Electro-hydraulic brake system and electro-hydraulic brake method

Abstract

An electronic hydraulic brake system comprises an oil tank, a hydraulic master cylinder, an auxiliary master cylinder, a simulation master cylinder, a driving mechanism, a pedal, a pedal simulator, a first pressure sensor, a stroke sensor, a first normally open valve, a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a control unit, the oil tank is connected with the hydraulic master cylinder, the auxiliary master cylinder and the simulation master cylinder respectively, the auxiliary master cylinder is connected with the hydraulic master cylinder in linkage, the driving mechanism is connected with the auxiliary master cylinder, the pedal is connected with the simulation master cylinder, and the stroke sensor is used for detecting the moving stroke of the pedal; the first pipeline and the second pipeline are connected with the hydraulic master cylinder; the third pipeline is connected between the auxiliary master cylinder and the simulation master cylinder, the first normally open valve and the first pressure sensor are connected with the third pipeline; the fourth pipeline is connected between the simulation master cylinder and the pedal simulator; and the control unit is connected with the driving mechanism, the stroke sensor, the first pressure sensor and the first normally open valve. The brake foot feeling can be ensured. The application further provides an electronic hydraulic brake method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of braking, in particular to an electronic hydraulic braking system and an electronic hydraulic braking method. BACKGROUND

[0002] With the popularity of automobile electrification and unmanned driving, the automobile brake system loses the convenient vacuum source, so the vacuum booster needs to be cancelled; in addition, the brake demand of unmanned driving puts forward higher requirements for the performance and service life of the system active brake, so that the currently widely used electronic stability control system (ESC) cannot meet the requirements, prompting the generation and gradual popularization of the new generation of brake-by-wire system, and the electronic booster is the most basic brake-by-wire system and is applied more and more.

[0003] The existing electronic hydraulic brake system has two basic forms, non-decoupling type and decoupling type; the electronic hydraulic brake system of the non-decoupling type applies the electronic booster device to the traditional master cylinder, and the brake force stepped on by the driver is used to realize braking together, since the brake foot feeling is poor, the software algorithm is complex, the reliability is poor, and there is a trend of gradually withdrawing from the market; the decoupling type electronic booster system includes mechanical decoupling, gap decoupling, hydraulic decoupling and the like, the mechanical decoupling brake foot feeling is poor, the gap decoupling brake stroke is too long in the backup mode, reducing the confidence of the driver, and the ordinary hydraulic decoupling, when matched with the ESC, the damping of the system itself reduces the active boosting capability of the ESC. SUMMARY

[0004] Therefore, the present application provides an electronic hydraulic braking system which can ensure brake foot feeling and avoid the problem of too long brake stroke in backup mode.

[0005] An electronic hydraulic braking system, comprising an oil tank, a hydraulic master cylinder, an auxiliary master cylinder, a simulation master cylinder, a driving mechanism, a pedal, a pedal simulator, a first pressure sensor, a stroke sensor, a first normally open valve, a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a control unit, the oil tank is connected with the hydraulic master cylinder, the auxiliary master cylinder and the simulation master cylinder respectively, the auxiliary master cylinder is connected with the hydraulic master cylinder in linkage, the driving mechanism is connected with the auxiliary master cylinder, the pedal is connected with the simulation master cylinder, and the stroke sensor is used for detecting the moving stroke of the pedal; the first pipeline and the second pipeline are connected with the hydraulic master cylinder, and the first pipeline and the second pipeline are used for outputting hydraulic pressure; the third pipeline is connected between the auxiliary master cylinder and the simulation master cylinder, the first normally open valve and the first pressure sensor are connected on the third pipeline; the fourth pipeline is connected between the simulation master cylinder and the pedal simulator; the control unit is electrically connected with the driving mechanism, the stroke sensor, the first pressure sensor and the first normally open valve respectively, and the control unit is used for controlling the driving mechanism to start or stop and controlling the first normally open valve to be powered on or powered off.

[0006] In the embodiment of the present application, the electronic hydraulic brake system further comprises a fifth pipeline and a second normally open valve, the fifth pipeline is connected between the second pipeline and the third pipeline, the second normally open valve is connected on the fifth pipeline, the second normally open valve is electrically connected with the control unit, and the control unit is used to control the second normally open valve to be electrified or de-energized.

[0007] In the embodiment of the present application, the electronic hydraulic brake system further comprises a second pressure sensor and a position sensor, the second pressure sensor is connected on the second pipeline, the position sensor is used to detect the driving position of the driving mechanism, and the second pressure sensor and the position sensor are electrically connected with the control unit.

[0008] In the embodiment of the present application, the electronic hydraulic brake system further comprises a first normally closed valve, the first normally closed valve is connected on the fourth pipeline, the first normally closed valve is electrically connected with the control unit, and the control unit is used to control the first normally closed valve to be electrified or de-energized.

