An electronic mechanical brake climbing transmission mechanism and an electronic mechanical brake

Abstract

The utility model discloses a kind of electronic mechanical brake hill-climbing transmission mechanism and electronic mechanical brake, belong to automobile brake field, including one end with EMB executor output end connection's cam spline shaft and cam nut, cam nut is successively compressed by snap spring and first wave spring and the other end of cam spline shaft, the outer circumferential side of cam nut is cooperated with the inner circumferential side of piston by thread;The opposite side of cam spline shaft and cam nut is provided with segmented propulsion component, for segmented propulsion cam nut. Above-mentioned kind of electronic mechanical brake hill-climbing transmission mechanism and electronic mechanical brake, replace traditional screw by hill-climbing transmission mechanism, utilize columnar roller to increase clamping force to increase axial bearing capacity, have the advantages of structure exquisite, wear-resistant durable, maintenance cost is low and layout flexible, significantly improve EMB brake performance.

Description

Technical Field

[0001] This utility model relates to the field of automotive braking technology, and in particular to an electromechanical brake climbing transmission mechanism and an electromechanical brake. Background Technology

[0002] The working principle of the existing electromechanical brake (EMB) is as follows: When the driver presses the brake pedal, a braking signal is sent. The vehicle's electronic control unit drives the EMB motor to rotate according to this braking signal. After the speed reduction and torque increase through the gearbox, the rotation is converted into linear motion by the linear motion mechanism, which pushes the brake piston forward. The piston then pushes the friction pads against the brake disc, thereby clamping the brake disc and achieving the deceleration effect until the vehicle stops.

[0003] Existing systems typically utilize lead screws to convert rotational motion into linear motion. However, due to the limited space within the caliper cylinder, the diameter and lead of the cylindrical rollers in the lead screw are significantly affected, thus limiting the axial load the lead screw can withstand. When the axial force exceeds the lead screw's rated load, its service life decreases dramatically. Furthermore, with the development of new energy vehicles and the increasing demand for diverse automotive electrical functions, new energy vehicles are heavier than traditional vehicles. The clamping force required for braking also increases accordingly. The lead screw, with its limited axial load, becomes a component that restricts the braking performance of electromechanical brakes. Utility Model Content

[0004] The purpose of this utility model is to provide an electromechanical brake climbing transmission mechanism and an electromechanical brake to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, this utility model provides an electromechanical brake climbing transmission mechanism, including a cam spline shaft and a cam nut, one end of which is connected to the output end of the EMB actuator. The cam nut is pressed against the other end of the cam spline shaft by a snap ring and a first wave spring in sequence. The outer circumference of the cam nut is threadedly engaged with the inner circumference of the piston. A segmented propulsion assembly is provided on the opposite side of the cam spline shaft and the cam nut for propulsing the cam nut in stages.

[0006] Preferably, the segmented propulsion assembly includes multiple segmented propulsion units arranged in a circular pattern and connected end to end. Each segmented propulsion unit includes a first ramp surface disposed on the side of the cam spline shaft facing the cam nut, a second ramp surface disposed on the side of the cam nut facing the cam spline shaft, and cylindrical rollers disposed on the first ramp surface and the second ramp surface. The first and second climbing surfaces form a climbing channel, which is divided into an initial section and a climbing section. During the advancing stage, the rolling is located in the initial section. During the clamping stage, the cam spline shaft drives the cylindrical roller to roll out from the initial section and roll along the climbing section. During the rolling process, it drives the cam nut to rotate and pushes the cam nut outward.

[0007] Preferably, the initial segment is a positioning groove formed by the grooves on the first and second climbing surfaces, and the climbing segment is an inclined surface that gradually convexes outward from the initial segment of the same climbing channel to the initial segment of the adjacent climbing channel. The uphill section transitions smoothly with a circular arc between it and the initial section.

[0008] Preferably, the protruding part of the cam spline shaft extends into the cam nut, and the part of the cam spline shaft extending into the cam nut also contacts the contact of the force sensor in sequence via the thrust bearing and the bearing washer, for measuring the clamping force; A copper sleeve is also provided between the cam spline shaft and the cam nut. The end of the copper sleeve is pressed against the force sensor by a second wave spring to position the force sensor.

