CN116674514A

CN116674514A - Split type decoupling vehicle electro-hydraulic brake system with redundancy function and method

Info

Publication number: CN116674514A
Application number: CN202310783586.2A
Authority: CN
Inventors: 程许添; 郝江脉; 于海涛; 黄锓城; 黄永伟; 楼天驰
Original assignee: Zhejiang Asia Pacific Mechanical and Electronic Co Ltd
Current assignee: Zhejiang Asia Pacific Mechanical and Electronic Co Ltd
Priority date: 2023-06-29
Filing date: 2023-06-29
Publication date: 2023-09-01

Abstract

The invention discloses a split type decoupling vehicle electro-hydraulic brake system with a redundancy function and a method. The brake actuating mechanism is divided into a pedal module, a pressure increasing module and a backup module, wherein the pedal module is directly connected with a brake pedal, the pedal module is connected with the pressure increasing module through an oil pipe, the pressure increasing module is connected with the backup module through an oil pipe, the pressure increasing module is provided with two paths of oil pipes which are communicated with a brake cylinder, the backup module is provided with two paths of oil pipes which are communicated with the brake cylinder, and the three blocks are respectively independent and are connected through the oil pipe. The invention can realize all functions of linear control and emergency mechanical braking, has small volume, simple structure, low cost and convenient installation, and the noise and vibration caused by the motor and the booster pump can not be transmitted to the pedal, thus having better comfort.

Description

Split type decoupling vehicle electro-hydraulic brake system with redundancy function and method

Technical Field

The invention relates to a vehicle electronic hydraulic brake system and a method, in particular to a split type full decoupling vehicle electronic hydraulic brake system with a redundancy function and a control method.

Background

Most of full decoupling electronic hydraulic brake systems with redundant functions used in the market at present are in an integrated scheme, a brake actuating mechanism is directly connected with a pedal, and noise and vibration generated during working can be directly transmitted to the pedal. The brake actuators are bulky and difficult to deploy in the cockpit.

Along with the development of intelligent driving technology, it is imperative to realize L4 level intelligent driving, and the backup module is added to enable the braking system to achieve L4 level intelligent driving. Most backup systems at present can only realize simple active pressurization and cannot cope with various special working conditions.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a split type decoupling vehicle electro-hydraulic brake system with a redundancy function. The backup system can realize active pressurization, ABS, ESC and other functions, can cope with various complex working conditions, and has accurate voltage regulation and low working noise.

The technical scheme adopted by the invention is as follows:

1. a split type decoupling vehicle electronic hydraulic brake system with a redundancy function comprises a pedal module, a pressurizing module and a backup module;

the pedal module is used for receiving external pedal acting force, detecting pedal displacement and then feeding back to the pressurizing module and the backup module, generating hydraulic pressure and transmitting the hydraulic pressure to the pressurizing module and the backup module, and comprises a pedal valve block, a main cylinder, a pedal simulator, a push rod, an oilcan and a displacement sensor, wherein the main cylinder is positioned in the pedal valve block, the push rod is connected with a piston of the main cylinder, the oilcan is used for providing brake fluid for the main cylinder and the pedal simulator, the displacement sensor is used for detecting the displacement of the push rod, and the push rod is connected with a brake pedal and receives the external pedal acting force;

The pressure increasing module is used for receiving pedal displacement and then generating hydraulic pressure to control a brake wheel cylinder to brake, and comprises a pressure increasing valve block, a pressure increasing motor, a pressure increasing pump, a pressure increasing oil pressure sensor group, a pressure increasing electromagnetic valve group and a pressure increasing controller, wherein the pressure increasing motor, the pressure increasing pump, the pressure increasing electromagnetic valve group are arranged in the pressure increasing valve block, the pressure increasing oil pressure sensor group is used for detecting the oil pressure of the main cylinder and the pressure increasing pump, the pressure increasing electromagnetic valve group is used for controlling the change of an oil path, and the pressure increasing controller is used for controlling the pressure increasing motor and the pressure increasing electromagnetic valve group; the output end of the booster pump is directly connected to the oilcan;

the backup module is used for receiving pedal displacement or hydraulic pressure when the pressure increasing module fails so as to generate hydraulic pressure to control the brake wheel cylinder to brake, and comprises a backup valve block, a backup motor, a backup pump, a backup oil pressure sensor for detecting oil pressure input from a master cylinder to the backup module, a backup solenoid valve group for controlling oil path change, and a backup controller for controlling the backup motor and the backup solenoid valve group;

and the brake wheel cylinder receives hydraulic pressure from the pedal module, the pressure increasing module and the backup module to generate braking force so as to realize vehicle braking.

The supercharged oil pressure sensor group comprises a first pressure sensor and a second pressure sensor;

the pressurizing electromagnetic valve group only comprises a simulator valve, a first coupling valve, a second coupling valve, a first oil supply valve, a second oil supply valve, a third oil supply valve, a first liquid inlet valve, a second liquid inlet valve, a third liquid inlet valve, a fourth liquid inlet valve, a first liquid outlet valve, a second liquid outlet valve, a third liquid outlet valve and a fourth liquid outlet valve;

Only one backup oil pressure sensor is the third pressure sensor;

the backup electromagnetic valve group comprises a fifth liquid inlet valve, a sixth liquid inlet valve, a fifth liquid outlet valve, a sixth liquid outlet valve, a fourth oil supply valve, a fifth oil supply valve and a first overflow valve.

The first overflow valve is an overflow valve which is adjustable through electrifying.

The brake fluid is arranged in the oil can, the main cylinder is provided with a front cavity and a rear cavity, the pedal simulator is provided with the front cavity and the rear cavity, the oil can is respectively and directly communicated with the front cavity and the rear cavity of the main cylinder, the front cavity of the main cylinder is connected with a first pressure sensor, the first pressure sensor is used for detecting the input pressure of the front cavity of the main cylinder, the front cavity of the pedal simulator is connected with the front cavity of the main cylinder through a simulator valve, and the rear cavity of the pedal simulator is connected with the oil can;

the two brake cylinders are connected with the front cavity of the main cylinder through first coupling valves, the first coupling valves control brake fluid in the front cavity of the main cylinder to enter the two brake cylinders, the other two brake cylinders are connected with the rear cavity of the main cylinder through second coupling valves, and the second coupling valves control brake fluid in the rear cavity of the main cylinder to enter the other two brake cylinders;

each brake cylinder is connected with the oil pot through a respective liquid outlet valve, the liquid outlet valve controls the brake cylinders to output brake liquid, each brake cylinder is connected with a respective corresponding coupling valve through a respective liquid outlet valve, and the liquid inlet valve controls the brake cylinders to input brake liquid;

The energy accumulator is connected with the output end of the booster pump through a first oil supply valve, and the first oil supply valve controls the inflow and outflow of brake fluid in the energy accumulator; the output end of the booster pump is connected with two of the brake cylinders through a second oil supply valve, the second oil supply valve controls the booster pump to output brake fluid into the two of the brake cylinders, the output end of the booster pump is connected with the other two of the brake cylinders through a third oil supply valve, and the third oil supply valve controls the booster pump to output brake fluid into the other two of the brake cylinders;

the output end of the booster pump is connected with a second pressure sensor, the second pressure sensor detects the oil pressure output by the booster pump, and meanwhile, the output end of the booster pump is directly connected to the oilcan.

In the backup module, a liquid inlet valve is arranged between the brake cylinder and the output end of the pressure increasing module, a one-way valve which only allows one-way conduction from the output end of the pressure increasing module to the brake cylinder is connected in parallel on the liquid inlet valve, and a pressure sensor is arranged between the liquid inlet valve and the output end of the pressure increasing module; the input end of the backup pump is connected with the oil can, the brake wheel cylinder is connected with the output end of the backup pump through a respective oil supply valve, meanwhile, the brake wheel cylinder is connected with the oil can through a respective liquid outlet valve, and the output end of the backup pump is connected with the oil can through a first overflow valve.

