Hydraulic control system and method for aircraft landing gear training device

Abstract

The present invention provides a hydraulic control system and method for an aircraft landing gear training device, which comprises a training device body, wherein the training device body comprises a T-shaped mounting platform, wherein three hydraulic lifting support legs for lifting and lowering the T-shaped mounting platform are fixedly mounted at the bottom of the T-shaped mounting platform, wherein a front landing gear assembly for simulating a front landing gear of an aircraft is mounted at the front end of the bottom of the T-shaped mounting platform, and a left rear landing gear assembly and a right rear landing gear assembly for simulating a rear landing gear of an aircraft are mounted on both sides of the rear end of the bottom of the T-shaped mounting platform; the three hydraulic lifting support legs, the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly are connected to a hydraulic control system for controlling the operation thereof, and the hydraulic control system is connected to a hydraulic power system for providing hydraulic energy.

Description

Technical Field

[0001] The invention relates to the field of aircraft operation training devices, in particular to a hydraulic control system of an aircraft landing gear training device. Background Art

[0002] Based on the training needs of the use and maintenance of the Y8 aircraft landing system, students will understand the basic configuration of the landing gear, master the disassembly and assembly methods of the landing gear system and the use of special tools, be familiar with the retraction and extension process of the landing gear system and the process of implementing the brakes, and have a deep understanding of the composition, working principle, main components and accessories of the aircraft landing gear system. Exercise students' hands-on practical ability, the ability to comprehensively apply knowledge, and the ability to skillfully use various general tools and special tools. It is necessary to develop and design a corresponding training device based on the actual structure of the Y8 aircraft's landing gear, and design a corresponding hydraulic control system for this device to meet actual use needs. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a hydraulic control system for an aircraft landing gear training device, which can be used to control the corresponding actions of the landing gear of the training device, so as to simulate the actual operation process of the Y8 aircraft landing gear and achieve the purpose of teaching and training.

[0004] In order to realize the above technical features, the object of the present invention is achieved as follows: A hydraulic control system for an aircraft landing gear training device, characterized in that: it comprises a training device body, the training device body comprises a T-shaped mounting platform, three hydraulic lifting support legs for lifting and lowering the T-shaped mounting platform are fixedly mounted at the bottom of the T-shaped mounting platform, a front landing gear assembly for simulating the front landing gear of an aircraft is mounted at the bottom front end of the T-shaped mounting platform, and a left rear landing gear assembly and a right rear landing gear assembly for simulating the rear landing gear of an aircraft are mounted on both sides of the bottom rear end of the T-shaped mounting platform;

[0005] The three hydraulic lifting support legs, the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly are connected to a hydraulic control system for controlling their operation, and the hydraulic control system is connected to a hydraulic power system for providing hydraulic energy.

[0006] The hydraulic power system includes an oil tank, which is connected to an electric pump and a manual pump in parallel through an oil pipe, an oil tank oil outlet switch is installed on the oil pipe, and a refueling port switch is installed between the oil tank oil outlet switch and the manual pump; the oil outlet pipes of the electric pump and the manual pump are connected to a multi-stage oil filter after converging, a sampling switch, a first pressure regulating valve and a first pressure gauge are installed on the oil pipe after the multi-stage oil filter, and finally connected to the platform oil supply hose of the hydraulic control system; the oil tank is connected to an oil return pipe, and the oil return pipe is connected to the platform oil return hose of the hydraulic control system through an oil filter, a second pressure regulating valve and a second pressure gauge.

[0007] A level gauge for displaying the liquid level and a thermometer for displaying the oil temperature are installed inside the oil tank, an air filter is fixedly installed on the top of the oil tank; an oil filter for filtering the oil is arranged inside the oil tank; and an oil tank drain switch is arranged at the bottom of the oil tank.

[0008] The oil outlet pipes of the electric pump and the manual pump are respectively installed with a first one-way valve, and a first overflow valve is installed on the pipeline after the first one-way valve, and the overflow port of the first overflow valve is connected to the oil tank.

