A hydraulic brake system and a hydraulic brake control method

Abstract

The present invention belongs to the field of automobile technology, and discloses a hydraulic brake system and a hydraulic brake control method. The hydraulic brake system includes: a fluid reservoir, which is used to contain brake fluid; a brake wheel cylinder mechanism and a fluid outlet control mechanism, the brake wheel cylinder mechanism is selectively connected to the fluid reservoir through the fluid outlet control mechanism; a brake hydraulic cylinder, which is connected to the fluid reservoir, and a brake piston is slidably arranged in the brake hydraulic cylinder; a brake pedal, which is connected to the brake piston through a push rod; a booster hydraulic cylinder, which is connected to the fluid reservoir, and a booster piston is slidably arranged in the booster hydraulic cylinder; a fluid inlet control mechanism, one end of which is selectively connected to the brake hydraulic cylinder and the booster hydraulic cylinder, and the other end is selectively connected to the brake wheel cylinder mechanism. The hydraulic brake system can realize the power-assisted braking function of the electric power-assisted brake system, and can also realize the function of the vehicle body stability system, thereby realizing the integration of the brake booster function and the vehicle body stability control function to improve the user experience.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a hydraulic brake system and a hydraulic brake control method. Background Art

[0002] As vehicles are currently moving towards electrification and intelligence, on the one hand, the demand for new energy vehicles is increasing, and on the other hand, the introduction of intelligent driving has also greatly promoted the development of vehicle intelligent control.

[0003] In terms of braking, most new energy vehicles currently use vacuum boosters and rely on the vacuum source of vacuum pumps to provide assistance. Affected by the current life of vacuum pumps, new energy vehicles have been recalled due to vacuum pumps. Another part of new energy vehicles has begun to use electronically controlled power-assisted braking systems, which meet the requirements of vehicle regulations in terms of durability, and their functionality far exceeds that of vacuum pumps, and have better advantages in terms of functions and matching with other modules.

[0004] In communication engineering, redundancy refers to the repeated configuration of some key components or functions based on considerations such as system safety and reliability. When a system fails, the redundantly configured components can be used as a backup to promptly take over the work of the failed components to reduce the system's failure time. With the development of intelligent driving, intelligent driving has put forward very high requirements for redundant backup of the braking system, that is, independent functional modules are required to achieve redundancy for braking, electronic brake force distribution (EBD), and anti-lock braking system (ABS). The combination of the existing electronically controlled power-assisted braking system and the electronic stability control system (ESC) can no longer meet this requirement, and the user experience is poor. Summary of the invention

[0005] The object of the present invention is to provide a hydraulic brake system and a hydraulic brake control method, which can simultaneously realize the power-assisted braking function and the vehicle body stabilization function, thereby improving the user experience.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A hydraulic brake system, comprising:

[0008] A fluid reservoir for containing brake fluid;

[0009] A brake wheel cylinder mechanism and a liquid discharge control mechanism, wherein the brake wheel cylinder mechanism is selectively connected to the liquid storage pot through the liquid discharge control mechanism;

[0010] A brake hydraulic cylinder, which is connected to the fluid reservoir, and a brake piston is slidably arranged in the brake hydraulic cylinder;

[0011] a brake pedal connected to the brake piston via a push rod;

[0012] A booster hydraulic cylinder, which is connected to the liquid storage pot, and a booster piston is slidably arranged in the booster hydraulic cylinder;

[0013] A fluid inlet control mechanism, one end of which is selectively connected to the brake hydraulic cylinder and the booster hydraulic cylinder, and the other end of which is selectively connected to the brake wheel cylinder mechanism.

[0014] Preferably, it further includes an isolation control mechanism, and the brake hydraulic cylinder is selectively connected to the fluid inlet control mechanism through the isolation control mechanism.

[0015] Preferably, a reverse control mechanism is further included, and the booster hydraulic cylinder is selectively connected to the fluid inlet control mechanism through the reverse control mechanism.

[0016] Preferably, it also includes a power-boosting isolation valve, which is arranged between the reverse control mechanism and the liquid inlet control mechanism and is respectively connected with them, and the connecting port between the reverse control mechanism and the power-boosting hydraulic cylinder and the connecting port between the power-boosting isolation valve and the power-boosting hydraulic cylinder are respectively arranged on both sides of the power-boosting piston.

[0017] Preferably, it also includes a one-way valve, which is arranged between the reverse control mechanism and the fluid inlet control mechanism, so that the brake fluid flowing out of the fluid inlet control mechanism flows back to the power-assisted hydraulic cylinder through the one-way valve and the reverse control mechanism.

