CN111891102A - Hydraulic Balanced Brake System for Vehicles - Google Patents

Abstract

The invention discloses a hydraulic balanced brake system for a vehicle, which comprises: the first brake circuit and the second brake circuit are used for braking wheels; the brake module is respectively connected with a brake pedal, a brake control system, an oil can, a first brake circuit and a second brake circuit of the vehicle; the electric power-assisted module is respectively connected with the oil can and a brake control system of the vehicle; a hydraulic balancing module connected between the electric power assist module and the first brake circuit, and between the electric power assist module and the second brake circuit. The invention can ensure that the braking hydraulic pressures of the four wheels are the same, so that the braking control precision and the control effect of the vehicle are better; and under the condition that the system fails, hydraulic pressure can be guaranteed to be generated in braking of at least two wheels, and braking safety is greatly improved.

Description

Hydraulic Balanced Brake System for Vehicles

technical field

The invention relates to vehicle hydraulic braking technology, in particular to a hydraulically balanced braking system for vehicles.

Background technique

With the gradual increase in the market share of electric vehicles, the integrated brake-by-wire system has become the latest product of chassis electronic brakes. In the normal working mode of the system, the hydraulic circuit of the master cylinder and the wheel cylinder is cut off, the hydraulic pressure of the wheel brake is generated by the electric assist, and the hydraulic pressure generated by the driver stepping on the pedal enters the simulator; in the system failure mode, the hydraulic pressure of the master cylinder and the wheel cylinder is The circuit is connected, and the hydraulic pressure produced by the driver's pedaling is directly applied to the wheel end.

Due to the fact that the brake fluid demand of the brakes of the same specification in the real vehicle is not the same, the distance between the friction pad and the brake disc is not exactly the same when the brake is installed, resulting in the two brake circuits of the vehicle braking at the same amount of brake fluid. Hydraulic inequalities are common.

In the prior art, the integrated brake-by-wire system (such as CN105163987A) adopts the H-type brake circuit arrangement to provide the same amount of brake fluid to the brake circuits on both sides respectively. The brake hydraulic pressure achieved by the same amount of brake fluid is not equal, which causes the pressure of the brake circuits on both sides to be unbalanced when the vehicle is braking, which affects the control accuracy and control effect; When replenishing fluid, it is necessary to quickly turn off the power and close the two normally closed solenoid valves arranged between the outlet of the electric cylinder and the wheel brake circuit to avoid the hydraulic pressure of the system brake circuit being reduced. The two solenoid valves need to be designed with springs with large installation force. Quick reset and close, and when the solenoid valve is powered on, it needs a large current to form a large enough electromagnetic force to overcome the spring force to open the solenoid valve to connect the electric cylinder and the wheel brake circuit. The valve is seriously heated, and the solenoid valve structure and coil need to be redesigned to reduce the solenoid valve working current or reduce the power-on time, resulting in increased costs or some working conditions cannot meet the requirements of the OEM.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a hydraulically balanced braking system for a vehicle is provided, comprising an oil can for providing brake fluid, and further comprising:

a first braking circuit, the first braking circuit is used to brake the two wheels;

a second brake circuit, the second brake circuit is used to brake the remaining two wheels;

The brake module is respectively connected with the brake pedal, the brake control system, the oil tank, the first brake circuit and the second brake circuit of the vehicle, and provides the pedal feeling required by the driver to brake during normal braking , providing braking force to the first braking circuit and the second braking circuit when the system fails to brake;

an electric booster module, which is connected to the oiler and the brake control system respectively, and is used for establishing and outputting the hydraulic braking force required by the brake control system;

A hydraulic balance module, the hydraulic balance module is connected between the electric booster module and the first brake circuit, and between the electric booster module and the second brake circuit, and is used to balance the hydraulic braking force output by the electric booster module into the first brake circuit and the second brake circuit.

Further, the first brake circuit and the second brake circuit respectively include: two pairs of normally open valves and two pairs of normally closed valves, one normally open valve and one normally closed valve corresponding to each wheel, and the normally closed valve is connected to the oil pot , the normally open valve is respectively connected with the hydraulic balance module and the brake module.