[0009] An electromechanical brake includes an EMB actuator and a caliper assembly. The EMB actuator is connected to the caliper assembly via an electromechanical brake climbing transmission mechanism. The EMB actuator includes a motor and a reducer connected to the output end of the motor. The output end of the reducer is connected to a cam spline shaft via an output spline shaft. The caliper assembly includes a bracket, a caliper body mounted on the bracket via a guide pin, and a friction pad assembly. The friction pad assembly includes an inner friction pad assembly and an outer friction pad assembly slidably distributed on both sides of the brake disc on the bracket. The inner friction pad assembly is aligned with the piston, and the outer friction pad assembly is connected to the caliper body via caliper jaws. The caliper body is mechanically connected to the force sensor of the electromechanical brake climbing transmission mechanism. The caliper body also has a guide hole, which is slidably connected to one end of a guide pin, and the other end of the guide pin is threadedly connected to the bracket. The caliper body is also fixedly connected to the retaining ring of the electromechanical brake climbing transmission mechanism.

[0010] Therefore, the present invention, employing the aforementioned electromechanical brake climbing transmission mechanism and electromechanical brake, has the following beneficial effects: 1. Improve braking performance: By advancing in stages, greater clamping force can be provided to meet the higher demands of new energy vehicles for braking clamping force due to increased weight, and solve the problem of limited axial load of traditional lead screws; 2. More compact structure: It can reduce the overall axial height of EMB, making it more flexible in the limited space at the wheel end of the car, adapting to more car models, and having wider applicability; 3. Low maintenance cost: The easily worn cylindrical rollers can be replaced individually in the later stages without replacing the entire transmission mechanism. Compared with traditional lead screws (where the easily worn parts need to be replaced as a whole), the maintenance cost is greatly reduced. 4. It has a wear compensation function: the thread between the cam nut and the piston can automatically compensate for the wear gap of the friction plate (after the friction plate is worn out, the piston rotates out of the cam nut a corresponding distance to compensate for the wear gap of the friction plate), ensuring stable braking performance; 5. Stable power transmission: Through structural design such as the pre-tensioning of the first wave plate spring, the transmission components are free from idling, the power transmission is efficient and reliable, and the braking process is smooth.

[0011] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0012] Figure 1 This is an axial cross-sectional view of an electromechanical brake climbing transmission mechanism according to the present invention. Figure 2 This is a schematic diagram of the segmented propulsion component of an electromechanical brake climbing transmission mechanism according to this utility model. Figure 3 This is a perspective view of the cam spline shaft of the climbing transmission mechanism of an electromechanical brake according to this utility model. Figure 4 This is a perspective view of the cam nut of the climbing transmission mechanism of an electromechanical brake according to this utility model. Figure 5 This is a perspective view of the cylindrical roller in the climbing transmission mechanism of an electromechanical brake according to this utility model. Figure 6 This is a perspective view of the piston in the climbing transmission mechanism of an electromechanical brake according to this utility model. Figure 7 This is an axial sectional view of an electromechanical brake according to the present invention; Figure 8 This is a perspective view of an electromechanical brake according to the present invention.

[0013] Figure Labels 1. Cam spline shaft; 2. Force sensor; 3. First wave spring; 4. Snap ring; 5. Piston; 6. Cam nut; 7. Cylindrical roller; 8. Thrust bearing; 9. Second wave spring; 10. Bearing washer; 11. First ramp surface; 12. Second ramp surface; 13. Reducer; 14. Caliper body; 15. Inner friction plate assembly; 16. Brake disc; 17. Outer friction plate assembly; 18. Motor; 19. Guide pin; 20. Initial section; 21. Ramp section; 22. Copper sleeve. Detailed Implementation

[0014] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0015] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0016] like Figures 1-6 As shown (it should be noted that, in Figure 2 To illustrate the principle of the segmented propulsion assembly, the structures of the cam spline shaft and cam nut have been simplified. Those skilled in the art should be able to deduce the specific structures of the cam spline shaft and cam nut without a doubt based on the other accompanying drawings. An electromechanical brake climbing transmission mechanism includes a cam spline shaft 1 and a cam nut 6, one end of which is connected to the output end of an EMB actuator. The cam nut 6 is pressed against the other end of the cam spline shaft 1 by a snap ring 4 and a first wave spring 3 in sequence. The outer circumference of the cam nut 6 is threadedly engaged with the inner circumference of the piston 5. A segmented propulsion assembly is provided on the opposite side of the cam spline shaft 1 and the cam nut 6 for propulsing the cam nut 6 in stages.