2. A self-checking method of an electronic hydraulic brake system of a vehicle comprises the following steps:

generally, after a preset number of miles of running or a preset number of times of execution of a braking function, when a brake pedal is kept still, a self-test of a braking system is started after the vehicle is ignited according to the following procedures:

and (3) self-checking:

controlling the first coupling valve and the second coupling valve to be electrified and not conducted;

firstly, electrifying a booster pump, controlling the output oil pressure of the booster pump to be under the unidirectional opening pressure of an oil supply valve, controlling the electrifying and conducting of a first oil supply valve, and communicating an accumulator with an oil way of the booster pump;

then, the second oil supply valve and the third oil supply valve are controlled to be powered off and not to be conducted, so that brake fluid in the energy accumulator and brake fluid output by the booster pump cannot flow to each liquid inlet valve through the second oil supply valve and the third oil supply valve, and the brake fluid output by the booster pump exist in a relatively closed oil path; the booster pump, the energy accumulator, the first oil supply valve, the second pressure sensor, the second oil supply valve and the third oil supply valve are normal when the pressure degree detected by the second pressure sensor is unchanged within a fixed time; otherwise, the device is abnormal;

and (3) self-checking: on the basis of the self-checking step, the second oil supply valve and the third oil supply valve are controlled to be electrified and conducted, and the first liquid inlet valve, the second liquid inlet valve, the third liquid inlet valve and the fourth liquid inlet valve are controlled to be electrified and not conducted, so that brake liquid in the energy accumulator and brake liquid output by the booster pump are circulated to each liquid inlet valve through the second oil supply valve and the third oil supply valve, but cannot enter each brake wheel cylinder through each liquid inlet valve and exist in a relatively closed oil path; the first liquid inlet valve, the second liquid inlet valve, the third liquid inlet valve, the fourth liquid inlet valve, the first coupling valve and the second coupling valve are normal when the degree of pressure detected by the second pressure sensor is unchanged within a fixed time; otherwise, the device is abnormal;

And (3) self-checking: on the basis of the self-checking step, the first liquid inlet valve, the second liquid inlet valve, the third liquid inlet valve and the fourth liquid inlet valve are controlled to be powered off and on, so that brake liquid in the energy accumulator and brake liquid output by the booster pump are circulated to each liquid inlet valve through the second oil supply valve and the third oil supply valve, enter each brake wheel cylinder through each liquid inlet valve and the fourth oil supply valve and the fifth oil supply valve of the backup module, and exist in a relatively closed oil path;

the first liquid outlet valve, the second liquid outlet valve, the third liquid outlet valve, the fourth liquid outlet valve, the fifth liquid outlet valve, the sixth liquid outlet valve, the fourth oil supply valve, the fifth oil supply valve and the four brake wheel cylinders are normal when the pressure degree detected by the second pressure sensor is unchanged and the pressure degree detected by the second pressure sensor is unchanged within a fixed time; otherwise, the device is abnormal.

3. A backup hydraulic braking method of a vehicle electronic hydraulic braking system comprises the following steps:

the method is characterized in that the backup module works according to different modes according to the conditions of whether a driver presses a brake pedal or not and whether pressurization, depressurization and pressure maintaining are needed to be carried out or not and whether two wheels are different in pressurization and depressurization, wherein the backup module comprises a conventional braking pressurization mode when the pressurization module fails, a conventional braking depressurization mode when the pressurization module fails, an (ABS) pressurization mode when the pressurization module fails, an (ABS) pressure maintaining mode when the pressurization module fails, a single-wheel pressurization mode and a single-wheel depressurization mode when the pressurization module fails:

If the driver presses the brake pedal, the backup module works according to a conventional braking pressurization mode when the pressurization module fails;

if the driver releases the brake pedal, the backup module works according to a conventional brake decompression mode when the supercharging module fails;

if the brake pedal is kept still and the traveling computer needs to be pressurized, the backup module works according to An (ABS) pressurizing mode when the pressurizing module fails;

if the brake pedal is kept still and the driving computer needs to decompress, the backup module works according to An (ABS) decompression mode when the supercharging module fails;

if the brake pedal is kept still and the traveling computer needs to keep pressure, the backup module works according to An (ABS) pressure keeping mode when the pressurizing module fails;

if the brake pedal is kept still and one wheel needs to be pressurized and the other wheel needs to be depressurized, the backup module works according to a single-wheel pressurizing and single-wheel depressurizing mode when the pressurizing module fails.

The invention divides a brake actuating mechanism into a pedal module, a pressure increasing module and a backup module, wherein the pedal module is directly connected with a brake pedal, the pedal module is connected with the pressure increasing module through an oil pipe, the pressure increasing module is connected with the backup module through the oil pipe, the pressure increasing module is provided with two paths of oil pipes which are communicated with a brake cylinder, and the backup module is provided with two paths of oil pipes which are communicated with the brake cylinder.

The pedal module, the pressurizing module and the backup module are respectively independent and connected through the oil pipe, so that all functions of linear control and braking can be realized, and emergency mechanical braking can be realized.

According to the invention, the overflow valve is additionally arranged in the pressurizing module, and the pressure is regulated through the overflow valve, so that the self-checking treatment of the brake oil way is realized. In the prior art, the main cylinder can be pushed forward during braking, the pressure maintaining capacity is changed through the energizing current of the overflow valve, the cost is reduced, the oil pressure adjusting time is increased, and the noise effect/advantage is reduced. And meanwhile, the effect/advantage of product stability can be improved by setting the self-check under the control of the overflow valve.

The booster motor and the backup motor are both brush motors, and the backup unit is additionally arranged, so that L4-level intelligent driving can be realized through the backup unit, and the L4-level intelligent driving effect/advantage can be realized by adopting the low-cost brush motor.

The boosting module and the backup module can enable the whole braking system to be suitable for automatic driving with L4 level and above, and braking and auxiliary driving can be carried out under the situation that a driver is thoroughly absent.

The beneficial effects of the invention are as follows:

the pedal module connected with the brake pedal has no driving device, does not generate noise and vibration, and is quiet and comfortable in working. The invention adopts three modules with smaller volume for connection, the modules are connected through the oil pipe, the arrangement is convenient, the invention is not limited by the arrangement space of the pedal firewall originally, the manufacturing cost is low, and the price is low.

Compared with an integrated vehicle electronic hydraulic braking system, the electronic hydraulic braking system has the advantages of small volume, simple structure, low cost, convenience in installation, better comfort and no noise and vibration caused by a motor and a booster pump transmitted to a pedal.

Most of the existing backup modules can only realize a simple active boosting braking function, and bad driving experience such as pedal top and the like can be caused during active boosting. The invention not only can realize the active pressurization of the backup module, but also can realize functions of ABS, single-wheel pressurization and the like, and has good driving experience and more accurate pressure control.

Drawings

FIG. 1 is a schematic illustration of pedal module components;

FIG. 2 is a schematic illustration of the components of the boost module;

FIG. 3 is a schematic diagram of components of a backup module;

FIG. 4 is a hydraulic schematic of a brake system;

FIG. 5 is a schematic diagram of a self-test step 1 of the pressurization module;

FIG. 6 is a schematic diagram of a boost module self-test step 2;

FIG. 7 is a schematic diagram of a self-test step 3 of the boost module;

FIG. 8 is a schematic diagram of the conventional brake boosting implemented by the backup module 3 when the boosting module 2 fails;

FIG. 9 is a schematic diagram of a backup module performing conventional brake decompression;

FIG. 10 is a hydraulic schematic diagram of a depressurization phase when the backup module is executing an ABS operation;

FIG. 11 is a hydraulic schematic diagram of a boost phase when the backup module is executing an ABS condition;

FIG. 12 is a hydraulic schematic diagram of a dwell phase when the backup module is executing ABS operation;

FIG. 13 is a hydraulic schematic diagram of a boost phase of the backup module executing a single-wheel boost and single-wheel depressurize condition;

fig. 14 is a schematic diagram of the supercharging and decompression with mechanical braking still present when both the supercharging module 2 and the backup module 3 fail.