Further, the braking module contains:

Brake master cylinder, the brake master cylinder includes a first cavity and a second cavity respectively connected with the oil pot and separated by the partition piston, the first cavity is respectively connected with the brake pedal, the pedal simulator and the first brake circuit, the first cavity is respectively connected with the brake pedal, the pedal simulator and the first brake circuit. The second chamber is connected to the second brake circuit, after the brake pedal is pressed, the brake fluid in the first chamber is compressed and pushes the partition piston to compress the brake fluid in the second chamber;

Brake pedal stroke sensor, the brake pedal stroke sensor is connected with the piston of the first cavity and used to detect the brake pedal stroke;

An analog diagnostic valve, which is arranged between the first chamber and the oiler, used to isolate the first chamber and the oiler during system self-diagnosis;

Further, the brake module further includes: a first pressure sensor, the first pressure sensor collects the hydraulic pressure output by the driver to the brake master cylinder;

Further, the brake module further includes: a brake pedal simulation valve, the brake pedal simulation valve is arranged between the first cavity and the brake pedal simulator, and is used to communicate or isolate the first cavity and the pedal simulator;

Pedal simulator, the pedal simulator is connected with the first cavity through the brake pedal simulation valve to provide the pedal feeling required by the driver for braking;

Further, the braking module also contains:

the first master cylinder isolation solenoid valve, the input port of the first master cylinder isolation solenoid valve is connected with the first cavity, and the output port is connected with the first brake circuit;

The second master cylinder isolation solenoid valve, the input port of the second master cylinder isolation solenoid valve is connected with the second cavity, and the output port is connected with the second brake circuit.

Further, the electric assist module includes:

The motor, which is connected to the brake control system;

Two-way power assist unit, the two-way power unit is connected with the motor, the oil can, the first brake circuit and the second brake circuit, and the motor drives the two-way power unit to establish hydraulic braking force in both forward and backward directions;

Motor position sensor, the motor position sensor collects the rotor position signal of the motor in real time for the brake control system to control the motor to drive the two-way power assist unit.

Further, the two-way power assist unit includes:

Electric cylinder, which is a cavity with an opening at one end;

Piston, the piston includes a front section and a rear section, the diameter of the front section matches the inner diameter of the electric cylinder, and the diameter of the rear section is smaller than the diameter of the front section; the front section divides the electric cylinder into the electric cylinder front cavity and the electric cylinder rear cavity, and the piston faces the inside of the electric cylinder. When the direction moves, the front cavity of the electric cylinder is compressed, the piston moves to the outside of the electric cylinder, and the rear cavity of the electric cylinder is compressed; the front cavity of the electric cylinder and the rear cavity of the electric cylinder are respectively connected with the oil can;

Transmission mechanism, the transmission mechanism is respectively connected with the output shaft of the motor and the rear section of the piston, and the motor drives the piston to reciprocate in the electric cylinder through the transmission mechanism;

Two-way pressure building solenoid valve, one end of the two-way pressure building solenoid valve is connected to the front chamber of the electric cylinder, and the other end is connected to the rear chamber of the electric cylinder and the hydraulic balance module respectively. The rear cavity of the electric cylinder is closed when the pressure is built up, and is opened when the rear cavity of the electric cylinder is compressed and released; the rear cavity of the electric cylinder is connected with the hydraulic balance module.

Further, the two-way power assist unit also includes: an electric cylinder liquid suction check valve, the electric cylinder liquid suction check valve is arranged between the oil pot and the front cavity of the electric cylinder, and the brake fluid flow direction of the electric cylinder liquid suction check valve is the oil pot. One-way flow to the front chamber of the electric cylinder.

Further, the two-way power assist unit may further include: an electric cylinder liquid outlet check valve, the electric cylinder liquid outlet check valve is connected in parallel with the two-way pressure building solenoid valve, and the brake fluid flow direction of the electric cylinder liquid outlet check valve is the front cavity of the electric cylinder. One-way outflow.

