Novel automobile electro-hydraulic braking system

Abstract

The invention discloses a novel automobile electro-hydraulic braking system. The device belongs to the technical field of automobile braking and comprises an automobile braking assisting mechanism, an automobile conventional electro-hydraulic braking system, an automobile basic braking system and a braking pedal foot feeling simulation mechanism. The defects of a traditional vacuum boosting system and a conventional electro-hydraulic braking system are overcome, the automobile braking boosting mechanism is simple in structure and convenient to control, a good braking boosting effect can be provided no matter whether conventional electro-hydraulic braking of an automobile fails or not, and the response speed is higher during braking implementation and braking release; in the automobile braking process, the pressure of each wheel cylinder is independently adjusted in real time, the ground adhesive force can be fully utilized, and the automobile braking effect and the braking safety and stability are improved; conical spiral springs are arranged in the front cavity of the brake master cylinder and the right end of the push rod, a throttle valve and a brake pedal arm return spring are supplemented, a pedal stroke simulator in a conventional electro-hydraulic brake system can be replaced, the pedal foot feeling effect is more obvious, and driving safety is better facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile braking and relates to a novel automobile electro-hydraulic braking system. Background Art

[0002] With the rapid development of automobile intelligence and electrification, higher requirements are placed on the performance and intelligent control capabilities of vehicle braking systems. The traditional hydraulic braking system relies on the driver's pedal force to transmit hydraulic pressure to the wheel brakes to achieve vehicle braking. Although its technology is mature and reliable, it has certain limitations in response speed, energy efficiency and control accuracy. In particular, it is difficult to achieve fast and accurate braking force adjustment during high-frequency braking or emergency braking.

[0003] The electro-hydraulic brake system (EHB) combines the advantages of electronic control and hydraulic transmission. It controls the braking process through electronic signals, and can achieve faster response time and higher control accuracy than traditional hydraulic systems. In the field of electric vehicles and hybrid vehicles, the electro-hydraulic brake system is particularly important. The EHB system can independently control the braking force of each wheel, which is beneficial to improving vehicle driving safety and stability.

[0004] However, the current automotive electro-hydraulic brake system still has certain shortcomings in practical applications; for example, the system structure is relatively complex, large in size, and high in cost, and the backup braking after the power-assisting mechanism designed in the existing electro-hydraulic brake system fails needs to rely entirely on manpower. The driver needs to apply a lot of pedal force when braking the vehicle, especially when emergency braking, which greatly increases the driver's operating intensity and reduces driving safety. Therefore, it is necessary to develop a new automotive electro-hydraulic brake system. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to propose a new type of automobile electro-hydraulic brake system, which can provide good pedal assist effect when both the conventional automobile electro-hydraulic brake system and the basic brake system are working, and can provide good pedal feel when the conventional automobile electro-hydraulic brake system is working. When the conventional automobile electro-hydraulic brake system fails, the automobile basic brake system can provide normal braking ability.

[0006] The technical solution of the present invention is: a novel automobile electro-hydraulic brake system described in the present invention comprises an automobile brake booster mechanism, a conventional automobile electro-hydraulic brake system, an automobile basic brake system and a brake pedal foot feeling simulation mechanism.

[0007] Among them, the automobile brake booster mechanism includes a double pump (i.e., left and right hydraulic pumps), an accumulator, a shuttle valve, a two-position two-way solenoid valve, a two-position four-way reversing valve, a booster cylinder, a one-way valve and a throttle valve.

[0008] Furthermore, the liquid inlets at the left and right ends of the shuttle valve are respectively connected to the pipelines of the left and right hydraulic pump outlets, and a throttle valve is arranged between the right liquid inlet of the shuttle valve and the pipeline of the right hydraulic pump outlet, so as to generate a pressure difference when the pressures of the left and right hydraulic pump outlets are the same so that the pressure of the shuttle valve outlet is not zero, and the shuttle valve outlet connects the high-pressure oil in the left and right oil circuits through the pipelines successively through the two-position two-way solenoid valve and the two-position four-way reversing valve to the booster cylinder, and high-pressure accumulators are respectively arranged on the double pump outlet oil circuit at the lower end of the connection point between the double pump and the shuttle valve, and the upper port of the two-position four-way reversing valve is respectively connected to the oil holes at the lower ends of the left and right chambers of the booster cylinder, and its return oil port is connected to the liquid storage tank; the booster cylinder is fixedly connected to the right end of the brake master cylinder, the piston inside the booster cylinder is fixedly connected to the push rod, a sealing ring is installed between the piston and the cylinder wall, and the two oil holes at the upper end of the booster cylinder on both sides of the piston are connected to the liquid storage tank through a one-way valve.

