JPH02259001A - Sliding plate for collecting current - Google Patents

Abstract

PURPOSE:To enhance mechanical strength and unify material quality and to improve lubricity and wear resistance by making a mat twisting metallic fibers as the main body and dispersing metal coated powder in the state of being embedded. CONSTITUTION:Before pressing, many fine spaces having different volumes developed by twisting of the metal fiber exist in the mat and on this, powder of carbon coated with metal and electric conductive ceramic is dispersed, and by executing the press-forming, the powder is spread in the width direction to become uniformly dispersed condition in three dimensions. This is just so that the powder is screened with a sieve having coarse opening, and fine particle size is fitted in small space of the mat and coarse particle size is fitted by invading into large space of the mat. Such a way, as metal coated powder is fixed under such condition that surrounding thereof is twisted with the metallic fiber, even if the mat is impregnated with large quantity of powder, a sliding plate having high mechanical strength and excellent electric characteristic, lubricity and wear resistance, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a current collector sliding plate used in a pantograph for a vehicle.

[Conventional technology]

Conventionally, current collecting plates for vehicles have been mainly copper-based because of the requirements for performance such as large current collecting capacity, good lubricity and wear resistance, and high mechanical strength.

Metal-based sliding plates such as iron are often used.

Most of these conventional metal-based sliding plates are press-formed by mechanically mixing the main material, copper or iron powder, with low-melting metal powder, which has good lubricity, or carbon powder, which has both lubricity and arc resistance. It is then sintered to produce sliding plates.

[Problem that the invention seeks to solve]

However, in conventionally manufactured current collector sliding plates, different types of powder are mechanically mixed to adjust the characteristics of the sliding plate, but it is difficult to uniformly disperse and mix powders with different specific gravities. . Further, carbon, which has excellent lubricity and arc resistance, has poor wettability with metals, and if a large amount of carbon is mixed in, the mechanical strength of the sliding plate will be reduced. Furthermore, powder sintering involves a variety of problems, including the fact that it produces a high-density molded body, which is a factor in improving mechanical strength, and requires a high-output press molding machine, which poses economic constraints.

The present invention was devised in view of the above-mentioned points, and its purpose is to create a material that has high mechanical strength, is uniform in quality, and is made of carbon or conductive ceramic that has poor wettability with metals. can be mixed in a relatively large amount, thereby providing a current collector sliding plate with excellent lubricity and wear resistance.

Means to Solve Problem C] In other words, the means to achieve this objective is to use a current collecting plate used in vehicle pantographs, which is made of carbon or metal-covered metal fiber mat. This uses a metal fiber composite in which conductive ceramic powder is dispersed and embedded in a mat by press molding to disperse it three-dimensionally.

Further, the metal fiber composite may be melted and impregnated with a metal having a lower melting point than the metal fiber.

Next, its effect will be explained.

[For production]

First, a metal fiber mat is a material in which thin long fibers are intertwined with each other and have a certain thickness like a non-woven fabric. (Hereinafter, simply referred to as mat) Since mats are intertwined with each other, it is easy to obtain considerable mechanical strength even if a high-density molded body cannot be obtained by press molding and sintering.

Next, the mat before press forming is made by dispersing metal-coated carbon or conductive ceramic powder onto the mat, which has many microscopic spaces of different sizes created by the entanglement of metal fibers. When this is done, the powder also spreads in the thickness direction and becomes three-dimensionally uniformly dispersed. This is just like passing powder through a coarse sieve; fine particles enter the small spaces of the mat, and large particles enter the large spaces of the mat and settle there. The difference in specific gravity between the metal fibers as the main material and the powder to be added is not a problem at all, and uniform dispersion can be easily achieved. Furthermore, if different types of powders with different specific gravity are differentiated in particle size distribution, a relatively uniformly mixed distribution can be obtained.

In addition, in order to fix powders with different particle size distributions in the mat, it is necessary to compress the mat appropriately in advance and adjust the size of the space where the metal fibers intertwine, thereby improving the consistency with the powder. can be obtained easily.

In this way, the metal-coated powder is entangled with metal fibers and fixed, so it has high mechanical strength even when impregnated with a fairly large amount of powder, and has excellent electrical properties, lubricity, and wear resistance. A printed board with excellent properties can be obtained.

An embodiment of the present invention will be described below.

〔Example〕

First, the material of the metal fiber mat is pure metal.

Materials including alloys that can be processed into a fibrous form and have a melting point of 100° C. or higher are suitable as the main material for the sliding board.

For example, iron fibers with a diameter of 15 μm and a length of 50 to 80 mm (
88-41) is 100100mm x 1000 thickness 10
It is in a cotton-like state with a size of 1.0 mm and a weight of about 10 y. It is degreased with trichlorene, and then diluted with dilute hydrochloric acid solution (5 yen).
%) for about 1 to 2 minutes to remove iron, and then perform electroless nickel plating to improve wettability with powder.

In this state, the amount and size of the space are excessive, so a press is used to compress it to a thickness of about 3 mm. Then, a mat with a thickness of 3 mm cut into the mold size is inserted into the mold, and a 150 to 350 mesh mat is coated with about 50 pieces of nickel at W% by electroless nickel plating.
of carbon powder is dispersed. Place the mat again on top of it and disperse the nickel-coated carbon powder.

After repeating this process to deposit the required amount of layers, sintering is performed at a temperature of 800°C for 60 minutes in a reducing mist atmosphere under a pressure of 3.5 to 4 tb. 88-41
) 65VoJi'ly Nickel 22VoJi'ly Carbon 13Vo1% sintered body exhibited the following characteristics: bending strength: 40 kP/mm2, specific resistance: 20μΩcm, density: 5.8f/cm3.

〔Effect of the invention〕

As explained above, according to the present invention, the main material is a mat in which the metal fibers P7 are intertwined, and the metal-coated powder is buried and dispersed in the mat, so that the mechanical strength is high and the material quality is high. It is also uniform. Furthermore, since relatively large amounts of carbon or conductive ceramics, which have poor wettability with metals, can be mixed in, it is possible to manufacture car-width current collection plates with excellent lubricity and wear resistance, making them extremely practical. It is something.

Claims (2)

[Claims] (1) In the current collector slide plate used in vehicle pantographs, the current collector slide plate is made by dispersing metal-coated carbon or conductive ceramic powder in a metal fiber mat and press-molding it into the mat. A current collector sliding board characterized by using an embedded metal fiber composite. (2) Claim (1) characterized in that the metal fiber composite is melted and impregnated with a metal having a lower melting point than the metal fibers.
Current collector sliding plate as described in section.