CN117184019A - Automobile electrohydraulic braking system and method adopting split type full decoupling structure - Google Patents

Abstract

The invention discloses an automobile electrohydraulic braking system and method adopting a split type full decoupling structure. The brake actuating mechanism is divided into a pedal module and a pressure increasing module, 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 provided with two paths of oil pipes which are communicated with a brake wheel cylinder, and the two blocks are respectively independent and are connected through the oil pipe; the pedal module is used for receiving external pedal acting force, detecting pedal displacement and then feeding back to the pressure increasing module, generating hydraulic pressure and transmitting the hydraulic pressure to the pressure increasing module, and the pressure increasing module is used for receiving the pedal displacement and then generating the hydraulic pressure to control the brake wheel cylinder to brake. 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

Automobile electrohydraulic braking system and method adopting split type full decoupling structure

Technical Field

The invention relates to an automobile electrohydraulic braking system and method, in particular to an automobile electrohydraulic braking system adopting a split type full decoupling structure and a control method.

Background

Most of fully-decoupling electro-hydraulic brake systems used in the current market 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.

The existing wire control execution system mostly adopts brushless motor control, the cost is high, and the requirements on the motor by adopting brush motor control are very high, so that the oil pressure error of control is large.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides an automobile electrohydraulic braking system adopting a split type full decoupling structure. The invention adopts the overflow valve and the brush motor for control, the pressure is regulated in two aspects together, the cost is low, and the pressure control is more accurate.

The technical scheme adopted by the invention is as follows:

1. an automobile electrohydraulic braking system adopting a split type full decoupling structure comprises a pedal module and a pressurizing module;

the pedal module is used for receiving external pedal acting force, detecting pedal displacement and then feeding back to the pressurizing module, generating hydraulic pressure and transmitting the hydraulic pressure to the pressurizing 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 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 connected to the oilcan through a valve in the booster electromagnetic valve group;

and the brake wheel cylinder receives hydraulic pressure from the pedal module and the pressure increasing 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 comprises a simulator valve, a first coupling valve, a second coupling valve, a first overflow 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.

The first overflow valve and the second overflow valve are all overflow valves which are adjustable through electrification.

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 connected to the oilcan through a first overflow valve.

2. A self-checking method of an electro-hydraulic brake system of an automobile 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 first overflow valve is controlled to be electrified and conducted, and the second oil supply valve and the third oil supply valve are controlled to be powered off and not conducted, so that brake liquid in the energy accumulator and brake liquid 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 liquid exists 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, the third oil supply valve and the first overflow 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 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.

The invention divides a brake actuating mechanism into a pedal module and a pressure increasing 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, and the pressure increasing module is provided with two oil pipes which are communicated with a brake wheel cylinder.

The pedal module and the pressurizing module are respectively independent, and are 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 in the invention is a brush motor.

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 two 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 automobile electrohydraulic braking system, the automobile electrohydraulic braking system has the advantages of small volume, simple structure, low cost, convenient installation, better comfort and no noise and vibration caused by a motor and a booster pump transmitted to a pedal.

Most of the parts used by the pressurizing module are the prior mature technology, and the manufacturing requirement on new products is reduced. The existing wire control movable products are controlled by adopting brushless motors, and the invention adopts the brush motors and overflow valves to realize the wire control effect, thereby having low cost and mature process.

According to the invention, the brush motor is used for pressure regulation, when the motor generates heat and is blocked, and oil pressure control is unstable, the overflow valve is added for common regulation, and redundant brake liquid can enter the oil can through the overflow valve, so that the pressure regulation is more accurate, the service life of the motor is prolonged, and the working noise of the motor is reduced.

