EMB electronic booster for automobile drum brake system

Abstract

The utility model provides an EMB electronic booster for an automobile drum brake system. The EMB electronic booster comprises a motor, a lead screw, a push rod and a ball head rod. The motor is provided with a hollow shaft for outputting power; the inner end of the lead screw is connected with the hollow shaft, and the lead screw is provided with a lead screw nut. The push rod is connected with the lead screw nut, the push rod is in sliding fit with an outer port of the shell, and a sliding bearing piece is arranged at the position of the outer port. The inner end of the ball rod is matched with the push rod. According to the utility model, through the arrangement of the hollow shaft, the end part of the lead screw can be directly connected and fixed in the motor, and the structure saves the distance in the axial direction, ensures that a transmission system of an EMB electronic brake is more stable, efficient and safe during operation, and meets the whole vehicle requirements of a whole vehicle drum type brake system; meanwhile, the cost and the weight are reduced; moreover, through the arrangement of the sliding bearing piece, the movement process of the push rod is more stable, the push rod is effectively supported in the radial direction, the service life is prolonged, and brake control is more accurate.

Description

Technical Field

[0001] The utility model relates to an EMB (Electro-Mechanical Brake, hereinafter referred to as EMB) electronic booster that can be used in an automotive drum brake system, and particularly to an electronic booster with a reduced brake rod distance and a stable structure. Background Art

[0002] At present, brakes on the market are mainly divided into two categories: disc brakes and drum brakes. Disc brakes have good comfort and operability, but some models that focus on cost still use drum brakes in their braking systems. Compared with disc brakes, drum brakes are relatively inexpensive and efficient. 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 brakes during different service lives to prevent the gap from increasing, which would lead to an extension of the braking time and distance. Previously, the adjusting arm was basically driven by a pneumatic device. The air chamber was connected to the adjusting arm through a U-shaped fork to push the adjusting arm to reciprocate, thereby achieving parking and emergency braking. However, pneumatic braking has a large noise, slow response, and complex control, making it difficult to follow the development trend of the current by-wire chassis and not suitable for the rapidly developing new energy vehicles and intelligent chassis systems.

[0003] In the field of electronic brakes, with the rapid development of technology and the continuous progress of the social economy, while people are enjoying the continuous improvement of comfort and power brought by automotive technology changes, the requirements for automotive safety are also constantly increasing. Among them, more and more attention is paid to the braking performance of automobiles. Good braking performance is an important guarantee for the safe driving of automobiles.

[0004] Due to the development of automotive autonomous driving technology, the pneumatic / hydraulic braking systems of traditional models can no longer meet the functional requirements of by-wire braking, autonomous driving, etc., and the EMB electronic brake has thus emerged and developed. EMB is a high-tech product that uses the power generated by a motor to assist the driver in electronic braking, which is pollution-free, energy-saving, and improves the operating performance of the vehicle. However, the existing motor drive methods usually have a motor output shaft, which increases the installation distance of the brake piston rod and results in unreasonable space utilization. Moreover, when the brake piston rod moves axially, there is a lack of support at the housing position, which causes uneven stress on the brake rod. After using for a period of time, the axial movement of the brake rod is misaligned, resulting in a decrease in braking accuracy. Summary of the Utility Model

[0005] Therefore, the technical problem to be solved by the present utility model is to overcome the deficiencies in the prior art, and thus provide a technology that reduces the braking distance between the motor and the brake shaft rod and has a compact structure combination.

[0006] To achieve the above object, the utility model provides an EMB electronic booster for an automotive drum brake system, which comprises a motor, a lead screw, a push rod and a ball head rod;

[0007] The motor has a hollow shaft for outputting power;

[0008] The inner end of the lead screw is connected to the hollow shaft, and a lead screw nut is provided on the lead screw;

[0009] The push rod is connected to the lead screw nut, and the push rod is slidably matched with the outer port of the housing, and a sliding bearing member is provided at the outer port position;

[0010] The inner end of the ball head rod is matched with the push rod.

[0011] Preferably, the end of the lead screw is an external thread, and is detachably and fixedly connected to the hollow shaft through the external thread;

[0012] Preferably, the end of the lead screw has an extended portion, and is fixed by interference fit with the inner hole of the central shaft of the motor through the extended portion.

[0013] Preferably, the lead screw nut and the push rod are assembled into one body by interference fit.

[0014] Preferably, it further has a U-shaped fork, the other side of the ball head rod is threadedly connected to the U-shaped fork, and a nut is provided at the connection part, and the nut is used to adjust the extended length of the U-shaped fork;

[0015] The ball head rod has a swing angle of 0 to X°.

[0016] Preferably, a spring washer is provided at the connection position between the lead screw and the hollow shaft.

[0017] Preferably, the sliding bearing member is a self-lubricating bushing or a sliding bearing.

[0018] Preferably, a dust cover is provided between the housing and the ball head rod.