[0018] Preferably, it further comprises a driving source, which is connected to the booster piston via a transmission mechanism.

[0019] Preferably, it further comprises a simulation control valve and a pedal simulator, wherein the simulation control valve and the brake pedal are respectively located on both sides of the brake piston, and the pedal simulator is selectively connected to the brake hydraulic cylinder through the simulation control valve.

[0020] To achieve the above object, the present invention further provides a hydraulic brake control method for controlling the above hydraulic brake system, the hydraulic brake control method comprising:

[0021] In the mechanical backup mode, after the brake pedal is stepped on, the brake pedal drives the brake piston to slide in the brake hydraulic cylinder through the push rod, so that the brake fluid flowing from the fluid reservoir to the brake hydraulic cylinder enters the brake wheel cylinder mechanism through the fluid inlet control mechanism. After the brake pedal is released, the brake fluid in the brake wheel cylinder mechanism flows back to the fluid reservoir through the fluid inlet control mechanism and the brake hydraulic cylinder;

[0022] In the first power-assisting mode, after the brake pedal is stepped on, the power-assisting piston is driven to slide in the power-assisting hydraulic cylinder from the initial position along the first direction, so that the brake fluid flowing from the reservoir into the power-assisting hydraulic cylinder enters the brake wheel cylinder mechanism through the fluid inlet control mechanism, and after the brake pedal is released, the brake fluid in the brake wheel cylinder mechanism flows back to the reservoir through the fluid inlet control mechanism and the power-assisting hydraulic cylinder;

[0023] In the second power-assisting mode, when the power-assisting piston slides to the extreme position along the first direction in the power-assisting hydraulic cylinder, the power-assisting piston is driven to slide in the second direction in the power-assisting hydraulic cylinder and in the direction close to the initial position, and the brake fluid in the power-assisting hydraulic cylinder enters the brake wheel cylinder mechanism through the fluid inlet control mechanism, wherein the first direction and the second direction are opposite.

[0024] Preferably, in the second power-assisting mode, if the brake pedal is not completely released, as the brake pedal is released, the power-assisting piston is driven to continue sliding in the power-assisting hydraulic cylinder along the second direction and in the direction close to the initial position, and the brake fluid in the brake wheel cylinder mechanism is controlled to flow back to the side of the power-assisting hydraulic cylinder close to the limit position through the fluid inlet control mechanism.

[0025] Preferably, in the second power-assisting mode, if the brake pedal is completely released, the power-assisting piston moves to the initial position, and the mechanical backup mode is started, so that the brake fluid in the brake wheel cylinder mechanism flows back to the fluid reservoir through the brake hydraulic cylinder via the fluid inlet control mechanism.

[0026] Beneficial effects of the present invention:

[0027] The hydraulic brake system provided by the present invention selectively connects the other end of the liquid inlet control mechanism to the brake wheel cylinder mechanism, and the brake wheel cylinder mechanism selectively connects to the liquid storage pot through the liquid outlet control mechanism. When the liquid inlet control mechanism is turned on and the liquid outlet control mechanism is turned off, the brake fluid continuously enters the brake wheel cylinder mechanism, but is not discharged from the liquid outlet control mechanism, thereby realizing the pressurization of the brake wheel cylinder mechanism; when the liquid inlet control mechanism is turned off and the liquid outlet control mechanism is turned on, no brake fluid enters the brake wheel cylinder mechanism, but the brake wheel cylinder mechanism continuously discharges brake fluid through the liquid outlet control mechanism, thereby realizing the decompression of the brake wheel cylinder mechanism; when both the liquid inlet control mechanism and the liquid outlet control mechanism are turned off, no brake fluid enters the brake wheel cylinder mechanism, and no brake fluid flows out from the brake wheel cylinder mechanism, thereby realizing the pressure maintenance of the brake wheel cylinder mechanism, thereby realizing the vehicle body stability control function. By selectively connecting one end of the liquid inlet control mechanism to the brake hydraulic cylinder and the booster hydraulic cylinder, the brake booster function of the brake wheel cylinder mechanism is realized.

[0028] The hydraulic brake system can realize both the power-assisted braking function of the electric power-assisted brake system and the function of the body stability system, thereby integrating the brake assist function and the body stability control function to improve the user experience.

