JPH0664940B2 - Flexible and vibration-resistant flexible conductor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flexible conductor having a large current capacity and excellent bending resistance and vibration resistance.

[Problems to be Solved by Conventional Techniques] For example, a lead wire for power supply of a spot welding machine using an industrial robot is shocked (electrodynamically) due to an extremely large current being applied each time welding is performed. Vibration occurs. In addition, the lead wire is swung around each time the robot operates, and is repeatedly bent under heating. The lead wire thus used is thus a flexible conductor.

This flexible conductor is usually made by collectively twisting strands of annealed copper wire, concentrically twisting this collective twisted wire into a composite twisted wire (child twist), and further twisting this composite twisted wire into a multiple composite twisted wire. It is composed of lines, and has a sectional structure as shown in FIG. 4, for example.

When the usage of the flexible conductor is observed, the strands of the composite multi-strand wire are rubbed at the portions in contact with each other during repeated bending and impact, and wear breakage occurs. When a part of the wire breaks, the resistance of the conductor increases, the part is overheated, and the wire breaks more easily, which repeats a vicious circle and the wire breaks.

This disconnection is most noticeable at the portion where the outermost layer twisted (2c ′) and the lower layer twisted (2b ′), which are double-composite twists, contact each other, and more particularly than the outermost layer twisted (2c ′). The child twist (2
The wire breakage in b ') is remarkable. Each child twist (2a ') (2
b ′) (2c ′) strands are made of pure annealed copper wire. According to the durability test of the compound composite stranded wire shown in FIG. 4, the outermost layer twisted layer (2c ′) and the lower layer twisted layer (2b ′) Among them, the breakage of the strand of the gathered stranded wire (1d ′) in the outer layer part was particularly remarkable.

Therefore, it is desirable for this type of flexible conductor to improve the bending resistance and vibration resistance under heating to prevent the wire breakage.

Therefore, from the above observation results, it is proposed that the outermost layer and the lower layer are twisted in the same twist direction so that the wires in contact with each other do not cross each other (Japanese Utility Model Application No. 63-879).
No. 06), but in this case, the wire breakage is less likely to occur as compared with the conventional product in which the strands cross, but a sufficiently satisfactory effect cannot be obtained.

Therefore, the inventors of the present invention, for the prevention of the above wear disconnection,
Furthermore, in the process of conducting various studies and studies, the friction coefficient is smaller when the dissimilar metal wires are in contact with each other than when the same metal wires are in contact with each other, especially when the pure annealed copper wires are in contact with each other. It has been found that wear disconnection due to rubbing or the like is significantly reduced.

Based on this, the twisting using a pure copper wire and the twisting using a wire of a copper alloy as described above are brought into contact with each other, and bending,
When a wear test was conducted by applying vibration, it was found that the wear resistance was greatly improved.

[Means for Solving the Problems] The present invention has been made based on the above findings, and is a child twist in a composite composite twisted wire in which breakage is most likely to occur, that is, a child twist of the lower layer in contact with the child twist of the outermost layer. The strand of, having excellent conductivity and heat resistance, and using a softening wire of the following copper alloy having excellent mechanical properties such as repeated bending strength and tensile strength,
As a result, it is possible to obtain a flexible conductor which is improved in bending resistance and vibration resistance without impairing conductivity, and is extremely effective in preventing abrasion and breakage of the wire.

The first aspect of the present invention is to use a composite twisted wire obtained by concentrically twisting a collective twisted wire as a child twist and further concentrically twisting the child twisted wire into a multiple composite twisted wire, which is the outermost layer of a flexible conductor. No. 1 is a pure annealed copper wire, and one of the following copper alloys (a) (b) (c) (d) is a softened wire in the lower twisted element wire that contacts the outermost layer child twist Is.

One of the copper alloys (a) contains 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, and 0.05 to 0.5% by weight of Pb, and the balance is copper.

