Method and system for rapid pressure relief of an aircraft wheel brake

Abstract

The application discloses a method and system for rapid pressure relief of an airplane wheel brake, which is characterized in that a cut-off valve is arranged between a brake pressure servo valve and a hydraulic system, the brake pressure servo valve and the cut-off valve are electrically connected with a BCU, the BCU receives brake working instructions in real time, judges, outputs a cut-off valve control signal, and connects the pressure supply of the brake pressure servo valve; meanwhile, the BCU outputs a control current of the brake pressure servo valve, the brake pressure servo valve outputs corresponding brake pressure, and brakes; during the braking process, when the wheel is in deep skidding or the brake pressure servo valve main valve core is stuck, the B port of the brake pressure servo valve cannot be relieved, the BCU does not output the cut-off valve control signal, the cut-off valve core returns to the initial position, the B port of the brake pressure servo valve is directly connected with the hydraulic system return port R, 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 directional control during ground taxiing, and is a critical system for ensuring safe takeoff and landing. Modern aircraft wheel hydraulic systems mostly utilize digital fly-by-wire control and consist of components such as command sensors, shut-off valves, brake pressure servo valves, pressure sensors, hydraulic fuses, wheel speed sensors, and brake control units. During operation, the brake pressure servo valve is a hydraulic component with a high failure rate. The brake pressure servo valve is an extremely precise hydraulic component, outputting proportional brake pressure based on the control signal from the internal torque motor. However, it is sensitive to contaminants in the hydraulic fluid, and a particularly serious failure mode is main valve spool jamming. Once the main valve spool of the brake pressure servo valve jams, the brake pressure cannot be released quickly, causing wheel lock, ultimately leading to tire blowout and loss of braking capability on the corresponding wheel. Furthermore, the high energy fragments generated by a tire explosion can damage piping and cables in the landing gear well or on the landing gear struts, potentially resulting in serious secondary hazards such as brake failure and fire, seriously compromising aircraft safety.

[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 this application is to provide a method and system for rapid pressure relief of aircraft wheel brakes to address the issue of main valve core stuck verification in existing wheel hydraulic systems, which affects aircraft safety. A method for rapid pressure relief of aircraft wheel brakes includes: providing a shut-off valve between a brake pressure servo valve and a hydraulic system, wherein the brake pressure servo valve and the shut-off valve are electrically connected to a control unit (BCU). The BCU receives brake operation instructions in real time, makes a judgment, and outputs a shut-off valve control signal to connect the pressure supply to the brake pressure servo valve. Simultaneously, the BCU outputs a control current to the brake pressure servo valve, which then outputs a corresponding brake pressure to apply braking. During braking, if the wheel is in deep slip or the main valve core of the brake pressure servo valve is stuck, preventing the brake pressure servo valve from releasing pressure at port B, the BCU does not output a shut-off valve control signal, and the shut-off valve core returns to its initial position, allowing port B of the brake pressure servo valve to directly connect to the hydraulic system's 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 braking command is received, the working state judgment module causes the BCU to output different control commands according to the actual working conditions.

[0007] Preferably, the P port and the R port of the shut-off valve are connected to the pressure supply and return oil 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 shut-off valve control signal, the shut-off valve connects the hydraulic system to the pressure supply to the brake pressure servo valve, and cuts off the connection between the B port of the brake pressure servo valve and the return oil of the hydraulic system. The brake pressure servo valve outputs a 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 the cut-off valve and brake pressure servo valve control signals, 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 embodiment, a system for rapid pressure relief of aircraft wheel brakes includes a shut-off valve, a brake pressure servo valve and a BCU; the BCU is a brake control unit, the BCU is electrically connected to the shut-off valve and the brake pressure servo valve, the P2 port of the shut-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 shut-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 implemented by arranging a shut-off valve between the brake pressure servo valve and the hydraulic system. During normal braking, the shut-off valve is controlled by the BCU to connect or disconnect the pressure supply from 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 a shut-off valve control signal, and the shut-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 solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this 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. Shut-off valve; 3. Brake pressure servo valve; 4. Braking device; 5. BCU. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts 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 shut-off valve 2 between the brake pressure servo valve 3 and the hydraulic system 1, and the brake pressure servo valve 3 and the shut-off valve 2 are electrically connected to the BCU5. The BCU5 receives the brake operation instruction in real time, makes a judgment, and outputs a control signal for the shut-off valve 2 to connect 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, if 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 shut-off valve 2 control signal, and the shut-off valve 2 valve core 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 shut-off valve 2 are connected to the pressure supply and return oil pipelines of the hydraulic system 1 respectively.

