Undercarriage electromechanical locking and releasing mechanism

Abstract

The invention relates to an undercarriage electromechanical locking and releasing mechanism which comprises a lock shell, a rocker arm, a connecting rod, a tension spring supporting column, a tension spring, a lock hook bolt, a lock hook and a servo actuator, the lock hook, the connecting rod and the rocker arm are connected through bolts to form a connecting rod mechanism, and the electromechanical servo actuator serves as a push rod to push the rocker arm in a locking mechanism system. Compared with an existing locking hook and locking key abutting mechanism, impact between parts of the mechanism is eliminated, serious abrasion generated when the mechanism bears large loads is avoided, the unlocking reliability of the mechanism under the large loads is improved, and the purposes of being small in size, light in weight, large in bearing capacity and high in reliability are achieved.

Description

Technical Field

[0001] The invention belongs to the field of aerospace equipment, and in particular relates to an electromechanical locking and releasing mechanism for a landing gear. Background Art

[0002] The landing gear locking and releasing mechanism is an important part of the landing gear retraction and extension system. It is mainly used to retract the landing gear and reliably lock it in the cabin door during the flight, factory transportation and landing return transportation of the aircraft; and release the landing gear during the return landing of the aircraft. At present, the traditional landing gear locking and releasing mechanism mainly adopts hydraulic oil (pneumatic pressure) drive to realize the landing gear release function. In order to ensure that the mechanism can still be unlocked normally when a failure occurs, the drive device of the mechanism needs to be set with redundant functions. Generally, two sets of independent (hydraulic, pneumatic medium) drive devices are used or a motor drive device is used for emergency operation.

[0003] Currently, most of the existing landing gear locking and releasing mechanisms are hydraulically driven, involving the patent "An aircraft landing gear upper lock structure" (CN110065623 A). This patent drives the upper lock actuator cylinder actuator rod through hydraulic oil, and the actuator rod manipulates the lock key to achieve locking and releasing of the landing gear. Although this method can achieve the landing gear locking and releasing function, it requires the use of two sets of hydraulic systems to achieve the normal release and emergency release functions of the landing gear, which results in a heavy system weight and numerous components. On the other hand, when the aircraft is flying, since the upper lock hook and the lock key are in abutment contact, the lock key will collide with the lock hook and the surface friction and wear will be serious. If the load borne by the mechanism is large, it will affect its unlocking reliability. The motor-driven landing gear lock release mechanism involves the patent "An electrically driven passive strut upper lock" (CN112572779 A). This patent receives and controls the swing of the unlocking rocker arm of the strut upper lock mechanism according to the unlocking control command of the upper computer through the electrically driven unlocking actuator, thereby driving the lock hook of the strut upper lock mechanism to rotate and realize the unlocking of the strut upper lock mechanism. The disadvantage of this upper lock is that in order to realize the actuator pushing the unlocking rocker arm, the length of the unlocking rocker arm is very large. At the same time, its unlocking actuator is installed on the outside of the lock shell, which further increases the size of the entire mechanism. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide an electromechanical locking and releasing mechanism for a landing gear, which achieves the purpose of small size, light weight, large load-bearing capacity and high reliability.

[0005] The above-mentioned purpose of the present invention is mainly achieved through the following technical solutions:

[0006] A landing gear electromechanical locking and releasing mechanism comprises a lock housing, a rocker arm, a connecting rod, a tension spring support, a tension spring, a lock hook and a servo actuator; the lock hook and the servo actuator are installed inside the lock housing, the rocker arm and the lock hook are connected to the lock housing, the rocker arm is connected to the connecting rod, the connecting rod is connected to the lock hook, a tension spring support is arranged on the connecting rod, one end of the tension spring is fixed on the tension spring support, and the other end is fixed on the support of the lock hook, and the servo actuator pushes the rocker arm to move to realize the locking and releasing of the landing gear.

