JP2002097455A - Friction material composition and friction material obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a friction material composition suitable for a friction material excellent in effective performances at a low vehicle speed and hardly generating brake squeals and noises at a time of stop, and a friction material excellent in effective performances at a low vehicle speed and hardly generating brake squeals and noises at a time of stop. SOLUTION: The friction material composition contains 1-20 wt.% of a phosphor bronze fiber 0.5-10 mm in length in the whole composition. The friction material is obtained by subjecting this friction material composition to heat pressure molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction material composition suitable for a friction material such as a disc brake pad and a brake lining used for braking automobiles, railway vehicles, various industrial machines, and the like. Friction material.

[0002]

2. Description of the Related Art Friction materials such as disc brake pads and brake linings are used for braking automobiles, railway cars, various industrial machines and the like. Currently used friction materials, for example, disc brake pads, as shown in JP-A-6-184525, etc., aramid fiber,
Non-Asbestos-Organic (hereinafter referred to as NAO), which uses a fibrous substance such as mineral fibers, friction modifiers such as cashew dust, graphite, etc., and generates less brake squeal and abnormal noise during braking ) -Based disc brake pads are the mainstream.

However, performance requirements for brakes in recent years tend to be diversified, and the effectiveness and wear resistance of conventional NAO materials are improved while the noise and vibration characteristics such as brake noise and abnormal noise are further improved. However, it is difficult for conventional disk brake pads as described above to fully satisfy all the characteristics.

[0004]

SUMMARY OF THE INVENTION The invention according to claim 1 provides a friction material composition which is excellent in effectiveness at low vehicle speeds and which is suitable for a friction material which generates little noise when braking and stopping. Things. The invention according to claim 2 is to provide a friction material which is excellent in performance at low vehicle speeds and generates less noise when braking and stopping.

[0005]

According to the present invention, a phosphor bronze fiber having a length of 0.5 to 10 mm is contained in a total composition at 1 to 20% by weight.
The present invention relates to a friction material composition contained therein. Also, the present invention
The present invention relates to a friction material obtained by heating and pressing the above friction material composition.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The phosphor bronze fiber used in the present invention has a fiber length of 0.5 to 10 mm, preferably 1 to 8 mm.
More preferably, the thickness is in the range of 2 to 6 mm. When the thickness is less than 0.5 mm, the effect of low vehicle speed (60 km / h or less) is reduced.
If it exceeds mm, brake noise and abnormal noise will worsen.

[0007] The content of the phosphor bronze fiber is in the range of 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 3 to 10% by weight in the total composition, and is less than 1% by weight. And the effectiveness of low vehicle speed (less than 60km / h)
Exceeding the weight percentage deteriorates brake noise and abnormal noise.

The thickness (diameter) of the phosphor bronze fiber is not particularly limited, but is preferably in the range of 30 to 300 μm, more preferably in the range of 50 to 250 μm, and more preferably in the range of 70 to 200 μm. More preferably, it is within the range.

The friction material composition of the present invention uses a fibrous substance other than phosphor bronze fiber, a binder, a friction modifier, a filler, and the like, and if necessary, a metal such as copper, brass, zinc, bronze and the like. Powder is used. In addition, as fibrous substances other than phosphor bronze fiber, steel fiber, brass fiber, copper fiber,
Aramid fibers, acrylic fibers, carbon fibers, ceramic fibers, rock wool, potassium titanate fibers, calcium carbonate whiskers, magnesium carbonate whiskers, and the like.

Examples of the binder include a phenolic resin, an epoxy resin, a melamine resin, and various modified resins thereof, for example, thermosetting resins such as cashew-modified and rubber-modified resins, and NB.
Rubber compositions such as R, SBR, BR, IR and the like can be mentioned. Examples of the friction modifier include organic dusts such as cashew dust, inorganic fillers such as antimony trisulfide, molybdenum disulfide, graphite, and coke, and inorganic abrasives such as alumina, zircon sand, mullite, zirconia, and silicon carbide. Can be Fillers include barium sulfate, calcium carbonate, magnesium carbonate, vermiculite,
Rubber powder and the like.

The content of the fibrous substance in the above is preferably 5 to 40% by weight, more preferably 10 to 35% by weight, and more preferably 15 to 35% by weight, based on the mechanical strength and the like. More preferably, it is 30% by weight. The content of the binder is preferably 3 to 15% by weight, more preferably 4 to 13% by weight, and more preferably 5 to 11% by weight in the whole composition from the viewpoint of moldability and the like. Is more preferred. The content of the friction modifier is preferably 4 to 50% by weight, more preferably 7 to 45% by weight, and more preferably 10 to 40% by weight, based on the friction coefficient and the stability thereof. More preferably, it is set to be% by weight.

