Pressure servo valve with quick pressure relief protection

Abstract

The application discloses a pressure servo valve with quick pressure relief protection, comprising a hydraulic servo valve and a hydraulic electromagnetic valve, wherein the hydraulic servo valve comprises a torque motor, a jet amplifier, a pilot stage and a power stage, the hydraulic electromagnetic valve comprises a spool valve assembly, a valve assembly and an electromagnet, the hydraulic servo valve and the hydraulic electromagnetic valve comprise an oil supply port J1, an oil supply port J2, an oil return port R0 and a pressure output port S0, the hydraulic electromagnetic valve comprises a relief hole, a second channel, a third channel, an oil return port R and a pressure output port S, the oil return port R0 and the oil return port R are directly communicated, the pressure output port S0, the pressure output port S and the relief hole are directly communicated, and the spool valve assembly can move left and right; when the spool valve assembly moves to the left end, the second channel is communicated with a second cavity; and when the spool valve assembly moves to the right end, the relief hole is communicated with a first cavity. The application can improve the reliability of an airplane brake system, realizes the quick pressure relief function without adding any parts, and does not increase the weight of the servo valve and the maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of electro-hydraulic pressure servo valve technology for aircraft braking systems, and in particular to a pressure servo valve with rapid pressure relief protection. Background Technology

[0002] Aircraft braking systems commonly use electro-hydraulic pressure servo valves to control output braking pressure. By inputting an electrical signal, the valve rapidly and proportionally outputs a corresponding high-precision braking pressure to achieve functions such as stopping, anti-skid, and braking. In the failure mode and hazard analysis of electro-hydraulic pressure servo valves in aircraft braking systems, the most serious failure mode is uncommanded braking pressure output, meaning that braking pressure persists even after the input signal is cut off, causing the anti-skid function of the braking system to fail. This failure can cause the aircraft wheels to lock up, leading to tire blowouts and posing a serious threat to aircraft safety.

[0003] Normally, when an aircraft braking system fails, it cuts off the input signal to the pressure servo valve, causing the brake pressure to drop rapidly to zero. However, if contaminants enter the pressure servo valve's spool clearance, causing the valve core to jam, the valve core cannot open the return port, preventing rapid pressure relief and potentially leading to wheel lockup. A common solution is to add a check valve to the valve body. This check valve allows for rapid pressure relief in the event of valve core jamming. However, this method requires high reliability and contamination resistance from the check valve. If the check valve fails, the system input pressure will be connected to the brake pressure output line, leading to a more serious wheel lockup failure.

[0004] The application number is 202111011747.3, and the title is "A Brake Control Servo Valve with Rapid Pressure Relief Protection". This patent achieves rapid pressure relief protection through a check valve, which has the risk of check valve failure and rapid pressure relief protection failure, and increases the weight of the servo valve as well as production and maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pressure servo valve with rapid pressure relief protection. This valve can achieve rapid pressure relief and prevent the aircraft's wheels from locking up due to uncommanded braking pressure output from the aircraft braking system, which could lead to a tire blowout. Without adding any components such as check valves, this pressure servo valve can achieve rapid pressure relief even if the valve core is stuck after the input signal is cut off, by improving the flow channel layout and valve body structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A pressure servo valve with rapid pressure relief protection includes a hydraulic servo valve and a hydraulic solenoid valve. The hydraulic servo valve includes a torque motor, a jet amplifier, a pilot stage, a power stage, and a first channel. The hydraulic solenoid valve includes a spool valve assembly, a valve assembly, and an electromagnet. Both the hydraulic servo valve and the hydraulic solenoid valve include an oil supply port J1, an oil supply port J2, a return port R0, and a pressure output port S0. The nozzle cavity of the jet amplifier is connected to the return port R0 through the first channel. The spool valve assembly includes three spaced-apart spool valve assembly sealing parts: a first spool valve assembly sealing part, a second spool valve assembly sealing part, and a third spool valve assembly sealing part. The hydraulic solenoid valve includes a pressure relief hole, a second channel, and a third channel. The system includes a channel, a return port R, and a pressure output port S. The supply ports J1 and J2 are connected via a third channel. A first cavity, connected to the return port R0, is formed between the first and second sealing parts of the spool valve assembly. A second cavity, connected to the supply port J2, is formed between the second and third sealing parts of the spool valve assembly. The return port R0 and the return port R are directly connected. The pressure output port S0, the pressure output port S, and the pressure relief hole are directly connected. The spool valve assembly can move left and right. When the spool valve assembly moves to the left end, the second channel connects to the second cavity. When the spool valve assembly moves to the right end, the pressure relief hole connects to the first cavity.

