JPH09263284A - Brake device of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a strong braking force without making a brake operation part, a master cylinder, and the like, in a large size. SOLUTION: A caliper main body 13 to support movable forward and rearward a caliper 12 to abutt a brake pad to both side surfaces of a disk rotor 10; a first cylinder 14 provided to the caliper main body 13; the first cylinder 14 provided to the caliper main body; a first piston to contact a brake pad to the disk rotor; a second cylinder 15 provided to the caliper main body; and a second piston 17 held elastically in the second cylinder 15 to project its one end to the opposing position to a fork; are provided, and while the first piston is composed of the front side piston holding the brake pad at the front end; and the rear side piston with the section form smaller than the rear end face of the front side; the first cylinder 14 is composed of a small form chamber fitting the rear side piston slidable; and a large form chamber to fit closely the front side piston slidable; and the second cylinder 15 is allowed to communicate thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device for a motorcycle, and more particularly to a braking device for a motorcycle in which a brake pad is pressed against a disc rotor fixed to a wheel to obtain a braking force.

[0002]

2. Description of the Related Art At present, a so-called oil disc brake is mainly used as a braking device for a motorcycle, in which a force applied to a brake operating portion such as a manual lever or a pedal is once converted into a hydraulic pressure, and the hydraulic pressure brakes a rear wheel. It is used. In this type of braking device, for example, by operating a manual lever, the piston of the master cylinder pumps the oil stored inside to the caliper via the brake hose, and the hydraulic pressure fixes the caliper to the front wheel. Brake pads are pressed against the left and right disc-shaped discs, and the front wheel is braked by the frictional force generated between the disc pads and the disc rotor.

Conventionally, various kinds of calipers for moving the brake pads have been proposed, but basically, all of them are provided in a caliper body so that a piston can advance and retreat, and the end face of the piston is used as a master cylinder. The brake pad is pressed by the hydraulic pressure of the brake oil, and the piston is projected toward the disc rotor to bring the brake pad into pressure contact with the disc rotor.

[0004]

However, in the above-described conventional braking device for a motorcycle, a large braking force is applied because the braking force applied to the disc rotor depends on the pressure applied to the brake operating portion by the rider. It was difficult to get. However, the pressing force applied to the brake operation unit by the rider is increased in the operation unit and the master cylinder, but in order to increase the increase rate, it is necessary to enlarge the shapes of the operation unit and the master cylinder. Therefore, there was a limit to the improvement of braking force, and it was difficult to set a strong braking force.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a braking device for a motorcycle capable of obtaining a strong braking force without increasing the size of the brake operating portion and the master cylinder. For the purpose of provision.

[0006]

According to the present invention, the brake pad is pressed against the side surface of a disc rotor fixed to a wheel that is rotatably supported by a fork of a motorcycle, so that the brake pad and the disc rotor are separated from each other. In a braking device for a motorcycle in which a wheel is braked by a frictional force generated between the caliper, the caliper is supported so as to be movable back and forth with respect to the fork along a surface direction intersecting a rotation axis of the wheel. A caliper main body, a first cylinder provided in the caliper main body, through which oil is supplied / sucked in association with the reciprocating movement of the brake operating portion, and a caliper main body, which is inserted in the first cylinder so as to be able to move forward and backward, and brakes when advancing A first piston for bringing the pad into contact with the disk rotor; and a first cylinder provided on the caliper body. A second cylinder communicating with the second cylinder and a second cylinder inserted into the second cylinder so that the second cylinder can advance and retreat, and elastically held so that one end of the second cylinder protrudes at a position facing the fork. And a front portion having a front end holding a brake pad, and a rear portion having a cross-sectional shape smaller than a rear end surface of the front portion, The first cylinder includes a small chamber in which a side surface of a rear portion of the first piston is slidably tightly fitted and a large chamber in which a front portion of the first piston is slidably tightly fitted. The second cylinder is configured to communicate with this large chamber.