[0019] Preferably, it further includes a transition bracket, and the transition bracket is connected and fixed to the vehicle self-adjusting arm bracket by bolts; in specific applications, the EMB electronic booster of the utility model is connected to the self-adjusting arm assembly of the vehicle to replace the pneumatic braking device in the prior art.

[0020] Innovative design of the transition bracket of the present utility model: According to the different installation methods of the drum-type EMB electronic brake and the original drum-type air brake system, the transition bracket is innovatively designed; the transition bracket is combined with the housing of the EMB electronic brake as a whole through a bolt connection method, and the front end is also combined with the self-adjusting arm mounting bracket of the whole vehicle through mounting bolts. Through this innovation, the installation problem that the drum-type EMB electronic brake cannot be directly assembled to the self-adjusting arm bracket of the whole vehicle is solved.

[0021] The beneficial effects of the present utility model are as follows: Through the setting of the hollow shaft, the end of the lead screw can be directly connected and fixed inside the motor. This structure saves distance in the axial direction, ensures that the transmission system of the EMB electronic brake operates more smoothly, efficiently and safely, and meets the vehicle requirements of the whole vehicle drum brake system; at the same time, it also reduces costs and weight; and through the setting of the sliding bearing part, the movement process of the push rod is more stable, effectively supported radially, the service life is extended, and the braking control is more accurate. Brief Description of the Drawings

[0022] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic cross-sectional structure diagram of the EMB assembly product of the present utility model;

[0024] Figure 2 It is a schematic external view of the EMB assembly of the present utility model;

[0025] Figure 3 It is a comparison diagram of the product of the present utility model and the air brake structure after installation on the vehicle;

[0026] Figure 4 It is an enlarged view of the transition bracket.

[0027] Explanation of the Reference Numerals in the Drawings:

[0028] 1. U-shaped fork; 4. Housing; 5. Motor; 6. Hollow shaft; 7. Lead screw; 8. Push rod; 9. Ball head rod; 10. Dust cover; 11. Nut; 12. Spring washer; 15. Self-lubricating bushing; 71. Extended part. Detailed Embodiments

[0029] The technical solution of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts belong to the scope of protection of the present utility model.

[0030] Embodiment 1:

[0031] As Figure 1 and Figure 2 shown, this embodiment provides an EMB electronic booster for an automotive drum brake system, which includes a motor 5, a lead screw 7, a push rod 8, and a ball head rod 9;

[0032] The motor 5 has a hollow shaft 6 for outputting power;

[0033] The inner end of the lead screw 7 is connected to the hollow shaft 6, and the lead screw 7 is provided with a lead screw nut;

[0034] The push rod 8 is connected to the lead screw nut, and the push rod 8 can perform axial movement, that is, when the lead screw 7 rotates, it will perform axial movement through the lead screw nut and the push rod 8; the push rod 8 is slidably matched with the outer port of the housing 4, and a sliding bearing member is provided at the outer port position; preferably, the sliding bearing member is a self-lubricating bushing 15 or a sliding bearing. Through two different forms of sliding bearing members, it can play a good supporting and sliding role for the axial movement of the push rod 8, and avoid the problem of reduced braking accuracy caused by the displacement of the push rod 8 in the radial direction.

[0035] The inner end of the ball head rod 9 is matched with the push rod 8. The ball head rod 9 is a transition member, which is respectively connected to the push rod 8 and the external U-shaped fork 1;

[0036] The U-shaped fork 1 is applied in the pneumatic braking structure in the prior art, and will not be elaborated here.

[0037] In this embodiment, through the setting of the hollow shaft, the end of the lead screw 7 can be directly connected and fixed inside the motor 5. This structure saves distance in the axial direction, ensuring that the transmission system of the EMB electronic brake operates more smoothly, efficiently, and safely; and, through the setting of the sliding bearing member, the axial movement process of the push rod 8 is more stable, effectively supported in the radial direction, the service life is extended, and the braking control is more accurate.

[0038] Embodiment 2:

[0039] As a preferred embodiment, in this embodiment, the end of the lead screw 7 is an external thread, and is detachably and fixedly connected to the hollow shaft through the external thread;

[0040] Preferably, the end of the lead screw 7 has an extended portion 71, which is fixed by interference fit with the inner hole of the central shaft of the motor 5 through the extended portion 71.

[0041] Preferably, the lead screw nut and the push rod 8 are assembled into one by interference fit. Preferably, the push rod 8 can only move axially, and is limited in the circumferential direction to prevent rotation, that is, when the lead screw moves, the rotation of the lead screw is transferred to the axial movement of the push rod 8. Further, even if the limit is not set, when this structure is applied to the vehicle adjusting arm, the circumferential movement of the push rod 8 is also restricted, so it can only move axially for braking.

