Brake assist system with failure handling function and method of operation thereof

Abstract

The application discloses a brake assisting system with a fault handling function and a working method thereof, and belongs to the field of vehicle braking control systems. The brake assisting system with the fault handling function comprises a push rod, a first assisting system, a second assisting system and a controller. The second assisting system comprises an electromagnetic valve, a guide core, a pushing frame and a second displacement sensor. The pushing frame comprises a first pushing part, a sliding guide part and a second pushing part. The first pushing part is abutted between the push rod and the output end of the first assisting system, and the second pushing part is connected with the output end of the electromagnetic valve. The guide core is slidably connected with the sliding guide part. According to the first assisting system signal and the second displacement sensor signal, the fault is judged, and the electromagnetic valve is driven by the controller to realize the second assisting system braking. When the motor-controlled assisting system is damaged, the brake of the vehicle cannot be applied in time due to insufficient driving force of the driver, and accidents are caused, and the safety of vehicle driving is improved.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle brake control systems, and more particularly, relates to a brake boosting system with a fault handling function and a working method thereof. Background Art

[0002] Traditional internal combustion engine vehicles' braking systems mostly use vacuum boosters to assist the driver in generating sufficient braking force, with the vacuum source coming from the engine or a mechanical vacuum pump. However, new energy vehicles (fuel cell vehicles and pure electric vehicles) lack an engine to provide a vacuum power source for braking assistance. Therefore, compared to traditional vacuum boosters, electric power-assisted braking systems do not require any vacuum source, making them ideal for electric vehicles.

[0003] When the existing electric power-assisted braking system is in normal working condition, Figure 1 and Figure 2 As shown, after the driver steps on the car pedal 200, the motor starts to work and directly converts the motor's rotation into the translational motion of the lead screw through the motor-screw transmission method, so that the lead screw inner rod 300 drives the push rod 100 to push it toward the brake master cylinder to achieve braking. At this time, the guide rod 500 outside the lead screw inner rod 300 provides guidance for it, and the outer rod 400 does not move significantly. During this process, under the drive of the motor, the force used to drive the push rod 100 comes mostly from the force of the motor, rather than the force of the driver's foot. Therefore, the driver does not need to apply too much force to stop the car.

[0004] However, the electric power-assist system inevitably malfunctions. When the motor or the motor output transmission mechanism malfunctions, the power assistance of the electric power-assist device fails. At this time, the driver can only rely on stepping on the car pedal 200 to make the outer rod 400 move horizontally, so as to drive the outer rod 400 to push the push rod 100 toward the brake master cylinder to achieve braking; at this time, the force driving the outer rod 400 to move is completely provided by the driver, and sudden braking during high-speed driving of the car requires overcoming great inertia, which will result in a great deal of force being required to drive the outer rod 400 to move. Many drivers do not have enough strength, which will result in not only a low response speed but also great difficulty in braking when the electric power-assist system malfunctions, thereby reducing the vehicle driving safety and easily causing vehicle driving accidents. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a brake power-assisting system with a fault handling function and a working method thereof, which can ensure that when the power-assisting system controlled by the motor is damaged, it can still provide power to push the push rod toward the master brake cylinder, thereby avoiding accidents caused by the driver's lack of strength when the power-assisting system controlled by the motor is damaged, resulting in the vehicle not being able to brake in time, thereby improving the safety of vehicle driving.

[0006] The present invention provides a brake booster system with a fault handling function, wherein the input end is connected to the pedal and the output end is connected to the brake master cylinder.

[0007] A push rod connected to the master brake cylinder at one end,

[0008] The first power assist system with the output end abutting against the other end of the push rod,

[0009] Second power assist system and controller;

[0010] The first power assist system is driven by a motor to drive the push rod to move after the pedal is subjected to force; the push rod is provided with an elastic member having elastic reset ability after compression movement;

[0011] The second power-assisting system includes a solenoid valve, a guide core, a push frame, and a second displacement sensor that is independent of whether the first power-assisting system is operating or not;

[0012] The pushing frame includes a first pushing portion, a sliding guide portion and a second pushing portion;

[0013] The first pushing portion is in contact with the push rod and the output end of the first power-assisting system, and the second pushing portion is connected to the output end of the solenoid valve, so that the pushing frame has the ability to push the push rod toward the brake master cylinder under the control of the solenoid valve;

[0014] The guide core is fixedly arranged on the outside of the push rod and is parallel to the push rod. The guide core is slidably connected to the sliding guide portion of the push frame to provide a guide for the movement of the push frame in the length direction of the push rod.

[0015] According to the first power-assisting system signal and the second displacement sensor signal, a fault is determined and the controller drives the electromagnetic valve to implement the second power-assisting system braking.

[0016] As a further improvement of the present invention, the first power-assisting system further includes a screw rod, an outer rod sleeved on the outer periphery of the screw rod, and a transmission mechanism sleeved on the outer periphery of the outer rod and slidably connected thereto;

[0017] One end of the screw rod is in contact with the push rod, and the other end is connected to the pedal; the screw rod is fixedly connected to a first sensor to detect the force or displacement of the screw rod;

[0018] One end of the outer rod is connected to the pedal so as to be forced to move along its length direction;

[0019] The controller is electrically connected to the motor, and the controller is electrically connected to the first sensor, the second displacement sensor and the solenoid valve respectively;

[0020] The transmission mechanism is connected to the output end of the motor so as to be able to control the screw rod to push the push rod toward the brake master cylinder under the drive of the motor;

[0021] The second displacement sensor is installed on the outer sleeve rod to detect displacement of the outer sleeve rod.

