Electric control execution device for drum brake

Abstract

The utility model provides an electric control execution device for a drum brake. The electric control execution device comprises a brushless motor, a motor shell, a motor base, a lead screw structure, an anti-rotation piece, a piston cylinder body and a ball head ejector rod. The utility model has the beneficial effects that a gas / liquid type power unit and a power assisting unit are cancelled, compared with the gas / liquid type power unit, the whole vehicle does not need to additionally provide a gas / liquid pressure source, and the noise and environmental pollution in the use process can be greatly reduced by the rotation of the motor in the control process. The motor is used for directly rotating the lead screw to push the piston, the response speed is higher, and the braking distance can be shortened; and the anti-rotation piece can play a good role in guiding and positioning, so that the operation of the nut is very stable. A power source only needs a control motor, and a brushless motor is used.

Description

Technical Field

[0001] The utility model relates to a braking device, in particular to a braking technology for a drum brake. Background Art

[0002] Currently, brakes on the market are mainly divided into two categories, disc brakes and drum brakes. Disc brakes are comfortable and easy to operate, but some cost-conscious vehicle braking systems still use drum brakes. Drum brakes are cheaper and more efficient than disc brakes. In addition, in some commercial trucks in Yunnan, Guizhou and Sichuan, due to the steep and rugged terrain, the vehicle brakes are used very frequently, and the heat is serious, so they need to be sprayed with water during driving. Disc brakes are prone to cracking when sprayed with water. The good durability of drum brakes is also an important reason why drum brakes still exist. A very important module used in drum brakes is called an adjusting arm. The function of the adjusting arm is to adjust the wear gap of the brake during different life cycles to prevent the gap from increasing and prolonging the braking time and distance. The adjusting arm was previously a pneumatic or hydraulic propulsion device, which was connected to the adjusting arm to provide a power source for the adjusting arm. However, pneumatic / hydraulic brakes are noisy, the brake fluid seriously pollutes the environment, the response is slow, and the control is complex and difficult to keep up with the current development trend of wire-controlled chassis. In addition, new energy vehicles currently have no engine to provide a power source, so the pneumatic type requires an additional power device. This patent aims to design an electronically controlled execution unit that can be used for drum brakes to replace the old pneumatic / hydraulic power unit. Utility Model Content

[0003] In order to solve the problems existing in the above-mentioned technology, the utility model provides a technology for replacing the movement of the existing drum brake adjusting arm with an electric drive mode.

[0004] The utility model provides an electronically controlled actuator for a drum brake, which comprises:

[0005] Brushless motor;

[0006] A motor housing is arranged outside the brushless motor;

[0007] A motor base is provided at one end of the motor housing and has a sliding channel inside the motor base;

[0008] a lead screw structure, a first end of which is connected to the rotor of the brushless motor, and the lead screw structure is provided with a movable lead screw nut;

[0009] An anti-rotation member, a first end of which is fixed to the motor base, the anti-rotation member having a limiting channel, the lead screw nut cooperating with the limiting channel for axial movement;

[0010] A piston cylinder body, one end of which is a cylindrical head fixedly connected to the lead screw nut, and the other end of which is a ball-and-socket structure; the piston cylinder body is movably disposed in the sliding channel;

[0011] The two ends of the ball head push rod are respectively a push rod cylindrical part and a push rod ball head, and the push rod ball head is matched with the ball socket structure.

[0012] Preferably, one end of the motor base has a mounting groove, a displacement sensor is embedded in the mounting groove, and the piston cylinder is arranged through the displacement sensor.

[0013] Preferably, a connecting piece is further included, one end of the connecting piece is connected to the cylindrical portion of the push rod, and the other end of the connecting piece is used to cooperate with the drum brake for braking.

[0014] Preferably, the connecting member is an adjusting fork, one end of which is a connecting portion and the other end is two flat structures, and the flat structures have a pin hole in the middle; the connecting portion is connected to the cylindrical portion of the push rod; the pin hole in the middle of the two flat structures is used to connect to the drum brake for braking.

