CN112623198B

CN112623198B - Lifting type undercarriage lower lock

Info

Publication number: CN112623198B
Application number: CN202011599136.0A
Authority: CN
Inventors: 张剑剑; 陶小将; 李永洁; 张立军; 焦斌昌
Original assignee: AVIC First Aircraft Institute
Current assignee: AVIC First Aircraft Institute
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2023-03-24
Anticipated expiration: 2040-12-29
Also published as: CN112623198A

Abstract

The invention belongs to the technical field of airplane design, and relates to an undercarriage down lock, which comprises: an unlocking actuator cylinder (20), a locking spring (11) and a locking key (13) fixed on the inclined strut (1); one end of the locking spring (11) is fixed on the unlocking actuating cylinder (20), and the other end is connected with one end of the locking key (13); the other end of the locking key (13) is matched with a locking hook-shaped cam (15) on the upper rocker arm (2); the middle part of the locking key (13) is rotationally connected with the inclined strut (1) through a locking key rotating shaft (16). The problem of locking a lower lock of the undercarriage in a small space is solved, and the aim of small weight is fulfilled.

Description

Lifting type undercarriage lower lock

Technical Field

The invention belongs to the technical field of airplane design, and relates to an undercarriage down lock of an airplane.

Background

The undercarriage lock functions to lock the undercarriage securely in the lowered position, and a currently common undercarriage lock is a strut type. The main stay bar bears and transmits large load on the ground, the lock stay bar only bears small locking load, and the main stay bar and the lock stay bar are required to be retracted and extended along with the landing gear strut, so that large space is required to be occupied to meet mechanism movement, and the corresponding weight is also large.

Disclosure of Invention

The purpose of the invention is as follows: the lifting type undercarriage down lock solves the problem of locking of the undercarriage down lock in a small space and aims to achieve low weight. The lower lock is locked by using a cam principle, a spring is mechanically locked, the mechanism is simple and reliable, the weight is light, the lower lock is combined with a deflection mechanism to be adaptively and integrally designed, the lock mechanism does not bear main load, the lock mechanism and the main load are reset and backed up, and the lower locking method is high in safety and universality.

The technical scheme of the invention is as follows: the invention provides an aircraft landing gear down lock, which comprises: an unlocking cylinder 20, a locking spring 11 and a locking key 13 fixed to the diagonal strut 1; one end of the locking spring 11 is fixed on the unlocking actuating cylinder 20, and the other end is connected with one end of the locking key 13; the other end of the latch key 13 is matched with a latch hook-shaped cam 15 on the upper rocker arm 2; the middle part of the lock key 13 is rotationally connected with the oblique strut 1 through a lock key rotating shaft 16;

when the landing gear is put down, the upper rocker arm 2 rotates clockwise around the rotating shaft of the upper rocker arm and is put down, and the locking hook-shaped cam 15 drives the locking key 13 to rotate clockwise; after the locking key 13 is separated from the locking hook-shaped cam 15, the locking key rotates anticlockwise under the action of the upper locking spring 11 and enters the locking hook-shaped cam shoulder groove to form meshing locking;

the unlocking actuator 20 is actuated, and the plunger 26 of the unlocking actuator 20 pushes the latch 13 to rotate clockwise, thereby releasing the engagement with the latch hook-shaped cam.

Further, the unlocking actuator cylinder 20 further comprises an outer cylinder 22, a piston rod 23 and a return spring 24;

the outer cylinder 22 is fixedly mounted on the oblique strut 1; the piston rod 23 divides the outer cylinder 22 into a rodless cavity and a rod cavity; the return spring 24 is sleeved between the piston rod 23 and the outer cylinder 22, one end of the return spring 24 is in contact with the piston rod 23, and the other end of the return spring is limited in the shell of the outer cylinder 22; the mandril 26 is positioned in the rod cavity and is connected with the piston rod 23;

one end of the outer cylinder 22 close to the rodless cavity is provided with a rodless cavity pipe joint 21, and the oil is fed through the rodless cavity pipe joint 21 to push the piston rod 23 and the ejector rod 26 to extend out; when the rodless cavity pipe nipple 21 is decompressed, the piston rod 23 is reset under the elastic force of the reset spring 24.

Further, a rod cavity pipe connector 25 is arranged in the middle of the outer cylinder 22, and the rod cavity pipe connector 25 is communicated with the rod cavity; the rod cavity contains liquid which is matched with a return spring and used for balancing pressure change in the oil inlet process of the rodless cavity pipe connector 21 and avoiding accidental unlocking caused by pressure change.

