JPS6069336A - Friction member - Google Patents

Abstract

PURPOSE:To tighten adhesion of an iron base plate and a friction body by applying soft nitriding treatment on the surface of the iron base plate. CONSTITUTION:A compound layer 2 is formed on the upper surface of an iron base plate 1, and the compound layer 2 is provided with a lot of kont-like or netlike projections 3. Adhesives 4 permeates in a space portion between the projections 3, and a friction body 5 is adhered to the iron base plate 1 by the adhesives 4. As the projections 3 are thus formed on the compound layer 2, the adhesive surface of the compound layer 2 and the adhesives 4 is increased so as to tighten adhesion of the iron base plate 1 and the friction body 5.

Description

[Detailed description of the invention] (Technical field) The present invention relates to improvements in friction members used in vehicles and the like.

[Prior art]

Many friction members are used in vehicles and the like.

For example, in an automobile automatic transmission, a friction member is used that does not function as a clutch in oil. This 1′! The J friction member consists of an iron substrate and a friction body made of paper as a base material and made hard by impregnating this paper with a friction modifier and resin, and the friction body is integrally bonded onto the iron substrate. be.

By the way, in the above-mentioned friction member, in order to strengthen the adhesion between the iron substrate and the friction body, conventionally, the surface of the iron substrate is subjected to a surface treatment such as shot blasting or V-doped blasting, and the surface is mechanically roughened. After that, the friction body is bonded to the surface of the iron substrate using an adhesive or the like.

When the surface of the iron substrate is subjected to shot blasting, sandblasting, etc. in this way, the general adhesion between the iron substrate and the friction body is improved. However, considering the usage of the friction member, it is preferable to use a friction member with even stronger adhesive force.

[Purpose of the invention]

The present invention has been made in view of the actual situation of the prior art described above. The purpose of the present invention is to improve the adhesive force between the iron substrate and the friction body, so that even when a strong displacement such as bending is applied, the iron VM plate and the friction body do not peel or hardly peel. To provide a friction member that has a strong adhesive force to the extent that it does not bind.

[Structure of the invention]

As a result of numerous experiments, the inventor of the present invention found that by subjecting the surface of an iron substrate to soft nitriding treatment and adhering a friction element to the surface, the adhesion between the iron substrate and the friction element can be strengthened. The present invention was completed based on the above findings.

The friction member of the present invention is composed of an iron substrate and a friction body integrally bonded to the substrate-L, and the iron substrate to which the friction body is bonded is subjected to nitrocarburizing treatment using a molten salt bath. The invention is characterized in that the adhesion between the friction body and the substrate is strengthened.

1 here? Typical examples of friction members include friction members used in manual transmissions or automatic transmissions, and friction members used in brake mechanisms. In this case, the iron substrate is a core plate of a friction member of a transmission, or a back metal of a disc brake pad, drum brake, etc. The iron substrate may be made of carbon steel, alloy steel, cast iron, cast steel, iron-based sintered material, or the like.

By the way, iron lII! which characterizes the friction member of the present invention! IM
The plate has been subjected to soft nitriding treatment using a melting JP bath.

The soft nitriding treatment is carried out by holding the iron substrate in a molten salt bath containing cyanide and cyanate as main components. The treatment temperature is lower than 723°C, which is the transformation point of steel.
It is desirable to set the temperature to about 70°C. Retention time is 0.5~
2.0 hours is desirable.

Additionally, air can be blown into the molten salt bath to maintain a constant suspension of cyanate.

A nitrogen-containing compound layer is formed on the surface of the iron 11 steel plate subjected to soft nitriding treatment as described above. When the iron substrate is made of carbon steel, a compound layer mainly composed of Fe 3NXFe aN is formed. If the iron substrate is alloy steel, F
A compound layer containing nitride such as CrN in addition to e3N1F04N is formed. The above-mentioned compound layer often has bump-like or network-like projections. Therefore, the surface roughness of the iron substrate subjected to soft nitriding is in the range of Ra0.1 to 2.0.

The friction body is pressed against the other party and comes into direct sliding contact with the other party. The friction body is integrally bonded to a soft-nitrided iron substrate. The friction body may be a paper friction material based on paper. Paper friction materials are made by using paper as a base material and impregnating gaps between paper fibers with various known friction modifiers and hardening resins. Phenol resin is usually used as the resin. IIJ
A plurality of sheets of paper are generally used in a stacked manner. As other friction bodies, those based on asbestos, glass fiber, or metal fiber can be used. These materials are usually mixed with friction modifiers, binders, etc. and molded in a mold, and are known as mold-type friction bodies. Specifically, the brake lining of a disc brake or drum brake is suitable for the friction of the present invention.

A phenolic resin can be used as the adhesive for bonding the iron substrate and the friction body. Phenolic resin refers to a resin obtained by polycondensing one or more phenols such as phenol and cresol with formaldehyde or a compound that is a source thereof.

