Hydraulic device for vehicle brake-by-wire system

Abstract

The present invention discloses a hydraulic device for a vehicle's brake-by-wire control system, comprising a fluid reservoir for storing a pressurized medium; a brake pedal for operating the brakes; a pedal master cylinder, a piston of which is fixedly connected to the brake pedal operating handle for providing initial brake pressure; a motor master cylinder, which is provided with a piston connected to a motor device and is used to provide pressure to the pressurized medium via the motor to operate the wheels for braking; and a pedal feel simulator, which is connected to the pedal master cylinder and is used to provide a reaction force in response to the operation of the brake pedal. In the present invention, when the brake pedal is depressed under normal braking conditions, the pedal master cylinder and the motor master cylinder are in a decoupled state. The motor master cylinder provides brake pressure and generates brake pressure in the left chamber, while the right chamber absorbs oil from the fluid reservoir. When the piston of the motor master cylinder moves to the right, the second motor decoupling valve is connected, the first motor decoupling valve is closed, and the hydraulic pressure generated in the right chamber of the motor master cylinder provides the wheel cylinder braking force. The oil circuit is simple and convenient to use.

Description

Technical Field

[0001] The present invention relates to the field of electronic brake systems, and in particular to a hydraulic device for a vehicle brake-by-wire system. Background Art

[0002] The braking system is an essential component of a vehicle. With the recent advancement of automotive technology and the advent of intelligent vehicles, various braking systems have been proposed to achieve stronger and more stable braking capabilities. In a drive-by-wire hydraulic brake system, a sensor detects the driver's pedal pressure and activates the motor. The hydraulic pressure in the motor's master cylinder adjusts the brake pressure at each wheel to achieve the driver's desired braking force. The braking system also integrates a range of functions, including the anti-lock braking system (ABS), traction control system (TCS), and active yaw control (AYC). Typically, the braking system also includes a pedal simulator. The simulator is connected to an oil reservoir, and a simulator valve is installed in the oil line connecting the simulator and the reservoir. The pedal simulator provides the driver with a reaction force based on the brake pedal force. Furthermore, if the motor or its hydraulic circuit fails, a mechanical backup brake can be used, where the pedal master cylinder provides the hydraulic pressure required to brake the wheels.

[0003] Chinese patent number CN201310049891.5 discloses an electric braking system for a vehicle. Its disadvantage is that the motor master cylinder can only generate hydraulic pressure on one side of the piston. In addition, the pedal master cylinder lacks a detection valve device, and it is impossible to know whether the master cylinder has a leakage problem. Chinese patent number CN201910343722.X discloses an electronic braking system and its working method. Its disadvantage is that the oil circuit at the outlet of the motor master cylinder is complicated and inconvenient to use. Summary of the Invention

[0004] The present invention aims to provide a hydraulic device for a vehicle brake-by-wire system to solve the problems mentioned in the background art, provide a stable pedaling feeling during braking, and enable precise pressure control.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] a liquid storage tank for storing a pressurized medium;

[0007] a brake pedal for operating the brakes;

[0008] A pedal master cylinder, whose piston is fixedly connected to the brake pedal operating handle and is used to provide initial brake pressure, the right chamber fluid inlet of the pedal master cylinder is connected to the oil outlet of the fluid reservoir, and the left chamber fluid inlet and fluid outlet of the pedal master cylinder are both connected to the fluid reservoir;

[0009] A motor master cylinder is provided with a piston connected to the motor device and is used to apply pressure to the pressurized medium through the motor to operate the wheel brake. The left and right chamber liquid inlets of the motor master cylinder are both connected to the oil outlet of the liquid storage tank;

[0010] a pedal feel simulator connected to the pedal master cylinder and used to provide a reaction force in response to the operation of the brake pedal to generate a brake pedal feel, wherein the oil inlet of the pedal feel simulator is connected to the oil outlet of the fluid reservoir;

[0011] a displacement sensor, disposed on the surface of the brake pedal operating handle and used to detect the displacement of the brake pedal operating handle and generate an electrical signal to transmit to the electronic control unit;

