Brake circuit type adjustable vehicle electro-hydraulic brake system

Abstract

The invention discloses a brake circuit type adjustable vehicle electro-hydraulic brake system. The system belongs to the technical field of automobile braking and comprises an automobile conventional electro-hydraulic braking system and an automobile backup braking system. The vehicle conventional electro-hydraulic braking system comprises a left hydraulic pump, a right hydraulic pump, an energy accumulator, a motor, an electromagnetic valve, a brake wheel cylinder, a left overflow valve, a right overflow valve, a hydraulic motor, a generator, a loop type selection switch, a liquid storage tank and the like. The vehicle backup brake system comprises an electromagnetic valve, a pedal travel simulator, a load sensing proportional valve, a brake master cylinder, a brake wheel cylinder, a push rod, a brake pedal arm, a liquid storage tank and the like. According to the invention, the brake loop type is timely switched through the loop type selection switch, and the advantages of X-type, H-type and B-type vehicle brake loops are fully utilized; when the conventional electro-hydraulic braking system of the vehicle fails, the backup braking system of the vehicle provides normal braking capacity; the design mode that the storage battery and the standby power supply respectively supply power to the electromagnetic valves in the two braking systems is adopted, and the service braking reliability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle braking, and relates to a vehicle electro-hydraulic braking system with adjustable braking circuit type. Background Art

[0002] With the rapid development of electronic control technology and the emergence of new vehicle structures, people have put forward higher requirements for vehicle driving safety and working reliability. The vehicle braking system is one of the most important systems in the eight major systems of the vehicle, and plays a vital role in ensuring driving safety. At present, the vehicle braking system generally adopts an electro-hydraulic braking system, and its braking circuit types mainly include X-type and H-type. The X-type is a diagonal layout type of the braking circuit. When the vehicle is braking in a straight line, even if one circuit fails, the remaining total braking force can maintain 50% of the normal value, and the front and rear axle braking force distribution ratio remains unchanged, which is conducive to improving braking stability. The main factor to be considered in the use of the X-type braking circuit is that the mass distribution of the vehicle installed with this layout type is biased towards the front wheel. When braking, a greater braking force should be formed on the rear wheel. If the front and rear wheels are independent, when the front brake line fails, the vehicle's emergency braking performance will be reduced due to the lack of rear wheel braking force. However, if the vehicle has a large load, the rear wheel load is not less than the front wheel load, and the vehicle's emergency braking performance meets the requirements, the H-type braking circuit (i.e., the front and rear wheel independent control method) can also be used. The H-type brake circuit can be used in conjunction with the traditional single-wheel cylinder drum brake. It is low-cost and widely used in various vehicles, especially trucks. However, if the rear brake circuit fails, once the front wheel is locked, the turning braking ability may be lost; for vehicles with front-wheel drive and stronger front brakes than rear brakes, when the front brake circuit fails and only the rear axle is used for braking, the braking force will be seriously insufficient. When the rear axle load is less than the front axle and the pedal force is too large, the rear wheel may be locked, thereby causing the vehicle to skid. At present, for specific vehicles, once a certain brake circuit type is selected during design, it cannot be changed during the use of the vehicle, thereby limiting the flexible application of different brake circuit types on the same vehicle. In order to effectively ensure the braking performance of the vehicle, give full play to the advantages of X-type, H-type and other vehicle brake circuits, and expand their scope of application, the present invention provides a vehicle electro-hydraulic brake system with adjustable brake circuit type. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to propose a vehicle electro-hydraulic brake system with adjustable brake circuit type, so as to realize timely switching of the brake circuit type through a circuit type selection switch according to the different loading weights and braking needs of the vehicle, so as to fully utilize the advantages of X-type, H-type and B-type (parallel type) vehicle brake circuits to ensure that the vehicle has good braking performance; when the conventional electro-hydraulic brake system of the vehicle fails, the vehicle backup brake system can provide normal braking ability; the design method of using batteries and backup power supplies to supply power to the solenoid valves in the conventional electro-hydraulic brake system of the vehicle and the backup brake system of the vehicle respectively is conducive to further improving the reliability of driving braking.

[0004] The technical solution of the present invention is: a vehicle electro-hydraulic brake system with adjustable brake circuit type described in the present invention comprises a conventional vehicle electro-hydraulic brake system and a vehicle backup brake system;

[0005] Among them, the conventional electro-hydraulic braking system of the vehicle includes a dual pump (i.e., left and right hydraulic pumps), an accumulator, a two-position two-way solenoid valve, a brake wheel cylinder, a motor, a relief valve, a hydraulic motor, a generator, a backup power supply, a battery, a brake switch, a circuit type selection switch and a fluid storage tank.

