A vertical velocity control device for an aircraft test stand

Abstract

The vertical speed control device for the aircraft test bench comprises an oil tank, a hydraulic cylinder and a hydraulic pump, the hydraulic cylinder is divided into a rod cavity and a rodless cavity by a piston, a piston rod of the hydraulic cylinder is connected with an aircraft tire, and the vertical speed control device further comprises a hydraulic energy accumulator, a first pilot electromagnetic valve, a first cartridge valve, a second pilot electromagnetic valve, a second cartridge valve and an electromagnetic reversing valve, the hydraulic energy accumulator is connected with the hydraulic pump and is arranged on a hydraulic oil circuit between the hydraulic pump and the hydraulic cylinder; control interfaces of the first pilot electromagnetic valve and the second pilot electromagnetic valve are respectively communicated with pressure oil of the hydraulic pump, the first cartridge valve is connected with the first pilot electromagnetic valve, the second cartridge valve is connected with the second pilot electromagnetic valve, the first cartridge valve and the second cartridge valve are respectively communicated with the rodless cavity of the hydraulic cylinder through hydraulic pipelines, and the electromagnetic reversing valve is provided with a main oil inlet P, a main oil return port T and two working oil ports, and the vertical speed control device can simulate the aircraft to provide a precise and adjustable vertical impact speed loading.

Description

TECHNICAL FIELD

[0001] The present application relates to an aircraft test bench, in particular to a vertical speed control device for an aircraft test bench. BACKGROUND

[0002] The aircraft tire is one of the important components of the aircraft, which plays a rolling and supporting role during the take-off, landing and taxiing process of the aircraft, and its performance directly determines the safety of the aircraft. Therefore, it is necessary to test the dynamic performance of the aircraft tire before the test flight. At present, the dynamic test technology of aircraft tires in China is basically in a blank state, and there is no dynamic test equipment for aircraft tires in China. Due to the lack of suitable test equipment, the current relevant research in China basically uses static test data and uses some empirical formulas in foreign literature to roughly estimate the mechanical properties of aviation tires for landing gear design stage, and then verifies through landing gear system test in the later period. Once the system test fails due to the dynamic performance of the tire, it is very difficult to handle in the absence of sufficient data. Based on the above situation, it is urgent to develop a usable aircraft tire dynamic test equipment.

[0003] The aircraft tire dynamic equipment mainly tests the stress and deformation of the aircraft tire by simulating the landing and taxiing process of the aircraft. During the landing and taxiing process of the aircraft, the aircraft tire impacts the ground at an uncertain vertical speed (the highest impact final speed is not less than 3.05 m / s), and at the same time, due to the action of the weight of the whole aircraft, it is subjected to the loading action of the downward stable vertical force. How to control the vertical speed of the aircraft test bench is a problem that must be faced. For example, a kind of aircraft wheel brake system test bench and test method (publication number: CN110816887A) in the prior art, which loads the system to simulate the ground load of the aircraft, integrates the driving system with the loading system, and completes the simulation of the whole machine landing brake system on the test bench to perform the ground taxi test of the wheel brake system on the aircraft runway, which reduces the risk in the test process, but does not provide precise adjustable vertical impact speed loading. SUMMARY

[0004] The purpose of the present application is to provide a vertical speed control device for an aircraft test bench to achieve precise adjustable vertical impact speed loading.

[0005] Based on the above purpose, the technical scheme of the present application is as follows:

[0006] A vertical speed control device for an aircraft test bench, comprising an oil tank, a hydraulic cylinder and a hydraulic pump, the hydraulic cylinder is provided with a piston and a piston rod, the piston divides the hydraulic cylinder into a rod cavity and a rodless cavity, one end of the piston rod is fixedly connected with the piston, the other end of the piston rod extends out of the cylinder cover of the hydraulic cylinder and is connected with an aircraft tire, the oil inlet of the hydraulic pump and the rod cavity of the hydraulic cylinder are connected with the oil tank through hydraulic pipelines or reversing valves, and the oil outlet of the hydraulic pump is connected with the rodless cavity of the hydraulic cylinder through hydraulic pipelines or reversing valves,

[0007] Further comprising a hydraulic energy accumulator, a first pilot electromagnetic valve, a first cartridge valve, a second pilot electromagnetic valve, a second cartridge valve, an electromagnetic reversing valve and a controller.

