JPH08210402A - Brake - Google Patents

Abstract

PURPOSE: To provide a brake high in durability which has friction property fit for application, use environment, and control method. CONSTITUTION: This is a multidisc type brake different in properties of carbon/ carbon composite material (A) and carbon/carbon composite material (B), consisting of a rotor disc having carbon/carbon composite material (A) for friction material and a stator disc having carbon/carbon composite material (B) for friction material.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a multi-disc brake.

[0002]

Disc brakes are widely used as various friction brakes in various applications such as motorcycles, automobiles, railway vehicles, and aircraft. These disc brakes are classified into disc pad type brakes, multi-disc type brakes, etc., depending on their types. Conventional disc brakes are made of organic materials, metal materials, carbon / carbon composite material materials, or the like.

The organic brake material is mainly used as a pad material of a disc pad type brake or a surface material (lining material) of the pad. A typical method for producing an organic brake material is to combine a thermosetting resin such as a phenolic resin with an organic fiber, a metal fiber, an inorganic fiber, etc. for reinforcement, and add various additives to adjust friction performance. It is used after being molded into the shape of, and subjected to heat treatment etc. depending on the application.

In the organic brake material, the organic components of its main constituents decompose at a temperature of about 300 ° C. or higher, so if it is used at a high speed or with a high pressing force, it is decomposed by frictional heat and deteriorates, which shortens its life significantly. However, there is a problem that sufficient braking force cannot be obtained due to a fade phenomenon or the like.

Typical examples of the metallic brake material include cast iron-based, forged steel-based, and alloy-based brakes. Metal-based brake materials are used as disk materials for disk-pad type brakes, and in recent years, application of aluminum alloy-based brake materials to disks has been considered for weight reduction. Further, alloy-based brake materials are also used as pad materials, and in particular, copper-based sintered alloys are widely used as pad materials. Metal-based brake materials are also widely used as disk materials for multi-disc brakes, and are mainly used mainly for aircraft brake materials.

When a metallic brake material is used at a high speed or with a high pressing force and frictional heat increases, a fade phenomenon occurs near the melting point of the metal which is the main constituent of the metallic brake material, and a sufficient frictional force cannot be obtained. was there. Further, when used at a temperature higher than the melting point, there was a problem that the disc and the lining were fused to each other after the suspension and could not be cut off, which necessitated extensive repair or replacement for restarting the operation.
Moreover, since the metal-based brake has a large specific gravity, the total weight of the entire vehicle on which it is mounted is large, which hinders reduction of fuel consumption and noise. Further, the metal-based brake material has a large coefficient of thermal expansion, which causes deterioration due to cracks and the like due to the impact of frictional heat.

The carbon / carbon composite material is a carbon material reinforced with carbon fiber. Since it has a smaller specific gravity than a metallic brake material, it can be significantly reduced in weight, and since it has no melting point, troubles such as fusion bonding can be avoided. It becomes possible. Further, the decomposition temperature is as high as about 3000 ° C. as compared with the organic brake material, and the deterioration due to frictional heat can be significantly reduced. Furthermore, the coefficient of thermal expansion is small, and the durability against thermal shock can be greatly improved.

[0008] Carbon / carbon composite material-based brake materials are used for applications requiring heat resistance and weight reduction, which are difficult to cope with with organic or metal-based brake materials. It is used for disc pad type brakes for auto-bye and competition cars, and multi-disc brakes for aircraft such as large passenger planes and fighters.

Among them, in the carbon / carbon composite material type multi-disc type brake, the carbon / carbon composite material usually used for the rotor disc and the carbon / carbon composite material used for the starter disc have the same characteristics. is there. Also the application,
Even if the characteristics of the carbon / carbon composite material are changed according to the usage environment and control method, the carbon / carbon composite material normally used for the rotor disk and the carbon / carbon composite material used for the stator disk are the same new ones. It has been changed to characteristics.

Further, even when the carbon / carbon composite material is improved in order to improve the durability and frictional characteristics, it is used for the carbon / carbon composite material and the starter disk which are usually used for the rotor disk. The carbon / carbon composites that have been modified have new identical properties.

The carbon / carbon composite material used in conventional multi-disc brakes wears down with use and requires regular replacement. In this case, usually new carbon /
It is replaced with a carbon composite material, but it may be replaced with a repair / recycled carbon / carbon composite material.

As a method for repairing and regenerating the worn carbon / carbon composite material, an example in which a worn carbon / carbon composite material is used as a core material and a surface material made of the carbon / carbon composite material is bonded to the core material (US Pat. No. 742, 948, Special Examination 4-
63026).

Further, although the carbon / carbon composite material disposed on the sliding surface has desired frictional characteristics, when the mechanical strength is insufficient under intended use conditions, a non-sliding internal part is provided for the purpose of reinforcing the mechanical strength. Alternatively, a report example in which a material of high strength different from the material of the sliding surface is bonded to the back surface (1992 2nd CP
C study group).

However, even in these conventional techniques, the sliding surface of the carbon / carbon composite material usually used for the rotor disk and the carbon / carbon composite material used for the starter disk is used as a friction material. A carbon / carbon composite material having the same properties was used for the material arranged in the.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly durable brake having friction characteristics tailored to the application, environment of use and control method.

