阅读说明：本技术 一种可延时加载的起落架收放作动筒 (Undercarriage folding and unfolding actuator cylinder capable of being loaded in delayed mode ) 是由 邓晓山 程国良 金军 马颖 张健全 路红伟 禹新鹏 冯广 陈永卿 李兆昕 于 2019-11-04 设计创作，主要内容包括：本发明公开了一种可延时加载的起落架收放作动筒,包括缸筒和活塞杆,缸筒内腔通过活塞分为有杆和无杆腔,有杆腔内设活门座、活门体、弹簧和活塞。活门座固定于有杆腔中,活门体轴向滑动于活门座的通孔中并将无杆腔分为第一、二腔,活门体外壁与通孔内壁之间具有连通第一、二腔的流道；活门体上设可与活门座抵接并关闭流道的止挡部；活门体具有内腔,活门体轴向方向一端开口,另一端开设有与第一腔连通的节流孔；活塞伸入内腔中并关闭内腔且可轴向滑移并压缩弹簧；活门体侧壁开设有出油孔,活塞滑移过程中可使出油孔连通流道和第二腔。本发明可使收放作动筒延时后输出载荷,不与开锁作动筒载荷产生抵触,降低锁机构内力,同时不增加系统附件。(The invention discloses a landing gear retraction actuator cylinder capable of being loaded in a delayed mode. The valve seat is fixed in the rod cavity, the valve body axially slides in the through hole of the valve seat and divides the rodless cavity into a first cavity and a second cavity, and a flow passage for communicating the first cavity and the second cavity is arranged between the outer wall of the valve body and the inner wall of the through hole; the stop part which can be abutted against the valve seat and close the flow channel is arranged on the valve body; the valve body is provided with an inner cavity, one end of the valve body in the axial direction is opened, and the other end of the valve body is provided with a throttling hole communicated with the first cavity; the piston extends into the inner cavity, closes the inner cavity, can axially slide and compresses the spring; the side wall of the valve body is provided with an oil outlet, and the oil outlet can be communicated with the flow passage and the second cavity in the sliding process of the piston. The invention can make the retracting actuator cylinder output load after time delay, and does not generate conflict with the unlocking actuator cylinder load, thereby reducing the internal force of the lock mechanism and simultaneously not increasing system accessories.)

1. A landing gear retractable actuator cylinder capable of being loaded in a delayed mode comprises a cylinder barrel (1) and a piston rod (2), wherein one end, provided with a working piston (12), of the piston rod (2) extends into the cylinder barrel (1) and can axially slide in the cylinder barrel (1) in a sealing mode, an inner cavity (E) of the cylinder barrel (1) is divided into a rod cavity (R) and a rodless cavity (F) through the piston, a rod cavity oil port (B) communicated with the rod cavity (R) and a rodless cavity oil port (A) communicated with the rodless cavity (F) are formed in the outer wall of the cylinder barrel (1); the damping valve is characterized in that a damping valve is arranged in the rod cavity (R), and the damping valve comprises a valve seat (10), a valve body (7), a damping spring (8) and a damping piston (9);

the valve seat (10) is clamped in the cylinder barrel (1) and fixed with the inner wall of the rod cavity (R), and the valve seat (10) is provided with a first through hole (101) along the axial direction of the cylinder barrel (1);

the valve body (7) penetrates through the first through hole (101) and can axially slide along the inner wall of the first through hole (101), the rodless cavity (F) is divided into a first cavity (F1) and a second cavity (F2) by the valve body (7), the first cavity (F1) is arranged close to the piston rod (2), the second cavity (F2) is communicated with the rodless cavity oil port (A), and a flow passage (C) for communicating the first cavity (F1) with the second cavity (F2) is arranged between the outer wall of the valve body (7) and the inner wall of the first through hole (101); an annular stopping portion (71) is arranged at one end, facing the second cavity (F2), of the valve body (7), and the annular stopping portion (71) can be abutted against the end, facing the second cavity (F2), of the valve seat (10) so as to prevent the valve body (7) from moving towards the piston rod (2) and close the flow channel (C);

the valve body (7) is provided with an inner cavity (E), one end of the valve body (7) along the axial direction of the cylinder barrel (1) is provided with an opening communicated with the inner cavity (E) and the second cavity (F2), and the other end of the valve body (7) along the axial direction of the cylinder barrel (1) is provided with a throttling hole (P) communicated with the first cavity (F1); the damping piston (9) extends into the inner cavity (E) from the opening and closes the inner cavity (E), hydraulic oil is filled in the inner cavity (E), the damping spring (8) is located in the inner cavity (E), and the damping piston (9) can slide in the inner cavity (E) along the axial direction of the cylinder barrel (1) and compress the damping spring (8); oil outlet (N) has been seted up with the position that damping piston (9) corresponds to the lateral wall of valve body (7), damping piston (9) can make oil outlet (N) intercommunication towards piston rod (2) slippage in-process runner (C) and second chamber (F2).