[0008] The first pilot electromagnetic valve is provided with three oil ports, the first oil port is in communication with an oil tank circuit, the second oil port is in communication with the hydraulic pump, and the third oil port is in communication with the control port of the first cartridge valve, and the first oil port is selectively in communication with the second oil port or the third oil port.

[0009] The second pilot electromagnetic valve is provided with three oil ports, the first oil port is in communication with an oil tank circuit, the second oil port is in communication with the hydraulic pump, and the third oil port is in communication with the control port of the second cartridge valve, and the first oil port is selectively in communication with the second oil port or the third oil port.

[0010] The electromagnetic reversing valve is provided with a main oil inlet port P, a main oil return port T, a working oil inlet port A and a working oil return port B, and the working oil inlet port A and the working oil return port B of the electromagnetic reversing valve are in communication with the rod cavity of the hydraulic cylinder and the rodless cavity of the hydraulic cylinder respectively.

[0011] The hydraulic energy accumulator is connected with the hydraulic pump and is arranged on the hydraulic oil circuit between the hydraulic pump and the hydraulic cylinder, the first oil inlet port of the first cartridge valve, the second oil port of the first pilot electromagnetic valve, the second oil port of the second pilot electromagnetic valve and the main oil inlet port P of the electromagnetic reversing valve are all connected with the hydraulic energy accumulator, the oil inlet port of the second cartridge valve and the rod cavity are in communication with the oil outlet port of the first cartridge valve, and the rodless cavity is in communication with the oil outlet port of the second cartridge valve.

[0012] The controller is connected with the first pilot electromagnetic valve, the first cartridge valve, the second pilot electromagnetic valve, the second cartridge valve and the electromagnetic reversing valve respectively.

[0013] When it is needed to provide loading for simulating the aircraft to receive downward vertical force, the electromagnetic reversing valve is powered off, the first pilot electromagnetic valve is powered on, the first cartridge valve is opened, the rod cavity and the rodless cavity of the hydraulic cylinder are communicated to form differential connection, at the same time, the second pilot electromagnetic valve is powered on, the second cartridge valve is synchronously opened, the high-pressure oil of the hydraulic energy accumulator is output to the differential circuit, the hydraulic cylinder is pushed to drive the aircraft tire to accelerate downward, and finally the aircraft tire impacts the ground at a set vertical speed; when it is needed to reset, the first pilot electromagnetic valve and the second pilot electromagnetic valve are powered off, the first cartridge valve and the second cartridge valve are synchronously closed, the electromagnetic reversing valve is opened, and the hydraulic cylinder is adjusted to drive the aircraft tire to reset.

[0014] As a further mode, the electromagnetic reversing valve is a three-position four-way electromagnetic reversing valve.

[0015] The electromagnetic reversing valve can be a two-position four-way electromagnetic reversing valve, a servo valve or a three-position four-way electromagnetic reversing valve, but the three-position four-way electromagnetic reversing valve is a preferred mode, the main oil inlet P of which is communicated with the hydraulic pump, the main oil return port T is communicated with the oil tank, and the working oil inlet A and the working oil return port B are respectively communicated with the rod cavity of the hydraulic cylinder and the rodless cavity of the hydraulic cylinder.

[0016] As a further mode, the first pilot electromagnetic valve and the second pilot electromagnetic valve are both two-position three-way electromagnetic valves.

[0017] The first oil port of the first pilot electromagnetic valve and the second pilot electromagnetic valve is communicated with the oil tank circuit, the second oil port of the first pilot electromagnetic valve and the second pilot electromagnetic valve is communicated with the hydraulic pump, the third oil port of the first pilot electromagnetic valve is communicated with the control port of the first cartridge valve, and the third oil port of the second pilot electromagnetic valve is communicated with the control port of the second cartridge valve.

[0018] As a further mode, the device further comprises a damping hole,

[0019] The damping hole is arranged at the oil inlet of the first pilot electromagnetic valve and the second pilot electromagnetic valve,

[0020] The damping hole is further arranged between the first pilot electromagnetic valve and the first cartridge valve, and between the second pilot electromagnetic valve and the second cartridge valve.

