Electromagnetic mechanical braking device of vehicle

Abstract

The invention discloses a vehicle electromagnetic mechanical braking device, and belongs to the technical field of vehicle braking. The device comprises a brake disc, caliper bodies, a brake assembly and an electromagnetic piston assembly, the caliper bodies are arranged on the two sides of an outer ring of the brake disc, and the brake assembly comprises a first brake lining and a second brake lining which are arranged on the two sides of the brake disc; the electromagnetic piston assembly comprises a first electromagnetic piston and a second electromagnetic piston which are coaxially arranged; coil windings are arranged in the first electromagnetic piston and the second electromagnetic piston, and mutual attraction or repulsion electromagnetic force is generated between the first electromagnetic piston and the second electromagnetic piston after electrification. According to the electromagnetic mechanical brake device for the vehicle, the brake lining is directly driven by electromagnetic force to make contact with or be separated from the brake disc, active elimination or release of the brake clearance can be completed under the condition that a motor reducer assembly is not started, noise generated when traditional mechanical transmission parts such as a ball screw and a gear run at a high speed is avoided, and the brake efficiency is improved. The mechanical noise in the braking process is remarkably reduced, and the response speed and the control precision are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle brake control systems or components, and in particular to a vehicle electromechanical brake device. BACKGROUND

[0002] With the development of automobile intelligence and electrification, the electromechanical brake system (EMB) as the core component of the next generation brake technology is gradually replacing the traditional hydraulic brake system. Disc brakes are widely used in modern vehicle brake systems due to their good heat dissipation performance and stable braking effect. A typical electromechanical brake device is usually composed 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: brake clearance elimination stage, brake clamping stage, and brake release stage. During brake execution, the motor drives the piston to move axially through multi-stage mechanical transmission, realizing the clamping and release of the brake disc, thus completing the brake action.

[0003] However, the electromechanical brake device in the prior art still has several key problems. First, in the clearance elimination and brake release stage, the motor needs to drive the ball screw and gear mechanical transmission components at high speed, resulting in significant mechanical noise of the system, and due to the complex transmission chain and multiple noise sources, it is difficult to effectively suppress the noise through conventional structure optimization or vibration isolation methods. Second, the mechanical transmission link (such as gear meshing and screw pair movement) has response delay and backstroke gap, affecting the brake response speed and control accuracy. Therefore, it is urgent to propose a new type of brake device and its control method to shorten the brake response time, reduce the working noise, and improve the system reliability and dynamic performance. SUMMARY

[0004] The present application provides a vehicle electromechanical brake device, which solves the technical problem of excessive noise caused by slow speed in the clearance elimination and release stages in the prior art.

[0005] The present application provides a vehicle electromechanical brake device, which comprises:

[0006] a brake disc;

[0007] a caliper body provided on the left and right sides of the outer ring of the brake disc;

[0008] a brake assembly comprising a first brake pad and a second brake pad provided on both sides of the brake disc, the first brake pad being fixedly installed in the caliper body, and the first and second brake pads being used to provide braking force to the brake disc;

[0009] An electromagnetic piston assembly, comprising a first electromagnetic piston and a second electromagnetic piston coaxially arranged on both sides of a caliper body, the first electromagnetic piston being away from a power input end of the brake device, the first electromagnetic piston being fixedly connected with the caliper body, the second electromagnetic piston being connected with the power input end of the brake device, the second electromagnetic piston being in clearance fit with the caliper body, the second brake pad being fixedly connected with the second electromagnetic piston, the second electromagnetic piston transmitting the pushing force of the power input end of the brake device to the second brake pad.

[0010] A coil winding arranged inside the first electromagnetic piston and the second electromagnetic piston, the coil windings on the first electromagnetic piston and the second electromagnetic piston being attracted to each other or repelled from each other after being energized.

[0011] In some embodiments, the brake device further comprises a caliper bracket, the caliper body being mounted in the caliper bracket, the caliper body being movable in the caliper bracket.

[0012] In some embodiments, the brake assembly further comprises a return mechanism, the return mechanism being at least two, the return mechanism being fixedly arranged on the caliper bracket close to the power input side of the brake device, the active end of the return mechanism being connected with the caliper body.

[0013] In some embodiments, the brake assembly further comprises a return spring, the return spring being at least two, the return spring being connected between the caliper body and the second electromagnetic piston.

[0014] In some embodiments, the brake assembly further comprises a thrust ring, a rotating shaft, a motor reducer assembly and a control driving module, the thrust ring being fixedly connected with the second electromagnetic piston, the rotating shaft being arranged inside the thrust ring, the output shaft of the motor reducer assembly being connected with the rotating shaft through a key, the control driving module being fixedly arranged on the motor reducer assembly, the control driving module, the first electromagnetic piston and the second electromagnetic piston all being electrically connected with the control driving module.

[0015] In some embodiments, the brake assembly further comprises a limiting plate, the limiting plate being fixedly connected with the rotating shaft, a through hole being arranged in the middle of the limiting plate, the output shaft of the motor reducer assembly passing through the through hole.

