A load-carrying unit interconnected landing gear support loading system and method

Abstract

This application relates to the field of aircraft structural strength testing, and more particularly to a landing gear support and loading system and method with interconnected load-bearing units. The system comprises three oil-pneumatic spring load-bearing units, three integrated modules, and three connecting oil circuits. The present application's interconnected load-bearing unit landing gear support and loading system and method are capable of supporting and loading landing gear in aircraft structural strength testing of single-strut, multi-wheel landing gear. Each wheel axle is equipped with a gas spring to achieve independent loading, and when coupled in a reasonable manner, a statically determinate support system that resists pitch oscillations can be formed.

Description

Technical Field

[0001] The present application relates to the field of aircraft structure strength testing, and in particular to a landing gear support loading system and method with interconnected load-bearing units. Background Art

[0002] In full-scale aircraft structural strength testing, a reasonable test support method is essential for conducting strength tests. Landing gear, with its high strength and stiffness, is the most common support component and facilitates aircraft load simulation. Full-aircraft test support requires statically determinate support in six directions, with three vertical support points. Currently, domestic support for multi-wheel landing gear typically utilizes a combined crowbar-column method and a hydraulic cylinder connection to form a single support point. Existing main landing support methods are primarily used for single-strut, two-wheel, multi-strut landing gear. These methods also lack impact mitigation during emergency unloading, potentially damaging the test piece if the impact load is excessive. For single-strut, six-wheel, trolley-type landing gear structures, active loads must be applied to each dummy wheel during the landing gear-to-fuselage connection. Existing support methods cannot achieve the required loads on each wheel and also present pitch oscillation issues. Replacing the loading device can address the test loading issue, but this significantly increases the test workload and increases the risk of collision with the frame during aircraft attitude adjustments, while oscillation issues still persist.

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

[0004] The purpose of the present application is to provide a landing gear support loading system and method with interconnected load-bearing units to solve at least one problem existing in the prior art.

[0005] The technical solution of this application is:

[0006] A first aspect of the present application provides a landing gear support loading system with interconnected load-bearing units, comprising:

[0007] A gas-oil spring bearing unit having cavity A, cavity B, cavity C, cavity D, cavity E, and cavity F. The gas-oil spring bearing unit includes a first gas-oil spring bearing unit connected to a dummy wheel on the front axle of the landing gear dummy, a second gas-oil spring bearing unit connected to a dummy wheel on the middle axle of the landing gear dummy, and a third gas-oil spring bearing unit connected to a dummy wheel on the rear axle of the landing gear dummy;

[0008] An integrated module, wherein the integrated module has a first inlet and outlet oil passage, a second inlet and outlet oil passage, and a third inlet and outlet oil passage. The integrated module includes a first integrated module, a second integrated module, and a third integrated module, wherein:

[0009] The first inlet and outlet oil circuit of the first integrated module is connected to the cavity A of the first oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the first oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the first oil and gas spring bearing unit;

[0010] The first inlet and outlet oil circuit of the second integrated module is connected to the cavity A of the second oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the second oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the second oil and gas spring bearing unit;

[0011] The first inlet and outlet oil circuit of the third integrated module is connected to the cavity A of the third oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the third oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the third oil and gas spring bearing unit;

[0012] The connecting oil passage includes a first connecting oil passage, a second connecting oil passage, and a third connecting oil passage, wherein:

[0013] The first connecting oil path connects the cavity A of the first oil-gas spring bearing unit, the cavity B of the second oil-gas spring bearing unit, and the cavity B of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the first connecting oil path;

[0014] The second connecting oil path connects the cavity B of the first oil-gas spring bearing unit, the cavity A of the second oil-gas spring bearing unit, and the cavity A of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the second connecting oil path;

[0015] The third connecting oil path connects the cavity D of the first oil-gas spring bearing unit, the cavity D of the second oil-gas spring bearing unit, and the cavity D of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the third connecting oil path.