In the figure:

1. pedal module 11, pedal valve block 12, main cylinder 13, pedal simulator 14, push rod 15, oilcan 16, displacement sensor;

2. the device comprises a pressurizing module 21, a pressurizing valve block 22, a pressurizing motor 23, a pressurizing pump 24, a pressurizing oil pressure sensor group 25, a pressurizing electromagnetic valve group 26, a pressurizing controller 27 and an energy accumulator;

3. the backup module 31, the backup valve block 32, the backup motor 33, the backup pump 34, the backup oil pressure sensor 35, the backup solenoid valve group 36 and the backup controller;

A first pressure sensor 241, a second pressure sensor 242;

simulator valve 2501, first coupling valve 2502, second coupling valve 2503, second oil supply valve 2504, third oil supply valve 2505, first liquid inlet valve 2506, second liquid inlet valve 2507, third liquid inlet valve 2508, fourth liquid inlet valve 2509, first liquid outlet valve 2510, second liquid outlet valve 2511, third liquid outlet valve 2512, fourth liquid outlet valve 2513, first oil supply valve 2515;

a third pressure sensor 341, a first relief valve 351, a fourth oil supply valve 352, a fifth oil supply valve 353, a fifth liquid inlet valve 354, a sixth liquid inlet valve 355, a fifth liquid outlet valve 356, and a sixth liquid outlet valve 357.

Detailed Description

The invention will be described in further detail with reference to the accompanying drawings and specific examples.

The pedal module 1, the supercharging module 2 and the backup module 3 of the invention;

as shown in fig. 1, a pedal module 1 for receiving an external pedal force, detecting a pedal displacement and feeding back to a booster module 2 and a backup module 3, and generating hydraulic pressure and transmitting to the booster module 2 and the backup module 3, comprises a pedal valve block 11, a master cylinder 12 positioned in the pedal valve block 11, a pedal simulator 13, a push rod 14 connected with a piston of the master cylinder 12, an oil can 15 for providing brake fluid to the master cylinder 12 and the pedal simulator 13, a displacement sensor 16 for detecting a displacement of the push rod 14, wherein one end of the push rod 14 is connected with the piston of the master cylinder 12, and the other end is connected with a brake pedal, and receiving the external pedal force; the displacement sensor 16 is disposed beside the push rod 14 to detect the displacement of the push rod 14.

In specific implementation, the pedal valve block 11 is provided with an oil outlet and an oil inlet, the master cylinder 12 is connected with the booster valve block 21 through an oil pipe, and the pedal simulator 13 is connected with the booster valve block 21. The pressure-increasing valve block 21 is provided with an oil outlet and an oil inlet, the two oil outlets are connected to the brake cylinder through oil pipes, and the two oil outlets are connected to the backup valve block 31 through oil pipes. The backup module 31 is provided with an oil outlet and an oil inlet, and the two oil outlets are connected to the other two brake cylinders.

An oil path exists in the pedal valve block 11, and a cavity formed by the master cylinder 12 is communicated with the booster valve block 21 through an oil pipe. An oil passage is provided in the pedal valve block 11, and the pedal simulator 13 communicates with the pressure increasing valve block 21 through an oil pipe. The master cylinder 12 is in the same valve block as the pedal simulator 13, and the pedal simulator 13 has one or more chambers of variable volume.

As shown in fig. 2, the pressure increasing module 2 is configured to receive pedal displacement when the backup module 3 is not in operation, and then generate hydraulic pressure to control a brake cylinder to perform pressure increasing, pressure reducing and pressure maintaining braking, and includes a pressure increasing valve block 21, a pressure increasing motor 22, a pressure increasing pump 23, a pressure increasing oil pressure sensor group 24 for detecting oil pressure of pipelines such as the master cylinder 12 and the pressure increasing pump 23, a pressure increasing electromagnetic valve group 25 for controlling oil passage change in the pressure increasing valve block 21, and a pressure increasing controller 26 for controlling the pressure increasing motor 22 and the pressure increasing electromagnetic valve group 25; the output shaft of the booster motor 22 is connected with the input shaft of the booster pump 23.

The pressurizing valve block 21 is internally provided with oil ways, two oil ways of the output oil ways of the pressurizing module pressurizing pump 23 are connected with the backup module, and the other two oil ways are connected with the brake calipers.

As shown in fig. 3, the backup module 3 is configured to receive pedal displacement or hydraulic pressure when the pressure increasing module 2 fails, and generate hydraulic pressure to control the brake cylinders of the two front wheels to perform pressure increasing, pressure reducing and pressure maintaining braking, and includes a backup valve block 31, a backup motor 32, a backup pump 33, a backup oil pressure sensor 34 for detecting oil pressure input from the master cylinder to the backup module, a backup solenoid valve block 35 for controlling oil path change inside the backup valve block 31, and a backup controller 36 for controlling the backup motor 32 and the backup solenoid valve block 35; the output shaft of the backup motor 32 is connected to the input shaft of the backup pump 33.

The brake wheel cylinders receive hydraulic pressure from the pedal module 1, the pressure increasing module 2 and the backup module 3 to generate braking force, so that vehicle braking is realized.

An oil path exists in the backup valve block 31, and two oil paths output by the backup module booster pump 33 are connected with the brake calipers. The backup oil pressure sensor 34 can detect the oil pressure input from the master cylinder to the backup module.

Under normal operation, the brake oil pressure of the wheel cylinders is supplied by the pump oil pressure increase of the pressure increasing module 2. When the driver steps on the pedal, brake fluid generated by the master cylinder 12 in the pedal module 1 enters the pedal simulator 13 through the pipe.

When the pressure increasing module 2 fails, the brake oil pressure of the wheel cylinders is partially supplied by the oil pumping pressure increasing of the backup module 3 and partially supplied by the master cylinder 12.

When both the pressure increasing module 2 and the backup module 3 fail, the driver steps on the pedal, and the brake fluid generated by the master cylinder 12 in the pedal module enters the wheel cylinders through the pipelines.

The boost oil pressure sensor group 24 includes a first pressure sensor 241, a second pressure sensor 242;

the booster solenoid valve group 25 includes a simulator valve 2501, a first coupling valve 2502, a second coupling valve 2503, a first oil supply valve 2515, a second oil supply valve 2504, a third oil supply valve 2505, a first liquid inlet valve 2506, a second liquid inlet valve 2507, a third liquid inlet valve 2508, a fourth liquid inlet valve 2509, a first liquid outlet valve 2510, a second liquid outlet valve 2511, a third liquid outlet valve 2512, and a fourth liquid outlet valve 2513;

the boost controller 26 receives detection signals of all pressure sensors in the boost oil pressure sensor group 24, so as to control the boost motor 22 and the boost solenoid valve group 25 to work, and the boost solenoid valve group 25 and the boost motor 22 jointly regulate the output pressure of the brake actuator and various liquid path states inside the boost valve block 21, so that the boost motor 22 can control the boost pump 23 to work.

Only one backup oil pressure sensor 34 is the third pressure sensor 341;

The backup solenoid valve group 35 includes a fifth inlet valve 354, a sixth inlet valve 355, a fifth outlet valve 356, a sixth outlet valve 357, a fourth oil supply valve 352, a fifth oil supply valve 353, and a first overflow valve 351.

The backup controller 36 receives the detection signal of the third pressure sensor 341 of the backup oil pressure sensor 34, so as to control the backup motor 32 and the backup solenoid valve group 35 to work, and the backup solenoid valve group 35 and the backup motor 32 jointly regulate the output pressure of the brake actuator and various liquid path states inside the backup valve block 31, and the backup motor 32 controls the backup pump 33 to work.