[0029] The hydraulic brake control method provided by the present invention sets a mechanical backup mode. When the electronic control fails, the brake pressure in the mechanical backup mode can be guaranteed to be within a certain range to meet the braking deceleration required by the regulations. Under the braking action of the brake hydraulic cylinder and the booster hydraulic cylinder, two brake control functions are integrated, and the control logic between each other is optimized to distribute and upgrade the functions more reasonably. The power sources of the brake hydraulic cylinder and the booster hydraulic cylinder are independent of each other, making the braking control process more precise and smooth. The hydraulic brake control method adopts a decoupling method, and the brake fluid in the brake wheel cylinder mechanism flows back to the fluid storage pot to realize different forms of brake energy recovery functions. By setting the first booster mode and the second booster mode, the booster piston can slide in the first direction and the second direction respectively in the booster mode, and can build pressure in both directions to ensure that the driver has enough brake fluid when braking on various road surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the hydraulic brake system of the present invention in a mechanical backup mode;

[0031] Figure 2 is a schematic diagram of the hydraulic brake system of the present invention in the first power-assisting mode;

[0032] Figure 3 It is a schematic diagram of the state of the hydraulic brake system of the present invention in the second power-assisting mode.

[0033] In the figure:

[0034] 1. Fluid storage pot; 2. Brake wheel cylinder mechanism; 3. Fluid discharge control mechanism; 4. Brake hydraulic cylinder; 5. Brake pedal; 6. Power-assisted hydraulic cylinder; 7. Fluid inlet control mechanism; 8. Isolation control mechanism; 9. Reverse control mechanism; 10. Driving source; 11. Power-assisted isolation valve; 12. One-way valve; 13. Simulation control valve; 14. Pedal simulator;

[0035] 21. Left front wheel cylinder; 22. Right rear wheel cylinder; 23. Right front wheel cylinder; 24. Left rear wheel cylinder;

[0036] 31. Left front wheel liquid outlet valve; 32. Right rear wheel liquid outlet valve; 33. Right front wheel liquid outlet valve; 34. Left rear wheel liquid outlet valve;

[0037] 71. Left front wheel fluid inlet valve; 72. Right rear wheel fluid inlet valve; 73. Right front wheel fluid inlet valve; 74. Left rear wheel fluid inlet valve;

[0038] 81. First isolation valve; 82. Second isolation valve;

[0039] 91. A first reverse control valve; 92. A second reverse control valve. DETAILED DESCRIPTION

[0040] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0043] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0044] This embodiment provides a hydraulic brake system, such as Figure 1 As shown, the hydraulic brake system includes a fluid reservoir 1, a wheel brake cylinder mechanism 2, a fluid discharge control mechanism 3, a brake hydraulic cylinder 4, a brake pedal 5, a booster hydraulic cylinder 6 and a fluid inlet control mechanism 7. The fluid reservoir 1 is used to contain brake fluid. The brake hydraulic cylinder 4 is connected to the fluid reservoir 1. A brake piston is slidably arranged in the brake hydraulic cylinder 4. The brake pedal 5 is connected to the brake piston through a push rod. The booster hydraulic cylinder 6 is connected to the fluid reservoir 1. A booster piston is slidably arranged in the booster hydraulic cylinder 6. One end of the fluid inlet control mechanism 7 is selectively connected to the brake hydraulic cylinder 4 and the booster hydraulic cylinder 6, and the other end is selectively connected to the wheel brake cylinder mechanism 2. The wheel brake cylinder mechanism 2 is selectively connected to the fluid reservoir 1 through the fluid discharge control mechanism 3.

[0045] The hydraulic brake system provided in this embodiment is provided with the other end of the liquid inlet control mechanism 7 selectively connected to the brake wheel cylinder mechanism 2, and the brake wheel cylinder mechanism 2 is selectively connected to the liquid storage pot 1 through the liquid outlet control mechanism 3. When the liquid inlet control mechanism 7 is turned on and the liquid outlet control mechanism 3 is turned off, the brake fluid continuously enters the brake wheel cylinder mechanism 2, but is not discharged from the liquid outlet control mechanism 3, so as to realize the pressurization of the brake wheel cylinder mechanism 2; when the liquid inlet control mechanism 7 is turned off and the liquid outlet control mechanism 3 is turned on, no brake fluid enters the brake wheel cylinder mechanism 2, but the brake wheel cylinder mechanism 2 continuously discharges brake fluid through the liquid outlet control mechanism 3, so as to realize the decompression of the brake wheel cylinder mechanism 2; when both the liquid inlet control mechanism 7 and the liquid outlet control mechanism 3 are turned off, no brake fluid enters the brake wheel cylinder mechanism 2, and no brake fluid flows out from the brake wheel cylinder mechanism 2, so as to realize the pressure maintenance of the brake wheel cylinder mechanism 2, thereby realizing the vehicle body stability control function. By providing one end of the liquid inlet control mechanism 7 selectively connected to the brake hydraulic cylinder 4 and the booster hydraulic cylinder 6, the brake booster function of the brake wheel cylinder mechanism 2 is realized.

