JPS6164850A - Pad for disc brake - Google Patents

Abstract

PURPOSE:To prevent noise generation during damping by disc brake, by manufacturing the titled pad with a cast iron having structure of bainite or martensite matrix and graphite flake. CONSTITUTION:A rear metal sheet 1 in the titled pad composed of said sheet 1 and a lining 2 is manufactured by the cast iron contg. by weight 3.7-4.5% C, 1.0-3.0% Si, 0.2-1.5% Mn, <0.1% P, <0.15% S and graphite flakes in bainite or martensite matrix. Vibration generated in damping by the disc brake is absorbed by the rear metal sheet made of cast iron, pad vibration is suppressed, and noise generation is decreased remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a disc brake pad consisting of a back metal and a lining, and is used for disc brakes of vehicles such as automobiles (prior art). As a pad for disc brakes, JP-A-57-120
There is a pad shown in Japanese Patent No. 741, in which a backing metal 1 and a lining 2 are fixed together as shown in FIG. It is formed from seven parts.

(Problems to be Solved by the Invention) In this conventional pad, the steel plate back metal 1 is integrally fixed to the lining 2, and the steel plate i back metal 1 has a weak effect of absorbing and damping vibrations of the lining 2. If the disc rotor (not shown) and the lining 2 come into contact during braking, there is a problem in that the pads are likely to vibrate and generate noise (squeal). Therefore, the problem to be solved by the present invention is to prevent noise (squeal) from occurring during braking.

(Means for solving the problem) A means for solving the above problem is that the backing metal has a weight ratio of C: 3.7 to 4.5%, Si: 1.0 to 3.0%, Mn: 0. 2 to 1.5% P: 0.1% or less S: 0.15% or less Fe: the remainder, the graphite is flaky graphite, and the matrix structure is bainite or martensite.

Carbon generates flake graphite and contributes to improving the damping ability. If the carbon content is less than 3.7%, sufficient damping ability cannot be obtained;
Silicon is an element that promotes flake graphitization, and if it exceeds 3.0%, the material becomes brittle and the strength decreases. let

If manganese is less than 0.2%, hardenability decreases and bainite or martensite formation is insufficient, i.
If it exceeds s%, chill is likely to occur and machinability deteriorates.

When phosphorus exceeds 0.1%, a eutectic of phosphorus is generated, and the material becomes brittle.

When sulfur exceeds 0.15%, sulfur segregates at grain boundaries and the material becomes brittle.

The reason why the base structure is made of bainite or martensite is that it has superior attenuation characteristics compared to pearlite base.

(effect) The above means works as follows.

Vibration transmitted to the back metal through the lining during braking is
The vibration energy is absorbed by the cast iron back metal made of bainite or martensitic structure and suppresses the vibration of the pad, so the pad vibrates smoothly and does not generate noise (squeal), or even if it does occur, it is small. It will be difficult to hear, but it will not cause any problem in practice.

(Example) Hereinafter, an example showing a specific example of the above means will be described.

As shown in FIG. 1, a pad was formed by integrally fixing a back metal 1 and a lining 2, and comparative tests were conducted on damping ability and squeal, and the results are shown in FIGS. 2 and 3.

The backing money used in this test is as shown in the table below.
The lining was asbestos.

(% by weight) In Figure 2, (A) shows the damping characteristics of the pad using backing metal (3), (B) shows the damping characteristics of the pad using backing metal (1), and (C) shows the damping characteristics of the pad using backing metal (2). Fig. 3 shows the evaluation results of the ease of squealing of pads using yL gold (1) and backing metal (2) and pads using backing metal (3). In other words, the damping capacity of the pad using the backing metal (1) and the backing metal (2) is relatively larger than that of the pad using the backing metal (3), and the pad using the backing metal (1) and the backing metal (2) produces less noise during braking. It turns out that this is less likely to occur.

(Effect of the invention) The present invention produces the following effects.

In conventional pads, the problems of the present invention can be solved by interposing a damping member such as an adhesive layer between the steel plate backing and the lining, but this weakens the rigidity of the pad. cause problems. In contrast, in the present invention, the backing metal is made of bainitic cast iron or martensitic cast iron, and the backing metal and the lining are strongly bonded to each other, so that the open side of the entire pad is increased and the responsiveness during braking is improved.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing a disc brake pad, Figure 2 is a schematic diagram showing a disc brake pad.
The figure is an explanatory diagram showing experimental results of damping characteristics, and FIG. 3 is an explanatory diagram of squeal test results.

Claims (1)

[Claims] In a disc brake pad in which a back metal and a lining are integrally fixed, the back metal has a weight ratio of C: 3.7 to 4.5%, Si: 1.0 to 3.0%, Mn: 0. .2 to 1.5% P: 0.1% or less S: 0.15% or less Fe: The remainder is characterized in that the graphite is flaky graphite and the matrix structure is bainite or martensite. Pads for disc brakes.