As shown in fig. 4, the master cylinder 12, the pedal simulator 13, the displacement sensor 16, and the oilcan 15 are on a pedal module.

As shown in fig. 4, the first pressure sensor 241, the second pressure sensor 242, the simulator valve 2501, the first coupling valve 2502, the second coupling valve 2503, the first oil supply valve 2515, the second oil supply valve 2504, the third oil supply valve 2505, the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508, the fourth liquid inlet valve 2509, the first liquid outlet valve 2510, the second liquid outlet valve 2511, the third liquid outlet valve 2512, and the fourth liquid outlet valve 2513 are on a pressurizing module.

As shown in fig. 4, the third pressure sensor 341, the fifth inlet valve 354, the sixth inlet valve 355, the fifth outlet valve 356, the sixth outlet valve 357, the fourth oil supply valve 352, the fifth oil supply valve 353, the first overflow valve 351 are on the backup module.

In the invention, the liquid inlet valve is a normally open valve; the liquid outlet valve is a normally closed valve; the coupling valve is a normally open valve; the oil supply valve is a normally closed valve; simulator valve 2501 is a normally closed valve. The normally open valve is in an open and conducting state under the condition of no power supply and in a closed and non-conducting state under the condition of power supply; the normally closed valve is in a closed and non-conductive state when not energized, and in an open and conductive state when energized.

The first relief valve 351 is a relief valve which is adjustable by energization, is a solenoid valve which has a linear pressure maintaining capability for supplying a linear current, is a normally closed valve without a spring, and can be opened by a very small oil pressure. The smaller the current flowing through the relief valve, the smaller the oil pressure that can be closed by itself, that is, the smaller the oil pressure threshold value that can flow through the relief valve, and the easier it is to flow out from the relief valve. Conversely, the larger the current of the relief valve, the larger the oil pressure that the relief valve can shut down, i.e. the larger the oil pressure threshold value that can flow through the relief valve, and the less likely the relief valve will flow out.

As shown in fig. 4, the brake fluid is contained in the oil can 15, the oil can 15 is located above the master cylinder 12, the master cylinder 12 has front and rear chambers, the pedal simulator 13 has front and rear chambers, and the rear chamber of the pedal simulator 13 has a spring, and a simulation reaction to the pedal is generated by the feedback force of the spring. The oil can 15 is directly communicated with the front cavity and the rear cavity of the main cylinder 12 respectively, the front cavity of the main cylinder 12 is connected with a first pressure sensor 241, the first pressure sensor 241 is used for detecting the input pressure of the front cavity of the main cylinder 12, the front cavity of the pedal simulator 13 is connected with the front cavity of the main cylinder 12 through an oil way of a simulator valve 2501, brake fluid controlling the front cavity of the main cylinder 12 enters the front cavity of the pedal simulator 13 through the simulator valve 2501, and the rear cavity of the pedal simulator 13 is connected with the oil can 15;

In the specific implementation, four brake cylinders are arranged, wherein two brake cylinders are connected with the front cavity of the main cylinder 12 through a first coupling valve 2502, the first coupling valve 2502 controls brake fluid in the front cavity of the main cylinder 12 to enter two brake cylinders, the other two brake cylinders are connected with the rear cavity of the main cylinder 12 through a second coupling valve 2503, and the second coupling valve 2503 controls brake fluid in the rear cavity of the main cylinder 12 to enter the other two brake cylinders;

each brake cylinder is connected with the oil pot 15 through a respective liquid outlet valve, the liquid outlet valve controls the brake cylinders to output brake liquid, each brake cylinder is connected with a respective corresponding coupling valve through a respective liquid outlet valve, and the liquid inlet valve controls the brake cylinders to input brake liquid; specifically, the four brake cylinders FR, RL, RR, FL are respectively connected to the oilcan 15 through the first, second, third and fourth liquid outlet valves 2510, 2511, 2512, 2513, and the respective first, second and first coupling valves 2506, 2507, 2502, respectively, and the two brake cylinders RR, FL are respectively connected to the respective third, fourth and second coupling valves 2508, 2509, 2503, respectively.

The accumulator 27 is connected with the output end of the booster pump 23 through a first oil supply valve 2515, and the first oil supply valve 2515 controls the inflow and outflow of brake fluid in the accumulator 27; the output end of the booster pump 23 is connected with two of the brake cylinders through a second oil supply valve 2504, the second oil supply valve 2504 controls the booster pump 23 to output brake fluid into the two of the brake cylinders, the output end of the booster pump 23 is connected with the other two of the brake cylinders through a third oil supply valve 2505, and the third oil supply valve 2505 controls the booster pump 23 to output brake fluid into the other two of the brake cylinders;

The output end of the booster pump 23 is connected with a second pressure sensor 242, the second pressure sensor 242 detects the oil pressure output by the booster pump 23, and the output end of the booster pump 23 is directly connected to the oilcan 15.

As shown in fig. 4, in the backup module 3, a liquid inlet valve is arranged between the brake cylinder and the first liquid inlet valve 2506 at the output end of the pressure increasing module 2, a one-way valve which only allows one-way conduction from the first liquid inlet valve 2506 at the output end of the pressure increasing module 2 to the brake cylinder is connected in parallel with the liquid inlet valve, and a pressure sensor is arranged between the liquid inlet valve and the first liquid inlet valve 2506 at the output end of the pressure increasing module 2; the input end of the backup pump 33 is connected with the oil can 15, the brake wheel cylinder is connected with the output end of the backup pump 33 through a respective oil supply valve, meanwhile, the brake wheel cylinder is connected with the oil can 15 through a respective liquid outlet valve, and the output end of the backup pump 33 is connected with the oil can 15 through a first overflow valve 351.

In the specific implementation, the backup module 3 is only connected to the brake cylinders FR and FL of the two front wheels of the vehicle, but not to the brake cylinders RL and RR of the two further wheels of the vehicle, and specifically connected to: the fifth liquid inlet valve 354 is connected between the brake cylinder FR and the first liquid inlet valve 2506 at the output end of the pressure increasing module 2, and a third pressure sensor 341 is arranged between the fifth liquid inlet valve 354 and the first liquid inlet valve 2506 at the output end of the pressure increasing module 2; the sixth fluid intake valve 355 is connected between the brake cylinder FL and the first fluid intake valve 2506 at the output end of the pressure increasing module 2, and the third pressure sensor 341 is provided between the sixth fluid intake valve 355 and the fourth fluid intake valve 2509 at the output end of the pressure increasing module 2; the brake wheel cylinder FR and the brake wheel cylinder FL are respectively connected with the oilcan 15 through a fifth liquid outlet valve 356 and a sixth liquid outlet valve 357, and are respectively connected with the output end of the booster pump 33 on the backup module 3 through a fourth oil supply valve 352 and a fifth oil supply valve 353.

The working process of the invention comprises the following working modes:

(66) Self-checking mode of the supercharging module 2

At this time, the driver is not on the vehicle, and the brake pedal is kept stationary, and the brake pedal displacement is unchanged.

The brake execution system has a self-checking function, and when the vehicle is ignited after running a certain mileage or the brake function is executed for a certain number of times, the self-checking is started.

Self-checking step 1: for detecting whether the booster pump 23, the accumulator 27, the first oil supply valve 2515, the second pressure sensor 242, the second oil supply valve 2504, and the third oil supply valve 2505 are normal.

The first coupling valve 2502 and the second coupling valve 2503 are kept energized so that the first coupling valve 2502 and the second coupling valve 2503 are not conductive.

