A method for controlling the clamping force of a vehicle electromagnetic mechanical brake device

Abstract

The application discloses a clamping force control method of a vehicle electromagnetic mechanical brake device and belongs to the technical field of vehicle braking. The control method comprises the following steps: comparing a target rotation angle with a maximum limit rotation angle of a rotating shaft under the restriction of a thrust ring, and adjusting a motor to perform a release action or a clamping action; and when the current rotation angle of an output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first electromagnetic piston and the second electromagnetic piston are powered off. In the clamping process, the electromagnetic attraction force generated after the first electromagnetic piston and the second electromagnetic piston are powered on is preferentially utilized to drive the brake pad to rapidly contact the brake disc, active pre-tightening elimination of the brake gap is realized without mechanical transmission, meshing noise and vibration generated by high-speed rotation of motor-driven ball screws, gears and other components are avoided, mechanical noise in the braking process is significantly reduced, and response speed and control accuracy are improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle braking control system or component technology, and in particular to a method for controlling the clamping force of a vehicle electromagnetic mechanical braking device. Background Technology

[0002] With the development of automotive intelligence and electrification, electromechanical braking systems (EMB), as a core component of next-generation braking technology, are gradually replacing traditional hydraulic braking systems. Disc brakes, due to their excellent heat dissipation and stable braking performance, are widely used in modern vehicle braking systems. A typical electromechanical braking device usually consists of a permanent magnet synchronous motor, a planetary gear reducer, a ball screw transmission mechanism, a piston assembly, and a caliper clamping mechanism. Its working process mainly includes three stages: the brake clearance elimination stage, the brake clamping stage, and the brake release stage. During braking, the motor drives the piston axially through multi-stage mechanical transmission, clamping and releasing the brake disc to complete the braking action.

[0003] However, existing electromechanical braking devices still have several key problems. First, during the backlash elimination and brake release phases, the motor needs to drive the ball screw and gears at high speed, resulting in significant mechanical noise. Furthermore, due to the complexity of the transmission chain and the presence of multiple noise sources, it is difficult to effectively suppress this noise through conventional structural optimization or vibration isolation methods. Second, the mechanical transmission links (such as gear meshing and screw pair movement) exhibit response delays and backlashes, affecting braking response speed and control accuracy. Therefore, there is an urgent need to propose a novel braking device and its control method to shorten braking response time, reduce operating noise, and improve system reliability and dynamic performance. Summary of the Invention

[0004] This application provides a clamping force control method for a vehicle electromagnetic mechanical braking device, which solves the technical problems of slow speed and excessive noise in the gap elimination and release stages of the prior art.

[0005] This application provides a method for controlling the clamping force of a vehicle electromagnetic mechanical braking device, the control method comprising:

[0006] Step 1: The control drive module receives the braking force command issued by the control drive module and calculates the target rotation angle of the output shaft of the control drive module.

[0007] Step 2: Compare the target rotation angle with the maximum limit rotation angle of the shaft under the limitation of the thrust ring to obtain the comparison result. Based on the comparison result, adjust the motor to perform the release action or clamping action.

[0008] Step 3: When the motor performs the clamping action, the electromagnetic force generated by the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the clamping of the brake pads and the brake disc.

[0009] Step 4: When the current rotation angle of the output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first and second electromagnetic pistons are de-energized.

[0010] In some embodiments, the comparison results include:

[0011] Step 21: If the target rotation angle is less than or equal to the maximum limit rotation angle, the current rotation angle of the motor rotor is obtained from the motor rotor position sensor, and the current rotation angle of the output shaft is calculated. If the current rotation angle of the output shaft is less than the target rotation angle, the clamping action is performed.

[0012] Step 22: If the target rotation angle is greater than the maximum limit rotation angle, then set the target rotation angle to the maximum limit rotation angle, and then execute step 21.

[0013] In some embodiments, step 3 includes:

[0014] Step 31: During the gap elimination stage, after the brake pads come into contact with the brake disc, the electromagnetic force generated by the energization of the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the action of the brake pads clamping the brake disc.

[0015] In some embodiments, step 3 further includes:

[0016] Step 32: Determine whether the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft;

[0017] Step 33: If the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft, then determine whether the current rotation angle of the output shaft is less than the second rotation angle of the output shaft.

[0018] Step 34: If the current rotation angle of the output shaft is less than or equal to the first rotation angle of the output shaft, then the delay time... Proceed to step 33.

[0019] In some embodiments, step 3 further includes:

[0020] Step 35: If the current rotation angle of the output shaft is greater than or equal to the second rotation angle of the output shaft, the drive control module controls the motor speed to make the current rotation angle of the output shaft equal to the target rotation angle.

[0021] Step 36: If the current rotation angle of the output shaft is less than the second rotation angle of the output shaft, the drive control module controls the motor position to make the current rotation angle of the output shaft equal to the second rotation angle of the output shaft, and then executes step 35.

[0022] In some embodiments, step 3 further includes:

[0023] Step 37: When the current rotation angle of the output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first and second electromagnetic pistons are de-energized.

[0024] Step 38: Determine whether the second rotation angle of the output shaft is less than the third rotation angle.

[0025] In some embodiments, step 4 includes:

[0026] Step 41: If the second rotation angle is less than the third rotation angle, update the second rotation angle according to the torque change curve during braking.

[0027] Step 42: If the second rotation angle is greater than or equal to the third rotation angle, the drive control module sends a brake pad over-wear flag to the vehicle bus.

