JP2521631Y2 - Disc brakes for vehicles - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake mounted on a bar handle vehicle such as a motorcycle.

[0002]

2. Description of the Related Art Generally, a disc brake for a bar handle vehicle is hydraulically applied to a master cylinder by rotating a brake lever provided at one end of the bar handle as shown in, for example, Japanese Patent Laid-Open No. 60-222384. This hydraulic pressure is supplied to the hydraulic pressure chamber of the caliper supported by the front fork, the piston is moved in the direction of the disc rotor, and the disc pad is pressed by the friction pad to perform the braking action.

By the way, in a vehicle disc brake,
During braking, the disc rotor entry side of the friction pad is strongly pulled in by the rotation of the disc rotor, causing more wear than the disc rotor exit side, which is so-called leading wear.

Therefore, for example, Japanese Patent Laid-Open No. 1-295032
, A plurality of cylinder holes arranged side by side in the circumferential direction of the disc rotor in the caliper are used to reduce the diameter of the cylinder hole on the turn-in side of the disc rotor and to arrange it on the turn-out side. Has a large diameter, and the surface pressure on the inflow side of the friction pad is lower than the surface pressure on the outflow side to reduce uneven wear of the friction pad.

[0005]

However, in the above-mentioned structure, the same hydraulic pressure is supplied from one master cylinder to the cylinder hole on the disk rotor inflow side and the cylinder hole on the outflow side. The moving amount of the piston fitted in the small diameter cylinder hole is larger than the moving amount of the piston fitted in the large diameter cylinder hole on the shunting side. Touch the rotor,
Since the feed side and the feed side do not contact at the same time, there is a problem that uneven wear of the friction pad cannot be effectively prevented.

Therefore, an object of the present invention is to provide a vehicle disc brake which reduces uneven wear due to the leading action of the friction pad.

[0007]

According to the above-mentioned object, the present invention rotatably supports a brake lever at one end of a bar handle, and the hydraulic pressure generated in a master cylinder by the rotation of the brake lever is In a disk brake for a vehicle, which is supplied to a plurality of cylinder holes arranged side by side in the circumferential direction of a disk rotor of a caliper to perform a braking action, a first master cylinder is provided at a position near a rotation fulcrum of the brake lever.
The second master cylinders are respectively arranged at distant positions, and at positions close to the rotation fulcrum of the brake lever,
A first pushing portion that pushes the piston of the first master cylinder and a second pushing portion that pushes the piston of the second master cylinder are formed at distant positions, respectively, and the disc rotor of the caliper is rotated. The cylinder hole arranged on the side of the disk rotor and the first master cylinder are connected to the cylinder hole arranged on the delivery side of the disk rotor, and the second master cylinder, respectively. It is characterized in that an adjuster is provided which is capable of changing the contact position between the first pushing portion and the second pushing portion and each piston.

[0008]

According to this structure, since the lever ratio of the first pushing portion and the second pushing portion of the brake lever is different, the hydraulic pressure generated in the first master cylinder is greater than the hydraulic pressure generated in the second master cylinder. The amount of the hydraulic fluid supplied from the first master cylinder to the cylinder hole on the disc rotor feed-in side is supplied from the second master cylinder to the cylinder hole on the disc rotor feed-out side. It can be smaller than the amount of hydraulic fluid.

Therefore, by adjusting the movement amount of the piston fitted in the cylinder hole on the disk rotor entry side and the piston fitted in the cylinder hole on the disk rotor entry side, the friction pad and the entry side of the friction pad are adjusted. It is possible to bring the disc rotor into contact with the disc rotor at the same time as the delivery side or the delivery side earlier than the delivery side, and the friction pad pressing force of the piston on the disc rotor delivery side can be applied to the disc rotor on the delivery side. Since the pressure can be made lower than the pressing force, it is possible to reduce uneven wear of the friction pad, which is caused by the fact that the turning-in side of the disc rotor is strongly pulled in by the rotation of the disc rotor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a vehicle disc brake having an opposed piston type caliper will be described with reference to the drawings.

A disc brake 1 of a motorcycle has a master cylinder body 3 attached to one end of a bar handle 2.
First master cylinder 3a and second master cylinder 3b
And the brake hoses 6a and 6b from the master cylinders 3a and 3b are rotatably supported by the brake lever 5 that pushes the pistons 4a and 4b inserted in the master cylinders 3a and 3b. , Is connected to a caliper 7 supported by a front fork (not shown).

The master cylinder body 3 has a lever bracket 3c extending to the outside of the front of the vehicle body, and a brake lever 5 is rotatably supported on the lever bracket 3c by a vertical pivot shaft 8.

Further, the master cylinder body 3 is provided with a first master cylinder 3a at a position near a rotation support shaft 8 which is a rotation support point of the brake lever 5, and a bar handle 2 at a far position.
The second master cylinder 3b on each side and the bar handle 2
And the reservoir 3d is provided above them.