[0012] The wheel cylinder group includes RR, FL, RL and FR, which refer to the right rear wheel cylinder, left front wheel cylinder, left rear wheel cylinder and right front wheel cylinder respectively, and are used to perform brake application action;

[0013] Preferably, a detection valve is provided between the left cavity liquid outlet of the pedal master cylinder and the oil inlet of the liquid storage tank, and the oil inlet and oil outlet of the detection valve are respectively connected to the left cavity liquid outlet of the pedal master cylinder and the oil inlet of the liquid storage tank, and a first motor decoupling valve, a connecting valve and a first stop valve are sequentially connected in series between the motor master cylinder and the pedal master cylinder, and the oil inlet and oil outlet of the first motor decoupling valve are respectively connected to the left cavity liquid outlet of the motor master cylinder and the oil inlet of the connecting valve.

[0014] Preferably, the oil inlet and oil outlet of the connecting valve are respectively connected to the oil outlet of the first motor decoupling valve and the oil outlet of the first stop valve, the oil inlet of the first stop valve is connected to the right chamber liquid outlet of the pedal master cylinder, and a second motor decoupling valve is provided between the other right chamber liquid inlet of the motor master cylinder and the connecting valve, the oil inlet and oil outlet of the second motor decoupling valve are respectively connected to the oil outlet of the connecting valve and the other right chamber liquid inlet of the motor master cylinder, and the first motor decoupling valve, the second motor decoupling valve and the connecting valve are all normally closed solenoid valves.

[0015] Preferably, a first boosting valve is provided between the connecting valve and RR, and the oil inlet and oil outlet of the first boosting valve are respectively connected to the oil outlet of the connecting valve and the oil inlet of RR; a second boosting valve is provided between the connecting valve and FL, and the oil inlet and oil outlet of the second boosting valve are respectively connected to the oil outlet of the connecting valve and the oil inlet of FL.

[0016] Preferably, the oil circuit between the detection valve and the wheel cylinders RR and FL is respectively connected to the second stop valve and the third stop valve, and the other end of the second stop valve is connected to the oil circuit between RR and the first boosting valve, and the other end of the third stop valve is connected to the oil circuit between FL and the boosting valve, and the first stop valve, the second stop valve and the third stop valve are all normally open solenoid valves.

[0017] Preferably, a third pressure-reducing valve is provided between the first shut-off valve and RL, and the oil inlet and oil outlet of the third pressure-reducing valve are connected to the oil outlet of the first shut-off valve and the oil inlet of RL respectively; a fourth pressure-reducing valve is provided between the first shut-off valve and FR, and the oil inlet and oil outlet of the fourth pressure-reducing valve are connected to the oil outlet of the first shut-off valve and the oil inlet of FR respectively; a first pressure-reducing valve and a second pressure-reducing valve are provided between the third pressure-reducing valve and the fourth pressure-reducing valve and the wheel cylinders RL and FR respectively, the oil inlet of the first pressure-reducing valve is connected to the oil outlet of the third pressure-reducing valve, the oil inlet of the second pressure-reducing valve is connected to the oil outlet of the fourth pressure-reducing valve, and the oil outlets of the first pressure-reducing valve and the second pressure-reducing valve are respectively connected to the oil inlet of the liquid storage tank; the first pressure-reducing valve, the second pressure-reducing valve, the third pressure-reducing valve and the fourth pressure-reducing valve are all connected in parallel with a one-way valve.

[0018] Preferably, a pedal master cylinder pressure sensor is provided in the middle of the pipeline between the right cavity liquid outlet of the pedal master cylinder and the oil inlet of the first shut-off valve and the liquid inlet of the pedal feel simulator, a motor master cylinder rear pressure sensor is provided in the middle of the pipeline between the oil outlet of the first shut-off valve and the oil inlet of the second motor decoupling valve, and a motor master cylinder left cavity pressure sensor is provided in the middle of the pipeline between the oil outlet of the first motor decoupling valve and the oil inlet of the connecting valve.