[0046] The hydraulic brake system can realize both the power-assisted braking function of the electric power-assisted brake system and the function of the body stability system, thereby integrating the brake assist function and the body stability control function to improve the user experience.

[0047] It can be understood that the new energy vehicle has four wheels, namely the left front wheel, the right rear wheel, the right front wheel and the left rear wheel. The brake wheel cylinder mechanism 2 includes a left front wheel cylinder 21, a right rear wheel cylinder 22, a right front wheel cylinder 23 and a left rear wheel cylinder 24. The left front wheel cylinder 21, the right rear wheel cylinder 22, the right front wheel cylinder 23 and the left rear wheel cylinder 24 correspond one by one to the left front wheel, the right rear wheel, the right front wheel and the left rear wheel respectively.

[0048] Correspondingly, the fluid inlet control mechanism 7 includes a left front wheel fluid inlet valve 71, a right rear wheel fluid inlet valve 72, a right front wheel fluid inlet valve 73 and a left rear wheel fluid inlet valve 74. The left front wheel fluid inlet valve 71, the right rear wheel fluid inlet valve 72, the right front wheel fluid inlet valve 73 and the left rear wheel fluid inlet valve 74 correspond one by one to the left front wheel cylinder 21, the right rear wheel cylinder 22, the right front wheel cylinder 23 and the left rear wheel cylinder 24 respectively, and are used to provide brake fluid to the corresponding wheel cylinders. The liquid outlet control mechanism 3 includes a left front wheel liquid outlet valve 31, a right rear wheel liquid outlet valve 32, a right front wheel liquid outlet valve 33 and a left rear wheel liquid outlet valve 34. The left front wheel liquid outlet valve 31, the right rear wheel liquid outlet valve 32, the right front wheel liquid outlet valve 33 and the left rear wheel liquid outlet valve 34 correspond to the left front wheel cylinder 21, the right rear wheel cylinder 22, the right front wheel cylinder 23 and the left rear wheel cylinder 24 respectively, and are used to discharge the brake fluid in the corresponding wheel cylinder to the liquid storage pot 1.

[0049] Furthermore, the hydraulic brake system also includes an isolation control mechanism 8, and the brake hydraulic cylinder 4 is selectively connected to the fluid inlet control mechanism 7 through the isolation control mechanism 8. Specifically, the isolation control mechanism 8 includes a first isolation valve 81 and a second isolation valve 82, and the hydraulic chamber of the brake hydraulic cylinder 4 is selectively connected to the left front wheel fluid inlet valve 71 and the right rear wheel fluid inlet valve 72 through the first isolation valve 81, and the hydraulic chamber of the brake hydraulic cylinder 4 is selectively connected to the right front wheel fluid inlet valve 73 and the left rear wheel fluid inlet valve 74 through the second isolation valve 82.

[0050] like Figure 1 As shown, the first isolation valve 81 and the second isolation valve 82 are both normally open valves. When the power is off, the first isolation valve 81 and the second isolation valve 82 are in the left position and are in the open state. After passing through the first isolation valve 81, the brake fluid in the brake hydraulic cylinder 4 is divided into two branches, one of which enters the left front wheel cylinder 21 through the left front wheel inlet valve 71, and the other enters the right rear wheel cylinder 22 through the right rear wheel inlet valve 72. After passing through the second isolation valve 82, the brake fluid in the brake hydraulic cylinder 4 is divided into two branches, one of which enters the right front wheel cylinder 23 through the right front wheel inlet valve 73, and the other enters the left rear wheel cylinder 24 through the left rear wheel inlet valve 74.

[0051] Further, the hydraulic brake system also includes a driving source 10, which is specifically a motor. The driving source 10 is connected to the booster piston through a transmission mechanism to drive the booster piston to move in the booster hydraulic cylinder 6. Optionally, the transmission mechanism includes a worm gear, a worm and a rack, the output end of the motor is connected to the worm, the worm and the rack are respectively arranged on both sides of the worm gear, the rack is connected to the booster piston through a connecting rod, the motor drives the worm and drives the rotation of the worm gear, and as the worm gear rotates, the rack is driven to move, so as to convert the rotational motion of the motor into the linear motion of the booster piston.