Further, the down lock includes a plurality of locking springs 11.

Further, one end of the latch key 13, which is matched with the latch hook-shaped cam 15, is provided with an offset cam, and the offset cam comprises a latch key cam upper surface 31 and a latch key cam lower surface 32; when the landing gear is down, the latch cam upper surface 31 is in contact with the latch hook cam lower surface 42 of the latch hook cam 15; the upper surface 31 of the latch cam, the lower surface 32 of the latch cam, the upper surface 41 of the latch hook-shaped cam and the lower surface 42 of the latch hook-shaped cam are all arc surfaces.

Further, in the engaged and locked state, the lower surface 32 of the latch cam is coaxial with the upper surface 41 of the latch hook-shaped cam, so as to ensure that the latch has no radial additional bending moment after the lock of the lower lock is locked.

Further, in the process of the counterclockwise rotation of the latch, the gap between the lower surface 32 of the latch cam and the upper surface 41 of the latch hook-shaped cam is at least 1mm, so as to ensure that the lower lock can be locked fully.

Further, the latch hook-shaped cam 15 is an integrated structure of the upper rocker arm 2.

The invention has the technical effects that: the invention relates to a novel lower lock form which adopts the cam principle to mechanically and automatically lock, and is a high-reliability lower lock method. The lock key is provided with independent double backup springs, and can be self-adaptive to automatic mechanical locking. After locking, the lock does not need to bear larger ground load, and the structural size and the weight of the lower lock are greatly reduced. The unlocking aspect is provided with normal hydraulic drive unlocking, and the normal hydraulic drive unlocking can be mechanically reset. The lock mechanism is novel in design, simple in mechanism, high in reliability and universality, and the problem of designing a lower lock with high reliability in narrow space can be solved well.

Drawings

FIG. 1 is a schematic view of the position of the down lock in the landing gear;

FIG. 2 is an enlarged schematic view of the installation position of the down lock in the landing gear;

FIG. 3 is a schematic diagram of a lock state of the down lock;

FIG. 4 is a schematic view of a down lock configuration;

FIG. 5 is a partial cross-sectional view of the down lock structure;

FIG. 6 is a schematic view showing an offset cam structure of the catch 13, and the lower view is a partially enlarged view of the upper view;

FIG. 7 is a structural schematic view of a latch hook-shaped cam, and the left drawing is a partial enlarged schematic view of the right drawing;

FIG. 8 is a schematic diagram of a clockwise rotation process of the down lock;

FIG. 9 is a schematic view of the rotation process of the down lock;

description of reference numerals: 1. the hydraulic cylinder comprises a diagonal strut, 2, an upper rocker arm, 3, a buffer, 4, a lower rocker arm, 5, a lower safety spring, 6, a connecting point of the upper rocker arm and the buffer, 7, a connecting point of the diagonal strut and the upper rocker arm, 8, a connecting point of the buffer and the lower rocker arm, 9, a lower lock mounting point at the diagonal strut, 10, a lower lock, 11, a locking spring, 13, a locking key, 14, a gap between the locking key and a latch hook-shaped cam, 15, a latch hook-shaped cam, 16, a locking key rotating shaft, 20, an unlocking actuating cylinder, 21, a rodless cavity pipe connector, 22, an outer cylinder, 23, a piston rod, 24, a return spring, 25, a rod cavity pipe connector, 26, a mandril, 31, an upper surface of the latch key cam, 32, a lower surface of the latch hook-shaped cam, 41, an upper surface of the latch hook-shaped cam, and 42, a lower surface of the latch hook-shaped cam.

Detailed Description

In the present embodiment, an aircraft landing gear down lock is provided, as shown in fig. 3 and 4, fig. 3 is a schematic view of a locked state of the down lock, and fig. 4 is a schematic view of a structure of the down lock. The down lock 10 includes: an unlocking cylinder 20, a locking spring 11 and a locking key 13 fixed to the diagonal strut 1; one end of the locking spring 11 is fixed on the unlocking actuating cylinder 20, and the other end is connected with one end of the locking key 13; the other end of the latch key 13 is matched with a latch hook-shaped cam 15 on the upper rocker arm 2; the middle part of the locking key 13 is rotatably connected with the oblique strut 1 through a locking key rotating shaft 16.