[0016] In some embodiments, the brake assembly further comprises a fixed bracket, the fixed bracket being fixedly arranged on the caliper body, the motor reducer assembly being fixedly connected with the fixed bracket.

[0017] In some embodiments, the rotating shaft is circumferentially uniformly arranged with a plurality of thrust grooves, the end of the thrust groove is provided with a straight slot along the axial direction of the rotating shaft, the inner side wall of the thrust ring is provided with a needle roller corresponding to the thrust groove, the needle roller is operable in the thrust groove, a sliding rod is arranged on the caliper body, and a sliding hole is arranged on the thrust ring corresponding to the sliding rod.

[0018] In some embodiments, the brake disc is made of a material with high magnetic permeability, and the thrust ring, the rotating shaft and the limiting plate are made of a material with low magnetic permeability.

[0019] In some embodiments, the attractive force between the electromagnetic piston and the caliper-side electromagnetic piston, the force of the electromagnetic piston and the caliper-side electromagnetic piston attracting the iron brake disc is greater than the force of the return spring assembly pushing the caliper body.

[0020] The application has the following advantages:

[0021] The vehicle electromagnetic mechanical brake device provided by the application sets a coil winding in the first electromagnetic piston and the second electromagnetic piston, uses the electromagnetic attraction or repulsion force between the two electromagnetic pistons after power-on to directly drive the brake pad to contact or separate from the brake disc, and actively eliminates or releases the initial gap without starting the motor reducer assembly, thereby fundamentally avoiding the noise problem caused by high-speed mechanical transmission. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application.

[0023] Figure 1 It is an exploded view of the electromagnetic mechanical brake device.

[0024] Figure 2 It is a perspective view of the electromagnetic mechanical brake device.

[0025] Figure 3 It is a perspective view of the rotating shaft.

[0026] Figure 4 It is a perspective view of the thrust ring.

[0027] Figure 5 It is a perspective view of the motor reducer assembly and the driving control assembly.

[0028] Figure 6 It is a schematic view of the rotating shaft ring assembly in a fully clamped state.

[0029] Figure 7 Figure 6 is a schematic view of a fully released state of the shaft ring assembly of the present application;

[0030] Figure 8 Figure 7 is a schematic view of the caliper body of the present application;

[0031] Figure 9 Figure 8 is a schematic view of the movement trajectory of the needle in the shaft thrust groove;

[0032] Figure 10 Figure 9 is a flow chart of the control method of the electromagnetic mechanical brake device of the present application.

[0033] Wherein, 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; 10, 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 DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0036] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection claimed by the present application.

[0037] The gap elimination stage refers to a movement stage in which the brake lining assembly and the brake disc have a gap, but the gap gradually decreases. The release stage refers to a movement stage in which the brake lining assembly and the brake disc have a gap, but the gap gradually increases. The clamping stage refers to a movement stage in which the brake lining assembly and the brake disc are in contact.

[0038] The technical problem of excessive noise caused by slow speed in the gap elimination stage and the release stage in the prior art is solved by providing a vehicle electromagnetic mechanical brake device and a clamping force control method.

[0039] To solve the above technical problem, the technical solution in the embodiments of the present application is as follows:

[0040] As shown in Figures 1-8 The vehicle electromagnetic mechanical brake device provided by the present 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 body structure made of low carbon steel or pure electrical iron, which serves as a rotating element of a friction pair to participate in braking. The caliper body 6 is arranged across the two sides of the outer periphery of the brake disc 1 and can be installed floatingly or fixedly along the axial direction of the brake disc 1. The first brake lining 3 is away from the power input end of the brake device, is fixed to the inside of the caliper body 6, and is installed in cooperation with the first electromagnetic piston 5. The second brake lining 2 is rigidly connected with the second electromagnetic piston 8 and moves synchronously with the second electromagnetic piston 8 in the axial direction. In the electromagnetic piston assembly, the first electromagnetic piston 5 is located on the side away from the power input end and serves as a fixed side electromagnetic unit, which is fixedly connected with the caliper body 6 through bolting or press fitting and has an annular or segmented coil winding embedded inside. The second electromagnetic piston 8 is located on the power input end side, is sleeved on the outside of the rotating shaft 10 or the push rod, and forms a gap cooperation sliding pair with the caliper body 6. The second electromagnetic piston 8 also has a coil winding integrated inside, which forms a magnetic circuit with the first electromagnetic piston 5 after being energized to generate an axial electromagnetic attractive force or repulsive force. The coil windings on the two electromagnetic pistons can be independently or synchronously energized to realize mutual attraction or repulsion by controlling the current direction. The coil winding is fixed in the piston inner cavity through an insulating skeleton and is connected to the driving control assembly 14 through a lead wire to lead out the current.

[0041] Alternatively, the coil winding can be arranged on the inner wall of the caliper body 6 and surrounds the electromagnetic piston, and the electromagnetic piston serves as a magnetic core to participate in the magnetic circuit, and the same electromagnetic driving function can still be achieved. In addition, a sealing ring is arranged on the surface of the electromagnetic piston to prevent dust and moisture from entering and ensure smooth movement and electrical safety.

