JPH08226478A - Disk brake - Google Patents

Abstract

PURPOSE: To set and control the coefficient of friction freely without being affected by a base material by fixing a frictional material on the surface of a brake disk in those areas where a brake pad is contacted so as to form a braking surface. CONSTITUTION: A countersunk part 12 formed in a brake disk 5 is formed larger than the head part 4a of a bolt 4 so as to form a clearance 13. Also a braking surface 6 is formed concentrically in the sliding area of a brake pad 8, and structured with a frictional material 14. The composition of the frictional material 14 is determined by the combination with the brake pad material. In either case of the same system composition and different system composition, consideration must be paid so that a coefficient of friction required between a braking surface and the brake pad is produced. In the same system, a component ratio is varied between the braking surface and the brake pad so as to control the coefficient of friction. Also, in the combination of different compositions, for example, when the brake pad is made of sintered alloy, the braking surface is formed with non-metal material so as to control the coefficient of friction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake used for motorcycles, automobiles and the like.

[0002]

2. Description of the Related Art Disc brakes having a brake disc sandwiched between a pair of brake pads are known, in which a steel ring is attached to the surface of a brake disc made of, for example, aluminum to improve the wear resistance of the braking face. Is. Further, JP-A-59-173234 discloses a material in which ceramic powder is dispersed in an aluminum alloy of a brake disk to improve wear resistance.

[0003]

By the way, when the above-mentioned steel ring is provided, the friction coefficient of the brake disk can be partially changed, but on the other hand, the weight is increased and the ring is separated due to long-term use. May occur.

On the other hand, according to the above-mentioned Japanese Patent Laid-Open Publication No. Sho, although such a problem is solved, since the ceramic is simply dispersed in the base material, it is strongly affected by the properties of the base material and the braking surface is independent of the base material. The friction coefficient cannot be freely set.

When the brake disk is made of aluminum alloy, the heat resistance during braking must be greatly improved, but this is extremely difficult. Then, this application aims at the solution of such a subject.

[0006]

In order to solve the above problems, the disk brake according to the present invention is characterized in that a friction material is fixed to the surface of the brake disk in the range where the brake pad slides to form a braking surface. And

At this time, the friction material forming the braking surface of the brake disk and the friction material forming the brake pad can have the same composition.

[0008]

Since the braking surface is made of a friction material, the friction coefficient of the braking surface can be freely set without being influenced by the base material. Further, the friction coefficient can be arbitrarily controlled by each combination of the friction material on the braking surface and the friction material on the brake pad.

At this time, if the friction material constituting the braking surface of the brake disc and the friction material constituting the brake pad have the same composition, even if the friction material of the brake pad adheres to the braking surface during braking, Since the composition of the side friction material is the same, the friction coefficient can be stabilized over a long period of time.

Moreover, since the friction material of the braking surface maintains the wear resistance, the base material can be made of a lightweight material such as aluminum alloy.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment configured for a motorcycle will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of a wheel. Brake discs 5 are attached to the left and right sides of a hub 3 provided at the center of a rim 2 having a tire 1 mounted on the outer periphery thereof in pairs by a bolt 4 on the left and right sides. There is. The brake disc 5 is made of aluminum alloy.

A braking surface 6 is formed on the outer peripheral side of the brake disk 5, and a brake pad 8 of a brake caliper 7 is slidably contactable so as to sandwich the brake pad 8 from the front and back.

FIG. 2 shows the brake disk 5 shown in FIG.
4 is an enlarged cross-sectional view of a part of FIG. 3, and FIG. 3 is a side view of only the brake disk 5.

As is apparent from these figures, the mounting hole 10 for passing the bolt 4 for mounting the brake disc 5 to the hub 3 is a long hole extending in the radial direction, and the inner periphery of the bolt 4 and the mounting hole 10 at the time of mounting. A clearance 11 is formed between the side line portion.

The counterbore 12 formed on the brake disk 5 is also formed to be larger than the head 4a of the bolt 4,
A similar clearance 13 is formed.

The braking surface 6 is formed concentrically within the sliding contact area of the brake pad 8 and is composed of a friction material 14 (FIG. 2).

The friction material 14 is prepared by treating an appropriate material such as phenol resin, metal fiber such as copper, carbon, glass powder, ceramic powder and the like by a known appropriate production method such as a dry method, a wet method and a molding method, This is fixed by a suitable means such as adhesion, coating or thermal spraying, preferably with a thickness of about 10 to 20 μm.

