JPH11193842A - Friction material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction material which is excellent in heat resistance and has the property of low-hardness material by spraying a friction material in which low-hardness material having a hardness lower than that of a base metal to the base metal to provide a friction coat for covering the base material. SOLUTION: A powdery friction material 3a obtained by adding tin in a copper alloy is set in a spray gun 5. The friction material 3a is sprayed to the surface of a base material 2 by HVOF spraying using oxygen-propylene gas. The friction material 3a is heated by a heat source 5a of the spray gun 5 to cover the base material 2 in its half-fused state. As the material is thus sprayed, fusion of the friction material 3a requires a very short time from when the material passes through the heat source 5a to when it is covered with the base material 2, so that the tin in the friction material 3a is hardly fused and coupled to the copper alloy. Accordingly, the seizure resistance and vibration inhibit force possessed by the tin which is a low-hardness material will not be damaged, so it is possible to obtain the friction material which has the seizure resistance and vibration inhibit force equal to those of an organic friction material and is excellent in strength and heat resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction material used for a clutch or a brake of a vehicle.

[0002]

2. Description of the Related Art Conventionally, friction materials used for clutches and brakes for vehicles are roughly classified into two types: organic friction materials and metal friction materials. The organic friction material is made of glass fibers in a string shape, and a metal resin such as brass for improving heat dissipation is bundled therein, and a binding resin and a compound rubber obtained by adding a friction modifier or the like to the string are used. It is impregnated and adhered, wound into a donut shape, thermoformed, and heat-treated. However, the organic friction material has low heat resistance, and when the temperature is 350 ° C. or more, the friction coefficient decreases and the amount of wear increases.

On the other hand, a metal-based friction material forms a friction member by sintering metal, which is a friction material. Since metal is used as the friction material, it has better heat resistance than organic friction materials, and is used for high loads.

[0004]

However, since the above-mentioned metal-based friction material is formed by sintering, the low-hardness material in the friction material is thermally decomposed during sintering and is fused and bonded to metal-based atoms. As a result, the characteristics (seizure resistance, vibration suppression force) of the low hardness material could not be sufficiently obtained. Therefore, when used in a vehicle clutch, the quietness and friction resistance of the device are inferior to organic friction materials, and metal friction materials are not suitable for use in ordinary passenger cars.

[0005] Therefore, an object of the present invention is to provide a friction material having excellent heat resistance and sufficient characteristics of a low-hardness material in order to solve the above problems.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a method in which a friction material in which a base material is added with a low hardness material having a lower hardness than the base material is coated on the base material by thermal spraying. A friction material having a friction film.

According to the first aspect, since the friction material is coated on the base material by thermal spraying, the time required for melting the friction material is very short as compared with sintering, and the low-hardness material in the friction material is completely removed from the base material. Does not fuse with the material. Therefore, the seizure resistance and vibration suppression power of the low hardness material are not impaired,
A friction material having seizure resistance and vibration suppression power comparable to an organic friction material and having excellent heat resistance can be obtained.

As a second aspect of the present invention, the base material of the friction material is copper, copper alloy, steel, alloy steel, nickel, nickel alloy, titanium, titanium alloy, or a combination thereof. When used, a metal-based friction material can be formed, and a friction material advantageous in strength can be formed.

Further, when a base material made of glass, ceramics, carbon, or an alloy containing glass, ceramics, or carbon is used as the base material, it is advantageous in terms of heat insulation and weight. A simple friction material can be formed.

As a low-hardness material, a soft metal such as tin, silver, zinc, lead, bismuth, cadmium, indium, or a mixture of a plurality of types of soft metals is used as the low-hardness material. It is preferable to use metal.

As a low-hardness material, a solid lubricant such as graphite or molybdenum disulfide, tungsten disulfide, lead antimony sulfide or the like, or a phenol resin, a fluororesin, an epoxy resin, a polyimide is preferably used. When a resin such as a resin is used, it has a lower hardness than a soft metal, so that a smaller amount of addition is sufficient as compared with a soft metal.

