A ball screw stop structure of an electromechanical brake execution device

Abstract

The application relates to a ball screw stop structure of an electromechanical brake execution device, which comprises a brake caliper body, a ball screw, a screw nut and a stop structure which are mutually meshed, the stop structure comprises a semi-closed limiting groove arranged on the bottom end face of the ball screw and a boss arranged on the screw nut, the screw nut comprises an annular sleeve wall arranged in the axial direction, a wall plate is arranged on one end of the annular sleeve wall in the radial direction, the boss is arranged on the inner wall of the wall plate, the screw nut moves in the axial direction when the ball screw rotates, and the ball screw and the screw nut are stopped after the limiting groove and the boss abut against each other, the ball screw and the screw nut are stopped in limited space, the structure design is reasonable, and the service life of the ball screw pair is prolonged.

Description

Technical Field

[0001] This application belongs to the field of automotive braking technology and relates to a braking actuator, particularly to a ball screw stop structure for an electromechanical brake. Background Technology

[0002] Braking by steer uses electrical signals instead of mechanical or fluid signals for braking control, offering advantages such as high precision, high response speed, and high decoupling, making it an advanced braking technology in the automotive field. Compared to the maturely applied electromechanical brakes (EHB) and pneumatic brakes (EBS), electromechanical brakes (EMB) are better suited to the technological development needs of new energy vehicles, such as full electronic and intelligent systems, and can be widely applied in autonomous driving fields such as unmanned shuttle buses and unmanned logistics vehicles.

[0003] In the field of existing wire-controlled braking systems, it is quite difficult to set a limiting mechanism between the ball screw and the screw sleeve in electromechanical brakes. Due to space limitations, conventionally designed limiting mechanisms cannot effectively provide a stop, and the limiting structure often fails after repeated use. Therefore, there is an urgent need to provide a ball screw stopping structure with high limiting stability. Utility Model Content

[0004] The purpose of this application is to provide a ball screw stop structure for an electromechanical brake, which solves the problem that existing electromechanical brakes cannot efficiently and stably provide limit functions.

[0005] The technical solution of this utility model is that this application provides a ball screw stop structure for an electromechanical braking actuator, comprising: The brake caliper body is equipped with a ball screw, a screw nut, and a stop structure that mesh with each other. The stop structure includes a semi-enclosed limiting groove provided on the bottom end face of the ball screw and a boss installed on the screw nut. The lead screw nut includes an annular sleeve wall arranged along the axial direction, and a wall plate is arranged radially at one end of the annular sleeve wall, with the boss disposed on the inner wall of the wall plate. When the ball screw rotates, the screw nut moves axially and stops after the limiting groove abuts against the boss.

[0006] Preferably, the ball screw includes a sleeve that at least partially surrounds the screw nut, and the semi-enclosed limiting groove is a recessed portion that is recessed into the bottom end face of the sleeve.

[0007] Preferably, the concave recess is an arc-shaped recess arranged along the annular sleeve end face, and a stop portion is arranged in the non-recessed area of ​​the annular sleeve end face. The arc-shaped areas extending along the annular sleeve end face on both sides of the stop portion are arc-shaped recesses.

[0008] Preferably, the area of ​​the arc-shaped recess is larger than the area of ​​the stop portion.

[0009] Preferably, the stop portion is configured as a protrusion extending from the annular end face of the sleeve towards the boss, and the surface area of ​​the protrusion gradually decreases with the extension direction.

[0010] Preferably, the bosses are configured as a pair opposite each other on the wall panel, and the stop portions are configured as a pair opposite each other on the end face of the sleeve, wherein the arc-shaped recesses on both sides of the pair of stop portions have the same area.

[0011] Preferably, the annular sleeve wall is integrally formed with the wall plate and the boss.

[0012] Preferably, at least one end face of the boss is attached to the annular sleeve wall, and the other end face is disposed on the wall plate.

[0013] Preferably, the boss is configured as a protrusion extending from the wall panel toward the limiting groove, and the surface area of ​​the protrusion gradually decreases with the extension direction.

[0014] Compared with the prior art, the advantages of this application are: (1) This application solves the problem that when the ball screw retracts to the bottom, the impact torque on the ball screw causes the axial force to squeeze the steel ball by setting stop mechanisms that can cooperate with each other to limit the movement.

[0015] (2) This application sets an arc-shaped limiting groove on the screw nut and a limiting protrusion on the ball screw, and both are set by an integral molding process, so that the strength of the limiting structure is large enough to ensure the service life of the ball screw pair.

[0016] (3) Setting a limiting groove on the sleeve of the ball screw makes full use of the internal space of the ball screw pair, while ensuring the strength of the limiting mechanism and making the processing more convenient.