Further, the two-way power assist unit further includes: a second pressure sensor, and the second pressure sensor collects the hydraulic pressure output by the two-way power assist unit.

Further, the hydraulic balance module includes a first hydraulic balance valve and a second hydraulic balance valve connected in series, one end connected with the first hydraulic balance valve and the second hydraulic balance valve is connected with the two-way pressure building solenoid valve and the back cavity of the electric cylinder, the first hydraulic pressure The other end of the balance valve is connected to the first brake circuit, and the other end of the second hydraulic balance valve is connected to the second brake circuit.

Further, the first hydraulic balance valve and the second hydraulic balance valve are pressure balance valves.

The hydraulically balanced braking system for a vehicle according to the embodiment of the present invention can not only ensure that the hydraulic pressure of the four wheels is the same, so that the braking control precision and control effect of the vehicle are better; moreover, in the case of system failure , at least two wheels can be braked with hydraulic pressure, which greatly improves the braking safety.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the claimed technology.

Description of drawings

FIG. 1 is a schematic diagram showing the principle of not being provided with an electric cylinder liquid outlet check valve in a hydraulically balanced braking system for a vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing the principle of the electric cylinder liquid outlet check valve provided in the hydraulically balanced braking system for a vehicle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the connection between the electric booster module and the hydraulic balance module in FIG. 1;

Figure 4 is a schematic diagram of the connection between the electric booster module and the hydraulic balance module in Figure 2;

Fig. 5 is the principle schematic diagram of the first braking circuit in Fig. 1 or Fig. 2;

FIG. 6 is a schematic diagram of the principle of the second braking circuit in FIG. 1 or FIG. 2 .

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to further illustrate the present invention.

First, a hydraulically balanced braking system for a vehicle according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6 . It is used for conventional braking, emergency braking, and system failure braking of a vehicle, which can be applied to conventional fuel vehicles. To the braking of autonomous driving vehicles, the application scenarios are very wide.

As shown in FIGS. 1-2 , the hydraulically balanced braking system for a vehicle according to the embodiment of the present invention has an oil can 1 for providing brake fluid, a first brake circuit 2, a second brake circuit 3, a brake module, electric booster module, hydraulic balance module, after the driver steps on the brake pedal 7, the brake module transmits the brake pedal stroke and the signal of the first pressure sensor 44 to the brake control system, the brake control system according to the brake pedal The travel signal and the signal of the first pressure sensor 44 control the electric assist module to output the corresponding hydraulic braking force to the first brake circuit 2 and the second brake circuit 3 at the wheel end, and the driver's brake pedal feel is generated by the pedal simulator 8 , so as to realize the physical decoupling of the driver's braking input and the braking output of the wheel end, and realize the brake-by-wire.

Specifically, as shown in Figures 1, 2, 5, and 6, the first braking circuit 2 is used for braking two wheels, and the second braking circuit 3 is used for braking the remaining two wheels. As shown in Figures 4 and 5, the first brake circuit 2 is provided with a pair of normally open valves 21, 22 and a pair of normally closed valves 23, 24, and the second brake circuit 3 is provided with a pair of normally open valves 31, 32 and a pair of normally closed valves 23, 24 For the normally closed valves 33 and 34, each wheel corresponds to a normally open valve and a normally closed valve, the normally closed valves of the four wheels are all connected to the oil pot 1, and the normally open valves are all connected to the electric booster module and the brake module. In this embodiment, when the brake hydraulic pressure of one or more wheels fails, the normally open valve corresponding to the wheel is closed to ensure that the remaining wheels can be braked.

Specifically, as shown in FIGS. 1 to 2 , the brake module is respectively connected with the brake pedal 7 , the brake control system, the oil can 1 , and the first brake circuit 2 and the second brake circuit 3 of the vehicle. The brake module has: a brake master cylinder 41, a brake pedal stroke sensor 42, and an analog diagnostic valve 43. In this embodiment, the brake module also has: a first pressure sensor 44, a brake pedal simulation valve 45, a pedal simulation valve 8 , the first master cylinder isolation solenoid valve 46 , and the second master cylinder isolation solenoid valve 47 .

