JPS58147534A - Dry sintered friction material - Google Patents

Abstract

PURPOSE:To obtain a dry friction material having a high coefft. of friction and improved attacking properties to its opposite material, by providing a specified composition contg. CaF2 to a bronze type dry friction material. CONSTITUTION:The titled material contains, by weight, 60-80% Cu, 3-20% Sn, 3-20% metallic oxide consisting of hard particles with >=4 Moh's hardness, 3- 10% graphite, 1-5% MoS2 and <=10% CaF2. CaF2 has lubricity under high temp. frictional conditions and a remarkable effect of improving the attacking properties of the material to its opposite material. Accordingly, by adding an adequate amount of CaF2, a dry friction material having a high coefft. of friction and controlled attacking properties to its opposite material is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bronze-based dry sintered friction material, which has a friction mS number of ^<, and is improved by 4 in its aggressiveness against mating materials.

Conventionally, in asbestos-based dry friction materials including dry friction clutches and brakes, the coefficient of friction tends to decrease due to thermal fade phenomenon and water fade phenomenon. Bronze-based friction materials have a small decrease in friction % due to water fading, but have the drawback of having a lower coefficient of friction than the asbestos-based materials.

If the coefficient of friction is further increased by 1, on the other hand, it will cause more wear, so it is required to simultaneously decide on the contradictory direction of the above-mentioned inspection point pipe material composition.

The present invention has been made in the above-mentioned points, and is a dry tIIIia friction material made of a bronze-based sintered alloy, in which the sintered alloy has a weight ratio of 60 to 80 -1 copper and 3 to 2 -2 tin.
0%, Morse Ill! [Provide a 1ml material tube of the dry type JI, which consists of hard particles of 4 or more, including T-3~20-1 black 83~10, molybdenum 1-511 and 7 hard particles, including It's 4.

The concept of the dry sintered material of the present invention will be explained below.
I will explain.

The dry sintered friction material of the present invention uses bronze-based annealed gold as a matrix component.

Conventional asbestos-based friction materials have a high coefficient of friction, but
h for the aforementioned heat fade jIK and water fade configurations.
Iron-based OIIa materials have low resistance, and have the disadvantage of low rust resistance and M1 wear resistance.

From these points of view, the present invention focuses on a bronze-based matrix material KjI, whose composition is 60 to 80% copper and 3 to 80% tin in terms of weight ratio (the same applies hereinafter) of the total amount of sintered bronze material.
A range of 20% was selected.

The selection criteria for this range was based on consideration of the stability of the surface of the grinding surface. In other words, the amount of the bronze-based matrix material to be added is determined to be within the appropriate range in order to stabilize the coefficient of friction during braking and to prevent an increase in wear during cracking. It is.

Friend, the dry sintered friction material of the present invention contains, as a wear-resistant component, true oxide t3 consisting of hard particles with a Mohs hardness of f4 or higher.
~20- Contains. The metal oxide is appropriately selected from silica (810!), alumina (mutzos), mullite (3A4xon/2810maro), and the like. f, this content increases the coefficient of friction and
The effect of scraping off layer transfer and reaction products generated during friction is small. For this reason, a Mohs hardness of 4 or more is considered to be 10, and a range of 3 to 20 is selected because if there is too much, the opponent's active tube will attack radically.

Furthermore, the dry sintered friction material of the present invention contains graphite 3 to 101% as a lubricating component. Molybdenum disulfide (MO81) 1~
15- and calcium fluoride (CaFm) 10- or less. The selection criteria are from improved aggressiveness towards the mating material and retention of a high II# cohesion coefficient in the ^Ilk-like line. That is, these components are I! In the process of temperature rise, graphite, Mo8m, and Ca gas exhibit steel scrap properties in each temperature range, and in each temperature range t
It is thinly made of duck as a friction coefficient improver. And in % OaFm, the # rowing action is To6 under the temperature friction condition,
In addition, the results of experiments on bridges revealed that it has the effect of improving the aggressiveness of opponent materials.

That is, the uninvented dry sintered friction material has a coefficient of friction of about α4 to α6, is a material with a high coefficient of friction, and is resistant to thermal fade phenomenon and water fade phenomenon. On the other hand, the aggressiveness towards the mating material has been improved.

Next, an example of the dry sintered friction material of the present invention will be described.

As a dry sintered friction material of the present invention, a sample of DG was manufactured as a comparative material for M~C1, and its component composition (unit weight) was as follows.

In the table below, regarding the above M~G, in the foot speed type** test machine,
Two test pieces were pressed against a mating plate (YC-20) under the conditions of a sliding speed of 20 m/-8 am and a pressure of 5 Yi, and the performance was compared.

As a result, for A-C of the present invention, *The cohesion coefficient was within the target range of 0.4 to 0.6, and the wear rate was also within a practically acceptable range.

On the other hand, the effect of adding CaFm is remarkable.
As a result, it was found that it was not aggressive against the opponent board and had excellent heat fade resistance.

On the other hand, although the comparative IIR example Glue and Ft had no aggressiveness against the mating board, they showed slightly inferior results in JIlik7 aid resistance. In addition, FFi, lll heat fade was good, but it showed the result of attacking the opponent's board, and further 4C
Although G had excellent heat fade resistance, it was extremely aggressive to the opponent board.

As for the amount of CaFm added, as a result of one test each, it was found that 10- or less is suitable. And 1oot
In addition, metal oxides KII containing 1% of silica and alumina were separately tested. It has also been found that a Mohs hardness of 4 or more is suitable.

As explained above, the present invention provides a dry sintered friction material of the bronze type, which has the following effects when a specific component composition is added with calcium fluoride. It is something that

First, a dry sintered friction material with a high ** coefficient is provided. In the present invention, a high J11 coefficient of about 0.4 to 0.6 is obtained, and the heat fade resistance is also excellent. This means that stable wear direction can be obtained, especially when sliding at high speeds.
It can be said that it is particularly suitable for automobiles.

Dry sintering with improved aggressiveness against the mating plate by @2%
Il! In general, the higher the wear coefficient, the greater the amount of wear, and the more aggressiveness with which it hits the opposing plate. However, in this invention, JII
Although the s coefficient is high, the wear rate is also suppressed. Therefore, the improvement in aggressiveness also leads to a reduction in so-called barking.

Dry type 'IA' improved for aI3 and water fade mJl! I! 1. The present invention provides that the rubbing material is compensated for by A.
Since it is based on a bronze matrix, it is highly resistant to water fading, making it particularly suitable for exposed two-wheeled vehicles. In this case, if stainless steel is used as the mating plate, the problem of rust will be solved at the same time.

Claims (1)

[Claims] A dry sintered friction material made of a bronze lA sintered alloy, wherein the sintered alloy has a weight ratio of 60 to 80 -1 copper and 3 to 2 -2 tin.
0 whisper, metal oxide t consisting of hard particles with a Mohs hardness of 4 or more t3~20 whisper, graphite 3~101, molybdenum disulfide 1~
A dry sintered friction material characterized by containing 5% and less than 10% calcium heptoxide.