A new energy vehicle brake-by-wire system energy recovery mechanism and control method

Abstract

A brake-by-wire system for new energy vehicles includes an energy recovery mechanism and control method, specifically a braking energy recovery system. An electronic control module receives braking signals, and a braking module executes the braking process. The energy recovery module converts the heat generated during braking into mechanical energy and then into electrical energy. Specifically, a pneumatic cylinder is horizontally fixed within a slot in the brake housing, with its bottom end contacting the fixed brake pads. A second pneumatic cylinder is vertically positioned at the bottom of the open end of the first pneumatic cylinder. The bottom ends of the two cylinders are connected and fixed via an air pipe. A flywheel is fixed to the outer end of the generator drive shaft. The flywheel has an eccentric shaft and is hinged to the outer piston ends of the first and second pneumatic cylinders via piston connecting rods one and two, respectively. The addition of the energy recovery module enables the timely recovery of a large amount of heat generated during braking and its conversion into electrical energy, effectively reducing braking failure caused by insufficient battery power.

Description

Technical Field

[0001] This invention relates to a braking energy recovery system, and more particularly to an energy recovery mechanism and control method for a brake-by-wire system used in new energy vehicles, belonging to the field of new energy vehicle research and development technology. Background Technology

[0002] Vehicle braking systems have a long history of development, evolving from vacuum hydraulic braking to a combination of electronic and hydraulic braking, and then gradually shifting to purely electric mechanical braking and more intelligent brake-by-wire systems with the development of new energy vehicles. Traditional vehicle braking methods generally use drum or disc friction brakes, converting the kinetic energy of the wheels into heat energy to achieve braking. While this meets the basic requirements of laws and regulations, it also has many problems, such as slow response, inability to automatically adjust, and difficulty in developing integrated vehicle control systems.

[0003] Brake-by-wire systems mainly include EHB braking systems and EMB braking systems, among which:

[0004] The EHB braking system primarily controls the pressure supply unit and high-speed switching valves to generate and store braking pressure. When the driver depresses the brake pedal, the data acquisition system gathers information such as pedal travel, pedal force, and vehicle driving status to the HCU for analysis. When it detects that the system needs to increase pressure, the HCU outputs a control signal to control the solenoid valves, increasing the inlet flow rate and decreasing the outlet flow rate until the required braking force is achieved. Conversely, when it detects that the system needs to decrease pressure, the HCU controls the inlet flow rate to decrease and the outlet flow rate to increase until the required braking force is achieved.

[0005] The EMB braking system replaces hydraulic components with electronic ones, making it an electromechanical integrated system. An electronic control unit (ECU) controls the current to the brake motor, distributing braking force to each wheel. Brake pads clamp the brake discs from both sides to achieve braking. When the vehicle is moving and deceleration is required, the driver presses the brake pedal. The ECU receives the braking command signal, calculates the optimal braking force based on the vehicle's current driving conditions, and the braking unit receives the output signal from the ECU, controlling the brake motor to output the necessary braking torque to achieve braking. Compared to traditional braking systems, the EMB braking system has a simpler and more compact structure, lower braking noise, and faster braking response.

[0006] However, due to the relatively short development time of the EMB braking system, there are still some problems that need to be solved. For example, insufficient power supply to the system can cause braking system failure, and the temperature generated by the brake pads during braking under harsh conditions can even reach hundreds of degrees. However, there is currently a lack of effective energy recovery mechanisms to recover and utilize the heat generated during braking. Summary of the Invention

[0007] To address the shortcomings of the prior art, this invention provides an energy recovery mechanism and control method for a brake-by-wire system in new energy vehicles. It adds an energy recovery module, which can promptly recover the large amount of heat generated during braking and convert it into electrical energy, effectively reducing braking failure caused by insufficient battery power.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An energy recovery mechanism for a brake-by-wire system in a new energy vehicle includes an electronic control module, a braking module, and an energy recovery module;

[0010] The electronic control module includes an ECU unit, a battery, an MCU unit, and an HCS sensor. The ECU unit receives braking commands from the brake pedal sensor, calculates them, and outputs the signals to the MCU unit. The MCU unit adjusts the speed of the brake motor according to the signals. The HCS sensor is connected between the MCU unit and the brake motor. The battery provides power to the electronic control module and other electrical equipment in the vehicle.

