CN220320156U

CN220320156U - Compact electromechanical brake actuating device

Info

Publication number: CN220320156U
Application number: CN202321525631.6U
Authority: CN
Inventors: 曾梁彬; 祝敏; 张宇宸; 钱飞飞
Original assignee: CRRC Qishuyan Institute Co Ltd
Current assignee: CRRC Qishuyan Institute Co Ltd
Priority date: 2023-06-15
Filing date: 2023-06-15
Publication date: 2024-01-09
Anticipated expiration: 2033-06-15

Abstract

The utility model relates to a compact electromechanical brake actuating device, and belongs to the technical field of automobile braking. The device comprises a brake caliper body provided with an axial constraint lead screw nut; the screw nut is meshed with the ball screw, the outer end of the screw nut is circumferentially restrained with the driven gear, and a circumferentially lockable restraining rod inserted in the central hole of the ball screw and the outer end of the ball screw form a moving pair; the brake caliper body is provided with a bowl-shaped brake piston which forms a moving pair with the brake caliper body and faces the brake caliper; the inner end of the ball screw is fixedly connected with the brake piston; the brake caliper main body laterally extends out of a driving cavity of which the inside is provided with a motor corresponding to the position of a screw nut, and an output shaft of the motor is meshed and driven with a driven gear through a reduction transmission mechanism at the outer end; the outer side of the driving cavity and the outer end of the restraining rod are respectively provided with a detachable end cover and a cover plate which are fixedly connected with the main body of the brake caliper. The axial size of the brake actuating device is greatly reduced, so that the brake actuating device is quite convenient to maintain, reliable brake release is ensured, and starting oil consumption is effectively reduced.

Description

Compact electromechanical brake actuating device

Technical Field

The utility model relates to a brake executing device, in particular to a compact type electromechanical brake executing device, and belongs to the technical field of automobile braking.

Background

The brake-by-wire control utilizes the electric signal to replace mechanical or fluid signals for brake control, has the advantages of high precision, high response speed, high decoupling performance and the like, and is an advanced brake technology in the current automobile field. Compared with the mature hydraulic brake by wire (EHB) and pneumatic brake by wire (EBS), the electromechanical brake by wire (EMB) is more suitable for the technical development requirements of full electronics, intellectualization and the like of new energy automobiles, and can be popularized and applied to the automatic driving fields of unmanned vehicles, unmanned logistics vehicles and the like.

The prior related researches are similar in structure principle and mainly comprise a motor, a speed reduction and moment increase mechanism and a motion conversion mechanism, wherein the motion conversion mechanism mostly adopts a ball screw to convert the rotary motion of the motor into the linear motion of a brake caliper main body. The typical structure is disclosed in the Chinese patent document of application number 201710414231.0, and the electromechanical brake may include: a nut member coupled to the plunger and transmitting an axial moving force to the plunger; a screw coupled to the nut member and rotated to move the nut member in an axial direction; a plurality of balls interposed between the nut member and the screw and transmitting a rotational force of the screw to the nut member; a compression coil spring having a first side mounted to the nut member; and a ball retainer installed at the other side of the compression coil spring, wherein the ball retainer is disposed adjacent to a rearmost ball among a plurality of balls interposed between the nut member and the screw, and pressurizes the compression coil spring while maintaining contact with the balls during braking pressurization. However, in the technical proposal of the patent application, the axial dimension of the electromechanical brake executing structure is larger, so that the installation space at the wheel is limited, and the steering performance of the front wheel is affected; the ball screw and the brake piston pushing the brake lining lack reliable connection relation, when braking is canceled, the brake lining is still pressed on the brake disc because the brake piston cannot return in time, so that larger dragging moment is generated, and the starting oil consumption of the vehicle is larger; when the actuating mechanism is powered off and can not release braking through motor reversal, the wheel can be locked even, but the existing actuating mechanism has no manual release function, and is inconvenient to maintain.

The similar technical solutions disclosed in the patent documents of China with application numbers 201110336002.4 and 201811491731.5, US2022/0024435 and US2021/0025476 are not suitable for solving the above problems.

