Vehicle electronic mechanical brake, braking system and control method

Abstract

The invention provides an electronic mechanical brake of a vehicle. The electronic mechanical brake comprises a driver, a planetary gear assembly and brake calipers. An axial first channel and a second channel perpendicular to the first channel are formed in the brake caliper, and the second channel is communicated with the tail end of the first channel. A planetary roller lead screw pair is installed in the first channel in the axial direction, the peripheral face of the planetary roller lead screw pair is sleeved with a piston, and the piston is in clearance fit with the inner wall of the first channel. A brake disc is installed in the second channel, a movable friction plate is arranged between the brake disc and the piston, and a fixed friction plate is arranged on the side, away from the first channel, of the brake disc. The planetary roller lead screw pair is connected with an output shaft of the planetary gear assembly, the driver drives the planetary gear assembly to rotate, and the planetary roller lead screw pair converts rotary motion into linear motion in the axial direction to push the movable friction plate and the fixed friction plate to clamp the brake disc. The invention further provides a braking system and a control method.

Description

Technical Field

[0001] The present invention relates to the field of vehicle braking, and in particular to a vehicle electronic mechanical brake, a braking system and a control method. Background Art

[0002] Wire-controlled chassis is one of the important development directions of commercial vehicles. Wire-controlled brake is the only technology of wire-controlled chassis that has not been commercially applied. Electromechanical braking technology meets the needs of wire-controlled brake and is the ultimate direction of wire-controlled brake development.

[0003] Compared with passenger cars, commercial vehicles require greater braking force and control accuracy. Traditional commercial vehicle brakes usually use pneumatic disc brakes. Due to the working characteristics of compressed air, this type of brake has the characteristics of braking hysteresis and long response time. At the same time, the braking accuracy is poor, and the size and weight are relatively large, which cannot meet the development needs of commercial vehicle brakes. The electronic mechanical brake system (EMB, Electronic Mechanical Brake) replaces the traditional pneumatic / hydraulic pipeline with a fully mechanical braking structure, and uses the output torque of the drive motor to press the brake disc to achieve vehicle braking through the method of deceleration and torque increase and movement direction conversion. It has huge advantages over traditional brakes in terms of response time, braking accuracy, size and weight.

[0004] The braking force of commercial vehicles can reach 4 times or more than that of passenger vehicles. Therefore, the roller screw pair used in the mainstream solution of passenger car electronic mechanical braking system is limited in its load-bearing capacity when used in commercial vehicle electronic mechanical braking system. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a vehicle electronic mechanical brake, a braking system and a control method, which can meet the high braking force and braking response time requirements of commercial vehicle brakes.

[0006] In order to solve the above technical problems, the present invention provides a vehicle electronic mechanical brake, comprising a driver, a planetary gear assembly, and a brake caliper; the brake caliper has an axial first channel and a second channel perpendicular to the first channel, and the second channel is connected to the end of the first channel;

[0007] A planetary roller screw pair is axially installed in the first channel, a piston is sleeved on the outer circumference of the planetary roller screw pair, and the piston is in clearance fit with the inner wall of the first channel;

[0008] A brake disc is installed in the second channel, a movable friction plate is arranged between the brake disc and the piston, and a fixed friction plate is arranged on the side of the brake disc away from the first channel;

[0009] The planetary roller screw pair is connected to the output shaft of the planetary gear assembly, and the driver drives the planetary gear assembly to rotate. The planetary roller screw pair converts the rotational motion into linear motion in the axial direction, pushing the movable friction plate and the fixed friction plate to clamp the brake disc.

[0010] In some embodiments, the planetary roller screw pair includes a planetary roller screw main shaft, a plurality of rollers, the outer surface of the rollers is provided with a threaded groove, and the outer surface of the planetary roller screw main shaft is provided with a spiral raceway meshing with the plurality of rollers.

[0011] In some embodiments, the planetary roller screw pair further includes a sleeve, and an inner spiral raceway is provided on the inner wall of the sleeve to mesh with a plurality of rollers.

[0012] In some embodiments, the planetary roller screw pair further includes a flange, the flange is provided with a plurality of embedding grooves along the circumference, and the rollers are embedded in the embedding grooves of the flange.

[0013] In some embodiments, the planetary roller screw pair further includes an end cover, the end cover is provided with a main shaft groove, the main shaft of the planetary roller screw is embedded in the main shaft groove, and the end cover covers the sleeve.

[0014] In some embodiments, the sleeve is provided with a flange along the circumference, and the piston is fixed to the flange by screws.