[0006] Further, the double pump is driven by a motor to operate synchronously, and a left accumulator and a right accumulator are respectively installed on the pipelines of the left and right hydraulic pump oil outlets, and a left X-type solenoid valve and a middle 2X-type solenoid valve are respectively connected in series between the oil inlet and outlet of the left accumulator and the left front wheel cylinder and the right rear wheel cylinder, and a left return oil solenoid valve and a middle 2 return oil solenoid valve are respectively connected in series between the oil outlets of the left X-type solenoid valve and the middle 2X-type solenoid valve and the oil inlet of the hydraulic motor, and a left B-type solenoid valve and a right B-type solenoid valve are connected in parallel between the oil inlet and outlet of the left accumulator and the oil inlet and outlet of the right accumulator;

[0007] A middle 1X solenoid valve and a right X-type solenoid valve are respectively connected in series between the oil inlet and outlet of the right accumulator and the right front wheel cylinder and the left rear wheel cylinder; a middle 1 oil return solenoid valve and a right oil return solenoid valve are respectively connected in series between the oil outlets of the middle 1X solenoid valve and the right X-type solenoid valve and the oil inlet of the hydraulic motor; a left H-type solenoid valve is connected in series between the oil circuit between the oil outlet of the middle 1X solenoid valve and the oil inlet of the middle 1 oil return solenoid valve on the right front wheel cylinder brake pipeline and the oil inlet and outlet of the left accumulator; a right H-type solenoid valve is connected in series between the oil circuit between the oil outlet of the middle 2X solenoid valve and the oil inlet of the middle 2 oil return solenoid valve on the right rear wheel cylinder brake pipeline and the oil inlet and outlet of the right accumulator;

[0008] A relief valve is connected in parallel between the oil inlet and outlet of the hydraulic pump, and the battery supplies power to the motor through the brake switch; the power output by the generator connected to the output shaft of the hydraulic motor is stored in the backup power supply to provide power for the solenoid valves of the backup brake system.

[0009] The vehicle backup brake system includes an isolation solenoid valve, a pedal travel simulator, a load-sensing proportional valve, a two-position two-way solenoid valve, a brake wheel cylinder, a brake master cylinder, a push rod, a brake pedal arm and a return spring, and a fluid storage tank.

[0010] Furthermore, each of the brake master cylinders has an oil inlet and an oil outlet, and an isolation solenoid valve and a pedal travel simulator are successively arranged on one branch of the brake master cylinder oil outlet circuit. The front left solenoid valve and the front right solenoid valve are respectively connected in series in the oil circuit between the brake master cylinder and the left front wheel cylinder and the right front wheel cylinder. A load-sensing proportional valve is arranged in another branch of the brake master cylinder oil outlet circuit, which is used to ensure the ratio of front and rear wheel loads during vehicle driving and prevent the rear wheels from locking during emergency braking of the vehicle, so as to shorten the braking distance and enhance the braking effect.

[0011] A rear right solenoid valve and a rear left solenoid valve are connected in series in the oil circuit between the load sensing proportional valve and the right rear wheel cylinder and the left rear wheel cylinder respectively;

[0012] The upper end of the brake pedal arm is connected to the vehicle frame via a rotating shaft, the left end of the push rod is connected to the brake pedal arm via a pin shaft, and the right end is fixedly connected to the brake master cylinder piston, and a piston return spring is provided at the right end of the piston; the brake pedal is arranged at the lower end of the brake pedal arm, and a return spring is provided on the right side of the brake pedal arm; the oil inlet of the brake master cylinder is connected to the fluid storage tank.

[0013] The solenoid valves in the conventional vehicle electro-hydraulic brake system and the vehicle backup brake system are both two-position two-way solenoid valves.

[0014] The beneficial effects of the present invention are as follows: the present invention adapts to the real-time switching requirements of the brake system circuit type for different vehicle models at different load masses, improves the versatility and adjustability of the brake system, and improves the vehicle braking effect; the on-off state of the solenoid valve in different circuit types can be switched by one button through the circuit type selection switch, and the operation is simple and the response is rapid; when the conventional electro-hydraulic brake system of the vehicle fails, the vehicle backup brake system provided with a load-sensing proportional valve can provide good braking performance under different load masses of the same vehicle model, and avoid the front wheel or rear wheel locking first; the solenoid valve of the vehicle brake system can be integrated and arranged, with a compact structure and convenient installation and maintenance, and the power supplies in the conventional electro-hydraulic brake system of the vehicle and the vehicle backup brake system are separately arranged, which can ensure reliable and effective vehicle braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 It is a working principle diagram of the circuit type selection switch in the present invention;

