JP7054482B2 - Manufacturing method of coated electric wire, manufacturing method of copper alloy wire, and manufacturing method of copper alloy stranded wire - Google Patents

Description

The present invention relates to covered electric wires, electric wires with terminals, copper alloy wires, and copper alloy stranded wires.

Conventionally, a wire harness in which a plurality of electric wires with terminals are bundled in a wiring structure of an automobile or an industrial robot has been used. An electric wire with a terminal is a conductor in which a terminal such as a crimp terminal is attached to a conductor exposed from an insulating coating layer at the end of the electric wire. Typically, each terminal is inserted into a plurality of terminal holes provided in the connector housing and mechanically connected to the connector housing. An electric wire is connected to the main body of the device via this connector housing. In some cases, the connector housings are connected to each other and the electric wires are connected to each other. Copper-based materials such as copper are the mainstream of the constituent materials of the conductor (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-156617

An electric wire having excellent impact resistance as well as excellent conductivity and strength is desired. In particular, even if the wire rod constituting the conductor is thin, an electric wire that is hard to break when subjected to an impact is desired.

In recent years, with the increasing performance and functionality of automobiles, the number of various electric devices and control devices mounted on vehicles has increased, and the number of electric wires used for these devices has also been increasing. Therefore, the weight of the electric wire is also increasing. On the other hand, in order to protect the environment, it is desired to reduce the weight of electric wires for the purpose of improving the fuel efficiency of automobiles. The wire rod made of the above-mentioned copper-based material tends to have high conductivity, but tends to increase in weight. For example, if a thin copper-based wire having a wire diameter of 0.5 mm or less is used for the conductor, high strength due to work hardening and weight reduction due to the small diameter can be expected. However, as described above, the thin wire rod has a small cross-sectional area, and the force that can be impacted when it is impacted tends to be small, so that it is easily broken when it is impacted. Therefore, a copper-based wire rod having excellent impact resistance is desired even if it is thin as described above.

In an electric wire used with terminals such as crimp terminals attached as described above, the cross-sectional area of the terminal attachment points that have been compressed in the conductor may be referred to as other points (hereinafter referred to as main line points). ) Is smaller than the cross section. For this reason, the terminal mounting location on the conductor tends to be a location that is easily broken when subjected to an impact. Therefore, even with the above-mentioned thin copper-based wire, it is desired that the vicinity of the terminal mounting portion is not easily broken when an impact is applied, that is, the impact resistance in the terminal mounted state is also excellent.

Further, it is conceivable that the electric wire for in-vehicle use may be pulled, bent or twisted at the time of arrangement, connection with the connector housing, etc., or may be subjected to vibration at the time of use. It is conceivable that electric wires for robot applications will be bent or twisted during use. It is more preferable to use an electric wire that is hard to break even by such repeated bending and twisting operations and has excellent fatigue resistance, and an electric wire having excellent adhesiveness to terminals such as crimp terminals as described above.

Therefore, one of the purposes of the present invention is to provide a coated electric wire, a wire with a terminal, a copper alloy wire, and a copper alloy stranded wire, which are excellent in conductivity and strength and also have excellent impact resistance.

The covered electric wire according to one aspect of the present invention is
A coated electric wire including a conductor and an insulating coating layer provided on the outside of the conductor.
The conductor is
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
It is composed of a copper alloy having a Fe / P of 4.0 or more by mass ratio.
It is a stranded wire obtained by twisting a plurality of copper alloy wires having a wire diameter of 0.5 mm or less.

The electric wire with a terminal according to one aspect of the present invention is
A covered electric wire according to the above aspect and a terminal attached to an end portion of the coated electric wire are provided.

The copper alloy wire according to one aspect of the present invention is
Copper alloy wire used for conductors
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
It is composed of a copper alloy having a Fe / P of 4.0 or more by mass ratio.
The wire diameter is 0.5 mm or less.

The copper alloy stranded wire according to one aspect of the present invention is
A plurality of copper alloy wires according to the above aspect are twisted together.

The coated electric wire, the electric wire with a terminal, the copper alloy wire, and the copper alloy stranded wire are excellent not only in conductivity and strength but also in impact resistance.

It is a schematic perspective view which shows the coated electric wire of an embodiment. It is a schematic side view which shows the vicinity of a terminal about the electric wire with a terminal of an embodiment. It is sectional drawing which cut | cut the electric wire with a terminal shown in FIG. 2 by the (III)-(III) cutting line. It is explanatory drawing explaining the measuring method of "impact resistance energy in a terminal-mounted state" measured in Test Examples 1 and 2.

[Explanation of Embodiment of the present invention]
First, the contents of the embodiments of the present invention will be listed and described.
(1) The covered electric wire according to one aspect of the present invention is
A coated electric wire including a conductor and an insulating coating layer provided on the outside of the conductor.
The conductor is
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
It is composed of a copper alloy having a Fe / P of 4.0 or more by mass ratio.
It is a stranded wire obtained by twisting a plurality of copper alloy wires having a wire diameter of 0.5 mm or less.
The above-mentioned stranded wire includes not only a plurality of copper alloy wires simply twisted together, but also a so-called compression stranded wire which is compression-molded after being twisted. The same applies to the copper alloy stranded wire of (10) described later. A typical twisting method is concentric twisting.
The wire diameter is the diameter when the copper alloy wire is a round wire, and is the diameter of a circle having an equivalent area in the cross section when the cross-sectional shape is a wire rod other than a circular wire.

