Compact type running and parking integrated electronic mechanical braking mechanism

Abstract

The invention relates to a compact type running and parking integrated electronic mechanical braking mechanism, and belongs to the technical field of braking equipment. Comprising a mounting frame, a brake assembly and a brake caliper body assembly, and the brake assembly comprises a service brake unit and a parking brake unit; the service braking unit comprises a braking motor and a reduction gear set; the brake caliper body assembly is provided with a brake caliper body, the brake caliper body is slidably installed on the installation frame, and one end of the brake caliper body is connected with the power end of the brake motor through a reduction gear set. The parking braking unit comprises a parking motor, a ratchet wheel and a pawl; the ratchet wheel is connected with the reduction gear set, the pawl is connected with the power end of the parking motor, and a buffering piece is arranged between the pawl and the power end of the parking motor and used for forming flexible connection between the pawl and the power end of the parking motor when the ratchet wheel is locked by the pawl and fails. Flexible connection is formed between the pawl and the power end of the parking motor, the parking stability is improved, frictional wear between parts is reduced, and the service life of the mechanism is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of brake equipment, and in particular to a compact traveling-stationary integrated electronic mechanical brake mechanism. Background Art

[0002] New energy vehicles are rapidly developing towards intelligence and unmanned operation. Braking-by-wire technology is well suited to the development trend of new energy vehicles due to its advantages such as fast response of braking force and easy modular integration with other control systems. Existing braking-by-wire technologies mainly include electronic hydraulic braking (EHB) and electronic mechanical braking (EMB). EHB uses the hydraulic circuit of the traditional automobile hydraulic braking system, which has the disadvantages of many hydraulic pipelines, complex structure, and relatively long braking response time. EMB uses an electromechanical system to replace the hydraulic system as the power source. It has a simple structure, fast response, precise control, and complete decoupling of braking force and brake pedal force. It is known as the ultimate technical form of braking-by-wire.

[0003] EMB has been studied since the 1990s, but it has not been widely used due to the bottleneck of motor drive control technology and restrictions on relevant regulations. With the development of electric drive technology and the technical needs of new energy vehicles, major domestic and foreign automotive parts suppliers, universities, research institutions, etc. have started related research. All parties believe that EMB technology has broad market prospects.

[0004] The working principles of the EMB transmission mechanisms of major manufacturers are basically similar. They are mainly composed of a drive motor, a deceleration gain mechanism, and a motion conversion mechanism. The deceleration gain mechanism is mainly a gear transmission mechanism, and there are also wedge-shaped force-enhancing devices or lever mechanisms. The motion conversion mechanism mostly uses a ball screw to convert rotational motion into translational motion to achieve clamping. In addition to considering driving brakes, the braking system also needs to consider parking. Most of the existing parking mechanisms use locking mechanisms such as ratchet pawls or hook pawls. The locking and release of the hook pawls are controlled by actuators. When parking is required, they are clamped and then locked according to the target braking force. However, the actuators of such mechanisms are in direct rigid contact with the force-bearing parts such as ratchets when parking. If the hook pawl does not just hook the ratchet groove, there is a situation of parking failure, and it bears the reaction force of the brake. When the brake needs to be released, there are problems such as large friction and severe wear of parts. In addition, the axial size of the EMB transmission mechanism in the prior art is large, and the installation space at the wheel is limited, which affects the steering performance of the front wheels. In addition, the parking mechanism will be larger in size in the future, which further limits the application occasions. Therefore, a compact electronic mechanical brake mechanism with both driving and parking is needed to solve the problem that the existing electronic mechanical brake mechanism adopts a ratchet parking method, has a rigid connection between the power part and the ratchet, resulting in large component wear, large axial size of the mechanism, and limited installation space. Summary of the invention

[0005] The object of the present invention is to provide a compact electromechanical brake mechanism with integrated motion and braking function to solve the problems mentioned in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a compact driving and parking integrated electronic mechanical brake mechanism, comprising a mounting frame, a brake assembly and a brake caliper assembly, the brake assembly comprising a driving brake unit and a parking brake unit; the driving brake unit comprises a brake motor and a reduction gear set; the brake caliper assembly is provided with a brake caliper body, the brake caliper body is slidably mounted on the mounting frame, and one end of the brake caliper body is connected to the power end of the brake motor through the reduction gear set; the parking brake unit comprises a parking motor, a ratchet and a pawl; the ratchet is connected to the reduction gear set, the pawl is connected to the power end of the parking motor, and a buffer is provided between the pawl and the power end of the parking motor, which is used to form a flexible connection between the pawl and the power end of the parking motor when the pawl locks the ratchet and fails.

