JPH06122866A - Abrasive material - Google Patents

Abstract

PURPOSE:To obtain the abrasive material capable of sufficiently resisting to high load braking on various races, etc., excellent in durability and wear resistance, low in its attacks to rotors, and reduced in abrasive wear. CONSTITUTION:This metallic abrasive material containing metal fibers such as steel fibers as a substrate and containing a thermosetting resin as a binder is characterized by compounding one kind or of antimony, bismuth, and their oxides in an amount of 5-30wt.% based on the metal fiber substrate in order to lower the counter material-attaching property of the abrasive material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction material having excellent wear resistance, which can be used as a high load friction material such as for a racing car, and particularly to a disc rotor as a mating material. Friction material with low aggression.

[0002]

2. Description of the Related Art As automobiles become faster and more sophisticated, the level of performance required for brakes also rises, and
The carcinogenicity of asbestos has also become clear, and it is difficult to deal with the conventional friction material made of a composite material based on asbestos. Furthermore, in a racing car, etc., the braking load is high, so the temperature of the friction material is only 700-800.
The temperature rises above ℃, and after a few braking operations, the conventional asbestos-based friction material is worn out and becomes useless at all.
As such a high load friction material, there is a C / C composite material for racing cars such as Formula 1, but it is extremely expensive and the coefficient of friction at low temperature is extremely low, so temperature maintenance is required. There are drawbacks such as

On the other hand, similar to the asbestos-based friction material, a phenolic thermosetting resin such as a phenolic resin or a phenol-modified resin and an imide thermosetting resin are used as the binder. , A steel fiber, and an inorganic or metallic friction and wear modifier added to this semi-metallic friction material is much more heat-resistant and wear-resistant than asbestos-based friction material. It is excellent and has been attracting attention.

The friction performance of such a friction material is determined by the ratio of the steel fiber as the base material and the friction and wear modifier blended with the base material. Abrasives such as quartz and barium sulfate,
Inorganic filler such as calcium carbonate, high hardness metal, etc.
In general, the desired frictional performance is produced by blending with a lubricant made of cashew dust, graphite, a soft metal such as copper or brass.

However, in order to improve the braking effectiveness and wear resistance, if the mixing ratio of steel fibers, abrasives, and other substances with high hardness increases, the rotor surface, which is a mating material, will cause these friction materials to come out in a predetermined amount. A frictional body such as a brake pad obtained by molding into a shape reduces the braking performance and shortens the life of the rotor. Abrasive (abrasiv)
e) There is a risk of causing a vicious cycle of causing wear and further lowering the friction performance.

[0006]

An object of the present invention is to provide a friction material which can sufficiently withstand a high load such as in various races, has excellent durability and wear resistance, has low rotor attack, and has less abrasive wear. The purpose is to do.

[0007]

The first gist of the present invention is a semi-metallic friction material containing a metal fiber as a base material and a thermosetting resin as a binder, which is selected from antimony, antimony oxide, bismuth and bismuth oxide. The friction material is characterized by containing 5 to 30% by weight of the weight of the metal fiber in order to reduce the attacking property of the mating material of the friction body.

A second aspect of the present invention is a semi-metallic friction material containing a metal fiber mainly composed of steel fiber as a base material and a thermosetting resin as a binder, which is selected from cobalt, nickel, tin and lead. For one or more metals,
One containing at least one substance selected from antimony, antimony oxide, bismuth, and bismuth oxide was added in an amount of 5 to 40% by weight based on the weight of the metal fiber in order to reduce the attacking property of the friction material of the friction material. The friction material is characterized by extremely little occurrence of abrasive wear. The details will be described below.

The friction material of the present application uses metal fibers as a base material.
20 to 65% by weight based on the total weight of the friction material, as a binder,
It contains 7 to 15% of thermosetting resin. Examples of the metal fiber include steel fiber, copper fiber, brass fiber, stainless fiber and the like. As the thermosetting resin, various modified phenol resins and polyimide resins such as bismaleimide triazine resin are used. In addition to the above, various substances commonly used as friction and wear modifiers are mixed according to the specifications required for the friction material. Examples of these friction and wear modifiers include organic fillers such as rubber and cashew dust, inorganic fillers such as barium sulfate and calcium carbonate, solid lubricants such as graphite and molybdenum disulfide, and alumina. An abrasive such as chromium oxide or quartz can be used.

