Running and parking brake executing mechanism of drum type electronic mechanical brake

Abstract

The utility model relates to the field of electronic brake actuating mechanisms, and discloses a running and parking brake actuating mechanism of a drum type electronic mechanical brake, which comprises a brake driving motor assembly, a brake cylinder, brake shoes and a brake drum, the connecting ends of the two brake shoes are movably installed on the two sides of the brake cylinder. The brake cylinder comprises a cylinder shell and a steel ball sleeve assembly, the steel ball sleeve assembly comprises a rotating wheel and push discs on the left side and the right side of the rotating wheel, the rotating wheel is in transmission connection with the brake driving motor assembly, and annular grooves are formed in the rotating wheel or / and the push discs on the left side and the right side opposite to the rotating wheel. Balls used for pushing the push disc are contained in the annular grooves in the left side and the right side correspondingly, and slope faces are arranged in the circumferential direction of the annular grooves. The rotary steel balls arranged on the two sides are opened in a sleeve mode and push the brake shoes to generate braking force, the axial size is small, occupied space is small, and response is rapid.

Description

Technical Field

[0001] The utility model relates to the field of electronic brake actuators, in particular to a parking brake actuator of a drum type electronic mechanical brake. Background Art

[0002] In vehicle braking systems, traditional hydraulic brakes are gradually being replaced by electric mechanical brakes (EMBs) due to their complex structure, inconvenient maintenance, and the risk of brake failure due to oil leakage. In particular, disc-type electronic mechanical brakes have been rapidly developed due to their advantages such as fast response speed and low space layout requirements. However, disc-type electronic mechanical brakes have not yet been quickly popularized and replaced traditional hydraulic brakes due to their complex structure, high manufacturing cost, and stability issues. There are also drum brakes, which have a large actual friction contact area. Under the same conditions, the braking force generated is greater than that of disc brakes. Drum brakes have good self-braking effects, but their structure leads to problems with accuracy and braking stability.

[0003] In order to overcome the limitations of the prior art, the utility model proposes a parking brake actuator for a drum-type electronic mechanical brake, aiming to provide a braking solution with simple structure, low cost and high stability to meet the requirements of modern vehicles for braking systems. Summary of the invention

[0004] The utility model aims at the shortcomings of the prior art and provides a parking brake actuator for a drum-type electronic mechanical brake.

[0005] To solve the above technical problems, the utility model is solved by the following technical solutions:

[0006] A parking brake actuator for a drum type electronic mechanical brake comprises a brake drive motor assembly, a brake cylinder, a brake shoe and a brake drum, wherein both brake shoes have a movable end and a connection end, and the connection ends of the two brake shoes are movably mounted on both sides of the brake cylinder. In a braking state, the two brake shoes are opened, and their movable ends are respectively in contact with the inner wall of the brake drum; the brake cylinder comprises a cylinder housing and a steel ball sleeve assembly, and the steel ball sleeve assembly comprises a rotating wheel and push plates on the left and right sides of the rotating wheel, the rotating wheel is connected to the brake drive motor assembly in a transmission manner, and the rotating wheel or the push plates on the left and right sides opposite thereto are provided with an annular groove, and the annular grooves on the left and right sides respectively contain balls for pushing the push plates, and the annular grooves are provided with a ramp surface in the circumferential direction, so that when the rotating wheel rotates, the balls move along the circumferential movement of the annular groove to drive the push plates on the left and right sides to push away or move toward each other. By rolling the steel balls on the ramp surface formed by the annular groove, the rotational motion of the gear driven by the motor is converted into the lateral motion of the brake push block, so that the overall structure is more precise, and the accuracy and stability of controlling the braking force are higher. The rotating steel balls arranged on both sides are used to open and push the brake shoes to generate braking force. The structure is simple, the axial dimension is short, the space occupied is small, and the response is fast.

