JPH1161103A - Friction material for synchronizer ring and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a friction material for a synchronizer ring having heat- resistance, abrasion resistance, antiseizing property and porosity and to provide a synchronizer ring having a friction material-layer composed of the friction material for synchronizer ring. SOLUTION: The ring-shaped main body 1 has a friction material layer 2 on its inner circumference. The friction material, contains 30-70 wt.% of a carbon material, 10-40 wt.% of a thermosetting resin, 5-30 wt.% of metal fibers and/or metal particles, 5-40 wt.% of inorganic fibers and/or inorganic particles and, as necessary, <=10 wt.% of organic fibers and/or <=10 wt.% of cashew dust and has a porosity of 10-50%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a friction material for a synchronizer ring and a method for producing the same. The present invention also relates to a synchronizer ring having a friction material layer made of such a synchronizer ring friction material.

[0002]

2. Description of the Related Art A synchronizer ring is incorporated in a transmission of an automobile or the like, and when a gear is switched by the transmission,
It is a ring-shaped member that rotates the two gears synchronously so that the two gears that are switched and meshed can smoothly mesh with each other.

The synchronizer ring has a friction material layer on a ring-shaped main body. The friction material layer may be provided only on the inner peripheral side of the ring-shaped main body, may be provided only on the outer peripheral side, or may be provided on both the inner peripheral side and the outer peripheral side. In either case,
The friction material layer is frictionally engaged with the tapered portion (conical portion) of the transmission gear.

Conventionally, copper alloys, for example, MBA-2 and MBA-5, are often used as the friction material in the friction material layer. A small number of paper materials are also used. Alternatively, molybdenum may be fixed to the ring-shaped body by thermal spraying.

On the other hand, the synchronizer ring is mainly required to have the following characteristics. (1) Since the two gears are synchronized by frictionally engaging with the tapered portion as the mating member, the coefficient of dynamic friction with the mating member must be large. (2) The friction coefficient at a relative speed close to zero (hereinafter referred to as "static friction coefficient") must be small in order to reduce the impact when meshing with the mating gear. (3) Do not burn out due to braking friction heat when braking is applied to the mating member. In particular, do not burn out due to braking friction heat generated when the clutch / shift lever is operated incorrectly.

[0006] The mistaken operation of the clutch / shift lever is as follows.
The act of moving the clutch shift lever without firmly depressing the clutch pedal.In the event of a mistake, the engine torque is transmitted to the other gear, and the torque is greater than the torque when the clutch is completely disengaged and idles. Since the other gear is rotated, the synchronizer ring generates a large heat load (up to ten times the normal load). As a result, the friction material is heated to a high temperature by the braking friction heat, and carbonization and abnormal wear may occur, thereby impairing the synchronization function.

Conventionally, among the above three properties, the property (3) tends to be prioritized. Therefore, copper alloys are often used as friction materials. However, the copper alloy has a problem that the characteristics (1) and (2) are inferior because the dynamic friction coefficient is smaller than that of other members.

Therefore, the frictional surface of the copper alloy is formed as a double or triple multilayer structure to increase the capacity for absorbing the braking friction heat and increase the dynamic friction coefficient, thereby improving the characteristics of (1). I'm trying. However, when the friction surface has a multi-layer structure, another problem occurs in that the mechanism of the transmission is complicated, large, and expensive.

On the other hand, although the paper material has the above-mentioned characteristics (1) and (2), there is a problem that the paper material may be burned out due to the frictional frictional heat generated when the clutch / shift lever is erroneously operated. ing. Further, molybdenum can withstand the frictional frictional heat generated when the clutch / shift lever is erroneously operated, as compared with the copper alloy, but has the problem that the characteristics (1) and (2) are inferior.

By the way, in order for the synchronizer ring to have good friction characteristics, it is necessary to form a large number of fine holes in the friction material. This is because, when a large number of micropores are formed in the friction material, when the synchronizer ring comes into contact with the partner member, an oil film is less likely to be formed on the friction interface, and the dynamic friction coefficient can be increased.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a friction for a synchronizer ring having heat resistance, abrasion resistance, seizure resistance and porosity. To provide materials. Another object of the present invention is to provide a method for manufacturing such a friction material for a synchronizer ring. It is a further object of the present invention to provide a synchronizer ring having a friction material layer made of such a synchronizer ring friction material.