Since the above-mentioned coated electric wire is provided with a wire having a small diameter (copper alloy wire) made of a copper-based material in the conductor, it is excellent in conductivity and strength and is lightweight. Since this copper alloy wire is composed of a copper alloy having a specific composition, the above-mentioned coated electric wire is excellent not only in conductivity and strength but also in impact resistance as described below. In the above copper alloy, Fe and P are typically present in the matrix (Cu) as precipitates and crystallizations containing Fe and P such as compounds such as Fe ₂ P, and have an effect of improving strength by strengthening precipitation and Cu. It has the effect of maintaining high conductivity by reducing the solid solution to copper. In particular, since Fe is contained in a large amount with respect to P, it is easy for Fe and P to form a compound without excess or deficiency, and it is possible to effectively prevent the excess P from being dissolved in the parent phase and lowering the conductivity. .. From this point, it is easier to maintain the high conductivity of Cu. Moreover, since Sn is contained in a specific range, a further strength improving effect can be obtained by strengthening the solid solution of Sn. Since it has high strength by the above-mentioned precipitation strengthening and solid solution strengthening, it has high strength even when elongation is increased by heat treatment, and also has high toughness and excellent impact resistance. The above-mentioned coated electric wire, the copper alloy stranded wire constituting the conductor of the coated electric wire, and the copper alloy wire which is each element of the copper alloy stranded wire have high conductivity, high strength, and high toughness in a well-balanced manner. It can be said that.

Further, since the above-mentioned coated electric wire uses a stranded wire of a high-strength and high-toughness copper alloy wire as a conductor as described above, the conductor (twisted wire) is compared with the case where a single wire having the same cross-sectional area is used as a conductor. As a whole, it tends to be superior in mechanical properties such as flexibility and twistability, and is excellent in fatigue resistance. Further, the twisted wire and the copper alloy wire tend to be easily work-hardened when subjected to plastic working such as compression working with a reduction in cross section. Therefore, when a terminal such as a crimp terminal is fixed, the coated electric wire can be firmly fixed to the terminal by work hardening, and has excellent stickability to the terminal. By this work hardening, the strength of the terminal connection point in the conductor (twisted wire) can be increased. Therefore, it is difficult to break at the terminal connection point when it receives an impact, and the above-mentioned covered electric wire is also excellent in impact resistance when the terminal is attached.

(2) As an example of the above-mentioned covered electric wire,
Examples of the copper alloy include a form containing 10 ppm or more and 500 ppm or less in total of one or more elements selected from C, Si, and Mn in terms of mass ratio.

By containing C, Si, and Mn in a specific range, they function as deoxidizers such as Fe, P, and Sn, reduce or prevent the oxidation of these elements, and have high conductivity due to the inclusion of these elements. The effects of sex and high strength can be appropriately obtained. In addition, the above-mentioned form is excellent in conductivity because it can suppress a decrease in conductivity due to an excessive content of C, Si, and Mn. Therefore, the above-mentioned form is superior in conductivity and strength.

(3) As an example of the above-mentioned covered electric wire,
Examples thereof include a form in which the breaking elongation of the copper alloy wire is 5% or more.

In the above embodiment, since the conductor is provided with a copper alloy wire having high breaking elongation, it is excellent in impact resistance, is not easily broken by bending or twisting, and is also excellent in bending property and twisting property.

(4) As an example of the above-mentioned covered electric wire,
Examples thereof include a form in which the conductivity of the copper alloy wire is 60% IACS or more and the tensile strength is 400 MPa or more.

The above-mentioned form is excellent in conductivity and strength because the conductor is provided with a copper alloy wire having high conductivity and tensile strength.

(5) As an example of the above-mentioned covered electric wire,
Examples thereof include a form in which the terminal fixing force is 45 N or more.
The method for measuring the terminal fixing force, (6) and (11) impact-resistant energy in the terminal-mounted state, and (7) and (12) impact-resistant energy, which will be described later, will be described later (see Test Examples 1 and 2).

In the above embodiment, when a terminal such as a crimp terminal is attached, the terminal can be firmly fixed, and the adhesiveness to the terminal is excellent. Therefore, the above-mentioned form is excellent in conductivity, strength and impact resistance, and is also excellent in terminal sticking property, and can be suitably used for the above-mentioned electric wire with a terminal.

(6) As an example of the above-mentioned covered electric wire,
An example is a form in which the impact resistance energy with the terminal attached is 3 J / m or more.

In the above form, the impact resistance energy is high when the terminal is crimped, such as a crimp terminal, and it is difficult to break at the terminal mounting location even when an impact is received while the terminal is mounted. Therefore, the above-mentioned form is excellent in conductivity, strength, and impact resistance, and is also excellent in impact resistance in a terminal-mounted state, and can be suitably used for the above-mentioned electric wire with a terminal.

(7) As an example of the above-mentioned covered electric wire,
Examples thereof include a form in which the impact resistance energy of only the coated electric wire is 6 J / m or more.