[0042] Preferably, the ball head rod 9 has a swing angle of 0 to X° within a spatial range, that is, the ball head rod 9 is hinged with the push rod 8 and has a certain swing freedom. The specific maximum swing angle X° of the ball head space is determined according to the vehicle type requirements, so as to meet the requirement that the assembled self-adjusting arm for matching has a space swing angle of 0 to X° during linear movement;

[0043] Preferably, there is also a U-shaped fork 1. The other side of the ball head rod 9 is threadedly connected to the U-shaped fork 1, and a nut 11 is provided at the connection part. The nut 11 is used to adjust the extended length of the U-shaped fork. That is, by adjusting the position of the nut 11 at the connection part, the installation position of the U-shaped fork is restricted. That is, when the U-shaped fork is connected and installed at the connection part, it only needs to abut against the nut 11, and it can achieve a stable purpose, and it is also more convenient when the U-shaped fork is connected and installed with the external adjusting arm.

[0044] Preferably, a spring washer 12 is provided at the connection position between the lead screw 7 and the hollow shaft 6.

[0045] Preferably, a dust cover 10 is provided between the housing and the ball head rod 9. The dust cover 10 ensures that the dust-proof and waterproof functions of the EMB electronic brake meet the requirements of the whole vehicle. The motor is a permanent magnet brushless motor.

[0046] As Figure 3 shown, in a specific application, the EMB electronic booster of the present invention is connected to the self-adjusting arm assembly of the vehicle to replace the pneumatic braking device 50 in the prior art; when the EMB electronic booster for the automotive drum brake system of the present application is applied to an actual vehicle, the drum-type EMB product of the present application is on the left, and is connected to the self-adjusting arm of the vehicle through the U-shaped fork 1. In comparison, the pneumatic braking device 50 in the prior art is on the right, and it is also connected to the self-adjusting arm. The drum-type EMB product can complete braking by axially driving the U-shaped fork 1.

[0047] Preferably, it further includes a transition bracket 3, and the transition bracket 3 is connected and fixed to the vehicle self-adjusting arm bracket 31 by bolts 2. That is, the transition bracket 3 provided by the present utility model is combined with the self-adjusting arm mounting bracket 31 of the whole vehicle through bolts 2. Through this innovation, the installation problem that the drum-type EMB electronic brake cannot be directly assembled to the self-adjusting arm bracket 31 of the whole vehicle is solved.

[0048] Compared with the prior art, the beneficial effects of the present utility model are as follows: The EMB electronic booster (replaces the pneumatic power unit of the current drum brake system of automobiles and realizes electronic braking in automobiles with drum brake systems; cancels the pneumatic power unit and the booster unit of the automobile drum brake system. Compared with the pneumatic power unit, the whole vehicle does not need to provide an additional air pressure source, which can greatly reduce the noise during use. The control unit of the EMB electronic booster product controls the permanent magnet brushless motor assembly to generate assistance according to the driver's braking request detected by the pedal travel sensor. The hollow shaft of the permanent magnet brushless motor assembly is assembled with the lead screw as a whole. The ECU controls the rotation of the motor shaft and the lead screw, thereby driving the axial movement and loading of the nut, and then driving the self-adjusting wall of the vehicle drum brake to reciprocate through the U-shaped fork, so as to realize the service braking function of the drum brake system; at the same time, the EMB electronic booster has a faster response speed and can shorten the braking distance.

[0049] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An EMB electronic booster for a car drum brake system, characterized in that: include: A motor (5) having a hollow shaft (6) for outputting power; A lead screw (7), the inner end of which is connected to the hollow shaft (6), and the lead screw (7) is provided with a lead screw nut; A push rod (8) connected to the lead screw nut, the push rod (8) being slidably matched with an outer port of the housing (4), and a sliding receiving member being provided at the position of the outer port; The inner end of the ball head rod (9) cooperates with the push rod (8).

2. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: The end of the lead screw (7) is an external thread, and is detachably fixedly connected to the hollow shaft (6) via the external thread.

3. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: The end of the lead screw (7) has a protruding portion (71), and the protruding portion (71) is fixed to the inner hole of the central shaft of the motor (5) through interference fit.

4. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: The lead screw nut and the push rod (8) are assembled into one body by interference fit.

5. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: It also has a U-shaped fork (1), the other side of the ball head rod (9) is connected to the U-shaped fork (1) by threading, and a nut (11) is provided at the connection part, and the nut (11) is used to adjust the extension length of the U-shaped fork (1); The ball head rod (9) has a swing angle of 0-X°.

6. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: A spring washer (12) is provided at the connection position between the lead screw (7) and the hollow shaft (6).

7. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: The sliding receiving member is a self-lubricating bushing (15) or a sliding bearing.

8. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: A dust cover (10) is provided between the housing (4) and the ball head rod (9).

9. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: The motor (5) is a permanent magnet brushless motor.

10. The EMB electronic booster for a vehicle drum brake system according to claim 1, characterized in that: It also comprises a transition bracket (3), wherein the transition bracket (3) is connected and fixed to the vehicle self-adjusting arm bracket (31) via bolts (2).

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