[0015] Preferably, the screw structure has a flat surface structure, which cooperates with the inner ring of the brushless motor; the cylindrical head is press-fitted with the screw nut by interference fit, and the screw nut and the cylindrical head are connected by a fastening screw.

[0016] Preferably, the ball head push rod and the piston cylinder are riveted together by hexagonal rivets.

[0017] Preferably, the ball head push rod is connected to the adjustment fork by threaded engagement.

[0018] Preferably, one end of the anti-rotation component is fixedly matched with the motor base to achieve radial locking, and the other end of the anti-rotation component is matched with the ball screw nut to limit the nut in the radial direction.

[0019] Preferably, it also includes a press-fit bushing, which is annular and cooperates with the piston cylinder. The press-fit bushing is interference pressed into the inner ring of the mounting seat, and the press-fit bushing cooperates with the piston cylinder to play a lubrication and guiding role.

[0020] Preferably, a PCB control circuit board is provided in the motor base.

[0021] Preferably, one end of the motor housing is a motor rear cover, a PCB control circuit board and an angle sensor are mounted on the motor rear cover, and one end of the lead screw structure passes through the angle sensor.

[0022] The beneficial effects of the present invention are as follows: (1) The gas / liquid power unit and the power assist unit are eliminated. Compared with the gas / liquid power unit, the entire vehicle does not need to provide an additional gas / liquid pressure source. The rotation of the motor during the control process can greatly reduce the noise and environmental pollution during use. (2) The motor is used to directly rotate the screw to push the piston, which has a faster response speed and can shorten the braking distance; the anti-rotation part can play a good guiding and positioning role, making the operation of the nut very stable. (3) The power source only needs to control the motor, and a brushless motor is used. (4) The single gas source / hydraulic pressure is eliminated, and it can be combined with the drum brake to achieve multi-wheel independent braking, which is more adaptable and greatly improves the feasibility of vehicle caliper selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of an electronically controlled actuator for a drum brake according to the present invention from one perspective;

[0024] Figure 2 This is a structural schematic diagram of an electronically controlled actuator for a drum brake according to the present invention from another perspective;

[0025] Figure 3 This utility model is an electronically controlled actuator for drum brakes. Figure 2 Structural diagram of the AA section view;

[0026] Figure 4 This is a schematic structural diagram of another structure of an electronically controlled actuator for a drum brake according to the present invention;

[0027] Figure 5 It is a schematic structural diagram of a cross-sectional view of an electronically controlled actuator for a drum brake according to the present invention;

[0028] Figure 6 The utility model is a diagram showing the matching relationship between a limit channel of an anti-rotation component and a nut of a ball screw in an electric-controlled actuator for a drum brake.

[0029] Description of reference numerals:

[0030] 1- Brushless motor;

[0031] 2-motor housing; 21-press-fit bushing; 22-motor rear cover;

[0032] 3-motor base; 31-sliding channel; 32-mounting slot; 33-displacement sensor; 331-angle sensor; 34-PCB control circuit board;

[0033] 4-screw structure; 41-screw nut; 42-protrusion block;

[0034] 5-anti-rotation part; 51-limiting channel;

[0035] 6-piston cylinder; 61-cylindrical head; 62-ball and socket structure;

[0036] 7-ball head push rod; 71-cylindrical part of push rod; 72-ball head of push rod;

[0037] 8-adjusting fork; 81-connecting part; 82-pin hole in the middle. DETAILED DESCRIPTION

[0038] Example 1:

[0039] like Figures 1 to 3 As shown, the electronically controlled actuator for a drum brake according to embodiment 1 includes a brushless motor 1, a motor housing 2, a motor base 3, a lead screw structure 4, and an anti-rotation member 5;

[0040] The motor housing 2 is arranged outside the brushless motor 1;

[0041] The motor base 3 is arranged at one end of the motor housing 2, and a sliding channel 31 is provided inside the motor base 3; the motor base 3 and the motor housing are detachably connected, and the detachable design of the two facilitates the replacement and maintenance of the screw nut 41 and the piston cylinder 6 after subsequent disassembly and assembly.