[0022] The fault condition is that the second displacement sensor operates to a certain distance threshold, neither the first sensor nor the motor operates; or the first sensor and / or the motor no longer operates after operating, and the second displacement sensor operates over the distance threshold and continues to operate.

[0023] As a further improvement of the application, the electromagnetic valve and the motor are arranged along the length direction of the push rod; the output direction of the output end of the electromagnetic valve is the same as the direction of the force pushing the push rod towards the brake master cylinder; the guide core extends away from the pedal, so that the length range of the guide core at least includes the electromagnetic valve and part of the output range of the output end of the electromagnetic valve.

[0024] As a further improvement of the application, the guide core is a guide rod originally arranged in the first power-assisted system and extended away from the pedal; the electromagnetic valve is arranged in the space behind the motor away from the pedal, so that the arrangement positions of the electromagnetic valve and the push frame are the only positions in the first power-assisted system.

[0025] As a further improvement of the application, the push frame is a Z-shaped frame with two ends respectively bent in opposite directions; the first push part of the push frame abutting against the push rod is arranged to be inclined to the push rod by a°, the angle between the first push part and the vertical line of the axis of the guide core is a°, and the degree of a° is between 2° and 5°; the second push part of the push frame is arranged to be inclined to the electromagnetic valve by b°; the angle between the second push part and the vertical line of the axis of the guide core is b°, and the degree of b° is between 2° and 5°.

[0026] As a further improvement of the application, the guide core is a rod-shaped guide core with the length direction consistent with the length direction of the push rod; the sliding guide part is a sliding sleeve, which is sleeved on the outer periphery of the guide core along the length direction of the guide core; the inner diameter of the sliding sleeve is larger than the outer diameter of the guide core, so that there is always a gap between the inner wall of the sliding sleeve and the guide core; a plurality of rolling balls are arranged in the gap, and the rolling balls abut against the inner wall of the sliding sleeve and the outer wall of the guide core at the same time to provide a guiding effect for the sliding of the sliding sleeve along the length direction of the guide core.

[0027] As a further improvement of the application, the number of guide cores is two, and the two guide cores are symmetrically arranged along the symmetry axis of the push rod; at least one of the guide cores is close to the side of the electromagnetic valve, and the sliding sleeve in the push frame is sleeved with the guide core close to the side of the electromagnetic valve.

[0028] As a further improvement of the present application, a partition is fixedly arranged between the electromagnetic valve and the guide core, the partition is fixedly connected with the electromagnetic valve, and a gap exists between the partition and the guide core, the gap ranges from 1.8 mm to 2.2 mm, so that the gap exists between the electromagnetic valve and the guide core; the gap is at least greater than the displacement distance generated by vibration when the electromagnetic valve works, so that the electromagnetic valve has the ability to prevent vibration from approaching the guide core when the electromagnetic valve works, and to prevent interference with the sliding of the sliding guide part.

[0029] As a further improvement of the present application, the controller is further electrically connected with an emergency braking detection system; the emergency braking detection system comprises an information collection part and an emergency braking judgment part; the information collection part is connected with a global positioning system to receive at least driving information of the vehicle and other vehicles; the emergency braking judgment part is electrically connected with the information collection part, so that the emergency braking judgment part judges whether the vehicle satisfies the condition of sending an emergency braking signal at least relative to the other vehicles according to information in the information collection part, to guide the controller to control the work of the electromagnetic valve.

[0030] A working method of a brake booster system, which is a working method of a brake booster system with a fault handling function, comprising the following steps: autonomously detecting whether the second booster system works normally before the vehicle starts and stops;

[0031] The emergency braking detection system monitors whether an emergency braking signal is sent in real time to guide the work of the electromagnetic valve;

[0032] When the driver actively steps on the pedal, if the first booster system works normally, the first booster system provides assistance to push the push rod to the brake master cylinder, and if the first booster system fails, the second booster system provides assistance to push the push rod to the brake master cylinder, and sends a fault signal to the outside.

[0033] As a further improvement of the present application, after the driver actively steps on the pedal, a working method of a brake booster system comprises the following steps:

[0034] S04: the first sensor generates a pressure / displacement signal, the second displacement sensor detects that the sheath rod appears displacement, and simultaneously transmits a signal to the controller; when both the first sensor and the second displacement sensor generate signals, S05 is performed; when the second displacement sensor has a signal but the first sensor has no signal, a first sensor damage alarm is sent to the outside, and S08 is performed;

[0035] S05: the controller works; when the controller detects that the motor works, S06 is performed, and when the controller detects that the motor does not work, S07 is performed;

[0036] S06: the first booster system works: the motor controls the screw rod to move along its length direction to approach the brake master cylinder, so as to synchronously push the push rod to the brake master cylinder, to control the vehicle to realize braking;

[0037] S07: The controller detects that the motor is not working, sends a motor damage alarm to the outside world, and proceeds to S08;

[0038] S08: The second displacement sensor detects that the outer rod has been displaced, and the displacement distance exceeds the spacing threshold, and then proceeds to S09;

[0039] S09: The second power assist system operates: The controller controls the solenoid valve to operate, and the output end of the solenoid valve acts on the second pushing part to push the pushing frame to move away from the solenoid valve, thereby pushing the push rod toward the brake master cylinder to control the vehicle to brake;

[0040] S10: When the displacement distance of the outer rod is completely returned to zero, the second displacement sensor does not generate a displacement signal, and the controller controls the solenoid valve to stop working so that the vehicle can move again; at this time, the push rod and the push frame move toward the direction close to the output end of the first power-assisting system under the drive of the elastic reset force until the first push part abuts against the output end of the first power-assisting system.