[0052] In order to further realize the boosting function, the hydraulic brake system further includes a reverse control mechanism 9, through which the boosting hydraulic cylinder 6 is selectively connected to the liquid inlet control mechanism 7. Specifically, the reverse control mechanism 9 includes a first reverse control valve 91 and a second reverse control valve 92, both of which are solenoid valves. When the power is off, Figure 1 As shown, the first reverse control valve 91 and the second reverse control valve 92 are in the left position, which is a closed state; when the power is turned on, as shown in FIG. Figure 2As shown, the first reverse control valve 91 and the second reverse control valve 92 are in the right position and are in the open state. As the booster piston moves, the brake fluid in the booster hydraulic cylinder 6 is divided into two branches through the first reverse control valve 91, one of which enters the left front wheel cylinder 21 through the left front wheel inlet valve 71, and the other enters the right rear wheel cylinder 22 through the right rear wheel inlet valve 72. After passing through the second reverse control valve 92, the brake fluid in the booster hydraulic cylinder 6 is divided into two branches, one of which enters the right front wheel cylinder 23 through the right front wheel inlet valve 73, and the other enters the left rear wheel cylinder 24 through the left rear wheel inlet valve 74.

[0053] Furthermore, the hydraulic brake system also includes a booster isolation valve 11, which is arranged between the reverse control mechanism 9 and the liquid inlet control mechanism 7 and is connected thereto respectively. The communication port between the reverse control mechanism 9 and the booster hydraulic cylinder 6, and the communication port between the booster isolation valve 11 and the booster hydraulic cylinder 6 are arranged on both sides of the booster piston respectively. The booster piston divides the hydraulic chamber of the booster hydraulic cylinder 6 into two chambers, the front chamber and the rear chamber. The front chamber is connected to the reverse control mechanism 9, and the rear chamber is connected to the booster isolation valve 11. The booster isolation valve 11 plays an auxiliary role for the reverse control mechanism 9. The two are disconnected at the same time to prevent the brake fluid in the front and rear chambers of the booster hydraulic cylinder 6 from flowing out. The two are opened at the same time to ensure the reverse reflux of the brake fluid, thereby realizing the recovery of the brake fluid.

[0054] Furthermore, the hydraulic brake system also includes a one-way valve 12, which is arranged between the reverse control mechanism 9 and the fluid inlet control mechanism 7. The one-way valve 12 limits the flow direction of the brake fluid, so that the brake fluid flowing out of the fluid inlet control mechanism 7 flows back to the power-assisted hydraulic cylinder 6 through the one-way valve 12 and the reverse control mechanism 9.

[0055] Furthermore, the hydraulic brake system also includes a simulation control valve 13 and a pedal simulator 14, and the pedal simulator 14 is selectively connected to the brake hydraulic cylinder 4 through the simulation control valve 13. The simulation control valve 13 and the brake pedal 5 are respectively located on both sides of the brake piston. The brake fluid passes through the simulation control valve 13 and builds pressure at the pedal simulator 14. The pedal simulator 14 simulates the pedaling feel of the brake pedal 5 to simulate the strength of the driver stepping on the brake pedal 5. The hydraulic damping structure of the pedal simulator 14 is used to simulate the pedaling feel of the simulated brake pedal 5, meet the different pedal feel requirements of users, and improve the user experience.

[0056] This embodiment also provides a hydraulic brake control method for controlling the above hydraulic brake system. The hydraulic brake control method includes:

[0057] Mechanical backup mode, such as Figure 1As shown, after the brake pedal 5 is stepped on, the brake pedal 5 drives the brake piston to slide in the brake hydraulic cylinder 4 through the push rod, so that the brake fluid flowing from the fluid reservoir 1 to the brake hydraulic cylinder 4 enters the brake wheel cylinder mechanism 2 through the fluid inlet control mechanism 7. After the brake pedal 5 is released, the brake fluid in the brake wheel cylinder mechanism 2 flows back to the fluid reservoir 1 through the brake hydraulic cylinder 4 through the fluid inlet control mechanism 7;

[0058] The first power-assist mode, such as Figure 2 As shown, after the brake pedal 5 is stepped on, the booster piston is driven to slide from the initial position along the first direction in the booster hydraulic cylinder 6, so that the brake fluid flowing from the reservoir 1 to the booster hydraulic cylinder 6 enters the wheel brake cylinder mechanism 2 through the fluid inlet control mechanism 7. After the brake pedal 5 is released, the brake fluid in the wheel brake cylinder mechanism 2 flows back to the reservoir 1 through the booster hydraulic cylinder 6 through the fluid inlet control mechanism 7;

[0059] Second assist mode, such as Figure 3 As shown, after the booster piston slides to the extreme position along the first direction in the booster hydraulic cylinder 6, the booster piston is driven to slide in the second direction in the booster hydraulic cylinder 6 and in the direction close to the initial position, and the brake fluid in the booster hydraulic cylinder 6 enters the brake wheel cylinder mechanism 2 through the fluid inlet control mechanism 7, wherein the first direction and the second direction are opposite.

