JP3059553B2 - Disc brakes for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake for a vehicle, and more particularly to a double disc brake for a motorcycle.

[0002]

2. Description of the Related Art Japanese Utility Model Publication No. 62-18148 and Japanese Patent Application Laid-Open No.
There are those described in each of the publications 200038. All of these have paired disc brakes on both sides of the hub of the wheel,
One is a first brake, the other is a second brake, and the caliper bracket of the first brake is movable, and the movable caliper bracket supports the first caliper,
When the first brake is actuated, the braking torque is transmitted to a second caliper constituting a second brake via a servo master cylinder to actuate the second brake.

[0003] Of the double disc brakes described in the above publications, the former has a movable caliper bracket of the first brake mounted coaxially with the axle. On the other hand, in the latter, the center of rotation is different from that of the axle by supporting the movable caliper bracket on the front fork.

[0004]

By the way, bearings are provided on both sides of the hub for supporting the axle, and there are cases where it is desired to increase the distance between the bearings as much as possible to increase the support rigidity of the wheels. However, in this case, when the movable caliper bracket of the first brake is mounted coaxially with the axle as in the former case, the width around the axle (axial dimension, the same applies hereinafter) increases, so that the weight and the air resistance increase. Problem.

On the other hand, the latter can solve such a problem, but the movable caliper bracket moves during braking, so that the position of the first caliper supported integrally therewith changes, and as a result, the brake There is a problem that uneven wear is apt to occur on the pad that slides on the disk. Therefore, an object of the present invention is to solve such problems at the same time.

[0006]

In order to solve the above-mentioned problems, a disk brake for a vehicle according to the present invention is provided so that one end of a movable caliper bracket is rotatable by shifting its center from an axle to a vehicle-side immovable portion near an axle. as well as axial wear, the first blanking
The rake pad will stay in the pad when the first brake is applied.
In a pad that passes through the heart and overlaps the radius of the brake disc
The pad center line has a non-operation of the first brake.
When the movable caliper bracket is rotated by operation of the first brake as a position apart from the center of the axle during movement, characterized in that it has come to rest passes over the center of the car <br/> axis.

[0007]

[Operation] The base end of the movable caliper bracket is pivotally supported near the axle, but is not supported coaxially with the axle.
The width around the axle becomes smaller. When the first caliper moves together with the movable caliper bracket when the first brake is actuated, the center line of the pad passes over the center of the axle, so that the center of rotation of the first caliper is offset from the axle. Instead, the entire surface of the pad slides evenly on the brake disc, and the wear becomes uniform.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment constructed for a front wheel of a motorcycle will be described with reference to FIGS. 3 shows a first brake 2 provided on the left side surface of the front wheel 1, and FIG. 4 shows a main part of a second brake 3 provided on the right side thereof from the opposite side.
3 shows a cross section of a main part along the line AA in FIG.

First, in FIG. 3, an axle 6 is rotatably supported at a lower end on the left side of a lower portion 5 of an inverted front fork 4 provided in a pair of right and left, and a boss 7 provided at a rear portion has The base end of the movable caliper bracket 8 is rotatably mounted on a shaft 9. The lower part 5 is an example of a vehicle-body-side stationary part in the present invention.

In the middle of the movable caliper bracket 8,
The first caliper 10 is supported, and the first caliper 10 is disposed along the outer periphery of the left brake disc 11. The first caliper 10 is connected to a master cylinder 13 of a handle (not shown) via a hose 12, and a piston of the first caliper 10 (described later) is operated by a hydraulic pressure generated in the master cylinder 13 by operating a handle lever (not shown). ) Can be operated to brake the left brake disc 11.

The outer end of the movable caliper bracket 8 is
4, the push rod 16 is axially attached to the outer end of the push rod 16 of the servo master cylinder 15. The push rod 16 is connected to a piston (described later) in the interlock master cylinder 15.

The servo master cylinder 15 is for generating a hydraulic pressure for operating the second brake 3 by the braking torque of the first brake 2, and is provided behind the lower portion 5 of the front fork 4 via a cylinder bracket 17. It is fixed to a stay 18 which protrudes.

The inside of the servo master cylinder 15 is connected to a reserve tank 20 via a hose 19, and the discharge port 21 is connected to a second caliper (described later) via a hose 22.

