JPH081228B2 - Disc brake rotor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a disc brake rotor that rotates integrally with a wheel of the present invention and a pad slides on the brake during braking.

(Prior Art) In a vehicle such as an automobile, when a pad slides on a disc brake rotor during braking, brake noise may occur. However, this brake noise is not sensually preferable and reduces the commercial value of the vehicle. It is what makes me.

Conventionally, the following is known from the result of observing and analyzing the friction surfaces of the disc brake rotor and the pad in order to prevent the generation of brake noise in the disc brake. That is, in order to reduce the brake noise, it is effective to avoid the state where the disk brake rotor is ground and the base metal is exposed, and the pad friction powder adheres to the surface of the disk brake rotor.
Further, as a phenomenon, while the base metal of the disc brake rotor is exposed, a lot of brake noise is generated when iron powder, which is rotor wear powder, adheres to the pad surface and the irons rub against each other. Therefore, in order to reduce the occurrence of brake noise, it is necessary to interpose an intermediate member between the disc brake rotor and the pad.

From such a point of view, as exemplified in Japanese Utility Model Laid-Open No. 53-68883, a solid lubricant such as graphite or molybdenum disulfide is arranged on the outer peripheral portion of the pad which is in sliding contact with the disk rotor,
Disc brakes are known in which the solid lubricant adheres to the disc brake rotor during braking to reduce brake noise.

(Problems to be Solved by the Invention) However, in this disc brake, if the solid lubricant provided is small, the effect of reducing brake noise is not exerted, but on the other hand, the amount of solid lubricant having the effect of reducing brake noise is reduced. When installed, there is a problem that the braking force of the brake is reduced. Further, in the above-mentioned disc brake, in order to maintain the braking force of the brake, it is troublesome that the amount of the solid lubricant must be determined corresponding to the components of various pads having various compositions.

(Object of the Invention) In view of the fact that the above problem is caused by disposing a solid lubricant on the pad, the present invention changes the idea and improves the rotor for a disc brake, thereby reducing the braking force of the brake. The purpose is to prevent the generation of brake noise without causing it.

(Means for Solving the Problems) In order to achieve the above object, the present invention is to dispose a heat-resistant inorganic material on a sliding contact surface with a pad in a disc brake rotor.

Specifically, the solving means taken by the present invention has a structure of a disc brake rotor that rotates integrally with a wheel, and a pad slides in contact with a brake during braking, by forming a large number of recesses on a slide contact surface with the pad. The concave portion is filled with a heat-resistant inorganic material composed of at least one of BaSO ₄ , CaSO ₄ , MgSO ₄ , BaCO ₃ and CaCO ₃ .

(Operation) With the above configuration, when the disc brake rotor and the pad are in sliding contact with each other during brake braking, the heat-resistant inorganic material filled in the recess of the sliding contact surface with the pad escapes from the recess and the sliding contact surface Adhere to. As a result, the disc brake rotor is less likely to be ground, the base metal is not exposed, and the iron comrades do not rub.

Further, since the heat resistant inorganic material is previously disposed on the sliding contact surface with the pad and it is not necessary to transfer the heat resistant inorganic material from the pad, the amount to be disposed may be small because it is efficient.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 1 (3) shows a sectional structure of a rotor A for disc brakes made of cast iron according to the present invention, in which a large number of concave portions 2 are formed in a sliding contact surface 1 with a pad, and these concave portions 2 are made of an inorganic material. 3 is filled.

FIGS. 1 (1) and 1 (2) show the manufacturing process of the disc brake rotor A.

First, a cast iron disc brake rotor A containing flake graphite 4 as shown in FIG. 1 (1) is heat-treated in an oxidizing atmosphere. By doing so, the so-called decarburization phenomenon occurs in which the graphite 4 exposed on the sliding contact surface 1 with the pad is oxidized, and the graphite 4 is gasified, and the trace thereof is as shown in FIG. 1 (2). A large number of recesses 2 are formed. In addition,
The method of forming the concave portion 2 is not limited to the above-mentioned heat treatment method, and may be an appropriate method such as partially corroding and dissolving the sliding contact surface 1 with the pad by an etching method.