2. A delay-loadable landing gear retraction ram according to claim 1, wherein the end face of the damping piston (9) facing the internal cavity (E) is provided with a guide slot (91) for receiving a damping spring (8).

3. The landing gear retractable actuator cylinder capable of being loaded with a delayed time according to claim 1, wherein a plurality of positioning blocks (72) for abutting against the hole wall of the first through hole (101) are arranged on the outer wall of the valve body (7), and the plurality of positioning blocks (72) are uniformly distributed along the circumferential direction of the valve body (7).

4. A delay loadable landing gear retraction actuator according to claim 1, wherein a sealing ring band (M) is provided on the end face of the annular stop (71) facing the valve seat (10).

5. The delay-loadable undercarriage retraction actuator according to claim 1, wherein the end of the cylinder (1) provided with the rodless cavity (F) is sealed by a cylinder cap (11), and the rodless cavity oil port (a) opens onto the cylinder cap (11).

6. A delay-loadable landing gear retraction actuator according to any of claims 1 to 5, wherein the piston rod (2) is provided with a damping means for absorbing the thrust exerted on the piston rod (2) by hydraulic oil flowing out of the orifice (P).

7. A delay-loadable undercarriage retraction actuator according to claim 6, wherein the piston rod (2) has a receiving recess (21) formed therein, and the working piston (12) has a second through-hole (121) formed therethrough the receiving recess (21) and the rodless cavity (F); buffer arranges in storage tank (21), buffer includes spring holder (3), buffer spring (4) and buffer piston (5), spring holder (3) are connected with the cell wall of storage tank (21), one side that spring holder (3) are close to the damping valve is located in buffer piston (5), buffer spring (4) are located between spring holder (3) and buffer piston (5), buffer piston (5) can follow cylinder (1) axial direction in storage tank (21) and seal and slide and compress buffer spring (4).

8. The delay loadable landing gear retraction actuator according to claim 7, wherein an air cavity (D) is defined between the spring seat (3), the wall of the receiving recess (21) and the damping piston (5), and the spring seat (3) is provided with an exhaust hole (31) communicating the air cavity (D) and the receiving recess (21).

9. A delay loadable landing gear retraction actuator according to claim 7, wherein the end faces of the spring cup (3) and the damping piston (5) facing each other are provided with guide slots for receiving the damping spring (4).

10. A delay loadable landing gear retraction actuator according to any of claims 7 to 9 wherein the wall of the second through bore (121) is provided with a threaded cap (6) and the outer wall of the threaded cap (6) engages the wall of the second through bore (121).

Technical Field

The invention relates to the technical field of aircraft landing gears, in particular to a landing gear retractable actuator cylinder capable of being loaded in a delayed mode, which is suitable for sequential coordination of unlocking and retracting actions of an aircraft landing gear and a cabin door.

Background

Retractable landing gear need lock through the mechanical lock in the position of putting down and the position of packing up. Normally, when the landing gear is retracted or released, the down lock or the up lock is unlocked by the unlocking actuating cylinders respectively and is driven to retract by the retracting actuating cylinders. In the process, the unlocking actuator cylinder preferably acts to unlock the vehicle, and then the load output by the retraction actuator cylinder drives the undercarriage to retract and retract. For a common landing gear mechanical lock mechanism, if an unlocking actuator cylinder and a retracting actuator cylinder act simultaneously, the output force of the unlocking actuator cylinder and the output force of the retracting actuator cylinder have mutual conflict effect, so that the lock mechanism can generate large internal force, the unlocking difficulty is caused, the service life of the lock mechanism is influenced, and the self-locking of the lock mechanism can not be opened when the lock mechanism is serious. However, in order to simplify the landing gear retraction system and improve the system reliability, the operation sequence of the unlocking actuator and the retraction actuator is generally not controlled by a dedicated logic control element such as an electromagnetic valve or a pressure sequence valve. The following methods are currently commonly used to avoid such problems:

1. a coordinating valve is arranged in the unlocking actuating cylinder. When the moving stroke of the unlocking actuating cylinder is enough to open the mechanical lock, an oil way leading to the retractable actuating cylinder in the unlocking actuating cylinder is opened to pressurize the retractable actuating cylinder. This has the disadvantage that the oil path to the retraction actuator must first pass through the unlocking actuator, limiting the flexibility of the system piping arrangement and increasing the weight of the system.

