JPH0721295B2 - Friction plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a friction plate, and more particularly to a friction plate for a brake of an aircraft, a railroad, an automobile, an industrial machine or the like.

(Prior Art) A brake using a carbon fiber reinforced carbon material (hereinafter abbreviated as CFRC) for a friction plate is used in aircrafts and the like, and the weight of the brake is reduced as compared with a conventional friction plate using a metal material. It has improved performance.

The CFRC friction has the advantage that it shows a stable and high friction coefficient even at a very high sliding speed, and the variation of the friction coefficient with temperature is small. Furthermore, since CFRC has excellent heat resistance and heat conduction, it can be used even under conditions that generate a large amount of frictional heat.

Since CFRC is also excellent in mechanical strength, CFRC alone can be used as a friction plate without using a reinforcing plate made of a metal material or the like.

(Problems to be Solved by the Invention) As described above, although CFRC exhibits excellent friction performance, it also has the drawback of being inferior in wear resistance. Used in aircraft friction plates
CFRC is said to have superior wear resistance compared to metal friction plates, but this is wear in the area where the friction surface temperature of the friction material is 400 ° C or higher, especially at low temperatures, especially around 100 ° C. The wear of CFRC is extremely bad. Furthermore, the wear of CFRC using carbon fibers having a fiber diameter of less than 10 μm was particularly large.

In view of the above, the present invention has been developed to solve such a problem of abrasion resistance without impairing its characteristics such as mechanical strength.

The present invention will be described in detail below.

As a method for improving the wear of CFRC, although the reason is not clear, it is effective to use carbon fiber having a fiber diameter of 10 μm or more. The strength of the carbon fiber and the fiber diameter have the relationship shown in Table 1, and if carbon fiber having a fiber diameter of 10 μm or more is used to improve the wear resistance, the fiber price will increase or the fiber strength will decrease.

Specifically, from fiber diameter 10μm or more, tensile strength 200Kg / mm
^{If two} or more carbon fibers are used, it is very expensive and the CFRC using the fibers becomes expensive and can be used only for friction plates in a very limited field.

On the other hand, CF that uses inexpensive carbon fiber with a fiber diameter of 10 μm or more
RC is inferior in mechanical strength and cannot be used as a friction plate by itself.

Therefore, the present inventor has added a mechanical strength required for a friction plate to CFRC using a carbon fiber which is excellent in abrasion resistance and has a diameter of 10 μm or more and is inexpensive, thereby making it inexpensive and excellent in abrasion resistance and mechanical strength. This is an excellent CFRC friction plate.

(Means for Solving Problems) That is, the friction plate (1) (see FIGS. 1 and 2) of the present invention comprises carbon fibers having a fiber diameter of 10 μm or more, a fiber diameter of less than 10 μm and a tensile strength of 200 kg / mm ² or more. In the carbon fiber with the strength of
10 to 75% by weight (wt%) of carbon fiber with a fiber diameter of 10 μm or more
It is characterized by being made of a carbon fiber reinforced carbon material using carbon fibers mixed in the ratio of.

The mixing ratio of carbon fibers having a fiber diameter of 10 μm or more is determined by the wear resistance and mechanical strength of the carbon fiber reinforced carbon material. If the mixing ratio of the fibers is less than 10 wt%, the effect of improving the wear resistance of the carbon material is not remarkable. , 75 wt%, the mechanical strength of the carbon material is not sufficient for use as a friction plate.

1 and 2 exemplify the friction plate of the present invention. FIG. 1 shows a friction disc and FIG. 2 shows a friction pad.

(Function) Carbon fiber having a fiber diameter of 10 μm or more, which is inexpensive and has excellent abrasion resistance as described above, and a fiber diameter of less than 10 μm, and a tensile strength of 200 kg / mm.
By mixing and using ^two or more carbon fibers with excellent mechanical strength, it is possible to satisfy both of the abrasion resistance and mechanical strength required for CFRC friction plates at the same time, and the price is low.
It is possible to get RC.

(Examples) Examples of the present invention will be described below.

Example 1: Carbon fibers A and B having a length of 10 to 30 mm were mixed in the proportions shown in Table 2 to prepare 6 kinds of CFRC. The carbon fiber content in each CFRC was adjusted to about 50 wt%.

Table 3 shows the apparent specific gravity and flexural strength of the 6 types of CFRC.

The carbon fiber A has a fiber diameter of 7 μm, a tensile strength of 310 kg / mm ² ,
The tensile elastic modulus is 23 TON / mm ² , and the carbon fiber B has a fiber diameter of 1
4.5 μm, tensile strength 74 kg / mm ² tensile elastic modulus 3 TON / mm ² .

As can be seen from Table 3, the strength drastically decreased as the mixing ratio of the carbon fibers B increased.

Example 2: Sample I shown in Table 2 of the CFRC made in Example 1,
Abrasion tests were conducted by processing II, III, and IV into the pad and rotor of the spot-type disc brake for automobiles.

Wear test uses inertia braking method and inertia load 3.5Kg ・ m ・ sec
² Rotating the disc rotor at 500 rpm, braking was performed until the rotor reached 0 rpm. As for the dimensions of the disk rotator, the friction area of the φ245 mm × 18 mm t pad was set to 45 cm ² .

The pressing force of the pad at that time was kept constant at 10 kg / cm ^2, and a thermocouple was embedded inside the rotor to start braking when the rotor temperature was 100 ° C or less.

As shown in Table 4, the wear amount of the CFRC pad after 1000 times of braking was drastically decreased as the mixing amount of the carbon fiber B was increased.

(Effect of the Invention) The friction plate of the present invention as described above is cheaper and more excellent in wear resistance than the conventional CFRC friction plate, and has the same heat resistance and lightness as the conventional CFRC. There is.

Since the friction plate of the present invention is inexpensive, it can be used in a wider range of applications than conventional products, specifically, it can be used as a brake for aircraft, railways, automobiles and the like.

[Brief description of drawings]

1 and 2 both illustrate perspective views of a friction plate according to the present invention. (1) …… Friction plate

Claims (1)

[Claims] 1. A fiber diameter of less than 10 μm and a tensile strength of 200 kg /
A friction plate made of carbon fiber reinforced carbon material, characterized in that carbon fibers having a strength of mm ² or more and carbon fibers having a fiber diameter of 10 μm or more are mixed at a ratio of 10 to 75% by weight.