JP3458144B2 - Method of producing sintered alloy current collector and sintered alloy for current collector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a copper-based sintered alloy having excellent lubricity and wear resistance, which is used for a current collecting sliding portion that does not use lubricating oil, and lubricity. And a current collector composed of a copper-based sintered alloy with excellent wear resistance, and particularly applicable to current collectors of various types of carrier equipment such as cranes, hoists, and electric carts that run at relatively low speeds. It is what

[0002]

2. Description of the Related Art A current collector material for various conveyors, which is commonly used at a relatively low speed (5 to 40 km / hour), is required to have characteristics different from those for a pantograph contact plate of a high speed electric vehicle. The material for a high speed electric car pantograph contact plate is constructed with emphasis on wear resistance during high speed sliding. However, when it is used for a current collector that slides at a low speed, the frictional force between the current collector and the overhead wire is reduced. It is large and causes a problem that the overhead line is damaged. For this reason, generally, a current collector for low-speed sliding has generally been a soft material in which fine particles of graphite or metal sulfide are dispersed in a bronze-based sintered alloy base material that does not contain hard components such as iron and chromium. ing.

[0003]

With the recent progress in labor saving and high efficiency in the industrial world, the operating rate of the carrier has improved, so that the time during which the current collector slides on the overhead wire has been extended. As a result, the problem that the sliding surface of the overhead wire is damaged is becoming conspicuous even if the current collector made of the soft material is used.
If the coarse damage of the overhead wire progresses and a projection called “burr” or “whisker” or a line-shaped peeling occurs, the overhead wires may come into contact with each other to cause a short circuit accident, and the vehicle may be unable to travel. If the content of the lubricating component graphite or metal sulfide is increased in order to prevent the above-mentioned contact wire rough damage within the range of the conventionally known technology, the mechanical strength of the current collector decreases, and Has an adverse effect of being worn out at an early stage. The occurrence of such a problem suggests that the action of graphite or a metal sulfide as a lubricating component in the prior art, that is, a non-metallic system that is finely dispersed in a copper-based sintered alloy matrix. Components (graphite and sulfide)
However, there is a limit to the effect of transferring the current collector to the contact surface on the overhead wire side to form a lubricating film. If the frequency with which the current collector slides with respect to the overhead wire increases, the ability of the graphite or metal sulfide to form a lubricating film decreases, leading to insufficient film formation and erasing of the film, and the sliding surface on the overhead wire side is damaged. In such a state, since both the main component of the current collector and the main component of the overhead wire are copper, adhesive wear progresses between them, which promotes wear of the contact sliding surface. The present invention has been made in view of the above circumstances, and has sufficient mechanical strength and wear resistance as a current collector for low-speed traveling, and self-lubricating property that does not require lubricating oil. An object of the present invention is to provide a method of manufacturing a current collector and a sintered alloy for a current collector, which has the same and can reduce damage and wear of an overhead wire as a mating member.

[0004]

The basic principle of the present invention created in order to achieve the above object will be briefly described. Graphite and a metal sulfide of a conventional example are formed as fine particles in a bronze base material. 1 to 7% by weight of bismuth as a lubrication strengthening component is added to the composition of the dispersed current collector made of a sintered alloy for low speed running. Since bismuth does not form a solid solution with copper, it does not easily adhere and is soft and non-abrasive, so when the lubrication function of graphite or metal sulfide between the current collector and the overhead wire decreases, the lubricity is supplemented. Controls wear. If the addition amount of bismuth is less than 1% by weight, the effect is small, and if it is 7% by weight or more, the mechanical strength is lowered. Therefore, the addition amount is preferably 1 to 7% by weight. When a small amount of phosphorus is added, the metal components are purified by the deoxidizing action of phosphorus during the formation of the sintered body, and the mechanical strength of the base alloy is increased. The amount of phosphorus added is 0.
If it is less than 1% by weight, the effect is small, and if it exceeds 1% by weight, the toughness is lowered. Therefore, the addition amount thereof is suitably 0.1 to 1% by weight. However, since the purpose of adding phosphorus is to deoxidize and purify the metal component, the amount of phosphorus added may be close to zero if the raw material powder and the inside of the furnace are clean .

When the above-mentioned addition amount of bismuth is blended, the graphite content is appropriately 2 to 13% by weight. If it is less than 2% by weight, the lubricating effect of graphite is insufficient, and 13% by weight
If it exceeds, the mechanical strength is lowered. The content of metal sulfide (MoS ₂ , WS ₂ ) is also the same for the same reason.
It is desirable that the total blending amount with graphite is 2 to 13% by weight. The compounding amount of tin that forms a sintered body by combining with copper is 4
-13% by weight is suitable.

If it is less than 4% by weight, the bonding strength with copper is weak and the base strength is insufficient, and if it exceeds 13% by weight, the mechanical strength is adversely affected and it becomes brittle.