[0042] The first end of the lead screw structure 4 is connected to the rotor of the brushless motor 1 , and the lead screw structure 4 has a movable lead screw nut 41 ;

[0043] The first end of the anti-rotation member 5 ( Figure 3 The middle and lower ends) are fixed to the motor base 3, and the anti-rotation component 5 has a limiting channel 51, and the screw nut 41 cooperates with the limiting channel 51 to move axially; the cooperation between the anti-rotation component 5 and the screw nut 41 can prevent the screw nut 41 from rotating, thereby achieving a stabilizing effect, and performing axially guided sliding for braking.

[0044] One end of the piston cylinder body 6 is a cylindrical head 61, which is fixedly connected to the screw nut 41, and the other end of the piston cylinder body 6 is a ball and socket structure 62; the piston cylinder body 6 is movably disposed in the sliding channel 31;

[0045] The two ends of the ball head push rod 7 are respectively a push rod cylindrical portion 71 and a push rod ball head 72, and the push rod ball head 72 cooperates with the ball socket structure 62;

[0046] Preferably, a connecting member is also included, one end of which is connected to the cylindrical portion 71 of the push rod, and the other end of the connecting member is used to cooperate with the drum brake for braking; the connecting member can be an adjusting fork 8, a rotating pin, a connecting pin or other structures that can complete the connection.

[0047] Preferably, when the connecting member is an adjusting fork, one end of the adjusting fork 8 is connected to the cylindrical portion 71 of the push rod, and the other end of the adjusting fork 8 is used to cooperate with the adjusting arm of the drum brake to brake. The adjusting arm of the drum brake is a prior art, and the adjusting fork 8 of the present patent is fixedly connected to the existing drum brake adjusting arm to achieve actuation, thereby applying the brake.

[0048] Preferably, one end of the motor base 3 has a mounting slot 32, in which a displacement sensor 33 is embedded. The piston-cylinder 6 is disposed through the displacement sensor 33. When the piston-cylinder 6 moves, the displacement sensor 33 generates an induction signal, which is used to determine the displacement distance of the piston-cylinder 6. The mounting slot 32 is located at the junction of the motor base 3 and the motor housing 2, making it easy to open the mounting slot 32 for installation and maintenance of the displacement sensor 33.

[0049] Preferably, one end of the adjustment fork 8 is a connecting portion 81, and the other end is two flat structures, and the flat structures have a pin hole 82 in the middle; the connecting portion 81 is connected to the cylindrical portion 71 of the push rod; the pin hole 82 in the middle of the two flat structures is used to connect to the drum brake for braking.

[0050] Preferably, the screw structure 4 has a flat surface structure, which cooperates with the inner ring of the brushless motor 1; the cylindrical head 61 is press-fitted with the screw nut 41 by interference fit, and the screw nut 41 and the cylindrical head 61 are connected by a fastening screw.

[0051] Example 2

[0052] like Figures 4 and 5 , which is an electronically controlled actuator for a drum brake according to Embodiment 2, includes a brushless motor 1, a motor housing 2, a motor base 3, a lead screw structure 4, and an anti-rotation member 5;

[0053] The motor housing 2 is arranged outside the brushless motor 1;

[0054] The motor base 3 is arranged at one end of the motor housing 2, and a sliding channel 31 is formed inside the motor base 3;

[0055] The first end of the lead screw structure 4 is connected to the rotor of the brushless motor 1 , and the lead screw structure 4 has a movable lead screw nut 41 ;

[0056] The first end of the anti-rotation member 5 ( Figure 5 The middle and lower end) is fixed to the motor base 3, the anti-rotation member 5 has a limiting channel 51, and the lead screw nut 41 cooperates with the limiting channel 51 to move axially;

