CN115574024A

CN115574024A - Actuating mechanism and electromechanical brake caliper

Info

Publication number: CN115574024A
Application number: CN202211223473.9A
Authority: CN
Inventors: 朱松; 魏跃; 董士龙; 其他发明人请求不公开姓名
Original assignee: Jiongyi Electronic Technology Suzhou Co ltd
Current assignee: Jiongyi Electronic Technology Suzhou Co ltd
Priority date: 2022-10-08
Filing date: 2022-10-08
Publication date: 2023-01-06

Abstract

The invention relates to the technical field of electromechanical brake calipers and discloses an actuating mechanism and an electromechanical brake caliper. The actuating mechanism comprises a screw rod, a piston and balls, and a first roller path which is spirally distributed is arranged on the periphery of the screw rod; the piston is provided with an axially through center hole, the hole wall of the center hole is provided with a second rolling way which is spirally distributed, the outer wall of the piston is provided with a limit groove which is axially distributed, and the outer wall of the piston is also provided with air holes; the balls are capable of moving along the first and second raceways simultaneously to transfer the force generated by the rotary motion of the screw to the piston. The invention can omit the arrangement of nuts, simplify the number of parts and enable the structure of the actuating mechanism to be more compact, thereby realizing the large-size design of the actuating mechanism under the same installation space and improving the load capacity and the durability of the actuating mechanism; secondly, the limiting groove is formed in the outer wall of the piston, so that the processing difficulty can be reduced; finally, the problems of abnormal sound and low driving efficiency can be avoided by arranging the air holes.

Description

Actuating mechanism and electromechanical brake caliper

Technical Field

The invention relates to the technical field of electromechanical brake calipers, in particular to an actuating mechanism and an electromechanical brake caliper.

Background

With the rapid development of technological progress in recent years, the change of automobile technology brings comfort and convenience to people, and simultaneously, the requirement on automobile safety is continuously improved. Among them, the braking performance of automobiles is also receiving more and more attention and attention as the most important line of defense for safe driving of automobiles, and excellent braking performance is an extremely important guarantee for safe driving of automobiles.

The development trend of an Electronic Mechanical Brake (EMB) system as an automobile Brake-by-wire technology has gradually popularized conditions through technical accumulation and development evolution for many years, and the EMB system has the characteristics of simple structure, excellent braking performance, energy conservation and environmental protection, and has wide market application prospect.

The prior art provides a structure of electromechanical brake caliper, which uses a ball screw mechanism to push a piston to move forward to implement a clamping force on a friction plate, and this structural design uses a split type piston and nut to cooperate. Due to the fact that the split type piston and nut matching structure design is adopted, when the ball screw is applied to the caliper with the smaller cylinder diameter, the ball screw is limited in outer diameter size due to size structure design, and therefore the structural load strength and the durability performance are insufficient.

Disclosure of Invention

The invention aims to provide an actuating mechanism and electromechanical brake calipers, which are compact in structure, can realize large-size design of the actuating mechanism in the same installation space, improve the load capacity and durability of the actuating mechanism, and can avoid the problems of abnormal sound and low driving efficiency caused by uneven air pressure in an inner cavity of a piston when a lead screw rotates.

In order to achieve the purpose, the invention adopts the following technical scheme:

an actuator, comprising:

the outer peripheral wall of the screw rod is provided with a first roller path in spiral distribution;

the piston is provided with a central hole which is axially communicated, the piston is sleeved on the periphery of the screw rod through the central hole, a second rolling way which is spirally distributed is arranged on the hole wall of the central hole, a limiting groove which is axially distributed is arranged on the outer wall of the piston, and a plurality of air holes which are communicated with the central hole are formed in the outer peripheral wall of the piston;

the ball bearings are arranged on the first rolling path and the second rolling path at the same time, and can move along the first rolling path and the second rolling path at the same time so as to transmit the force generated by the rotation of the screw rod to the piston.

As the preferred technical scheme of the actuating mechanism, a flange plate is sleeved on the screw rod.

As the preferred technical scheme of actuating mechanism, the ring flange face the one end of first raceway is provided with first restriction boss, the pore wall of the centre bore of piston is provided with the second restriction boss, just the second restriction boss is located the second raceway is close to one side of ring flange, when the lead screw drives the piston and moves to the direction that is close to the ring flange, first restriction boss can with the butt of second restriction boss, in order to restrict the piston is towards the extreme position that moves in the direction of ring flange.

As a preferred technical solution of the actuator, the lead screw includes a first cylindrical section, a second cylindrical section, and a third cylindrical section that are connected in sequence, and diameters of the first cylindrical section, the second cylindrical section, and the third cylindrical section decrease in sequence, the first raceway is disposed on the first cylindrical section, the flange is disposed on the second cylindrical section and abuts against a shaft shoulder formed by the first cylindrical section and the second cylindrical section, and the third cylindrical section is used for being connected with the driving mechanism.