[0015] In some embodiments, the output shaft of the planetary gear assembly is connected to the planetary roller screw spindle via a coupling.

[0016] In some of the embodiments, the planetary gear assembly is circumferentially mounted with ball bearings.

[0017] The present invention also provides a vehicle electronic mechanical brake system, comprising a control assembly and the above-mentioned vehicle electronic mechanical brake, wherein the control assembly generates a braking force signal based on collected data and transmits the braking force signal to the vehicle electronic mechanical brake to control the braking of the vehicle electronic mechanical brake.

[0018] The present invention also provides a control method for the above-mentioned vehicle electronic mechanical braking system, comprising the following steps:

[0019] Step 1: When the vehicle is running, the brake pedal displacement sensor and the accelerator pedal displacement sensor are used to collect pedal displacement data in real time;

[0020] Step 2: The control assembly determines the driver's deceleration or braking intention and generates a braking force signal based on the accelerator pedal displacement data and brake pedal displacement data collected in step 1;

[0021] Step 3: The vehicle's electronic mechanical brake performs braking operations according to the braking force signal of the control assembly, clamps the brake disc by pushing the movable friction plate, and generates braking force.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The vehicle electronic mechanical brake provided by the present invention reduces the torque of the output torque of the driver through the planetary gear assembly and increases the torque, and changes the rotational motion into linear motion along the axial direction through the planetary roller screw, pushing the piston to drive the movable friction plate to press the brake disc, and providing equal and opposite braking friction forces on both sides to achieve the driving brake of commercial vehicles. The electronic mechanical brake using the structure of the present invention can have a faster braking response time and braking comfort after the driver steps on the brake pedal, and also meets the small size and high integration of the electronic mechanical brake, which is convenient for introducing sensors or mechanical auxiliary mechanisms.

[0024] The braking system provided by the present invention uses a driver intention recognition method, which can effectively determine the braking scheme to be adopted, thereby improving the braking response speed and braking comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a vehicle electronic mechanical brake of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the planetary roller screw pair of the present invention;

[0027] Figure 3 is a schematic diagram of a braking process of a vehicle electronic mechanical braking system of the present invention;

[0028] Figure 4 It is a schematic diagram of a control method of a vehicle electronic mechanical braking system of the present invention.

[0029] 1. Driver; 2. Planetary gear assembly; 3. Brake caliper; 4. Coupling; 5. Piston; 6. Fixed friction plate; 7. Brake disc; 8. Planetary roller screw pair; 9. Movable friction plate; 10. Small screws; 11. Planetary gear assembly output shaft; 12. Ball bearing; 13. Sleeve; 14. Planetary roller screw spindle; 15. Roller; 16. Flange; 17. End cover. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] This embodiment provides a vehicle electronic mechanical brake, including a driver 1, a planetary gear assembly 2, a brake caliper 3, a coupling 4, a piston 5, a fixed friction plate 6, a brake disc 7, a planetary roller screw pair 8, and a movable friction plate 9;

[0034] The brake caliper 3 has a first axial channel and a second channel perpendicular to the first channel, and the second channel is connected to the end of the first channel;

[0035] A planetary roller screw pair 8 is axially installed in the first channel. The planetary roller screw pair 8 includes a sleeve 13 , a planetary roller screw main shaft 14 , a plurality of roller posts, a flange 16 , and an end cover 17 .

[0036] The planetary roller screw pair 8 of this embodiment realizes efficient transmission through a precisely designed multi-point meshing structure. Specifically, the outer surface of the roller 15 is provided with a thread groove, and the outer surface of the planetary roller screw main shaft 14 is provided with a spiral raceway meshing with multiple rollers 15. The inner wall of the sleeve 13 is provided with an inner spiral raceway meshing with multiple rollers 15, forming a uniform load distribution structure with multiple contact points, thereby effectively reducing the stress concentration of single-point contact and extending the service life of the component. The flange 16 is provided with multiple embedded grooves along the circumference, and the roller 15 is embedded in the embedded groove of the flange 16. The flange 16 structure of this embodiment can fix the roller 15 and play a guiding role, ensuring the smooth operation of the roller 15 during operation. The end cover 17 is provided with a spindle groove, and the planetary roller screw main shaft 14 is embedded in the spindle groove. The end cover 17 covers the sleeve 13, thereby encapsulating the roller assembly and playing a role in dust and pollution prevention.

[0037] The sleeve 13 of the planetary roller screw pair 8 is provided with a flange along the circumferential direction, and the outer circumferential surface of the planetary roller screw pair 8 is sleeved with a piston 5 , and the piston 5 is fixed to the flange by means of small screws 10 .

