A highly reliable integrated frame stabilizing buffer actuating device

Abstract

The invention discloses a highly reliable integrated vehicle frame stabilization buffer actuating device, which comprises an outer cylinder (11) and a piston rod (9). One end of the piston rod is connected to the vehicle frame, and the other end is slidably installed in the outer cylinder. A front floating piston and a rear floating piston are sequentially installed in the outer cylinder in a floating manner. The interior of the piston rod is hollow. The front floating piston, the rear floating piston and the piston rod divide the inner cavity of the actuating device into four cavities. The inner cavity of the piston rod forms a first cavity connected to the aircraft hydraulic system. A second cavity is formed between the front inner wall surface of the outer cylinder and the front floating piston. A third cavity is formed between the rear floating piston and the tail of the outer cylinder. A fourth cavity used as an air cavity is formed between the front floating piston and the rear floating piston. A filling port (7) is provided on the third cavity. The third cavity is connected to the second cavity through a hydraulic conduit. An integrated pipe joint (8) is installed at one end of the hydraulic conduit. The end diameter of the oil passage of the integrated pipe joint is larger than the middle diameter.

Description

Technical Field

[0001] The invention relates to an aircraft landing device, in particular to a high-reliability integrated frame stabilizing buffering actuating device. Background Art

[0002] Modern large and medium-sized aircraft have large landing gear loads. In order to reduce the pressure of tires on the runway, improve the aircraft's take-off and landing taxiing capabilities on front-line dirt runways, and improve the aircraft's floatation, the method of increasing the number of wheels is often used on the basis of the front three-point landing gear structure layout, that is, a landing gear with a multi-wheel frame structure layout is adopted. However, the landing gear with this structure layout needs to consider the different attitude control requirements of the frame relative to the buffer pillar after the landing gear is lowered or retracted, and at the same time, it needs to solve the problem of violent swinging of the frame during take-off, landing and ground movement of the aircraft.

[0003] At present, in order to solve this problem, a frame stabilizing buffer actuator is usually arranged between the buffer pillar and the frame. The frame stabilizing buffer actuator is installed between the frame and the buffer pillar, and is required to realize the functions of folding and lowering the frame, and also partially absorb the work of the external load generated during taxiing, take-off run, landing run and initial impact of landing.

[0004] Chinese invention CN201210579209.9 introduces a frame position control actuator that can retract and extend the main landing gear frame at a large angle, which can adjust the frame crossbeam posture and follow the ground load. However, due to the large difference in the oil pressure areas corresponding to the two chambers of the actuator cylinder, when following the ground, the extension and retraction of the piston rod causes the actuator cylinder to discharge oil to the system return oil circuit or input oil from the system oil circuit, or a separate oil replenishment or oil discharge device needs to be arranged, resulting in increased system design complexity and insufficient independence when realizing functions.

[0005] Chinese invention CN201710806239.1 proposes a passive stabilizing buffer that is not connected to the aircraft hydraulic system. This type of frame stabilizing buffer only realizes the dynamic buffering function of the frame when the aircraft is taxiing on the ground, and does not have the function of retracting the frame relative to the angle position of the buffer support. Therefore, the retracting form of the landing gear, the door opening and the storage space will be restricted by the frame posture, thereby affecting the optimal design and diversified design of the landing gear structure layout.

[0006] Chinese invention CN201810627214.X proposes a frame stabilization buffer actuator that integrates multiple functions, which can realize the large-angle retraction and extension of the frame of the frame-type main landing gear and the dynamic buffer function of the frame when the aircraft lands and passes through uneven roads. The structural composition of this type of frame stabilization buffer actuator is divided into two modules: the actuator cylinder assembly and the hydraulic control valve assembly. In terms of mechanical structure design, it fails to integrate multiple functions into a single actuator, resulting in its integration to be improved. When realizing the dynamic buffer function, the two chambers of the actuator cylinder need to rely on the hydraulic system retraction and extension solenoid valve and the hydraulic control valve integrated with itself to form a complete damping oil circuit, resulting in insufficient functional independence. Summary of the invention

