JP2001132783A - Disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost by reduction of the number of the parts of a mechanical disc brake used in brake of a light vehicle, such as an automobile. SOLUTION: The base end part of a brake lever 8 is displaced toward a rotor 1, as a result of cam parts 7 and 7 being engaged with engaging pieces 9 and 9 along with the turning of a brake lever 8 centered around a pivot 6. The rotor 1 is nipped between first and second friction materials 3 and 4 to effect braking. By holding the first and second friction materials 3 and 4 directly at a caliper 2 and the brake lever 8, respectively, this problem described is solved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A disc brake according to the present invention is used for braking a light vehicle such as a bicycle or a wheelchair, or a light vehicle such as a motorcycle.

[0002]

2. Description of the Related Art Among disc brakes used for braking a light vehicle, ones having a structure that exerts a braking force based on a pulling force of a cable instead of a general hydraulic pressure, For example, Japanese Patent Publication No. 58-137
No. 63, JP-A-48-52242 are known. However, the disc brakes described in each of these publications have a large number of parts, and inevitably increase the cost, for example, complicating parts processing and assembling work. In view of such circumstances, the present invention has been made to provide a disc brake that can be manufactured at low cost with a reduced number of parts.

[0003]

According to a second aspect of the present invention, there is provided a disk brake including a rotor, a caliper, first and second friction members, a cam plate, a pivot, The vehicle includes a braking lever and a cam. The rotor is fixed to a rotating member such as a wheel coaxially with the rotating member. Further, the caliper is fixed to a fixed portion such as a frame of a bicycle or a wheelchair so as to straddle a portion near an outer periphery of the rotor and to be displaceable in an axial direction of the rotor. The first friction material is directly supported by a portion of the caliper that faces a portion of the caliper near the outer periphery on one side. The cam plate is supported by a portion of the caliper that faces a portion of the caliper near the outer periphery of the other side surface of the rotor. The pivot is protruded from one side surface of the cam plate toward the rotor. Further, the brake lever pivotally supports a base end portion of the pivot.
The cam portion is provided on one of the side surface of the cam plate and the other side surface of the base end portion of the braking lever opposite to each other, and extends in an arc direction around the pivot axis. Therefore, the cam plate is inclined in such a direction that the distance between one side surface of the cam plate and the other side surface of the other end of the base end of the braking lever gradually decreases. Further, the second friction material is directly supported on a portion of one side surface of the base end portion of the braking lever opposite to a portion near the outer periphery of the other side surface of the rotor. The braking lever moves to the side where the distance from the other side surface of the rotor is shorter with the rotation during braking.

[0004]

When braking is performed by the disk brake as described above, the brake lever is rotated. As a result, the base end of the brake lever approaches the other side of the rotor based on the engagement with the cam portion, and the second friction material supported on the base end of the brake lever is attached to the other side of the rotor. Press. As a result, the first and second friction members press both side surfaces of the rotor to exert a braking force based on the frictional force acting between the surface of each friction member and both side surfaces of the rotor. In particular, in the case of the disc brake of the present invention, the first and second friction members are formed of only the friction members by directly supporting the first and second friction members on a caliper or a braking lever. For example, the number of parts can be reduced. Therefore, cost can be reduced by reducing the number of parts.

[0005]

1 to 7 show a state in which a disc brake for braking a bicycle is constructed as an example of an embodiment of the present invention corresponding to all of the first to fifth aspects. ing. This disc brake includes a rotor 1, a caliper 2, first and second friction members 3, 4, a cam plate 5, a pivot 6, cams 7, 7, a braking lever 8, and a plurality (shown in the figure). In this example, three engaging pieces 9 and 9 and a cable 10 are provided. Of these, the rotor 1 is coaxially fixed to the center of the wheel of the bicycle, which is a rotating member, and rotates together with the wheel.

[0006] The caliper 2 includes an inner body 1.
1 and the outer body 12 (the upper right half of FIG.
The upper half of FIG.
And is fixedly connected. At one end (the left end in FIG. 1 and the lower end in FIG. 3) of the inner body 11, there is provided a mounting portion 16 for fixing the caliper 2 to the bicycle frame 15 with screws. Also, the tip of the inner body 11 (upper right end in FIG. 1, upper end in FIG. 3)
, A locking piece 17 for locking an end of an outer tube (not shown) into which the cable 10 is inserted is supported and fixed.