[0007] Preferably, the brake cylinder further includes an input worm, the brake drive motor assembly is spline-connected to the input worm, the outer surface of the rotating wheel is a worm gear, and the worm outer teeth of the input worm mesh with the worm gear so that the input worm rotates to drive the rotating wheel to rotate. Due to the self-locking characteristics of the worm gear transmission structure, the braking force required for parking the vehicle can be maintained in the parking brake condition without the need for an additional transmission locking device.

[0008] Preferably, the inner surface of the slave pump housing is provided with a rotation-stopping groove, and the outer ring of the push plate is provided with a rotation-stopping block, which is engaged with the rotation-stopping groove, and the rotation-stopping groove extends in the left-right direction to limit the movement of the push plate along the extension direction of the rotation-stopping groove. The rotation-stopping block and the rotation-stopping groove cooperate with each other to form a rotation-stopping structure to prevent the push plate from being driven to rotate by the rotating wheel.

[0009] Preferably, the brake drive motor assembly includes a drive motor, an ECU housing and a PCB board. An output gear is provided in the drive motor, and a motor angle magnet is installed on the top of the output gear. The motor angle magnet cooperates with the PCB board installed on the upper part thereof to detect the current motor rotation angle to adjust the output torque of the drive motor, and accurately control the braking process, thereby improving the accuracy and intelligence level of braking.

[0010] Preferably, a plurality of annular grooves are provided on the push plate, and the plurality of annular grooves are evenly spaced and distributed along the circumference of the push plate.

[0011] Preferably, a brake push block is provided on the outer side of the push plates on the left and right sides, and the outer side of the brake push block is connected to the brake shoe. A wave spring is provided between the push plate and the brake push block on the same side of the left and right sides of the rotating wheel.

[0012] Preferably, at least one of the left and right sides of the rotating wheel is provided with a pressure sensor, and the wave spring is located between the pressure sensor and the corresponding brake push block and is in a compressed state, and the two sides of the pressure sensor are respectively in contact with the end faces of the push plate and the brake push block. The wave spring is pressed between the push plate and the brake push block. If a pressure sensor is provided on this side, the pressure sensor is located between the push plate and the brake push block, and the wave spring can be pressed on the end face of the pressure sensor to press the pressure sensor against the push plate. The wave spring can be a single-turn or multi-turn wave spring, which is used to provide a push plate pressure on one side to fit the push plate with the rotating wheel in the middle, and the other side will fit the push plate together with the rotating wheel by providing a thrust of the pressure sensor, thereby eliminating the axial gap, so as to improve the transmission accuracy between the ball ramp formed by the ball and the annular groove. The pressure sensor detects the braking force in real time, making the safety performance of the braking system more reliable.

[0013] Preferably, the two brake shoes are provided with return springs near the connection ends to assist the opened brake shoes to return to their original positions.

[0014] The utility model has significant technical effects due to the adoption of the above technical solutions:

[0015] 1. The rotating steel balls arranged on both sides are used to open and push the brake shoes to generate braking force. The structure is simple, the axial dimension is short, the space occupied is small, and the response is fast. Compared with the disc type electronic mechanical brake assembly solution, it has the characteristics of simple structure and low cost. Compared with the traditional hydraulic brake system, it more effectively reduces the space occupied and weight of the vehicle, making the internal space layout of the vehicle simpler.

[0016] 2. Due to the compact design of the brake cylinder and brake shoe, the motor basically does not need to move after output, so the entire brake actuator occupies a small space, which is suitable for the strict space requirements of modern vehicles. By setting an annular groove on the push plate and using a wave spring to reduce the axial clearance, the stability and reliability of the brake actuator are improved.