[0007] The technical problem to be solved by the present invention is that, in view of the shortcomings of the existing frame stabilization buffer actuating device, which has a low degree of integration and a complex structure, the present invention provides a high-reliability and multifunctional integrated frame stabilization buffer actuating device. When the landing gear is retracted, the landing gear frame crossbeam and the buffer pillar are at a certain angle and are retracted into the landing gear compartment in a correct posture, thereby reducing the storage space occupied by the landing gear and facilitating the optimization of the landing gear structure layout; when the aircraft takes off, lands and taxis, it can provide dynamic buffering to suppress the high-frequency longitudinal swing of the frame, thereby improving the passability of the aircraft on the ground and increasing the service life of the landing gear frame.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is:

[0009] A highly reliable integrated frame stabilization buffer actuating device comprises a hollow outer cylinder, a piston rod, a front floating piston, and a rear floating piston. One end of the piston rod is connected to the frame, and the other end is slidably installed in the outer cylinder. The front floating piston and the rear floating piston are sequentially installed in the outer cylinder in a floating manner, and the interior of the piston rod is hollow. The front floating piston, the rear floating piston and the piston rod divide the inner cavity of the actuating device into four independent cavities. The inner cavity of the piston rod forms a first cavity connected to the aircraft hydraulic system, a second cavity is formed between the front inner wall surface of the outer cylinder and the front floating piston, a third cavity is formed between the rear floating piston and the tail of the outer cylinder, and a fourth cavity is formed between the front floating piston and the rear floating piston. A liquid filling port is provided on the third cavity, and an air filling port is provided on the fourth cavity. The third cavity is connected to the second cavity through a hydraulic conduit. An integrated one-piece pipe joint is installed at one end of the hydraulic conduit, and the end diameter of the oil passage of the integrated one-piece pipe joint is larger than the middle diameter.

[0010] The outer end of the piston rod of the frame stabilizing buffering actuating device of the present invention is connected to the frame, and the interior of the piston rod is hollow and forms the first chamber connected to the aircraft hydraulic system, so the active retraction and extension of the frame can be achieved by controlling the pressure of the first chamber by the aircraft hydraulic system. In addition, the second chamber and the third chamber of the present invention are connected to form a self-sealing system independent of the hydraulic system, and the fourth chamber filled with nitrogen or compressed air is formed between the second chamber and the third chamber, and the front floating piston and the rear floating piston used to separate the second chamber, the third chamber and the fourth chamber can slide in the outer cylinder under the pressure, so that the second chamber, the third chamber and the fourth chamber can self-balance the internal pressure of the three chambers through internal pressure transmission when the horizontal state of the frame changes, that is, the pressure P2 of the second chamber = the pressure P3 of the third chamber = the pressure P4 of the fourth chamber, so that the frame can return to the horizontal state, and the neutral position of the frame is maintained, that is, the passive buffering effect of the frame is achieved. When the vehicle frame is subjected to severe external load, since the integrated one-piece pipe joint is integrated with the function of the damping valve, that is, the oil passage of the integrated one-piece pipe joint is stepped (the end diameter is larger than the middle diameter), the oil inlet diameter entering the oil passage of the integrated one-piece pipe joint is large and the middle diameter is small. The smaller middle diameter has a damping effect on the hydraulic oil. Under the action of the external load, the hydraulic oil in the second chamber enters the third chamber through the damping hole (the middle of the oil passage) of the integrated one-piece pipe joint and compresses the fourth chamber at the same time, or the hydraulic oil in the third chamber enters the second chamber through the damping hole and compresses the fourth chamber at the same time. In this way, the incompressible hydraulic oil passes through the damping hole of the integrated one-piece pipe joint at high speed to dissipate most of the external load, thereby realizing dynamic buffering of the frame.

[0011] Preferably, a system pipe joint is provided on the first chamber, and the system pipe joint is connected to the aircraft hydraulic system through a hydraulic conduit, so that the hydraulic oil of the aircraft hydraulic system enters the first chamber (active hydraulic chamber) through the hydraulic conduit, and the piston rod is driven to extend relative to the outer cylinder under the action of the hydraulic driving force. In this way, through the control of the hydraulic oil of the aircraft hydraulic system, the piston rod is extended and retracted to drive the frame to rotate around the hinge point, and the frame is placed in a predetermined retracted and extended position, realizing the retracting and lowering function of the frame.

