JP2004307746A - Friction reducing agent and method for preventing brake squeak by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep a brake from squeaking for a prolonged time period without using any special type brake pad, and to facilitate the process of friction reducing agent application. <P>SOLUTION: The friction reducing agent comprises microcapsules containing a specified lubricating agent and a binder for applying and attaching the microcapsules to a specified surface. The lubricating agent may be a mineral oil, a synthesized oil, and/or a lubricating grease, or the like. The binder may be a nonreaction type resin (solidifying upon solvent volatilization), such as gelatine, sodium alginate, a PVA (polyvinyl alcohol), an epoxy resin, an acrylic resin, a urethane resin, and a silicone resin, or may be a reaction type resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３４】
従って、前記各種実験の結果によれば、表１に示されるように、実施例１〜４では、試験片２２の摩耗が見られず、これに起因するブレーキ鳴き音の発生も見られなかった。
【００３５】
なお、所定の潤滑剤が内包されたマイクロカプセルを、当該潤滑剤と同一若しくは異なる性質を有する他の潤滑剤中に含んでなる摩擦低減剤についても、実施例１〜４で得られた効果と略同一の効果が得られた。また、バインダー中にも潤滑剤を配合した系（実施例４）では、更にブレーキ鳴き音の発生を抑制できる。
【００３６】
【発明の効果】
以上説明したように、本発明によれば、塗布側に特別な構造を採用しなくても、長期間に亘ってブレーキ鳴き音を抑制することができ、しかも、摩擦低減剤の塗布作業時における作業性を良好にすることができる。
【図面の簡単な説明】
【図１】本発明の摩擦低減剤が塗布されるブレーキ装置の一例を示す概略分解斜視図。
【図２】図１のＡ−Ａ線に沿う方向におけるブレーキパッドの断面図。
【図３】摩擦摩耗試験機を説明するための概念図。
【符号の説明】
１０ ディスクブレーキ装置
１１ ブレーキパッド
１４ パッドクリップ
１６Ａ 爪
１７ 摩擦材
１７Ａ 側面
１８ 裏金
１９ シム
２０Ａ ピストン[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a friction reducing agent and a method of preventing brake squeal using the same, and more particularly to a friction reducer capable of suppressing the brake squeal of a disk brake device of a vehicle, and a method of preventing brake squeal using the same. About.
[0002]
[Prior art]
A known disc brake device applied to an automobile or the like includes a disc rotor that rotates together with wheels, a pair of brake pads arranged to sandwich the disc rotor, and a caliper that supports the brake pads. I have. This disc brake device applies a braking force to a vehicle by pressing a friction material of a brake pad against a disc rotor by driving a hydraulic cylinder provided on a caliper. However, at the time of this braking, a brake squeal that may cause discomfort to the occupant may be generated due to the shape of the friction material, the friction coefficient of the friction material, and the like.
[0003]
In order to reduce the above-mentioned brake squeal, there is known a method of chamfering a contact surface of a friction material with a disk rotor (see Patent Document 1). In addition, it is widely used to apply viscous grease between a brake pad and a caliper at the time of manufacture or maintenance of a vehicle. Further, a pad structure capable of preventing brake squeal noise by enclosing a microencapsulated lubricant in a groove or a hole provided in the friction material is known (see Patent Document 2).
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. Sho 62-18439 [Patent Document 2]
JP-A-8-170660 [0005]
[Problems to be solved by the invention]
However, in the above-described method of chamfering a friction material, since the friction material gradually disappears due to wear, there is an inconvenience that the effect of reducing the brake squeal decreases with time.
In the method of applying viscous grease between the brake pad and the caliper, the deterioration of the grease with time due to the use environment of the vehicle, and the deterioration or outflow of the lubricating component of the grease due to running in rainy weather or car washing, etc. For example, there is a disadvantage that the effect of reducing the brake squeal cannot be maintained for a long period of time. Furthermore, during application of grease, if viscous grease adheres to hands or tools, removal becomes troublesome, and if it cannot be completely removed, the lubricant will adhere to unexpected places secondarily. There is also an inconvenience of causing a defect. Further, since the lubricant is in a viscous state, there is also an inconvenience that it is difficult to apply the lubricant in a stable amount at the time of manufacture, repair, or the like.
Further, the pad structure disclosed in Patent Document 2 has a disadvantage that the processing is troublesome and the cost is extremely high.