[0041] As a further improvement of the present invention, the step of autonomously detecting whether the second power-assisting system is operating normally before the vehicle starts and stops includes: the controller controls the solenoid valve to operate so that the solenoid valve drives the push frame to move in the direction away from the solenoid valve, so that the first push part drives the push rod toward the master brake cylinder; if the master brake cylinder is detected to be operating, the second power-assisting system is intact; if the master brake cylinder is detected to be not operating, the second power-assisting system fails and an alarm is issued.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) When the driver actively steps on the pedal, the first power assist system will provide assistance when the first power assist system works normally, and the second power assist system will provide assistance when the first power assist system fails. This ensures that when the power assist system controlled by the motor is damaged, it can still provide assistance to push the push rod toward the master brake cylinder, avoiding accidents caused by the driver's lack of strength due to failure or damage of the first power assist system, which leads to the vehicle not being able to brake in time. This improves the safety of vehicle driving, solves the problem of excessive braking during the braking process, and improves the driver's driving experience. Moreover, when the first power assist system is working, the second power assist system does not work and does not consume energy, which is close to the energy consumption difference of the traditional brake assist system.

[0044] (2) Since the second power-assist system is controlled by a solenoid valve, the solenoid valve has a fast response speed. When the current provided is large enough, the thrust of the solenoid valve can instantly push the push rod to the master brake cylinder. On the one hand, it makes up for the reaction delay that may be caused by the failure of the first power-assist system. On the other hand, it is conducive to the rapid braking of the vehicle, ensuring that the brakes are applied at the first time to avoid accidents.

[0045] (3) The solenoid valve and the motor are arranged along the length of the push rod, which conforms to the principle of compactness. The length range of the guide core includes at least the solenoid valve and part of the output range of the solenoid valve output end. On the one hand, it provides movement space for the push frame. On the other hand, this design makes this solution only change the length direction compared with the existing technology, which is conducive to the optimization and upgrading of vehicles. In addition, the internal structure changes little, and it can be achieved by changing the size of some parts without the need for a large number of new molds to be designed and manufactured, thereby reducing production costs.

[0046] (4) Due to long-term use, the force applied by the output end of the solenoid valve to the push frame will push its end toward the direction away from the solenoid valve and deform. Similarly, the other end of the push frame will also tilt and deform toward the direction away from the push rod, thereby affecting the use effect of the push frame. Therefore, the inclined setting of the two ends of the push frame slows down the occurrence of this deformation to a certain extent, while avoiding the deformation affecting the work efficiency and extending the service life;

[0047] (5) A ball bearing is provided between the sleeve and the guide core to reduce friction and provide a guide for the sleeve to slide along the length of the guide core;

[0048] (6) In the prior art, guide rods with the same length as the push rod are provided on both sides of the push rod. In this solution, the original guide rods are used as guide cores to guide the second power-assisting system, so that the second power-assisting system can provide power in the event of a failure of the first power-assisting system. This solution has a small structural change and a large effect, which is of positive significance, low optimization cost and great market benefits.

[0049] (7) The design of two guide cores and two sliding sleeves not only makes full use of the original structure, but also makes the force on the push frame more uniform, avoids deformation and deflection that may occur after long-term use, makes the push frame slide more smoothly, extends its service life, and improves its efficiency;

[0050] (8) After the second displacement sensor reaches the distance threshold and starts the second power assist system, the solenoid valve will stop working only when the displacement distance of the outer rod is completely zero and the second displacement sensor does not generate a displacement signal. This makes it unnecessary for the driver to keep braking during the braking process. Taking into account the fatigue caused by long-term braking, the driver's braking and driving experience are optimized;

[0051] (9) With the design of the emergency brake detection system, the vehicle's driving process is always monitored by the emergency brake detection system. Once a situation requires emergency braking, even if the driver cannot react in time, the emergency brake detection system will guide the controller to work to achieve emergency braking, adding double insurance to the vehicle's driving safety and ensuring the driver's personal safety during driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural diagram of an existing brake assist system in the background art;

[0053] Figure 2 It is a structural diagram of an existing brake assist system in the background art;

[0054] Figure 3 It is a structural schematic diagram of the brake assist system of the present invention;

[0055] Figure 4 Schematic diagram of the cross-sectional structure of the brake assist system of the present invention;

[0056] Figure 5 Schematic diagram of the cross-sectional structure of the brake assist system of the present invention in a working state;

[0057] Figure 6 Schematic diagram of the cross-sectional structure of the brake assist system of the present invention in a working state;

[0058] Figure 7 It is a schematic diagram of the structure between the pushing frame and the guide core of the present invention;

[0059] Figure 8 It is a workflow diagram of the present invention;

[0060] Figure 9 It is a structural diagram of a specific embodiment 2 of the present invention.