[0011] The braking module includes a brake motor, a ball screw, a brake housing, a brake block, a movable brake pad, a brake disc, and a fixed brake pad. The edge of the brake disc extends into the brake housing. The movable brake pad and the fixed brake pad are installed inside the brake housing and are located on both sides of the edge of the brake disc, respectively. The brake motor is drivenly connected to one end of the ball screw, and a nut is screwed onto the other end of the ball screw. The nut is slidably connected to a mounting hole in the brake housing. The brake block is installed inside the brake housing and is rotatably connected to the nut to transmit braking pressure to the movable brake pad.

[0012] The energy recovery module includes a second pneumatic cylinder, a first pneumatic cylinder, a flywheel, and a generator. The first pneumatic cylinder is horizontally installed and fixed in a pre-set slot in the brake housing, with its bottom end in contact with the fixed brake pad. The second pneumatic cylinder is vertically installed at the bottom of the open end of the first pneumatic cylinder. The bottom ends of the two side walls are connected and fixed by an air pipe. The generator is fixedly installed, and the flywheel is coaxially fixed at the outer end of its drive shaft. The flywheel is provided with an eccentric shaft and is hinged to the outer piston ends of the first and second pneumatic cylinders through piston connecting rods one and two, respectively.

[0013] A control method for an energy recovery mechanism in a brake-by-wire system for new energy vehicles includes the following steps:

[0014] During braking, the ECU unit outputs a signal to the MCU unit to adjust the speed of the brake motor. The rotation of the ball screw causes the nut to push the movable brake pad. The movable brake pad clamps the brake disc with the fixed brake pad, generating friction. The heat generated by the fixed brake pad is transferred to the first pneumatic cylinder, which changes from a cold cylinder to a hot cylinder, causing the gas inside to expand. A pressure difference is formed between the first and second pneumatic cylinders. The expanded gas in the first pneumatic cylinder is transferred through the air pipe to the still cold second pneumatic cylinder, pushing the piston connecting rod 2 to drive the flywheel to rotate. During this stage, the gas in the second pneumatic cylinder cools and contracts. At the same time, due to the rotational inertia of the flywheel, the piston in the first pneumatic cylinder contracts inward, pulling the piston connecting rod 1 to drive the flywheel to rotate until the gas volume in the first and second pneumatic cylinders reaches its minimum. The gas inside the first pneumatic cylinder is heated and expands again, continuously driving the flywheel to rotate and causing the generator to rotate and generate electricity.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the present invention is applicable to the brake-by-wire system of new energy vehicles. By adding an energy recovery module with a mechanical pneumatic structure, the conversion of thermal energy into mechanical energy and then into electrical energy during the braking process is realized, which effectively reduces the braking failure caused by insufficient battery power, improves braking safety, recovers a large amount of heat generated during the braking process in a timely manner, reduces energy loss, and the recovered electricity can also compensate other electrical equipment on the vehicle. The overall structure is simple and compact and easy to maintain. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the energy recovery mechanism of the brake-by-wire system of the present invention;

[0017] Figure 2 This is a schematic diagram of the energy recovery module in this invention;

[0018] Figure 3 This is a schematic diagram of the motion and change process of the energy recovery module in this invention;

[0019] Figure 4 This invention provides a curve showing the change in heat of the fixed brake pads over braking time during the braking process.

[0020] Figure 5 This is the curve showing the change of generator release current with braking time during the energy recovery process of this invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1-2 As shown, an energy recovery mechanism for a brake-by-wire system in a new energy vehicle includes an electronic control module, a braking module, and an energy recovery module.