[0017] (4) Two sets of limit mechanisms are symmetrically set, which disperses the load of each set of limit mechanisms and further extends the service life of the ball screw pair. Attached Figure Description

[0018] The present application will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall mechanism of an electromechanical brake according to this application; Figure 2 This is a schematic diagram of the overall structure of a ball screw stop structure for an electromechanical brake according to this application. Figure 3 This is a cross-sectional view of a ball screw stop structure for an electromechanical brake according to this application; Figure 4 This is a schematic diagram of the sleeve structure of a ball screw stop structure for an electromechanical brake according to this application.

[0019] in: 100. Brake caliper body; 110. Ball screw; 1101. Sleeve; 1101A. Recess; 1101B. Stop part; 120. Lead screw nut; 1201. Annular sleeve wall; 1202. Wall plate; 130, Stop structure; 1301, Limiting groove; 1302, Boss; 140. Actuator; 150. Brake pad. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely one embodiment of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0021] The term "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of the embodiments of this application, it should be understood that the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," and "third," etc., may explicitly or implicitly include one or more of that feature. Furthermore, the terms "first," "second," and "third," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Moreover, the terms "comprising" and "being," and any variations thereof, are intended to cover non-exclusive inclusion.

[0022] like Figure 1As shown in the figure, this embodiment illustrates an electromechanical braking actuator, including a brake caliper body 100. A ball screw 110 and a screw nut 120 are mounted on the brake caliper body 100. The ball screw 110 is installed inside the screw nut 120 and meshes with it. An actuator 140 and a brake pad 150 are respectively provided at both ends of the brake caliper body 100. The actuator 140 is used to drive the ball screw 110. The brake pads 150 are usually a pair arranged opposite each other, located on both sides of the brake disc. By driving the ball screw 110 to rotate through the actuator 140, the screw nut 120 is driven to rotate, thereby driving the pair of brake pads 150 to brake the brake disc.

[0023] like Figure 2 As shown in the figure, this embodiment illustrates a schematic diagram of a ball screw pair, including a ball screw 110 and a screw nut 120 that mesh with each other. An internal thread is provided on the inner wall of the screw nut 120. The ball screw 110 reciprocates along the axial direction of the screw nut 120 within the inner wall of the screw nut 120. In order to provide a limit for the screw nut and the ball screw during operation, this embodiment provides a stop structure 130. The overall structure of the ball screw pair is relatively compact, and the ways to set the limit are limited. In order to set a limit structure with good stability in a limited and compact space, this embodiment sets the stop structure 130 on the side away from the actuator 140.

[0024] like Figure 3 As shown in the figure, this example illustrates a schematic diagram of a stop mechanism. The stop structure 130 includes a semi-enclosed limiting groove 1301 disposed on the bottom end face of the ball screw 110 and a boss 1302 mounted on the screw nut 120. During the relative rotation of the ball screw 110 and the screw nut 120, the limiting groove 1301 abuts against the boss 1302 to achieve the stop of the ball screw 110 and the screw nut 120.

[0025] In this embodiment, the boss 1302 is typically mounted on the bottom end face of the lead screw nut 120. This end face is the area extending radially from the lead screw nut 120 and is usually integrally formed. However, to increase the strength of the stopping mechanism, the boss 1302, the end face, and the lead screw nut 120 can be integrally formed. Specifically, the lead screw nut 120 includes an annular sleeve wall 1201 arranged axially and a wall plate 1202 extending radially from the bottom end face of the annular sleeve wall 1201. Thus, the lead screw nut 120 is set as a semi-closed nut, and the boss 1302 is disposed on the wall plate 1202. Normally, when the annular sleeve wall 1201, the wall plate 1202, and the boss 1302 of the lead screw nut 120 are integrally formed, the boss 1302, as part of the stopping mechanism, has sufficient and stable strength, and can still guarantee the limiting strength after long-term use.

[0026] To make the boss 1302 more stable, in this embodiment, at least one end face of the boss 1302 is attached to the annular sleeve wall 1201, and the other end face is disposed on the wall plate 1202. Thus, the boss 1302 is fixed on at least two surfaces, which further extends the service life of the boss 1302.

[0027] like Figure 4 As shown, the sleeve 1101 is a through hole with openings at both ends. A recessed portion 1101A is provided at one end of the sleeve 1101 near the wall plate 1202. The recessed portion 1101A is an arc-shaped recessed portion arranged along the end face of the annular sleeve 1101. A stop portion 1101B is arranged in the non-recessed area of ​​the end face of the annular sleeve 1101. The arc-shaped areas extending along the end face of the annular sleeve 1101 on both sides of the stop portion 1101B are arc-shaped recessed portions 1101A. After the ball screw 110 and the screw nut 120 are assembled, the boss 1302 located on the screw nut 120 can rotate along an arc-shaped movement trajectory within the area of ​​the arc-shaped recessed portion 1101A. When the boss 1302 abuts against the stop portion 1101B, the ball screw 110 and the screw nut 120 are limited and stopped. In this embodiment, a portion of the arc-shaped area is creatively removed from the end face of the lead screw nut 120. This not only allows the boss 1302 to rotate normally, but also retains the stop portion 1101B for stopping the stroke of the boss 1302. Furthermore, the inventor further sets the area of ​​the arc-shaped recess 1101A to be larger than the area of ​​the stop portion 1101B, thereby better achieving stopping during movement.

