阅读说明：本技术 一种基于四杆机构运作的起落架收放作动装置 (Undercarriage receive and releases actuator based on four-bar linkage operation ) 是由 田佳杰 于 2020-06-17 设计创作，主要内容包括：本发明涉及起落架设计领域,尤其涉及一种基于四杆机构运作的起落架收放作动装置,包括收放作动筒、摇臂、摇臂撑杆、可折叠支撑臂、安装梁以及设置有转轴组件的减震支柱；安装梁与减震支柱通过转轴组件活动连接；摇臂连机端与机身活动连接,收放作动筒的两端分别与摇臂作动端和减震支柱活动连接,摇臂撑杆的两端分别与摇臂辅助动作点和转轴组件活动连接,可折叠支撑臂的两端分别与机身和减震支柱连接。本发明将传统的三角结构布置形式改为联动的三套四杆机构形式,利用四杆机构的特点,在起落架收起过程中,使连接作动装置的上端连接点绕机身的某一固定点转动,作动装置输出载荷的力臂保持不变小,同时作动装置的作动行程缩短。(The invention relates to the field of undercarriage design, in particular to an undercarriage folding and unfolding actuating device based on four-bar mechanism operation, which comprises a folding and unfolding actuating cylinder, a rocker arm supporting rod, a foldable supporting arm, an installation beam and a shock absorption support column provided with a rotating shaft assembly, wherein the folding and unfolding actuating cylinder is arranged on the upper portion of the folding and unfolding actuating cylinder; the mounting beam is movably connected with the shock absorption strut through a rotating shaft assembly; the rocker arm connecting end is movably connected with the machine body, the two ends of the retractable actuating cylinder are respectively movably connected with the rocker arm actuating end and the shock absorption strut, the two ends of the rocker arm supporting rod are respectively movably connected with the rocker arm auxiliary actuating point and the rotating shaft assembly, and the two ends of the foldable supporting arm are respectively connected with the machine body and the shock absorption strut. The invention changes the traditional triangle structure arrangement form into a linkage three-set four-bar mechanism form, and utilizes the characteristics of the four-bar mechanism to ensure that the upper end connecting point connected with the actuating device rotates around a certain fixed point of the machine body in the retraction process of the undercarriage, the force arm of the output load of the actuating device is kept unchanged, and the actuating stroke of the actuating device is shortened.)

1. The utility model provides an undercarriage receive and releases actuator based on four-bar linkage operation which characterized in that: the foldable shock absorption device comprises a retractable actuator cylinder (1), a rocker arm (2), a rocker arm brace rod (3), a foldable support arm (4), a shock absorption strut (5) and a mounting beam (6) for arranging the shock absorption strut (5);

a rotating shaft assembly (7) is arranged at the top of the shock absorption strut (5), and the mounting beam (6) is movably connected with the shock absorption strut (5) through the rotating shaft assembly (7); the rocker arm (2) comprises a connecting end (2.1), an actuating end (2.2) and an auxiliary action point (2.3) between the connecting end (2.1) and the actuating end (2.2); the connecting end (2.1) of the rocker arm (2) is movably connected with the machine body; one end of the rocker arm support rod (3) is movably connected with the auxiliary action point (2.3) of the rocker arm (2), and the other end of the rocker arm support rod is movably connected with the rotating shaft component (7); one end of the retractable actuating cylinder (1) is movably connected with the actuating end (2.2) of the rocker arm (2), and the other end of the retractable actuating cylinder is movably connected with the waist of the shock absorption strut (5); one end of the foldable support arm (4) is fixedly connected with the machine body, the other end of the foldable support arm is movably connected with the waist of the shock absorption strut (5), and the connection point of the foldable support arm (4) on the shock absorption strut (5) is located at the position of the lower end of the connection point of the retractable actuating cylinder (1) on the shock absorption strut (5).

2. A four-bar linkage based landing gear retraction actuator according to claim 1, wherein: the auxiliary action point (2.3) is arranged close to one end of the action end (2.2) of the rocker arm (2).