As a preferred technical scheme of the actuating mechanism, the center of the first cylindrical section is provided with lightening holes distributed along the axial direction.

As a preferable technical solution of the actuator, a revolving groove is provided on the piston, a revolving member is provided in the revolving groove, and the revolving member is configured to make the balls revolve in the first raceway and the second raceway.

As a preferred technical scheme of the actuating mechanism, two process planes are arranged on the piston and are axially and symmetrically arranged.

As a preferable technical scheme of the actuating mechanism, one end, far away from the lead screw, of the piston is provided with an end cover.

As a preferable technical scheme of the actuating mechanism, the end cover is provided with a sealing ring groove and an application groove.

An electromechanical brake caliper comprising an actuator according to any of the above aspects.

The invention has the beneficial effects that:

according to the actuating mechanism provided by the invention, firstly, the piston is provided with the central hole, the hole wall of the central hole is processed with the second rolling way matched with the first rolling way on the screw rod, and the balls are arranged in the first rolling way and the second rolling way, so that the balls and the first rolling way and the second rolling way form a ball screw pair, the arrangement of nuts can be omitted, the number of parts is simplified, the structure of the actuating mechanism is more compact, the large-size design of the actuating mechanism under the same installation space can be realized, and the load capacity and the durability of the actuating mechanism are improved; secondly, a limiting groove for limiting the rotation of the piston is formed in the outer wall of the piston and extends along the axial direction of the piston, so that the processing difficulty can be reduced; finally, through setting up the bleeder vent, can avoid the abnormal sound and the low problem of drive efficiency that lead to because of the atmospheric pressure inequality in the piston inner chamber when the lead screw is rotatory.

Drawings

FIG. 1 is a schematic structural view of an electromechanical brake caliper provided in accordance with an embodiment of the present invention;

FIG. 2 is an exploded view of an actuator according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a screw according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of a lead screw according to an embodiment of the present invention;

fig. 5 is a schematic structural view of a piston according to an embodiment of the present invention;

fig. 6 is a sectional view of a piston according to an embodiment of the present invention.

In the figure:

10. a friction plate; 20. a housing;

31. a lead screw; 311. a first cylindrical section; 3111. a first raceway; 3112. lightening holes; 312. a second cylindrical section; 313. a third cylindrical section; 32. a piston; 321. a second raceway; 322. a limiting groove; 323. a second limit boss; 323a, a second stop surface; 324. a rotary trough; 325. a rotating member; 326. air holes are formed; 327. a process plane; 33. a flange plate; 331. a first limit boss; 331a, a first stop surface; 34. an end cap; 341. a seal ring groove; 342. a force application groove; 35. a ball bearing;

40. a limit bolt; 50. and a bearing.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings and the embodiment. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1, an embodiment of the present invention provides an electromechanical brake caliper, which includes two friction plates 10, a housing 20, an actuator and a driving mechanism, wherein the two friction plates 10 are respectively disposed on two sides of a brake disc, the actuator is disposed on the housing 20, the driving mechanism is in driving connection with the actuator, the actuator can convert a rotational motion of the driving mechanism into a linear motion, and the actuator can drive the two friction plates 10 to approach or move away from each other to clamp or release the brake disc. The embodiment mainly improves the actuating mechanism, and other mechanisms are in the prior art and are not described in detail herein.

Specifically, as shown in fig. 2 to 6, the actuator according to the embodiment of the present invention includes a screw 31, a piston 32, and balls 35, wherein an outer peripheral wall of the screw 31 is provided with a first raceway 3111 spirally distributed; the piston 32 is provided with an axially through center hole, the piston 32 is sleeved on the periphery of the screw rod 31 through the center hole, the hole wall of the center hole is provided with the second roller paths 321 which are spirally distributed, and the piston 32 adopts an axial through hole type structural design, so that the second roller paths 321 can be machined, and the machining difficulty of parts can be reduced; the balls 35 are simultaneously disposed on the first and second ball tracks 3111 and 321, and the balls 35 can simultaneously move along the first and second ball tracks 3111 and 321 to transmit the force generated by the rotation of the screw 31 to the piston 32.