As shown in fig. 5, first, the booster pump 23 is energized, the output oil pressure of the booster pump 23 is controlled to be under the unidirectional opening pressure of the oil supply valve, and the first oil supply valve 2515 is energized, so that the first oil supply valve 2515 is conducted, and the accumulator 27 is in oil path communication with the booster pump 23;

then, the second oil supply valve 2504 and the third oil supply valve 2505 are disconnected, so that the second oil supply valve 2504 and the third oil supply valve 2505 are not conducted, and the brake fluid in the accumulator 27 and the brake fluid output by the booster pump 23 cannot flow to each liquid inlet valve through the second oil supply valve 2504 and the third oil supply valve 2505, and exist in a relatively closed oil path;

For a period of time, the degree of pressure detected by the second pressure sensor 242 is unchanged, which indicates that the booster pump 23, the accumulator 27, the first oil supply valve 2515, the second pressure sensor 242, the second oil supply valve 2504 and the third oil supply valve 2505 are normal.

Self-checking step 2: is used for detecting whether the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508, the fourth liquid inlet valve 2509, the first coupling valve 2502 and the second coupling valve 2503 are normal or not.

As shown in fig. 6, on the basis of the self-checking step 1, after the second oil supply valve 2504 and the third oil supply valve 2505 are electrified, the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are electrified, so that the second oil supply valve 2504 and the third oil supply valve 2505 are conducted, the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are not conducted, so that the brake liquid in the accumulator 27 and the brake liquid output by the booster pump 23 are circulated to each liquid inlet valve through the second oil supply valve 2504 and the third oil supply valve 2505, but cannot enter each brake through each liquid inlet valve, and exist in a relatively closed oil path;

for a period of time, the degree of pressure detected by the second pressure sensor 242 is unchanged, which indicates that the first inlet valve 2506, the second inlet valve 2507, the third inlet valve 2508, the fourth inlet valve 2509, the first coupling valve 2502 and the second coupling valve 2503 are normal.

Self-checking step 3: for detecting whether the first, second, third, fourth, fifth, and 4 brake cylinders 2510, 2512, 2513, 356, 357, 352, 353, and 353 are normal.

As shown in fig. 8, on the basis of the self-checking step 2, the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are powered off, so that the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are all conducted, so that the brake liquid in the accumulator 27 and the brake liquid output by the booster pump 23 are circulated to each liquid inlet valve through the second oil supply valve 2504 and the third oil supply valve 2505, then enter each brake wheel cylinder through each liquid inlet valve and the fourth oil supply valve 352 and the fifth oil supply valve 353 of the backup module 3, and are in a relatively closed oil path;

for a period of time, the degree of pressure detected by the second pressure sensor 242 is unchanged, which indicates that the first fluid outlet valve 2510, the second fluid outlet valve 2511, the third fluid outlet valve 2512, the fourth fluid outlet valve 2513, the fifth fluid outlet valve 356, the sixth fluid outlet valve 357, the fourth fluid supply valve 352, the fifth fluid supply valve 353 and the four brake cylinders are normal.

After the three detection steps are finished, the whole supercharging module 2 is normal, and self-checking detection of the supercharging module 2 is completed.

(7) Conventional braking boost mode of backup module 3 when boost module 2 fails

The booster module 2 fails and is powered off to be inoperable, namely, the booster motor 22, the booster pump 23, the booster oil pressure sensor group 24, the booster solenoid valve group 25 and the booster controller 26 in the booster module 2 are powered off, only the backup module 3 is started, and the backup solenoid valve group 35 is controlled to be powered on or powered off locally to operate.

The backup module 3 is connected to only the brake cylinders of the two front wheels of the vehicle, that is, the brake cylinder FR and the brake cylinder FL.

At this time, when the driver steps on the brake pedal, the brake fluid in the front and rear chambers of the master cylinder 12 flows out, and the brake pedal displacement increases.

As shown in fig. 8, the first coupling valve 2502 and the second coupling valve 2503 are controlled to be powered off and turned on, and the simulator valve 2501 is controlled to be powered off and turned off, so that brake fluid cannot enter the pedal simulator 13 through the simulator valve 2501; the second oil supply valve 2504 and the third oil supply valve 2505 are powered off and not conducted, and brake fluid cannot enter the oil way of the booster pump 23; the first fluid inlet valve 2506, the second fluid inlet valve 2507, the third fluid inlet valve 2508 and the fourth fluid inlet valve 2509 are powered off and conducted, the first fluid outlet valve 2510, the second fluid outlet valve 2511, the third fluid outlet valve 2512 and the fourth fluid outlet valve 2513 are powered off and not conducted, and brake fluid in the master cylinder 12 sequentially passes through the two coupling valves and then enters each brake wheel cylinder through each fluid inlet valve, so that the brake fluid of each brake wheel cylinder is increased.

When the brake fluid flows through the fifth fluid inlet valve 354 and the sixth fluid inlet valve 355 of the backup module 3, the fifth fluid inlet valve 354 and the sixth fluid inlet valve 355 are electrified and non-conducted, for example, the fifth fluid inlet valve 354 of the brake cylinder FR is electrified and non-conducted, and the brake fluid flows into the brake cylinder through the one-way valve connected with the fluid inlet valve of the backup module 3 in parallel.

The third pressure sensor 341 detects the oil pressure input from the master cylinder 12 to the brake cylinders, the current value of the backup pump 33 required to control the backup motor 32 is calculated according to the current state of the vehicle and the oil pressure detected by the third pressure sensor 341, the backup motor 32 is electrified, the brake fluid in the reservoir 15 is pumped from the input end to the output end of the backup pump 33 by the backup pump 33, the fourth oil supply valve 352 is electrified and conducted, the fifth oil supply valve 353 is electrified and conducted, and the backup pump 33 outputs the brake fluid to enter each brake cylinder through each oil supply valve of the backup module 3.

The first relief valve 351 is given a current according to the current state of the vehicle, the first relief valve 351 is fed with a current value corresponding to the required oil pressure for controlling the backup pump 33 to output the oil pressure, and when the oil pressure of the brake cylinder is greater than the required oil pressure, the redundant brake fluid can return to the oilcan 15 through the first relief valve 351.

The brake fluid output from the backing pump 33 is mainly boosted in the brake cylinders FR and FL, and the fifth and sixth fluid intake valves 354 and 355 are provided with check valves, so that part of the hydraulic pressure input from the master cylinder 12 is supplied to the brake cylinders FR and FL through the check valves, thereby boosting the fluid and assisting the boosting pressure.

For the brake cylinders RL and RR, only the brake fluid in the master cylinder 12 sequentially passes through the two coupling valves and then enters the brake cylinders RL and RR through the second fluid inlet valve 2507 and the third fluid inlet valve 2508, and the brake fluid in the brake cylinders RL and RR is increased to play a sole role in pressure increasing.

(8) Conventional braking decompression mode of backup module 3 when booster module 2 fails

When the driver releases the brake pedal, the brake fluid in the front and rear chambers of the master cylinder 12 flows back, and the brake pedal displacement becomes small.

As shown in fig. 9, the first coupling valve 2502 and the second coupling valve 2503 are controlled to be powered off and turned on, the simulator valve 2501 is controlled to be powered off and turned off, and brake fluid of the master cylinder cannot enter the pedal simulator 13 through the simulator valve 2501; the second and third oil supply valves 2504 and 2505 are powered off and not turned on, so that the brake fluid of the master cylinder cannot enter the oil passage of the booster pump 23; the first fluid intake valve 2506, the second fluid intake valve 2507, the third fluid intake valve 2508, and the fourth fluid intake valve 2509 are powered off and turned on, the first fluid outlet valve 2510, the second fluid outlet valve 2511, the third fluid outlet valve 2512, and the fourth fluid outlet valve 2513 are powered off and turned off, the fifth fluid intake valve 354 and the sixth fluid intake valve 355 are powered on and turned off, and brake fluid in the master cylinder 12 is circulated to each fluid intake valve through two coupling valves and then is communicated to the brake cylinders RL and RR, but is not communicated to the brake cylinders FR and FL.