[0016]

SUMMARY OF THE INVENTION The present invention is directed to a rotor disk having a carbon / carbon composite material (A) as a friction material and a starter having a carbon / carbon composite material (B) as a friction material. A disk, which is composed of the carbon / carbon composite material (A) and carbon /
The present invention relates to a multi-disc brake in which the characteristics of the carbon composite material (B) are different.

First, the multi-disc brake according to the present invention will be described in detail. The rotor disc and the starter disc included in the multi-disc brake according to the present invention have a friction material on the surface thereof. In the present invention, a carbon / carbon composite material is used as the friction material. In the present invention, the entire rotor disk or the entire stator disk may be made of carbon / carbon composite material.

The material of the portion of the multi-disc brake of the present invention excluding the friction material is not particularly limited, and conventionally known materials can be used. For example, various metal materials such as carbon steel, cast iron or aluminum can be used for the back plate for fixing the friction material, the cylinder for driving to press the disks against each other, the main shaft for rotating the rotor disk, and the like.

The multi-disc type brake according to the present invention may be provided with a measure for preventing the carbon / carbon composite material, which has been heated to a high temperature due to frictional heat, from being consumed by oxidation. For example, the periphery of the break disk can be made an inert atmosphere. A protective cover may be attached to a part of the carbon / carbon composite material. Alternatively, a part of the carbon / carbon composite material can be provided with an oxidation resistant coating. Further, a part of the carbon / carbon composite material can be modified into an oxidation resistant material.

In the multi-disc type brake according to the present invention, one or more rotating rotor discs and one or more non-rotating stator discs are pressed to obtain a braking force. By being pressed, the sliding portions of the friction materials that rub against each other generate a frictional force, which is used as a braking force.
The entire surface having a sliding portion is called a sliding surface, and the non-sliding portion is included in this sliding surface. The non-sliding surface is a surface that does not have a sliding portion and is composed of only a non-sliding portion.

In the multi-disc type brake according to the present invention, depending on the application or required frictional characteristics,
It is possible to variously select the number and arrangement of the starter disk and the starter disk. Depending on the arrangement, one side or both sides of each disk can be used as a sliding surface, and a disk having no sliding surface can also be used.

When the rotor disk and the stator disk are adjacent to each other, this interface serves as a sliding surface. Also the rotor
When the disks are adjacent to each other or the stator disks are adjacent to each other, this interface is a non-sliding surface. In addition, the surface without adjacent disks is a non-sliding surface.

The sliding surface becomes hot due to frictional heat. On the other hand, the non-sliding surface does not generate frictional heat. Further, when the non-sliding surface receives heat conduction from the inside of the disk, it dissipates heat to the adjacent disk or components other than the disk or the atmosphere, and cools the disk.

Further, when the disk becomes high in temperature due to frictional heat, the non-sliding surface and the non-sliding portion in the sliding surface are exposed to the atmosphere and are easily attacked by oxidation. On the other hand, the sliding portion in the sliding surface that constantly slides during braking is not exposed to the atmosphere and is less susceptible to oxidative invasion.

Further, the stator disk is always non-rotating, whereas the rotor disk is always rotating or at the time of braking. Therefore, the rotor disk needs to have sufficient strength against the tensile stress caused by the centrifugal force generated by the rotation. In addition, since a disk having a drive device for pressing and separating on the back surface is low in heat resistance of parts made of materials other than the carbon / carbon composite material, it is necessary to consider heat insulation on the back surface.

As described above, in the multi-disc type brake, since the roles of the rotor disc and the starter disc are different and the usage conditions are different, it is important to give each friction material its own characteristic.

Therefore, a multi-disc brake comprising a rotor disk having the carbon / carbon composite material (A) as the friction material and a starter disk having the carbon / carbon composite material (B) as the friction material. In the above, by using the carbon / carbon composite material (A) and the carbon / carbon composite material (B) having different characteristics, a novel and highly durable material having friction characteristics tailored to the application, use environment and control method. It came to get a multi-disc type brake.

Each of the carbon / carbon composite materials having different characteristics is processed as necessary and a jig or the like is attached to the carbon / carbon composite material.
They can be the whole or a part of the friction material of the rotor disk and the stator disk, respectively.

When a plurality of stator disks are used, the carbon / carbon composite material used for one or more of them is different from the carbon / carbon composite material used for the rotor disk. It is also possible to When a plurality of rotor disks are used, the carbon / carbon composite material used for one or more of them should have different characteristics from the carbon / carbon composite material used for the starter disk. Is also possible.

Further, two or more kinds of carbon / carbon composite materials having different characteristics are processed as required, and a jig or the like is attached by using an adhesive, and the rotor disk or the stator is respectively attached. It can also be arranged and arranged in one part and in the other part of the friction material of the disc.

As described above, a carbon / carbon composite material having different characteristics is arranged as a friction material at a desired portion of the rotor disk and the stator disk in accordance with the use, the use environment and the control method. As a result, it is possible to obtain a highly durable multi-disc brake having a desired friction characteristic.

