0003] Based on the above description of the use of the tail landing gear of the helicopter, in order to keep the tail landing gear in the turning locking state in the case of slope landing, taxiing and the like, the pilot needs to be able to control the tail wheel locking in the parking, taxiing, and air phases. However, the tail landing gear cannot be kept in the neutral position for a long time in the taxiing phase, and it is most difficult to lock the tail wheel in this phase. The tail wheel locking difficulty (low locking rate) problem occurs to varying degrees during the development of various types of helicopters. In addition, when the tail wheel is unlocked, the tail wheel unlocking jam phenomenon may occur due to the existence of the lateral force. SUMMARY

[0004] The purpose of the present application: In order to solve the above-mentioned problems, the helicopter tail wheel locking system and the tail wheel control method provided by the embodiments of the present application solve the problem that the tail wheel is most difficult to lock in the taxiing phase in the design of locking and unlocking the tail wheel of the helicopter, and the tail wheel unlocking jam phenomenon occurs due to the existence of the lateral force when unlocking.

[0005] The technical scheme of the present application: The helicopter tail wheel locking system provided by the embodiments of the present application comprises: a tail wheel lock 3, a tail landing gear buffer device 4, an electromechanical management unit 6, and a switch 2.

[0006] The electromechanical management unit 6 is electrically connected with the switch 2 and the tail wheel lock 3 installed on the tail landing gear buffer device 4, respectively.

[0007] The helicopter tail wheel locking system is used for sending a tail wheel lock control signal to the electromechanical management unit 6 by the pilot operating the switch 2, transmitting the received control signal to the tail wheel lock 3 by the electromechanical management unit 6, driving the output shaft of the electric mechanism in the tail wheel lock 3 to perform corresponding movement, thereby driving the linked mechanical lock and lock pin in the tail wheel lock 3 to produce linked movement, and realizing the electric locking, electric unlocking, or electric locking after manual unlocking of the tail wheel lock 3.

[0008] Optionally, in the helicopter tail wheel locking system as described above, the avionics display unit 1 and the prompt lamp box 5 are respectively connected with the electromechanical management unit 6.

[0009] The helicopter tail wheel locking system is further configured to feed back the current state of the tail wheel lock 3 to the prompt lamp box 5 and the avionics display unit 1 through the electromechanical management unit 6, including the tail wheel unlocking state, the tail wheel locking state and the tail wheel jamming state.

[0010] Optionally, in the helicopter tail wheel locking system as described above, the tail take-off buffer device 4 has a fixed structure and a rotating structure, the fixed structure is provided with an upper locking hole, and the rotating structure is provided with a lower locking hole matched with the upper locking hole; the tail wheel lock 3 comprises an electric mechanism 310, a mechanical lock 320 connected with the electric mechanism 310, and a locking pin 328 connected with the mechanical lock 320, the locking pin 328 is inserted into the fixed upper locking hole.

[0011] The electric mechanism 310 is electrically connected with the electromechanical management unit 6, and the electric mechanism 310 is driven by the control signal of the electromechanical management unit 6 to perform the movement of the corresponding position, and drives the mechanical lock 320 and the locking pin 328 to move, so as to control the locking pin 328 to be inserted into or pulled out of the lower locking hole.

[0012] Optionally, in the helicopter tail wheel locking system as described above,

[0013] The tail take-off buffer device 4 comprises a nut 41, a center rod 42, an outer cylinder 43, a rotating cylinder 44, a piston 45 and a piston rod 46.

[0014] The outer cylinder 43 is fixed on the fuselage structure, the rotating cylinder 44 is embedded and installed on the outer cylinder 43, and can rotate around the outer cylinder 43, the inner end of the rotating cylinder 44 abuts against the same side end of the outer cylinder 43, the center rod 42 passes through the same side end of the rotating cylinder 44 and the outer cylinder 43, and the inner end of the rotating cylinder 44 is abutted against the outer cylinder 43 through the annular boss in the middle of the center rod 42, the protruding end of the center rod 42 is fixed through the nut 41, so as to fix the center rod 42 and the outer cylinder 43, the other end of the rotating cylinder 44 is installed in the piston rod 45, and the piston 45 in the piston rod 46 divides the cavity between the rotating cylinder 44 and the piston rod 45 into an oil cavity and an air cavity, and the bottom end of the piston rod 46 is connected with the wheel 47.

[0015] The opening end of the outer cylinder 43 is provided with an annular boss, the middle part of the cylinder wall of the rotating cylinder 44 is provided with a middle boss, and the middle boss abuts against the bottom of the annular boss; the annular boss is provided with an upper locking hole, and the middle boss is provided with a lower locking hole matched with the upper locking hole; the upper locking hole is located at the fixed position of the tail take-off buffer device, and the lower locking hole rotates with the rotating shaft of the tail take-off buffer device.

[0016] Optionally, in the helicopter tail wheel locking system as described above,

[0017] When the tail wheel lock 3 is locking the tail wheel, the lock pin of the tail wheel lock 3 is inserted into the lower lock hole from the upper lock hole through the control of the electric mechanism 310, so as to limit the rotation of the rotating cylinder 44, i.e. limit the rotation of the tail landing gear; when the tail wheel is unlocked, the lock pin of the tail wheel lock 3 is withdrawn from the lower lock hole to the upper lock hole through the control of the electric mechanism 310, so as to make the rotating cylinder 44 freely rotate, i.e. make the tail landing gear freely rotate.

[0018] Optionally, in the helicopter tail wheel locking system as described above,

[0019] In the structure of the tail wheel lock 3, the mechanical lock 320 comprises a lock housing 321, a linkage pull rod 322, a mechanical lock spring 323, a lower pull rod 324, an upper pull rod 325, an upper lock spring 326, and a steel ball 327; wherein the mechanical lock spring 323 is installed in the lock housing 321, the top end of the mechanical lock spring 323 abuts against the inner wall of the top end of the housing 321, the mechanical lock spring 323 is connected with the lower pull rod 324, and the lower pull rod 324 is connected with the lock pin 328; an upper lock is installed in the top end platform of the lower pull rod 324.