In this copper alloy, the content of Fe added to improve the mechanical strength of the copper alloy is set to 0.02 to 1% by weight. When the content of Fe is less than 0.02% by weight, repeated bending strength, tensile strength and heat resistance are improved. This is because there is little improvement effect, and on the other hand, when it exceeds 1% by weight, the decrease in conductivity of the copper alloy becomes large. In addition, it is effective that the content of P is 15 to 80% by weight of the Fe content in order to further enhance the above characteristics due to the addition of Fe and to suppress the decrease in conductivity caused by the addition of Fe. If the amount is less than the lower limit of the range, the effect due to the addition of P is not exerted, and conversely, if the amount of P exceeds the upper limit, the conductivity is lost. Further, the content of Pb is set to 0.01 to 0.5% by weight because when it is less than 0.01% by weight, the effect of improving the above-mentioned repeated bending strength, tensile strength and heat resistance is small, and when it exceeds 0.5% by weight, the conductivity decreases. Because it becomes larger.

Such a copper alloy is disclosed in Japanese Patent Application No. 59-186126 proposed by the present applicants, and has good conductivity as described in the specification of the same patent, and
Excellent performance such as repeated bending strength, tensile strength and heat resistance.

Another copper alloy (b) selectively used in the present invention is 0.02 to 1% by weight of Fe, and P is 1 to Fe.
It contains 5 to 80% by weight, 0.05 to 0.5% by weight of Sb, and the balance is copper.

In this copper alloy, the Fe content is 0.02 to 1% by weight, and the P content is 15 to 80% by weight with respect to the Fe content.
The reason is the same as in the case of the copper alloy (a). Further, the content of Sb is set to 0.05 to 0.5% by weight,
Again, if it is less than 0.01% by weight, the effect of improving the repeated bending strength, tensile strength and heat resistance will be small, and conversely if it exceeds 0.5% by weight, the conductivity will be greatly reduced.

This copper alloy is disclosed in Japanese Patent Application No. Sho 59-1 proposed by the present applicant.
It has been disclosed in Japanese Patent No. 86127 and has good conductivity as described in the specification, and has excellent performances such as repeated bending strength, tensile strength and heat resistance.

Still another copper alloy (c) selectively used in the present invention contains 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, and further contains In. , Sn, Pb and Sb containing at least one or more substances, and the total content including In is 0.01 to 0.5.
The content of each of In and one or more other substances is 0.006% by weight or more, and the balance is copper.

In this copper alloy, the Fe content is 0.002 to 1% by weight.
The reason why the P content is 15 to 80% by weight with respect to the Fe content is the same as in the case of the copper alloy (a). Further, in order to more efficiently improve the repetitive bending strength, tensile strength and heat resistance due to the above-mentioned Fe content and to maintain the conductivity more efficiently due to the P-containing content, further In, Sn,
One or more kinds of Pb and Sb are contained, and particularly by containing In, stable repeated bending strength is obtained. If the total content of In and one or more of Sn, Pb and Sb is less than 0.01% by weight, the heat resistance is not sufficiently improved, while if it exceeds 0.5% by weight, high conductivity is maintained. Can not. Further, even if the content of any one of In, Sn, Pb and Sb is less than 0.006% by weight, the heat resistance will not be sufficiently improved.

This copper alloy is disclosed in Japanese Patent Application No. Sho 59-1 proposed by the present applicant.
No. 98101, which has good conductivity as described in the specification, and has excellent performances such as repeated bending strength, tensile strength and heat resistance.

Further, another copper alloy (b) which is selectively used in the present invention is 0.02 to 0.7% by weight of Fe, 15 to 80% by weight of P relative to Fe, and In, Sn, Pb, Sb. It contains 0.01 to 0.5% by weight of Zr and two kinds selected from the group, and the balance is copper.

In this copper alloy, the Fe content is 0.02 to 0.7% by weight.
The reason for this is that if the content exceeds 0.7% by weight, the decrease in conductivity becomes large, while if it is less than 0.02% by weight, the effect of improving cyclic bending strength, tensile strength and heat resistance becomes small. In addition, the content of P, which is useful for further improving the above-mentioned characteristics when Fe is added, is set to 15 to 80% of the Fe content.
The reason for setting the content by weight is that if the amount is less than the lower limit of the above range, the effect of adding P is not exhibited, whereas if it exceeds the upper limit, the conductivity of the copper alloy is rather lost. The preferred content of P is about 28% by weight of Fe.

