JPH039131A - Two-layer clutch facing - Google Patents

Abstract

PURPOSE:To improve burst strength by having reinforcing material on the back side of resin mould group friction material plied together with reinforcing fiber composed of short fiber of specified elasticity and formed into cords in a spirally wound manner. CONSTITUTION:Friction base material, resin mould group, is made up with fiber base material composed of nonorganic fiber such as glass fiber and heat resistant organic fiber, bonding agent such as phenol resin and friction regulating agent, and bonded on the back side by binder integrally with reinforcing material, which is composed of reinforcing fiber and formed into cords in a spirally wound manner. The reinforcing fiber is plied together with short fiber, which is used with different types of aromatic polyamide fiber or aromatic polyamide fiber and carbon fiber and is 7000kgf/mm<2> or more in elasticity, and formed into cords. It is thus possible to improve burst strength and reduce unbalanced quantity, resulting in better durability, lighter wt. and less centrifugal force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a reinforcing material for a resin molded two-layer clutch facing.

[Prior art] As a clutch facing for a clutch disc, a fiber base material such as glass fiber or carbon fiber, a binder such as phenol resin, a friction modifier, etc. are blended, and the mixture is filled into a mold and heated and pressurized. Resin mold-based friction base materials are known. This resin mold type clutch facing lacks mechanical performance such as burst strength when using the friction base material alone, so it has a two-layer structure with a reinforcing material formed on the back side and integrally bonded when heated and pressurized. It is normal to This reinforcement material is
For example, as disclosed in Japanese Unexamined Patent Publication No. 63-203936, it is known that reinforcing fibers such as glass fiber rovings are impregnated with a binder and formed into a string shape, which is then wound into a spiral shape. It is being

With the two-layer clutch facing configured in this way,
The overall performance is realized by the reinforcement material having mechanical properties such as burst strength, and the friction base material having friction properties.

[Problems to be Solved by the Invention] However, even in the above-mentioned conventional two-layer clutch facing, it could not be said that the burst strength sufficiently satisfies the required performance. Therefore, there was a problem that the durability was low and the need for replacement was frequent. Incidentally, if the amount of glass fiber is increased, the burst strength is improved to some extent, but there is a problem that as the amount of strain increases, the amount of unbalance increases, and ff1ffi increases. Also,
The above-mentioned publication discloses the combined use of long fibers of aromatic polyamide together with glass fibers.

Although the weight could be reduced in this way, the amount of imbalance was large and the improvement in burst strength was small.

The present invention aims to improve mechanical performance such as burst strength, reduce unbalance, and reduce weight by improving the composition of the reinforcing material.

[Means for Solving the Problems] The two-layer clutch facing of the present invention is composed of a resin-molded friction base material and a reinforcing material integrally bonded to the back side of the friction base material, and the reinforcing material is made of reinforcing fibers. In a two-layer clutch facing formed by winding the formed string in a spiral shape, the reinforcing fibers include short fibers with an elastic modulus of 7000 kOf/mm2 or more, and the reinforcing fibers are twisted together in the string. It is characterized by

Further, a further improvement of this Talatch facing is characterized in that the reinforcing material is composed of two or more types of short fibers having different moduli of elasticity.

The friction base material is a resin mold type material, and is composed of a fiber base material, a binder, a friction modifier, etc., as in the past.

As the base fiber, inorganic fibers such as glass fibers, ceramic fibers, and metal fibers, or heat-resistant organic fibers such as aromatic polyamide fibers and phenol fibers can be used. This fiber base material usually uses short fibers, and is blended in an amount of 10 to 70 parts by weight in 100 parts by weight of the entire friction base material.

The binder binds and holds the fiber base material and the friction modifier, and as in the past, phenol resin is mainly used. This binder is usually blended in an amount of 5 to 50 parts by weight per 100 parts by weight of the entire friction base material.

The friction modifier adjusts the friction characteristics of the friction base material, and as in the past, rubber dust, cashew dust, graphite, or inorganic powders such as barium sulfate and metal oxides can be used. This friction modifier is usually blended in an amount of 20 to 80 parts by weight per 100 parts by weight of the entire friction base material.

The reinforcing material is integrally bonded to the back side of the friction base material. This reinforcing material is composed of reinforcing fibers and a binder as in the conventional case. The reinforcing fibers are made into strings, wound into a spiral shape, and bound together with a binder.

The greatest feature of the present invention lies in the structure of the reinforcing fibers of the reinforcing material. That is, the reinforcing fiber has an elastic modulus of 700Qkgf/mm.
It contains two or more short fibers, and the string is characterized in that the reinforcing fibers are twisted together.

Conventionally, long fibers have been used as reinforcing fibers, but in the present invention, short fibers with an elastic modulus of 7000 kof/mmz are used, and the short fibers are twisted to form strings.

In the present invention, since the reinforcing material is formed from strings having short fibers, stress concentration is prevented. Therefore, it is possible to improve burst strength and the like.