[0006]
[Object of the invention]
The present invention has been devised in view of such inconvenience, and an object of the present invention is to provide a friction that can prevent brake squeal for a long period of time without using a special brake pad. An object of the present invention is to provide a reducing agent and a method for preventing a brake squeal using the same.
[0007]
Another object of the present invention is to provide a friction reducing agent capable of improving workability at the time of coating and a method of preventing a brake squeal using the same.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the friction reducing agent according to the present invention employs a configuration in which a microcapsule containing a predetermined lubricant and a binder for attaching the microcapsule to a predetermined application surface are included. ing. According to such a configuration, when a pressure causing a brake noise is applied to the lubricant application surface, the microcapsules are gradually broken, and the lubricating action of the lubricant expressed thereby causes the brake noise. Sound can be suppressed. Since the microcapsules here are firmly fixed to the application surface via a binder, the performance deterioration and outflow of the lubricant in the microcapsules is suppressed, and the effect of suppressing the brake noise is maintained for a long time. can do. Further, since the application of the friction reducing agent makes it possible to suppress the noise of the brake squeal, it is not necessary to provide a brake pad or the like with a special structure, and the invention can be applied to various vehicles. Furthermore, even if viscous grease is used as a lubricant to be blended with the friction reducing agent, the grease is included in the microcapsules. In addition to preventing adhesion, it is also possible to lower the viscosity of the entire friction reducing agent to promote stabilization of the amount of application, thereby improving workability during application.
[0009]
Here, the binder can be formed into a dry film by drying and solidifying or reaction curing. Thus, after the application of the friction reducing agent, the friction reducing agent is formed into a dry film, whereby the friction reducing agent can be adhered to the application surface for a long period of time.
[0010]
Further, the present invention can adopt a configuration in which a lubricant is further contained in the binder. At this time, it is preferable that the lubricant contained in the microcapsules and the lubricant contained in the binder have the same properties. Even with such a configuration, since the microcapsules containing the lubricant and the lubricant having the same properties as the lubricant are contained in the binder, the brake noise can be prevented for a long time. be able to.
[0011]
Furthermore, the present invention is a method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent to a disk brake device of the vehicle,
The friction reducing agent is applied to a side surface or a back metal of a brake pad provided in the disc brake device. According to such a method, the microcapsules in the lubricant interposed between the back metal and the caliper are crushed by the operation of the disc brake device, and the microcapsules are gradually destroyed. Due to this destruction, the vibration of the brake pad is absorbed by the lubricant that has come out of the microcapsule, and the generation of the brake squeal caused by the vibration can be prevented for a long time.
[0012]
Further, a method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent to a disc brake device,
The friction reducing agent may be applied to at least one of a mating surface of a shim of a brake pad provided on the disc brake device and a back metal, and this may also employ a shim for preventing brake squeal. The combined use makes it possible to more reliably suppress the brake squeal.
[0013]
Further, by applying the friction reducing agent to a disk brake device, a method of preventing a brake squeal during braking of the vehicle,
A method of applying the friction reducing agent to at least one of the piston and the pawl provided in the disc brake device can be adopted, and the above-mentioned object can also be achieved. Here, the friction reducing agent may be applied between a back metal of a brake pad provided in the disc brake device and a shim attached to the back metal. Even with such a method, the effect of suppressing the brake squeal can be further enhanced.
[0014]
Further, a method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent to a disc brake device,
A method of applying the friction reducing agent to at least one of a pad clip provided on the disc brake device and a back metal side of the brake pad can be adopted. According to such a method, it is possible to suppress brake squeal caused by sliding between the pad clip and the back metal during braking of the vehicle.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The friction reducing agent according to the present invention is applied to the disc brake device 10 illustrated in FIG.
