JP4782738B2 - Disc brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk brake apparatus of simple structure capable of surely assembling a housing in a cylinder hole by improving strength of a lock portion formed in the housing. <P>SOLUTION: A thrust transmitting plate 14b, a driving cam plate 12 and a cam spring 15 for energizing the thrust transmitting plate 14b toward the driving cam plate 12 are housed in a nearly cylindrical housing 16. Portions of the peripheral wall of the housing 16 are protruded outwardly in convex shapes by presswork to form a plurality of locking parts 16g arranged in the circumferential direction. The housing 16 is assembled in the cylinder hole 8 by latching the locking parts 16g to a circumferential groove 8f formed in the cylinder hole 8. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a disc brake device, and more specifically, a piston that presses a friction pad by hydraulic pressure, an adjuster for automatically adjusting a gap between the friction pad and the disc rotor, and a ball ramp type thrust conversion mechanism. The present invention relates to a disc brake device including a parking brake that presses a piston via an adjuster.

  As a disc brake device used for a four-wheeled vehicle or the like, there is a disc brake device with a parking brake that includes a hydraulic operation mechanism using a brake pedal and a mechanical operation mechanism that is pulled by a hand lever or a foot pedal. In this disc brake device with a parking brake, generally, a piston that constitutes a hydraulic operating mechanism is disposed on the end opening side of a cylinder hole provided in a caliper body, and an adjuster having an adjusting nut and an adjusting bolt on the rear surface side of the piston. And a thrust conversion mechanism constituting a mechanical operating mechanism is disposed on the bottom side of the cylinder hole.

Conventionally, a ball ramp type has been widely used as a thrust conversion mechanism. This thrust conversion mechanism, an adjuster having a thrust transmission plate, and a cam spring that presses the thrust transmission plate in the direction of the thrust conversion mechanism are substantially cylindrical. A plurality of locking portions are formed by cutting and raising a part of the peripheral wall to the outside, and a C-ring is formed on the cylinder hole opening side of the locking portion. And the housing is assembled to the housing mounting portion of the cylinder hole via the C-ring (see, for example, Patent Document 1).
Japanese Patent No. 2739879

  However, in the above-mentioned, since the locking portion formed in the housing is formed by cutting and raising the peripheral wall of the housing, it is difficult to ensure the strength, and the thickness of the locking portion is increased by increasing the thickness of the housing. In order to increase the strength, the weight increases and it is difficult to design and process the adjusting mechanism and the cylinder hole.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a disc brake device that can increase the strength of a locking portion formed in a housing with a simple structure and can securely assemble the housing to a cylinder hole.

In order to achieve the above object, the present invention provides a piston housed on the tip opening side of a cylinder hole, a thrust conversion mechanism disposed on the bottom side of the cylinder hole, and between the thrust conversion mechanism and the piston. An adjusting nut and an adjusting bolt having an adjusting bolt, the disc brake device pushing the piston through the adjuster from the thrust converting mechanism, the thrust converting mechanism being attached to the bottom wall of the cylinder hole A fixed cam plate, a cam shaft penetrating the cylinder hole bottom wall and the fixed cam plate so as to be rotatable and movable in the cylinder axial direction, and a cylinder hole opening side end of the cam shaft. Drive-side cam plate, ramp grooves formed at positions opposed to the drive-side cam plate and the fixed-side cam plate, and cam bearers accommodated in the ramp grooves, respectively. And the adjuster includes a thrust transmission plate at a cylinder hole bottom side end facing the drive cam plate of one of an adjustment nut and an adjustment bolt, the thrust transmission plate, and the drive cam In a disc brake device in which a plate and a cam spring for urging the thrust transmission plate in the direction of the driving cam plate are housed in a substantially cylindrical housing mounted in the cylinder hole, the housing 16 is pressed. A housing in which a plurality of engaging portions protruding in a radially outward direction are formed on the peripheral wall of the housing by piercing in the circumferential direction when processing, and an end surface of the engaging portion is provided in a cylinder hole and retained by engaging the cylinder bore opening side end surface of the mounting portion, the housing 16 at the time of press working, to piercing the middle portion of the peripheral wall of the housing Stop engaging portion which projects convexly radially outward circumferential direction to form a plurality, missing the end face of the engaging portion is engaged with the cylinder bore open side end surface of the housing mounting portion provided in the cylinder bore The housing is assembled to the cylinder hole.