[0007] Preferably, the brake caliper body assembly includes a slide rail and a ball screw pair; the slide rail is installed on the mounting frame, the brake caliper body is slidably installed on the slide rail, and one end of it is connected to the nut end of the ball screw pair, the screw of the ball screw pair is rotatably installed on the mounting frame, and one end of it is connected to the power output end of the reduction gear set.

[0008] Preferably, the reduction gear set includes a driving gear, an output gear and a plurality of idle gears; the driving gear is fixedly connected to the power end of the brake motor, the output gear is mounted on the screw of the ball screw pair, and the driving gear and the output gear are connected by meshing with each other through a plurality of idle gears.

[0009] Preferably, a plurality of idler gears are provided with double gears for connecting driving gears or idler gears or output gears located in different planes; the double gears include a first gear and a second gear which are integrally formed and coaxially arranged, the first gear is meshed with the driving gear or the adjacent idler gear to form a power input end, and the second gear is meshed with the output gear or the adjacent idler gear to form a power output end.

[0010] Preferably, the ratchet is fixedly mounted on the power end of the brake motor; a mounting hole is provided in the middle of the ratchet, and the ratchet is interference mounted on the power end of the brake motor through the mounting hole.

[0011] Preferably, the parking brake unit is provided with a mounting guide sleeve, and the parking motor is provided with a telescopic extending shaft to constitute a power end; the mounting guide sleeve is fixedly installed on the mounting frame, and the mounting guide sleeve is provided with a mounting through hole, the pawl is slidably installed in the mounting through hole, and one end thereof is connected to the extending shaft through a buffer, and the other end extends to the outside of the mounting through hole to form a locking end.

[0012] Preferably, the shape of the mounting through hole of the mounting guide sleeve is adapted to the shape of the pawl; the buffer member includes a lock tongue and a spring; one end of the lock tongue is connected to the extended shaft of the parking motor, and the other end is provided with a columnar mounting rod; the pawl body of the pawl is provided with a mounting groove, and a spring is provided on the outer side of the mounting rod of the lock tongue, the pawl is sleeved on the mounting rod through the mounting groove, and is slidably installed on the mounting rod by abutting against the spring.

[0013] Preferably, the bottom of the mounting rod of the lock tongue protrudes outward radially to form a boss, and a pin hole perpendicular to the rod body is provided on the rod body near the top of the mounting rod; a strip-shaped limit groove is provided in the mounting groove of the pawl and the groove corresponding to the pin hole of the mounting rod along the sliding direction of the pawl; a limit pin is installed in the pin hole of the mounting rod, and the two ends of the limit pin extend to the outside of the pin hole respectively to form limit ends on both sides; when the pawl is slidably installed on the mounting rod, the limit ends on both sides of the limit pin are slidably installed in the strip-shaped limit groove of the pawl respectively to limit the sliding stroke of the pawl; the spring is sleeved on the outside of the mounting rod, one side of which is stopped at the pawl, and the other end is stopped at the boss of the mounting rod.