[0008] The torque motor supplies oil through the oil supply port J1. The oil is injected into the two receiving holes through the jet amplifier. After the torque motor is powered on, it outputs a rotation angle, which drives the nozzle to deviate from the injection position of the receiver, causing the recovery pressure in the two receiving holes to be different. As a result, the valve core in the pilot stage generates a certain displacement, which is transmitted to the torque motor through the feedback spring assembly, so that the nozzle is re-stabilized in a new position. The power stage amplifies the power of the differential pressure signal of the jet amplifier, outputs pressure S0, and feeds this pressure back to the valve core to realize the closed-loop control of the power stage.

[0009] When the nozzle shifts to the left, a pressure difference is formed in the two control chambers of the receiver. This pressure difference acts on the annular area of ​​the valve core of the power stage, causing the valve core of the power stage to move to the right, resulting in the return port R0 being covered and the supply port J2 opening. Oil enters the pressure output port S0 from the supply port J2, and this oil pressure acts on the feedback end face of the valve core of the power stage until the feedback force and the control force are balanced. When there is no current input, the pressure output port S0 is connected to the return port R0, the supply port J2 is closed, and the pressure in the pressure output chamber is equal to the return pressure.

[0010] The power stage includes a power stage sealing part one and a power stage sealing part two, and a third cavity is formed between the power stage sealing part one and the power stage sealing part two, which is connected to the pressure output port S0.

[0011] In the initial state, the hydraulic solenoid valve is energized and opened, and the hydraulic servo valve has not yet received a current signal. The spool valve assembly is located on the leftmost side under the pressure of the oil entering from the oil supply port P. The oil supply ports J1 and J2 are connected to the oil supply port P through the second channel. The oil from the oil supply port J1 is ejected from the nozzle of the jet amplifier. The power stage is located on the leftmost side under the action of the spring force, closing the oil supply port J2. There is no pressure output at the pressure output port S0. The oil overflowing from the pilot stage flows out through the first channel, the return port R0, and the return port R. At this time, the braking system has no braking pressure.

[0012] During the pressure build-up phase, the hydraulic solenoid valve is energized and opened, and the hydraulic servo valve receives an input current signal. Under the pressure of the oil entering from the oil supply port P, the spool valve assembly is positioned on the far left. Oil supply ports J1 and J2 are connected to the oil supply port P through the second channel. The oil from the oil supply port J1 is ejected from the nozzle of the jet amplifier. The pressure in the left flow channel of the pilot stage is greater than that in the right flow channel. The valve core of the power stage moves to the right, opening the oil supply port J2. The oil enters the pressure output port S0 through the oil supply port J2 and is output to the pressure output port S, thereby establishing the braking pressure. The oil overflowing from the pilot stage flows out through the first channel, the return port R0, and the return port R.

[0013] In operation, the hydraulic solenoid valve is energized and opened, and the hydraulic servo valve receives an input current signal. Under the pressure of the oil entering from the oil supply port P, the spool valve assembly is positioned on the far left. The oil supply ports J1 and J2 are connected to the oil supply port P through the second channel. The output brake pressure applies a leftward hydraulic pressure to the valve core through the valve core feedback port of the power stage. When this feedback force and spring force are equal to the force generated by the pressure difference of the jet amplifier, the valve core of the power stage moves to the left again to close the oil supply port J2. The pressure in the brake chamber is maintained, and the valve core of the power stage is in a stable state. The oil overflowing from the pilot stage flows out through the first channel, the return port R0, and the return port R.

[0014] In normal depressurization state, the hydraulic solenoid valve is energized and opened, the hydraulic servo valve receives an input current signal, and the spool valve assembly is positioned on the far left under the pressure of the oil entering from the oil supply port P. Oil supply ports J1 and J2 are connected to oil supply port P through the second channel. Oil from oil supply port J1 is ejected from the nozzle of the jet amplifier. The input current signal of the hydraulic servo valve decreases from the working state, and the pressure in the left flow channel of the power stage is less than that in the right flow channel. The valve core of the power stage moves to the left, opening the return port R0. The brake system pressure is depressurized through the pressure output port S0 from port R0. As the brake pressure decreases, the pressure feedback force of the valve core of the power stage decreases simultaneously until a new equilibrium is reached. The valve core of the power stage moves to the right to close the return port R0, returning to the steady state. The oil overflowing from the pilot stage flows out through the first channel, return port R0, and return port R.