The left brake disk 11 is covered with a disk cover 23 to prevent the surface temperature of the left brake disk 11 from lowering. A duct 24 is opened forward of a portion of the disk cover 23 below the axle 6 so as to guide the traveling wind to the first caliper 10 to cool it. Such a disk cover is also provided on a right-side disk brake described later.

In the second brake 3 shown in FIG. 4, a second caliper 25 is fixedly attached to a stay 27 formed on the lower portion 5 of the right front fork 4 via a fixed caliper bracket 26.

The second caliper 25 is disposed along the outer periphery of the right brake disc 28, communicates with the servo master cylinder 15 via the hose 22, and operates by hydraulic pressure given from the servo master cylinder 15. It has become.

As shown in FIG. 5, a left brake disc 11 and a right brake disc 28 are mounted on both sides of an outer peripheral portion of a hub 30 which rotatably supports the axle 6 at the center by bolts 31, respectively. Has become.

The first caliper 10 has an opposed piston structure, and a pair of pistons 32 are provided to face each other with the left brake disc 11 interposed therebetween. Further, since two pistons 32 are arranged in parallel on each side of the left brake disk 11 (see FIG. 1), a total of four pistons 32 are provided. Each piston 3
The side facing the left side brake disk 11 of the second support plate 3
3 is in contact. Pads 34 are respectively provided on surfaces of the support plate 33 that face each other across the left brake disc 11, and each pad 34 can slide on the left brake disc 11.

The structure of the second caliper 25 is also the first caliper 1
0, a total of four pistons 35 are provided as a set of two (see FIG. 4) and opposed to each other with the right brake disc 28 interposed therebetween.
6 and each support plate 36 has a right brake disc 2
There is provided a pad 37 which can be slid into contact with 8.

The left and right brake discs 11 and 2
The pads 8 and the pads 34 and 37 are each made of a known carbon fiber.

Bearings 39 are provided at both ends of an axle hole 38 provided in the hub 30 to support the axle 6. Since the portion of the hub 30 supporting the axle 6 is provided with a substantially full length between the left and right front forks 4, the distance between the left and right bearings 39 is as long as possible.

FIG. 1 is a diagram showing a detailed structure of the first brake 2. The pad 34 is longer to overlap the two pistons 32 along the circumferential direction of the left brake disc 11, and its center line L points to a point B which is shifted from the center point C of the axle 6 by a dimension D. doing. At this time, a part of the pad 34 is displaced inward (in the direction of the axle 6), and is located between the outer edge of the pad 34 (in the radial direction of the axle 6) and the outer periphery of the left brake disc 11. A shift portion 40 is formed.

The master cylinder 15 for servo is a piston 4
One end of 1 is connected to the push rod 16. When the movable caliper bracket 8 rotates counterclockwise in the drawing, the piston 41 slides toward the discharge port 21 against the return spring 42 to generate hydraulic pressure.

FIG. 2 shows the state of the first brake 2 during braking. When the pad 34 slides on the left brake disk 11 rotating in the direction of arrow E, the first caliper 10 is moved by the braking torque to the movable caliper bracket 8. The pad 34 is rotated by a certain amount so that the center line L of the pad 34 is directed to the center point C which is the center of the axle 6. At this time, the outer periphery of the pad 34 coincides with the outer periphery of the left brake disc 11, and the shift portion 40 that has occurred in FIG. 1 has been eliminated. That is, the pad 34 operates the first brake 2
At the time of braking, that is, the outer peripheral portion of the brake disc 11
It has an outer peripheral portion that overlaps in a concentric arc shape, and has a center line L of the pad 34.
Goes through the middle of the pad 34 in the longitudinal direction and the first brake
2 overlaps with the radius of the brake disc 11 when actuated (see FIG.
2), when the first brake 2 is not operated, the axle 6
It passes through a position away from the center C by D
(FIG. 1).

On the other hand, in the second caliper 25, FIG.
As is apparent from the above, the center line L of the pad 37 is set so as to be directed to the center point C of the axle 6 from the beginning.

Next, the operation of this embodiment will be described. In FIG. 1, when braking is applied while the left brake disc 11 is rotating in the direction of arrow E, first the hydraulic pressure is applied from the master cylinder 13 to the first caliper 10, and each piston 32 of the first caliper 10 To both surfaces of the left brake disc 11.