[0016] In at least one embodiment of the present application, the oil-gas spring bearing unit includes:

[0017] A cylinder, wherein two partitions are provided in the cylinder, and the two partitions divide the interior of the cylinder into three cavities, namely a first cavity, a second cavity, and a third cavity;

[0018] A rod piston, comprising a first rod piston and a second rod piston, wherein the first rod piston is disposed in the first cavity and divides the first cavity into cavity A and cavity B, and the second rod piston is disposed in the second cavity and divides the second cavity into cavity C and cavity D;

[0019] a floating piston, the floating piston being disposed in the third cavity and dividing the third cavity into cavity E and cavity F;

[0020] a piston rod, one end of which is connected to the first rod-mounted piston and the second rod-mounted piston, respectively, and the other end of which is connected to the corresponding landing gear dummy component and dummy wheel;

[0021] The load-bearing unit oil circuit, one end of which is connected to the cavity D, and the other end is connected to the cavity E. The load-bearing unit oil circuit is provided with a ball valve, a one-way throttle valve and an electrically controlled reversing valve;

[0022] Among them, cavity A, cavity B, cavity D, and cavity E are filled with oil, cavity C is connected to the atmosphere, and cavity F is filled with high-pressure inert gas.

[0023] In at least one embodiment of the present application, a displacement sensor is installed on the piston rod.

[0024] In at least one embodiment of the present application, in the integrated module:

[0025] The first inlet and outlet oil circuit includes a first inlet and outlet main oil circuit and two first inlet and outlet branch oil circuits arranged in parallel. One end of the first inlet and outlet main oil circuit is connected to the cavity A, and the other end is connected to the two first inlet and outlet branch oil circuits arranged in parallel. One of the first inlet and outlet branch oil circuits is provided with a hydraulically controlled reversing valve and a servo valve, and the first inlet and outlet branch oil circuit is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other first inlet and outlet branch oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve, and the first inlet and outlet branch oil circuit is connected to the low-pressure oil circuit.

[0026] The second inlet and outlet oil circuit includes a second inlet and outlet main oil circuit and two second inlet and outlet branch oil circuits arranged in parallel. One end of the second inlet and outlet main oil circuit is connected to the cavity B, and the other end is connected to the two second inlet and outlet branch oil circuits arranged in parallel. One of the second inlet and outlet branch oil circuits is provided with a hydraulically controlled reversing valve and a servo valve, and the second inlet and outlet branch oil circuit is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other second inlet and outlet branch oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve, and the second inlet and outlet branch oil circuit is connected to the low-pressure oil circuit.

[0027] 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 provided on the third inlet and outlet oil circuit.

[0028] In at least one embodiment of the present application, the integrated module also includes a reversing valve hydraulic control oil circuit, one end of the reversing valve hydraulic control oil circuit is respectively connected to each hydraulically controlled reversing valve in the first inlet and outlet oil circuit and the second inlet and outlet oil circuit, and the other end is respectively connected to the high-pressure oil circuit and the low-pressure oil circuit, and an electrically controlled reversing valve is arranged on the reversing valve hydraulic control oil circuit.

[0029] A second aspect of the present application provides a method for supporting and loading a landing gear with interconnected load-bearing units, based on the above-mentioned system for supporting and loading a landing gear with interconnected load-bearing units, comprising:

[0030] In height adjustment mode: close the ball valves on the oil circuit and 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 into cavities A and B, and at the same time control the oil circuit of the oil-gas spring load-bearing unit to fill or drain oil into cavity D, thereby adjusting the piston rod extension to the 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.

[0031] In the shutdown mode: close the ball valve on the 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, cut off the power to the electronically controlled reversing valve and the integrated module on the oil circuit of the oil-gas spring load-bearing unit, and cut off the inlet and outlet oil circuits of the integrated module;

[0032] In support mode: the electronically controlled reversing valve and integrated module on the oil circuit of the oil-gas spring bearing unit are powered off, and the ball valves on the oil circuit and the connecting oil circuit of the oil-gas spring bearing unit are opened. The cavities D of the three oil-gas spring bearing units are connected, and the cavities A and B between the oil-gas spring bearing units of the center axle and the rear axle are connected in parallel. These cavities are then cross-connected with the cavities A and B of the oil-gas spring bearing unit of the front axle to achieve static support.

[0033] In loading mode: close the ball valve on the oil circuit of the oil-gas spring load-bearing unit, the electronically controlled reversing valve on the oil circuit of the oil-gas spring load-bearing unit does not work, cavity D is always connected with the inlet and outlet oil circuits of the integrated module through the one-way throttle valve, and the inlet and outlet oil circuits of the integrated module are controlled to fill or drain oil into cavities A and B to realize active loading of the landing gear.