The different characteristics of the carbon / carbon composite material means that at least one item of the thermophysical properties, mechanical properties, oxidation properties or other physical properties of the carbon / carbon composite material is different.

Examples of thermophysical properties include thermal conductivity and thermal expansion coefficient. Mechanical properties include hardness, tensile strength,
The compressive elastic modulus and the interlaminar shear strength are included. Examples of the oxidation characteristics include the oxidation rate and the oxidation start temperature. Examples of other physical properties of the material include density.

This will be described in detail below. By meeting any one or more of the following items, a multi-disc brake exhibiting new characteristics corresponding to each intended use, use condition or control method. Can be obtained. The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the stator disk have a thermal conductivity of 0.1 to 1000 W / mK.
Those in the range of are desirable.

In the present invention, carbon / carbon composite materials having different characteristics can be obtained by having different thermal conductivities. In this case, the difference between one and the other of the carbon / carbon composite materials having different thermal conductivities is 0.1 to 700 W / m · K in the outer direction of the sliding surface, and more preferably 1 to 30.
It is 0 W / m · K, most preferably 5 to 100 W / m · K. 1 to 450 W / mK in the sliding surface direction,
It is more preferably 2-250 W / m · K, most preferably 10-150 W / m · K.

The higher thermal conductivity is preferably 5 to 700 W / mK in the outer sliding surface direction, more preferably 10 to 300 W / mK, and more preferably 10 to 300 W / mK in the inner sliding surface direction. 10 to 450 W / m · K is desirable, and more preferably 20 to 350 W / m · K.

On the other hand, the lower thermal conductivity is preferably 0.1 to 600 W / mK in the outer direction of the sliding surface, and more preferably 0.1 to 200 W / mK. In the inward direction, 1 to 350 W / mK is desirable,
More preferably, it is 1 to 150 W / m · K.

The carbon contained in the rotor disk /
Carbon contained in the starter disk rather than carbon composite material /
The carbon composite material has a higher thermal conductivity in the direction outside the sliding surface, or the carbon / carbon composite material of the stator disk has a better sliding property than the carbon / carbon composite material of the rotor disk. It is desirable that the thermal conductivity in the in-plane direction is low.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have a Shore hardness of 1 to 14 on the sliding surface.
A value of 0, preferably in the range of 30 to 140 is desirable.

In the present invention, carbon / carbon composite materials having different properties can be obtained by setting different Shore hardnesses. In this case, carbon with different Shore hardness /
The difference between one and the other of the carbon composite material is preferably 1 to 60,
It is more preferably 5 to 30.

The higher Shore hardness is 60 to 1
It is preferably 40, more preferably 70 to 140, while the lower Shore hardness is preferably 30 to 100, more preferably 30 to 90. It is desirable that the carbon / carbon composite material of the stator disk has a higher Shore hardness than the carbon / carbon composite material of the rotor disk.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have a tensile strength of 20 in the sliding surface.
It is preferably in the range of up to 1000 MPa.

In the present invention, carbon / carbon composite materials having different properties can be obtained by setting different tensile strengths. In this case, the difference between one and the other of the carbon / carbon composite materials having different tensile strengths is preferably 1 to 200 MPa, more preferably 5 to 100 MPa, and most preferably 10 to 50 MPa.

The higher tensile strength is 50 to 10
00 MPa is desirable, more preferably 60 to 400
MPa, while the lower tensile strength is 20-40
0 MPa is desirable, and more preferably 30 to 300 M
Pa.

The carbon / carbon composite material of the rotor disk is better than the carbon / carbon composite material of the stator disk.
It is desirable that the carbon composite material has a higher tensile strength, and that the inner circumferential portion of the rotor disk has a higher circumferential direction.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have a compressive elastic modulus in the outer direction of the sliding surface of 0.1 to 0.1. The range of 300 GPa is desirable.

In the present invention, carbon / carbon composite materials having different characteristics can be obtained by setting different compressive elastic moduli. In this case, carbon with different compression modulus /
The difference between one side and the other side of the carbon composite material is 0.1 to 200 GPa
Is desirable, and more preferably 0.1 to 10 GPa.

The higher compression elastic modulus is 1 to 30.
0 GPa is desirable, more preferably 1 to 200 GP
a, while the lower compression modulus is 0.1-20
0 GPa is desirable, more preferably 0.5 to 100
It is GPa. It is desirable that the carbon / carbon composite material of the rotor disk has a higher compressive elastic modulus than the carbon / carbon composite material of the stator disk.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have an interlaminar shear strength of 0.1 to 0.1 in the sliding surface. A pressure in the range of 30 MPa, preferably 1 to 30 MPa is desirable.

In the present invention, carbon / carbon composite materials having different properties can be obtained by using different interlaminar shear strengths. In this case, the difference between one and the other of the carbon / carbon composite materials having different interlaminar shear strengths is 0.1-20MP.
a is desirable, and more preferably 1 to 15 MPa.

