TREA

BRAKE CALIPER DEVICE HAVING AUTOMATIC PAD WEAR COMPENSATION MECHANISM

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Information

  • Patent Application
  • 20220018405
  • Publication Number
    20220018405
  • Date Filed
    July 16, 2020
    3 years ago
  • Date Published
    January 20, 2022
    2 years ago
Information
Abstract
A brake caliper device is adapted to be used with a brake disk, and includes a main body unit, first and second pads, a caliper actuator unit, and a positioning unit. The caliper actuator unit includes an actuating member, a bolt member that abuts against the actuating member, and a threaded sleeve that is threadedly engaged to the bolt member. When the actuating member is driven by an external force, the actuating member is capable of vibrating axially to cause an axial vibration of the bolt member, which prompts the threaded sleeve to rotate relative to the bolt member for pushing the first pad toward the brake disk, thereby automatically providing a travel stroke that compensates for pad wear.
Description
FIELD

The disclosure relates to a brake caliper device, and more particularly to a brake caliper device having automatic pad wear compensation mechanism.


BACKGROUND

A conventional brake caliper device disclosed in Taiwanese Utility Model Patent No. M394267 includes a main body unit, a rocker arm unit that is rotatably coupled to the main body unit, two pad units, a brake cable unit and a hydraulic piston unit, and is adapted to be used with a brake disk for braking. The main body unit has an operating space, the rocker arm unit has two rocker arms respectively and rotatably coupled to two opposite sides of the operating space, each of the pad units has a pad that is adapted to be disposed between a corresponding one of the rocker arms and the brake disk, and the brake cable unit has an outer tube and a steel cable extending therethrough. One end of the outer tube abuts against aside of one of the rocker arms, and the steel cable has a sleeved end portion that is fixedly embedded to the other one of the rocker arms, and a lever end portion that is operable to be pulled by a handbrake lever.


A user is permitted to perform brake operation via a brake pedal, which triggers the hydraulic piston unit to drive the pad units to abut against the brake disk, or via the handbrake lever, which triggers the brake cable unit to pull the rocker arms to drive the pad units to abut against the brake disk.


Another conventional brake caliper device disclosed in Taiwanese Utility Model Patent No. M415088 includes a main body unit, a piston unit, a pad unit and a handbrake unit. The main body unit has two opposite sides and an operating space, the pad unit has two positioning members that are connected to the piston unit and two pads respectively mounted to the positioning members, and the handbrake unit has an actuating member and two abutment members respectively disposed in proximity to the opposite sides of the main body unit. The abutment members are driven by first and second actuating portions of the actuating member to move away from the sides to push the two pads toward a brake disk for braking.


However, the pad units of the abovementioned brake caliper devices may wear off over a period of time under regular usage, causing to braking to be less effective if the devices are not regularly maintenance and replaced.


SUMMARY

Therefore, an object of the disclosure is to provide a brake caliper device that can alleviate the drawback of the prior art.


According to the disclosure, the brake caliper device is adapted to be used with a brake disk, which has a first side surface and a second side surface opposite to the first side surface. The brake caliper device includes a main body unit, first and second pads, a caliper actuator unit, and a positioning unit. The main body unit includes a first seat that is adapted to be disposed proximally to the first side surface of the brake disk, and that is formed with a mounting hole extending along a mounting axis (L), and a second seat that is co-movably connected to the first seat, that is adapted to be disposed proximally to the second side surface of the brake disk, and that cooperates with the first seat to define a receiving space therebetween for receiving a part of the brake disk.


The first pad is adapted to be disposed between the first seat and the first side surface of the brake disk, and the second pad is adapted to be disposed between the second seat and the second side surface of the brake disk.


The caliper actuator unit is mounted to the mounting hole of the first seat, and includes an actuating member, a bolt member that abuts against the actuating member, and a threaded sleeve that is threadedly engaged to the bolt member.