[0017] 3. Since the structure of the utility model can adapt to different vehicle models and braking requirements, it is suitable for accurately realizing driving braking or parking braking to complete self-locking, and has good market adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an exploded view of the brake cylinder assembly structure of the utility model;

[0019] Figure 2It is a structural explosion diagram of the steel ball sleeve assembly of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the rotating wheel of the utility model;

[0021] Figure 4 It is a structural schematic diagram of the left and right push plates of the utility model;

[0022] Figure 5 This is a working diagram of the steel ball sleeve assembly of the utility model from the initial state to the braking state;

[0023] Figure 6 This is a working principle diagram of the steel ball sleeve assembly of the utility model during braking;

[0024] Figure 7 This is a cross-sectional view of the brake cylinder assembly of the utility model;

[0025] Figure 8 This is a cross-sectional view of the electric mechanical brake actuator of the utility model;

[0026] Fig. 9 This is a three-dimensional diagram of the brake cylinder housing of the utility model;

[0027] Fig.10 It is a schematic diagram of a drum brake applied to an electronic mechanical drive brake according to the utility model;

[0028] Fig.11 This is an exploded view of the brake drive motor assembly structure of the utility model.

[0029] The parts indicated by the numerical symbols in the above drawings are as follows: 1. brake drive motor assembly; 11. drive motor; 12. ECU housing; 13. PCB board; 14. motor angle magnet; 15. output gear; 2. brake wheel cylinder; 21. wheel cylinder housing; (21-1, 21-2) anti-rotation groove; 22. input worm; 22-1, worm outer teeth; 23. steel ball sleeve assembly; 23-1, rotating wheel; 23-11, annular groove; 23-12, worm gear; (23-2, 23-3) push plate; (23-22, 23-32) anti-rotation block; (23-4, 23-5) ball; 24. pressure sensor; (25-1, 25-2) wave spring; (27-1, 27-2) brake push block; (3-1, 3-2) brake shoe; 3-3, return spring; 4. brake drum. DETAILED DESCRIPTION

[0030] The utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] Example 1

[0032] The technical scheme of the mechanism assembly is as follows:

[0033] A parking brake actuator for a drum type electronic mechanical brake, such as Figure 1 and Fig.10 As shown, it includes a brake drive motor assembly 1, a brake cylinder 2, brake shoes 3-1, 3-2 and a brake drum 4. The two brake shoes 3-1, 3-2 have a movable end and a connecting end. The connecting ends of the two brake shoes 3-1, 3-2 are movably installed on both sides of the brake cylinder 2. In the braking state, the two brake shoes 3-1, 3-2 are opened, and their movable ends are respectively in contact with the inner wall of the brake drum 4; the brake cylinder 2 includes a cylinder housing 21 and a steel ball sleeve assembly 23. The steel ball sleeve assembly 23 includes a rotating wheel 23-1 and push plates 23-2, 23-3 on the left and right sides of the rotating wheel 23-1. The rotating wheel 23-1 is connected to the brake drive motor assembly 1 in a transmission manner. The rotating wheel 23-1 or | and the push plates 23-2 and 23-3 on the left and right sides thereof are provided with an annular groove 23-11. The annular grooves 23-11 on the left and right sides respectively contain balls 23-4 and 23-5 for pushing the push plates 23-2 and 23-3. The annular grooves 23-11 are provided with a slope surface in the circumferential direction, so that when the rotating wheel 23-1 rotates, the balls 23-4 and 23-5 move along the annular grooves 23-11 in the circumferential direction to drive the push plates 23-2 and 23-3 on the left and right sides to push and move or move towards each other. The rotating wheel 23-1 or the push plates 23-2 and 23-3 on the left and right sides thereof are provided with an annular groove 23-11 on one side. One side of the annular groove 23-11 is located on the slope surface, and the other side of the balls is in contact with the plane. When annular grooves 23-11 are provided on both sides of the rotating wheel 23-1 and the left and right push plates 23-2 and 23-3 opposite thereto, the annular grooves 23-11 on both sides cooperate to form a ball motion track with slope surfaces on both sides, and the accuracy will be higher.

[0034] The brake cylinder 2 also includes an input worm 22, the brake drive motor assembly 1 is spline-connected to the input worm 22, the outer surface of the rotating wheel 23-1 is a worm gear 23-12, and the worm outer teeth 22-1 of the input worm 22 are meshed with the worm gear 23-12 to rotate the input worm 22 and drive the rotating wheel 23-1 to rotate.