3. A four-bar linkage based landing gear retraction actuator according to claim 1, wherein: the retractable actuating cylinder (1) comprises an outer cylinder (1.1) and a piston rod (1.2) with a piston (1.3); one end of the outer cylinder (1.1) is sleeved with a piston rod (1.2), and the other end is movably connected with the shock absorption strut (5); one end of the piston rod (1.2) is positioned in the outer cylinder (1.1) together with the piston (1.3), and the other end is movably connected with the rocker arm (2).

4. A four-bar linkage based landing gear retraction actuator according to claim 3, wherein: the inside of the retractable actuating cylinder (1) is also provided with a built-in lock (1.4).

5. A four-bar linkage based landing gear retraction actuator according to claim 1, wherein: the rotating shaft assembly (7) comprises a rotating shaft (7.1) and a sleeve (7.2) arranged outside the rotating shaft (7.1), the top of the buffering supporting rod is fixedly connected with the sleeve (7.2), and the rocker arm supporting rod (3) is movably connected with the sleeve (7.2).

6. A four-bar linkage based landing gear retraction actuator according to claim 1, wherein: the foldable supporting arm (4) comprises an upper arm (4.1) with a double parallel straight rod structure and a lower arm (4.2) with a single straight rod structure; one end of the upper arm (4.1) is movably connected with one end of the lower arm (4.2), and at the joint of the upper arm (4.1) and the lower arm (4.2), the single straight rod of the lower arm (4.2) is positioned between the double parallel straight rods of the upper arm (4.1); the other end of the upper arm (4.1) is provided with a positioning piece (4.3) fixedly connected with the machine body, and the positioning piece (4.3) is movably connected with the upper arm (4.1); the other end of the lower arm (4.2) is movably connected with the waist part of the shock absorption strut (5).

Technical Field

The invention relates to the field of undercarriage design, in particular to an undercarriage folding and unfolding actuating device based on four-bar mechanism operation.

Background

After the aircraft takes off, the landing gear needs to be retracted to a specific position, so that the purpose of reducing aerodynamic resistance and improving the climbing rate of the aircraft is achieved, and the retraction and extension of the landing gear is generally realized by adopting a hydraulic actuator cylinder or an electric push rod. The design process of the actuating device relates to the determination of parameters such as the distance between the joints at the two ends of the actuating cylinder, an actuating stroke, the minimum dead structure length and the like, and further, the parameters need to meet the conditions that the dead structure length of the actuating device is not less than the minimum dead structure length.

When the landing gear is in a retracted state, the output load of the actuating device is mostly used for realizing the moment caused by overcoming the self gravity of the landing gear (particularly a strut part); when the undercarriage is in a down state, the center of gravity of the strut is basically distributed on a center of gravity vertical line of the retracting rotating shaft; in the retraction process of the undercarriage, the center of gravity of the strut gradually deviates from the perpendicular line of the center of gravity of the retraction rotating shaft, so that the moment caused by the self gravity of the undercarriage and required to be overcome is increased. Therefore, the magnitude of the moment caused by the weight of the landing gear and to be overcome is actually in positive correlation with the retraction angle, i.e. the moment output by the actuator increases with increasing retraction angle. The retraction rate of the system is an index for measuring the reasonability of the arrangement of the actuating device when the retraction device of the landing gear is designed, and usually, when the amplitude change of the output load of the actuating device is small, the retraction efficiency of the system is high.

Traditional undercarriage receiving and releasing device, the one end that will actuate the device usually articulates on the urceolus of undercarriage pillar, and the other end is installed on the aircraft organism, and undercarriage, actuation device and fuselage structure are the triangle structure form and arrange, but owing to have characteristics such as aircraft assembly space compactness, main load frame roof beam structure biography power route do not allow to break, traditional undercarriage receiving and releasing device has following defect: the actuating device has a longer actuating stroke, so that the total length of the actuating device needs to be increased to ensure that the length of a dead structure of the actuating device meets requirements, the weight is increased, the volume is increased, and the requirement on a retraction space is further increased; the arm of force of the load output by the actuating device in the retraction state of the undercarriage is small, so that the undercarriage is not favorable for locking in the retraction state; and thirdly, the output load amplitude of the retraction actuating device is changed greatly, and the retraction efficiency of the system is lower.