Fig. 8 is a schematic diagram of a clockwise rotation process of the lower lock, fig. 9 is a schematic diagram of a rotation process of the lower lock, and the locking principle of the lower lock is shown in fig. 8 and fig. 9 in combination: when the landing gear is put down, the upper rocker arm 2 rotates clockwise around the rotating shaft of the upper rocker arm and is put down, and the locking hook-shaped cam 15 drives the locking key 13 to rotate clockwise; after the locking key 13 is separated from the locking hook-shaped cam 15, the locking key rotates anticlockwise under the action of the upper locking spring 11 and enters the locking hook-shaped cam shoulder groove to form meshing locking. When the unlocking actuator 20 is actuated, the plunger 26 of the unlocking actuator 20 pushes the latch 13 to rotate clockwise, and the latch is disengaged from the latch-shaped cam. As one of the preferred embodiments, the down lock of the present embodiment includes a plurality of locking springs 11; the latch hook cam 15 is an integrated structure of the upper rocker arm 2.

Fig. 5 is a partial cross-sectional view of the down lock structure, and in conjunction with fig. 5, the unlocking actuator cylinder 20 of the present embodiment further includes an outer cylinder 22, a piston rod 23, a push rod 26, and a return spring 24. In fig. 5, the dashed line represents another position of movement of the catch 13.

The outer cylinder 22 is fixedly mounted on the oblique strut 1; the piston rod 23 divides the outer cylinder 22 into a rodless cavity and a rod cavity; the return spring 24 is sleeved between the piston rod 23 and the outer cylinder 22, one end of the return spring 24 is in contact with the piston rod 23, and the other end of the return spring is limited in the shell of the outer cylinder 22; the ram 26 is located within the rod chamber and is connected to the piston rod 23. In this embodiment, the unlocking actuator 20 is in the form of a push-key 13, which increases the reliability of the mechanism compared to a conventional pull-load unlocking.

Specifically, when the main landing gear needs to be retracted, hydraulic oil flows in through the rodless cavity pipe joint 21 and pushes the piston rod 23, and meanwhile, the return spring 24 is compressed, so that the ejector rod 26 pushes the locking key 13 to rotate clockwise, and the locking key is disengaged from the locking hook during rotation. When the landing gear is retracted to the proper position, the lower lock unlocking actuator cylinder releases pressure, and the return spring 24 pushes the piston rod 23 into the outer cylinder 22 to restore the position.

Fig. 6 is a schematic view of an offset cam structure of the latch 13, fig. 7 is a schematic view of a latch hook-shaped cam structure, and in combination with fig. 6 and 7, in the present embodiment, an offset cam is provided at an end of the latch 13, which is engaged with the latch hook-shaped cam 15, and includes a latch cam upper surface 31 and a latch cam lower surface 32; when the landing gear is down, the latch cam upper surface 31 is in contact with the latch hook cam lower surface 42 of the latch hook cam 15; the upper surface 31 of the latch cam, the lower surface 32 of the latch cam, the upper surface 41 of the latch hook-shaped cam and the lower surface 42 of the latch hook-shaped cam are all arc surfaces.

As a preferred embodiment of the present embodiment, in the engagement locking state, the latch cam lower surface 32 is coaxial with the latch hook cam upper surface 41 to ensure that the latch has no radial additional bending moment after the lock of the lower lock. In the process of the counterclockwise rotation of the latch, the gap between the lower surface 32 of the latch cam and the upper surface 41 of the latch hook-shaped cam is at least 1mm, so as to ensure that the lower lock can be locked fully.

Fig. 2 is an enlarged schematic view of the installation position of the lower lock in the landing gear, and in the embodiment, the lower lock mechanism is simple and compact and is installed on the side wall of the inclined strut 1 through three lower locks at the installation point 9 of the inclined strut.

Fig. 1 is a schematic view of the position of the down lock in the landing gear, and referring to fig. 1 and 2, when the landing gear is in the down position, the connection point 6 of the upper rocker arm and the buffer is lower than the line connecting the connection point 7 of the inclined strut and the upper rocker arm and the connection point 8 of the buffer and the lower rocker arm, that is, the landing gear retraction device has downward flexibility; the downward deflection is kept by a lower safety spring 5, so that the function of a common stay bar lock is achieved, and the lower lock can be fully ensured not to bear larger ground load; the independent lower lock is powerful supplement, the two locks are reset and backed up, and the safety of the lower lock is greatly improved.