[0020] The motor output shaft 311 of the electric mechanism 310 extends into the lock housing 321, the bottom end of the motor output shaft 311 is connected with the upper pull rod 325, the lower end of one side of the upper pull rod 325 is provided with a lower convex upper lock unlocking boss; the linkage pull rod 322 is arranged between the upper pull rod 325 and the lower pull rod 324; the upper lock arranged in the top end platform of the lower pull rod 324 is used for locking the lock pin 328 in the unlocking position.

[0021] Optionally, in the helicopter tail wheel locking system as described above,

[0022] The upper lock comprises the upper lock spring 326 and the steel ball 327 arranged in the top end platform of the lower pull rod 324, and when the mechanical lock 320 is in the unlocking position, the steel ball 327 is embedded in the groove in the middle of the lock housing 321, so as to limit the movement of the lower pull rod 324.

[0023] Optionally, in the helicopter tail wheel locking system as described above, the tail wheel lock 3 further comprises a manual unlocking mechanism 350 for manually unlocking the tail wheel;

[0024] The manual unlocking mechanism 350 comprises a top pin 351, a mounting bracket 352, and a handle 353; wherein the manual unlocking mechanism 350 is mounted on the rotating cylinder 44 through the mounting bracket 352, the handle 353 is hinged with the mounting bracket 352 to rotate around the hinge point of the mounting bracket 352, the top pin 351 is located at the bottom of the lock pin 328, and the other end of the top pin 328 is connected with the waist-shaped hole on the handle 353, so as to realize manual unlocking by lifting the lock pin 328 into the upper lock hole.

[0025] Optionally, in the helicopter tail wheel locking system as described above,

[0026] The tail wheel lock 3 further comprises an unlocking micro switch 340 arranged at the unlocking position of the lock pin 328, and a locking micro switch 330 arranged at the locking position of the lock pin 328.

[0027] The unlocking micro switch 340 and the locking micro switch 330 are respectively connected to the indicator light box 5, for indicating the locking state and the unlocking state of the tail wheel lock 3 through the indicator light box 5.

[0028] Optionally, in the helicopter tail wheel locking system as described above,

[0029] The tail wheel lock 3 has a lock pin jamming indication function, and the electric mechanism 310 judges whether the lock pin 328 is jammed through internal current during the unlocking process.

[0030] Optionally, in the helicopter tail wheel locking system as described above,

[0031] The electric mechanism 310 judges whether the lock pin 328 is jammed through internal current in the following manner: during the electric unlocking process, when the current in the electric mechanism 310 increases, and when the current increases to a preset threshold value and lasts for 3 seconds, the electric mechanism 310 outputs a jamming signal to the avionics display unit and the indicator light box 5 through the electromechanical management unit 6, to prompt the pilot to adjust the centering position of the upper and lower lock holes in the tail wheel buffer device 4 and then perform unlocking.

[0032] Optionally, in the helicopter tail wheel locking system as described above,

[0033] The tail wheel lock 3 is provided with 2 stages of travel, and the electric mechanism 310 has 3 positions, namely, an unlocking position, a locking position and an unlocking upper position locking position.

[0034] Optionally, in the helicopter tail wheel locking system as described above,

[0035] The switch 2 is provided as a 3-gear switch, and has a locking gear, an initial gear and an unlocking gear, and will automatically return to the initial gear after each electric locking or electric unlocking.

[0036] The embodiment of the application further provides a helicopter tail wheel control method, which adopts the helicopter tail wheel locking system as described above to perform the helicopter tail wheel control method, and the helicopter tail wheel control method comprises the following steps:

[0037] Electrically locking the tail wheel, electrically unlocking the tail wheel, manually locking the tail wheel, and electrically locking the tail wheel after manual unlocking.

[0038] Optionally, in the helicopter tail wheel control method as described above,

[0039] The helicopter tail wheel locking system performs the electric locking of the tail wheel in the following manner: after the electric mechanism 310 receives the locking signal sent by pressing the switch 2, the drive motor output shaft 311 moves downward, driving the upper pull rod 325 to move downward, and the upper lock unlocking boss of the upper pull rod 325 presses the steel ball 327 into the inside of the lower pull rod 324, so that the lower pull rod 324 is unlocked. After the lower pull rod 324 is unlocked, the lock pin 328 is driven to move downward by the mechanical lock spring 323, the lock pin 328 is inserted into the lower lock hole from the upper lock hole, and the electric locking is completed.

[0040] Optionally, in the helicopter tail wheel control method described above,

[0041] The helicopter tail wheel locking system performs the electric unlocking of the tail wheel in the following manner: after the electric mechanism 310 receives the unlocking signal sent by pressing the switch 2, the drive motor output shaft 311 moves upward, driving the upper pull rod 325, the linkage pull rod 322 and the lower pull rod 324 to move upward, so as to drive the lock pin 328 to pull out of the lower lock hole. The upper lock spring 326 in the lower pull rod 324 drives the steel ball 327 into the groove on the inner wall of the lock housing 321, locks the lock pin 328 in the unlocked position, and realizes the electric unlocking.

[0042] Optionally, in the helicopter tail wheel control method described above,

[0043] The helicopter tail wheel locking system performs the manual locking of the tail wheel in the following manner: the lock pin 328 is manually unlocked by the manual unlocking mechanism to the unlocked position. In the unlocked position of the lock pin 328, the upper lock spring 326 in the lower pull rod 324 drives the steel ball 327 into the groove on the inner wall of the lock housing 321, so as to lock the lock pin 328 in the unlocked position, and realize the manual unlocking.