Cylinder hole 3e of the first master cylinder 3a
And the cylinder hole 3f of the second master cylinder 3b are formed to have the same diameter, the piston 4a for hydraulic pressure generation is formed in the cylinder hole 3e of the first master cylinder 3a, and the cylinder hole 3f of the second master cylinder 3b is formed. Piston 4b for hydraulic pressure generation
Are respectively inserted to define hydraulic chambers (not shown) between the tip ends of the pistons 4a and 4b and the bottom portions of the cylinder holes 3e and 3f, and the rear ends thereof are projected to the outside of the vehicle body. Brake hose connecting portions 3g and 3h are formed on the vehicle body center side of the master cylinder 3a and the second master cylinder 3b.

The brake lever 5 extends from the rotary support shaft 8 to the outside of the vehicle body, and the brake lever 5 extends from the rotary support shaft 8 toward the center of the vehicle body and contacts the side portion of the master cylinder body 3 when not in operation. It has a stopper portion 5b in contact with it, and a first pushing portion 5c and a second pushing portion 5d extending from the rotation support shaft 8 to the bar handle 2 side.

The first pushing portion 5c is a cam-like member disposed in a recess 5e formed in the vicinity of the shaft 8 of the brake lever 5 and rotatably supported by the shaft 8, and the tip thereof is the first master cylinder. The piston 3a is in contact with the rear end surface of the piston 4a, and the retreat limit is regulated by the adjusting bolt 5f.

The second pushing portion 5d is an arm portion 5g extending toward the bar handle 2 side of the first pushing portion 5c, and an adjusting bolt 5h is screwed to the arm portion 5g. It is in contact with the rear end surface of the piston 4b of the master cylinder 3b.

Therefore, the first pushing portion 5c uses the adjusting bolt 5f, and the second pushing portion 5d uses the adjusting bolt 5h.
By screwing each of them, the contact position with the piston 4a and the piston 4b can be changed, and the invalid stroke of the piston 4a and the piston 4b is adjusted.

On the other hand, the caliper 7 has a pair of caliper halves 10 on both sides of a disk rotor 9 which rotates integrally with the wheels.
In the caliper halves 10 and 11, two cylinder holes 10a, 10b, 11a and 11 are arranged in the circumferential direction of the disc rotor 9, respectively.
b are provided side by side.

Further, both caliper halves 10 and 11 have cylinder holes 10a and 11a on the entry side of the disc rotor 9, respectively.
Cylinder holes 10b and 11b are provided on the delivery side of the disk rotor 9.
Are opposed to each other, and both side portions of the bridge portions 10c and 11c straddling the outer periphery of the disk rotor 9 are connected by connecting bolts 12, respectively.

Each cylinder hole 10a, 10b, 11a, 1
1b is formed with the same diameter, and pistons 13a, 13b, 14
a and 14b are liquid-tightly and movably fitted,
Hydraulic chambers 15a, 15b, 16a, 16b are defined between the pistons 13a, 13b, 14a, 14b and the bottoms of the cylinder holes 10a, 10b, 11a, 11b.

A connecting portion 17a of the brake hose 6a is provided at the bottom of the cylinder hole 10a, a connecting portion 17b of the brake hose 6b is provided at the bottom of the cylinder hole 10b, and the hydraulic chamber 15a and the hydraulic chamber 15a are connected to each other. The pressure chamber 16a and the hydraulic chamber 15b are connected to each other by a communication pipe 18 and a communication pipe 19, respectively.

Then, the disk rotor 9 and the piston 13
a, 13b, and between the disc rotor 9 and the piston 1
A pair of friction pads 20 and 20 are provided between the friction pads 4a and 14b.
Is suspended by a hanger pin 21 temporarily provided in the bridge portions 10c and 11c so as to be movable in the axial direction of the disc rotor 9.

With this structure, when the grip portion 5a of the brake lever 5 is gripped and the brake lever 5 is rotated about the rotation support shaft 8, the first pushing portion 5c of the brake lever 5 is moved. Piston 4a of first master cylinder 3a
The second pushing portion 5d pushes the pistons 4b of the second master cylinder 3b, and the brake hydraulic fluid from the first master cylinder 3a causes the hydraulic fluid chambers 15a and 16a of the caliper 7 on the disc rotor 9 rotation side. The second master cylinder 3b
Brake fluid from the disc rotor 9 of the caliper 7
It is supplied to the hydraulic chambers 15b and 16b on the delivery side, respectively.

At this time, in the first pushing portion 5c and the second pushing portion 5d of the brake lever 5, the lever ratio of the first pushing portion 5c is lower than that of the second pushing portion 5d. The hydraulic pressure of the brake hydraulic fluid supplied from the first master cylinder 3a is lower than the hydraulic pressure of the brake hydraulic fluid supplied from the second master cylinder 3b, and the amount of the hydraulic fluid is small.

Therefore, the disk rotor 9 of the caliper 7
The delivery side pistons 13b and 14b move to the disc rotor 9 side earlier than the delivery side pistons 13a and 14a, and the delivery side of the friction pads 20 and 20 moves to the disc rotor 9 side before the delivery side. Press on the side.