The lower lock and the locking method provided by the invention can better solve the problem of locking the lower lock of the undercarriage in a smaller space, and also can achieve the aim of small weight. The locking method adopts cam locking and spring mechanical locking, the mechanism is simple and reliable, the weight is light, and the mechanism is combined with the flexibility mechanism adaptability fusion design, and the lock mechanism does not bear main load, so that a secondary locking mechanism is formed. The lower lock mechanism is simple, compact in space, strong in locking capacity, capable of adapting to a specific narrow space of the landing gear and has certain universality.

Claims

1. An aircraft landing gear down lock, comprising: an unlocking actuator cylinder (20), a locking spring (11) and a locking key (13) fixed on the inclined strut (1); one end of the locking spring (11) is fixed on the unlocking actuating cylinder (20), and the other end is connected with one end of the locking key (13); the other end of the locking key (13) is matched with a locking hook-shaped cam (15) on the upper rocker arm (2); the middle part of the lock key (13) is rotationally connected with the inclined strut (1) through a lock key rotating shaft (16);

when the landing gear is put down, the upper rocker arm (2) rotates clockwise around the rotating shaft of the upper rocker arm and is put down, and the latch hook-shaped cam (15) drives the latch key (13) to rotate clockwise; after the locking key (13) is separated from the locking hook-shaped cam (15), the locking key rotates anticlockwise under the action of the upper locking spring (11) and enters a shoulder groove of the locking hook-shaped cam to form meshing locking;

the unlocking actuating cylinder (20) is actuated, and a mandril (26) of the unlocking actuating cylinder (20) pushes the lock key (13) to rotate clockwise to release the engagement with the lock hook-shaped cam;

wherein, one end of the latch key (13) matched with the latch hook-shaped cam (15) is provided with an offset cam, and the offset cam comprises a latch key cam upper surface (31) and a latch key cam lower surface (32); when the landing gear is down, the upper surface (31) of the latch key cam is contacted with the lower surface (42) of the latch hook cam (15); the upper surface (31) of the latch key cam, the lower surface (32) of the latch key cam, the upper surface (41) of the latch hook-shaped cam and the lower surface (42) of the latch hook-shaped cam are all arc surfaces.

2. An aircraft landing gear down lock according to claim 1, wherein the unlocking ram (20) further comprises an outer barrel (22), a piston rod (23) and a return spring (24);

the outer cylinder (22) is fixedly arranged on the oblique strut (1); the piston rod (23) divides the outer cylinder (22) into a rodless cavity and a rod cavity; the reset spring (24) is sleeved between the piston rod (23) and the outer cylinder (22), one end of the reset spring (24) is in contact with the piston rod (23), and the other end of the reset spring is limited in the shell of the outer cylinder (22); the ejector rod (26) is positioned in the rod cavity and connected with the piston rod (23);

one end of the outer cylinder (22) close to the rodless cavity is provided with a rodless cavity pipe joint (21), and the piston rod (23) and the ejector rod (26) are pushed to extend out through oil inlet of the rodless cavity pipe joint (21); when the rodless cavity pipe connector (21) is decompressed, the piston rod (23) is reset under the action of the elastic force of the reset spring (24).

3. An aircraft landing gear down-lock according to claim 1, characterised in that the outer barrel (22) is provided with a rod cavity tube nipple (25) in the middle, the rod cavity tube nipple (25) communicating with the rod cavity; the rod cavity is filled with liquid and matched with a return spring to balance pressure change in the oil inlet process of the rodless cavity pipe connector (21) so as to avoid accidental unlocking caused by pressure change.

4. An aircraft landing gear down-lock according to claim 1, characterised in that the down-lock comprises a plurality of locking springs (11).

5. An aircraft landing gear down lock according to claim 1, wherein in the engaged locked condition the lower catch cam surface (32) is co-axial with the upper catch cam surface (41) to ensure that the catch is free of radially applied bending moments after locking of the down lock.

6. An aircraft landing gear down lock according to claim 5, wherein the clearance between the lower surface (32) of the latch cam and the upper surface (41) of the latch hook cam is at least 1mm during counter clockwise rotation of the latch to ensure that the down lock is fully locked.

7. An aircraft landing gear down lock according to claim 6, characterised in that the latch hook-like cam (15) is of integral construction with the upper rocker arm (2).