[0044] Optionally, in the helicopter tail wheel control method described above,

[0045] The helicopter tail wheel locking system performs the electric locking of the tail wheel in the following manner: after the electric mechanism 310 receives the locking signal sent by pressing the switch 2, the drive motor output shaft 311 moves downward, driving the upper pull rod 325 to move downward, and the upper lock unlocking boss of the upper pull rod 325 presses the steel ball 327 into the inside of the lower pull rod 324, so that the lower pull rod 324 is unlocked. After the lower pull rod 324 is unlocked, the lock pin 328 is driven to move downward by the mechanical lock spring 323, the lock pin 328 is inserted into the lower lock hole from the upper lock hole, and the electric locking is completed.

[0046] Optionally, in the helicopter tail wheel control method described above,

[0047] The electric mechanism 310 automatically returns to the locked position after reaching the unlocked upper lock position.

[0048] The helicopter tail wheel locking system and tail wheel control method provided by the embodiment of the present application can realize the electric locking and unlocking of the tail wheel by using the motor driving mode, and has a manual driving mechanism to realize the manual locking of the tail wheel.

[0049] 1. The tail wheel lock can be arranged at a position far away from the pilot or the hydraulic source in the form of electric driving, and the energy and signals are transmitted through wires, so that the tail wheel lock has the advantages of light weight and high reliability.

[0050] 2. The tail wheel locking function in the ground sliding stage is realized by using the spring driving lock pin mode, and the mode can realize 100% locking rate.

[0051] 3. The conical lock pin mode is used to solve the unlocking jamming problem and realize 100% unlocking.

[0052] 4. The tail wheel lock can realize the automatic switching between manual and automatic modes, and three-grade resettable switches and two-grade stroke tail wheel locks are used to realize the function.

[0053] 5. The lock pin has a shearing groove design, which can protect the surrounding structure in the case of misoperation.

[0054] 6. The tail wheel locking state is accurately indicated by three signals of "tail wheel locking", "tail wheel unlocking" and "tail wheel locking jamming", which is convenient for the pilot to operate.

[0055] 7. The overload protection function is realized by setting the shearing groove on the lock pin of the tail wheel lock. When the lateral load exceeds the design value, the lock pin is sheared at the shearing groove, which can protect the surrounding structure. DETAILED DESCRIPTION

[0056] The accompanying drawings are used to further understand the technical scheme of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical scheme of the present application, and do not constitute a limitation on the technical scheme of the present application.

[0057] Figure 1 A system architecture schematic diagram of the helicopter tail wheel locking system provided by the embodiment of the present application is shown in the figure.

[0058] Figure 2 A structure schematic diagram of a tail wheel locking system of the helicopter provided by the embodiment of the present application is shown in the figure.

[0059] Figure 3 A structure schematic diagram of a tail wheel locking system of the helicopter provided by the embodiment of the present application is shown in the figure. Figure 2The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes;

[0060] Figure 4 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes; Figure 3 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes; Figure 4 Fig. a is the unlocking state, and Fig. b is the locking state;

[0061] Figure 5 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes;

[0062] Figure 6 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes; and Figure 6 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes;

[0063] Figure 7 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes; Figure 6 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes;

[0064] Figure 8 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes; Figure 6 The tail wheel lock pin of the tail wheel lock of the tail take-off buffer device is shown in the schematic view of the upper and lower lock holes;

[0065] Figure 9 The gear position of the switch in the embodiment of the application is shown in the schematic view. DETAILED DESCRIPTION

[0066] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0067] As described above in the background, based on the use of the tail landing gear of the helicopter, the pilot needs to be able to control the tail wheel locking in the parking, taxiing, and air stages. However, the helicopter tail wheel locking and unlocking have the following two problems: on the one hand, the tail landing gear cannot be kept in the neutral position for a long time in the taxiing stage, and therefore, the difficulty of locking the tail wheel in this stage is the greatest; on the other hand, due to the lateral force when unlocking, the tail wheel unlocking is stuck. That is, the locking and unlocking of the tail wheel in the taxiing stage is the design difficulty of the tail wheel locking system.

[0068] At present, although the way of increasing the locking force and the unlocking force can improve the success probability of locking and unlocking to a certain extent, it cannot fundamentally solve the problem of difficulty in locking and unlocking the tail wheel.

[0069] Ground crew also need to unlock the tail wheel when towing a helicopter for a turn. The usual method is to manually switch the tail wheel lock to manual mode. In manual mode, the tail wheel is unlocked manually because the locking pin is disengaged from the actuator. In manual mode, the pilot cannot operate the tail wheel lock. If ground crew fail to switch the tail wheel lock to automatic mode after towing the helicopter for a turn, there is a safety hazard. Furthermore, if the tail wheel lock is not unlocked before towing and turning, the tail landing gear may be damaged due to excessive load.

[0070] Helicopters with a tricycle landing gear configuration can operate the nose wheel lock and unlock manually or hydraulically. However, for helicopters with a tailwheel landing gear, the tail wheel lock is located further away from the pilot, making manual or hydraulic operation more costly. Therefore, an electric system is more suitable.

[0071] To address the aforementioned problems, embodiments of the present invention provide a helicopter tail wheel locking system, and the tail wheel locking system provided by the embodiments of the present invention is required to solve the following problems:

[0072] 1. Capable of locking and unlocking the tail wheel during coasting;

[0073] 2. It can automatically switch between manual and automatic modes, allowing the pilot to use the aircraft normally after ground crew unlocks the tail wheel;

[0074] 3. It can prevent damage to the tail landing gear due to misoperation during towing;

[0075] 4. The electric design allows for easy placement at a distance from the pilot.