Further, as shown in FIGS. 1 to 2 , the master brake cylinder 41 includes a first cavity 411 and a second cavity 412 respectively connected to the oil pot 1 and separated by a partition piston 413 , wherein the first cavity 411 is respectively connected to the brake pedal 7. The pedal simulator 8 is connected to the first brake circuit 2, and the second chamber 412 is connected to the second brake circuit 3. After the brake pedal 7 is pressed, the brake fluid in the first chamber 411 is compressed and pushed to separate The piston 413 compresses the brake fluid in the second chamber 412 . During normal operation, the brake fluid in the first chamber 411 enters the pedal simulator 8 through the brake pedal simulator valve 45 to provide the driver with a brake pedal feel. When the system fails to brake, the first chamber 411 and the second chamber 412 The hydraulic pressures are synchronized to the first brake circuit 2 and the second brake circuit 3 respectively and output at the same pressure.

Further, as shown in FIGS. 1 and 2 , the brake pedal stroke sensor 42 is connected to the piston of the first chamber of the brake master cylinder pushed by the brake pedal 7 to detect the stroke of the brake pedal 7 for braking The control system controls the built-in hydraulic pressure to output appropriate braking force.

Further, as shown in FIGS. 1-2 , the analog diagnostic valve 43 is arranged between the first chamber 411 and the oiler 1, and the analog diagnostic valve 43 is connected with the brake control system and the first chamber 411 for isolation during system self-diagnosis The first chamber 411 is connected to the oil can 1 so that the brake control system can build up a suitable pressure to diagnose whether there is any leakage in the hydraulically balanced brake system.

Further, as shown in FIGS. 1 and 2 , the first pressure sensor 44 collects the hydraulic pressure output by the driver in the master brake cylinder 41 for the brake control system to further judge and confirm the driver's braking intention.

Further, as shown in FIGS. 1 and 2 , the brake pedal simulation valve 45 is disposed between the first cavity 411 and the brake pedal simulator 8 for communicating or isolating the first cavity 411 and the brake pedal simulator 8 .

Further, as shown in FIGS. 1 to 2 , the input port of the first master cylinder isolation solenoid valve 46 is connected to the first cavity 411 , and the output port is connected to the first brake circuit 2 ; the input port of the second master cylinder isolation solenoid valve 47 is connected Connected to the second cavity 412 , the output port is connected to the second brake circuit 3 . The first master cylinder isolation solenoid valve 46 and the second master cylinder isolation solenoid valve 47 prevent the hydraulic pressure of the electric booster module from flowing into the brake master cylinder 41 and the pedal simulator 8 during normal operation. When the system fails to brake, the brake module is connected to the pedal simulator 8. The first brake circuit 2 and the second brake circuit 3.

Specifically, as shown in Figures 1 and 2, the electric booster module is respectively connected to the oiler 1, the brake module and the hydraulic balance module for establishing and outputting the hydraulic braking force required by the brake control system. The electric assist module includes a motor 51 , a bidirectional assist unit, and a motor position sensor 53 . Wherein, the motor 51 is connected with the braking control system; the two-way power assist unit is connected with the motor 51, the oil pot 1, the first brake circuit 2 and the second brake circuit 3; the motor position sensor 53 collects the rotor position signal of the motor 51 in real time, For the brake control system to control the movement stroke of the motor 51 to drive the bidirectional power assist unit. The motor 51 drives the two-way power assist unit to establish hydraulic braking force in both forward and backward directions, and is transmitted to the first brake circuit 2 and the second brake circuit 3 by the two-way power assist unit to realize the braking of the vehicle, and through the motor position The sensor 53 collects signals to ensure output control of the hydraulic braking force by the brake control system.