[0023] The electronic control module (ECU) is responsible for receiving braking signals and includes an ECU unit 1, a battery 2, an MCU unit 3, and an HCS sensor 4. The ECU unit 1 receives braking commands from the brake pedal sensor, calculates the optimal braking force required for the current braking action, and outputs the signal to the MCU unit 3. When the driver depresses the brake pedal, the brake pedal sensor detects braking signals such as the brake pedal's acceleration, displacement, and pedal force, and issues a braking command. The ECU unit 1 receives the braking command through the vehicle network and, by integrating other sensor signals from the vehicle's current situation, identifies the driver's braking intention and calculates the optimal braking force required for the current braking action. This part is existing technology and will not be elaborated further. The MCU unit 3 adjusts the speed of the brake motor 5 according to the signal. The HCS sensor 4 is connected between the MCU unit 3 and the brake motor 5 to collect current signals and achieve precise control of the brake motor 5's speed. The battery 2 supplies power to the electronic control module and other electrical equipment in the vehicle.

[0024] The braking module is responsible for executing the braking process and includes a brake motor 5, a ball screw 8, a nut 9, a brake housing 10, a brake block 11, a movable brake pad 12, a brake disc 13, and a fixed brake pad 14. The brake housing 10 is mounted on a base plate 7 via guide pins 6. The edge of the brake disc 13 extends into the brake housing 10. The movable brake pad 12 and the fixed brake pad 14 are installed inside the brake housing 10 and located on opposite sides of the edge of the brake disc 13. The brake motor 5 receives control signals from the MCU unit 3, outputs the required rotational speed to complete the torque response during braking, and transmits the braking torque to the ball screw 8. One end of the ball screw 8 is connected to the brake motor 5, and the other end of the ball screw 8 is screwed with a nut 9. The nut 9 is connected to the brake housing 10. The sliding connection of the mounting hole restricts rotation. The ball screw 8 and the nut 9 cooperate to convert the torque output by the brake motor 5 from rotational motion to linear motion. The brake pressure block 11 is installed inside the brake housing 10 and is rotatably connected to the nut 9. The displacement generated by the nut 9 acts on the brake pressure block 11 to transmit braking pressure to the movable brake pad 12. During braking, the brake pressure block 11 pushes the movable brake pad 12 to contact the brake disc 13 and generate friction. The brake disc 13 is pressed by the braking pressure and contacts the fixed brake pad 14 to generate friction, converting the vehicle's forward kinetic energy into frictional heat energy and thus achieving braking.

[0025] The energy recovery module uses a mechanical pneumatic structure to convert the heat generated during braking into mechanical energy and then into electrical energy. It includes an air pipe 15, a second pneumatic cylinder 16, a first pneumatic cylinder 17, a first piston rod 18, a flywheel 19, a generator 20, and a second piston rod 21. The first pneumatic cylinder 17 is horizontally installed and fixed in a pre-set slot in the brake housing 10, with its bottom end in contact with the fixed brake pad 14. The second pneumatic cylinder 16 is vertically installed at the bottom of the opening end of the first pneumatic cylinder 17. Both the second pneumatic cylinder 16 and the first pneumatic cylinder 17 are filled with expanding gas and equipped with pistons. The second pneumatic cylinder 16 and the bottom end of the side wall of the first pneumatic cylinder 17 are connected and fixed through an air pipe 15. The air pipe 15 is L-shaped, and its vertical branch is embedded and fixed inside the brake housing 10 to enhance stability. The generator 20 is fixedly installed, and its outer end of the drive shaft is coaxially fixed with a flywheel 19. The flywheel 19 is equipped with an eccentric shaft and is hinged to one end of the piston connecting rod 18 and the second piston connecting rod 21. The other end of the piston connecting rod 18 is hinged to the outer end of the piston of the first pneumatic cylinder 17, and the other end of the piston connecting rod 21 is hinged to the outer end of the piston of the second pneumatic cylinder 16. Among them, the pre-set slotted contact position between the pneumatic cylinder 17 and the brake housing 10, the contact position between the pneumatic cylinder 17 and the fixed brake pad 14, the interface position between the pneumatic cylinder 17 and the air pipe 15, and the interface position between the pneumatic cylinder 2 16 and the air pipe 15 are all sealed.