In the above form, the impact resistance energy of the coated electric wire itself is high, it is hard to break even when it receives an impact, and it is excellent in impact resistance.

(8) The electric wire with a terminal according to one aspect of the present invention is
The covered electric wire according to any one of (1) to (7) above, and a terminal attached to an end portion of the coated electric wire are provided.

Since the above-mentioned electric wire with a terminal includes the above-mentioned coated electric wire, it is excellent in conductivity and strength as described above, and is also excellent in impact resistance. Further, since the above-mentioned electric wire with a terminal includes the above-mentioned covered electric wire, it is excellent in fatigue resistance, adhesion to a terminal such as a crimp terminal, and impact resistance in a terminal-mounted state as described above.

(9) The copper alloy wire according to one aspect of the present invention is
Copper alloy wire used for conductors
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
It is composed of a copper alloy having a Fe / P of 4.0 or more by mass ratio.
The wire diameter is 0.5 mm or less.

Since the above copper alloy wire is a small-diameter wire made of a copper-based material, it has excellent conductivity and strength when used as a conductor such as an electric wire in the state of a single wire or a stranded wire. Contributes to weight reduction. In particular, the above-mentioned copper alloy wire is composed of a copper alloy having a specific composition including Fe, P, and Sn, and is excellent in conductivity and strength as described above and also in impact resistance. Therefore, by using the above-mentioned copper alloy wire as the conductor of the electric wire, the electric wire having excellent conductivity and strength and also having excellent impact resistance, fatigue resistance, adhesion to terminals such as crimp terminals, and terminals. It is possible to construct an electric wire with excellent impact resistance in the mounted state.

(10) The copper alloy stranded wire according to one aspect of the present invention is
A plurality of copper alloy wires according to (9) above are twisted together.

The copper alloy stranded wire substantially maintains the composition and characteristics of the copper alloy wire of the above (9), and is excellent in conductivity and strength as well as impact resistance. Therefore, by using the above-mentioned copper alloy stranded wire for the conductor of the electric wire, the electric wire having excellent conductivity and strength and also having excellent impact resistance, fatigue resistance, and sticking property to terminals such as crimp terminals can be improved. It is possible to construct an electric wire with excellent impact resistance when the terminal is attached.

(11) As an example of the above-mentioned copper alloy stranded wire,
An example is a form in which the impact resistance energy with the terminal attached is 1.5 J / m or more.

The above-mentioned form has high impact resistance energy when the terminal is attached. If the copper alloy stranded wire of the above-mentioned form is used as a conductor and the coated electric wire is provided with an insulating coating layer, the coated electric wire having higher impact resistance energy in the terminal-mounted state, typically the coating of (6) above. You can build electric wires. Therefore, the above-described embodiment can be suitably used for conductors such as coated electric wires and electric wires with terminals, which are excellent in electrical conductivity, strength and impact resistance, and also have excellent impact resistance in a terminal-mounted state.

(12) As an example of the above-mentioned copper alloy stranded wire,
Examples thereof include a form in which the impact resistance energy of only the copper alloy stranded wire is 4 J / m or more.

In the above form, the impact resistance energy of the copper alloy stranded wire itself is high. If such a copper alloy stranded wire of the above-mentioned form is used as a conductor and a coated electric wire provided with an insulating coating layer is used, a coated electric wire having higher impact resistance energy, typically the coated electric wire of the above-mentioned (7) can be constructed. Therefore, the above-mentioned form can be suitably used for conductors such as coated electric wires and electric wires with terminals, which are excellent in electrical conductivity and strength and also excellent in impact resistance.

[Details of Embodiments of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the figure, the same reference numerals indicate the same names. The content of the element shall be mass ratio (mass% or mass ppm) unless otherwise specified.

[Copper alloy wire]
(composition)
The copper alloy wire 1 of the embodiment is used for a conductor of an electric wire such as a coated electric wire 3 (FIG. 1), and is composed of a copper alloy containing a specific additive element in a specific range. The copper alloy contains Fe of 0.2% or more and 1.6% or less, P of 0.05% or more and 0.4% or less, Sn of 0.05% or more and 0.7% or less, and the balance is Cu and It is a Fe—P—Sn—Cu alloy composed of impurities. In particular, in the copper alloy, the ratio Fe / P of the Fe content to the P content is 4.0 or more in terms of mass ratio. The above impurities mainly refer to unavoidable ones. Hereinafter, each element will be described in detail.

・ Fe
Fe is mainly present in the Cu which is the matrix phase and contributes to the improvement of strength such as tensile strength.
When Fe is contained in an amount of 0.2% or more, precipitates containing Fe and P can be satisfactorily generated, and the copper alloy wire 1 having excellent strength can be obtained by strengthening the precipitation. Moreover, the solid dissolution of P in the matrix can be suppressed by the above-mentioned precipitation, and the copper alloy wire 1 having high conductivity can be obtained. Although it depends on the amount of P and the production conditions, the higher the content of Fe, the higher the strength of the copper alloy wire 1 tends to be. If it is desired to increase the strength, the Fe content can be more than 0.35%, more 0.4% or more, and 0.45% or more.
When Fe is contained in the range of 1.6% or less, it is easy to suppress the coarsening of precipitates containing Fe. As a result, it is possible to reduce the breakage starting from the coarse precipitate and to have excellent strength, and in the manufacturing process, it is difficult to break the wire at the time of wire drawing, and the manufacturability is also excellent. Although it depends on the amount of P and the production conditions, the smaller the content of Fe, the easier it is to suppress the coarsening of the above-mentioned precipitates. If it is desired to suppress the coarsening of the precipitate (reduce breakage and disconnection), the Fe content should be 1.5% or less, 1.2% or less, 1.0% or less, and less than 0.9%. Can be.