[0009] The hydraulic control system comprises a first electromagnetic reversing valve, which is connected to a platform oil supply hose of a hydraulic power system. The outlet of the first electromagnetic reversing valve is divided into three routes. The first route is connected to a front landing gear lower lock actuator cylinder of a front landing gear assembly and controls the locking or releasing thereof. The front landing gear lower lock actuator cylinder is connected to a front lifting and retracting actuator cylinder through a throttle nozzle; the second route is connected to a main lifting and retracting small actuator cylinder and a main lifting and retracting large actuator cylinder of a left rear landing gear assembly and a right rear landing gear assembly, and enables the main landing gear to be unlocked and retracted; the third route passes through a pressure reducing valve and is connected to the brake wheels of the left rear landing gear assembly and the right rear landing gear assembly through a brake oil circuit; the return oil chambers of the front lifting and retracting actuator cylinder and the main lifting and retracting small actuator cylinder are connected to a platform oil return hose through a first conversion valve, a second conversion valve and a first electromagnetic reversing valve; the platform oil supply hose is connected to a front wheel turning actuator cylinder through a second electromagnetic reversing valve, a throttle valve and a safety valve.

[0010] The overflow port of the first electromagnetic reversing valve is connected to the platform oil return hose through the second one-way valve.

[0011] The brake oil circuit includes a third one-way valve, a third conversion valve, a dosing device and a pressure sensor; the third conversion valve is also connected to a manual reversing valve, and the manual reversing valve is connected to the platform oil supply hose through a first solenoid valve.

[0012] A throttle valve is installed on the oil circuit of the main lifting and retracting small actuator, and also includes an upper lock and a hydraulic manual valve.

[0013] The method for the hydraulic control system to control the aircraft landing gear training device:

[0014] Retracting the landing gear:

[0015] First, synchronously raise the three hydraulic lifting support legs of the platform so that the wheels are off the ground to a height suitable for the retraction and extension of the landing gear. Insert the safety pin, firmly connect the platform oil supply hose to the hydraulic power system, turn on the power, check that the electrical and control switches are normal, then start the electric pump and adjust the pressure to the set pressure A; operate the landing gear handle on the operating table and turn it to the retracted position. The pressure oil is divided into three paths after passing through the first electromagnetic reversing valve. One path goes to the front landing gear lower lock actuator to open the lock. At the same time, the pressure oil passes through the throttle nozzle and enters the retraction chamber of the front lifting and retraction actuator to retract the front landing gear assembly; the other path goes to the main lifting and retraction small actuator and the main lifting and retraction large actuator to retract the main landing gear assembly. The gear is unlocked and retracted; another path passes through the pressure reducing valve and the brake oil circuit to brake the brake wheels of the left and right main landing gears; the oil in the lowering chamber of the front retracting and lifting cylinder and the main retracting and lifting small cylinder returns to the oil tank through the first conversion valve, the second conversion valve and the first electromagnetic reversing valve, and the oil in the lowering chamber of the main retracting and lifting large cylinder directly returns to the oil tank of the power system; the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly are suspended in the retracted position by the upper lock. After the landing gear is retracted, the micro switch is turned on and the three red lights on the operating console are on; when the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position;

[0016] To lower the landing gear:

[0017] Pull the landing gear handle to the down position. The pressure oil is divided into two paths after passing through the first electromagnetic reversing valve. One path passes through the second conversion valve to the front up lock to open the lock, and at the same time, it also goes to the down chamber of the front up and down actuator cylinder to lower the front landing gear. The oil in the up chamber of the front up and down actuator cylinder passes through the throttle nozzle and then returns to the oil tank through the first electromagnetic reversing valve; the other path passes through the first conversion valve to the landing gear and up lock of the left rear landing gear assembly and the right rear landing gear assembly, opens the left and right main up locks, and goes to the throttle valve to the main up and down small actuator cylinder on the folding strut. Under the action of oil pressure and gravity, the main landing gear is lowered and locked; the oil in the other chamber of the main retractable small actuator merges with the return oil of the front landing gear actuator, and then the first electromagnetic reversing valve returns to the oil tank; the main retractable large actuator has no pressure oil during the main landing gear lowering process. When the piston rod extends, the oil is sucked in from the return oil circuit, and the oil in the other chamber of the piston flows back to the oil tank; after the landing gear is lowered, the micro switch is turned on, and the three green lights on the operating console are on. When the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position;

[0018] Emergency landing gear extension:

[0019] In case of power failure on the operating console, the landing gear emergency release can be operated manually. The landing gears of the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly can be opened. The emergency release hydraulic manual valve can be controlled and the manual pump can be shaken. The pressure oil passes through the hydraulic manual valve and the first conversion valve along the main landing gear oil line to lower the main landing gear of the left rear landing gear assembly and the right rear landing gear assembly; the pressure oil passes through the second conversion valve along the front landing gear oil line to lower the front landing gear of the front landing gear assembly. When other operations are performed, the two hydraulic manual valves are closed.

