Redundant electro-mechanical parking brake system with mutual coupling of driving brake and parking brake

Abstract

The invention belongs to an electromechanical braking system in the technical field of vehicles, and discloses a driving and parking braking torque mutual coupling redundancy electromechanical braking system which comprises a brake assembly, an MGU and shell, a driving braking motor and gear reducing mechanism assembly, a gear system bearing support and an ECU controller assembly. The service braking gear reduction mechanism assembly comprises a service braking first-stage reduction gear train mounting mechanism, a second-stage reduction gear train mounting mechanism and a bearing, and the parking braking gear reduction mechanism assembly comprises a parking first-stage reduction worm and gear mechanism, a second-stage reduction worm and gear mechanism and a mounting bearing. The braking torque of the driving braking and the braking torque of the parking braking are mutually coupled, the two systems can share the braking output gear shaft assembly, the driving braking and the parking braking can be independently operated, and meanwhile the parking braking can assist the driving braking when needed. By means of the design, the safety and reliability of the braking system are improved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile electronic mechanical parking brakes, in particular to an electronic mechanical parking brake system with redundant mutually coupled driving and parking brakes. Background Art

[0002] The electronic mechanical brake system (EMB) uses the motor as the driving source of the braking force, and converts the power of the motor into braking force through a mechanical transmission mechanism to clamp the vehicle's brake disc or brake drum, thereby achieving the purpose of braking. Compared with the traditional hydraulic brake system, EMB has a higher response speed and more precise control ability, which can achieve more efficient energy recovery and better braking performance.

[0003] The electronic mechanical brake system includes two components: service brake and parking brake. Service brake generally uses a single or two motors for service brake, which is a known prior art. Parking brake usually uses another parking motor to drive a system with a one-way self-locking mechanism (one-way bearing, worm gear, screw, etc.) to park the vehicle, or drives a ratchet pawl mechanism through an electromagnetic valve to park the vehicle.

[0004] CN 117905881 A discloses a parking lock mechanism for an electronic mechanical brake actuator, comprising an electromagnetic locking assembly arranged in a motor housing and a locking disk fixed on a driving shaft of a driving motor, wherein a plurality of locking holes evenly distributed in a circumference are provided on the locking disk; the electromagnetic locking assembly comprises an electromagnetically driven telescopic component and a locking head connected to the output end of the electromagnetically driven telescopic component, wherein the locking head extends into the locking hole. The parking lock mechanism and working method for the electronic mechanical brake actuator are adopted, and the locking is performed by the electromagnetic locking assembly cooperating with the locking disk fixed on the driving gear shaft. Since the driving gear has a low torque, the impact on the locking head is small, and the service life of the mechanism can be extended. The disadvantages are: 1. The electromagnetic locking assembly adopted includes a bistable electromagnet, a double electromagnetic coil, an iron core and a locking head, and the structure is relatively complex, and the additional current sensor and magnetic field strength sensor are costly; 2. There is a risk that the multiple locking holes evenly distributed in a circumference provided on the locking disk and the electromagnetically driven telescopic locking head are misaligned, resulting in a risk of failure to park.

[0005] CN 117905879 A discloses an electronic mechanical parking self-locking mechanism, a control method and a vehicle. The electronic mechanical parking self-locking mechanism includes: a controller, a brake motor, a controller, a ratchet and a pawl. The controller is connected to a solenoid valve, and a push rod is provided at the end of the solenoid valve. When the solenoid valve is energized, the push rod extends to push the pawl to limit the reverse rotation of the ratchet, which is a locked state. When the solenoid valve is de-energized, the push rod retracts and disengages from the pawl, and the ratchet can rotate forward and backward, which is an unlocked state; the structure is simple, and no sensor is required, which reduces production costs. The disadvantages are: 1. It is necessary to accurately control the inspection and verification of the driving brake and the parking brake, and there is a risk that the pawl and the ratchet gear will be disengaged too early or difficult to disengage or get stuck. 2. The locking mechanism using the pawl and ratchet cannot ensure that the parking is locked at any position. Due to the limited number of ratchet teeth, the parking force is attenuated.