[0012]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a carbon material, a thermosetting resin, a metal fiber and / or
Alternatively, the present inventors have found that the above object can be achieved by a material having a specific porosity containing metal particles and inorganic fibers and / or inorganic particles at a specific mixing ratio, and completed the present invention.

That is, the friction material for a synchronizer ring of the present invention comprises 30 to 70% by weight of a carbon material and 10 to 4% by weight.
It contains 0% by weight of a thermosetting resin, 5 to 30% by weight of metal fibers and / or metal particles, and 5 to 40% by weight of inorganic fibers and / or inorganic particles, and has a porosity of 10 to 50%. There is something.

The method for producing a friction material for a synchronizer ring according to the present invention comprises the steps of:
A mixture of 0 to 40 parts by weight of a thermosetting resin, 5 to 30 parts by weight of metal fibers and / or metal particles, and 5 to 40 parts by weight of inorganic fibers and / or inorganic particles is mixed with a porosity of 10 to 50. %
This is a method of using a friction material.

In the present invention, "porosity" refers to a hole opening toward the surface, and "porosity" refers to the volume ratio of the pores formed in the friction material to the friction material. Means The measurement of the value of "porosity" is based on JIS
The test was performed according to Z-2506 “Testing method for effective porosity of sintered oil-impregnated metal”.

Further, the synchronizer ring of the present invention is a synchronizer ring comprising a ring-shaped main body and a friction material layer provided on the inner peripheral side and / or the outer peripheral side of the ring-shaped main body. Are formed from the synchronizer ring friction material of the present invention or the synchronizer ring friction material obtained by the method of the present invention.

Hereinafter, the present invention will be described in detail.
The friction material for a synchronizer ring according to the present invention has a thickness of 30-7.
Contains 0% by weight of carbon material. Carbon materials have excellent heat resistance and improve the heat resistance of friction materials. For this reason, the synchronizer ring can endure, for example, the frictional frictional heat generated when the clutch / shift lever is operated incorrectly, and the seizure of the synchronizer ring to the mating member is reduced.

When the amount of the carbon material is less than 30% by weight, the heat resistance of the friction material decreases, while when the amount of the carbon material exceeds 70% by weight, the rigidity of the friction material decreases. The preferred compounding amount of the carbon material is 40 to 65% by weight.

Although the carbon material is not particularly limited, for example, porous graphite particles are preferable. In particular, porous graphite particles in which 50% or more of the total number of particles have a particle diameter of 44 to 250 μm are preferred. When such porous graphite particles are used as a friction material component, a desired porosity as a friction material can be obtained, and the diameter of pores formed in the friction material can be a desired value. For this reason, the dynamic friction coefficient of the friction material can be made larger than that of a conventional friction material made of metal. Incidentally, the particle diameter of the porous graphite particles,
It is a value measured by a sieve shaking method (60 mesh to
325 mesh).

The friction material for a synchronizer ring of the present invention contains 10 to 40% by weight of a thermosetting resin. The thermosetting resin serves as a binder for each component of the friction material, and increases the rigidity of the friction material.

If the amount of the thermosetting resin is less than 10% by weight, the rigidity of the friction material decreases. On the other hand, when the compounding amount of the thermosetting resin exceeds 40% by weight, the amount of the thermosetting resin softened by heat increases, and it becomes difficult to obtain a desired porosity, and the dynamic friction coefficient of the friction material increases. Can not. The preferred amount of the thermosetting resin is 15 to 35% by weight.

Examples of the thermosetting resin include, but are not particularly limited to, phenol resins, epoxy resins, unsaturated polyester resins, vinyl ester resins, melamine resins, diallyl phthalate resins, benzoguanamine-melamine resins, and silicone resins. And at least one selected from the group consisting of polyimide resins. All of these have sufficient heat resistance when using a synchronizer ring. Of these, phenol resins, epoxy resins, unsaturated polyester resins, and the like are preferable.

The phenol resin is, for example, at least one selected from the group consisting of novolak type phenol resins, epoxy-modified phenol resins, melamine-modified phenol resins, cashew-modified phenol resins, hydrocarbon resin-modified phenol resins, and cresol-modified phenol resins. Seeds can be used. Among these, a novolak type phenol resin is more preferable because the molding of the friction material is facilitated. Further, it is preferable because the manufacturing cost of the friction material can be reduced. Only one thermosetting resin may be used, or two or more thermosetting resins may be used in combination.

