A single-strut six-wheel landing gear support loading system and method

Abstract

This application belongs to the field of aircraft structural strength tests, and particularly relates to a single-strut six-wheel landing gear support loading system and method. The system includes: 6 oil-gas spring bearing units, 6 integrated modules, and 5 connected oil circuits. The single-strut six-wheel landing gear support loading system and method of this application can achieve the support loading of the landing gear in the aircraft structural strength test in the form of a single-strut six-wheel landing gear. By setting an oil-gas spring bearing unit for each dummy wheel, independent loading can be achieved, and after being coupled in a reasonable manner, a statically determinate support system that resists pitching oscillation can be formed.

Description

Technical Field

[0001] This application belongs to the field of aircraft structural strength tests, and particularly relates to a single-strut six-wheel landing gear support loading system and method. Background Art

[0002] In full-scale aircraft structural strength tests, a reasonable test support method is a basic condition for carrying out strength tests. Landing gears with relatively high strength and stiffness are the most common support parts and are also convenient for simulating aircraft load conditions. The full-aircraft test support requires static support with six-direction constraints, and the vertical support points must be three. Currently in China, for the support of multi-wheel landing gears, the combined crowbar-column method and the oil cylinder connection method are usually used to form a support point. The existing main landing gear support methods are mainly applied to multi-strut multi-wheel landing gears with single-strut two wheels, and there is a lack of shock mitigation during emergency unloading. When the impact load is too large, it may cause damage to the test piece. For the landing gear structure of a single-strut six-wheel trolley type, in the connection condition between the landing gear and the fuselage, active loads need to be applied at each dummy wheel. The existing support methods cannot apply the required loads to each wheel, which requires replacing the loading device, greatly increasing the test workload and also increasing the risk of collision with the frame during aircraft attitude adjustment.

[0003] Therefore, it is desirable to have a technical solution to overcome or at least mitigate at least one of the above-mentioned defects of the prior art. Summary of the Invention

[0004] The purpose of this application is to provide a single-strut six-wheel landing gear support loading system and method to solve at least one problem existing in the prior art.

[0005] The technical solution of this application is as follows:

[0006] The first aspect of this application provides a single-strut six-wheel landing gear support loading system, including:

[0007] An oil-gas spring bearing unit, the oil-gas spring bearing unit has cavity A, cavity B, cavity C, and cavity D, and the oil-gas spring bearing unit includes 6, wherein,

[0008] The first oil-gas spring bearing unit is connected to the left dummy wheel of the front axle of the landing gear dummy;

[0009] The second oil-gas spring bearing unit is connected to the right dummy wheel of the front axle of the landing gear dummy;

[0010] The third oil-gas spring bearing unit is connected to the left dummy wheel of the middle axle of the landing gear dummy;

[0011] The fourth oil-gas spring bearing unit is connected to the right dummy wheel of the middle axle of the landing gear dummy;

[0012] The fifth oil-gas spring bearing unit is connected to the left false wheel of the rear axle of the landing gear dummy;

[0013] The sixth oil-gas spring bearing unit is connected to the right false wheel of the rear axle of the landing gear dummy;

[0014] An integrated module, the integrated module has a first inlet and outlet oil circuit, a second inlet and outlet oil circuit, and a third inlet and outlet oil circuit. There are 6 integrated modules, among which,

[0015] The first inlet and outlet oil circuit of the first integrated module is communicated with chamber A of the first oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the first oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the first oil-gas spring bearing unit;

[0016] The first inlet and outlet oil circuit of the second integrated module is communicated with chamber A of the second oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the second oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the second oil-gas spring bearing unit;

[0017] The first inlet and outlet oil circuit of the third integrated module is communicated with chamber A of the third oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the third oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the third oil-gas spring bearing unit;

[0018] The first inlet and outlet oil circuit of the fourth integrated module is communicated with chamber A of the fourth oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the fourth oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the fourth oil-gas spring bearing unit;

[0019] The first inlet and outlet oil circuit of the fifth integrated module is communicated with chamber A of the fifth oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the fifth oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the fifth oil-gas spring bearing unit;

[0020] The first inlet and outlet oil circuit of the sixth integrated module is communicated with chamber A of the sixth oil-gas spring bearing unit, the second inlet and outlet oil circuit is communicated with chamber B of the sixth oil-gas spring bearing unit, and the third inlet and outlet oil circuit is communicated with chamber D of the sixth oil-gas spring bearing unit;

[0021] A connecting oil circuit, including a first connecting oil circuit, a second connecting oil circuit, a third connecting oil circuit, a fourth connecting oil circuit, and a fifth connecting oil circuit. Among them,