[0020] Wheel brakes:

[0021] The landing gear is in the lowered position. Raise the T-shaped installation platform to lift the wheels off the ground. Check the wheel brakes on the ground. The pressure gauge on the operating table indicates normal. Press the brake button. The brake indicator light is on. At this time, the pressure gauge has no indication. Operate the brake handle and observe the brake pressure indication. Push it up for the left brake and pull it down for the right brake. The brake pressure changes with the position of the operating handle. When it reaches the maximum set pressure A at the extreme positions at both ends, it will automatically return to the middle position when released, releasing the brake.

[0022] Front wheel turning:

[0023] With the landing gear in the lowered position, raise the T-shaped mounting platform so that the wheels are just off the ground, and use the wheel jack to lift the front landing gear so that its buffer strut is compressed by 100 to 120 mm. At this time, the turn indicator light on the operating panel will light up, and the front wheel can be turned. Connect the ground hydraulic power system to the operating table, increase the pressure to the set pressure A, operate the turn switch, and the pressure oil enters the front wheel turning actuator through the second solenoid reversing valve and the throttling valve to rotate the front wheel. The oil in the other chamber returns to the oil tank through the throttling valve and the second solenoid reversing valve.

[0024] The present invention has the following beneficial effects:

[0025] 1. This hydraulic control system can be used to control the corresponding actions of the landing gear of the training device, so that it can simulate the actual operation process of the Y8 aircraft landing gear and achieve the purpose of teaching and training.

[0026] 2. The hydraulic power system is mainly used to provide hydraulic power, and the electric pump can realize the electric oil pumping operation process, and the manual pump can realize the manual oil pumping operation. The above oil supply method ensures that its adaptability is enhanced.

[0027] 3. The first relief valve can be used to control the system pressure.

[0028] 4. The above-mentioned hydraulic control system can be used to control the movement of the training device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 It is a front view of the training device body of the present invention.

[0031] Figure 2 It is a top view of the training device body of the present invention.

[0032] Figure 3 It is the principle diagram of the hydraulic control system of the present invention.

[0033] Figure 4 It is the principle diagram of the hydraulic power system of the present invention.

[0034] Figure 5 A hydraulically operated console panel for the training device of the present invention.

[0035] In the figure: the first solenoid valve 1, the hydraulic manual valve 2, the first conversion valve 3, the second conversion valve 4, the second non-return valve 5, the first solenoid reversing valve 6, the second solenoid reversing valve 7, the throttle valve 8, the safety valve 9, the front wheel turning cylinder 10, the front lifting and retracting cylinder 11, the throttle nozzle 12, the front landing gear lower lock cylinder 13, the upper lock 14, the third way through the pressure reducing valve 15, the third non-return valve 16, the manual reversing valve 17, the third conversion valve 18, the meter 19, the pressure sensor 20, the brake wheel 21, the main lifting and retracting small cylinder 22, the throttle valve 23, the main lifting and retracting large cylinder 24, the temperature meter 25, air filter 26, fuel tank 27, liquid level gauge 28, oil filter 29, oil filter 29, fuel tank oil outlet switch 31, first overflow valve 32, manual pump 33, first check valve 34, electric pump 35, multi-stage oil filter 36, first pressure regulating valve 37, sampling switch 38, first pressure gauge 39, second pressure gauge 40, platform oil return hose 41, platform oil return hose 41, platform oil supply hose 42, front landing gear assembly 43, right rear landing gear assembly 44, left rear landing gear assembly 45, hydraulic lifting support leg 46, T-shaped mounting platform 47, refueling port switch 49, second pressure regulating valve 50. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0037] Embodiment 1:

[0038] See also Figure 1-5The hydraulic control system of an aircraft landing gear training device comprises a training device body, the training device body comprises a T-shaped mounting platform 47, three hydraulic lifting support legs 46 for lifting and lowering the training device are fixedly mounted at the bottom of the T-shaped mounting platform 47, a front landing gear assembly 43 for simulating the front landing gear of an aircraft is mounted at the bottom front end of the T-shaped mounting platform 47, and a left rear landing gear assembly 45 and a right rear landing gear assembly 44 for simulating the rear landing gear of an aircraft are mounted on both sides of the bottom rear end of the T-shaped mounting platform 47; the three hydraulic lifting support legs 46, the front landing gear assembly 43, the left rear landing gear assembly 45 and the right rear landing gear assembly 44 are connected to a hydraulic control system for controlling their operation, and the hydraulic control system is connected to a hydraulic power system for providing hydraulic energy. This hydraulic control system can be used to control the corresponding action of the landing gear of the training device, so that it simulates the actual operation process of the Y8 aircraft landing gear, and achieves the purpose of teaching and training.

