CN210941729U

CN210941729U - Electronic hydraulic brake system driven by double-acting brake master cylinder

Info

Publication number: CN210941729U
Application number: CN201920502572.8U
Authority: CN
Inventors: 孙浩宇; 陈齐平; 王宁; 田玥; 王亮
Original assignee: East China Jiaotong University
Current assignee: East China Jiaotong University
Priority date: 2020-01-01
Filing date: 2020-01-01
Publication date: 2020-07-07
Anticipated expiration: 2030-01-01

Abstract

The utility model relates to a two effect brake master cylinder driven electronic hydraulic braking system, include: the electronic control unit ECU is used for integrating vehicle information and sensor feedback information, making decisions and sending control instructions and is connected with the motor controller and each sensor through an electronic circuit; a brake master cylinder which is directly driven by the reduction gear pair and can work in two directions; a hydraulic pressure sensor for detecting the pressure state of the pipeline in real time; the acceleration sensor detects the motion information of the pedal push rod in real time; the pedal cylinder is used for generating pedal feedback pressure and outputting hydraulic oil; and a secondary braking route of failure protection braking is realized. The utility model discloses a braking system can improve the pressure output performance of brake master cylinder through the high pressure oil of double-acting brake master cylinder constantly output, can provide more reliable brake force when the inefficacy braking, has guaranteed the higher reliability of system.

Description

Electronic hydraulic brake system driven by double-acting brake master cylinder

Technical Field

The utility model belongs to the technical field of the car braking and specifically relates to a two effect brake master cylinder driven electronic hydraulic braking system.

Background

An Electro-hydraulic Brake System (EHB) is a Brake System using a wire control technique, and particularly relates to a first-entering line control System which is well integrated with a traditional hydraulic Brake System. Generally, the electronic hydraulic brake system has superior performance which is difficult to break through in the traditional hydraulic brake system, such as high control precision, fast system response, reliable execution and the like, however, although the electronic hydraulic brake system has great performance improvement on the basis of the traditional hydraulic brake system, the electronic hydraulic brake system also inevitably has some problems to be improved or optimized, such as larger arrangement space, further improved brake efficiency, better adaptation to the automatic driving technology and the like, so that the brake-by-wire automobile brake system which can reduce the arrangement space, greatly improve the brake response speed and well adapt to the brake requirement of the automatic driving is a key research direction for improving the driving active safety of the automobile.

Chinese patent application publication No. CN104760586A discloses a dual-motor driven electronic hydraulic brake system capable of actively simulating pedal feel, which adopts two motors as power sources of a first electronic control linear motion module and a second electronic control linear motion module, and transmits power to a single-stage hydraulic cylinder in a gear and lead screw transmission mode to obtain hydraulic energy, and in addition, a motor drives a gear pair to move so as to enable a pedal push rod hinged with a lead screw to move together; obviously, two sets of devices with the same or similar sizes are required to be used for driving by adopting the double motors, and the devices comprise the motors, the speed reducing mechanisms and the hydraulic cylinder driving mechanisms, so that the requirement on larger arrangement space is caused, and the space reduction is not facilitated.

Chinese patent application publication No. CN 103754206A discloses a "mechanical electronic hydraulic brake system" which mainly uses two linear motors connected in series to generate and transmit braking force. As is apparent from the above description of the preferred embodiment,

the two motors are adopted to work in series, so that the difficulties in power matching and coordination work exist, the coupling degree of the brake pedal and the brake system is high, and in a failure mode, the brake wheel cylinder is driven by the power input by the brake pedal by a driver to generate braking force, so that efficient braking is difficult to realize.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned problems, the present invention provides a system scheme for a double-acting brake master cylinder drive, by which the brake master cylinder can continuously and rapidly pressurize the system until the system requirements are met. Furthermore, the utility model discloses take the major-minor route that has two motors, can also improve failure brake reliability effectively on the basis that satisfies the footboard sensation.