[0015] In emergency rapid pressure relief mode, the hydraulic solenoid valve is de-energized and closed, and the hydraulic servo valve can be opened or closed with or without an input current signal. The oil enters the left chamber of the spool valve assembly through the fourth channel, pushing the spool valve assembly to the far right. The second channel is closed, and the oil supply ports J1 and J2 are disconnected from the second channel. No oil is ejected from the jet amplifier, and the oil in the brake system is rapidly depressurized from the pressure relief hole, the first chamber, and the return port R.

[0016] The hydraulic solenoid valve includes a fourth channel and a fifth channel. The oil in the fourth channel can be depressurized through the fifth channel, the first chamber, and the return port R.

[0017] The beneficial effects of this invention are:

[0018] 1. Even when the valve core of the pressure servo valve is stuck due to foreign objects or other reasons, and the valve core cannot open the return port or close the supply port, it can still achieve rapid pressure relief of the aircraft braking system. It is not affected by the servo valve signal input, reduces the risk of aircraft wheel lock-up, avoids tire blowout caused by the inability to relieve aircraft brake pressure in time, and improves the overall reliability of the aircraft braking system.

[0019] Second, the internal check valve was removed, the internal oil circuit of the valve body was improved, the internal structure of the pressure servo valve was simplified, the reliability of the servo valve was improved, and the rapid pressure relief function was achieved without adding any parts, without increasing the weight of the servo valve or maintenance costs, and the pressure relief effect remained unchanged after removing the internal check valve. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the invention in its initial state.

[0021] Figure 2 This is a schematic diagram of the present invention in the working pressure build-up state (transient).

[0022] Figure 3 This is a schematic diagram of the present invention in its working state (steady state).

[0023] Figure 4 This is a schematic diagram of the present invention in a normal depressurization state (transient).

[0024] Figure 5 This is a schematic diagram of the present invention in an emergency rapid pressure relief state.

[0025] Figure 6 This is a structural diagram of the hydraulic servo valve of the present invention.

[0026] Figure 7 This is a structural diagram of the hydraulic solenoid valve of the present invention.

[0027] In the diagram: hydraulic servo valve 1, torque motor 11, jet amplifier 12, pilot stage 13, power stage 14, power stage seal 141, power stage seal 2 142, first channel 15, hydraulic solenoid valve 2, pressure relief port 21, spool valve assembly 22, spool valve assembly seal 1 221, spool valve assembly seal 222, spool valve assembly seal 3 223, valve assembly 23, electromagnet 24, second channel 25, third channel 26, fourth channel 27, fifth channel 28. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0029] like Figures 1 to 7 As shown, a pressure servo valve with rapid pressure relief protection includes a hydraulic servo valve 1 and a hydraulic solenoid valve 2. Both the hydraulic servo valve 1 and the hydraulic solenoid valve 2 include an oil supply port J1, an oil supply port J2, an oil return port R0, and a pressure output port S0.

[0030] Reference Figure 6 The hydraulic servo valve 1 includes a torque motor 11, a jet amplifier 12, a pilot stage 13, a power stage 14, and a first channel 15. The torque motor 11 consists of a permanent magnet, upper and lower magnetic conductors, an armature, a control coil, and a Bourdon tube. The torque motor 11 is fixed to the upper part of the hydraulic servo valve 1 and connected to the jet amplifier 12 to convert electrical signals into mechanical motion, driving the jet amplifier 12 to operate. The torque motor 11 is supplied with oil through the oil supply port J1. The torque motor 11 generates a polarized magnetic field from the permanent magnet, and the electrical control signal generates a control magnetic field through the control coil. The interaction between the two magnetic fields produces a torque proportional to the control signal and capable of responding to the polarity of the control signal, thereby causing mechanical motion of displacement in its moving parts.