According to the disc brake device of the present invention, since the locking portion is formed by projecting a part of the peripheral wall of the housing into a convex shape by pressing, the length of the locking portion in the housing axial direction and the circumferential direction is determined. It is possible to sufficiently ensure the length and the protruding dimension toward the outer periphery of the housing, improve the strength, and securely assemble the housing into the cylinder hole. Further, since the locking portion is formed by piercing at the same time when the housing is pressed, it can be easily formed.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 is an enlarged cross-sectional view of the main part of the disc brake device, FIG. 2 is a cross-sectional view taken along II-II in FIG. 1, FIG. 3 is an exploded perspective view of a thrust conversion mechanism, an adjusting nut, and a housing. FIG.

  The disc brake device 1 of the present embodiment includes a hydraulic operating mechanism 3 that is operated by a brake pedal (not shown) on the caliper body 2, and a mechanical operating mechanism for a parking brake that is operated by a hand lever and a foot pedal (not shown). The caliper body 2 is mounted on a caliper bracket 6 fixed to the vehicle body on one side of the disc rotor 5 via a pair of sliding pins (not shown). It is supported so as to be movable in the disk axial direction.

  The caliper body 2 includes an action part 2a and a reaction part 2b that are arranged to face both sides of the disk rotor 5, and a bridge part 2c that straddles the outside of the disk rotor 5 and connects them. A pair of friction pads 7 are disposed between the disk rotor 5 and the reaction portion 2b.

  A cylinder hole 8 that opens to the disk rotor side is formed in the action portion 2a. The cylinder hole 8 has a large-diameter portion 8a on the opening side of the tip and a small-diameter portion 8b on the bottom side of the cylinder hole. The large-diameter portion 8a is provided with a seal groove 8c and a boot groove 8d on the opening side. Three engaging grooves 8e are provided in the cylinder shaft direction at equal intervals in the circumferential direction of the small-diameter portion 8b, and a circumferential groove 8f that connects the axial intermediate portions of the engaging grooves 8e (the housing of the present invention). A mounting portion) is formed. In addition, a bleeder hole 8g is formed on the upper side of the action portion 2a so as to communicate with one of the engagement grooves 8e and the circumferential groove 8f and to be positioned above the vehicle body when the vehicle body is attached.

  The cylinder hole 8 has a large-diameter portion 8 a that houses a bottomed cylindrical piston 9 that constitutes the hydraulic operating mechanism 3, and a small-diameter portion 8 b that houses a thrust conversion mechanism 10 that constitutes the mechanical operating mechanism 4. In addition, an adjuster 11 for automatically adjusting the braking gap between the disc rotor 5 and the friction pad 7 is disposed between the piston 9 and the thrust conversion mechanism 10. A fixed cam plate 12 is disposed on the cylinder hole bottom wall 8h.

  The adjuster 11 includes an adjusting bolt 13 and an adjusting nut 14, and a small-diameter piston 13 a and a clutch plate 13 b are provided on the head of the adjusting bolt 13. The adjustment nut 14 is internally formed with a multi-threaded screw 14a that is screwed with the adjustment bolt 13, and a thrust transmission plate 14b is provided at the end on the cylinder hole bottom side. A cylindrical housing 16 that accommodates the cam spring 15 and the thrust transmission plate 14 b is disposed in the cylinder hole 8 on the outer peripheral side of the adjustment nut 14.

  The piston 9 is accommodated in the large-diameter portion 8a of the cylinder hole 8 with the bottom wall 9a facing the disk rotor side, and the adjusting nut 14 and the adjusting bolt 13 are provided on the inner central axis of the piston 9. ing. A fitting hole 9b is provided on the inner surface of the bottom wall of the piston 9, and the small-diameter piston 13a is fitted into the fitting hole 9b via a sealing material, and the clutch plate 13b is an opening portion of the fitting hole 9b. Is pressed against the conical surface 9c that expands from the bottom by the action of the spring member 17.

  One end of the spring member 17 is in contact with the bearing receiver 18, and the other end is in contact with a retaining ring 19 provided on the outer peripheral portion of the adjustment nut 14, and the adjustment bolt 13 is moved to the bottom wall 9 a side through the bearing receiver 18 and the bearing 20. It is energized in a rotatable state.

  The thrust conversion mechanism 10 includes a camshaft 21 that is pivotable with respect to the cylinder hole bottom wall 8h and the fixed cam plate 12 and that is movable in the cylinder axis direction, and a cylinder hole opening in the camshaft 21. A driving cam plate 21a provided at a side end, three ramp grooves 22 formed at positions opposed to the driving cam plate 21a and the fixed cam plate 12, respectively, and three received in the lamp grooves 22 And a cam bearing 23.

  The driving side cam plate 21a has a cylindrical portion 21b protruding from the center of the cylinder hole opening side end portion, and the thrust transmission plate 14b abuts against the cylinder hole opening side surface through a thrust bearing 24 and a spacer 25.