Disclosure of Invention

The utility model aims at: aiming at the problems in the prior art, through structural improvement, the compact electromechanical brake actuating device which is small in axial size, capable of effectively reducing dragging moment and convenient to maintain is provided, so that the installation requirement of a place with a small space is met, energy is saved, and the maintenance of the device is convenient.

In order to achieve the above object, the basic technical scheme of the compact electromechanical brake actuating device of the present utility model is as follows: comprises a brake caliper main body provided with an axial constraint lead screw nut; the screw nut is meshed with the ball screw, the outer end of the screw nut is circumferentially restrained with the driven gear, and a circumferentially lockable restraining rod inserted into the central hole of the ball screw and the outer end of the ball screw forms a moving pair; the brake caliper body is provided with a bowl-shaped brake piston which forms a moving pair with the brake caliper body and faces the brake caliper; the inner end of the ball screw is fixedly connected with the brake piston; the brake caliper main body laterally extends out of a driving cavity with a motor arranged inside corresponding to the position of the screw nut, and an output shaft of the motor is meshed and driven with the driven gear through a reduction transmission mechanism at the outer end; the outer side of the driving cavity and the outer end of the constraint rod are respectively provided with a detachable end cover and a cover plate which are fixedly connected with the main body of the brake caliper.

In particular, the inner end of the ball screw is provided with a positioning recess and a central screw hole, a positioning boss matched with the positioning recess at the inner end of the ball screw which stretches into the positioning recess is formed in the brake piston, the positioning boss is provided with a central hole which is internally provided with a countersunk head fastening screw from outside to inside, and the inner end of the countersunk head fastening screw is fixedly connected with the central screw hole in a screwing mode.

And an output shaft of the motor is meshed with an idler gear through a planet gear transmission system planet carrier at the outer end, and the idler gear is meshed with the driven gear.

After the utility model is adopted, the side-extending structure of the main body of the brake caliper changes the original serial connection of the axes of the motor and the planetary gear transmission and the axes of the ball screw into parallel connection, and the motor and the planetary gear transmission are organically combined with a screw nut mechanism which drives the screw to axially move by the rotation of the nut, and the traditional structure of driving the nut to translate by the rotation of the screw is changed, so that the axial dimension of the brake actuating device is greatly reduced by avoiding the axial dimension required by the traditional structure of directly driving the screw by a speed reducing mechanism; meanwhile, as the detachable end cover and the cover plate are respectively and correspondingly arranged, the maintenance is quite convenient and the space is opened. In addition, the brake piston and the ball screw are directly fixedly connected, so that when braking is canceled and the motor is reversed, the brake piston can be separated from a brake lining embedded by braking along with the ball screw synchronously to be reliably reset, dragging moment is obviously reduced, reliable braking release is ensured, and starting oil consumption is effectively reduced.

The utility model is further perfected that the end cover extends outwards to form a mounting chamber with a closed cover plate at the position corresponding to the screw nut and is used for mounting the ratchet locking mechanism.

The utility model is further perfected that the outer end of the constraint rod is provided with a ratchet wheel, the cover plate is provided with a locking pawl meshed with the ratchet wheel, and the locking pawl tends to a locking position and has a hand-off position; when in the locked position, the restraining bar is locked circumferentially; when in the hand-off position, the restraining bar is circumferentially rotatable. Therefore, during maintenance and troubleshooting, the screw rod can be reversed by manually pushing the piston, so that manual release is realized, and the brake lining is convenient to detach.

The utility model is further perfected that the outer end of the constraint rod is fixedly connected with the ratchet wheel, the cover plate is provided with a locking pawl which forms a telescopic moving pair with the constraint rod, the locking pawl is meshed with the ratchet wheel, and a reset spring which enables the locking pawl to tend to be meshed with the ratchet wheel is arranged in a counter bore at the inner end of the locking pawl.

The utility model is further perfected that the outer end of the constraint rod is fixedly connected with the ratchet wheel, the middle part of the lever-shaped locking pawl is hinged in the installation chamber, one end of the locking pawl is a claw which can be clamped into the ratchet wheel, and the other end of the locking pawl is a poking arm which extends out of the installation chamber.

The utility model is further perfected that the outer end of the lead screw nut extending out of the brake caliper main body is provided with a diameter-reducing section which is circumferentially restrained and axially limited with the driven gear, and the cross section of the diameter-reducing section is in a cross section shape matched with the polygonal inner hole of the driven gear.

