Combined electronic mechanical hydraulic brake-by-wire system of new energy automobile

Abstract

The invention relates to the technical field of automobile intelligent brake systems, and discloses a new energy automobile combined electronic mechanical hydraulic drive-by-wire brake system which comprises an electronic control unit, an oil can and brake execution devices, and each wheel is matched with a set of brake execution device; the brake executing device comprises a driving motor and a reciprocating actuating mechanism, the driving motor serves as a power source, rapid and accurate linear change of brake pressure is achieved through reciprocating motion of the reciprocating actuating mechanism, the defects and defects of EHB and EMB are effectively overcome, cost can be effectively reduced, pipelines are simplified, the using amount of brake fluid is reduced, and the unsprung mass is reduced. Therefore, the brake pressure control precision is effectively improved, the maneuverability and stability of the vehicle are improved, and the active safety performance of the whole vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile intelligent braking systems, and in particular to a freely combinable electronic mechanical hydraulic brake-by-wire system for new energy vehicles. Background Art

[0003] The traditional mechanical braking system is that the driver applies energy through the brake pedal, which leads to slow response, low braking deceleration, and easy braking action lag; EVP (electronic vacuum booster pump) technology has obvious defects such as poor braking effect, high noise, and short life compared to wire control braking. Therefore, the wire control braking system will be the key to the future vehicle braking mode. Wire control braking replaces some mechanical components with electronic components, and embeds corresponding software programs in the electronic control braking system to achieve the control and distribution of braking force. Compared with the above technologies, wire control braking has faster response and better braking effect.

[0004] At present, the development direction of the wire-controlled air brake system is mainly electronic hydraulic brake EHB and electronic mechanical brake EMB. The EMB solution has more advantages. It does not require braking medium, and the braking control is faster and more precise. However, its braking ability is overly dependent on the driving power of the motor, requires a 42V power supply system, and increases the unsprung mass of the vehicle, affecting the maneuverability and stability of the vehicle. The EHB system has complex and long pipeline layout, resulting in a certain lag in braking response, and a large lag in the response of the front and rear axles. Summary of the invention

[0005] In order to overcome the shortcomings and deficiencies of existing wire-controlled hydraulic brake systems for new energy vehicles, the present invention aims to provide a combined EMHB (Electronic Mechanical Hydraulic Brake) wire-controlled brake system for new energy vehicles that can reduce the unsprung mass and a control method thereof, which can be arbitrarily combined and is suitable for brake systems from single-road vehicles to multi-axle vehicles.

[0006] The technical solution adopted by the present invention is: a combined electronic mechanical hydraulic wire control braking system for new energy vehicles, including an electronic control unit, an oil pot and a brake actuator, the brake actuator includes a drive motor, a reciprocating mechanism and a normally closed pressure reducing valve, the normally closed pressure reducing valve is built into the brake actuator, and is respectively connected to the oil pot and the brake caliper, the drive motor is connected to the reciprocating mechanism, the drive motor drives the reciprocating mechanism to reciprocate rapidly, completes the application and release of the wheel braking force, and realizes rapid, precise and linear pressure regulation. Preferably, the electronic mechanical hydraulic wire control braking system provided by the present invention is a combined type, each wheel is matched with a set of brake actuators, and one electronic control unit controls one set of brake actuators; or each wheel is matched with a set of brake actuators; one electronic control unit controls two sets of brake actuators; or each wheel is matched with a set of brake actuators; one electronic control unit controls four sets of brake actuators. The brake actuator also includes a pressure sensor and a rotor position sensor; the drive motor, pressure sensor and rotor position sensor are electrically connected to the electronic control unit, and the rotor position sensor is placed inside the drive motor; the reciprocating mechanism is provided with three oil ports, two of which are connected to the oil pot, and the other is connected to the brake caliper, and the pressure sensor is located at the oil port where the reciprocating mechanism is connected to the brake caliper; the reciprocating mechanism adopts a lead screw nut structure, and the nut is driven to move by the rotation of the lead screw. At the same time, an elastic limit device is provided at the bottom to prevent the nut from detaching from the reciprocating mechanism when it is quickly retreated, which can effectively protect the reciprocating mechanism and effectively increase the volume of the plunger cylinder. The electronic mechanical hydraulic wire control brake system of new energy vehicles includes ABS system, EBD system, TCS system, and ESC system.