[0006] And no matter which parking structure is used above, there are certain problems: All parking mechanisms require the service brake to be applied first, and then the parking mechanism is locked; this parking method must ensure that the service brake function is normal before the parking brake can work. Once the service brake fails, parking cannot be completed, and the parking mechanism also loses the brake safety redundancy function; The service brake and parking brake are relatively independent, which means that the two systems need to consider their respective clamping force requirements, which puts higher requirements on the motors and acceleration mechanisms of each system, resulting in a relatively complex system and high energy consumption; When force control is used in current electronic mechanical brakes, if force sensors are not installed, the subsequent control algorithm will be complicated and precise control will not be achieved; Therefore, there is currently a lack of a dual-redundancy design for driving and parking brakes, in which the braking and parking torques are coupled to each other, and the normal operation of the electronic parking function can be guaranteed after one of the motors fails, or dual-motor power distribution can be performed. Summary of the invention

[0007] The object of the present invention is to provide an electronic mechanical parking brake system with redundant mutually coupled driving and parking brakes, so as to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions: The invention discloses an electronic mechanical parking brake system with redundant mutually coupled driving and parking brakes, comprising a brake assembly, a driving brake motor and a gear reduction mechanism assembly provided with a driving brake secondary reduction output gear, a gear system bearing bracket connected to the brake assembly, an ECU controller assembly, and a parking motor and a gear reduction mechanism assembly provided with a parking secondary reduction input worm gear, wherein a secondary reduction gear system mounting shaft is rotatably provided on the gear system bearing bracket, the driving brake secondary reduction output gear and the parking secondary reduction input worm gear are jointly assembled on the secondary reduction gear system mounting shaft, and the parking secondary reduction input worm gear is coupled to the driving brake secondary reduction output gear.

[0009] Preferably, the ECU controller assembly is electrically connected to the service brake motor and gear reduction mechanism assembly and the parking motor and gear reduction mechanism assembly. The ECU controller assembly communicates signals with the entire vehicle via a CAN bus.

[0010] Preferably, the service brake motor and gear reduction mechanism assembly includes a service brake motor and a primary reduction gear system mounting shaft, the output shaft of the service brake motor is sleeved with a service brake primary reduction input gear, the primary reduction gear system mounting shaft is sleeved with a service brake primary reduction output gear and a service brake secondary reduction input gear, the service brake primary reduction output gear is meshed with the service brake primary reduction input gear, and the service brake secondary reduction input gear is meshed with the service brake secondary reduction output gear.

[0011] The first-stage reduction gear system mounting shaft is provided with first-stage reduction gear system mounting bearings at both ends; the second-stage reduction gear system mounting bearings are provided at both ends of the reduction gear system mounting shaft. More preferably, a first-stage reduction gear system mounting bearing is provided between the first-stage reduction gear system mounting shaft and the MGU housing, the inner ring of the first-stage reduction gear system mounting bearing is fixedly connected to the first-stage reduction gear system mounting shaft, and the outer ring of the first-stage reduction gear system mounting bearing is fixedly connected to the MGU housing. More preferably, the reduction gear system mounting shaft is fixedly mounted on the MGU housing and the gear system bearing bracket through the second-stage reduction gear system mounting bearing.

[0012] Preferably, the parking motor and gear reduction mechanism assembly includes a parking brake motor, a parking first-stage reduction input worm and a parking second-stage reduction input worm, the parking first-stage reduction input worm is fixedly connected to the output shaft of the parking brake motor, the parking second-stage reduction input worm is fixedly provided with a parking first-stage reduction input worm wheel, the parking first-stage reduction input worm wheel is meshed with the parking first-stage reduction input worm, and the parking second-stage reduction input worm is meshed with the parking second-stage reduction input worm wheel.

[0013] Two ends of the parking secondary reduction input worm are provided with secondary reduction worm mounting bearings. Specifically, a secondary reduction worm mounting bearing is provided between the parking secondary reduction input worm and the MGU housing, the inner ring of the secondary reduction worm mounting bearing is fixedly connected to the parking secondary reduction input worm, and the outer ring of the secondary reduction worm mounting bearing is fixedly connected to the MGU housing.

[0014] Preferably, the spoke end face of the parking brake secondary reduction input worm wheel is provided with a first concave groove, and the first concave groove is provided with a protrusion 1 and a protrusion 2. The spoke end face of the service brake secondary reduction output gear is provided with a second concave groove, and the second concave groove is provided with a concave block 1 and a concave block 2 corresponding to the protrusion 1 and the protrusion 2. The protrusion 1 and the protrusion 2 extend into the second concave groove and abut against the side surfaces of the concave block 1 and the concave block 2.