[0022] The first connecting oil circuit respectively connects chamber A of the first oil-gas spring bearing unit, chamber B of the fourth oil-gas spring bearing unit, and chamber B of the sixth oil-gas spring bearing unit. A ball valve is provided on the first connecting oil circuit;

[0023] The second connecting oil passage communicates the cavity B of the first oil-gas spring bearing unit, the cavity A of the fourth oil-gas spring bearing unit, and the cavity A of the sixth oil-gas spring bearing unit with each other, and a ball valve is provided on the second connecting oil passage;

[0024] The third connecting oil passage communicates the cavity A of the second oil-gas spring bearing unit, the cavity B of the third oil-gas spring bearing unit, and the cavity B of the fifth oil-gas spring bearing unit with each other, and a ball valve is provided on the third connecting oil passage;

[0025] The fourth connecting oil passage communicates the cavity B of the second oil-gas spring bearing unit, the cavity A of the third oil-gas spring bearing unit, and the cavity A of the fifth oil-gas spring bearing unit with each other, and a ball valve is provided on the fourth connecting oil passage;

[0026] The fifth connecting oil passage communicates the cavity D of the first oil-gas spring bearing unit, the cavity D of the second oil-gas spring bearing unit, the cavity D of the third oil-gas spring bearing unit, the cavity D of the fourth oil-gas spring bearing unit, the cavity D of the fifth oil-gas spring bearing unit, and the cavity D of the sixth oil-gas spring bearing unit with each other, and a ball valve is provided on the fifth connecting oil passage.

[0027] In at least one embodiment of the present application, the oil-gas spring bearing unit includes:

[0028] A cylinder body, in which two partition plates are provided, and the two partition plates divide the interior of the cylinder body into three cavities, namely a first cavity, a second cavity, and a third cavity;

[0029] A piston, including a first piston and a second piston, the first piston is arranged in the first cavity and divides the first cavity into a cavity A and a cavity B, and the second piston is arranged in the second cavity and divides the second cavity into a cavity C and a cavity D;

[0030] A piston rod, one end of the piston rod is respectively connected to the first piston and the second piston, and the other end is correspondingly connected to the false wheel of the landing gear dummy;

[0031] A bearing unit oil passage, one end of the bearing unit oil passage is communicated with the cavity D, and the other end is connected to an accumulator, and a ball valve, a one-way throttle valve, and an electro-control reversing valve are provided on the bearing unit oil passage;

[0032] Wherein, the cavity A, the cavity B, and the cavity D are filled with oil, and the cavity C is communicated with the atmosphere.

[0033] In at least one embodiment of the present application, a displacement sensor is installed on the piston rod.

[0034] In at least one embodiment of the present application, in the integrated module:

[0035] The first inlet / outlet oil circuit includes a first inlet / outlet main oil circuit and two parallel first inlet / outlet branch oil circuits. One end of the first inlet / outlet main oil circuit is connected to chamber A, and the other end is connected to the two parallel first inlet / outlet branch oil circuits. Among them, a hydraulic control directional valve and a servo valve are arranged on one first inlet / outlet branch oil circuit, and this first inlet / outlet branch oil circuit is respectively connected to the high-pressure oil circuit and the low-pressure oil circuit. A hydraulic control directional valve and a one-way throttle valve are arranged on the other first inlet / outlet branch oil circuit, and this first inlet / outlet branch oil circuit is connected to the low-pressure oil circuit;

[0036] The second inlet / outlet oil circuit includes a second inlet / outlet main oil circuit and two parallel second inlet / outlet branch oil circuits. One end of the second inlet / outlet main oil circuit is connected to chamber B, and the other end is connected to the two parallel second inlet / outlet branch oil circuits. Among them, a hydraulic control directional valve and a servo valve are arranged on one second inlet / outlet branch oil circuit, and this second inlet / outlet branch oil circuit is respectively connected to the high-pressure oil circuit and the low-pressure oil circuit. A hydraulic control directional valve and a one-way throttle valve are arranged on the other second inlet / outlet branch oil circuit, and this second inlet / outlet branch oil circuit is connected to the low-pressure oil circuit;

[0037] One end of the third inlet / outlet oil circuit is connected to chamber D, and the other end is connected to the low-pressure oil circuit. A one-way throttle valve is arranged on the third inlet / outlet oil circuit.