[0009] In the embodiment of the present application, the electronic hydraulic brake system further comprises a sixth pipeline and a one-way valve, the inlet end and the outlet end of the sixth pipeline are connected with the fourth pipeline, the first normally closed valve is located between the inlet end and the outlet end, and the one-way valve is connected on the sixth pipeline.

[0010] In the embodiment of the present application, the electronic hydraulic brake system further comprises an auxiliary liquid inlet pipe and a second normally closed valve, the auxiliary liquid inlet pipe is connected between the oil can and the auxiliary master cylinder, the second normally closed valve is connected on the auxiliary liquid inlet pipe, the second normally closed valve is electrically connected with the control unit, and the control unit is used to control the second normally closed valve to be electrified or de-energized.

[0011] In the embodiment of the present application, the electronic hydraulic brake system further comprises a plurality of wheel cylinders or ABS / ESCs, the outlet ends of the first pipeline and the second pipeline are connected with a plurality of wheel cylinders or ABS / ESCs respectively.

[0012] In the embodiment of the present application, the control unit comprises a self-checking circuit, the self-checking circuit can determine the sealing property of the system loop according to the signals collected by the first pressure sensor and the second pressure sensor.

[0013] In the embodiment of the present application, the hydraulic master cylinder comprises a first master cylinder and a first piston assembly, the first piston assembly is installed in the first master cylinder, the auxiliary master cylinder comprises a second master cylinder and a second piston assembly, the second master cylinder is connected with the first master cylinder, the second piston assembly is installed in the first master cylinder and the second master cylinder, one end of the second piston assembly is connected with the first piston assembly, and the other end of the second piston assembly passes through the second master cylinder and is connected with the driving mechanism.

[0014] The present application also provides an electronic hydraulic braking method, which is used in the electronic hydraulic braking system, and comprises the following steps:

[0015] When the driving mechanism is not failed:

[0016] The first normally open valve is controlled to be powered off to open the third pipeline;

[0017] When the driver steps on the pedal to drive the simulation master cylinder, the control unit starts the driving mechanism according to the signals detected by the first pressure sensor and the stroke sensor, the driving mechanism drives the auxiliary master cylinder and the hydraulic master cylinder, and the first pipeline and the second pipeline output hydraulic pressure.

[0018] When the driving mechanism is failed:

[0019] The first normally open valve is controlled to be powered off to open the third pipeline;

[0020] When the driver steps on the pedal to drive the simulation master cylinder, the control unit starts the driving mechanism according to the signals detected by the first pressure sensor and the stroke sensor, the driving mechanism drives the auxiliary master cylinder and the hydraulic master cylinder, and the first pipeline and the second pipeline output hydraulic pressure.

[0021] In the embodiment of the present application, the first normally closed valve is connected to the fourth pipeline;

[0022] When the driving mechanism is failed and braking is performed, the first normally closed valve is controlled to be powered off to open the fourth pipeline.

[0023] In the embodiment of the present application, the fifth pipeline is connected between the second pipeline and the third pipeline, and the second normally open valve is connected to the fifth pipeline;

[0024] When the driving mechanism is failed and braking is performed:

[0025] The first normally open valve is controlled to be powered off to open the third pipeline, the second normally open valve is controlled to be powered off to open the fifth pipeline, and the first normally closed valve is controlled to be powered off to open the fourth pipeline;

[0026] Pedaling the pedal makes the simulation master cylinder apply brake force, and brake fluid enters the auxiliary master cylinder and the hydraulic master cylinder through the third pipeline and the five pipelines, so that the first pipeline and the second pipeline output hydraulic pressure.

[0027] In the embodiment of the present application, the second pressure sensor is connected to the second pipeline, the auxiliary liquid inlet pipe is connected between the oil can and the auxiliary master cylinder, and the second normally closed valve is connected to the auxiliary liquid inlet pipe; the method for detecting the sealing of the electronic hydraulic brake system comprises the following steps:

[0028] controlling the driving mechanism to start and controlling the first normally open valve to be powered and the second normally open valve to be unpowered;

[0029] determining the sealing of the loop composed of the hydraulic master cylinder, the auxiliary master cylinder and the first normally open valve according to the signal collected by the second pressure sensor.

[0030] In the embodiment of the present application, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0031] controlling the driving mechanism to start and controlling the first normally open valve to be unpowered and the second normally open valve to be powered;

[0032] determining the sealing of the loop composed of the hydraulic master cylinder and the second normally open valve according to the signal collected by the second pressure sensor.

[0033] In the embodiment of the present application, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0034] controlling the driving mechanism to start and controlling the first normally open valve, the second normally open valve, the first normally closed valve and the second normally closed valve to be unpowered;

[0035] determining the sealing of all loops except the pedal simulator according to the signals collected by the first pressure sensor and the second pressure sensor.

[0036] In the embodiment of the present application, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0037] controlling the driving mechanism to start and controlling the first normally closed valve to be powered and the first normally open valve, the second normally open valve and the second normally closed valve to be unpowered;

[0038] determining the sealing of all loops of the system according to the signals collected by the first pressure sensor and the second pressure sensor.