If the modulus of elasticity of the short fibers is less than 7000k (7 f/mm2), it is difficult to improve the burst strength.If the reinforcing fibers are composed of two or more types of short fibers with different moduli of elasticity, the burst strength can be improved. For example, the combination of different types of aromatic polyamide fibers such as copolyparaphenylene, 3゜4'oxydiphenylene, terephthalamide and polymetaphenylene isophthalamide, and aromatic Various choices can be made, such as the combination of polyamide fibers and carbon fibers.The larger the difference in elastic modulus between the two or more types of short fibers used, the better.

The reinforcing fibers may be composed only of the short fibers described above, or may be a combination of the short fibers and long fibers such as rovings of glass fibers. When long fibers are used together, the short fibers have a content of 40% by volume when the entire reinforcing i-thread is taken as 100.
It is desirable to set the above. When the blending amount of short fibers decreases, it becomes difficult to improve the burst strength.

As the binder, phenolic resin is mainly used as in the past. In addition, by attaching 10 to 15% by weight of a rubber compound together with a phenolic resin to the string, the adhesive force between the two layers of the friction base material and the reinforcing material is improved, and the transfer of the binder to the friction base material is prevented. can do.

To manufacture the two-layer clutch facing of the present invention, a friction base material and a reinforcing material are laminated, placed in a mold at a predetermined temperature, and pressurized. As a result, the two layers are temporarily integrated, and then by heating for a predetermined period of time, the binder and the binder are cured and the two layers are integrally bonded. After cooling, it is polished and shaped into a clutch facing.

[Function] In the two-layer clutch facing of the present invention, the reinforcing fibers of the reinforcing material include short fibers with an elastic modulus of 7000 k (7 f/mm2 or more), and the reinforcing fibers are twisted together in the string. When a large centrifugal force is applied, the stress applied to the string is partially absorbed and reduced by the relative movement of the short fibers, and is uniformly applied to each short fiber.

Conventionally, since strings were formed from long fibers, stress tended to concentrate in the structurally weak parts of the strings, making it impossible to expect an improvement in burst strength. However, in the present invention, the stress is reduced, dispersed, and acts uniformly on each short fiber, and the short fiber has a high elastic modulus, so that the burst strength is improved.

Here, two types of short fibers, FtJ'1. When the above is blended, it is possible to improve mechanical strength such as burst strength with short m fibers having a high elastic modulus. However, if the modulus of elasticity of the string becomes too high, the difference in expansion rate during heating and the difference in contraction rate during cooling with the friction base material will increase, and distortion will likely occur in the resulting clutch facing. Moreover, the amount of unbalance also increases. Therefore, by using short fibers with a small elastic modulus in combination and adjusting the degree of expansion and contraction of the entire string within an appropriate range, it is possible to reduce the amount of unbalance.

[Example code] Hereinafter, this will be explained in detail using examples.

(Example 1) Copolyparaphenylene・3,4-oxydiphenylene・
Terephthalamide ("Technora", aromatic polyamide fiber manufactured by Yojin Co., Ltd., elastic modulus 7000 kclf/mm2)
short fibers (diameter 12 μm, length 38-51 mm), polymetaphenylene isophthalamide (“Conex”, aromatic polyamide fiber manufactured by Yojin Co., Ltd., elastic modulus 900 kgf)
/mm") short fibers (diameter 13~14μm, length 38~
51 mm) and long fiber glass roving (diameter 9 μm,
400TEX) to form a single yarn. These two single yarns were twisted together to obtain a string. The composition of this string was 20% by weight of glass roving, 40% by weight of "Technora" and 40% by weight of "Conex J," and the weight of the string was 1.60 q/m.

This string is impregnated with 10 to 30% by weight of phenolic resin, and further has a weight% of SBR: 26, HAF near, clay: 54, sulfur: 8, zinc oxide: 4, CZ: 0.5, TS.
A rubber compound consisting of :0.5 was deposited in an amount of 10 to 20% by weight. Then, it was wound into a spiral shape to form a perforated disk-shaped reinforcing material.

On the other hand, 42% by weight of a mixture of 27% by weight of short aromatic polyamide fibers and 15% by weight of short fibers of glass fibers, 30% by weight of phenolic resin, 5% by weight of aliphatic polyamide fibers and 23% by weight of barium sulfate, A friction base material was formed by preforming.

Then, the reinforcing material and the friction base material are stacked and put into a mold kept at 170℃, and 300kQ/
A molded article was obtained by holding at a pressure of cm2 for 10 minutes. Thereafter, the molded body was further heated at 250° C. for 13 hours to harden the phenol resin, and polished to obtain the two-layer clutch facing of this example. This two-layer taratch facing is
Outer diameter 23.6cm, inner diameter 15cm, reinforcing material thickness 2.1
mm, and the friction base material is in the shape of a perforated disc with a thickness of 1.4 mm.

The apparent specific gravity, hardness, burst strength, amount of distortion, and amount of unbalance of this two-layer clutch facing were measured and the results are shown in Table 1. In addition, the burst strength is at room temperature and 200℃.
It was measured at two levels. Strain M was determined by placing a two-layer taratch facing on a surface plate, and measuring the height of the part that rose from the surface plate. The amount of unbalance was measured based on J15BO905 when it was placed on a jig and rotated.