[0038] In at least one embodiment of the present application, the integrated module further includes a hydraulic control oil circuit for the directional valve. One end of the hydraulic control oil circuit for the directional valve is respectively connected to each hydraulic control directional valve in the first inlet / outlet oil circuit and the second inlet / outlet oil circuit, and the other end is respectively connected to the high-pressure oil circuit and the low-pressure oil circuit. An electrically controlled directional valve is arranged on the hydraulic control oil circuit for the directional valve.

[0039] The second aspect of the present application provides a method for supporting and loading a single-strut six-wheel landing gear, based on the single-strut six-wheel landing gear support and loading system as described above, including:

[0040] In the height adjustment mode: Close the ball valves on the bearing unit oil circuit and the connecting oil circuit of the oil-gas spring bearing unit, control the inlet / outlet oil circuit of the integrated module to fill or drain oil from chambers A and B, and at the same time control the bearing unit oil circuit of the oil-gas spring bearing unit to fill or drain oil from chamber D, so as to adjust the piston rod extension amount to a predetermined position. After the adjustment is completed, power off the integrated module and cut off the inlet / outlet oil circuit of the integrated module;

[0041] In the shutdown mode: Close the ball valve on the bearing unit oil circuit of the oil-gas spring bearing unit, open the ball valve on the connecting oil circuit. After the adjustment is completed, power off the electrically controlled directional valve on the bearing unit oil circuit of the oil-gas spring bearing unit and the integrated module, and cut off the inlet / outlet oil circuit of the integrated module;

[0042] In the support mode: Power off the electro-control reversing valve and the integrated module on the bearing unit oil circuit of the oil-gas spring bearing unit, open the ball valves on the bearing unit oil circuit and the connecting oil circuit of the oil-gas spring bearing unit, connect the cavities D of the six oil-gas spring bearing units, connect the cavities A and B between the oil-gas spring bearing units of the middle axle and the rear axle in parallel, and then connect them diagonally and crosswise with the cavities A and B of the oil-gas spring bearing unit of the front axle to achieve static support;

[0043] In the loading mode: Close the ball valve on the bearing unit oil circuit of the oil-gas spring bearing unit. The electro-control reversing valve on the bearing unit oil circuit of the oil-gas spring bearing unit does not work. The cavity D is always connected to the inlet and outlet oil circuits of the integrated module through a one-way throttle valve. Control the inlet and outlet oil circuits of the integrated module to fill or drain oil from the cavities A and B to achieve active loading of the landing gear.

[0044] In at least one embodiment of the present application, in the support mode, when an emergency unloading occurs, power off and connect the electro-control reversing valve on the bearing unit oil circuit of the oil-gas spring bearing unit. The accumulator mitigates the load impact, and the oil fluid consumes the impact energy through the one-way throttle valve to maximize the protection of the test piece safety.

[0045] In at least one embodiment of the present application, in the loading mode, when an emergency unloading occurs, control the inlet and outlet oil circuits of the integrated module to drain oil from the cavities A and B to complete the unloading.

[0046] The invention has at least the following beneficial technical effects:

[0047] The support and loading system of the single-strut six-wheel landing gear of the present application can simultaneously meet the support and independent loading requirements of each wheel of the single-strut six-wheel trolley landing gear, and has functions such as attitude adjustment, buffering emergency unloading impact, and eliminating pitch oscillation, which can greatly reduce the replacement workload in the test and maximize the protection of the test piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a schematic diagram of the support distribution form of the single-strut six-wheel landing gear in an embodiment of the present application;

[0049] Figure 2 is a schematic diagram of the oil-gas spring bearing unit in an embodiment of the present application;

[0050] Figure 3 is a schematic diagram of the support and loading system of the single-strut six-wheel landing gear in an embodiment of the present application.

[0051] Wherein:

[0052] 1 - piston rod; 2 - displacement sensor; 3 - cylinder body; 4 - piston; 5 - ball valve; 6 - one-way throttle valve; 7 - electro-control reversing valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] To make the purpose, technical solutions, and advantages of the present application more clear, the following will describe the technical solutions in the embodiments of the present application in more detail in combination with the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application. The following will describe the embodiments of the present application in detail in combination with the accompanying drawings.

[0054] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of the present application.

[0055] The following will further describe the present application in detail in combination with the attached Figures 1 to 3 drawings.

[0056] The first aspect of the present application provides a single-strut six-wheel landing gear support loading system, including: 6 oil-gas spring bearing units, 6 integrated modules, and 5 connecting oil circuits.