[0039] The pedal simulator of the electronic hydraulic brake system of the application can perfectly simulate the foot feeling required by the driver without producing side effects, overcomes the problem of poor brake foot feeling of non-decoupling and mechanical decoupling, ensures the brake foot feeling, and avoids the problem of too long brake stroke in the backup mode. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a structural schematic diagram of the electronic hydraulic brake system of the application;

[0041] Figure 2 is a schematic diagram of the electronic hydraulic brake system of the application in normal braking;

[0042] Figure 3 is a schematic diagram of the electronic hydraulic brake system of the application in the first backup braking working state;

[0043] Figure 4 is a schematic diagram of the electronic hydraulic brake system of the application in the second backup braking working state;

[0044] Figure 5 is a schematic diagram of the electronic hydraulic brake system of the application in the first self-checking working state;

[0045] Figure 6 is a schematic diagram of the electronic hydraulic brake system of the application in the second self-checking working state;

[0046] Figure 7 is a schematic diagram of the electronic hydraulic brake system of the application in the third self-checking working state;

[0047] Figure 8 is a schematic diagram of the electronic hydraulic brake system of the application in the fourth self-checking working state. DETAILED DESCRIPTION

[0048] The application provides an electronic hydraulic brake system.

[0049] In order for those skilled in the art to better understand the application scheme, the technical solutions in the embodiments of the application will be clearly and completely described in the following with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the application.

[0050] In order to facilitate the understanding of those skilled in the art, the application provides the specific implementation process of the technical solutions by the following embodiments.

[0051] Figure 1 is a structural schematic diagram of an electronic hydraulic brake system of the present application, as Figure 1 shown, the electronic hydraulic brake system comprises an oil pot 11, a hydraulic master cylinder 12, an auxiliary master cylinder 13, a simulation master cylinder 14, a driving mechanism 15, a pedal 16, a pedal simulator 17, a first pressure sensor 18, a stroke sensor 19, a first normally open valve 20, a first pipeline 21, a second pipeline 22, a third pipeline 23, a fourth pipeline 24 and a control unit (not shown in the figure), wherein:

[0052] The oil pot 11 is connected with the hydraulic master cylinder 12, the auxiliary master cylinder 13 and the simulation master cylinder 14 respectively, the auxiliary master cylinder 13 is connected with the hydraulic master cylinder 12 in linkage, the driving mechanism 15 is connected with the auxiliary master cylinder 13, the pedal 16 is connected with the simulation master cylinder 14, and the stroke sensor 19 is used for detecting the moving stroke of the pedal 16;

[0053] The first pipeline 21 and the second pipeline 22 are connected with the hydraulic master cylinder 12, and the first pipeline 21 and the second pipeline 22 are used for outputting hydraulic pressure;

[0054] The third pipeline 23 is connected between the auxiliary master cylinder 13 and the simulation master cylinder 14, and the first normally open valve 20 and the first pressure sensor 18 are connected on the third pipeline 23;

[0055] The fourth pipeline 24 is connected between the simulation master cylinder 14 and the pedal simulator 17;

[0056] The control unit is electrically connected with the driving mechanism 15, the stroke sensor 19, the first pressure sensor 18 and the first normally open valve 20 respectively, and is used for controlling the driving mechanism 15 to start or stop and controlling the first normally open valve 20 to be electrified or de-energized; the first normally open valve 20 is blocked when electrified, and the third pipeline 23 is conducted when de-energized.

[0057] When the electronic hydraulic brake system brakes under normal conditions (the driving mechanism 15 is not failed), the control unit controls the first normally open valve 20 to be electrified to block the third pipeline 23, at this time, the pedal 16 is stepped on to drive the simulation master cylinder 14, at the same time, the stroke sensor 19 detects the moving stroke of the pedal 16 in real time, a part of the hydraulic pressure output by the simulation master cylinder 14 reaches the first normally open valve 20 through the third pipeline 23, and the fluid pressure in the third pipeline 23 is sensed by the first pressure sensor 18, another part reaches the pedal simulator 17 through the fourth pipeline 24 to realize foot feeling simulation, the control unit starts the driving mechanism 15 according to the signals collected by the stroke sensor 19 and the first pressure sensor 18, and then the driving mechanism 15 drives the auxiliary master cylinder 13, and then the auxiliary master cylinder 13 drives the hydraulic master cylinder 12 to realize the hydraulic pressure output of the first pipeline 21 and the second pipeline 22.

[0058] When the electronic hydraulic brake system brakes in the first backup working state (drive mechanism 15 fails), the control unit controls the first normally open valve 20 to lose power to open the third pipeline 23, at this time, the pedal 16 is stepped on to drive the simulation master cylinder 14, the simulation master cylinder 14 outputs hydraulic pressure, part of the hydraulic pressure reaches the auxiliary master cylinder 13 through the third pipeline 23, and then the auxiliary master cylinder 13 drives the hydraulic master cylinder 12 to realize the hydraulic pressure output of the first pipeline 21 and the second pipeline 22; the other part of the hydraulic pressure reaches the pedal simulator 17 through the fourth pipeline 24 to realize the simulation of the foot feeling.