[0076] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0077] Example 1

[0078] Figure 1 This is a schematic diagram of the system architecture of a helicopter tailwheel locking system provided in an embodiment of the present invention. The helicopter tailwheel locking system provided in this embodiment of the present invention comprises: a tailwheel lock 3, a taillift buffer device 4, an electromechanical management unit 6, an avionics display unit 1, an indicator light box 5, and a switch 2.

[0079] like Figure 1 In the structure of the helicopter tail wheel locking system shown, the electromechanical management unit 6 is electrically connected to the avionics display unit 1, the switch 2, the indicator light box 5, and the tail wheel lock 3 installed on the tail lift buffer device 4.

[0080] The helicopter tail wheel locking system sends a tail wheel lock control signal (including a locking signal and an unlocking signal) to the electromechanical management unit 6 through the operation of the pilot on the switch 2, and the electromechanical management unit 6 transmits the received control signal to the tail wheel lock 3 to drive the output shaft of the electric mechanism in the tail wheel lock 3 to perform corresponding movement, thereby driving the linked mechanical lock and lock pin in the tail wheel lock 3 to produce linkage, realizing the electric locking, electric unlocking, or electric locking after manual unlocking of the tail wheel lock 3.

[0081] The helicopter tail wheel locking system in the embodiment of the application can feed back the current state of the tail wheel lock 3 to the prompt lamp box 5 and the avionics display unit 1 through the electromechanical management unit 6, including the tail wheel unlocking state, the tail wheel locking state, and the tail wheel jamming state.

[0082] In the specific implementation, after the electromechanical management unit 6 receives the locking and unlocking state signals sent by the tail wheel lock 3, the state signals are transmitted to the prompt lamp box 5 and the avionics display unit 1. After receiving the locking state signal, the "tail wheel locking" prompt lamp on the prompt lamp box 5 is lit, and the avionics display unit 1 displays "tail wheel locking". After receiving the unlocking state signal, the "tail wheel unlocking" prompt lamp on the prompt lamp box 5 is lit, and the avionics display unit 1 displays "tail wheel unlocking". When the tail wheel lock 3 sends a jamming state signal, the electromechanical management unit 6 sends a "tail wheel lock jamming" signal to the prompt lamp box 5, and the avionics display unit 1 displays "tail wheel lock jamming".

[0083] The tail wheel locking system provided by the embodiment of the application can realize the automatic switching function of the electric and manual modes. After power-on, the tail wheel locking or unlocking can be controlled through the switch 2. The manual unlocking function can be realized in the power-on and power-off states. After manual unlocking, the electric locking can be realized, and the electric mode does not need to be manually switched in this process.

[0084] In this embodiment, the tail buffer device 4 has a fixed structure and a rotating structure, the fixed structure is provided with an upper locking hole, and the rotating structure is provided with a lower locking hole matched with the locking; the tail wheel lock 3 includes an electric mechanism 310, a mechanical lock 320 connected with the electric mechanism 310, and a lock pin 328 connected with the mechanical lock 320, and the lock pin 328 is inserted into the fixed upper locking hole.

[0085] The electric mechanism 310 is electrically connected with the electromechanical management unit 6, and moves to the corresponding position through the control signal sent by the electromechanical management unit 6, and drives the mechanical lock 320 and the lock pin 328 to move, so as to control the lock pin 328 to be inserted into or pulled out of the lower locking hole.

[0086] The implementation modes of the above functions are described in detail below through the structure forms of the tail buffer device 4 and the tail wheel lock 3.

[0087] Embodiment 2

[0088] As Figure 2 shown, a structural schematic diagram of a tail buffer device in a helicopter tail wheel locking system provided by an embodiment of the present application. The tail buffer device provided by the embodiment of the present application comprises a nut 41, a center rod 42, an outer cylinder 43, a rotating cylinder 44, a piston 45 and a piston rod 46; the tail buffer device is installed on a machine wheel 47 through the piston rod 46.

[0089] As Figure 2 shown, in the structure of the tail buffer device 4, the outer cylinder 43 is fixed on the fuselage structure, the rotating cylinder 44 is embeddedly installed inside the outer cylinder 43 and can rotate around the outer cylinder 43, the inner end of the rotating cylinder 44 abuts against the same side end of the outer cylinder 43, the center rod 42 passes through the same side end of the rotating cylinder 44 and the outer cylinder 43, and then abuts the inner end of the rotating cylinder 44 against the inner wall of the outer cylinder 43 through the annular boss in the middle of the center rod 42, the protruding end of the center rod 42 is fixed through the nut 41 to fix the center rod 42 and the outer cylinder 43; the other end of the rotating cylinder 44 is installed in the piston rod 45, and the piston 45 in the piston rod 46 divides the cavity between the rotating cylinder 44 and the piston rod 45 into an oil cavity and an air cavity, and the bottom end of the piston rod 46 is connected with the machine wheel 47.

[0090] In the tail buffer device 4, the annular boss is arranged on the opening end of the outer cylinder 43, the middle boss is arranged in the middle of the cylinder wall of the rotating cylinder 44, and the middle boss abuts against the bottom of the annular boss; the upper lock hole is arranged on the annular boss, and the lower lock hole is arranged on the middle boss in cooperation. The upper lock hole is located at the fixed position of the tail buffer device, and the lower lock hole can rotate with the rotating shaft of the tail buffer device. As Figure 3 shown, a schematic diagram of the lock pin of the tail wheel lock and the upper and lower lock holes in the tail buffer device provided by the embodiment. Figure 2 Figure 4 As Figure 3 shown, a schematic diagram of the principle of the tail wheel locking in the tail buffer device provided by the embodiment, Figure 4 wherein, Fig. a is an unlocking state, and Fig. b is a locking state. In the unlocked state, the rotating cylinder 44 and the piston rod 46 in the tail buffer device 4 can rotate with the landing gear.