The backup motor 32 is electrified, brake fluid in the oiler 15 is pumped from the input end to the output end of the backup pump 33 by the backup pump 33, but the current which is controlled to be electrified into the backup motor 32 is reduced, the rotating speed is reduced, and the oil quantity of the backup pump 33 is driven to be reduced.

The current flowing into the first relief valve 351 is controlled to be small, the oil pressure which the first relief valve 351 can shut down is small, and the backup pump 33 pumps out excessive brake fluid to enter the oilcan 15 through the first relief valve 351.

The fourth and fifth oil supply valves 352 and 353 are energized and turned on for the brake cylinders FR and FL, and the brake fluid of the brake cylinders FR and FL is introduced into the reservoir 15 through the fourth and fifth oil supply valves 352 and 353 and the first relief valve 351, so that the brake fluid of the brake cylinders FR and FL is reduced and reduced in pressure.

In addition, since the check valve connected in parallel with the liquid inlet valve of the backup module 3 only allows one-way conduction from the master cylinder to the brake cylinders, the brake liquid reduced by the brake cylinders FR and FL cannot flow back to the master cylinder through the liquid inlet valve of the backup module 3.

For the brake cylinders RL, RR, the brake fluid of two brake cylinders RL and RR flows back to the master cylinder through the feed liquor valve of the pressure increasing module 2, and the pressure reducing effect is achieved.

(9) ABS decompression mode of backup module 3 when supercharging module 2 fails

When the driver keeps the brake pedal stationary, the brake fluid in the front and rear chambers of the master cylinder 12 does not flow out or in, and the brake pedal displacement is unchanged.

As shown in fig. 10, the first coupling valve 2502 and the second coupling valve 2503 are controlled to be powered off and turned on, the simulator valve 2501 is controlled to be powered off and turned off, and brake fluid of the master cylinder cannot enter the pedal simulator 13 through the simulator valve 2501; the second and third oil supply valves 2504 and 2505 are powered off and not turned on, so that the brake fluid of the master cylinder cannot enter the oil passage of the booster pump 23; the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are powered off and conducted, the first liquid outlet valve 2510, the second liquid outlet valve 2511, the third liquid outlet valve 2512 and the fourth liquid outlet valve 2513 are powered off and conducted, the fifth liquid inlet valve 354 and the sixth liquid inlet valve 355 are powered on and conducted, brake liquid in the master cylinder 12 flows to the liquid inlet valves through the two coupling valves and then can be communicated to the brake wheel cylinders RL and RR, but cannot be communicated to the brake wheel cylinders FR and FL, and the brake liquid in front and rear cavities of the master cylinder 12 does not flow out and does not flow in.

The backup motor 32 is electrified, the brake fluid in the oiler 15 is pumped from the input end to the output end of the backup pump 33 by the backup pump 33, but the current which is fed into the backup motor 32 is controlled to be unchanged, the rotating speed is unchanged, and the oil pumping quantity of the backup pump 33 is driven to be unchanged.

The current flowing into the first overflow valve 351 is controlled to be unchanged, the oil pressure which can be closed by the first overflow valve 351 is unchanged, and the backup pump 33 pumps out excessive brake fluid to enter the oilcan 15 through the first overflow valve 351.

The fourth and fifth oil supply valves 352 and 353 are turned off and not turned on, so that the brake fluid output from the backup pump 33 cannot enter the oil passages of the brake cylinders FR and FL via the fourth and fifth oil supply valves 352 and 353, and the surplus brake fluid can return to the reservoir 15 only via the first relief valve 351.

The fifth fluid outlet valve 356 and the sixth fluid outlet valve 357 are energized and turned on, and the brake fluid in the brake cylinders FR and FL returns to the reservoir 15 through the fifth fluid outlet valve 356 and the sixth fluid outlet valve 357, so that the hydraulic pressure in the brake cylinders is reduced and a pressure reducing effect is exerted.

For the brake cylinders RL, RR, the brake fluid of the two brake cylinders RL and RR flows back to the fifth fluid inlet valve 354, the sixth fluid inlet valve 355 of the backup module of the brake cylinders FR, FL through the fluid inlet valve of the pressure increasing module 2, and the check valves connected in parallel with the fifth fluid inlet valve 354, the sixth fluid inlet valve 355 of the backup module 3 only allow one-way conduction from the master cylinder to the brake cylinders, so the brake fluid flows to the brake cylinders FR, FL through the check valves of the fifth fluid inlet valve 354, the sixth fluid inlet valve 355, and returns to the oilcan 15 through the fifth fluid outlet valve 356, the sixth fluid outlet valve 357, thereby playing a role of pressure reduction.

(10) ABS supercharging mode of backup module 3 when supercharging module 2 fails

As shown in fig. 11, the first coupling valve 2502 and the second coupling valve 2503 are controlled to be powered off and turned on, the simulator valve 2501 is controlled to be powered off and turned off, and brake fluid of the master cylinder cannot enter the pedal simulator 13 through the simulator valve 2501; the second and third oil supply valves 2504 and 2505 are powered off and not turned on, so that the brake fluid of the master cylinder cannot enter the oil passage of the booster pump 23; the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are powered off and conducted, the first liquid outlet valve 2510, the second liquid outlet valve 2511, the third liquid outlet valve 2512 and the fourth liquid outlet valve 2513 are powered off and conducted off, the fifth liquid inlet valve 354 and the sixth liquid inlet valve 355 are kept powered on and conducted off, brake liquid in the master cylinder 12 flows to each liquid inlet valve through two coupling valves and then can be communicated to brake wheel cylinders RL and RR, but cannot be communicated to the brake wheel cylinders FR and FL, and the brake liquid in front cavities and back cavities of the master cylinder 12 cannot flow out and flow in.

The current flowing into the first relief valve 351 is controlled to be unchanged, the oil pressure which the first relief valve 351 can shut is unchanged, and the redundant brake liquid pumped by the backup pump 33 also enters the oil can 15 through the first relief valve 351.

For the brake cylinders FR, FL, the fourth oil supply valve 352 and the fifth oil supply valve 353 are energized and turned on, so that the brake fluid output by the backup pump 33 enters the brake cylinders FR and FL via the fourth oil supply valve 352 and the fifth oil supply valve 353, and the fifth fluid outlet valve 356 and the sixth fluid outlet valve 357 are de-energized and non-turned on, so that the brake fluid of the brake cylinders FR, FL cannot return to the reservoir 15 via the fifth fluid outlet valve 356 and the sixth fluid outlet valve 357, and the oil pressure is reduced, thereby increasing the pressure.

As for the brake cylinders RL and RR, the fifth and sixth fluid intake valves 354 and 355 are energized and non-conductive, so that the brake cylinders RL and RR are not communicated with the brake cylinders FR and FL, the oil pressure is unchanged, and the pressure maintaining function is achieved.

(11) ABS pressure maintaining mode of backup module 3 when pressurizing module 2 fails

As shown in fig. 12, the first coupling valve 2502 and the second coupling valve 2503 are controlled to be turned off and turned on, the simulator valve 2501 is controlled to be turned off and turned off, and brake fluid of the master cylinder cannot enter the pedal simulator 13 through the simulator valve 2501; the second and third oil supply valves 2504 and 2505 are powered off and not turned on, so that the brake fluid of the master cylinder cannot enter the oil passage of the booster pump 23; the first liquid inlet valve 2506, the second liquid inlet valve 2507, the third liquid inlet valve 2508 and the fourth liquid inlet valve 2509 are powered off and conducted, the first liquid outlet valve 2510, the second liquid outlet valve 2511, the third liquid outlet valve 2512 and the fourth liquid outlet valve 2513 are powered off and conducted, the fifth liquid inlet valve 354 and the sixth liquid inlet valve 355 are powered on and conducted, brake liquid in the master cylinder 12 flows to the liquid inlet valves through the two coupling valves and then can be communicated to the brake wheel cylinders RL and RR, but cannot be communicated to the brake wheel cylinders FR and FL, and the brake liquid in front and rear cavities of the master cylinder 12 does not flow out and does not flow in.