Further, when a groove is formed from the friction film to the substrate as set forth in claim 16 to claim 18, when distortion occurs in the friction material, the strain stress is concentrated on the bottom of the groove. It is possible to prevent the friction coating sprayed on the surface from peeling off from the substrate due to distortion as much as possible.

Further, when the friction films are coated on both surfaces of the base material so as not to overlap in the axial direction of the base material, the influence of frictional heat transmitted to the base material is reduced. As a result, the cooling efficiency of the substrate is improved.

As shown in claims 21 to 23,
Providing a suitable friction material according to the intended use of the friction material by coating the friction film with a plurality of layers or changing the coating thickness of the friction film according to each location of the substrate or the surface of the substrate. It becomes possible.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of the friction material of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. FIG. 3 is a diagram illustrating a method of manufacturing a friction material according to the present embodiment.

The friction material 1 in the present embodiment is disposed between a prime mover (not shown) and a transmission (not shown), and can transmit power from the prime mover to the transmission side by frictional engagement. Dry friction material used for clutch. The friction material 1 includes a hollow base material 2 and a friction film 3. In addition, friction material 1
A groove 4 is provided radially on the side on which the friction film 3 is formed.

The substrate 2 is made of a rolled material of a steel alloy and has a thickness of 1.8 mm. The friction film 3 is made of a copper alloy as a base material, to which 30% by volume of tin is added as a low-hardness material having a lower hardness than the copper alloy, and has a thickness of 0.7 mm.

Next, a method of manufacturing the friction material 1 will be described with reference to FIG. First, a powdery friction material 3a formed by adding tin to a copper alloy is set in the thermal spray gun 5. In the present embodiment, the friction material 3a is sprayed on the surface of the base material 2 by HVOF spraying using oxygen-propylene gas as a spraying method. The set friction material 3a is used as the heat source 5 of the thermal spray gun 5.
The substrate 2 is heated and heated in a semi-molten state. By using the thermal spraying in this manner, the friction material 3a is melted for a very short time (0.001 to 0.05 seconds) from when the friction material 3a passes through the heat source 5a to when the friction material 3a is coated on the base material 2. Most of the tin in the material 3a does not fuse with the copper alloy. Therefore, the seizure resistance and vibration suppression force of tin, which is a low-hardness material, are not impaired, and the seizure resistance and vibration suppression power of an organic friction material are excellent, and the friction is excellent in strength and heat resistance. Material 1 can be obtained.

The groove 4 of the friction material 1 is provided radially from the friction film 3 side to the base material 2 and the width of the groove 4 is 1.5.
The diameter and the depth are 1.6 mm from the surface of the friction coating 3. Even if the friction material 1 is distorted when the friction material 1 transmits power from the prime mover due to the groove 4, stress concentrates on the bottom 4a of the groove 4, so that the friction film 3 is not distorted. Therefore, even if the friction film 3 is coated on the surface of the base material 2 by thermal spraying,
The friction film 3 does not peel off from the base material 2 due to distortion due to use of the clutch.

In the present embodiment, the base material is made of a copper alloy. However, a metal other than the copper alloy, or a nonmetal such as glass or ceramic may be used. For example, when ceramic is used as the base material, The heat insulating effect on the base material is improved, and adverse effects on the base material due to heat can be suppressed. Also,
In the present embodiment, tin is used as the low hardness material to be added. However, the same effect can be obtained by using a soft metal other than tin, such as silver, zinc, or lead, or a white metal obtained by mixing these soft metals. Obtainable. In addition, graphite, molybdenum disulfide, which has a lower hardness than soft metal,
Solid lubricant or epoxy resin such as lead antimony sulfide,
It is also possible to use a phenolic resin, a polyimide resin or a fluororesin resin. In this case, sufficient seizure resistance and vibration suppressing power can be obtained with a smaller amount of addition than a soft metal.

FIGS. 4 and 5 show a friction material 11 according to a second embodiment of the present invention and a friction material 21 according to a third embodiment of the present invention. The second embodiment is different from the above-described embodiment in that the grooves 14 provided on the surface of the friction material are concentric, and the rest is the same as the first embodiment. According to a second embodiment,
This is advantageous in preventing the friction film from peeling when distortion occurs on the inner peripheral side and the outer peripheral side of the friction material 11.