When the electromechanical brake caliper works, the screw 31 is driven by the driving mechanism to rotate, the balls 35 are driven by the screw 31 to advance spirally in the first raceway 3111 and the second raceway 321, so that the balls 35 transmit the force generated by the rotation of the screw 31 to the piston 32, the force exerted on the piston 32 by the balls 35 is decomposed to form a first decomposed force which drives the piston 32 to move linearly in the axial direction and a second decomposed force which drives the piston 32 to move rotationally in the circumferential direction, and the second decomposed force which drives the piston 32 to rotate normally is suppressed to enable the piston 32 to move linearly, so that the piston 32 can drive the two friction plates 10 to move close to or away from each other to clamp or release the brake disc. In this embodiment, the outer wall of the piston 32 is provided with a limit groove 322 distributed along the axial direction, the housing 20 is provided with a limit bolt 40, and the end of the limit bolt 40 extends into the limit groove 322. By the arrangement of the stopper bolt 40 and the stopper groove 322, the rotational movement of the piston 32 can be restricted so that the piston 32 can move in the axial direction. The above-mentioned structural style of spacing groove 322 does not influence the whole processing technology of piston 32, can normally process when processing the excircle of piston 32 promptly, for example can carry out normal grinding, later independently again through milling or other forms accomplish the processing of spacing groove 322 once, compare in the prior art special-shaped form of preventing changeing, wholly can reduce the processing degree of difficulty. Meanwhile, the overall shape of the piston 32 is not affected by the structural form of the limiting groove 322, the piston 32 still has an overall round shape, the effect of round forward movement can be achieved, the forward resistance is small, and the reciprocating movement is smoother. In addition, the limiting groove 322 is formed in the piston 32, so that the situation that a groove is formed in the shell 20 can be avoided, only one hole needs to be formed in the shell 20, and the limiting groove 322 is matched with a pin or a bolt to lock the hole, and compared with the situation that a groove is formed in the shell 20, the processing technology is simpler.

According to the actuator provided by the embodiment of the invention, the piston 32 is provided with the center hole, the hole wall of the center hole is provided with the second rolling way 321 matched with the first rolling way 3111 on the screw rod 31, and the balls 35 are arranged in the first rolling way 3111 and the second rolling way 321, so that the balls 35, the first rolling way 3111 and the second rolling way 321 form a ball screw pair, the arrangement of nuts can be omitted, the number of parts is simplified, the structure of the actuator is more compact, the large-size design of the actuator in the same installation space can be realized, and the load capacity and the durability of the actuator are improved.

The screw 31 is sleeved with the flange 33, the flange 33 and the screw 31 can be in interference fit, the screw 31 and the flange 33 adopt a split design, a rolling process in the manufacturing process of the first roller path 3111 on the screw 31 is convenient to realize, and the process difficulty of part processing is reduced. A bearing 50 is arranged between the flange plate 33 and the shell 20, and the flange plate 33 and the bearing 50 are matched to rotate so as to bear axial load generated when the actuating mechanism moves. Preferably, the screw 31 comprises a first cylindrical section 311, a second cylindrical section 312 and a third cylindrical section 313 which are connected in sequence, the diameters of the first cylindrical section 311, the second cylindrical section 312 and the third cylindrical section 313 are reduced in sequence, the first raceway 3111 is arranged on the first cylindrical section 311, the flange plate 33 is arranged on the second cylindrical section 312 and abuts against a shaft shoulder formed by the first cylindrical section 311 and the second cylindrical section 312, and the third cylindrical section 313 is used for connecting with a driving mechanism. The structure is reasonable, and the flange plate 33 is convenient to position and mount. Preferably, the center of the first cylindrical section 311 is provided with weight-reducing holes 3112 distributed along the axial direction for weight reduction and process positioning. Preferably, the thickness of the second cylindrical section 312 is equal to the thickness of the flange 33, which further facilitates the installation of the flange 33.

The flange plate 33 is provided with a first limit boss 331 at one end facing the first raceway 3111, the first limit boss 331 can be formed rapidly by a cold heading stamping process, the machining efficiency of parts is improved, the hole wall of the central hole of the piston 32 is provided with a second limit boss 323, the second limit boss 323 is located at one side of the second raceway 321 close to the flange plate 33, and when the screw 31 drives the piston 32 to move in the direction close to the flange plate 33, the first limit surface 331a of the first limit boss 331 can abut against the second limit surface 323a of the second limit boss 323 to limit the limit position of the piston 32 moving in the direction close to the flange plate 33. Through the arrangement, when the piston 32 moves to the limit position in the direction close to the flange 33, a certain gap is left between the piston 32 and the flange 33, and the problem that the piston 32 and the lead screw 31 are blocked is avoided.

The piston 32 is provided with a rotation groove 324, and a rotation member 325 is provided in the rotation groove 324, and the rotation member 325 is configured to rotate the balls 35 in the first raceway 3111 and the second raceway 321. By providing the rotary member 325, the balls 35 can smoothly rotate in the first and

second raceways

3111 and 321.