[0042] By setting the coil winding inside the first electromagnetic piston 5 and the second electromagnetic piston 8, the electromagnetic attraction force or repulsion force between the two electromagnetic pistons after energization is used to directly drive the brake pad to contact or separate from the brake disc 1, and the initial gap is actively eliminated or released without starting the motor reducer assembly 13, thereby fundamentally avoiding the noise problem caused by high-speed mechanical transmission. The specific structure of the coil winding can be realized in the prior art, and therefore the specific structure of the coil winding is not shown.

[0043] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0044] Preferably, as shown in Figure 1 、 Figure 2 , the brake device further comprises a caliper bracket 4, and the caliper body 6 is installed in the caliper bracket 4 and can move in the caliper bracket 4.

[0045] The caliper body 6 is installed in the caliper bracket 4 through a guide structure and can slide axially along the brake disc 1 within the range defined by the bracket, forming a typical floating caliper structure. When the brake command is issued, the second electromagnetic piston 8 pushes the second brake pad 2 towards the inside of the brake disc 1 under the combined action of the power input end thrust and the electromagnetic force, and the reaction force is transmitted to the caliper bracket 4 through the caliper body 6, so that the caliper body 6 moves outward as a whole along the guide direction of the bracket, driving the first brake pad 3 to press tightly against the outside of the brake disc 1, realizing synchronous clamping on both sides. In the gap elimination stage, the coil winding in the first electromagnetic piston 5 and the second electromagnetic piston 8 is energized to generate mutual electromagnetic force, directly driving the second brake pad 2 to approach the brake disc 1, while pulling the caliper body 6 to move in the opposite direction, so that the first brake pad 3 approaches the brake disc 1 synchronously, thereby quickly eliminating the brake gap without relying on the movement of mechanical transmission components. This structure actively pre-tensions through electromagnetic force, significantly shortens the brake response time, avoids the noise and wear caused by the motor-driven ball screw and other mechanical components during high-speed operation, and improves the system quietness and dynamic response performance. At the same time, the caliper bracket 4 provides stable support and precise guidance for the entire brake unit, ensuring uniform distribution of brake force on both sides and improving brake stability and reliability.

[0046] Further, as shown in Figure 1 、 Figure 2 , the brake assembly further comprises a return mechanism 7, and the return mechanism 7 is at least two, the return mechanism 7 is fixedly arranged on the power input side of the caliper bracket 4 close to the brake device, and the movable end of the return mechanism is connected with the caliper body 6.

[0047] The fixed end of the return mechanism 7 is connected with the caliper bracket 4, and the movable end is connected with the caliper body 6, which is used to provide a reset force when the brake is released. The return mechanism 7 can be a coil spring, a disc spring or a rubber elastic element, preferably a coil spring cooperating with a guide rod structure, wherein the guide rod is fixed to the caliper bracket 4, and the spring is sleeved outside the guide rod, one end abuts against the caliper bracket 4, and the other end is connected with the caliper body 6, which exerts an axial pulling force after the brake is released, so as to reset the caliper body 6, make the first brake pad 3 and the second brake pad 2 synchronously separate from the surface of the brake disc 1, and eliminate residual friction. As an equivalent solution, the return mechanism 7 can also be an elastic metal sheet or a hydraulic buffer reset device, as long as it can provide a stable axial reset force to achieve the same function. This structure not only ensures the reliable recovery of the brake clearance and prevents drag wear, but also cooperates with the electromagnetic drive to improve the dynamic response consistency of the brake system. At the same time, the multiple-point arrangement of the return mechanism enhances the stability of the movement of the caliper body 6, avoids unilateral jamming or inclined wear, prolongs the service life of the brake pad, and improves the brake reliability and safety.

[0048] Further, as shown in Figure 1 , the brake assembly further comprises return springs 15, and the return springs 15 are at least two, and the return springs 15 are connected between the caliper body 6 and the second electromagnetic piston 8.

[0049] The return springs 15 are arranged between the caliper body 6 and the second electromagnetic piston 8, at least two are arranged, and are arranged symmetrically along the circumference of the second electromagnetic piston 8, one end of which is connected with the caliper body 6, and the other end is connected with the second electromagnetic piston 8, which is used to provide a reset elastic force during the brake release stage. The return spring 15 can be in the form of a spiral compression spring or a torsional spring, and can also be replaced by an elastic rubber pad or a bellows type elastic element, which is installed in the spring groove on the outer periphery of the second electromagnetic piston 8, or is fixed by a pin shaft between the connecting lug of the caliper body 6 and the piston, so as to ensure uniform force and smooth movement. When the brake is finished, the electromagnetic coil is de-energized, and the power input end is removed, the return spring 15 releases the stored elastic potential energy, pushes the second electromagnetic piston 8 to move away from the brake disc 1 relative to the caliper body 6, drives the second brake pad 2 to quickly separate from the surface of the brake disc 1, and cooperates with the overall reset action of the caliper body 6 to realize the synchronous reset of the double-sided brake pad, effectively avoiding brake drag and energy loss.