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 hydraulic schematic of a brake system;

FIG. 4 is a hydraulic schematic of conventional braking in a normal operating mode;

FIG. 5 is a hydraulic schematic diagram of the depressurization phase during execution of the ABS operating mode in the normal operating mode;

FIG. 6 is a hydraulic schematic diagram of the boost phase when ABS operation is performed in a normal operating mode;

FIG. 7 is a hydraulic schematic diagram of the dwell phase when ABS operation is performed in normal operating mode;

fig. 8 is a hydraulic schematic diagram of a boost phase in a normal operating mode when an ESC single-wheel boost and single-wheel depressurize condition is performed;

FIG. 9 is a schematic diagram of a self-test step 1 of the pressurization module;

FIG. 10 is a schematic diagram of a boost module self-test step 2;

FIG. 11 is a schematic diagram of a boost module self-test step 3;

fig. 12 is a schematic diagram of the supercharging and decompression in which mechanical braking still exists when the supercharging module 2 fails.

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;

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 overflow valve 2514, and first oil supply valve 2515.

Detailed Description

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

The pedal module 1 and the supercharging module 2 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 generating hydraulic pressure and transmitting to the booster module 2, comprises a pedal valve block 11, a master cylinder 12, a pedal simulator 13, a push rod 14 connected with a piston of the master cylinder 12, an oil can 15 for supplying brake fluid to the master cylinder 12 and the pedal simulator 13, and 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 receives 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, and the two oil outlets are connected to the brake cylinder through an oil pipe.

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 and 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.

An oil way is arranged in the booster valve block 21, and two oil ways of an output oil way of the booster pump 23 of the booster module are connected with the brake calipers.

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

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 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 pipes.

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 relief valve 2514, 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.

As shown in fig. 3, 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. 3, 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 relief valve 2514, 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.

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 2514 and the second relief valve 351 are both relief valves which are adjustable by energization, are solenoid valves which have a linear pressure maintaining capability for supplying linear current, are normally closed valves without springs, and are 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. 3, 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 connected to the oilcan 15 via a first relief valve 2514.

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

(1) Conventional braking mode of the supercharging module 2 (including supercharging and depressurizing)

In fig. 4, the thick line is a high-pressure oil line, the thin line is a low-pressure oil line, the open arrow indicates the direction of brake fluid flow when the wheel cylinder is pressurized, the solid arrow indicates the direction of brake fluid flow when the wheel cylinder is depressurized, and the lower graph indicates the same.

Only the booster module 2 is locally powered on or powered off by controlling the booster solenoid valve group 25.

2501. 2502, 2503, 2504, 2505 are normally energized solenoid valves.

When the brake pedal is depressed or released, the displacement of the push rod 14 and thus the pedal displacement is detected by the displacement sensor 16.

As shown in fig. 4, when the driver depresses the brake pedal, the brake fluid in the front and rear chambers of the master cylinder 12 flows out, the brake pedal displacement increases, and the supercharging process is performed:

the simulator valve 2501 is electrified, the first coupling valve 2502 is electrified, and the second coupling valve 2503 is electrified, so that the simulator valve 2501 is conducted, the first coupling valve 2502 and the second coupling valve 2503 are not conducted, brake fluid output from the front cavity of the master cylinder 12 enters the pedal simulator 13, and brake fluid from the front cavity of the master cylinder 12 and the rear cavity of the master cylinder 12 cannot directly enter the brake cylinder through the first coupling valve 2502 and the second coupling valve 2503.

The first oil supply valve 2515 is turned on, the accumulator 27 is communicated with the output end of the booster pump 23, at this time, the oil pressure in the accumulator 27 is higher than the oil pressure at the output end of the booster pump 23, so that the brake fluid stored in the accumulator 27 enters into the oil path at the output end of the booster pump 23, when the oil pressure of the accumulator 27 is the same as that of the booster pump 23, the first oil supply valve 2515 is powered off, the brake fluid is stored in the accumulator 27, and the effects of rapid fluid supplementing and braking response improvement are generated through the accumulator 27.

The current value needed to be given to the booster motor 22 is calculated according to the current state of the vehicle, the booster motor 22 is electrified to control the booster pump 23 to generate a current value corresponding to the needed oil pressure, and brake fluid in the oil can 15 is pumped to the output end of the booster pump 23 from the input end by the booster pump 23.