[0061] Description of the numbers in the figure:

[0062] 1 push rod, 11 springs,

[0063] 2 pedals,

[0064] 31 screw rod, 32 sliding outer rod, 33 gear set, 34 first sensor, 35 drive motor,

[0065] 41 push frame, 411 upper push plate, 412 lower push plate, 413 sliding sleeve, 42 guide core, 43 solenoid valve, 44 second displacement sensor,

[0066] 5. Brake master cylinder. DETAILED DESCRIPTION

[0067] Specific embodiment 1: Please refer to Figure 3-4 A brake booster system with a fault handling function, one end of which is connected to the pedal 2 and the other end is connected to the brake master cylinder 5, so as to provide power when the pedal 2 is stepped on, so that the brake master cylinder 5 is more easily driven;

[0068] A brake boosting system with a fault handling function comprises a housing, a push rod 1 connected to a brake master cylinder 5 at one end, a first boosting system and a second boosting system.

[0069] The interior of the housing 1 is a closed chamber, and the push rod 1, the first power-assisting system and the second power-assisting system are all arranged in the chamber.

[0070] The first power-assisting system includes a screw rod 31 , a sliding outer rod 32 , a gear set 33 , a first sensor 34 and a drive motor 35 .

[0071] One end of the screw rod 31 is fixedly connected to the pedal 2 to bear force, and the other end of the screw rod 31 abuts against the end of the push rod 1 away from the master brake cylinder 5. The length direction of the screw rod 31 is the same as the length direction of the push rod 1, so that the displacement of the screw rod 31 in the length direction drives the synchronous displacement of the push rod 1, so that the screw rod 31 has the ability to drive the push rod 1 to move in the direction of the master brake cylinder 5 to drive the master brake cylinder 5 to work.

[0072] The outer sliding rod 32 is sleeved on the outer circumference of the screw rod 31 , and the length direction of the outer sliding rod 32 is the same as that of the screw rod 31 .

[0073] The gear set 33 is arranged on the outer periphery of the sliding outer rod 32. The rotation of the gear set 33 has the ability to control the displacement of the screw rod 31 in the length direction. The gear set 33 is slidably connected to the sliding outer rod 32.

[0074] The gear set 33 is connected to the output end of the drive motor 35 so that the output end of the drive motor 35 controls the rotation of the gear set 33 ; the drive motor 35 drives the gear set 33 to rotate, thereby indirectly controlling the displacement of the screw rod 31 in the length direction.

[0075] A first sensor 34 is connected to the end of the screw rod 31 near the push rod 1. The first sensor 34 is a displacement sensor or a pressure sensor. The first sensor 34 has the function of sensing the displacement of the screw rod 31 after being subjected to force or sensing the pressure applied to the screw rod 31. The pressure comes from the pedal force applied by the user on the pedal 2.

[0076] The first sensor 34 is electrically connected to the controller so that the signal generated by the pressure sensed by the first sensor 34 is transmitted to the controller; the controller has the ability to receive the signal from the first sensor 34; the controller is electrically connected to the drive motor 35 so that the controller has the ability to control the operation of the drive motor 35, and the controller also has the ability to receive the signal when the drive motor 35 is working to monitor whether it is working.

[0077] It should be noted that the structure and principle of the first power-assisting system are the same as those of the existing brake power-assisting system. The setting and working principle of the first power-assisting system are both existing technologies, so they are not described in detail in this application.

[0078] A spring 11 is sleeved on the outer circumference of the push rod 1 along its length direction, one end of the spring 11 is fixedly connected to the brake master cylinder 5, and the other end is fixedly connected to the end of the push rod 1 away from the brake master cylinder 5; so that as the push rod 1 moves toward the brake master cylinder 5, the spring 11 tends to be compressed and generates an elastic restoring force.

[0079] The second power-assisting system includes a pushing frame 41 , a guide core 42 , a solenoid valve 43 and a second displacement sensor 44 .

[0080] The solenoid valve 43 is arranged on the side of the drive motor 35 away from the pedal 2, so that the solenoid valve 43 and the drive motor 35 are arranged along the length direction of the push rod 1; the output end of the solenoid valve 43 is arranged on the side away from the drive motor 35; the solenoid valve 43 is electrically connected to the controller so that the controller has the ability to control the operation of the solenoid valve 43.

[0081] It should be noted that the controller electrically connected to the solenoid valve 43 and the controller electrically connected to the drive motor 35 may be the same controller or different controllers.

[0082] The number of guide cores 42 is at least one, and the guide core 42 is fixedly arranged on one side of the push rod 1. The length direction of the guide core 42 is the same as the length direction of the push rod 1. The guide core 42 extends in a direction away from the pedal 2, so that the length range of the guide core 42 at least includes the solenoid valve 43 and at least part of the output range of the output end of the solenoid valve 43.

[0083] It should be noted that the guide core 42 can be set by extending the guide rod in the original brake assist system in the direction away from the pedal 2, that is, the guide core 42 can be set by extending the guide rod in the first assist system in the direction away from the pedal (2); the solenoid valve 43 is set in the empty space at the rear of the drive motor 35 away from the pedal 2, so that the setting position of the solenoid valve 43 is the only position in the first assist system.

[0084] The second displacement sensor 44 includes a displacement sensor, which is fixedly connected to the sliding outer rod 32 so that the second displacement sensor 44 has the ability to detect the displacement of the sliding outer rod 32 and generate an electrical signal; the second displacement sensor 44 is electrically connected to the controller so that the signal generated in the second displacement sensor 44 is transmitted to the controller.