The friction material for a synchronizer ring of the present invention contains 5 to 30% by weight of metal fibers and / or metal particles. Metal fibers and metal particles suppress the heat fade phenomenon,
It is possible to prevent the dynamic friction coefficient of the friction material from being reduced by the braking friction heat.

The thermal fade phenomenon is a phenomenon in which when the synchronizer ring is continuously pressed against the mating member for a long time, the oil between the friction material layer and the mating member runs out, and the coefficient of kinetic friction of the friction material decreases due to frictional heat. Say. When the thermal fade phenomenon occurs in the friction material layer, it takes a long time to operate the synchronizer ring.

When the amount of the metal fibers and / or metal particles is 5
When the amount is less than% by weight, the dynamic friction coefficient of the friction material decreases. On the other hand, when the compounding amount of the metal fibers and / or metal particles is 30
If the content is more than the weight percentage, the synchronizer ring may adhere to the mating member. A preferred blending amount of the metal fibers and / or metal particles is 7 to 25% by weight.

The metal fibers and / or metal particles are not particularly limited.
Examples include alloys containing copper, iron, nickel, zinc, and / or lead as a main component. Examples of such metal fibers and metal particles include stainless steel fibers, steel fibers, copper fibers, brass fibers, aluminum fibers, iron-nickel fibers, nickel fibers, zinc particles, and the like. As the metal fibers and / or metal particles, only one kind may be used, or two or more kinds may be used in combination.

The friction material for a synchronizer ring of the present invention contains 5 to 40% by weight of inorganic fibers and / or inorganic particles. The inorganic fibers and / or inorganic particles reinforce the thermosetting resin as a binder so that a desired porosity can be obtained.

The amount of the inorganic fibers and / or inorganic particles is 5
When the amount is less than the weight percentage, the reinforcing effect of the thermosetting resin becomes weak. On the other hand, the compounding amount of the inorganic fibers and / or inorganic particles is 40
If the content is more than the weight percentage, the flexibility of the friction material is impaired, and the friction material layer rubs the mating member. A preferred blending amount of the inorganic fibers and / or inorganic particles is 10 to 35% by weight.

The inorganic fibers and / or inorganic particles are not particularly limited, but include, for example, barium sulfate,
Examples thereof include those composed of potassium titanate, alumina, silicon carbide, silicon nitride, mullite, aluminum borate, calcium carbonate, wollastonite, zonotolite, glass or rock wool.

More specifically, for example, barium sulfate particles, potassium titanate whiskers, alumina whiskers, alumina fibers, silicon carbide whiskers, silicon nitride whiskers, mullite whiskers, aluminum borate whiskers, calcium carbonate whiskers, wollastonite, Zonotolite, glass fiber, rock wool and the like. As the inorganic fibers and / or inorganic particles, only one type may be used, or two or more types may be used in combination.

The friction material for a synchronizer ring of the present invention may further contain up to 10% by weight of organic fibers and / or up to 10% by weight of cashew dust in addition to the above-mentioned components.

When an organic fiber is blended with the friction material, the coefficient of kinetic friction of the friction material can be increased to the same level as that of paper, and the porosity of the friction material can be increased to 30% or more to impart flexibility to the friction material. .

The organic fibers are not particularly limited, but include, for example, heat-resistant organic synthetic fibers such as aramid fibers, metaphenylenediamine fibers, polybenzimidazole fibers, phenol fibers, acrylic fibers and fluorine fibers. At least one selected from fibers can be used. More specifically, aramid pulp, aramid chop, acrylic pulp, acrylic chop and the like can be mentioned. Only one kind of organic fiber may be used.
More than one species may be used in combination.

When the organic fiber is used, the compounding amount is usually 1
Up to 0% by weight is suitable. If it exceeds 10% by weight, the other components will not be uniformly dispersed, and the fluidity of the friction material during molding of the synchronizer ring will decrease.
It becomes difficult to form a synchronizer ring. Further, the heat resistance of the friction material layer also decreases.

When cashew dust is mixed with the friction material, the flexibility of the friction material can be improved and the dynamic friction coefficient can be increased. When cashew dust is used, the amount is usually up to 10% by weight. If it exceeds 10% by weight, the coefficient of kinetic friction of the friction material becomes too large, and the friction material layer tends to seize to the mating member.

The synchronizer ring friction material of the present invention has a porosity of 10 to 50%. With such a porosity, an oil film is less likely to be formed at the friction interface between the synchronizer ring and the mating member, and the friction material has a large dynamic friction coefficient.

