JP2000243139A - Bending resisting composite conductor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel bending resisting composite conductor capable of significantly improving the tensile strength and bending resistance without deteriorating the conductivity and a method for manufacturing it. SOLUTION: This bending resisting composite conductor comprises a coating layer 3 having a composition of Cu-0.01-0.3 wt.% Zr on the circumference of a core wire 2 consisting of a copper alloy obtained by adding 0.01-0.3 wt.% of one or two of Sn, In, Cr, Zr, Fe and P to pure copper, or a copper alloy obtained by adding 1-20 wt.% of either one of Ag and Nb or an alloy thereof to pure core. According to this, since the core wire 2 ensures excellent conductivity, and the coating layer 3 exhibits excellent tensile strength and bending resistance, this conductor can be prevented from being ruptured or buckled even to a sever bending stress without sacrificing the conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending-resistant composite conductor used as a wiring member for a movable portion wired to a movable portion of an electronic device such as a medical device or an industrial robot, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, a movable portion wiring member wired to a movable portion of an electronic device such as a medical device or an industrial robot has a stress such as severe bending, twisting, or tension due to its nature. In particular, the conductor is required to have excellent bending resistance and tensile strength.

For this reason, recently, as a conductor used for such a movable portion wiring material, tough pitch copper (TPC) has been used.
Or pure copper wire such as oxygen-free copper (OFC)
Alloys having improved tensile strength and bending resistance by adding an appropriate amount of Sn to these pure coppers have been developed, and some of them have been put to practical use.

On the other hand, in response to the recent demand for smaller, lighter, and higher-performance electronic devices, such movable section wiring members have been required to have smaller diameters for smaller and lighter weight and to increase the amount of information transmission. Although high conductivity has been demanded, at present, no small-diameter conductor that satisfies high conductivity as well as tensile strength and bending resistance has been proposed.

That is, when the above-mentioned conventional copper alloy is used as a material for a small-diameter conductor, it is necessary to further increase the addition amount of Sn in order to improve the tensile strength and the bending resistance accompanying the reduction in the diameter. However, there is a disadvantage that the conductivity is remarkably reduced, and it is impossible to satisfy all of tensile strength, bending resistance, and high conductivity at a high level.

Accordingly, the present invention has been devised in order to effectively solve such a problem, and an object of the present invention is to significantly improve the tensile strength and the bending resistance without lowering the conductivity. It is intended to provide a novel flex-resistant composite conductor which can be made to work and a method for manufacturing the same.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for producing pure copper using Sn, In, Cr, Zr, Fe, P
Of a copper alloy in which one or two of the above are added in an amount of 0.01 to 0.3 wt%, or a copper alloy in which either Ag or Nb is added to pure copper or an alloy thereof is added in an amount of 1 to 20 wt%, Cu A coating layer having a composition of 0.01 to 0.3 wt% Zr and a conductivity of 70% IACS
As described above, the wire diameter is φ0.01 to 0.5 mm.

As a result, the tensile strength and the bending resistance can be greatly improved without lowering the conductivity, so that the tensile strength, the bending resistance and the high conductivity are all satisfied at a high level. Becomes possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a bending-resistant composite conductor 1 according to the present invention.

As shown in FIG.
Is provided with a coating layer 3 having excellent bending resistance and tensile strength around a core wire 2 having excellent conductivity.
It is formed to a thickness of 0.01 to 0.5 mm.

The core wire 2 is made of highly conductive pure copper such as tough pitch copper (TPC) or oxygen-free copper (OFC) such as Sn, In,
One or two of Cr, Zr, Fe, and P may be used in the amount of 0.
It is made of a copper alloy added with 01 to 0.3 wt%, or a copper alloy added with either Ag or Nb or 1 to 20 wt% of the alloy, so that excellent conductivity can be exhibited similarly to conventional pure copper. It has become. Here, Sn, In, Cr, Zr, Fe, P, or Ag, Nb is contained in the copper alloy.
The reason why was added is to increase the conductivity of the core wire itself by adding these additives to pure copper as described above, and to maintain the overall conductivity of 70% IACS or more. This is because the electric conductivity is lower than that of the conventional Cu-Sn alloy. Among these additives, Sn,
The reason why the amount of addition of In, Cr, Zr, Fe, and P is limited to 0.01 to 0.3 wt% is that 0.01 wt.
% Or less, the electrical conductivity satisfies 70% IACS or more. However, due to insufficient strength, the flex life when a flex test is performed under the conditions described in claim 3 is a soft tough pitch steel (TCP).
This is because three times or more of the above is not satisfied, and at 0.3 wt% or more, the conductivity does not satisfy 70% IACS or more. Further, when Ag and Nb are used,
The reason why the content is limited to 20 wt% is that if the content is 1 wt% or less, the strength is insufficient and the flex life when a flex test is performed under the conditions described in claim 3 does not satisfy three times or more of the soft tough pitch steel (TCP). If the content is 20 wt% or more, casting and wire drawing become difficult, which is not practical.