[0091] In this embodiment, when the tail wheel is locked, the lock pin of the tail wheel lock 3 is inserted into the lower lock hole from the upper lock hole, so as to limit the rotation of the rotating cylinder 44, that is, to limit the rotation of the tail landing gear. When the tail wheel is unlocked, the lock pin of the tail wheel lock 3 is withdrawn from the lower lock hole to the upper lock hole, at this time, the rotating cylinder 44 can rotate freely, so that the tail landing gear can rotate freely, as shown in Figure 2 and Figure 3 .

[0092] Embodiment 3

[0093] ​The main reason why locking the tail wheel is difficult during the helicopter's taxiing phase is that when the tail wheel is not locked, the rotation of the rotating cylinder 44 causes the central boss and the lower locking hole to rotate, making it impossible for the upper and lower locking holes fixed on the tail lift buffer device 4 to remain aligned. Figure 4 In order to lock within a short alignment time, the present invention uses a spring-driven locking pin 328 for locking. By reasonably selecting the spring, the locking pin 328 can be inserted into the lower locking hole in a very short time.

[0094] like Figure 5 The diagram shown is a structural schematic of the locking pin in the tail wheel lock provided in an embodiment of the present invention. To solve the problem of unlocking jamming, the present invention adopts a conical locking pin structure. When unlocking, the locking pin moves upward and can instantly disengage from the lower locking hole, thereby avoiding unlocking jamming.

[0095] Furthermore, such as Figure 5 The locking pin structure is shown. An annular shear groove is provided in the middle of the locking pin 328. When locked, the annular shear groove is located at the contact surface of the upper and lower locking holes. In the event of a misoperation (rotating the tail wheel while it is not unlocked), the lateral load increases to a certain level, and the locking pin will shear off at the shear groove, thus protecting the surrounding structure.

[0096] like Figure 6 The diagram shown is a structural schematic of the tail wheel lock in the helicopter tail wheel locking system provided in an embodiment of the present invention. In a specific implementation of the present invention, the tail wheel lock 3 includes: an electric mechanism 310, a mechanical lock 320 connected to the electric mechanism 310, and a locking pin 328 connected to the mechanical lock 320.

[0097] like Figure 6 The mechanical lock 320 shown has the following structure: a lock housing 321, a linkage rod 322, a mechanical lock spring 323, a pull rod 324, an upper pull rod 325, an upper lock spring 326, and a steel ball 327. The mechanical lock spring 323 is installed in the lock housing 321, with its top end abutting against the inner wall of the top end of the housing 321. The mechanical lock spring 323 is connected to the pull rod 324, and the pull rod 324 is connected to the locking pin 328. An upper lock is installed in the top platform of the pull rod 324, which includes an upper lock spring 326 and a steel ball 327 placed within the top platform of the pull rod 324. When the mechanical lock 320 is in the unlocked position, the steel ball 327 is embedded in a groove in the middle of the lock housing 321 to restrict the movement of the pull rod 324.

[0098] The motor output shaft 311 of the electric mechanism 310 extends into the lock housing 321. The bottom end of the motor output shaft 311 is connected to the upper pull rod 325. A downwardly protruding upper lock unlocking boss is provided on one side of the lower end of the upper pull rod 325. A linkage pull rod 322 is provided between the upper pull rod 325 and the lower pull rod 324. An upper lock is provided in the upper platform at the top of the lower pull rod 324 to lock the lock pin 328 in the unlocked position. Figure 6 The upper lock shown is a steel ball lock configuration, consisting of an upper lock spring 326 and a steel ball 327.

[0099] In one embodiment of the present invention, the tail wheel lock further includes a manual unlocking mechanism 350, comprising a top pin 351, a mounting bracket 352, and a handle 353. The manual unlocking mechanism 350 is mounted on the rotating cylinder 44 via the mounting bracket 352. The handle 353 is hinged to the mounting bracket 352 and can rotate around the hinge point of the mounting bracket 352. The top pin 351 is located at the bottom of the locking pin 328; when lifted, one end contacts the locking pin 328, pushing the locking pin 328 into the upper locking hole to achieve manual unlocking. The other end of the top pin 328 is connected to an oblong hole on the handle 353.

[0100] Example 4

[0101] This embodiment provides an implementation method for performing tail wheel operation using a helicopter tail wheel locking system. For example... Figure 6 As shown, this invention employs a two-stage stroke tail wheel lock 3, as... Figure 6 The electric mechanism 310 has three positions: unlocked position, locked position, and unlocked upper lock position. The tail wheel lock 3 in this embodiment of the invention performs the following actions: electrically locking the tail wheel, electrically unlocking the tail wheel, manually locking the tail wheel, manually unlocking the tail wheel, and manually unlocking and then electrically locking the tail wheel.

[0102] (1) The electric locking method for the tail wheel is as follows: The pilot presses switch 2, sending a locking signal to the electromechanical management unit 6, which then forwards it to the electric mechanism 310 of the tail wheel lock 3. After receiving the locking signal, the electric mechanism 310's motor output shaft 311 moves downward, driving the upper pull rod 325 downward. The upper lock unlocking boss on the upper pull rod 325 presses the steel ball 327 into the lower pull rod 324, unlocking the lower pull rod 324. That is, after unlocking the lower pull rod 324 through the upper lock, the lower pull rod 324, under the action of the mechanical lock spring 323, drives the locking pin 328 downward. The locking pin 328 is inserted from the upper lock hole into the lower lock hole, realizing the electric locking function of the tail wheel. After the electric mechanism 310 reaches the unlocked upper lock position, it will automatically return to the locked position. Figure 6 The diagram shown illustrates the principle of the tail wheel lock's electric locking mechanism.