[0012] Preferably, a vent plug is provided on the second chamber to release the air that enters the second chamber and the third chamber during the filling process, so that the second chamber and the third chamber become simple passive hydraulic chambers.

[0013] Preferably, before filling nitrogen into the IV chamber, a certain volume of No. 15 aviation hydraulic oil is filled into the IV chamber (nitrogen chamber) to effectively reduce the friction and wear of the front floating piston and the rear floating piston relative to the inner wall of the outer cylinder, and at the same time prevent corrosion of the inner wall surface of the outer cylinder, thereby ensuring more reliable operation of the first, second and third sealing rings.

[0014] Preferably, the interior of the front floating piston is hollow, the end of the piston rod is sealed and installed in the front floating piston, the first chamber is formed between the inner wall surface of the piston rod and the front floating piston, and the second chamber is formed between the outer circular surface of the piston rod and the inner wall surface of the front floating piston.

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

[0016] 1: The present invention utilizes a complementary functional design to integrate the active retraction and extension function and the passive vibration suppression function required by the frame-type landing gear stabilization and buffering actuator into a single actuator cylinder (line replaceable unit (LRU)), which has the characteristics of highly integrated functions.

[0017] 2: All components of the frame-type landing gear buffer actuation device of the present invention are mechanical structural components and connections, and have the characteristics of compact structure, high reliability, no special application restrictions, etc., and can be widely used in various large-scale frame-type landing gear systems.

[0018] 3: The frame-type landing gear buffer actuator of the present invention can provide a two-stage dynamic buffer function when realizing the vibration suppression function of the frame, wherein the first-stage dynamic buffer is a pure oil type, and when the oil passes through the damping hole of the integrated one-piece pipe joint at high speed, most of the energy is dissipated through heat, and it has the characteristics of high vibration suppression efficiency and fast response; the second-stage dynamic buffer is started for part of the energy that is not dissipated, and this part of the energy continues to push the rear floating piston to compress the gas in the IV chamber to do work, and the dynamic buffer realization process has the characteristics of large vibration suppression work at the beginning and small work at the end and self-adaptation.

[0019] 4: When the volume of the II or III chambers of the high-reliability integrated frame stabilization buffer actuator of the present invention is reduced under the action of an external load, the two chambers can exchange oil after the internal oil is damped by the integrated one-piece pipe joint. Since the oil pressure areas of the II and III chambers are not equal when the frame is subjected to tensile and compressive loads, the excess hydraulic oil discharged during the oil exchange between the two chambers can be compensated in volume by compressing the rear floating piston, and therefore there is no need to separately set up an oil compensation device or set the two chamber areas to a structure with equal oil pressure areas.

[0020] 5: Since the temperature profile of the frame landing gear is -55℃~+135℃, with the increase of temperature or factors such as violent high-frequency swing or the comprehensive influence of multiple stresses, the oil and gas in the second cavity, the third cavity and the fourth cavity generate expansion energy under high temperature conditions, and the expansion energy does work. The hydraulic oil discharged from the two hydraulic cavities compresses the front floating piston or the rear floating piston at the same time. By utilizing the compressibility of the gas, the front floating piston or the rear floating piston acts to compress the fourth cavity and realizes the equilibrium state of the second cavity, the third cavity and the fourth cavity. When in the extreme low temperature state, the oil and gas in the three cavities shrink under the low temperature state. Under the action of the gas filled inside, the gas pushes the front floating piston and the rear floating piston to move to realize the pressure balance state of the three cavities. Therefore, the present invention solves the influence of temperature on the posture maintenance of the frame, improves its environmental use mission profile and improves its mission reliability. Regardless of whether the temperature rises or falls, as long as the three are reasonably matched, the damping stability and action stability can be guaranteed, ensuring that the damping function of the actuator is not affected.