The characteristic feature of the friction material of the present invention is that, in such a constitution, for the purpose of lowering the attacking property of the friction material of the friction material, the above-mentioned substances centered from metal antimony, antimony oxide, metal bismuth, and bismuth oxide are mixed. Its use is as a content. These substances are used in the form of powder, foil or other friction material that can be uniformly dispersed. The amount used is 5 to 30% of the weight of the metal fiber as the base material.
The intended purpose can be achieved by blending to some extent. Antimony trioxide and antimony pentoxide are used as antimony oxide.

In particular, when steel fiber or steel fiber is mainly used as the base material, it is selected from cobalt, nickel, tin and lead together with these metal antimony, metal bismuth, antimony oxide and bismuth oxide. The coexistence of the above metals facilitates formation of a protective film containing these metals on the surface of the cast iron rotor, which is a mating member, and is more effective in suppressing the aggression of the rotor by the friction material. The amount of these metals used is 1 to 10% of the weight of the steel fiber as the base material.
If added within the range of, the desired effect can be obtained.

Using a friction material composed of a mixture containing the above-mentioned substances, a friction body is obtained by the same method as a conventional resin mold type friction body (disk pad, brake lining). is there. A friction body constituted by the friction material of the present application, when used in a high load state, forms a heat-resistant alloy with a fibrous metal fiber base material and one or more of antimony, bismuth, antimony oxide, and bismuth oxide at high temperature. However, it is presumed that the properties of the metal fiber base materials including steel fibers and the abrasives change, and the aggressiveness to the mating surface is remarkably alleviated.

The formation of this alloy layer becomes more remarkable when one or more metals selected from cobalt, nickel, tin and lead coexist. Since the alloy layer is formed on the contact surface with the mating material, it has the effect of smoothing the friction surface and improving the wear resistance of the contact surfaces of both the rotor and the friction body. In the above, the compounding amount of one or more of antimony, bismuth, antimony oxide and bismuth oxide is 2%.
In the following, the effect is practically difficult to recognize, and 30%
As described above, the desired effect is gradually reduced, and if the compounding ratio is further increased, the effect of reducing the aggressiveness of the mating material is rapidly reduced and the friction coefficient is also reduced. Examples will be given below.

[0014]

Example 1 Powders of the substances shown in Table 2 were added to a brake material having a composition as shown in Table 1 to prepare a disc pad based on a conventional dry manufacturing method, and abrasion resistance was measured with a single brake dynamometer. Tested. The measurement is
With the pressing force of the inertia and pad kept constant, the rotation speed of the rotor, that is, the vehicle speed from 200 Km / hr to a low speed of 50 K
The braking operation for dropping to m / hr was performed 50 times at the same rotor temperature to measure the amount of wear, and the average value thereof was obtained, and changes in the surfaces of the rotor and the friction pad were observed. All percentages mean percent by weight.

[0015]

[Table 1] ------------------ Modified phenolic resin 8% Steel fiber 45% Abrasive material 4 % Organic-inorganic filler, lubricant Amount to make 100% of the whole ---------------------------------------------

[0016]

[Table 2] -------------------------------------------- Antimony compounding amount Rotor temperature Wear amount Rotor surface friction Coefficient (%) (° C) (mm) Roughness average −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 0 3500 0.023 +++ 0.354 2 350 0.025 ++ 0.317 5 350 0.028 − 0.315 (5) 350 0.029 − 0.301 10 350 350 0.028 − 0.324 (10) 350 0.0. 031-0.315 15 350 350 0.027-0.328 (15) 350 0.032-0.300 20 350 350 0.025-0.303 30 350 350 0.036-0.298 40 350 0.048 ++ 0. .250 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−− -----

In the above table,-: Shallow concentric wear marks on the surface of the rotor is 50% or less, +: Shallow record disc-shaped concentric wear marks are recognized on almost the entire surface of the rotor, ++: Shallow record plate formed on the entire surface of the rotor The thick groove-shaped wear marks represent less than about 30% of the thick groove-shaped concentric wear marks, and ++: about 30% or more of the thick groove-shaped concentric wear marks. The numbers in parentheses are metal instead of antimony oxide. The case where antimony is used is shown. As is clear from the above results, the friction material of the present invention containing antimony oxide and metal antimony has a markedly low attack on the rotor, which is the mating material.