[0014] Preferably, a plurality of ratchet gears are evenly spaced on the outer side of the ratchet wheel surface, and a ratchet groove is formed between two adjacent ratchet gears; the body of the ratchet gear is provided with tooth surfaces on both sides, one tooth surface of the two tooth surfaces is a plane structure perpendicular to the ratchet wheel surface, and the other tooth surface is an arc-shaped structure from the tooth root to the tooth top; the locking end of the pawl is a gear structure adapted to the ratchet gear; the gear structure of the locking end is provided with locking tooth surfaces on both sides and locking tooth top surfaces, one tooth surface of the two locking tooth surfaces is a plane structure perpendicular to the ratchet wheel surface, and the other tooth surface is an arc-shaped structure from the tooth root to the tooth top; The locking tooth surface of the pawl is an arc-shaped structure from the tooth root to the tooth top; when the pawl locks the ratchet, the locking tooth top surface of the pawl stops at the bottom of the ratchet groove, and the locking tooth surface of the plane structure of the locking end abuts against the tooth surface of the plane structure of the ratchet gear to limit the rotational movement of the ratchet along the brake release direction. When the locking tooth top surface of the pawl abuts against the tooth top of the ratchet gear, the ratchet rotates along the brake release direction to drive the locking tooth top surface of the pawl to slide along the tooth surface of the arc-shaped structure of the ratchet gear.

[0015] Preferably, the brake assembly is provided with an electronic control unit and a pressure sensor, the brake motor and the sensor are electrically connected to the electronic control unit respectively, the pressure sensor is sleeved on the screw shaft of the ball screw pair, one side of the sensing end is in contact with the end face of the screw shaft, and the other side is in contact with the brake caliper body to detect the brake clamping force; the width dimension of the ratchet groove is larger than the width dimension of the pawl locking end. Beneficial Effects

[0016] The electronic mechanical brake mechanism of the present invention is provided with a brake assembly and a brake caliper assembly, wherein the brake assembly includes a service brake unit and a parking brake unit, and the service brake unit includes a brake motor and a reduction gear set; the brake caliper assembly is provided with a brake caliper body, which is slidably mounted on a mounting frame, and one end of which is connected to the power end of the brake motor through a reduction gear set. In order to achieve power output through the power end of the brake motor, the braking force of the brake motor is increased after the reduction and increase of the distance by the reduction gear set, and then the brake caliper body is driven to slide along the mounting frame toward the brake disc to achieve service braking. The parking brake unit adopts a parking motor, a ratchet and a pawl, and the ratchet is connected to the reduction gear set. The ratchet is locked by driving the pawl through the power end of the parking motor to achieve the effect of parking braking. The present invention provides a buffer between the power end of the parking motor and the pawl, so that when the pawl fails to lock the ratchet, a flexible connection is formed between the pawl and the power end of the parking motor, so that the power end of the parking motor is prevented from directly bearing the reaction force of the brake, so that when the brake needs to be released, the friction between the pawl and the ratchet is reduced, and the wear of the components is reduced. The pawl of the present invention forms a flexible connection with the power end of the parking motor, improves the stability of parking, reduces the friction and wear between the components, and prolongs the service life of the mechanism.

[0017] On the basis of the above, the reduction gear set of the present invention includes a driving gear, an output gear and a plurality of idler gears; the driving gear is fixedly connected to the power end of the brake motor, the output gear is installed on the screw of the ball screw pair, and the driving gear and the output gear are connected by a plurality of idler gears that mesh with each other. The present invention adopts multi-stage parallel shaft gears for reduction transmission. Compared with the planetary gear system, while meeting the transmission ratio requirements, the axial size of the mechanism is reduced, making the mechanism structure compact and simple, easy to disassemble and maintain, and avoiding interference with the existing vehicle chassis space.

[0018] On the basis of the above, several idler gears of the present invention are provided with double gears for connecting driving gears or idler gears or output gears located in different planes, so as to realize a multi-layer plane meshing structure between the gears of the reduction gear in space, so as to further reduce the component installation space and improve the compactness of component installation. At the same time, the center distance between the driving gear and the output gear is shortened, the loss of braking force is reduced, and the stable transmission of braking torque is utilized.