[0050] Preferably, as shown in Figures 1-7As shown, the brake assembly further comprises a thrust ring 9, a rotating shaft 10, a motor reducer assembly 13 and a control driving module, the thrust ring 9 is fixedly connected with the second electromagnetic piston 8, the rotating shaft 10 is arranged inside the thrust ring 9, the output shaft 13a of the motor reducer assembly 13 is connected with the rotating shaft 10 through a key, and the control driving module is fixedly arranged on the motor reducer assembly 13. The control driving module, the first electromagnetic piston 5 and the second electromagnetic piston 8 are electrically connected with the control driving module.

[0051] The thrust ring 9 is rigidly connected with the second electromagnetic piston 8 through bolts, and serves as an intermediate medium for transmitting mechanical thrust. The inner hole of the thrust ring 9 is provided with a needle roller 9a, which cooperates with a thrust groove 10a on the outer periphery of the rotating shaft 10 to convert the rotary motion of the rotating shaft 10 into axial thrust. The rotating shaft 10 has a stepped shaft structure, one end of which extends into the inside of the thrust ring 9 and interacts with the inclined surface of the thrust groove 10a through the needle roller 9a to push the thrust ring 9 and the second electromagnetic piston 8 to move axially when rotating; the other end is connected with the output shaft 13a of the motor reducer assembly 13 through a key and a pin shaft to reliably transmit torque. The motor reducer assembly 13 comprises a permanent magnet synchronous motor and a planetary gear reducer, which are integrated and arranged outside the caliper. The output shaft 13a drives the rotating shaft 10 to rotate after being increased in torque through reduction, thereby providing the required thrust for braking. The control driving module is fixed to the shell of the motor reducer assembly 13 and internally integrated with a controller and a driver to receive upper brake instructions, control the start-stop, rotation speed and position of the motor, and output driving current to the coil winding of the first electromagnetic piston 5 and the second electromagnetic piston 8 to independently regulate and control electromagnetic force. During braking, the control driving module receives controller signals and converts external power supply into three-phase sinusoidal alternating current to drive the permanent magnet synchronous motor to rotate, and the driver converts external power supply into direct current voltage for the electromagnetic piston on the side of the caliper and controls the on-off of current. The reducer input shaft is fixedly connected with the permanent magnet synchronous motor rotor, and the reducer output shaft 13a is the output shaft 13a. The reducer can realize the effect of speed reduction and torque increase.

[0052] Specifically, the connection between the rotating shaft 10 and the output shaft 13a can adopt spline, pin coupling or elastic coupling.

[0053] Further, as shown in Figure 1 、 Figure 6 、 Figure 7 The brake assembly further comprises a limiting plate 11, the limiting plate 11 is fixedly connected with the rotating shaft 10, a through hole is arranged in the middle of the limiting plate 11, and the output shaft 13a of the motor reducer assembly 13 passes through the through hole.

[0054] The limiting plate 11 is connected with the rotating shaft 10 through thread or pin shaft, forming a whole synchronous movement, with a through hole in the center, the output shaft 13a of the motor reducer assembly 13 passes through the hole and realizes torque transmission with the input end of the rotating shaft 10 through key and pin shaft, the limiting plate 11 is located between the thrust ring 9 and the motor reducer, with an outer diameter larger than that of the thrust ring 9, used to limit the excessive displacement of the thrust ring 9 to the motor side. When the rotating shaft 10 rotates to push the thrust ring 9 to move to the direction of the brake disc 1, the limiting plate 11 prevents further axial movement of the thrust ring 9 through mechanical contact with the end face of the thrust ring 9, ensuring the stability and reliability of the thrust transmission path, preventing assembly interference or damage caused by mechanism overstroke.

[0055] Further, as shown in Figure 1 、 Figure 2 , the brake assembly further comprises a fixed support 12, which is fixedly arranged on the caliper body 6, and the motor reducer assembly 13 is fixedly connected with the fixed support 12.

[0056] The fixed support 12 is rigidly connected to the outer side of the caliper body 6 in the non-movement area by bolts or welding, serving as the mounting base of the motor reducer assembly 13, which has an L-shaped or U-shaped structure with sufficient rigidity and strength to withstand the vibration and torque reaction generated during motor operation. The motor reducer assembly 13 is connected with the fixed support 12 through multiple mounting screws, and the coaxiality between the output shaft 13a and the rotating shaft 10 is guaranteed by means of positioning pins, ensuring smooth power transmission and reducing wear. The setting of the fixed support 12 makes the motor reducer assembly 13 float synchronously with the caliper body 6, which is suitable for floating caliper structure, and can adapt to the overall displacement of the caliper without additional flexible coupling during braking, simplifying the layout of the transmission system.