[0019] Preferably, the oil outlet of the pedal feel simulator is provided with a simulator valve, and the left chamber liquid inlet position and the right chamber liquid inlet position of the motor master cylinder are respectively provided with a one-way valve, and the liquid inlets of the one-way valves are both connected to the liquid storage tank, and a pressure relief valve is connected in parallel between the left chamber liquid inlet position of the motor master cylinder and the one-way valve.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Under normal braking conditions, the present invention decouples the pedal master cylinder and the motor master cylinder from each other, with the motor master cylinder providing braking pressure. The motor master cylinder piston moves leftward, generating braking pressure in the left chamber. The first motor decoupling valve is then connected, the second motor decoupling valve is closed, and the right chamber of the motor master cylinder draws fluid from the fluid reservoir. When the motor master cylinder piston moves rightward, the second motor decoupling valve is connected, the first motor decoupling valve is closed, and the hydraulic pressure generated in the right chamber of the motor master cylinder provides the wheel cylinder braking force. This simple and convenient oil circuit allows for mechanical backup braking of the pedal master cylinder in the event of motor hydraulic pressure generation failure, ensuring safety.

[0022] 2. The present invention can also perform pressure leakage detection on the pedal master cylinder. In the initial state, the first stop valve, simulator valve, second stop valve and third stop valve are closed, the detection valve is connected, the brake pedal is stepped on, and the pressure measured by the first motor decoupling valve in the front chamber of the motor master cylinder is recorded. Then the detection valve is closed, the brake pedal is stepped on again, and the pressure measured by the first motor decoupling valve is recorded. The difference is compared with the normal value to determine the leakage situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of a hydraulic device for a vehicle brake-by-wire system according to the present invention;

[0024] Figure 2 This is a conventional brake oil flow diagram of a hydraulic device of a vehicle wire control brake system of the present invention;

[0025] Figure 3 This is a flow diagram of the oil circuit for the wheel cylinder to quickly decompress after the brake pedal is released in a hydraulic device of a vehicle's brake-by-wire system according to the present invention;

[0026] Figure 4 This is a flow diagram of the separate pressurization oil circuit of the RR wheel cylinder of a hydraulic device of a vehicle's wire control brake system according to the present invention;

[0027] Figure 5 This is an oil flow diagram of a vehicle brake-by-wire system hydraulic device RR, RL when pressurizing, and FR, RL when releasing pressure;

[0028] Figure 6 This is a flow diagram of the mechanical backup brake oil circuit of a hydraulic device in a vehicle's brake-by-wire system according to the present invention.

[0029] In the figure: 1. Fluid reservoir; 2. Brake pedal; 3. Pedal master cylinder; 4. Motor master cylinder; 5. Pedal feel simulator; 6. Displacement sensor; 7. Pedal master cylinder pressure sensor; 8. Motor master cylinder left chamber pressure sensor; 9. Motor master cylinder rear pressure sensor; 10. One-way valve; 11. First motor decoupling valve; 12. Second motor decoupling valve; 13. Connecting valve; 14. First stop valve; 15. First boost valve; 16. Second boost valve; 17. Third boost valve; 18. Fourth boost valve; 19. Second stop valve; 20. Third stop valve; 21. First pressure reducing valve; 22. Second pressure reducing valve; 23. Detection valve; 24. Simulator valve; 25. Pressure relief valve. DETAILED DESCRIPTION

[0030] 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.

[0031] See also Figure 1-6 , the present invention provides a technical solution: including:

[0032] A liquid storage tank 1, which is used to store pressurized medium;

[0033] A brake pedal 2, used for operating the brake action;

[0034] The pedal master cylinder 3 has a piston fixedly connected to the operating handle of the brake pedal 2 and is used to provide initial brake pressure. The right chamber fluid inlet of the pedal master cylinder 3 is connected to the oil outlet of the fluid reservoir 1, and the left chamber fluid inlet and fluid outlet of the pedal master cylinder 3 are both connected to the fluid reservoir 1;