[0034] In at least one embodiment of the present application, in the support mode, when emergency unloading occurs, the electrically controlled reversing valve on the oil circuit of the oil-gas spring bearing unit is disconnected and connected, the cavity F mitigates the load impact, and the oil consumes the impact energy through the one-way throttle valve, thereby maximizing the protection of the test piece's safety.

[0035] In at least one embodiment of the present application, in loading mode, when emergency unloading occurs, the inlet and outlet oil passages of the integrated module are controlled to drain oil from cavities A and B to complete the unloading.

[0036] The invention has at least the following beneficial technical effects:

[0037] The load-bearing unit interconnected landing gear support and loading system of the present application can simultaneously meet the support and loading requirements of each wheel of the single-pillar six-wheel trolley landing gear, and has functions such as posture adjustment, emergency unloading impact buffering, and vibration elimination. It can greatly reduce the workload of changing equipment during the test and maximize the protection of the test piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the distribution of a single-pillar six-wheel landing gear according to one embodiment of the present application;

[0039] Figure 2 This is a schematic structural diagram of an oil-gas spring bearing unit according to one embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of a landing gear support loading system with interconnected load-bearing units according to one embodiment of the present application;

[0041] in:

[0042] 1-piston rod; 2-displacement sensor; 3-cylinder; 4-rod piston; 5-floating piston; 6-ball valve; 7-one-way throttle valve; 8-electrically controlled reversing valve. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be understood as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0044] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as limiting the scope of protection of this application.

[0045] The following is combined with Figures 1 to 3 This application is described in further detail.

[0046] A first aspect of the present application provides a landing gear support loading system with interconnected load-bearing units, comprising: three oil-gas spring load-bearing units, three integrated modules, and three connecting oil circuits.

[0047] Specifically, the oil-gas spring bearing unit has six chambers: chamber A, chamber B, chamber C, chamber D, chamber E, and chamber F. The oil-gas spring bearing unit includes a first oil-gas spring bearing unit, a second oil-gas spring bearing unit, and a third oil-gas spring bearing unit. The first oil-gas spring bearing unit is connected to the dummy wheel on the front axle of the landing gear dummy, the second oil-gas spring bearing unit is connected to the dummy wheel on the center axle of the landing gear dummy, and the third oil-gas spring bearing unit is connected to the dummy wheel on the rear axle of the landing gear dummy. The front, center, and rear axles of the landing gear dummy are each equipped with two dummy wheels, which are connected to the dummy wheels of the front, center, and rear axles via three oil-gas spring bearing units.

[0048] 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. The integrated module includes a first integrated module, a second integrated module, and a third integrated module, wherein the first inlet and outlet oil circuit of the first integrated module is connected to the cavity A of the first oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the first oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the first oil and gas spring bearing unit; the first inlet and outlet oil circuit of the second integrated module is connected to the cavity A of the second oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the second oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the second oil and gas spring bearing unit; the first inlet and outlet oil circuit of the third integrated module is connected to the cavity A of the third oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the third oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the third oil and gas spring bearing unit.

[0049] The connecting oil circuit includes a first connecting oil circuit, a second connecting oil circuit, and a third connecting oil circuit, wherein the first connecting oil circuit respectively connects the cavity A of the first oil and gas spring bearing unit, the cavity B of the second oil and gas spring bearing unit, and the cavity B of the third oil and gas spring bearing unit to each other, and a ball valve is provided on the first connecting oil circuit; the second connecting oil circuit respectively connects the cavity B of the first oil and gas spring bearing unit, the cavity A of the second oil and gas spring bearing unit, and the cavity A of the third oil and gas spring bearing unit to each other, and a ball valve is provided on the second connecting oil circuit; the third connecting oil circuit respectively connects the cavity D of the first oil and gas spring bearing unit, the cavity D of the second oil and gas spring bearing unit, and the cavity D of the third oil and gas spring bearing unit to each other, and a ball valve is provided on the third connecting oil circuit.