On the other hand, a coating layer 3 coated on the core wire 2
Is made of a copper alloy having a composition of Cu-0.01 to 0.3 wt% Zr, and can exhibit excellent bending resistance and tensile strength. Here, the use of the Cu-Zr alloy as the coating material not only improves the bending resistance and tensile strength, but also ages the solution-treated material to provide a conductivity of 90% IACS or more. Is obtained. Further, the addition amount of Zr is 0.01 to 0.3.
The reason for limiting to wt% is that if it is 0.01 wt% or less, the strength when formed into a composite material is insufficient and a desired flex life cannot be obtained, and if it is 0.3 wt% or more, the solution treatment is performed. This is because Zr does not completely form a solid solution in Cu, and a Cu—Zr-based compound having a size of several microns is generated, which causes disconnection during wire drawing. The coating thickness of the coating layer 3 is not particularly limited,
Preferably, the diameter is about 1/10 to 1/5 of the wire diameter φ of the conductor 1.
For example, when the wire diameter φ of the conductor 1 is 0.1 mm,
The thickness of the coating layer 3 is optimally about 0.01 to 0.02 mm.

Next, as a method for manufacturing the bending-resistant composite conductor 1 of the present invention having the above-described structure, first, a 10 mm-diameter welded pipe is manufactured from a Cu-Zr alloy strip whose surface is sufficiently polished. At the same time, a core obtained by adding a predetermined amount of Sn or the like to pure copper is inserted and assembled to form a composite, and then these are drawn to, for example, about φ8 mm. Next, this material is annealed at a predetermined temperature for several hours, for example, about 450 ° C. for about 2 hours to diffuse the bead of the welded portion.
By performing wire drawing to about 1 to 0.5 mm, the bending-resistant composite conductor 1 of the present invention can be obtained.

In the bending-resistant composite conductor 1 of the present invention having such a configuration, the core wire 2 exhibits excellent conductivity equal to or higher than that of the conventional one, and the surrounding coating layer 3 forms the core wire 2. Since the bending resistance and the tensile strength of the conductor 1 are compensated for and the bending resistance and the tensile strength of the entire conductor 1 are improved, not only the conductivity but also the excellent bending resistance and the tensile strength can be exhibited. Specifically, a load equivalent to 20% of the breaking load was applied to the conductor of the present invention having a diameter of 0.1 mm, and a bending strain of 1% was applied.
%, The bending life when repeatedly bent 90 degrees to the left and right can exhibit three times or more of that of soft tough pitch copper (TCP).

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described.

(Embodiment) A tough pitch copper having a diameter of 10 mm was prepared by using several kinds of Cu-Zr alloy strips having different addition amounts of Zr, and then polishing the surface sufficiently to produce a φ10 mm welded pipe. (TPC)
After being drawn to 8 mm, they are annealed at 450 ° C. for 2 hours to diffuse the bead of the welded portion. Thereafter, they are further drawn to φ0.1 m to form a sample conductor, and the sample conductor is bent. A test and conductivity measurement were performed, and a comprehensive evaluation was performed from the test results.

Here, as a bending test method, as shown in FIG. 2, an end of the sample conductor 1 is fixed to a bending head 4 and
A load of 100 gf was applied to the other side, and bending r = 5 mm
90 ° left and right with a pair of rollers 5 and 5 (1% bending strain)
The bending was repeated, and the number of times of bending until breakage was defined as the bending life. Three times or more of the soft TPC was passed, and three times or less was rejected. In the evaluation of conductivity, the conductivity passed 70% IACS or more, and 70% IA
In the same manner, each of them was indicated as × in Table 1 as a rejection when the value was less than CS. Furthermore, the overall evaluation is φ0.1
mm, a load equivalent to 20% of the breaking load was applied, and the bending life when repeatedly bending 90 ° left and right with a bending strain of 1% passed at least 3 times that of soft tough pitch copper (TCP).
In the table 1, 以下 or less was indicated as unacceptable.