The third embodiment is different from the above-described embodiment in that grooves provided on the surface of the friction material are of two types, that is, a concentric shape 24a and a radial shape 24b, and the other features are the same as those of the first embodiment. is there. According to the third embodiment, the friction material 2
This is advantageous for preventing the friction coating from peeling off when distortion occurs on the inner peripheral side and the outer peripheral side of 1 and when distortion occurs at different parts in the circumferential direction.

Next, FIG. 6 shows a fourth embodiment which is a specific configuration when the friction material of the present invention is actually adopted for a clutch disk. FIG. 6 is a plan view showing a case where the thermal spraying is directly performed on the plate material 32 as the base material, and FIG. 7 is a sectional view taken along the line BB of FIG. In the fourth embodiment, it is possible to discharge abrasion powder generated by engagement / disengagement of the clutch to the outside, and since the groove 34 has an angle with respect to the radial direction, the fourth embodiment is different from the first embodiment. Groove 34
Becomes longer, and the durability against the frictional resistance applied to the friction film 33 when the clutch rotates is improved. In the fourth embodiment, the clutch disk provided with the damper mechanism on the inner peripheral side of the clutch disk is disclosed. However, it is needless to say that the clutch disk may not be provided with the damper mechanism.

FIG. 12 is a view showing a fifth embodiment. In the fourth embodiment, a friction coating is not directly sprayed on a plate, but a cone-shaped plate 37 in which a friction coating 36 is previously coated. 3 shows a case where the disc spring 35 is mounted. In the fifth embodiment, a case where one disc spring 35 is used is shown, but a flat disc spring may be employed. Further, two flat disk springs can be stacked to increase the spring load.

FIG. 8 is a view showing a sixth embodiment.
The damper mechanism on the inner peripheral side of the clutch disk is omitted. Sixth
In the embodiment, the friction coating 43 is sprayed in such a shape that there is no portion protruding in the rotation direction of the clutch disk, so that the friction coating 43 can be separated from the base material 42 by engagement of the clutch. Can be eliminated.

FIG. 9 shows a seventh embodiment. In this embodiment, a friction film 5 is coated on one surface 52a and the other surface 52b of a disk plate 52 as a base material.
Each surface is covered so that 3a and 53b may not overlap. By coating in this manner, the effect of frictional heat transmitted to the disk plate 52 is reduced, and the cooling efficiency of the disk plate 52 is improved.

FIG. 10 shows an eighth embodiment. FIG.
In this embodiment, a friction film 63 is formed on each back plate 62 using a back plate 62 separate from the disk spring 65 as a base material, and the two back plates 62 are attached to the disk spring 65 with rivets 66. Since the friction material according to the present invention is excellent in strength and heat resistance, the coating area of the friction coating 63 can be reduced as shown in FIG. In the seventh embodiment, escape grooves 68a, 69a are formed in the pressure plate 68 and the flywheel 69 so that the pressure plate 68 and the flywheel 69 do not contact the rivet 66. The back plate 62 and the disc spring 65
Can be attached by welding instead of rivets.

FIG. 11 is a diagram showing a ninth embodiment of the present invention. The ninth embodiment shows a case where the friction material of the present invention is used as a thrust lining member for generating hysteresis in the torsional characteristics of a clutch disk. According to the ninth embodiment, the hub 7 as the base material
2, the thrust lining member 73, which is a friction film, does not need to be provided separately, so that the number of parts can be reduced and the axial size of the clutch disk can be shortened.

FIGS. 13 and 14 show a tenth embodiment of the present invention. In the tenth embodiment, a spring member 85 is further provided between two back plates 82 coated with a friction film 83. FIG. 13 shows a state in which the clutch is not engaged, and FIG. FIG. 4 shows a cross-sectional view at the time of engagement. According to the tenth embodiment, the impact at the moment of clutch engagement is alleviated by the spring member 85, so that the occurrence of peeling of the friction film 83 can be suppressed.

