Rapid pressure relief method and system for airplane wheel braking

Abstract

According to the rapid pressure relief method and system for airplane wheel braking, the stop valve is arranged between the brake pressure servo valve and the hydraulic system, and the brake pressure servo valve and the stop valve are electrically connected with the BCU. The BCU receives a brake work instruction in real time, judges the brake work instruction, outputs a stop valve control signal and switches on pressure supply of a brake pressure servo valve; meanwhile, the BCU outputs control current of a brake pressure servo valve, and the brake pressure servo valve outputs corresponding brake pressure for braking; in the braking process, when an airplane wheel is in a deep slipping state or a main valve element of the brake pressure servo valve is blocked and consequently the pressure of a port B of the brake pressure servo valve cannot be relieved, the BCU does not output a stop valve control signal, the valve element of the stop valve returns to the initial position, the port B of the brake pressure servo valve is directly communicated with an oil return port R of the hydraulic system, and the purpose of rapid pressure relief of the hydraulic system is achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft wheel hydraulic system design, and in particular relates to a method and system for rapid pressure relief of aircraft wheel brakes. Background Art

[0002] The wheel hydraulic system is used for deceleration and auxiliary direction control during the ground taxiing of the aircraft. It is a key system to ensure the safety of aircraft take-off and landing. Most of the wheel hydraulic systems of modern aircraft adopt digital electric-by-wire control, which consists of accessories such as command sensors, cut-off valves, brake pressure servo valves, pressure sensors, hydraulic fuses, wheel speed sensors and brake control units. During use, the brake pressure servo valve is a hydraulic accessory with a high failure rate. The brake pressure servo valve is an extremely precise hydraulic accessory. It outputs proportional brake pressure according to the control signal of the internal torque motor, but it is more sensitive to pollutants in the hydraulic oil. Among its failure modes, the main valve core is stuck. Once the main valve core of the brake pressure servo valve is stuck, the brake pressure cannot be released quickly, causing the wheel to lock, and eventually leading to tire blowout and loss of braking ability of the corresponding wheel. In addition, the fragments generated by the tire blowout have high energy, which may cause damage to the pipelines and cables on the landing gear compartment or the landing gear struts, and then cause serious secondary hazards such as serious brake failure and fire, which seriously affect the safety of the aircraft.

[0003] Therefore, how to avoid the main valve core from getting stuck and causing the wheel to lock and tire blowout is a problem that needs to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a method and system for rapid pressure relief of aircraft wheel brakes, so as to solve the problem that the main valve core stuck in the existing wheel hydraulic system affects the safety of the aircraft. A method for rapid pressure relief of aircraft wheel brakes, comprising: setting a cut-off valve between the brake pressure servo valve and the hydraulic system, and the brake pressure servo valve and the cut-off valve are electrically connected to the BCU. The BCU receives the brake working instruction in real time, makes a judgment, outputs the cut-off valve control signal, and connects the pressure supply of the brake pressure servo valve; at the same time, the BCU outputs the control current of the brake pressure servo valve, and the brake pressure servo valve outputs the corresponding brake pressure to brake; during the braking process, when the wheel is in deep slip or the main valve core of the brake pressure servo valve is stuck, causing the brake pressure servo valve B port to be unable to release pressure, the BCU does not output the cut-off valve control signal, and the cut-off valve core returns to the initial position, so that the brake pressure servo valve B port is directly connected to the hydraulic system oil return port R.

[0005] Preferably, the shut-off valve is configured as a two-position four-way solenoid valve.

[0006] Preferably, a working state judgment module is provided in the BCU. When a brake command is received, the working state judgment module causes the BCU to output different control commands according to actual working conditions.

[0007] Preferably, the P port and the R port of the cut-off valve are connected to the pressure supply and oil return pipelines of the hydraulic system respectively.

[0008] Preferably, when braking is not performed, the BCU does not output control signals of the cut-off valve and the brake pressure servo valve, and the B port of the brake pressure servo valve is directly connected to the return oil through the cut-off valve; the cut-off valve cuts off the pressure supply from the hydraulic system to the brake pressure servo valve.