[0031] The jet amplifier 12 is a non-throttling hydraulic amplifier, consisting of a jet tube, a nozzle, and a receiver. Based on the output angle of the torque motor 11, the jet tube drives the nozzle to deviate from the spray position of the receiver, causing a difference in the recovery pressure in the two receiving holes, thereby achieving the conversion and amplification of control power. The nozzle cavity of the jet amplifier 12 is connected to the return port R0 through the first channel 15.

[0032] The pilot stage 13 consists of a compression spring, a valve core, and a valve body, and is used to ensure the linearity and stability of the control. When the jet amplifier 12 has a pressure output and controls the movement of the valve core, the spring force generated by the compression spring is balanced with the control force acting on the control valve core. The valve core generates a certain displacement and is transmitted to the torque motor 11 through the feedback spring assembly, so that the nozzle is re-stabilized in a new position.

[0033] Power stage 14 is the second-stage hydraulic amplifier in hydraulic servo valve 1, consisting of a valve core, valve body, and bushing. It amplifies the power of the differential pressure signal from jet amplifier 12, outputs pressure to the load chamber, and feeds this pressure back to the valve core to achieve closed-loop control of power stage 14, ensuring that the output pressure is proportional to the input current. Power stage 14 is supplied with oil through oil supply port J2.

[0034] The valve core of the power stage 14 includes a power stage sealing part 141 and a power stage sealing part 142, and a third cavity is formed between the power stage sealing part 141 and the power stage sealing part 142, which communicates with the pressure output port S0.

[0035] The working principle of the hydraulic servo valve 1 is as follows: the torque motor 11 supplies oil through the oil supply port J1, and the oil is injected into the two receiving holes through the jet amplifier 12. After the torque motor 11 is energized, it outputs a rotation angle, which drives the nozzle to deviate from the injection position of the receiver, causing the recovery pressure in the two receiving holes to be different. As a result, the valve core in the pilot stage 13 produces a certain displacement, which is transmitted to the torque motor 11 through the feedback spring assembly, so that the nozzle is re-stabilized in a new position. The power stage 14 amplifies the power of the differential pressure signal of the jet amplifier 12, outputs pressure S0, and feeds this pressure back to the valve core to realize the closed-loop control of the power stage 14.

[0036] When the positive control current flows through the coil of the torque motor 11, a control torque is generated, causing the armature assembly to deflect clockwise, the jet tube to shift to the left, and a pressure difference is formed in the two control chambers of the receiver. This pressure difference acts on the annular area of ​​the valve core of the power stage 14 (i.e., the left end face of the power stage sealing part 141), causing the valve core to move to the right, resulting in the return port R0 being covered and the supply port J2 opening. The pressure oil source enters the pressure output port S0 (i.e., the load pressure output port) from the supply port J2. This pressure then acts on the feedback end face of the valve core of the power stage 14 (i.e., the right end face of the power stage sealing part 141), causing the valve core to move to the left until the feedback force and the control force are balanced. When there is no current input, the pressure output port S0 is connected to the return port R0, and the inlet port J2 is closed. Figure 6 (State), the pressure in the pressure output chamber is equal to the return oil pressure.

[0037] Reference Figure 7 The hydraulic solenoid valve 2 includes a slide valve assembly 22, a valve assembly 23, and an electromagnet 24.

[0038] The electromagnet 24 mainly consists of a coil assembly, a movable iron core, a push rod, and a spring. It is used to convert electrical signals into mechanical motion to drive the valve assembly. The voltage applied across the coil of the electromagnet 24 generates a constant current in the coil, thereby establishing a magnetomotive force of a certain ampere-turns. Under the action of this magnetomotive force, a magnetic flux loop is formed along the movable iron core and the working air gap, causing the electromagnet 24 to generate a certain attractive force, and the push rod of the electromagnet to move accordingly.

[0039] Valve assembly 23 serves as the pilot control switch for hydraulic solenoid valve 2. It consists of inner and outer steel ball seats and a steel ball. After hydraulic solenoid valve 2 is energized, the push rod of electromagnet 24 pushes the steel ball against the sealing ring of the inner steel ball seat, thus closing the valve. Figure 1-4 In this state, the control oil circuit (fourth channel 27) and return port R of hydraulic solenoid valve 2 are connected; after hydraulic solenoid valve 2 is de-energized, under the action of hydraulic pressure, the steel ball is pressed onto the sealing ring of the outer steel ball seat, and the valve opens, i.e. Figure 5 In this state, the control oil circuit (fourth channel 27) of the hydraulic solenoid valve 2 is connected to the oil supply port P.