The content of the filler is preferably 20 to 60% by weight, more preferably 25 to 50% by weight, and more preferably 30 to 50% by weight, based on the filling density and the like.
More preferably, it is set to 40 wt%. Further, the content of the metal powder to be added as needed is 1 to
The content is preferably 8% by weight, more preferably 2 to 7% by weight, and still more preferably 3 to 6% by weight. These components are blended so that the total composition becomes 100% by weight.

The friction material according to the present invention is prepared by uniformly mixing the above-described friction material composition, preforming the mixture, inserting a backing metal and a preform into a mold, and then heating and pressing. It is obtained by molding by a molding method and then performing a heat treatment. If necessary, the surface of the molded body may be baked at a high temperature of 400 to 700 ° C. after the heat treatment. The heating temperature at the time of molding is preferably 130 to 170 ° C, and 140 to 16 ° C.
0 ° C. is more preferred. The pressure is preferably from 20 to 60 MPa, more preferably from 30 to 50 MPa. Heat treatment temperature is 1
80-300 degreeC is preferable and 200-250 degreeC is more preferable.

[0014]

The present invention will be described below with reference to examples.

Examples 1 to 6, Comparative Examples 1 to 6 The components shown in Table 1, Table 2, Table 3 and Table 4 were blended and uniformly mixed by a mixer to obtain a friction material composition. Next, after preforming the friction material composition into a predetermined shape, a backing metal and a preformed body are inserted into a mold, and then 140 ± 5 ° C. and a pressure of 5 ° C.
Heat and pressure molding under the condition of 0MPa for 10 minutes
Heat treatment was performed at 5 ° C. for 5 hours, followed by cooling and polishing to obtain a disc brake pad.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

Next, with respect to the disc brake pad using the friction material composition according to the embodiment of the present invention and the disc brake pad using the friction material composition of the comparative example, the effect (friction coefficient), brake squeal, and abnormal noise were measured. A comparative test was performed. Table 5 shows the test results. The test conditions are as follows.

(1) Effectiveness A dynamo test was conducted according to JASO C402, and the friction coefficient of a low-speed vehicle (50 km / h) was compared. (2) Brake squeal and abnormal noise The actual vehicle test was performed according to JASO C402, and the brake squeal and the abnormal noise during the test were measured, and the occurrence rate of brake squeal of 75 dB or more and the number of abnormal noises at the time of stoppage were determined. In addition, all the above tests were performed using a brake unit of Civic (13 inch size) manufactured by Honda Motor Co., Ltd.

[0022]

[Table 5]

As shown in Table 5, the disc brake pad using the friction material composition according to the embodiment of the present invention is:
It is clear that the effectiveness of the low vehicle speed is high, and the occurrence of brake squeal and abnormal noise is small. On the other hand, the disc brake pads of Comparative Examples 1 and 3 have low effectiveness at a low vehicle speed (50 km / h), and the disc brake pads of Comparative Examples 2 and 4 generate much brake noise and abnormal noise. The disc brake pads of Comparative Examples 5 and 6 exhibited a low vehicle speed (50
km / h) was less effective and more noise was generated.

[0024]

According to the first aspect of the present invention, the friction material composition can provide a friction material which is excellent in the performance at low vehicle speeds and generates less noise when braking and stopping. The friction material according to the second aspect is excellent in effectiveness at low vehicle speeds, generates little noise when braking and stops, and is industrially extremely suitable.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16D 69/02 F16D 69/02 G F term (reference) 3J058 BA21 BA23 FA01 FA11 FA21 FA31 GA07 GA15 GA20 GA24 GA28 GA37 GA40 GA55 GA65 GA92 GA95 4F071 AA41 AB12 AE12 AH07 AH19 DA01 DA04 DA09 DA22 4J002 AC011 AC031 AC061 AC081 CC031 CC181 CD001 DC006 FA046 FD016 FD206 GM00 GT00

Claims (2)

[Claims] 1. A friction material composition comprising 1 to 20% by weight of a phosphor bronze fiber having a length of 0.5 to 10 mm in the whole composition. 2. A friction material formed by heating and pressing the friction material composition according to claim 1.