A portion of the first half (lower half of FIG. 3) of the outer body 12 which faces the outer diameter portion on one side (the right side in FIGS. 2 and 3) of the rotor 1 is supported on the outer side. The section 19 is provided. On the other hand, a portion of the intermediate portion of the inner body 11 that faces the outer surface of the rotor 1 on the other side surface (the left side surface in FIGS. 2 and 3) is an inner support portion 18. On the other hand, the caliper 2 configured as described above straddles the outer peripheral portion of the rotor 1, that is, the inner peripheral support portion 18 and the outer support portion 19 move the outer peripheral portion of the rotor 1 from both sides in the axial direction. In the state of being sandwiched, it is fixed to the frame 15 by the mounting portion 16.

The first friction material 3 is formed by sintering a copper-based metal into a disk shape and forms the inner surface of the outer support portion 19, that is, the outer periphery of one side of the rotor 1. It is supported by a portion facing the shift portion. For this reason, in the case of the present example, a first holding concave portion 20 is formed on the inner surface of the outer-side support portion 19 so as to match the shape (circular in the illustrated example) of the first friction material 3. I have. The first friction material 3 formed by sintering and shaping a copper-based metal into a disc shape has its base end (the right end in FIGS. 2 and 3) at the first holding recess 2.
0, and is held on the inner side surface of the outer side support portion 19 in a state where the inner side is fitted without looseness by press-fitting.

The cam plate 5 is supported on the inner surface of the inner support portion 18, that is, the portion facing the outer surface of the rotor 1 on the other side. For this reason, in the illustrated example, a stud 21 is screwed to the center of the inner support portion 18. That is, the inner support portion 18
A through hole 22 is formed at the center of the hole, and a hexagonal fitting concave portion 23 is formed at the opening on the inner side of the through hole 22. Then, a nut 24 is internally fixed to the fitting concave portion 23 by interference fitting to form a screw hole for screwing the stud 21. The stud 21 is screwed to the nut 24 and has both ends protruding from the inner and outer sides of the inner support portion 18. still,
A lock nut 25 is screwed onto a portion protruding from the outer side surface (left side surface in FIGS. 2 and 3) of the inner support portion 18 at one end portion (left end portion in FIGS. 2 and 3) of the stud 21. .

The cam plate 5 is abutted and supported on the other end (the right end in FIGS. 2 and 3) of the stud 21 screwed and supported on the inner support portion 18 as described above.
In the illustrated example, the cam plate 5 has a straight edge 26 at one end edge (the upper right edge in FIG. 1 and the upper edge in FIG. 3), and a central portion of the outer surface (the left side surface in FIG. 2). The other end (Fig. 2
(Right end portions of No. 3 to No. 3) are formed with a circular concave portion 27 for rotatably fitting. The cam plate 5 having such a shape is provided with the stud 21 and the circular recess 27 in a state where the straight edge 26 is engaged with a step 28 formed on the inner surface of the inner support portion 18. By fitting the end portion inside, the inner side supporting portion 18 is supported on the inner side surface portion so as not to rotate around the stud 21 and to be able to move to and away from the rotor 1.

The pivot 6 is provided concentrically with the stud 21 at the center of the other end surface (the right end surface in FIG. 2) of the stud 21. In order to insert the pivot 6, a circular insertion hole 29 is formed in a part of the cam plate 5 at the center of the circular recess 27. With the other end of the stud 21 fitted in the circular recess 27, the pivot 6 is inserted through the insertion hole 29 and the inner surface of the cam plate 5 (FIGS.
3 right side). Further, the cam portions 7 are formed on the inner surface of the cam plate 5. In the case of the example shown in the figure, the cam portions 7 are arc-shaped concave grooves having an arc-shaped cross section and having the pivot 6 as a center. The depths of the concave grooves forming the cam portions 7 and 7 gradually change in the direction of an arc centered on the pivot 6. Therefore, the distance between the bottom surface of the cam portions 7 and the other side surface of the rotor 1 is
It gradually decreases in the direction of the arc.

The brake lever 8 pivotally supports the pivot 6 at its base end (upper left end in FIG. 1 and upper end in FIG. 2). For this purpose, a circular hole 30 for rotatably inserting the pivot 6 is formed at the base end of the braking lever 8, and the distal end of the pivot 6 is inserted into the circular hole 30. or,
Inside surface of the base end of the brake lever 8 (right side in FIGS. 2 and 3)
Thus, a circular second holding concave portion 31 is formed in a portion facing the outer peripheral portion of the rotor 1 on the other side. Similarly to the first friction material 3, the second friction material 4 is formed by sintering a copper-based metal into a disk shape and forming the disk.
3 are retained on the inner surface of the base end of the brake lever 8 in a state in which the left end of the brake lever 8 is fitted into the second holding recess 31 without looseness by press-fitting.