[0021] 6: The hydraulic energy when the frame is folded is used to realize the folding of the frame. When folding, the oil in the second chamber enters the third chamber and compresses the gas in the fourth chamber. The compressed gas volume realizes the energy storage when it is lowered. The stored energy can lower the frame to the lowered position when the landing gear is lowered. The hydraulic energy of the landing gear system is used to realize the self-sustaining energy for normal lowering of the frame while the landing gear frame is folded, which has the characteristics of self-sustaining energy when the frame is folded. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the composition and motion status of the frame-type landing gear mechanism.

[0024] Figure 2 It is a structural schematic diagram of the high-reliability integrated frame stabilization buffer actuating device of the present invention (neutral position).

[0025] Figure 3 for Figure 2 The corresponding schematic diagram of the frame being in a horizontal state.

[0026] Figure 4 This is a schematic diagram of the working principle of the high-reliability integrated frame stabilization and buffering actuating device of the present invention.

[0027] Figure 5 for Figure 4 Schematic diagram of the motion state when the frame is folded.

[0028] Figure 6 This is a diagram showing the working principle of the high-reliability integrated frame stabilization buffer actuator of the present invention under pressure.

[0029] Figure 7 for Figure 6 Schematic diagram of the motion state when the main rear wheel of the frame is lifted.

[0030] Figure 8 This is a diagram showing the tensile working principle of the high-reliability integrated frame stabilization and buffering actuating device of the present invention.

[0031] Fig. 9 for Figure 8 Schematic diagram of the motion state when the main front wheel of the frame is lifted.

[0032] Fig.10 This is a simplified structural diagram of an integrated pipe joint.

[0033] In the figure: 1-system pipe joint, 2-first sealing ring, 4-second sealing ring, 6-third sealing ring, 3-vent plug, 5-inflating port, 7-liquid filling port, 8-integrated one-piece pipe joint, 9-piston rod, 10-front floating piston, 12-rear floating piston, 11-outer cylinder, 13-buffer strut, 14-high-reliability integrated frame stabilization buffer actuator, 81-oil channel, 82-throttle hole, 100-frame, 110-wheel, 120-frame crossbeam, Ⅰ-Ⅰ chamber, Ⅱ-Ⅱ chamber, Ⅲ-Ⅲ chamber, Ⅳ-Ⅳ chamber, P1~P4 are the inner chamber pressures. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0035] For the convenience of description, the relative position relationship of each component, such as up, down, left, right, etc., is described according to the layout direction of the drawings in the specification, and does not limit the structure of this patent.

[0036] like Figure 1 As shown, the high-reliability integrated frame stabilization buffer actuator 14 of the present invention is installed on the landing gear in a suitable manner, an earring bolt is provided at the rear end of the outer tube 11, a spherical bearing is provided on the earring bolt, and the earring bolt of the outer tube 11 is connected to the landing gear buffer strut 13 through a high-strength bolt, and a mounting ear piece is provided on the frame cross beam 120, and the mounting ear piece is connected to the outer end of the piston rod 9 through a high-strength bolt. If necessary, the length of the earring bolt is adjusted to meet the installation requirements of the frame stabilization buffer actuator on the frame.

[0037] The high-reliability integrated frame stabilization buffer actuator 14 of the present invention, together with the frame and other components of the landing gear, constitute a frame stabilization system. When the landing gear is retracted, the high-reliability integrated frame stabilization buffer actuator 14 of the present invention makes the landing gear frame cross beam 120 and the buffer pillar 13 form a certain angle, and then retracts into the landing gear compartment in a correct posture. When the aircraft takes off, lands and taxis, the high-reliability integrated frame stabilization buffer actuator 14 of the present invention can suppress the high-frequency longitudinal swing of the frame.