[0007] The servo actuator includes a push rod, a mounting plate, a travel switch, a motor, a control driver and an actuator cylinder assembly; the push rod is mounted on the top of the actuator assembly, and when the push rod is extended, it contacts the top of the rocker arm. Under the thrust of the push rod, the rocker arm rotates around the bolt; the mounting plate is mounted on the top of the actuator cylinder assembly through a threaded connection, and a travel switch is arranged on one side of the mounting plate. The output side of the travel switch is connected to the rocker arm, and when the rocker arm is separated from the travel switch, an unlocking signal is sent; the motor is connected to the actuator assembly through screws to provide power for the servo actuator, and the control driver is mounted on the side of the motor housing; after receiving the command, the control driver drives the motor to rotate, and converts the motor's rotational motion into the linear motion of the push rod through the actuator assembly.

[0008] The rocker arm includes a trigger plate for triggering the travel switch.

[0009] The actuator cylinder assembly includes a ball screw pair, a rolling bearing and a bearing nut. The ball bearing is installed on the ball screw pair and locked by the bearing nut. The input side of the ball screw pair is connected to the motor output shaft, and the output side is threadedly connected to the push rod.

[0010] The actuator assembly also includes displacement sensors. Two sets of displacement sensors are symmetrically arranged on both sides of the ball screw pair. The displacement sensors provide real-time feedback on the position of the ball screw pair to achieve closed-loop position control.

[0011] When the rocker arm is in the stop position, the clearance value L between the rocker arm and the push rod is 0.5-1.5mm.

[0012] The tension spring material is spring stainless steel wire with a diameter of 2.6mm, and the tension spring hook ring is in the form of a long-arm force semicircular hook ring.

[0013] When the tension spring (5) is locked, the tension force is 200±20N.

[0014] It also includes a lock hook bolt, through which the lock hook and the lock housing are fixed; the rocker arm is connected to the lock housing and the connecting rod respectively through bolts, and the connecting rod is connected to the lock hook through bolts.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] (1) The present invention connects the lock hook, the connecting rod and the rocker arm by bolts to form a connecting rod mechanism. The mechanism moves in a rotational motion and uses an electromechanical servo actuator as a push rod to push the rocker arm in the locking mechanism system. Compared with the existing mechanism in which the lock hook and the lock key abut against each other, the present invention eliminates the collision between the parts of the mechanism, avoids the serious wear of the mechanism when it is subjected to a large load, and improves the unlocking reliability of the mechanism under a large load;

[0017] (2) The integrated design of the electromechanical servo actuator, servo controller and locking mechanism provided by the present invention significantly reduces the size and weight of the mechanism, and the size can be reduced by more than 30%;

[0018] (3) When the mechanism of the present invention is locked, the rocker arm contacts the mounting plate, and the clearance L between the push rod and the rocker arm ranges from 0.5 to 1.5 mm. The use of the mounting plate limits the movement of the rocker arm, and the clearance between the push rod and the rocker arm does not generate friction and wear, thereby improving the reliability of unlocking;

[0019] (4) The mounting plate of the present invention is equipped with a travel switch and an integrated displacement sensor of the actuator assembly, both of which can realize the monitoring function of the locking and release of the landing gear, thereby improving the reliability of the monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of the landing gear locking and releasing mechanism of the landing gear electromechanical locking and releasing mechanism of the present invention in a locked state;

[0021] Figure 2 It is a cross-sectional view of the landing gear locking and releasing mechanism in the unlocked state of the landing gear electromechanical locking and releasing mechanism of the present invention;

[0022] Figure 3 It is a composition diagram of the landing gear locking and releasing mechanism of the landing gear electromechanical locking and releasing mechanism of the present invention in a locked state;

[0023] Figure 4 A top view of the servo actuator of the landing gear electromechanical locking release mechanism of the present invention;

[0024] Figure 5 It is a front view of the servo actuator of the landing gear electromechanical locking release mechanism of the present invention;

[0025] Figure 6 It is a cross-sectional view of the rocker arm and push rod structure in the locked state of the landing gear electromechanical locking release mechanism of the present invention;

[0026] Figure 7 This is a composition diagram of the landing gear locking and releasing mechanism in the unlocked state of the landing gear electromechanical locking and releasing mechanism of the present invention;

[0027] Figure 8 It is a cross-sectional view of the actuator cylinder assembly of the landing gear electromechanical locking release mechanism of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0029] like Figure 1 , 2 As shown in Figures 3 and 4, an electromechanical landing gear locking and releasing mechanism of the present invention comprises a lock housing 1, a rocker arm 2, a connecting rod 3, a tension spring support 4, a tension spring 5, a lock hook bolt 6, a lock hook 7 and a servo actuator 8. The servo actuator 8 is installed inside the lock housing 1, wherein a trigger plate 21 is installed on the rocker arm 2. The lock hook 7 is installed inside the lock housing 1 and fixed by the lock hook bolt 6; the rocker arm 2 is connected to the lock housing 1 and the connecting rod 3 by bolts; the connecting rod 3 is connected to the lock hook 7 by bolts; and the tension spring 5 is fixed at the support of the tension spring support 4 and the lock hook 7.

