JPH03202230A - Manufacture of copper flake for brake material - Google Patents

Abstract

PURPOSE:To manufacture the fine copper flake having the excellent adhesion and mixing property with other material economically by throwing a copper thin plate made of rolled scrap copper wire or rolled scrap coated copper wire respectively having a micro diameter into a crusher, and crushing it finely to obtain the copper flake. CONSTITUTION:After rolling the copper wire material such as copper wire, plated copper wire, enamel baked copper wire and coated copper wire into a thin plate, it is crushed to obtain the fine particle of which surface area is complex, namely, large. Consequently, the fine particle as the friction coefficient adjusting material is mixed with other material well, and while adhesion is improved. Next, since the copper wire material as the raw material has excellent expansionability, it can be rolled easily, and since it has high copper purity, the copper flake having the excellent friction characteristic as a brake can be obtained. In the case that the waste material such as stripping line in streets of communication cable is used as the copper wire material to be used as the raw material, the copper flake can be manufactured at low cost, and contribution to the effective use of resources is large.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (INDUSTRIAL APPLICATION) The present invention relates to a process for economically producing copper flakes useful as friction and reinforcing materials in various disc brake shoes.

(Prior Art) The demand for metal fibers as friction and reinforcing materials used in disc brakes and clutches of automobiles, railway vehicles, industrial machinery, etc. is rapidly increasing.

Additionally, as the use of asbestos (asbestos) is currently being heavily regulated from the perspective of environmental pollution, the use of cut wool, which is made by cutting steel wool into short lengths, is being considered as a friction and reinforcing material for brake shoes or brake pads in place of asbestos. ing.

As a method for manufacturing such metal fibers in large quantities, cutting methods such as wire cutting method and chatter vibration cutting are widely used.

(Problems to be Solved by the Invention) However, with these cutting methods, it is difficult to efficiently and inexpensively manufacture fibers of non-ferrous metals such as copper.

In other words, in the production of non-ferrous metal fibers by the cutting method,
The yield was as low as about 60%, and the production capacity was also low, leading to high prices.

In addition, the use of cut wool as a friction material to replace asbestos improves both the disadvantages of asbestos pads, namely the increase in friction coefficient at high temperatures and the decrease in the coefficient of friction.
Although it has the advantage of improved durability, it has disadvantages such as being susceptible to rust, having a low coefficient of friction at low temperatures, and producing unpleasant noises and sparks during friction.

Therefore, instead of such iron fibers, the use of friction materials made of non-ferrous metals such as copper and brass is being considered.

On the other hand, copper, which is a type of non-ferrous metal, has attracted attention due to its high thermal conductivity, and the demand for copper fine materials such as copper powder and copper fibers as heat dissipating and heat absorbing additives is increasing.

As demand increases, fine copper materials of various sizes are required, and there is a desire to produce finer materials that are finer and have better adhesion to other materials.

The present invention was made in response to these problems, and it uses fine copper flakes that have excellent adhesion and mixability with other materials.
The purpose is to provide an economical method for manufacturing using waste materials such as communication cables.

[Structure of the Invention] (Means for Solving the Problems) The method for manufacturing brake material crude steel flakes of the seventh invention involves rolling a minute diameter scrap copper wire or scrap coated copper wire into a thin copper plate, and pulverizing the thin copper plate. Pour it into a machine and grind it finely until the average particle size is 1.
It is characterized by obtaining copper flakes of 1III or less.

In the present invention, the minute diameter scrap copper wire used is
For example, waste copper wire such as bare scrap copper wire, scrap plated copper wire, scrap enamel-baked copper wire, scrap coated copper wire, etc. produced in the manufacturing process of electric wires and cables with an outer diameter of about 0.91 or less is used.

These wires have uniform wire diameters and can be handled in sufficient quantities at one time, making it possible to produce large amounts of copper flakes with stable dimensions, shapes, and quality at low cost. can.

In the present invention, these copper wires have their sheaths removed;
An average of 0.1+
The copper sheet is rolled to a thin thickness of approximately 100 mm.