[0019] The parking motor of the present invention is provided with a telescopic extension shaft, and the pawl is installed on the extension shaft through a buffer. The parking brake unit of the present invention is provided with a mounting guide sleeve, and the mounting guide sleeve is provided with a mounting through hole. The pawl is slidably installed in the mounting through hole, and one end thereof extends outside the mounting through hole to form a locking end. After the parking brake is realized, the reaction force caused by the clamping force of the brake caliper body will be reversely transmitted to the power end of the brake motor through the reduction gear set and then transmitted to the ratchet, so the locking end of the pawl will bear the tangential force brought by the ratchet. Since the locking end is slidably installed in the mounting through hole of the mounting guide sleeve, the outer wall of the locking end will always fit the hole wall of the mounting through hole, and the mounting guide sleeve is installed on the mounting frame, and this tangential force will eventually be transmitted to the mounting frame for bearing. Therefore, the extension shaft of the parking motor will no longer bear other external forces except the elastic force of the buffer in the axial direction, thereby ensuring the smoothness and reliability of its axial movement.

[0020] On the basis of the above, the buffer of the present invention includes a lock tongue and a spring; one end of the lock tongue is connected to the extended shaft of the parking motor, and the other end is provided with a columnar mounting rod; the pawl body of the pawl is provided with a mounting groove, and the outer side of the mounting rod of the lock tongue is sleeved with a spring, and the pawl is sleeved on the mounting rod through the mounting groove, and is slidably installed on the mounting rod against the spring. In addition, a pin hole is provided on the mounting rod of the lock tongue of the present invention to install a limit pin, and a boss is provided at the bottom of the mounting rod. By providing a strip limit groove in the mounting groove of the pawl, the pawl is slidably installed on the mounting rod of the lock tongue under the limiting action of the limit pin. When the parking brake is applied, if the locking end of the pawl is not locked in the gear groove of the ratchet, the locking end will collide with the tooth top of the ratchet gear, and the locking end will squeeze the spring at this time. Due to the buffering of the spring, the extended shaft of the parking motor is prevented from directly rigidly contacting with the ratchet, so as to avoid the jamming and damage between the components of the parking brake unit.

[0021] On the basis of the above, the outer wheel surface of the ratchet wheel of the present invention is evenly distributed with ratchet gears, and a ratchet groove is formed between two adjacent ratchet gears. The tooth surfaces on both sides of the body of the ratchet gear are set as a plane structure and an arc structure, and the locking end of the pawl of the present invention adopts a gear structure adapted to the ratchet gear, and the locking tooth surfaces on both sides of the gear structure of the locking end are set as a plane structure and an arc structure, so that when parking, the locking end abuts against the ratchet groove of the ratchet wheel, and the locking tooth surface of the plane structure of the locking end abuts against the tooth surface of the plane structure of the ratchet gear, so as to limit the rotational movement of the ratchet wheel along the first direction. When the brake fails, the top surface of the locking tooth of the pawl will abut against the top of the ratchet gear tooth, and the parking motor will be driven by the control unit to lock the parking vehicle again. At this time, the brake motor drives the ratchet to rotate in the braking direction to drive the top surface of the locking tooth of the pawl to slide along the tooth surface of the ratchet gear to the bottom of the ratchet groove until the parking brake is completed. During this process, the locking end of the pawl is always in contact with the tooth surface of the ratchet gear under the action of the spring, preventing the locking end from quickly hitting the ratchet groove from the top of the ratchet gear tooth. The arc-shaped locking tooth surface of the locking end of the pawl and the arc-shaped tooth surface of the ratchet gear can enable the brake motor to rotate stably under the action of the specified torque and spring force, thereby ensuring the stable operation of the parking brake components and reducing damage to the components due to abnormal impact.