[0028] In some embodiments, the comparison result further includes: if the target rotation angle is less than or equal to the maximum limit rotation angle, the current rotation angle of the output shaft is calculated based on the current rotation angle of the motor rotor obtained from the motor rotor position sensor; if the current rotation angle of the output shaft is greater than or equal to the target rotation angle, a release action is performed.

[0029] In some embodiments, the process of performing the release action further includes:

[0030] Step 43: When the current rotation angle of the output shaft is equal to the target rotation angle, the drive control module controls the motor to stop rotating.

[0031] In some embodiments, the method further includes the following steps prior to step 43:

[0032] Step 23: Determine if the target rotation angle is less than the second rotation angle;

[0033] Step 24: If the target rotation angle is less than the second rotation angle, then the first and second electromagnetic pistons are de-energized, the drive control module controls the motor speed, and the motor output shaft rotates in the opposite direction.

[0034] Step 25: If the target rotation angle is greater than or equal to the second rotation angle, then the first and second electromagnetic pistons are de-energized, the drive control module controls the motor position, and the motor output shaft rotates in the opposite direction.

[0035] The beneficial effects of this application are as follows:

[0036] The clamping force control method of the vehicle electromagnetic mechanical braking device provided in this application prioritizes the electromagnetic attraction generated after the first and second electromagnetic pistons are energized during the clamping process, driving the brake pads to quickly contact the brake disc, thereby achieving active, non-mechanical transmission-free pre-tightening elimination of the braking gap. This avoids the meshing noise and vibration generated by the high-speed operation of components such as ball screws and gears driven by the motor, significantly reducing mechanical noise during the braking process and improving response speed and control accuracy. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0038] Figure 1 This is a flowchart illustrating the clamping force control method of a vehicle electromagnetic mechanical braking device according to the present invention.

[0039] Figure 2 This is a detailed flowchart of the clamping force control method of a vehicle electromagnetic mechanical braking device according to the present invention;

[0040] Figure 3 This is an exploded view of an electromagnetic mechanical braking device according to the present invention;

[0041] Figure 4 This is a three-dimensional schematic diagram of an electromagnetic mechanical braking device according to the present invention;

[0042] Figure 5 This is a three-dimensional schematic diagram of the rotating shaft of the present invention;

[0043] Figure 6 This is a three-dimensional schematic diagram of the thrust ring of the present invention;

[0044] Figure 7 This is a three-dimensional schematic diagram of the motor reducer assembly and drive control assembly of the present invention;

[0045] Figure 8 This is a schematic diagram of the fully clamped state of the rotating shaft ring assembly of the present invention;

[0046] Figure 9 This is a schematic diagram of the fully released state of the rotating shaft ring assembly of the present invention;

[0047] Figure 10 This is a three-dimensional schematic diagram of the caliper body of the present invention;

[0048] Figure 11 This is a schematic diagram of the motion trajectory of the needle roller in the thrust groove of the rotating shaft.

[0049] The components are as follows: 1. Brake disc; 2. Second brake pad; 3. First brake pad; 4. Caliper bracket; 5. First electromagnetic piston; 6. Caliper body; 6a. Slide rod; 7. Return mechanism; 8. Second electromagnetic piston; 9. Thrust ring; 9a. Needle roller; 10. Rotary shaft; 10a. Thrust groove; 11. Limiting plate; 12. Fixed bracket; 13. Motor reducer assembly; 13a. Output shaft; 14. Drive control assembly; 15. Return spring. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0051] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0052] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0053] The clearance elimination stage refers to the movement stage where a clearance exists between the brake pad assembly and the brake disc, but the clearance gradually decreases. The release stage refers to the movement stage where a clearance exists between the brake pad assembly and the brake disc, but the clearance gradually increases. The clamping stage refers to the movement stage where the brake pad assembly comes into contact with the brake disc.

[0054] This application provides a vehicle electromagnetic mechanical braking device and clamping force control method, which solves the technical problem in the prior art where slow speed during the gap elimination and release stages leads to excessive noise.

[0055] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0056] like Figure 1As shown, this application provides a clamping force control method for a vehicle electromagnetic mechanical braking device, the control method comprising:

[0057] Step 1: The control drive module receives the braking force command issued by the control drive module and calculates the target rotation angle of the output shaft of the control drive module.

[0058] Step 2: Compare the target rotation angle with the maximum limit rotation angle of the shaft under the limitation of the thrust ring to obtain the comparison result. Based on the comparison result, adjust the motor to perform the release action or clamping action.

[0059] Step 3: When the motor performs the clamping action, the electromagnetic force generated by the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the clamping of the brake pads and the brake disc.

[0060] Step 4: When the current rotation angle of the output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first and second electromagnetic pistons are de-energized.

[0061] During the clamping process, the electromagnetic attraction generated by the first and second electromagnetic pistons after they are energized is used first to drive the brake pads to quickly contact the brake disc, thereby achieving active, mechanical transmission-free pre-tightening elimination of the brake gap. This avoids the meshing noise and vibration generated by the high-speed operation of components such as ball screws and gears driven by the motor, significantly reducing mechanical noise during the braking process and improving response speed and control accuracy.

[0062] Specifically, such as Figure 2 As shown, the control method includes:

[0063] Step 1: The control drive module receives the braking force command issued by the control drive module and calculates the target rotation angle of the output shaft of the control drive module. .