[0035] The motor master cylinder 4 is provided with a piston connected to the motor device and is used to apply pressure to the pressurized medium through the motor to operate the wheel brake. The left and right chamber liquid inlets of the motor master cylinder 4 are both connected to the oil outlet of the liquid storage tank 1;

[0036] a pedal feel simulator 5 connected to the pedal master cylinder 3 and used to provide a reaction force in response to the operation of the brake pedal 2 to generate a brake pedal feel, and an oil inlet of the pedal feel simulator 5 is connected to an oil outlet of the fluid reservoir 1;

[0037] A displacement sensor 6 is provided on the surface of the brake pedal 2 operating handle and is used to detect the displacement of the brake pedal 2 operating handle and generate an electrical signal to transmit to the electronic control unit. When the driver steps on the brake pedal 2, the pedal master cylinder 3 outputs the driver's braking intention as an electrical signal through the pedal displacement sensor 6, thereby operating the motor and converting the motor's rotational force into linear motion;

[0038] Wheel cylinder group, the wheel cylinder group includes RR, FL, RL and FR.

[0039] A detection valve 23 is arranged between the left cavity liquid outlet of the pedal master cylinder 3 and the oil inlet of the liquid storage tank 1. The oil inlet and oil outlet of the detection valve 23 are respectively connected to the left cavity liquid outlet of the pedal master cylinder 3 and the oil inlet of the liquid storage tank 1. A first motor decoupling valve 11, a connecting valve 13 and a first stop valve 14 are respectively provided between the motor master cylinder 4 and the pedal master cylinder 3. The oil inlet and oil outlet of the first motor decoupling valve 11 are respectively connected to the left cavity liquid outlet of the motor master cylinder 4 and the oil inlet of the connecting valve 13. The first motor decoupling valve 11, the second motor decoupling valve 12 and the connecting valve 13 are all normally open solenoid valves.

[0040] The oil inlet and oil outlet of the connecting valve 13 are respectively connected to the oil outlet of the first motor decoupling valve 11 and the oil outlet of the first stop valve 14, the oil inlet of the first stop valve 14 is connected to the right chamber liquid outlet of the pedal master cylinder 3, and a second motor decoupling valve 12 is provided between the other right chamber liquid inlet of the motor master cylinder 4 and the connecting valve 13, and the oil inlet and oil outlet of the second motor decoupling valve 12 are respectively connected to the oil outlet of the connecting valve 13 and the other right chamber liquid inlet of the motor master cylinder 4.

[0041] A first boosting valve 15 is provided between the connecting valve 13 and RR, and the oil inlet and oil outlet of the first boosting valve 15 are respectively connected to the oil outlet of the connecting valve 13 and the oil inlet of RR. A second boosting valve 16 is provided between the connecting valve 13 and FL, and the oil inlet and oil outlet of the second boosting valve 16 are respectively connected to the oil outlet of the connecting valve 13 and the oil inlet of FL.

[0042] The oil circuit between the detection valve 23 and the wheel cylinders RR and FL is connected to the second stop valve 19 and the third stop valve 20 respectively, and the other end of the second stop valve 19 is connected to the oil circuit between RR and the first boosting valve 15, and the other end of the third stop valve 20 is connected to the oil circuit between FL and the boosting valve 16. The first stop valve 14, the second stop valve 19 and the third stop valve 20 are all normally open solenoid valves.

[0043] A third pressure-boosting valve 17 is provided between the first shutoff valve 14 and the wheel cylinder RL. Its oil inlet and outlet are connected to the oil outlet of the first shutoff valve 14 and the oil inlet of the wheel cylinder RL, respectively. A fourth pressure-boosting valve 18 is provided between the first shutoff valve 14 and the wheel cylinder FR, with its oil inlet and outlet connected to the oil outlet of the first shutoff valve 14 and the oil inlet of the wheel cylinder FR, respectively. A first pressure-reducing valve 21 and a second pressure-reducing valve 22 are provided between the third pressure-reducing valve 17 and the wheel cylinder RL, respectively. The oil inlet of the first pressure-reducing valve 21 is connected to the oil outlet of the third pressure-reducing valve 17, and the oil inlet of the second pressure-reducing valve 22 is connected to the oil outlet of the fourth pressure-reducing valve 18. The oil outlets of the first and second pressure-reducing valves 21 and 22 are both connected to the oil inlet of the fluid reservoir 1.