The higher interlaminar shear strength is 1 to 3
0 MPa is desirable, and more preferably 3 to 20 MPa
On the other hand, the lower interlaminar shear strength is 0.1 to 20.
MPa is desirable, and more preferably 1 to 15 MPa. It is desirable that the carbon / carbon composite material of the stator disk has a higher interlaminar shear strength than the carbon / carbon composite material of the rotor disk.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have an oxidation rate in the atmosphere in the temperature range of 600 to 1200 ° C. It is desirable that the is small.
Specifically, the oxidation rate is 10 ^-10 per minute at 600 ° C.
~ 0.1 kg / kg, 10 ^-6 / min at 800 ℃
0.2 kg / kg, at 1000 ° C 10 ^-3 min ^-1
The smaller one is desirable within the range of 0.3 kg / kg.

In the present invention, carbon / carbon composite materials having different characteristics can be obtained by using different oxidation rates. In this case, the difference between the oxidation rates of one and the other of the carbon / carbon composite materials having different oxidation rates in the atmosphere is 6
At 00 ° C, 10 ^{-10 to} 0.2 kg / kg per minute is desirable, and more preferably 10 ^{-6 to} 0.01 kg / k per minute.
g.

[0054] Also, the smaller is desirably min 10 ^-10 ~0.01kg / kg oxidation rate in air at 600 ° C., more preferably min 10 ^-10 ~0.008k
g / kg, on the other hand, the one having a higher oxidation rate in the atmosphere at 600 ° C. is preferably 10 ^{−6 to} 0.1 kg / kg per minute, more preferably 10 ^{−4 to} 0.1 kg / kg per minute.
Is. It is desirable that the carbon / carbon composite material of the rotor disk has a lower oxidation rate in the atmosphere than the carbon / carbon composite material of the stator disk.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk were 1 mass% when the temperature was raised at 10 ° C./min in the atmosphere. When the reduction start time is defined as the oxidation start temperature, the oxidation start temperature is preferably higher within the range of 300 to 1200 ° C.

In the present invention, carbon / carbon composite materials having different characteristics can be obtained by setting different oxidation start temperatures. In this case, the difference between the oxidation start temperatures of one and the other of the carbon / carbon composite materials having different oxidation start temperatures in the atmosphere is preferably 1 to 700 ° C., more preferably 1
It is 0 to 200 ° C.

Further, the one having a higher oxidation start temperature in the atmosphere is preferably 600 to 1200 ° C., more preferably 70 to 1200 ° C.
0 to 1200 ° C., on the other hand, one having a lower oxidation start temperature in the atmosphere is preferably 300 to 900 ° C., more preferably 300 to 750 ° C. It is desirable that the carbon / carbon composite material of the rotor disk has a higher oxidation start temperature in the atmosphere than the carbon / carbon composite material of the stator disk.

The carbon / carbon composite material used for the rotor disk and the carbon / carbon composite material used for the starter disk have a density of 1.5 × 10 ^{3 to} 2.2.
It is preferably in the range of × 10 ³ kg / m ³ .

In the present invention, carbon / carbon composite materials having different characteristics can be obtained by making the densities different. In this case, the difference between one and the other of the carbon / carbon composite materials having different densities is 0.01 × 10 ^{3 to} 0.7 × 10 ³ k.
g / m ³ , preferably 0.1 × 10 ^{3 to} 0.3 × 10 ³ k
g / m ³ .

The higher density is 1.5 × 10 ^3.
To 2.2 × 10 ³ kg / m ³ is desirable, and more preferably 1.7 × 10 ^{3 to} 2.1 × 10 ³ kg / m ³ , while the lower density is 1.4 × 10 ^3. ~ 2.0 x 10 ³ k
g / m ³ is desirable, and more preferably 1.6 × 10 ³ ~
It is 1.9 × 10 ³ kg / m ³ . It is desirable that the density of the carbon / carbon composite material of the stator disk is lower than that of the carbon / carbon composite material of the rotor disk.

In the present invention, in order to obtain a highly durable multi-disc brake having a desired friction characteristic, a carbon / carbon composite material having different characteristics can be obtained by changing the physical properties of materials other than the above. You can

In the present invention, in order to obtain particularly desired frictional characteristics, a carbon / carbon composite material having different thermal conductivity or hardness is used as a rotor disk in accordance with the application, use environment and control method. And it is desirable to place it at a desired portion of the stator disk.

Next, the carbon / carbon composite material used in the present invention will be described in detail. In the present invention, the carbon / carbon composite material is a composite material containing carbon fibers and / or precursor fibers and a carbonaceous matrix as main components.

The carbon / carbon composite material used in the present invention has a fiber volume content of usually 10 to 80 vol%, preferably 20 to 70 vol%, more preferably 25 to 65 v.
ol%. When the fiber volume content is less than the above range, the effect of fiber reinforcement is not sufficient, and the material becomes brittle and has a low impact strength and fracture toughness value, resulting in a brake material having sufficient performance and durability as a multi-disc brake. I can't exercise my abilities. On the other hand, when the fiber volume content exceeds the above range, the adhesive strength between the fibers is not sufficient, which is not preferable.