Disclosure of Invention

The invention aims to provide a landing gear retraction actuating device based on four-bar mechanism operation, which changes the traditional triangular structure arrangement form into a linkage three-set four-bar mechanism form, utilizes the characteristics of the four-bar mechanism, and enables an upper end connecting point connected with an actuating device to rotate around a certain fixed point of a machine body in the retraction process of the landing gear, so that the force arm of the load output by the actuating device is kept unchanged, and the actuating stroke of the actuating device is shortened.

It should be noted that the fuselage mentioned in the technical scheme is an aircraft fuselage structure, and the movable connections mentioned in the technical scheme are all hinged, and the method is specifically realized through the following technical scheme:

a landing gear retraction actuating device based on four-bar mechanism operation comprises a retraction actuating cylinder, a rocker arm brace rod, a foldable support arm, a shock absorption strut and a mounting beam for arranging the shock absorption strut; the damping strut is a bearing strut with a shock absorber, the bearing strut is usually used as an outer cylinder of the shock absorber, the bottom end of the damping strut is provided with an airplane wheel with a pneumatic tire, and the damping strut transmits impact load to an airplane body in the landing and gliding processes of the airplane; the mounting beam is directly connected with the machine body and is a part of the machine body; the top of the shock-absorbing strut is provided with a rotating shaft assembly, and the mounting beam is movably connected with the shock-absorbing strut through the rotating shaft assembly; the rocker arm comprises a connecting end, an actuating end and an auxiliary action point between the connecting end and the actuating end; the connecting end of the rocker arm is movably connected with the machine body; one end of the rocker arm supporting rod is movably connected with the auxiliary action point of the rocker arm, and the other end of the rocker arm supporting rod is movably connected with the rotating shaft component; one end of the retractable actuating cylinder is movably connected with the actuating end of the rocker arm, and the other end of the retractable actuating cylinder is movably connected with the waist of the shock absorption strut; one end of the foldable support arm is fixedly connected with the machine body, the other end of the foldable support arm is movably connected with the waist of the shock-absorbing strut, and the connection point of the foldable support arm on the shock-absorbing strut is positioned at the lower end of the connection point of the retractable actuating cylinder on the shock-absorbing strut; the waist of the shock strut is a part between the top end and the bottom end of the shock strut and close to the middle of the shock strut, the waist of the shock strut has a certain range, and the specific connection position of the retractable actuating cylinder and the foldable support arm can determine an optimal position according to an actual test structure. The invention adds two important structures of a rocker arm and a rocker arm brace rod in the aircraft landing gear retraction actuating device, so that a first set of four-bar mechanism is formed by a machine body, the rocker arm brace rod and a rotating shaft component; the machine body, the rocker arm, the rotating shaft assembly and the retractable actuating cylinder form a second set of four-bar mechanism; the rocker arm, the rocker arm brace rod, the rotating shaft assembly and the retraction actuating device form a third set of four-bar mechanism. In summary, the invention has three sets of four-bar mechanisms, the movements of the three sets of four-bar mechanisms are all located in the same plane, the three sets of four-bar mechanisms can be linked with each other through the rocker arm support rod, and the only actuating force comes from the retractable actuating cylinder.

Based on the upward movement track of the rocker arm in the retraction process of the landing gear, the rocker arm support rod needs to be connected to one side, close to the retractable actuator cylinder, of the rotating shaft assembly, and further, the auxiliary action point is arranged close to one end of the rocker arm action end.