  The thrust transmission plate 14b is formed with the cylindrical portion 21b and a receiving hole 14c for receiving the tip of the threaded portion of the adjusting bolt 13 at the center of the cylinder hole bottom side end portion, and three engaging protrusions on the outer periphery. 14d are provided at equal intervals in the circumferential direction.

  The fixed-side cam plate 12 is formed in a disc shape, and is provided with an insertion hole 12a through which the camshaft 21 is inserted at the center, and three engagements respectively engaged with the engagement grooves 8e of the cylinder hole 8 on the outer peripheral side. Joint ribs 12b are provided at regular intervals in the circumferential direction. Furthermore, between the adjacent engaging ribs 12b, 12b, locking grooves 12c of the housing 16 are formed at equal intervals in the circumferential direction.

  The housing 16 includes a large-diameter cylindrical portion 16a formed slightly smaller than the diameter of the small-diameter portion 8b of the cylinder hole 8 and a small-diameter cylindrical portion having an inner diameter larger than the outer diameter of the thrust transmission plate 14b formed in the adjusting nut 14. 16b, and a through-hole 16c penetrating the inside and outside of the housing 16 is formed in the peripheral wall of the small-diameter cylindrical portion 16b. Further, flat portions 16d in the cylinder axial direction are formed at equal intervals in the circumferential direction on the outer peripheral portion of the small diameter cylindrical portion 16b, and from the cylinder hole opening side of the flat portion 16d to the cylinder hole bottom side of the large diameter cylindrical portion 16a. In the meantime, three engaging holes 16e are formed in which the engaging projections 14d of the thrust transmission plate 14b are engaged so as to be movable only in the axial direction. Further, a support piece 16f of the cam spring 15 projects from the inner peripheral side of the end portion of the small diameter cylindrical portion 16b on the cylinder opening side.

  On the bottom side of the cylinder hole of the large-diameter cylindrical portion 16a, three engaging portions 16g that are respectively engaged with the respective engaging grooves 8e of the cylinder hole 8 and are fitted into the circumferential grooves 8f are equally spaced in the circumferential direction. The peripheral wall between adjacent locking portions 16g of the large-diameter cylindrical portion 16a extends toward the bottom of the cylinder hole, and is a bent piece 16h that engages with the locking groove 12c of the fixed-side cam plate 12. Is formed. Further, a gap is formed between adjacent bent pieces 16h on the cylinder hole bottom side of the locking portion 16g, and this gap communicates with the inside and outside of the housing 16 after the disc brake device is assembled. 16i.

  The locking portion 16g is formed at the same time by piercing when the housing 16 is pressed, and the peripheral wall of the large-diameter cylindrical portion 16a protrudes in a convex shape on the outer peripheral side, so that the locking portion 16g extends in the housing axial direction. The length dimension of the housing 16 is formed to be longer than the dimension of the plate thickness of the housing 16, and the length dimension and the projecting dimension in the circumferential direction of the housing can be inserted into the engagement groove 8e of the cylinder hole 8, and It is formed in a dimension that can be securely fitted in the direction groove 8f.

  The disc brake device 1 of this embodiment formed in this way is assembled by inserting the cam spring 15 from the opening on the bottom side of the cylinder hole of the housing 16 and abutting one end of the cam spring 15 on the support piece 16f. An adjustment nut 14 is inserted through the inner periphery. The other end of the cam spring 15 is brought into contact with the cylinder hole opening side end of the thrust transmission plate 14b provided on the adjustment nut 14, and the engagement protrusion 14d of the adjustment nut 14 is engaged with the engagement hole 16e of the housing 16. Thus, the thrust transmission plate 14b is prevented from rotating while being movable in the cylinder axial direction.

  Next, the cylindrical portion 21b of the drive side cam plate 21a through which the spacer 25 and the thrust bearing 24 are inserted is accommodated in the accommodation hole 14c of the thrust transmission plate 14b, and the cylinder hole bottom side and the drive side cam plate of the thrust transmission plate 14b are accommodated. The cylinder hole opening end portion 21 a is brought into contact with the spacer 25 and the thrust bearing 24. Next, the camshaft 21 is passed through the insertion hole 12a of the fixed cam plate 12 so that each cam bearing 23 is accommodated in each ramp groove 22, and the engaging rib 12b of the fixed cam plate 12 and the locking portion 16g of the housing 16 are inserted. Is aligned with the cylinder axis direction, and the bent piece 16h of the housing 16 is bent and locked to the bottom surface of the fixed cam plate 12.