[0085] The push frame 41 is a Z-shaped frame and is made of stainless steel to provide resilience. The push frame 41 includes a sliding sleeve 413, an upper push plate 411 and a lower push plate 412 bent in opposite directions from both ends of the sliding sleeve 413, thereby forming a Z-shaped frame.

[0086] The sliding sleeve 413 is sleeved on the outer circumference of the guide core 42 along its length. The inner diameter of the sliding sleeve 413 is larger than the outer diameter of the guide core 42, so that a gap always exists between the inner wall of the sliding sleeve 413 and the outer wall of the guide core 42. Ball bearings are disposed in the gap, one on each of the upper and lower sides of the guide core 42. The outer surfaces of the balls abut against both the inner wall of the sliding sleeve 413 and the outer wall of the guide core 42, thereby reducing friction and providing guidance for the sliding of the sliding sleeve 413 along the length of the guide core 42.

[0087] The upper push plate 411 is made of a rigid material, and the upper push plate 411 is solid. The upper push plate 411 is arranged at the end of the sliding sleeve 413 away from the brake master cylinder 5, and the upper push plate 411 is arranged on the side of the sliding sleeve 413 close to the push rod 1. The upper push plate 411 is arranged between the screw rod 31 and the push rod 1; when the spring 11 is in a free state, the upper push plate 411 is in contact with the screw rod 31 and the push rod 1 at the same time to achieve indirect contact between the screw rod 31 and the push rod 1, so that the displacement of the screw rod 31 in the length direction synchronously drives the displacement of the push rod 1 in the length direction; the upper push plate 411 is inclined a° toward the push rod 1, and the angle between the upper push plate 411 and the vertical line of the axis of the guide core 42 toward the push rod 1 is a°, and the range of a° is 2°~5°;

[0088] The lower push plate 412 is made of rigid material, the lower push plate 412 is solid, and the lower push plate 412 is arranged on the end of the sleeve 413 near the brake master cylinder 5. The lower push plate 412 is arranged on one side of the sleeve 413 near the solenoid valve 43, so that the lower push plate 412 is connected to the output end of the solenoid valve 43, so that the solenoid valve 43 has the ability to control the displacement of the lower push plate 412, and since the sleeve 413 fixedly connected to the lower push plate 412 slides along the length direction of the guide core 42, the movement direction of the lower push plate 412 is also along the length direction of the guide core 42; the movement range of the lower push plate 412 in the length direction is between the output end of the solenoid valve 43 and the end of the guide core 42 away from the pedal 2, and the movement range of the lower push plate 412 in the length direction at least includes the displacement range of the push rod 1 when working; the lower push plate 412 is inclined b° toward the solenoid valve 43, and the angle between the lower push plate 412 and the vertical line of the axis of the guide core 42 is b°, and the range of b° is 2°~5°.

[0089] The electromagnetic valve 43 and the guide core 42 are provided with a partition plate, the partition plate is fixedly connected with the electromagnetic valve 43, the partition plate is fixedly connected with the shell, and a gap exists between the partition plate and the guide core 42, the range of the gap is 1.8-2.2 mm, so that the gap exists between the electromagnetic valve 43 and the guide core 42; the gap is at least greater than the displacement distance generated by vibration when the electromagnetic valve 43 works, so as to have the ability to prevent the electromagnetic valve 43 from vibrating to approach the guide core 42 when working, and to prevent the sliding of the sliding sleeve 413.

[0090] The controller is also electrically connected with an emergency braking detection system; the emergency braking detection system includes an information collection part and an emergency braking judgment part;

[0091] The information collection part is connected with a global positioning system to receive driving information of the vehicle and other vehicles, and the driving information includes vehicle positioning and vehicle driving speed;

[0092] The emergency braking judgment part is electrically connected with the information collection part to receive the vehicle driving information from the information collection part, and the emergency braking judgment part is used to judge whether the vehicle satisfies the condition of sending an emergency braking signal relative to the other vehicles according to the driving information; the condition of sending the emergency braking signal is that the speed of the vehicle is greater than a safety speed, the distance between the other vehicle and the vehicle is less than a safety distance, and the other vehicle and the vehicle are driving in the same lane; at this time, the emergency braking judgment part judges that emergency braking is needed, and transmits the emergency braking signal to the controller to control the electromagnetic valve 43 to work;

[0093] It should be noted that the greater the current connected when the electromagnetic valve 43 works, the greater the output of the electromagnetic valve 43, the faster the movement speed of the pushing frame 41 controlled by the electromagnetic valve 43, and the faster the pushing rod 1 is pushed to the brake master cylinder 5, so compared with the displacement driving of the screw rod 31 controlled by the driving motor 35, the braking efficiency is higher, so the electromagnetic valve 43 is used during emergency braking, at this time, the response is faster, and it is more beneficial to safety guarantee in emergency situations.

[0094] Working principle: during the driving process of the automobile, after the driver steps on the pedal 2, the first sensor 34 detects displacement / pressure and sends an electric signal to the controller, the controller controls the driving motor 35 to work to control the screw rod 31 to move along the length direction thereof to the direction close to the brake master cylinder 5, so as to push the pushing rod 1 to move to the direction of the brake master cylinder 5, so as to drive the brake master cylinder 5 to work and control the vehicle brake;

[0095] As Figure 6As shown, the first power-assisting system is working at this time. Since the upper push plate 411 is arranged between the screw rod 31 and the push rod 1, the upper push plate 411 moves synchronously therewith, so that the sleeve 413 slides in the same direction on the guide core 42, and the lower push plate 412 moves in the direction away from the solenoid valve 43; at this time, the solenoid valve 43 does not work, and when the first power-assisting system is working, the solenoid valve 43 does not work, and no energy is consumed, which is no different from the energy consumption of the traditional brake assist system.