・ P
In the copper alloy wire 1, P mainly exists as a precipitate together with Fe and contributes to the improvement of strength such as tensile strength, that is, mainly functions as a precipitation strengthening element.
When P is contained in an amount of 0.05% or more, precipitates containing Fe and P can be satisfactorily generated, and the copper alloy wire 1 having excellent strength can be obtained by strengthening the precipitation. Although it depends on the amount of Fe and the production conditions, the higher the content of P, the higher the strength of the copper alloy wire 1 tends to be. If it is desired to increase the strength, the P content can be more than 0.1%, more preferably 0.11% or more, and 0.12% or more. It should be noted that a part of the contained P functions as a deoxidizing agent and allows it to be present as an oxide in the matrix.
When P is contained in the range of 0.4% or less, coarsening of precipitates containing Fe and P can be easily suppressed, and breakage and disconnection can be reduced. Although it depends on the amount of Fe and the production conditions, the smaller the content of P, the easier it is to suppress the above-mentioned coarsening. If it is desired to suppress the coarsening of the precipitate (reduce breakage and disconnection), the P content can be 0.35% or less, further 0.3% or less, and 0.25% or less.

・ Fe / P
In addition to containing Fe and P in the above-mentioned specific range, when Fe is appropriately contained with respect to P, especially when Fe is contained at the same level or more with respect to P, Fe and P are present as a compound. easy. As a result, the effect of improving the strength by strengthening precipitation can be appropriately obtained, and the effect of maintaining the high conductivity of the parent phase by reducing the solid solution of excess P can be appropriately achieved. It can be a copper alloy wire 1.
When Fe / P is 4.0 or more, the conductivity is excellent and the strength is high as described above. The larger the Fe / P, the more excellent the conductivity tends to be, and the Fe / P can be more than 4.0 and further 4.1 or more. Fe / P can be selected in the range of, for example, 30 or less, but when it is 20 or less and further 10 or less, it is easy to suppress the coarsening of precipitates due to excessive Fe.

・ Sn
Sn mainly exists in a solid solution in Cu, which is a matrix phase, and contributes to an improvement in strength such as tensile strength, that is, mainly functions as a solid solution strengthening element.
When Sn is contained in an amount of 0.05% or more, the copper alloy wire 1 having higher strength can be obtained. The higher the Sn content, the higher the strength tends to be. If high strength is desired, the Sn content can be 0.08% or more, further 0.1% or more, and 0.12% or more.
When Sn is contained in the range of 0.7% or less, the copper alloy wire 1 having high conductivity can be obtained by suppressing a decrease in conductivity due to excessive solid solution of Sn in Cu. In addition, it is easy to perform plastic working such as wire drawing by suppressing deterioration of workability due to excessive solid solution of Sn, and it is also excellent in manufacturability. When high conductivity and good processability are desired, the Sn content can be 0.6% or less, further 0.55% or less, 0.5% or less.

The copper alloy wire 1 of the embodiment has high strength by strengthening the precipitation of Fe and P and strengthening the solid solution of Sn as described above. Therefore, even when artificial aging and softening are performed in the manufacturing process, the copper alloy wire 1 having high strength and high toughness can be obtained by having high strength and high elongation.

・ C, Si, Mn
The copper alloy constituting the copper alloy wire 1 of the embodiment can contain an element having a deoxidizing effect on Fe, P, Sn and the like. Specifically, it may contain at least 10 ppm or more and 500 ppm or less of one or more elements selected from C, Si, and Mn in terms of mass ratio.

Here, if an oxygen-containing atmosphere such as an air atmosphere is used in the manufacturing process, elements such as Fe, P, and Sn may be oxidized. When these elements become oxides, the above-mentioned precipitates and the like cannot be formed properly or can not be dissolved in the matrix phase, resulting in high conductivity and high strength due to the inclusion of Fe and P, and the inclusion of Sn. There is a risk that the effect of strengthening the solid solution will not be obtained properly. These oxides may become the starting point of fracture during wire drawing, which may lead to a decrease in manufacturability. It contains at least one element of C, Mn, and Si, preferably two elements (in this case, C and Mn, or C and Si are preferable), and more preferably all three elements in a specific range. Therefore, it is possible to obtain a copper alloy wire 1 having excellent conductivity and high strength by more reliably strengthening precipitation by precipitation of Fe and P, ensuring high conductivity, and strengthening solid solution of Sn.

When the above-mentioned total content is 10 ppm or more, oxidation of the above-mentioned elements such as Fe can be prevented. The larger the total content is, the easier it is to obtain the antioxidant effect, and the amount can be 20 ppm or more, further 30 ppm or more.
When the total content is 500 ppm or less, the conductivity is less likely to be lowered due to the excessive content of these deoxidizing agent elements, and the conductivity is excellent. The smaller the total content is, the easier it is to suppress the decrease in conductivity. Therefore, the total content can be 300 ppm or less, further 200 ppm or less, and 150 ppm or less.