  As a result, the fixed cam plate 12 is disposed on the bottom side of the cylinder hole of the housing 16, and the thrust conversion mechanism 10, the thrust transmission plate 14b, and the cam spring 15 can be assembled into the housing 16 to form a unit. The engaging ribs 12b of the fixed cam plate 12 and the locking portions 16g of the housing 16 are arranged one by one on the same cylinder axial line.

  The unit assembled in this manner engages the engagement rib 12b of the fixed cam plate 12 and the locking portion 16g of the housing 16 with the engagement groove 8e formed in the small diameter portion 8b of the cylinder hole 8, respectively. Is inserted into the cylinder hole 8 toward the cylinder hole bottom wall 8h, and the housing 16 is rotated in a state where the locking portion 16g is inserted to the position of the circumferential groove 8f, and the locking portion 16g of the housing 16 is moved in the circumferential direction. While engaging with the groove 8f, the bent piece 16h is engaged with the locking groove 12c of the fixed cam plate 12, and the camshaft 21 protruding from the fixed cam plate 12 is inserted through the insertion hole 12a of the cylinder hole bottom wall 8h. Project outside. The housing 16 is reliably prevented from coming off by engaging the end face 16k of the locking portion 16g with the cylinder hole opening side end face 8i of the circumferential groove 8f, and the engaging rib 12b of the fixed cam plate 12 is attached to the cylinder 16 By engaging with the engaging grooves 8e of the holes 8, respectively, the rotation of the fixed cam plate 12 and the housing 16 can be restricted. A communication hole 16i formed in the housing 16 is disposed at the position of the engagement groove 8e communicating with the bleeder hole 8g, and the inside of the housing 16 and the bleeder hole 8g are connected to the communication hole 16i and the engagement groove 8e. Communicate via and.

  On the other hand, inside the piston 9, an adjusting bolt 13, a bearing 20, a bearing receiver 18, a spring member 17, and a retaining ring 19 are mounted in this order, which is also a single unit. Next, the piston 9 is pushed into the cylinder hole 8 while the adjustment bolt 13 is screwed into the adjustment nut 14, and the operation lever 26 is attached to the protruding end of the camshaft 21. As a result, the hydraulic operating mechanism 3, the mechanical operating mechanism 4, and the adjuster 11 are assembled to the caliper body 2. Each sealing material is attached at an appropriate stage.

  In the disc brake device 1 assembled in this way, the three locking portions 16g formed on the large-diameter cylindrical portion 16a include the length of the locking portion 16g in the housing axial direction and the circumferential direction, and the housing outer peripheral side. Therefore, the housing 16 can be reliably assembled to the circumferential groove 8 f of the cylinder hole 8.

  In this disc brake device 1, in the brake operation using the hydraulic operation mechanism 3, the piston 9 is pushed in the direction of the disc rotor by the pressure of the hydraulic fluid introduced into the cylinder hole 8, and the friction pad 7 of the action portion 2 a is applied. Is pressed against one side of the disk rotor 5, and the reaction force causes the caliper body 2 to move in the direction of the action part 2a, so that the reaction part 2b presses the friction pad 7 on the reaction part 2b side against the other side of the disk rotor 5. A braking action is performed.

  At this time, when the braking gap between the friction pad 7 and the disk rotor 5 is within a predetermined range, the adjustment is performed only by the movement amount of the piston 9 moving the backlash between the adjustment bolt 13 and the adjustment nut 14. Absent. When the brake gap with the disk rotor 5 exceeds a predetermined value due to wear of the friction pad 7, the piston 9 moves greatly to the disk rotor side beyond the backlash, so that the adjustment bolt 13 rotates and moves forward, and the clutch plate 13b And the conical surface 9c of the piston 9 abut. When the brake operation is released in this state, the piston 9 and the adjusting bolt 13 are moved backward by the backlash, so that the braking gap between the friction pad 7 and the disk rotor 5 is automatically adjusted to a predetermined range.

  In the parking brake operation by the mechanical operating mechanism 4, when the operation lever 26 is rotated by the hand lever or the foot pedal, the driving cam plate 21a is rotated together with the cam shaft 21, and the driving cam plate 21a is rotated. As the phase of each ramp groove 22 and each ramp groove 22 of the stationary cam plate 12 in the non-rotating state shifts, each cam bearing 23 moves to a shallow portion of the ramp groove 22, and from the fixed cam plate 12. The drive side cam plate 21a moves toward the disc rotor side so as to separate. The axial movement of the drive cam plate 21a is transmitted from the adjustment nut 14 to the piston 9 through the adjustment bolt 13, and becomes a thrust force that pushes the piston 9 toward the disk rotor. The braking action is performed in the same manner as the braking action.