The positioning unit is mounted between the threaded sleeve and the first pad, and includes a first positioning module, a second positioning module, a ball retainer, and a plurality of balls. The first positioning module is disposed on the threaded sleeve, and has a plurality of angularly spaced-apart first recess holes that surround the mounting axis. The second positioning module is positioned relative to the first pad, and has a plurality of angularly spaced-apart second recess holes that surround the mounting axis and that respectively correspond in position to the first recess holes. The ball retainer is disposed between the first and second positioning modules, and has a plurality of angularly spaced-apart through holes that surround the mounting axis. The balls are mounted to the ball retainer, and are respectively and rotatably nested to the through holes. Each of the balls has two opposite sides respectively in contact with one of the first recess holes and one of the second recess holes.


When the actuating member is driven by an external force, the actuating member is capable of vibrating axially to cause an axial vibration of the bolt member, which prompts the threaded sleeve to rotate relative to the bolt member for pushing the first pad toward the brake disk, thereby automatically providing a travel stroke that compensates for pad wear.





BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment with reference to the accompanying drawings, of which:



FIG. 1 is a perspective view of an embodiment of a brake caliper device according to the disclosure;



FIG. 2 is an exploded perspective view of the embodiment;



FIG. 3 is a fragmentary exploded perspective view of the embodiment;



FIG. 4 is a schematic sectional view of the embodiment;



FIG. 5 is a fragmentary schematic sectional view of the embodiment;



FIG. 6 is a view similar to FIG. 4, illustrating the embodiment in a braking state;



FIGS. 7 to 9 are views similar to FIG. 4, illustrating the embodiment undergoing automatic pad wear compensation; and



FIG. 10 is a view taken along line X-X in FIG. 4.





DETAILED DESCRIPTION

Referring to FIGS. 1, 2 and 4, an embodiment of a brake caliper device 100 according to the disclosure is adapted to be used with a brake disk 200. The brake disk 200 has a first side surface 210, and a second side surface 220 opposite to the first side surface 210. The brake caliper device includes a main body unit 10, a first pad 20, a second pad 30, a pad squeezing unit 40, a caliper actuator unit 50, and a positioning unit 60.


The main body unit 10 includes a first seat 11 that is adapted to be disposed proximally to the first side surface 210 of the brake disk 200, a second seat 12 that is co-movably connected to the first seat 11 and that is adapted to be disposed proximally to the second side surface 220 of the brake disk 200, and two guiding rods 13 that interconnect the first and second seats 11, 12. The first and second seats 11, 12 cooperatively define a receiving space 14 therebetween for receiving a part of the brake disk 200. The first seat 11 is formed with amounting hole 111 extending along a mounting axis (L) and in spatial communication with the receiving space 14. In addition, each of the first and second seats 11, 12 is formed with two cylindrical grooves 15 that are for piston units (not shown) to be installed thereto to drive the first and second pads 20, 30. The mechanism by which the piston units drive the first and second pads 20, 30 is not the subject of this disclosure, and is therefore not further described.


The first pad 20 is adapted to be disposed between the first seat 11 and the first side surface 210 of the brake disk 200, and the second pad 30 is adapted to be disposed between the second seat 12 and the second side surface 220 of the brake disk 200.


