JPH07224872A - Manufacture of clutch facing - Google Patents

Abstract

PURPOSE:To reliably manufacture a clutch facing which has an excellent high temperature strength and a strength during high rotation connection. CONSTITUTION:Manufacture of a clutch facing comprises a molding process wherein after a base material 6 formed by weaving fibers is preliminarily molded by using resin 7 serving as a binder, the base material is heated and pressurized and a molded product approximately in the shape of a clutch facing is formed; and an impregnating process wherein the molded product is impregnated with rubber 8. A matrix is formed of the base material 6 and crosslinked resin 7 and a pore part is then impregnated with the rubber 8. There is no chance for rubber to form a matrix.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a clutch facing used for a clutch of an automobile.

[0002]

BACKGROUND OF THE INVENTION Dry clutch facings for automobiles are
A base material impregnated with a binder is composed of a base material formed in a string shape from glass fibers, a binder impregnated in the base material, and a compounding agent such as a friction modifier mixed in the binder. After being formed into a disk shape, it is heated and pressed in a mold to be molded.

By using a thermosetting resin such as a phenol resin as the binder, heat resistance and high strength are obtained, and strength at high temperature and wear resistance at high rotation joint are improved. However, since the resin has a low viscosity when impregnated into the base material, it is difficult to add a friction modifier or the like, and the friction coefficient at the time of high rotation joining may be small. On the other hand, when rubber is used as a binder, it has an advantage that it has a high viscosity and a friction modifier and the like can be easily blended, but it has a drawback that it has low strength at high temperatures and low wear resistance at high rotation joints. .

Therefore, in the conventional clutch facing, both the resin and the rubber are used together as the binder to compensate for the defects of both. As a conventional clutch facing manufacturing method, a method is generally used in which both resin and rubber are attached to a string-shaped base material, preformed into a disk shape, heated and pressed to be molded, and then polished. It was However, in this method, the rubber component may partially form a matrix,
There is a drawback that the strength at the time of high rotation joining is low.

Therefore, in recent years, first, a resin is attached to a string-like base material and dried, and then a compounded rubber is further adhered to the base material, which is then wound into a disk shape to be preformed, and then heated and pressed by a mold. The method of molding is adopted. However, in the above method, the resin is attached so as to cover the surface of the string-shaped base material,
Further, since rubber is attached to the surface of the base material, there is a drawback that the rubber does not impregnate the inside of the cord-shaped base material.
Therefore, there have been problems that the coefficient of friction is lowered and that the friction characteristics are locally varied to cause judder.

Therefore, Japanese Patent Laid-Open No. 5-32796 discloses that
A manufacturing method is disclosed in which a string-shaped base material is impregnated with a resin, mechanically defibrated, rubber is adhered to the string-shaped base material, preformed into a disc shape, and then heated and pressed. According to this method, since the rubber is uniformly attached to each fiber, stable friction characteristics can be obtained.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the clutch facing manufactured by the manufacturing method described in Japanese Patent No. 2796, there is a problem that the wear rate increases as the compounding ratio of rubber increases, and the high temperature strength and the strength at the time of high rotation joint are not sufficient. The present invention has been made in view of the above circumstances, and an object of the present invention is to reliably manufacture a clutch facing having excellent high-temperature strength and strength at the time of high rotation joint.

[0008]

A method for manufacturing a clutch facing of the present invention which solves the above-mentioned problems is a method of preforming a base material formed by weaving fibers by using a resin as a binder, heating and pressurizing the base material into a substantially clutch facing shape. It is characterized by comprising a molding step of forming a molded body and an impregnation step of impregnating the molded body with rubber.

[0009]

In the method for manufacturing the clutch facing of the present invention, first, a base material formed by weaving fibers is prepared. This base material is impregnated with a resin, and is preformed into, for example, a perforated disk shape. A cord-shaped substrate is wound into a spiral shape or a thermoid shape and dried to form a preform. Then, it is heated and pressed in a mold or the like to obtain a molded body.

At this time, the impregnated resin is cured in the molded body, and the fibers are in a state of being bonded by crosslinking with the resin. And when rubber is impregnated in the next impregnation step,
The rubber is impregnated into the pores formed during the cross-linking with the resin, and is held in place by the subsequent drying and heat treatment. Therefore, in the clutch facing obtained by the present invention, since the fibers are in a state of being crosslinked with the resin, the high temperature strength and the strength at the time of high rotation splicing are excellent. Since the rubber is evenly held and present in the crosslinked structure of the resin, a large amount of friction modifier and the like can be stably and uniformly supplied at the time of joining, and stable friction characteristics can be obtained.

