JPH09264357A - Frictional material and manufacture of frictional material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically strengthen the front surface or the inside of a frictional material brittle in a single body by means of fibers, by integrating a network structural body formed of fibers with a frictional material main body. SOLUTION: Aramid fibers, glass fibers, carbon fibers, or the like are used as fibers 1. A network structural body 2 is formed by making the fibers 1 into a three-dimensional fabric, any weaving structure may be adopted. When the network structural body 2 is formed into a box shape, it is so formed as to be provided with a bottom and no cover, and the bottom surface is formed into a trapezoidal shape, a sector or the like. The box-like network structural body 2 has relatively flexibility in a single body, it is drastically strengthened with forming of the frictional material raw material to be filled inside, and it acts as a frame of a frictional material 3. The raw materials of a frictional material main body 6 are integrally pressurized and formed with the network structural body 2 and taken as the frictional material 3. Therefore, a back plate can be omitted, the structure of a die can be simplified, and a frictional material capable of obtaining the uniform quality can be obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a friction material used for a brake.

[0002]

2. Description of the Related Art Disc brakes are provided with disc pads which are pressed against a disc rotor to generate a braking force. As shown in FIG. 6, the disc pad is pressed against the disc rotor 12 by a piston 11 provided in the caliper 10.

The disc pad 13 is constructed by adhering a friction material 15 on a back plate 14, and its manufacturing method is (1) removing dirt such as oil and fat on the surface of the back plate 14 and then ( 2) Apply an adhesive to the surface of the back plate 14 on which the friction material 15 is bonded. Then, (3) the back plate 14 is inserted into the bottom of the cavity of a press die (not shown) so as not to move horizontally. (4) The back plate 14 is filled with a mixture of about 10 to 20 kinds of raw materials as the raw material of the friction material 15, and pressure molding is performed at a high temperature. (5) After that, the product is completed through finishing processes such as heat treatment, polishing, and painting.

The reason for providing the back plate 14 is to reinforce the friction material 15 which is easily broken and to protect the edge of the friction material 15 which is pressed against the caliper (brake fixing part) 10 by strong energy during braking. is there. That is, the metal back plate 14
Protect the friction material 15 by applying stress to
It ensures safety.

[0005]

However, the presence of this back plate causes the following problems. Firstly, in (1) and (2) of the manufacturing process, various equipments and processes are required to integrate the back plate and the friction material, which causes an increase in manufacturing cost.

Secondly, in the steps (3) and (4), it is necessary to load the back plate in the mold of the hot press, which complicates the structure of the mold and further requires a working time for loading. Therefore, it is a problem in terms of cost and productivity.

Further, since the mold becomes complicated, the temperature distribution between the molds also becomes non-uniform, which causes a variation in the molding state of the friction material. As described above, the conventional friction material (disk pad) has various problems caused by the back plate.

The present invention has been made in view of the above matters, and it is a technical object to provide a friction material having increased strength. Further, it is a technical object to provide a friction material that can omit the back plate, simplify the structure of the mold, and obtain uniform quality.

Further, it is a technical object to provide a method for producing such a friction material.

[0010]

The present invention has been made as follows in order to solve the above technical problems. That is, in claim 1, the mesh structure 2 formed of the fibers 1 is integrated with the friction material main body 6 to form the friction material 3.

Further, in claim 2, the reticulated structure 2
Is the friction material 3 that integrally covers the friction material body 6 on the surface of the friction material body 6 excluding the friction surface 7. Further, in claim 3, the mesh structure 2 has a partition wall 4 inside.
It was formed into a box shape divided into a plurality of pieces.

As a method of manufacturing the friction material 3, a step of loading the reticulated structure 2 formed of the fibers 1 in a molding die, and a method of manufacturing the friction material 3 in the die in which the reticulated structure 2 is loaded. And a step of compressing the inside of the mold filled with the raw material of the mesh structure 2 and the friction material. [Fiber 1] As the fiber 1, aramid fiber, glass fiber,
An example is carbon fiber. Aramid fiber is an aromatic polyamide fiber, which is a type of organic fiber, has excellent strength and heat resistance, has a tensile strength 5 to 7 times that of iron, a breaking elongation of 4.2%, and an extremely high elastic modulus. is there.

The glass fiber is obtained by stretching molten glass or blowing it away by centrifugal force to a thickness of several thousandths of a millimeter, and it is possible to obtain a tensile strength equivalent to that of an iron wire having the same thickness.

The carbon fiber is a high-strength, high-rigidity fiber made of graphite-based carbon, and is manufactured from an acrylic resin or the like as a raw material at 1000 to 1500 ° C. under an inert condition in which a chemical reaction such as oxidation does not occur. A polyacrylonitrile type is preferable.

Besides, it is also possible to use metal fibers. That is, it is desirable that the fiber 1 has the same quality as the material used as the raw material of the friction material 3. However, the material is not limited to the raw material of the friction material 3, and any material may be used as long as it does not deteriorate the braking performance. [Reticulated Structure 2] The reticulated structure 2 is formed by forming the above-described fibers into, for example, a three-dimensional woven fabric. As the woven structure, for example, a velor weave can be exemplified, but any woven structure may be used. When the net-like structure 2 is formed in a box shape, it is possible to exemplify a shape with a bottom and an open bottom having a trapezoidal bottom surface, a fan shape, or another shape. The box-shaped net-like structure 2 is relatively flexible by itself, but is dramatically strengthened as the friction material raw material filled therein is molded, and acts as a skeleton of the friction material 3. Further, since the surface of the friction material 3 is covered, it has an effect of preventing chipping due to external force.