[0015] Preferably, the convex block 1 and the convex block 2 are arranged at 180° relative to each other, and the concave block 1 and the concave block 2 are also arranged at 180° relative to each other, and the outer diameters of the convex block 1 and the convex block 2 are smaller than the inner diameter of the secondary reduction output gear of the service brake, and larger than the outer diameter of the gear sleeve, and the two sets of convex blocks and concave blocks cooperate with each other in a surface contact manner to transmit torque.

[0016] Preferably, both ends of the parking secondary reduction input worm gear are provided with a convex block 1 and a convex block 2; and both ends of the service brake secondary reduction output gear are provided with a concave block 1 and a concave block 2.

[0017] Preferably, the parking secondary reduction input worm gear is connected to the secondary reduction gear system mounting shaft through a bearing or a bushing, and the parking secondary reduction input worm gear and the service brake secondary reduction output gear have no fixed assembly relationship. When the whole vehicle is in service braking, since the number of rotations of the service brake secondary reduction output gear is less than 1 / 2, the protrusions 1 and 2 of the parking secondary reduction input worm gear and the concave blocks 1 and 2 in the first concave groove of the service brake secondary reduction output gear have a clearance margin and will not interfere with each other. When the vehicle starts, the parking secondary reduction input worm gear first returns to its initial position, and the service brake secondary reduction output gear then returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0018] When the protrusions 1 and 2 at the end of the parking secondary reduction input worm wheel of the parking motor and gear reduction mechanism assembly contact the side walls of the concave blocks 1 and 2 in the second concave groove of the service brake secondary reduction output gear, both the service brake motor and the parking brake motor stop working, and parking is achieved by the self-locking function of the parking worm gear of the parking brake system.

[0019] The service brake first-stage reduction input gear is fixedly connected to the output shaft of the service brake motor. The service brake first-stage reduction input gear, the service brake second-stage reduction input gear, and the service brake second-stage reduction output gear are fixedly connected to their respective mounting shafts by means of keyways, splines, etc., or are integrally formed. Bearings or bushings are installed at both ends of each mounting shaft to reduce friction and improve efficiency.

[0020] In order to prevent installation errors, the convex block features of the parking secondary reduction input worm gear and the concave block features of the service brake secondary reduction output gear can be designed at the two ends, with two convex block and concave block structures set at each end, so that there is no need to distinguish the installation direction.

[0021] When the vehicle performs conventional service braking, the service brake motor drives the first and second gear reduction mechanisms of the service brake to output the braking torque through the secondary reduction gear shaft, thereby pushing the brake actuator to realize the braking function; when the vehicle requires braking force beyond conventional braking under some special working conditions, the parking brake motor drives the worm wheel to rotate through the worm gear reduction mechanism. When the protrusion at the end of the worm wheel contacts the protrusion in the groove at the end of the secondary reduction output gear of the service brake, the motor superimposed torque is output together with the service brake system to meet the braking force requirements under extreme braking conditions.

[0022] When service braking is ended and parking braking is required, the parking motor drives the worm gear to rotate the worm wheel. When the protrusion at the end of the parking secondary reduction worm wheel contacts the concave block in the groove of the service brake secondary gear, the two motors stop working and parking is achieved through the worm gear of the parking system. When the vehicle requires a larger parking force under some special working conditions, in addition to the clamping force generated by the service brake, the parking motor can also apply a certain clamping force through its own reduction mechanism and superimpose the clamping force of the service brake to achieve a greater parking force.

[0023] When the service brake system fails, the parking motor drives the worm gear to rotate through its own reduction mechanism. When the protrusion at the end of the worm gear contacts the protrusion in the groove of the service brake reduction gear, it drives the service brake gear to rotate and still achieves a certain service brake function.

[0024] Preferably, the parking secondary reduction input worm gear is rotationally connected to the secondary reduction gear system mounting shaft, the service brake secondary reduction output gear is fixedly connected to the secondary reduction gear system mounting shaft, the service brake secondary reduction output gear is transmission connected to the service brake motor and gear reduction mechanism assembly, and the parking secondary reduction input worm gear is transmission connected to the parking motor and gear reduction mechanism assembly.