The utility model is further perfected that the diameter reducing part of the diameter reducing perforation at the outer end of the brake caliper main body supports a screw nut through a bearing, a thrust roller bearing is arranged between one axial end of a diameter expanding flange in the middle of the screw nut and the diameter reducing part, and the other axial end of the diameter expanding flange is limited by an axial position clamping spring to form an axially restrained rotatable structure.

Drawings

The utility model will be described in further detail below with reference to the drawings and to specific examples.

FIG. 1 is a schematic diagram of a first embodiment of the present utility model;

fig. 2 is a schematic perspective exploded view of the embodiment of fig. 1.

FIG. 3 is a schematic view of a partially enlarged ratchet lock of the embodiment of FIG. 1.

FIG. 4 is a schematic view of the ratchet release partial enlarged construction of the embodiment of FIG. 1.

Fig. 5 is a schematic structural diagram of a second embodiment of the present utility model.

In the figure: 1. the brake caliper comprises a brake caliper body 2, a motor 3, a sun gear 4, a planet gear 5, a gear ring 6, a planet carrier 7, an end cover 8, a step pin 9, an idler gear 10, a pin shaft 11, a driven gear 12, a ratchet locking mechanism 13, a cover plate 14, a constraint rod 15, a ball screw 16, a screw nut 17, an oil-free lubrication bearing 18, a gasket 19, a thrust roller bearing 20, a gasket 21, a gasket 22, an axle position clamp spring 23, a wear ring 24, a brake piston 25 and countersunk head fastening screws.

Detailed Description

Examples

As shown in fig. 1 and 2, the compact electromechanical brake actuator of this embodiment has a basic structure, in which a diameter-reducing portion of a diameter-reducing hole at the outer end of a caliper body 1 is supported by a lead screw nut 16 having no oil lubrication bearing 17 (substantially a self-lubricating bush having an antifriction function), a thrust roller bearing 19 sandwiched by two shims 18 and 20 is provided between one axial end of an enlarged diameter flange in the middle of the lead screw nut 16 and the diameter-reducing portion of the diameter-reducing hole, and the other axial end of the enlarged diameter flange is restrained by an axial clamp spring 23 with a washer 21 interposed therebetween, thereby forming an axially restrained rotatable structure. The screw nut 16 is engaged with the ball screw 15 passing therethrough. The outer end of the screw nut 16 extending out of the brake caliper body 1 is provided with a diameter-reducing section which is limited by the circumference of the driven gear 11 and limited in the axial direction, and specifically, the cross section of the diameter-reducing section of the outer end of the screw nut 16 is in a cross section shape matched with the polygonal inner hole of the driven gear 11. The center hole of the ball screw 15 and the constraint rod 14 with a hexagonal section which is inserted at the outer end and can be locked in the circumferential direction form a moving pair.

The inner end of the caliper body 1 is provided with a bowl-shaped brake piston 24 which forms a moving pair with the caliper body and faces the caliper. A wear ring 23 is mounted between the inner bore of the brake piston 24 and the outer circumference of the lead screw nut 16. The brake piston 24 and the inner end of the outer end shrinkage perforation of the brake caliper main body 1 are provided with sealing structures. The inner end of the ball screw 15 is provided with a positioning recess and a central screw hole, a positioning boss matched with the positioning recess of the inner end of the ball screw which extends into the positioning recess is formed in the brake piston 24, the positioning boss is provided with a central hole which is internally provided with a countersunk head fastening screw 25 from outside to inside, and the inner end of the countersunk head fastening screw 25 is fixedly connected with the central screw hole of the inner end of the ball screw in a screwing way.

The brake caliper main body 1 laterally extends out of a driving cavity with a motor 2 arranged inside corresponding to the position of a screw nut 16, the open end of the driving cavity is fixedly connected with a detachable end cover 7, and the end cover 7 extends to a reducing perforation position at the outer end of the brake caliper main body 1 to cover the driven gear 11. The output shaft of the motor 2 is driven by a planetary gear transmission system consisting of an outer sun gear 3, a planetary gear 4 and a planetary gear 5 and a planetary carrier 6, wherein the planetary carrier 6 is meshed with an idler gear 9 which takes a pin shaft 10 as a rotating shaft through a connected driving gear, and the idler gear 9 is meshed with a driven gear 11. The cantilever-shaped pin shafts 10 and the step pins 8 supporting the center of rotation of the planet carrier 6 are all mounted inside the end cover 7. The end cover 7 extends outwards from a mounting chamber closed by the cover plate 13 at a position corresponding to the screw nut 16 for mounting the ratchet locking mechanism 12.