[0007] Compared with the prior art, the present invention has the following beneficial effects: 1. The EMHB brake-by-wire system equips each wheel with a set of brake actuators. The oil tank is connected to the oil inlet and outlet of each brake actuator, which can effectively ensure the oil supply and avoid the generation of pressure and vacuum.

[0008] 2. The EMHB brake-by-wire system integrates multiple intelligent braking functions such as ABS, EBD, TCS, and ESC. It relies on the drive motor to drive the hydraulic brake actuator, effectively making up for the deficiencies and shortcomings of EHB and EMB. It can effectively reduce costs, simplify pipelines, reduce the use of brake fluid, and reduce unsprung mass, thereby effectively improving the brake pressure control accuracy, enhancing the vehicle's maneuverability and stability, as well as the active safety performance of the entire vehicle.

[0009] 3. The brake actuator can be combined at will and is suitable for single-wheel to multi-axle vehicle braking systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1It is a hydraulic principle diagram of the combined EMHB brake-by-wire system of the present invention; Figure 2 It is a structural schematic diagram of the combined EMHB brake-by-wire system of the present invention; Figure 3 It is a schematic diagram of the reciprocating actuating mechanism of the combined EMHB brake-by-wire system of the present invention; Figure 4 It is a schematic diagram of the combined EMHB brake-by-wire system of the present invention (single wheel); Figure 5 The schematic diagram of the combined EMHB brake-by-wire system of the present invention (single axis); Figure 6 It is a structural schematic diagram of the combined EMHB brake-by-wire system of the present invention (single wheel); Figure 7 It is a structural schematic diagram of the combined EMHB brake-by-wire system of the present invention (single axis).

[0011] Among them: 1. Oil pot; 2. Reciprocating mechanism; 3. Brake caliper; 4. Normally closed pressure reducing valve; 5. Drive motor; 6. Electronic control unit ECU; 21. FL brake actuator; 22. FR brake actuator; 23. RL brake actuator; 24. RR brake actuator; 31. FL brake caliper; 32. FR brake caliper; 33. RL brake caliper; 34. RR brake caliper; 41. FL normally closed pressure reducing valve; 42. FR normally closed pressure reducing valve; 43. RL normally closed pressure reducing valve; 44. RR normally closed pressure reducing valve; 51, FL drive motor; 52, FR drive motor; 53, RL drive motor; 54, RR drive motor; 61, FL electronic control unit ECU; 62, FR electronic control unit ECU; 63, RL electronic control unit ECU; 64, RR electronic control unit ECU; 101, front axle oil pot; 102, rear axle oil pot; 601, front axle electronic control unit ECU; 602, rear axle electronic control unit ECU; 201, fixed screw; 202, moving nut; 7, rotor position sensor; 8, pressure sensor. Implementation

[0012] The combined electronic mechanical hydraulic wire control brake system for new energy vehicles provided by the present invention uses a drive motor as a power source and reciprocates through a reciprocating actuating mechanism to achieve rapid and precise linear changes in brake pressure. The invention is further described below in conjunction with the accompanying drawings.

[0013] See also Figure 1The combined EMHB brake-by-wire system includes an oil pot 1, a reciprocating mechanism 2, a brake caliper 3, a normally closed pressure reducing valve 4, a drive motor 5, and an electronic control unit ECU 6. The FL reciprocating mechanism 2 and the normally closed pressure reducing valve 4 are respectively connected to the oil pot 1; the reciprocating mechanism 2 and the normally closed pressure reducing valve 4 are connected to the brake caliper 3; the reciprocating mechanism 2 is connected to the drive motor 5; the electronic control unit ECU 6 is used to send control instructions and receive feedback signals from the reciprocating mechanism 2 and the drive motor 5.

[0014] See also Figure 2 The structure of the combined EMHB brake-by-wire system includes an electronic control unit 6, a drive motor 5, a rotor position sensor 7, a reciprocating mechanism 2, a pressure sensor 8, an oil inlet and outlet, and brake calipers 31-34. The pressure sensor 8 and the rotor position sensor 7 send signals to the electronic control unit 6 respectively; the electronic control unit 6 is connected to the drive motor 5 and sends signals to control the motor; the rotor position sensor 7 is integrated in the drive motor 5; the reciprocating mechanism 2 is connected to the drive motor 5; the oil pot 1 is connected to the reciprocating mechanism 2 through the oil inlet and outlet; the brake caliper is connected to the reciprocating mechanism 2 through the oil inlet and outlet; the pressure sensor 8 is placed between the reciprocating mechanism 2 and the brake caliper.