[0017] In the figure, 1 is a frame, 2 is a rotating shaft, 3 is a brake pedal arm, 4 is a pin shaft, 5 is a brake pedal, 6 is a return spring, 7 is a push rod, 8 is a brake master cylinder, 9 is a fluid reservoir, 10 is an isolation solenoid valve, 11 is a pedal travel simulator, 12 is a left oil return solenoid valve; 13 is a center 1 oil return solenoid valve, 14 is a center 2 oil return solenoid valve, 15 is a right oil return solenoid valve, 16 is a left X-type solenoid valve, 17 is a center 1X-type solenoid valve, 18 is a center 2X-type solenoid valve, 19 is a left X-type solenoid valve, 20 is a left X-type solenoid valve, 21 is a left X-type solenoid valve, 22 is a left X-type solenoid valve, 23 is a left X-type solenoid valve, 24 is a left X-type solenoid valve, 25 is a left X-type solenoid valve, 26 is a left X-type solenoid valve, 27 is a left X-type solenoid valve, 28 is a left X-type solenoid valve, 29 is a left X-type solenoid valve, 30 is a left X-type solenoid valve, 31 is a left X-type solenoid valve, 32 is a left X-type solenoid valve, 33 is a left X-type solenoid valve, 34 is a left X-type solenoid valve, 35 is a left X-type solenoid valve, 36 is a left X-type solenoid valve, 37 is a left X-type solenoid valve, 38 is a left X-type solenoid valve, 39 is a left X-type solenoid valve, 40 is a left X-type solenoid valve, 41 is a left X-type solenoid valve It is the right X-type solenoid valve, 20 is the hydraulic motor, 21 is the front left solenoid valve, 22 is the front right solenoid valve, 23 is the rear right solenoid valve, 24 is the rear left solenoid valve, 25 is the load-sensing proportional valve, 26 is the left H-type solenoid valve, 27 is the left B-type solenoid valve, 28 is the right B-type solenoid valve, 29 is the right H-type solenoid valve, 30 is the left accumulator, 31 is the right accumulator, 32 is the left overflow valve, 33 is the left hydraulic pump, 34 is the right hydraulic pump, 35 is the motor, and 36 is the right overflow valve. DETAILED DESCRIPTION

[0018] The specific technical scheme of the present invention is further described in detail below with reference to specific examples.

[0019] As shown in the figure, a vehicle electro-hydraulic brake system with adjustable brake circuit type described in the present invention includes a conventional vehicle electro-hydraulic brake system and a vehicle backup brake system.

[0020] Among them, the conventional electro-hydraulic braking system of the vehicle includes a double pump (i.e., a left hydraulic pump 33 and a right hydraulic pump 34), a left accumulator 30, a right accumulator 31, a two-position two-way solenoid valve, a brake wheel cylinder, a motor 35, a left overflow valve 32, a right overflow valve 36, a hydraulic motor 20, a generator, a backup power supply, a battery, a brake switch, a circuit type selection switch and a fluid storage tank 9, etc.

[0021] Further, the double pump is driven by the motor 35 to operate synchronously, a left accumulator 30 is installed on the pipeline of the oil outlet of the left hydraulic pump 33, and a right accumulator 31 is installed on the pipeline of the oil outlet of the right hydraulic pump 34. A left X-type solenoid valve 16 and a middle 2X-type solenoid valve 18 are respectively connected in series between the oil inlet and outlet of the left accumulator 30 and the left front wheel cylinder and the right rear wheel cylinder, a left return oil solenoid valve 12 and a middle 2 return oil solenoid valve 14 are respectively connected in series between the oil outlets of the left X-type solenoid valve 16 and the middle 2X-type solenoid valve 18 and the oil inlet of the hydraulic motor 20, and a left B-type solenoid valve 27 and a right B-type solenoid valve 28 are connected in parallel between the oil inlet and outlet of the left accumulator 30 and the oil inlet and outlet of the right accumulator 31;

[0022] A middle 1X type solenoid valve 17 and a right X type solenoid valve 19 are connected in series between the oil inlet and outlet of the right accumulator 31 and the right front wheel cylinder and the left rear wheel cylinder, respectively; a middle 1 oil return solenoid valve 13 and a right oil return solenoid valve 15 are connected in series between the oil outlets of the middle 1X type solenoid valve 17 and the right X type solenoid valve 19 and the oil inlet of the hydraulic motor 20, respectively; a left H type solenoid valve 26 is connected in series between the oil circuit between the oil outlet of the middle 1X type solenoid valve 17 and the oil inlet of the middle 1 oil return solenoid valve 13 on the right front wheel cylinder brake pipeline and the oil inlet and outlet of the left accumulator 30; a right H type solenoid valve 29 is connected in series between the oil circuit between the oil outlet of the middle 2X type solenoid valve 18 and the oil inlet of the middle 2 oil return solenoid valve 14 on the right rear wheel cylinder brake pipeline and the oil inlet and outlet of the right accumulator 31;

[0023] A left overflow valve 32 is connected in parallel between the oil inlet and outlet of the left hydraulic pump 33, and a right overflow valve 36 is connected in parallel between the oil inlet and outlet of the right hydraulic pump 34. The battery supplies power to the motor 35 through the brake switch; the power output by the generator connected to the output shaft of the hydraulic motor 20 is stored in the backup power supply to provide power for the solenoid valves of the backup braking system.