[0050] In a preferred embodiment of the present application, Figure 2As shown, the oil-gas spring bearing unit includes: a cylinder 3, a rod piston 4, a floating piston 5, a piston rod 1 and an oil circuit of the bearing unit, wherein two partitions are provided in the cylinder 3, and the two partitions divide the interior of the cylinder 3 into three cavities, namely the first cavity, the second cavity and the third cavity; the rod piston 4 includes a first rod piston and a second rod piston, the first rod piston is provided in the first cavity, dividing the first cavity into cavity A and cavity B, the second rod piston is provided in the second cavity, dividing the second cavity into cavity C and cavity D; the floating piston 5 is provided in the third cavity, dividing the third cavity The floating piston 5 isolates gas and oil from the landing gear. A displacement sensor 2 for monitoring landing gear displacement is mounted on the piston rod 1. One end of the piston rod 1 is connected to the first and second rod pistons, respectively, and the other end is connected to the corresponding landing gear dummy wheel, enabling load transfer. The load-bearing unit oil circuit is connected to cavity D at one end and cavity E at the other. A ball valve 6, a one-way throttle valve 7, and an electrically controlled reversing valve 8 are installed on the load-bearing unit oil circuit. Cavities A, B, D, and E are filled with oil, cavity C is connected to the atmosphere, and cavity F is filled with high-pressure inert gas. Ball valve 6 is used to open and close the oil circuit. The one-way throttle valve 7 and the electrically controlled reversing valve 8 cooperate to transfer air pressure between cavities D and E, mitigating impacts. Cavity C ensures stroke adjustment and prevents pressure buildup.

[0051] In a preferred embodiment of the present application, Figure 3 As shown, the first inlet and outlet oil circuit of the integrated module includes a first inlet and outlet main oil circuit and two first inlet and outlet branch oil circuits arranged in parallel. One end of the first inlet and outlet main oil circuit is connected to the cavity A, and the other end is connected to the two first inlet and outlet branch oil circuits arranged in parallel. Among them, a hydraulically controlled reversing valve and a servo valve are provided on one of the first inlet and outlet branch oil circuits. The first inlet and outlet branch oil circuits are connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other first inlet and outlet branch oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve. The first inlet and outlet branch oil circuit is connected to the low-pressure oil circuit; the second inlet and outlet oil circuit includes a second inlet and outlet main oil circuit and Two second inlet and outlet oil circuits are arranged in parallel. One end of the second inlet and outlet main oil circuit is connected to cavity B, and the other end is connected to the two second inlet and outlet oil circuits arranged in parallel. Among them, one second inlet and outlet oil circuit is provided with a hydraulically controlled reversing valve and a servo valve. The second inlet and outlet oil circuit is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other second inlet and outlet oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve. The second inlet and outlet oil circuit is connected to the low-pressure oil circuit. One end of the third inlet and outlet oil circuit is connected to cavity D, and the other end is connected to the low-pressure oil circuit. The third inlet and outlet oil circuit is provided with a one-way throttle valve. In addition, the integrated module also includes a reversing valve hydraulic control oil circuit. One end of the reversing valve hydraulic control oil circuit is connected to each hydraulically controlled reversing valve in the first inlet and outlet oil circuit and the second inlet and outlet oil circuit respectively, and the other end is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The reversing valve hydraulic control oil circuit is provided with an electronically controlled reversing valve.

[0052] The supporting and loading system of the landing gear of the present application with interconnected load-bearing units adopts oil-gas springs as load-bearing and loading units. The oil-gas spring load-bearing units adopt a specially designed oil cylinder structure. Two liquid-filled rod chambers (cavity A and cavity B) are mainly used for loading. One rod chamber (cavity C) connected to the atmosphere ensures the movement stroke of the piston rod. The upper rodless chamber is used for load-bearing during support and has no effect during loading. The high-pressure gas chamber (cavity F) is initially filled with high-pressure inert gas of the required pressure. After the two liquid-filled rodless chambers (cavity D and cavity E) are connected, they can buffer the load impact during emergency unloading. During loading, each oil-gas spring load-bearing unit is independent of each other. When serving as support, the oil-gas spring load-bearing units of the front and rear parts of the landing gear strut are internally connected in parallel, and then cross-connected to achieve static support and eliminate pitch oscillations. The principle of the interconnected support and loading system of the oil-gas spring load-bearing units of the single-strut six-wheel landing gear is as follows: Figure 3 As shown, the interconnection principle is that the oil and gas spring bearing unit cavities A and B of the front and rear parts of the landing gear strut are internally connected in parallel and then cross-connected.