Referring to fig. 3 and 4, the outer end of the restraining bar 14 is fixedly connected with the ratchet wheel 123, the cover plate 13 is provided with a locking pawl 122 forming a telescopic moving pair with the locking pawl 122, the locking pawl 122 is meshed with the ratchet wheel 123, and a reset spring 121 which enables the locking pawl to be in a locking position in which the locking pawl is meshed with the ratchet wheel 123 is arranged in a counter bore at the inner end of the locking pawl. In operation, as shown in fig. 3, under the action of the return spring 121, the locking pawl 122 is engaged with the ratchet wheel 123, and the restraining bar 14 is locked circumferentially and is not indexable randomly. When the lock pawl 122 is pressed into the working chamber against the urging force of the return spring 121 as shown in fig. 4, the lock pawl 122 is disengaged from the ratchet wheel 123, and the restraining bar 14 is in the circumferentially indexable, hand-off position.

After the planetary gear is installed, the starting motor drives the sun gear 3 to rotate, the sun gear 3 is meshed with the planetary gears, the planetary gears drive the driving gears on the planetary carriers 6 to rotate, and the driving gears are meshed with the idler gears 9, so that the driven gears 11 are driven to rotate, and speed reduction and torque increase transmission is realized. Then, the driven gear 11 drives the screw nut 18 to rotate, and then drives the ball screw 17 to push the brake piston 24 to move forwards, so as to push the brake linings to press the brake disc to realize braking.

Because the brake piston 24 is fixedly connected with the ball screw 15 through the countersunk head fastening screw, when braking is canceled and the motor rotates reversely, the brake piston 24 and the ball screw 15 can synchronously move away from the brake lining, so that the brake lining is ensured to realize homing, the dragging moment is greatly reduced, braking release is realized, and meanwhile, the fuel consumption of the vehicle is also reduced. In addition, the ball screw 15 is locked against rotation during normal operation by the restraining bar 14 and the ratchet locking mechanism 12, and by means of this mechanism the function can be manually relieved for disassembly during maintenance.

Examples

The basic structure of the compact electromechanical brake actuator of this embodiment is basically the same as that of the first embodiment, except that the ratchet locking mechanism 12 is shown in fig. 5, the outer end of the restraining rod 14 is also fixedly connected with the ratchet 123, the locking pawl 122 is lever-shaped, the middle part is hinged in the mounting chamber, one end is a claw that can be clamped into the ratchet 123, the other end is a pulling arm that extends out of the mounting chamber, and the return spring 121 is a torsion spring that makes the claw tend to be clamped into the ratchet 123. This constitutes a hook-type ratchet locking mechanism which is different from the push-button type structure of the embodiment. When the pulling arm is pulled by hand to overcome the acting force of the torsion spring to enable the hook claw to be separated from the ratchet wheel, the constraint rod 14 can be positioned at the hand-off position of circumferential indexing, and maintenance and troubleshooting operations are facilitated.

The two embodiments adopt the following organically combined innovative structural design: the device comprises a primary planetary gear and primary parallel gear speed reducing mechanism which can be accommodated in a smaller axial space, a conversion mechanism for driving a screw rod to axially translate through nut rotation, a fixed connection structure of a brake piston and a ball screw rod, and a button-type or drag hook ratchet locking mechanism; thus, the following significant advantages are achieved:

1) The combination of the parallel connection of the motor speed reduction transmission and the screw rod nut pair and the screw rod axial movement mechanism ensures that the axial dimension of the whole device is very compact on the premise of realizing the required service braking function, thereby being convenient for the installation and maintenance in a narrow space;

2) The direct fixed connection of the brake piston and the ball screw obviously reduces the braking dragging moment of the driving and reduces the fuel consumption of the vehicle;

3) The ratchet locking structure realizes the manual release function of the actuating mechanism, and is greatly convenient for installation, disassembly and maintenance.