[0039] During specific use, hydraulic power is provided by the hydraulic power system, and the hydraulic lifting support legs 46, the front landing gear assembly 43, the left rear landing gear assembly 45 and the right rear landing gear assembly 44 of the training device body are controlled by the hydraulic control system to complete the movements of the corresponding aircraft landing gear, ultimately achieving the purpose of training.

[0040] Furthermore, the training device is used to suspend the front and main landing gear of the Y8 aircraft. The operation console simulates the actions of retracting and lowering the landing gear, emergency release, etc., and the wheel jack can be used to lift the wheels off the ground for disassembly and assembly of the wheels. It is mainly composed of a platform for suspending the landing gear, three hydraulic lifting support legs, a hydraulic operation console and a movable hydraulic power source. The total length of the installation jig is about 6m from front to back, 7m from left to right, 1.5m from front to back, 4m in length, and 2.75m in height. Its total height is determined by the height of the support legs.

[0041] Furthermore, the T-shaped mounting platform 47 of the training device body is T-shaped, and the mounting form is completely in accordance with the mounting method on the aircraft, and the mounting size is consistent with the actual mounting size. When installing the landing gear, push it under the platform to install the landing gear fixing place, which is the same as the method of installing the landing gear on the aircraft. The beam that suspends the landing gear is welded with rectangular tubes, and the fulcrum and fixing ring that fix the landing gear are processed with 30CrMnSiA materials and connected with bolts. In order to facilitate transportation, the platform is divided into front and rear parts, which are connected into one body with bolts during installation. The operating console and seat are fixed on the front platform, the front landing gear and accessories are fixed below, and the main landing gear and accessories are fixed on both sides of the rear bottom. A 2.5mm thick patterned steel plate is laid on the platform, and guardrails are installed around it. A ladder is set on the side to facilitate operators to get on and off the platform. The three supporting legs of the platform are used to support the platform, and hydraulic operation is used to raise and lower the platform and adjust the height of the landing gear from the ground. The support legs and the top of the platform are designed to be spherically connected to prevent tilting when the three support legs are raised and lowered asynchronously.

[0042] Furthermore, three hydraulic lifting support legs 46 are used to prop up the platform. The upper part of the leg is connected to the platform in a spherical movable manner, and the lower part is fixed to the ground. Each leg is equipped with a hydraulic cylinder, on which is installed an oil tank, a manual pump and a switch to operate the lifting platform. Each leg is operated independently, which is equivalent to three aircraft jacks. They are lifted up at the same time to lift the landing gear off the ground to the retracted height, and the stop pin is inserted to prevent the platform from descending.

[0043] Furthermore, the hydraulic power system includes an oil tank 27, the oil tank 27 is connected in parallel with an electric pump 35 and a manual pump 33 through an oil pipe, an oil tank oil outlet switch 31 is installed on the oil pipe, and a refueling port switch 49 is installed between the oil tank oil outlet switch 31 and the manual pump 33; the oil outlet pipes of the electric pump 35 and the manual pump 33 are connected to the multi-stage oil filter 36 after converging, and a sampling switch 38, a first pressure regulating valve 37 and a first pressure gauge 39 are installed on the oil pipe after the multi-stage oil filter 36, and finally connected to the platform oil supply hose 42 of the hydraulic control system; the oil tank 27 is connected with an oil return pipe, and the oil return pipe is connected to the platform oil return hose 41 of the hydraulic control system through an oil filter, a second pressure regulating valve 50 and a second pressure gauge 40. The above-mentioned hydraulic power system is mainly used to provide hydraulic power, and the electric pump 35 can realize the electric pumping oil operation process, and the manual pump 33 can realize the manual pumping oil action. The above-mentioned oil supply method ensures that its adaptability is enhanced.