FIGS. 15 and 16 show an eleventh embodiment of the present invention. FIG. 15 is a sectional view when the clutch is disengaged, and FIG. 16 is a sectional view when the clutch is engaged. The eleventh embodiment shows a case in which a friction film 97 is formed by thermal spraying using the head of the rivet 96 as a base material in a clutch disk in which friction facings 93 are attached to both surfaces of a disk spring 95 with rivets 96. . According to the eleventh embodiment, it is possible to provide a clutch disk whose heat resistance is improved by the area of the friction film 97 with respect to the conventional friction facing and which can withstand a high load.

In the above-described embodiment, the dry friction material used for the clutch for transmitting the power from the prime mover to the transmission by frictional engagement has been described. However, the present invention is not limited to the dry friction material. However, the present invention can also be applied to wet friction materials such as clutches and brakes of transmissions.

When the base material is coated with a plurality of friction films, for example, if the base material of the friction film coated on the base material side is metal, a high-strength friction film is formed, and the friction film is formed on the base material. It is possible to provide a friction material having seizure resistance and vibration suppression power similar to that of an organic friction material without peeling off from the friction material. If the friction film coated on the base material side is made of non-metal such as ceramics, it acts as a heat insulating material with the friction material surface, so the heat generated on the friction material surface when the clutch is engaged will be applied to the base material. It is difficult to be transmitted, and deterioration of the effect of the substrate as a spring can be suppressed.

Further, the coating thickness of the friction film is made to be different at each position of the base material (for example, one surface and the other surface of the base material, or the inner and outer peripheral sides of the base material). Thus, it is possible to form an optimal friction material according to the use environment.

[0035]

According to the first aspect, since the friction material is coated on the base material by thermal spraying, the friction material is melted in a much shorter time than sintering, and the low-hardness material in the friction material is completely removed from the base material. Does not fuse with the material. Therefore, the seizure resistance and vibration suppression force of the low-hardness material are not impaired, and a friction material having seizure resistance and vibration suppression force comparable to an organic friction material and having excellent heat resistance can be obtained.

As a second aspect of the present invention, the base material of the friction material is copper, copper alloy, steel, alloy steel, nickel, nickel alloy, titanium, titanium alloy, or a combination thereof. When used, a metal-based friction material can be formed, and a friction material advantageous in strength can be formed.

In addition, when the base material is made of glass, ceramics, carbon, or an alloy containing glass, ceramics, or carbon, it is advantageous in terms of heat insulation and weight. A simple friction material can be formed.

As a low-hardness material, a soft metal such as tin, silver, zinc, lead, bismuth, cadmium, indium or a mixture of a plurality of types of soft metals is used as the low-hardness material. It is preferable to use metal.

As a low-hardness material, graphite or a solid lubricant such as molybdenum disulfide, tungsten disulfide, lead antimony sulfide or the like, a phenol resin, a fluororesin, an epoxy resin, a polyimide is used as the low-hardness material. When a resin such as a resin is used, it has a lower hardness than a soft metal, so that a smaller amount of addition is sufficient as compared with a soft metal.

According to the twelfth and thirteenth aspects, the base material is made of a rolled or ingot material of a metal such as copper, copper alloy, steel, alloy steel, nickel, nickel alloy, titanium, and titanium alloy. A strong substrate is obtained, which is advantageous in strength.

According to the fourteenth and fifteenth aspects, when the base material is made of a nonmetal such as glass, carbon, or ceramic, it is lighter than metal and is advantageous in weight.

According to the sixteenth to eighteenth aspects, by forming a groove from the friction film to the substrate, when the friction material is distorted, the stress of the distortion is concentrated on the bottom of the groove. The friction coating sprayed on the substrate can be prevented from peeling off from the substrate due to the distortion as much as possible.

According to the nineteenth and twentieth aspects, by coating the friction coating on both surfaces of the base material so as not to overlap in the axial direction of the base material, the influence of frictional heat transmitted to the base material can be reduced, The cooling efficiency of the substrate is also improved.

According to the twenty-first to twenty-third aspects, a friction material is coated by coating a plurality of friction films, or by changing the coating thickness of the friction film according to each part of the base material or the surface of the base material. It is possible to provide an appropriate friction material according to the purpose of use.

[Brief description of the drawings]

FIG. 1 is a front view of a friction material according to an embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a diagram illustrating a method of manufacturing a friction material according to the present embodiment.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a third embodiment of the present invention.