[0024] The circuit type selection switch is arranged in the vehicle cab, and is used by the driver to select the vehicle braking circuit type such as X type, H type, B type, etc. according to the different loading weights and braking requirements of the vehicle during driving.

[0025] The vehicle backup brake system includes an isolation solenoid valve 10, a pedal travel simulator 11, a load-sensing proportional valve 25, a two-position two-way solenoid valve, a brake wheel cylinder, a brake master cylinder 8, a push rod 7, a brake pedal arm 3 and a return spring 6, and a fluid storage tank 9.

[0026] Furthermore, each of the brake master cylinders 8 has an oil inlet and an oil outlet, an isolation solenoid valve 10 and a pedal travel simulator 11 are successively arranged on a branch of the brake master cylinder 8 oil outlet circuit, a front left solenoid valve 21 and a front right solenoid valve 22 are respectively connected in series in the oil circuit between the brake master cylinder 8 and the left front wheel cylinder and the right front wheel cylinder, and a load sensing proportional valve 25 is arranged in another branch of the brake master cylinder 8 oil outlet circuit, so as to ensure the ratio of the front and rear wheel loads during the vehicle driving process and prevent the rear wheels from locking when the vehicle is braked in an emergency, so as to shorten the braking distance and enhance the braking effect;

[0027] A rear right solenoid valve 23 and a rear left solenoid valve 24 are connected in series in the oil circuit between the load sensing proportional valve 25 and the right rear wheel cylinder and the left rear wheel cylinder, respectively;

[0028] The upper end of the brake pedal arm 3 is connected to the vehicle frame 1 via the rotating shaft 2, the left end of the push rod 7 is connected to the brake pedal arm 3 via the pin shaft 4, and the right end is fixedly connected to the piston of the brake master cylinder 8, and a piston return spring is installed at the right end of the piston;

[0029] The brake pedal 5 is arranged at the lower end of the brake pedal arm 3 , a return spring 6 is installed on the right side of the brake pedal arm 3 , and the oil inlet of the brake master cylinder 8 is connected to a fluid storage tank 9 .

[0030] The solenoid valves in the conventional vehicle electro-hydraulic brake system and the vehicle backup brake system are both two-position two-way solenoid valves.

[0031] The working principle of the present invention is as follows: when the vehicle does not need to brake, the brake switch is disconnected, the motor 35 does not run, the left hydraulic pump 33 and the right hydraulic pump 34 do not work, the circuit type selection switch is placed in the O position, the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, the right return oil solenoid valve 15, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, and the right B-type solenoid valve 28 in the conventional electro-hydraulic brake system of the vehicle are all powered off, and the power-off solenoid valve valve The cores are all in the cut-off position, disconnecting all oil circuits, and no brake fluid enters the wheel cylinder; at the same time, the isolation solenoid valve 10 in the vehicle's backup braking system is powered off, and its valve core is in the upper position, disconnecting the oil circuit from the active master cylinder 8 to the pedal stroke simulator 11, and the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all powered off, and the valve cores of the power-off solenoid valves are all in the upper position, allowing all oil circuits to pass. However, since the brake pedal 5 is not pressed, the piston of the brake master cylinder 8 is at the left end under the action of the piston return spring, and no brake fluid flows out of the brake master cylinder 8, so no brake fluid enters the wheel cylinder, and the vehicle does not brake.