[0059] The pedal simulator 17 of the electronic hydraulic brake system of the present application can perfectly simulate the foot feeling required by the driver without side effects, overcomes the problem of poor brake foot feeling of the non-decoupling type and the mechanical decoupling type, ensures the brake foot feeling, and avoids the problem of too long brake stroke in the backup mode.

[0060] Optionally, the electronic hydraulic brake system further comprises a fifth pipeline 25 and a second normally open valve 26, the fifth pipeline 25 is connected between the second pipeline 22 and the third pipeline 23, the second normally open valve 26 is connected on the fifth pipeline 25, the second normally open valve 26 is electrically connected with the control unit, the control unit is used for controlling the second normally open valve 26 to be powered or lose power, the second normally open valve 26 loses power to block the fifth pipeline 25, and the second normally open valve 26 loses power to open the fifth pipeline 25. When the electronic hydraulic brake system brakes in the second backup working state (drive mechanism 15 fails), the control unit controls the first normally open valve 20 to lose power to open the third pipeline 23 and controls the second normally open valve 26 to lose power to open the fifth pipeline 25, at this time, the pedal 16 is stepped on to drive the simulation master cylinder 14, the simulation master cylinder 14 outputs hydraulic pressure, part of the hydraulic pressure reaches the auxiliary master cylinder 13 and the hydraulic master cylinder 12 through the third pipeline 23 and the fifth pipeline 25 and the second pipeline 22 respectively, to drive the auxiliary master cylinder 13 and the hydraulic master cylinder 12 to realize the hydraulic pressure output of the first pipeline 21 and the second pipeline 22; the other part of the hydraulic pressure reaches the pedal simulator 17 through the fourth pipeline 24 to realize the simulation of the foot feeling.

[0061] Optionally, the electronic hydraulic brake system further comprises a second pressure sensor 27 and a position sensor 28, the second pressure sensor 27 is connected on the second pipeline 22, and the position sensor 28 is used for detecting the driving position of the drive mechanism 15, the second pressure sensor 27 and the position sensor 28 are electrically connected with the control unit. In the embodiment, the control unit can control the power, start or stop of the drive mechanism 15 in real time according to the signals detected by the second pressure sensor 27 and the position sensor 28.

[0062] Optionally, the electronic hydraulic brake system further comprises a first normally closed valve 29 connected to the fourth pipeline 24, the first normally closed valve 29 being electrically connected to the control unit, the control unit being configured to control the first normally closed valve 29 to be powered or de-powered, the first normally closed valve 29 being powered to open the fourth pipeline 24, and the first normally closed valve 29 being de-powered to block the fourth pipeline 24. When the electronic hydraulic brake system is braking in the first backup working state or the second backup working state, the control unit can control the first normally closed valve 29 to be de-powered to block the fourth pipeline 24, so as to avoid that the brake fluid enters the pedal simulator 17 and is consumed.

[0063] It is worth mentioning that even if the first normally open valve 20, the second normally open valve 26 and the first normally closed valve 29 all fail to work, the electronic hydraulic brake system of the present application can still guarantee the braking effect in the backup working state, that is, the first normally open valve 20 and the second normally open valve 26 fail to work, at this time, the third pipeline 23 and the fifth pipeline 25 are both in the open state, and the first normally closed valve 29 fails to work to block the fourth pipeline 24.

[0064] Optionally, the electronic hydraulic brake system further comprises a sixth pipeline 30 and a one-way valve 31, the inlet end and the outlet end of the sixth pipeline 30 being connected to the fourth pipeline 24, the first normally closed valve 29 being located between the inlet end and the outlet end, and the one-way valve 31 being connected to the sixth pipeline 30. When the driver steps on the pedal 16 to drive the simulation master cylinder 14, the brake fluid cannot pass through the one-way valve 31; when the driver releases the pedal 16, the brake fluid in the pedal simulator 17 can flow back to the simulation master cylinder 14 through the one-way valve 31; the one-way valve 31 helps the brake fluid to quickly retreat when the driver releases the pedal 16.

[0065] Optionally, the electronic hydraulic brake system further comprises an auxiliary liquid inlet pipe 32 and a second normally closed valve 33, the auxiliary liquid inlet pipe 32 being connected between the oil can 11 and the auxiliary master cylinder 13, and the second normally closed valve 33 being connected to the auxiliary liquid inlet pipe 32, the second normally closed valve 33 being electrically connected to the control unit, the control unit being configured to control the second normally closed valve 33 to be powered or de-powered, the second normally closed valve 33 being powered to open the auxiliary liquid inlet pipe 32, and the second normally closed valve 33 being de-powered to block the auxiliary liquid inlet pipe 32, so that the oil can 11 supplies the brake fluid to the auxiliary master cylinder 13 through the auxiliary liquid inlet pipe 32. In the embodiment, the second normally closed valve 33 is configured to control the brake fluid supplement of the auxiliary master cylinder 13 and a channel for system vacuum filling.