[0009] The conventional automobile electro-hydraulic brake system comprises a motor, a duplex pump, an overflow valve, an accumulator, a two-position two-way solenoid valve, a three-position three-way solenoid valve, and a wheel brake cylinder. An overflow valve is respectively arranged between the inlet and outlet of the left and right hydraulic pumps. When the oil pressure at the outlet of the hydraulic pump exceeds the opening pressure set by the overflow valve, the overflow valve opens to return oil. Left and right high-pressure accumulators are respectively arranged on the output oil lines of the left and right hydraulic pumps so that a certain hydraulic pressure is always maintained in the brake pipeline. Left and right two-position two-way solenoid valves are respectively arranged at the lower parts of the left and right high-pressure accumulators. The left two-position two-way solenoid valve is connected to the left front and right high-pressure accumulators. A three-position three-way solenoid valve is arranged between the right rear wheel brake cylinders, and a three-position three-way solenoid valve is arranged between the right two-position two-way solenoid valve and the left rear and right front wheel brake cylinders. The three-position three-way solenoid valve has a first port connected to the two-position two-way solenoid valve, a second port connected to the brake wheel cylinder, and a third port connected to the fluid storage tank; the power-on and power-off states of the motor are controlled by a brake switch installed on the brake pedal arm. After the driver steps on the brake pedal, the brake switch is closed, the motor is powered on to drive the double pump to work, and after the brake pedal is released, the brake switch is disconnected, the motor is powered off, and the double pump stops working.

[0010] The basic braking system of the automobile comprises a brake pedal, a brake pedal arm, a push rod, a brake master cylinder, a fluid storage tank, a two-position two-way solenoid valve, a three-position three-way solenoid valve, a wheel brake wheel cylinder, a brake switch, and a brake pedal return spring. The push rod passes through the inside of the brake master cylinder and the booster cylinder. The front and rear chamber pistons in the brake master cylinder are fixedly connected to the push rod. A sealing ring is installed between the front and rear chamber pistons and the cylinder wall. A shaping spring is installed between the front and rear chamber pistons. The spring can effectively keep the piston in effective contact with the cylinder wall. The front chamber piston is connected to the inner wall of the brake master cylinder. A first conical coil spring is installed, which gradually increases its stiffness during compression; a second conical coil spring is installed between the right end of the push rod and the right protective cover of the booster cylinder; the upper oil holes of the front and rear chambers of the brake master cylinder are connected to the fluid storage tank, the lower oil hole of the rear chamber of the brake master cylinder is connected to the left front and right rear wheel brake cylinders through a pipeline successively through a two-position two-way solenoid valve and a three-position three-way solenoid valve, respectively; the lower oil hole of the front chamber of the brake master cylinder is connected to the left rear and right front wheel brake cylinders through a pipeline successively through a two-position two-way solenoid valve and a three-position three-way solenoid valve;

[0011] The upper end of the brake pedal arm is connected to the frame via a rotating shaft, a brake switch is installed between the upper end of the brake pedal arm and the frame, and the left end of the push rod is connected to the brake pedal arm via a pin shaft; the brake pedal is arranged at the lower end of the brake pedal arm, and a brake pedal arm return spring is arranged on the right side of the brake pedal arm.

[0012] The automobile pedal foot feeling simulation mechanism comprises a first and a second conical coil spring, a throttle valve, a two-position two-way solenoid valve, and a brake pedal arm return spring. The oil holes at the lower ends of the front and rear chambers of the brake master cylinder are connected to the throttle valve, and the throttle valve controls the oil outlet rate of the front and rear chambers of the brake master cylinder and maintains the effect of linear pressure relief. A two-position two-way solenoid valve is arranged between the throttle valve and the fluid reservoir so as to control the oil to flow back to the fluid reservoir when the conventional electro-hydraulic brake system of the automobile is working, the basic brake system of the automobile is not working, and the brake pedal is pressed. Under the joint action of the first and the second conical coil springs and the brake pedal arm return spring, the automobile pedal foot feeling simulation mechanism can provide a pedal feedback force consistent with the pedal displacement.

[0013] The output oil of the left two-position two-way solenoid valve under the brake master cylinder and the left two-position two-way solenoid valve under the accumulator are merged into the same oil circuit, and the output oil of the right two-position two-way solenoid valve under the brake master cylinder and the right two-position two-way solenoid valve under the accumulator are merged into the same oil circuit. Each oil circuit controls the pressure of two wheel cylinders of the vehicle respectively. According to the optimal slip rate requirements of the wheels, the braking pressure of each wheel cylinder is precisely adjusted by the three-position three-way solenoid valve.

[0014] During the operation of the conventional electro-hydraulic brake system of an automobile, if a hydraulic pump in the double pump or a two-position two-way solenoid valve at the lower end of the high-pressure accumulator fails, the oil at the outlet of the hydraulic pump that has not failed can still enter the vehicle's brake wheel cylinder through the two-position two-way solenoid valve that has not failed to achieve braking of half of the wheels;

[0015] A one-way valve is set at the upper end of the power-boosting cylinder so that when negative pressure occurs in the right chamber and the left chamber of the power-boosting cylinder, oil can be replenished from the liquid storage tank to the corresponding chamber of the power-boosting cylinder in time to ensure sufficient power-boosting effect.