[0057] Specifically, the oil-gas spring bearing unit has cavities A, B, C, and D. Among them, the first oil-gas spring bearing unit is connected to the left false wheel of the front axle of the landing gear dummy; the second oil-gas spring bearing unit is connected to the right false wheel of the front axle of the landing gear dummy; the third oil-gas spring bearing unit is connected to the left false wheel of the middle axle of the landing gear dummy; the fourth oil-gas spring bearing unit is connected to the right false wheel of the middle axle of the landing gear dummy; the fifth oil-gas spring bearing unit is connected to the left false wheel of the rear axle of the landing gear dummy; the sixth oil-gas spring bearing unit is connected to the right false wheel of the rear axle of the landing gear dummy. Each oil-gas spring bearing unit is respectively connected to a false wheel.

[0058] The integrated module has a first inlet / outlet oil path, a second inlet / outlet oil path, and a third inlet / outlet oil path. There are 6 integrated modules. Among them, the first inlet / outlet oil path of the first integrated module is connected to chamber A of the first hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the first hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the first hydro-pneumatic spring bearing unit; the first inlet / outlet oil path of the second integrated module is connected to chamber A of the second hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the second hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the second hydro-pneumatic spring bearing unit; the first inlet / outlet oil path of the third integrated module is connected to chamber A of the third hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the third hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the third hydro-pneumatic spring bearing unit; the first inlet / outlet oil path of the fourth integrated module is connected to chamber A of the fourth hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the fourth hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the fourth hydro-pneumatic spring bearing unit; the first inlet / outlet oil path of the fifth integrated module is connected to chamber A of the fifth hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the fifth hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the fifth hydro-pneumatic spring bearing unit; the first inlet / outlet oil path of the sixth integrated module is connected to chamber A of the sixth hydro-pneumatic spring bearing unit, the second inlet / outlet oil path is connected to chamber B of the sixth hydro-pneumatic spring bearing unit, and the third inlet / outlet oil path is connected to chamber D of the sixth hydro-pneumatic spring bearing unit.

[0059] The connected oil paths include a first connected oil path, a second connected oil path, a third connected oil path, a fourth connected oil path, and a fifth connected oil path. Among them, the first connected oil path connects chamber A of the first hydro-pneumatic spring bearing unit, chamber B of the fourth hydro-pneumatic spring bearing unit, and chamber B of the sixth hydro-pneumatic spring bearing unit to each other, and a ball valve is provided on the first connected oil path; the second connected oil path connects chamber B of the first hydro-pneumatic spring bearing unit, chamber A of the fourth hydro-pneumatic spring bearing unit, and chamber A of the sixth hydro-pneumatic spring bearing unit to each other, and a ball valve is provided on the second connected oil path; the third connected oil path connects chamber A of the second hydro-pneumatic spring bearing unit, chamber B of the third hydro-pneumatic spring bearing unit, and chamber B of the fifth hydro-pneumatic spring bearing unit to each other, and a ball valve is provided on the third connected oil path; the fourth connected oil path connects chamber B of the second hydro-pneumatic spring bearing unit, chamber A of the third hydro-pneumatic spring bearing unit, and chamber A of the fifth hydro-pneumatic spring bearing unit to each other, and a ball valve is provided on the fourth connected oil path; the fifth connected oil path connects chamber D of the first hydro-pneumatic spring bearing unit, chamber D of the second hydro-pneumatic spring bearing unit, chamber D of the third hydro-pneumatic spring bearing unit, chamber D of the fourth hydro-pneumatic spring bearing unit, chamber D of the fifth hydro-pneumatic spring bearing unit, and chamber D of the sixth hydro-pneumatic spring bearing unit to each other, and a ball valve is provided on the fifth connected oil path.

[0060] In a preferred embodiment of the present application, as Figure 2 shown, the oil-gas spring bearing unit includes: a cylinder 3, a piston 4, a piston rod 1, and a bearing unit oil circuit. Among them, two partitions are provided in the cylinder 3, and the two partitions divide the interior of the cylinder 3 into three cavities, namely a first cavity, a second cavity, and a third cavity; the piston 4 includes a first piston and a second piston. The first piston is arranged in the first cavity and divides the first cavity into cavity A and cavity B. The second piston is arranged in the second cavity and divides the second cavity into cavity C and cavity D; a displacement sensor 2 is installed on the piston rod 1 for monitoring the displacement of the landing gear. One end of the piston rod 1 is respectively connected to the first piston and the second piston, and the other end is connected to the corresponding false wheel of the landing gear false part to transmit the load; one end of the bearing unit oil circuit is communicated with cavity D, and the other end is connected to an accumulator 8. A ball valve 5, a one-way throttle valve 6, and an electro-hydraulic reversing valve 7 are arranged on the bearing unit oil circuit; among them, the cavities A, B, and D are filled with oil, and the cavity C is communicated with the atmosphere. The ball valve 5 is used for opening and closing the oil circuit, and the one-way throttle valve 6 and the electro-hydraulic reversing valve 7 cooperate to realize the transmission of air pressure and shock mitigation between the cavity D and the accumulator 8, and the cavity C can ensure the adjustment stroke and avoid pressure buildup.