[0030] like Figure 4 , 5 As shown, the servo actuator 8 includes a push rod 81, a mounting plate 82, a travel switch 83, a motor 84, a control driver 85 and an actuator cylinder assembly 86; the push rod 81 is installed on the top of the actuator assembly 86, and when the push rod 81 is extended, it contacts the top of the rocker arm 2. Under the thrust of the push rod 81, the rocker arm 2 rotates around the bolt; the mounting plate 82 is installed on the top of the actuator cylinder assembly 86 through a threaded connection, and a travel switch 83 is provided on one side of the mounting plate 82. The output side of the travel switch 83 is connected to the rocker arm 2. When the rocker arm 2 is separated from the travel switch 83, an unlocking signal is sent; the motor 84 is connected to the actuator assembly 86 through a screw to provide power for the servo actuator 8, and the control driver 85 is installed on the side of the motor 84 housing; after receiving the command, the control driver 85 drives the motor 84 to rotate, and converts the rotational motion of the motor 84 into the linear motion of the push rod 81 through the actuator assembly 86.

[0031] Extension spring 5 Extension spring material is The spring is made of stainless steel wire, and the tension spring hook is in the form of a long-arm force semicircular hook. When the tension spring 5 is locked, the tension is 200±20N.

[0032] The landing gear locking and releasing functions are implemented as follows:

[0033] Landing gear locking function: When the landing gear is retracted, the control driver 85 receives the locking signal, the servo actuator 8 works, the push rod 81 retracts, and the landing gear lock pin further squeezes the upper end surface of the lock hook 7, causing the lock hook 7 and the rocker arm 2 to rotate counterclockwise, and the connecting rod 3 to rotate clockwise. When the rocker arm 2 and the connecting rod 3 are in a straight line, the deployment movement of the rocker arm and the connecting rod is restricted. At this time, the tension spring force generated by the tension spring 5 that has been acting on the connecting rod 3 will cause the rocker arm 2 to continue to move counterclockwise. The rocker arm 2 contacts the mounting plate 82 to limit the rocker arm 2. The rocker arm 2 rotates to the stop position. At this time, the gap value L between the rocker arm 2 and the push rod 81 is 0.5~1.5mm, and the upper lock is locked. At the same time, the trigger plate 21 on the rocker arm triggers the travel switch 83, and the travel switch 83 sends a locking signal to complete the locking process. The locking state of the mechanism is as follows Figure 1 , Figure 3 As shown, the schematic diagram of the clearance between the rocker arm and the push rod is shown in Figure 6 shown.

[0034] Landing gear release function: After receiving the unlocking signal, the control driver 8-5 drives the servo actuator 8 to work, and the actuator push rod 81 extends, and the push rod 81 drives the rocker arm 2 to rotate clockwise. Under the thrust of the servo actuator, the lock hook 7 rotates clockwise around the lock hook bolt 6, and the landing gear lock pin is disengaged from the lock hook 7. At the same time, the trigger plate 21 on the rocker arm 2 is separated from the travel switch, and the travel switch sends an unlocking signal to complete the unlocking process. The unlocking state of the mechanism is as follows Figure 7 shown.

[0035] like Figure 8 As shown, the actuator assembly 86 of the present invention is composed of a ball screw pair 861, a displacement sensor 862, a rolling bearing 863, and a bearing nut 864. Two sets of displacement sensors 862 are symmetrically arranged on both sides of the ball screw pair 861. During operation, the control driver 85 drives the output shaft of the motor 84 to rotate after receiving the unlocking signal, and converts the rotational motion of the motor 84 into a linear output of the push rod 81 through the ball screw pair 861, pushing the rocker arm 2 to rotate clockwise to release the landing gear. During operation, the displacement sensor 862 feeds back the position of the ball screw pair 861 in real time to achieve position closed-loop control. The ball bearing 863 is installed on the ball screw pair 861 and is locked by the bearing nut 864. The input side of the ball screw pair 861 is connected to the output shaft of the motor 84, and the output side is threadedly connected to the push rod 81.