Further, by performing the impregnation step by providing a pressure difference between the inside and outside of the molded body, it becomes easier to impregnate the rubber into the pores of the molded body. Therefore, the density of the clutch facing becomes higher and the performance becomes stable. Considering the rubber impregnability, it is desirable that the porosity of the molded body is high,
The strength decreases as the porosity increases. Therefore, it is desirable that the porosity be in the range of 20 to 50%. When the porosity is less than 20%, the impregnation of rubber is reduced, so that the friction characteristics are deteriorated, and when it exceeds 50%, the strength becomes too low. By providing a pressure difference inside and outside the molded body such as vacuuming or pressurizing during the impregnation step, the rubber can be more reliably impregnated into the pores, and the porosity of the molded body can be 2
Stable friction characteristics can be obtained even at about 0%.

[0012]

EXAMPLES Hereinafter, examples and comparative examples will be specifically described. (Example) A glass roving prepared by aligning glass fibers having a diameter of 6 to 9 μm was prepared, and immersed in a resol type melamine modified phenol resin solution to attach a phenol resin. The amount of adhesion is 30 to 50 parts by weight based on 100 parts by weight of glass roving in terms of phenol resin solid content.

The glass roving to which the phenol resin is attached is dried at 100 to 120 ° C. and wound in a spiral or thermoid form into a perforated disk-shaped preform, which is then heated in a mold at a temperature of 150 to 180 ° C. , Pressure 1.
A molded body was obtained by molding at 0 to 1.5 Pa. The porosity of this molded product was 30%. Next, a compounded rubber solution having the following composition was prepared.

SBR (rubber) 15 to 50 wt% Barium sulfate (friction modifier) 15 to 50 wt% Organic dust 5 to 15 wt% Vulcanizing agent / vulcanization accelerator 10 to 35 wt% Then, in the impregnating apparatus shown in FIG. A molded body was placed and impregnated with the compounded rubber solution.

Here, the impregnating apparatus shown in FIG.
And a vacuum pump 2 connected to the upper part of the vacuum container 1 via a cock 20, and a container 3 connected to the lower part of the vacuum container 1 via a cock 30 and containing the compounded rubber solution 4. An inner container 10 having an opening at the top is put in the vacuum container 1, and a molded body 5 is arranged in the inner container 10.

In the impregnation step, the molded body 5 is placed in the inner container 10 to seal the vacuum container 1, the cock 30 is closed and the cock 20 is opened to drive the vacuum pump 2. Then, after confirming that the inside of the vacuum container 1 is -100 Pa (-750 mmHg) by the vacuum gauge 21, the cock 20 is closed and the cock 30 is closed.
Is opened and the compounded rubber solution 4 is supplied into the inner container 10.

The compounded rubber solution 4 until the molded body 5 is sufficiently immersed.
, The cock 30 is closed, the cock 20 is opened, and the atmosphere is introduced into the vacuum container 1. At this time, the pores in the molded body 5 are in a vacuum state, and the compounded rubber solution 4 is impregnated into the pores by the atmospheric pressure. The molded body 5 is kept under atmospheric pressure for at least 1 hour or more so that the pores inside the molded body 5 are sufficiently impregnated. The impregnated amount of the compounded rubber solution 4 is 30% by weight in terms of solid content.

Thereafter, the molded body 5 was dried at 100 to 120 ° C., then heat treated at 200 to 250 ° C. for 4 to 5 hours and polished to obtain a clutch facing having a desired shape. (Comparative Example) This comparative example uses the manufacturing method described in JP-A-5-32796. First, the same compounded rubber solution 4 as in the example was impregnated into a glass roving to which the same phenol resin as in the example was attached. Compounded rubber solution 4
The impregnation amount of is 30 % by weight in terms of solid content.

Next, after drying at 100 to 120 ° C., it was molded in a mold at a temperature of 150 to 180 ° C. and a pressure of 1.5 to 2.0 Pa, and polished to obtain a clutch facing having the same shape as that of the embodiment. . (Test) A plurality of types of clutches were obtained in the same manner as in the above-described Examples and Comparative Examples, except that the impregnated amount (blending rate) of the compounded rubber solution 4 was changed by adjusting the porosity of the resin-only molded body. Facing manufactured. And for each clutch facing, friction coefficient at high rotation joint (condition 4000 rpm, 200 ° C.), wear rate at high rotation joint (condition 4000 rpm, 200 ° C.) and 200
The burst strength at ° C (rotational increase at a condition of 200 rpm / min) was measured. The results are shown in FIGS. 2 to 4, respectively.