The content of C alone is preferably 10 ppm or more and 300 ppm or less, more preferably 10 ppm or more and 200 ppm or less, and particularly preferably 30 ppm or more and 150 ppm or less.
The content of Mn alone or Si alone is preferably 5 ppm or more and 100 ppm or less, and more preferably more than 5 ppm and 50 ppm or less. The total content of Mn and Si is preferably 10 ppm or more and 200 ppm or less, and more preferably more than 10 ppm and 100 ppm or less.
When C, Mn, and Si are contained in the above ranges, the antioxidant effect of the above-mentioned elements such as Fe can be easily obtained. For example, the oxygen content in the copper alloy can be 20 ppm or less, 15 ppm or less, and further 10 ppm or less.

(Organization)
Examples of the structure of the copper alloy constituting the copper alloy wire 1 of the embodiment include a structure in which precipitates and crystals containing Fe and P are dispersed. By having a dispersed structure such as precipitates, preferably a structure in which fine precipitates and the like are uniformly dispersed, it is expected to increase the strength by strengthening the precipitation and secure high conductivity by reducing the solid solution of P and the like into Cu. can.

Further, examples of the structure of the copper alloy include a fine crystal structure. In this case, the above-mentioned precipitates and the like are likely to be uniformly dispersed and exist, and further increase in strength can be expected. In addition, since there are few coarse crystal grains that can be the starting point of fracture and it is difficult to fracture, toughness such as elongation tends to increase, and it is expected to be more excellent in impact resistance. Further, in this case, if the copper alloy wire 1 of the embodiment is used as a conductor of an electric wire such as a coated electric wire 3, and a terminal such as a crimp terminal is attached to this conductor, the terminal can be firmly fixed and the terminal fixing force can be easily increased.

Quantitatively, when the average crystal grain size is 10 μm or less, the above-mentioned effect can be easily obtained, and it can be 7 μm or less, further 5 μm or less. The crystal grain size can be adjusted, for example, by adjusting the production conditions (processing degree, heat treatment temperature, etc., the same below) according to the composition (Fe, P, Sn content, Fe / P value, etc., the same below). It can be made to a predetermined size.

The average crystal grain size is measured as follows. A cross section subjected to cross-section polisher (CP) processing is taken, and this cross section is observed with a scanning electron microscope. From the observation image, an observation range with a predetermined area S ₀ is taken, and all the crystal numbers N existing in the observation range are examined. The area (S ₀ / N) obtained by dividing the area S ₀ by the number of crystals N is defined as the area Sg of each crystal grain, and the diameter of the circle having an area equivalent to the area Sg of the crystal grains is defined as the diameter R of the crystal grains. The average of the diameters R of the crystal grains is defined as the average crystal grain size. The observation range may be a range in which the number of crystals n is 50 or more, or the entire cross section. By sufficiently widening the observation range in this way, it is possible to sufficiently reduce the error caused by something other than crystals (precipitate or the like) that may exist in the area _S0 .

(Wire diameter)
The copper alloy wire 1 of the embodiment can have a predetermined wire diameter by adjusting the degree of processing (cross-sectional reduction rate) at the time of wire drawing in the manufacturing process. In particular, if the copper alloy wire 1 is a thin wire having a wire diameter of 0.5 mm or less, it can be suitably used as a conductor of an electric wire for which weight reduction is desired, for example, a conductor for an electric wire to be wired to an automobile. The wire diameter can be 0.35 mm or less, and further can be 0.25 mm or less.

(Cross-sectional shape)
The cross-sectional shape of the copper alloy wire 1 of the embodiment can be appropriately selected. A typical example of the copper alloy wire 1 is a round wire having a circular cross section. The cross-sectional shape changes depending on the shape of the die used for wire drawing, the shape of the molding die when the copper alloy wire 1 is used as a compression stranded wire, and the like. The copper alloy wire 1 can be, for example, a rectangular wire having a rectangular cross-sectional shape, a polygonal wire such as a hexagon, or a deformed wire having an elliptical shape. The copper alloy wire 1 constituting the compression stranded wire is typically an irregular wire having an irregular cross-sectional shape.

(Characteristic)
-Tensile strength, elongation at break, conductivity The copper alloy wire 1 of the embodiment is composed of the copper alloy having the above-mentioned specific composition, so that it has excellent conductivity and high strength. By being manufactured by applying appropriate heat treatment, it has high strength, high toughness, and high conductivity in a well-balanced manner. Quantitatively, the copper alloy wire 1 has at least one, preferably two, having a tensile strength of 400 MPa or more, a breaking elongation of 5% or more, and a conductivity of 60% IACS or more. One, more preferably, all three are satisfied. As an example of the copper alloy wire 1, a copper alloy wire 1 having a conductivity of 60% IACS or more and a tensile strength of 400 MPa or more can be mentioned. Alternatively, as an example of the copper alloy wire 1, a wire having a breaking elongation of 5% or more can be mentioned.

