JPS58217653A - Cast alloy for current collector - Google Patents

Abstract

PURPOSE:To provide a cast alloy for a current collector low in welding relative to an aerial line and arc loss, obtained by containing a specific amount of Bi, a graphite particle, P, Cu, Si or a Misch metal in Cu or a Cu-Sn alloy. CONSTITUTION:As the material of a current collector such as the slider for the pantagraph of a tram-car, a Cu alloy obtained by containing 0.5-8wt% Bi, 0.5- 12wt% graphite particle with a particle size of 50-2,000mum, 0.2-0.8wt% P, 0.2-3.0wt% Cr or Si, 0.4-0.8wt% Misch metal containing Ce, La or the like and 0.2-2.0wt% Ti in a Cu-Sn alloy containing 5% or less Cu or Sn is used. This current collector is rich in lubricity and excellent in anti-wear property, arc resistance, and welding resistance.

Description

[Detailed description of the invention] The present invention relates to a casting alloy for a current collector.

In general, many of the current collecting plates used in trains, cranes, hoists, etc. come in contact with overhead lines and collect current from this point, and these are sliders for pantographs.

Most of them are members that collect current while sliding (current collectors) such as slide plates, current collector shoes, or trolley wheels.

Recently, trains have become faster and their current collection capacity has increased.

Furthermore, as the frequency of passing electric cars increases, wear and tear on the trolley wire and collector has increased significantly due to an increase in the rate of disconnection between the trolley wire and the collector, and an increase in the occurrence of arcs that occur during disconnection. In particular, as wear and tear on trolley wires increases, maintenance costs such as replacement of overhead wires are more than 10 times the cost required for collectors. For this reason, it has been desired to develop a trolley wire with less wear. Recently, tinned hard copper overhead wires have been developed as overhead wires with superior wear resistance compared to the currently used pure copper overhead wires, and are now being used as trolley wires for mono-luminium vehicles. Here, what is tinned hard steel overhead wire?S
It is a work-hardened wire containing 0.1 to 1% by weight of n and 0.05 to 0.5% by weight of Si. However, research and development on current collector materials for tinned hard copper overhead wires is insufficient. The current current collector material was developed for pure copper overhead wires, and its composition is Cu-Feeif=
F-h number is Cu for cast materials such as Cu-Zn-pb.
It is an oil-impregnated sintered steel alloy containing a solid lubricant such as. As a result of carrying out current wear tests on these current collector materials using tinned hard copper overhead wires as a mating material under the conditions shown in Table 1, it was found that various current current collector materials do not exhibit welding or arcing when compared to tinned hard steel overhead wires. The amount of wear and tear was severe, and no correlation was observed between the pure copper overhead wire and the hard copper overhead wire.

Table 1 An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a cast alloy for current collectors that can be applied to hard steel overhead wires.

The inventors investigated the amount of arc wear caused by (1) current wear test, (2) arc discharge test, and (3)
As a result of comprehensively examining the amount of wear due to structural deterioration caused by arc discharge, we discovered a new copper alloy current collector that achieves the above objectives.

The main component of the present invention is a steel alloy containing up to 5% by weight of CU or Sn, including KBio, 5 to 8% by weight.

Graphite particles 0.5-12 weight ratio, P 0.2-0.8 weight ratio
A, Cr and/or Si 0.2-3.0% by weight, Mitsushmetal 064-0.8% by weight and Ti 0.2-2
．． It relates to a casting alloy for a current collector containing 0% by weight.

In the present invention, the amount of Sn in the copper alloy serving as the base material is 5 weight e
Up to s. If it exceeds 5% by weight, the amount of wear on the overhead wire and current collector will increase, and if it exceeds 7% by weight, it will become unusable as a current collector due to severe welding to the overhead wire. The cause of this increased amount of wear and welding is thought to be the wear of the cage material with the overhead wire. Its earlier use was found as a substitute for PB, which contributes to the prevention of weld wear through its lubricating effect. That is, the use of Pb is unfavorable from the viewpoint of pollution prevention and occupational safety and health. If the B content is less than 0.5% by weight, welding with the overhead wire will occur, and if it exceeds 8% by weight, the mechanical strength of the current collector will decrease. The amount of Bum used is in the range of 0.5 to 8 weight value.

Since graphite is a solid lubricant, the dispersion of graphite particles in the cast alloy, combined with the fI4 sliding effect of B1, reduces the amount of wear on the overhead wire and current collector. The graphite material may be either naturally produced graphite or artificial graphite. The size of graphite particles is 50-2000μ
m is preferable in terms of wear resistance. The amount of graphite particles contained in the cast alloy is 0.5% by weight (approximately 1.7% by volume) to 12% by weight.
If it is less than 0.5% by weight, there is no effect of improving wear resistance, and if it exceeds 12% by weight, the material becomes brittle and cannot be used as an industrial material.