[0025] Preferably, it also includes an MGU housing and a sealing cover plate, the MGU housing and the sealing cover plate are combined to form a box with an accommodating cavity, the service brake motor and gear reduction mechanism assembly, the gear system bearing bracket, the ECU controller assembly and the parking motor and gear reduction mechanism assembly are all placed in the accommodating cavity, the MGU housing is provided with a through hole for the drive input shaft of the brake assembly to extend into, and the MGU housing is fixedly connected to the housing of the brake assembly.

[0026] The present invention is further explained and illustrated below: The technical problem to be solved by the present invention is to improve the safety and reliability of the electronic mechanical brake system, especially the redundant safety function when the brake system fails. This redundant design includes three aspects to ensure that the parking brake system can provide braking force even when the main service brake system of the vehicle fails, thereby ensuring the safety of the vehicle.

[0027] First, the mechanical transmission system redundancy of the service brake system and the parking brake system; The second is the coupling and decoupling of the braking torque. The driving brake and the parking brake of the present invention are coupled to each other. The two systems can share the brake output gear shaft assembly. The driving brake and the parking brake can work independently. At the same time, the parking brake can also assist the driving brake when necessary. This design improves the efficiency and reliability of the braking system.

[0028] The third is the redundancy of the motor drive controller ECU. The ECU is connected to the electronic mechanical brake assembly through the CAN bus, providing dual control protection to ensure that the braking system can still work normally when a single control system fails.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. Redundant safety function: The electronic mechanical braking system design of the present invention includes a redundant braking mode to solve the problem of vehicle braking deceleration when the braking system fails, and improve the safety of the vehicle when the braking system fails. This redundant design ensures that even if the main driving braking system of the vehicle fails, the parking brake system can still provide braking force to ensure vehicle safety.

[0030] 2. Coupling and decoupling of braking torque: The braking torques of the service brake and the parking brake of the present invention are coupled to each other. The two systems can share the brake output gear shaft assembly. The service brake and the parking brake can be operated independently. At the same time, the parking brake can also assist the service brake when necessary. This design improves the efficiency and reliability of the braking system.

[0031] 3. Miniaturized and integrated design: The present invention arranges the parking brake motor and the service brake motor in parallel, adopts a large-speed-ratio two-stage worm gear transmission mechanism, and a common output gear shaft assembly, thereby reducing the size of the structural layout, achieving miniaturization and integration of the system, and helping to adapt to the narrow wheel side space.

[0032] 4. Advantages and application prospects: The electronic mechanical braking system of the present invention is particularly suitable for the wheel-side braking system of modern vehicles due to its advantages such as small size, fast response, reliable performance, safety and environmental protection.

[0033] In summary, an electromechanical brake with mutually coupled redundant driving and parking braking torques provides an efficient, safe and responsive braking solution through its unique design, which is suitable for advanced driver assistance systems (ADAS) and autonomous driving systems in modern automobiles.

[0034] The detailed structure of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of an electronic mechanical parking brake system with redundant mutually coupled driving and parking brakes according to the present invention; Figure 2 It is a schematic diagram of the structure of the driving and parking brake assembly of the present invention; Figure 3 It is a schematic diagram of the driving and parking brake reduction gear transmission mechanism of the present invention; Figure 4 It is a schematic diagram of the structure of the driving and parking brake coupling gear assembly of the present invention; Figure 5 It is a schematic diagram of the bearing assembly of the parking two-stage reduction input worm belt installation of the present invention; Figure 6 It is a schematic diagram of the service brake two-stage reduction output gear assembly of the present invention; Among them: 1. Brake assembly; 2. MGU housing; 3. Service brake motor and gear reduction mechanism assembly; 4. Gear system bearing bracket; 5. ECU controller assembly; 6. Sealing cover plate; 7. Parking motor and gear reduction mechanism assembly; 31. Service brake motor; 32. Service brake primary reduction input gear; 33. Service brake primary reduction output gear; 34. Service brake secondary reduction input gear; 35. Service brake secondary reduction output gear; 36. Primary reduction gear system mounting bearing; 37. Secondary reduction gear system mounting bearing; 38. Primary reduction gear system mounting shaft; 39. Secondary reduction gear system mounting shaft; 310. Concave block 1; 311. Gear sleeve; 312. Concave block 2; 313. Second concave groove; 71. Parking brake motor; 72. Parking first-stage reduction input worm; 73. Parking first-stage reduction input worm wheel; 74. Parking second-stage reduction input worm; 75. Second-stage reduction worm mounting bearing; 76. Parking second-stage reduction input worm wheel; 77. Bump one; 78. Bump two; 79. Second-stage reduction input worm wheel bearing; 710. First concave groove. DETAILED DESCRIPTION