If higher strength is desired, the tensile strength can be 405 MPa or more, 410 MPa or more, and further 415 MPa or more.
If higher toughness is desired, the elongation at break can be 6% or more, 7% or more, 8% or more, 9.5% or more, and further 10% or more.
If higher conductivity is desired, the conductivity can be 62% IACS or higher, 63% IACS or higher, and 65% IACS or higher.

-Work hardening index As an example of the copper alloy wire 1 of the embodiment, a work hardening index of 0.1 or more can be mentioned.
The work hardening index is defined as the index n of the true strain ε in the equation σ = C × ε ⁿ of the true stress σ and the true strain ε in the plastic strain region when the test force of the tensile test is applied in the uniaxial direction. Will be done. In the above equation, C is an intensity constant.
The above index n can be obtained by performing a tensile test using a commercially available tensile tester and creating an SS curve (see also JIS G 2253 (2011)).

The larger the work hardening index, the easier it is to work harden, and in the work part, the effect of improving the strength by work hardening can be obtained. For example, when a copper alloy wire 1 is used as a conductor of an electric wire such as a coated electric wire 3 and a terminal such as a crimp terminal is crimped to the conductor, the terminal attachment point on the conductor is subjected to plastic working such as compression processing. It will be the processed part that has been applied. Although this machined portion is subjected to plastic working such as compression working with a reduction in cross section, it is harder than before the plastic working and its strength is increased. Therefore, it is possible to reduce that the processed portion, that is, the terminal mounting portion of the conductor and its vicinity thereof becomes a weak point of strength. When the work hardening index is 0.11 or more, further 0.12 or more, and 0.13 or more, it is easy to obtain the effect of improving the strength by work hardening. Depending on the composition and manufacturing conditions, it can be expected that the terminal mounting points on the conductor will maintain the same strength as the main line points on the conductor. Since the work hardening index changes depending on the composition and manufacturing conditions, there is no particular upper limit.

The tensile strength, elongation at break, conductivity, and work hardening index can be set to predetermined sizes by adjusting the composition and production conditions. For example, when Fe, P, Sn are increased or the degree of wire drawing is increased (thinned), the tensile strength tends to increase. For example, if the heat treatment temperature is increased when the heat treatment is performed after the wire is drawn, the elongation at break and the conductivity tend to be high, and the tensile strength tends to be low.

-Weldability The copper alloy wire 1 of the embodiment also has an effect of being excellent in weldability. For example, when a copper alloy wire 1 or a copper alloy stranded wire 10 described later is used as a conductor of an electric wire and another conductor wire or the like is welded in order to take a branch from this conductor, the welded portion is hard to break and the welding strength is high. Is high.

[Copper alloy stranded wire]
The copper alloy stranded wire 10 of the embodiment uses the copper alloy wire 1 of the embodiment as a strand, and a plurality of copper alloy wires 1 are twisted together. The copper alloy stranded wire 10 substantially maintains the composition, structure, and characteristics of the copper alloy wire 1 which is a strand, and its cross-sectional area tends to be larger than that of a single strand, so that the impact is impacted. It can increase the force that can be received at times and is superior in impact resistance. Further, the copper alloy stranded wire 10 is easier to bend and twist than a single wire having the same cross-sectional area, and is also excellent in bendability and twistability. It is difficult to break the wire due to repeated bending. Further, since a plurality of copper alloy wires 1 that are easily processed and hardened are collected in the copper alloy stranded wire 10 as described above, the copper alloy stranded wire 10 is used as a conductor of an electric wire such as a coated electric wire 3 to form this conductor. When a terminal such as a crimp terminal is attached, the above terminal can be fixed more firmly. In FIG. 1, seven concentric twisted copper alloy stranded wires 10 are illustrated, but the number of twisted wires and the twisting method can be appropriately changed.

The copper alloy stranded wire 10 can be a compression stranded wire (not shown) that has been compression-molded after being twisted. Since the compressed stranded wire is excellent in stability in a twisted state, when the compressed stranded wire is used as a conductor of an electric wire such as a coated electric wire 3, it is easy to form an insulating coating layer 2 or the like on the outer periphery of the conductor. Also, the compressed stranded wire tends to have better mechanical properties and a smaller diameter than simply twisted.

The wire diameter, cross-sectional area, twist pitch, and the like of the copper alloy stranded wire 10 can be appropriately selected according to the wire diameter, cross-sectional area, number of twisted wires, and the like of the copper alloy wire 1.
When the cross-sectional area of the copper alloy stranded wire 10 is, for example, 0.03 mm ² or more, the conductor cross-sectional area is large, so that the electric resistance is small and the conductivity is excellent. Further, when the copper alloy stranded wire 10 is used as a conductor of an electric wire such as a coated electric wire 3 and a terminal such as a crimp terminal is attached to this conductor, the cross-sectional area is large to some extent, so that the terminal can be easily attached. Further, as described above, the terminal can be firmly fixed to the copper alloy stranded wire 10, and the impact resistance when the terminal is attached is also excellent. The cross-sectional area can be 0.1 mm ² or more. If the cross-sectional area is, for example, 0.5 mm ² or less, a lightweight copper alloy stranded wire 10 can be obtained.
If the twist pitch of the copper alloy stranded wire 10 is, for example, 10 mm or more, it is easy to twist even a thin wire having a strand (copper alloy wire 1) of 0.5 mm or less, and the manufacturability of the copper alloy stranded wire 10 is improved. Excellent. When the twist pitch is, for example, 20 mm or less, the twist is not unraveled even when bent or the like, and the flexibility is excellent.