2 selected from the group of In, Sn, Pb and Sb
A metal alloy containing Zr and Zr is contained in a copper alloy. Zr has the effect of increasing the heat resistance of the copper alloy. If two kinds of each of the above metals are added to the copper alloy and coexist, the effect is further enhanced. . The total content of Zr and the two metals in the copper alloy is 0.01 to 0.5% by weight. If the total content is less than 0.01% by weight, the effect of improving heat resistance is small,
On the other hand, if it exceeds 0.5% by weight, the conductivity of the copper alloy cannot be maintained.

The above-mentioned copper alloy is disclosed in Japanese Patent Application No.
It is disclosed in JP-A-58794, and as described in the specification, it has excellent heat resistance and has improved properties such as conductivity, repeated bending strength, tensile strength, and elongation.

A second aspect of the present invention is that the strand break of the aggregated twisted wire in the outer layer portion is remarkable among the child twists of the lower layer in contact with the child twist of the outermost layer, and the cost of the copper alloy is considered. In the flexible conductor by the same complex composite twisted wire as described above, the element wire of the child twist forming the outermost layer is a pure annealed copper wire, and the outer layer part of the child twist of the lower layer in contact with the child twist of the outermost layer. Characterized in that the strands of the assembled stranded wire of (1) is a softened wire of any one of the above copper alloys (a) (b) (c) (d), and the strands of other assembled stranded wires are pure soft copper wires. And

[Operation] According to the above-mentioned first flexible conductor of the present invention, the outermost layer of the child-twisted element wire of the composite composite stranded wire is a pure annealed copper wire, and the lower-layer child-twisted element wire in contact with this is described above. By using a softened wire of copper alloy, dissimilar metal wires contact each other at the contact portion between the outermost layer child twist and the lower layer child twist in which the wear breakage of the strand is remarkable The friction coefficient is smaller than in the case, the wear resistance is greatly improved, and the wear disconnection is extremely unlikely to occur. However, this is because the lower layer (first layer) of the twisted element wire, which is apt to be broken, uses a softened wire of a copper alloy having excellent properties such as conductivity, heat resistance, repeated bending strength and tensile strength. Together, the effect of preventing wire wear and wire breakage can be enhanced, and the rate of wire breakage can be greatly reduced.

Further, according to the second aspect of the invention, among the child twists of the lower layer in contact with the child twists of the outermost layer, the strands of the gathered twisted wires in the outer layer portion that are most likely to cause abrasion breakage are the softened wires of the copper alloy, and Since the strands of the assembled stranded wire of are made of pure annealed copper wire, the contact portion between this child twist and the outermost child twist becomes a contact between different metal wires, and like the above, frictional disconnection is unlikely to occur in this part. In addition to the above, dissimilar metal wires also come into contact with each other at the contact portion between the gathered twisted wire in the outer layer portion and the gathered twisted wire in the central portion, and abrasion and disconnection at this contact portion hardly occur. Moreover, since the strands of the assembled stranded wire other than the outer layer portion are pure annealed copper wires, there is no problem in the flexibility of the flexible conductor as a whole.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross-sectional structure of a flexible conductor made of a complex composite stranded wire according to the first aspect of the present invention. In the figure, (1) is a set stranded wire in which 26 strands having a diameter of 0.26 mm are set and stranded, (2)
Is a composite twisted wire obtained by concentrically twisting the seven twisted wires (1). The flexible conductor (3) of the multiple composite twists has one composite twisted wire (2) as the child twist (2a) of the center layer, and six compound twists as the child twist (2b) of the outer first layer. The wire (2) is further concentrically twisted by arranging twelve composite twisted wires (2) as the second layer child twist (2c) on the outer side thereof.

The first layer child twist (2c) and the outermost layer child twist (2b) are concentric twists in opposite directions as in the conventional case, and both layer child twists (2c) and (2b) are in the same direction. There may be concentric twists.
In the latter case, the strands of the child strands (2c) and (2b) come into contact with each other along the twisting direction, and the conventional strands are strongly contacted locally like flexible conductors that cross each other and come into contact. Therefore, the effect of preventing wear and disconnection due to contact between different types of metal wires, which will be described later, is further enhanced.