The matrix volume content of the carbon / carbon composite material used in the present invention is determined by the fiber volume content and the void volume, and is usually 19
It is about 89 vol%, preferably about 25-80 vol%.

The void volume ratio of the carbon / carbon composite material used in the present invention is usually 1 to 30 vol%, preferably 2 to 25 vol%, more preferably 2 to 10 vol%.
Is. Here, if the void volume ratio is less than the above range, the densification step becomes complicated, and improvement in performance commensurate with the increase in manufacturing time cannot be observed. On the other hand, when the void volume ratio exceeds the above range, the strength as a brake material becomes insufficient. Especially, it is not preferable to be applied to a rotating rotor disk material.

Hereinafter, an example of the method for producing the carbon / carbon composite material used in the present invention will be described in detail. Examples of carbon fibers used in the carbon / carbon composite material include pitch-based, polyacrylonitrile (PAN) -based, and rayon-based carbon fibers. Incidentally, the carbon fiber is a carbon fiber pre-carbonized by firing the precursor fiber as a raw material in an inert gas,
Refers to graphitized fiber. The precursor fibers used in the carbon / carbon composite material include pitch fibers, infusible fibers, PAN fibers, flame-resistant fibers obtained by treating PAN fibers at 200 to 450 ° C. in an oxidizing atmosphere, rayon fibers, and rayon fibers with phosphoric acid. Various fibers such as fibers treated with salt or nitrate may be mentioned. At least one fiber selected from these carbon fibers and precursor fibers can be used for the carbon / carbon composite material, but pitch-based carbon fibers and their precursor fibers are particularly preferred because they can easily enhance the wear resistance.

As the carbonaceous pitch which is a raw material of the pitch-based carbon fiber, coal-based, petroleum-based or synthetic pitch having a softening point of usually 100 to 400 ° C., preferably 150 to 350 ° C. is used. To be As the carbonaceous pitch, either an optically isotropic pitch or an anisotropic pitch can be used, but an optically anisotropic pitch is preferable, and an optically anisotropic phase content of 60 to 60 is particularly preferable. 100 vol
An optically anisotropic pitch within the range of% is particularly preferably used. Melt spinning of the carbonaceous pitch by a known method gives pitch fibers having an average diameter of usually 5 to 100 μm, preferably 7 to 30 μm. Next, the pitch fiber is usually heated to 50 to 400 in an oxidizing gas atmosphere.
C., and preferably infusible within the temperature range of 100 to 350.degree. As the oxidizing gas,
Examples thereof include air, oxygen, nitrogen compounds, sulfur compounds, halogens, or a mixture thereof. The infusibilizing treatment time is usually 10 minutes to 20 hours. The obtained infusibilized fiber is further subjected to an inert gas atmosphere, usually 350 to 3000.
The carbon fiber can be obtained by treating at a temperature of ℃, preferably 400 to 2800 ℃ for 1 second to 5 hours.

The carbon fiber or precursor fiber is usually used as a fiber bundle of about 500 to 25,000 continuous carbon fibers. Further, at least one of these continuous fibers can be used as a unidirectional sheet or a laminate thereof, a two-dimensional woven fabric or a laminate thereof, a three-dimensional woven fabric, or a mat-like molded product.

It is also possible to use the continuous carbon fiber and / or precursor fiber cut to a desired length, or the carbon fiber and / or precursor fiber produced as a short fiber by a spinning process. I can. This fiber bundle can be opened and used as an aggregate of random short fiber filaments. Further, this short fiber can be used as a felt-like sheet, a laminate thereof, or a mat-like molded product.

Further, it is possible to use a molded product made of the above-mentioned carbon fiber and / or precursor fiber and at least one fiber selected from the fibers as it is or in the form of a plate, block or cylinder. Therefore, these are collectively referred to as a carbon fiber molded body. As this molding method, a known method such as a laminating method, a needle punching method, a hot pressing method, a filament winding method can be used, or a plurality of these methods can be used.

In the present invention, the carbonaceous matrix refers to those obtained by heat treatment of an organic precursor and those obtained by thermal decomposition of a gas phase precursor such as hydrocarbon. The organic precursors include thermoplastic ones and thermosetting ones.

A typical example of the thermoplastic organic precursor is carbonaceous pitch. As the carbonaceous pitch, coal-based, petroleum-based or synthetic pitch having a softening point of usually 60 to 400 ° C., preferably 60 to 350 ° C. is used.

As the binder pitch and the impregnating pitch, any one or more of the above pitches can be used, but as the binder pitch, a pitch having a softening point in the temperature range of 200 to 400 ° C. is particularly preferably used and impregnated. A pitch having a softening point in the temperature range of 60 to 200 ° C. is particularly preferably used as the working pitch.

As the binder pitch and the impregnating pitch, either an optically isotropic pitch or an anisotropic pitch can be used. In particular, as the binder pitch, an optically anisotropic pitch having an optically anisotropic phase content of 60 to 100 vol% is preferably used.

After the above-mentioned thermoplastic organic precursor is impregnated into carbon fiber or a carbon fiber molded body, a firing treatment is carried out to produce a carbon / carbon composite material. The firing treatment can be performed in a reduced pressure atmosphere or a normal pressure atmosphere, but is usually performed in a pressurized atmosphere or a uniaxial pressure press.