Impact-resistant energy in the terminal-mounted state The copper alloy stranded wire 10 of the embodiment is used as a conductor such as a coated electric wire because the copper alloy wire 1 composed of a specific copper alloy is used as a wire as described above. Therefore, when a terminal such as a crimp terminal is attached to the end of this conductor and an impact is applied, it is difficult to break near the terminal attachment location. Quantitatively, in the copper alloy stranded wire 10, the impact resistance energy (impact resistance energy in the terminal mounted state) in the state where the terminal is attached is 1.5 J / m or more. The larger the impact resistance energy in the terminal mounted state, the more difficult it is to break in the vicinity of the terminal mounting location when an impact is applied. If such a copper alloy stranded wire 10 is used as a conductor, it is possible to construct a coated electric wire having excellent impact resistance in a terminal-mounted state. The impact resistance energy of the copper alloy stranded wire 10 in the terminal mounted state is preferably 1.6 J / m or more, more preferably 1.7 J / m or more, and the upper limit is not particularly set.

-Impact resistant energy Since the copper alloy stranded wire 10 of the embodiment is made of a copper alloy wire 1 composed of a specific copper alloy as described above, it is difficult to break when it receives an impact or the like. Quantitatively, the impact resistance energy of only the copper alloy stranded wire 10 is 4 J / m or more. The larger the impact resistance energy, the more difficult it is for the copper alloy stranded wire 10 itself to break when subjected to an impact. If such a copper alloy stranded wire 10 is used as a conductor, a coated electric wire having excellent impact resistance can be constructed. The impact resistance energy of the copper alloy stranded wire 10 is preferably 4.2 J / m or more, more preferably 4.5 J / m or more, and the upper limit is not particularly defined.

As for the single copper alloy wire 1, it is preferable that the impact resistance energy and the impact resistance energy in the terminal mounted state satisfy the above range. The copper alloy stranded wire 10 of the embodiment tends to have higher impact resistance energy and impact resistance energy in the terminal mounted state as compared with the single wire copper alloy wire 1.

[Covered wire]
The copper alloy wire 1 and the copper alloy stranded wire 10 of the embodiment can be used as a conductor as they are, but if an insulating coating layer is provided on the outer periphery, the insulating property is excellent. The coated electric wire 3 of the embodiment includes a conductor and an insulating coating layer 2 provided on the outside of the conductor, and the conductor is the copper alloy stranded wire 10 of the embodiment. As another covered electric wire of the embodiment, the conductor is a copper alloy wire 1 (single wire). FIG. 1 illustrates a case where the conductor is provided with the copper alloy stranded wire 10.

Examples of the insulating material constituting the insulating coating layer 2 include polyvinyl chloride (PVC), a non-halogen resin (for example, polypropylene (PP)), and a material having excellent flame retardancy. Known insulating materials can be used.
The thickness of the insulating coating layer 2 can be appropriately selected according to a predetermined dielectric strength, and is not particularly limited.

-Terminal fixing force The coated electric wire 3 of the embodiment has a terminal such as a crimp terminal because the conductor is provided with a copper alloy stranded wire 10 having a copper alloy wire 1 composed of a specific copper alloy as a wire as described above. The terminal can be firmly fixed when it is attached by crimping. Quantitatively, the terminal fixing force is 45 N or more. The greater the terminal fixing force, the stronger the terminal can be fixed, and the easier it is to maintain the connected state between the covered electric wire 3 (conductor) and the terminal, which is preferable. The terminal fixing force is preferably 50 N or more, 55 N or more, and further 58 N or more, and the upper limit is not particularly set.

Impact-resistant energy in the terminal-mounted state The impact-resistant energy in the terminal-mounted state of the coated electric wire 3 of the embodiment and the impact-resistant energy of the coated electric wire 3 are the bare conductors having no insulating coating layer 2, that is, the embodiment. It tends to be higher than that of the copper alloy stranded wire 10. Depending on the constituent materials and thickness of the insulating coating layer 2, the impact resistance energy of the coated electric wire 3 in the terminal mounted state and the impact resistance energy of only the coated electric wire 3 may be further enhanced as compared with the bare conductor. be. Quantitatively, the impact resistance energy of the covered electric wire 3 in the terminal mounted state is 3 J / m or more. The larger the impact resistance energy of the coated electric wire 3 in the terminal mounted state, the more difficult it is to break in the vicinity of the terminal mounting location, preferably 3.2 J / m or more, more preferably 3.5 J / m or more, and the upper limit is Not specified.

-Impact resistance energy Quantitatively, the impact resistance energy of only the coated electric wire 3 (hereinafter, may be referred to as the impact resistance energy of the main line) is 6 J / m or more. The larger the impact resistance energy of the main line, the more difficult it is to break when it receives an impact, and it is preferably 6.5 J / m or more, more preferably 7 J / m or more, and 8 J / m or more, and the upper limit is not particularly set.