[0060] The hydraulic brake control method provided in this embodiment sets a mechanical backup mode. When the electronic control fails, the brake pressure in the mechanical backup mode can be guaranteed to be within a certain range to meet the regulatory braking deceleration. Under the braking action of the brake hydraulic cylinder 4 and the booster hydraulic cylinder 6, two brake control functions are integrated, and the control logic between each other is optimized, so as to distribute and upgrade the functions more reasonably. The power sources of the brake hydraulic cylinder 4 and the booster hydraulic cylinder 6 are independent of each other, making the braking control process more precise and smoother. The hydraulic brake control method adopts a decoupling method, and the brake fluid in the brake wheel cylinder mechanism 2 flows back to the fluid storage pot 1 to realize different forms of brake energy recovery functions. By setting the first booster mode and the second booster mode, the booster piston can slide in the first direction and the second direction respectively in the booster mode, and can build pressure in both directions to ensure that the driver has enough brake fluid when braking on various road surfaces.

[0061] Furthermore, in the second power-assisting mode, if the brake pedal 5 is not completely released, as the brake pedal 5 is released, the power-assisting piston is driven to continue to slide in the power-assisting hydraulic cylinder 6 along the second direction and in the direction close to the initial position, and the brake fluid in the brake wheel cylinder mechanism 2 is controlled to flow back to the side of the power-assisting hydraulic cylinder 6 close to the extreme position through the fluid inlet control mechanism 7.

[0062] Furthermore, in the second power-assisting mode, if the brake pedal 5 is completely released, the power-assisting piston moves to the initial position, and the mechanical backup mode is started, so that the brake fluid in the brake wheel cylinder mechanism 2 flows back to the fluid reservoir 1 through the brake hydraulic cylinder 4 via the fluid inlet control mechanism 7.

[0063] The specific steps of the hydraulic brake control method provided in this embodiment are as follows:

[0064] Mechanical backup mode

[0065] like Figure 1 As shown, when the braking mode fails and is in a power-off state, the analog control valve 13 is disconnected. At this time, the driver steps on the brake pedal 5, and the brake fluid of the brake hydraulic cylinder 4 is divided into two branches after passing through the first isolation valve 81, one of which enters the left front wheel cylinder 21 through the left front wheel inlet valve 71, and the other branch enters the right rear wheel cylinder 22 through the right rear wheel inlet valve 72. After the brake fluid of the brake hydraulic cylinder 4 passes through the second isolation valve 82, it is divided into two branches, one of which enters the right front wheel cylinder 23 through the right front wheel inlet valve 73, and the other branch enters the left rear wheel cylinder 24 through the left rear wheel inlet valve 74. After achieving the braking effect that satisfies the driver, the driver releases the brake pedal 5, and the brake fluid returns to the hydraulic chamber of the brake hydraulic cylinder 4 along the original path. It can be understood that in the mechanical backup mode, the second reverse control valve 92 can also be in a closed state.

[0066] First assist mode

[0067] like Figure 2 As shown, when the driver steps on the brake pedal 5, the pedal position sensor is triggered, and the analog control valve 13 is controlled to open, the brake fluid passes through the analog control valve 13 and builds pressure at the pedal simulator 14, and the pedal simulator 14 simulates the stepping feel of the brake pedal 5. At this time, the first reverse control valve 91 and the second reverse control valve 92 are controlled to be in an open state.

[0068] When the driver steps on the brake pedal 5, the driving source 10 is turned on. The driving source 10 drives the booster piston to move in the booster hydraulic cylinder 6 through the transmission mechanism. After the control module ECU receives the signal from the pedal position sensor, it controls the driving source 10 to be turned on. The driving source 10 drives the booster piston to move in the booster hydraulic cylinder 6 along the first direction through the transmission mechanism, that is, moves to the left to build up pressure, so that the brake fluid passes through the first reverse control valve 91 and the second reverse control valve 92 through the left front wheel inlet valve 71 to brake the left front wheel cylinder 21, and passes through the right rear wheel inlet valve 72 to brake the right rear wheel cylinder 22; at the same time, the brake fluid passes through the second reverse control valve 92 and the booster isolation valve 11 through the right front wheel inlet valve 73 to brake the right front wheel cylinder 23, and passes through the left rear wheel inlet valve 74 to brake the left rear wheel cylinder 24.