[0032] When the conventional electro-hydraulic brake system of the vehicle can work normally and the vehicle needs to brake with an X-type brake circuit, the circuit type selection switch is placed in the X position, and after the brake pedal 5 is stepped on, the brake switch is closed, the motor 35 runs, and the left hydraulic pump 33 and the right hydraulic pump 34 both work. At this time, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, and the right B-type solenoid valve 28 in the conventional electro-hydraulic brake system of the vehicle are all powered off, and the solenoid valve cores are all in the cut-off position to disconnect the corresponding oil circuit, and the left X-type solenoid valve 16, the middle 2X-type solenoid valve 18, the middle 1X-type solenoid valve 17, and the right X-type solenoid valve 19 are all powered on, and the energized solenoid valve cores are all in The left and right positions are in the corresponding oil circuits, the brake fluid enters the wheel cylinders, the left oil return solenoid valve 12, the middle 1 oil return solenoid valve 13, the middle 2 oil return solenoid valve 14, and the right oil return solenoid valve 15 are all powered off, the power-off solenoid valve spools are in the right position, and all the wheel cylinder oil return circuits are disconnected, the wheel cylinders are in a pressurized state, and the wheel braking force gradually increases; when the wheel slip rate is in the set optimal slip rate range, the left X-type solenoid valve 16, the middle 2X-type solenoid valve 18, the middle 1X-type solenoid valve 17, the right X-type solenoid valve 19 and the left oil return solenoid valve 12, the middle 1 oil return solenoid valve 13, the middle 2 oil return solenoid valve 14, and the right oil return solenoid valve 15 are all powered off, the power-off solenoid valve spools are in The left and right X-type solenoid valves 16, 18, 17 and 19 are in the cut-off position, and the oil inlet and return paths of all wheel cylinders are disconnected, and the wheel cylinders are in a pressure-maintaining state; if the wheel braking force continues to increase and the wheel is close to locking, the left X-type solenoid valve 16, the middle 2X-type solenoid valve 18, the middle 1X-type solenoid valve 17 and the right X-type solenoid valve 19 continue to be de-energized, and the valve cores of the de-energized solenoid valves are all in the left position, and the corresponding oil paths leading to the wheel cylinders are disconnected, and the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14 and the right return oil solenoid valve 15 are energized, and the valve cores of the energized solenoid valves are all in the left position, and the brake fluid of each wheel cylinder passes through the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14 and the right return oil solenoid valve 15 respectively. The magnetic valve 15 flows to the hydraulic motor 20, and the wheel cylinder is in a decompression state; at the same time, the brake fluid flowing through the hydraulic motor 20 drives the hydraulic motor 20 to rotate, drives the generator to generate electricity and stores the electrical energy in the backup power supply for use by the solenoid valves of the backup braking system; through the left X-type solenoid valve 16, the middle 2X-type solenoid valve 18, the middle 1X-type solenoid valve 17, the right X-type solenoid valve 19 and the left return oil solenoid valve 12, the middle 1 oil return solenoid valve 13, the middle 2 oil return solenoid valve 14, and the right return oil solenoid valve 15, the pressure increase, pressure maintenance, and pressure reduction cycles of each wheel cylinder are realized, ensuring that the slip rate of each wheel can be in the optimal slip rate range, thereby improving the vehicle braking effect.During this process, the isolation solenoid valve 10 in the vehicle's backup braking system is energized, and its valve core is in the lower position, connecting the oil circuit from the brake master cylinder 8 to the pedal travel simulator 11, thereby improving the driver's pedal feel; the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all energized, and the valve cores of the energized solenoid valves are all in the lower position, thereby disconnecting all oil circuits, and the brake fluid in the brake master cylinder 8 does not enter the wheel cylinder.

[0033] When the conventional electro-hydraulic brake system of the vehicle can work normally and the vehicle needs to brake with an H-type brake circuit, the circuit type selection switch is set to the H position, and after the brake pedal 5 is stepped on, the brake switch is closed, the motor 35 runs, and the left hydraulic pump 33 and the right hydraulic pump 34 both work. At this time, the left B-type solenoid valve 27, the right B-type solenoid valve 28, the middle 1X-type solenoid valve 17, and the middle 2X-type solenoid valve 18 in the conventional electro-hydraulic brake system of the vehicle are all powered off, and the power-off solenoid valve cores are all in the cut-off position to disconnect the corresponding oil circuit, and the left X-type solenoid valve 16, the left H-type solenoid valve 26, the right X-type solenoid valve 19, and the right H-type solenoid valve 29 are all powered on, and the power-on solenoid valve cores are all When the wheel slip rate is in the set optimal slip rate range, the left X-type solenoid valve 16, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the right X-type solenoid valve 19 and the left return oil solenoid valve 12, the center 1 oil return solenoid valve 13, the center 2 oil return solenoid valve 14, and the right return oil solenoid valve 15 are all powered off, and the power-off solenoid valve spools are all in the right position to disconnect the return oil circuits of all wheel cylinders, the wheel cylinders are in a pressurized state, and the wheel braking force gradually increases; when the wheel slip rate is in the set optimal slip rate range, the left X-type solenoid valve 16, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the right X-type solenoid valve 19 and the left return oil solenoid valve 12, the center 1 oil return solenoid valve 13, the center 2 oil return solenoid valve 14, and the right return oil solenoid valve 15 are all powered off, and the power-off solenoid valve spools All of them are in the cut-off position, and the oil inlet and return paths of all wheel cylinders are disconnected, and the wheel cylinders are in a pressure-maintaining state; if the wheel braking force continues to increase and the wheel is close to locking, at this time, the left X-type solenoid valve 16, the left H-type solenoid valve 26, the right H-type solenoid valve 29, and the right X-type solenoid valve 19 continue to be de-energized, and the valve cores of the de-energized solenoid valves are all in the cut-off position, and the corresponding oil paths leading to the wheel cylinders are disconnected, and the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, and the right return oil solenoid valve 15 are energized, and the valve cores of the energized solenoid valves are all in the left position, and the brake fluid of each wheel cylinder passes through the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, and the right return oil solenoid valve 15 respectively. The oil solenoid valve 15 flows to the hydraulic motor 20, and the wheel cylinder is in a decompression state; at the same time, the brake fluid flowing through the hydraulic motor 20 drives the hydraulic motor 20 to rotate, drives the generator to generate electricity and stores the electrical energy in the backup power supply for use by the solenoid valves of the backup braking system; through the left X-type solenoid valve 16, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the right X-type solenoid valve 19 and the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, and the right return oil solenoid valve 15, the pressure increase, pressure maintenance, and pressure reduction cycles of each wheel cylinder are realized, ensuring that the slip rate of each wheel can be in the optimal slip rate range, thereby improving the vehicle braking effect.During this process, the isolation solenoid valve 10 in the vehicle's backup braking system is energized, and its valve core is in the lower position, connecting the oil circuit from the active master cylinder 8 to the pedal stroke simulator 11, thereby improving the driver's pedal feel; the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all energized, and the valve cores of the energized solenoid valves are all in the lower position, thereby disconnecting all oil circuits, and the brake fluid in the brake master cylinder 8 does not enter the wheel cylinder.