2. The system pressure is supplied to the unlocking actuating cylinder and the releasing actuating cylinder simultaneously, and the pressure of two cavities of the releasing actuating cylinder is balanced through a pressure transmitting cylinder and a throttle valve which are arranged in an oil way during unlocking, so that the output force is reduced, and the internal force of the lock mechanism is reduced. In addition, the design of the throttle valve needs to consider the retraction speed requirement of the undercarriage, and the coordination and the guarantee are not easy to realize.

3. The system pressure is simultaneously supplied to the unlocking actuator cylinder and the releasing actuator cylinder (the unlocking load and the releasing load are simultaneously applied to the lock mechanism), and the unlocking and bearing requirements of the lock mechanism are ensured by improving the output force of the unlocking actuator cylinder and increasing the structural strength of the lock. This approach does not solve the problem of high lock mechanism forces, which increases the size and weight of the structure.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a landing gear retractable actuator cylinder capable of being loaded in a delayed manner, so that the requirements of a system pipeline and a special accessory are not increased, and the requirements that in the unlocking process of a landing gear lock mechanism, when the retractable actuator cylinder and the unlocking actuator cylinder are pressurized at the same time, the retractable actuator cylinder outputs a load after a certain time and does not collide with the load of the unlocking actuator cylinder are met, the internal force of a lock mechanism is reduced.

In order to solve the technical problems, the invention adopts the following technical scheme:

a landing gear retractable actuator cylinder capable of being loaded in a delayed mode comprises a cylinder barrel and a piston rod, wherein one end, provided with a working piston, of the piston rod extends into the cylinder barrel and can axially slide in the cylinder barrel in a sealing mode, an inner cavity of the cylinder barrel is divided into a rod cavity and a rodless cavity through the piston, and a rod cavity oil port communicated with the rod cavity and a rodless cavity oil port communicated with the rodless cavity are formed in the outer wall of the cylinder barrel; the damping valve is arranged in the rod cavity and comprises a valve seat, a valve body, a damping spring and a damping piston;

the valve seat is clamped in the cylinder barrel and fixed with the inner wall of the rod cavity, and a first through hole is formed in the valve seat along the axial direction of the cylinder barrel;

the valve body penetrates through the first through hole and can axially slide along the inner wall of the first through hole, the rodless cavity is divided into a first cavity and a second cavity by the valve body, the first cavity is arranged close to the piston rod, the second cavity is communicated with an oil port of the rodless cavity, and a flow passage for communicating the first cavity with the second cavity is arranged between the outer wall of the valve body and the inner wall of the first through hole; an annular stopping part is arranged at one end of the valve body facing the second cavity and can be abutted against the end part of the valve seat facing the second cavity so as to prevent the valve body from moving towards the piston rod and close the flow passage;

the valve body is provided with an inner cavity, one end of the valve body along the axial direction of the cylinder barrel is provided with an opening communicated with the inner cavity and the second cavity, and the other end of the valve body along the axial direction of the cylinder barrel is provided with a throttling hole communicated with the first cavity; the damping piston extends into the inner cavity from the opening and closes the inner cavity, hydraulic oil is filled in the inner cavity, the damping spring is located in the inner cavity, and the damping piston can slide in the inner cavity along the axial direction of the cylinder barrel and compress the damping spring; an oil outlet is formed in the side wall of the valve body and corresponds to the damping piston, and the damping piston can enable the oil outlet to be communicated with the flow channel and the second cavity in the sliding process towards the piston rod.

The principle of the invention for realizing the delayed loading of the undercarriage retractable actuating cylinder capable of being delayed loaded is as follows:

when the system pressurizes the retracting actuator cylinder and the unlocking actuator cylinder simultaneously, after pressure oil enters the second cavity through the oil port of the rodless cavity, the pressure oil pushes the valve body to close the flow passage, the damping valve forms a reverse opening sealing state, the pressure oil cannot directly enter the first cavity so as not to push the piston rod to do work externally, the damping spring force can only be overcome to push the damping piston to move, the radial oil hole in the valve body is covered by the damping piston, the pressure oil in the valve body can only be discharged through the throttling hole at the bottom of the valve body, and the damping action of the throttling hole enables the damping piston to move slowly, so that the retracting action is delayed. Due to the damping effect, the oil supply pressure of a system cannot be reduced in the oil discharging process of the damping valve, and the pressure loss of other executing elements (such as an unlocking actuating cylinder) cannot be caused, so that the other executing elements can perform pressurization action in advance, the unlocking actuating cylinder can be quickly unlocked due to no system internal force during the delay of the retraction action, and when the unlocking is finished, the damping piston moves for a certain stroke to expose the oil outlet, so that the oil outlet is communicated with the flow passage and the second cavity, and the actuating cylinder starts to normally feed oil and output load. When the actuating cylinder returns to work, the flow passage is opened under the oil return pressure, no damping effect exists, and the system can work normally.