[0057] One end of the piston cylinder body 6 is a cylindrical head 61, which is fixedly connected to the screw nut 41, and the other end of the piston cylinder body 6 is a ball and socket structure 62; the piston cylinder body 6 is movably disposed in the sliding channel 31;

[0058] The two ends of the ball head push rod 7 are respectively a push rod cylindrical portion 71 and a push rod ball head 72, and the push rod ball head 72 cooperates with the ball socket structure 62;

[0059] One end of the adjusting fork 8 is connected to the cylindrical portion 71 of the push rod, and the other end of the adjusting fork 8 is used to cooperate with the adjusting arm of the drum brake to perform braking.

[0060] Preferably, the ball head push rod 7 and the piston cylinder 6 are riveted together by hexagonal rivets.

[0061] Preferably, the ball head push rod 7 and the adjustment fork 8 are connected by threaded engagement to facilitate replacement and disassembly.

[0062] Preferably, a PCB control circuit board 34 is provided in the motor base 3 , and the PCB control circuit board 34 is used to control the operation of the motor.

[0063] Preferably, one end of the motor housing 2 is the motor rear cover 22, on which a PCB control circuit board 34 and an angle sensor 331 are mounted. One end of the lead screw structure 4 passes through the angle sensor 331. During the rotation of the lead screw structure 4, the angle of rotation is monitored by the angle sensor 331 in the prior art, so that the braking travel distance can be determined, thereby facilitating the operation control of the motor.

[0064] Example 3

[0065] Preferably, one end of the anti-rotation member 5 is fixedly matched with the motor base 3 to achieve radial locking; the limiting channel 51 of the anti-rotation member 5 cooperates with the nut 41 of the ball screw to limit the nut 41 in the radial direction (to prevent rotation); there are two radial limiting methods for the screw nut 41 and the limiting channel 51 of the anti-rotation member 5. Figure 6 As shown, the screw nut 41 has a protrusion 42, which penetrates into the groove of the limiting channel 51 to achieve cooperation, playing the role of guiding sliding and radial (circumferential) limiting; or the screw nut 41 has a recessed portion, and the limiting channel 51 has an extended protrusion, which cooperates with the recessed portion to guide sliding, and can also achieve the role of radial (circumferential) limiting.

[0066] Preferably, it also includes a press-fit bushing 21, which is annular and cooperates with the piston cylinder 6. The press-fit bushing 21 is interference pressed into the inner ring of the mounting seat. The press-fit bushing 21 cooperates with the piston cylinder 6 to play a lubrication and guiding role.

[0067] In specific applications,

[0068] Service braking: After receiving the braking request of the entire vehicle, the controller issues a power-on command to the motor. The rotation of the motor drives the screw structure 4 to move, and the screw structure 4 pushes the nut 41 forward. The nut 41 pushes the piston cylinder 6 to move, and then the adjusting fork 8 pushes the adjusting arm (not shown in the figure), thereby driving the drum brake to brake the entire vehicle.

[0069] At this time, the axial movement distance of the piston cylinder 6 is monitored by the displacement sensor 33 in Example 1, or the motor angle information is detected by the angle sensor 331 in Example 2 to identify whether the target value is reached. If the target value is reached, the motor maintains the pressure. If a brake release command is received, the motor reverses to release the pressure.

[0070] Parking brake: After receiving the parking request of the whole vehicle, the controller issues a power-on command to the motor. The motor rotates to drive the screw structure 4, and the screw structure 4 pushes the nut 41 forward. The adjusting fork 8 pushes the adjusting arm, driving the drum brake to brake the whole vehicle. The nut 41 pushes the piston cylinder 6 to move. At this time, the angle sensor 331 is also detecting the motor angle information to identify whether it has reached the target value. If it has reached the target value, the motor maintains pressure, and the power is cut off and locked to achieve vehicle parking, and it is combined with the service brake.