[0064] The braking force command is issued by the upper-level controller, and the rotation angle of the output shaft can be calculated using the following formula:

[0065] ;

[0066] In the formula, The target rotation angle of the output shaft. For the needle roller to move to such Figure 11 The rotation angle at point D is shown. The increase in the rotation angle of the output shaft that generates the mechanical braking torque. The relationship between braking force and the input braking force can be determined experimentally. Based on the input braking force command, the result can be calculated. value.

[0067] Step 2: Determine the target rotation angle Is it less than or equal to the maximum limit rotation angle of the shaft under the constraint of the thrust ring? The comparison results are obtained, and based on these results, the motor is adjusted to perform either a release or clamping action. If the output shaft reaches its maximum limit angle during rotation... The output shaft stops rotating.

[0068] Specifically, the comparison results include:

[0069] Step 21: If the target rotation angle Less than or equal to the maximum limit angle of rotation The current rotation angle of the motor rotor is obtained from the motor rotor position sensor, and the rotation angle of the output shaft is calculated. If the current rotation angle of the output shaft is greater than or equal to the target rotation angle, a release action is performed; if the current rotation angle of the output shaft is less than the target rotation angle, a clamping action is performed.

[0070] Step 22: If the target rotation angle is greater than the maximum limit rotation angle Then, set the target rotation angle to equal the maximum limit rotation angle, and then execute step 21.

[0071] Furthermore, step 3 includes:

[0072] Step 31: During the gap elimination stage, after the brake pads come into contact with the brake disc, the electromagnetic forces generated by the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the action of the brake pads clamping the brake disc.

[0073] Step 3 also includes:

[0074] Step 32: Determine whether the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft. .

[0075] This represents the rotation angle of the output shaft as the needle roller moves between points AF. If the current rotation angle of the output shaft is greater than... If the needle roller's trajectory is not on AF, then the output shaft can begin to rotate. In an ideal situation... However, there is often a gap between the needle roller and the thrust groove, so in actual control, a certain amount of clearance is required. .

[0076] Step 33: If the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft. Then determine whether the current rotation angle of the output shaft is less than the second rotation angle of the output shaft. ;

[0077] Step 34: If the current rotation angle of the output shaft is less than or equal to the first rotation angle of the output shaft. Then the delay time Proceed to step 33.

[0078] Step 3 also includes:

[0079] Step 35: If the current rotation angle of the output shaft is greater than or equal to the second rotation angle of the output shaft. Then the drive control module controls the motor speed so that the current rotation angle of the output shaft is equal to the target rotation angle. .

[0080] At this point, the precise clamping force output is used as the control target, and the motor controller input is the target rotation angle of the motor rotor. The relationship between the motor rotor rotation angle and the output shaft rotation angle is as follows:

[0081] ;

[0082] In the formula, The rotation angle of the motor rotor. The output shaft rotation angle. This is the reduction ratio.

[0083] Step 36: If the current rotation angle of the output shaft is less than the second rotation angle of the output shaft. Then the drive control module controls the motor position so that the current rotation angle of the output shaft is equal to the second rotation angle of the output shaft. The shortest braking force loading time is taken as the control target, the maximum motor speed is input to the motor controller, and then step 35 is executed.

[0084] Step 3 also includes:

[0085] Step 37: The current rotation angle of the output shaft equals the target rotation angle. The motor's output shaft stops rotating, and the first and second electromagnetic pistons are de-energized.

[0086] Step 38: Determine the second rotation angle Is it less than the third rotation angle? , is the rotation angle when the output shaft rotates to point E. If it is less than, the brake pad thickness is considered normal. If it is greater than or equal to, the brake pad is considered worn.

[0087] Step 4 includes:

[0088] Step 41: The second rotation angle is less than the third rotation angle. The second rotation angle is updated based on the torque change curve during braking. The torque variation curve can be obtained through a thrust sensor or calculated through a state observation algorithm.

[0089] Step 42: The second rotation angle is greater than or equal to the third rotation angle. The drive control module sends a brake pad wear warning signal to the vehicle bus.

[0090] In step 2, the comparison result further includes: if the target rotation angle is less than or equal to the maximum limit rotation angle, the current rotation angle of the motor rotor is obtained according to the motor rotor position sensor, and the current rotation angle of the output shaft is calculated; if the current rotation angle of the output shaft is greater than or equal to the target rotation angle, then a release action is performed.

[0091] The release process also includes:

[0092] Step 43: When the current rotation angle of the output shaft is equal to the target rotation angle, the drive control module controls the motor to stop rotating.

[0093] The steps preceding step 43 also include:

[0094] Step 23: If the current rotation angle of the output shaft is greater than or equal to the target rotation angle. Then determine the target rotation angle. Is it less than the second rotation angle? ;like Less than If no additional clamping force is applied to the brake disc, the control target should be the shortest clamping force release time. Greater than If a clamping force is applied to the brake disc, the control target should be a precise clamping force output.

[0095] Step 24: If the target rotation angle is less than the second rotation angle Then, the first and second electromagnetic pistons are de-energized, the drive control module controls the motor speed, and the motor's output shaft rotates in the opposite direction.

[0096] Step 25: If the target rotation angle is greater than or equal to the second rotation angle Then, the first and second electromagnetic pistons are de-energized, the drive control module controls the motor position, and the motor's output shaft rotates in the opposite direction.

[0097] Then, proceed to step 43: if the current rotation angle of the output shaft is equal to the target rotation angle. Then the drive control module will control the motor to stop rotating.

[0098] Example 1: The current rotation angle of the output shaft is 0, the braking force command is the maximum designed braking force, and the brake pads show no wear.