The retractable actuating cylinder comprises an outer cylinder and a piston rod with a piston; because the outer cylinder is thicker than the piston rod and is smaller based on the size of the rocker arm, one end of the outer cylinder is sleeved with the piston rod, and the other end of the outer cylinder is movably connected with the shock absorption strut; one end of the piston rod is positioned in the outer barrel together with the piston, and the other end of the piston rod is movably connected with the rocker arm; but the position of the connecting point of the outer cylinder and the piston rod can be reversed according to the actual arrangement condition of the landing gear, even if the outer cylinder is connected with the rocker arm, the piston rod is connected with the shock absorption supporting column.

In order to prevent the landing gear from being automatically put down in the flying process and automatically retracted when being impacted, preferably, a built-in lock is further arranged inside the retraction actuator cylinder, and the built-in lock is a retraction position lock and is used for realizing the locking of the landing gear after being retracted or put down.

The rotating shaft assembly comprises a rotating shaft and a sleeve arranged outside the rotating shaft, the sleeve structure is matched with the rotating shaft, and further the sleeve can rotate around the rotating shaft; the top of the shock-absorbing strut is fixedly connected with the sleeve, and preferably, the strut and the sleeve are integrated, so that the structure is more stable; the rocker arm brace rod is movably connected with the sleeve.

The foldable support arm comprises an upper arm with a double parallel straight rod structure and a lower arm with a single straight rod structure; one end of the upper arm is movably connected with one end of the lower arm, and at the joint of the upper arm and the lower arm, a single straight rod of the lower arm is positioned between two parallel straight rods of the upper arm, namely, one straight rod of the lower arm is clamped between the two straight rods of the upper arm; the other end of the upper arm is provided with a positioning piece fixedly connected with the machine body, and the positioning piece is movably connected with the upper arm; the other end of the lower arm is movably connected with the waist part of the shock strut.

The invention has the following beneficial effects:

the technical scheme includes that the three sets of four-bar mechanisms are included, and by utilizing the working principle of the four-bar mechanisms, the rocker arm and the rocker arm support rod are added in the retractable actuating device, so that the actuating stroke of the retractable actuating device is shortened, and the total length of the retractable actuating device is shortened, therefore, the weight and the volume of the retractable actuating device are reduced, and the space requirement of the retractable actuating device is further reduced.

And secondly, in the process that the undercarriage is retracted from the down position to the up position, the actuating cylinder force arm is initially the minimum value, the load output by the retractable actuating device can reach a larger value in the initial stage, the actuating cylinder force arm is increased along with the increase of the retraction angle, the load of the actuating cylinder is not changed greatly while the retractable load moment of the undercarriage is increased, and therefore the efficiency of the retractable system is improved.

When the undercarriage is in a retracted state, the force arm of the load output by the retractable actuating device is larger than the force arm of the actuating cylinder in the traditional triangular structure arrangement form, the undercarriage can be reliably locked only by retracting and releasing the built-in lock in the actuating cylinder, and the external lock of the undercarriage is not required to be added.

Drawings

The foregoing and following detailed description of the invention will be apparent when read in conjunction with the following drawings, in which:

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic illustration of the landing gear down condition of the present invention;

FIG. 3 is a schematic view of the landing gear of the present invention in a semi-retracted state;

FIG. 4 is a schematic view of the landing gear of the present invention in a fully stowed condition;

FIG. 5 is a partial schematic view of the locking condition of the retractable actuator of the present invention;

in the figure:

1. retracting and releasing the actuating cylinder; 1.1, an outer cylinder; 1.2, a piston rod; 1.3, a piston; 1.4, a built-in lock; 2. a rocker arm; 2.1, connecting the machine end; 2.2, an actuating end; 2.3, auxiliary action points; 3. a rocker arm brace rod; 4. a collapsible support arm; 4.1, upper arm; 4.2, a lower arm; 4.3, positioning parts; 5. A shock strut; 6. mounting a beam; 7. a rotating shaft assembly; 7.1, a rotating shaft; 7.2, sleeve.

Detailed Description

The technical solutions for achieving the objects of the present invention are further illustrated by the following specific examples, which should be construed that the above examples only represent some embodiments of the present invention, and the description thereof is more specific and detailed, but not to limit the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.