[0071] This patented solution can be used for single-wheel independent braking function:

[0072] During vehicle driving, after the vehicle issues a single-wheel or multi-wheel braking command through analysis of the wheel speed and the entire vehicle, the execution unit actively increases the pressure on a single wheel adjustment arm or multiple wheel adjustment arms together to ensure vehicle driving stability and avoid failures such as steering not meeting expectations and rollover.

[0073] This patented solution can also be used for ABS (Antil Lock Brake System) functions:

[0074] During the vehicle's driving process, after the vehicle issues a single-wheel or multi-wheel braking command through analysis of the wheel speed and the entire vehicle, the execution unit operates a single wheel adjusting arm or multiple wheel adjusting arms together, and operates the adjusting arm to move forward and backward periodically to ensure that the vehicle's steering function is normal, the tires roll, and the vehicle is driving within the high-efficiency friction range of braking, which can make the vehicle driving stable and shorten the driving distance.

Claims

1. An electronically controlled actuator for a drum brake, characterized in that: include: Brushless motor (1); A motor housing (2) is arranged outside the brushless motor (1); A motor base (3) is arranged at one end of the motor housing (2), and a sliding channel (31) is provided inside the motor base (3); A lead screw structure (4), a first end of which is connected to the rotor of the brushless motor (1), and a movable lead screw nut (41) is provided on the lead screw structure (4); An anti-rotation component (5) having a first end fixed to the motor base (3), the anti-rotation component (5) having a limiting channel (51), and the lead screw nut (41) cooperates with the limiting channel (51) to move axially; A piston cylinder (6), one end of the piston cylinder (6) is a cylindrical head (61), the cylindrical head (61) is fixedly connected to the screw nut (41), and the other end of the piston cylinder (6) is a ball and socket structure (62); the piston cylinder (6) is movably arranged in the sliding channel (31); The ball head push rod (7) has two ends respectively comprising a push rod cylindrical portion (71) and a push rod ball head (72), and the push rod ball head (72) cooperates with the ball socket structure (62).

2. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: One end of the motor base (3) has a mounting groove (32), a displacement sensor (33) is embedded in the mounting groove (32), and the piston cylinder (6) is arranged through the displacement sensor (33).

3. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: It also includes a connecting piece, one end of which is connected to the cylindrical portion (71) of the push rod, and the other end of which is used to cooperate with a drum brake for braking.

4. The electronically controlled actuator for a drum brake according to claim 3, characterized in that: The connecting member is an adjustment fork (8); one end of the adjustment fork (8) is a connecting portion (81), and the other end is two flat structures, and the flat structures have a central pin hole (82); the connecting portion (81) is connected to the cylindrical portion of the push rod (71); the central pin hole (82) of the two flat structures is used to connect to a drum brake for braking.

5. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: The lead screw structure (4) has a flat surface structure, which is matched with the inner ring of the brushless motor (1); the cylindrical head (61) is press-fitted with the lead screw nut (41) by interference fit, and the lead screw nut (41) and the cylindrical head (61) are connected by a fastening screw.

6. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: The ball head push rod (7) and the piston cylinder (6) are riveted together by hexagonal rivets; the ball head push rod (7) and the adjustment fork (8) are connected by threaded engagement.

7. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: One end of the anti-rotation component (5) is fixedly matched with the motor base (3) to achieve radial locking, and the other end of the anti-rotation component (5) is matched with the ball screw nut to limit the nut in the radial direction.

8. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: The utility model also includes a press-fitting bushing (21), which is annular and cooperates with the piston cylinder body (6). The press-fitting bushing (21) is interference-pressed into the inner ring of the mounting seat, and the press-fitting bushing (21) cooperates with the piston cylinder body (6) to play a lubricating and guiding role.

9. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: A PCB control circuit board (34) is provided in the motor base (3).

10. The electronically controlled actuator for a drum brake according to claim 1, characterized in that: One end of the motor housing (2) is a motor rear cover (22), a PCB control circuit board (34) and an angle sensor (331) are mounted on the motor rear cover (22), and one end of the lead screw structure (4) passes through the angle sensor (331).

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