JP2011202726A - Shim for disc brake, and vibration-proof material used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shim for a disc brake that is easy of manufacturing, has a good retention property of grease, has a good vibration-damping factor, and sufficiently prevents the occurrence of brake noise, and to provide a vibration-proof material used for the same.SOLUTION: The shim 10 for the disc brake is constituted of: the vibration-proof material 1 which includes a plurality of layers of a film laminate 4 comprising a fluorine resin film 2 and a grease layer 3 applied thereto; and a metal thin plate 11 on which the vibration-proof material 1 is laminated.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake shim used in a disc brake of an automobile or the like and a vibration isolating material used therein, and more particularly to a disc brake shim suitable for preventing brake squeal occurring when a disc brake is operated, and a vibration isolating used therein. Regarding materials.

  A disc brake widely used in an automobile or the like generally has a structure in which a disc rotor that rotates integrally with a wheel is pressed from both sides by a brake pad that is moved by the operation of a piston (pressing member). In the disc brake, when braking, that is, when the brake pad is pressed against the disc rotor, an abnormal noise generally called “squeal” may occur. Even if a squeal occurs, it does not affect the braking performance, but it can be heard as an unpleasant sound for the driver and passengers.

  The squealing of the brake is considered to be caused by frictional vibration between the disc rotor and the brake pad, which is generated by resonance with the brake components and the vehicle body, and is improved to some extent by the design of the brake system. Is done. However, the frictional state of the disk rotor, which is the source of vibration, and the brake pad change over time, and it is a complex phenomenon that combines structural vibrations. Not found.

  One effective measure that can prevent squealing without significantly affecting the structure and braking characteristics of the brake system is to install a shim with high vibration damping between the brake pad and the piston (pressing member). Examples of such shims are described in Patent Document 1 or Patent Document 2.

  In Patent Document 1, the shim has a structure in which a damping steel plate and a grease layer are laminated, and the shim is mounted between the brake pad and the piston (pressing member) with the grease layer side facing the brake pad. It has become. The disc brake shim described in Patent Document 2 has a configuration in which a sintered coating made of a low friction material having a friction coefficient of 0.2 or less is formed on one surface or both surfaces of a thin metal plate.

Japanese Patent Laid-Open No. 08-232998 JP 2007-232136 A

  As described in Patent Document 1, a shim having a structure in which a damping steel plate and grease are laminated has a high damping property for grease, and compared with a case where only the damping steel plate is used, the contact between the brake pad and the piston is limited. It has the advantage of being able to adjust. However, it is somewhat difficult to apply the grease to the damping steel plate and keep it there, and there is still room to solve in developing a higher performance disc brake.

  The disc brake shim described in Patent Document 2 forms a sintered coating made of a low friction material on one or both surfaces of a thin metal plate, but its manufacturing process is somewhat difficult.

  The present invention has been made in view of the above circumstances, is easy to manufacture, has good grease retention, has a good vibration damping rate, and greatly suppresses the occurrence of brake squeal. DISCLOSURE OF THE INVENTION DISCLOSURE OF DISK BRAKE SHIM CAN

  The vibration-proof material used in the disc brake shim according to the present invention includes at least a film-like laminate including a fluorine-based resin film and a grease layer applied thereto.

  In the vibration isolator used in the disc brake shim according to the present invention, preferably, the film thickness of the fluororesin film is 5 to 20 μm.

  In the vibration isolating material used in the disc brake shim according to the present invention, preferably, the vibration isolating material includes a configuration in which the film-like laminate of 4 to 10 layers is laminated.

  Further, the disc brake shim according to the present invention is characterized in that it has at least a structure in which any of the above-mentioned vibration-proofing materials is laminated on a thin metal plate.

  The vibration-proof material used in the disc brake shim according to the present invention described above is a film-like laminate structure formed by applying grease on a fluorine-based resin film as a base sheet, and is high as a base sheet. By providing the fluororesin film having heat resistance, it has high heat resistance of about 200 ° C. to 300 ° C., and handling properties as a vibration-proof material are improved as compared with the case of the grease layer alone. This facilitates the work when assembling as a disc brake shim. In addition, grease for general machinery having low heat resistance can be used as it is.

  Further, as shown in the following examples, the vibration isolator according to the present invention has a high vibration damping rate, and the disc brake is constructed using the disc brake shim including the vibration isolator according to the present invention. The brake squeal is also reliably suppressed.

  As described above, in the vibration isolator used in the disc brake shim according to the present invention, it is preferable that the film thickness of the fluororesin film is in the range of 5 to 20 μm. If the film thickness is less than 5 μm, the mechanical strength is insufficient and handling of the vibration isolator becomes inconvenient. Also, the heat resistance is insufficient. Those exceeding 20 μm are over-spec in both strength and heat resistance, resulting in high costs.