[0018]

[Example 2] Powders of the substances shown in Table 4 were added to a brake material having a composition as shown in Table 3 to prepare a disc pad based on a conventional dry production method, and the disc pad was made to have an abrasion resistance by a single brake dynamometer. Tested. The measurement is
With the pressing force of the inertia and pad kept constant, the rotation speed of the rotor, that is, the vehicle speed from 200 Km / hr to a low speed of 50 K
The braking operation for dropping to m / hr was performed 50 times at the same rotor temperature to measure the amount of wear, and the average value thereof was obtained, and changes in the surfaces of the rotor and the friction pad were observed. All percentages mean percent by weight.

[0019]

[Table 3] ------------------ Modified phenol resin 9% Steel fiber 45% Copper fiber 5 % Abrasives 4% Organic-inorganic fillers, lubricants 100% of the total amount ---------------------------------------- ---

[0020]

[Table 4] ------------------------------------------------------------------------------------------------------------------------------------------------------------- Bismuth oxide compounding amount Rotor temperature Wear amount Rotor surface friction Coefficient (%) (° C) (mm) Roughness average −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 0 3500 0.026 +++ 0.342 5 350 350 0.027-0.343 15 350 350 0.028-0.318 25 350 350 0.032-0.300 35 350 0.0038+ 0.248 Bi ₂ O ₃ (15%) , Co (5%) 350 0.023-0.367 Bi ₂ O ₃ (35%), Ni (5%) 350 0.032-0.338 --------------------- −−−−−−−−−−−−−−−−−−−−

In Table 4,-: shallow concentric wear streaks of 50% or less on the surface of the rotor, +: shallow record disc-shaped concentric wear streaks on almost the entire surface of the rotor, ++: shallow generated on the entire surface of the rotor The record disc-shaped wear streaks represent thick groove-shaped concentric wear streaks of less than about 30%, and ++: thick groove-shaped concentric wear streaks of about 30% or more, respectively. As is clear from the above results, by adding bismuth oxide, the aggressiveness to the rotor, which is the mating material, decreases, and by incorporating cobalt, etc., the rotor aggressiveness reducing effect and the friction coefficient Improvement effect can be seen.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyoshi Kobayashi 1091 Nagatoro, Saku City, Nagano Prefecture MK Kashiyama Co., Ltd.

Claims (5)

[Claims] 1. In a semi-metallic friction material containing a metal fiber as a base material and a thermosetting resin as a binder, one or more substances selected from antimony, antimony oxide, bismuth and bismuth oxide are added to a friction body. A friction material comprising 5 to 30% by weight of the weight of the metal fiber in order to reduce the aggressiveness of the mating material. 2. A metal fiber comprising steel fiber or steel fiber as a main component, and one or more of copper fiber, brass fiber and stainless fiber added thereto.
Friction material. 3. A semi-metallic friction material containing a metal fiber mainly composed of steel fiber as a base material and a thermosetting resin as a binder, wherein at least one metal selected from cobalt, nickel, tin and lead is added, One containing at least one substance selected from antimony, antimony oxide, bismuth, and bismuth oxide was added in an amount of 5 to 40% by weight based on the weight of the metal fiber in order to reduce the attacking property of the friction material of the friction material. Friction material characterized by 4. The friction material according to claim 3, wherein one or more kinds of metals selected from cobalt, nickel, tin and lead are blended in an amount of 1 to 10% of the steel fiber base material. 5. The friction material according to claim 1, wherein the metal fibers are contained in an amount of 20 to 65% by weight based on the total weight of the friction material.