[0040] The spool valve assembly 22 consists of a valve core, valve sleeve, valve body, and piston. It is the actuator of the hydraulic solenoid valve 2 and functions similarly to a two-position two-way valve. When the control oil circuit is connected to the inlet, the hydraulic solenoid valve 2 is closed (i.e., the spool valve assembly 22 is located at the rightmost end), and the oil inlet (inlet J1 and inlet J2) of the hydraulic servo valve 1 is cut off. When the control oil circuit is connected to the return oil, the hydraulic solenoid valve 2 is opened (i.e., the spool valve assembly 22 is located at the leftmost end), and the oil inlet of the hydraulic servo valve 1 is opened.

[0041] The valve core of the slide valve assembly 22 includes three spaced-apart slide valve assembly sealing parts: a first slide valve assembly sealing part 221, a second slide valve assembly sealing part 222, and a third slide valve assembly sealing part 223. A first cavity communicating with the return oil port R0 is formed between the first slide valve assembly sealing part 221 and the second slide valve assembly sealing part 222, and a second cavity communicating with the supply oil port J2 is formed between the second slide valve assembly sealing part 222 and the third slide valve assembly sealing part 223.

[0042] When electromagnet 24 is energized, its push rod pushes the steel ball against the sealing ring of the inner steel ball seat assembly, closing the valve. At this time, the control oil circuit (fourth channel 27) of the hydraulic solenoid valve 2 is connected to the return port R. The electromagnetic force is greater than the hydraulic pressure, so the valve is closed. The valve core 22 is at its left limit position under the action of the oil pressure, and the oil supply circuit (oil supply port J1, oil supply port J2) of the hydraulic servo valve 1 is connected. When electromagnet 24 is de-energized, the steel ball is pressed against the sealing ring of the outer steel ball seat under the action of the hydraulic pressure, opening the valve. The control oil circuit (fourth channel 27) of the hydraulic solenoid valve 2 is connected to the oil supply port P. The valve is in the open state under the action of the oil supply pressure at the oil supply port P. The oil supply pressure acts on the left end face of the sealing part 221 of the slide valve assembly, pushing the valve core 22 to the right limit position, and the oil supply circuit (oil supply port J1, oil supply port J2) of the hydraulic servo valve 1 is cut off.

[0043] The hydraulic solenoid valve 2 includes a pressure relief port 21, a second channel 25, a third channel 26, a return port R, and a pressure output port S. The supply ports J1 and J2 are connected through the third channel 26. The return ports R0 and R are directly connected. The pressure output ports S0 and S are directly connected to the pressure relief port 21. The slide valve assembly 22 can move left and right. When the slide valve assembly 22 moves to the left end, the second channel 25 is connected to the second cavity. When the slide valve assembly 22 moves to the right end, the pressure relief port 21 is connected to the first cavity.

[0044] like Figure 1 As shown, in the initial state, the hydraulic solenoid valve 2 is energized and opened, the hydraulic servo valve 1 has not yet received a current signal, the spool valve assembly 22 is located on the leftmost side under the pressure of the oil entering from the oil supply port P, the oil supply ports J1 and J2 are connected to the oil supply port P through the second channel 25, the oil from the oil supply port J1 is ejected from the nozzle of the jet amplifier 12, the hydraulic servo valve 1 has no input current, the jet pipe is in the middle position, the pressure of the left and right flow channels of the jet amplifier 12 is equal, the valve core of the power stage 14 is located on the leftmost side under the action of the spring force, closing the oil supply port J2, the pressure output port S0 has no pressure output, that is, at this time the braking system has no braking pressure, the oil overflowing from the pilot stage 13 flows out through the first channel 15, the return port R0, and the return port R.

[0045] like Figure 2 As shown, during the working pressure build-up state (transient), the hydraulic solenoid valve 2 is energized and opened, the hydraulic servo valve 1 receives a current signal, and the spool valve assembly 22 is located on the leftmost side under the pressure of the oil entering from the oil supply port P. The oil supply ports J1 and J2 are connected to the oil supply port P through the second channel 25. The oil from the oil supply port J1 is ejected from the nozzle of the jet amplifier 12. The jet tube rotates to the left by a certain angle under the electromagnetic force of the armature assembly. The pressure in the left flow channel of the pilot stage 13 is greater than the pressure in the right flow channel, and it overcomes the spring force to move the valve core of the power stage 14 to the right, opening the oil supply port J2. The oil enters the pressure output port S0 through the oil supply port J2 and is output to the pressure output port S (brake chamber), thereby establishing the brake pressure. The oil overflowing from the pilot stage 13 flows out through the first channel 15, the return port R0, and the return port R.