[0066] Optionally, the electronic hydraulic brake system further comprises a first liquid inlet pipe 34, a second liquid inlet pipe 35 and a third liquid inlet pipe 36, the first liquid inlet pipe 34 and the second liquid inlet pipe 35 are connected to the oil can 11 and the hydraulic master cylinder 12 at intervals, the oil can 11 supplies liquid to the hydraulic master cylinder 12 through the first liquid inlet pipe 34 and the second liquid inlet pipe 35, one end of the third liquid inlet pipe 36 is connected to the auxiliary liquid inlet pipe 32 between the oil can 11 and the second normally closed valve 33, the other end of the third liquid inlet pipe 36 is connected to the simulation master cylinder 14, the oil can 11 supplies liquid to the simulation master cylinder 14 through the third liquid inlet pipe 36.

[0067] Optionally, as shown in Figure 1 the electronic hydraulic brake system further comprises a plurality of wheel cylinders or ABS / ESC 37, the liquid outlet ends of the first pipe 21 and the second pipe 22 are connected to the plurality of wheel cylinders or ABS / ESC 37. When the first pipe 21 and the second pipe 22 are connected to the ESC (electronic stability control system), the composition of the system can ensure the active pressurization capability of the ESC.

[0068] Optionally, the control unit comprises a self-checking circuit (not shown in the figure), which can determine the sealing of the system loop according to the signals collected by the first pressure sensor 18 and the second pressure sensor 27.

[0069] When the control unit controls the driving mechanism 15 to start and controls the first normally open valve 20 to be powered and controls the second normally open valve 26 to be unpowered, the self-checking circuit determines the sealing of the loop composed of the hydraulic master cylinder 12, the auxiliary master cylinder 13, the wheel cylinder and the first normally open valve 20 according to the signal collected by the second pressure sensor 27, that is, when the pressure value detected by the second pressure sensor 27 is within the set pressure interval, the loop composed of the hydraulic master cylinder 12, the auxiliary master cylinder 13, the wheel cylinder and the first normally open valve 20 is not leaking, otherwise the loop has leaked.

[0070] When the control unit controls the driving mechanism 15 to start and controls the first normally open valve 20 to be unpowered and controls the second normally open valve 26 to be powered, the self-checking circuit determines the sealing of the loop composed of the hydraulic master cylinder 12, the wheel cylinder and the second normally open valve 26 according to the signal collected by the second pressure sensor 27, that is, when the pressure value detected by the second pressure sensor 27 is within the set pressure interval, the loop composed of the hydraulic master cylinder 12, the wheel cylinder and the second normally open valve 26 is not leaking, otherwise the loop has leaked.

[0071] When the control unit controls the driving mechanism 15 to start and controls the first normally open valve 20, the second normally open valve 26, the first normally closed valve 29 and the second normally closed valve 33 to be all de-energized, the self-checking circuit determines the sealing of all circuits except the pedal simulator 17 according to the signals collected by the first pressure sensor 18 and the second pressure sensor 27, i.e. when the pressure value detected by the second pressure sensor 27 is within the set pressure interval, all circuits except the pedal simulator 17 are not leaked, otherwise the circuits are leaked.

[0072] When the control unit controls the driving mechanism 15 to start and controls the first normally closed valve 29 to be energized and controls the first normally open valve 20, the second normally open valve 26 and the second normally closed valve 33 to be all de-energized, the self-checking circuit determines the sealing of all circuits according to the signals collected by the first pressure sensor 18 and the second pressure sensor 27, i.e. when the pressure values detected by the first pressure sensor 18 and the second pressure sensor 27 are within the set pressure interval, all circuits are not leaked, otherwise the circuits are leaked.

[0073] Optionally, the hydraulic master cylinder 12 comprises a first master cylinder 121 and a first piston assembly 122, the first piston assembly 122 is installed in the first master cylinder 121, the auxiliary master cylinder 13 comprises a second master cylinder 131 and a second piston assembly 132, the second master cylinder 131 is connected with the first master cylinder 121, the second piston assembly 132 is installed in the first master cylinder 121 and the second master cylinder 131, one end of the second piston assembly 132 is connected with the first piston assembly 122, the other end of the second piston assembly 132 passes through the second master cylinder 131 and is connected with the driving mechanism 15. In the embodiment, the first piston assembly 122 comprises a first piston 1221 and a first spring 1222, the first piston 1221 is slidably installed in the first master cylinder 121, one end of the first spring 1222 is connected with the inner wall of the first master cylinder 121, the other end of the first spring 1222 is connected with the first piston 1221; the second piston assembly 132 comprises a second piston 1321, a second spring 1322 and a first driving shaft 1323, one end of the second piston 1321 is slidably installed in the first master cylinder 121, the other end of the second piston 1321 is slidably installed in the second master cylinder 131, one end of the second spring 1322 is connected with the first piston 1221, the other end of the second spring 1322 is connected with the second piston 1321, one end of the first driving shaft 1323 is movably connected with the side of the second piston 1321 away from the second spring 1322, the other end of the first driving shaft 1323 passes through the second master cylinder 131 and is connected with the driving mechanism 15.