The addition of T] is effective in promoting the dispersion of graphite particles into the molten metal. The amount of Ti varies depending on the size and amount of graphite particles, but when the amount of graphite is 0.5 to 12% by weight, the particle size is 50 to 2.
0.2 to 2.000 μm graphite particles are used.
Requires 0% by weight. If it is less than 0.2% by weight, it will not be effective, and if it exceeds 2.0% by weight, it will affect the conductivity, which is not preferable.

PC) addition is effective in improving wear resistance. P is effective in strengthening the base of the alloy, and also forms a CuP film during sliding, exhibiting a +14 effect. The amount of P used is 0.2 to 0.8% by weight.

If it is less than 0.2% by weight, it is not effective (if it exceeds 0.8% by weight, the current collector base becomes brittle and it becomes difficult to form a CuP film.

The addition of Cr and/or Sl is effective in improving and increasing the corrosion resistance and at the same time improving high temperature hardening.Or
And/or Si element is the result of examining various elements by arc discharge test.

This element was selected as the most effective element for arc resistance. The amount of Cr and/or 8i added is 0.2 to 3.0% by weight; if it is less than 0.2% by weight, there is no effect on arc resistance, and if it exceeds triple tcIb, the arc resistance does not decrease. However, many hard precipitates are scattered in the base material, increasing the amount of wear on the overhead wire.

Note that the amount of Cr and/or sI added is 1.5 parts and 1 part, respectively.
The softening temperature expressed as % was 500°C.

Mitshu metal made of Ce, La, etc. is added for the purpose of refining crystal grains and improving mechanical strength, but by refining crystal grains, it is also effective in improving structural deterioration caused by arc discharge. be. The amount of Mitshu metal necessary for grain refinement is 0.4 to 0.8% by weight.

If it is less than 0.4% by weight, it will have no effect; if it exceeds 0.8% by weight, it will cause a decrease in conductivity or embrittlement of the cast alloy.

The present invention will be explained below with reference to two examples.

EXAMPLES Regarding the cast alloy for collectors of the present invention having the composition shown in Table 2 and the oil-impregnated sintered steel alloy currently used by Japanese national railways or private railways as a comparison material, the following were processed into the shape of a collector: The amount of arc wear caused by the arc discharge test and the structurally degraded layer caused by the arc discharge were compared. What is the arc discharge test method?

A tinned hard steel overhead wire was used as the mating material, and a direct current of 48 V and 550 A was applied between the overhead wire and the current collector using the current collector of the present invention and the current collector as movable test pieces. This is a method in which the contact and release operations between the collectors are performed 50 times in a row. The amount of arc wear was measured from the change in the weight of the current collector after the test was completed, and the thickness of the altered layer was measured from observation of the cross-sectional structure of the current collector.

As is clear from Table 2, the collector according to the present invention is superior to the current collector in terms of arc wear and deterioration layer thickness, reduces wear caused by arc during disconnection, and improves the collector and catenary. It is found that wear and tear is reduced. In Table 2, MM is Mitsushmetal.

The cast alloys for current collectors according to the present invention and the current cast alloys for collectors shown in Table 2 were subjected to electrical abrasion tests using a tin-shaped hard steel overhead wire as a mating material, and the results are also shown in FIG.

The test method involves rotating a tin-filled hard steel overhead wire that is attached to a disk with a diameter of 4 m. Casting alloys for collectors are currently in use) (
Approximately 174 similar pantographs (2
The method is to take two current collectors processed to a size of 5w x 10t x 901w) and press them against a tinned hard steel overhead wire to wear them by sliding. The sliding conditions are shown in Table 1. As is clear from FIG. 1, the current cast alloy 415.16°18 for current collectors adheres to overhead wires so badly that a wear test is impossible. Also Ken 1
7 is 0.8 to 2 cm at sliding distance of 100Kii”
Compared to this, the wear amount of the cast alloy for current collector of the present invention during 100KII sliding was 0.05 to 0.2 c.
It shows that the wear amount is one order of magnitude smaller than that of the current alloy for current collectors, indicating that it has superior wear resistance compared to the currently used cast alloys for current collectors.

The cast alloy for current collector according to the present invention is rich in +14 lubricity,
It has excellent abrasion resistance and arc resistance, and can be used in combination with Xirenru hardened steel overhead wires, which is not possible with current cast alloys for current collectors.

[Brief explanation of drawings]

FIG. 1 is a graph showing the results of an electrical wear test of a cast alloy for a current collector.

Claims (1)

[Claims] 1. The main component is a Cu alloy containing up to 5% by weight of Cu or an, with B i 0.5-8% by weight mooring graphite 0.5-12% by weight, and Po 2-0% by weight. .8% by weight. A casting alloy for a current collector containing 0.2 to 3.0% by weight of Cr and/or 8i, 0.4 to 0.8% by weight of Mitsushi metal, and 0.2 to 2.0% by weight of Ti.