[0057] Preferably, as shown in Figure 1 、 Figure 3 、 Figure 4 , the rotating shaft 10 is uniformly arranged with multiple thrust grooves 10a in the circumferential direction, the thrust grooves 10a have a spiral slope structure, which is used to convert the rotary motion of the rotating shaft 10 into the axial displacement of the thrust ring 9, and the end of the thrust groove 10a is provided with a straight slot along the axial direction of the rotating shaft 10, which does not have the function of axial thrust; the inner side wall of the thrust ring 9 is provided with a needle 9a corresponding to the thrust groove 10a, the needle 9a is operable in the thrust groove 10a, the caliper body 6 is provided with a slide rod 6a, and the thrust ring 9 is provided with a slide hole corresponding to the slide rod 6a.

[0058] When the rotating 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 slot area, no axial force is generated. In addition, at least one slide rod 6a is arranged on the caliper body 6 and fixedly installed in the axial direction, and a corresponding slide hole is formed on the thrust ring 9, the slide rod 6a and the slide hole are in clearance fit, forming a guide structure, limiting the circumferential rotation of the thrust ring 9, ensuring that it can only move axially, thereby ensuring the effective transmission of the thrust force.

[0059] As shown in the schematic diagram of the movement 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, and when the electromagnetic mechanical brake performs the release action, the electromagnetic piston and the thrust ring 9 move to the right. Figure 9

[0060] Wherein, A point represents the position of the needle roller 9a when the brake clearance is maximum; B point is the position of the needle roller 9a when the brake pad is not worn and the rotating shaft 10 starts to apply axial thrust to the thrust ring 9 under ideal conditions; E point is the position of the needle roller 9a when the wear degree of the brake pad reaches the critical point during the clamping process, and the rotating shaft applies thrust to the thrust ring; F point is the position of the needle roller 9a when the wear degree of the brake pad reaches the limit value during the clamping process, and the brake pad starts to contact the brake disc 1; D point represents any point on the line segment BE, which is the position of the needle roller 9a when the rotating shaft 10 rotates and pushes the thrust ring 9 to start generating thrust; E point is the limit position of D point, that is, when the needle roller 9a moves to the right of E point to start generating thrust, it indicates that the brake clearance is too large and the wear degree of the brake pad is too large; C point is the limit position of the movement of the needle roller 9a limited by the size of the thrust groove 10a. A-B-E-C is the movement trajectory of the needle roller 9a under ideal conditions during the clamping process, or the movement trajectory of the needle roller 9a during the release process; A-B'-E-C is the movement trajectory of the needle roller 9a during the clamping process when the brake pad is worn, but the wear degree is within the normal range; A-F-E-C is the movement trajectory of the needle roller 9a when the brake pad is worn and the wear degree reaches the limit value and needs to be replaced during the clamping process.

[0061] Specifically, the brake disc 1 is made of a material with high magnetic permeability, the thrust ring 9, the rotating shaft 10 and the limiting plate 11 are made of a material with low magnetic permeability, and the attractive force between the electromagnetic piston and the caliper-side electromagnetic piston and the force of the electromagnetic piston and the caliper-side electromagnetic piston attracting the iron brake disc 1 are greater than the force of the return spring 15 assembly pushing the caliper body 6.

[0062] ​The brake disc 1 is made of high magnetic permeability material such as low carbon steel or electrical pure iron, which can effectively conduct magnetic lines to form a low magnetic resistance loop, thereby enhancing the adsorption capacity between the electromagnetic piston and the brake disc 1. When the coil winding in the first electromagnetic piston 5 and the second electromagnetic piston 8 is energized, the magnetic flux path passes through the electromagnetic piston, the brake disc 1, the opposite electromagnetic piston and the air gap in turn, forming a closed magnetic circuit and generating strong axial electromagnetic attraction force; the attraction force not only acts between the two electromagnetic pistons, but also realizes synchronous suction on both sides through the brake disc 1 as a common magnetic conductor, ensuring that the brake pad is quickly attached to the surface of the brake disc 1. The thrust ring 9, the shaft 10 and the limiting plate 11 are made of non-magnetic material with low magnetic 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 the increase of friction or movement failure caused by magnetic adsorption. At the same time, the design strength of the electromagnetic attraction force is greater than the reset force of the return spring 15 assembly, which ensures that the electromagnetic drive can overcome the spring pre-tightening force and reliably complete the active elimination of the brake clearance when the brake command is issued, and after the release stage is powered off, the return spring 15 can overcome the friction force to realize the complete separation of the brake pad. The magnetic circuit optimization design improves the efficiency of electromagnetic drive, enhances the response speed and control reliability, and realizes functional decoupling through material selection to ensure the independent and stable operation of the mechanical transmission and electromagnetic drive system.

[0063] As shown in Figure 10 , the application also provides a clamping force control method of a vehicle electromagnetic mechanical brake device, the control method comprising:

[0064] Step 1: The control driving module receives the brake force command issued by the control driving module, and calculates the target rotation angle of the output shaft of the control driving module .