In addition to the embodiments described above, other embodiments of the utility model are possible. For example, a common screw is used instead of a ball screw or the like. All technical schemes formed by equivalent substitution or equivalent transformation fall within the protection scope of the utility model.

Claims

1. A compact electromechanical brake actuator, characterized by: comprises a brake caliper main body provided with an axial constraint lead screw nut; the screw nut is meshed with the ball screw, the outer end of the screw nut is circumferentially restrained with the driven gear, and a circumferentially lockable restraining rod inserted into the central hole of the ball screw and the outer end of the ball screw forms a moving pair; the brake caliper body is provided with a bowl-shaped brake piston which forms a moving pair with the brake caliper body and faces the brake caliper; the inner end of the ball screw is fixedly connected with the brake piston; the brake caliper main body laterally extends out of a driving cavity with a motor arranged inside corresponding to the position of the screw nut, and an output shaft of the motor is meshed and driven with the driven gear through a reduction transmission mechanism at the outer end; the outer side of the driving cavity and the outer end of the constraint rod are respectively provided with a detachable end cover and a cover plate which are fixedly connected with the main body of the brake caliper.

2. The compact electromechanical brake actuator according to claim 1, wherein: the inner end of the ball screw is provided with a positioning recess and a central screw hole, and a positioning boss matched with the positioning recess at the inner end of the ball screw which extends into the brake piston is formed in the brake piston.

3. The compact electromechanical brake actuator according to claim 2, wherein: the positioning boss is provided with a central hole for accommodating a countersunk head fastening screw from outside to inside, and the inner end of the countersunk head fastening screw is fixedly connected with the central screw hole in a screwing way.

4. A compact electromechanical brake actuator according to claim 3, wherein: and an output shaft of the motor is meshed with an idler gear through a planet gear transmission system planet carrier at the outer end, and the idler gear is meshed with the driven gear.

5. The compact electromechanical brake actuator according to claim 4, wherein: and the end cover extends outwards to form a mounting chamber with a closed cover plate at a position corresponding to the screw nut and is used for mounting the ratchet locking mechanism.

6. The compact electromechanical brake actuator according to claim 5, wherein: the outer end of the constraint rod is provided with a ratchet wheel, the cover plate is provided with a locking pawl meshed with the ratchet wheel, and the locking pawl tends to a locking position and has a hand-off position; when in the locked position, the restraining bar is locked circumferentially; when in the hand-off position, the restraining bar is circumferentially rotatable.

7. The compact electromechanical brake actuator according to claim 6, wherein: the outer end of the restraining rod is fixedly connected with the ratchet wheel, the cover plate is provided with a locking pawl which forms a telescopic moving pair with the cover plate, and the locking pawl is meshed with the ratchet wheel.

8. The compact electromechanical brake actuator according to claim 7, wherein: the locking pawl is provided with a reset spring which is arranged in a counter bore at the inner end of the locking pawl and enables the reset spring to be in a locking position in which the reset spring is in a way of being meshed with the ratchet wheel.

9. The compact electromechanical brake actuator according to claim 5, wherein: the outer end of the restraining rod is fixedly connected with the ratchet wheel, the middle part of a lever-shaped locking pawl is hinged in the mounting chamber, one end of the locking pawl is a claw which can be clamped into the ratchet wheel, and the other end of the locking pawl is a poking arm which extends out of the mounting chamber.

10. The compact electromechanical brake actuator according to claim 6, 7, 8 or 9, wherein: the outer end of the screw nut, which extends out of the brake caliper main body, is provided with a diameter-reducing section which is circumferentially restrained and axially limited by the driven gear, and the section of the diameter-reducing section is in a section shape matched with the polygonal inner hole of the driven gear.

11. The compact electromechanical brake actuator according to claim 10, wherein: the reducing part of the reducing perforation at the outer end of the brake caliper main body supports the screw nut through a bearing.

12. The compact electromechanical brake actuator according to claim 11, wherein: and a thrust roller bearing is arranged between one axial end of the diameter-expanding flange in the middle of the screw nut and the diameter-reducing part, and the other axial end of the diameter-expanding flange is limited by an axial clamp spring to form an axially restrained rotatable structure.