[0061] In a preferred embodiment of the present application, as Figure 3 shown, the first inlet and outlet oil circuit of the integrated module includes a first inlet and outlet main oil circuit and two parallel first inlet and outlet branch oil circuits. One end of the first inlet and outlet main oil circuit is communicated with the cavity A, and the other end is communicated with the two parallel first inlet and outlet branch oil circuits. Among them, a hydraulic control reversing valve and a servo valve are arranged on one first inlet and outlet branch oil circuit, and this first inlet and outlet branch oil circuit is respectively communicated with a high-pressure oil circuit and a low-pressure oil circuit. A hydraulic control reversing valve and a one-way throttle valve are arranged on the other first inlet and outlet branch oil circuit, and this first inlet and outlet branch oil circuit is communicated with the low-pressure oil circuit; the second inlet and outlet oil circuit includes a second inlet and outlet main oil circuit and two parallel second inlet and outlet branch oil circuits. One end of the second inlet and outlet main oil circuit is communicated with the cavity B, and the other end is communicated with the two parallel second inlet and outlet branch oil circuits. Among them, a hydraulic control reversing valve and a servo valve are arranged on one second inlet and outlet branch oil circuit, and this second inlet and outlet branch oil circuit is respectively communicated with a high-pressure oil circuit and a low-pressure oil circuit. A hydraulic control reversing valve and a one-way throttle valve are arranged on the other second inlet and outlet branch oil circuit, and this second inlet and outlet branch oil circuit is communicated with the low-pressure oil circuit; one end of the third inlet and outlet oil circuit is communicated with the cavity D, and the other end is communicated with the low-pressure oil circuit. A one-way throttle valve is arranged on the third inlet and outlet oil circuit. In this embodiment, the integrated module further includes a hydraulic control oil circuit for the reversing valve. One end of the hydraulic control oil circuit for the reversing valve is respectively connected to each hydraulic control reversing valve in the first inlet and outlet oil circuit and the second inlet and outlet oil circuit, and the other end is respectively communicated with the high-pressure oil circuit and the low-pressure oil circuit. An electro-hydraulic reversing valve is arranged on the hydraulic control oil circuit for the reversing valve.

[0062] The single-strut six-wheel landing gear support loading system of the present application uses an oil-gas spring as the load-bearing and loading unit. The oil-gas spring load-bearing unit adopts a specially designed oil cylinder structure. Two liquid-filled rod chambers (chamber A, chamber B) mainly achieve loading, and a rod chamber (chamber C) communicating with the atmosphere ensures the movement stroke of the piston rod. The rodless chamber (chamber D) bears the load when in support and does not function during loading. The high-pressure gas chamber of the accumulator 8 is initially filled with high-pressure inert gas at the required pressure, and after being controlled by an electro-hydraulic reversing valve to communicate with the oil cylinder, it realizes the load impact during buffer emergency unloading. During loading, each oil-gas spring load-bearing unit is independent. When in support, the oil-gas spring load-bearing units in the front and rear parts of the landing gear strut are internally paralleled respectively, and then diagonally cross-connected to achieve statically determinate support and eliminate pitching oscillation. The principle of the interconnected support loading system of the oil-gas spring load-bearing unit of the single-strut six-wheel landing gear is as Figure 3 shown.

[0063] The second aspect of the present application provides a method for supporting and loading a single-strut six-wheel landing gear. Based on the above single-strut six-wheel landing gear support loading system, it includes:

[0064] In the height adjustment mode: close the ball valves on the load-bearing unit oil circuit and the connecting oil circuit of the oil-gas spring load-bearing unit, control the inlet and outlet oil circuits of the integrated module to fill or drain oil from chambers A and B, and at the same time, fill or drain oil from chamber D through the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, so as to adjust the piston rod extension amount to a predetermined position. After the adjustment is completed, power off the integrated module and cut off the inlet and outlet oil circuits of the integrated module;

[0065] In the shutdown mode: close the ball valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, open the ball valve on the connecting oil circuit, and after the adjustment is completed, power off the electro-hydraulic reversing valve and the integrated module on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, and cut off the inlet and outlet oil circuits of the integrated module;