[0053] A second aspect of the present application provides a method for supporting and loading a landing gear with interconnected load-bearing units, based on the above-mentioned system for supporting and loading a landing gear with interconnected load-bearing units, comprising:

[0054] In height adjustment mode: close the ball valves on the oil circuit and 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 into cavities A and B, and at the same time control the oil circuit of the oil-gas spring load-bearing unit to fill or drain oil into cavity D, thereby adjusting the piston rod extension to the 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.

[0055] In the shutdown mode: close the ball valve on the 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, cut off the power to the electronically controlled reversing valve and the integrated module on the oil circuit of the oil-gas spring load-bearing unit, and cut off the inlet and outlet oil circuits of the integrated module;

[0056] In support mode: the electronically controlled reversing valve and the integrated module on the bearing unit oil circuit of the oil and gas spring bearing unit are powered off, the ball valves on the bearing unit oil circuit and the connecting oil circuit of the oil and gas spring bearing unit are opened, the cavities D of the three oil and gas spring bearing units are connected, the cavities A and B between the oil and gas spring bearing units of the center axle and the rear axle are connected in parallel, and then cross-connected with the cavities A and B of the oil and gas spring bearing unit of the front axle to achieve static support; in support mode, when emergency unloading occurs, the electronically controlled reversing valve on the bearing unit oil circuit of the oil and gas spring bearing unit is powered off and connected, cavity F mitigates the load impact, and the oil consumes the impact energy through the one-way throttle valve to maximize the protection of the test piece.

[0057] In loading mode: close the ball valve on the oil circuit of the oil-gas spring load-bearing unit, the electronically controlled reversing valve on the oil circuit of the oil-gas spring load-bearing unit does not work, cavity D is always connected with the inlet and outlet oil circuits of the integrated module through the one-way throttle valve, and the inlet and outlet oil circuits of the integrated module are controlled to fill or drain oil into cavities A and B to realize active loading of the landing gear; in loading mode, when emergency unloading occurs, the inlet and outlet oil circuits of the integrated module are controlled to drain oil from cavities A and B to complete unloading.

[0058] The supporting loading method of the landing gear with interconnected load-bearing units of the present application is as follows: when the height needs to be adjusted, all ball valves are closed, and the integrated module is controlled in the position control mode to fill or drain oil into or out of cavities A and B. At the same time, cavity D is filled or drained 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, ball valves I, II, and III are closed, and the remaining ball valves are opened. All the electrically controlled reversing valves are powered off, and the inlet and outlet oil of the integrated module are disconnected. In the supporting state, the inlet and outlet oil circuits of the integrated module are disconnected and do not function. The electrically controlled reversing valve DT1 is powered on and closed, and all ball valves are opened. The cavity D of the oil-gas spring load-bearing unit is connected, and the 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 cross-connected with the cavities A and B of the oil-gas spring load-bearing unit of the front axle, thereby achieving static support and eliminating pitch oscillation. If an emergency unloading event occurs during the support process, the electronically controlled directional valve DT1 is de-energized and connected. The gas chamber mitigates the load impact, and the oil dissipates the impact energy through the one-way throttle valve, maximizing the safety of the test piece. When applying active load, all ball valves are closed, the electronically controlled directional valve DT1 is deactivated, and cavity D is always connected to the return oil via the one-way throttle valve. DAT2 and DAT3 (or DAT4) within the integrated module are energized, and high-pressure oil controls the four hydraulically controlled directional valves 1-1, 1-2, 2-1, and 2-2. High-pressure and low-pressure oil flow from hydraulically controlled directional valves 2-1 and 2-2 into cavities A and B, respectively, completing active loading of the landing gear in force-controlled mode. In the event of an emergency unloading event, the electronically controlled directional valves DT2 and DAT3 (or DAT4) are de-energized and closed. The four hydraulically controlled directional valves return to their initial positions under the action of springs, and cavities A and B are connected to the return oil via hydraulically controlled directional valves 1-1 and 1-2 and the one-way throttle valve, completing the unloading operation.