[0034] When the conventional electro-hydraulic brake system of the vehicle can work normally and the vehicle needs to brake quickly with the B-type brake circuit, the circuit type selection switch is placed in the B position, and after the brake pedal 5 is stepped on, the brake switch is closed, the motor 35 runs, and the left hydraulic pump 33 and the right hydraulic pump 34 both work. At this time, the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, and the right B-type solenoid valve 28 in the conventional electro-hydraulic brake system of the vehicle are all energized, and the valve cores of the energized solenoid valves are all in the conducting position to enable all oil circuits to pass through, and the left hydraulic The brake fluid pumped out by the pump 33 and the right hydraulic pump 34 enters the wheel cylinder in parallel through the energized solenoid valves, and the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, and the right return oil solenoid valve 15 are all powered off, and the valve cores of the power-off solenoid valves are all in the right position to disconnect the return oil circuits of all wheel cylinders, the wheel cylinders are in a pressurized state, and the wheel braking force gradually increases; when the wheel slip rate is in the set optimal slip rate range, the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, and the right B-type solenoid valve 2 8 are all powered off, the power-off solenoid valve cores are in the cut-off position to disconnect the oil inlet circuits of all wheel cylinders, the left return oil solenoid valve 12, the middle 1 return oil solenoid valve 13, the middle 2 return oil solenoid valve 14, and the right return oil solenoid valve 15 are all powered off, and the power-off solenoid valve cores are in the right position to disconnect the oil return circuits of all wheel cylinders, and the wheel cylinders are in a pressure-maintaining state; if the wheel braking force continues to increase and the wheel is close to locking, at this time, the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, and the right B-type solenoid valve 28 continue to be powered off, and all The valve cores of the power-off solenoid valves are all in the cut-off position, thus disconnecting the corresponding oil circuits leading to the wheel cylinders. The left oil return solenoid valve 12, the middle oil return solenoid valve 13, the middle oil return solenoid valve 2, and the right oil return solenoid valve 15 are energized. The valve cores of the energized solenoid valves are all in the left position. The brake fluid of each wheel cylinder flows to the hydraulic motor 20 through the left oil return solenoid valve 12, the middle oil return solenoid valve 13, the middle oil return solenoid valve 2, and the right oil return solenoid valve 15, respectively, and the wheel cylinder is in a decompression state; at the same time, the brake fluid flowing through the hydraulic motor 20 drives the hydraulic motor 20 to rotate, drives the generator to generate electricity and stores the electrical energy in the backup power supply for use by each solenoid valve of the backup brake system;By quickly switching on and off the power of the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27, the right B-type solenoid valve 28 and the left return oil solenoid valve 12, the middle 1 oil return solenoid valve 13, the middle 2 oil return solenoid valve 14, and the right return oil solenoid valve 15, the pressure increase, pressure maintenance, and pressure reduction cycles of each wheel cylinder are realized, ensuring that the slip rate of each wheel can be in the optimal slip rate range, thereby improving the vehicle braking effect. During this process, the isolation solenoid valve 10 in the vehicle backup brake system is energized, and its valve core is in the lower position, connecting the oil circuit from the active master cylinder 8 to the pedal travel simulator 11, improving the driver's pedal feel; the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all energized, and the valve cores of the energized solenoid valves are all in the lower position to disconnect all oil circuits, and the brake fluid in the brake master cylinder 8 does not enter the wheel cylinder. ;