Further, a portion of the outer surface of the base end of the braking lever 8 (the left side surface in FIG. 2) which is aligned with the cam portions 7 is provided with:
The engagement pieces 9 are provided. Each of these engagement pieces 9, 9
Are made of a slippery material such as an oil-impregnated metal or a synthetic resin, and each includes a hemispherical engaging portion 32 and a cylindrical support portion 33. Each of the engagement pieces 9, 9 is configured such that each support portion 33 is connected to the base end of the brake lever 8 in a state where the respective engagement portion 32 protrudes from the outer surface of the base end of the brake lever 8. The brake lever 8 is fixed to the base end of the brake lever 8 by being tightly fitted into the support holes 34, 34 formed therein. In this state, the engaging portions 32, 32
It is slidably engaged with each of the cam portions 7,7. Each of these hemispherical engaging portions 32, 32 can be integrally formed from the braking lever 8 by a punching process using a press. Also, a cam portion is provided on both sides facing each other,
A mechanism for displacing the base end of the brake lever 8 may be constituted by a pole ramp mechanism in which a ball is held between these two surfaces.

Further, the end of the cable 10 is connected to the tip of the brake lever 8 (the lower right end in FIG. 1 and the lower end in FIG. 2). That is, a nut screwed into the mounting screw 36 in a state where the distal end of the cable 10 is inserted through a small through hole 37 formed in an mounting screw 36 inserted through an mounting hole 35 formed at the distal end of the braking lever 8. The distal end of the cable 10 is connected and fixed to the distal end of the brake lever 8 by tightening the 38. Also, this cable 10
Of the outer tube (not shown), which constitutes a Bowden wire together with the cable 10, abuts against a step surface 40 formed at an intermediate portion of a stepped hole 39 formed in the locking piece 17. ing. The base end of the cable 10 is connected and fixed to a brake lever (not shown). A return spring 41, which is a compression coil spring, is provided between the mounting screw 36 and the locking piece 17.
A direction in which braking is released from the braking lever 8;
That is, the elasticity in the clockwise direction is given in FIG.

When braking is performed by the disk brake of the present invention configured as described above, the cable 10 is pulled upward in FIG. 1 by operating a brake lever (not shown). The cable 10 rotates the brake lever 8 about the pivot 6 in the counterclockwise direction in FIG. Along with this rotation, the engaging pieces 9 are moved to the side of the cam portions 7 where the distance from the other side surface of the rotor 1 is short (the side where the concave groove is shallow). Let it. Due to this movement, the base end of the brake lever 8 approaches the other side surface of the rotor 1, and the second friction material 4 supported on the base end portion of the brake lever 8 is pressed against the other side surface of the rotor 1. . As shown in FIG. 3, the caliper 2 is
The rotor 1 is movably supported by a gap e (for example, about 2 mm) in the axial direction of the rotor 1 between the mounting portion 16 and the flange 43 of the flanged bolt 42. Accordingly, the caliper 2 is displaced in the axial direction of the rotor 1 as the second friction material 4 is pressed against the other side surface of the rotor 1. Therefore, one side surface of the rotor 1 is pressed against the first friction material 3. As a result, the first and second friction members 3 and 4 press both sides of the rotor 1, and the frictional force acting between the surfaces of the friction members 3 and 4 and both sides of the rotor 1 is reduced. Demonstrate the braking force based on.

By repeating the braking, each of the friction materials 3,
When the wheel 4 is worn, first, an adjustment mechanism provided on the side of the brake lever prevents the operation amount of the brake lever from becoming excessive. Further, if the increase in the operation amount cannot be prevented by the adjustment mechanism on the brake lever side, the stud 21
The cam plate 5 is moved closer to the other side of the rotor 1. That is, when the friction members 3 and 4 are not worn, the outer surface of the cam plate 5 is in contact with the inner surface of the inner support portion 18 as shown in FIG. In a state where the friction members 3 and 4 are worn, as shown in FIG.
The outer surface of the cam plate 5 is separated from the inner surface of the inner support portion 18 so as to approach the other side of the rotor 1. This operation is performed by rotating the stud 21 with the lock nut 25 loosened. When the cam plate 5 is displaced toward the rotor 1 by a desired amount, the lock nut 25 is tightened to prevent the stud 21 from rotating carelessly.