[0038] like Figure 2 As shown, the high-reliability integrated frame stabilization buffer actuating device of the present invention is mainly composed of an outer tube 11, a piston rod 9, a front floating piston 10, a rear floating piston 12, an air filling port 5, a vent plug 3, a liquid filling port 7 and other main parts. One end of the piston rod 9 is connected to the frame crossbeam 120, and the other end is slidably installed in the outer tube 11 through a first sealing ring 2, and the piston rod 9 is coaxially installed with the outer tube 11. The front floating piston 10 is floatingly installed in the outer tube 11 through a second sealing ring 4, and the rear floating piston 12 is floatingly installed in the outer tube 11 through a third sealing ring 46. The interior of the piston rod 9 is hollow, and the front floating piston 10, the rear floating piston 12 and the piston rod 9 divide the internal closed space of the high-reliability integrated frame stabilization buffer actuator of the present invention into four physically independent cavities: the inner cavity of the piston rod 9 forms the first cavity, the front end inner wall surface of the outer tube 11 and the front floating piston 10 form the second cavity, the rear floating piston 12 and the tail of the outer tube 11 form the third cavity, and the front floating piston 10 and the rear floating piston 12 form the fourth cavity. The first cavity serves as an active hydraulic cavity, and a system pipe connector 1 is provided on the cavity, and the system pipe connector 1 is connected to the aircraft hydraulic system through a hydraulic conduit. The third cavity and the second cavity serve as passive hydraulic cavities, respectively, and the two are connected through a hydraulic conduit, and the filling port 7 is provided on the third cavity. An integrated pipe joint 8 is provided at one end of the hydraulic conduit. The end diameter of the oil passage 81 of the integrated pipe joint 8 is larger than the middle diameter, that is, a throttle hole 82 is provided in the middle of the oil passage 81. Fig.10 The IV cavity is used as an air cavity, and the inflation port 5 is arranged on the cavity.

[0039] In this embodiment, the front floating piston 10 is hollow inside, the end of the piston rod 9 is sealed and installed in the front floating piston 10, the first cavity is formed between the inner wall surface of the piston rod 9 and the front floating piston 10, and the second cavity is formed between the outer cylindrical surface of the piston rod 9 and the inner wall surface of the front floating piston 10. Obviously, the present invention is not limited to this form, for example, the front floating piston 10 can also be directly installed on the end of the piston rod 9.

[0040] In order to remove the gas mixed into the second chamber and the third chamber during the process of filling the second chamber and the third chamber with hydraulic oil, a vent plug 3 is provided on the second chamber.

[0041] When the high-reliability integrated frame stabilization buffer actuating device of the present invention is used, a certain volume of aviation hydraulic oil is filled into the IV cavity through the charging port 5, and then a certain pressure of dry nitrogen or compressed air is filled into the IV cavity through the charging port 5; aviation hydraulic oil is filled into the III cavity and the II cavity through the filling port 7, and the gas mixed into the II cavity and the III cavity during the filling of the II cavity and the III cavity with hydraulic oil is discharged through the vent plug 3; when the pressure P2 of the II cavity = the pressure P3 of the III cavity = the pressure P4 of the IV cavity, the landing gear frame is kept in the neutral position, that is, the wheel axle frame is in a horizontal position (such as Figure 3 As shown in the figure, when the aircraft takes off, lands and taxis, the piston rod 9, under the action of external load, drives the oil in the second and third chambers to absorb the energy of the longitudinal swing of the axle frame through the blocking effect of the integrated one-piece pipe joint 8 and the friction effect of the piston seal, thereby improving the stability of the aircraft's ground movement.

[0042] like Figure 4 As shown in FIG. 1 , when the landing gear is retracted, the system hydraulic oil enters the first chamber through the system pipe joint 1 on the piston rod 9, and the pressure P1 of the first chamber increases. Under the action of the hydraulic load, the piston rod 9 extends outward, making the volume of the second chamber smaller. The hydraulic oil in the second chamber enters the third chamber through the hydraulic conduit, and at the same time compresses the nitrogen inside the fourth chamber to do work and reserve energy. The actively extended piston rod 9 drives the frame to flip forward, and the axle frame rises to a position almost parallel to the buffer support 13, as shown in FIG. Figure 5 As shown, when the frame is in this posture, it can be retracted into the landing gear bay in a correct posture.

[0043] When the landing gear needs to be lowered, the system oil return line is connected, the compressed nitrogen releases energy to push the rear floating piston 12, the hydraulic oil in the third chamber enters the second chamber through the hydraulic conduit to push the front floating piston 10 to move rightward, and the hydraulic oil in the piston rod 9 flows back to the oil tank through the hydraulic system oil return line pipeline. Finally, under the action of the piston rod 9, the frame is restored to the neutral position, that is, the landing gear axle frame is in a horizontal state, such as Figure 3 Right side view.