The second oil supply valve 2504 is electrified, and the third oil supply valve 2505 is electrified, so that the second oil supply valve 2504 and the third oil supply valve 2505 are conducted, and brake fluid at the output end of the booster pump 23 enters the brake cylinder.

The current value required to be given to the first relief valve 2514 is calculated according to the current state of the vehicle, the first relief valve 2514 is energized, and the first relief valve 2514 is energized to control the booster pump 23 to output a current value corresponding to the required oil pressure. When the oil pressure of the brake cylinder is greater than the demand, the surplus brake fluid is returned to the reservoir 15 through the first relief valve 2514. The other solenoid valves do not operate.

As shown in fig. 4, when the driver releases the brake pedal, the brake fluid in the front and rear chambers of the master cylinder 12 flows in, the brake pedal displacement becomes small, and the pressure reducing process is performed:

the given current of the booster motor 22 becomes smaller, the rotation speed becomes slower, the amount of oil pumped by the booster pump 23 becomes smaller, the given current of the first relief valve 2514 becomes smaller, the oil pressure that the first relief valve 2514 can shut down becomes smaller, and the excessive brake fluid enters the reservoir 15. The current to first relief valve 2514 is thus adjusted to decrease so that more brake fluid enters reservoir 15 through first relief valve 2514.

When the brake pedal is fully released, the brake pedal displacement is zero:

the brake fluid of the brake cylinder returns to the oilcan 15 through the fluid outlet valve, the oilcan 15 supplements the brake fluid to the front cavity of the master cylinder 12, and the oilcan 15 supplements the brake fluid to the pedal simulator 13.

(2) ABS decompression mode of supercharging module 2

Only the booster module 2 is locally powered on or powered off by controlling the booster solenoid valve group 25.

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

As shown in fig. 5, the energization state of the simulator valve 2501, the first coupling valve 2502, the second coupling valve 2503, the second oil feed valve 2504, and the third oil feed valve 2505 is kept unchanged, and the energization current of the booster motor 22 is unchanged. First oil supply valve 2515 is de-energized and accumulator 27 is not connected and is not operational.

Energizing 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, wherein each fluid inlet valve is not conducted, so that brake fluid output by the booster pump 23 cannot enter each brake cylinder through each fluid inlet valve;

energizing the first relief valve 2514, the first relief valve 2514 is energized to control the output oil pressure of the booster pump 23 to be at a current value corresponding to the required oil pressure, so that the output oil path of the booster pump 23 maintains the required oil pressure, and excessive brake fluid can jack the first relief valve 2514 and return to the oilcan 15;

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 electrified, and all the liquid outlet valves are conducted, so that brake fluid of all the brake cylinders enters the oil pot 15 through the liquid outlet valves, and the oil pressure of all the brake cylinders is reduced.

(3) ABS boost mode of boost module 2

Only the booster module 2 is locally powered on or powered off by controlling the booster solenoid valve group 25.

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

As shown in fig. 6, the energization states of the simulator valve 2501, the first coupling valve 2502, the second coupling valve 2503, the second oil feed valve 2504, and the third oil feed valve 2505 are kept still.

The first oil supply valve 2515 is powered off at first, the current of the booster motor 22 is regulated, the rotation speed of the booster motor 22 is increased, the oil pressure output by the booster pump 23 is larger than the oil pressure required by the brake wheel cylinder end, the first oil supply valve 2515 is powered on, the brake fluid stored by the accumulator 27 enters the output end of the booster pump 23, when the oil pressure of the accumulator 27 is the same as that of the booster pump 23, the first oil supply valve 2515 is powered off, the brake fluid is stored in the accumulator 27, and quick fluid supplementing is performed when the brake fluid is pressurized next time, so that the response is improved.