[0009] Preferably, when braking, the BCU outputs a cut-off valve control signal, the cut-off valve connects the hydraulic system to the brake pressure servo valve, cuts off the connection between the B port of the brake pressure servo valve and the return oil of the hydraulic system, and the brake pressure servo valve outputs proportional brake pressure at the B port according to the control signal.

[0010] Preferably, when the wheel is in deep slip, the BCU does not output control signals of the cut-off valve and the brake pressure servo valve, the cut-off valve cuts off the pressure supply from the hydraulic system to the brake pressure servo valve, the B port of the brake pressure servo valve is directly connected to the return oil, and the brake pressure is quickly released.

[0011] Preferably, the BCU outputs a cut-off valve control signal but does not output a brake pressure servo valve control signal. However, when the pressure at port B of the brake pressure servo valve does not decrease along with the brake pressure servo valve control signal, the BCU does not output a cut-off valve control signal, and the cut-off valve cuts off the pressure supply from the hydraulic system to the brake pressure servo valve. Port B of the brake pressure servo valve is directly connected to the return oil of the hydraulic system, and the brake pressure is quickly released.

[0012] Preferably, the pressure servo valve is a two-position three-way valve.

[0013] As a specific implementation, a system for rapid pressure relief of aircraft wheel brakes includes a cut-off valve, a brake pressure servo valve and a BCU; the BCU is a brake control unit, the BCU is electrically connected to the cut-off valve and the brake pressure servo valve, the P2 port of the cut-off valve is connected to the P port of the brake pressure servo valve, and the B port is connected to the B port of the brake pressure servo valve 3; the B port of the brake pressure servo valve is connected to the brake device, and the cut-off valve P1 and R port, and the R port of the brake pressure servo valve are connected to the hydraulic system.

[0014] The method and system for rapid pressure relief of aircraft wheel brakes of the present application are provided with a cut-off valve between the brake pressure servo valve and the hydraulic system. During normal braking, the cut-off valve is controlled by the BCU to connect or disconnect the pressure supply of the hydraulic system to the brake pressure servo valve. When the main valve core of the brake pressure servo valve is stuck or the wheel is in a deep slip state, the BCU does not output the cut-off valve control signal, and the cut-off valve directly connects the B port of the brake pressure servo valve and the return oil of the hydraulic system, thereby achieving the purpose of rapid pressure relief of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0016] Figure 1 This is a schematic diagram of the overall structure of this application;

[0017] Figure 2 This is a schematic diagram of the normal brake working state for this application;

[0018] Figure 3 This is a schematic diagram of the rapid pressure relief state of the servo valve main valve core stuck in this application.

[0019] 1. Hydraulic system; 2. Cut-off valve; 3. Brake pressure servo valve; 4. Braking device; 5. BCU. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] A method for rapidly releasing pressure from aircraft wheel brakes, such as Figure 1 , including: setting a cut-off valve 2 between the brake pressure servo valve 3 and the hydraulic system 1, and the brake pressure servo valve 3 and the cut-off valve 2 are electrically connected to the BCU5. The BCU5 receives the brake work instruction in real time, makes a judgment, outputs the control signal of the cut-off valve 2, and connects the pressure supply of the brake pressure servo valve 3; at the same time, the BCU5 outputs the control current of the brake pressure servo valve 3, and the brake pressure servo valve 3 outputs the corresponding brake pressure to brake; during the braking process, when the wheel is in deep slip or the main valve core of the brake pressure servo valve 3 is stuck, so that the B port of the brake pressure servo valve 3 cannot release pressure, the BCU5 does not output the control signal of the cut-off valve 2, and the valve core of the cut-off valve 2 returns to the initial position, so that the B port of the brake pressure servo valve 3 is directly connected to the return oil port R of the hydraulic system 1.

[0022] Preferably, the shut-off valve 2 is configured as a two-position four-way solenoid valve.