[0017] The segmented propulsion assembly includes multiple segmented propulsion units arranged circumferentially and connected end to end. Each segmented propulsion unit includes a first ramp surface 11 on the side of the cam spline shaft 1 facing the cam nut 6, a second ramp surface 12 on the side of the cam nut 6 facing the cam spline shaft 1, and cylindrical rollers 7 on the first ramp surface 11 and the second ramp surface 12. The first ramp surface 11 and the second ramp surface 12 form a ramp channel, which is divided into an initial section 20 and a ramp section 21. During the propulsion stage (this stage also includes cases where the output torque of the motor 18 is less than 0.1 NM), the rollers are located in the initial section 20. During the clamping stage, the cam spline shaft 1 drives the cylindrical rollers 7 to roll out of the initial section 20 and roll along the ramp section 21, driving the cam nut 6 to rotate during the rolling process and pushing the cam nut 6 outward. It should be noted that during the propulsion stage, the first ramp surface 11 and the second ramp surface 12 of the same ramp channel are arranged alternately.

[0018] This embodiment sets up 4 phased advancement units.

[0019] The initial segment 20 is a positioning groove formed by the groove on the first climbing surface 11 and the groove on the second climbing surface 12. The climbing segment 21 is an inclined surface that gradually convexes outward from the initial segment 20 of the same climbing channel to the initial segment 20 of the adjacent climbing channel. The climbing segment 21 and the initial segment 20 are connected by an arc transition.

[0020] The protruding part of the cam spline shaft 1 extends into the cam nut 6. The part of the cam spline shaft 1 that extends into the cam nut 6 also contacts the contact of the force sensor 2 in sequence via the thrust bearing 8 and the bearing washer 10, for measuring the clamping force. A copper sleeve 22 is also provided between the cam spline shaft 1 and the cam nut 6. The end of the copper sleeve 22 is pressed against the force sensor 2 via the second wave spring 9 to position the force sensor 2.

[0021] like Figure 7 and Figure 8 As shown, an electromechanical brake includes an EMB actuator and a caliper assembly. The EMB actuator is connected to the caliper assembly via an electromechanical brake climbing transmission mechanism. The EMB actuator includes a motor 18 and a reducer 13 connected to the output end of the motor 18. The output end of the reducer 13 is connected to a cam spline shaft 1 via an output spline shaft. The caliper assembly includes a bracket, a caliper body 14 mounted on the bracket via a guide pin 19, and a friction pad assembly. The friction pad assembly includes an inner friction pad assembly 15 and an outer friction pad assembly 17 slidably distributed on both sides of the brake disc 16 on the bracket. The inner friction pad assembly 15 is aligned with the piston 5, and the outer friction pad assembly 17 is connected to the caliper body 14 via caliper jaws. The caliper body 14 is mechanically connected to the force sensor 2 of the electromechanical brake climbing transmission mechanism. The caliper body 14 also has a guide hole, which is slidably connected to one end of the guide pin 19, and the other end of the guide pin 19 is threadedly connected to the bracket. The caliper body 14 is also fixedly connected to the retaining spring 4 of the electromechanical brake climbing transmission mechanism.

[0022] Working process: During braking, the motor 18 first drives the cam spline shaft 1 to rotate via the reducer 13. At this time, since the friction pad assembly is not in contact with the brake disc 16, the piston 5 is in an unloaded state (advancement stage). At this time, the cylindrical roller 7 is located in the positioning groove. Under the preload of the first wave spring 3, the cam spline shaft 1 and the cam nut 6 rotate together as a whole. Then, under the threaded engagement between the cam nut 6 and the piston 5, the piston 5 is driven to move axially, which in turn pushes the inner friction pad assembly 15 to move towards the brake disc 16. At this time, under the interaction of forces, the cam spline shaft 1 pushes the caliper body 14 to move via the thrust bearing 8, the bearing washer 10 and the force sensor 2. The caliper body 14 drives the outer friction pad assembly 17 to move via the caliper jaws until the inner friction pad assembly 15 and the outer friction pad assembly 17 are respectively in contact with the two sides of the brake disc 16. Continue the operation until the output torque of motor 18 is greater than 0.1 NM; enter the clamping stage, while cam nut 6 rotates, cam spline shaft 1 drives cylindrical roller 7 to roll out of initial section 20 and roll along climbing section 21 towards the adjacent climbing channel. During the rolling process, the convex structure pushes the convex nut outward to increase the clamping force.