[0016] The beneficial effects of the present invention are as follows: the present invention overcomes the shortcomings of traditional vacuum boosters and conventional electro-hydraulic brake systems, the automobile brake booster mechanism has a novel design, a simple structure, and is easy to control, and can provide a good brake booster effect regardless of whether the conventional electro-hydraulic brake of the automobile fails or not, and has a faster response speed when applying and releasing the brake; the wheel cylinder pressure of each wheel during the automobile braking process can be independently adjusted in real time, thereby making full use of the ground adhesion, improving the vehicle braking effect as well as the braking safety and stability; a conical coil spring is arranged in the front chamber of the brake master cylinder and the right end of the push rod, assisted by a throttle valve and a brake pedal arm return spring, which can effectively replace the pedal travel simulator in the conventional electro-hydraulic brake system, and the pedal feel effect is more obvious, which is more conducive to driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] 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 brake pedal arm return spring, 7 is a push rod, 8 is a first two-position two-way solenoid valve, 9 is a first throttle valve, 10 is a second two-position two-way solenoid valve, 11 is a third two-position two-way solenoid valve, 12 is a three-position three-way solenoid valve; 13 is a fourth two-position two-way solenoid valve, 14 is a fifth two-position two-way solenoid valve, 15 is a sixth two-position two-way solenoid valve, 16 is a high-pressure accumulator, 17 is a two-position four-way reversing valve, 18 is a second throttle valve, and 19 is a shuttle valve , 20 is the first overflow valve, 21 is the motor, 22 is the duplex pump, 23 is the second overflow valve, 24 is the second conical coil spring, 25 is the push rod cover, 26 is the first one-way valve, 27 is the booster cylinder piston, 28 is the first sealing ring, 29 is the second one-way valve, 30 is the booster cylinder, 31 is the first conical coil spring, 32 is the front chamber piston of the brake master cylinder, 33 is the second sealing ring, 34 is the fixed spring, 35 is the rear chamber piston of the brake master cylinder, 36 is the third sealing ring, 37 is the brake master cylinder, 38 is the fluid reservoir, and 39 is the brake switch. DETAILED DESCRIPTION

[0019] The specific technical scheme of the present invention is further described in detail below with reference to specific examples.

[0020] As shown in the figure, a novel automobile electro-hydraulic brake system described in the present invention includes an automobile brake booster mechanism, an automobile conventional electro-hydraulic brake system, an automobile basic brake system and a brake pedal feel simulation mechanism.

[0021] Among them, the automobile brake booster mechanism includes a double pump 22, a high-pressure accumulator 16, a shuttle valve 19, a fourth two-position two-way solenoid valve 13, a two-position four-way reversing valve 17, a booster cylinder 30, a first one-way valve 26, a second one-way valve 29 and a second throttle valve 18.

[0022] Furthermore, the liquid inlets at the left and right ends of the shuttle valve 19 are respectively connected to the pipelines of the left and right hydraulic pump outlets, and a second throttle valve 18 is arranged between the right liquid inlet of the shuttle valve 19 and the pipeline of the right hydraulic pump outlet, so as to generate a pressure difference when the pressures of the left and right hydraulic pump outlets are the same so that the outlet pressure of the shuttle valve 19 is not zero. The liquid outlet of the shuttle valve 19 connects the high-pressure oil on the left and right ends of the oil circuit through the pipeline through the fourth two-position two-way solenoid valve 13 and the two-position four-way reversing valve 17 to the booster cylinder 30, and the double pump 22 is connected to the shuttle valve 19 at the lower end of the double pump 22. High-pressure accumulators 16 are arranged on the liquid outlet pipeline of the pump 22, and the upper port of the two-position four-way reversing valve 17 is respectively connected to the oil holes at the lower ends of the left and right chambers of the power-boosting cylinder 30, and its return oil port is connected to the liquid storage tank 38; the power-boosting cylinder 30 is fixedly connected to the right end of the brake master cylinder 37, and the power-boosting cylinder piston 27 inside the power-boosting cylinder 30 is fixedly connected to the push rod 7, and a first sealing ring 28 is installed between the power-boosting cylinder piston 27 and the cylinder wall, and the two oil holes at the upper end of the power-boosting cylinder 30 on both sides of the power-boosting cylinder piston 27 are connected to the liquid storage tank 38 through the first one-way valve 26, the second one-way valve 29.

[0023] Furthermore, the conventional automobile electro-hydraulic brake system includes a motor 21, a double pump 22, a first overflow valve 20, a second overflow valve 23, a high-pressure accumulator 16, a fifth two-position two-way solenoid valve 14 and a sixth two-position two-way solenoid valve 15, a three-position three-way solenoid valve 12, and a wheel brake cylinder;

[0024] A first relief valve 20 and a second relief valve 23 are respectively arranged between the inlet and outlet of the left and right hydraulic pumps. When the oil pressure at the outlet of the hydraulic pump exceeds the opening pressure set by the relief valve, the relief valve opens to return oil. High-pressure accumulators 16 are respectively arranged on the left and right sides of the output oil circuits of the left and right hydraulic pumps, so that a certain hydraulic pressure is always maintained in the brake pipeline. A fifth two-position two-way solenoid valve 14 and a sixth two-position two-way solenoid valve 15 are respectively arranged at the lower parts of the left and right high-pressure accumulators 16. A three-position three-way solenoid valve 12 is respectively arranged between the fifth two-position two-way solenoid valve 14 and the left front and right rear wheel brake cylinders. A three-position three-way solenoid valve 12 is respectively arranged between the sixth two-position two-way solenoid valve 15 and the left rear and right front wheel brake cylinders. The first ports of the three-position three-way solenoid valve 12 are respectively connected to the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 15, the second port thereof is connected to the brake wheel cylinder, and the third port thereof is connected to the fluid storage tank 38.