For the firing in a pressurized atmosphere, a pressure firing apparatus, a hot isostatic pressurizing apparatus or the like is used, and the atmosphere is 0.1 to 1000 MPa, preferably 0.5 to 100 MPa in an inert gas or reducing gas atmosphere. Pressurized to a pressure within the range of about 100 MPa, usually 400 to 2000 ° C., preferably 500 to 15
It is performed within a temperature range of about 00 ° C.

The calcination under the uniaxial pressure press is usually performed by a device such as a hot press under a uniaxial pressure within a range of 0.1 to 50 MPa, preferably 0.4 to 5 MPa and a maximum of 4
The temperature is in the range of about 00 to 2000 ° C, preferably about 500 to 1000 ° C. The atmosphere pressure in this case can be selected from vacuum, reduced pressure, normal pressure and increased pressure,
Further, the atmosphere gas can be selected from vacuum, an inert atmosphere, a reducing atmosphere and an atmospheric atmosphere.

The thermosetting organic precursor is usually a carbonizable resin, specifically, for example, phenol resin, furan resin,
Examples thereof include carbonizable thermosetting resins such as carbodiimide resins. The curing temperature of these thermosetting resins is usually 80.
To 200 ° C, preferably 110 to 150 ° C. Carbon fiber or a carbon fiber molded product was impregnated with the thermosetting organic precursor, molded, cured within the above curing temperature range, and optionally post-cured within a temperature range of 140 to 300 ° C. Then, a carbon / carbon composite material can be manufactured by performing a firing treatment.

The molding treatment is a lamination method, a hot pressing method,
Known methods such as a filament winding method and a roll forming method can be used, and a plurality of these methods can also be used.

The curing treatment and the post-curing treatment can be carried out during the molding treatment, after the molding treatment, or at both stages. The firing treatment is usually 200 to
It can be carried out in a temperature range of 3000 ° C., preferably 500 to 2500 ° C. under vacuum, reduced pressure, in an inert atmosphere or a reducing atmosphere.

Specific examples of the inert gas include those generally used as inert gases such as nitrogen, argon and helium, and the reducing gas includes hydrogen, carbon monoxide and the like. Can be mentioned. The term "under vacuum or under reduced pressure" refers to a state in which the inert gas, reducing gas or atmosphere exists below atmospheric pressure, and at least 10 ^-5 Pa
It refers to a state that exists.

As the gas phase precursor, all compounds containing a carbon atom which can be gasified can be used. A carbon / carbon composite material can be obtained by depositing pyrolytic carbon obtained by pyrolyzing a vapor-phase precursor on carbon fiber or a carbon fiber molded body.

The treatment of depositing pyrolytic carbon is a method of vapor-decomposing hydrocarbons and the like to form carbon, which is generally called chemical vapor deposition (CVD). Is. Specifically, for example, hydrocarbons such as methane, ethane, acetylene, propane, benzene, natural gas, etc., or at least one of these hydrocarbons diluted with an inert gas or hydrogen is used as a raw material, and pyrolytic carbon is formed into carbon fiber molded bodies. Deposit.

At this time, the thermal decomposition temperature is usually 700 to 300.
It is in the range of 0 ° C, preferably 800 to 2500 ° C.
Moreover, although the pressure at the time of thermal decomposition can be performed at normal pressure,
The pressure is preferably reduced, specifically 50 to 1000
It is within the range of 0 Pa, preferably about 50 to 5000 Pa.

The carbon / carbon composite material thus obtained is
When the target carbon / carbon composite material has physical properties such as density, matrix volume content or void volume ratio, the carbon / carbon composite material is used as it is or after polishing or the like is processed to produce a friction for a brake. It can be a material.

The obtained carbon / carbon composite material does not have the desired physical properties of the carbon / carbon composite material, such as density, matrix volume content, void volume ratio, hardness and thermal conductivity. In this case, the carbon / carbon composite material is further impregnated with the above-mentioned organic precursor and subjected to a firing treatment, or a treatment of depositing pyrolytic carbon is performed once or more to obtain the desired physical properties. It is also possible to obtain a carbon / carbon composite material having This process step is called a densification process.

Further, the obtained carbon / carbon composite material is
When the target carbon / carbon composite material does not have the physical properties such as density, matrix volume content, void volume ratio, hardness, thermal conductivity, etc., the carbon / carbon composite material is densified as described above. After the treatment, a firing treatment can be performed.

The baking treatment is performed on the carbon / carbon composite material by
This is a process of baking in an inert atmosphere under reduced pressure, normal pressure or pressure, and the pressure of this inert atmosphere is 10 ^-8 to 2
It is within the range of 00 MPa, preferably 0.1 to 100 MPa. The processing temperature is usually 1500 to 3000 ° C., though it varies depending on the desired physical properties.

Further, the firing treatment can be carried out each time after the densification treatment or discontinuously after any number of times according to the physical properties of the intended carbon / carbon composite material, and the temperature thereof can also be changed. It can be selected for each firing process.