[0074] Optionally, the driving mechanism 15 comprises a motor 151, an output shaft 152 connected with the motor 151, and a linkage assembly 153 connected between the first driving shaft 1323 and the output shaft 152. In other embodiments, the driving mechanism 15 comprises an oil cylinder or a gas cylinder.

[0075] Optionally, the simulation master cylinder 14 comprises a third master cylinder 141 and a third piston assembly 142, one end of the third piston assembly 142 is installed in the third master cylinder 141, and the other end of the third piston assembly 142 is connected with the pedal 16. In this embodiment, the third piston assembly 142 comprises a third piston 1421, a third spring 1422, and a second driving shaft 1423, the third piston 1421 is slidably installed in the third master cylinder 141, one end of the third spring 1422 is connected with the inner wall of the third master cylinder 141, the other end of the third spring 1422 is connected with the third piston 1421, one end of the second driving shaft 1423 is movably connected with the side of the third piston 1421 away from the third spring 1422, and the other end of the second driving shaft 1423 passes through the third master cylinder 141 and is connected with the pedal 16.

[0076] Optionally, the electronic hydraulic braking system further comprises a brake light switch 38, both the brake light switch 38 and the stroke sensor 19 are connected with the second driving shaft 1423. When the driver steps on the pedal 16 to drive the second driving shaft 1423 and the third piston 1421 to move, the brake light switch 38 is turned on to provide a braking start signal for other systems, and at the same time, the stroke sensor 19 detects the moving position of the second driving shaft 1423 in real time.

[0077] Optionally, the pedal simulator 17 is provided with a movable cavity, a sliding plate and a spring installed in the movable cavity, to simulate the foot feeling.

[0078] Figure 2 is a schematic diagram of the electronic hydraulic braking system of the present application in normal braking, Figure 3 is a schematic diagram of the first backup braking working state of the electronic hydraulic braking system of the present application, as Figure 2 and Figure 3 The present application further provides an electronic hydraulic braking method, which is used in the above-mentioned electronic hydraulic braking system, and comprises the following steps:

[0079] When the driving mechanism 15 is not failed:

[0080] controlling the first normally open valve 20 to be electrified to block the third pipeline 23;

[0081] Pedal 16 drives the simulation master cylinder 14, the control unit according to the signal detected by the first pressure sensor 18 and stroke sensor 19 to start the drive mechanism 15, drive mechanism 15 drive auxiliary master cylinder 13 and hydraulic master cylinder 12, the first pipeline 21 and the second pipeline 22 output hydraulic pressure;

[0082] When the drive mechanism 15 fails:

[0083] The control of the first normally open valve 20 loss of power to open the third pipeline 23;

[0084] Pedal 16 makes the simulation master cylinder 14 to apply brake force, brake fluid through the third pipeline 23 drive auxiliary master cylinder 13 and hydraulic master cylinder 12, the first pipeline 21 and the second pipeline 22 output hydraulic pressure.

[0085] Optionally, the first normally closed valve 29 is connected to the fourth pipeline 24;

[0086] When the drive mechanism 15 fails and braking, control the first normally closed valve 29 loss of power to block the fourth pipeline 24.

[0087] Optionally, Figure 4 is the second backup braking working state of the electronic hydraulic brake system of the present application, as shown in Figure 4 The fifth pipeline 25 is connected between the second pipeline 22 and the third pipeline 23, and the second normally open valve 26 is connected to the fifth pipeline 25;

[0088] When the drive mechanism 15 fails and braking:

[0089] Control the first normally open valve 20 loss of power to open the third pipeline 23, control the second normally open valve 26 loss of power to open the fifth pipeline 25, and control the first normally closed valve 29 loss of power to block the fourth pipeline 24;

[0090] Pedal 16 makes the simulation master cylinder 14 to apply brake force, brake fluid through the third pipeline 23 and five pipeline into the auxiliary master cylinder 13 and hydraulic master cylinder 12, the first pipeline 21 and the second pipeline 22 output hydraulic pressure.

[0091] Optionally, Figure 5 is the first self-checking working state of the electronic hydraulic brake system of the present application, as shown in Figure 5 The second pressure sensor 27 is connected to the second pipeline 22, the auxiliary liquid inlet pipe 32 is connected between the oil can 11 and the auxiliary master cylinder 13, and the second normally closed valve 33 is connected to the auxiliary liquid inlet pipe 32; The method for detecting the sealing performance of the electronic hydraulic brake system comprises:

[0092] Control the drive mechanism 15 to start and control the first normally open valve 20 to be powered on and control the second normally open valve to lose power;

[0093] The sealing of the circuit composed of the hydraulic master cylinder 12, the auxiliary master cylinder 13, the wheel cylinder and the first normally open valve 20 is determined according to the signal collected by the second pressure sensor 27.