[0021] The damping hole is arranged to prevent the output pressure from being affected by load changes, that is, to maintain stable output pressure.

[0022] As a further mode, the hydraulic energy accumulator is a high-pressure energy accumulator.

[0023] The high-pressure energy accumulator is an energy storage unit in a hydraulic pneumatic device, and the minimum working pressure of the high-pressure energy accumulator needs to be greater than the pre-charging pressure. The high-pressure energy accumulator first converts the energy in the system into compressed energy or potential energy and stores it, and when the system needs it, the compressed energy or potential energy is converted into hydraulic pressure or gas pressure and released to supply the system again. When the instantaneous demand power of the system increases, it can absorb part of the energy to ensure the normal pressure of the entire system. The hydraulic energy accumulator can instantaneously release high-pressure hydraulic oil with large flow, which provides high-pressure oil with large flow for the loading cylinder during vertical speed operation, and reduces the installed power of the hydraulic system.

[0024] As a further mode, the device further comprises a displacement sensor arranged on the hydraulic cylinder and connected to the controller.

[0025] The displacement of the hydraulic cylinder is controlled by the working position of the controller electromagnetic reversing valve, and the displacement of the hydraulic cylinder is fed back to the controller by the displacement sensor, and the controller realizes the PID closed-loop control of the position of the hydraulic cylinder, so as to ensure the control accuracy of the initial set position of the hydraulic cylinder.

[0026] The beneficial effects realized by the present application are:

[0027] 1. The present application provides loading for simulating that the airplane receives downward stable vertical force;

[0028] 2. The present application utilizes the characteristics of the hydraulic energy accumulator that can instantaneously release high-pressure hydraulic oil with large flow, which provides high-pressure oil with large flow for the loading hydraulic cylinder during vertical speed operation, and reduces the installed power of the hydraulic device;

[0029] 3. The present application can improve the degree of automation control of the test bench through the program setting of the controller. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a schematic diagram of the principle of the embodiment of the present application;

[0031] Figure 2 It is a controller control schematic diagram of the embodiment of the present application.

[0032] Among them: 1, hydraulic pump, 2, electromagnetic reversing valve, 3, hydraulic cylinder, 4, airplane tire, 5, first pilot electromagnetic valve, 6, first cartridge valve, 7, second pilot electromagnetic valve, 8, second cartridge valve, 9, hydraulic energy accumulator, 10, oil tank, 20, damping hole, 100, controller, 101, displacement sensor. DETAILED DESCRIPTION

[0033] As Figure 1 And Figure 2As shown, a vertical speed control device for an aircraft test bench includes a tank 10, a hydraulic cylinder 3 and a hydraulic pump 1. The hydraulic cylinder 3 is provided with a piston and a piston rod. The piston divides the hydraulic cylinder 3 into a rod cavity and a rodless cavity. One end of the piston rod is fixedly connected with the piston, and the other end of the piston rod extends out of the cylinder cover of the hydraulic cylinder 3 and is connected with an aircraft tire 4. The oil inlet of the hydraulic pump 1 and the rod cavity of the hydraulic cylinder 3 are connected with the tank 10 through hydraulic pipelines. The oil outlet of the hydraulic pump 1 is connected with the rodless cavity of the hydraulic cylinder 3 through a hydraulic pipeline. The outlet of the hydraulic pump 1 is provided with a hydraulic accumulator 9 for providing large-flow hydraulic oil required by the hydraulic cylinder 3 when simulating the vertical speed of the aircraft tire. The hydraulic accumulator 9 is a high-pressure accumulator. A first cartridge valve 6 is connected between the hydraulic accumulator 9 and the rod cavity of the hydraulic cylinder 3. The opening and closing of the first cartridge valve 6 is controlled by a first pilot electromagnetic valve 5. A second cartridge valve 8 is connected between the rod cavity of the loading hydraulic cylinder 3 and the rodless cavity of the loading hydraulic cylinder 3. When the second cartridge valve 8 is opened, the rodless cavity and the rod cavity of the hydraulic cylinder 3 are connected in differential connection. The opening and closing of the second cartridge valve 8 is controlled by a second pilot electromagnetic valve 7. An electromagnetic reversing valve 2 is used to adjust the height of the aircraft tire 4 from the ground by adjusting the extension and retraction of the hydraulic cylinder 3.