Among the above-mentioned carbon / carbon composite material production methods, carbon fiber species, precursor fiber species, carbon fiber and precursor fiber production methods, carbon fiber volume content, two or more carbon fibers and precursors When body fiber is used, its compounding ratio,
The type of carbon fiber molded product, the type of matrix raw material, the volume content of the matrix, the product with two or more types of matrix, the composite ratio, the volume content of voids, the densification treatment method or its conditions, the firing treatment conditions, etc. By appropriately setting one or more of these conditions, it is possible to obtain a carbon / carbon composite material having at least one or more different properties.

[0092]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 A two-dimensional woven fabric of petroleum pitch-based carbon fiber was used as a reinforcing fiber, and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix was used as a rotor disk material. And

A felt mat of petroleum pitch-based carbon fiber was used as a reinforcing fiber, and a felt mat-reinforced carbon / carbon composite material B using a carbonaceous matrix made of petroleum pitch as a raw material was used as a starter disk material. Table 1 shows various physical properties of A and B.

At this time, the out-of-plane thermal conductivity of the stator disk material B is higher than that of the rotor disk material A. The in-plane thermal conductivity of the rotor disk material A is higher than that of the stator disk material B. The Shore hardness of the sliding surface is low.
The stator disk material B is higher than the stator disk material A.

A multi-disc type brake composed of one rotor disc A and one stator disc B was evaluated by using a break tester, and the friction coefficient and the wear amount were evaluated. Was measured. Table 2 shows the test conditions at this time.
Shown in As a result, the friction coefficient was 0.30, the total specific wear amount of the disk was 15 mm ³ / MJ, and a highly durable brake was obtained (Table 3).

Example 2 A two-dimensional woven fabric of petroleum pitch-based carbon fiber was used as a reinforcing fiber, and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix was used as a rotor disk material. And

Further, a mat of reinforced petroleum pitch type carbon fiber is used as the reinforcing fiber, a carbonaceous matrix made of phenolic resin as a raw material for the matrix, and a mat-reinforced carbon / carbon composite material C using vapor-phase pyrolyzed carbon are used. Used as a disk material. Table 1 shows the physical properties of A and C.

At this time, the in-plane thermal conductivity of the rotor disk material A is higher than that of the stator disk material C. The Shore hardness of the sliding surface is better than that of the rotor disc material A.
Tar disk material C is higher.

A multi-disc type brake composed of one rotor disc A and one stator disc C was evaluated using a break tester, and the friction coefficient and the wear amount were evaluated. Was measured. Table 2 shows the test conditions at this time.
Shown in As a result, the friction coefficient was 0.51, the total specific wear amount of the disk was 30 mm ³ / MJ, and a brake having a large braking force was obtained (Table 3).

Comparative Example 1 A two-dimensional woven fabric of petroleum pitch-based carbon fiber as a reinforcing fiber and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix were used as a rotor disk material. And a stator disk material. Various physical properties of A are shown in Table 1.

A multi-disc type break composed of one rotor disc A and one stator disc A was evaluated by using a break tester, and the friction coefficient and the wear amount were evaluated. Was measured. Table 2 shows the test conditions at this time.
Shown in As a result, the friction coefficient was 0.21, the total specific wear amount of the disk was 25 mm ³ / MJ, and a brake having a slightly small braking force was obtained (Table 3).

Example 3 A two-dimensional woven fabric of petroleum pitch-based carbon fiber as a reinforcing fiber and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix were used as a rotor disk material. And

Further, a felt mat of petroleum pitch-based carbon fiber was used as the reinforcing fiber, and a felt mat-reinforced carbon / carbon composite material B using a carbonaceous matrix made of petroleum pitch as a matrix was used as a starter disk material. Table 1 shows various physical properties of A and B.

At this time, the out-of-plane thermal conductivity of the stator disk material B is higher than that of the rotor disk material A. The in-plane thermal conductivity of the rotor disk material A is higher than that of the stator disk material B. The Shore hardness of the sliding surface is low.
The stator disk material B is higher than the stator disk material A.

One stator disk B and two rotor disks
A multi-disc type brake, in which a starter disc A and one starter disc B are arranged in series,
Evaluation was performed using a tester, and the friction coefficient and the amount of wear were measured. Table 2 shows the test conditions at this time. As a result, the friction coefficient was 0.33, and the total specific wear amount of the disk was 2.0 ×.
It was 10 ^-2 mm ³ / MJ, and a highly durable brake was obtained (Table 3).

Example 4 A two-dimensional woven fabric of petroleum pitch-based carbon fiber was used as a reinforcing fiber, and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix was used as a rotor disk material. And

Further, the felt mat of petroleum pitch-based carbon fiber was used as the reinforcing fiber, and the felt mat-reinforced carbon / carbon composite material B using the carbonaceous matrix made of petroleum pitch as a matrix was used as one of the stator disk materials. did.

Also, a mat of reinforced carbon / carbon composite material C using a petroleum pitch-based carbon fiber mat as the reinforcing fiber, a carbonaceous matrix made of phenolic resin as a raw material for the matrix, and vapor-phase pyrolysis carbon is used. It is one of the tar disk materials. Table 1 shows the physical properties of A, B and C.