[0038] Furthermore, a brake disc 7 is installed in the second channel, a movable friction plate 9 is arranged between the brake disc 7 and the piston 5, and a fixed friction plate 6 is arranged on the side of the brake disc 7 away from the first channel.

[0039] The output shaft 11 of the planetary gear assembly is connected to the main shaft of the planetary roller screw through the coupling 4, and the driver 1 is connected to the main shaft of the planetary gear assembly 2. The driver 1 drives the planetary gear assembly 2 to rotate, and the planetary gear assembly 2 drives the planetary roller screw main shaft 14 to rotate. The spiral raceway on the surface of the planetary roller screw main shaft 14 meshes with the roller 15, causing the roller 15 to roll along the main shaft direction. At the same time, since the outer surface of the roller 15 is provided with a spiral groove that matches the spiral raceway in the sleeve 13, the rotation of the roller 15 will produce axial movement, thereby converting the rotational motion into linear motion in the axial direction.

[0040] The planetary roller screw pair 8 converts the rotational motion into linear motion, pushing the piston 5 connected thereto to move toward the brake disc 7. The piston 5 and the inner wall of the first channel are clearance-fitted, so the axial movement and axial rotation of the piston 5 do not affect the brake caliper 3.

[0041] As the piston 5 moves forward, the movable friction plate 9 and the fixed friction plate 6 gradually clamp the brake disc 7 to generate braking force, achieving the purpose of slowing down or stopping the vehicle. Push the movable friction plate 9 and the fixed friction plate 6 to clamp the brake disc 7. In this process, the coupling 4 ensures the coaxiality and stability of power transmission, and the brake caliper 3 applies the entire braking force to the brake disc 7 to achieve efficient braking force output. When the brake is released, the drive motor runs in the reverse direction, and the planetary roller screw pair 8 drives the piston 5 to retract, so that the movable friction plate 9 leaves the brake disc 7, thereby releasing the clamping force on the brake disc 7 and restoring the normal operation of the vehicle.

[0042] In order to reduce friction loss and improve work efficiency, in this embodiment, the planetary gear assembly 2 is provided with a ball bearing 12 along the circumferential direction. The ball bearing 12 limits the radial and axial floating of the planetary gear assembly 2.

[0043] The vehicle electronic mechanical brake of this embodiment cooperates with the control assembly to form a vehicle electronic mechanical brake system, and realizes the recognition and execution of the driver's braking intention through precise signal acquisition and processing. The specific control method includes the following steps:

[0044] Step 1: When the driver steps on the brake pedal, the brake pedal sensor or accelerator pedal sensor collects brake / accelerator pedal data and converts it into an electrical signal to transmit to the electronic mechanical brake control assembly.

[0045] Step 2: The control assembly calculates the driver's braking intention (mild deceleration, moderate deceleration, strong deceleration; mild braking, moderate braking, strong braking) based on the pedal displacement and force feedback data collected in step 1 and a preset algorithm, and generates a corresponding braking force signal;

[0046] Step 3: The braking force signal is transmitted to the driver 1 of the vehicle electronic mechanical brake of this embodiment. After receiving the signal, the driver 1 drives the actuator of the electronic mechanical brake (i.e., the planetary gear assembly 2 and the planetary roller screw pair 8) to perform the braking action, and the brake disc 7 is clamped by pushing the brake piston 5 and the friction plate to generate the braking force.

[0047] At the same time, the braking system also collects feedback signals of the braking status in real time, including information such as braking force, actuator position and motion status, and transmits them back to the control assembly. The control assembly makes dynamic adjustments based on the difference between the feedback signal and the target braking force signal to ensure rapid response and precise control of the braking process.

[0048] The entire process achieves accurate recognition of the driver's intention and efficient braking through rapid signal transmission and closed-loop control mechanism. The electronic mechanical braking system designed by the present invention has the advantages of fast response speed, stable and reliable braking force, and can meet the braking requirements of commercial vehicles under high-frequency use conditions.

[0049] like Figure 4 As shown, according to the driver's braking intention, intention recognition is divided into six situations, including light deceleration, moderate deceleration, strong deceleration, and light braking, moderate braking, and strong braking, and corresponding control strategies are executed according to different intentions to meet the safety and comfort needs of the vehicle.

[0050] When the deceleration intention is present, the system prioritizes the smooth deceleration of the vehicle. The electronic mechanical brake control assembly calculates the target braking force based on the driver's pedal input signal, and the actuator generates braking force by gradually adjusting the displacement of the planetary roller screw pair 8, and dynamically tracks the driver's input intention to ensure that the braking force output is linear and smooth, thereby improving passenger comfort.