At this time, a trough-like feeder with grooves parallel to the input direction and vibrating in this direction is arranged at the material input port to the rolling roll or pressure press, and the steel materials are fed in in a lined up state in the same direction. It is preferable to prevent this from happening.

Further, as the rolling roll, a grooved roll having grooves formed on the surface can also be used.

When such a grooved roll is used, the grooves are transferred to the surface of the copper flakes to form irregularities. For this reason,
Copper flakes with even higher bonding strength when mixed with resin etc. can be obtained.

In order to cut or crush rolled copper thin plates, it is possible to align the copper thin plates and feed them at a constant speed into a cutting machine with a cutting blade to cut them into short pieces with the same length. A method such as pulverizing a thin plate using a rotary pulverizer can be adopted.

At this time, if you mix the drawn wire diluted with water on a thin copper plate, the pulverization will be smoother.

A rotary crusher is, for example, a crusher configured to crush copper wire between a fixed blade embedded in the inner peripheral surface of a crushing container and a rotating blade that continuously rotates inside the container. is available.

In the present invention, sieving is usually used to separate the copper wire and copper flakes after cutting or crushing.

Sieving is carried out by passing through a sieve with a defined mesh, or, especially when crushing is carried out using a rotary crusher of the structure described above, such a sieve (screen) is placed at the bottom of the crusher vessel. It is preferable to continuously crush the thin copper plate provided and introduced until it becomes smaller than a certain diameter or length.

Finally, fine copper flakes with a grain size of less than 1 square inch are obtained.

The size of the copper flakes can be varied by controlling the diameter of the screen holes at the bottom of the crusher.

(Function) In the method for producing copper flakes for brake materials of the present invention, copper wire materials such as copper wire, plated copper wire, enamelled copper wire, coated copper wire, etc. are rolled into a thin plate shape and then pulverized. By doing so, fine particles with a complex (ie, large) surface area can be obtained.

Therefore, it mixes well with other materials as a friction coefficient adjusting material and improves adhesion.

The raw material copper wire rod has extremely high ductility, making it easy to roll, and the high purity of the copper makes it possible to obtain copper flakes with good frictional properties as a brake.

In addition, when waste materials such as recovered wires from communication cables are used as the raw material copper wire material, it can be manufactured at an extremely low cost and greatly contributes to the effective use of resources.

(Example) Next, an example of the production method of copper flakes for brake materials of the present invention will be described.

First, a medium-sized recovered electric wire with a diameter of 0.7 square meters is prepared as raw copper waste material.

The sheath of the raw copper waste material is stripped off to take out only the copper wire inside, which is then rolled to obtain a copper thin plate.

Thereafter, this thin copper plate is crushed in a crusher and sieved through a sieve having meshes with a diameter of BNRA, and the remaining copper particles are crushed again to obtain copper flakes having a diameter of 1 square inch or less. The pulverization was carried out using a pulverizer in a conventional manner.

In this example, since the copper material was made of a thin plate, there was less load on the pulverizer during pulverization, and pulverization was carried out stably.

In addition, the pulverized copper particles were fine, had various complex shapes, and had a large surface area, so they had good adhesion with other materials and excellent mixability.

[Effects of the Invention] As explained above, according to the method of manufacturing copper flakes for brake materials of the present invention, copper flakes having a complex shape and a large surface area can be efficiently manufactured.

The complexity of the shape improves the friction properties and the bonding strength to the base material such as resin, resulting in better d-compatibility.

Furthermore, by using copper scrap materials such as scrap copper wire and wires recovered from communication cables as raw materials, it greatly contributes to cost reduction and effective use of resources.

Claims (1)

[Claims] (1) Scrap copper wire or scrap coated copper wire of minute diameter is rolled into a copper thin plate, and this copper thin plate is fed into a crusher and finely crushed to obtain copper flakes with an average particle size of 1 mm or less. A method for producing copper flakes for brake materials.