[0044] Furthermore, the hydraulic power system uses 3 mobile hydraulic power sources, which are mainly used to provide hydraulic source for the landing gear and to perform performance testing and debugging on the landing gear hydraulic system. The hydraulic vehicle mainly consists of a frame chassis, a hydraulic pipeline system, a cooling system, an electrical control system and other parts.

[0045] Furthermore, a level gauge 28 for displaying the liquid level and a thermometer 25 for displaying the oil temperature are installed inside the oil tank 27, an air filter 26 is fixedly installed on the top of the oil tank 27, an oil filter 29 for filtering the oil is arranged inside the oil tank 27, and an oil tank drain switch 43 is arranged at the bottom of the oil tank 27. The above auxiliary components ensure the normal operation of the oil tank 27.

[0046] Furthermore, the oil outlet pipes of the electric pump 35 and the manual pump 33 are respectively installed with a first one-way valve 34, and a first overflow valve 32 is installed on the pipeline after the first one-way valve 34, and the overflow port of the first overflow valve 32 is connected to the oil tank 27. The first overflow valve 32 can be used to control the system pressure.

[0047] Furthermore, the hydraulic control system includes a first electromagnetic reversing valve 6, which is connected to the platform oil supply hose 42 of the hydraulic power system. The outlet of the first electromagnetic reversing valve 6 is divided into three routes. The first route is connected to the front landing gear down-lock actuator 13 of the front landing gear assembly 43, and controls its locking or release. The front landing gear down-lock actuator 13 is connected to the front lifting and retraction actuator 11 through the throttle nozzle 12; the second route is connected to the main lifting and retraction small actuator 22 of the left rear landing gear assembly 45 and the right rear landing gear assembly 44, and The main lifting and retracting large actuator cylinder 24 is connected to unlock and retract the main landing gear; the third route passes through the pressure reducing valve 15, and is connected to the brake wheels 21 of the left rear landing gear assembly 45 and the right rear landing gear assembly 44 through the brake oil circuit; the return oil chamber of the front lifting and retracting actuator cylinder 11 and the main lifting and retracting small actuator cylinder 22 is connected to the platform return oil hose 41 through the first conversion valve 3, the second conversion valve 4 and the first electromagnetic reversing valve 6; the platform oil supply hose 42 is connected to the front wheel turning actuator cylinder 10 through the second electromagnetic reversing valve 7, the throttle valve 8 and the safety valve 9. The above-mentioned hydraulic control system can be used to control the action of the training device.

[0048] Furthermore, the overflow port of the first electromagnetic reversing valve 6 is connected to the platform oil return hose 41 through the second one-way valve 5 .

[0049] Furthermore, the brake oil circuit includes a third one-way valve 16, a third conversion valve 18, a metering device 19 and a pressure sensor 20; the third conversion valve 18 is also connected to the manual reversing valve 17, and the manual reversing valve 17 is connected to the platform oil supply hose 42 through the first solenoid valve 1.

[0050] Furthermore, a throttle valve 23 is installed on the oil circuit of the main lifting and retracting small actuator 22, and it also includes an upper lock 14 and a hydraulic manual valve 2.

[0051] Furthermore, it also includes a hydraulic operating console, which is installed on the platform and connected to the mobile hydraulic power source and then to each actuator on the landing gear. The landing gear is moved by operating the solenoid valve. The panel is equipped with an oil pressure gauge, signal indicator light, landing gear retraction and extension handle, front wheel turning switch, brake operating handle and brake pressure display. The connecting pipe is made of stainless steel pipe and fixed to the platform with a fixing card. The console panel is as follows Figure 5 .

[0052] Embodiment 2:

[0053] The method for the hydraulic control system to control the aircraft landing gear training device:

[0054] Retracting the landing gear:

[0055] First, the three hydraulic lifting support legs 46 of the platform are synchronously raised upwards, so that the wheels are off the ground to a height suitable for the retracting and extending of the landing gear, the safety pin is inserted, the platform oil supply hose 42 is firmly connected to the hydraulic power system, the power is turned on, and after checking that the electrical and control switches are normal, the electric pump 35 is started to adjust the pressure to the set pressure A; the landing gear handle is operated on the operating table to the retracted position, and the pressure oil is divided into three paths after passing through the first electromagnetic reversing valve 6. One path goes to the front landing gear lower lock actuator 13 to open the lock, and at the same time, the pressure oil passes through the throttle nozzle 12 and enters the retracting chamber of the front retracting actuator 11 to retract the front landing gear assembly 43; the other path goes to the main retracting small actuator 22 and the main retracting large actuator 24 to retract the main landing gear Unlock and retract; another path passes through the pressure reducing valve 15 and the brake oil circuit to brake the brake wheels 21 of the left and right main landing gears; the oil in the lowering chamber of the front lifting and retracting actuator 11 and the main lifting and retracting small actuator 22 returns to the oil tank through the first conversion valve 3, the second conversion valve 4 and the first electromagnetic reversing valve 6, and the oil in the lowering chamber of the main lifting and retracting large actuator 24 directly returns to the oil tank of the power system; the front landing gear assembly 43, the left rear landing gear assembly 45 and the right rear landing gear assembly 44 are suspended in the retracted position by the upper lock 14. After the landing gear is retracted, the micro switch is turned on and the three red lights on the operating console are on; when the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position;

[0056] To lower the landing gear:

[0057] The landing gear handle is turned to the lowering position. The pressure oil is divided into two paths after passing through the first electromagnetic reversing valve 6. One path passes through the second conversion valve 4 to the front up position lock 14 to open the lock, and at the same time, it also goes to the lowering chamber of the front up and down actuator cylinder 11 to lower the front landing gear. The oil in the retracting chamber of the front up and down actuator cylinder 11 passes through the throttle nozzle 12 and then returns to the oil tank through the first electromagnetic reversing valve 6; the other path passes through the first conversion valve 3 to the landing gear and up position locks of the left rear landing gear assembly 45 and the right rear landing gear assembly 44, opens the left and right main up position locks 14, and goes to the throttle valve 23 to the main lift on the folding strut. The retractable small actuator 22, under the action of oil pressure and gravity, lowers the main landing gear and puts it in a locked state; the oil in the other chamber of the main retractable small actuator 22 merges with the return oil of the front landing gear actuator, and then the first electromagnetic reversing valve 6 returns to the oil tank; the main retractable large actuator 24 has no pressure oil during the main landing gear lowering process. When the piston rod extends, the oil is sucked in from the return oil circuit, and the oil in the other chamber of the piston flows back to the oil tank; after the landing gear is lowered, the micro switch is turned on, and the three green lights on the operating table are on. When the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position;

[0058] Emergency landing gear extension:

[0059] In the case of power failure on the operating console, the landing gear emergency release can be operated manually to open the front landing gear assembly 43, the left rear landing gear assembly 45 and the right rear landing gear assembly 44, control the emergency release hydraulic manual valve 2, shake the manual pump 33, and the pressure oil passes through the hydraulic manual valve 2 and the first conversion valve 3 along the main landing gear release oil circuit to lower the main landing gear of the left rear landing gear assembly 45 and the right rear landing gear assembly 44; and passes through the second conversion valve 4 along the front landing gear release oil circuit to lower the front landing gear of the front landing gear assembly 43. When other operations are performed, the two hydraulic manual valves 2 are closed;

[0060] Wheel brakes:

[0061] The landing gear is in the lowered position. Raise the T-type mounting platform 47 to lift the wheels off the ground. Check the wheel brakes on the ground. The pressure gauge on the operating console indicates normal. Press the brake button. The brake indicator light is on. At this time, the pressure gauge has no indication. Operate the brake handle and observe the brake pressure indication. Push it up for the left brake and pull it down for the right brake. The brake pressure changes with the position of the operating handle. When the maximum set pressure A is reached at the extreme positions at both ends, it will automatically return to the middle position when released, and the brake is released.

[0062] Front wheel turning:

[0063] The landing gear is in the lowered position. Raise the T-shaped mounting platform 47 so that the wheels are just off the ground. Use the wheel jack to lift the front landing gear so that its buffer strut is compressed by 100 to 120 mm. At this time, the turn indicator light on the operating panel lights up, and the front wheel can be turned. Connect the ground hydraulic power system to the operating table, increase the pressure to the set pressure A, operate the turning switch, and the pressure oil enters the front wheel turning actuator 10 through the second electromagnetic reversing valve 7 and the throttle valve 8 to rotate the front wheel. The oil in the other chamber returns to the oil tank through the throttle valve 8 and the second electromagnetic reversing valve 7.