Further, as shown in FIGS. 1 and 2 , the two-way power assist unit has: an electric cylinder 521 , a piston 522 , a transmission mechanism 523 , and a two-way pressure building solenoid valve 524 .

Further, as shown in FIGS. 1 and 2 , the electric cylinder 521 is a cavity with an opening at one end, which is used for the installation and movement of the piston 522 .

Further, as shown in Figures 1-2, the piston 522 has a front section 5221 and a rear section 5222, the diameter of the front section 5221 matches the inner diameter of the electric cylinder 521, the diameter of the rear section 5222 is smaller than the diameter of the front section 5221, and the front section 5221 connects the electric cylinder 521 The electric cylinder front cavity 5211 and the electric cylinder rear cavity 5212 are separated from each other. The inner cavity of the electric cylinder in front of the front section 5221 is the electric cylinder front cavity 5211, and the electric cylinder inner cavity behind the front section 5221 is the electric cylinder rear cavity 5212. , the front cavity 5211 of the electric cylinder and the rear cavity 5212 of the electric cylinder are respectively connected with the oiler 1 . In this embodiment, the brake fluid in the electric cylinder front cavity 5211 can smoothly enter the electric cylinder rear cavity 5212, the first brake circuit 2 and the second brake circuit 3 when the forward pressure builds up, and the electric cylinder front cavity 5211, The hydraulic pressure in the rear chamber 5212 of the electric cylinder, the first brake circuit 2 and the second brake circuit 3 are equal. When the forward pressure build-up is switched to the reverse build-up pressure, the system has no pressure reduction and no time delay for pressure build-up, and the system has high dynamic Response characteristics.

Further, as shown in Figures 1-2, in this embodiment, the two-way power assist unit also has: an electric cylinder liquid suction check valve 526, and the electric cylinder liquid suction check valve 526 is arranged in the oil pot 1 and the electric cylinder front cavity 5211 During this time, the brake fluid of the electric cylinder suction check valve 526 flows in one direction from the oil can 1 to the electric cylinder front cavity 5211 to ensure the supply of brake fluid in the electric cylinder front cavity 5211 and prevent backflow into the oil can 1 .

Further, as shown in Figures 1 and 2, the transmission mechanism 523 is connected with the motor 51 and the rear section 5222. The motor 51 drives part or all of the piston 522 to move back and forth in the electric cylinder 521 through the transmission mechanism 523. When the electric cylinder 521 moves in the inner direction, the electric cylinder front cavity 5211 is compressed, and the electric cylinder rear cavity 5212 increases. Cavity 5212 shrinks.

Further, the transmission mechanism 523 converts the rotational motion of the motor 51 to the linear motion of the rear section 5222 to drive the piston 522 to move back and forth to establish hydraulic pressure in the front cavity 5211 of the electric cylinder and the rear cavity 5212 of the electric cylinder. In this embodiment, the transmission mechanism 523 may adopt a screw transmission mechanism.

Further, as shown in FIGS. 1 to 4 , one end of the two-way pressure building solenoid valve 524 is connected to the electric cylinder front chamber 5211 , and the other end is connected to the hydraulic balance module and the electric cylinder rear chamber 5212 . Further, the two-way pressure building solenoid valve 524 opens when the piston 522 moves forward, and the brake fluid in the electric cylinder front cavity 5211 enters the electric cylinder rear cavity 5212 and the hydraulic balance module at the same time; when the piston 522 retreats to build up pressure, the two-way pressure building solenoid valve 524 Close, cut off the brake fluid flow between the electric cylinder front cavity 5211 and the electric cylinder rear cavity 5212, the hydraulic pressure of the electric cylinder rear cavity 5212 cannot enter the electric cylinder front cavity 5211 but can only enter the hydraulic balance module, which realizes the process of forward and backward. Both can build up pressure, and when the piston 522 retreats to release the pressure, the two-way pressure building solenoid valve 524 is opened to ensure that the brake fluid flows back into the front cavity 5211 of the electric cylinder.