[0025] The power-on and power-off states of the motor 21 are controlled by a brake switch 39 installed at the brake pedal arm 3. After the driver steps on the brake pedal 5, the brake switch 39 is closed, the motor 21 is powered on to drive the double pump 22 to work. After the brake pedal 5 is released, the brake switch 39 is disconnected, the motor 21 is powered off, and the double pump 22 stops working.

[0026] The automobile basic brake system comprises a brake pedal 5, a brake pedal arm 3, a push rod 7, a brake master cylinder 37, a fluid reservoir 38, a second two-position two-way solenoid valve 10 and a third two-position two-way solenoid valve 11, a three-position three-way solenoid valve 12, a wheel brake cylinder, a brake switch 39, and a brake pedal return spring 6;

[0027] The push rod 7 passes through the inside of the brake master cylinder 37 and the booster cylinder 30. The brake master cylinder front chamber piston 32 in the brake master cylinder 37 is fixedly connected to the brake master cylinder rear chamber piston 35 and the push rod 7. A second sealing ring 33 and a third sealing ring 36 are respectively installed between the brake master cylinder front chamber piston 32, the brake master cylinder rear chamber piston 35 and the cylinder wall. A shaping spring 34 is installed between the brake master cylinder front chamber piston 32 and the brake master cylinder rear chamber piston 35. The shaping spring 34 can effectively keep the piston in effective contact with the cylinder wall. A first conical coil spring 33 is installed between the brake master cylinder front chamber piston 32 and the inner wall of the brake master cylinder 37. 1, the spring will gradually increase its stiffness during the compression process, and a second conical coil spring 24 is installed between the right end of the push rod 7 and the push rod cover 25 on the right side of the booster cylinder 30; the upper oil holes of the front and rear chambers of the brake master cylinder 37 are connected to the fluid storage tank 38, and the lower oil hole of the rear chamber of the brake master cylinder 37 is connected to the left front wheel brake cylinder and the right rear wheel brake cylinder through a pipeline in sequence through a second two-position two-way solenoid valve 10 and a three-position three-way solenoid valve 12, respectively, and the lower oil hole of the front chamber of the brake master cylinder 37 is connected to the left rear wheel brake cylinder and the right front wheel brake cylinder through a pipeline in sequence through a third two-position two-way solenoid valve 11 and a three-position three-way solenoid valve 12.

[0028] The upper end of the brake pedal arm 3 is connected to the frame 1 via the rotating shaft 2, a brake switch 39 is installed between the upper end of the brake pedal arm 3 and the frame 1, the left end of the push rod 7 is connected to the brake pedal arm 3 via the pin shaft 4, the brake pedal 5 is arranged at the lower end of the brake pedal arm 3, and a brake pedal arm return spring 6 is arranged on the right side of the brake pedal arm 3.

[0029] The automobile pedal feel simulation mechanism comprises a first conical coil spring 31, a second conical coil spring 24, a first throttle valve 9, a first two-position two-way solenoid valve 8, and a brake pedal arm return spring 6;

[0030] The oil holes at the lower ends of the front and rear chambers of the brake master cylinder 37 are connected to the first throttle valve 9, which controls the oil outlet rate of the front and rear chambers of the brake master cylinder 37 and maintains the effect of linear pressure relief; a first two-position two-way solenoid valve 8 is installed between the first throttle valve 9 and the fluid reservoir 38 to control the oil to flow back to the fluid reservoir 38 when the conventional electro-hydraulic braking system of the automobile is working, the basic braking system of the automobile is not working, and the brake pedal 5 is pressed; under the joint action of the first conical coil spring 31 and the second conical coil spring 24, the first throttle valve 9, the first two-position two-way solenoid valve 8 and the brake pedal arm return spring 6, the automobile pedal feel simulation mechanism can provide a pedal feedback force consistent with the pedal displacement.

[0031] The oil outputs of the second two-position two-way solenoid valve 10 under the brake master cylinder 37 and the fifth two-position two-way solenoid valve 14 under the high-pressure accumulator 16 are merged into the same oil circuit. The oil outputs of the third two-position two-way solenoid valve 11 under the brake master cylinder 37 and the sixth two-position two-way solenoid valve 15 under the high-pressure accumulator 16 are merged into the same oil circuit. Each oil circuit controls the pressure of two wheel cylinders of the vehicle respectively. According to the optimal slip rate requirement of the wheel, the braking pressure of each wheel cylinder is precisely adjusted by the three-position three-way solenoid valve 12.

[0032] Working principle of the present invention:

[0033] When the vehicle is running normally and does not need to brake, under the joint action of the first conical coil spring 31, the second conical coil spring 24 and the brake pedal arm return spring 6, the brake pedal 5 is in the initial position, the brake switch 39 is disconnected, the front chamber piston 32 of the brake master cylinder and the rear chamber piston 35 of the brake master cylinder are in the initial position in the brake master cylinder 37, no brake fluid flows out of the brake master cylinder 37, the motor 21 and the double pump 22 do not work, and the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 1 5 is powered off, closing the oil circuit between the high-pressure accumulator 16 and the three-position three-way solenoid valve 12, no brake fluid enters the vehicle brake wheel cylinder, and the wheel is not braked; the fourth two-position two-way solenoid valve 13 is powered off, closing the oil circuit between the shuttle valve 19 and the booster cylinder 30, at this time the two-position four-way reversing valve 17 is also powered off, the booster cylinder piston 27 is located at the initial position in the booster cylinder 30, the second two-position two-way solenoid valve 10, the third two-position two-way solenoid valve 11, the first two-position two-way solenoid valve 8 and the three-position three-way solenoid valve 12 are all powered off.