Claims

1. A hydraulic control system for an aircraft landing gear training device, characterized in that: The training device comprises a training device body, which comprises a T-shaped mounting platform, three hydraulic lifting support legs for lifting and lowering the T-shaped mounting platform are fixedly mounted at the bottom of the T-shaped mounting platform, a front landing gear assembly for simulating the front landing gear of an aircraft is mounted at the front end of the bottom of the T-shaped mounting platform, and a left rear landing gear assembly and a right rear landing gear assembly for simulating the rear landing gear of an aircraft are mounted on both sides of the rear end of the bottom of the T-shaped mounting platform; three hydraulic lifting support legs, a front landing gear assembly, a left rear landing gear assembly and a right rear landing gear assembly and a hydraulic control system for controlling the operation thereof; The hydraulic power system includes an oil tank, an electric pump and a manual pump are connected in parallel to the oil tank through an oil pipe, an oil tank oil outlet switch is installed on the oil pipe, and a refueling port switch is installed between the oil tank oil outlet switch and the manual pump; the oil outlet pipes of the electric pump and the manual pump are connected to the multi-stage oil filter after being converged, a sampling switch, a first pressure regulating valve and a first pressure gauge are installed on the oil pipe after the multi-stage oil filter, and finally connected to the platform oil supply hose of the hydraulic control system; the oil tank is connected to an oil return pipe, and the oil return pipe is connected to the platform oil return hose of the hydraulic control system through an oil filter, a second pressure regulating valve and a second pressure gauge; The hydraulic control system comprises a first electromagnetic reversing valve, which is connected to a platform oil supply hose of a hydraulic power system. The outlet of the first electromagnetic reversing valve is divided into three routes. The first route is connected to a front landing gear lower lock actuator cylinder of a front landing gear assembly and controls the locking or releasing thereof. The front landing gear lower lock actuator cylinder is connected to a front lifting and retracting actuator cylinder through a throttle nozzle; the second route is connected to a main lifting and retracting small actuator cylinder and a main lifting and retracting large actuator cylinder of a left rear landing gear assembly and a right rear landing gear assembly, and enables the main landing gear to be unlocked and retracted; the third route passes through a pressure reducing valve and is connected to the brake wheels of the left rear landing gear assembly and the right rear landing gear assembly through a brake oil circuit at the same time; the return oil chambers of the front lifting and retracting actuator cylinder and the main lifting and retracting small actuator cylinder are connected to a platform oil return hose through a first conversion valve, a second conversion valve and a first electromagnetic reversing valve; the platform oil supply hose is connected to a front wheel turning actuator cylinder through a second electromagnetic reversing valve, a throttle valve and a safety valve.

2. The hydraulic control system of the aircraft landing gear training device according to claim 1, characterized in that: A level gauge for displaying the liquid level and a thermometer for displaying the oil temperature are installed inside the oil tank. An air filter is fixedly installed on the top of the oil tank; an oil filter for filtering the oil is arranged inside the oil tank; and an oil tank drain switch is arranged at the bottom of the oil tank.

3. The hydraulic control system of the aircraft landing gear training device according to claim 2, characterized in that: The oil outlet pipes of the electric pump and the manual pump are respectively installed with a first one-way valve, a first overflow valve is installed on the pipeline after the first one-way valve, and the overflow port of the first overflow valve is connected to the oil tank.

4. The hydraulic control system of the aircraft landing gear training device according to claim 3, characterized in that: The overflow port of the first electromagnetic reversing valve is connected to the platform oil return hose through the second one-way valve.

5. The hydraulic control system of the aircraft landing gear training device according to claim 4, characterized in that: The brake oil circuit includes a third one-way valve, a third conversion valve, a dosing device and a pressure sensor; the third conversion valve is also connected to the manual reversing valve, and the manual reversing valve is connected to the platform oil supply hose through the first solenoid valve.

6. The hydraulic control system of the aircraft landing gear training device according to claim 5, characterized in that: A throttle valve is installed in the oil circuit of the main lifting and retracting small actuator, which also includes an upper lock and a hydraulic manual valve.