In this embodiment, as shown in FIGS. 2 and 4 , the two-way power assist unit also has: a check valve 525 for discharging liquid from the electric cylinder, and the one-way valve 525 for discharging liquid from the electric cylinder is connected in parallel with the two-way pressure building solenoid valve 524, The flow direction of the brake fluid of the fluid check valve 525 is one-way outflow from the front cavity 5211 of the electric cylinder.

Further, in this embodiment, as shown in FIGS. 1 to 4 , the two-way power assist unit further includes: a second pressure sensor 527 for collecting the hydraulic pressure output by the two-way power assist unit.

Specifically, as shown in FIGS. 1 to 4 , the hydraulic balance module is connected between the electric booster module and the first brake circuit, and between the electric booster module and the second brake circuit, and is used to balance the hydraulic pressure output by the electric booster module. The dynamic balance is input to the first brake circuit 2 and the second brake circuit 3 . The hydraulic balance module has: a first hydraulic balance valve 61 and a second hydraulic balance valve 62 connected in series, in this embodiment, the first hydraulic balance valve 61 and the second hydraulic balance valve 62 are identical; the first hydraulic balance valve 61 and One end of the second hydraulic balance valve 62 is connected to the two-way pressure building solenoid valve 524 and the electric cylinder rear cavity 5212 , the other end of the first hydraulic balance valve 61 is connected to the first brake circuit 2 , and the other end of the second hydraulic balance valve 62 is connected to the first brake circuit 2 . One end is connected to the second brake circuit 3 . Through the first hydraulic balance valve 61 and the second hydraulic balance valve 62, when the system fails, the motor 51 and all solenoid valves are powered off, and the first hydraulic balance valve 61 disconnects the two-way power assist unit from the first brake circuit 2. The second hydraulic balance valve 62 disconnects the connection between the two-way power assist unit and the second brake circuit 3 to realize the safe isolation of the wheel brake circuit and the two-way power assist unit. At the same time, the first hydraulic balance valve 61 and the second hydraulic balance valve 62 are connected in series. Isolate the first brake circuit 2 and the second brake circuit 3 as backup for each other to achieve safety redundancy; and, when the pressure is built forward and backward, the hydraulic pressure of the two-way booster unit is connected to the same hydraulic balance valve through two identical hydraulic balance valves. The first brake circuit 2 and the second brake circuit 3 on both sides are communicated, thereby ensuring that the hydraulic pressure of the four wheel brakes is the same, and the vehicle braking control precision and control effect are better.

Further, in this embodiment, the first hydraulic balance valve 61 and the second hydraulic balance valve 62 select pressure balance valves to ensure that when the system fails, the brake hydraulic pressure generated by the driver stepping on the brake pedal 7 acts on the pressure balance valve. It cannot flow into the rear cavity of the electric cylinder, so that the brake hydraulic pressure can directly flow into the wheel for braking.

When the system is working normally, as shown in Figures 1 and 2, after the brake control system receives the braking signal, it controls the motor 51 to rotate, and the transmission mechanism 523 converts the rotation of the motor 51 into linear motion, pushing the piston 522 forward to compress the electric cylinder The front chamber 5211 builds up pressure; when the back chamber 5212 builds pressure, the motor 51 rotates in the opposite direction, the piston 5232 moves backward, provides the pulling force required for reverse build-up, and compresses the back chamber 5212 of the electric cylinder to build up pressure to achieve backward build-up. When the pressure is built forward, the two-way pressure building solenoid valve 524 is controlled to be in an open state, so that the brake fluid at both ends of the solenoid valve can flow. A part of the fluid enters the rear cavity 5212 of the electric cylinder, and the other part enters the first brake circuit 2 and the second brake circuit 3 through the first hydraulic balance valve 61 and the second hydraulic balance valve 62 respectively, and the electric cylinder front cavity 5211, the electric cylinder The hydraulic pressure of the rear chamber 5212 is the same as that of the first brake circuit 2 and the second brake circuit 3; when the pressure builds up in reverse, the two-way pressure buildup solenoid valve 524 is controlled to be in a closed state, cutting off the electric cylinder front cavity 5211 and the electric cylinder rear cavity 5212 The hydraulic pressure in the rear cavity 5212 of the electric cylinder cannot enter the front cavity 5212 of the electric cylinder, but can only enter the first brake circuit 2 and the second brake through the first hydraulic balance valve 61 and the second hydraulic balance valve 62 respectively. Circuit 3, so as to realize the two-way braking of forward and reverse without delay, not only has high dynamic response characteristics, can meet the fast response requirements of automatic emergency braking, high-level assistance and automatic driving functions, but also the hydraulic pressure of the four wheels is the same , to achieve hydraulic balance. When the pressure is released at the end of braking, the wheel brake fluid returns to the front chamber 5211 of the electric cylinder through the first hydraulic balance valve 61, the second hydraulic balance valve 62, and the two-way pressure building solenoid valve 524 to realize the release of the wheel brake hydraulic pressure. The brake fluid in the cylinder rear cavity 5212 returns to the electric cylinder front cavity 5211 to realize the return of the electric cylinder 521 .