When the composition of the friction material 14 is selected, it is determined by the combination with the material of the brake pad 8, and there are combinations of the same system composition and different compositions, both of which are between the braking surface 6 and the brake pad 8 during braking. Care is taken to produce the required coefficient of friction.

In the case of the same system, the friction coefficient can be further controlled in various ways by changing the component ratio between the braking surface 6 and the brake pad 8.

In the case of a combination of different compositions, for example, when the brake pad 8 is made of a sintered metal, the braking surface 6 can be made to have a non-metallic composition such as carbon or phenol resin, and the same control of the friction coefficient can be realized. To do.

Further, as shown in FIG. 2, if a concave portion 15 such as a concentric circular groove is formed on the surface of the brake disk 5 forming the braking surface 6 to form an uneven surface, the friction material 14 is fixed to the brake disk 5. Can be made more powerful. In FIG. 2, the thickness of the braking surface 6 and the size of the recess 15 are exaggerated.

Next, the operation of this embodiment will be described. When the brake pad 8 is pressed against the braking surface 6 for braking, the brake pad 8 comes into sliding contact with the friction material 14 forming the braking surface 6 to generate friction. At this time, the friction coefficient is determined between the brake pad 8 and the braking surface 6 regardless of the brake disc 5.

Therefore, the brake pad 8 and the braking surface 6
If a predetermined coefficient of friction is generated by selecting the material of No. 3, there will be no problem in terms of wear resistance and heat resistance of the brake disk 5. Therefore, the brake disc 5 made of a lightweight aluminum alloy can be used.

Moreover, by appropriately changing the composition of the braking surface 6 and the brake pad 8 or the combination thereof, the friction coefficient can be controlled arbitrarily regardless of the brake disc 5. Therefore, the brake disk 5 can be determined mainly by physical properties such as weight and rigidity without being restricted by the friction coefficient.

In addition, the braking surface 6 of the brake disc 5
If the friction materials of the brake pad 8 and the brake pad 8 have the same composition, even if the friction material of the brake pad 8 adheres to the braking surface 6 at the time of braking, the friction material 14 on the braking surface side has the same composition, so that the friction is maintained for a long time The coefficient can be stabilized.

In this embodiment, the brake disc 5 is made of aluminum alloy having a large coefficient of thermal expansion, but the mounting hole 1
0 is a long hole that is long in the radial direction, and mounting hole 10 and counterbore 1
Since the clearances 11 and 13 are provided in 2, the bolt 4 is not subjected to shearing force even when the brake disk 5 is thermally expanded during braking, and as a result, deformation of the mounting portion can be prevented.

The present invention is not limited to the above-mentioned embodiment and can be applied in various ways. For example, the brake disk 5 can be appropriately changed to a light alloy other than an aluminum alloy, a metal such as steel, or a non-metal such as carbon fiber. .

[0028]

In the disk brake according to the present invention, since the braking surface is formed of the friction material, the friction coefficient can be freely set without being influenced by the base material by each combination of the friction material of the braking surface and the friction material of the brake pad. You can control it.

At this time, if the friction material forming the braking surface of the brake disk and the friction material forming the brake pad have the same composition, even if the friction material of the brake pad adheres to the braking surface during braking, Since the composition of the side friction material is the same, the friction coefficient can be stabilized over a long period of time.

In addition, since the abrasion resistance is maintained by the friction material on the braking surface, the base material can be made of a lightweight material such as aluminum alloy.

[Brief description of drawings]

FIG. 1 is a sectional view of a wheel according to an embodiment.

FIG. 2 is an enlarged partial sectional view of an essential part of the embodiment.

FIG. 3 is a side view of the brake disc according to the embodiment.

[Explanation of symbols]

3: hub, 4: bolt, 5: brake disc, 6: braking surface, 8: brake pad, 10: mounting hole, 14: friction material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyo Takahashi 1-4-1 Chuo, Wako City, Saitama Prefecture

Claims (2)

[Claims] 1. A disc brake comprising a braking surface formed by fixing a friction material to the surface of a brake disk in a range where a brake pad slides. 2. The disc brake according to claim 1, wherein the friction material forming the braking surface of the brake disc and the friction material forming the brake pad have the same composition.