The first relief valve 2514 is supplied with current, and the first relief valve 2514 is supplied with current corresponding to the required oil pressure to control the output oil pressure of the booster pump 23, and controls the output oil pressure of the booster pump 23 to the required oil pressure.

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 all the liquid outlet valves are not conducted, so that brake liquid of all the brake cylinders does not enter the oil can 15 through all the liquid outlet valves.

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 each fluid inlet valve is conducted, so that brake fluid output by the booster pump 23 enters each brake cylinder through each fluid inlet valve.

(4) ABS pressure maintaining mode of pressurizing module 2

Only the booster module 2 is locally powered on or powered off by controlling the booster solenoid valve group 25.

As shown in fig. 7, the energization states of the simulator valve 2501, the first coupling valve 2502, the second coupling valve 2503, the second oil feed valve 2504, the third oil feed valve 2505, and the first relief valve 2514 are kept unchanged. First oil supply valve 2515 is de-energized and accumulator 27 is not connected and is not operational.

Energizing 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, wherein each fluid inlet valve is not conducted, so that brake fluid output by the booster pump 23 cannot enter each brake cylinder through each fluid inlet valve;

simultaneously, 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, all the liquid outlet valves are not conducted, and the brake liquid of all the brake wheel cylinders is not led into the oil can 15 through all the liquid outlet valves.

Thus, the brake fluid at the cylinder end of each brake wheel cannot flow out and flow in, and is in a relatively closed oil path, the brake fluid cannot be reduced, and the oil pressure of each brake wheel cylinder is unchanged.

(5) Single-wheel supercharging and single-wheel decompression modes of supercharging module 2

As shown in fig. 8, when the vehicle needs to adjust the pressure by the wheel cylinders on one side, the pressure increase of the wheel cylinders FR and the pressure decrease of the wheel cylinders RL are taken as examples, which indicate the working condition when the same oil path has single-wheel pressure increase and the other wheel cylinder needs pressure decrease, and the principle of single-wheel pressure increase is consistent with the FR pressure increase. The single wheel boost circuit is represented by the open arrow and the single wheel depressurize circuit is represented by the solid arrow.

Only the booster module 2 is locally powered on or powered off by controlling the booster solenoid valve group 25.

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

Under the working conditions of single-wheel pressure increase and single-wheel pressure reduction, the brake wheel cylinder FR pressure is required to be increased, and the brake wheel cylinder RL pressure is reduced, so that the following steps are carried out:

the first coupling valve 2502 and the second oil supply valve 2504, which are connected together by the first oil supply valve 2515, the brake cylinder FR and the brake cylinder RL, are energized, the first oil supply valve 2515 and the second oil supply valve 2504 are conductive, and the first coupling valve 2502 is nonconductive.

The current of the booster motor 22 is regulated to make the rotation speed of the booster motor 22 faster, the oil pressure output by the booster pump 23 is larger than the oil pressure required by the brake wheel cylinder end, the first oil supply valve 2515 is electrified, the brake fluid stored by the accumulator 27 enters the output end of the booster pump 23 through the first oil supply valve 2515, and when the oil pressure of the accumulator 27 is the same as the oil pressure of the booster pump 23, the first oil supply valve 2515 is powered off, and the brake fluid is stored in the accumulator 27.

The first relief valve 2514 is supplied with current, and the first relief valve 2514 is supplied with current corresponding to the required oil pressure to control the oil pressure output from the booster pump 23, and controls the oil pressure output from the booster pump 23 to be at the required value.

The first liquid inlet valve 2506 of the brake cylinder FR is not electrified, the second liquid inlet valve 2507 of the brake cylinder RL is electrified, and the brake liquid output by the booster pump 23 enters the brake cylinder FR through the first liquid inlet valve 2506 and cannot enter the brake cylinder RL through the second liquid inlet valve 2507;

simultaneously, the first liquid outlet valve 2510 of the brake wheel cylinder FR is powered off, the second liquid outlet valve 2511 of the brake wheel cylinder RL is powered on, so that brake liquid of the brake wheel cylinder FR cannot enter the oil can 15 through the first liquid outlet valve 2510, and brake liquid of the brake wheel cylinder RL enters the oil can 15 through the second liquid outlet valve 2511.