For the brake cylinders FR, FL, the fifth liquid outlet valve 356, the sixth liquid outlet valve 357 are energized to conduct the brake fluid of the brake cylinders FR, FL, the brake fluid cannot return to the reservoir 15 through the fifth liquid outlet valve 356, the sixth liquid outlet valve 357, and the fourth oil supply valve 352 and the fifth oil supply valve 353 are de-energized and non-conducted, the brake fluid output by the backup pump 33 cannot enter the brake cylinders FR and the brake cylinders FL through the fourth oil supply valve 352 and the fifth oil supply valve 353, and the brake fluid pumped by the backup pump 33 can only return to the reservoir 15 directly through the first relief valve 351, so that the oil pressure of the brake cylinders FR, FL is unchanged, and the pressure maintaining function is achieved.

(12) Single-wheel supercharging and single-wheel decompression modes of backup module 3 when supercharging module 2 fails

As shown in fig. 13, when the vehicle requires the one-side brake cylinder to adjust the pressure, the brake cylinder FR is pressurized and the brake cylinder FL is depressurized. The single wheel boost circuit is represented by the open arrow and the single wheel depressurize circuit is represented by the solid arrow.

When the brake cylinder FR is single-wheel-boosted:

the current of the backup motor 32 is regulated to make the motor speed faster, so that the oil pressure output by the backup pump 33 is larger than the oil pressure required by the brake cylinder; the first relief valve 351 is supplied with current, and the first relief valve 351 controls the backup pump 33 to output oil pressure at a current value corresponding to the required oil pressure, and controls the backup pump 33 to output oil pressure to the fourth oil supply valve 352 at the required value.

The fifth fluid inlet valve 354 is electrified and not conducted, and the brake fluid in the master cylinder 12 cannot be communicated to the brake cylinder FR after passing through the coupling valve, so that the brake fluid in the front and rear cavities of the master cylinder 12 cannot flow out or flow in.

The fourth oil supply valve 352 is powered off and is not turned on, so that the brake fluid output by the booster pump 33 enters the brake wheel cylinder FR through the fourth oil supply valve 352, the fifth fluid outlet valve 356 is powered on and turned on, and the brake fluid of the brake wheel cylinder FL cannot enter the oilcan 15 through the fifth fluid outlet valve 356, so that the oil pressure of the brake wheel cylinder FR is increased, and a boosting effect is achieved.

When the brake cylinder FL is depressurized by a single wheel:

the sixth fluid intake valve 355 is energized and non-conductive, so that the brake fluid in the master cylinder 12 cannot be communicated to the brake cylinder FL after passing through the coupling valve, and the brake fluid in the front and rear chambers of the master cylinder 12 does not flow out or flow in.

The fifth oil supply valve 353 is turned off and not turned on, so that the brake fluid output from the booster pump 33 cannot enter the brake cylinder FL through the fifth oil supply valve 353, the sixth fluid outlet valve 357 is turned on, the brake fluid of the brake cylinder FL enters the oilcan 15 through the sixth fluid outlet valve 357, and the oil pressure of the brake cylinder FL is reduced, thereby achieving a pressure reducing effect.

(13) Boost and depressurization mode of purely mechanical braking when both boost module 2 and backup module 3 fail

As shown in fig. 14, when all the solenoid valves are powered off, that is, the booster solenoid valve group 25 and the backup solenoid valve group 35 are powered off, the brake fluid in the front chamber of the master cylinder 12 enters two paths of brake cylinders along the pipeline through the coupling valve which is normally open when the power is off and the feed valve which is normally open when the power is off by the booster module 2, and the brake fluid in the rear chamber of the master cylinder 12 enters the other two paths of brake cylinders along the pipeline through the coupling valve which is normally open when the power is off and the feed valve which is normally open when the power is off by the booster module 2, and meanwhile, the liquid outlet valve which is normally closed when the power is not off by the booster module 2 cannot enter the oil can 15, and the oil supply valve which is normally closed when the power is off by the booster module 2 cannot flow back to the oil can 15. So that the brake system can still provide a brake oil pressure of at least 5MPa per brake cylinder.

Claims

1. A split type decoupling vehicle electronic hydraulic braking system with redundant function is characterized in that: the system comprises a pedal module (1), a pressurizing module (2) and a backup module (3);

the pedal module (1) is used for receiving external pedal acting force, detecting pedal displacement and feeding back to the pressurizing module (2) and the backup module (3) and generating hydraulic pressure to transmit to the pressurizing module (2) and the backup module (3), and comprises a pedal valve block (11), a main cylinder (12) positioned in the pedal valve block (11), a pedal simulator (13), a push rod (14) connected with a piston of the main cylinder (12), an oilcan (15) for providing brake fluid for the main cylinder (12) and the pedal simulator (13), a displacement sensor (16) for detecting displacement of the push rod (14), wherein the push rod (14) is connected with a brake pedal and receives external pedal acting force;

The pressure increasing module (2) is used for receiving pedal displacement and then generating hydraulic pressure to control a brake wheel cylinder to brake, and comprises a pressure increasing valve block (21), a pressure increasing motor (22) positioned in the pressure increasing valve block (21), a pressure increasing pump (23), a pressure increasing oil pressure sensor group (24) for detecting oil pressure of a master cylinder (12) and the pressure increasing pump (23), a pressure increasing electromagnetic valve group (25) for controlling oil passage change, and a pressure increasing controller (26) for controlling the pressure increasing motor (22) and the pressure increasing electromagnetic valve group (25); the output end of the booster pump (23) is directly connected to the oilcan (15);

the backup module (3) is used for receiving pedal displacement or hydraulic pressure when the pressure increasing module (2) fails so as to generate hydraulic pressure to control a brake cylinder to brake, and comprises a backup valve block (31), a backup motor (32) positioned in the backup valve block (31), a backup pump (33), a backup oil pressure sensor (34) for detecting oil pressure input from a master cylinder to the backup module, a backup electromagnetic valve group (35) for controlling oil passage change, and a backup controller (36) for controlling the backup motor (32) and the backup electromagnetic valve group (35);

and the brake wheel cylinder receives hydraulic pressure from the pedal module (1), the pressure increasing module (2) and the backup module (3) to generate braking force so as to realize vehicle braking.

2. The split redundant vehicle electro-hydraulic brake system of claim 1 wherein: the supercharging oil pressure sensor group (24) comprises a first pressure sensor (241) and a second pressure sensor (242);

The pressurizing electromagnetic valve group (25) only comprises a simulator valve (2501), a first coupling valve (2502), a second coupling valve (2503), a first oil supply valve (2515), a second oil supply valve (2504), a third oil supply valve (2505), a first liquid inlet valve (2506), a second liquid inlet valve (2507), a third liquid inlet valve (2508), a fourth liquid inlet valve (2509), a first liquid outlet valve (2510), a second liquid outlet valve (2511), a third liquid outlet valve (2512) and a fourth liquid outlet valve (2513);

only one backup oil pressure sensor (34) is the third pressure sensor (341);

the backup electromagnetic valve group (35) comprises a fifth liquid inlet valve (354), a sixth liquid inlet valve (355), a fifth liquid outlet valve (356), a sixth liquid outlet valve (357), a fourth oil supply valve (352), a fifth oil supply valve (353) and a first overflow valve (351).

3. The split redundant vehicle electro-hydraulic brake system of claim 2 wherein: the first overflow valve (351) is an overflow valve which is adjustable by electrifying.