[0099] First, step 1 is executed, where the control drive module receives the braking force command and calculates the output shaft rotation angle command value. At this moment, point D coincides with point B. ,at this time, For its maximum value, Execute step 2 to determine the output shaft rotation angle command value. Is it less than or equal to? If the output shaft rotation angle command value Is it greater than Then set the output shaft rotation angle command value. equal Output shaft rotation angle command value Less than or equal to ; Perform step 21 to determine if the current rotation angle of the output shaft is less than The current rotation angle of the output shaft is less than ; Execute step 31, the electromagnetic piston and the caliper-side electromagnetic piston are energized, and the braking clearance begins to be eliminated; Execute step 32, determine whether the current rotation angle of the output shaft is greater than The current rotation angle of the output shaft is less than or equal to Execute step 34, delay time Afterwards, the needle roller moves to point B; step 33 is executed to determine whether the current rotation angle of the output shaft is less than... At this point, point D coincides with point B, so the judgment result is negative. Step 35 is executed, and the drive control module performs position control on the motor until the output shaft rotates by an angle. ; Execute step 37, the output shaft rotation angle reaches The output shaft stops rotating, and the electromagnetic piston and the caliper-side electromagnetic piston are de-energized; proceed to step 38 to determine... Is it less than Assuming that the brake pads are already in contact with the brake disc when the needle rollers reach point B during this braking process, then The judgment result is yes; proceed to step 41, update the torque change curve during braking. The value, The output shaft rotation angle is the angle at which the needle roller moves to point D.

[0100] Example 2: The current rotation angle of the output shaft is 10% of the maximum rotation angle. The braking force command is 80% of the maximum design braking force. The brake pads are worn, but the degree of wear is within the normal range. After this braking operation, the wear is still within the normal range.

[0101] First, step 1 is executed, where the control drive module receives the braking force command and calculates the output shaft rotation angle command value. Point D lies between B and E. ,at this time, For the output shaft rotation angle increment corresponding to 80% braking force, execute step 2 to determine the output shaft rotation angle command value. Has it been achieved? ,at this time Less than Execute step 3 to determine if the current rotation angle of the output shaft is less than 1. If the judgment result is yes, proceed to step 31: energize the electromagnetic piston and the caliper-side electromagnetic piston to attract the brake disc and provide a certain clamping force. Proceed to step 32: determine whether the current rotation angle of the output shaft is greater than... At this point, the output shaft rotates by 10%. If the judgment result is yes, proceed to step 33 to determine whether the output shaft rotation angle is less than 1 / 3. If the judgment result is yes, proceed to step 36, whereby the drive control module controls the motor speed until the output shaft rotation angle equals... In step 35, the drive control module performs position control on the motor until the output shaft rotation angle equals... After executing step 37, the output shaft rotation angle reaches... The output shaft stops rotating, the electromagnetic piston and the caliper-side electromagnetic piston are de-energized, and step 38 is executed to determine... Is it less than Based on the actual change curve of the braking clamping force, it is determined that when the output shaft rotation angle is... At that time, the clamping force changes significantly, and If the judgment result is yes, proceed to step 41 and update the torque change curve during the braking process. The value of .

[0102] Example 3: The current rotation angle of the output shaft is 10% of the maximum rotation angle. The braking force command is 80% of the maximum design braking force. The brake pads showed wear, but the degree of wear was within the normal range. However, after this braking operation, the brake pads were excessively worn. .

[0103] First rotation angle The first rotation angle is the angle of rotation of the output shaft as the needle roller moves between points AF; the second rotation angle is... The rotation angle of the output shaft at point D is the needle roller position; the third rotation angle is... The rotation angle of the output shaft at point E represents the position of the needle roller.

[0104] The execution process of steps 1, 2, and 3 is the same as in Example 2.

[0105] Execute step 38 to determine Is it less than Based on the actual change curve of the braking clamping force, it is determined that when the output shaft rotation angle is... At that time, the clamping force changes significantly, and If the judgment result is negative, proceed to step 42, whereby the drive control module sends a brake pad excessive wear flag to the vehicle bus.

[0106] Example 4: The current rotation angle of the output shaft is 80% of the maximum rotation angle. The braking force command is 10% of the maximum design braking force. The brake pads are worn, but the degree of wear is within the normal range.

[0107] In step 1, the control drive module receives the braking force command and calculates the output shaft rotation angle command value. Execute step 2 to determine the output shaft rotation angle command value. Is it less than If the judgment result is yes, proceed to step 3: determine whether the current rotation angle of the output shaft is less than... If the result is negative, proceed to step 23 for further judgment. Is it less than If the judgment result is yes, proceed to step 24. The electromagnetic piston and the caliper-side electromagnetic piston are de-energized. The drive control module controls the motor speed, causing the output shaft to rotate in the opposite direction. Proceed to step 43, where the output shaft rotation angle reaches the commanded value. At that time, the output shaft stops rotating.