[0096] When the driver steps on the pedal 2, the first power-assisting system does not respond, which may be due to damage to the drive motor 35. At this time, the pressure of the pedal 2 will cause the sliding outer rod 32 to move a distance toward the brake master cylinder 5. The second displacement sensor 44 detects the displacement signal and sends it to the controller. The controller controls the solenoid valve 43 to work, and the output end of the solenoid valve 43 acts on the lower push plate 412 and pushes the lower push plate 412 away from the solenoid valve 43. At the same time, the sliding sleeve 413 and the upper push plate 411 move in the same direction to drive the push rod 1 to push the brake master cylinder 5, so as to drive the brake master cylinder 5 to work and control the vehicle braking. Figure 5 As shown, at this time, the screw rod 31 is not moving, and the second power-assisting system assists the brake;

[0097] Therefore, when the first power-assisting system fails, the second power-assisting system will immediately provide brake assistance; the failure condition is: the second displacement sensor 44 runs to a certain distance threshold, and the first sensor 34 and the motor are not running; or, the first sensor 34 and / or the motor run and then stop running, while the second displacement sensor 44 runs beyond the distance threshold and continues to run; to avoid the situation where only the driver's pedaling force can push the push rod 1 to provide braking after the first power-assisting system fails, resulting in a slow brake response, thereby improving the safety of the vehicle during driving; avoiding the situation where the brakes are too hard, thereby improving the driver's user experience.

[0098] It should be noted that when the second power assist system is working, the force applied to the lower push plate 412 by the output end of the solenoid valve 43 drives the lower push plate 412 to move in the direction away from the solenoid valve 43. After long-term use, the lower push plate 412 will be deformed and tilted in the direction away from the solenoid valve 43, thereby affecting its use effect. Therefore, the setting of the lower push plate 412 tilted b° toward the solenoid valve 43 slows down the occurrence of such deformation to a certain extent, so that the force driving the displacement of the push frame 41 is always coaxial with the guide core 42, so as to ensure the movement direction of the push frame 41, while improving work efficiency and extending service life; similarly, the push rod 1 will also generate a force on the upper push plate 411 that drives it to tilt in the direction away from the push rod 1, so the upper push plate 411 is tilted a° toward the push rod 1.

[0099] A method for operating a brake assist system is provided, which is the method for operating a brake assist system with a fault handling function, comprising the following steps:

[0100] S01: The driver starts the car and before driving on the road, the controller checks whether the second power-assisting system is intact; if the second power-assisting system is intact, the controller proceeds to S02; if the second power-assisting system fails, the controller issues an alarm;

[0101] Specifically, it includes: the controller controls the solenoid valve 43 to work, so that the solenoid valve 43 drives the lower push plate 412 to move in the direction away from the solenoid valve 43, so as to drive the sliding sleeve 413 and the upper push plate 411 to move in the same direction, so as to drive the push rod 1 to push toward the master brake cylinder 5; if it is detected that the master brake cylinder 5 is working, the second power-assisting system is intact and S02 is performed; if it is detected that the master brake cylinder 5 is not working, the second power-assisting system fails and an alarm is issued.

[0102] S02: The driver drives the vehicle on the road, and the emergency brake detection system monitors in real time whether an emergency brake signal is needed; when the conditions for sending an emergency brake signal are met, the emergency brake detection system sends an emergency brake signal to the controller and proceeds to S09; when the conditions for sending an emergency brake signal are not met, the vehicle continues to drive and proceeds to S03.

[0103] S03: The driver actively brakes and presses pedal 2.

[0104] S04: The first sensor 34 detects pressure and transmits a signal to the controller, and the second displacement sensor 44 detects displacement of the sliding outer rod 32 and transmits a signal to the controller; when both the first sensor 34 and the second displacement sensor 44 generate signals, S05 is performed; when the second displacement sensor 44 has a signal but the first sensor 34 has no signal, an alarm indicating damage to the first sensor 34 is sent to the outside world, and S08 is performed.

[0105] S05: The controller sends a signal to the drive motor 35 to drive it to work; if the drive motor 35 is working, then S06 is performed; if the drive motor 35 is not working, then S07 is performed.

[0106] S06: The first power assist system works: the drive motor 35 works, and the screw rod 31 moves along its length direction toward the direction close to the master brake cylinder 5, so as to push the push rod 1 to move synchronously toward the master brake cylinder 5, so as to drive the master brake cylinder 5 to work and control the vehicle braking.

[0107] S07: The controller detects that the drive motor 35 does not work, sends a damage alarm of the drive motor 35 to the outside world, and proceeds to S08.

[0108] S08: The second displacement sensor 44 detects that the sliding outer rod 32 has displaced, and the displacement distance of the sliding outer rod 32 exceeds a spacing threshold, and then proceeds to S09. In this embodiment, the spacing threshold is 30% of the length of the sliding outer rod 32.