[0019]

[Table 1]

As a result, the samples 1 to 3 according to the present invention reached the acceptable levels in all of the electrical conductivity, the bending rate, and the overall evaluation, but the samples 4 to 7 of the comparative examples which are out of the scope of the present invention all. The level that did not satisfy the overall evaluation was reached.
That is, in the case of Sample 4 in which the amount of Zr added was equal to or less than the range of the present invention, the conductivity passed, but neither the flex life nor the comprehensive evaluation reached a sufficient level. On the other hand, Z
In the case of Sample 5 in which the amount of r added exceeds the range of the present invention,
Disconnection occurred at the time of wire drawing, and it was not possible to perform the property evaluation itself at φ0.1 mm. In the case of Sample 6 in which Sn was used instead of Zr, the flex life reached the acceptable level, but neither the conductivity nor the overall evaluation reached the acceptable level. Further, in Sample 7 in which the coating material was not used, the conductivity passed as in Sample 4, but neither the flex life nor the comprehensive evaluation reached a sufficient level.

[0021]

In summary, according to the present invention, the tensile strength and the bending resistance can be greatly improved without sacrificing the conductivity. As a result, tensile strength, flex resistance,
All of the high conductivity can be satisfied at a high level. The use of such a bending-resistant composite conductor of the present invention makes it possible to greatly contribute to the miniaturization, weight reduction, high performance, and the like of medical equipment, electronic equipment, and the like, and their movable parts. Can be demonstrated.

[Brief description of the drawings]

FIG. 1A is an enlarged sectional view showing one embodiment of a bending-resistant composite conductor according to the present invention. (B) is an enlarged side view showing one embodiment of the bending-resistant composite conductor according to the present invention.

FIG. 2 is an explanatory view showing a bending test method adopted in this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bending-resistant composite conductor 2 Core wire 3 Coating layer 4 Bending head 5 Roller

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01B 13/00 501 H01B 13/00 501F // C22F 1/00 625 C22F 1/00 625 627 627 661 661 661A 680 680 680 685 685Z (72) Inventor Masayoshi Aoyama 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Power Systems Co., Ltd. (72) Inventor Osamu 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Hitachi Cable F-term in Hidaka factory (reference) 5G301 AA01 AA07 AA08 AA09 AA11 AA20 AA24 AA30 AB05 5G307 BA01 BB02 BC03

Claims (5)

[Claims] 1. Pure copper is made of Sn, In, Cr, Zr, Fe,
One or two types of P are 0.01 to 0.3 wt%
A coating layer having a composition of Cu-0.01 to 0.3 wt% Zr around a core wire made of an added copper alloy or a copper alloy in which either Ag or Nb or 1 to 20 wt% of the alloy is added to pure copper. And a conductivity of 70% IAC
A flex-resistant composite conductor having a wire diameter of at least S and a diameter of 0.01 to 0.5 mm. 2. The flex-resistant composite conductor according to claim 1, wherein the pure copper is tough pitch copper (TPC) or oxygen-free copper (OFC). 3. A tough pitch copper (TC) having a flex life of 0.1% in diameter, a load equivalent to 20% of the rupture load, and a bending life of 1% when repeatedly bent 90 ° left and right.
3. The method according to claim 1, which is at least three times P).
2. The flexible composite conductor according to item 1. 4. Pure copper is made of Sn, In, Cr, Zr, Fe,
One or two types of P are 0.01 to 0.3 wt%
The copper alloy added, or a copper alloy obtained by adding 1 to 20 wt% of either Ag or Nb or its alloy to pure copper,
After incorporating a copper strip having a composition of 0.01 to 0.3 wt% Zr into a welded copper alloy pipe,
A method for producing a bending-resistant composite conductor, characterized in that the wire is drawn to 0.5 mm. 5. The tough pitch copper (TP) as the pure copper.
The method for producing a flex-resistant composite conductor according to claim 4, wherein either C) or oxygen-free copper (OFC) is used.