[0016]
The disc brake device 10 includes a disc rotor 11 that rotates together with wheels, a pair of brake pads 12 arranged so as to sandwich the surface of the disc rotor 11, a pad support 13 that supports the brake pads 12, A pad clip 14 interposed between the brake pad 12 and the pad support 13 and a caliper 16 attached to the pad support 13 are provided. As shown in FIG. 2, the brake pad 12 has a substantially block-shaped friction material 17 which comes into contact with the surface of the disk rotor 11 during braking of the vehicle, and a plate fixed on the lower surface side of the friction material 17 in FIG. The back metal 18 has a thin plate-shaped shim 19 attached to a back surface 18A (lower surface side in FIG. 2) of the back metal 18 opposite to the friction material 17 and preventing brake noise. . As shown in FIG. 1, the caliper 16 includes a hydraulic cylinder 20 that moves the brake pads 12, 12 toward each other when a brake is operated. When the hydraulic cylinder 20 is driven, the side edges 18B, 18B of the back metal 18 slide while contacting the pad clip 14, whereby the friction members 17, 17 are pressed against the disk rotor 11, thereby controlling the vehicle. Power will be applied. In FIG. 1, reference numeral 16A indicates a nail.
[0017]
Here, the friction reducing agent is applied to the next part of the disc brake device 10. That is, it is applied to the side surface 17A of the friction material 17, the back surface 18A of the back metal 18, the piston 20A side of the hydraulic cylinder 20, and / or the back metal 18 side of the pad clip 14. In particular, when applying the friction reducing agent to the back surface 18A, it is preferable to apply the friction reducing agent between the back surface 18A and the shim 19. Further, when a layer of a friction reducing agent is provided on the side surface of the friction material 17, the microcapsules in the layer are broken and the lubricant seeps out. Since it continuously appears on the contact surface, brake squeal can be reduced or prevented until the thickness of the friction material 17 reaches the durable limit.
[0018]
The lubricant in the present invention is not particularly limited. For example, a conventionally known mineral or synthetic lubricating oil and / or a grease-like lubricant can be used. In addition, the viscosity of the lubricating oil can be arbitrarily selected depending on the application. Further, an extreme pressure additive, a carbon powder, a lubricating filler such as polytetrafluoroethylene (PTFE), molybdenum disulfide or the like may be dissolved or dispersed in the lubricant.
[0019]
The microcapsules containing the lubricant are manufactured by, for example, a conventionally known interfacial polymerization method, in-situ polymerization method, in-liquid drying method, coacervation method, or the like. At this time, the material of the partition wall of the capsule is also not particularly limited, and for example, conventionally known gelatin, melamine, urea, urethane resin, polystyrene and the like can be used. In the case where the lubricant is contained in the microcapsules, it is preferable to use a liquid lubricating oil whose viscosity is adjusted in consideration of the production efficiency.
[0020]
The binder in the present invention is not particularly limited. For example, non-reactive binders such as conventionally known gelatin, sodium alginate, PVA (polyvinyl alcohol), epoxy resin, acrylic resin, urethane resin and silicone resin are used. (Solidified by solvent evaporation) or a reactive resin can be used. In particular, when the friction reducing agent is applied to the disc brake device 10, considering that the disc brake device 10 becomes hot due to friction, it is preferable to use a binder resin having high heat resistance such as an epoxy resin or a silicone resin. preferable.
[0021]
In addition, inorganic or organic fibers may be added for the purpose of improving the strength of the binder resin, and in addition, additives such as a thickener, a filler, an antifoaming agent, and a rust inhibitor may be added. You can also. In addition, the above-mentioned mineral and synthetic lubricating oils and / or grease-like lubricants, as well as lubricating fillers such as polytetrafluoroethylene (PTFE) and molybdenum disulphide, may be used in combination with the binder resin for compatibility or dispersion. It may be appropriately selected in consideration of the properties and added directly to the binder.
[0022]
Here, the blending ratio of the binder and the lubricant is not particularly defined because it greatly changes depending on the type of the lubricant to be blended, but is generally in the range of 10 to 500 parts by weight of the lubricant with respect to 100 parts by weight of the binder. . The particle size of the microcapsules depends on the thickness of a lubricating layer formed by applying a lubricant to a predetermined application surface, but there is no particular problem as long as the thickness is smaller than the thickness of the lubricating layer. . Further, when a lubricating layer is formed on the back metal 18 of the brake pad 12, since a load is repeatedly applied to the lubricating layer by the operation of the disc brake device 10, several kinds of microcapsules having different film strengths may be added or particles may be added. It is preferable to add microcapsules having different diameters. In this case, lubricity is maintained for a longer period. The method for forming the lubricating layer is, for example, to apply the friction reducing agent to the above-mentioned application surface with a dispenser, apply by dipping, apply by screen printing, and then volatilize the solvent in the friction reducing agent. Thereby, the lubricating layer is dried and solidified, or the binder resin is reactively cured (polymerized and cured) to obtain a dry film-formed lubricating layer.