[0065] The brake force command is issued by the upper controller, and the rotation angle of the output shaft can be calculated by the following formula:

[0066] ;

[0067] In the formula, is the target rotation angle of the output shaft, is the rotation angle when the needle moves to the D point as shown in Figure 9 , and is the increase of the rotation angle of the output shaft for generating mechanical brake torque. The relationship between the brake force and the rotation angle of the output shaft can be measured by experiment, and the value of can be calculated according to the input brake force command.

[0068] Step 2: Determine whether the target rotation angle is less than or equal to the maximum limit rotation angle of the shaft under the limitation of the thrust ring , if the output shaft reaches the maximum limit rotation angle during rotation , the output shaft cannot continue to rotate.

[0069] Step 3: if the target rotation angle is less than or equal to the maximum limit rotation angle , the current motor rotor rotation angle is obtained according to the motor rotor position sensor, the output shaft rotation angle is calculated, if the current output shaft rotation angle is greater than the target rotation angle, the release action is performed; if the current output shaft rotation angle is less than the target rotation angle, the clamping action is performed.

[0070] Step 4: if the target rotation angle is greater than the maximum limit rotation angle , the target rotation angle is equal to the maximum limit rotation angle, and then step 3 is executed;

[0071] Step 5: in the gap elimination stage, after the brake pad contacts the brake disc, the electromagnetic force generated by the first electromagnetic piston and the second electromagnetic piston and the force of the rotating shaft pushing the thrust ring act together to realize the action of clamping the brake disc by the brake pad;

[0072] Step 6: determine whether the current output shaft rotation angle is greater than the first rotation angle of the output shaft .

[0073] the rotation angle of the output shaft when the needle moves between the AF points. If the current output shaft rotation angle is greater than , it is considered that the motion trajectory of the needle is not on the AF, and the output shaft can start to rotate. In ideal conditions, , but there is often a gap between the needle and the thrust groove, so is taken in actual control.

[0074] Step 7: if the current output shaft rotation angle is greater than the first rotation angle of the output shaft , determine whether the current output shaft rotation angle is less than the second rotation angle of the output shaft ;

[0075] Step 8: if the current output shaft rotation angle is less than or equal to the first rotation angle of the output shaft , delay time Step 7 is executed;

[0076] Step 9: if the current output shaft rotation angle is greater than or equal to the second rotation angle of the output shaft , the motor speed is controlled by the drive control module to make the current output shaft rotation angle equal to the target rotation angle .

[0077] At this time, the motor controller inputs the target rotation angle of the motor rotor as the control target with the accurate clamping force output. The relationship between the rotation angle of the motor rotor and the rotation angle of the output shaft is:

[0078] ;

[0079] In the formula, is the rotation angle of the motor rotor, is the rotation angle of the output shaft, is the reduction ratio.

[0080] Step 10: 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 so that the current rotation angle of the output shaft is equal to the second rotation angle of the output shaft , and the motor controller inputs the maximum motor rotation speed as the control target with the shortest braking force loading time, and then step 9 is executed.

[0081] Step 11: 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 electromagnetic piston and the second electromagnetic piston are powered off.

[0082] Step 12: It is judged whether the second rotation angle is less than the third rotation angle , and the third rotation angle is the rotation angle of the output shaft when the needle is at E point. If it is less than, it is considered that the brake pad thickness is normal, and if it is greater than or equal to, it is considered that the brake pad is excessively worn.

[0083] Step 13: The second rotation angle is less than the third rotation angle , and the second rotation angle is updated according to the torque change curve in the braking process . The torque change curve can be obtained through the thrust sensor or calculated through the state observation algorithm.

[0084] Step 14: The second rotation angle is greater than or equal to the third rotation angle , and the drive control module sends a brake pad excessive wear flag to the vehicle bus.

[0085] The first rotation angle is the rotation angle of the output shaft when the needle moves between AF points; the second rotation angle is the rotation angle of the output shaft when the needle is at D point; and the third rotation angle is the rotation angle of the output shaft when the needle is at E point.

[0086] Step 15: If the current rotation angle of the output shaft is greater than or equal to the target rotation angle if the target rotation angle is less than the second rotation angle if the target rotation angle is less than the second rotation angle ; if the target rotation angle is less than the second rotation angle if the target rotation angle is less than the second rotation angle , no additional clamping force is applied to the brake disc, and the shortest clamping force release time should be taken as the control target, if the target rotation angle is greater than the second rotation angle , the target rotation angle is greater than the second rotation angle , the target rotation angle is greater than the second rotation angle.

[0087] Step 16: if the target rotation angle is less than the second rotation angle , the first electromagnetic piston and the second electromagnetic piston are controlled to be de-energized, the drive control module controls the motor speed, and the output shaft of the motor rotates in the reverse direction.

[0088] Step 17: if the target rotation angle is greater than or equal to the second rotation angle , the first electromagnetic piston and the second electromagnetic piston are controlled to be de-energized, the drive control module controls the motor position, and the output shaft of the motor rotates in the reverse direction.

[0089] Step 18: if the current output shaft rotation angle is equal to the target rotation angle , the drive control module controls the motor to stop rotating.