When the inside of the box-shaped structure 5 formed of the net-like structure 2 is divided into a plurality of partitions (net-like structures) 4 also formed of the fibers 1, the number of divisions is two or more, and the division is arbitrary. The shape may be used, but it may be determined in consideration of the directionality of stress when the friction material is used. Further, in order to divide the inside of the box-shaped structure 5, it may be divided in either the vertical direction or the horizontal direction, or may be divided in the horizontal direction.

The net-like structure 2 may be made of a yarn made of the same material, or may be made of a yarn made of a plurality of materials. [Friction Material 3, Friction Material Main Body 6] The components of the friction material main body 6 itself are compounded in the same manner as general ones. That is, a thermosetting resin binder such as phenol resin, a fiber base material such as glass fiber and aramid fiber, and all raw material powders such as rubber dust, cashew dust, friction modifiers such as metal powder are uniformly mixed and stirred. It becomes the raw material of the friction material main body 6, and the friction material 3 is obtained by press-molding this raw material integrally with the mesh structure 2.

As described above, the net-like structure 2 significantly strengthens the friction material 3 which is brittle by itself. Therefore, when the disc brake is used, it is not necessary to provide the friction material with the back plate.

[0019]

1 to 5 show an embodiment of the present invention.
It will be described based on. 2 to 4 show a structure (5) in which a net-like structure 2 knitted with fibers 1 is formed into a box shape. As the fiber 1, aramid fiber, glass fiber, or carbon fiber is used. The reticulated structure 2 is
It is formed as a three-dimensional woven fabric.

The box-shaped structure 5 shown in FIG. 2 has a bottom shape in which only one side of a rectangle is curved, and is partitioned into four chambers by a partition wall 4. The box-shaped structure 5 shown in FIG. 3 has the same appearance as that shown in FIG.
Divided into 9 rooms by partition walls.

Further, the box-shaped structure 5 shown in FIG. 4 has a rectangular curved shape, and is partitioned into four chambers by a partition wall 4. When manufacturing the friction material 3, the box-shaped structure 5 having the above-described shape is mounted in a mold (not shown), and after the raw material of the friction material body 6 is filled therein, pressure is applied. Harden (it may be just a preliminary pressing stage here). Then, by thermoforming, the box-shaped structure 5 and the friction material main body 6 are completely integrated to complete the friction material 3 (FIG. 1) having a strong outer wall.

When manufacturing friction materials for disc brakes, protrusions such as a back plate are eliminated.
The shape of the mold can be greatly simplified. Further, since there is no back plate whose thermal conductivity is different from that of the friction material 3,
All surfaces are heat treated on average to facilitate quality control.

Further, since the back plate which is a metal plate is not necessary, the weight can be reduced and the unsprung load of the brake device can be reduced. Next, FIG. 5 shows an example in which the friction material 3 is mounted on an actual brake device.

The disk rotor 12 is rotating in the direction of the arrow, and when the piston 11 presses the friction material 3 toward the disk rotor 12 side to operate the brake, the friction material 3 is directed in the same direction as the rotation direction of the disk rotor 12. Is generated, and the P portion of the friction material 3 strongly contacts the caliper (brake fixing portion) 10. However, since the outer wall of the friction material 3 is protected by the mesh structure 2, no chipping or cracking occurs. The opening in the box-shaped structure 5 (the friction material raw material filling port at the time of molding) becomes the exposed portion of the friction material main body 6, and the friction material 3
And the friction surface 7 with the disk rotor 12.

When the friction surface 7 of the friction material 3 is worn by the braking operation, the mesh structure 2 is also worn together with the friction material main body 6 so that the friction material 3 is not unevenly worn.

[0026]

According to the present invention, the surface or the inside of a friction material, which is fragile by itself, can be significantly reinforced with fibers. Therefore, it is possible to provide a brake pad that does not require a back plate.

Further, in manufacturing the friction material, the structure of the molding die can be simplified, and at the same time, the quality of the molded product can be made uniform.

[Brief description of drawings]

FIG. 1 is a perspective view of a friction material according to an embodiment of the present invention.

FIG. 2 shows a first box-shaped structure according to an embodiment of the present invention.
FIG.

FIG. 3 is a second box-shaped structure according to the embodiment of the present invention.
FIG.

FIG. 4 shows a third box-shaped structure according to the embodiment of the present invention.
FIG.

FIG. 5 is a sectional view of the inside of the brake device according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view of the inside of a brake device showing a conventional brake disc pad.

[Explanation of symbols]

 1 ・ ・ Fiber 2 ・ ・ Reticulated structure 3 ・ ・ Friction material 4 ・ ・ Partition wall 5 ・ ・ Box-shaped structure 6 ・ ・ Friction material body 7 ・ ・ Friction surface 10 ・ ・ Caliper 11 ・ ・ Piston 12 ・ ・ Disk rotor

Claims (4)

[Claims] 1. A friction material characterized in that a mesh structure formed of fibers is integrated with a friction material main body. 2. The friction material according to claim 1, wherein the net-like structure integrally covers the friction material body on the surface of the friction material body excluding the friction surface. 3. The friction material according to claim 1, wherein the net-like structure is formed into a box-like shape having an interior divided into a plurality of parts by partition walls. 4. A step of loading a net-like structure formed of fibers into a molding die, a step of filling a raw material of a friction material into the mold filled with the net-like structure, and filling the inside of the die. Of the friction material and the step of compressing the reticulated structure and the friction material.