[0036] like Figure 1-2 As shown, the driving and parking brakes are coupled to each other redundantly. The main components include a brake assembly 1, an MGU housing 2, a driving brake motor and gear reduction mechanism assembly 3, a gear system bearing bracket 4, an ECU controller assembly 5, a sealing cover plate 6 and a parking motor and gear reduction mechanism assembly 7. The present invention arranges the parking brake motor 71 in parallel with the driving brake motor 31 and adopts a large-speed-ratio two-stage worm gear transmission mechanism to change the transmission direction of the braking force to realize a shared output gear shaft assembly 39, thereby reducing the size of the structural layout, realizing miniaturization and integration of the system, and helping to adapt to the narrow wheel side space of the vehicle.

[0037] The ECU controller assembly 5 is connected to the electronic mechanical brake assembly via the CAN bus, providing dual control protection to ensure that the brake system can still work normally when a single control system fails.

[0038] The ECU controller assembly 5 has fault detection and alarm functions. The system should be able to detect power supply faults, brake signal faults, control system faults and electronic mechanical brake system assembly faults, and display alarm errors through the instrument when a fault is detected.

[0039] A threaded fixing structure is provided at the end of the brake assembly 1 to be fixed to the MGU housing 2. The service brake motor and parking motor assembly 3 are installed and fixed by the fixing and limiting structures on the MGU housing 2. The service gear reduction mechanism and the parking gear reduction mechanism are fixed and installed to the MGU housing 2 by the gear system bearing bracket 4. The sealing cover plate 6 and the ECU controller assembly 5 are fixed to the MGU housing 2 by threaded connection.

[0040] Specifically, the actuator of the brake assembly 1 is a ball screw or other torque conversion mechanism.

[0041] Specifically, the service brake gear reduction mechanism assembly 3 includes a service brake first-stage reduction input gear 32, a service brake first-stage reduction output gear 33, a service brake second-stage reduction input gear 34, a service brake second-stage reduction output gear 35, and first-stage and second-stage reduction gear system mounting shafts and mounting bearings. The parking gear reduction mechanism assembly 7 includes parking first-stage and second-stage reduction input worm gears and mounting bearings, parking second-stage reduction input worm gears and mounting bearings.

[0042] Specifically, the service brake first-stage reduction input gear 32 is fixedly connected to the output shaft of the service brake motor 31, and the service brake first-stage reduction input gear 32, the service brake second-stage reduction input gear 33, and the service brake second-stage reduction output gear 34 are fixedly connected to their respective mounting shafts by keyways, splines, etc., or are forged into one piece; bearings or bushings are installed at both ends of each mounting shaft to reduce friction and improve efficiency.

[0043] Specifically, the parking brake secondary reduction worm gear 76 is connected to the service brake secondary reduction gear system mounting shaft 39 through a bearing or a bushing, and the two protrusions of the parking secondary reduction input worm gear 76 are tightly fitted with the two concave blocks in the second concave groove 313 of the service brake secondary reduction gear 35 respectively. When the vehicle is braking, the service brake motor 31 drives the gear reduction system to work, and the parking brake motor 71, as a redundant backup, does not need to work synchronously. In addition, since the secondary reduction gear needs to rotate 1 / 2 circle before the two protrusions of the parking secondary reduction input worm wheel 76 can contact the other side of the two concave blocks of the service brake secondary reduction gear 35, the secondary reduction mechanism designed by the present invention has a working rotation number of the secondary reduction gear that is less than 1 / 2 circle, and the two protrusions of the parking secondary reduction input worm wheel 76 and the two concave blocks in the second concave groove 313 of the service brake secondary reduction gear 35 have a clearance margin and will not interfere with each other. When the vehicle is started, the parking brake can be released manually or automatically before the service brake, that is, the parking secondary reduction input worm wheel 76 first returns to its initial position, and the secondary reduction gear then returns to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0044] Specifically, the end of the parking brake secondary reduction input worm wheel is provided with two protrusions with an angle of 180° relative to each other; the end of the service brake secondary reduction gear 35 is provided with a second concave groove 313, and the second groove 313 also has two concave block features with an angle of 180° relative to each other, which cooperate with each other; preferably, in order to prevent installation errors, the protrusion features of the parking brake secondary reduction input worm wheel and the service brake secondary reduction gear can be distributed at both ends, so that there is no need to distinguish the installation direction.