An electronic hydraulic brake system driven by a double-acting brake master cylinder is characterized in that:

the double-acting brake master cylinder comprises a driving gear (6-1), a driven gear (6-2), a piston push rod (6-3), a first working cavity piston (6-4), a distance measuring sensor (6-5), a first liquid supplementing port (6-6), a first liquid outlet (6-7), a first working cavity (6-8), a second working cavity piston (6-9), a second working cavity (6-10), a second liquid supplementing port (6-11) and a second liquid outlet (6-12); wherein, the driving wheel (6-1) is arranged on the output shaft of the motor (4) and is in meshed transmission with the driven wheel (6-2); gear teeth are processed on the outer circular surface of the piston push rod (6-3) and are used for being meshed with the driven wheel (6-2) for transmission, so that the change from rotary motion to linear reciprocating motion is realized, and power is converted into hydraulic pressure to generate hydraulic energy; the first working cavity piston (6-4) and the second working cavity piston (6-9) are rigidly connected with the piston push rod (6-3) or are processed into a whole; the distance measuring sensor (6-5) is used for detecting the displacement of the gear pair (6-1, 6-2) and the piston push rod (6-3) towards two sides in real time so as to send a signal to the ECU (1) in time to enable the main motor controller (2) to control the main motor (4) to rotate reversely, and a displacement sensor with larger occupied space is not suitable, and a light distance sensor with small volume and high sensitivity is suitable; the first fluid infusion port (6-6) and the second fluid infusion port (6-11) are connected to the fluid reservoir (5) through one-way valves so as to restrict the oil absorption direction of the chamber; the first liquid outlet (6-7) and the second liquid outlet (6-12) are respectively connected to a two-position two-way electromagnetic directional valve (7); the piston push rod (6-3) is driven by a gear to enable the first working cavity (6-8) to output pressure oil when compressed, and liquid is replenished from the liquid storage tank (5) to the second working cavity (6-10) through the second liquid replenishing port (6-11) and the one-way valve; when the stroke is close (measured by a distance measuring sensor (6-5)), the main motor (4) is driven reversely, the second working cavity (6-10) compresses and outputs pressure oil, and the first working cavity (6-8) replenishes liquid from the liquid storage tank (5).

The internal engagement helical tooth transmission mechanism (13) comprises a distance measuring sensor (13-1), a brake auxiliary cylinder push rod (13-2) and a motor output shaft (13-3); wherein, the distance measuring sensor (13-1) is fixedly arranged at a certain position on the push rod (13-2) of the auxiliary brake cylinder, and samples the distance to the end part of the auxiliary brake cylinder (12) in real time after being enabled; the end part of the brake auxiliary cylinder push rod (13-2) is processed with external screw teeth, the end part of the motor output shaft (13-3) is processed with internal screw teeth, the brake auxiliary cylinder push rod and the motor output shaft (13-3) can be meshed for transmission like thread transmission, and the size ensures that the brake auxiliary cylinder push rod (13-2) and the motor output shaft (13-3) are in certain clearance fit.

Compare with current electron hydraulic braking system, the utility model discloses following beneficial effect has:

1. a double-acting hydraulic cylinder driven by a gear is adopted in a main braking route, and braking pressure can be quickly and continuously established;

2. an internal meshing helical gear transmission mechanism is adopted in the auxiliary braking route to drive an auxiliary braking hydraulic cylinder, so that the transmission is reliable and effective, and a certain arrangement space can be reduced;

drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural view of the double-acting brake master cylinder of the present invention.

FIG. 3 is a schematic diagram of the internal structure of the ABS/ESP of the present invention.

Fig. 4 is a schematic structural view of the internal engagement helical gear transmission mechanism of the present invention.

Fig. 5 is a flowchart of the start-up logic of the system of the present invention.

In fig. 1, an electronic control unit ECU (1), a main motor controller (2), a check valve (3), a main motor (4), a liquid storage tank (5), a hydraulic pressure main unit (6), a two-position two-way servo solenoid valve (7), an ABS/ESP (8), a hydraulic pressure sensor (9), a wheel speed sensor (10), a brake wheel cylinder (11), a brake sub-cylinder (12), an inner-meshing helical gear transmission mechanism (13), a sub-motor (14), a pedal cylinder (15), a sub-motor controller (16), a pedal cylinder push rod (17), an acceleration sensor (18) and a brake pedal (19).