When the system fails, as shown in FIG. 1 , the brake master cylinder 41 builds up pressure, wherein the brake pressure of the first chamber 411 enters the first brake circuit 2 through the first master cylinder isolation solenoid valve 46 , wherein the second chamber 412 The brake pressure of the second master cylinder enters the second brake circuit 3 through the second master cylinder isolation solenoid valve 47. Due to the isolation effect of the second hydraulic balance valve 61, the brake fluid of the first brake circuit 2 cannot be returned to the oil pot through the two-way booster unit. 1, so the first brake circuit 2 can build up pressure independently. Due to the isolation effect of the second hydraulic balance valve 62, the brake fluid of the second brake circuit 3 cannot return to the oil pot 1 through the two-way booster unit, so the second brake Circuit 3 is able to build pressure independently. During this four-wheel mechanical backup braking process, the driver's braking force acts on the first brake circuit 2 and the second brake circuit 3 respectively, and the brake hydraulic pressures of the two brake circuits are independent of each other.

When the two-wheel mechanical backup brake is caused by the failure of the first brake circuit 2, as shown in Figures 1 and 2, the driver depresses the brake pedal 7, the brake master cylinder 41 builds up pressure, and the second chamber 412 brakes The pressure enters the second brake circuit 3 through the second master cylinder isolation solenoid valve 47. Since the first hydraulic balance valve 61 and the second hydraulic balance valve 62 are in a closed state during the mechanical backup braking, the braking of the second brake circuit 3. The dynamic fluid cannot enter the first brake circuit 2, and because the second hydraulic balance valve 62 prevents the brake hydraulic pressure of the second brake circuit 3 from returning to the oil pot 1 through the two-way booster unit, the second brake circuit 3 can be established independently pressure. In such two-wheel mechanical backup braking, the first hydraulic balance valve 61 and the second hydraulic balance valve 62 completely isolate the first brake circuit 2 and the second brake circuit 3, and will not be affected by the first brake circuit 2 The failure of the second brake circuit 3 causes the four wheels to lose braking force. The second hydraulic balance valve 62 completely isolates the second brake circuit 3 from the two-way booster unit, and the brake fluid will not return to the oil tank 1. During the two-wheel mechanical backup braking, the driver's braking force acts on the second braking circuit 3 to cause the vehicle to decelerate.

When the two-wheel mechanical backup brake is caused by the failure of the second brake circuit 3, as shown in Figures 1-2, the driver depresses the brake pedal 7, the brake master cylinder 41 builds up pressure, and the first chamber 411 brakes The pressure enters the first brake circuit 2 through the first master cylinder isolation solenoid valve 46. Since the first hydraulic balance valve 61 and the second hydraulic balance valve 62 are in a closed state during mechanical backup braking, the braking of the first brake circuit 2. The dynamic fluid cannot enter the second brake circuit 3, and because the first hydraulic balance valve 61 prevents the brake hydraulic pressure of the first brake circuit 2 from returning to the oil pot 1 through the two-way booster unit, the first brake circuit 2 can be established independently pressure. During such two-wheel mechanical backup braking, the first hydraulic balance valve 61 and the second hydraulic balance valve 62 completely isolate the first brake circuit 2 and the second brake circuit 3, and will not be affected by the second brake circuit 3 The failure of the first brake circuit 2 causes the four wheels to lose braking force. The first hydraulic balance valve 61 completely isolates the first brake circuit 2 from the two-way booster unit, and the brake fluid will not return to the oil tank 1. During the two-wheel mechanical backup braking, the driver's braking force acts on the first braking circuit 2 to cause the vehicle to decelerate.