[0034] When the car needs to brake during driving, the driver steps on the brake pedal 5, overcomes the elastic force of the brake pedal arm return spring 6 and drives the brake pedal arm 3 to rotate around the rotating shaft 2, and the brake switch 39 is closed. When the conventional electro-hydraulic brake system of the car works normally, the motor 21 connected to the brake switch 39 circuit is energized to drive the double pump 22 to pump oil into the oil circuit. At this time, the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 15 are energized to open the oil circuit between the double pump 22, the high-pressure accumulator 16 and the three-position three-way solenoid valve 12, the three-position three-way solenoid valve 12 is powered off, the left oil circuit is connected, and the oil at the outlet of the double pump 22 and the oil in the high-pressure accumulator 16 enter the vehicle's brake wheel cylinder to achieve wheel braking; at the same time , the second two-position two-way solenoid valve 10 and the third two-position two-way solenoid valve 11 are energized to close the oil circuit between the brake master cylinder 37 and the three-position three-way solenoid valve 12, the fourth two-position two-way solenoid valve 13 is energized to open the oil circuit between the shuttle valve 19 and the two-position four-way reversing valve 17, the two-position four-way reversing valve 17 is de-energized to connect its right oil circuit, the oil of the left hydraulic pump in the double pump 22 enters the left oil inlet of the shuttle valve 19, the oil of the right hydraulic pump in the double pump 22 enters the right oil inlet of the shuttle valve 19 through the second throttle valve 18, the high-pressure oil at the oil outlet of the shuttle valve 19 enters the left chamber of the booster cylinder 30 through the fourth two-position two-way solenoid valve 13 and the two-position four-way reversing valve 17, pushing the booster cylinder piston 27 and the push rod 7 fixedly connected thereto to move right, thereby realizing The vehicle brakes with power, the oil in the right chamber of the power cylinder 30 flows back to the reservoir 38 through the pipeline, the first two-position two-way solenoid valve 8 is powered off, and the oil in the front chamber and the rear chamber of the brake master cylinder 37 flows back to the reservoir 38 through the first throttle valve 9 and the first two-position two-way solenoid valve 8 respectively; in the process of pressing the brake pedal 5 forward, under the joint action of the first conical coil spring 31 with variable stiffness characteristics, the second conical coil spring 24 and the brake pedal arm return spring 6 elastic force, the automobile pedal foot feel simulation mechanism can provide a pedal feedback force consistent with the pedal displacement size, the greater the displacement of the brake pedal 5, the greater the elastic force of the first conical coil spring 31 and the second conical coil spring 24, the stronger the pedal feel, which is conducive to the driver's safe driving; when the vehicle brakes, During the process, the slip rate of each wheel is calculated in real time according to the vehicle speed and the signal collected by each wheel speed sensor, and the current of the three-position three-way solenoid valve 12 coil connected to each wheel brake cylinder is independently adjusted in real time according to the set optimal wheel slip rate. When the three-position three-way solenoid valve 12 coil is not energized, the valve core is in the left position, and the oil at the outlet of the double pump 22 and the oil in the high-pressure accumulator 16 enter the vehicle brake wheel cylinder to achieve brake boost. When the three-position three-way solenoid valve 12 coil is energized by a medium current, the valve core is in the middle position, and the oil in the vehicle brake wheel cylinder is closed to achieve brake pressure maintenance. When the three-position three-way solenoid valve 12 coil is energized by a large current, the valve core is in the right position, and the oil in the vehicle brake wheel cylinder flows back to the fluid storage tank 38 to achieve brake decompression.

[0035] During the operation of the conventional electro-hydraulic brake system of an automobile, if any of the hydraulic pumps in the dual pump 22 or the fifth two-position two-way solenoid valve 14 or the sixth two-position two-way solenoid valve 15 fails, the high-pressure oil pumped out by the hydraulic pump that has not failed can still enter the vehicle's brake wheel cylinder through the two-position two-way solenoid valve that has not failed to achieve braking of half of the wheels.

[0036] When the brake pedal remains in a certain position during the braking process, the fourth two-position two-way solenoid valve 13 is powered off, cutting off the oil circuit between the shuttle valve 19 and the two-position four-way reversing valve 17, and the power-assisting cylinder 30 does not assist. At this time, the two-position four-way reversing valve 17 is also powered off, and the power-on and power-off states of the remaining solenoid valves are the same as the conventional electro-hydraulic braking process of the above-mentioned automobile.