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

[0026] Preferably, when braking is not performed, the BCU5 does not output control signals of the shut-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 shut-off valve 2; the shut-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 of the wheel speed. When anti-skid, the pressure servo valve signal is 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, the pressure can be forced to be released to ensure that there is no tire blowout.

[0028] like Figure 2 Preferably, when braking, BCU5 outputs a control signal for the shut-off valve 2, the shut-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.

[0029] Preferably, when the wheel is in deep slip, the BCU5 does not output control signals to the shut-off valve 2 and the brake pressure servo valve 3, the shut-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, the BCU5 outputs a control signal for the shutoff valve 2 but not a control signal for the brake pressure servo valve 3. However, if the pressure at port B of the brake pressure servo valve 3 does not decrease in response to the control signal, this indicates that the main valve core is stuck, preventing the brake line from releasing pressure. The BCU5 then stops outputting a control signal for the shutoff valve 2, causing the shutoff valve 2 to cut off the pressure supplied by the hydraulic system 1 to the brake pressure servo valve 3. Port B of the brake pressure servo valve 3 then connects directly to the return oil of the hydraulic system 1, rapidly releasing the brake pressure.

[0031] To summarize, the present application sets a shut-off valve 2 between the brake pressure servo valve 3 and the hydraulic system 1. During normal braking, the shut-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 shut-off valve 2 control signal, and the shut-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 embodiment, a system for rapid pressure relief of aircraft wheel brakes is also included. This system utilizes the aforementioned design and includes a shut-off valve 2, a brake pressure servo valve 3, and a BCU 5. The BCU 5 is a brake control unit electrically connected to the shut-off valve 2 and the brake pressure servo valve 3. Port P2 of the shut-off valve 2 is connected to port P of the brake pressure servo valve 3, while port B is connected to port B of the brake pressure servo valve 3. Port B of the brake pressure servo valve 3 is connected to a brake device 4. Ports P1 and R of the shut-off valve 2, as well as port R 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. Other structures can refer to common designs. In the absence of conflicts, 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 scope of protection 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 provided 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 a brake operation 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 a control current of the brake pressure servo valve (3), and the brake pressure servo valve (3) outputs a corresponding brake pressure to perform braking; 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, resulting in the brake pressure servo valve (3) B port being unable to release pressure, the BCU (5) does not output a control signal of the cut-off valve (2), and the valve core of the cut-off valve (2) returns to an initial position, so that the brake pressure servo valve (3) B port 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 according to claim 1, wherein: 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 according to claim 1, wherein: A working state judgment module is provided in the BCU (5). 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 according to claim 3, wherein: 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 according to 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 according to 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 hydraulic system (1) to supply pressure to the brake pressure servo valve (3), cutting 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 according to claim 4, wherein: When the wheel is in deep slip, the BCU (5) does not output the control signal 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 according to claim 4, wherein: The BCU (5) outputs a control signal to the brake pressure servo valve (3), but when the pressure at the B port of the brake pressure servo valve (3) does not decrease along with the control signal, 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 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 of the hydraulic system (1), and the brake pressure is quickly released.

9. The method for rapid pressure relief of aircraft wheel brakes according to claim 1, wherein: The pressure servo valve (3) is a two-position three-way valve.

10. A system for rapid pressure relief of aircraft wheel brakes, employing 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 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).

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