Therefore, the braking torque is reduced by the first caliper 10.
To the movable caliper bracket 8, and the movable caliper bracket 8 rotates around the shaft 9 in the counterclockwise direction in the figure. As a result, the push rod 16 connected to one end of the movable caliper bracket 8 is pushed into the servo master cylinder 15 against the return spring.

FIG. 2 shows this state. First, the first caliper 10 rotates counterclockwise integrally with the movable caliper bracket 8, and the center line L of the pad 34 is set at the center point C of the axle 6.
The point B on the center line L coincides with the center point C, and the outer edge of the pad 34 overlaps the outer periphery of the left brake disc 11, and the shift portion 4 existing in FIG.
0 is canceled when the brake is operated. For this reason, the pad 34 is formed relatively long in advance so as to overlap with the two pistons, and the entire surface of the pad 34 is on average on the entire left brake disk 11 despite the fact that the positional relationship with the piston 32 tends to shift due to the rotation. Can be in sliding contact with the pad 3
4 has less uneven wear.

At the same time, the push rod 16 is pushed into the servo master cylinder 15, so that the piston 41 moves toward the discharge port 21 while resisting the elasticity of the return spring, and generates hydraulic pressure. When the second brake 3 is operated, a pair of pads 37 of the second brake 3 presses both surfaces of the right brake disk 28.

At this time, the second caliper 25 of the second brake 3 is fixedly attached to the lower portion 5 of the right front fork 4 via the fixed caliper bracket 26, and the center line L of the pad 37 is initially set to the axle 6 , The state in which the center line L points at the center point C does not change even during braking. Therefore, the pad 37 of the second brake 3 is in average sliding contact with the right brake disc 28 over the entire surface, and is less likely to be unevenly worn.

Further, since the second brake 3 is braked using the braking torque of the first brake 2, a servo effect can be obtained. Therefore, the left and right brake discs 11 and 28
Even though the pads 34 and 37 are made of carbon, each of the brake disks 11 and 28
The bite to the surface becomes good.

As is apparent from FIG. 5, the movable caliper bracket 8 is attached to the front fork 4,
Even if the width of the axle 6 is made the same as that of the conventional case, the width of the hub 30 can be increased, and the distance between the left and right bearings 39 can be increased accordingly, and the rigidity of the front wheel supporting portion can be increased.

[0033]

According to the present invention, the first caliper bracket is mounted at another place so that the axle and the axis do not coincide with each other, and the pad center line of the first caliper deviates from the center of the axle during non-braking and coincides with the center during braking. Provided.

Therefore, it is not necessary to increase the width of the portion around the axle, so that an increase in weight and an increase in running resistance can be suppressed. In addition, even when the first caliper moves integrally with the movable caliper bracket during braking, the entire surface of the pad can be pressed against the brake disc with a uniform force, so that uneven wear of the pad can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a first brake according to an embodiment.

FIG. 2 is a view similar to FIG. 1 in an operating state;

FIG. 3 is a left side view of a front wheel portion of the motorcycle according to the embodiment.

FIG. 4 is a diagram showing a second brake main part according to the embodiment;

FIG. 5 is a sectional view showing a main part along line AA in FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 front wheel 2 first brake 3 second brake 6 axle 8 movable caliper bracket 10 first caliper 11 left brake disc 15 master cylinder for servo 25 second caliper 28 right brake disc 30 hub 32 piston 34 pad 35 piston 37 pad 39 axle Bearings for support

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62L 1/00 B62L 3/00-3/02

Claims (1)

(57) [Claims] A first brake and a second brake are provided, and a second brake is operated by transmitting a braking torque generated by the first brake to a piston of a servo master cylinder via a movable caliper bracket of the first brake. In this structure, one end of the movable caliper bracket is rotatably mounted on a vehicle body-side immovable portion near the axle so that the center of the movable caliper bracket is shifted from the center of the axle, and a pad for the first brake is provided.
Passes through the center of the pad and
Have a pad center line that overlaps the radius of the rake disc,
The pad center line of the axle
As the position apart from the center, when the movable caliper bracket by operation of the first brake is rotated, the vehicle disc brake, characterized in that it has come to rest passes over center in the vehicle axis.