[0022] On the basis of the above, the parking brake unit of the present invention is provided with an electronic control unit and a sensor, the brake motor and the pressure sensor are electrically connected to the electronic control unit respectively, and the pressure sensor is sleeved on the screw shaft of the ball screw pair, and one side of its sensing end contacts the end face of the screw shaft, and the other side contacts the brake caliper body to detect the brake clamping force. The electronic control unit detects the ratio between the actual parking brake force and the target parking brake force. If the actual parking brake force is detected to be too large, the electronic control unit will determine that the parking is invalid, so as to park again to confirm that the locking end of the pawl is stopped in the ratchet groove. The width dimension of the ratchet groove of the present invention is larger than the width dimension of the locking end of the pawl, so that when the parking needs to be released, the brake motor rotates a little angle in the braking direction to eliminate the above-mentioned tangential force borne by the locking end and reduce the friction when the locking end is retracted. After rotating a little angle, since the width of the ratchet groove is larger than the locking end, the locking end is still in the ratchet groove at this time, so as to ensure that the vehicle can still be locked when an accident occurs, and ensure the safety of parking. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a brake assembly of a compact walking-stationary integrated electronic mechanical brake mechanism of an embodiment; Figure 2 It is a structural exploded view of the brake assembly of the compact walking-stationing integrated electronic mechanical brake mechanism of the embodiment; Figure 3 It is a structural exploded view of the parking brake unit of the compact parking-integrated electronic mechanical brake mechanism of the embodiment; Figure 4 It is a structural schematic diagram of a parking brake unit of a compact driving-parking integrated electronic mechanical brake mechanism according to an embodiment. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the embodiments. For the sake of clarity, the brake motor of the present embodiment is clamped when it rotates clockwise, and is released when it rotates counterclockwise.

[0025] See also Figure 1-Figure 4 The present embodiment provides a compact driving and parking integrated electronic mechanical brake mechanism, comprising a mounting frame, a brake assembly 1 and a brake caliper assembly (not shown), the brake assembly comprising a driving brake unit and a parking brake unit; the driving brake unit comprises a brake motor 1-1 and a reduction gear set 1-3; the brake caliper assembly is provided with a brake caliper body, the brake caliper body is slidably mounted on the mounting frame, and one end of the brake caliper body is connected to the power end of the brake motor through the reduction gear set; the parking brake unit comprises a parking motor 1-2, a ratchet 1-208 and a pawl 1-207; the ratchet 1-208 is connected to the reduction gear set 1-3, the pawl is connected to the power end of the parking motor, and a buffer is provided between the pawl and the power end of the parking motor, which is used to form a flexible connection between the pawl and the power end of the parking motor when the pawl locks the ratchet and fails.

[0026] The brake caliper body assembly of this embodiment includes a slide rail (not shown) and a ball screw pair (only the screw is shown); the slide rail is installed on the mounting frame, the brake caliper body (not shown) is slidably installed on the slide rail, and one end of it is connected to the nut end of the ball screw pair, the screw 1-4 of the ball screw pair is rotatably installed on the mounting frame, and one end of it is connected to the power output end of the reduction gear set.

[0027] The reduction gear set 1-3 of this embodiment includes a driving gear 1-301, an output gear 1-304 and two idler gears; the driving gear 1-301 is fixedly connected to the power end 1-102 of the brake motor 1-1, and the torque is transmitted through the axial surface 1-101 of the power end; the output gear 1-304 is installed on the external spline at the end of the screw 1-4 of the ball screw pair by providing an internal spline 1-305, and the driving gear and the output gear are connected by two idler gears that mesh with each other. A double gear 1-302 is provided in the two idler gears, and the double gear 1-302 is combined with the driving gear 1-301 of the brake motor, and is used to connect the idler gears located in different planes from the driving gear; the double gear includes a first gear and a second gear that are integrally formed and coaxially arranged, the first gear meshes with the driving gear 1-301 to form a power input end, the second gear meshes with the adjacent idler gear 1-303 to form a power output end, and the output gear meshes with the adjacent idler gear. The ratchet 1-208 of this embodiment is fixedly mounted on the power end 1-102 of the brake motor; a mounting hole is provided in the middle of the ratchet, and the ratchet 1-208 is interference mounted on the power end of the brake motor through the mounting hole.