[0103] (2) The electric unlocking mode of the tail wheel is as follows: the pilot presses the switch 2, sends an unlocking signal to the electromechanical management unit 6, and forwards the signal to the electric mechanism 310 of the tail wheel lock 3. After receiving the unlocking signal, the electric mechanism 310 drives the motor output shaft 311 to move upward, which drives the upper pull rod 325, the linkage pull rod 322 and the lower pull rod 324 to move upward, thereby driving the locking pin 328 to move from the locking position to the unlocking position (i.e., the locking pin 328 is pulled out of the lower locking hole). When the locking pin 328 is in the unlocking position (corresponding to the unlocking position of the motor output shaft 311 in the electric mechanism 310), the upper locking spring 326 in the lower pull rod 324 drives the steel ball 327 to enter the groove in the inner wall of the lock housing 321, thereby locking the locking pin 328 in the unlocking position, achieving electric unlocking. As shown in Figure 7 , the principle diagram of the tail wheel lock provided in the embodiment shown in Figure 6 to perform electric unlocking is shown.

[0104] (3) The manual unlocking mode of the tail wheel is as follows: when manually unlocking, the locking pin 328 is manually lifted to the unlocking position by the manual unlocking mechanism. Since the lower pull rod 324 follows the locking pin 328, when the locking pin 328 is in the unlocking position, the upper locking spring 326 in the lower pull rod 324 drives the steel ball 327 to enter the groove in the inner wall of the lock housing 321, thereby locking the locking pin 328 in the unlocking position, achieving manual unlocking. As shown in Figure 8 , the principle diagram of the tail wheel lock provided in the embodiment shown in Figure 6 to perform manual unlocking is shown.

[0105] (4) The electric locking mode of the tail wheel after manual unlocking is as follows: after manual unlocking, the electric mechanism 310 of the tail wheel lock 3 and the upper pull rod 325, the linkage pull rod 322 of the mechanical lock 320 are still in the tail wheel lock locking position. At this time, after receiving the locking signal, the electric mechanism 310 drives the motor output shaft 311 to move downward, which drives the upper pull rod 325 to move downward. The upper locking unlocking boss in the upper pull rod 325 will press the steel ball 327 into the top platform of the lower pull rod 324, so that the lower pull rod 324 is unlocked. The lower pull rod 324 moves downward under the action of the mechanical lock spring 323, achieving the locking function. The electric mechanism 310 automatically returns to the locking position after reaching the unlocking upper locking position. As shown in Figure 6 .

[0106] Example 5

[0107] The tail wheel lock 3 provided by the embodiment of the present application is arranged with a micro switch in the unlocking position and the locking position of the lock pin 328, namely the unlocking micro switch 340 and the locking micro switch 330, which are connected to the indicator lamp box 5 to indicate the locking and unlocking state of the tail wheel lock 3. When the tail wheel lock 3 is in the locking state (the lock pin 328 is in the locking position), a locking signal is output, and when the tail wheel lock 3 is in the unlocking state, an unlocking signal is output. The tail wheel lock 3 has the lock pin jamming indication function. If the lock pin 328 is jammed during the unlocking process, a jamming signal will be output.

[0108] In the specific implementation, the lock pin 328 jamming is determined by the current in the electric mechanism 310. If the lock pin 328 is jammed during the electric unlocking process, the motor output shaft 311 needs to pull the upper pull rod 325 with greater output force, at this time, the current in the electric mechanism 310 will greatly increase, and when the current increases to a certain value (the current value corresponding to the maximum output power of the electric mechanism 310) for 3 seconds, the electric mechanism 310 will provide a jamming signal to the outside to prompt the pilot to adjust the centering position of the upper and lower locking holes in the tail buffer device 4 and then execute the unlocking.

[0109] It should be noted that after the tail wheel lock 3 in the embodiment of the present application is electrically unlocked, the motor output shaft 311 is located at the unlocking position, and the upper pull rod 325 and the linkage pull rod 322 are driven to the corresponding positions by the output shaft 311.

[0110] However, after manual unlocking, the lower pull rod 324 is pushed to the upper locking position and locked by the upper lock, but since the motor does not act, the output shaft 311 is still in the locking position, and the upper pull rod 325 and the linkage pull rod 322 are also in the locking position; therefore, the reason why it is difficult to electrically lock after manual unlocking. To solve the above problem, the three-position switch 2 is used in the embodiment of the present application, and a switch with only two positions of locking and unlocking cannot be used. The two-position switch is in the locking position after the electric locking is operated. After the tail wheel lock 3 is manually unlocked (at this time, the switch 2 is still in the locking position), the electric locking operation still needs to be performed again, and the two-position switch cannot realize this function.

[0111] The locking signal and the unlocking signal are provided by the micro switch. The conventional two-position switch cannot realize the electric locking operation after manual unlocking. In the embodiment of the present application, the three-position switch with the automatic reset function is used. As shown in Figure 9 the position diagram of the switch in the embodiment of the present application. The middle position is the initial position, and the initial position will be automatically restored after each electric locking or electric unlocking. Any operation can be performed according to the needs, so as to realize the electric locking function after manual unlocking.

[0112] The helicopter tail wheel locking system and tail wheel control method provided by the embodiment of the application can realize electric locking and electric unlocking of the tail wheel by using a motor driving mode, and has a manual driving mechanism to realize manual locking of the tail wheel, and the electric mechanism of the tail wheel lock is continuously powered by a power supply and will perform corresponding actions after receiving an instruction.

[0113] 1. The application adopts an electric driving form, the tail wheel lock can be arranged at a position far from a pilot or a hydraulic source, and energy and signals are transmitted through wires, so that the tail wheel lock has the advantages of light weight and high reliability.

[0114] 2. The application realizes the function of locking the tail wheel in the ground sliding stage by adopting a spring driving lock pin mode, and the mode can realize 100% locking rate.

[0115] 3. The application solves the unlocking jamming problem by adopting a conical lock pin mode, and realizes 100% unlocking.