[0023]
【Example】
Hereinafter, examples of the present invention will be described together with comparative examples.
[0024]
[Example 1]
40 parts by weight of a styrene-maleic anhydride copolymer (Polymalon 351 manufactured by Arakawa Chemical Industries, Ltd.) were dissolved in 180 parts by weight of water. 100 parts by weight of mineral oil (200 #) was added to this aqueous solution, and the mixture was stirred at 150 rpm to emulsify. After emulsification, 35 parts by weight of Sumirezu Resin M-3 manufactured by Sumitomo Chemical Co., Ltd. were added, and the solution was heated at 80 ° C. for 2 hours to react to obtain a melamine microcapsule suspension.
When the particle diameter of the obtained microcapsules was measured, the average diameter was 500 microns.
To this suspension, 4000 parts by weight of an aqueous solution obtained by adding 800 parts by weight of polyvinyl alcohol (GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) to 3200 parts by weight of water were added, and a suspension containing microcapsules and a binder was added. Got.
[0025]
[Example 2]
40 parts by weight of a styrene-maleic anhydride copolymer (Polymalon 351 manufactured by Arakawa Chemical Industries, Ltd.) were dissolved in 180 parts by weight of water. To this aqueous solution, 100 parts by weight of mineral oil (200 #) was added and emulsified by stirring at 500 rpm. After emulsification, 35 parts by weight of Sumirezu Resin M-3 manufactured by Sumitomo Chemical Co., Ltd. were added, and the solution was heated at 80 ° C. for 2 hours to react to obtain a melamine microcapsule suspension.
When the particle diameter of the obtained microcapsules was measured, the average diameter was 100 microns.
To this suspension, 4000 parts by weight of an aqueous solution obtained by adding 800 parts by weight of polyvinyl alcohol (GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) to 3200 parts by weight of water were added, and a suspension containing microcapsules and a binder was added. Got.
[0026]
[Example 3]
40 parts by weight of a styrene-maleic anhydride copolymer (Polymalon 351 manufactured by Arakawa Chemical Industries, Ltd.) were dissolved in 180 parts by weight of water. 100 parts by weight of mineral oil (200 #) was added to this aqueous solution, and the mixture was emulsified by stirring at 7000 rpm. After emulsification, 35 parts by weight of melamine prepolymer (Sumitomo Chemical Co., Ltd. Sumirezuresin M-3) was added, and the solution was heated at 80 ° C. for 2 hours to react to obtain a melamine microcapsule suspension.
When the particle diameter of the obtained microcapsules was measured, the average diameter was 0.1 μm.
To this suspension, 4000 parts by weight of an aqueous solution obtained by adding 800 parts by weight of polyvinyl alcohol (GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) to 3200 parts by weight of water were added, and a suspension containing microcapsules and a binder was added. Got.
[0027]
[Example 4]
40 parts by weight of a styrene-maleic anhydride copolymer (Polymalon 351 manufactured by Arakawa Chemical Industries, Ltd.) were dissolved in 180 parts by weight of water. 100 parts by weight of mineral oil (200 #) was added to this aqueous solution, and the mixture was stirred at 150 rpm to emulsify. After emulsification, 35 parts by weight of Sumirezu Resin M-3 manufactured by Sumitomo Chemical Co., Ltd. were added, and the solution was heated at 80 ° C. for 2 hours to react to obtain a melamine microcapsule suspension.
When the particle diameter of the obtained microcapsules was measured, the average diameter was 500 microns.
To this suspension, 175 parts by weight of PTFE (Rublon L-5, manufactured by Polytetrafluoroethylene Daikin Industries, Ltd .; particle size: 3 to 7 microns), and polyvinyl alcohol (GH-23, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 8000 parts by weight of an aqueous solution obtained by adding 1600 parts by weight to 6400 parts by weight of water was added to obtain a suspension containing microcapsules, PTFE, and a binder.
[0028]
[Comparative Example 1]
100 parts by weight of polyvinyl alcohol (GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was added to 400 parts by weight of water to obtain 500 parts by weight of an aqueous solution.