Next, inside the large number of recesses 2 formed on the pad sliding contact surface 1, BaSO ₄ (barium sulfate), CaSO ₄ (calcium sulfate), MgSO ₄ (magnesium sulfate), BaCO ₃ (barium carbonate) and CaCO ₃ A heat-resistant inorganic material 3 made of one of (calcium carbonate) or a mixture thereof is filled. The reason for filling these inorganic materials 3 is as follows. That is, since the sliding contact surface of the disk brake rotor A with the pad becomes extremely loud when braking, it is necessary that the filler has a melting point of 1000 ° C. or higher. BaSO ₄ (barium sulfate): 1580 ℃, CaSO ₄ (calcium sulfate): 1450 ℃, MgSO ₄
(Magnesium sulfate): 1185 ℃, BaCO (Barium carbonate: 14
50 ° C, CaCO ₃ (calcium carbonate): 1339 ° C and all 1000
This is because it has a melting point exceeding 0 ° C. Further, all of these inorganic materials 3 are preferable in that they have chemically similar properties and are industrial materials that can be obtained at low cost.

Figure 2 shows BaSO ₄ (barium sulfate) filled in the recess 2.
Is a graph showing the relationship between the amount of the brake noise and the probability of occurrence of brake noise. BaSO ₄ (barium sulfate) is a weight ratio to a disc brake rotor A made of cast iron having a normal thickness. The probability is the number of times brake noise is generated with respect to the total number of braking times.
As is clear from this graph, when 4% to 5% by weight of BaSO ₄ (barium sulfate) is filled, the brake noise hardly occurs. Therefore, the maximum filling amount of the inorganic material 3 is 4.
5% is sufficient.

Hereinafter, the influence on the other performance of the brake by filling the concave portion 2 formed on the sliding contact surface 1 with the pad with the inorganic material 3, that is, the influence on the braking force of the brake and the wear of the disc brake rotor A will be described. To do.

First, in order to study the influence on the braking force of the brake, the relationship between the amount (% by weight) of BaSO ₄ (barium sulfate) filled in the recess 2 and the friction coefficient (μ) is shown in FIG. When the filling amount of BaSO ₄ (barium sulfate) is large, the friction coefficient is slightly lower than that when it is not filled, but since the reduction amount is small, there is no substantial adverse effect on the braking force of the brake.

Next, in order to study the influence of the wear of the disc brake rotor A, the amount (% by weight) of BaSO ₄ (barium sulfate) filled in the recess 2 and the rotor A in FIG. 4 were examined.
The relationship with the wear amount (mm) of the sliding contact surface 1 is shown. As a result, even if BaSO ₄ (barium sulfate) is filled, the amount of wear of the rotor A hardly changes as compared with the case of no filling, so that it can be seen that the present invention has no effect on the wear of the disc brake rotor A.

(Effects of the Invention) As described above, according to the disc brake rotor of the present invention, the heat-resistant inorganic material adheres to the sliding contact surface with the pad during braking, exposing the base metal and causing friction between the iron and steel. This prevents the brake noise from occurring. Further, since the amount of heat-resistant inorganic material to be arranged is smaller than that of the conventional one, there is no fear that the braking force of the brake is reduced.

[Brief description of drawings]

1 (1) to (3) are cross-sectional views showing the manufacturing process of the disc brake rotor according to the present invention, and FIG. 2 is the amount of BaSO ₄ (barium sulfate) and the probability of occurrence of brake noise in the disc rotor. Fig. 3 is a graph showing the relationship between the amount of BaSO ₄ (barium sulfate) and the friction coefficient, and Fig. 4 is a graph showing the relationship between the amount of BaSO ₄ (barium sulfate) and the wear amount of the rotor. It is a graph which shows. A ... Disc brake rotor, 1 ... Sliding contact surface with pad, 2 ... Recess, 3 ... Inorganic material, 4 ... Graphite.

Claims (1)

[Claims] 1. A disc brake rotor that rotates integrally with a wheel and has a pad in sliding contact with the pad when braking, wherein a large number of recesses are formed on a sliding contact surface with the pad.
A disc brake rotor, which is filled with a heat-resistant inorganic material composed of at least one of BaSO ₄ , CaSO ₄ , MgSO ₄ , BaCO ₃ and CaCO ₃ .