[0035] The inner surface of the sub-pump housing 21 is provided with anti-rotation grooves 21-1, 21-2, and the outer rings of the push plates 23-2, 23-3 are provided with anti-rotation blocks 23-22, 23-32. The anti-rotation blocks 23-22, 23-32 are snap-fitted with the anti-rotation grooves 21-1, 21-2. The anti-rotation grooves 21-1, 21-2 extend in the left-right direction and are used to limit the movement of the push plates 23-2, 23-3 along the extension direction of the anti-rotation grooves 21-1, 21-2.

[0036] The brake drive motor assembly 1 includes a drive motor 11, an ECU housing 12 and a PCB board 13. An output gear 15 is provided inside the drive motor 11. A motor angle magnet 14 is installed on the top of the output gear 15. The motor angle magnet 14 cooperates with the PCB board 13 installed on the upper part thereof to detect the current motor rotation angle to adjust the output torque of the drive motor 11.

[0037] A plurality of annular grooves 23-11 are formed on the push plates 23-2 and 23-3, and the plurality of annular grooves 23-11 are evenly spaced along the circumference of the push plates 23-2 and 23-3.

[0038] Braking push blocks 27-1 and 27-2 are respectively arranged on the outer sides of the push plates 23-2 and 23-3 on the left and right sides. The outer sides of the brake push blocks 27-1 and 27-2 are connected to the brake shoes 3-1 and 3-2. On the left and right sides of the rotating wheel 23-1, wave springs 25-1 and 25-2 are arranged between the push plates 23-2 and 23-3 on the same side and the brake push blocks 27-1 and 27-2.

[0039] A pressure sensor 24 is provided on at least one of the left and right sides of the rotating wheel 23-1. The wave springs 25-1 and 25-2 are located between the pressure sensor 24 and the corresponding brake push blocks 27-1 and 27-2 and are in a compressed state. The two sides of the pressure sensor 24 are respectively in contact with the end faces of the push plates 23-2 and 23-3 and the brake push blocks 27-1 and 27-2.

[0040] The working principle of the utility model is described below in conjunction with the accompanying drawings:

[0041] like Figure 8 and Fig.11 The figure shows an exploded view of the brake drive motor assembly 1 of the utility model, which is composed of a drive motor 11, an ECU housing 12 and a PCB board 13. A motor angle magnet 14 is installed on the top of the output gear 15 in the drive motor. The motor angle magnet 14 cooperates with the PCB board 13 installed on the upper part thereof to detect the current motor rotation angle to adjust the output torque of the motor 11.

[0042] like Figure 1 The figure shows an exploded view of the brake cylinder assembly structure of the utility model, which consists of a cylinder housing 21, an input worm 22, a steel ball sleeve assembly 23, a pressure sensor 24, wave springs 25-1, 25-2, shaft sleeves 26-1, 26-2 and brake push blocks 27-1, 27-2.

[0043] like Figure 2 The figure shows an exploded view of the structure of the steel ball sleeve assembly 23, which consists of a rotating wheel 23-1, left and right push plates 23-2, 23-3 and left and right balls 23-4, 23-5.

[0044] like Figure 3The figure shows a schematic diagram of a rotating wheel, the outer side of which is a worm gear 23-12, and the bottoms of both sides are designed with annular grooves 23-11 with sloped surfaces for accommodating balls 23-4 and 23-5.

[0045] like Figure 4 and Fig. 9 The figure shows a schematic diagram of the left and right push plates 23-2 and 23-3, one side of which is also processed with an annular groove 23-11 with a sloped surface for accommodating the balls 23-4 and 23-5, and the other end is processed with a stop block 23-22 and 23-32 that cooperates with the stop grooves 21-1 and 21-2 inside the sub-pump housing 21, so that the left and right push plates 23-2 and 23-3 are restricted to move axially only along the stop grooves 21-1 and 21-2.