[0051] Under strong deceleration intention, the system recognizes the driver's urgent deceleration needs, and the control assembly will quickly calculate the target braking force and prioritize the use of the brake reserve capacity. At this time, the displacement of the planetary roller screw pair 8 is close to the maximum value, but it will not trigger strong braking action to avoid excessive impact, while ensuring the vehicle's rapid deceleration needs.

[0052] When the driver has a slight or moderate braking intention, the control system takes comfort as the primary goal and adjusts the displacement of the planetary roller screw pair 8 so that the braking force is gradually superimposed and keeps dynamic tracking with the pedal input. This process uses a closed-loop control algorithm to adjust the matching degree between the braking force output and the driver's input intention in real time to ensure smooth deceleration or parking of the vehicle.

[0053] When the driver has a strong braking intention (such as emergency braking), the control system prioritizes safety and quickly pushes the planetary roller screw pair 8 to reach the maximum displacement and applies the maximum braking force. At this time, the brake operates at full power to ensure that the brake disc 7 is in full contact with the friction plate, thereby providing the shortest braking distance and meeting the vehicle's safety braking needs in emergency situations.

[0054] The above is only a preferred specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the present invention within the technical scope disclosed by the present invention shall be deemed to infringe the protection scope of the present invention.

Claims

1. A vehicle electromechanical brake, characterized in that: It includes a driver, a planetary gear assembly, and a brake caliper; the brake caliper has a first axial channel and a second channel perpendicular to the first channel, and the second channel is connected to the end of the first channel; A planetary roller screw pair is axially installed in the first channel, a piston is sleeved on the outer circumference of the planetary roller screw pair, and the piston is in clearance fit with the inner wall of the first channel; A brake disc is installed in the second channel, a movable friction plate is arranged between the brake disc and the piston, and a fixed friction plate is arranged on the side of the brake disc away from the first channel; The planetary roller screw pair is connected to the output shaft of the planetary gear assembly, and the driver drives the planetary gear assembly to rotate. The planetary roller screw pair converts the rotational motion into linear motion in the axial direction, pushing the movable friction plate and the fixed friction plate to clamp the brake disc.

2. The vehicle electronic mechanical brake according to claim 1, characterized in that: The planetary roller screw pair comprises a planetary roller screw main shaft, a plurality of rollers, the outer surface of the rollers is provided with a thread groove, and the outer surface of the planetary roller screw main shaft is provided with a spiral raceway meshing with the plurality of rollers.

3. The vehicle electronic mechanical brake according to claim 2, characterized in that: The planetary roller screw pair also includes a sleeve, and an inner spiral raceway is arranged on the inner wall of the sleeve to mesh with a plurality of rollers.

4. The vehicle electronic mechanical brake according to claim 2, characterized in that: The planetary roller screw pair also includes a flange, and the flange is provided with a plurality of embedding grooves along the circumferential direction, and the rollers are embedded in the embedding grooves of the flange.

5. The vehicle electronic mechanical brake according to claim 3, characterized in that: The planetary roller screw pair also includes an end cover, on which a main shaft groove is provided, the main shaft of the planetary roller screw is embedded in the main shaft groove, and the end cover covers the sleeve.

6. The vehicle electronic mechanical brake according to claim 3, characterized in that: The sleeve is provided with a flange along the circumference, and the piston is fixed to the flange by screws.

7. The vehicle electronic mechanical brake according to claim 2, characterized in that: The output shaft of the planetary gear assembly is connected to the planetary roller screw main shaft through a coupling.

8. The vehicle electronic mechanical brake according to claim 1, characterized in that: The planetary gear assembly is provided with ball bearings along the circumference.

9. A vehicle electronic mechanical brake system, comprising a control assembly and the vehicle electronic mechanical brake according to any one of claims 1 to 8, wherein the control assembly generates a braking force signal based on collected data and transmits the braking force signal to the vehicle electronic mechanical brake to control the braking of the vehicle electronic mechanical brake.

10. A control method for a vehicle electronic mechanical brake system as claimed in claim 9, characterized in that: The following steps are involved: Step 1: When the vehicle is running, the brake pedal displacement sensor and the accelerator pedal displacement sensor are used to collect pedal displacement data in real time; Step 2: The control assembly determines the driver's deceleration or braking intention and generates a braking force signal based on the accelerator pedal displacement data and brake pedal displacement data collected in step 1; Step 3: The vehicle's electronic mechanical brake performs braking operations according to the braking force signal of the control assembly, clamps the brake disc by pushing the movable friction plate, and generates braking force.

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