[0035] Regardless of whether the vehicle is braked in the X-type, H-type or B-type brake circuit type, when the vehicle brakes are released, the left X-type solenoid valve 16, the middle 1X-type solenoid valve 17, the middle 2X-type solenoid valve 18, the right X-type solenoid valve 19, the left H-type solenoid valve 26, the right H-type solenoid valve 29, the left B-type solenoid valve 27 and the right B-type solenoid valve 28 are all in a power-off state, and the valve cores of the power-off solenoid valves are all in the cut-off position to cut off the brake fluid from entering the wheel cylinder oil circuit. At the same time, the left return oil solenoid valve 12 and the middle 1 return oil solenoid valve 18 are in a power-off state. The solenoid valve 13, the middle 2 oil return solenoid valve 14, and the right oil return solenoid valve 15 are all energized, and the valve cores of the energized solenoid valves are in the on position, so that the brake fluid in the wheel cylinder flows out to release the brake; during the brake release process, the isolation solenoid valve 10 continues to be energized, its valve core is in the lower position, and the oil circuit in the pedal stroke simulator 11 returns to the active master cylinder 8. When the brake pedal 5 is reset, the isolation solenoid valve 10 is de-energized, and its valve core is in the upper position, cutting off the oil circuit between the active master cylinder 8 and the pedal stroke simulator 11.

[0036] The left accumulator 30 and the right accumulator 31 provide pre-pressure for the conventional electro-hydraulic brake system of the vehicle. When the vehicle needs to brake and the outlet pressures of the left hydraulic pump 33 and the right hydraulic pump 34 are low, the left accumulator 30 and the right accumulator 31 assist in providing brake fluid with higher pressure to the oil circuit. When the outlet pressures of the left hydraulic pump 33 and the right hydraulic pump 34 are high, part of the brake fluid pumped out by the left hydraulic pump 33 and the right hydraulic pump 34 enters the left accumulator 30 and the right accumulator 31 respectively for energy storage; when the outlet pressures of the left hydraulic pump 33 and the right hydraulic pump 34 exceed the set pressures of the left overflow valve 32 and the right overflow valve 36, the left overflow valve 32 and the right overflow valve 36 open for overflow.

[0037] When the conventional electro-hydraulic brake system of the vehicle fails due to failure of the battery, brake switch, motor and other components, and the vehicle needs to brake, the vehicle backup brake system will take effect. The isolation solenoid valve 10 in the vehicle backup brake system is powered off, and its valve core is in the upper position, disconnecting the oil path from the brake master cylinder 8 to the pedal stroke simulator 11; the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all powered off, and the valve cores of the power-off solenoid valves are all in the upper position to make all oil paths accessible. When the brake pedal 5 is stepped on, the brake pedal arm 3 rotates around the rotating shaft 2, and drives the push rod 7 and the brake master cylinder 8 piston to move right through the pin 4 to overcome the piston return spring force, and the brake fluid in the brake master cylinder 8 directly enters the left front wheel cylinder and the right front wheel cylinder through the front left solenoid valve 21 and the front right solenoid valve 22, and the brake fluid in the brake master cylinder 8 enters the right rear wheel cylinder and the left rear wheel cylinder through the load-sensing proportional valve 25, the rear right solenoid valve 23, and the rear left solenoid valve 24 to achieve vehicle braking.

[0038] When the brakes need to be released, the isolation solenoid valve 10 is powered off and its valve core is in the upper position, disconnecting the oil circuit between the pedal stroke simulator 11 and the brake master cylinder 8; the front left solenoid valve 21, the front right solenoid valve 22, the rear right solenoid valve 23, and the rear left solenoid valve 24 are all powered off, and the valve cores of the power-off solenoid valves are all in the upper position, allowing the oil circuit between the wheel cylinder and the brake master cylinder 8 to pass, and the brake pedal 5 returns to its original position under the action of the return spring 6, and the brake master cylinder piston moves to the left under the joint action of the push rod 7 and the piston return spring, and the wheel cylinder brake fluid flows back to the brake master cylinder 8, thereby releasing the vehicle brakes.