[0046] like Figure 5 and Figure 6 The figure shows the working diagram of the ball sleeve assembly 23. The worm gear 23-1 rotates after being driven by the worm outer teeth 22-1 and drives the internal balls 23-4 and 23-5 on both sides to roll along the slope surface annular groove 23-11. At this time, the push plates 23-2 and 23-3 on both sides are pushed outward by the corresponding balls 23-4 and 23-5.

[0047] like Figure 7 The figure shows a cross-sectional view of the brake cylinder assembly, in which the worm outer teeth 22-1 mesh with the worm gear 23-12. The wave springs 25-1 and 25-2 are compressed and installed between the pressure sensor 24 and the cylinder housing 21, and the wave springs 25-1 and 25-2 press the pressure sensor 24 and the push plate 23-3. The end faces of the brake push blocks 27-1 and 27-2 abut against the end faces of the pressure sensor 24. The pressure sensor 24, the push plate 23-3 and the brake push blocks 27-1 and 27-2 abut against each other to transmit thrust. The wave springs 25-1 and 25-2 are compressed and installed between the push plates 23-2 and 23-3 and the cylinder housing 21. Under the action of the spring force of the wave springs 25-1 and 25-2, the two push plates 23-2 and 23-3 limit their corresponding balls 23-4 and 23-5 axially in the annular groove 23-11 on the ramp surface.

[0048] Braking working conditions:

[0049] When the driver steps on the brake pedal for a certain distance, the electric mechanical brake receives the current pedal travel signal and converts it into the braking force signal required by the current vehicle, which is sent to the brake drive motor assembly 1 through the connector 12-1. The brake motor starts to work, and the motor gear 17 drives the output gear 15 to rotate through the intermediate gear 16. The output gear 15 cooperates with the output spline 15-1 and the worm spline 22-2 to transmit the torque to the input worm 22 and thereby drives the rotating wheel 23-1 to rotate; the rotating rotating wheel 23-1 moves upward along the annular groove 23-11 on the ramp surface through the balls 23-4 and 23-5 on both sides and pushes the corresponding push plates 23-2 and 23-3 on both sides outward, thereby the brake push blocks 27-1 and 27-2 on both sides abutting against it push the brake shoes 3-1 and 3-2 in the brake base plate to contact the inner wall of the brake drum 4, thereby generating braking force on the vehicle.

[0050] During the vehicle's driving braking process, the reaction force of the inner wall of the brake drum 4 on the brake shoes 3-1 and 3-2 on both sides is transmitted to the force sensor 24 through the brake push blocks 27-1 and 27-2-push plates 23-2 and 23-3. The force sensor 24 transmits the current vehicle braking force signal to the PCB13 of the ECU controller. The ECU controller PCB13 adjusts the output torque of the drive motor assembly 1 according to the angle position and braking force of the magnet assembly 14 to ensure that the current required braking force matches the output braking force. After the driver releases the brake pedal, the drive motor assembly 1 controls the gear set to retreat to the original position, and the balls 23-4 and 23-5 retreat to the bottom of the anti-rotation grooves 21-1 and 21-2 at the same time. The brake shoes 3-1 and 3-2 on both sides are driven by the return spring 3-3 to shrink inward and push the corresponding brake push blocks 27-1 and 27-2 on both sides back at the same time, and the vehicle stops braking. In particular, due to the self-locking characteristics of the worm gear transmission structure, the braking force required for parking the vehicle can be maintained without the need for an additional transmission structure in the parking brake condition.

[0051] In the description of the present utility model, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0052] In short, the above is only a preferred embodiment of the present utility model, and all equivalent changes and modifications made according to the scope of the patent application of the present utility model should fall within the scope of the present utility model patent.