During the rotation of the screw, negative pressure is generated inside the piston 32, which affects the rotation of the balls 35, reduces the driving efficiency, and generates undesirable noise. Therefore, in the present embodiment, a plurality of air holes 326 are formed on the piston 32, and the air holes 326 are communicated with the central hole. Through setting up bleeder vent 326, can make the inside atmospheric pressure of piston 32 flow evenly smoothly, avoid the problem that the abnormal sound and the drive efficiency are low because of the inhomogeneous leads to of atmospheric pressure in the piston 32 inner chamber when lead screw 31 rotates. Preferably, the plurality of air holes 326 are spaced along the circumference of the piston 32, so that the resistance to the system is reduced while the pressure balance between the inside and the outside of the piston 32 is maintained.

In addition, the size of the vent holes requires care, and if too small, sharp airflow may occur resulting in a whistle sound, thus requiring special verification and selection of the corresponding size of the holes. For example, if the diameter of the air hole is within 1cm, sound may be generated due to high speed, and for example, adjustment to 2cm or more may have a good effect, and particularly, adjustment verification needs to be performed according to the size of the space.

Two process planes 327 are further machined on the piston 32, and the two process planes 327 are axially symmetrically arranged. By providing the process plane 327, it is possible to provide a tool holding and positioning function for processing the piston 32.

The end of the piston 32 remote from the flange 33 is also provided with an end cap 34, and the end cap 34 may be an interference fit with the piston 32. By providing the end cap 34, impurities can be prevented from entering the piston cavity to protect the balls 35. Preferably, the end cap 34 is provided with a seal groove 341, and a seal ring can be assembled in the seal groove 341, and the seal ring is used for sealing a gap between the end cap 34 and the housing 20 to prevent external dust, moisture and the like from polluting the piston kinematic pair and the screw kinematic pair. Preferably, the end cap 34 is further provided with a force application groove 342, and the force application groove 342 is used for providing a force application point for the tool when the actuator is assembled or maintained.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An actuator, comprising:

the screw rod (31), the peripheral wall of the screw rod (31) is provided with a first raceway (3111) which is spirally distributed;

the piston (32) is provided with a central hole which is axially communicated, the piston (32) is sleeved on the periphery of the screw rod (31) through the central hole, the hole wall of the central hole is provided with a second rolling way (321) which is spirally distributed, the outer wall of the piston (32) is provided with a limiting groove (322) which is axially distributed, and the outer peripheral wall of the piston (32) is also provided with a plurality of air holes (326) which are communicated with the central hole;

balls (35), the balls (35) are arranged on the first raceway (3111) and the second raceway (321) at the same time, and the balls (35) can move along the first raceway (3111) and the second raceway (321) at the same time so as to transmit the force generated by the rotation of the screw (31) to a piston (32).

2. Actuator according to claim 1, wherein the threaded spindle (31) is provided with a flange (33).

3. Actuator according to claim 2, wherein the end of the flange (33) facing the first raceway (3111) is provided with a first stop projection (331), the bore wall of the central bore of the piston (32) is provided with a second stop projection (323), and the second stop projection (323) is located on the side of the second raceway (321) close to the flange (33), and the screw (31) is provided with an extreme position in which the first stop projection (331) can abut against the second stop projection (323) to limit the movement of the piston (32) in the direction close to the flange (33) when the screw moves the piston (32) in the direction close to the flange (33).

4. Actuator according to claim 2, wherein the screw (31) comprises a first cylindrical section (311), a second cylindrical section (312) and a third cylindrical section (313) connected in series, and wherein the first cylindrical section (311), the second cylindrical section (312) and the third cylindrical section (313) have successively decreasing diameters, the first track (3111) being arranged on the first cylindrical section (311), the flange (33) being arranged on the second cylindrical section (312) and abutting against a shoulder formed by the first cylindrical section (311) and the second cylindrical section (312), the third cylindrical section (313) being intended to be connected to a drive.

5. Actuator according to claim 4, wherein the first cylindrical section (311) is provided with weight-reducing holes (3112) in the centre thereof, distributed in the axial direction.

6. Actuator according to claim 1, wherein a revolution groove (324) is provided on the piston (32), a revolution member (325) is provided in the revolution groove (324), the revolution member (325) being configured to realize revolution of the balls (35) in the first raceway (3111) and the second raceway (321).

7. Actuator according to claim 1, wherein two process planes (327) are provided on the piston (32), and wherein the two process planes (327) are arranged in axial symmetry.

8. Actuator according to claim 1, wherein the end of the piston (32) remote from the screw (31) is provided with an end cap (34).

9. Actuator according to claim 8, wherein the end cap (34) is provided with a sealing ring groove (341) and a force application groove (342).

10. Electromechanical brake calliper, characterised in that it comprises an actuator according to any of claims 1-9.