[0069] After achieving a braking effect that satisfies the driver, the driver releases the brake pedal 5, and the brake fluid in the left front wheel cylinder 21 and the right rear wheel cylinder 22 returns through their respective inlet valves and returns to the power-boosting hydraulic cylinder 6 via the first reverse control valve 91; at the same time, the brake fluid in the right front wheel cylinder 23 and the left rear wheel cylinder 24 returns through their respective inlet valves and returns to the power-boosting hydraulic cylinder 6 via the first reverse control valve 91.

[0070] Second assist mode

[0071] like Figure 3 As shown, in the first power-assisting mode, after the power-assisting piston slides to the limit position along the first direction in the power-assisting hydraulic cylinder 6, the first reverse control valve 91 and the second reverse control valve 92 are in the closed state, and the driving source 10 drives the power-assisting piston to move along the second direction in the power-assisting hydraulic cylinder 6 through the transmission mechanism, that is, moves to the right to build up pressure, so that the brake fluid in the rear chamber of the power-assisting hydraulic cylinder 6 passes through the one-way valve 12 through the left front wheel inlet valve 71 and the right rear wheel inlet valve 72 to brake the left front wheel wheel cylinder 21 and the right rear wheel wheel cylinder 22 respectively; at the same time, through the power-assisting isolation valve 11 through the right front wheel inlet valve 73 and the left rear wheel inlet valve 74 to brake the right front wheel wheel cylinder 23 and the left rear wheel wheel cylinder 24 respectively.

[0072] After achieving the braking effect that satisfies the driver, the pedal position sensor determines the force with which the driver releases the brake pedal 5. If the brake pedal 5 is completely released, the booster piston in the booster hydraulic cylinder 6 moves to the initial position, the first isolation valve 81 and the second isolation valve 82 open, and the mechanical backup mode is started, so that the brake fluid in the brake wheel cylinder mechanism 2 flows back to the fluid storage pot 1 through the brake hydraulic cylinder 4 via the fluid inlet control mechanism 7.

[0073] If the driver has not completely released the brake pedal 5, as the driver releases the brake pedal 5, the driving booster piston continues to slide in the booster hydraulic cylinder 6 along the second direction and in the direction close to the initial position, and at the same time opens the first reverse control valve 91, and the brake fluid in the right front wheel cylinder 23 and the left rear wheel cylinder 24 flows back to the front chamber of the booster hydraulic cylinder 6 through the booster isolation valve 11, the one-way valve 12, and the first reverse control valve 91, and the brake fluid in the left front wheel cylinder 21 and the right rear wheel cylinder 22 can flow back to the front chamber of the booster hydraulic cylinder 6 through the first reverse control valve 91.

[0074] In the description herein, it should be understood that the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0075] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0076] In addition, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A hydraulic brake system, characterized in that: include: A fluid reservoir (1) for containing brake fluid; A brake wheel cylinder mechanism (2) and a liquid discharge control mechanism (3), wherein the brake wheel cylinder mechanism (2) is selectively connected to the liquid storage pot (1) via the liquid discharge control mechanism (3); The brake wheel cylinder mechanism (2) comprises a left front wheel cylinder (21), a right rear wheel cylinder (22), a right front wheel cylinder (23) and a left rear wheel cylinder (24); A brake hydraulic cylinder (4) which is connected to the fluid storage pot (1), and a brake piston is slidably arranged in the brake hydraulic cylinder (4); A brake pedal (5) connected to the brake piston via a push rod; A booster hydraulic cylinder (6) which is connected to the liquid storage pot (1), and a booster piston is slidably arranged in the booster hydraulic cylinder (6); A fluid inlet control mechanism (7), one end of which is selectively connected to the brake hydraulic cylinder (4) and the booster hydraulic cylinder (6), and the other end of which is selectively connected to the brake wheel cylinder mechanism (2); When the liquid inlet control mechanism (7) is turned on and the liquid outlet control mechanism (3) is turned off, the brake wheel cylinder mechanism (2) is pressurized; when the liquid inlet control mechanism (7) is turned off and the liquid outlet control mechanism (3) is turned on, the brake wheel cylinder mechanism (2) is depressurized; and when both the liquid inlet control mechanism (7) and the liquid outlet control mechanism (3) are turned off, the brake wheel cylinder mechanism (2) is pressure-maintained; The liquid inlet control mechanism (7) comprises a left front wheel liquid inlet valve (71), a right rear wheel liquid inlet valve (72), a right front wheel liquid inlet valve (73) and a left rear wheel liquid inlet valve (74); It also includes a reverse control mechanism (9), through which the booster hydraulic cylinder (6) is selectively connected to the liquid inlet control mechanism (7); The reverse control mechanism (9) comprises a first reverse control valve (91) and a second reverse control valve (92). When the first reverse control valve (91) and the second reverse control valve (92) are in an open state, as the booster piston moves, the brake fluid in the booster hydraulic cylinder (6) is divided into two branches through the first reverse control valve (91), one of which enters the left front wheel cylinder (21) through the left front wheel inlet valve (71), and the other of which enters the right rear wheel cylinder (22) through the right rear wheel inlet valve (72); after the brake fluid in the booster hydraulic cylinder (6) passes through the second reverse control valve (92), it is divided into two branches, one of which enters the right front wheel cylinder (23) through the right front wheel inlet valve (73), and the other of which enters the left rear wheel cylinder (24) through the left rear wheel inlet valve (74); It also includes a one-way valve (12), which is arranged between the reverse control mechanism (9) and the fluid inlet control mechanism (7) so that the brake fluid flowing out of the fluid inlet control mechanism (7) flows back to the booster hydraulic cylinder (6) through the one-way valve (12) and the reverse control mechanism (9); It also comprises a booster isolation valve (11), which is arranged between the reverse control mechanism (9) and the liquid inlet control mechanism (7) and is respectively connected thereto, and a communication port between the reverse control mechanism (9) and the booster hydraulic cylinder (6) and a communication port between the booster isolation valve (11) and the booster hydraulic cylinder (6) are respectively arranged on both sides of the booster piston.