[0036] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0037] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A landing gear electromechanical locking release mechanism, characterized in that: The invention comprises a lock housing (1), a rocker arm (2), a connecting rod (3), a tension spring support (4), a tension spring (5), a lock hook (7) and a servo actuator (8); the lock hook (7) and the servo actuator (8) are installed inside the lock housing (1); the rocker arm (2) and the lock hook (7) are connected to the lock housing (1); the rocker arm (2) is connected to the connecting rod (3); the connecting rod (3) is connected to the lock hook (7); a tension spring support (4) is arranged on the connecting rod (3); one end of the tension spring (5) is fixed on the tension spring support (4) and the other end is fixed on the support of the lock hook (7); the servo actuator (8) pushes the rocker arm (2) to move to realize the locking and releasing of the landing gear.

2. The landing gear electromechanical locking release mechanism according to claim 1, characterized in that: The servo actuator (8) comprises a push rod (81), a mounting plate (82), a travel switch (83), a motor (84), a control driver (85) and an actuator cylinder assembly (86); the push rod (81) is mounted on the top of the actuator assembly (86); when the push rod (81) is extended, it contacts the rocker arm (2); under the thrust of the push rod (81), the rocker arm (2) rotates around the bolt; the mounting plate (82) is mounted on the top of the actuator cylinder assembly (86) by threaded connection; a travel switch (83) is provided on one side of the mounting plate (82). The switch (83) is connected to the rocker arm (2) at the output side of the travel switch (83). When the rocker arm (2) is separated from the travel switch (83), an unlocking signal is sent. The motor (84) is connected to the actuator assembly (86) through screws to provide power for the servo actuator (8). The control driver (85) is installed on the side of the motor (84) housing. After receiving the command, the control driver (85) drives the motor (84) to rotate, and converts the rotational motion of the motor (84) into the linear motion of the push rod (81) through the actuator assembly (86).

3. The landing gear electromechanical locking release mechanism according to claim 2, characterized in that: The rocker arm (2) comprises a trigger plate (21) for triggering a travel switch (83).

4. The landing gear electromechanical locking release mechanism according to claim 2, characterized in that: The actuator cylinder assembly (86) comprises a ball screw pair (861), a rolling bearing (863) and a bearing nut (864). The ball bearing (863) is mounted on the ball screw pair (861) and is locked by the bearing nut (864). The input side of the ball screw pair (861) is connected to the output shaft of the motor (84), and the output side is threadedly connected to the push rod (81).

5. The landing gear electromechanical locking release mechanism according to claim 4, characterized in that: The actuator assembly (86) further comprises a displacement sensor (862). Two sets of displacement sensors (862) are symmetrically arranged on both sides of the ball screw pair (861). The displacement sensor (862) provides real-time feedback of the position of the ball screw pair (861) to achieve position closed-loop control.

6. The landing gear electromechanical locking release mechanism according to claim 2, characterized in that: When the rocker arm (2) is located at the stop position, the clearance value L between the rocker arm (2) and the push rod (81) is 0.5-1.5 mm.

7. The landing gear electromechanical locking release mechanism according to claim 1, characterized in that: The tension spring (5) is made of a spring stainless steel wire with a diameter of 2.6 mm, and the tension spring hook is in the form of a long-arm force semicircular hook.

8. The landing gear electromechanical locking release mechanism according to claim 1, characterized in that: When the tension spring (5) is locked, the tension force is 200±20N.

9. The landing gear electromechanical locking release mechanism according to claim 1, characterized in that: It also includes a lock hook bolt (6), and the lock hook (7) and the lock housing (1) are fixed by the lock hook bolt (6); the rocker arm (2) and the lock housing (1) and the connecting rod (3) are respectively connected by bolts, and the connecting rod (3) and the lock hook (7) are connected by bolts.

Images