The invention does not need to increase system accessories and pipelines, does not influence the arrangement of the pipelines of the system, and can effectively reduce the internal force of the lock mechanism.

As a further improvement of the above technical solution:

in order to avoid the damping spring from moving in the compression process, the end face of the damping piston facing the inner cavity is provided with a guide groove for accommodating the damping spring.

In order to realize reliable positioning of the valve body, a plurality of positioning blocks used for being abutted to the hole wall of the first through hole are arranged on the outer wall of the valve body, and the plurality of positioning blocks are uniformly distributed along the circumferential direction of the valve body. The positioning block divides the flow channel into a plurality of sub-flow channels.

And a sealing ring belt is arranged on the end face, facing the valve seat, of the annular stopping part so as to ensure that the flow channel is closed.

The end of the cylinder barrel, which is provided with the rodless cavity, is sealed by the cylinder cover, and the oil port of the rodless cavity is arranged on the cylinder cover.

And the piston rod is provided with a buffer device, and the buffer device is used for absorbing the thrust applied to the piston rod by the hydraulic oil flowing out of the throttling hole. So as to avoid the oil pressure rise of the rodless cavity during the unlocking period from pushing the piston rod to do work outwards.

The piston rod is internally provided with a containing groove, and the working piston is provided with a second through hole which penetrates through the containing groove and the rodless cavity; the buffer device is arranged in the accommodating groove and comprises a spring seat, a buffer spring and a buffer piston, the spring seat is connected with the groove wall of the accommodating groove, the buffer piston is arranged on one side, close to the damping valve, of the spring seat, the buffer spring is arranged between the spring seat and the buffer piston, and the buffer piston can slide and compress in the accommodating groove along the axial direction of the cylinder barrel in a sealing mode.

Thus, the thrust force applied to the piston rod by the hydraulic oil flowing out of the orifice pushes the cushion piston to move and compress the spring, the thrust force is balanced with the compression force of the spring, and therefore the pressure of the actuator cylinder does not rise in the moving stroke, and the actuator cylinder does not output a large load.

An air cavity is formed by enclosing the spring seat, the groove wall of the accommodating groove and the buffer piston, and an exhaust hole for communicating the air cavity and the accommodating groove is formed in the spring seat. The exhaust hole is communicated with the atmosphere or the accommodating groove, the moving pressure of the buffer valve is low, and the actuator cylinder is ensured not to have larger load output.

And guide grooves for accommodating the buffer springs are formed in the end faces, opposite to each other, of the spring seat and the buffer piston. So as to ensure that the buffer spring is not moved in the compression process.

In order to avoid piston abrasion caused by the fact that the piston is touched in the moving process of the valve body, a screw cap is arranged on the hole wall of the second through hole, and the outer wall of the screw cap is matched with the hole wall of the second through hole.

Compared with the prior art, the invention has the advantages that:

the invention meets the requirement that when the retraction actuator cylinder and the unlocking actuator cylinder are pressurized simultaneously in the unlocking process of the undercarriage lock mechanism, the retraction actuator cylinder outputs load after a certain time without colliding with the load of the unlocking actuator cylinder, thereby reducing the internal force of the lock mechanism and simultaneously not increasing system pipelines and special accessories.

Drawings

FIG. 1 is a schematic diagram of a time delay loadable landing gear retraction actuator according to an embodiment of the present invention.

Fig. 2 is a sectional structure view of a damping valve body in the embodiment of the invention.

FIG. 3 is a side view of a damping valve body according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of the delayed loading of the actuator cylinder according to the embodiment of the present invention.

Fig. 5 is a schematic diagram of the normal loading operation of the ram in an embodiment of the present invention.

Fig. 6 is a schematic diagram of the return stroke operation of the ram in an embodiment of the present invention.

Illustration of the drawings: 1. a cylinder barrel; 2. a piston rod; 21. a containing groove; 3. a spring seat; 31. an exhaust hole; 4. a buffer spring; 5. a cushion piston; 6. a screw cap; 7. a valve body; 71. an annular stop; 72. positioning blocks; 8. a damping spring; 9. a damping piston; 91. a guide groove; 10. a valve seat; 101. a first through hole; 11. a cylinder cover; 12. a working piston; 121. a second through hole; A. a rodless cavity oil port; B. a rod cavity oil port; C. a flow channel; E. an inner cavity; r, a rod cavity; F. a rodless cavity; f1, first cavity; f2, second chamber; m, sealing a ring belt; n, oil outlet holes; p, an orifice; D. an air cavity.

Detailed Description

The invention is further described below with reference to specific preferred embodiments, without thereby limiting the scope of protection of the invention.