Claims

1. A vehicle electro-hydraulic brake system with adjustable brake circuit type, characterized in that: Including a vehicle conventional electro-hydraulic brake system and a vehicle backup brake system connected to each other; The conventional vehicle electro-hydraulic brake system comprises a left hydraulic pump (33), a right hydraulic pump (34), an accumulator, a motor (35), a solenoid valve, a brake wheel cylinder, a left overflow valve (32), a right overflow valve (36), a hydraulic motor (20), a generator, a backup power supply, a battery, a brake switch, a circuit type selection switch and a fluid storage tank (9); The left hydraulic pump (33) and the right hydraulic pump (34) are driven by a connected motor (35) to operate synchronously, and a left accumulator (30) and a right accumulator (31) are respectively installed on the pipelines of the oil outlets of the left hydraulic pump (33) and the right hydraulic pump (34); A left X-type solenoid valve (16) and a middle 2X-type solenoid valve (18) are respectively connected in series between the oil inlet and outlet of the left accumulator (30) and the installed left front wheel cylinder and right rear wheel cylinder; A middle 1X-type solenoid valve (17) and a right X-type solenoid valve (19) are respectively connected in series between the oil inlet and outlet of the right accumulator (31) and the installed right front wheel cylinder and left rear wheel cylinder.

2. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 1, characterized in that: A left B-type solenoid valve (27) and a right B-type solenoid valve (28) are connected in parallel between the oil inlet and outlet of the left energy accumulator (30) and the oil inlet and outlet of the right energy accumulator (31).

3. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 1, characterized in that: A left oil return solenoid valve (12) and a middle 2 oil return solenoid valve (14) are respectively connected in series between the oil outlets of the left X-type solenoid valve (16) and the middle 2X-type solenoid valve (18) and the oil inlet of the hydraulic motor (20); A middle oil return solenoid valve (13) and a right oil return solenoid valve (15) are respectively connected in series between the oil outlets of the middle X-type solenoid valve (17) and the right X-type solenoid valve (19) and the oil inlet of the hydraulic motor (20).

4. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 1, characterized in that: A left H-type solenoid valve (26) is connected in series between the oil outlet of the middle 1X-type solenoid valve (17) on the right front wheel cylinder brake pipeline and the oil inlet of the middle 1 oil return solenoid valve (13) and the oil inlet and outlet of the left accumulator (30); A right H-type solenoid valve (29) is connected in series between the oil outlet of the middle 2X-type solenoid valve (18) on the right rear wheel cylinder brake pipeline and the oil inlet of the middle 2 oil return solenoid valve (14) and the oil inlet and outlet of the right accumulator (31).

5. The vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 1, characterized in that: A left overflow valve (32) and a right overflow valve (36) are connected in parallel between the oil inlet and outlet ports of the left hydraulic pump (33) and the right hydraulic pump (34); The storage battery is connected to the motor (35) via the installed brake switch, and supplies power to the motor (35) via the brake switch; A generator connected to the output shaft of the hydraulic motor (20) is connected to a backup power supply and stores the output power in the backup power supply. The circuit type selection switch is arranged in the vehicle driving cabin and is used by the driver to select the vehicle braking circuit type with one key while driving.

6. The vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 1, characterized in that: The vehicle backup brake system comprises a solenoid valve, a brake wheel cylinder, a pedal travel simulator (11), a load-sensing proportional valve (25), a brake master cylinder (8), a push rod (7), a brake pedal arm (3), a return spring (6) and a fluid storage tank (9); An oil inlet and an oil outlet are provided on the brake master cylinder (8), an isolation solenoid valve (10) and a pedal travel simulator (11) are successively installed on a branch of the brake master cylinder (8) oil outlet, a front left solenoid valve (21) and a front right solenoid valve (22) are respectively connected in series in the oil circuit between the brake master cylinder (8) and the connected left front wheel cylinder and right front wheel cylinder, and a load sensing proportional valve (25) is installed in another branch of the brake master cylinder (8) oil outlet.

7. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 6, characterized in that: A rear right electromagnetic valve (23) and a rear left electromagnetic valve (24) are respectively connected in series in the oil circuit between the load sensing proportional valve (25) and the right rear wheel cylinder and the left rear wheel cylinder.

8. The vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 6, characterized in that: It also includes a vehicle frame (1), a rotating shaft (2), a pin shaft (4), a brake pedal (5) and a return spring (6); The upper end of the brake pedal arm (3) is connected to the vehicle frame (1) via a rotating shaft (2), the left end of the push rod (7) is connected to the brake pedal arm (3) via a pin shaft (4), and the right end is fixedly connected to the piston of the brake master cylinder (8). A piston return spring is installed at the right end of the piston, and the oil inlet of the brake master cylinder (8) is connected to a fluid storage tank (9).

9. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to claim 8, characterized in that: The brake pedal (5) is arranged at the lower end of the brake pedal arm (3), and a return spring (6) is arranged on the right side of the brake pedal arm (3).

10. A vehicle electro-hydraulic brake system with adjustable brake circuit type according to any one of claims 1, 2, 3, 4, 6 and 7, characterized in that: The solenoid valves are all two-position two-way solenoid valves.

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