The pad squeezing unit 40 is slidably coupled to the main body unit 10 to slide along the mounting axis (L), and includes a fixed seat 41 that is disposed at an outer side of the first seat 11 opposite to the receiving space 14, a movable seat 42 that is disposed between the second seat 12 and the second pad 30, and a connecting member 43 that interconnects the fixed and movable seats 41, 42. The fixed seat 41 has an inner seat body 410 that is connected to the connecting member 43 and an outer seat body 420 that is coupled to a side of the inner seat body 410 distal from the connecting member 43, and is formed with a central hole 411 that is centered at the mounting axis (L) and that extends through the inner seat body 410 and the outer seat body 420. The central hole 411 includes an enlarged section 412 that is defined by the inner and outer seat bodies 410, 420, a front shrunk section 413 that extends along the mounting axis (L) from a side of the enlarged section 412 through the outer seat body 420, a rear shrunk section 414 that extends along the mounting axis (L) from a side of the enlarged section 412 distal from the front shrunk section 413 through the inner seat body 410, a front shoulder surface 415 that is formed on the outer seat body 420 and that interconnects the enlarged section 412 and the front shrunk section 413, and a rear shoulder surface 416 that is formed on the inner seat body 410 and that interconnects the enlarged section 412 and the rear shrunk section 414. The enlarged section 412 has a non-circular part 417 proximate to the front shoulder surface 415. The connecting member 43 has two guiding slots 431 that permit the guiding rods 13 to respectively and slidably extend therethrough.


The caliper actuator unit 50 is mounted to the mounting hole 111 of the first seat 11 and the central hole 411 of the fixed seat 41, and includes a positioning member 51, an actuating member 52, a plurality of roller members 53 that are disposed between the positioning member 51 and the actuating member 52, a bolt member that abuts against the actuating member 52, a threaded sleeve 55 that is threadedly engaged to the bolt member 54, a restoring member 56, a resilient member 57, a push block 58 that is fixed to the first pad 20, and a thrust bearing 59 that is mounted between the bolt member 54 and the resilient member 57.


The positioning member 51 is fixed to the fixed seat 41, abuts against the front shoulder surface 415, and is disposed at a side of the actuating member 52. Specifically, the positioning member 51 is mounted to the enlarged section 412 of the fixed seat 41, and is fixed to the front shoulder surface 415 such that the positioning member 51 is nonrotatable. The positioning member 51 has a first side surface 511 that faces the actuating member 52 and that are formed with a plurality of angularly and equidistantly spaced-apart first grooves 512 surrounding the mounting axis (L).


The actuating member 52 extends along the mounting axis (L), is rotatable relative to the positioning member 51, and is mounted to the central hole 411 of the fixed seat 41. Specifically, the actuating member 52 has an actuating disk 521 that is mounted to the enlarged section 412 of the fixed seat 41 and that is proximate to the positioning member 51, and an actuating rod 522 that is connected to the actuating disk 521 and that extends through the front shrunk section 413. The actuating disk 521 has a second side surface 523 that faces the positioning member 51 and that are formed with a plurality of angularly and equidistantly spaced-apart second grooves 524 surrounding the mounting axis (L). In the embodiment, each of the first and second grooves 512, 524 is elongated, extends about the mounting axis (L), and has a groove depth that varies in the extending direction thereof. Specifically, the groove depth is largest at a middle part of each of the first and second grooves 512, 524, and decreases gradually away from the middle part (See FIG. 10). The actuating rod 522 extends through the front shrunk section 413 in such a way that a portion thereof is exposed to the external environment.


The roller members 53 are respectively nested in the first grooves 512, with exposed ends thereof in contact with the actuating member 52. When the actuating member 52 rotates relative to the positioning member 51, the second grooves 524 are permitted to be nested or to be unnested from the roller members 53.


The bolt member 54 is mounted to the central hole 411 of the fixed seat 41. Specifically, the bolt member 54 has an abutment disk 541 that abuts against the actuating member 52 in the enlarged section 412 of the fixed seat 41, and a threaded rod portion 542 that is connected to the abutment disk 541 and that extends away from the actuating member 52. The abutment disk 541 has a non-circular cross-sectional shape that corresponds in shape to the non-circular part 417 of the enlarged section 412, such that the bolt member 54 is nonrotatable relative to the fixed seat 41.


The threaded sleeve 55 is slidably mounted between the central hole 411 of the fixed seat 41 and the mounting hole 111 of the first seat 11, and is formed with a threaded hole 551 that threadedly engage the threaded rod portion 542 of the bolt member 54.