[0066] In the support mode: power off the electro-hydraulic reversing valve and the integrated module on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, open the ball valves on the load-bearing unit oil circuit and the connecting oil circuit of the oil-gas spring load-bearing unit, connect chambers D of the six oil-gas spring load-bearing units, parallel chambers A and B between the oil-gas spring load-bearing units of the middle axle and the rear axle, and then diagonally cross-connect them with chambers A and B of the oil-gas spring load-bearing unit of the front axle to achieve statically determinate support; in the support mode, when an emergency unloading occurs, power off and connect the electro-hydraulic reversing valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, the accumulator mitigates the load impact, and the oil fluid consumes the impact energy through the one-way throttle valve to protect the test piece safety to the greatest extent.

[0067] In the loading mode: close the ball valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit. The electro-controlled reversing valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit becomes inoperative. Chamber D is always connected to the inlet and outlet oil circuits of the integrated module through the one-way throttle valve. Control the inlet and outlet oil circuits of the integrated module to fill or drain oil from Chambers A and B to achieve active loading of the landing gear. When emergency unloading occurs, control the inlet and outlet oil circuits of the integrated module to drain oil from Chambers A and B to complete the unloading.

[0068] For the single-strut six-wheel landing gear support loading method of this application, when the height needs to be adjusted, close all ball valves. In the position control mode, control the integrated module to fill or drain oil from Chambers A and B, and at the same time fill or drain oil from Chamber D through the one-way throttle valve to adjust the piston rod extension to the required position. After the adjustment is completed, the integrated module is powered off and the inlet and outlet oil circuits are cut off. In the shutdown state, close ball valves ①-⑥, open the remaining ball valves, and all electro-controlled reversing valves are powered off, and the inlet and outlet oil of the integrated module is disconnected. In the support state, the inlet and outlet oil circuits of the integrated module are disconnected and inoperative. The electro-controlled reversing valve DT1 is in the energized closed state, and all ball valves are opened. The oil-gas spring load-bearing unit Chamber D is connected. The Chambers A and B between the oil-gas spring load-bearing units on the same side of the rear four wheels of the landing gear strut are connected in parallel, and then diagonally cross-connected with the Chambers A and B of the oil-gas spring load-bearing unit in front of the landing gear strut to achieve static support and eliminate pitch oscillation. Once emergency unloading occurs during the support process, the electro-controlled reversing valve DT1 is powered off and connected. The accumulator 8 mitigates the load impact, and the oil fluid consumes the impact energy through the one-way throttle valve to protect the test piece safety to the greatest extent. When applying an active load, close all ball valves. The electro-controlled reversing valve DT1 is inoperative. Chamber D is always connected to the return oil through the one-way throttle valve. DAT2 and DAT3 (or DAT4) in the integrated module are energized. The high-pressure oil controls the four hydraulic control reversing valves 1-1, 1-2, 2-1, and 2-2 to reverse. The high and low pressure oil hydraulic control reversing valves 2-1 and 2-2 enter Chambers A and B respectively to complete the active loading of the landing gear in the force control mode. When emergency unloading occurs, the electro-controlled reversing valves DT2 and DAT3 (or DAT4) are powered off and closed. The four hydraulic control reversing valves return to their initial positions under the action of the spring force. Chambers A and B are connected to the return oil through the hydraulic control reversing valves 1-1, 1-2 and the one-way throttle valve to complete the unloading.

[0069] The single-strut six-wheel landing gear support loading system and method of the present application can achieve landing gear support loading in the aircraft structural strength test of the single-strut six-wheel landing gear form. By setting an oil-gas spring bearing unit for each dummy wheel, independent loading can be achieved. After being coupled in a reasonable manner, a statically determinate support system that resists pitch oscillation can be formed. The present application has both the functions of test support and loading and can be quickly switched. The internal coupling of the system ensures statically determinate support and can effectively eliminate the change of the pitching moment before and after the landing gear strut and avoid pitch oscillation; it can effectively absorb the load impact during emergency unloading and attenuate energy, and can absorb the impact of the entire test system on the support point structure at the moment of emergency unloading to ensure the safety of the test piece structure; it can accurately adjust the aircraft attitude according to requirements; it can be conveniently extended and applied to other single-strut multi-wheel landing gear structures.