The friction material for a synchronizer ring of the present invention comprises 30 to 70 parts by weight of a carbon material, 10 to 40 parts by weight of a thermosetting resin, and 5 to 30 parts by weight of metal fibers and / or metal particles. , 5 to 40 parts by weight of inorganic fibers and / or inorganic particles, and if necessary, up to 10 parts by weight of organic fibers and / or up to 10 parts by weight of cashew dust, and a porosity of 10 to 50%. Can be obtained.

This mixing method is not particularly limited, but can be performed using a known mixer such as a Henschel mixer, a double cone mixer, a ribbon mixer, or the like.

Next, a method of manufacturing a synchronizer ring using the friction material for a synchronizer ring of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view along a radial direction of the synchronizer ring, and FIG.
FIG. 2 is a partially enlarged view of FIG. 1. In FIG. 1, the synchronizer ring (3) has a friction material layer (2) on the inner peripheral side of the ring-shaped main body (1).

The manufacturing method of the synchronizer ring includes:
For example, there are the following methods, and any of the methods can be applied using the synchronizer ring friction material of the present invention.

(First Manufacturing Method) A material (for example, brass) for a ring-shaped main body and a friction material are filled in a molding die, and
Heat to 80 to 300 ° C. to integrally mold the ring-shaped main body and the friction material layer. Thereafter, the integrated ring-shaped main body and the friction material layer are kept at 230 to 500 ° C. for 20 to 30 minutes. Finally, the inner periphery of the friction material layer (2) is cut into a tapered (conical) shape to form a groove (4) and a top land (5) on the inner periphery.

(Second Manufacturing Method) The material of the ring-shaped main body and the friction material are filled in a molding die, and an electric current is applied to the molding die.
Heat to about 350 ° C. to integrally mold the ring-shaped body and the friction material layer. Then, the inner circumference of the friction material layer (2) is cut into a tapered shape (conical shape), and the groove (4) and top land
Form (5).

(Third Manufacturing Method) The material of the ring-shaped main body and the friction material are filled in a mold, heated to 1200 ° C. by plasma discharge, and the ring-shaped main body is reduced under a reducing atmosphere or a reduced-pressure atmosphere. The friction material layer is integrally formed. Thereafter, the inner periphery of the friction material layer (2) is cut into a tapered (conical) shape to form a groove (4) and a top land (5) on the inner periphery.

(Fourth Manufacturing Method) A small amount of a binder (for example, methylcellulose) is added to the friction material, and the friction material is formed into a sheet by pressing with a roll, pressing with a press, or the same manufacturing method as in papermaking. After molding and punching this sheet into a desired shape, it is integrated with the ring-shaped body.

(Other Manufacturing Method) The friction material is preformed in a ring shape, and this is integrated with the ring-shaped main body.

According to the friction material for a synchronizer ring of the present invention, a carbon material, a thermosetting resin, metal fibers and / or
Alternatively, since it contains metal particles and inorganic fibers and / or inorganic particles in a specific mixing ratio and has a specific porosity, it has heat resistance, abrasion resistance, seizure resistance, and porosity. Further, according to the synchronizer ring of the present invention, since the synchronizer ring has the friction material layer composed of the synchronizer ring friction material, (1) the dynamic friction coefficient with respect to the mating member is large, (2) the static friction coefficient is small, and (3) ) Burnout does not occur due to braking friction heat when braking is applied to the mating member.

[0048]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. [Example 1] Porous graphite particles (50% or more of the total
Having a particle diameter of 4 to 250 μm) 55 parts by weight;
20 parts by weight of novolak type phenol resin as thermosetting resin, and 10 parts by weight of stainless steel fiber as metal fiber,
15 parts by weight of barium sulfate as inorganic particles were mixed with a Henschel mixer for 5 minutes to obtain a friction material composition.

The friction material composition and the brass as the ring-shaped body material are filled in a mold having a predetermined shape and heated to 300 ° C. in accordance with the first manufacturing method described above, and the ring-shaped body and the friction material layer are formed. And were integrally molded. The porosity of the friction material was 25% as measured according to JIS Z-2506 “Testing method for effective porosity of sintered oil-impregnated metal”.

Thereafter, the integrated ring-shaped main body (1) and friction material layer (2) were kept at 300 ° C. for 30 minutes. Thereafter, the inner periphery of the friction material layer (2) was cut into a tapered shape to form a groove (4) and a top land (5) on the inner periphery. In this way, a synchronizer ring was manufactured.