Thus, the hydraulic pressure of the brake cylinder FR increases, and the hydraulic pressure of the brake cylinder RL decreases, and the single wheel is increased in pressure and reduced in pressure.

(6) 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: to detect 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, the third oil supply valve 2505, and the first relief valve 2514 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. 9, 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 first relief valve 2514 is electrified, the second oil supply valve 2504 and the third oil supply valve 2505 are disconnected, so that the first relief valve 2514 is conducted, the second oil supply valve 2504 and the third oil supply valve 2505 are not conducted, and therefore brake fluid in the accumulator 27 and 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 the brake fluid exists 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, the third oil supply valve 2505, and the first relief valve 2514 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. 10, 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: is used to detect whether the first, second, third, fourth and 4 brake cylinders 2510, 2511, 2512, 2513 are normal.

As shown in fig. 11, 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, and 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 and then enter each brake wheel cylinder through each liquid inlet valve, so that the brake liquid exists in a relatively closed oil way;

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 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.

(13) Boost and depressurization mode for purely mechanical braking in case of failure of boost module 2

As shown in fig. 12, when all the solenoid valves are powered off, that is, the pressure-increasing solenoid valve group 25 is powered off, the brake fluid in the front chamber of the master cylinder 12 enters two paths of brake cylinders along the coupling valve which is normally open when the power is off and the fluid inlet valve which is normally open when the power is off for the pressure-increasing 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 coupling valve which is normally open when the power is off for the power, and the fluid inlet valve which is normally open when the power is off for the pressure-increasing module 2, meanwhile, each path of brake cylinders cannot enter the oil can 15 through the fluid outlet valve which is normally closed when the power is off for the pressure-increasing module 2, and cannot flow back to the oil can 15 through the fluid inlet valve which is normally closed when the power is off for the pressure-increasing module 2. So that the brake system can still provide a brake oil pressure of at least 5MPa per brake cylinder.

Claims (5)

1. An automobile electrohydraulic braking system adopting a split type full decoupling structure, which is characterized in that: the system comprises a pedal module (1) and a pressurizing module (2);

the pedal module (1) is used for receiving external pedal acting force, detecting pedal displacement and then feeding back to the pressurizing module (2) and generating hydraulic pressure to transmit to the pressurizing module (2), 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 the 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 connected to the oilcan (15) through a valve in the booster electromagnetic valve group (25);

and the brake wheel cylinders receive hydraulic pressure from the pedal module (1) and the pressure increasing module (2) to generate braking force so as to realize vehicle braking.

2. An automotive electro-hydraulic braking system employing a split full decoupling structure as claimed in 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) comprises a simulator valve (2501), a first coupling valve (2502), a second coupling valve (2503), a first overflow valve (2514), 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).

3. An automotive electro-hydraulic braking system employing a split full decoupling structure as claimed in claim 2, wherein: the first overflow valve (2514) and the second overflow valve (351) are all overflow valves which are adjustable by electrifying.

4. An automotive electro-hydraulic braking system employing a split full decoupling structure as claimed in 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 connected to the oil can (15) through a first overflow valve (2514).

5. A self-test method for an electro-hydraulic brake system of an automobile as claimed in any one of claims 1 to 4, 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 first overflow valve (2514) is controlled to be electrified and conducted, and the second oil supply valve (2504) and the third oil supply valve (2505) are controlled to be powered off and disconnected, so that brake liquid in the accumulator (27) and brake liquid 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 way; the booster pump (23), the accumulator (27), the first oil supply valve (2515), the second pressure sensor (242), the second oil supply valve (2504), the third oil supply valve (2505) and the first overflow valve (2514) 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 energy 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 exist in a relatively closed oil path;

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.