[0026] like Figures 1-3 As shown, a control method for an energy recovery mechanism in a brake-by-wire system for new energy vehicles includes the following steps:

[0027] Before braking begins, both pneumatic cylinder 16 and pneumatic cylinder 17 are cold cylinders and connected by air pipe 15. Since there is no pressure difference, the internal air pressure of pneumatic cylinder 16 and pneumatic cylinder 17 is balanced, the flywheel 19 does not rotate, and the generator 20 does not work.

[0028] When braking begins, ECU unit 1 outputs a signal to MCU unit 3 to adjust the speed of brake motor 5. The ball screw 8 rotates, causing nut 9 to push the movable brake pad 12. The movable brake pad 12 clamps the brake disc 13 with the fixed brake pad 14, generating friction. The heat generated by the fixed brake pad 14 is transferred to pneumatic cylinder 17, causing it to change from a cold cylinder to a hot cylinder, resulting in the expansion of the gas inside. A pressure difference is created between pneumatic cylinder 17 and pneumatic cylinder 2 16. The expanded gas in pneumatic cylinder 17 is transferred through air pipe 15 to pneumatic cylinder 2 16, which is still a cold cylinder, and pushes piston connecting rod 21, causing flywheel 19 to rotate. During this stage, the gas in pneumatic cylinder 2 16 contracts due to cooling. Simultaneously, due to the rotational inertia of flywheel 19, the piston in pneumatic cylinder 17 contracts inward, pulling piston connecting rod 18 to rotate flywheel 19 until the gas volume in pneumatic cylinder 17 and pneumatic cylinder 2 16 reaches its minimum. The energy recovery module's motion changes during this period are combined with... Figure 3As shown in EFMN, during the rotation of flywheel 19, it drives generator 20 to rotate and generate electricity. If the braking process continues, the gas inside pneumatic cylinder 17 will be heated and expanded again, continuously driving flywheel 19 to rotate and generator 20 to rotate and generate electricity.

[0029] After braking ends, the heat generated by the fixed brake pad 14 does not disappear immediately, but there is a period of residual heat dissipation. During this period, the pneumatic cylinder 17 can still be kept in a hot cylinder state. The flywheel 19 rotates to make the generator 20 rotate to generate electricity until the residual heat of the fixed brake pad 14 disappears. The pneumatic cylinder 17 changes from a hot cylinder to a cold cylinder, the pressure difference between the pneumatic cylinder 17 and the pneumatic cylinder 2 16 disappears, and the energy recovery module stops working.

[0030] Combination Figure 4 As shown, this is a curve showing the change of heat energy generated by the fixed brake pad 14 over time during braking. When the movable brake pad 12 and the fixed brake pad 14 clamp the brake disc 13, friction is generated, producing a large amount of heat energy. The vehicle starts braking at time T1 and stops braking at time T2. From time T1 to time T2, the heat energy generated by the fixed brake pad 14 increases sharply. After braking stops at time T2, the heat energy generated by the fixed brake pad 14 does not disappear immediately, but slowly decays until time T3.