[0044] A pedal master cylinder pressure sensor 7 is provided in the middle of the pipeline between the right cavity liquid outlet of the pedal master cylinder 3 and the oil inlet of the first stop valve 14 and the liquid inlet of the pedal feel simulator 5. A motor master cylinder rear pressure sensor 9 is provided in the middle of the pipeline between the oil outlet of the first stop valve 14 and the oil inlet of the second motor decoupling valve 12. A motor master cylinder left cavity pressure sensor 8 is provided in the middle of the pipeline between the oil outlet of the first motor decoupling valve 11 and the oil inlet of the connecting valve 13.

[0045] The oil outlet of the pedal feel simulator 5 is provided with a simulator valve 24, and the left chamber liquid inlet position and the right chamber liquid inlet position of the motor master cylinder 4 are respectively provided with a one-way valve 10. The pressure relief valve 25 is connected in parallel between the left chamber liquid inlet position of the motor master cylinder 4 and the one-way valve 10. The oil outlet, oil inlet, liquid outlet, liquid inlet, etc. in the text are not a single way to determine the liquid flow direction. In different modes, the liquid flow direction of the liquid inlet and liquid outlet can be interchangeable.

[0046] Working principle: When in use, under normal braking conditions, the driver of the invention steps on the brake pedal 2, the pedal master cylinder 3 and the motor master cylinder 4 are in a decoupled state, and the motor master cylinder 4 provides braking pressure. When the piston of the motor master cylinder 4 moves to the left, the first motor decoupling valve 11, the connecting valve 13, the first boosting valve 15, the second boosting valve 16, the third boosting valve 17, the fourth boosting valve 18, the detection valve 23 and the simulator valve 24 are connected, and the remaining valves are closed. The left chamber of the motor master cylinder 4 generates braking pressure, and the right chamber of the motor master cylinder 4 absorbs oil from the fluid reservoir 1. The pedal master cylinder 3 generates a braking foot feel through the pedal feel simulator 5. When the piston of the motor master cylinder 4 moves to the right, the second motor decoupling valve 12 is connected, the first motor decoupling valve 11 is closed, and the hydraulic pressure generated in the right chamber of the motor master cylinder 4 provides the wheel cylinder braking force.

[0047] When brake pedal 2 is released and the piston of motor master cylinder 4 moves rightward, first motor decoupling valve 11, second motor decoupling valve 12, connecting valve 13, first booster valve 15, second booster valve 16, third booster valve 17, fourth booster valve 18, and detection valve 23 are connected, allowing the oil in the wheel brake cylinder to return to the left chamber of motor master cylinder 4, achieving the purpose of rapid pressure reduction. When the piston of motor master cylinder 4 moves leftward, pressure relief valve 25 opens and first motor decoupling valve 11 closes, allowing the oil in the wheel brake cylinder to return to the right chamber of motor master cylinder 4.

[0048] Select any wheel cylinder for individual boosting, taking the RR wheel cylinder as an example. At this time, the piston of the motor master cylinder 4 moves to the left, the first motor decoupling valve 11, the first boosting valve 15, the detection valve 23, and the simulator valve 24 are connected, and the remaining valves are closed. The brake hydraulic pressure generated by the motor master cylinder 4 acts on the wheel cylinder RR, and the remaining wheel cylinders are in a pressure-maintaining state; when the piston of the motor master cylinder 4 moves to the right, the first motor decoupling valve 11 is closed, and the second motor decoupling valve 12 is opened, achieving the same boosting effect on the wheel cylinder RR.