[0109] It should be noted that in order to avoid sudden braking due to the driver's accidental braking in the event of damage to the first power-assisting system, a spacing threshold is adopted; the spacing threshold is the distance that the sliding outer rod 32 can move after the driver applies the force he wants to brake to step on the pedal 2 during vehicle operation; since the braking during vehicle driving will be subject to inertial resistance, when the driver steps on the pedal 2, the sliding outer rod 32 will be driven to move a certain distance, but when the distance the driver wants to drive the sliding outer rod 32 to move is greater than the spacing threshold, it will be very strenuous due to the effect of inertial resistance, that is, the brakes will feel too hard, so the detection of the second displacement sensor 44 and the assistance of the second power-assisting system are required.

[0110] S09: The second power assist system works: the controller controls the solenoid valve 43 to work, the output end of the solenoid valve 43 acts on the lower push plate 412, and pushes the lower push plate 412 away from the solenoid valve 43. At the same time, the sleeve 413 and the upper push plate 411 move in the same direction to drive the push rod 1 to push toward the master brake cylinder 5, so as to drive the master brake cylinder 5 to work and control the vehicle brake.

[0111] S10: When the displacement distance of the sliding outer rod 32 detected by the second displacement sensor 44 is completely zero, it means that the driver releases the pedal 2. At this time, the second displacement sensor 44 does not generate a displacement signal, and the controller controls the solenoid valve 43 to stop working to cancel the brake so that the vehicle can move again; at this time, the push rod 1 and the push frame 41 move toward the direction close to the screw rod 31 under the drive of the elastic reset force of the spring 11 until the upper push plate 411 abuts against the screw rod 31.

[0112] S11: After the driver parks the vehicle and before the vehicle is turned off, the controller checks whether the second power-assist system is intact; if the second power-assist system is intact, parking is completed; if the second power-assist system is faulty, an alarm is sounded;

[0113] Specifically, it includes: the controller controls the solenoid valve 43 to work, so that the solenoid valve 43 drives the lower push plate 412 to move in the direction away from the solenoid valve 43, thereby driving the sliding sleeve 413 and the upper push plate 411 to move in the same direction, thereby driving the push rod 1 to push toward the master brake cylinder 5; if it is detected that the master brake cylinder 5 is working, the second power assist system is intact and the parking is completed; if it is detected that the master brake cylinder 5 is not working, the second power assist system fails and an alarm is issued.

[0114] Specific embodiment 2: Based on the specific embodiment 1, Figure 9 As shown,

[0115] The number of guide cores 42 is two, and the two guide cores 42 are fixedly arranged on both sides of the push rod 1 and symmetrically arranged along the symmetry axis in the length direction of the push rod 1;

[0116] The push frame 41 is a Z-shaped frame, and the number of sliding sleeves 413 is two, and the two sliding sleeves 413 are symmetrically arranged along the symmetry axis in the length direction of the push rod 1, and the two sliding sleeves 413 are respectively sleeved on the outer periphery of the two guide cores 42;

[0117] The upper push plate 411 is arranged at the end of the sliding sleeve 413 away from the brake master cylinder 5, and the upper push plate 411 is fixedly connected with the two sliding sleeves 413;

[0118] The lower push plate 412 is arranged at the end of the sliding sleeve 413 close to the brake master cylinder 5, and the lower push plate 412 is fixedly connected with the two sliding sleeves 413.

[0119] It should be noted that in the prior art, the two sides of the push rod 1 are respectively provided with a rod having the same length direction, and in the present application, the original rod is used as a guide core 42 for the guiding function of the second assist system, so as to realize the assist function of the second assist system in the case of failure of the first assist system, which changes the structure and realizes the function, has positive significance, and optimizes the cost and has large market benefit;

[0120] And the two sliding sleeves 413 are arranged in the push frame 41, which not only fully utilizes the original structure, but also makes the stress of the push frame 41 more uniform. If there is only one sliding sleeve 413, the sliding sleeve 413 is arranged only on the side of the upper push plate 411 and the lower push plate 412, at this time, the sliding of the side of the upper push plate 411 and the lower push plate 412 which is not provided with the sliding sleeve 413 is more difficult than the side of the upper push plate 411 and the lower push plate 412 which is provided with the sliding sleeve 413, and long-term use may cause deflection, resulting in incomplete pushing of the push rod 1, affecting the service life and use efficiency; and the two sliding sleeves 413 make the upper push plate 411 and the lower push plate 412 move uniformly, so that the sliding is smoother, prolongs the service life and improves the use efficiency.