[0045] like Figure 2As shown, the service brake motor and gear reduction mechanism assembly 3 includes a service brake primary reduction input gear 32, a service brake primary reduction output gear 33, a service brake secondary reduction input gear 34, a service brake secondary reduction output gear 35, and a primary reduction gear system mounting bearing 36, a secondary reduction gear system mounting shaft and a mounting bearing 37. The parking gear reduction mechanism assembly includes a parking primary reduction input worm 72, a parking primary reduction input worm wheel 73, a parking secondary reduction input worm 74, a secondary reduction worm mounting bearing 75, and a parking secondary reduction input worm wheel with a mounting bearing assembly 76. The inner ring of the primary reduction gear system mounting bearing 36 is fixedly connected to the primary reduction gear system mounting shaft 38, and the outer ring of the primary reduction gear system mounting bearing 36 is fixedly connected to the MGU housing 2; the secondary reduction gear system mounting shaft 39 is fixedly mounted on the MGU housing 2 and the gear system bearing bracket 4 through the secondary reduction gear system mounting shaft and the mounting bearing 37.

[0046] Specifically, the service brake first-stage reduction input gear 32 is fixedly connected to the output shaft of the service brake motor 31, and the service brake first-stage reduction input gear 32, the second-stage reduction input gear 34, and the second-stage reduction output gear 35 are fixedly connected to their respective mounting shafts by keyways, splines, etc., or are integrally formed; bearings or bushings are installed at both ends of each mounting shaft to reduce friction and improve efficiency.

[0047] Specifically, the parking motor and gear reduction mechanism assembly 7 includes a parking brake motor 71, a parking first-stage reduction input worm 72 and a parking second-stage reduction input worm 74. The parking first-stage reduction input worm 72 is fixedly connected to the output shaft of the parking brake motor 71. The parking second-stage reduction input worm 74 is fixedly provided with a parking first-stage reduction input worm wheel 73. The parking first-stage reduction input worm wheel 73 is meshed with the parking first-stage reduction input worm 72. The parking second-stage reduction input worm 74 is meshed with the parking second-stage reduction input worm wheel 76.

[0048] Specifically, a secondary reduction worm mounting bearing 75 is provided between the parking secondary reduction input worm 74 and the MGU housing, the inner ring of the secondary reduction worm mounting bearing 75 is fixedly connected to the parking secondary reduction input worm 74, and the outer ring of the secondary reduction worm mounting bearing 75 is fixedly connected to the MGU housing.

[0049] Specifically, the parking secondary reduction input worm 74 is provided with either a keyway or a spline for fixing and mounting the parking primary reduction input worm wheel 73 .

[0050] Specifically, the parking secondary reduction input worm 74 and the parking primary reduction input worm wheel 73 are forged into one piece.

[0051] like Figure 3-6 As shown, the spoke end face of the parking brake secondary reduction input worm wheel is provided with a first concave groove 710, and the first concave groove 710 contains a protrusion 1 77 and a protrusion 2 78. The spoke end face of the service brake secondary reduction output gear 35 is provided with a second concave groove 313, and the second concave groove 313 contains a concave block 1 310 and a concave block 2 312 corresponding to the protrusion 1 77 and the protrusion 2 78. The protrusion 1 77 and the protrusion 2 78 extend into the second concave groove 313 and abut against the concave block 1 310 and the concave block 2 312.

[0052] The parking brake secondary reduction input worm wheel 76 is connected to the secondary reduction gear system mounting shaft 39 through a bearing or a bushing. The parking secondary reduction input worm wheel 76 and the service brake secondary reduction output gear 35 have no fixed assembly relationship. When the vehicle is in service braking, since the number of rotations of the service brake secondary reduction gear output gear 35 is less than 1 / 2, the protrusions 1 77 and 78 of the secondary reduction input worm wheel 76 and the concave blocks 1 310 and 312 in the second concave groove 313 of the secondary reduction output gear 35 have a clearance margin and will not interfere with each other. When the vehicle is started, the parking secondary reduction input worm wheel 76 first rotates to its initial position, and the secondary reduction output gear 35 then rotates to its initial position. Therefore, the service brake and the parking brake can work independently without affecting each other.