[0028] Furthermore, the parking brake unit of the present embodiment is provided with a mounting guide sleeve 1-206, and the parking motor 1-2 is provided with a telescopic extension shaft 1-202 to constitute a power end; the mounting guide sleeve 1-206 is fixedly installed on the mounting frame, and the mounting guide sleeve is provided with a mounting through hole, and the pawl 1-207 is slidably installed in the mounting through hole, and one end thereof is connected to the extension shaft 1-202 through a buffer, and the other end extends to the outside of the mounting through hole to form a locking end 1-216. The shape of the mounting through hole of the mounting guide sleeve 1-206 of this embodiment is adapted to the shape of the pawl, and the outer side wall 1-209 of the pawl fits into the hole wall of the mounting through hole; the buffer member includes a lock tongue 1-204 and a spring 1-203; one end of the lock tongue 1-204 is connected to the extending shaft 1-202 of the parking motor, and the other end is provided with a columnar mounting rod; the pawl body of the pawl is provided with a mounting groove, and a spring is provided on the outer side of the mounting rod of the lock tongue, and the pawl is sleeved on the mounting rod through the mounting groove, and is slidably installed on the mounting rod by abutting against the spring. Specifically, the bottom of the mounting rod protrudes radially outward to form a boss, and a pin hole perpendicular to the rod body is opened on the rod body near the top of the mounting rod; a strip limit groove is opened in the mounting groove of the pawl and the groove corresponding to the pin hole of the mounting rod along the sliding direction of the pawl; a limit pin 1-205 is installed in the pin hole of the mounting rod, and the two ends of the limit pin extend to the outside of the pin hole respectively to form limit ends on both sides; when the pawl is slidably installed on the mounting rod, the limit ends on both sides of the limit pin are respectively slidably installed in the strip limit groove 1-210 of the pawl to limit the sliding stroke of the pawl; the spring 1-203 is sleeved on the outside of the mounting rod, one side of which is stopped at the pawl 1-207, and the other end is stopped at the boss of the mounting rod.

[0029] In addition, a plurality of ratchet gears are evenly spaced on the outer side of the wheel surface of the ratchet wheel of the present embodiment, and a ratchet groove 1-212 is formed between two adjacent ratchet gears; the body of the ratchet gear is provided with tooth surfaces and tooth top surfaces 1-214 on both sides, and the tooth surface 1-211 on one side of the tooth surfaces on both sides is a plane structure perpendicular to the ratchet wheel surface, and the tooth surface 1-213 on the other side is an arc-shaped structure from the tooth root to the tooth top; the locking end 1-216 of the pawl is a gear structure adapted to the ratchet gear; The gear structure is provided with locking tooth surfaces and locking tooth top surfaces 1-217 on both sides. The tooth surface 1-215 on one side of the locking tooth surfaces on both sides is a plane structure perpendicular to the pawl, and the locking tooth surface 1-218 on the other side is an arc-shaped structure from the tooth root to the tooth top; when the pawl locks the ratchet, the locking tooth top surface of the pawl stops at the bottom of the ratchet groove, and the locking tooth surface of the plane structure of the locking end is abutted against the tooth surface of the plane structure of the ratchet gear to limit the rotational movement of the ratchet along the brake release direction.

[0030] Furthermore, the brake assembly of this embodiment is provided with an electronic control unit and a pressure sensor. The brake motor and the pressure sensor are electrically connected to the electronic control unit respectively. The pressure sensor is sleeved on the screw shaft of the ball screw pair. One side of the sensing end thereof contacts the end face of the screw shaft, and the other side contacts the brake caliper body to detect the brake clamping force. The width dimension of the ratchet groove is larger than the width dimension of the pawl locking end.

[0031] Working principle: When the compact driving and parking integrated electronic mechanical brake mechanism of this embodiment is in use, when the vehicle is driving, the brake motor and the parking motor are in the unactivated state, and the extended shaft of the parking motor is in the retracted position to drive the pawl to the retracted position, and the locking end of the pawl has no contact with the ratchet.

[0032] During service braking, the brake motor starts, and the power end drives the driving gear to rotate, which in turn drives the double gear to transmit the braking force of the brake motor to the output gear through the idler gear, thereby driving the screw of the ball screw pair to rotate, driving the nut end to slide along the screw, and finally driving the brake caliper body to slide along the slide rail toward the brake disc for braking and deceleration.