The pressing force with which the pistons 13a, 14a of the caliper 7 on the entry side of the disk rotor 9 press the entry side of the friction pads 20, 20 against the side surface of the disk rotor 9 is:
Since it is lower than the pistons 13b and 14b on the feed side, the surface pressure on the feed side of the friction pads 20, 20 is lower than the surface pressure on the feed side.

Therefore, the entry side of the friction pads 20, 20 is not strongly pulled in by the rotation of the disk rotor 9, and uneven wear due to the so-called leading action can be reduced.

In this embodiment, the first master cylinder 3
a and the second master cylinder 3b have the same diameter, and the cylinder holes 10a, 11 on the side of the caliper 7 on which the disk rotor 9 is inserted.
Since the cylinder holes 10b and 11b on the delivery side and the delivery side have the same diameter, the delivery side of the friction pads 20 and 20 press against the side surface of the disk rotor 9 before the delivery side, but the first master cylinder 3a The diameter is larger than that of the second master cylinder 3b, or the cylinder holes 10a and 11a of the caliper 7 on the disk rotor 9 turn-in side are moved to the discharge side cylinder holes 10b and 11b.
The friction pad 20,
It is possible to simultaneously press the turn-in side and the turn-out side of 20 against the side surface of the disc rotor 9.

Further, although the present embodiment has been described as being applied to a vehicle disc brake having a piston facing type caliper, the present invention has a caliper having a plurality of cylinder holes arranged side by side in the circumferential direction of the disc rotor. Needless to say, the present invention can be applied to, for example, a pin slide type.

[0031]

As described above, according to the present invention, the first master cylinder is located closer to the pivot fulcrum of the brake lever rotatably supported at one end of the bar handle, and the second master cylinder is located farther from the pivot fulcrum. With each of the
A first pusher for pushing the piston of the first master cylinder at a position close to the pivot of the brake lever;
Cylinders each having a second pushing portion for pushing the piston of the second master cylinder formed at a distant position, and arranged on the disc rotor entry side of a plurality of cylinder holes arranged side by side in the circumferential direction of the disc rotor of the caliper. Since the hole and the first master cylinder are connected to the cylinder hole arranged on the disk rotor feeding side and the second master cylinder, respectively,
Since the lever ratios of the first pushing portion and the second pushing portion of the brake lever are different, the hydraulic pressure generated in the first master cylinder can be made lower than the hydraulic pressure generated in the second master cylinder. The amount of hydraulic fluid supplied from the first master cylinder can be made smaller than the amount of hydraulic fluid supplied from the second master cylinder.

Therefore, by adjusting the movement amounts of the piston fitted in the cylinder hole on the disc rotor entry side and the piston fitted in the cylinder hole on the disc rotor entry side, the friction pad and the entry side of the friction pad are adjusted. It is possible to bring the disc rotor into contact with the disc rotor at the same time as the delivery side or the delivery side earlier than the delivery side, and the friction pad pressing force of the piston on the disc rotor delivery side can be applied to the disc rotor on the delivery side. Since the pressure can be made lower than the pressing force, it is possible to reduce uneven wear of the friction pad, which is caused by the fact that the turning-in side of the disc rotor is strongly pulled in by the rotation of the disc rotor.

[Brief description of drawings]

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

FIG. 2 is an enlarged partial plan view of the master cylinder portion of FIG.

FIG. 3 is an enlarged partial plan view of the caliper of FIG.

[Explanation of symbols]

1 ... Vehicle disc brake, 2 ... bar handle, 3 ...
Master cylinder body, 3a ... first master cylinder, 3
b ... 2nd master cylinder, 3c ... Lever bracket, 4
a ... Piston of first master cylinder, 4b ... Piston of second master cylinder, 5 ... Brake lever, 5c ... First
Pushing portion, 5d ... Second pushing portion, 5f, 5h ... Adjust bolt, 6a, 6b ... Brake hose, 7 ... Caliper, 8
... Rotating support shaft, 9 ... Disk rotor, 10a, 10b, 1
1a, 11b ... Cylinder holes, 13a, 13b, 14a,
14b ... Piston

Claims (2)

(57) [Scope of utility model registration request] 1. A brake lever is rotatably supported at one end of a bar handle, and a plurality of hydraulic pressures generated in a master cylinder by the rotation of the brake lever are arranged side by side in a circumferential direction of a disc rotor of a caliper. In a vehicle disc brake that supplies a braking action to a cylinder hole, a first master cylinder is arranged at a position near a rotation fulcrum of the brake lever, and a second master cylinder is arranged at a position far from the rotation fulcrum of the brake lever. A first pushing portion for pushing the piston of the first master cylinder, and a second pushing portion for pushing the piston of the second master cylinder at a far position from the rotation fulcrum. A cylinder hole arranged on the disc rotor turning-in side of the caliper and the first master cylinder arranged on the disc rotor turning-out side A disc brake for a vehicle, wherein a hole and the second master cylinder are connected to each other. 2. A disc brake for a vehicle according to claim 1, further comprising an adjuster capable of changing a contact position between each piston and the first pushing portion and the second pushing portion.