Example 2 The same procedure as in Example 1 was carried out except that the blending amounts were 65 parts by weight of porous graphite particles, 15 parts by weight of a novolak type phenol resin, 10 parts by weight of stainless fiber, and 10 parts by weight of barium sulfate. Thus, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 3 The same procedure as in Example 1 was carried out except that the mixing amounts were 40 parts by weight of porous graphite particles, 35 parts by weight of a novolak type phenol resin, 10 parts by weight of stainless steel fiber, and 15 parts by weight of barium sulfate. Thus, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 4 The same procedure as in Example 1 was carried out except that the mixing amounts were 40 parts by weight of porous graphite particles, 15 parts by weight of a novolak type phenol resin, 25 parts by weight of stainless steel fiber, and 20 parts by weight of barium sulfate. Thus, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 5 The same procedures as in Example 1 were carried out except that the mixing amounts were 40 parts by weight of porous graphite particles, 15 parts by weight of a novolak type phenol resin, 25 parts by weight of stainless fiber, and 20 parts by weight of barium sulfate. Thus, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 6 55 parts by weight of the porous graphite particles, 20 parts by weight of the novolak phenol resin, 10 parts by weight of zinc particles as metal particles, and 15 parts by weight of barium sulfate
A friction material composition was obtained in the same manner as in Example 1 except that parts by weight were used. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 7 Example 7 was the same as Example 1 except that 55 parts by weight of the porous graphite particles, 20 parts by weight of the novolak type phenol resin, 10 parts by weight of the stainless steel fiber, and 15 parts by weight of the alumina fiber as the inorganic fiber were used. Similarly, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

[Example 8] 55 parts by weight of the porous graphite particles, 20 parts by weight of the novolak type phenol resin, 10 parts by weight of the stainless steel fiber, 10 parts by weight of the alumina fiber as the inorganic fiber, and acrylic chop 5 as the organic fiber.
A friction material composition was obtained in the same manner as in Example 1 except that parts by weight were used. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 9 Except that 50 parts by weight of the porous graphite particles, 20 parts by weight of the novolak type phenol resin, 10 parts by weight of the stainless steel fiber, 15 parts by weight of the barium sulfate, and 5 parts by weight of cashew dust were used. A friction material composition was obtained in the same manner as in Example 1. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Example 10 50 parts by weight of the porous graphite particles, 15 parts by weight of the novolak type phenol resin, 10 parts by weight of the stainless steel fiber, 15 parts by weight of the barium sulfate, 2 parts by weight of the acrylic chop as the organic fiber,
A friction material composition was obtained in the same manner as in Example 1, except that 8 parts by weight of the cashew dust was used. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 1 20 parts by weight of porous graphite particles
A friction material composition was obtained in the same manner as in Example 1, except that 50 parts by weight of a novolak type phenol resin, 10 parts by weight of stainless steel fiber, and 15 parts by weight of barium sulfate were used. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 2 A friction material composition was prepared in the same manner as in Example 1 except that 80 parts by weight of the porous graphite particles, 10 parts by weight of the novolak type phenol resin, and 10 parts by weight of barium sulfate were used. Obtained. From this friction material composition,
A synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 3 10 parts by weight of porous graphite particles
A friction material composition was obtained in the same manner as in Example 1, except that 20 parts by weight of a novolak type phenol resin, 50 parts by weight of stainless steel fiber, and 30 parts by weight of barium sulfate were used. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 4 A friction material composition was obtained in the same manner as in Example 1 except that 20 parts by weight of the porous graphite particles, 30 parts by weight of the resole type phenol resin, and 50 parts by weight of the barium sulfate were used. Was. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 5 The procedure of Example 1 was repeated except that 50 parts by weight of the porous graphite particles, 20 parts by weight of the resol-type phenol resin, 15 parts by weight of barium sulfate, and 20 parts by weight of the cashew dust were used. Thus, a friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

Comparative Example 6 The procedure of Example 1 was repeated except that 55 parts by weight of the ground graphite, 20 parts by weight of the resole novolak type phenol resin, 10 parts by weight of the stainless steel fiber, and 15 parts by weight of the barium sulfate were used. A friction material composition was obtained. From this friction material composition, a synchronizer ring was manufactured in the same manner as in Example 1.