[0023] After braking is completed, the driver releases the brake pedal. At this time, the vehicle's electronic control unit sends a reverse signal to the motor 18, which in turn drives the cam spline shaft 1 to rotate in the opposite direction through the reducer 13. This drives the cylindrical roller 7 to roll in the opposite direction until it returns to the initial section 20. During this process, the cam nut 6 and piston 5 retract under the action of the climbing channel. When the cylindrical roller 7 returns to the initial section 20, under the preload of the first wave spring 3, the cam spline shaft 1, cylindrical roller 7, and cam nut 6 rotate in the opposite direction as a whole. At this time, under the threaded engagement of the cam nut 6 and piston 5, piston 5 retracts further until it reaches the initial position. After the inner friction plate assembly 15 loses the pressure of piston 5, it resets under the action of the return spring. Similarly, the outer friction plate assembly 17 resets under the action of the return spring, waiting for the next braking.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. An electromechanical brake climbing transmission mechanism, characterized in that: It includes a cam spline shaft and a cam nut, one end of which is connected to the output end of the EMB actuator. The cam nut is pressed against the other end of the cam spline shaft by a snap ring and a first wave spring in sequence. The outer circumference of the cam nut is threadedly engaged with the inner circumference of the piston. A segmented propulsion assembly is provided on the opposite side of the cam spline shaft and the cam nut for propulsing the cam nut in stages.

2. The electromechanical brake climbing transmission mechanism according to claim 1, characterized in that: The segmented propulsion assembly includes multiple segmented propulsion units arranged in a circular pattern and connected end to end. Each segmented propulsion unit includes a first ramp surface disposed on the side of the cam spline shaft facing the cam nut, a second ramp surface disposed on the side of the cam nut facing the cam spline shaft, and cylindrical rollers disposed on the first ramp surface and the second ramp surface. The first and second climbing surfaces form a climbing channel, which is divided into an initial section and a climbing section. During the advancing stage, the rolling is located in the initial section. During the clamping stage, the cam spline shaft drives the cylindrical roller to roll out from the initial section and roll along the climbing section. During the rolling process, it drives the cam nut to rotate and pushes the cam nut outward.

3. The electromechanical brake climbing transmission mechanism according to claim 2, characterized in that: The initial section is a positioning groove formed by the grooves on the first and second climbing surfaces. The climbing section is an inclined surface that gradually convexes outward from the initial section of the same climbing channel to the initial section of the adjacent climbing channel. The uphill section transitions smoothly with a circular arc between it and the initial section.

4. The electromechanical brake climbing transmission mechanism according to claim 3, characterized in that: The protruding part of the cam spline shaft extends into the cam nut. The part of the cam spline shaft that extends into the cam nut also contacts the contact of the force sensor in sequence through the thrust bearing and bearing gasket, which is used to measure the clamping force. A copper sleeve is also provided between the cam spline shaft and the cam nut. The end of the copper sleeve is pressed against the force sensor by a second wave spring to position the force sensor.

5. An electromechanical brake, comprising an EMB actuator and a caliper assembly, characterized in that: The EMB actuator is connected to the caliper assembly via the electromechanical brake climbing transmission mechanism as described in claim 4. The EMB actuator includes a motor and a reducer connected to the output end of the motor. The output end of the reducer is connected to the cam spline shaft via the output spline shaft. The caliper assembly includes a bracket, a caliper body mounted on the bracket via a guide pin, and a friction pad assembly. The friction pad assembly includes an inner friction pad assembly and an outer friction pad assembly slidably distributed on both sides of the brake disc on the bracket. The inner friction pad assembly is aligned with the piston, and the outer friction pad assembly is connected to the caliper body via caliper jaws. The caliper body is mechanically connected to the force sensor of the electromechanical brake climbing transmission mechanism. The caliper body also has a guide hole, which is slidably connected to one end of a guide pin, and the other end of the guide pin is threadedly connected to the bracket. The caliper body is also fixedly connected to the retaining ring of the electromechanical brake climbing transmission mechanism.

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