[0046] like Figure 3As shown, in the working state (steady state), the hydraulic solenoid valve 2 is energized and opened, the hydraulic servo valve 1 receives a current signal, and the spool valve assembly 22 is located on the leftmost side under the action of the oil pressure entering from the oil supply port P. The oil supply ports J1 and J2 are connected to the oil supply port P through the second channel 25. During the working pressure building state (transient state), the output brake pressure applies a leftward hydraulic pressure to the valve core through the valve core feedback port of the power stage 14. When this feedback force and spring force are equal to the force generated by the pressure difference of the jet amplifier 12, the valve core of the power stage 14 moves to the left again to close the oil supply port J2. The pressure in the brake chamber is maintained, and the valve core of the power stage 14 is in a stable state. The oil overflowing from the pilot stage 13 flows out through the first channel 15, the return port R0, and the return port R.

[0047] like Figure 4 As shown, in the normal pressure relief state (transient state), the hydraulic solenoid valve 2 is energized and opened, the hydraulic servo valve 1 receives an input current signal, and the spool valve assembly 22 is positioned on the leftmost side under the pressure of the oil entering from the oil supply port P. Oil supply ports J1 and J2 are connected to oil supply port P through the second channel 25. The oil from oil supply port J1 is ejected from the nozzle of the jet amplifier 12. The input current signal of the hydraulic servo valve 1 decreases from the working state (steady state), and the jet pipe rotates to the left by an angle under the electromagnetic force of the armature assembly. As the pressure decreases, the pressure in the left flow channel of power stage 14 is less than that in the right flow channel. The valve core of power stage 14 moves to the left, opening the return port R0. The brake system pressure is released from port R0 through the pressure output port S0. As the brake pressure decreases, the pressure feedback force of the valve core of power stage 14 decreases simultaneously until a new equilibrium is reached. The valve core of power stage 14 then moves to the right to close the return port R0, returning to a steady state. The oil overflowing from pilot stage 13 flows out through the first channel 15, return port R0, and return port R.

[0048] like Figure 5 As shown, in the emergency rapid pressure relief state, the hydraulic solenoid valve 2 is de-energized and closed. The hydraulic servo valve 1 can operate with or without an input current signal. When the valve core of the hydraulic servo valve 1 is stuck, the normal pressure relief function fails. At this time, the emergency rapid pressure relief function is activated, and the hydraulic solenoid valve 2 is de-energized. The oil enters the left chamber of the slide valve assembly 22 through the fourth channel 27, pushing the slide valve assembly 22 to the far right. The second channel 25 is closed, and the oil supply ports J1 and J2 are disconnected from the second channel 25. No oil is ejected from the jet amplifier 12, and the input signal current of the hydraulic servo valve 1 has no effect on the output. The oil in the braking system is rapidly depressurized from the pressure relief port 21, the first chamber, and the return port R, realizing the emergency rapid pressure relief of the aircraft braking system.

[0049] The hydraulic solenoid valve 2 includes a fourth channel 27 and a fifth channel 28. The oil in the fourth channel 27 can be depressurized through the fifth channel 28, the first chamber, and the return port R. When... Figure 5When the state is switched, that is, when the push rod of the electromagnet 24 pushes the steel ball to press onto the sealing ring of the inner steel ball seat assembly, the valve closes and the slide valve assembly 22, which was originally located on the far right, is moved to the far left. During this process, the oil located on the far left of the slide valve assembly 22 (including the oil in the fourth channel 27) is discharged through the fifth channel 28.

[0050] Normally, hydraulic solenoid valve 2 remains open throughout the aircraft's flight. Braking pressure in the aircraft's braking system is increased and decreased via hydraulic servo valve 1. If the valve core of power stage 14 of hydraulic servo valve 1 becomes stuck, it will be locked at the far right of its stroke, blocking the return port R0. This prevents the oil in the brake load chamber from draining properly through the return port R0, causing the aircraft wheel braking system to fail and posing a risk of wheel lockup. In this situation, cutting off the input signal to hydraulic solenoid valve 2 (i.e., de-energizing electromagnet 24) causes the spool valve assembly 22 to move to the right, cutting off its oil supply. Simultaneously, the pressure relief port 21 connects to the return port R, allowing the oil at the pressure output port S to flow out quickly through the pressure relief port 21 and finally be depressurized through the return port R, thus preventing wheel lockup.