The figure shows an enlarged sectional view of a typical S ring member of the present invention. In this figure, a compound layer 2 is formed on the upper surface of an iron substrate 1. A large number of protrusions 3 in the form of a mesh are formed in this compound layer 2.As shown in the figure, the protrusions 3 have a shape that becomes thicker toward the tip.

An adhesive 4 penetrates into the space between the protrusions 3, and the friction body 5 is adhered to the iron substrate 1 by this adhesive 4. Here, since the protrusions 3 are formed on the compound layer 2, the bonding area between the compound layer 2 and the adhesive 4 increases accordingly.

(Effects of the Invention) In the friction member of the present invention, the adhesion between the iron substrate and the friction body is strong.Therefore, even when a large displacement such as bending is applied to the friction member, the friction body does not peel off. Although there are various possible reasons for this,
At present, the main reason is assumed to be as follows.

That is, when an iron substrate is subjected to soft nitriding treatment, a compound layer having bump-like or mesh-like protrusions is generated on the surface of the iron substrate as described above. It is presumed that the adhesive penetrates between the protrusions of this compound layer, increasing the so-called anchor effect, and that this increase in anchor effect strengthens the adhesion between the friction body and the iron l11.1 plate.

Further, in the friction member of the present invention, since a compound layer is formed on the surface of the iron substrate by soft nitriding treatment, the rust prevention properties of the substrate can be improved.

〔Example〕

This embodiment is applied to a friction member used in an automatic transmission of an automobile.

This friction member is made by t2 X! The board has a diameter of 127m1
The core plate has a size of 102nv in diameter and 1.5nlnl in thickness, and is made of carbon steel (S-35CM).The core plate is placed in a molten salt bath mainly composed of cyanide and cyanate. Soft nitriding treatment is performed by immersing the steel.

The treatment temperature was 570°C and the treatment time was 1 hour.

The surface roughness of the core plate subjected to such nitrocarburizing treatment was Ra0.28. Also, the surface hardness is 1-IRC20
Met. Next, the surface of the core plate subjected to soft nitriding treatment was cleaned, an adhesive was applied to the surface, and then dried. In this case, a phenolic resin was used as the adhesive, and drying was performed with warm air. Next, we created a friction body based on paper.
It was adhered to the nitrocarburized surface of the core plate, and then molded and heat treated. Adhesion was performed using a molding press. Further, the heat treatment was carried out in a hot air atmosphere by incorporating it into a crimping jig.

A 90 degree bending test was conducted on 10 friction members manufactured by the method described above. The 90 degree bending test was conducted by bending the center portion of the friction member 90 degrees in a dry state.

In this test, the friction body of 10 out of 10 1710 members did not separate from the core plate. Therefore, the survival rate of the friction member of this example in the bending test is 1
It was 00%.

Next, as a comparative example, 90% of 10 friction members were manufactured without nitrocarburizing treatment and under all other conditions as in the example.
A degree bending [y test was also conducted. The test result is 1113
The survival rate of the body was approximately 70%.

As another comparative example, 90% of a friction member was manufactured by treating the surface of the core plate with various acids as conventionally practiced, and then adhering the friction body in the same manner as in the example.
A bending test was also conducted. Acid treatments include sulfuric acid treatment, zinc phosphate treatment, phosphoric acid treatment, and manganese phosphate treatment.

The adhesive used was the same as in the previous example. As a result of the test, the residual rate of the friction body was 5 when treated with sulfuric acid.
0%, and when treated with zinc phosphate, the residual rate of the friction body is 10 to 20%, and when treated with phosphoric acid, the residual rate is 10 to 20%, and the residual rate of the friction body is 10 to 20% when treated with zinc phosphate. When treated, the residual rate was 10 to 20%.

From the above test results, it can be seen that when the core plate is subjected to soft nitriding 9Q treatment, the adhesive force between the core plate and the friction body increases.

[Brief explanation of the drawing]

The figure is an enlarged sectional view of a typical friction member of the present invention.
' In the figure, 1 is an iron substrate, 2 is a compound layer, 3 is a protrusion, 4 is an adhesive, and 5 is a friction body.

Claims (1)

[Scope of Claims] (1) In a friction member composed of an iron substrate and a friction body integrally bonded to the substrate, the iron substrate to which the friction body is bonded is immersed in a molten salt bath. A friction member characterized by being subjected to soft nitriding treatment to strengthen the adhesion between the friction body and the substrate. (2>82!F' The friction member according to claim 1, wherein the substrate is a core plate of an automatic transmission of a vehicle, and the friction body is a paper friction material based on paper. (3) Iron substrate is a back metal of a disc brake pad of a vehicle, and the friction member is a molded friction material. (4) The surface of the iron substrate has a surface roughness Ra of 0°. The friction member according to claim 1, which is formed of the surfaces of two or more nitrocarburized layers. (5) The friction member according to claim 1, wherein the adhesive is a phenolic adhesive.