[0116] 4. The application can realize automatic switching between manual and automatic modes, and three-grade resettable switches and two-grade stroke tail wheel locks are used to realize the function.

[0117] 5. The lock pin of the application has a shearing groove design, which can protect the surrounding structure in the case of misoperation.

[0118] 6. The application accurately indicates the tail wheel locking state through three signals of "tail wheel locking", "tail wheel unlocking" and "tail wheel lock jamming", which is convenient for the pilot to operate.

[0119] 7. The application realizes the overload protection function by setting a shearing groove on the lock pin of the tail wheel lock. When the lateral load exceeds the design value, the lock pin is sheared at the shearing groove, which can protect the surrounding structure.

[0120] Although the embodiments disclosed by the application are as above, the content is only the embodiment adopted for the purpose of understanding the application, and is not used to limit the application. Any person skilled in the art of the application can make any modification and change in the form and details without departing from the spirit and scope of the application disclosed, but the patent protection scope of the application shall be subject to the scope defined by the appended claims.

Claims

1. A helicopter tailwheel locking system, characterized in that, include: Tail wheel lock (3), tail lift buffer device (4), electromechanical management unit (6) and switch (2); The electromechanical management unit (6) is electrically connected to the switch (2) and the tail wheel lock (3) installed on the tail lift buffer device (4); The helicopter tail wheel locking system is used to send a tail wheel lock control signal to the electromechanical management unit (6) by the pilot operating the switch (2). The electromechanical management unit (6) then transmits the received control signal to the tail wheel lock (3) to drive the output shaft of the electric mechanism in the tail wheel lock (3) to perform corresponding movements, thereby driving the mechanical lock and locking pin in the tail wheel lock (3) to generate linkage movements, so as to realize the electric locking, electric unlocking, or electric locking after manual unlocking of the tail wheel lock (3). The tail wheel lock (3) includes a mechanical lock (320) comprising: a lock housing (321), a linkage rod (322), a mechanical lock spring (323), a pull rod (324), an upper rod (325), an upper lock spring (326), and a steel ball (327); wherein, the lock housing (321) is equipped with a mechanical lock spring (323), the top of the mechanical lock spring (323) abuts against the inner wall of the top of the lock housing (321), the mechanical lock spring (323) is connected to the pull rod (324), and the pull rod (324) is connected to the lock pin (328); an upper lock is installed in the platform at the top of the pull rod (324); The motor output shaft (311) of the electric mechanism (310) extends into the lock housing (321). The bottom end of the motor output shaft (311) is connected to the upper pull rod (325). A protruding upper lock unlocking boss is provided on the lower end of one side of the upper pull rod (325). A linkage pull rod (322) is provided between the upper pull rod (325) and the lower pull rod (324). An upper lock is provided in the upper platform at the top of the lower pull rod (324) to lock the lock pin (328) in the unlocked position. The upper lock includes an upper lock spring (326) and a steel ball (327) placed in the top platform of the pull rod (324). When the mechanical lock (320) is in the unlocked position, the steel ball (327) is embedded in the groove in the middle of the lock housing (321) to restrict the movement of the pull rod (324). The tail wheel lock (3) has two stroke levels, and the electric mechanism (310) has three positions: unlock position, lock position and unlock upper lock position. The switch (2) is set to a 3-position switch with a locking position, an initial position and an unlocking position. It will automatically return to the initial position after each electric locking or electric unlocking.

2. The helicopter tailwheel locking system according to claim 1, characterized in that, Also includes: The avionics display unit (1) and the indicator light box (5) are respectively connected to the electromechanical management unit (6); The helicopter tail wheel locking system is also used to provide feedback on its current status, including tail wheel unlocking status, tail wheel locking status and tail wheel jamming status, from the tail wheel lock (3) to the indicator light box (5) and avionics display unit (1) via the electromechanical management unit (6).

3. The helicopter tailwheel locking system according to claim 2, characterized in that, The tail wheel buffer device (4) has a fixed structure and a rotating structure. The fixed structure is provided with an upper locking hole, and the rotating structure is provided with a lower locking hole for locking. The tail wheel lock (3) includes: an electric mechanism (310), a mechanical lock (320) connected to the electric mechanism (310), and a locking pin (328) connected to the mechanical lock (320). The locking pin (328) is inserted into the fixed upper locking hole. The electric mechanism (310) is electrically connected to the electromechanical management unit (6). The control signal initiated by the electric management unit (6) executes the movement of the corresponding position and drives the mechanical lock (320) and the locking pin (328) to move, so as to control the locking pin (328) to be inserted into or pulled out of the lower locking hole.

4. The helicopter tailwheel locking system according to claim 3, characterized in that, The tail-start buffer device (4) includes: nut (41), center rod (42), outer cylinder (43), rotating cylinder (44), piston (45) and piston rod (46). The outer cylinder (43) is fixed to the body structure. The rotating cylinder (44) is embedded in the outer cylinder (43) and can rotate around the outer cylinder (43). Its inner end is in contact with the same side end of the outer cylinder (43). The central rod (42) passes through the same side end of the rotating cylinder (44) and the outer cylinder (43) and then the inner end of the rotating cylinder (44) is pressed against the outer cylinder (43) by the annular boss in its middle. The protruding end of the central rod (42) is fixed by the nut (41) to fix the central rod (42) and the outer cylinder (43). The other end of the rotating cylinder (44) is fitted with the piston rod (46). The piston (45) in the piston rod (46) divides the cavity between the rotating cylinder (44) and the piston rod (46) into an oil cavity and an air cavity. The bottom end of the piston rod (46) is connected to the wheel (47). The outer cylinder (43) has an annular boss at its open end, and the rotating cylinder (44) has a central boss in the middle of its cylinder wall, and the central boss abuts against the bottom of the annular boss; the annular boss has an upper locking hole, and the central boss has a lower locking hole for locking; the upper locking hole is located at the fixed position of the tail-lift buffer device, and the lower locking hole rotates with the shaft of the tail-lift buffer device.