Claims

1. A brake assist system with a fault handling function, wherein the input end is connected to a pedal (2) and the output end is connected to a brake master cylinder (5), characterized in that: include A push rod (1) connected to the brake master cylinder (5) at one end, A first power assist system having an output end abutting against the other end of the push rod (1), Second power assist system and controller; The first power-assisting system is driven by a motor to drive the push rod (1) to move after the pedal (2) is subjected to force; an elastic member having elastic reset capability after compression movement is provided on the push rod (1); The second power-assisting system comprises a solenoid valve (43), a guide core (42), a push frame (41), and a second displacement sensor that is independent of whether the first power-assisting system is operating; The pushing frame (41) comprises a first pushing portion, a sliding guide portion and a second pushing portion; The first pushing portion abuts between the push rod (1) and the output end of the first power-assisting system, and the second pushing portion is connected to the output end of the electromagnetic valve (43), so that the pushing frame (41) has the ability to push the push rod (1) toward the brake master cylinder (5) under the control of the electromagnetic valve (43); The guide core (42) is fixedly arranged on the outside of the push rod (1) and is parallel to the push rod (1). The guide core (42) is slidably connected to the sliding guide portion of the push frame (41) to provide a guide for the movement of the push frame (41) in the length direction of the push rod (1). According to the first power-assisting system signal and the second displacement sensor signal, a fault is determined and the controller drives the electromagnetic valve (43) to achieve the second power-assisting system brake; The solenoid valve (43) and the motor are arranged along the length direction of the push rod (1); the output direction of the output end of the solenoid valve (43) is the same as the direction of the force that pushes the push rod (1) toward the brake master cylinder (5); the guide core (42) extends in a direction away from the pedal (2), so that the length range of the guide core (42) includes at least the solenoid valve (43) and a part of the output range of the output end of the solenoid valve (43); The first power-assisting system further includes a screw rod, an outer rod sleeved on the outer periphery of the screw rod, and a transmission mechanism sleeved on the outer periphery of the outer rod and slidably connected thereto; One end of the screw rod abuts against the push rod (1), and the other end is connected to the pedal (2); a first sensor (34) is fixedly connected to the screw rod to detect the force or displacement of the screw rod; One end of the outer rod is connected to the pedal (2) so that it is forced to move along its length direction; The controller is electrically connected to the motor, and the controller is electrically connected to the first sensor (34), the second displacement sensor (44) and the solenoid valve (43) respectively; The transmission mechanism is connected to the output end of the motor so as to be capable of controlling the screw rod to push the push rod (1) toward the brake master cylinder (5) under the drive of the motor; A second displacement sensor (44) is mounted on the outer rod to detect the displacement of the outer rod; The fault condition is: the second displacement sensor (44) runs to a certain spacing threshold, and the first sensor (34) and the motor do not run; or the first sensor (34) and / or the motor run and then stop running, while the second displacement sensor (44) runs beyond the spacing threshold and continues to run; The guide core (42) is a guide rod originally provided in the first power-assisting system, which is extended in a direction away from the pedal (2). The solenoid valve (43) is provided in an empty space at the rear of the motor away from the pedal (2), so that the setting position of the solenoid valve (43) and the pushing frame (41) is the only position in the first power-assisting system.

2. A brake assist system with fault handling function according to claim 1, characterized in that: The pushing frame (41) is a Z-shaped frame with two ends bent in opposite directions; the first pushing portion of the pushing frame (41) abutting against the push rod (1) is inclined at a° toward the push rod (1), and the angle between the first pushing portion and the vertical line of the push rod (1) and the axis of the guide core (42) is a°; the second pushing portion of the pushing frame (41) is inclined at b° toward the solenoid valve (43); the angle between the second pushing portion and the vertical line of the axis of the guide core (42) is b°.

3. The brake assist system with fault handling function according to claim 1, characterized in that: The guide core (42) is rod-shaped, the length direction of which is consistent with the length direction of the push rod (1); the sliding guide portion is a sliding sleeve (413), and the sliding sleeve (413) is sleeved on the outer periphery of the guide core (42) along the length direction of the guide core (42); the inner diameter of the sliding sleeve (413) is larger than the outer diameter of the guide core (42), so that there is always a gap between the inner wall of the sliding sleeve (413) and the guide core (42); a ball is provided in the gap, and the ball abuts against the inner wall of the sliding sleeve (413) and the outer wall of the guide core (42) at the same time, so as to provide a guiding effect for the sliding of the sliding sleeve (413) along the length direction of the guide core (42).

4. The brake assist system with fault handling function according to claim 3, characterized in that: There are two guide cores (42), and the two guide cores (42) are symmetrically arranged along the symmetry axis of the push rod (1); at least one guide core (42) is close to the side of the solenoid valve (43), and the sliding sleeve (413) in the push frame (41) is sleeved with the guide core (42) close to the side of the solenoid valve (43).

5. The brake assist system with fault handling function according to claim 1, characterized in that: A partition is fixedly provided between the solenoid valve (43) and the guide core (42), the partition being fixedly connected to the solenoid valve (43), and a gap being present between the partition and the guide core (42), so that a gap is present between the solenoid valve (43) and the guide core (42); the gap being at least greater than a displacement distance caused by vibration when the solenoid valve (43) is operating, so as to prevent the solenoid valve (43) from vibrating close to the guide core (42) when operating, thereby interfering with the sliding of the sliding guide portion.

6. The brake assist system with fault handling function according to claim 1, characterized in that: The controller is also electrically connected to an emergency brake detection system; the emergency brake detection system includes an information collection unit and an emergency brake judgment unit; the information collection unit is connected to a global positioning system to at least receive driving information of the vehicle and other vehicles; the emergency brake judgment unit is electrically connected to the information collection unit so that the emergency brake judgment unit judges whether the vehicle meets the conditions for issuing an emergency brake signal at least relative to the other vehicles based on the information in the information collection unit, so as to guide the controller to control the operation of the solenoid valve (43).

7. A method for operating a brake assist system, characterized in that: The operating method of a brake assist system with a fault handling function according to any one of claims 1 to 6 comprises the following steps: autonomously detecting whether the second assist system is operating normally before the vehicle starts and stops; The emergency brake detection system monitors in real time whether an emergency brake signal is issued to guide the operation of the solenoid valve (43); When the driver actively steps on the pedal (2), if the first power assist system works normally, the first power assist system provides power to push the push rod (1) toward the brake master cylinder (5); if the first power assist system fails, the second power assist system provides power to push the push rod (1) toward the brake master cylinder (5) and sends a fault signal to the outside world.

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