[0051] This embodiment is an improvement and optimization of existing technology, exhibiting good operational stability and reliability. Through improved and optimized internal oil circuit layout, the design of the pressure relief hole 21 prevents pressurized oil from clogging the pressure output port S, effectively avoiding tire blowouts caused by aircraft brake lock-up. Furthermore, the pressure servo valve in this embodiment has high integration, strong anti-contamination capabilities, and is manufactured using a modular design. The internal oil circuit structure of the valve body is simple, facilitating use and maintenance.

[0052] 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 within the protection scope of the present invention.

Claims

1. A pressure servo valve with quick pressure relief protection, comprising a hydraulic servo valve (1) and a hydraulic solenoid valve (2), the hydraulic servo valve (1) comprising a torque motor (11), a fluidic amplifier (12), a pilot stage (13), a power stage (14), a first channel (15), the hydraulic solenoid valve (2) comprising a spool valve assembly (22), a valve assembly (23), a solenoid (24), the hydraulic servo valve (1) and the hydraulic solenoid valve (2) each comprising an oil supply port J1, an oil supply port J2, an oil return port R0, a pressure output port S0, a cavity where a nozzle of the fluidic amplifier (12) is located is communicated with the oil return port R0 through the first channel (15), the spool valve assembly (22) comprising a spool valve assembly sealing part one (221), a spool valve assembly sealing part two (222), a spool valve assembly sealing part three (223) which are distributed at intervals, characterized in that, The hydraulic electromagnetic valve (2) includes a pressure relief hole (21), a second channel (25), a third channel (26), an oil return port R, a pressure output port S, the oil supply port J1 and the oil supply port J2 are communicated through the third channel (26), a first cavity is formed between the spool assembly sealing part one (221) and the spool assembly sealing part two (222) and is communicated with the oil return port R0, a second cavity is formed between the spool assembly sealing part two (222) and the spool assembly sealing part three (223) and is communicated with the oil supply port J2, the oil return port R0 and the oil return port R are directly communicated, the pressure output port S0, the pressure output port S and the pressure relief hole (21) are directly communicated, the spool assembly (22) can move left and right, when the spool assembly (22) moves to the left end, the second channel (25) is communicated with the second cavity, when the spool assembly (22) moves to the right end, the pressure relief hole (21) is communicated with the first cavity.

2. A pressure servo valve with quick pressure relief protection as claimed in claim 1, characterized in that The torque motor (11) is supplied with oil through the oil supply port J1, the oil is injected into two receiving holes through the jet amplifier (12), the torque motor (11) outputs a rotation angle after being energized, drives the nozzle to offset the jet position of the receiver, causes the restoring pressures in the two receiving holes to be different, so that the valve core in the pilot stage (13) generates a certain displacement and is transmitted to the torque motor (11) through the feedback spring assembly, so that the nozzle is stabilized at a new position, the power stage (14) amplifies the power of the pressure difference signal of the jet amplifier (12), outputs a pressure S0, and feeds back the pressure to the valve core to realize closed-loop control of the power stage (14).

3. A pressure servo valve with quick pressure relief protection as claimed in claim 2, characterized in that When the nozzle offsets to the left, a pressure difference is formed in the two control cavities of the receiver, the pressure difference acts on the annular area of the valve core of the power stage (14), the valve core of the power stage (14) moves to the right, causing the oil return port R0 to be covered and the oil supply port J2 to be opened; the oil enters the pressure output port S0 from the oil supply port J2, and the oil pressure acts on the feedback end surface of the valve core of the power stage (14) until the feedback force and the control force are balanced; when there is no current input, the pressure output port S0 is communicated with the oil return port R0, the oil supply port J2 is closed, and the pressure of the pressure output cavity is equal to the back pressure.

4. The pressure servo valve with quick pressure relief protection of claim 1, wherein, The power stage (14) includes a power stage sealing part one (141) and a power stage sealing part two (142), and a third cavity is formed between the power stage sealing part one (141) and the power stage sealing part two (142) and is communicated with the pressure output port S0.