5. The helicopter tailwheel locking system according to claim 4, characterized in that, When the tail wheel lock (3) locks the tail wheel, the locking pin of the tail wheel lock (3) is inserted from the upper locking hole into the lower locking hole by the control of the electric mechanism (310), thereby restricting the rotation of the rotating cylinder (44), that is, restricting the rotation of the tail landing gear; when the tail wheel is unlocked, the locking pin of the tail wheel lock (3) is retracted from the lower locking hole to the upper locking hole by the control of the electric mechanism (310), thereby allowing the rotating cylinder (44) to rotate freely, that is, allowing the tail landing gear to rotate freely.

6. The helicopter tailwheel locking system according to any one of claims 1 to 5, characterized in that, The tail wheel lock (3) further includes: a manual unlocking mechanism (350) for manually unlocking the tail wheel. The manual unlocking mechanism (350) includes a top pin (351), a mounting bracket (352), and a handle (353). The manual unlocking mechanism (350) is mounted on the rotating cylinder (44) via the mounting bracket (352). The handle (353) is hinged to the mounting bracket (352) to rotate around the hinge point of the mounting bracket (352). The top pin (351) is located at the bottom of the locking pin (328). After being lifted, one end contacts the locking pin (328) and pushes the locking pin (328) into the upper locking hole to achieve manual unlocking. The other end of the top pin (351) is connected to the waist-shaped hole on the handle (353).

7. The helicopter tailwheel locking system according to claim 6, characterized in that, The tail wheel lock (3) further includes: an unlocking micro switch (340) provided in the unlocking position of the locking pin (328), and a locking micro switch (330) arranged in the locking position of the locking pin (328). The unlocking micro switch (340) and the locking micro switch (330) are respectively connected to the indicator light box (5) to indicate the locked and unlocked states of the tail wheel lock (3) through the indicator light box (5).

8. The helicopter tailwheel locking system according to claim 7, characterized in that, The tail wheel lock (3) has a locking pin jamming indication function. During the unlocking process, the electric mechanism (310) uses internal current to determine whether the locking pin (328) is jammed.

9. The helicopter tailwheel locking system according to claim 8, characterized in that, The electric mechanism (310) determines whether the locking pin (328) is stuck by means of internal current: during the electric unlocking process, when the current inside the electric mechanism (310) increases, and when the current increases to a preset threshold and lasts for 3 seconds, the electric mechanism (310) outputs a stuck signal to the avionics display unit and indicator box (5) through the electromechanical management unit (6) to prompt the pilot to adjust the centering position of the upper and lower locking holes in the tail boom buffer device (4) before unlocking.

10. A method for controlling the tailwheel of a helicopter, characterized in that, The method for controlling a helicopter tailwheel using the helicopter tailwheel locking system as described in claim 9 includes: Electric locking of the tail wheel, electric unlocking of the tail wheel, manual locking of the tail wheel, and manual unlocking followed by electric locking of the tail wheel.

11. The helicopter tailwheel control method according to claim 10, characterized in that, The helicopter tail wheel locking system performs electric locking of the tail wheel as follows: After receiving the locking signal sent by the push switch (2), the electric mechanism (310) drives the output shaft (311) of the motor to move downward, which drives the upper pull rod (325) to move downward. The upper lock unlocking boss presses the steel ball (327) into the lower pull rod (324) to unlock the lower pull rod (324). After the lower pull rod (324) is unlocked, it drives the locking pin (328) to move downward under the action of the mechanical lock spring (323). The locking pin (328) is inserted from the upper lock hole into the lower lock hole to complete the electric locking.

12. The helicopter tailwheel control method according to claim 10, characterized in that, The helicopter tail wheel locking system performs electric unlocking of the tail wheel in the following manner: After receiving the unlocking signal sent by the push switch (2), the electric mechanism (310) drives the output shaft (311) of the motor to move upward, which drives the upper pull rod (325), the linkage pull rod (322) and the lower pull rod (324) to move upward, thereby driving the locking pin (328) to be pulled out from the lower lock hole. The upper locking spring (326) in the lower pull rod (324) drives the steel ball (327) to enter the groove in the inner wall of the lock housing (321), locking the locking pin (328) in the unlock position, thus realizing electric unlocking.

13. The helicopter tailwheel control method according to claim 10, characterized in that, The helicopter tail wheel locking system performs manual locking of the tail wheel in the following manner: the locking pin (328) is pushed upward to the unlock position by the manual unlocking mechanism. In the unlock position of the locking pin (328), the upper locking spring (326) in the pull rod (324) drives the steel ball (327) into the groove of the inner wall of the lock housing (321), thereby locking the locking pin (328) in the unlock position and realizing manual unlocking.

14. The helicopter tailwheel control method according to claim 10, characterized in that, The helicopter tail wheel locking system performs electric tail wheel locking after manual unlocking in the following manner: After manual unlocking, the upper pull rod (325) and linkage pull rod (322) in the electric mechanism (310) and mechanical lock (320) of the tail wheel lock (3) are in the tail wheel lock locking position; after receiving the locking signal, the tail wheel lock (3) is driven by the electric mechanism (310), the motor output shaft (311) moves downward, driving the upper pull rod (325) to move downward, and the upper lock unlocking boss of the upper pull rod (325) presses the steel ball (327) into the top platform of the lower pull rod (324), so that the lower pull rod (324) is unlocked; the lower pull rod (324) moves downward under the action of the mechanical lock spring (323) to realize the locking function.

15. The helicopter tailwheel control method according to claim 11 or 14, characterized in that, After the electric mechanism (310) reaches the unlocked upper lock position, it automatically returns to the locked position.

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