[0108] This clamping force control method achieves efficient, quiet, and intelligent management of the braking process through the coordinated control of electromagnetic drive and mechanical transmission. In the initial braking stage, the electromagnetic attraction generated by energizing the first and second electromagnetic pistons actively pulls the brake pads towards the brake disc, rapidly eliminating the braking gap. This process eliminates the need to start the motor reducer assembly, avoiding the mechanical noise generated by the high-speed drive of the ball screw and gear pair in traditional systems, significantly improving braking quietness. By judging the relationship between the current rotation angle of the output shaft and key thresholds, such as the first, second, and third rotation angles, the control strategy is dynamically switched: during clamping, if the current angle is less than the target angle, high-speed speed control is prioritized to establish braking force in the shortest time, followed by switching to precise position control to ensure the accuracy of the clamping force output; during release, based on the comparison between the target angle and the wear threshold, the system selects either maximum speed reverse rotation or precise return to position, balancing release speed and control accuracy. Meanwhile, by monitoring the movement position and torque change curve of the needle rollers in real time, key angle parameters are automatically updated to achieve online identification of the brake pad wear condition. When the second rotation angle is greater than or equal to the third rotation angle, an excessive wear flag is promptly sent to the vehicle bus, improving system safety and maintainability. The overall control logic is clear and responsive, taking into account multiple performance requirements such as braking response speed, control accuracy, noise suppression, and condition monitoring.

[0109] like Figures 3-9 As shown, the vehicle electromagnetic mechanical braking device provided in this application includes a brake disc 1, a caliper body 6, a brake assembly, and an electromagnetic piston assembly. The brake disc 1 is a conventional ventilated or solid disc structure, made of low-carbon steel or electrical pure iron, and participates in braking as a rotating element of the friction pair. The caliper body 6 spans both sides of the outer periphery of the brake disc 1 and can float or be fixedly installed along the axial direction of the brake disc 1. The first brake pad 3 is located away from the power input end of the braking device and is fixed inside the caliper body 6. The first brake pad 3 is installed in conjunction with the first electromagnetic piston 5. The second brake pad 2 is rigidly connected to the second electromagnetic piston 8 and moves axially synchronously with the second electromagnetic piston 8. In the electromagnetic piston assembly, the first electromagnetic piston 5 is located on the side away from the power input end, serving as a fixed-side electromagnetic unit. It is fixedly connected to the caliper body 6 by bolts or press-fitting, and has an internally embedded annular or segmented coil winding. The second electromagnetic piston 8 is located on the power input end side, sleeved on the outside of the rotating shaft 10 or the thrust rod, forming a sliding pair with the caliper body 6 with a clearance fit. It also integrates a coil winding, and when energized, it forms a magnetic circuit with the first electromagnetic piston 5, generating axial electromagnetic attraction or repulsion. The coil windings on the two electromagnetic pistons can be energized independently or synchronously, and mutual attraction or repulsion can be achieved by controlling the direction of the current. The coil windings are fixed to the piston cavity by an insulating frame, and a lead wire channel is provided to lead the current out to the drive control component 14.

[0110] Yes, it's possible. The coil winding can be installed on the inner wall of the caliper body 6 and arranged around the electromagnetic piston. The electromagnetic piston, as a magnetic core, participates in the magnetic circuit, still achieving the same electromagnetic drive function. In addition, the surface of the electromagnetic piston is equipped with a sealing ring to prevent dust and moisture intrusion, ensuring smooth movement and electrical safety.

[0111] By setting coil windings inside the first electromagnetic piston 5 and the second electromagnetic piston 8, the electromagnetic attraction or repulsion between the two electromagnetic pistons after energization can directly drive the brake pads to contact or disengage from the brake disc 1. This achieves the active elimination or release of the initial gap without starting the motor reducer assembly 13, thereby fundamentally avoiding the noise problem caused by high-speed mechanical transmission. Setting coil windings inside the first electromagnetic piston 5 and the second electromagnetic piston 8 is feasible in the prior art, so the specific structure of the coil windings will not be shown.

[0112] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0113] Preferred, such as Figure 3 , Figure 4 As shown, the braking device also includes a caliper bracket 4, and the caliper body 6 is installed in the caliper bracket 4 and can move within the caliper bracket 4.

[0114] The caliper body 6 is mounted within the caliper bracket 4 via a guide structure, allowing it to slide axially along the brake disc 1 within the bracket's defined range, forming a typical floating caliper structure. When a braking command is issued, the second electromagnetic piston 8, under the combined action of the power input thrust and electromagnetic force, pushes the second brake pad 2 against the inner side of the brake disc 1. The reaction force is transmitted through the caliper body 6 to the caliper bracket 4, causing the caliper body 6 to move outward along the bracket's guide direction, thus pressing the first brake pad 3 against the outer side of the brake disc 1, achieving simultaneous clamping on both sides. During the gap elimination phase, the coil windings within the first electromagnetic piston 5 and the second electromagnetic piston 8 are energized, generating mutually attracting electromagnetic forces that directly drive the second brake pad 2 towards the brake disc 1. Simultaneously, this pulls the caliper body 6 in the opposite direction, causing the first brake pad 3 to synchronously approach the brake disc 1, thereby quickly eliminating the braking gap without relying on the movement of mechanical transmission components. This structure, through active pre-tensioning by electromagnetic force, significantly shortens the braking response time, avoids the noise and wear generated by mechanical components such as the motor-driven ball screw during high-speed operation, and improves the system's quietness and dynamic response performance. Meanwhile, the caliper bracket 4 provides stable support and precise guidance for the entire braking unit, ensuring uniform distribution of braking force on both sides and improving braking stability and reliability.

[0115] Furthermore, such as Figure 3 , Figure 4As shown, the braking assembly also includes a return mechanism 7, and there are at least two return mechanisms 7. The return mechanism 7 is fixedly disposed on the caliper bracket 4 near the power input side of the braking device, and the movable end of the return mechanism is connected to the caliper body 6.