[0049] The wheel cylinder pressure control takes the wheel cylinders RR and RL as an example of pressurizing and the wheel cylinders FL and FR as a example. At this time, the piston of the motor master cylinder 4 moves to the left, the first motor decoupling valve 11, the connecting valve 13, the first boosting valve 15, the second boosting valve 16, the third boosting valve 17, the fourth boosting valve 18, the third stop valve 20, the second pressure reducing valve 22, the detection valve 23 and the simulator valve 24 are connected, and the remaining valves are closed. This can make the wheel cylinders RR and RL pressurized while the wheel cylinder pressures of FL and FR are partially released, thereby achieving the purpose of controlling different wheel cylinder pressures; when the piston of the motor master cylinder 4 moves to the right, the first motor decoupling valve 11 is closed and the second motor decoupling valve 12 is opened, thereby achieving the same effect.

[0050] Mechanical backup brake: When the motor hydraulic part fails, the mechanical backup brake is activated. The driver steps on the brake pedal 2, and the pedal master cylinder 3 provides hydraulic braking force to ensure safe driving. At this time, the connecting valve 13, the first stop valve 14, the first boosting valve 15, the second boosting valve 16, the third boosting valve 17, the fourth boosting valve 18, the second stop valve 19 and the third stop valve 20 are connected, and the remaining valves are closed, so that the brake hydraulic pressure generated by the pedal master cylinder 3 provides braking force for the four wheel cylinders;

[0051] Pressure leakage detection of the pedal master cylinder 3. In the initial state, the first stop valve 14, simulator valve 24, second stop valve 19 and third stop valve 20 are closed, and the detection valve 23 is connected. Step on the brake pedal 2 and record the pressure measured by the first motor decoupling valve 11 in the front chamber of the motor master cylinder 4. Then close the detection valve 23 and step on the brake pedal 2 again to record the pressure measured by the first motor decoupling valve 11. Compare the difference with the normal value to determine the leakage situation.

[0052] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0053] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic device for a vehicle brake-by-wire system, characterized in that: include: A liquid storage tank (1) for storing a pressurized medium; a brake pedal (2) for operating the brakes; The wheel cylinder group includes RR, FL, RL and FR, which refer to the right rear wheel cylinder, left front wheel cylinder, left rear wheel cylinder and right front wheel cylinder respectively, and are used to perform brake application action; A pedal master cylinder (3), the piston of which is fixedly connected to the operating handle of the brake pedal (2) for providing initial brake pressure, the right chamber liquid inlet of the pedal master cylinder (3) is connected to the oil outlet of the liquid storage tank (1), the left chamber liquid inlet and liquid outlet of the pedal master cylinder (3) are both connected to the liquid storage tank (1), and a detection valve (23) is provided between the left chamber liquid outlet of the pedal master cylinder (3) and the oil inlet of the liquid storage tank (1); A motor master cylinder (4) is provided with a piston connected to a motor device and is used to provide pressure to a pressurized medium through a motor to operate the wheel for braking. The left chamber liquid inlet and the right chamber liquid inlet of the motor master cylinder (4) are both connected to the oil outlet of the liquid storage tank (1). A first motor decoupling valve (11), a connecting valve (13) and a first stop valve (14) are sequentially connected in series between the motor master cylinder (4) and the pedal master cylinder (3). The oil inlet and oil outlet of the first motor decoupling valve (11) are respectively connected to the left chamber liquid outlet of the motor master cylinder (4) and the oil inlet of the connecting valve (13). The other right chamber liquid inlet of the motor master cylinder (4) is connected to the connecting valve (13). (13) is provided with a second motor decoupling valve (12), the oil inlet and oil outlet of the second motor decoupling valve (12) are respectively connected to the oil outlet of the connecting valve (13) and the other right chamber liquid inlet of the motor master cylinder (4), a first boosting valve (15) is provided between the connecting valve (13) and RR, the oil inlet and oil outlet of the first boosting valve (15) are respectively connected to the oil outlet of the connecting valve (13) and the oil inlet of RR, a second boosting valve (16) is provided between the connecting valve (13) and FL, the oil inlet and oil outlet of the second boosting valve (16) are respectively connected to the oil outlet of the connecting valve (13) and the oil inlet of FL; a pedal feeling simulator (5) connected to the pedal master cylinder (3) and used to provide a reaction force in response to the operation of the brake pedal (2) to generate a brake pedal feel, wherein the oil inlet of the pedal feeling simulator (5) is connected to the oil outlet of the fluid reservoir (1); A displacement sensor (6) is arranged on the surface of the brake pedal (2) operating handle and is used to detect the displacement of the brake pedal (2) operating handle and generate an electrical signal to transmit to the electronic control unit; The oil circuit between the detection valve (23) and the wheel cylinders RR and FL is respectively connected to a second stop valve (19) and a third stop valve (20), and the other end of the second stop valve (19) is connected to the oil circuit between RR and the first boosting valve (15), and the other end of the third stop valve (20) is connected to the oil circuit between FL and the boosting valve (16). A third boosting valve (17) is provided between the first stop valve (14) and RL, and the oil inlet and oil outlet of the third boosting valve (17) are respectively connected to the oil outlet of the first stop valve (14) and the oil inlet of RL. A fourth boosting valve (18) is provided between the first stop valve (14) and FR, and the oil inlet and oil outlet of the fourth boosting valve (18) are respectively connected to the oil outlet of the first stop valve (14) and the oil inlet of FR. The third boosting valve (17) and the fourth boosting valve (18) are respectively provided between the wheel cylinders RL and FR. A first pressure reducing valve (21) and a second pressure reducing valve (22), wherein the oil inlet of the first pressure reducing valve (21) is connected to the oil outlet of the third pressure boosting valve (17), the oil inlet of the second pressure reducing valve (22) is connected to the oil outlet of the fourth pressure boosting valve (18), and the oil outlets of the first pressure reducing valve (21) and the second pressure reducing valve (22) are respectively connected to the oil inlet of the liquid storage tank (1). A pedal master cylinder pressure sensor (7) is provided in the middle of the pipeline between the right cavity liquid outlet of the pedal master cylinder (3), the oil inlet of the first stop valve (14), and the liquid inlet of the pedal feeling simulator (5). A motor master cylinder rear pressure sensor (9) is provided in the middle of the pipeline between the oil outlet of the first stop valve (14) and the oil inlet of the second motor decoupling valve (12). A motor master cylinder left cavity pressure sensor (8) is provided in the middle of the pipeline between the oil outlet of the first motor decoupling valve (11) and the oil inlet of the connecting valve (13).