FIG. 6 is a diagram showing a fourth embodiment of the present invention.

FIG. 7 is a sectional view taken along the line BB of FIG. 6;

FIG. 8 is a diagram showing a sixth embodiment of the present invention.

FIG. 9 is a diagram showing a seventh embodiment of the present invention.

FIG. 10 is a diagram showing an eighth embodiment of the present invention.

FIG. 11 is a diagram showing a ninth embodiment of the present invention.

FIG. 12 is a diagram showing a fifth embodiment of the present invention.

FIG. 13 is a diagram showing a tenth embodiment of the present invention.

FIG. 14 is a diagram showing another state of FIG. 13;

FIG. 15 is a diagram showing an eleventh embodiment of the present invention.

FIG. 16 is a diagram showing another state of FIG. 15;

[Explanation of symbols]

1, 11, 21 ... friction material 2, 32, 35, 42, 52, 62, 72, 82, 96
... Base materials 3, 33, 36, 43, 53, 63, 73, 83, 97
... Friction film 4, 14, 24a, 24b, 34 ... Groove

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16D 69/02 F16D 69/02 D (72) Inventor Teruo Matsukawa 2-1-1 Asahimachi, Kariya City, Aichi Prefecture Aisin Seiki Co., Ltd. In company

Claims (23)

[Claims] 1. A friction material having a friction film formed by coating a base material by thermal spraying with a friction material obtained by adding a low hardness material having a lower hardness than the base material to the base material. 2. The friction material according to claim 1, wherein said base material is made of metal. 3. The friction material according to claim 1, wherein the base material is made of a non-metal or an alloy containing a non-metal. 4. The base material is copper, copper alloy, steel, alloy steel,
3. The method according to claim 2, wherein the material comprises nickel, a nickel alloy, titanium, a titanium alloy, or a combination thereof.
Friction material. 5. The friction material according to claim 3, wherein the base material is made of glass, ceramics, carbon, or an alloy containing glass, ceramics, and carbon. 6. The friction material according to claim 1, wherein the low hardness material is made of a soft metal or a white metal obtained by mixing a plurality of types of soft metals. 7. The soft metal includes tin, silver, zinc, lead,
7. The friction material according to claim 6, comprising bismuth, cadmium, indium or a combination thereof. 8. The friction material according to claim 1, wherein the low-hardness material is made of a solid lubricant. 9. The friction material according to claim 8, wherein the solid lubricant is made of graphite, molybdenum disulfide, tungsten disulfide, lead antimony sulfide, or a combination thereof. 10. The friction material according to claim 1, wherein the low hardness material of the friction material is a resin. 11. The friction material according to claim 10, wherein the resin is an epoxy resin, a phenol resin, a polyimide resin, or a fluororesin. 12. The friction material according to claim 1, wherein the base material is made of a metal. 13. The material according to claim 12, wherein the base material is made of a rolled material or an ingot material such as copper, copper alloy, steel, alloy steel, nickel, nickel alloy, titanium, and titanium alloy.
Friction material. 14. The friction material according to claim 1, wherein the base material is made of a nonmetal or an alloy containing a nonmetal. 15. The base material is a glass-based, carbon-based,
15. The friction material according to claim 14, wherein the friction material is made of a non-metal such as ceramics or an alloy containing these. 16. A groove is formed on the surface of the friction material from the friction film to the base material.
The friction material according to claim 15. 17. The friction material according to claim 16, wherein the grooves on the surface of the friction material are formed radially. 18. The friction material according to claim 16, wherein the groove on the surface of the friction material is formed concentrically. 19. The friction material according to claim 1, wherein said friction film is coated on both surfaces of said base material. 20. The friction material according to claim 1, wherein the friction films coated on both surfaces of the base material are coated so as not to overlap in the axial direction. 21. The friction material according to claim 1, wherein a plurality of the friction films are coated. 22. The friction material according to claim 1, wherein a coating thickness of the friction film is different depending on each position of the base material. 23. The friction material according to claim 22, wherein the coating thickness of the friction coating is different between one surface and the other surface of the base material.