[0116] The fixed end of the return mechanism 7 is connected to the caliper bracket 4, and the movable end is connected to the caliper body 6, providing a restoring force during brake release. The return mechanism 7 can be a helical spring, disc spring, or rubber elastic element, preferably a helical spring with a guide rod structure. The guide rod is fixed to the caliper bracket 4, and the spring is sleeved outside the guide rod, with one end abutting against the caliper bracket 4 and the other end connected to the caliper body 6. After braking, an axial pulling force is applied, causing the caliper body 6 to return to its original position, allowing the first brake pad 3 and the second brake pad 2 to simultaneously detach from the surface of the brake disc 1, eliminating residual friction. In embodiments where the electromagnetic piston generates a repulsive force, the return mechanism 7 can assist in accelerating the release process and shortening the brake release time. As an equivalent solution, the return mechanism 7 can also use an elastic metal sheet or a hydraulic buffer reset device, as long as a stable axial restoring force can be provided to achieve the same function. This structure not only ensures reliable recovery of the brake clearance and prevents dragging wear, but also works in conjunction with the electromagnetic drive to improve the consistency of the dynamic response of the braking system. Meanwhile, the multi-point return mechanism enhances the smoothness of the caliper body 6 movement, avoids unilateral jamming or tilting wear, extends the service life of the brake pads, and improves braking reliability and safety.

[0117] Furthermore, such as Figure 3 As shown, the braking assembly also includes a return spring 15, and there are at least two return springs 15, which are connected between the caliper body 6 and the second electromagnetic piston 8.

[0118] A return spring 15 is disposed between the caliper body 6 and the second electromagnetic piston 8. At least two springs are configured and symmetrically arranged around the second electromagnetic piston 8. One end of the spring is connected to the caliper body 6, and the other end is connected to the second electromagnetic piston 8. It is used to provide a reset force during the brake release phase. The return spring 15 can be a helical compression spring or a torsion spring. Alternatively, the return spring 15 can be replaced with an elastic rubber pad or a bellows-type elastic element, installed in a spring groove on the outer periphery of the second electromagnetic piston 8, or fixed between the caliper body 6 and the piston connecting lug by a pin, ensuring uniform force and smooth movement. When braking ends, the electromagnetic coil is de-energized, and the thrust at the power input end is removed, the return spring 15 releases the stored elastic potential energy, pushing the second electromagnetic piston 8 to move away from the brake disc 1 relative to the caliper body 6. This causes the second brake pad 2 to quickly detach from the surface of the brake disc 1. Simultaneously, in conjunction with the overall reset action of the caliper body 6, the brake pads on both sides retract synchronously, effectively avoiding brake drag and energy loss.

[0119] Preferred, such as Figures 3-10 As shown, the braking assembly also includes a thrust ring 9, a rotating shaft 10, a motor reducer assembly 13, and a control drive module. The thrust ring 9 is fixedly connected to the second electromagnetic piston 8. The rotating shaft 10 is disposed inside the thrust ring 9. The output shaft 13a of the motor reducer assembly 13 is connected to the rotating shaft 10 via a key. The control drive module is fixedly disposed on the motor reducer assembly 13. The control drive module, the first electromagnetic piston 5, and the second electromagnetic piston 8 are all electrically connected to the control drive module.

[0120] The thrust ring 9 and the second electromagnetic piston 8 are rigidly connected by bolts or an interference fit, serving as the medium for transmitting mechanical thrust. Its inner bore is provided with a thrust groove 10a or a helical raceway, which cooperates with the needle rollers 9a or rolling elements on the outer circumference of the rotating shaft 10 to convert the rotational motion of the rotating shaft 10 into axial thrust. The rotating shaft 10 has a stepped shaft structure, with one end extending into the thrust ring 9. Through the interaction between the needle rollers 9a and the inclined surface of the thrust groove 10a, it pushes the thrust ring 9 and the second electromagnetic piston 8 axially during rotation. The other end is connected to the output shaft 13a of the motor reducer assembly 13 via a key and a pin, achieving reliable torque transmission. The motor reducer assembly 13 includes a permanent magnet synchronous motor and a planetary gear reducer, integrated and mounted on the outside of the caliper. The output shaft 13a, after reduction and torque amplification, drives the rotating shaft 10 to rotate, providing the high thrust required for braking. The control drive module is fixed to the housing of the motor reducer assembly 13. It integrates a controller and a driver, receives braking commands from the upper layer, controls the motor's start / stop, speed, and position, and simultaneously outputs drive current to the coil windings of the first electromagnetic piston 5 and the second electromagnetic piston 8, achieving independent control of the electromagnetic force. During braking, the control drive module receives signals from the controller and converts the external power supply into three-phase sinusoidal AC power to drive the permanent magnet synchronous motor to rotate. Simultaneously, the driver converts the external power supply into DC voltage for the caliper-side electromagnetic pistons and controls the current flow. The reducer input shaft is fixedly connected to the permanent magnet synchronous motor rotor, and the reducer output shaft 13a is the output shaft 13a. The reducer achieves speed reduction and torque increase.

[0121] Specifically, the connection between the rotating shaft 10 and the output shaft 13a can be achieved by using a spline, pin connection, or flexible coupling.

[0122] Furthermore, such as Figure 3 , Figure 8 , Figure 9 As shown, the braking assembly also includes a limiting plate 11, which is fixedly connected to the rotating shaft 10. A through hole is provided in the middle of the limiting plate 11, and the output shaft 13a of the motor reducer assembly 13 passes through the through hole.