In the case of the disk brake according to the present invention, which is constructed and operates as described above, the first and second friction members are directly supported by a caliper or a braking lever, so that the first and second friction members are supported. The number of parts can be reduced, for example, it is possible to configure the friction material only with the friction material. Therefore, cost can be reduced by reducing the number of parts.

[0018]

Since the present invention is constructed and operates as described above, it is possible to reduce the cost of a mechanically operated disc brake used for braking a light vehicle such as a bicycle.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially cut-away view taken in the direction of arrow B in FIG. 1;

FIG. 4 is a sectional view taken along the line CC of FIG. 1, showing only the cam plate.

FIG. 5 is an exploded perspective view.

FIG. 6 is a view corresponding to the center of FIG. 2, showing a state in which the friction material is not worn.

FIG. 7 is a view corresponding to the center of FIG. 2, showing the friction material in a worn state.

[Description of Signs] 1 Rotor 2 Caliper 3 First friction material 4 Second friction material 5 Cam plate 6 Axis 7 Cam portion 8 Brake lever 9 Engagement piece 10 Cable 11 Inner body 12 Outer body 13 Bolt 14 Nut 15 Frame DESCRIPTION OF SYMBOLS 16 Attachment part 17 Locking piece 18 Inner side support part 19 Outer side support part 20 First holding recessed part 21 Stud 22 Through hole 23 Fitting recessed part 24 Nut 25 Lock nut 26 Straight edge 27 Circular recessed part 28 Step part 29 Insertion hole 30 Circular hole 31 Second holding concave part 32 Engagement part 33 Support part 34 Support hole 35 Mounting hole 36 Mounting screw 37 Small through hole 38 Nut 39 Stepped hole 40 Step surface 41 Return spring 42 Flanged bolt 43 Flange

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideyuki Fujinami 195-1 Nihonbashi Koamicho, Chuo-ku, Tokyo Inside Akebono Brake Industry Co., Ltd. (72) Inventor Shin Shibuya 19th Nihonbashi Koamicho, Chuo-ku, Tokyo No.5 Akebono Brake Industry Co., Ltd. F-term (reference) 3J058 AA43 AA48 AA53 AA69 AA73 AA79 AA87 BA61 BA62 CC08 CC52 CC66 CC76 FA02 FA09 FA50

Claims (5)

[Claims] In a disc brake, a pair of friction members are pressed against both side surfaces of a rotor with rotation of a braking lever about a pivot to brake a rotating member to which the rotor is fixed. A friction member provided on the brake lever side is supported on one side of the brake lever, and a cam mechanism is provided on the other side of the brake lever for bringing the brake lever closer to the rotor with its rotation. A disc brake, characterized in that a convex engaging piece is fixed. 2. The disc brake according to claim 1, wherein the friction material is directly supported on the brake lever by press-fitting the friction material into a holding recess provided in the brake lever. 3. A rotor fixed coaxially to the rotating member with respect to the rotating member, a caliper straddling a portion near the outer periphery of the rotor and displaceable in the axial direction of the rotor; A first friction material directly supported on a portion of the rotor facing the outer peripheral portion on one side, and a cam plate supported on a portion of the caliper opposite the outer peripheral portion of the rotor on the other side. A pivot protruding from one side of the cam plate on the rotor side, a brake lever pivotally supporting a base end of the cam plate, and an outer periphery of the other side of the rotor on one side of the base end of the brake lever. A portion opposed to the shift portion is provided on at least one side of the second friction material directly supported, and one side of the cam plate and the other side of the base end of the brake lever facing each other. Centering on the above axis A cam portion inclined in a direction in which a distance between one side surface of the cam plate and the other side surface of the base end portion and the other side surface of the brake lever gradually decreases in an arc direction; A disk brake in which the lever moves to the side where the distance from the other side of the rotor is shorter as the lever rotates during braking. 4. The first for a caliper and a brake lever.
4. The disk brake according to claim 3, wherein the second friction material is directly supported by press-fitting the first and second friction materials into holding cavities provided in the caliper and the brake lever. 5. A return spring for biasing a braking lever in a direction in which a distance from the other side surface of the rotor to a longer side of the cam portion moves, and the cam plate is formed by a stud screwed to a caliper. 4. The stud is supported so as to be able to move freely with respect to the other side surface of the rotor, and the pivot is provided concentrically with the stud at the tip end of the stud.
A disc brake according to any one of claims 1 to 4.