[0090] Example 1: the current rotation angle of the output shaft is 0, the brake force instruction is the maximum designed brake force, and the brake pad has no wear:

[0091] First, step 1 is executed, the drive module is controlled to receive the brake force instruction, and the output shaft rotation angle instruction value is calculated. At this time, point D coincides with point B, at this time, is its maximum value, step 2 is executed, the output shaft rotation angle instruction value is judged whether it is less than or equal to , the output shaft rotation angle instruction value is equal to , step 3 is executed, and the current output shaft rotation angle is judged whether it is less than , the current output shaft rotation angle is less than , step 5 is executed, the electromagnetic piston and the caliper side electromagnetic piston are energized, the brake clearance begins to be eliminated, step 6 is executed, and the current output shaft rotation angle is judged whether it is greater than , the current output shaft rotation angle is less than or equal to , step 8 is executed, and after the delay time , the roller moves to point B, step 7 is executed, and the current output shaft rotation angle is judged whether it is less than , point D coincides with point B, the result is no, step 9 is executed, the drive control module controls the motor in position until the output shaft rotation angle , step 11 is executed, the output shaft rotation angle reaches , the output shaft stops rotating, the electromagnetic piston and the caliper-side electromagnetic piston are powered off, step 12 is executed, and is determined whether it is less than , assuming that the brake pad has contacted the brake disc when the roller moves to point B during the current braking process, then , the result is yes, step 13 is executed, the value of is updated according to the torque change curve during the braking process, is the output shaft rotation angle when the roller moves to point B.

[0092] Example 2: The current output shaft rotation angle is 10% of the maximum rotation angle , the brake force instruction is 80% of the maximum designed brake force, , the brake pad has wear, but the wear degree is within the normal range, and the wear is still within the normal range after the current braking is completed.

[0093] First, step 1 is executed, the control drive module receives the brake force instruction, and the output shaft rotation angle instruction value is calculated, point D is located between BE, , at this time, is the output shaft rotation angle increment corresponding to 80% brake force, step 2 is executed, and the output shaft rotation angle instruction value is determined whether it reaches , at this time is less than , step 3 is executed, and the current output shaft rotation angle is determined whether it is less than , the result is yes, step 5 is executed, the electromagnetic piston and the caliper-side electromagnetic piston are powered on, the electromagnetic piston and the caliper-side electromagnetic piston are powered on, the brake disc is attracted, and a certain clamping force is provided, step 6 is executed, and the current output shaft rotation angle is determined whether it is greater than , at this time the output shaft rotation angle is 10% , the result is yes, step 7 is executed, and the output shaft rotation angle is determined whether it is less than , the result is yes, step 10 is executed, the drive control module controls the motor in speed until the output shaft rotation angle is equal to , step 9 is executed, the drive control module controls the motor in position until the output shaft rotation angle is equal to , step 11 is executed, the output shaft rotation angle reaches , the output shaft stops rotating, the electromagnetic piston and the caliper-side electromagnetic piston are powered off, step 12 is executed, and is determined whether it is less than According to the actual change curve of the clamping force in this braking, when the rotation angle of the output shaft is , the clamping force changes greatly, and , the result of the judgment is yes, step 13 is executed, and the value of is updated according to the change curve of the torque in the braking process.

[0094] In example 3, the current rotation angle of the output shaft is 10% of the maximum rotation angle, , the brake force instruction is 80% of the maximum designed brake force, , the brake pad has wear, but the wear degree is within the normal range, and after the end of this braking, the brake pad is excessively worn, .

[0095] The execution processes of steps 1, 2, 3, 5, 6, 7, 9, 10, 11 are the same as those in example 2.

[0096] Step 12 is executed, and is judged to be less than , according to the actual change curve of the clamping force in this braking, when the rotation angle of the output shaft is , the clamping force changes greatly, and , the result of the judgment is no, step 14 is executed, and the drive control module sends a brake pad excessively worn flag to the vehicle bus.

[0097] In example 4, the current rotation angle of the output shaft is 80% of the maximum rotation angle, , the brake force instruction is 10% of the maximum designed brake force, , the brake pad has wear, but the wear degree is within the normal range.

[0098] Step 1 is executed, the drive control module receives the brake force instruction, and the rotation angle instruction value of the output shaft is calculated, step 2 is executed, and the rotation angle instruction value of the output shaft is judged to be less than , the result of the judgment is yes, step 3 is executed, and the current rotation angle of the output shaft is judged to be less than , the result of the judgment is no, step 15 is executed, and is judged to be less than , the result of the judgment is yes, step 16 is executed, the electromagnetic piston and the caliper-side electromagnetic piston are powered off, the drive control module controls the speed of the motor, the output shaft rotates reversely, step 18 is executed, and when the rotation angle of the output shaft reaches the instruction value , the output shaft stops rotating.