[0015] See also Figure 3 The reciprocating actuating mechanism of the combined EMHB wire-controlled braking system includes a driving motor 5, a moving nut 202, and a fixed screw 201; the driving motor 5 is connected to the fixed screw 201 and passes through the moving nut 202; one end of the fixed screw 201 is fixed to the housing, and the other end is connected to the driving motor 5.

[0016] See also Figure 4 The combined EMHB brake-by-wire system (single wheel) includes an electronic control unit 61-64, a normally closed pressure reducing valve 41-44, a drive motor 51-54, an oil pot 11-14, a FL brake actuator 21, a FR brake actuator 22, a RL brake actuator 23, a RR brake actuator 24, a FL brake caliper 31, a FR brake caliper 32, a RL brake caliper 33, a RR brake caliper 34; a FL brake caliper 31, a FR brake caliper 32, a RL brake caliper 33, a RR brake caliper 34 are respectively connected to the FL brake actuator 21, the FR brake actuator 22, the RL brake actuator 23, the RR brake actuator 24 and the corresponding normally closed pressure reducing valves 41-44; the normally closed pressure reducing valves 41-44 and the brake actuators 21-24 are respectively connected to the corresponding oil pots 11-14; the drive motors 51-54 are respectively connected to the corresponding brake actuators 21-24; the electronic control units 61-64 are respectively connected to the corresponding normally closed pressure reducing valves 41-44 and the drive motors 51-54.

[0017] See also Figure 5 The combined EMHB brake-by-wire system (single axis) includes a front axle electronic control unit ECU 601, a rear axle electronic control unit ECU 602, normally closed pressure reducing valves 41-44, drive motors 51-54, fuel tanks 101, 102, FL brake actuator 21, FR brake actuator 22, RL brake actuator 23, RR brake actuator 24, FL brake caliper 31, FR brake caliper 32, RL brake caliper 33, RR brake caliper 34; the FL brake caliper 31, FR brake caliper 32, RL brake caliper 33, RR brake caliper 34 are respectively connected to the FL brake actuator 21, FR brake actuator 22, RL brake caliper 33, RR brake caliper 34. The brake actuator 23 and the RR brake actuator 24 are connected to the corresponding normally closed pressure reducing valves 41-44; the normally closed pressure reducing valve 41 and the normally closed pressure reducing valve 42 and the FL brake actuator 21 and the FR brake actuator 22 are respectively connected to the corresponding fuel tank 101; the normally closed pressure reducing valve 43 and the normally closed pressure reducing valve 44 and the RL brake actuator 23 and the RR brake actuator 24 are respectively connected to the corresponding fuel tank 102; the drive motors 51-54 are respectively connected to the corresponding brake actuators 21-24; the front axle electronic control unit ECU 601 is connected to the normally closed pressure reducing valve 41 and the normally closed pressure reducing valve 42 and the drive motor 51 and the motor 52; the rear axle electronic control unit ECU 602 is connected to the normally closed pressure reducing valve 43 and the normally closed pressure reducing valve 44 and the drive motor 53 and the motor 54.

[0018] See also Figure 6 The structure of the combined EMHB brake-by-wire system (single wheel) includes a CAN bus, four electronic control units ECU, four pressure sensors, four reciprocating mechanisms, four rotor position sensors, and four brake calipers; the brake calipers are respectively connected to the pressure sensors and the reciprocating mechanisms; the pressure sensors, brake actuators, and rotor position sensors are respectively connected to the corresponding electronic control units ECU; the electronic control unit ECU is connected to the CAN bus for communication.

[0019] See also Figure 7 The structure of the combined EMHB brake-by-wire system (single axis) includes a CAN bus, two electronic control units ECU, four pressure sensors, four reciprocating actuating mechanisms, four rotor position sensors, and four brake calipers; the brake calipers are respectively connected to the pressure sensors and the reciprocating actuating mechanisms; the two pressure sensors, the two brake actuators, and the two rotor position sensors are simultaneously connected to an electronic control unit ECU; the electronic control unit ECU 6 is connected to the CAN bus for communication.

[0020] The working principle of the present invention will be described in detail below through embodiments.