The hydraulic balance braking system for a vehicle according to an embodiment of the present invention is described above with reference to FIGS. 1 to 6 , which can ensure that the hydraulic pressure of the four wheels is the same, so that the braking control accuracy and control effect of the vehicle are better. Moreover, in the case of system failure, at least two wheels can be braked with hydraulic pressure, which greatly improves the braking safety.

It should be noted that, in this specification, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements , but also other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or device that includes the element.

While the content of the present invention has been described in detail by way of the above preferred embodiments, it should be appreciated that the above description should not be construed as limiting the present invention. Various modifications and alternatives to the present invention will be apparent to those skilled in the art upon reading the foregoing. Accordingly, the scope of protection of the present invention should be defined by the appended claims.

Claims (5)

1. A hydraulic balanced brake system for a vehicle comprising an oil can for providing brake fluid, the hydraulic balanced brake system further comprising:

a first brake circuit for braking two wheels;

a second brake circuit for braking the remaining two wheels;

the brake module is respectively connected with a brake pedal, a brake control system, an oil can and the first brake circuit and the second brake circuit of a vehicle and is used for providing braking force for the first brake circuit and the second brake circuit;

the electric power-assisted module is respectively connected with the oil can and the brake control system and is used for establishing and outputting hydraulic braking force required by the brake control system;

the hydraulic balancing module is connected between the electric power-assisted module and the first brake circuit, and between the electric power-assisted module and the second brake circuit, and is used for balancing and inputting the hydraulic braking force output by the electric power-assisted module into the first brake circuit and the second brake circuit.

2. The hydraulic balanced brake system for a vehicle according to claim 1, wherein the electric booster module comprises an electric motor, a bidirectional booster unit, a motor position sensor, an electric cylinder, a piston, a transmission mechanism, and a bidirectional pressure-building solenoid valve, the piston divides the electric cylinder into an electric cylinder front chamber and an electric cylinder rear chamber, one end of the bidirectional pressure-building solenoid valve is connected to the electric cylinder front chamber, and the other end thereof is respectively connected to the electric cylinder rear chamber and the hydraulic balance module, the bidirectional pressure-building solenoid valve is opened when the electric cylinder front chamber is compressed and built up, closed when the electric cylinder rear chamber is compressed and built up, and opened when the electric cylinder rear chamber is compressed and decompressed; and the electric cylinder rear cavity is connected with the hydraulic balance module.

3. The hydraulically balanced brake system for a vehicle of claim 2, wherein said bi-directional booster unit further comprises: the electric cylinder liquid outlet one-way valve is connected with the bidirectional piezoelectric solenoid valve in parallel, and the brake fluid of the electric cylinder liquid outlet one-way valve flows out in one direction of the electric cylinder front cavity.

4. The hydraulically balanced brake system for a vehicle as claimed in claim 1, wherein the hydraulic balancing module comprises a first hydraulic balancing valve and a second hydraulic balancing valve connected in series, one end of the first hydraulic balancing valve and the second hydraulic balancing valve is connected to the two-way build solenoid valve and the rear chamber of the cylinder, the other end of the first hydraulic balancing valve is connected to the first brake circuit, and the other end of the second hydraulic balancing valve is connected to the second brake circuit.

5. The hydraulically balanced brake system for a vehicle of claim 4, wherein the first and second hydraulic balancing valves are pressure balancing valves.

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