[0037] When the vehicle needs to release the brake, the driver releases the brake pedal 5, the brake pedal arm return spring 6 returns and drives the brake pedal arm 3 to rotate around the rotating shaft 2, the brake switch 39 is disconnected, the motor 21 is powered off and stops, and the double pump 22 does not pump oil to the oil circuit. At this time, the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 15 are powered off, closing the oil circuit between the high-pressure accumulator 16 and the three-position three-way solenoid valve 12, and the three-position three-way solenoid valve 12 passes a large current, the right oil circuit is connected, and the oil in the vehicle brake wheel cylinder flows back to the reservoir 38, so that the wheel brake is released; at the same time, the second two-position two-way solenoid valve 10 and the third two-position two-way solenoid valve 11 are energized to close the oil circuit between the brake master cylinder 37 and the three-position three-way solenoid valve 12 to ensure that no negative pressure is generated in the oil circuit, and the fourth two-position two-way solenoid valve 13 is energized to open the oil circuit between the shuttle valve 19 and the two-position four-way reversing valve 17, and the two-position four-way reversing valve 17 is energized to connect its left oil circuit, and the left accumulator The oil in the accumulator 16 enters the left oil inlet of the shuttle valve 19, and the oil in the right accumulator 16 enters the right oil inlet of the shuttle valve 19 through the second throttle valve 18. The high-pressure oil at the oil outlet of the shuttle valve 19 enters the right chamber of the booster cylinder 30 through the fourth two-position two-way solenoid valve 13 and the two-position four-way reversing valve 17, pushing the booster cylinder piston 27 and the push rod 7 fixedly connected thereto to move left, thereby realizing the pedal return boost. The oil in the left chamber of the booster cylinder 30 flows back to the reservoir 38 through the pipeline, and the first two-position two-way solenoid valve 8 is powered off. The oil in the reservoir 38 flows into the front chamber and the rear chamber of the brake master cylinder 37 through the first two-position two-way solenoid valve 8 and the first throttle valve 9; after the brake pedal 5 is released, under the joint action of the first conical coil spring 31 with variable stiffness characteristics, the second conical coil spring 24, the booster cylinder 30 piston boost, and the brake pedal arm return spring 6 elastic force, the brake pedal 5 and the push rod 7 return quickly, which is conducive to realizing the rapid release of vehicle braking.

[0038] When the car needs to brake during driving, the driver steps on the brake pedal 5, overcomes the elastic force of the brake pedal arm return spring 6 and drives the brake pedal arm 3 to rotate around the rotating shaft 2, and the brake switch 39 is closed. When the conventional electro-hydraulic brake system of the car fails completely (such as the double pump 22 does not work), the basic brake system of the car works at this time, the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 15 are powered off, and the oil circuit between the high-pressure accumulator 16 and the three-position three-way solenoid valve 12 is closed. The three-position three-way solenoid valve 12 is powered off, the left oil circuit is connected, the second two-position two-way solenoid valve 10 and the third two-position two-way solenoid valve 11 are powered off, and the oil circuit between the brake master cylinder 37 and the three-position three-way solenoid valve 12 is opened, and the first two-position two-way solenoid valve 8 is powered on. The oil in the left accumulator 16 enters the left oil inlet of the shuttle valve 19, and the oil in the right accumulator 16 enters the right oil inlet of the shuttle valve 19 through the second throttle valve 18. The high-pressure oil at the oil outlet of the shuttle valve 19 enters the left chamber of the booster cylinder 30 through the fourth two-position two-way solenoid valve 13 and the two-position four-way reversing valve 17, pushing the booster cylinder piston 27 and the push rod 7 fixedly connected thereto to move right, thereby realizing the vehicle braking booster, and the oil in the right chamber of the booster cylinder 30 flows back to the reservoir 38 through the pipeline; when the piston of the booster cylinder 30 assists Under the combined effect of force and pedal force, the oil in the front chamber and rear chamber of the brake master cylinder 37 quickly enters the wheel brake cylinder through the third two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 10 respectively; during the forward movement of the brake pedal 5, under the combined effect of the first conical coil spring 31 with variable stiffness characteristics, the second conical coil spring 24 and the brake pedal arm return spring 6 elastic force, the automobile pedal foot feel simulation mechanism can provide a pedal feedback force consistent with the pedal displacement. The greater the displacement of the brake pedal 5, the greater the elastic force of the first conical coil spring 31 and the second conical coil spring 24, and the stronger the pedal feel, which is conducive to the driver's safe driving; during the vehicle braking process, according to the vehicle speed and the signal collected by each wheel speed sensor, the vehicle pedal foot feel simulation mechanism can provide a pedal feedback force consistent with the pedal displacement. The slip rate of each wheel is calculated at the same time, and the current of the coil of the three-position three-way solenoid valve 12 connected to the brake wheel cylinder of each wheel is independently adjusted in real time according to the set optimal wheel slip rate. When the coil of the three-position three-way solenoid valve 12 is not energized, the valve core is in the left position, and the oil in the front chamber and the rear chamber of the brake master cylinder 37 quickly enters the vehicle brake wheel cylinder through the third two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 10 respectively, so as to achieve brake boost. When the coil of the three-position three-way solenoid valve 12 is passed with a medium current, the valve core is in the middle position, and the oil in the vehicle brake wheel cylinder is closed to achieve brake pressure maintenance. When the coil of the three-position three-way solenoid valve 12 is passed with a large current, the valve core is in the right position, and the oil in the vehicle brake wheel cylinder flows back to the reservoir 38 to achieve brake decompression.