[0023] Preferably, the pressure servo valve 3 is a two-position three-way valve.

[0024] Preferably, the P port and the R port of the cut-off valve 2 are connected to the pressure supply and oil return pipelines of the hydraulic system 1 respectively.

[0025] Preferably, a working state judgment module is provided in the BCU5. After receiving a brake command, the working state judgment module outputs different control commands according to the actual working conditions.

[0026] Preferably, when braking is not performed, BCU5 does not output control signals of the cut-off valve 2 and the brake pressure servo valve 3, and the B port of the brake pressure servo valve 3 is directly connected to the return oil through the cut-off valve 2; the cut-off valve 2 cuts off the pressure supply from the hydraulic system 1 to the brake pressure servo valve 3.

[0027] When braking, both the cut-off valve and the brake pressure servo valve have control signals. The servo valve adjusts the pressure according to the change in wheel speed. When preventing slipping, the pressure servo valve signal will be adjusted to a very small value. If the output pressure of the pressure servo valve does not decrease at this time, it means that the valve core is stuck and the cut-off valve cannot reduce the pressure. After adopting the present invention, pressure relief can be forced to ensure that there is no tire blowout.

[0028] like Figure 2 Preferably, when braking, BCU5 outputs a control signal of the cut-off valve 2, the cut-off valve 2 connects the pressure supply from the hydraulic system 1 to the brake pressure servo valve 3, and cuts off the connection between the B port of the brake pressure servo valve 3 and the return oil of the hydraulic system 1, and the brake pressure servo valve 3 outputs a proportional brake pressure at the B port according to the control signal.

[0029] Preferably, when the wheel is in deep slip, BCU5 does not output control signals of the cut-off valve 2 and the brake pressure servo valve 3, the cut-off valve 2 cuts off the pressure supply from the hydraulic system 1 to the brake pressure servo valve 3, the B port of the brake pressure servo valve 3 is directly connected to the return oil, and the brake pressure is quickly released.

[0030] like Figure 3 Preferably, BCU5 outputs the control signal of the cut-off valve 2, and does not output the control signal of the brake pressure servo valve 3. However, when the pressure of the B port of the brake pressure servo valve 3 does not decrease along with the control signal of the brake pressure servo valve, it indicates that the main valve core is stuck and the brake pipeline cannot be depressurized. BCU5 does not output the control signal of the cut-off valve 2, and the cut-off valve 2 cuts off the pressure supplied by the hydraulic system 1 to the brake pressure servo valve 3. The B port of the brake pressure servo valve 3 is directly connected to the return oil of the hydraulic system 1, and the brake pressure is quickly released.

[0031] To summarize, the present application sets a cut-off valve 2 between the brake pressure servo valve 3 and the hydraulic system 1. During normal braking, the cut-off valve 2 is controlled by the BCU5 to connect or disconnect the pressure supply from the hydraulic system 1 to the brake pressure servo valve 3. When the main valve core of the brake pressure servo valve 3 is stuck or the wheel is in a deep slip state, the BCU5 does not output the cut-off valve 2 control signal, and the cut-off valve 2 directly connects the B port of the brake pressure servo valve 3 and the return oil of the hydraulic system 1, thereby achieving the purpose of rapid pressure relief of the hydraulic system 1.

[0032] As a specific implementation, a system for rapid pressure relief of aircraft wheel brakes is also included, which adopts the above design and includes a cut-off valve 2, a brake pressure servo valve 3 and a BCU5. The BCU5 is a brake control unit, which is electrically connected to the cut-off valve 2 and the brake pressure servo valve 3. The P2 port of the cut-off valve 2 is connected to the P port of the brake pressure servo valve 3, and the B port is connected to the B port of the brake pressure servo valve 3. The B port of the brake pressure servo valve 3 is connected to the brake device 4, and the P1 and R ports of the cut-off valve 2 and the R port of the brake pressure servo valve 3 are connected to the hydraulic system 1.