[0053] The protrusion 1 77 and the protrusion 2 78 in the first concave groove 710 at the end of the parking brake secondary reduction input worm wheel 76 are arranged at 180 degrees relative to each other; the concave block 1 310 and the concave block 2 312 in the second concave groove 313 at the end of the service brake secondary reduction gear 35 are also arranged at 180 degrees relative to each other, and the outer diameter of the protrusion 1 77 and the protrusion 2 78 is smaller than the inner diameter of the secondary reduction output gear 35, and larger than the outer diameter of the gear sleeve 311. The two groups of protrusions and concave blocks cooperate with each other in a surface contact manner to transmit torque.

[0054] Preferably, in order to prevent installation errors, the convex block features of the parking brake secondary reduction input worm wheel 76 and the service brake secondary reduction gear 35 can be distributed at two ends, and two convex blocks and concave blocks are respectively set at each end so that there is no need to distinguish the installation direction.

[0055] like Figure 2 As shown, when the vehicle performs conventional service braking, the service brake motor 31 drives the service brake primary reduction input gear 32 and the secondary reduction input and output gear 34. The two-stage gears are engaged to transmit the torque to the output shaft through the secondary reduction gear 35 to transmit the braking torque, thereby pushing the brake assembly 1 actuator to realize the braking function.

[0056] Furthermore, when the vehicle needs a braking force exceeding that of conventional braking under some special working conditions, the parking brake motor 71 engages the parking first-speed reduction input worm gear through the parking first-speed reduction input worm 72, and decelerates and increases torque to input the parking braking torque through the parking second-speed reduction input worm 74 and the second-speed reduction input worm gear 76. When the protrusion at the end of the parking second-speed reduction input worm gear 76 contacts the protrusion in the end groove of the service brake second-speed reduction output gear 35, the motor superposition torque is output together with the service brake second-speed reduction output gear 35 to meet the braking force requirements under extreme braking conditions.

[0057] When the service brake is terminated and the parking brake is required, the parking brake motor 71 drives the parking first reduction input worm 72 and the parking first reduction input worm wheel 73, and the parking second reduction input worm 74 and the second reduction input worm wheel 76 are meshed and rotated to output the parking brake torque. When the two protrusions 1 77 and 2 78 at the end of the parking second reduction input worm wheel 76 contact the side walls of the concave block 1 310 and the concave block 2 312 in the second concave groove 313 at the end of the service brake second reduction output gear 35, the service brake motor 31 and the parking brake motor 71 stop working, and the parking is achieved through the parking worm self-locking function of the parking brake system, wherein 74 is fixed to the MGU housing 2 through the second reduction worm mounting bearing 75.

[0058] Furthermore, when the vehicle requires a larger parking brake force under some special working conditions, in addition to the clamping force generated by the service brake motor 31, the parking brake motor 71 can also apply a certain clamping force through its own deceleration mechanism to superimpose the clamping force of the service brake to achieve a larger parking force.

[0059] Furthermore, when the service brake system fails, the parking brake motor 71 drives the worm wheel 76 to rotate through its own worm gear reduction mechanism. When the protrusion at the end of the worm wheel 76 contacts the concave block of the second concave groove 313 of the service brake reduction gear, it drives the service brake gear 35 to rotate, and a certain service brake function can still be achieved.

[0060] The above is a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes according to the technical solutions and concepts of the present invention, which should be covered by the protection scope of the claims of the present invention.

Claims

1. An electronic mechanical parking brake system with redundant driving and parking brakes coupled to each other, comprising a brake assembly (1), a driving brake motor and gear reduction mechanism assembly (3) provided with a driving brake secondary reduction output gear (35), a gear system bearing bracket (4) connected to the brake assembly (1), an ECU controller assembly (5) and a parking motor and gear reduction mechanism assembly (7) provided with a parking secondary reduction input worm gear (76), characterized in that: A secondary reduction gear system mounting shaft (39) is rotatably provided on the gear system bearing bracket (4); a service brake secondary reduction output gear (35) and a parking secondary reduction input worm gear (76) are assembled together on the secondary reduction gear system mounting shaft (39); and the parking secondary reduction input worm gear (76) and the service brake secondary reduction output gear (35) are coupled.

2. The electronic mechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 1, characterized in that: The ECU controller assembly (5) is electrically connected to the service brake motor and gear reduction mechanism assembly (3) and the parking motor and gear reduction mechanism assembly (7).