[0039] When the brake pedal remains in a certain position during the braking process, the fourth two-position two-way solenoid valve 13 is powered off, cutting off the oil circuit between the shuttle valve 19 and the two-position four-way reversing valve 17, and the power-assisting cylinder 30 does not assist. At this time, the two-position four-way reversing valve 17 is powered off, and the power-on and power-off states of the remaining solenoid valves are the same as the above-mentioned basic braking process of the automobile.

[0040] When the vehicle needs to release the brake, the driver releases the brake pedal 5, the brake pedal arm return spring 6 returns and drives the brake pedal arm 3 to rotate around the rotating shaft 2, the brake switch 39 is disconnected, the fifth two-position two-way solenoid valve 14 and the sixth two-position two-way solenoid valve 15 are powered off, the oil circuit between the high-pressure accumulator 16 and the three-position three-way solenoid valve 12 is closed, the three-position three-way solenoid valve 12 is passed with a large current, the right oil circuit is connected, and the oil in the vehicle brake wheel cylinder flows back to the reservoir 38, so that the wheel brake is released; at the same time, the second two-position two-way solenoid valve 10 and the third two-position two-way solenoid valve 11 are powered off, the oil circuit between the brake master cylinder 37 and the three-position three-way solenoid valve 12 is opened, the fourth two-position two-way solenoid valve 13 is powered on, the oil circuit between the shuttle valve 19 and the two-position four-way reversing valve 17 is opened, the two-position four-way reversing valve 17 is powered on to connect its left oil circuit, and the oil in the left accumulator 16 enters the left inlet of the shuttle valve 19 The oil in the right accumulator 16 enters the right oil inlet of the shuttle valve 19 through the second throttle valve 18, and the high-pressure oil at the oil outlet of the shuttle valve 19 enters the right chamber of the booster cylinder 30 through the fourth two-position two-way solenoid valve 13 and the two-position four-way reversing valve 17, pushing the booster cylinder piston 27 and the push rod 7 fixedly connected thereto to move left, thereby realizing the pedal return assistance, and the oil in the left chamber of the booster cylinder 30 flows back to the reservoir 38 through the pipeline; the first two-position two-way solenoid valve 8 is powered off, and the oil in the reservoir 38 flows into the front chamber and the rear chamber of the brake master cylinder 37 through the first two-position two-way solenoid valve 8 and the first throttle valve 9; after the brake pedal 5 is released, under the joint action of the first conical coil spring 31 with variable stiffness characteristics, the second conical coil spring 24, the booster cylinder 30 piston assistance, and the brake pedal arm return spring 6 elastic force, the brake pedal 5 and the push rod 7 return quickly, which is conducive to realizing the rapid release of vehicle brakes.

Claims

1. A new type of automobile electro-hydraulic brake system, characterized in that: It includes an automobile brake booster mechanism, an automobile conventional electro-hydraulic brake system, an automobile basic brake system and a brake pedal foot feeling simulation mechanism that are interconnected; The automobile brake booster mechanism comprises a fourth two-position two-way solenoid valve (13), a high-pressure accumulator (16), a two-position four-way reversing valve (17), a second throttle valve (18), a shuttle valve (19), a first overflow valve (20), a double pump (22), a second overflow valve (23), a first check valve (26), a second check valve (29), a booster cylinder (30) and a liquid storage tank (38); Wherein, the double pump (22) includes a left hydraulic pump and a right hydraulic pump.

2. A novel automobile electro-hydraulic brake system according to claim 1, characterized in that: The liquid inlets at the left and right ends of the shuttle valve (19) are respectively connected to the pipelines of the left and right hydraulic pump outlets, and a second throttle valve (18) is arranged between the right liquid inlet of the shuttle valve (19) and the pipeline of the right hydraulic pump outlet. The liquid outlet of the shuttle valve (19) connects the high-pressure oil in the oil circuits at the left and right ends thereof through the pipelines, successively through the fourth two-position two-way solenoid valve (13) and the two-position four-way reversing valve (17) to the booster cylinder (30).

3. A novel automobile electro-hydraulic brake system according to claim 2, characterized in that: A high-pressure accumulator (16) is installed on the oil outlet of the double pump at the lower end of the connection point between the double pump (22) and the shuttle valve (19), and the upper port of the two-position four-way reversing valve (17) is connected to the lower oil holes of the left and right chambers of the booster cylinder (30), and its oil return port is connected to the liquid storage tank (38); The booster cylinder (30) is fixedly connected to the right end of the brake master cylinder (37); the booster cylinder piston (27) arranged inside the booster cylinder (30) is fixedly connected to the push rod (7); a first sealing ring (28) is arranged between the booster cylinder piston (27) and the cylinder wall of the booster cylinder (30); and two oil holes at the upper end of the booster cylinder (30) on both sides of the booster cylinder piston (27) are connected to the liquid storage tank (30) via a first one-way valve (26) and a second one-way valve (29).