At this time, the out-of-plane thermal conductivity of the stator disk material B is higher than that of the rotor disk material A. The in-plane thermal conductivity of the rotor disk material A is higher than that of the stator disk materials B and C. The Shore hardness of the sliding surface is higher in the stator disk materials B and C than in the rotor disk material A.

One stator disk B and two rotor disks
A multi-disc type brake, in which a starter disc A and one starter disc C are arranged in series,
Evaluation was performed using a tester, and the friction coefficient and the amount of wear were measured. Table 2 shows the test conditions at this time. As a result, the friction coefficient was 0.53, and the total specific wear amount of the disc was 3.5 ×.
It was 10 ^-2 mm ³ / MJ, and a brake with a large braking force was obtained (Table 3).

Example 5 A two-dimensional woven fabric of petroleum pitch-based carbon fiber as a reinforcing fiber and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix were used as a rotor disk material. And one of them.

One of the rotor disc materials is a felt mat of petroleum pitch-based carbon fiber as the reinforcing fiber, and a felt mat-reinforced carbon / carbon composite material B using a carbonaceous matrix made of petroleum pitch as a matrix. And a stator disk material. Table 1 shows the physical properties of A and B.
Shown in

At this time, the out-of-plane thermal conductivity of the stator disk material B is higher than that of the material A used for one of the rotor disks. The in-plane thermal conductivity is the same as the stator disk material B.
The material A used for one of the rotor disks is higher than the material for the rotor disk. The Shore hardness of the sliding surface is higher in the stator disk material B than in the material A used for one of the rotor disks.

One stator disk B has one rotor disk.
A multi-disc type brake in which a data disc A, a rotor disc B, and a stator disc B were arranged in series was evaluated using a break tester,
The coefficient of friction and the amount of wear were measured. Table 2 shows the test conditions at this time. As a result, the coefficient of friction was 0.44, and the total specific wear amount of the disk was 1.8 × 10 ^-2 mm ³ / MJ,
A brake having a high durability and a large braking force was obtained (Table 3).

Example 6 A two-dimensional woven fabric of petroleum pitch-based carbon fiber as a reinforcing fiber and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix were used as a rotor disk material. And

Next, a two-dimensional woven fabric of petroleum pitch-based carbon fiber was used as a reinforcing fiber, and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix was used as a starter disk. I used it as the base material. This station
Eight threaded holes were formed on the sliding average diameter of the target disk by machining, the total area of which corresponds to 10% of the sliding area. A screw made by processing a felt mat of petroleum pitch-based carbon fiber as a reinforcing fiber and a felt mat reinforced carbon / carbon composite material B using a carbonaceous matrix made of petroleum pitch as a raw material was attached to the matrix. At the time of this mounting, in order to prevent loosening, a carbon-based adhesive was applied to the threaded surface, baked at 1000 ° C., and fixed. The A + B materials thus prepared were used as a starter disk.

At this time, the out-of-plane thermal conductivity of the material B used for a part of the stator disk is higher than that of the rotor disk material A. The in-plane thermal conductivity of the rotor disk material A is higher than that of the material B used for a part of the stator disk. Further, the Shore hardness of the sliding surface is higher in the material B used for a part of the stator disk than in the rotor disk material A.

One stator disk A + B, two rotor disks A and one stator disk A
A multi-disc type brake having + B arranged in series was evaluated by using a break tester, and the friction coefficient and the wear amount were measured. Table 2 shows the test conditions at this time. As a result, the friction coefficient was 0.29, the total specific wear amount of the disk was 2.8 × 10 ^-2 mm ³ / MJ, and a brake with an adjusted braking force was obtained (Table 3).

Comparative Example 2 A two-dimensional woven fabric of petroleum pitch-based carbon fiber as a reinforcing fiber and a two-dimensional reinforced carbon / carbon composite material A using a carbonaceous matrix made of petroleum pitch as a matrix were used as a rotor disk material. And a stator disk material. Various physical properties of A are shown in Table 1.

One stator disk A and two rotor disks
A multi-disc type brake in which a starter disc A and one stator disc A are arranged in series
Evaluation was performed using a tester, and the friction coefficient and the amount of wear were measured. Table 2 shows the test conditions at this time. As a result, the friction coefficient was 0.25, and the total specific wear amount of the disc was 2.9 ×.
A standard brake of 10 ^-2 mm ³ / MJ was obtained (Table 3).

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[Table 1]

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[Table 2]

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[Table 3]

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According to the present invention, it is possible to obtain a highly durable multi-disc type brake having a friction characteristic suited to the application, the use environment and the control method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C09K 3/14 520 FF 16D 65/12 U 69/02 B

Claims (1)

[Claims] 1. A rotor disk having a carbon / carbon composite material (A) as a friction material, and a starter disk having a carbon / carbon composite material (B) as a friction material.
A multi-disc brake characterized in that the carbon composite material (A) and the carbon / carbon composite material (B) have different characteristics.