JPS6217089A - Manufacture of current collecting material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing current collecting materials such as pantograph sliders and trolley wheels.

(Prior Art) The current collecting material includes cast alloys, sintered alloys, carbon materials, etc. Among these, carbon materials have excellent arc resistance and self-lubricating properties, and are suitable for mating materials such as trolley wires and power supply rails. while having the advantage of reducing wear and tear.

It has the drawbacks of low mechanical strength and wear resistance, high single-air resistance, and easy generation of heat during current collection. In order to improve this, it has been proposed that the carbon material is impregnated with copper-lead, Babbitt, and other various metals.

(Problems to be solved by the invention) However, as the speed of railway vehicles increases, the current collecting capacity increases, etc., the usage conditions for current collecting materials are becoming more severe. Although there is a demand for a slider for use in electric motors, a current collector material that satisfactorily satisfies the above characteristics has not yet been obtained.

An object of the present invention is to provide a method for producing a current collecting material that has excellent current collecting performance and wear resistance even under conditions of high speed and large current collection.

(Means for Solving the Problems) The inventors of the present invention have repeatedly studied methods for producing metal-impregnated carbon materials that have high mechanical strength, self-lubricating properties, and excellent wear resistance. The present invention was completed by discovering that it is effective to use gas coke as the main raw material.

The present invention relates to a method for producing a current collector material, which comprises extruding and firing a kneaded mixture of carbon aggregate containing gas coke powder and a binder, and then impregnating it with metal.

In the present invention, carbon aggregate is mainly composed of gas coke powder, to which natural or artificial graphite powder is added in order to prevent cracks and stabilize sintering. This does not preclude the addition of powder, carbon black, or other inorganic powder.

Gas coke is a byproduct obtained by carbonizing coal to obtain city gas, and since it contains a large amount of water, it is dried, dehydrated, and then crushed to be used as gas coke powder. The particle size is preferably 150 μm or less, more preferably 75 μm or less.

In addition to pitch and tar, thermosetting resins such as phenol resins may be used as the binding material.

The kneading, extrusion molding and firing of the aggregate and binder are performed by known methods, and there are no particular limitations.

The metal to be impregnated after firing is preferably one with excellent conductivity and/or lubricity, such as 9 normal steel and antimono.

Babbitt, copper-lead mixtures, etc. are used, but are not limited thereto. For metal impregnation, a known method of applying pressure after impregnating under reduced pressure is preferred.

(Example) Next, an example will be described.

Example 1 Gas coke (manufactured by Tokyo Gas) containing a moisture content of 17% by weight, a volatile content of 1.2% by weight, and an ash content of 12% by weight was dried at 110°C to reduce the moisture content to 0.5% by weight or less, and then subjected to impact. 1 with a crusher
The powder was ground to 50 μm or less to obtain gas coke powder. Aggregate 10 was prepared by adding 5 parts by weight of coke-based artificial graphite powder of 100 μm or less to 95 parts by weight of the gas coke powder and mixing with a V-type mixer.
Based on 0 parts by weight.

Tar pitch (JISK2
Add 36 parts by weight of 439, general medium pitcher) and heat to 150°C.
After kneading for 2 hours, the mixture was extruded using a ram extruder to obtain a molded product of 40φ×100 l (on).

This compact was heated in a nitrogen gas atmosphere furnace at 30°C per hour up to 250°C, 1.5°C per hour from 250 to 500°C, and 5°C per hour up to 250°C.
00 to 1000℃ and increase the temperature at a rate of 5℃ per hour to 1000℃
Firing was performed with

This fired product was placed in an autoclave, the pressure was reduced to 10 mmHg or less, and the pressure was maintained for 1 hour.
Inject molten alloy consisting of 45kg/cm2 by weight%
A current collecting material was obtained by impregnation by applying pressure for 30 minutes.

Example 2 Example 1 was added to the gasco material obtained by crushing the gas coke after the drying process in Example 1 to 74 μm or less using an impact crusher.
Adding 40 parts by weight of tar pitch in Example 1 below.
A current collecting material was obtained in the same manner as above.

Comparative Example 1 A current collecting material was obtained in the same manner as in Example 1 except that pitch coke (manufactured by Nippon Steel Chemical Co., Ltd., trade name: LPC-A) was used instead of the gas coke in Example IK.

Comparative Example 2 Powders of 8 tin, 1.2% iron, 3% nickel, 4% graphite, and the balance copper were mixed by weight and compression molded at a pressure of 4.5 mm/cm2 to a thickness of 12 mm. [[IIn x width 50 marks x length 100g molded body, this was 85% in total hydrogen gas atmosphere.
A current collector material of a sintered alloy was obtained by sintering at 0°C.

10 mm square x 60 mm long from each current collector material obtained in the above Examples and Comparative Examples. (Except for Comparative Example 2, the length is the extrusion 2 during molding.
The electrical resistivity in the extrusion direction and the mechanical properties (bending strength and hardness) in the direction perpendicular to the extrusion direction were measured.

On the other hand, a test piece with a thickness of 10 mm x width of 25 mm x length of 60 marks (excluding Comparative Example 2, the length is in the extrusion direction during molding) was cut out.
7.5 kg was applied to the hard copper mating material using a simulated cohesive galvanic wear tester.
Pressed with a pressure of 60k/hour through a 100A DC current.
A sliding test was conducted at a speed of m, and the wear ratio was calculated using the following formula.

The above measurement results and test results are shown in Table 1.

Table 1 below shows that the current collector material of Comparative Example 2 is a sintered alloy, so its specific resistance is extremely low, but in the sliding test, arc welding occurred on the surface of the mating material, which deteriorated the sliding properties. Marks were observed;
It is thought that this welding phenomenon caused the specific wear amount to show a large value. No bath adhesion phenomenon was observed in the metal-impregnated carbon current collector material, and the specific wear amount of the example was 1/3 to 1/3 of that of Comparative Example 1.
1/4, and the value of specific resistance is also smaller than that of the example.

(Effects of the Invention) According to the present invention, a current collecting material with excellent wear resistance and arcing properties can be obtained.

Claims (1)

[Claims] 1. A method for producing a current collector material, which comprises extruding and firing a kneaded mixture of carbon aggregate containing gas coke powder and a binder, and then impregnating it with metal.