In fig. 2, a driving gear (6-1), a driven gear (6-2), a piston push rod (6-3), a first working chamber piston (6-4), a distance measuring sensor (6-5), a first fluid infusion port (6-6), a first fluid outlet (6-7), a first working chamber (6-8), a second working chamber piston (6-9), a second working chamber (6-10), a second fluid infusion port (6-11), and a second fluid outlet (6-12).

In fig. 3, a brake line 1(8-1), a brake line 2(8-2), an electromagnetic valve (8-3), a line to the right front wheel cylinder (8-4), a line to the left rear wheel cylinder (8-5), a line to the right rear wheel cylinder (8-6), and a line to the left front wheel cylinder (8-7).

In FIG. 4, a distance measuring sensor (13-1), a brake sub-cylinder push rod (13-2), and a motor output shaft (13-3).

Detailed Description

Electronic hydraulic braking system have two work routes, can realize three kinds of operating condition of brake wheel cylinder, fig. 5 has demonstrated the utility model provides an electronic hydraulic braking system's start-up logic flow.

In fig. 1, when a driver steps on a brake pedal (19) in a normal state of a main brake line, a pedal cylinder push rod (17) pushes a piston of a pedal cylinder (15) to move through a mechanical connection, a pedal resistance feeling is provided by spring resistance and oil damping force in the process, and certain pressure oil is input to an ABS/ESP (8) through a pipeline and a one-way valve (3). When receiving the brake signal sampled by the acceleration sensor (18), the electronic control unit ECU (1) immediately sends a control pulse to the ABS/ESP (8) to start the same, and then the calculation of the braking force is carried out. The electronic control unit ECU (1) calculates and analyzes the braking strength required by the braking request according to the acquired braking signal, and finally obtains the magnitude of the brake fluid pressure required by the braking system according to the information such as the whole vehicle mass, the predefined tire model, the real-time vehicle information and the regenerative braking force.

An electronic control unit ECU (1) controls the operation of the engine according to a predetermined control strategySlightly adjusting system parameters, combining pressure information in a front pipeline of a wheel cylinder sampled by a hydraulic pressure sensor (9), sending a certain rotating speed control signal to a main motor controller (2), driving a main motor (4) to work and driving a brake master cylinder piston push rod (6-3) to work through a reduction gear pair (6-1, 6-2), wherein the driving gear (6-1) is arranged on an output shaft of the motor and meshed with a driven gear (6-2), and the transmission ratio is Z₂/Z₁Wherein Z is₁And Z₂The gear pair (6-1, 6-2) and the brake master cylinder piston push rod (6-3) are in gear and rack transmission. When braking starts, the main motor (4) is driven to start to rotate forwards, the piston push rod (6-3) of the brake master cylinder is driven to compress the first working cavity (6-8), at the moment, the first liquid outlet (6-7) outputs pressure oil, and liquid is replenished into the second working cavity (6-10) from the liquid storage tank (5) through the second liquid replenishing port (6-11) and the one-way valve; when the piston approaches the end of the stroke, the main motor (4) starts to drive reversely, the second working chambers (6-10) compress and output pressure oil, and the first working chambers (6-8) supplement liquid from the liquid storage tank (5).

The pressure oil output by the hydraulic pressure main unit (6) is led into a hydraulic pressure control unit ABS/ESP (8) through a two-position two-way servo electromagnetic valve (7), namely a unit mainly composed of a four-way two-position two-way servo electromagnetic valve (9-3), and the control unit is controlled by an electronic control unit ECU (1). In order to implement an ABS control strategy and an ESP control strategy, an electronic control unit ECU (1) comprehensively analyzes pressure signals and other vehicle information sampled by a hydraulic pressure sensor and sends control signals to four-way solenoid valves (8-3) in an ABS/ESP (8), and the pressure of each pipeline is regulated so that the vehicle shows excellent comprehensive performance of greatly utilizing a ground adhesion coefficient and ensuring stable running in the braking process.

In the process of increasing the hydraulic pressure of the brake wheel cylinder, when a hydraulic pressure sensor (9) detects that the hydraulic pressure in a pipeline reaches a target value, an electronic control unit ECU (1) sends a control signal to a two-position two-way servo electromagnetic valve (7) to cut off a communicated oil way, so that the brake wheel cylinder enters a pressure maintaining state.