[0059] The load-bearing unit interconnected landing gear support loading system and method of the present application can realize the landing gear support loading in the aircraft structure strength test of single-pillar multi-wheel landing gear. The two dummy wheels share one axle, and each axle is provided with an oil-gas spring load-bearing unit, which can realize independent loading. After being coupled in a reasonable way, it can form a statically determinate support system that resists pitch oscillation. The present application has the functions of test support and loading at the same time and can be switched quickly. The internal coupling of the system ensures static support and can effectively eliminate the pitch moment change of the landing gear strut and avoid pitch oscillation. It can effectively absorb the load impact and attenuate energy during emergency unloading. At the moment of emergency unloading, it can absorb the impact of the entire test system on the support point structure to ensure the safety of the test piece structure. It can accurately adjust the aircraft attitude according to needs. It can be easily expanded and applied to other single-pillar multi-wheel landing gear structures.

[0060] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A landing gear support loading system with interconnected load-bearing units, characterized in that: include: A gas-oil spring bearing unit having cavity A, cavity B, cavity C, cavity D, cavity E, and cavity F. The gas-oil spring bearing unit includes a first gas-oil spring bearing unit connected to a dummy wheel on the front axle of the landing gear dummy, a second gas-oil spring bearing unit connected to a dummy wheel on the middle axle of the landing gear dummy, and a third gas-oil spring bearing unit connected to a dummy wheel on the rear axle of the landing gear dummy; An integrated module, wherein the integrated module has a first inlet and outlet oil passage, a second inlet and outlet oil passage, and a third inlet and outlet oil passage. The integrated module includes a first integrated module, a second integrated module, and a third integrated module, wherein: The first inlet and outlet oil circuit of the first integrated module is connected to the cavity A of the first oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the first oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the first oil and gas spring bearing unit; The first inlet and outlet oil circuit of the second integrated module is connected to the cavity A of the second oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the second oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the second oil and gas spring bearing unit; The first inlet and outlet oil circuit of the third integrated module is connected to the cavity A of the third oil and gas spring bearing unit, the second inlet and outlet oil circuit is connected to the cavity B of the third oil and gas spring bearing unit, and the third inlet and outlet oil circuit is connected to the cavity D of the third oil and gas spring bearing unit; The connecting oil passage includes a first connecting oil passage, a second connecting oil passage, and a third connecting oil passage, wherein: The first connecting oil path connects the cavity A of the first oil-gas spring bearing unit, the cavity B of the second oil-gas spring bearing unit, and the cavity B of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the first connecting oil path; The second connecting oil path connects the cavity B of the first oil-gas spring bearing unit, the cavity A of the second oil-gas spring bearing unit, and the cavity A of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the second connecting oil path; The third connecting oil path connects the cavity D of the first oil-gas spring bearing unit, the cavity D of the second oil-gas spring bearing unit, and the cavity D of the third oil-gas spring bearing unit to each other, and a ball valve is provided on the third connecting oil path; The oil-gas spring bearing unit includes: A cylinder, wherein two partitions are provided in the cylinder, and the two partitions divide the interior of the cylinder into three cavities, namely a first cavity, a second cavity, and a third cavity; A rod piston, comprising a first rod piston and a second rod piston, wherein the first rod piston is disposed in the first cavity and divides the first cavity into cavity A and cavity B, and the second rod piston is disposed in the second cavity and divides the second cavity into cavity C and cavity D; a floating piston, the floating piston being disposed in the third cavity and dividing the third cavity into cavity E and cavity F; a piston rod, one end of which is connected to the first rod-mounted piston and the second rod-mounted piston, respectively, and the other end of which is connected to the corresponding landing gear dummy component and dummy wheel; The load-bearing unit oil circuit, one end of which is connected to the cavity D, and the other end is connected to the cavity E. The load-bearing unit oil circuit is provided with a ball valve, a one-way throttle valve and an electrically controlled reversing valve; Among them, cavity A, cavity B, cavity D, and cavity E are filled with oil, cavity C is connected to the atmosphere, and cavity F is filled with high-pressure inert gas.