(Example 2) To manufacture the reinforcing material, without using glass roving,
Same as Example 1 except that 50% by weight of short fibers of "Technora" and 50% by weight of short fibers of "Conex" were used to form a single yarn, and two of these single yarns were twisted together to form a cord. to form a two-layer clutch facing. Then, each physical property was measured in the same manner, and the results are shown in Table 1. Note that the weight of the string is 1.40 CJ/m.

(Example 3) To manufacture the reinforcing material, without using glass roving,
Conex" short fibers (60% by weight) and carbon fiber short fibers) "Carbon f", made by Nippon Sheet Glass, diameter 13μm, length 5mm, elastic modulus 4000kgf/mm2) 40% by weight
A two-layer clutch facing was formed in the same manner as in Example 1, except that a single yarn was formed from the two single yarns, and a cord was formed by twisting the two single yarns together. Then, each physical property was measured in the same manner, and the results are shown in Table 1. Note that the weight of the string is 1.40Q/m.

(Example 4) To produce a reinforcing material, a single yarn was formed from 40% by weight of glass roving and 60% by weight of "Technora" short fibers,
A two-layer clutch facing was formed in the same manner as in Example 1, except that the two single yarns were twisted together to form a cord. Then, each physical property was measured in the same manner, and the results are shown in Table 1. Note that the weight of the string is 1.500/m.

(Comparative Example 1) A two-layer clutch facing was formed in the same manner as in Example 1, except that only three glass rovings were twisted together to form a string to produce a reinforcing material. Then, each physical property was measured in the same manner, and the results are shown in Table 1. Note that the weight of the string is 2.35 g/m.

(Comparative Example 2) To manufacture the reinforcing material, one glass roving and short flame-retardant fibers (Kynol, manufactured by Nippon Kynor,
Diameter 10-40μm, length 1-10Qmm, elastic modulus 600
A two-layer taratch facing was formed in the same manner as in Example 1, except that three single yarns of kof/mm2> were twisted together to form a cord. Then, each physical property was measured in the same manner, and the results are shown in Table 1. In addition, the weight of the string is 1.5
The composition is 40% by weight of glass roving and 60% by weight of Kynol fiber.

(Comparative Example 3) A two-layer clutch was produced in the same manner as in Example 1, except that to manufacture the reinforcing material, one glass roving and one short fiber of "Technora" were combined and twisted to form a string. A facing was formed. Then, each physical property was measured in the same manner, and the results are shown in Table 1. In addition, the weight of the string is 1.55 cx/m,
Glass roving is 70ffla1%, "Technora"
is 30% by weight.

(Comparative Example 4) To manufacture a reinforcing material, a medium yarn was formed from 40% by weight of glass roving and 60% by weight of "Conex" short fibers, and two of these single yarns were twisted together to form a string. A two-layer clutch facing was formed in the same manner as in Example 1 except for the formation. Then, each physical property was measured in the same manner, and the results are shown in Table 1.

Note that the weight of the string is 1.50Q/m.

(Evaluation) In all of the two-layer clutch facings of the examples, the burst strength is improved compared to the comparative example.

Especially when comparing Example 4 with Comparative Example 3 and Comparative Example 4,
It is clear that the burst strength is improved by using the short fibers of "Technora" which has a high modulus of elasticity. Similarly, ``Technora'' has no effect on long fibers, and ``Cornetex'', which has a low elastic modulus, has no effect on improving burst strength.

In the facings of Comparative Examples 1 and 2, in which the reinforcing material did not contain short aromatic polyamide fibers, the burst strength was low and the amount of imbalance was large.

In addition, in the facing of Example 4, although the burst strength is good, the amount of distortion is large and the amount of unbalance is also large. However, from the results of Examples 1 and 2, it is clear that by using "Technora" and "Conex" together, it is possible to maintain high burst strength while reducing the amount of distortion and unbalance.

Furthermore, from Example 3, it is clear that even if short 1li11t carbon fibers having a high elastic modulus are used instead of "Technora", the amount of distortion and the amount of unbalance can be reduced while maintaining high burst strength.

(Effects of the invention) As detailed above, according to the two-layer clutch facing of the present invention, the burst strength is improved and the amount of unbalance is reduced compared to the conventional one, so durability is significantly improved. Also, since the specific gravity is smaller, it contributes to weight reduction and reduction of centrifugal force.

Claims (2)

[Claims] (1) Consists of a resin mold friction base material and a reinforcing material integrally bonded to the back side of the friction base material, and the reinforcing material is made by winding a string made of reinforcing fibers into a spiral shape. In the formed two-layer clutch facing, the reinforcing fibers include short fibers having an elastic modulus of 7000 kgf/mm^2 or more, and the strings are formed by twisting the reinforcing fibers. Facing. (2) The two-layer clutch facing according to claim 1, wherein the reinforcing fibers are composed of two or more types of short fibers having different moduli of elasticity.