[0033] After the service brake is completed, when the vehicle stops and the parking brake is required, the electronic control unit controls the parking motor to start, so as to drive the extension shaft of the parking motor to extend, and drive the pawl on the lock tongue to extend toward the ratchet wheel, until the locking tooth top surface of the locking end of the pawl abuts against the ratchet groove of the ratchet wheel, and at the same time, the locking tooth surface of the plane structure of the locking end of the pawl abuts against the tooth surface of the plane structure of the ratchet gear of the ratchet wheel to lock, so as to limit the ratchet wheel from rotating in the counterclockwise direction. It should be noted that if the locking end of the pawl does not abut against the ratchet groove of the ratchet wheel when it is extended, but abuts against the tooth top surface 1-214 of the ratchet gear, at this time, the extension shaft of the parking motor continues to extend, the pawl will compress the spring, and drive the mounting rod of the lock tongue to slide along the pawl mounting groove, at this time, the sensor on the extension shaft will detect that the actual parking clamping force increases until it exceeds the target parking clamping force, and the electronic control unit determines that the parking fails, and then performs parking again to drive the brake motor to rotate in the clockwise direction to brake. As the power end of the brake motor rotates, the ratchet rotates in a clockwise direction, driving the locking end of the pawl to slide along the tooth top surface of the ratchet gear toward the ratchet groove until the pawl slides into the ratchet groove and stops on the tooth surface of the planar structure of the ratchet gear, completing the parking brake.

[0034] In addition, when the parking brake needs to be released, the brake motor first rotates a little clockwise to eliminate the tangential force of the ratchet on the locking end and reduce the friction when the pawl retracts. Since the width of the ratchet groove is designed to be larger than the width of the locking end, the locking end is still in the ratchet groove after the ratchet rotates a little, ensuring that the vehicle can still be locked in the event of an accident, ensuring parking safety.

[0035] As above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A compact electromechanical brake mechanism comprising a mounting frame, a brake assembly and a brake caliper assembly, characterized in that: The brake assembly includes a service brake unit and a parking brake unit; the service brake unit includes a brake motor and a reduction gear set; the brake caliper assembly is provided with a brake caliper body, the brake caliper body is slidably mounted on a mounting frame, and one end of the brake caliper body is connected to the power end of the brake motor through a reduction gear set; the parking brake unit includes a parking motor, a ratchet and a pawl; the ratchet is connected to the reduction gear set, the pawl is connected to the power end of the parking motor, and a buffer is provided between the pawl and the power end of the parking motor.

2. A compact electronic mechanical brake mechanism according to claim 1, characterized in that: The brake caliper body assembly includes a slide rail and a ball screw pair; the slide rail is installed on a mounting frame, the brake caliper body is slidably installed on the slide rail, and one end of the brake caliper body is connected to the nut end of the ball screw pair, the screw of the ball screw pair is rotatably installed on the mounting frame, and one end of the brake caliper body is connected to the power output end of the reduction gear set.

3. A compact electronic mechanical brake mechanism according to claim 1, characterized in that: The reduction gear set includes a driving gear, an output gear and a plurality of idle gears; the driving gear is fixedly connected to the power end of the brake motor, the output gear is installed on the screw of the ball screw pair, and the driving gear and the output gear are connected by meshing with each other through a plurality of idle gears.

4. A compact electronic mechanical brake mechanism according to claim 3, characterized in that: Several of the idler gears are provided with double gears for connecting driving gears or idler gears or output gears located in different planes; the double gears include a first gear and a second gear that are integrally formed and coaxially arranged, the first gear is meshed with the driving gear or the adjacent idler gear to form a power input end, and the second gear is meshed with the output gear or the adjacent idler gear to form a power output end.

5. A compact electronic mechanical brake mechanism according to claim 3, characterized in that: The ratchet is fixedly mounted on the power end of the brake motor; a mounting hole is provided in the middle of the ratchet, and the ratchet is interference mounted on the power end of the brake motor through the mounting hole.