7. A method for controlling an aircraft landing gear training device using the hydraulic control system of claim 6, characterized in that: Retracting the landing gear: First, synchronously raise the three hydraulic lifting support legs of the platform so that the wheels are off the ground to a height suitable for the retraction and extension of the landing gear. Insert the safety pin, firmly connect the platform oil supply hose to the hydraulic power system, turn on the power, check that the electrical and control switches are normal, then start the electric pump and adjust the pressure to the set pressure A; operate the landing gear handle on the operating table and turn it to the retracted position. The pressure oil is divided into three paths after passing through the first electromagnetic reversing valve. One path goes to the front landing gear lower lock actuator to open the lock. At the same time, the pressure oil passes through the throttle nozzle and enters the retraction chamber of the front lifting and retraction actuator to retract the front landing gear assembly; the other path goes to the main lifting and retraction small actuator and the main lifting and retraction large actuator to retract the main landing gear assembly. The gear is unlocked and retracted; another path passes through the pressure reducing valve and the brake oil circuit to brake the brake wheels of the left and right main landing gears; the oil in the lowering chamber of the front retracting and lifting cylinder and the main retracting and lifting small cylinder returns to the oil tank through the first conversion valve, the second conversion valve and the first electromagnetic reversing valve, and the oil in the lowering chamber of the main retracting and lifting large cylinder directly returns to the oil tank of the power system; the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly are suspended in the retracted position by the upper lock. After the landing gear is retracted, the micro switch is turned on and the three red lights on the operating console are on; when the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position; To lower the landing gear: Pull the landing gear handle to the down position. The pressure oil is divided into two paths after passing through the first electromagnetic reversing valve. One path passes through the second conversion valve to the front up lock to open the lock, and at the same time, it also goes to the down chamber of the front up and down actuator cylinder to lower the front landing gear. The oil in the up chamber of the front up and down actuator cylinder passes through the throttle nozzle and then returns to the oil tank through the first electromagnetic reversing valve; the other path passes through the first conversion valve to the landing gear and up lock of the left rear landing gear assembly and the right rear landing gear assembly, opens the left and right main up locks, and goes to the throttle valve to the main up and down small actuator cylinder on the folding strut. Under the action of oil pressure and gravity, the main landing gear is lowered and locked; the oil in the other chamber of the main retractable small actuator merges with the return oil of the front landing gear actuator, and then the first electromagnetic reversing valve returns to the oil tank; the main retractable large actuator has no pressure oil during the main landing gear lowering process. When the piston rod extends, the oil is sucked in from the return oil circuit, and the oil in the other chamber of the piston flows back to the oil tank; after the landing gear is lowered, the micro switch is turned on, and the three green lights on the operating console are on. When the system pressure reaches the set pressure A, after T seconds, the landing gear switch is placed in the neutral position; Emergency landing gear extension: In case of power failure on the operating console, the landing gear emergency release can be operated manually. The landing gears of the front landing gear assembly, the left rear landing gear assembly and the right rear landing gear assembly can be opened. The emergency release hydraulic manual valve can be controlled and the manual pump can be shaken. The pressure oil passes through the hydraulic manual valve and the first conversion valve along the main landing gear oil line to lower the main landing gear of the left rear landing gear assembly and the right rear landing gear assembly; the pressure oil passes through the second conversion valve along the front landing gear oil line to lower the front landing gear of the front landing gear assembly. When other operations are performed, the two hydraulic manual valves are closed. Wheel brakes: The landing gear is in the lowered position. Raise the T-shaped installation platform to lift the wheels off the ground. Check the wheel brakes on the ground. The pressure gauge on the operating table indicates normal. Press the brake button. The brake indicator light is on. At this time, the pressure gauge has no indication. Operate the brake handle and observe the brake pressure indication. Push it up for the left brake and pull it down for the right brake. The brake pressure changes with the position of the operating handle. When it reaches the maximum set pressure A at the extreme positions at both ends, it will automatically return to the middle position when released, releasing the brake. Front wheel turning: With the landing gear in the lowered position, raise the T-shaped mounting platform so that the wheels are just off the ground, and use the wheel jack to lift the front landing gear so that its buffer strut is compressed by 100 to 120 mm. At this time, the turn indicator light on the operating panel will light up, and the front wheel can be turned. Connect the ground hydraulic power system to the operating table, increase the pressure to the set pressure A, operate the turn switch, and the pressure oil enters the front wheel turning actuator through the second solenoid reversing valve and the throttling valve to rotate the front wheel. The oil in the other chamber returns to the oil tank through the throttling valve and the second solenoid reversing valve.

8. The method for controlling an aircraft landing gear training device using a hydraulic control system according to claim 7, characterized in that: The set pressure A is 14.7Mp; the time T is 5s.

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