5. The pressure servo valve with quick pressure relief protection of claim 1, wherein, In the initial state, the hydraulic electromagnetic valve (2) is energized and opened, the hydraulic servo valve (1) has not input a current signal, the spool assembly (22) is located at the leftmost side under the action of the oil pressure from the oil supply port P, the oil supply port J1 and the oil supply port J2 are connected with the oil supply port P through the second channel (25), the oil in the oil supply port J1 is ejected from the nozzle of the jet amplifier (12), the power stage (14) is located at the leftmost side under the action of the spring force, the oil supply port J2 is closed, the pressure output port S0 has no pressure output, the overflowed oil of the pilot stage (13) flows out through the first channel (15), the oil return port R0 and the oil return port R, and at this time, the brake system has no brake pressure.

6. The pressure servo valve with quick pressure relief protection of claim 1, wherein, When the pressure building state, the hydraulic solenoid valve (2) is powered on, the hydraulic servo valve (1) input current signal, spool assembly (22) under the action of the oil pressure from the oil supply port P is located in the leftmost side, oil supply port J1, oil supply port J2 through the second channel (25) and oil supply port P connection, oil supply port J1 of the oil from the nozzle of the jet amplifier (12) is ejected, the left side of the pilot stage (13) flow passage pressure is greater than the right side flow passage pressure, the power stage (14) of the spool to the right move, the oil supply port J2 is opened, the oil through the oil supply port J2 into the pressure output port S0, and output to the pressure output port S, thereby establishing brake pressure, the pilot stage (13) overflow oil through the first channel (15), the return oil port R0, the return oil port R outflow.

7. The pressure servo valve with quick pressure relief protection of claim 1, wherein, When the working state, the hydraulic solenoid valve (2) is powered on, the hydraulic servo valve (1) input current signal, spool assembly (22) under the action of the oil pressure from the oil supply port P is located in the leftmost side, oil supply port J1, oil supply port J2 through the second channel (25) and oil supply port P connection, output brake pressure through the power stage (14) of the valve core feedback port to the valve core exert left hydraulic pressure, when the feedback force and spring force and the jet amplifier (12) pressure difference generated force is equal, the power stage (14) of the spool again left move will close the oil supply port J2, brake chamber pressure is maintained, the power stage (14) of the spool is in a stable state, the pilot stage (13) overflow oil through the first channel (15), the return oil port R0, the return oil port R outflow.

8. The pressure servo valve with quick pressure relief protection of claim 1, wherein, When the normal pressure relief state, the hydraulic solenoid valve (2) is powered on, the hydraulic servo valve (1) input current signal, spool assembly (22) under the action of the oil pressure from the oil supply port P is located in the leftmost side, oil supply port J1, oil supply port J2 through the second channel (25) and oil supply port P connection, oil supply port J1 of the oil from the nozzle of the jet amplifier (12) is ejected, the hydraulic servo valve (1) input current signal is reduced on the basis of the working state, the power stage (14) left side flow passage pressure is less than the right side flow passage pressure, the power stage (14) of the spool to the left move, make the return oil port R0 open, brake system pressure through the pressure output port S0 from R0 port pressure relief, with the brake pressure drops, the power stage (14) of the spool pressure feedback force is reduced at the same time, until a new balance is reached, the power stage (14) of the spool to the right move close the return oil port R0, restore to steady state, the pilot stage (13) overflow oil through the first channel (15), the return oil port R0, the return oil port R outflow.

9. The pressure servo valve with quick pressure relief protection of claim 1, wherein, When the emergency fast pressure relief state, the hydraulic solenoid valve (2) is powered off, the hydraulic servo valve (1) has no input current signal can, the oil through the fourth channel (27) into the left cavity of the spool assembly (22), the spool assembly (22) is pushed to the rightmost side, the second channel (25) is closed, oil supply port J1, oil supply port J2 and the second channel (25) are disconnected, the jet amplifier (12) no oil is ejected, the oil in the brake system from the relief hole (21), the first cavity, the return oil port R fast pressure relief.

10. The pressure servo valve with quick pressure relief protection of claim 1, wherein, The hydraulic electromagnetic valve (2) comprises a fourth channel (27) and a fifth channel (28), and the oil in the fourth channel (27) can be discharged through the fifth channel (28), the first cavity and the oil return port R.

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