[0070] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A single-strut six-wheel landing gear support loading system, characterized in that, Including: An oil-gas spring load-bearing unit, which has cavities A, B, C, and D. There are 6 oil-gas spring load-bearing units, among which, The first oil-gas spring load-bearing unit is connected to the left false wheel of the front axle of the landing gear dummy; The second oil-gas spring load-bearing unit is connected to the right false wheel of the front axle of the landing gear dummy; The third oil-gas spring load-bearing unit is connected to the left false wheel of the middle axle of the landing gear dummy; The fourth oil-gas spring load-bearing unit is connected to the right false wheel of the middle axle of the landing gear dummy; The fifth oil-gas spring load-bearing unit is connected to the left false wheel of the rear axle of the landing gear dummy; The sixth oil-gas spring load-bearing unit is connected to the right false wheel of the rear axle of the landing gear dummy; An integrated module, which has a first inlet / outlet oil path, a second inlet / outlet oil path, and a third inlet / outlet oil path. There are 6 integrated modules, among which, The first inlet / outlet oil path of the first integrated module is communicated with cavity A of the first oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the first oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the first oil-gas spring load-bearing unit; The first inlet / outlet oil path of the second integrated module is communicated with cavity A of the second oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the second oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the second oil-gas spring load-bearing unit; The first inlet / outlet oil path of the third integrated module is communicated with cavity A of the third oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the third oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the third oil-gas spring load-bearing unit; The first inlet / outlet oil path of the fourth integrated module is communicated with cavity A of the fourth oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the fourth oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the fourth oil-gas spring load-bearing unit; The first inlet / outlet oil path of the fifth integrated module is communicated with cavity A of the fifth oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the fifth oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the fifth oil-gas spring load-bearing unit; The first inlet / outlet oil path of the sixth integrated module is communicated with cavity A of the sixth oil-gas spring load-bearing unit, the second inlet / outlet oil path is communicated with cavity B of the sixth oil-gas spring load-bearing unit, and the third inlet / outlet oil path is communicated with cavity D of the sixth oil-gas spring load-bearing unit; A connecting oil path, including a first connecting oil path, a second connecting oil path, a third connecting oil path, a fourth connecting oil path, and a fifth connecting oil path. Among them, The first connecting oil path connects cavity A of the first oil-gas spring load-bearing unit, cavity B of the fourth oil-gas spring load-bearing unit, and cavity B of the sixth oil-gas spring load-bearing unit to each other, and a ball valve is provided on the first connecting oil path; The second connecting oil path connects cavity B of the first oil-gas spring load-bearing unit, cavity A of the fourth oil-gas spring load-bearing unit, and cavity A of the sixth oil-gas spring load-bearing unit to each other, and a ball valve is provided on the second connecting oil path; The third connecting oil passage communicates the cavity A of the second hydro-pneumatic spring bearing unit, the cavity B of the third hydro-pneumatic spring bearing unit, and the cavity B of the fifth hydro-pneumatic spring bearing unit with each other, and a ball valve is provided on the third connecting oil passage; The fourth connecting oil passage communicates the cavity B of the second hydro-pneumatic spring bearing unit, the cavity A of the third hydro-pneumatic spring bearing unit, and the cavity A of the fifth hydro-pneumatic spring bearing unit with each other, and a ball valve is provided on the fourth connecting oil passage; The fifth connecting oil passage communicates the cavity D of the first hydro-pneumatic spring bearing unit, the cavity D of the second hydro-pneumatic spring bearing unit, the cavity D of the third hydro-pneumatic spring bearing unit, the cavity D of the fourth hydro-pneumatic spring bearing unit, the cavity D of the fifth hydro-pneumatic spring bearing unit, and the cavity D of the sixth hydro-pneumatic spring bearing unit with each other, and a ball valve is provided on the fifth connecting oil passage; The hydro-pneumatic spring bearing unit includes: A cylinder body in which two partition plates are provided, and the two partition plates divide the interior of the cylinder body into three cavities, namely a first cavity, a second cavity, and a third cavity; A piston, including a first piston and a second piston. The first piston is arranged in the first cavity and divides the first cavity into a cavity A and a cavity B. The second piston is arranged in the second cavity and divides the second cavity into a cavity C and a cavity D; A piston rod, one end of which is connected to the first piston and the second piston respectively, and the other end is correspondingly connected to the false wheel of the landing gear dummy; A bearing unit oil passage, one end of which is communicated with the cavity D and the other end is connected to an accumulator. A ball valve, a one-way throttle valve, and an electro-hydraulic reversing valve are provided on the bearing unit oil passage; Wherein, the cavity A, the cavity B, and the cavity D are filled with oil, and the cavity C is communicated with the atmosphere.

2. The single-pillar six-wheel landing gear support loading system according to claim 1, characterized in that, A displacement sensor is installed on the piston rod.