[0099] The clamping force control method realizes efficient, silent and intelligent management of the braking process through the collaborative control of electromagnetic drive and mechanical transmission. In the initial stage of braking, the electromagnetic attraction force generated by energizing the first electromagnetic piston and the second electromagnetic piston is used to actively pull the brake pad towards the brake disc, completing the rapid elimination of the brake clearance. This process does not need to start the motor reducer assembly, avoiding the mechanical noise generated by the high-speed driving of the ball screw and gear pair in the traditional system, significantly improving the braking silence performance. By judging the relationship between the current rotation angle of the output shaft and the key threshold value, such as the first rotation angle, the second rotation angle and the third rotation angle, the dynamic switching of the control strategy is realized: in the clamping process, if the current angle is less than the target angle, high-speed rotation control is preferred to establish the braking force in the shortest time, and then switch to precise position control to ensure the accuracy of the clamping force output; in the release process, according to the comparison result of the target angle and the wear threshold, the maximum reverse rotation speed or precise return is selected, taking into account the release speed and control accuracy. At the same time, by real-time monitoring of the motion position of the needle and the torque change curve, the key angle parameters are automatically updated to realize online identification of the wear state of the brake pad. When the second rotation angle is greater than or equal to the third rotation angle, the excessive wear flag bit is sent to the vehicle bus in time to improve the 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 state monitoring.

[0100] Although preferred embodiments of the application have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once they have the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the application.

[0101] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A vehicle electromagnetic mechanical braking device, characterized in that, The braking device includes: Brake disc; The caliper body is disposed on the left and right sides of the outer ring of the brake disc; A braking assembly, comprising a first brake pad and a second brake pad disposed on both sides of the brake disc, wherein the first brake pad is fixedly installed in the caliper body, and the first brake pad and the second brake pad are used to provide braking force to the brake disc; An electromagnetic piston assembly includes a first electromagnetic piston and a second electromagnetic piston located on both sides of the caliper body and coaxially arranged. The first electromagnetic piston is away from the power input end of the braking device and is fixedly connected to the caliper body. The second electromagnetic piston is connected to the power input end of the braking device and is clearance-fitted to the caliper body. The second brake pad is fixedly connected to the second electromagnetic piston. The second electromagnetic piston transmits the thrust from the power input end of the braking device to the second brake pad. The coil windings are disposed inside the first electromagnetic piston and the second electromagnetic piston. When the coil windings on the first electromagnetic piston and the second electromagnetic piston are energized, they attract or repel each other.

2. The vehicle electromagnetic mechanical braking device as described in claim 1, characterized in that, The braking device also includes a caliper bracket, the caliper body is mounted in the caliper bracket, and the caliper body is movable in the caliper bracket.

3. The vehicle electromagnetic mechanical braking device as described in claim 2, characterized in that, The braking assembly also includes a return mechanism, of which there are at least two. The return mechanism is fixedly disposed on the caliper bracket near the power input side of the braking device, and the movable end of the return mechanism is connected to the caliper body.

4. The vehicle electromagnetic mechanical braking device as described in claim 1, characterized in that, The braking assembly also includes return springs, at least two of which are connected between the caliper body and the second electromagnetic piston.

5. The vehicle electromagnetic mechanical braking device as described in claim 1, characterized in that, The braking assembly further includes a thrust ring, a rotating shaft, a motor reducer assembly, and a control drive module. The thrust ring is fixedly connected to the second electromagnetic piston. The rotating shaft is disposed inside the thrust ring. The output shaft of the motor reducer assembly is connected to the rotating shaft via a key. The control drive module is fixedly disposed on the motor reducer assembly. The control drive module, the first electromagnetic piston, and the second electromagnetic piston are all electrically connected to the control drive module.

6. The vehicle electromagnetic mechanical braking device as described in claim 5, characterized in that, The braking assembly also includes a limiting plate, which is fixedly connected to the rotating shaft. A through hole is provided in the middle of the limiting plate, and the output shaft of the motor reducer assembly passes through the through hole.

7. The vehicle electromagnetic mechanical braking device as described in claim 5, characterized in that, The braking assembly also includes a fixed bracket, which is fixedly mounted on the caliper body, and the motor reducer assembly is fixedly connected to the fixed bracket.

8. The vehicle electromagnetic mechanical braking device as described in claim 5, characterized in that, The rotating shaft is evenly arranged with multiple thrust grooves around its circumference. The end of each thrust groove is provided with a straight groove along the axial direction of the rotating shaft. The inner sidewall of the thrust ring is provided with a needle roller corresponding to the thrust groove. The needle roller can move operably in the thrust groove. The caliper body is provided with a sliding rod. The thrust ring is provided with a corresponding sliding hole. The sliding rod is configured to cooperate with the sliding hole.

9. The vehicle electromagnetic mechanical braking device as described in claim 6, characterized in that, The brake disc is made of a material with high magnetic permeability, while the thrust ring, rotating shaft, and limiting plate are made of a material with low magnetic permeability.

10. The vehicle electromagnetic mechanical braking device as described in claim 6, characterized in that, 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, are greater than the force by which the return spring assembly pushes the caliper body.

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