[0034] Specifically, the hydraulic accumulator 9 is a high-pressure accumulator, the electromagnetic reversing valve 2 is a three-position four-way electromagnetic reversing valve, the first pilot electromagnetic valve 5 and the second pilot electromagnetic valve 7 are both two-position three-way valves, and a damping hole is arranged at the oil inlet of the first pilot electromagnetic valve 5, at the oil inlet of the second pilot electromagnetic valve 7, between the first pilot electromagnetic valve 5 and the first cartridge valve 6, and between the second pilot electromagnetic valve 7 and the second cartridge valve 8. A displacement sensor 101 is arranged on the hydraulic cylinder 3 and connected with a controller 100. The displacement of the hydraulic cylinder 3 is controlled by controlling the working position of the electromagnetic reversing valve 2. The displacement of the hydraulic cylinder 3 is fed back to the controller 100 through the displacement sensor 101. The controller controls the position of the hydraulic cylinder 3 through PID closed-loop control, so as to ensure the control accuracy of the initial set position of the hydraulic cylinder 3.

[0035] According to the law of conservation of energy, ignoring the effects of friction and back pressure, the kinetic energy of the aircraft tire 4 at the moment of landing is equal to the sum of the work done by the hydraulic system and gravity on the hydraulic cylinder 3. At the same time, ignoring the compressibility of the hydraulic oil, the flow rate of the pressure oil output by the hydraulic accumulator 9 is equal to the difference between the volume changes of the rodless cavity and the rod cavity of the hydraulic cylinder 3. At the same time, assuming that the process of releasing pressure oil by the hydraulic accumulator (high-pressure accumulator) 9 is an adiabatic process, the relationship between the set vertical target speed V of the aircraft tire 4 and the initial height H of the aircraft tire 4 is determined. In this process, the minimum working pressure P2 of the hydraulic accumulator (high-pressure accumulator) 9 needs to be greater than the pre-charging pressure P0, i.e. P2>P0.

[0036] In order to realize the purpose of automatic control, the device is further provided with a controller 100, which is connected with all electrical devices in the device, i.e. the controller is connected with the first pilot electromagnetic valve 5, the second pilot electromagnetic valve 7 and the electromagnetic reversing valve 2 respectively. The controller 100 can set programs, and according to the program setting of the controller 100, the controller 100 can preset the lifting height according to the vertical target speed, which reduces the labor intensity of the operator and is beneficial to improve the degree of automatic control of the test bench.

[0037] The specific working process is as follows:

[0038] 1. Preparation stage: start the hydraulic pump 1, according to the set vertical target speed, adjust the hydraulic cylinder 3 through the control electromagnetic reversing valve 2 to drive the aircraft tire 4 to rise to the preset height, when the aircraft tire reaches the preset height, the electromagnetic reversing valve loses power, and the hydraulic cylinder remains at the set height position; at the same time, the hydraulic pump 1 outputs pressure oil to the hydraulic energy accumulator (high pressure energy accumulator) 9 to store in the form of pressure energy;

[0039] 2. Falling stage: the electromagnetic reversing valve 2 loses power, the first pilot electromagnetic valve 5 gets power, the a port and the c port of the first pilot electromagnetic valve 5 are communicated, the control port X of the first cartridge valve 6 is communicated with the oil tank through the first pilot electromagnetic valve 5, the A1 and the A2 of the first cartridge valve 6 are communicated, and the rod cavity and the rod cavity of the hydraulic cylinder 3 are communicated to form a differential connection. Similarly, the second pilot electromagnetic valve 7 gets power, the second cartridge valve 8 is opened synchronously, the hydraulic energy accumulator 9 outputs high pressure oil to the differential circuit, and pushes the hydraulic cylinder 3 to drive the aircraft tire 4 to accelerate downward, and finally impacts the ground at the set vertical speed;

[0040] 3. Reset stage: the first pilot electromagnetic valve 5 and the second pilot electromagnetic valve 7 lose power, the b port and the c port of the first pilot electromagnetic valve 5 and the second pilot electromagnetic valve 7 are communicated, the control port X of the first cartridge valve 6 is communicated with the hydraulic energy accumulator 9 through the first pilot electromagnetic valve 5, and under the action of high pressure control oil, the A1 and the A2 of the first cartridge valve 6 and the second cartridge valve 8 are closed synchronously. Open the electromagnetic reversing valve 2, adjust the hydraulic cylinder 3 to drive the aircraft tire 4 to reset upward.