Then, in the flexible conductor having the above structure, the outermost layer child twist (2
c) using pure annealed copper wire for the wire, and the lower twisted wire (2b) in contact with this twisted wire (2c), the above-mentioned copper alloy
(a) (b) (c) (d), that is, Japanese Patent Application Nos. 59-186126, 59-186127 and 59
-198101 Specification and Japanese Patent Application No. 59-19810
The softening wire is one of the copper alloys described in No. 1 specification. Therefore, the outermost layer and the lower layer are twisted
(2c) and (2b) are in contact with each other, and dissimilar metal wires are in contact with each other, and the friction coefficient of this portion is small, so that abrasion disconnection hardly occurs. In the drawings, hatching is shown only in the portion using the softening line of the copper alloy. The strands constituting the core twist (2a) of the center layer can be the same copper alloy as the core twist (2b) of the first layer, but as a result of the durability test, the core twist (2a) If pure annealed copper wire is used as the element wire, the contact portion between the center layer and the child twist (2a) (2b) of the first layer becomes contact between dissimilar metal wires, and the wear breakage of the element wire is reduced. In addition, the flexibility is not deteriorated, and the amount of expensive copper alloy used is smaller than that of annealed copper wire, which is more preferable in practice.

FIG. 2 shows a sectional structure of a second flexible conductor of the present invention.
Lower layer (first layer) composite stranded wire in contact with the outermost child strand (2c)
Of the twisted wires (2b) according to (2), the strands of the assembled stranded wire (1d) in the outer layer portion where wear breakage is likely to occur are the above-mentioned copper alloy softened wires, and other assembled stranded wires, mainly in the case of the figure Part stranded wire
The element wire of (1e) is a pure annealed copper wire similar to the outermost layer of the twisted wire (2c). In the figure, hatching is shown only in the portion of the gathered stranded wire made of a softened wire of a copper alloy.

In this case as well, since the dissimilar metal wires come into contact with each other at the contact portion between the outermost layer twist (2c) and the lower layer twist (2b), abrasion disconnection is less likely to occur at this portion. Also, the amount of copper alloy used is small.

Regarding the twist (2a) of the center layer, there are cases of softening wire of the copper alloy and cases of pure soft copper wire as in the above.

As in the conventional case, the flexible conductor (3) has the connection terminals (4) fixed to both ends as shown in FIG. 3, and the insulating outer cylinder (5) is covered between the terminals. The cooling water is kept watertight so that it can be circulated, and is used as a lead wire for supplying power to the welding robot.

(Effect Confirmation Test) The flexible conductor of the embodiment shown in FIG. 1 and the flexible conductor of the embodiment shown in FIG. 2 and the flexible conductor shown in FIG. 4 (all strands are made of pure annealed copper wire). Of the outermost layer (the second layer) and the lower layer (the first layer) of the twisted yarns, which are concentric and concentric with each other. The twisted product (B) was tested by a welding robot under the same conditions, the durability of spot welding was compared, and the wear disconnection condition was observed. The results were as follows. In Examples, almost the same results were obtained when any of the above (a) (b) (c) (d) was used as the copper alloy.

Samples Twisting direction Number of spots Example of Figure 1 A 40 to 500,000 times Same as B 600,000 times or more Example of Figure 2 A 300 to 400,000 times Same as B 500,000 times or more Figure 4 (Conventional product) A Approximately 100,000 times (Comparative Example) B 300 to 400,000 times As is apparent from the above, the conventional product suffers wear disconnection at about 100,000 spots, and its disconnection rate is 25% to 35% at both ends near the connection terminal. However, in the case of the present invention, each of them withstands the use of the spot number of 3 to 6 times or more as compared with the conventional product, and the disconnection rate becomes 10% or less at both end portions. When the outermost layer and the lower layer were twisted in the same twist direction, abrasion breakage was more difficult to occur.