[0123] The limiting plate 11 is connected to the rotating shaft 10 by a threaded connection or a pin, forming a synchronously moving whole. It has a through hole at its center, through which the output shaft 13a of the motor reducer assembly 13 passes, and transmits torque to the input end of the rotating shaft 10 via a key and a pin. The limiting plate 11 is located between the thrust ring 9 and the motor reducer, and its outer diameter is larger than the axial movement range of the thrust ring 9, used to limit excessive displacement of the thrust ring 9 towards the motor side. When the rotating shaft 10 rotates and pushes the thrust ring 9 towards the brake disc 1, the limiting plate 11 prevents further axial movement by mechanically contacting the end face of the thrust ring 9, ensuring the stability and reliability of the thrust transmission path and preventing assembly interference or damage caused by overtravel of the mechanism.

[0124] Furthermore, such as Figure 3 , Figure 4 As shown, the braking assembly also includes a fixed bracket 12, which is fixedly mounted on the caliper body 6, and the motor reducer assembly 13 is fixedly connected to the fixed bracket 12.

[0125] The fixed bracket 12 is rigidly connected to the outer non-moving area of ​​the caliper body 6 by bolts or welding, serving as the mounting base for the motor reducer assembly 13. Its structure is L-shaped or U-shaped, possessing sufficient rigidity and strength to withstand the vibrations and torque reaction forces generated during motor operation. The motor reducer assembly 13 is connected to the fixed bracket 12 by multiple mounting screws, and the coaxiality between the output shaft 13a and the rotating shaft 10 is ensured by locating pins, guaranteeing smooth power transmission and reducing wear. The fixed bracket 12 allows the motor reducer assembly 13 to float synchronously with the caliper body 6, suitable for floating caliper structures. During braking, it can adapt to the overall displacement of the caliper without the need for an additional flexible coupling, simplifying the layout of the transmission system.

[0126] Preferred, such as Figure 3 , Figure 5 , Figure 6 , Figure 10 As shown, the rotating shaft 10 has multiple thrust grooves 10a evenly arranged around its circumference. The main body of the thrust groove 10a is a spiral inclined surface structure, which is used to convert the rotational motion of the rotating shaft 10 into the axial displacement of the thrust ring 9. The end of the thrust groove 10a is provided with a straight groove along the axial direction of the rotating shaft 10. The straight groove does not have an axial thrust function, allowing the rotating shaft 10 to rotate freely in the absence of thrust output. The inner sidewall of the thrust ring 9 is provided with a needle roller 9a corresponding to the thrust groove 10a. The needle roller 9a can be operated to move in the thrust groove 10a. The caliper body 6 is provided with a sliding rod 6a, and the thrust ring 9 is provided with a corresponding sliding hole. The sliding rod 6a is configured to cooperate with the sliding hole.

[0127] When the shaft 10 rotates, the needle roller 9a climbs along the helical section of the thrust groove 10a, pushing the thrust ring 9 to move axially. When the needle roller 9a enters the straight groove area, no axial force is generated. In addition, at least one slide rod 6a is provided on the caliper body 6 and is fixedly installed axially. A corresponding sliding hole is opened on the thrust ring 9. The slide rod 6a and the sliding hole are fitted with a clearance to form a guide structure, which restricts the circumferential rotation of the thrust ring 9 and ensures that it can only move axially, thereby ensuring the effective transmission of thrust.

[0128] like Figure 11 The diagram shows the motion trajectory of the needle roller 9a in the thrust groove 10a of the rotating shaft 10. When the electromagnetic mechanical brake performs the clamping action, the electromagnetic piston and the thrust ring 9 move to the left. When the electromagnetic mechanical brake performs the release action, the electromagnetic piston and the thrust ring 9 move to the right.

[0129] Point A represents the position of needle roller 9a when the brake clearance is at its maximum; Point B represents the position of needle roller 9a under ideal conditions, when the brake pads are unworn and the rotating shaft 10 begins to apply axial thrust to the thrust ring 9; Point E represents the position of needle roller 9a when the brake pads are worn during clamping and begin to contact the brake disc 1; Point F represents the position of needle roller 9a when the wear of the brake pads reaches its limit during clamping and begins to contact the brake disc 1; Point D represents any point on line segment BE, representing the position of needle roller 9a when the rotating shaft 10 rotates and pushes the thrust ring 9 to generate thrust; Point E represents the extreme position of point D, that is, when needle roller 9a moves to the right of point E before generating thrust, it indicates that the brake clearance is too large and the wear of the brake pads is too great; Point C represents the extreme position of needle roller 9a's movement limited by the size of the thrust groove 10a. ABEC represents the ideal movement trajectory of needle roller 9a during clamping, or the movement trajectory of needle roller 9a during release; A-B'-EC represents the movement trajectory of needle roller 9a during clamping when the brake pads are worn, but the degree of wear is within the normal range; AFEC represents the movement trajectory of needle roller 9a during clamping when the brake pads are worn and the degree of wear reaches the limit and needs to be replaced.

[0130] Specifically, the brake disc 1 is made of a material with high magnetic permeability, while the thrust ring 9, the rotating shaft 10, and the limiting plate 11 are made of a material with low magnetic permeability. The attraction between the electromagnetic piston and the caliper-side electromagnetic piston, and the force by which the electromagnetic piston and the caliper-side electromagnetic piston attract the iron brake disc 1, are greater than the force by which the return spring 15 assembly pushes the caliper body 6.