Therefore, in the present invention, when the brake operating portion is moved forward, the first piston provided on the caliper main body moves forward by hydraulic pressure to bring the brake pad into contact with the disc rotor, and the contact is generated by the contact. Due to the frictional force generated, the caliper body moves together with the brake pad by the rotational force of the disc rotor, one end of the second piston contacts the fork, and is pushed inward of the second cylinder. As a result, hydraulic pressure is generated in the second cylinder, and the hydraulic pressure is also transmitted to the first cylinder and applied to the front end rear end surface of the first piston. Therefore, the pressing force applied to the first piston is the hydraulic pressure generated by the second piston in addition to the hydraulic pressure directly generated by the pressing operation of the brake operating unit, and therefore the pressing force applied to the brake pad. Is greatly increased, and a strong braking force can be obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory side view showing a motorcycle to which an embodiment of the present invention is applied, FIG. 2 is a partially longitudinal side view showing a main part according to the embodiment of the present invention, and FIG. 3 is one shown in FIG. XX sectional drawing, FIG.4 and FIG.5 is operation | movement explanatory drawing of what was shown in FIG.

The motorcycle shown in FIG. 1 is a road sports vehicle having a double cradle type frame 1.
A steering shaft 4 holding a handlebar 5 is rotatably supported on a head pipe 2 provided at a front end of the frame 1, and a front fork 6 rotatably supporting a front wheel 7 on the steering shaft 4. Further, a swing arm 8 for rotatably supporting a rear wheel 9 is supported on a main tube 3 constituting the frame 1 so as to be vertically swingable by a pivot 8a. The handle bar 5 has a brake lever 5a (see FIG. 2) as an operating portion for performing a brake operation on the front wheel 7, and the brake hose 20 is operated by operating the brake lever 5a.
There is provided a master cylinder 5b or the like for sending oil under pressure to a caliper which will be described later.

A disk-shaped disc rotor 10 is fixed to the hub of the front wheel 7 concentrically with the front wheel 7. The caliper 11 provided on the front fork 6 acts on the disc rotor 10. , The front wheel 7 is braked. The motorcycle braking device in this embodiment includes the caliper 11 and the disc rotor 10.

FIG. 2 shows the caliper 11 in this embodiment.
FIG. In the figure, reference numeral 12 denotes a caliper provided on the front fork 6. The caliper 12 is a caliper body 13 provided on the front fork 6.
And the first cylinder 1 formed in the caliper body 13
The first piston 16 is slidably tightly fitted into the inside of the caliper 4, and the second piston 17 is slidably tightly fitted into the second cylinder 15 also formed in the caliper body 13.

Of these, the caliper body 13 is composed of a plate-shaped mounting portion 13a and a cylinder forming portion 13b fixed to the upper end portion thereof by screws 13c and 13c. The lower end of the mounting portion 13a is rotatably supported by a shaft 18, and is held by a screw shaft 19 inserted through an arc-shaped elongated hole 13a1 formed in a side edge portion of the mounting portion 13a. Can swing about the shaft 18 within the range of the elongated hole 13a1. However,
The caliper main body 13 is always driven by the biasing force of the return spring 6c interposed between the spring receiving portion 6b formed on the front fork 6 and the spring receiving portion 13a2 formed on the mounting portion 13a, and the screw shaft 19 is always provided. Are held in contact with the front end of the long hole 13a1 (see FIG. 2).

As shown in FIG. 3, the first cylinder 14 formed in the cylinder forming portion 13b has a cylindrical large chamber 14a located on the front side with respect to the left side surface 10a of the disc rotor 10. , Small chamber 14b communicating with this
And are formed concentrically, and their central axis L
1 is orthogonal to the disc rotor 10. The rear end of the small chamber 14b is connected to the master cylinder 5b via the hose 20 inserted in the hose connecting hole 14c. A brake pad 22a is fixed to the caliper body 13 at a portion 13b1 facing the right side surface 10b of the disc rotor 10.