As shown in FIG. 2, the clutch facings of the examples show a tendency that the rubber compounding ratio increases and the friction coefficient at the time of high rotation coupling increases, and has the same preferable characteristics as the comparative examples. I understand. Meanwhile, FIG. 3 and FIG.
The wear rate and the burst strength tend to deteriorate as the rubber compounding ratio increases, but the tendency is smaller in the example than in the comparative example, and the rubber compounding ratio in the example is 20 to 45% by weight. If it is%, it is clear that it satisfies the level required for clutch facing.

5 and 6 are schematic views of the internal structures of the clutch facings of the examples and comparative examples. In the embodiment, as shown in FIG. 5, the glass rovings 6 are cross-linked with each other by the resin 7, and the rubber 8 is present in the cross-linking gap. However, in the comparative example shown in FIG. 6, the glass roving 6 is made of resin 7
However, they are independently present in the sea of rubber 8 like islands. Therefore, in the embodiment, since the matrix is composed of the cross-linked resin 7,
It is considered that the matrix exhibited higher strength than the comparative example in which the matrix was composed of rubber 8, and as a result, the wear rate was also reduced.

Although glass roving was used as the base material in this embodiment, glass fiber, ceramic fiber,
Various kinds of carbon fibers, inorganic fibers such as rock wool, metal fibers such as copper wires and brass wires, organic fibers such as aromatic polyamide fibers, rayon and acrylonitrile fibers can be selected and used. The base material has a yarn shape, a roving shape, a felt shape, a ribbon shape, a string shape, or the like, and those formed from the above long fibers or short fibers can be used.

As the resin, in addition to the phenol resin used in this embodiment, a thermosetting resin such as a straight phenol resin, a melamine resin, a phthalate resin and various modified phenol resins can be used. And SB as rubber
In addition to R, BR, IR, EPM, CR, NBR, CS
Various rubbers such as M and ACM can be used. SBR and NBR are particularly preferable.

As the friction modifier, clay, talc, graphite, cashew dust, lead sulfate and the like can be used in addition to those used in the above-mentioned examples. Further, in the present embodiment, the difference between the reduced pressure and the atmospheric pressure is used as the pressure difference, but the impregnation may be performed in the atmospheric pressure state where there is no pressure difference, or the pressure difference may be provided by using pressurized air or the like.

[0025]

That is, according to the method for producing a clutch facing of the present invention, since the matrix can be reliably formed from the crosslinked resin and the rubber is prevented from forming the matrix, the friction characteristics, the high temperature strength and the high rotation joint are obtained. It is possible to stably and reliably manufacture the clutch facing having excellent strength.

Further, by providing a pressure difference inside and outside the molded body in the impregnation step, impregnation becomes easier, the number of steps can be reduced, and the performance of the obtained clutch facing is further improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an impregnating device used in a manufacturing method according to an embodiment.

FIG. 2 is a graph showing a relationship between a rubber compounding ratio and a friction coefficient at high rotation.

FIG. 3 is a graph showing the relationship between the rubber compounding rate and the wear rate at high rotation speed.

FIG. 4 is a graph showing the relationship between the rubber compounding ratio and the burst strength at 200 ° C.

FIG. 5 is a schematic diagram of the structure of the clutch facing obtained in the example.

FIG. 6 is a schematic diagram of a structure of a clutch facing obtained in a comparative example.

[Explanation of symbols]

1: Vacuum container 2: Vacuum pump 3: Container 4: Compounded rubber solution 5: Molded body 6: Glass roving (base material) 7: Resin 8: Rubber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // B29L 31:30

Claims (2)

[Claims] 1. A molding step of pre-molding a base material formed by weaving fibers using a resin as a binder, followed by heating and pressing to form a substantially clutch facing shaped molded body, and an impregnating step of impregnating the molded body with rubber. And a clutch facing manufacturing method. 2. The method for producing a clutch facing according to claim 1, wherein the impregnating step is performed by providing a pressure difference so that the pressure inside the molded body is lower than that outside the molded body.