Based on the above-mentioned principle, the constitution of the method of the invention according to claim 1 is ₂ to 13% by weight of one kind or plural kinds of graphite or metal sulfide (MoS ₂ , WS ₂ ) as a lubricating component. 1 to 7% by weight of Bi as a lubrication enhancing component, 1% by weight or less of P as a sintering matrix component, and S
A powder raw material containing 4 to 13% by weight of n and the balance of Cu is prepared, mixed and compression-molded, and the green compact is heated in a non-oxidizing atmosphere or a reducing atmosphere and baked. Characterized by obtaining a union. According to the method of the first aspect of the present invention described above, good wear resistance is exhibited without using a lubricating oil in a low-speed traveling range, and there is a risk of cracking or chipping having sufficient mechanical strength. In addition, it is possible to industrially manufacture a current collector that does not have the possibility of causing cohesive wear on the overhead wire that is a mating member.

According to a second aspect of the present invention, there is provided a current collector configured as a current collector made of a compression-molded sintered alloy, which comprises 2-1.
3% by weight of graphite or metal sulfide (MoS ₂ , WS ₂ )
1 to 7% by weight of Bi and 1% or less of P and 4-1.
It is characterized by containing 3% Sn and the balance being Cu . According to the current collector according to the invention of claim 2 described above, when used in a low-speed traveling range without using a lubricating oil, it exhibits excellent self-lubricating property and wear resistance, and has sufficient mechanical strength. It does not cause premature wear, cracks or defects. In addition, an excellent practical effect is obtained in that there is no risk of adhesive wear occurring on the overhead wire, which is a mating member.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an example in which a current collector according to the present invention is manufactured by applying the method of the present invention will be described.

Cu-Sn-P (provided that P
<1% by weight) as a substrate, to which graphite or MoS ₂ as a lubricating component is added, or graphite and MoS ₂ or WS ₂ are added to form the compounding compositions of Examples 1 to 4 and Reference Examples 1 to 4. Then, 3% by weight or 5% by weight of bismuth powder (60 mesh or less) was added to each of the above-mentioned Examples and Reference Examples to obtain compounded raw materials shown in Table 1. In Table 1, as a comparative example, the composition of a known copper-based sintered alloy containing graphite and the composition of a known copper-based sintered alloy containing graphite and MoS ₂ are shown together.

[0011]

[Table 1]

A powder having the composition shown in Table 1 above is
Mix evenly with a V-type mixer and mix powder to 400MP
It was compression-molded in a, held at 750 ° C. for 90 minutes in a reducing atmosphere and sintered to obtain Examples 1 to 4, Reference Examples 1 to 4 and Comparative Examples 1 and 2. Table 2 shows the physical and mechanical properties of these examples, reference examples and comparative examples.

[0013]

[Table 2]

The standard values shown in Table 2 are one example of the inspection standards for current collectors for trolley ducts by major electrical machinery manufacturers in Japan. As is clear from Table 2, Examples 1 to 1
All of the copper-based sintered alloys obtained in No. 4 have electrical and mechanical characteristics as a current collector.

Test pieces of 10 × 25 × 90 mm were cut out from the current collectors constructed as the above-mentioned Examples , Reference Examples and Comparative Examples, and these test pieces were attached to a rotary type current-collecting sliding tester, and a pushing force of 20 N, Energizing current AC30A, sliding speed 2
It was slid on the overhead wire for 120 minutes without lubrication at 0 km / hour. Specific wear amount of the test piece in the sliding test,
Table 3 shows the wear rate of the overhead wire, which is a mating member, and the state of the sliding surface of the test piece.

[0016]

[Table 3]

As is clear from Table 3, Examples 1 to 1
In all of the cases of No. 4 , compared with Comparative Examples 1 and 2, the wear of the test piece and the wear of the overhead wire could be significantly reduced.

[0018]

As is clear from the above embodiments, according to the method of the first aspect of the present invention, good wear resistance is exhibited in the low-speed range without using lubricating oil, It is possible to industrially manufacture a current collector that has excellent mechanical strength and is free from the risk of cracking or chipping, and is free from the risk of causing cohesive wear to the overhead wire that is a mating member. According to the current collector of the invention of claim 2,
When used in a low speed range without using a lubricating oil, it exhibits excellent self-lubricating property and wear resistance, and has sufficient mechanical strength to prevent premature wear, cracking, and chipping. In addition, there is an excellent practical effect that there is no possibility of causing adhesive wear to the overhead wire, which is a mating member.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kentaro Kurozu Inventor Kentaro Kurozu 3100-3 Shimo-gun, Oita City, Oita Prefecture Within Teikoku Carbon Industry Co., Ltd. (56) Reference JP 62-196351 (JP, A) JP Heihei 6-33163 (JP, A) JP-A-9-301256 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 9/02 C22C 1/10 C22C 9/00 H01R 43 / 06

Claims (2)

(57) [Claims] 1. ₂ to 13% by weight of one kind or a plurality of kinds of graphite or metal sulfide (MoS ₂ , WS ₂ ) as a lubricating component
And 1 to 7% by weight of Bi as a lubrication enhancing component, 1% by weight or less of P and 4 to 13% by weight of Sn as a sintering base component, and the rest is a powder raw material made of Cu , and mixed. And compression molding and heating the green compact in a non-oxidizing atmosphere or a reducing atmosphere to obtain a sintered body. 2. A current collector made of a compression-molded sintered alloy, comprising 2 to 13% by weight of graphite or metal sulfide (MoS).
₂ , WS ₂ ) containing 1 or more types of 1 to 7
Contains Bi by weight and contains less than 1% P and 4-13%
Sintering alloy collector which is characterized by containing Sn and the balance being Cu .