[0041] Finally, it should be noted that the content illustrated in the above embodiments should be understood as these embodiments only for more clearly illustrating the present application, and not for limiting the scope of the present application, after reading the present application, the various equivalent forms of the present application modified by the person skilled in the art all fall within the scope defined by the claims attached to the present application.

Claims

1. A vertical speed control device for an aircraft test stand, comprising an oil tank, a hydraulic cylinder and a hydraulic pump, a piston and a piston rod being arranged in the hydraulic cylinder, the piston dividing the hydraulic cylinder into a rod cavity and a rodless cavity, one end of the piston rod being fixedly connected with the piston, the other end of the piston rod extending out of a cylinder head of the hydraulic cylinder and being connected with an aircraft tire, an oil inlet of the hydraulic pump and the rod cavity of the hydraulic cylinder being connected with the oil tank through hydraulic pipelines or a reversing valve, an oil outlet of the hydraulic pump being connected with the rodless cavity of the hydraulic cylinder through hydraulic pipelines or the reversing valve, characterized in that, further comprising a hydraulic accumulator, a first pilot solenoid valve, a first cartridge valve, a second pilot solenoid valve, a second cartridge valve, an electromagnetic reversing valve and a controller. The first pilot solenoid valve is provided with three oil ports, a first oil port of which is in communication with an oil tank circuit, a second oil port of which is in communication with the hydraulic pump, and a third oil port of which is in communication with a control port of the first cartridge valve, the first oil port being in selective communication with the second oil port or the third oil port. The second pilot solenoid valve is provided with three oil ports, a first oil port of which is in communication with an oil tank circuit, a second oil port of which is in communication with the hydraulic pump, and a third oil port of which is in communication with a control port of the second cartridge valve, the first oil port being in selective communication with the second oil port or the third oil port. The electromagnetic reversing valve is provided with a main oil inlet port P, a main oil return port T, a working oil inlet port A and a working oil return port B, the working oil inlet port A and the working oil return port B of the electromagnetic reversing valve being in communication with the rod cavity of the hydraulic cylinder and the rodless cavity of the hydraulic cylinder respectively. The hydraulic accumulator is connected with the hydraulic pump and arranged on a hydraulic oil circuit between the hydraulic pump and the hydraulic cylinder, the first oil port of the first cartridge valve, the second oil port of the first pilot solenoid valve, the second oil port of the second pilot solenoid valve and the main oil inlet port P of the electromagnetic reversing valve being connected with the hydraulic accumulator, the oil inlet port of the second cartridge valve and the rod cavity being in communication with the oil outlet port of the first cartridge valve, and the rodless cavity being in communication with the oil outlet port of the second cartridge valve. The controller is connected with the first pilot solenoid valve, the first cartridge valve, the second pilot solenoid valve, the second cartridge valve and the electromagnetic reversing valve respectively. The electromagnetic reversing valve is a three-position four-way electromagnetic reversing valve.

2. The vertical speed control apparatus for an aircraft test stand of claim 1, wherein, 3. The vertical speed control device for an aircraft test stand according to claim 1, characterized in that, The first pilot solenoid valve and the second pilot solenoid valve are both two-position three-way electromagnetic valves. Further comprising a damping hole, 4. The vertical speed control apparatus for an aircraft test stand of claim 1, wherein, The damping hole is arranged at the oil inlet ports of the first pilot solenoid valve and the second pilot solenoid valve, The damping hole is further arranged between the first pilot solenoid valve and the first cartridge valve, and between the second pilot solenoid valve and the second cartridge valve. The hydraulic accumulator is a high-pressure accumulator.

5. The vertical speed control apparatus for an aircraft test stand of claim 1, wherein, Further comprising a displacement sensor, the displacement sensor being arranged on the hydraulic cylinder and connected with the controller.

6. A vertical speed control device for an aircraft test stand according to any one of claims 1 to 5, characterized in that ​

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