The restoring member 56 is a compression spring that has two opposite ends respectively abutting against the rear shoulder surface 416 of the first seat 41 and the abutment disk 541 of the bolt member 54, and that generates a restoring force for resiliently pushing the actuating disk 521 of the actuating member 52 to be in contact with the positioning member 51. The resilient member 57 has two opposite ends respectively abutting against the abutment disk 541 of the bolt member 54 (via the first bearing 591 as shown in FIG. 3) and the threaded sleeve 55 for pushing the threaded sleeve 55 away from the abutment disk 541 of the bolt member 54 and toward the first pad 20. The push block 58 is fastened to the first pad 20 and provides a larger contact surface area between the threaded sleeve 55 and the first pad 20.


The thrust bearing 59 is mounted between the abutment disk 541 of the bolt member 54 and the resilient member 57, and enables free rotation of the threaded sleeve 55 relative to the bolt member 54.


Referring to FIGS. 3 and 5, the positioning unit 60 is mounted between the threaded sleeve 55 and the first pad 20. In this embodiment, the positioning unit 60 includes a first positioning module 61 the is disposed on the threaded sleeve 55, a second positioning module 62 that is positioned relative to the first pad 20 and that is disposed on the push block 58, a ball retainer that si disposed between the first and second positioning modules 61, 62, and a plurality of balls 64 that are mounted to the ball retainer 63. The first positioning module 61 has a plurality of angularly spaced-apart first recess holes 611 that surround the mounting axis (L). The second positioning module 62 has a plurality of angularly spaced-apart second recess holes 621 that surround the mounting axis (L) and that respectively correspond in position to the first recess holes 611. The ball retainer 63 has a plurality of angularly spaced-apart through holes 631 that surround the mounting axis (L). The balls 64 are respectively and rotatably nested to the through hole 631. Each of the balls 64 has two opposite sides respectively in contact with one of the first recess holes 611 and one of the second recess holes 621.


A number of the first recess holes 611 of the positioning unit 60 is greater than a number of the balls 64, and a number of the second recess holes 621 is greater than the number of the balls 64. Preferably, the number of the first recess holes 611 of the positioning unit 60 is twice as many as the number of the balls 64, and the number of the second recess holes 621 is twice as many as the number of the balls 64. In this embodiment, the numbers of the first recess holes 611 and the second recess holes are respectively eighteen, and the number of the balls 64 is nine.


Referring back to FIGS. 1 and 4, after the brake caliper device 100 is fully assembled and is fixedly mounted to the brake disk 200, in an unused circumstance where the brake caliper device has not been activated, there exists gaps respectively between the first side surface 210 and the first pad 20, and between the second side surface 220 and the second pad 30.


Referring to FIG. 6, when a user applies an external force (via handbrake) to rotate the actuating rod 522 of the actuating member 52 for the first time, the roller members 53 would constantly be in contact with and be nested in and out of the first grooves 512 of the positioning member 51 and the second grooves 524 of the actuating member 52 (as long as the second grooves 524 revolves around the mounting axis (L)), and push the actuating disk 521 axially away from the positioning member 51 whenever the roller members 53 are not nested in the first and second grooves 512, 524. At the same time, the abutment disk 541 of the bolt 54 is pushed by the actuating disk 521 of the actuating member 52, so that bolt member 54 and the threaded sleeve 55 drives the positioning unit 60 and the first pad 20 toward the first side surface 210 of the brake disk 200, thus initiating a braking state of the brake caliper device. Whenever the abutment disk 541 is driven to move along the mounting axis (L), both the restoring member 56 and the resilient member 57 are prompted to generate the restoring force. While in the braking state, the gaps directly adjacent to the brake disk 200 disappear, while new gaps appear between the first seat 11 and the push blocks 58 and between the second seat 12 and the movable seat 42.