3. The electronic mechanical parking brake system with redundant driving and parking brake coupling according to claim 1 or 2, characterized in that: The service brake motor and gear reduction mechanism assembly (3) comprises a service brake motor (31) and a primary reduction gear system mounting shaft (38); a service brake primary reduction input gear (32) is sleeved on the output shaft of the service brake motor (31); a service brake primary reduction output gear (33) and a service brake secondary reduction input gear (34) are sleeved on the primary reduction gear system mounting shaft (38); the service brake primary reduction output gear (33) is meshed with the service brake primary reduction input gear (32); and the service brake secondary reduction input gear (34) is meshed with the service brake secondary reduction output gear (35).

4. The electromechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 3, characterized in that: Both ends of the first-stage reduction gear train mounting shaft (38) are provided with first-stage reduction gear train mounting bearings (36); and both ends of the reduction gear train mounting shaft (39) are provided with second-stage reduction gear train mounting bearings (37).

5. The electronic mechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 1 or 2, characterized in that: The parking motor and gear reduction mechanism assembly (7) comprises a parking brake motor (71), a parking first-stage reduction input worm (72) and a parking second-stage reduction input worm (74); the parking first-stage reduction input worm (72) is fixedly connected to the output shaft of the parking brake motor (71); a parking first-stage reduction input worm wheel (73) is fixedly provided on the parking second-stage reduction input worm wheel (74); the parking first-stage reduction input worm wheel (73) is meshed with the parking first-stage reduction input worm wheel (72); and the parking second-stage reduction input worm wheel (74) is meshed with the parking second-stage reduction input worm wheel (76).

6. The electromechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 5, characterized in that: Two ends of the parking secondary reduction input worm (74) are provided with secondary reduction worm mounting bearings (75).

7. The electronic mechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 1 or 2, characterized in that: The spoke end surface of the parking brake secondary reduction input worm wheel (76) is provided with a first concave groove, and a convex block 1 (77) and a convex block 2 (78) are provided in the first concave groove. The spoke end surface of the service brake secondary reduction output gear (35) is provided with a second concave groove, and a concave block 1 (310) and a concave block 2 (312) corresponding to the convex block 1 (77) and the convex block 2 (78) are provided in the second concave groove. The convex block 1 (77) and the convex block 2 (78) extend into the second concave groove and abut against the side surfaces of the concave block 1 (310) and the concave block 2 (312).

8. The electromechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 7, characterized in that: The convex block 1 (77) and the convex block 2 (78) are arranged at 180 degrees relative to each other, and the concave block 1 (310) and the concave block 2 (312) are also arranged at 180 degrees relative to each other. The outer diameters of the convex block 1 (77) and the convex block 2 (78) are smaller than the inner diameter of the service brake secondary reduction output gear (35).

9. The electromechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 8, characterized in that: Both ends of the parking secondary reduction input worm wheel (76) are provided with a first convex block (77) and a second convex block (78); and both ends of the service brake secondary reduction output gear (35) are provided with a first concave block (310) and a second concave block (312).

10. The electromechanical parking brake system with redundant mutually coupled driving and parking brakes according to claim 1, characterized in that: The parking secondary reduction input worm gear (76) is rotationally connected to the secondary reduction gear system mounting shaft (39), the service brake secondary reduction output gear (35) is fixedly connected to the secondary reduction gear system mounting shaft (39), the service brake secondary reduction output gear (35) is transmission-connected to the service brake motor and gear reduction mechanism assembly (3), and the parking secondary reduction input worm gear (76) is transmission-connected to the parking motor and gear reduction mechanism assembly (7).

11. The electromechanical parking brake system with mutually coupled redundant driving and parking brakes according to claim 1, characterized in that: The invention also comprises an MGU housing (2) and a sealing cover plate (6), wherein the MGU housing (2) and the sealing cover plate (6) are covered to form a box body having a housing cavity, wherein the service brake motor and gear reduction mechanism assembly (3), the gear system bearing bracket (4), the ECU controller assembly (5) and the parking motor and gear reduction mechanism assembly (7) are all placed in the housing cavity, and the MGU housing (2) is provided with a through hole for the drive input shaft of the brake assembly (1) to extend therethrough, and the MGU housing (2) is fixedly connected to the housing of the brake assembly (1).

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