[Comparative Examples 7 to 10] As a conventional example,
Brass [Comparative Example 7], paper-based friction material [Comparative Example 8], and Mo sprayed on the ring-shaped main body, respectively, as friction materials.
[Comparative Example 9], using a resin-based friction material [Comparative Example 10]
A synchronizer ring was made. Table 1 shows the components and the porosity of each friction material composition.

[0067]

[Table 1]

Next, the following various tests were performed on the synchronizer rings thus manufactured.

(Single Friction and Wear Test) A synchronizer ring of 70 k is attached to a tapered mating member of material SCM420 which rotates at an inertia of 0.010 kgfm / sec ² and a rotation speed of 1,600 rpm in gear oil at 80 ° C.
Pressing with a force of gf to stop the partner member was repeated 10,000 times. In this test, the dynamic friction coefficient and the static friction coefficient of the friction material layer of the synchronizer ring were measured at the 200th and 10,000th times. Further, in a single friction and wear test, the length of the friction material layer of the synchronizer ring that was worn in the axial direction was measured, and this value was defined as the friction material wear amount.

Further, in the unitary friction and wear test, the degree to which the polished surface of the mating member was damaged by the friction material layer was visually inspected, and this degree was regarded as mating member damage. The degree of damage to the mating member was expressed as follows: "Fogging": The mating member surface was worn to the degree of clouding. "Sliding marks": The surface of the mating member was worn to such an extent that marks remained on the surface. “Black discoloration”: Burned on the friction material layer, and the surface of the mating member was discolored black. "Step wear": The surface of the mating member was worn to the extent that a step was formed on the surface.

(Severe Condition Test) Rotational Speed 1,600 rpm
The synchronizer ring is pressed against the tapered mating member of the material SCM420 rotating at m for 2 seconds with a force of 100 kgf for 2 seconds, and released for 30 seconds as one cycle. They were checked for burning or damage. “Back contact”: The friction material layer of the synchronizer ring is worn, and the inner peripheral surface of the brass ring-shaped main body (1) is in contact with the gear of the mating member.

(Compression fatigue test) Material SC stopped
The synchronizer ring was pressed against the M420 tapered mating member with a force of 250 kgf for 4 seconds and released for 2 seconds as one cycle. After repeating this 10,000 cycles, the pressing force was increased in steps of 250 kgf. Each time was increased, the synchronizer ring was pressed 10,000 times against the mating member (pressing for 4 seconds and releasing for 2 seconds in one cycle), and finally, it was examined how many kgf of pressing force the friction material layer could withstand. . Table 2 shows the results of the above tests.
Are shown together.

[0073]

[Table 2]

From Table 2, it can be seen that the synchronizer rings of Examples 1 to 10 cause less damage to the mating member than the synchronizer rings of Comparative Examples 1 to 10 (see the column of mating member damage). Further, it can be seen that each value of the severe condition test and the compression fatigue test is also high. That is, the friction material of the synchronizer rings of Examples 1 to 10 according to the present invention has both heat resistance, abrasion resistance, and seizure resistance, and also has excellent rigidity, and has sufficient performance for practical use. Is evident.

In particular, in the synchronizer rings of Examples 8 and 10 in which organic fibers were blended in the friction material, the coefficient of kinetic friction of the friction material was as large as that of paper, and the porosity of the friction material was 30% or more. , A flexible friction material. In the synchronizer rings of Examples 9 and 10 in which cashew dust was blended in the friction material,
The flexibility of the friction material has been improved, and the dynamic friction coefficient of the friction material has been increased.

On the other hand, in Comparative Example 1, the carbon material was 20% by weight.
Therefore, the heat resistance of the friction material is insufficient, and the friction material layer seizes on the mating member as shown in the severe condition test column. Further, since the thermosetting resin is as large as 50% by weight, the amount of the thermosetting resin softened by heat becomes too large, and a desired porosity cannot be obtained. Therefore, the dynamic friction coefficient of the friction material is small.