  As described above, in the vibration isolator used in the disc brake shim according to the present invention, the film-like laminate may be a single layer, but preferably 4-10 layers of the film-like laminate are laminated. Configured. As shown in the following examples, when there are less than four layers, a vibration damping rate sufficient as a vibration isolating material cannot be obtained. If it exceeds 10 layers, the vibration damping rate will improve, but the thickness as a vibration isolator will increase, and when constructed as a disc brake shim, it will be inserted into the gap between the brake pad and piston (pressing member) There are cases where it is impossible.

  In the vibration isolator used in the disc brake shim according to the present invention, the grease to be used is not particularly limited, and a conventionally known grease comprising a base oil, a thickener and an appropriate additive can be appropriately used. As an example, grease as shown in Table 1 can be mentioned.

  As shown in the examples below, even when lubricating grease for general machinery whose base oil is mineral oil, it can be applied to a fluororesin film to increase the vibration damping rate. It was possible to obtain an anti-vibration material that was satisfactory in terms of heat resistance and mechanical strength. The consistency of the grease may be the same as that of the conventional brake squealing grease, and may be about 250 to 350.

  Although the thickness of the grease layer to be applied depends on the degree of the target vibration attenuation rate, according to the experiments by the present inventors, if the thickness is around 10 μm, a practically significant vibration attenuation rate is provided. An anti-vibration material could be obtained.

  According to the present invention, a disc brake shim that is easy to manufacture, has a good grease layer retention, has a good vibration damping rate, and can greatly suppress the occurrence of brake squeal, and there An anti-vibration material that is a film-like laminate used can be obtained.

The schematic diagram which shows an example of the vibration isolator used for the shim for disc brakes by this invention. The schematic diagram which shows an example of the shim for disc brakes by this invention.

  Hereinafter, the present invention will be described based on embodiments. FIG. 1 is a schematic view showing an example of a vibration isolator 1 used in a disc brake shim 10 according to the present invention.

  As shown in FIG. 1A, the vibration isolator 1 is a film-like laminate 4 made of a laminate of a fluorine-based resin film 2 functioning as a base sheet and a grease layer 3 applied thereon. Basically composed. The thickness of the fluorine-based resin film 2 is usually about 5 to 20 μm in consideration of mechanical strength and the like. The thickness of the grease layer 3 is experimentally determined in consideration of the vibration damping factor required for the disc brake shim 10 using the vibration isolator 1, but is usually about 5 to 20 μm. Application of the grease layer 3 to the fluorine-based resin film 2 may be performed by a conventionally known means for applying a thickener to a thin film, and examples thereof include spatula coating.

  FIG. 1 (b) shows another embodiment of the vibration isolator 1, and a fluorine-based resin film 2 is further formed on the grease layer 3 in the film-like laminate 4 shown in FIG. 1 (a). It is configured by stacking.

  FIG. 1 (c) shows still another embodiment of the vibration isolator 1, in which four layers of the film-like laminate 4 shown in FIG. 1 (a) are laminated to form the uppermost film. The fluorine-based resin film 2 is further laminated on the grease layer 3 of the laminated laminate 4.

  The vibration isolator 1 used in the disc brake shim 10 according to the present invention comprises a film-like laminate comprising a fluororesin film 2 and a grease layer 3 applied thereto, as shown in FIG. In addition to the configuration shown in FIG. 1B and the configuration shown in FIG. 1C, the grease layer 3 is provided on both surfaces of the fluororesin film 2 although not shown. The uppermost fluorine-based resin film 2 is formed from what is formed, that is, the one in which a plurality of layers of the film-like laminate 4 shown in FIG. 1A are laminated, that is, the one shown in FIG. The removed form and the like are also within the range of the vibration isolator 1 according to the present invention. Further, the number of the laminated layers 4 is preferably about 4 to 10 layers.

  FIG. 2 shows several examples of a disc brake shim 10 according to the present invention. In the embodiment shown in FIG. 2A, any one of the vibration damping materials 1 shown in FIG. 1 is laminated on one surface of the metal thin plate 11. In the embodiment shown in FIG. 2 (b), one of the vibration damping materials 1, 1 shown in FIG. 1 is laminated on the metal thin plate 11 on both surfaces of the metal thin plate 11. Further, in the embodiment shown in FIG. 2C, the metal thin plates 11 are laminated on both surfaces of any one of the vibration isolator 1 shown in FIG.

  In addition, the metal thin plate 11 can use arbitrarily the metal thin plate currently used by the shim for disk brakes known conventionally, A plated steel plate, an iron plate, a stainless steel plate etc. can be illustrated.

  Although not shown, the disc brake shim 10 according to the present invention is disposed between a brake pad of the disc brake and a piston (pressing member) that presses the brake pad against the disc rotor, as in the conventional disc brake shim. Used.

  Hereinafter, the present invention will be described with reference to examples and comparative examples.