[0094] Optionally, Figure 6 is a schematic diagram of the second self-check working state of the electronic hydraulic brake system of the present application, as Figure 6 shown, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0095] controlling the driving mechanism 15 to start and controlling the first normally open valve 20 to lose power and the second normally open valve 26 to gain power;

[0096] The sealing of the circuit composed of the hydraulic master cylinder 12, the wheel cylinder and the second normally open valve 26 is determined according to the signal collected by the second pressure sensor 27.

[0097] Optionally, Figure 7 is a schematic diagram of the third self-check working state of the electronic hydraulic brake system of the present application, as Figure 7 shown, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0098] controlling the driving mechanism 15 to start and controlling the first normally open valve 20, the second normally open valve 26, the first normally closed valve 29 and the second normally closed valve 33 to lose power;

[0099] The sealing of all circuits except the pedal simulator 17 is determined according to the signals collected by the first pressure sensor 18 and the second pressure sensor 27.

[0100] Optionally, Figure 8 is a schematic diagram of the fourth self-check working state of the electronic hydraulic brake system of the present application, as Figure 8 shown, the method for detecting the sealing of the electronic hydraulic brake system further comprises:

[0101] controlling the driving mechanism 15 to start and controlling the first normally closed valve 29 to gain power and the first normally open valve 20, the second normally open valve 26 and the second normally closed valve 33 to lose power;

[0102] The sealing of all circuits of the system is determined according to the signals collected by the first pressure sensor 18 and the second pressure sensor 27.

[0103] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details of the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application. In the above-described specific embodiments, various specific technical features are described, and in the case of no contradiction, any suitable combination can be made. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

Claims

1. An electro-hydraulic brake system, characterized in that, The electronic hydraulic brake system comprises an oil tank, a hydraulic master cylinder, an auxiliary master cylinder, a simulation master cylinder, a driving mechanism, a pedal, a pedal simulator, a first pressure sensor, a stroke sensor, a first normally open valve, a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a control unit. The oil tank is connected with the hydraulic master cylinder, the auxiliary master cylinder and the simulation master cylinder respectively, the auxiliary master cylinder is connected with the hydraulic master cylinder in linkage, the driving mechanism is connected with the auxiliary master cylinder, the pedal is connected with the simulation master cylinder, and the stroke sensor is used for detecting the moving stroke of the pedal. The first pipeline and the second pipeline are connected with the hydraulic master cylinder, and the first pipeline and the second pipeline are used for outputting hydraulic pressure. The third pipeline is connected between the auxiliary master cylinder and the simulation master cylinder, the first normally open valve and the first pressure sensor are connected on the third pipeline. The fourth pipeline is connected between the simulation master cylinder and the pedal simulator. The control unit is electrically connected with the driving mechanism, the stroke sensor, the first pressure sensor and the first normally open valve respectively, and the control unit is used for controlling the driving mechanism to start or stop and controlling the first normally open valve to be electrified or de-energized. The electronic hydraulic brake system further comprises a fifth pipeline and a second normally open valve, the fifth pipeline is connected between the second pipeline and the third pipeline, the second normally open valve is connected on the fifth pipeline, the second normally open valve is electrically connected with the control unit, and the control unit is used for controlling the second normally open valve to be electrified or de-energized. When the electronic hydraulic brake system brakes in the second backup working state, the control unit controls the first normally open valve to be de-energized to open the third pipeline and controls the second normally open valve to be de-energized to open the fifth pipeline, at this time, the pedal is stepped to drive the simulation master cylinder, the simulation master cylinder outputs hydraulic pressure, the hydraulic pressure reaches the auxiliary master cylinder and the hydraulic master cylinder through the third pipeline, the fifth pipeline and the second pipeline respectively, and the auxiliary master cylinder and the hydraulic master cylinder are driven to realize the hydraulic pressure output of the first pipeline and the second pipeline.

2. The electro-hydraulic brake system of claim 1, wherein, The electronic hydraulic brake system further comprises a second pressure sensor and a position sensor, the second pressure sensor is connected on the second pipeline, the position sensor is used for detecting the driving position of the driving mechanism, and the second pressure sensor and the position sensor are electrically connected with the control unit.

3. The electro-hydraulic brake system of claim 2, wherein, The electronic hydraulic brake system further comprises a first normally closed valve, the first normally closed valve is connected on the fourth pipeline, the first normally closed valve is electrically connected with the control unit, and the control unit is used for controlling the first normally closed valve to be electrified or de-energized.

4. The electro-hydraulic brake system of claim 3, wherein, The electronic hydraulic brake system further comprises a sixth pipeline and a one-way valve, the inlet end and the outlet end of the sixth pipeline are connected with the fourth pipeline, the first normally closed valve is located between the inlet end and the outlet end, and the one-way valve is connected on the sixth pipeline.