In Comparative Example 2, since the carbon material was as large as 80% by weight, the rigidity of the friction material was insufficient, and as shown in the compression fatigue test column, the pressing force with which the friction material layer could withstand was small. In addition, since no metal fibers or metal particles are contained, the coefficient of dynamic friction of the friction material is small. In Comparative Example 3, since the metal fibers or metal particles were as large as 50% by weight, the mating member was worn. In Comparative Example 4, the content of the inorganic fibers or the inorganic particles was 50% by weight.
Therefore, the flexibility of the friction material is impaired, and the mating member is worn. In addition, since no metal fibers or metal particles are contained, the coefficient of dynamic friction of the friction material is small. In Comparative Example 5,
Although metal fibers or metal particles are not included and are excluded from the present invention, since the cashew dust is also contained in an amount of 20% by weight, the coefficient of kinetic friction of the friction material becomes too large, and the friction material layer becomes a mating member. It tends to burn. In Comparative Example 6, the friction coefficient was small, and the expected performance was not obtained. The conventional examples of Comparative Examples 7 to 10 are all practically insufficient.

[0078]

As described above, the friction material for a synchronizer ring of the present invention is excellent in heat resistance, wear resistance, seizure resistance, and porosity. Therefore, the seizure of the friction material layer can be prevented, the wear amount can be reduced, and the useful life of the synchronizer ring can be extended. Further, the synchronizer ring can be operated in a short time.

The synchronizer ring of the present invention having a friction material layer made of the above-mentioned synchronizer ring friction material has a large dynamic friction coefficient with respect to a mating member, a small static friction coefficient, and has a small friction coefficient when braking is applied to the mating member. It does not burn out due to braking friction heat, and is extremely excellent in practical use.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along a radial direction of a synchronizer ring of the present invention.

FIG. 2 is a partially enlarged view of FIG.

[Explanation of symbols]

 (1): Ring-shaped body (2): Friction material layer (3): Synchronizer ring (4): Groove (5): Top land

Claims (11)

[Claims] 1 to 30% by weight of a carbon material;
It contains 0% by weight of a thermosetting resin, 5 to 30% by weight of metal fibers and / or metal particles, and 5 to 40% by weight of inorganic fibers and / or inorganic particles, and has a porosity of 10 to 50%. There is a friction material for synchronizer rings. 2. The friction material for a synchronizer ring according to claim 1, wherein the carbon material is porous graphite particles. 3. The synchronizer ring friction material according to claim 2, wherein at least 50% of the total number of the porous graphite particles has a particle diameter of 44 to 250 μm. 4. The thermosetting resin is at least selected from the group consisting of a phenol resin, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a melamine resin, a diallyl phthalate resin, a benzoguanamine-melamine resin, a silicone resin and a polyimide resin. One kind,
The friction material for a synchronizer ring according to claim 1. 5. The thermosetting resin is at least one selected from the group consisting of a novolak-type phenol resin, an epoxy-modified phenol resin, a melamine-modified phenol resin, a cashew-modified phenol resin, a hydrocarbon resin-modified phenol resin, and a cresol-modified phenol resin. The friction material for a synchronizer ring according to any one of claims 1 to 4, which is a seed. 6. The method according to claim 1, wherein the metal fibers and / or the metal particles are made of an alloy containing aluminum, copper, iron, nickel, zinc and / or lead as a main component. The friction material for a synchronizer ring according to the above. 7. The inorganic fibers and / or inorganic particles are made of barium sulfate, potassium titanate, alumina, silicon carbide, silicon nitride, mullite, aluminum borate, calcium carbonate, wollastonite, zonotolite, glass or rock wool. , Any one of claims 1 to 6
Item 4. The friction material for a synchronizer ring according to Item 1. 8. The synchronizer ring friction material according to claim 1, further comprising up to 10% by weight of organic fibers and / or up to 10% by weight of cashew dust. 9. The synchronizer according to claim 8, wherein the organic fiber is at least one selected from the group consisting of aramid fiber, metaphenylenediamine fiber, polybenzimidazole fiber, phenol fiber, acrylic fiber and fluorine fiber. Friction material for rings. 10. A carbon material of 30 to 70 parts by weight,
40 parts by weight of a thermosetting resin, 5 to 30 parts by weight of metal fibers and / or metal particles, and 5 to 40 parts by weight of inorganic fibers and / or inorganic particles are mixed, and the porosity is 10 to 50%. A method for producing a friction material for a synchronizer ring, wherein a friction material is obtained. 11. A synchronizer ring comprising a ring-shaped main body and a friction material layer provided on an inner peripheral side and / or an outer peripheral side of the ring-shaped main body, wherein the frictional material layer is provided. A synchronizer ring formed of the friction material for a synchronizer ring according to any one of the preceding claims or the friction material for a synchronizer ring obtained by the method according to claim 10.