[0028] To further enhance the strength of the limiting mechanism, the applicant configured the stop portion 1101B as a protrusion extending from the end face of the annular sleeve 1101 towards the boss 1302, and the surface area of ​​the protrusion gradually decreases with the extension direction. The boss 1302 is configured as a protrusion extending from the wall plate 1202 towards the limiting groove 1301, and the surface area of ​​the protrusion gradually decreases with the extension direction. When the boss 1302 contacts the stop portion 1101B, the area of ​​the portion near the lead screw nut 120 and the portion near the sleeve 1101 increases, thereby ensuring that the limiting mechanism can withstand a larger force after contact.

[0029] In another embodiment of this application, the bosses 1302 are configured as a pair facing each other on the wall panel 1202, and the stop portions 1101B are configured as a pair facing each other on the end face of the sleeve 1101. The strength of the limit mechanism is further enhanced by the cooperation of the two sets of limiting mechanisms. Furthermore, the area of ​​the arc-shaped recesses 1101A on both sides of the pair of stop portions 1101 is set to be the same, and the design method of equal division is adopted, so that the stop of the ball screw 110 and the screw nut 120 after rotation is stable, and the service life of the ball screw pair is also extended.

[0030] The above embodiments are merely illustrative of the technical concept and features of this application, intended to enable those skilled in the art to understand the content of this application and implement it accordingly, and should not be construed as limiting the scope of protection of this application. It is obvious to those skilled in the art that this application is not limited to the details of the above exemplary embodiments, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this application is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within this application.

Claims

1. A ball screw stop structure for an electromechanical braking actuator, comprising: The brake caliper body (100) is equipped with a ball screw (110), a screw nut (120), and a stop structure (130) that mesh with each other. The stop structure (130) is characterized in that it includes a semi-enclosed limiting groove (1301) provided on the bottom end face of the ball screw (110) and a boss (1302) installed on the screw nut (120). The lead screw nut (120) includes an annular sleeve wall (1201) arranged along the axial direction, and a wall plate (1202) is arranged radially at one end of the annular sleeve wall (1201), and the boss (1302) is disposed on the inner wall of the wall plate (1202); When the ball screw (110) rotates, the screw nut (120) moves axially and stops the ball screw (110) and the screw nut (120) after the limiting groove (1301) abuts against the boss (1302).

2. The ball screw stop structure of the electromechanical braking actuator according to claim 1, characterized in that, The ball screw (110) includes a sleeve (1101) that at least partially surrounds the screw nut (120), and the semi-enclosed limiting groove (1301) is a recessed portion that is recessed into the bottom end face of the sleeve (1101).

3. The ball screw stop structure of an electromechanical braking actuator according to claim 2, characterized in that, The recessed portion is an arc-shaped recess (1101A) arranged along the end face of the annular sleeve. A stop portion (1101B) is arranged in the non-recessed area of ​​the end face of the annular sleeve (1101). The arc-shaped areas extending along the end face of the annular sleeve (1101) on both sides of the stop portion (1101B) are arc-shaped recesses (1101A).

4. The ball screw stop structure of an electromechanical braking actuator according to claim 3, characterized in that, The area of ​​the arc-shaped recess (1101A) is larger than the area of ​​the stop portion (1101B).

5. The ball screw stop structure of an electromechanical braking actuator according to claim 4, characterized in that, The stop portion (1101B) is configured as a protrusion extending from the annular end face of the sleeve (1101) toward the boss (1302), and the surface area of ​​the protrusion gradually decreases with the direction of extension.

6. The ball screw stop structure of an electromechanical braking actuator according to claim 4, characterized in that, The bosses (1302) are configured as a pair facing each other on the wall panel (1202), and the stop portions (1101B) are configured as a pair facing each other on the end face of the sleeve (1101). The arc-shaped recesses (1101A) on both sides of the pair of stop portions (1101B) have the same area.

7. The ball screw stop structure of an electromechanical braking actuator according to claim 6, characterized in that, The annular sleeve wall (1201) is integrally formed with the wall panel (1202) and the boss (1302).

8. The ball screw stop structure of an electromechanical braking actuator according to claim 7, characterized in that, At least one end face of the boss (1302) is attached to the annular sleeve wall (1201), and the other end face is disposed on the wall plate (1202).

9. The ball screw stop structure of an electromechanical braking actuator according to claim 5, characterized in that, The boss (1302) is configured as a protrusion extending from the wall panel (1202) toward the limiting groove (1301), and the surface area of ​​the protrusion gradually decreases with the extension direction.

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