JPH07174173A - Brake pad for disk made of aluminum alloy - Google Patents

Abstract

PURPOSE:To provide a brake pad with good wear resistance further with a high friction coefficient obtained for a brake disk made of aluminum alloy. CONSTITUTION:In a brake pad for an aluminum alloy-made disk, a heat and wear resistant aggregate and an extender are dispersedly buried in a base material composed of thermo-setting resin. As the heat and wear resistant aggregate, ceramics powder, consisting of one kind or more of Si or Al carbide, oxide, nitride, is used.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a brake pad used for an aluminum alloy brake disc.

[0002]

2. Description of the Related Art Pads for disc brakes are required to have high heat resistance and wear resistance because they reach a high temperature of 400 ° C. or higher, and locally reach 800 ° C. due to frictional heat. For this reason, conventionally, as the pad material, asbestos has been mainly used as a heat-resistant and abrasion-resistant aggregate, which is integrally combined with a thermosetting resin as a base material.

However, since asbestos has a problem in terms of occupational health, in recent years, instead of asbestos, a pad integrated with steel fibers as an aggregate has been used. On the other hand, in recent years, weight reduction of parts has been desired from the viewpoint of weight reduction of automobiles and energy saving, and brake discs have also been made of heat-resistant aluminum alloy. As such a heat-resistant aluminum alloy, there is an Al-Si powder alloy containing Si in an amount of about 13 wt% or more.
In the powder alloy, fine primary crystal Si is dispersed in the matrix,
Excellent high temperature characteristics such as heat resistance. Also, JP-A-62-47
Japanese Patent No. 448 discloses a heat resistant aluminum alloy powder containing 10 wt% or more of Fe in a supersaturated state. The powder alloy may be prepared by using the rapidly solidified powder alone or Si
It is manufactured by hot plastic working together with a dispersion strengthening material such as C powder to join and integrate the powders.

[0004]

The conventional pad integrally formed by using steel fibers as an aggregate is intended for a brake disc made of cast iron (FC25), and has no friction against a brake disc made of aluminum alloy. There is a problem that the coefficient is low and a sufficient braking torque cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a brake pad having good wear resistance and a high friction coefficient with respect to an aluminum alloy brake disc.

[0006]

An aluminum alloy disc brake pad according to the present invention is a brake pad in which a heat and abrasion resistant aggregate and an extender are dispersed and embedded in a base material made of a thermosetting resin. As the heat and wear resistant aggregate, a ceramic powder made of one or more of Si or Al carbides, oxides and nitrides is used.

[0007]

In the disk and the pad, after the abrasive wear (rubbing wear) occurs at the initial stage of friction, the friction film is subsequently formed. In the case of the pad of the present invention, the Si or Al-based hard ceramic powder is dispersed and embedded in the friction film formed between the disc and the aluminum alloy disc, and the film is strong and difficult to peel off. Therefore, the wear resistance is good and the friction coefficient is also improved. Moreover, since the ceramic powder as the heat and wear resistant aggregate is lightweight, it is possible to contribute to the weight reduction of the pad.

[0008]

Example A brake pad for an aluminum alloy disc according to the present invention is one in which a heat-resistant and abrasion-resistant aggregate and an extender are dispersed and embedded in a base made of a thermosetting resin. Barium sulfate is mainly used as the material, and phenol resin, epoxy resin or the like is used as the thermosetting resin. On the other hand, S is used as the heat and wear resistant aggregate.
Ceramic powder consisting of one or more of i, Al carbides, oxides, and nitrides, such as SiC, Al ₂ O ₃ ,
One or more powders of Si ₃ N ₄ are used. Regarding the particle size of the ceramic powder, fine powder is used so as to be dispersed and embedded in the friction film, and the average particle size is preferably 10 μm or less (preferably 5 μm or less). In addition to the above components, a lubricity improving material such as cashew dust or a friction coefficient improving material such as Kepler pulp may be added.

As in the conventional case, the amount of each powder compounded is 10 to 40 wt% for heat and abrasion resistant aggregate and 10 to 30 wt% for thermosetting resin.
The balance is composed of a filler. Incidentally, a lubricity improving material or a friction coefficient improving material can be appropriately mixed in place of a part of the filler. Next, specific examples will be given. As the heat and abrasion resistant aggregate, SiC powder (average particle diameter 5 μm) was used as an example or steel fiber was used as a conventional example.
wt%, barium sulfate 50 wt%, phenol resin 10 wt%, Kepler pulp 5 wt% and cashew dust 10 wt% were mixed and kneaded. This mixture was preformed and then hot pressed at 180 ° C. and 15 MPa to produce a pad sample. A friction test (slide test) was carried out by a pin-on-disk tester using the sample and a disk made of an aluminum powder alloy (Si: 27 wt%, the balance being substantially Al) to measure the friction coefficient. The test conditions are
The stress was 1 MPa and the disk rotation speed was 4 m / s. The results are shown in Table 1.

[0010]

[Table 1]

From Table 1, the embodiment is 350 compared with the conventional example.
Although the friction coefficient is low in the low temperature range of ℃ or less, in the temperature range of 400 ℃ or more which is the practical use condition of the pad, the embodiment has a larger friction coefficient than the conventional example and is stable. I understand. This is because the SiC dispersion pad according to the example has a substantially higher friction coefficient, and the friction film formed in the initial wear stage between the disk and the pad is stronger and has a larger contact area. Presumed. The embodiment is of course lighter than the conventional example.

[0012]

As described above, the aluminum alloy disc brake pad of the present invention uses, as the heat-resistant aggregate, a ceramic powder made of one or more of Si or Al carbides, oxides, and nitrides. , A predetermined ceramic powder is dispersed and embedded in the friction film formed between the aluminum alloy disc and the film, and the film is strong and difficult to peel off, so good wear resistance is obtained and friction is reduced. The coefficient also improves. Moreover, since lightweight ceramic powder is used, it is possible to contribute to weight reduction of the pad.

Claims (1)

[Claims] 1. A brake pad in which a heat and wear resistant aggregate and an extender are dispersed and embedded in a base material made of a thermosetting resin, wherein the heat and wear resistant aggregate is a carbide of Si or Al, an oxide. Brake pad for disc made of aluminum alloy, which is characterized by using a ceramic powder made of one or more kinds of oxides and nitrides.