  In the above-described disc brake device, since the housing 16 can be reliably assembled to the circumferential groove 8f of the cylinder hole 8 with a simple structure, the parking brake operation by the mechanical operating mechanism 4 is always performed stably and reliably. Can do.

  Note that, as in the above-described embodiment, the present invention includes three engagement grooves in the cylinder axial direction in the cylinder hole, and circumferential grooves that connect the intermediate portions in the axial direction of the engagement grooves. The groove is not limited to locking the locking portion of the housing, but a circumferential engagement groove is formed in the cylinder hole, and a C-ring is attached to the cylinder hole opening side of the locking portion of the housing. In this case, the engaging portion may be engaged with the engaging groove of the cylinder hole. Furthermore, the thrust transmission plate is formed on the adjustment nut and the adjustment nut is accommodated in the housing, but the thrust transmission plate may be formed on the adjustment bolt and the adjustment bolt may be accommodated in the housing.

It is a principal part expanded sectional view of the disc brake apparatus which shows one example of this invention. It is II-II sectional drawing of FIG. It is a disassembled perspective view of a thrust conversion mechanism, an adjustment nut, and a housing similarly. It is a cross-sectional front view of the disc brake device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Disc brake device, 2 ... Caliper body, 2a ... Action part, 2b ... Reaction part, 2c ... Bridge part, 3 ... Hydraulic action mechanism, 4 ... Mechanical action mechanism, 5 ... Disc rotor, 6 ... Caliper bracket, 7 ... friction pad, 8 ... cylinder hole, 8a ... large diameter part, 8b ... small diameter part, 8c ... seal groove, 8d ... boot groove, 8e ... engagement groove, 8f ... circumferential groove, 8g ... bleeder hole, 8h ... Cylinder hole bottom wall, 8i ... cylinder hole opening side end surface, 9 ... piston, 9a ... bottom wall, 9b ... fitting hole, 9c ... conical surface, 10 ... thrust conversion mechanism, 11 ... adjuster, 12 ... fixed side cam plate, 12a ... Insertion hole, 12b ... Engagement rib, 12c ... Locking groove, 13 ... Adjustment bolt, 13a ... Small diameter piston, 13b ... Clutch plate, 14 ... Adjustment nut, 14a ... Multi-thread screw, 14b ... Thrust transmission plate, 14c ... 14d ... engagement projection, 15 ... cam spring, 16 ... housing, 16a ... large diameter cylinder, 16b ... small diameter cylinder, 16c ... through hole, 16d ... flat part, 16e ... engagement hole, 16f ... Supporting piece, 16g ... locking portion, 16h ... bent piece, 16i ... communication hole, 16k ... end face, 17 ... spring member, 18 ... bearing receiver, 19 ... retaining ring, 20 ... bearing, 21 ... camshaft, 21a ... Drive side cam plate, 21b ... cylindrical portion, 22 ... ramp groove, 23 ... cam bearing, 24 ... thrust bearing, 25 ... spacer, 26 ... operating lever

Claims (1)

A piston housed on the tip opening side of the cylinder hole, a thrust converting mechanism disposed on the bottom side of the cylinder hole, and an adjuster having an adjusting nut and an adjusting bolt provided between the thrust converting mechanism and the piston A disc brake device that pushes the piston through an adjuster from a thrust conversion mechanism, wherein the thrust conversion mechanism includes a fixed cam plate attached to a bottom wall of the cylinder hole, and the cylinder hole bottom A camshaft penetrating the wall and the fixed cam plate so as to be rotatable and movable in the cylinder axial direction; a drive cam plate provided at a cylinder hole opening side end of the camshaft; and the drive side A ramp groove formed at a position opposed to the cam plate and the fixed cam plate, and a cam bearing accommodated in the ramp groove, and the adjuster includes: A thrust transmission plate is provided at the cylinder hole bottom side end facing the drive side cam plate of any one of a just nut and an adjustment bolt, and the thrust transmission plate, the drive side cam plate, and the thrust transmission plate are In a disc brake device in which a cam spring biased in the direction of the drive side cam plate is housed in a substantially cylindrical housing mounted in the cylinder hole, the peripheral wall of the housing is pressed when the housing 16 is pressed. A cylinder hole opening of a housing mounting portion in which a plurality of engaging portions protruding in a radially outward direction are formed in a circumferential direction by piercing the intermediate portion of the housing, and an end surface of the engaging portion is provided in the cylinder hole A disc brake device characterized by being engaged with a side end face to prevent it from coming off and assembling the housing into a cylinder hole.

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