Referring to FIG. 7, once the user has finished operating the actuating rod 522 of the actuating member 52, the restoring force of the restoring member 56 is instantaneously released to push the abutment disk 541 and the actuating disk 521 toward the positioning member 51. At this time, due to the uneven nature of the second grooves 524, the actuating disk 521 generates vibration while moving toward the positioning member 51. Since there are gaps (i.e., backlash) between threads of the threaded sleeve 55 and the bolt member 54, and since the resilient member 57 also releases the restoring force to push the bolt member 54 at this time, the vibration generated by the actuating disk 521 further triggers rotation of the threaded sleeve 55 relative to the bolt member 54. Such rotation causes the combined length of the bolt member 54 and the threaded sleeve 55 along the mounting axis (L) to be longer, such that the abutment disk 541 remains to abut against the actuating disk 521.


During the rotation of the threaded sleeve 55 relative to the bolt member 54, the first recess holes 611 on the threaded sleeve 55 rotate about the mounting axis (L). The balls 64 are permitted to reduce rotational friction of the threaded sleeve 55, so that the threaded sleeve 55 is able to rotate smoothly. As the balls 64 are engaged between the first and second positioning modules 61, 62 when fully assembled (see FIG. 5), the threaded sleeve 55 would not rotate in reverse after the initial rotation, therefore ensuring that the automatic pad wear compensation mechanism of the brake caliper device works as intended.


Since the number of the first recess holes 611 of the positioning unit 60 is twice as many as the number of the balls 64, and since the number of the second recess holes 621 is twice as many as the number of the balls 64, the first recess holes 611 on the threaded sleeve 55 may rotate about the mounting axis (L) to be positioned relative to the second recess holes 621 by a relatively small increment for a more precise rotational positioning.


Referring to FIGS. 8 and 9, during operation of the piston units after the first and second pads 20, 30 been worn off, when the user applies the external force (via handbrake) to rotate the actuating rod 522 of the actuating member 52 again, the roller members 53 would yet again be constantly in contact with and be nested in and out of the first grooves 512 of the positioning member 51 and the second grooves 524 of the actuating member 52 and perform operations disclosed in FIGS. 5 and 6 for automatically providing a travel stroke that compensates for pad wear.


Overall, when the user rotates the actuating rod 522 of the actuating member 52, the force generated by vibration of the positioning member 51, the actuating member 52 and the roller members 53 of the caliper actuator unit 50 enables rotation of the threaded sleeve 55 relative to the bolt member 54, automatically providing a travel stroke to compensates for pad wear.


In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure.


While the disclosure has been described in connection with what is considered the exemplary embodiment, it is understood that this disclosure is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.