3. The single strut six-wheel landing gear support loading system according to claim 2, characterized in that, In the integrated module: The first inlet and outlet oil passage includes a first inlet and outlet main oil passage and two parallel first inlet and outlet sub-oil passages. One end of the first inlet and outlet main oil passage is communicated with the cavity A, and the other end is communicated with the two parallel first inlet and outlet sub-oil passages. Among them, a liquid-controlled reversing valve and a servo valve are provided on one first inlet and outlet sub-oil passage, and this first inlet and outlet sub-oil passage is respectively communicated with a high-pressure oil passage and a low-pressure oil passage. A liquid-controlled reversing valve and a one-way throttle valve are provided on the other first inlet and outlet sub-oil passage, and this first inlet and outlet sub-oil passage is communicated with the low-pressure oil passage; The second inlet and outlet oil passage includes a second inlet and outlet main oil passage and two parallel second inlet and outlet sub-oil passages. One end of the second inlet and outlet main oil passage is communicated with the cavity B, and the other end is communicated with the two parallel second inlet and outlet sub-oil passages. Among them, a liquid-controlled reversing valve and a servo valve are provided on one second inlet and outlet sub-oil passage, and this second inlet and outlet sub-oil passage is respectively communicated with a high-pressure oil passage and a low-pressure oil passage. A liquid-controlled reversing valve and a one-way throttle valve are provided on the other second inlet and outlet sub-oil passage, and this second inlet and outlet sub-oil passage is communicated with the low-pressure oil passage; One end of the third inlet and outlet oil passage is communicated with the cavity D, and the other end is communicated with the low-pressure oil passage. A one-way throttle valve is provided on the third inlet and outlet oil passage.

4. The single-strut six-wheel landing gear support loading system according to claim 3, characterized in that, The integrated module further includes a hydraulic control oil circuit for a directional control valve. One end of the hydraulic control oil circuit for the directional control valve is respectively connected to each hydraulic control directional control valve in the first inlet / outlet oil circuit and the second inlet / outlet oil circuit, and the other end is respectively communicated with a high-pressure oil circuit and a low-pressure oil circuit. An electrically controlled directional control valve is arranged on the hydraulic control oil circuit for the directional control valve.

5. A single-strut six-wheel landing gear support loading method, based on the single-strut six-wheel landing gear support loading system described in claim 4, characterized in that, Comprising: In the height adjustment mode: close the ball valves on the load-bearing unit oil circuit and the communication oil circuit of the oil-gas spring load-bearing unit, control the inlet / outlet oil circuit of the integrated module to fill or drain oil from cavities A and B, and at the same time control the load-bearing unit oil circuit of the oil-gas spring load-bearing unit to fill or drain oil from cavity D, so as to adjust the piston rod extension amount to a predetermined position. After the adjustment is completed, power off the integrated module and cut off the inlet / outlet oil circuit of the integrated module. In the shutdown mode: close the ball valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit, open the ball valve on the communication oil circuit. After the adjustment is completed, power off the electrically controlled directional control valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit and the integrated module, and cut off the inlet / outlet oil circuit of the integrated module. In the support mode: power off the electrically controlled directional control valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit and the integrated module, open the ball valves on the load-bearing unit oil circuit and the communication oil circuit of the oil-gas spring load-bearing unit. Cavity D of the six oil-gas spring load-bearing units is communicated. Cavities A and B between the oil-gas spring load-bearing units of the middle axle and the rear axle are connected in parallel, and then diagonally cross-connected with cavities A and B of the oil-gas spring load-bearing unit of the front axle to achieve statically determinate support. In the loading mode: close the ball valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit. The electrically controlled directional control valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit is ineffective. Cavity D is always communicated with the inlet / outlet oil circuit of the integrated module through a one-way throttle valve. Control the inlet / outlet oil circuit of the integrated module to fill or drain oil from cavities A and B to achieve active loading of the landing gear.

6. The single-strut six-wheel landing gear support loading method according to claim 5, characterized in that, In the support mode, when an emergency unloading occurs, power off and connect the electrically controlled directional control valve on the load-bearing unit oil circuit of the oil-gas spring load-bearing unit. The accumulator mitigates the load impact, and the oil fluid consumes the impact energy through the one-way throttle valve to protect the test piece safety to the greatest extent.

7. The single-pillar six-wheel landing gear support loading method according to claim 5, characterized in that, In the loading mode, when an emergency unloading occurs, control the inlet / outlet oil circuit of the integrated module to drain oil from cavities A and B to complete the unloading.

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