4. The split redundant vehicle electro-hydraulic brake system of claim 2 wherein: the brake fluid is arranged in the oil can (15), the main cylinder (12) is provided with a front cavity and a rear cavity, the pedal simulator (13) is provided with the front cavity and the rear cavity, the oil can (15) is respectively and directly communicated with the front cavity and the rear cavity of the main cylinder (12), the front cavity of the main cylinder (12) is connected with a first pressure sensor (241), the first pressure sensor (241) is used for detecting the input pressure of the front cavity of the main cylinder (12), the front cavity of the pedal simulator (13) is connected with the front cavity of the main cylinder (12) through a simulator valve (2501), and the rear cavity of the pedal simulator (13) is connected with the oil can (15);

The two brake cylinders are connected with the front cavity of the main cylinder (12) through a first coupling valve (2502), the first coupling valve (2502) controls brake fluid in the front cavity of the main cylinder (12) to enter the two brake cylinders, the other two brake cylinders are connected with the rear cavity of the main cylinder (12) through a second coupling valve (2503), and the second coupling valve (2503) controls brake fluid in the rear cavity of the main cylinder (12) to enter the other two brake cylinders;

each brake cylinder is connected with an oil pot (15) through a respective liquid outlet valve, the liquid outlet valve controls the brake cylinders to output brake liquid, each brake cylinder is connected with a respective corresponding coupling valve through a respective liquid outlet valve, and the liquid inlet valve controls the brake cylinders to input brake liquid;

the energy accumulator (27) is connected with the output end of the booster pump (23) through a first oil supply valve (2515), and the first oil supply valve (2515) controls the inflow and outflow of brake fluid in the energy accumulator (27); the output end of the booster pump (23) is connected with two of the brake cylinders through a second oil supply valve (2504), the second oil supply valve (2504) controls the booster pump (23) to output brake fluid into the two of the brake cylinders, the output end of the booster pump (23) is connected with the other two of the brake cylinders through a third oil supply valve (2505), and the third oil supply valve (2505) controls the booster pump (23) to output brake fluid into the other two of the brake cylinders;

The output end of the booster pump (23) is connected with a second pressure sensor (242), the second pressure sensor (242) detects the oil pressure output by the booster pump (23), and meanwhile, the output end of the booster pump (23) is directly connected to the oil can (15).

5. The split redundant vehicle electro-hydraulic brake system of claim 2 wherein: in the backup module (3), a liquid inlet valve is arranged between the output ends of the brake cylinder and the pressure increasing module (2), a one-way valve which only allows one-way conduction from the output end of the pressure increasing module (2) to the brake cylinder is connected in parallel on the liquid inlet valve, and a pressure sensor is arranged between the liquid inlet valve and the output end of the pressure increasing module (2); the input end of the backup pump (33) is connected with the oil can (15), the brake wheel cylinder is connected with the output end of the backup pump (33) through a respective oil supply valve, meanwhile, the brake wheel cylinder is connected with the oil can (15) through a respective liquid outlet valve, and the output end of the backup pump (33) is connected with the oil can (15) through a first overflow valve (351).

6. A self-test method for an electro-hydraulic brake system of a vehicle as set forth in any one of claims 1-5, characterized by: when the brake pedal is kept still, the self-checking of the brake system is started after the vehicle is ignited according to the following process:

Self-checking step (1):

controlling the first coupling valve (2502) and the second coupling valve (2503) to be electrified and not conducted;

firstly, energizing a booster pump (23), controlling the output oil pressure of the booster pump (23) to be under the unidirectional opening pressure of an oil supply valve, controlling the first oil supply valve (2515) to be energized and conducted, and communicating an accumulator (27) with an oil way of the booster pump (23);

then, the second oil supply valve (2504) and the third oil supply valve (2505) are controlled to be powered off and not powered on, so that the brake fluid in the accumulator (27) and the brake fluid output by the booster pump (23) cannot flow to each liquid inlet valve through the second oil supply valve (2504) and the third oil supply valve (2505) and exist in a relatively closed oil path; the booster pump (23), the accumulator (27), the first oil supply valve (2515), the second pressure sensor (242), the second oil supply valve (2504) and the third oil supply valve (2505) are normal when the pressure degree detected by the second pressure sensor (242) is unchanged within a fixed time; otherwise, the device is abnormal;

self-checking step (2): then, the second oil supply valve (2504) and the third oil supply valve (2505) are controlled to be electrified and conducted, the first liquid inlet valve (2506), the second liquid inlet valve (2507), the third liquid inlet valve (2508) and the fourth liquid inlet valve (2509) are controlled to be electrified and non-conducted, so that brake liquid in the accumulator (27) and brake liquid output by the booster pump (23) are enabled to flow to each liquid inlet valve through the second oil supply valve (2504) and the third oil supply valve (2505), but cannot enter each brake wheel cylinder through each liquid inlet valve, and the brake liquid exists in a relatively closed oil way; the first liquid inlet valve (2506), the second liquid inlet valve (2507), the third liquid inlet valve (2508), the fourth liquid inlet valve (2509), the first coupling valve (2502) and the second coupling valve (2503) are normal when the pressure degree detected by the second pressure sensor (242) is unchanged within a fixed time; otherwise, the device is abnormal;

Self-checking step (3): on the basis of the self-checking step (2), a first liquid inlet valve (2506), a second liquid inlet valve (2507), a third liquid inlet valve (2508) and a fourth liquid inlet valve (2509) are controlled to be powered off and on, so that brake liquid in an accumulator (27) and brake liquid output by a booster pump (23) are circulated to each liquid inlet valve through a second oil supply valve (2504) and a third oil supply valve (2505), enter each brake wheel cylinder through each liquid inlet valve and a fourth oil supply valve (352) and a fifth oil supply valve (353) of a backup module (3), and exist in a relatively closed oil way;

the degree of pressure detected by the second pressure sensor (242) is unchanged within a fixed time period, and the degree of pressure detected by the second pressure sensor (242) is unchanged, so that the first liquid outlet valve (2510), the second liquid outlet valve (2511), the third liquid outlet valve (2512), the fourth liquid outlet valve (2513), the fifth liquid outlet valve (356), the sixth liquid outlet valve (357), the fourth oil supply valve (352), the fifth oil supply valve (353) and the four brake wheel cylinders are normal; otherwise, the device is abnormal.

7. A backup hydraulic braking method for a vehicle electro-hydraulic braking system as set forth in any one of claims 1-5, characterized by: according to the method, the backup module (3) works according to different modes according to the conditions of whether a driver presses a brake pedal or not and whether pressurization, depressurization and pressure maintaining are needed and whether two wheels are pressurized and depressurized, wherein the backup module comprises a conventional braking pressurization mode when the pressurization module (2) fails, a conventional braking depressurization mode when the pressurization module (2) fails, a pressurization mode when the pressurization module (2) fails, a pressure maintaining mode when the pressurization module (2) fails, single-wheel pressurization and single-wheel depressurization modes when the pressurization module (2) fails:

If a driver presses a brake pedal, the backup module (3) works according to a conventional braking pressurization mode when the pressurization module (2) fails;

if a driver releases a brake pedal, the backup module (3) works according to a conventional brake decompression mode when the supercharging module (2) fails;

if the brake pedal is kept motionless and needs to be pressurized, the backup module (3) works according to a pressurizing mode when the pressurizing module (2) fails;

if the brake pedal is kept motionless and needs to be depressurized, the backup module (3) works according to a depressurization mode when the pressurization module (2) fails;

if the brake pedal is kept motionless and pressure maintaining is needed, the backup module (3) works according to the pressure maintaining mode when the pressurizing module (2) fails;

if the brake pedal is kept still and one wheel needs to be pressurized and the other wheel needs to be depressurized, the backup module (3) works according to a single-wheel pressurizing and single-wheel depressurizing mode when the pressurizing module (2) fails.