The first piston 16 tightly fitted in the first cylinder 14 is a cylindrical bottomed front piston (front portion) slidably fitted in the large chamber 14a.
16a and a bottomed cylindrical rear piston (rear portion) 16b slidably fitted in the small chamber 14b,
A disc rotor 1 is attached to the head of the front piston 16a.
The brake pad 22a is fixed so as to face the left side surface 10a of 0. The brake pad 22a faces the brake pad 22b via the disc rotor 10. In the figure, 14d, 14e and 14f are annular sealing members.

On the other hand, the second cylinder 15 is shown in FIG.
As shown in FIGS. 4 and 5, it has a bottomed cylindrical shape, and its central axis L2 is parallel to the disc rotor 10. A hose connecting hole 15a is formed at an intermediate position of the second cylinder 15, and the second cylinder 15 and the oil tank 21 are connected by a brake hose 23 connected thereto. As the oil tank 21, a well-known oil reservoir tank connected to the master cylinder 5b may be used, or an oil tank separate from this may be used. Further, a connection flow path 13d is formed between the second cylinder 15 and the first cylinder 14, one end of which is near the bottom 15b of the second cylinder 15 and the other end is The large chamber 14a of the first cylinder 14 is located near the bottom portion 14a1.

The second piston 17 fitted into the second cylinder 15 has a front piston 17a whose one end faces the abutting portion 6a of the front fork 6.
It is composed of a rear piston 17b located behind it. A spring bearing 17c is fitted to the rear end of the rear piston 17b, and a spring 17d is interposed between the spring bearing 17c and the bottom portion 15b of the second cylinder 15, and the spring 17d Due to the urging force, one end of the front piston 17a is always held at a position protruding from the open end of the cylinder 15. In addition, in FIG. 2, FIG. 4, and FIG.
Reference numeral 17e indicates a boot, and 17f indicates a circlip.

In the motorcycle braking device having the above structure, when the brake lever 5a is in the released state,
Brake pads 22a, 22 held by the caliper 12
Both b are separated from the disc rotor 10, and the braking force on the front wheel 7 is released. Further, the caliper 12 is held at a steady position by the return spring 6c, and the
7a is kept in non-contact with the contact portion 6a of the front fork 6.

When the brake lever 5a is operated in the braking direction, the oil in the master cylinder 5b passes through the brake hose 20 and the first cylinder 14 of the caliper 12 is pushed.
Is sent under pressure to the small chamber 14b, and the hydraulic pressure moves the rear piston 16b in the direction toward the disc rotor 10 (direction C), pushing the front piston 16a in the same direction. As a result, the front piston 16a presses the one brake pad 22a fixed to the front end thereof against the left side surface 10a of the disc rotor 10, and the reaction force moves the caliper main body 13 as a whole in the D direction. The other brake pad 22b is brought into pressure contact with the right side surface 10b of the disc rotor 10.

As a result, both brake pads 22a, 22
A frictional force is generated between b and the disk rotor 10, and the rotational force F1 of the disk rotor 10 is applied to the caliper 12 by the frictional force, and the rotational force F1 causes the caliper 12 to rotate in the arrow A direction about the shaft 18. Rotate to. Due to this rotation, the front piston 17a of the second piston 17 provided on the caliper 12 abuts on the abutting portion 6a provided on the front fork 6, and then the caliper 12
Rotates in the A direction. Due to the rotation of the caliper 12, the front piston 17a is relatively moved to the second cylinder 1
The rear piston 17b and the spring receiver 17c also move in the E direction against the spring 17e due to the pressing force F2.

The piston 17a and the second cylinder 15
When the relative movement with respect to is started, as shown in FIG.
Since the side surfaces of the spring bearing 17c and the rear piston 17b block the communication state between the brake hose 23 and the space from the bottom portion 15b of the cylinder 15 to the spring bearing 17c, the pistons 17a and 17b are further moved to the second state from this state.
When moving in the direction E relative to the cylinder 15, the brake oil filled in the space 17g passes through the connecting passage 13d and the large chamber 1 of the first piston 16 is discharged.
4a, and the hydraulic pressure of the first piston 1
A pressing force in the C direction is applied to the front piston 16 a of No. 6.