4. A novel automobile electro-hydraulic brake system according to claim 1, characterized in that: The conventional automobile electro-hydraulic brake system comprises a three-position three-way solenoid valve (12), a fifth two-position two-way solenoid valve (14), a sixth two-position two-way solenoid valve (15), a high-pressure accumulator (16), a first overflow valve (20), a motor (21), a double pump (22), a second overflow valve (23) and a wheel brake cylinder. A first overflow valve (20) and a second overflow valve (23) are respectively arranged between the liquid inlet and the liquid outlet of the left and right hydraulic pumps; A high-pressure accumulator (16) is installed on the left and right hydraulic pump output oil circuits, and a fifth two-position two-way solenoid valve (14) and a sixth two-position two-way solenoid valve (15) are installed at the lower parts of the left and right high-pressure accumulators (16) respectively; A three-position three-way solenoid valve (12) is installed between the fifth two-position two-way solenoid valve (14) and the left front wheel brake cylinder and the right rear wheel brake cylinder, respectively; a three-position three-way solenoid valve (12) is installed between the sixth two-position two-way solenoid valve (15) and the left rear wheel brake cylinder and the right front wheel brake cylinder, respectively.

5. A novel automobile electro-hydraulic brake system according to claim 4, characterized in that: The first port of the three-position three-way solenoid valve (12) is respectively connected to the fifth two-position two-way solenoid valve (14) and the sixth two-position two-way solenoid valve (15), the second port thereof is connected to the wheel brake cylinder, and the third port thereof is connected to the fluid storage tank (38).

6. A novel automobile electro-hydraulic brake system according to claim 1, characterized in that: The automobile basic brake system comprises a vehicle frame (1), a rotating shaft (2), a brake pedal arm (3), a brake pedal (5), a brake pedal return spring (6), a push rod (7), a second two-position two-way solenoid valve (10), a third two-position two-way solenoid valve (11) and a three-position three-way solenoid valve (12), a wheel brake cylinder, a front chamber piston of a brake master cylinder (32), a rear chamber piston of a brake master cylinder (35), a brake master cylinder (37), a fluid storage tank (38) and a brake switch (39); The push rod (7) passes through the inside of the brake master cylinder (37) and the booster cylinder (30), and the brake master cylinder front chamber piston (32) and the brake master cylinder rear chamber piston (35) in the brake master cylinder (37) are fixedly connected to the push rod (7); A second sealing ring (33) and a third sealing ring (36) are respectively arranged between the front chamber piston (32) of the brake master cylinder, the rear chamber piston (35) of the brake master cylinder and the cylinder wall, and a shaping spring (34) is arranged between the front chamber piston (32) of the brake master cylinder and the rear chamber piston (35) of the brake master cylinder.

7. A novel automobile electro-hydraulic brake system according to claim 6, characterized in that: A first conical coil spring (31) is arranged between the front chamber piston (32) of the brake master cylinder and the inner wall of the brake master cylinder (37); A second conical coil spring (24) is arranged between the right end of the push rod (7) and a push rod protective cover (25) arranged on the right side of the boost cylinder (30); The upper oil holes of the front and rear chambers of the brake master cylinder (37) are connected to the fluid storage tank (38), and the lower oil hole of the rear chamber of the brake master cylinder (37) is connected to the left front wheel brake cylinder and the right rear wheel brake cylinder respectively through a pipeline, a second two-position two-way solenoid valve (10) and a three-position three-way solenoid valve (12); The oil hole at the lower end of the front chamber of the brake master cylinder (37) is connected to the left rear wheel brake cylinder and the right front wheel brake cylinder respectively through a pipeline, successively through a third two-position two-way solenoid valve (11) and a three-position three-way solenoid valve (12).

8. A novel automobile electro-hydraulic brake system according to claim 7, characterized in that: The upper end of the brake pedal arm (3) is connected to the vehicle frame (1) via a rotating shaft (2), a brake switch (39) is arranged between the upper end of the brake pedal arm (3) and the vehicle frame (1), and the left end of the push rod (7) is connected to the brake pedal arm (3) via an arranged pin shaft (4); A brake pedal (5) is arranged at the lower end of the brake pedal arm (3), and a brake pedal arm return spring (6) is also arranged on the right side of the brake pedal arm (3).

9. A novel automobile electro-hydraulic brake system according to claim 1, characterized in that: The automobile pedal feel simulation mechanism comprises a brake pedal arm return spring (6), a first two-position two-way solenoid valve (8), a first throttle valve (9), a second conical coil spring (24) and a first conical coil spring (31); The oil holes at the lower ends of the front and rear chambers of the brake master cylinder (37) are connected to a first throttle valve (9), and a first two-position two-way solenoid valve (8) is arranged between the first throttle valve (9) and the liquid storage tank (38).

10. A novel automobile electro-hydraulic brake system according to claim 9, characterized in that: The output oil of the second two-position two-way solenoid valve (10) arranged below the brake master cylinder (37) and the fifth two-position two-way solenoid valve (14) arranged below the high-pressure accumulator (16) are merged into the same oil circuit; The output oil of the third two-position two-way solenoid valve (11) arranged below the brake master cylinder (37) and the sixth two-position two-way solenoid valve (15) arranged below the high-pressure accumulator (16) are merged into the same oil circuit, and each oil circuit controls the pressure of two wheel cylinders of the vehicle respectively.

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