2. The hydraulic brake system according to claim 1, characterized in that: It also includes an isolation control mechanism (8), through which the brake hydraulic cylinder (4) is selectively connected to the fluid inlet control mechanism (7).

3. The hydraulic brake system according to claim 1, characterized in that: It also comprises a driving source (10), wherein the driving source (10) is connected to the booster piston via a transmission mechanism.

4. The hydraulic brake system according to any one of claims 1 to 3, characterized in that: It also includes a simulation control valve (13) and a pedal simulator (14), wherein the simulation control valve (13) and the brake pedal (5) are respectively located on both sides of the brake piston, and the pedal simulator (14) is selectively connected to the brake hydraulic cylinder (4) through the simulation control valve (13).

5. A hydraulic brake control method, characterized in that: Used to control the hydraulic brake system according to any one of claims 1 to 4, the hydraulic brake control method comprising: In the mechanical backup mode, after the brake pedal (5) is stepped on, the brake pedal (5) drives the brake piston to slide in the brake hydraulic cylinder (4) through the push rod, so that the brake fluid flowing from the fluid reservoir (1) into the brake hydraulic cylinder (4) enters the brake wheel cylinder mechanism (2) through the fluid inlet control mechanism (7); after the brake pedal (5) is released, the brake fluid in the brake wheel cylinder mechanism (2) flows back to the fluid reservoir (1) through the brake hydraulic cylinder (4) through the fluid inlet control mechanism (7); In the first power-assisting mode, after the brake pedal (5) is stepped on, the power-assisting piston is driven to slide in the power-assisting hydraulic cylinder (6) from an initial position along a first direction, so that the brake fluid flowing from the fluid reservoir (1) into the power-assisting hydraulic cylinder (6) enters the brake wheel cylinder mechanism (2) through the fluid inlet control mechanism (7); after the brake pedal (5) is released, the brake fluid in the brake wheel cylinder mechanism (2) flows back into the fluid reservoir (1) through the power-assisting hydraulic cylinder (6) via the fluid inlet control mechanism (7); In the second assist mode, after the assist piston slides in the first direction to the extreme position in the assist hydraulic cylinder (6), the assist piston is driven to slide in the second direction in the assist hydraulic cylinder (6) and in a direction close to the initial position, and the brake fluid in the assist hydraulic cylinder (6) enters the brake wheel cylinder mechanism (2) through the fluid inlet control mechanism (7), wherein the first direction and the second direction are opposite.

6. The hydraulic brake control method according to claim 5, characterized in that: In the second power-assisting mode, if the brake pedal (5) is not completely released, as the brake pedal (5) is released, the power-assisting piston is driven to continue sliding in the power-assisting hydraulic cylinder (6) along the second direction and in a direction close to the initial position, and the brake fluid in the brake wheel cylinder mechanism (2) is controlled to flow back to the side of the power-assisting hydraulic cylinder (6) close to the limit position through the fluid inlet control mechanism (7).

7. The hydraulic brake control method according to claim 5 or 6, characterized in that: In the second power-assisting mode, after the brake pedal (5) is completely released, the power-assisting piston moves to the initial position, and the mechanical backup mode is activated, so that the brake fluid in the brake wheel cylinder mechanism (2) flows back into the fluid storage pot (1) through the brake hydraulic cylinder (4) via the fluid inlet control mechanism (7).

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