[0131] The brake disc 1 is made of a high-permeability material such as low-carbon steel or electrical pure iron, which can effectively conduct magnetic lines of force and form a low magnetic reluctance circuit, thereby enhancing the attraction between the electromagnetic piston and the brake disc 1. When the coil windings in the first electromagnetic piston 5 and the second electromagnetic piston 8 are energized, the magnetic flux path passes sequentially through the electromagnetic piston, the brake disc 1, the opposite electromagnetic piston, and the air gap, forming a closed magnetic circuit and generating a strong axial electromagnetic attraction. This attraction not only acts between the two electromagnetic pistons, but also achieves synchronous attraction on both sides through the brake disc 1 as a common magnetic conductor, ensuring that the brake pads quickly adhere to the surface of the brake disc 1. The thrust ring 9, the rotating shaft 10, and the limiting plate 11 are made of non-magnetic materials with low permeability, such as aluminum alloy, copper alloy, or austenitic stainless steel, which effectively blocks the leakage path of magnetic flux in the mechanical transmission components, prevents electromagnetic force from interfering with the normal operation of the thrust transmission mechanism, and avoids jamming, increased friction, or movement failure caused by magnetic adsorption. Meanwhile, the design strength of the electromagnetic attraction is greater than the restoring force applied by the return spring 15 assembly, ensuring that when the braking command is issued, the electromagnetic drive can overcome the spring preload and reliably complete the active elimination of the braking gap. After power is cut off during the release phase, the return spring 15 can overcome the residual magnetic force and frictional force to achieve complete disengagement of the brake pads. This optimized magnetic circuit design improves the efficiency of the electromagnetic drive, enhances the response speed and control reliability, and achieves functional decoupling through material selection, ensuring the independent and stable operation of the mechanical transmission and electromagnetic drive systems.

[0132] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0133] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for controlling the clamping force of a vehicle electromagnetic mechanical braking device, characterized in that, The control method includes: Step 1: The control drive module receives the braking force command issued by the control drive module and calculates the target rotation angle of the output shaft of the control drive module. Step 2: Compare the target rotation angle with the maximum limit rotation angle of the shaft under the limitation of the thrust ring to obtain the comparison result. Based on the comparison result, adjust the motor to perform the release action or clamping action. The comparison results include: Step 21: If the target rotation angle is less than or equal to the maximum limit rotation angle, the current rotation angle of the motor rotor is obtained from the motor rotor position sensor, and the current rotation angle of the output shaft is calculated. If the current rotation angle of the output shaft is less than the target rotation angle, the clamping action is performed. Step 22: If the target rotation angle is greater than the maximum limit rotation angle, then set the target rotation angle to the maximum limit rotation angle, and then execute step 21; Step 3: When the motor performs the clamping action, the electromagnetic force generated by the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the clamping of the brake pads and the brake disc. Specifically, it includes: Step 31: During the gap elimination stage, after the brake pads come into contact with the brake disc, the electromagnetic force generated by the energization of the first and second electromagnetic pistons and the force of the rotating shaft pushing the thrust ring work together to achieve the action of the brake pads clamping the brake disc. Step 32: Determine whether the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft; Step 33: If the current rotation angle of the output shaft is greater than the first rotation angle of the output shaft, then determine whether the current rotation angle of the output shaft is less than the second rotation angle of the output shaft. Step 34: If the current rotation angle of the output shaft is less than or equal to the first rotation angle of the output shaft, then the delay time... Perform step 33; Step 4: When the current rotation angle of the output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first and second electromagnetic pistons are de-energized.

2. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 1, characterized in that, Step 3 also includes: Step 35: If the current rotation angle of the output shaft is greater than or equal to the second rotation angle of the output shaft, the drive control module controls the motor speed to make the current rotation angle of the output shaft equal to the target rotation angle. Step 36: If the current rotation angle of the output shaft is less than the second rotation angle of the output shaft, the drive control module controls the motor position to make the current rotation angle of the output shaft equal to the second rotation angle of the output shaft, and then executes step 35.

3. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 2, characterized in that, Step 3 also includes: Step 37: When the current rotation angle of the output shaft is equal to the target rotation angle, the output shaft of the motor stops rotating, and the first and second electromagnetic pistons are de-energized. Step 38: Determine whether the second rotation angle of the output shaft is less than the third rotation angle.

4. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 3, characterized in that, Step 4 includes: Step 41: If the second rotation angle is less than the third rotation angle, update the second rotation angle according to the torque change curve during braking. Step 42: If the second rotation angle is greater than or equal to the third rotation angle, the drive control module sends a brake pad over-wear flag to the vehicle bus.

5. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 1, characterized in that, The comparison results also include: if the target rotation angle is less than or equal to the maximum limit rotation angle, the current rotation angle of the motor rotor is obtained according to the motor rotor position sensor, and the current rotation angle of the output shaft is calculated; if the current rotation angle of the output shaft is greater than or equal to the target rotation angle, then a release action is performed.

6. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 5, characterized in that, The release process also includes: Step 43: When the current rotation angle of the output shaft is equal to the target rotation angle, the drive control module controls the motor to stop rotating.

7. The clamping force control method for the vehicle electromagnetic mechanical braking device as described in claim 6, characterized in that, The steps preceding step 43 also include: Step 23: Determine if the target rotation angle is less than the second rotation angle; Step 24: If the target rotation angle is less than the second rotation angle, then the first and second electromagnetic pistons are de-energized, the drive control module controls the motor speed, and the motor output shaft rotates in the opposite direction. Step 25: If the target rotation angle is greater than or equal to the second rotation angle, then the first and second electromagnetic pistons are de-energized, the drive control module controls the motor position, and the motor output shaft rotates in the opposite direction.

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