2. The load-carrying unit interconnected landing gear support loading system according to claim 1, characterized in that: A displacement sensor is installed on the piston rod.

3. The load-carrying unit interconnected landing gear support loading system according to claim 2, characterized in that: In the integrated module: The first inlet and outlet oil circuit includes a first inlet and outlet main oil circuit and two first inlet and outlet branch oil circuits arranged in parallel. One end of the first inlet and outlet main oil circuit is connected to the cavity A, and the other end is connected to the two first inlet and outlet branch oil circuits arranged in parallel. One of the first inlet and outlet branch oil circuits is provided with a hydraulically controlled reversing valve and a servo valve, and the first inlet and outlet branch oil circuit is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other first inlet and outlet branch oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve, and the first inlet and outlet branch oil circuit is connected to the low-pressure oil circuit. The second inlet and outlet oil circuit includes a second inlet and outlet main oil circuit and two second inlet and outlet branch oil circuits arranged in parallel. One end of the second inlet and outlet main oil circuit is connected to the cavity B, and the other end is connected to the two second inlet and outlet branch oil circuits arranged in parallel. One of the second inlet and outlet branch oil circuits is provided with a hydraulically controlled reversing valve and a servo valve, and the second inlet and outlet branch oil circuit is connected to the high-pressure oil circuit and the low-pressure oil circuit respectively. The other second inlet and outlet branch oil circuit is provided with a hydraulically controlled reversing valve and a one-way throttle valve, and the second inlet and outlet branch oil circuit is connected to 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 provided on the third inlet and outlet oil circuit.

4. The load-carrying unit interconnected landing gear support loading system according to claim 3, characterized in that: The integrated module also includes a reversing valve hydraulic control oil circuit, one end of which is connected to each hydraulically controlled reversing valve in the first inlet and outlet oil circuit and the second inlet and outlet oil circuit, and the other end is connected to the high-pressure oil circuit and the low-pressure oil circuit, respectively. An electrically controlled reversing valve is provided on the reversing valve hydraulic control oil circuit.

5. A method for supporting and loading a landing gear with interconnected load-bearing units, based on the system for supporting and loading a landing gear with interconnected load-bearing units according to claim 4, characterized in that: include: In height adjustment mode: close the ball valves on the oil circuit and 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 into cavities A and B, and at the same time control the oil circuit of the oil-gas spring load-bearing unit to fill or drain oil into cavity D, thereby adjusting the piston rod extension to the 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. In the shutdown mode: close the ball valve on the 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, cut off the power to the electronically controlled reversing valve and the integrated module on the oil circuit of the oil-gas spring load-bearing unit, and cut off the inlet and outlet oil circuits of the integrated module; In support mode: the electronically controlled reversing valve and integrated module on the oil circuit of the oil-gas spring bearing unit are powered off, and the ball valves on the oil circuit and the connecting oil circuit of the oil-gas spring bearing unit are opened. The cavities D of the three oil-gas spring bearing units are connected, and the cavities A and B between the oil-gas spring bearing units of the center axle and the rear axle are connected in parallel. These cavities are then cross-connected with the cavities A and B of the oil-gas spring bearing unit of the front axle to achieve static support. In loading mode: close the ball valve on the oil circuit of the oil-gas spring load-bearing unit, the electronically controlled reversing valve on the oil circuit of the oil-gas spring load-bearing unit does not work, cavity D is always connected with the inlet and outlet oil circuits of the integrated module through the one-way throttle valve, and the inlet and outlet oil circuits of the integrated module are controlled to fill or drain oil into cavities A and B to realize active loading of the landing gear.

6. The method for supporting and loading a landing gear with interconnected load-bearing units according to claim 5, characterized in that: In the support mode, when emergency unloading occurs, the electronically controlled reversing valve on the oil circuit of the oil-gas spring load-bearing unit is disconnected and connected, cavity F alleviates the load impact, and the oil consumes the impact energy through the one-way throttle valve, thereby protecting the safety of the test piece to the greatest extent.

7. The method for supporting and loading a landing gear with interconnected load-bearing units according to claim 5, characterized in that: In loading mode, when emergency unloading occurs, the inlet and outlet oil passages of the control integrated module are used to drain oil from cavities A and B to complete the unloading.

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