Therefore, one brake pad 22a further strongly presses the surface 10a of the disc rotor 10,
The reaction force also strongly presses the other brake pad 22b against the disc rotor 10. As a result, the front wheel 7 has the brake lever 5a and the master cylinder 5
In addition to b and the braking force generated by the first cylinder 14 and the like, a strong braking force generated by the rotational force of the disk rotor 10 is applied via the second cylinder 15 to the front wheel 7. On the other hand, an excellent braking ability can be obtained. Further, when the brake lever 5a is released, the hydraulic pressure applied by the master cylinder 5b is released, and the caliper 12 is returned to the steady position by the return spring 6c.
2a and 22b are separated from the disc rotor 10 and the braking force is released.

In the above-described embodiment, the case where the caliper having the piston is used only at the position facing the surface of the disc rotor 10 has been described as an example, but the both sides of the disc rotor 10 are opposed to each other. The present invention is also applicable to the case of using a so-called opposed piston type caliper having a piston. Further, the present invention is not limited to braking the front wheel 7, but can be applied to a braking device that brakes the rear wheel, and the present invention is not particularly limited to the above embodiment. Absent.

[0023]

As described above, according to the braking device for a motorcycle of the present invention, the braking force for the wheel is generated by using the rotational force of the wheel, so that the brake operating portion, the master cylinder, etc. It is possible to obtain a strong braking force without increasing the size of the vehicle and to obtain an excellent braking ability.

[Brief description of drawings]

FIG. 1 is an explanatory side view showing a motorcycle to which an embodiment of the present invention is applied.

FIG. 2 is a partially longitudinal side view showing a main part according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line XX of what is shown in FIG.

FIG. 4 is an operation explanatory view of what is shown in FIG.

FIG. 5 is an explanatory view of the operation of what is shown in FIG.

[Explanation of symbols]

 6 front fork 7 wheel 10 disc rotor 12 caliper 13 caliper body 14 first cylinder 14a large chamber 14b small chamber 15 second cylinder 16 first piston 16a front piston (front part) 16b rear piston (rear part) 17 Second piston 22a Brake pad 22b Brake pad

Claims (1)

[Claims] 1. A wheel is urged by frictional force generated between the brake pad and the disc rotor by pressing the brake pad against the side surface of the disc rotor fixed to the wheel rotatably supported by the fork of the motorcycle. In the motorcycle braking device adapted to apply braking to the caliper, the caliper is supported on the caliper main body so as to be capable of advancing and retracting with respect to the fork along a surface direction intersecting with a rotation axis of the wheel. A first cylinder which is provided and through which oil is supplied and sucked in association with the reciprocating movement of the brake operating portion, and a first pad which is inserted into the first cylinder so as to be able to advance and retreat, and a brake pad is brought into contact with the disc rotor when advancing A first piston is provided on the caliper body, communicates with the first cylinder, and is internally opened. And a second piston that is inserted into the second cylinder so as to be able to move forward and backward and that is elastically held at a position facing the fork so that one end thereof projects. The first piston is composed of a front portion having a front end holding a brake pad, and a rear portion having a cross-sectional shape smaller than the rear end surface of the front portion. A small chamber in which a side surface of a rear portion of the first piston is slidably tightly fitted, and a large chamber in which a front portion of the first piston is slidably tightly fitted are formed. The second cylinder is made to communicate with the shape chamber, the brake pad and the disc rotor are brought into contact with each other by the advance of the first piston, and the caliper main body is advanced together with the brake pad toward the fork. Brake pad by the first piston by abutting one end of the ton on the fork and moving it toward the inside of the second cylinder to force the oil from the second cylinder to the large chamber of the first cylinder. A braking device for a motorcycle, wherein the pressure contact force between the wheel and the disc rotor is increased to increase the braking force applied to the wheel.