[Advantages of the Invention] As described above, according to the present invention, the bending resistance and the vibration resistance can be remarkably improved as compared with the conventional products without impairing the conductivity, and as a lead wire for power supply of a welding robot or the like. As a flexible conductor of this kind to be used, it is possible to prevent wear disconnection for a long period of time and to greatly enhance its durability. Moreover, since the copper alloy is used only for the lower twisted strands that are in contact with the outermost layer, the amount of relatively expensive copper alloy used can be small. Especially, of the lower layer twists that are in contact with the outermost layer twists, the strands of the outer strands that are most prone to wear breakage are the softened strands of copper alloy, and the strands of the other strands are pure soft copper. In the case of a wire, the amount of the copper alloy used is much smaller, and the wire can be manufactured and provided at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a sectional structure showing an embodiment of a flexible conductor of the present invention, FIG. 2 is a schematic view of a sectional structure showing another example of the present invention, and FIG. FIG. 4 is a plan view showing a usage state in which a flexible conductor is connected to a connection terminal, and FIG. 4 is a schematic view of a cross-sectional structure of a conventional flexible conductor. (1) ... Assembled stranded wire, (1d) ... Assembled stranded wire in outer layer part, (1e) ... Assembled stranded wire in central part, (2) ... Composite stranded wire, (2a) (2b) (2c) ... Each layer Child twist, (3) ... Flexible conductor.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toru Matsui 2-3-1, Iwata-cho, Higashi-Osaka City, Osaka Prefecture Tatsuta Electric Wire Co., Ltd. (56) References: 60-164710 Kai 63-108113 (JP, U) Copper Technology Research Journal Vol. 16, 1977 pp. 165-176 Metal Handbook p. 622

Claims (2)

[Claims] 1. A flexible conductor having a composite twisted wire obtained by concentrically twisting a set twisted wire as a child twist, and further concentrically twisting the child twisted wire into a double composite twisted wire, a child twist element constituting an outermost layer thereof. The wire is a pure annealed copper wire, and the element wire of the lower layer twisted wire that is in contact with the outermost layer child twist is a softened wire of any one of the following (a), (b), (c), and (d). A flexible conductor which is resistant to bending and vibration. (a) A copper alloy containing 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, 0.05 to 0.5% by weight of Pb, and the balance being copper. (b) A copper alloy containing 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, 0.05 to 0.5% by weight of Sb, and the balance being copper. (c) 0.02 to 1% by weight of Fe, 15 to 80% by weight of P relative to Fe, further containing In, Sn, Pb
And containing at least one substance of Sb,
A copper alloy in which the total content including In is 0.01 to 0.5% by weight, the content of each of In and one or more other substances is 0.006% by weight or more, and the balance is copper. (d) 0.02 to 0.7% by weight of Fe, 15 to 80% by weight of P with respect to Fe, and 0.01 to 0.5 of two kinds selected from the group consisting of In, Sn, Pb and Sb and Zr in a total amount. A copper alloy containing wt% and the balance being copper. 2. A flexible conductor comprising a composite twisted wire obtained by concentrically twisting a gathered twisted wire as a child twist, and further concentrically twisting the child twisted wire into a composite twisted wire, which is an outermost layer of a child twisted wire. Is a pure annealed copper wire, and the strand of the aggregated twisted wire in the outer layer part of the lower layer of the child twisting layer that is in contact with the outermost layer of the twisted wire is one of the following (a), (b), (c), (d) copper A flexible conductor which is resistant to bending and vibration, characterized in that it is a softened alloy wire and the other twisted strands are pure annealed copper wires. (a) A copper alloy containing 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, 0.05 to 0.5% by weight of Pb, and the balance being copper. (b) A copper alloy containing 0.02 to 1% by weight of Fe, 15 to 80% by weight of P with respect to Fe, 0.05 to 0.5% by weight of Sb, and the balance being copper. (c) 0.02 to 1% by weight of Fe, 15 to 80% by weight of P relative to Fe, further containing In, Sn, Pb
And containing at least one substance of Sb,
A copper alloy in which the total content of In is 0.01 to 0.5% by weight, the content of each of In and one or more other substances is 0.006% by weight or more, and the balance is copper. (d) 0.02 to 0.7% by weight of Fe, 15 to 80% by weight of P relative to Fe, and 0.01 to 0.5 in total of Zr and two kinds selected from the group consisting of In, Sn, Pb, and Sb. A copper alloy containing wt% and the balance being copper.