According to a predefined control strategy, when an electronic control unit ECU (1) receives a brake pedal release return signal or a vehicle speed signal reaches a certain limit value, the brake task is judged to be nearly completed, a control signal is sent to a four-way electromagnetic valve (8-3) in an ABS/ESP (8), and a passage connected with an oil tank is switched to enable a brake wheel cylinder to enter an unloading state.

In the braking process, the whole electronic control system is in a dynamic monitoring state, and an electronic control unit ECU (1) receives, analyzes and processes feedback information of a sensor at a microsecond-level running speed and sends various control signals.

According to the requirements of national regulations, the brake system must include a brake system which can generate larger brake efficiency and maintain certain strength when the condition that a normal brake route fails and some brake components are in failure are considered. The utility model discloses in also considered the failure protection scheme.

When the main braking route is in a failure state, as shown in figure 1, when a driver presses a pedal (19) to send a braking request to the system, the electronic control unit ECU (1) immediately sends a control signal to the auxiliary motor controller (16) and enables the distance measuring sensor (13-1) to start sampling, and the auxiliary motor (14) enters a working state. As shown in fig. 4, when the auxiliary motor (14) rotates forwards, the auxiliary motor output shaft (13-3) and the internal screw tooth of the brake auxiliary cylinder push rod (13-2) are engaged for transmission, so that the brake auxiliary cylinder push rod (13-2) compresses oil in the cylinder and inputs the oil into the ABS/ESP (8) through the one-way valve (3) to be communicated with the brake pipeline 1(8-1) and the brake pipeline 2 (8-2); when the signal sampled by the distance measuring sensor (13-1) reaches the set limit value, the electronic control unit ECU (1) controls the auxiliary motor controller (16) to enable the auxiliary motor (14) to rotate reversely, and the brake auxiliary cylinder (12) is supplemented with oil from the liquid storage tank (5) through the one-way valve (3) so as to carry out the next working stroke. In addition, when a driver steps on the brake pedal (19), the pedal cylinder (15) can still input hydraulic oil into the ABS/ESP (8) to play a certain boosting role.

Claims

1. The electronic hydraulic brake system driven by the double-acting brake master cylinder comprises an electronic control unit ECU (1), a main motor controller (2), a one-way valve (3), a main motor (4), a liquid storage tank (5), a hydraulic pressure main unit (6), a two-position two-way servo electromagnetic valve (7), an ABS/ESP (anti-lock brake system)/hydraulic pressure sensors (9), a wheel speed sensor (10), a brake wheel cylinder (11), a brake auxiliary cylinder (12), an inner meshing screw tooth transmission mechanism (13), an auxiliary motor (14), a pedal cylinder (15), an auxiliary motor controller (16), a pedal cylinder push rod (17), an acceleration sensor (18) and a brake pedal (19).

2. A double-acting master cylinder actuated electro-hydraulic brake system according to claim 1, wherein: in the structural composition of the hydraulic pressure main unit (6), the top of the cylinder body is provided with a section of slot for mounting the driven wheel (6-2), and the outer circular surface of the piston push rod (6-3) is provided with gear teeth for meshing transmission with the driven wheel (6-2).

3. A double-acting master cylinder actuated electro-hydraulic brake system according to claim 1, wherein: in the structural composition of the hydraulic pressure main unit (6), a first working cavity piston (6-4) and a second working cavity piston (6-9) are rigidly connected with a piston push rod (6-3) or are processed into a whole; the distance measuring sensor (6-5) is used for detecting the displacement of the gear pair (6-1, 6-2) and the piston push rod (6-3) towards two sides in real time, and is preferably an optical distance measuring sensor with small volume and high sensitivity.

4. A double-acting master cylinder actuated electro-hydraulic brake system according to claim 1, wherein: in the structural composition of the hydraulic pressure main unit (6), a first liquid supplementing port (6-6) and a second liquid supplementing port (6-11) are connected to a liquid storage tank (5) through a one-way valve, and a first liquid outlet (6-7) and a second liquid outlet (6-12) are respectively connected to the one-way valve (3).