Claims
  • 1. A brake caliper device adapted to be used with a brake disk, the brake disk having a first side surface and a second side surface opposite to the first side surface, said brake caliper device comprising: a main body unit that includes a first seat adapted to be disposed proximally to the first side surface of the brake disk, and formed with a mounting hole extending along a mounting axis, anda second seat co-movably connected to said first seat, adapted to be disposed proximally to the second side surface of the brake disk, and cooperating with said first seat to define a receiving space therebetween for receiving a part of the brake disk;a first pad that is adapted to be disposed between said first seat and the first side surface of the brake disk;a second pad that is adapted to be disposed between said second seat and the second side surface of the brake disk;a caliper actuator unit that is mounted to said mounting hole of said first seat and that includes an actuating member,a bolt member abutting against said actuating member, anda threaded sleeve threadedly engaged to said bolt member; anda positioning unit that is mounted between said threaded sleeve and said first pad, and that includes a first positioning module disposed on said threaded sleeve, and having a plurality of angularly spaced-apart first recess holes surrounding the mounting axis,a second positioning module positioned relative to said first pad, and having a plurality of angularly spaced-apart second recess holes surrounding the mounting axis and respectively corresponding in position to said first recess holes,a ball retainer disposed between said first and second positioning modules, and having a plurality of angularly spaced-apart through holes surrounding the mounting axis, and
  • 2. The brake caliper device as claimed in claim 1, further comprising: a pad squeezing unit slidably coupled to said main body unit to slide along the mounting axis, and including a fixed seat that is formed with a central hole centered at the mounting axis and that is disposed at an outer side of said first seat opposite to said receiving space, a movable seat that is disposed between said second seat and said second pad, and a connecting member that interconnects said fixed and movable seats;wherein, said actuating member and said bolt member are mounted to said central hole of said fixed seat, and said threaded sleeve is slidably mounted between said central hole of said fixed seat and said mounting hole of said first seat; andwherein, when said threaded sleeve is driven to push said first pad to the brake disk, said second pad is also pushed via the pad squeezing unit toward the brake disk for automatically providing a travel stroke that compensates for pad wear.
  • 3. The brake caliper device as claimed in claim 2, wherein: said caliper actuator unit further includes a positioning member fixed to said fixed seat and disposed at a side of said actuating member, and a plurality of roller members that are disposed between said positioning member and said actuating member;said positioning member has a first side surface that faces said actuating member and that are formed with a plurality of angularly spaced-apart first grooves surrounding the mounting axis;said actuating member has a second side surface that faces said positioning member and that are formed with a plurality of angularly spaced-apart second grooves surrounding the mounting axis;said roller members are respectively nested in said first grooves, with exposed ends thereof in contact with said actuating member for driving reciprocating displacement of said actuating member along the mounting axis to generate vibration force; andsaid brake caliper device further comprises a restoring member that resiliently abuts against said first seat and said bolt member, and that generates a restoring force for pushing said actuating member to be in contact with the positioning member whenever said actuating member is driven to move along the mounting axis.
  • 4. The brake caliper device as claimed in claim 3, wherein each of said first and second grooves is elongated, extends about the mounting axis, and has a groove depth that varies in the extending direction thereof.
  • 5. The brake caliper device as claimed in claim 4, wherein the groove depth is largest at a middle part of each of said first and second grooves, and decreases gradually in two opposite angular directions from said middle part.
  • 6. The brake caliper device as claimed in claim 3, wherein: said first grooves are equidistantly spaced-apart; andsaid second grooves are equidistantly spaced-apart.
  • 7. The brake caliper device as claimed in claim 3, wherein: said caliper actuator unit further includes a resilient member that is resiliently disposed between said bolt member and said threaded sleeve for pushing said threaded sleeve toward said first pad, and a push block that is fixed to said first pad; andsaid second positioning module is disposed on said push block.
  • 8. The brake caliper device as claimed in claim 7, wherein said caliper actuator unit further includes a thrust bearing mounted between said bolt member and said resilient member.
  • 9. The brake caliper device as claimed in claim 8, wherein: said bolt member of said caliper actuator unit has an abutment disk that abuts against said actuating member and a threaded rod portion that is connected to said abutment disk; andsaid thrust bearing is mounted between said abutment disk of said bolt member and said resilient member.
  • 10. The brake caliper device as claimed in claim 9, wherein: said fixed seat has an inner seat body that is connected to said connecting member and an outer seat body that is coupled to a side of said inner seat body distal from said connecting member;said central hole extends through said inner seat body and said outer seat body, and includes an enlarged section that is defined by said inner and outer seat bodies; andsaid enlarged section has a non-circular part defined by an inner surface of said outer seat body, said abutment disk having a non-circular cross-sectional shape that corresponds in shape to said non-circular part of said enlarged section for restricting rotation of said bolt member.
  • 11. The brake caliper device as claimed in claim 1, wherein a number of said first recess holes of said positioning unit is greater than a number of said balls, and a number of said second recess holes is greater than the number of said balls.
  • 12. The brake caliper device as claimed in claim 11, wherein the number of said first recess holes of said positioning unit is twice as many as the number of said balls, and a number of said second recess holes is twice as many as the number of said balls.