[0029]
[Comparative Example 2]
For 175 parts by weight of solid lubricant PTFE (Rublon L-5 manufactured by Polytetrafluoroethylene Daikin Industries, Ltd .; particle size: 3 to 7 microns), polyvinyl alcohol (GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 800 A PTFE-containing liquid was obtained by adding 4000 parts by weight of an aqueous solution obtained by adding 3 parts by weight of water to 3200 parts by weight of water.
[0030]
The following tests were performed on Examples 1 to 4 and Comparative Examples 1 and 2.
[0031]
Wear (lubrication) test:
The solutions obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were applied to iron test pieces (SPCC-SB manufactured by Nippon Test Panel Co., Ltd.) and dried to obtain test pieces.
The wear test was performed using a friction and wear tester as shown in FIG. That is, in the wear test, a cylindrical mating member 23 is placed on the upper surface side of the test piece 22 to be subjected to the wear test in the drawing, and the mating material 23 is pressed while the mating material 23 is pressed by the mating material 23. Was rotated around the central axis. In this wear test, the material of the mating member 23 was S45C, the load applied to the mating member 23 as the pressing force of the test piece 22 was 5 kg / cm ² , the linear velocity of the mating member 23 was 1 m / min, and the lubrication state was dry. The test piece 22 and the mating member 23 are rotated relative to each other continuously for 20 hours, and the state of wear of the test piece 22 after that is evaluated in three stages: ○; almost no wear, Δ; The results were evaluated and the results are shown in Table 1.
[0032]
Evaluation test of brake squeal:
The solutions obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were applied to various parts of the above-described disc brake device 10 and dried. Thereafter, the presence or absence of a brake squeal is checked by operating the disk brake device 10 in the actual vehicle, and the state of the brake squeal is determined as follows: ；; no or almost no squeal; △; , And the results are shown in Table 1.
[0033]
[Table 1]

[0034]
Therefore, according to the results of the various experiments, as shown in Table 1, in Examples 1 to 4, no abrasion of the test piece 22 was observed, and no brake noise was generated due to the wear. .
[0035]
In addition, the effects obtained in Examples 1 to 4 are also applied to a friction reducing agent including a microcapsule containing a predetermined lubricant in another lubricant having the same or different properties as the lubricant. Approximately the same effect was obtained. Further, in the system in which the lubricant is also mixed in the binder (Example 4), the generation of the brake squeal can be further suppressed.
[0036]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress brake squeal for a long period of time without employing a special structure on the application side, and at the time of applying the friction reducing agent. Workability can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic exploded perspective view showing an example of a brake device to which a friction reducing agent of the present invention is applied.
FIG. 2 is a sectional view of the brake pad in a direction along the line AA in FIG. 1;
FIG. 3 is a conceptual diagram for explaining a friction and wear tester.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Disc brake device 11 Brake pad 14 Pad clip 16A Claw 17 Friction material 17A Side 18 Back metal 19 Shim 20A Piston

Claims (9)

A friction reducing agent comprising: microcapsules containing a predetermined lubricant; and a binder for attaching the microcapsules to a predetermined application surface. 2. The friction reducing agent according to claim 1, wherein a dry film can be formed by drying and solidifying or curing the binder. The friction reducing agent according to claim 1, wherein a lubricant is further contained in the binder. The friction reducing agent according to claim 3, wherein the lubricant contained in the microcapsules and the lubricant contained in the binder have the same property. A method for preventing a brake noise at the time of braking the vehicle by applying the friction reducing agent according to any one of claims 1 to 4 to a disk brake device of the vehicle,
A method for preventing brake squeal, comprising applying the friction reducing agent to a side surface or a back metal of a brake pad provided in the disc brake device. A method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent according to any one of claims 1 to 4 to a disk brake device,
A method for preventing brake squeal, comprising applying the friction reducing agent to at least one of a mating surface of a shim and a back metal of a brake pad provided in the disc brake device. A method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent according to any one of claims 1 to 4 to a disk brake device,
A method for preventing brake squeal, comprising applying the friction reducing agent to at least one of a piston and a pawl provided in the disc brake device. The method according to claim 7, wherein the friction reducing agent is further applied between a back metal of a brake pad provided on the disc brake device and a shim attached to the back metal. . A method for preventing a brake squeal during braking of the vehicle by applying the friction reducing agent according to any one of claims 1 to 4 to a disk brake device,
A method for preventing brake squeal, comprising applying the friction reducing agent to at least one of a pad clip provided on the disc brake device and a back metal side of the brake pad.

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