5. The electro-hydraulic brake system of claim 4, wherein, The electronic hydraulic brake system further comprises an auxiliary inlet pipe connected between the oil pot and the auxiliary master cylinder, and a second normally closed valve connected on the auxiliary inlet pipe, wherein the second normally closed valve is electrically connected with the control unit, and the control unit is configured to control the second normally closed valve to be powered or unpowered.

6. The electro-hydraulic brake system of claim 5, wherein, The electronic hydraulic brake system further comprises a plurality of wheel cylinders or ABS / ESCs, and outlet ends of the first pipe and the second pipe are connected with the plurality of wheel cylinders or ABS / ESCs.

7. The electro-hydraulic brake system of claim 5, wherein, The control unit comprises a self-checking circuit configured to determine the sealing of the system loop according to signals collected by the first pressure sensor and the second pressure sensor.

8. The electro-hydraulic brake system according to any one of claims 1 to 7, characterized in that The hydraulic master cylinder comprises a first master cylinder and a first piston assembly installed in the first master cylinder, and the auxiliary master cylinder comprises a second master cylinder connected with the first master cylinder and a second piston assembly installed in the first master cylinder and the second master cylinder, wherein one end of the second piston assembly is connected with the first piston assembly, and the other end of the second piston assembly penetrates through the second master cylinder and is connected with the driving mechanism.

9. An electro-hydraulic braking method, characterized in that, The electronic hydraulic brake method is used in the electronic hydraulic brake system of any one of claims 1 to 8, and the electronic hydraulic brake method comprises: when the driving mechanism is not failed: controlling the first normally open valve to be powered to block the third pipe; stepping on the pedal to drive the simulation master cylinder, and the control unit starts the driving mechanism according to signals detected by the first pressure sensor and the stroke sensor, and the driving mechanism drives the auxiliary master cylinder and the hydraulic master cylinder to output hydraulic pressure from the first pipe and the second pipe; when the driving mechanism is failed: controlling the first normally open valve to be unpowered to open the third pipe; stepping on the pedal to make the simulation master cylinder apply a braking force, and brake fluid drives the auxiliary master cylinder and the hydraulic master cylinder through the third pipe to output hydraulic pressure from the first pipe and the second pipe.

10. The electro-hydraulic brake method of claim 9, wherein, connecting a first normally closed valve on the fourth pipe; when the driving mechanism is failed and braking is performed, controlling the first normally closed valve to be unpowered to block the fourth pipe.

11. The electro-hydraulic brake method of claim 10, wherein, connecting a fifth pipe between the second pipe and the third pipe, and connecting a second normally open valve on the fifth pipe; when the driving mechanism is failed and braking is performed: controlling the first normally open valve to be unpowered to open the third pipe, controlling the second normally open valve to be unpowered to open the fifth pipe, and controlling the first normally closed valve to be unpowered to block the fourth pipe; stepping on the pedal to make the simulation master cylinder apply a braking force, and brake fluid enters the auxiliary master cylinder and the hydraulic master cylinder through the third pipe and the fifth pipe to output hydraulic pressure from the first pipe and the second pipe.

12. The electro-hydraulic brake method of claim 11, wherein, connecting a second pressure sensor on the second pipe, connecting an auxiliary inlet pipe between the oil pot and the auxiliary master cylinder, and connecting a second normally closed valve on the auxiliary inlet pipe; the method for detecting the sealing of the electronic hydraulic brake system comprises: controlling the driving mechanism to start and controlling the first normally open valve to be powered and the second normally open valve to be unpowered; determining the sealing of the loop composed of the hydraulic master cylinder, the auxiliary master cylinder and the first normally open valve according to the signal collected by the second pressure sensor.

13. The electro-hydraulic brake method of claim 12, wherein, The method for detecting the sealing of the electronic hydraulic brake system further comprises: controlling the driving mechanism to start and controlling the first normally open valve to be unpowered and the second normally open valve to be powered; determining the sealing of the loop composed of the hydraulic master cylinder and the second normally open valve according to the signal collected by the second pressure sensor.

14. The electro-hydraulic brake method of claim 13, wherein, The method for detecting the sealing of the electronic hydraulic brake system further comprises: controlling the driving mechanism to start and controlling the first normally open valve, the second normally open valve, the first normally closed valve and the second normally closed valve to be unpowered; determining the sealing of all the loops except the pedal simulator according to the signals collected by the first pressure sensor and the second pressure sensor.

15. The electro-hydraulic brake method of claim 14, wherein, The method for detecting the sealing of the electronic hydraulic brake system further comprises: controlling the driving mechanism to start and controlling the first normally closed valve to be powered and the first normally open valve, the second normally open valve and the second normally closed valve to be unpowered; determining the sealing of all the loops of the system according to the signals collected by the first pressure sensor and the second pressure sensor.

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