[0021] The combined EMHB wire-controlled brake system has basic braking functions of boosting, building pressure and maintaining pressure. In the boosting condition, the EMHB wire-controlled hydraulic brake system receives the CAN bus message data, and the electronic control unit ECU 6 of the brake actuator of each wheel controls the drive motor 5 to rotate, and the drive motor 5 drives the fixed screw 201 in the reciprocating mechanism 2 to rotate, so that the moving nut 202 moves to push the brake fluid into the brake caliper 3 to increase the braking pressure. In the decompression condition, the EMHB wire-controlled hydraulic brake system receives the CAN bus message data, and the electronic control unit ECU 6 of the brake actuator of each wheel controls the drive motor 5 to rotate in the opposite direction, and the drive motor 5 drives the fixed screw 201 in the reciprocating mechanism 2 to rotate in the opposite direction, so that the moving nut 202 moves in the direction close to the drive motor 5. The brake fluid in the brake caliper 3 flows to the reciprocating mechanism 2 under the action of pressure and returns to the oil pot 1. In order to speed up the reflux of the brake fluid, the normally closed pressure reducing valve 4 in the brake actuator is energized to connect the brake caliper and the oil pot to achieve rapid release of the brake pressure. During the pressure-maintaining condition, the EMHB wire-controlled hydraulic brake system receives the CAN bus message data, and the electronic control unit ECU 6 of the brake actuator of each wheel controls the drive motor 5 to stop, so that the pressure in the reciprocating mechanism 2 and the brake caliper is maintained in a stable pressure range.

[0022] The EMHB wire-controlled brake system can realize active pressure regulation. After receiving the pressure signal, wheel speed signal and rotor position signal, the electronic control unit ECU 6 of the brake actuator of each wheel controls the drive motor 5 to rotate rapidly forward and reverse. The drive motor 5 drives the fixed screw 201 in the reciprocating mechanism 2 to rotate rapidly forward and reverse, so that the moving nut 202 moves back and forth rapidly, thereby realizing active, rapid and precise regulation of the pressure in the brake caliper. When an emergency occurs, the EMHB wire-controlled hydraulic brake system receives the CAN bus message data, and the electronic control unit ECU 6 of the brake actuator of each wheel performs weak magnetic control on the drive motor 5 to increase its speed in the low torque stage, thereby further ensuring the rapid establishment of pressure and reducing the response time.

Claims

1. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles, comprising an electronic control unit, an oil tank and a brake actuator, Features: The brake actuator includes a drive motor, a reciprocating mechanism and a normally closed pressure reducing valve. The normally closed pressure reducing valve is built into the brake actuator and is respectively connected to the oil tank and the brake caliper. The drive motor is connected to the reciprocating mechanism. The drive motor drives the reciprocating mechanism to move back and forth rapidly, completes the application and release of the wheel braking force, and realizes fast, precise and linear pressure regulation.

2. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles according to claim 1, Features: Each wheel is matched with a set of brake actuators; one electronic control unit controls one set of brake actuators.

3. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles according to claim 1, Features: Each wheel is matched with a set of brake actuators; one electronic control unit controls 2 sets of brake actuators.

4. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles according to claim 1, Features: Each wheel is matched with a set of brake actuators; one electronic control unit controls 4 sets of brake actuators.

5. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles according to any one of claims 2 to 4, Features: The brake actuator also includes a pressure sensor and a rotor position sensor; the drive motor, the pressure sensor and the rotor position sensor are electrically connected to the electronic control unit, and the rotor position sensor is placed inside the drive motor; the reciprocating mechanism is provided with three oil ports, two of which are connected to the oil pot, and the other is connected to the brake caliper, and the pressure sensor is located at the oil port where the reciprocating mechanism is connected to the brake caliper; the reciprocating mechanism adopts a screw-nut structure, and the nut is driven to move by the rotation of the screw, and an elastic limit device is provided at the bottom to prevent the nut from detaching from the reciprocating mechanism when it is quickly retreated, which can effectively protect the reciprocating mechanism and effectively increase the volume of the plunger cylinder.

6. A combined electronic mechanical hydraulic brake-by-wire system for new energy vehicles according to any one of claims 2 to 4, Features: The electronic mechanical hydraulic brake-by-wire system of the new energy vehicle includes an ABS system, an EBD system, a TCS system, and an ESC system.

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