[0031] Combination Figure 5 As shown, the curve of the current generated by generator 20 during braking is a curve of change over time. When the vehicle starts braking at time T1, generator 20 starts generating current, and the current generated gradually increases with time until braking stops at time T2, when the current generated by generator 20 reaches its peak. During the time period from T2 to T3, the current generated by generator 20 slowly decreases until it becomes 0, and the energy recovery module stops working.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An energy recovery mechanism for a brake-by-wire system in a new energy vehicle, characterized in that: Includes an electronic control module, a braking module, and an energy recovery module; The electronic control module includes an ECU unit (1), a battery (2), an MCU unit (3), and an HCS sensor (4). The ECU unit (1) receives braking commands from the brake pedal sensor, calculates them, and outputs the signals to the MCU unit (3). The MCU unit (3) adjusts the speed of the brake motor (5) according to the signals. The HCS sensor (4) is connected between the MCU unit (3) and the brake motor (5). The battery (2) provides power to the electronic control module and other electrical equipment in the vehicle. The braking module includes a brake motor (5), a ball screw (8), a brake housing (10), a brake block (11), a movable brake pad (12), a brake disc (13), and a fixed brake pad (14). The edge of the brake disc (13) extends into the interior of the brake housing (10). The movable brake pad (12) and the fixed brake pad (14) are installed inside the brake housing (10) and are located on both sides of the edge of the brake disc (13). The brake motor (5) is connected to one end of the ball screw (8). The other end of the ball screw (8) is screwed with a nut (9). The nut (9) is slidably connected to the mounting hole in the brake housing (10). The brake block (11) is installed inside the brake housing (10) and is rotatably connected to the nut (9) to transmit braking pressure to the movable brake pad (12). The energy recovery module includes a second pneumatic cylinder (16), a first pneumatic cylinder (17), a flywheel (19), and a generator (20). The first pneumatic cylinder (17) is horizontally installed and fixed in a pre-set slot in the brake housing (10), and its bottom end is in contact with the fixed brake pad (14). The second pneumatic cylinder (16) is vertically installed at the bottom of the opening end of the first pneumatic cylinder (17). The bottom ends of the two side walls are connected and fixed through an air pipe (15). The generator (20) is fixedly installed, and its outer end of the drive shaft is coaxially fixed to the flywheel (19). The flywheel (19) is provided with an eccentric shaft and is hinged to the outer piston ends of the first pneumatic cylinder (17) and the second pneumatic cylinder (16) through the first piston rod (18) and the second piston rod (21), respectively.

2. The energy recovery mechanism for a brake-by-wire system in a new energy vehicle according to claim 1, characterized in that: Both the second pneumatic cylinder (16) and the first pneumatic cylinder (17) are filled with expanding gas.

3. The energy recovery mechanism for a brake-by-wire system in a new energy vehicle according to claim 1, characterized in that: The air pipe (15) is L-shaped and its vertical branches are embedded and fixed inside the brake housing (10).

4. The energy recovery mechanism for a brake-by-wire system in a new energy vehicle according to claim 1, characterized in that: The pre-set slotted contact positions of the first pneumatic cylinder (17) and the brake housing (10), the contact positions of the first pneumatic cylinder (17) and the fixed brake pad (14), the interface positions of the first pneumatic cylinder (17) and the air pipe (15), and the interface positions of the second pneumatic cylinder (16) and the air pipe (15) are all sealed.

5. A control method for an energy recovery mechanism in a brake-by-wire system for new energy vehicles, characterized in that: The control method of the energy recovery mechanism according to claim 1 includes the following steps: During braking, the ECU unit (1) outputs a signal to the MCU unit (3) to adjust the speed of the brake motor (5). The ball screw (8) rotates, causing the nut (9) to push the movable brake pad (12). The movable brake pad (12) and the fixed brake pad (14) clamp the brake disc (13) and generate friction. The heat generated by the fixed brake pad (14) is transferred to the first pneumatic cylinder (17). The first pneumatic cylinder (17) changes from a cold cylinder to a hot cylinder, causing the gas inside to expand due to heat. A pressure difference is formed between the first pneumatic cylinder (17) and the second pneumatic cylinder (16). The gas that expands in the first pneumatic cylinder (17) passes through the air... The pipe (15) is transferred to the still cold cylinder (16) and pushes the piston connecting rod (21) to drive the flywheel (19) to rotate. During this stage, the gas in the cylinder (16) is cooled and contracts. At the same time, due to the rotational inertia of the flywheel (19), the piston of the cylinder (17) contracts inward, pulling the piston connecting rod (18) to drive the flywheel (19) to rotate until the gas volume in the cylinder (17) and cylinder (16) reaches its minimum. The gas inside the cylinder (17) is heated and expands again, continuously driving the flywheel (19) to rotate, causing the generator (20) to rotate and generate electricity.

6. The control method according to claim 5, characterized in that: After braking, the fixed brake pad (14) has a period of residual heat dissipation. During this period, the pneumatic cylinder (17) remains in a hot cylinder state, and the flywheel (19) rotates to make the generator (20) rotate to generate electricity.

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