[0044] like Figure 7 As shown, when the rear wheel of the landing gear is lifted, the high-reliability integrated frame stabilization buffer actuator of the present invention is subjected to a compressive load P 压 , the piston rod 9 is compressed into the outer cylinder 11 (such as Figure 6As shown in the figure, the volume of the second chamber increases, P2 decreases, and the oil in the third chamber is squeezed into the second chamber through the hydraulic conduit, while compressing the fourth chamber. In this process, the high-speed hydraulic oil is blocked by the throttle hole of the integrated one-piece pipe joint 8 to form a dynamic buffer, absorbing the energy generated by the compressive load P. When the compressive load P disappears, the nitrogen in the fourth chamber releases energy, squeezing the oil from the second chamber back to the third chamber, so that the landing gear frame stabilization buffer actuator returns to the neutral position, as shown in the figure. Figure 3 shown.

[0045] like Fig. 9 As shown, when the front wheel of the landing gear is lifted, the frame stabilizing buffer actuator of the present invention is subjected to a tensile load P 拉 , the piston rod 9 is stretched out of the outer tube (such as Figure 8 As shown in the figure, the volume of the second chamber decreases, P2 increases, and the hydraulic oil enters the third chamber after dissipating most of the energy through the throttle hole of the integrated pipe joint 8 and compresses the nitrogen in the fourth chamber to do work. In this way, a dynamic buffer is formed through the blocking effect of the oil to absorb the pulling load P. 拉 Energy generated. When pulling towards load P 拉 After disappearing, the nitrogen in the IV chamber releases energy, pushing the oil from the III chamber back to the II chamber, thereby returning the frame stabilization buffer actuator to the neutral position. Figure 3 shown.

[0046] The above is only a specific implementation scheme of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art can make many possible changes and modifications to the technical scheme of the present invention by using the technical content disclosed above without departing from the scope of the technical scheme of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical scheme of the present invention should fall within the protection scope of the technical scheme of the present invention.

Claims

1. A highly reliable integrated frame stabilization buffer actuating device, comprising a hollow outer cylinder (11), a piston rod (9), a front floating piston (10), and a rear floating piston (12), characterized in that: One end of the piston rod is connected to the vehicle frame, and the other end is slidably installed in the outer tube. The front floating piston and the rear floating piston are floatingly installed in the outer tube in sequence, and the interiors of the piston rod and the front floating piston are hollow. The end of the piston rod is sealed and installed in the front floating piston. The front floating piston, the rear floating piston and the piston rod divide the inner cavity of the actuating device into four independent cavities. The inner cavity of the piston rod and the bottom surfaces of the piston rod and the front floating piston form the first cavity connected to the aircraft hydraulic system. The outer cylindrical surface of the piston rod is connected to the front A second chamber is formed between the inner wall surface of the front floating piston and the outer wall surface of the front floating piston and the inner wall surface of the front end of the outer tube, a third chamber is formed between the rear floating piston and the tail of the outer tube, and a fourth chamber is formed between the front floating piston and the rear floating piston. A liquid filling port (7) is provided on the third chamber, and an air filling port (5) is provided on the fourth chamber. The third chamber is connected to the second chamber via a hydraulic conduit. An integrated pipe joint (8) is provided at one end of the hydraulic conduit. The end diameter of the oil passage of the integrated pipe joint is larger than the middle diameter.

2. The high-reliability integrated frame stabilization buffer actuator according to claim 1, characterized in that: The first chamber is provided with a system pipe joint (1), and the system pipe joint is connected to the aircraft hydraulic system via a hydraulic conduit.

3. The high-reliability integrated frame stabilization buffer actuator according to claim 1, characterized in that: The second cavity is provided with a venting plug (3).

4. The high-reliability integrated frame stabilization buffer actuator according to claim 1, characterized in that: The IV cavity is filled with a certain volume of aviation hydraulic oil.

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