Claims

1. A parking brake actuator for a drum-type electronic mechanical brake, comprising a brake drive motor assembly (1), a brake cylinder (2), brake shoes (3-1, 3-2) and a brake drum (4), wherein both brake shoes (3-1, 3-2) have a movable end and a connection end, and the connection ends of the two brake shoes (3-1, 3-2) are movably mounted on both sides of the brake cylinder (2), and in a braking state, the two brake shoes (3-1, 3-2) are opened, and their movable ends are respectively in contact with the inner wall of the brake drum (4); characterized in that: The brake cylinder (2) comprises a cylinder housing (21) and a steel ball sleeve assembly (23); the steel ball sleeve assembly (23) comprises a rotating wheel (23-1) and push plates (23-2, 23-3) on the left and right sides of the rotating wheel (23-1); the rotating wheel (23-1) is drivingly connected to the brake drive motor assembly (1); the rotating wheel (23-1) and the push plates (23-2, 23-3) on the left and right sides thereof are provided with an annular groove (23-11); The annular grooves (23-11) on the left and right sides respectively contain balls (23-4, 23-5) for pushing the push plates (23-2, 23-3), and the annular grooves (23-11) are provided with a slope surface in the circumferential direction, so that when the rotating wheel (23-1) rotates, the balls (23-4, 23-5) move along the circumferential direction of the annular grooves (23-11) to drive the push plates (23-2, 23-3) on the left and right sides to push apart or move towards each other.

2. The parking brake actuator of a drum type electromechanical brake according to claim 1, characterized in that: The brake cylinder (2) further comprises an input worm (22), the brake drive motor assembly (1) is spline-connected to the input worm (22), the outer surface of the rotating wheel (23-1) is a worm gear (23-12), and the worm outer teeth (22-1) of the input worm (22) are meshed with the worm gear (23-12) so that the input worm (22) rotates and drives the rotating wheel (23-1) to rotate.

3. The parking brake actuator of a drum type electromechanical brake according to claim 1, characterized in that: The inner surface of the slave cylinder housing (21) is provided with anti-rotation grooves (21-1, 21-2), and the outer rings of the push plates (23-2, 23-3) are provided with anti-rotation blocks (23-22, 23-32). The anti-rotation blocks (23-22, 23-32) are engaged with the anti-rotation grooves (21-1, 21-2), and the anti-rotation grooves (21-1, 21-2) extend in the left-right direction and are used to limit the movement of the push plates (23-2, 23-3) along the extension direction of the anti-rotation grooves (21-1, 21-2).

4. The parking brake actuator of a drum type electromechanical brake according to claim 1, characterized in that: The brake drive motor assembly (1) comprises a drive motor (11), an ECU housing (12) and a PCB board (13). An output gear (15) is arranged inside the drive motor (11). A motor angle magnet (14) is arranged on the top of the output gear (15). The motor angle magnet (14) cooperates with the PCB board (13) installed on the top thereof to detect the current motor rotation angle so as to adjust the output torque of the drive motor (11).

5. The parking brake actuator of a drum type electromechanical brake according to claim 1, characterized in that: A plurality of annular grooves (23-11) are provided on the push plates (23-2, 23-3), and the plurality of annular grooves (23-11) are evenly spaced and distributed along the circumference of the push plates (23-2, 23-3).

6. The parking brake actuator of a drum type electromechanical brake according to claim 5, characterized in that: Braking push blocks (27-1, 27-2) are respectively arranged on the outer sides of the push plates (23-2, 23-3) on the left and right sides, and the outer sides of the brake push blocks (27-1, 27-2) are connected to the brake shoes (3-1, 3-2). Wave springs (25-1, 25-2) are arranged between the push plates (23-2, 23-3) and the brake push blocks (27-1, 27-2) on the same side on the left and right sides of the rotating wheel (23-1).

7. The parking brake actuator of a drum type electromechanical brake according to claim 6, characterized in that: A pressure sensor (24) is provided on at least one of the left and right sides of the rotating wheel (23-1); the wave springs (25-1, 25-2) are located between the pressure sensor (24) and the corresponding brake push blocks (27-1, 27-2) and are in a compressed state; and the two sides of the pressure sensor (24) are respectively in contact with the end faces of the push plates (23-2, 23-3) and the brake push blocks (27-1, 27-2).

8. The parking brake actuator of a drum type electromechanical brake according to claim 1, characterized in that: A return spring (3-3) is arranged near the connection end of the two brake shoes (3-1, 3-2).

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