[0033] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0034] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for rapid pressure relief of aircraft wheel brakes, characterized in that: include: A cut-off valve (2) is arranged between the brake pressure servo valve (3) and the hydraulic system (1), and the brake pressure servo valve (3) and the cut-off valve (2) are electrically connected to the BCU (5); the BCU (5) receives the brake working instruction in real time, makes a judgment, outputs a control signal of the cut-off valve (2), and connects the pressure supply of the brake pressure servo valve (3); at the same time, the BCU (5) outputs the control current of the brake pressure servo valve (3), and the brake pressure servo valve (3) outputs the corresponding brake pressure to brake; during the braking process, when the wheel is in deep slip or the main valve core of the brake pressure servo valve (3) is stuck, so that the B port of the brake pressure servo valve (3) cannot release pressure, the BCU (5) does not output the control signal of the cut-off valve (2), and the valve core of the cut-off valve (2) returns to the initial position, so that the B port of the brake pressure servo valve (3) is directly connected to the oil return port R of the hydraulic system (1).

2. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 1, characterized in that: The cut-off valve (2) is configured as a two-position four-way solenoid valve.

3. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 1, characterized in that: The BCU (5) is provided with a working state judgment module. When a brake command is received, the working state judgment module outputs different control commands according to the actual working conditions.

4. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 3, characterized in that: The P port and the R port of the cut-off valve (2) are respectively connected to the pressure supply and oil return pipelines of the hydraulic system (1).

5. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 4, characterized in that: When the brake is not applied, the BCU (5) does not output control signals to the cut-off valve (2) and the brake pressure servo valve (3), and the port B of the brake pressure servo valve (3) is directly connected to the return oil through the cut-off valve (2); the cut-off valve (2) cuts off the pressure supplied by the hydraulic system (1) to the brake pressure servo valve (3).

6. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 4, characterized in that: When braking, the BCU (5) outputs a control signal to the cut-off valve (2), and the cut-off valve (2) connects the pressure supply from the hydraulic system (1) to the brake pressure servo valve (3), and cuts off the connection between the B port of the brake pressure servo valve (3) and the return oil of the hydraulic system (1). The brake pressure servo valve (3) outputs a proportional brake pressure at the B port according to the control signal.

7. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 4, characterized in that: When the wheel is in deep slip, the BCU (5) does not output control signals to the cut-off valve (2) and the brake pressure servo valve (3), the cut-off valve (2) cuts off the pressure supplied by the hydraulic system (1) to the brake pressure servo valve (3), the B port of the brake pressure servo valve (3) is directly connected to the return oil, and the brake pressure is quickly released.

8. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 4, characterized in that: When the BCU (5) outputs a control signal to the brake pressure servo valve (3), but the pressure at the B port of the brake pressure servo valve (3) does not decrease along with the control signal to the brake pressure servo valve (3), the BCU (5) does not output a control signal to the cut-off valve (2), and the cut-off valve (2) cuts off the pressure supplied by the hydraulic system (1) to the brake pressure servo valve (3), and the B port of the brake pressure servo valve (3) is directly connected to the return oil of the hydraulic system (1), so that the brake pressure is rapidly released.

9. The method for rapid pressure relief of aircraft wheel brakes as claimed in claim 1, characterized in that: The pressure servo valve (3) is a two-position three-way valve.

10. A system for rapid pressure relief of aircraft wheel brakes, using the method according to any one of claims 1 to 9, characterized in that: The invention comprises a cut-off valve (2), a brake pressure servo valve (3) and a BCU (5); the BCU (5) is a brake control unit, the BCU (5) is electrically connected to the cut-off valve (2) and the brake pressure servo valve (3), the P2 port of the cut-off valve (2) is connected to the P port of the brake pressure servo valve (3), and the B port is connected to the B port of the brake pressure servo valve (3); the B port of the brake pressure servo valve (3) is connected to a brake device (4), and the P1 and R ports of the cut-off valve (2) and the R port of the brake pressure servo valve (3) are connected to a hydraulic system (1).

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