6. A compact electronic mechanical brake mechanism according to claim 2, characterized in that: The parking brake unit is provided with a mounting guide sleeve, and the parking motor is provided with a telescopic extension shaft to form a power end; the mounting guide sleeve is fixedly installed on the mounting frame, and the mounting guide sleeve is provided with a mounting through hole, the pawl is slidably installed in the mounting through hole, and one end of the pawl is connected to the extension shaft through a buffer, and the other end extends to the outside of the mounting through hole to form a locking end.

7. A compact electronic mechanical brake mechanism according to claim 6, characterized in that: The shape of the mounting through hole of the mounting guide sleeve is adapted to the shape of the pawl; the buffer member includes a lock tongue and a spring; one end of the lock tongue is connected to the extended shaft of the parking motor, and the other end is provided with a columnar mounting rod; the pawl body of the pawl is provided with a mounting groove, and the spring is sleeved on the outer side of the mounting rod of the lock tongue, and the pawl is sleeved on the mounting rod through the mounting groove, and is slidably installed on the mounting rod by abutting against the spring.

8. A compact electronic mechanical brake mechanism according to claim 7, characterized in that: The bottom of the mounting rod of the lock tongue protrudes outward in the radial direction to form a boss, and a pin hole perpendicular to the rod body is provided on the rod body near the top of the mounting rod; a strip-shaped limiting groove is provided in the mounting groove of the pawl and the groove corresponding to the pin hole of the mounting rod along the sliding direction of the pawl; a limiting pin is installed in the pin hole of the mounting rod, and the two ends of the limiting pin extend to the outside of the pin hole respectively to form limiting ends on both sides; when the pawl is slidably installed on the mounting rod, the limiting ends on both sides of the limiting pin are slidably installed in the strip-shaped limiting groove of the pawl respectively to limit the sliding stroke of the pawl; the spring is sleeved on the outside of the mounting rod, one side of which is stopped at the pawl, and the other end is stopped at the boss of the mounting rod.

9. A compact electronic mechanical brake mechanism according to claim 6, characterized in that: A plurality of ratchet gears are evenly spaced on the outer side of the ratchet wheel surface, and a ratchet groove is formed between two adjacent ratchet gears; the body of the ratchet gear is provided with tooth surfaces on both sides, one tooth surface of the two tooth surfaces is a plane structure perpendicular to the ratchet wheel surface, and the other tooth surface is an arc-shaped structure from the tooth root to the tooth top; the locking end of the pawl is a gear structure adapted to the ratchet gear; the gear structure of the locking end is provided with locking tooth surfaces on both sides and locking tooth top surfaces, one tooth surface of the two locking tooth surfaces is a plane structure perpendicular to the ratchet wheel surface, and the other tooth surface is an arc-shaped structure from the tooth root to the tooth top; the locking end of the pawl is a gear structure adapted to the ratchet gear; the gear structure of the locking end is provided with locking tooth surfaces on both sides and locking tooth top surfaces, and one tooth surface of the two locking tooth surfaces is a plane structure perpendicular to the pawl. The locking tooth surface of the pawl is an arc-shaped structure from the tooth root to the tooth top; when the pawl locks the ratchet, the locking tooth top surface of the pawl stops at the bottom of the ratchet groove, and the locking tooth surface of the plane structure of the locking end abuts against the tooth surface of the plane structure of the ratchet gear to limit the rotational movement of the ratchet along the braking release direction. When the locking tooth top surface of the pawl abuts against the tooth top of the ratchet gear, the ratchet rotates in the braking direction to drive the locking tooth top surface of the pawl to slide along the tooth surface of the arc-shaped structure of the ratchet gear.

10. A compact electronic mechanical brake mechanism according to claim 9, characterized in that: The brake assembly is provided with an electronic control unit and a pressure sensor. The brake motor and the sensor are electrically connected to the electronic control unit respectively. The pressure sensor is sleeved on the screw shaft of the ball screw pair. One side of the sensing end is in contact with the end face of the screw shaft, and the other side is in contact with the brake caliper body to detect the parking clamping force. The width dimension of the ratchet groove is greater than the width dimension of the pawl locking end.

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