[Examples 1 to 4]
[Manufacture of specimens]
Grease was applied to one side of the fluororesin film to form a film-like laminate. The process of laminating a fluororesin film on the applied grease layer and applying the grease thereon was repeated to form a laminate having 1, 4, 5, 8, 10 layers as film laminates. Five types of test bodies were obtained by further laminating the same fluororesin film on the uppermost film-like laminate in each laminate.

The fluororesin film used is a polytetrafluoroethylene film having a thickness of 10 μm, and the applied grease is mainly used for general machinery. The base oil is mineral oil (kinematic viscosity: 100 mm ² / s @ 40 ° C.), which contains an antioxidant (bindered phenolic antioxidant) as an additive, and has a consistency of 280.

  The thickness of each applied grease layer was made as uniform as possible technically. The average layer thickness per film laminate in each laminate was 20 μm.

[Test method]
The vibration attenuation rate of the above five types of specimens was tested. The test was conducted by the ball drop method. That is, a test body cut to a size of 50 × 50 × 0.5 mm is pasted on a steel plate 200 × 150 × 1.6 mm, and a steel ball (diameter 12.7 mm) is placed on the test body from a height of 70 mm. The sound pressure level (A) was measured with a pickup sensor. Further, the sound pressure level (B) of only the steel plate was measured in the same manner. And the attenuation factor was calculated | required by the following formula.
Formula: Damping rate (%) = 100 (A−B) / B

[Criteria]
The evaluation criteria for the attenuation rate were set as follows, and Δ + or higher was regarded as acceptable. The results are shown in Table 2.
A: Attenuation rate of 80% or more,
○: Attenuation rate 60 to less than 80%,
Δ +: attenuation rate of 50 to less than 60%,
Δ-: attenuation rate of 30 to less than 50%,
X: Attenuation rate is less than 30%.

[Comparative Example 1]
The sound pressure level of only the steel plates used in the examples was measured in the same manner as in the examples. This value corresponds to the sound pressure level (B) of only the steel plate in the example. The evaluation is shown in Table 3.

[Comparative Example 2]
Only one grease layer was applied to the steel plate used in the example in the same manner as in the example without disposing a fluororesin film. Then, the attenuation rate was measured and evaluated in the same manner as in Example 1. The evaluation is shown in Table 3.

[Comparative Example 3]
Only the fluororesin film | membrane used in the Example was laminated | stacked on the steel plate used in the Example in five layers like the Example. The attenuation rate was measured and evaluated in the same manner as in Example 1. The evaluation is shown in Table 3.

[Comparative Example 4]
Only one fluororesin film used in the example was laminated on the steel plate used in the example in the same manner as in the example. The attenuation rate was measured and evaluated in the same manner as in Example 1. The evaluation is shown in Table 3.

  In Tables 2 and 3, the evaluation is (good) ◎> ◯> Δ +> Δ−> × (bad).

[Evaluation]
In the test methods in the above Examples and Comparative Examples, the “steel plate 200 × 150 × 1.6 mm” used can be regarded as corresponding to a conventional disc brake shim made of a simple steel plate. Therefore, the test body having a high sound pressure level compared to the steel sheet, that is, the test body having a large damping rate, when using it as a disc brake shim, compared to the case of a single steel sheet, It can be analogized that the brake squeal can be suppressed.

  From that point of view, those of Examples 1 to 5 have an attenuation factor of 50 or more compared with those of Comparative Example 1, and the fluorine resin film according to the present invention and the grease layer applied thereto are used. It is shown that the anti-vibration material comprising the film-like laminate is effective in suppressing brake noise. In particular, in Example 2, the attenuation rate is 60 to less than 80%, in Examples 3 to 5 the attenuation rate is 80% or more, and the vibration-damping material composed of four or more layers of the film-like laminate according to the present invention is effective. Is shown.

  Even in the case of only the grease layer as in Comparative Example 2 or the fluorine resin film as in Comparative Example 3, a high attenuation rate cannot be obtained as compared with Comparative Example 1, and this is also advantageous of the present invention. Recognize.

1 ... Anti-vibration material used for shims for disc brake
2… Fluorine resin film,
3 ... grease layer,
4 ... Film-like laminate
10 ... Shim for disc brake,
11 ... Metal thin plate.

Claims (4)

  An anti-vibration material used for a disc brake shim, wherein the anti-vibration material includes at least a film-like laminate comprising a fluorine-based resin film and a grease layer applied thereto.   The vibration-proof material according to claim 1, wherein the fluororesin film has a thickness of 5 to 20 μm.   The anti-vibration material according to claim 1 or 2, comprising a configuration in which 4 to 10 layers of the film-like laminate are laminated.   A disc brake shim comprising at least a structure in which the vibration-proof material according to any one of claims 1 to 3 is laminated on a thin metal plate.

Images