2. The hydraulic device of a vehicle brake-by-wire system according to claim 1, characterized in that: The oil inlet and the oil outlet of the detection valve (23) are respectively connected to the left cavity liquid outlet of the pedal master cylinder (3) and the oil inlet of the liquid storage tank (1).

3. The hydraulic device of a vehicle brake-by-wire system according to claim 2, characterized in that: The oil inlet and oil outlet of the connecting valve (13) are respectively connected to the oil outlet of the first motor decoupling valve (11) and the oil outlet of the first stop valve (14); the oil inlet of the first stop valve (14) is connected to the right chamber liquid outlet of the pedal master cylinder (3); the first motor decoupling valve (11), the second motor decoupling valve (12) and the connecting valve (13) are all normally closed solenoid valves.

4. The hydraulic device of a vehicle brake-by-wire system according to claim 3, characterized in that: The first stop valve (14), the second stop valve (19) and the third stop valve (20) are all normally open solenoid valves.

5. The hydraulic device of a vehicle brake-by-wire system according to claim 4, characterized in that: The first boosting valve (15), the second boosting valve (16), the third boosting valve (17) and the fourth boosting valve (18) are all connected in parallel to the one-way valve.

6. The hydraulic device of a vehicle brake-by-wire system according to claim 5, characterized in that: The oil outlet of the pedal feeling simulator (5) is provided with a simulator valve (24), the left chamber liquid inlet position and the right chamber liquid inlet position of the motor master cylinder (4) are respectively provided with a one-way valve (10), the inlets of the corresponding chamber one-way valves are connected to the liquid storage tank (1), and a pressure relief valve (25) is connected in parallel between the left chamber liquid inlet position of the motor master cylinder (4) and the one-way valve (10).

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