When the insulating coating layer 2 is removed from the coated electric wire 3 to make it a state of only a conductor, that is, a state of only a copper alloy stranded wire 10, and the impact resistance energy and the impact resistance energy of this conductor in the terminal mounted state are measured, the above-mentioned It takes substantially the same value as the copper alloy stranded wire 10. Specifically, the impact resistant energy of the conductor provided in the coated electric wire 3 in the terminal mounted state is 1.5 J / m or more, and the impact resistant energy of the conductor provided in the coated electric wire 3 is 4 J / m or more. Can be mentioned.

Even in a coated electric wire having a single copper alloy wire 1 as a conductor, it is preferable that at least one of the terminal fixing force, the impact resistance energy in the terminal mounted state, and the impact resistance energy of the main wire satisfies the above range. The coated electric wire 3 of the embodiment in which the conductor is a copper alloy stranded wire 10 has a terminal fixing force, an impact resistant energy in a terminal mounted state, and an impact resistant energy of the main wire, as compared with a coated electric wire having a single copper alloy wire 1 as a conductor. Tends to be higher.

The terminal fixing force of the coated electric wire 3 and the like of the embodiment, the impact resistance energy in the terminal mounted state, and the impact resistance energy of the main wire are determined by the composition and manufacturing conditions of the copper alloy wire 1, the constituent materials and the thickness of the insulating coating layer 2. By adjusting, it can be made into a predetermined size. For example, the composition and manufacturing conditions of the copper alloy wire 1 may be adjusted so that the above-mentioned characteristic parameters such as tensile strength, elongation at break, conductivity, and work hardening index satisfy the above-mentioned specific ranges.

[Electric wire with terminal]
As shown in FIG. 2, the terminal-equipped electric wire 4 of the embodiment includes the coated electric wire 3 of the embodiment and the terminal 5 attached to the end of the coated electric wire 3. Here, as the terminal 5, a female or male fitting portion 52 is provided at one end, an insulation barrel portion 54 for gripping the insulating coating layer 2 is provided at the other end, and a conductor (copper alloy in FIG. 2) is provided in the middle portion. An example is a crimp terminal provided with a wire barrel portion 50 that grips the stranded wire 10). The crimp terminal is crimped to the end of the conductor exposed by removing the insulating coating layer 2 at the end of the coated electric wire 3 and is electrically and mechanically connected to the conductor. Examples of the terminal 5 include a crimping type such as a crimping terminal and a molten type to which a molten conductor is connected. As another electric wire with a terminal of another embodiment, an electric wire provided with a coated electric wire having the above-mentioned copper alloy wire 1 (single wire) as a conductor can be mentioned.

As shown in FIG. 2, the electric wire 4 with terminals includes a form in which one terminal 5 is attached to each covered electric wire 3, and a form in which one terminal 5 is provided for a plurality of coated electric wires 3. That is, the electric wire 4 with a terminal includes one coated electric wire 3 and one terminal 5, a form including a plurality of coated electric wires 3 and one terminal 5, a plurality of coated electric wires 3 and a plurality of terminals. Examples thereof include a form comprising 5. When a plurality of electric wires are provided, it is easy to handle the electric wire 4 with a terminal by bundling the plurality of electric wires with a binding tool or the like.

[Characteristics of copper alloy wire, copper alloy stranded wire, coated wire, and wire with terminal]
Each of the strands of the copper alloy stranded wire 10 of the embodiment, each of the strands constituting the conductor of the coated electric wire 3, and each of the strands constituting the conductor of the wire with terminal 4 have the composition, structure, and structure of the copper alloy wire 1. Maintains or has similar properties. Therefore, as an example of each of the above strands, a form satisfying at least one of a tensile strength of 400 MPa or more, a breaking elongation of 5% or more, and a conductivity of 60% IACS or more. Can be mentioned.

As a terminal used for measuring the terminal fixing force of the terminal-equipped electric wire 4 and the impact resistance energy in the terminal-mounted state, a terminal 5 such as a crimp terminal provided in the terminal-attached electric wire 4 itself can be used.

[Use of copper alloy wire, copper alloy stranded wire, coated wire, wire with terminal]
The covered electric wire 3 of the embodiment can be used for a wiring portion of various electric devices and the like. In particular, the covered electric wire 3 of the embodiment is suitably used for applications in which the terminal 5 is attached to the end, for example, wiring of a transport device such as an automobile or an airplane, or a control device such as an industrial robot. can. The electric wire 4 with a terminal of the embodiment can be used for wiring of various electric devices such as the above-mentioned transport device and control device. The covered electric wire 3 and the electric wire 4 with terminals of such an embodiment can be suitably used as components of various wire harnesses such as wire harnesses for automobiles. The wire harness provided with the covered electric wire 3 and the electric wire 4 with terminals of the embodiment can easily maintain a good connection state with the terminal 5 and can improve reliability. The copper alloy wire 1 of the embodiment and the copper alloy stranded wire 10 of the embodiment can be used as a conductor of an electric wire such as a coated electric wire 3 and an electric wire with a terminal 4.

[effect]
The copper alloy wire 1 of the embodiment is made of a specific copper alloy containing Fe, P, and Sn, and is excellent in conductivity and strength as well as impact resistance. Similarly, the copper alloy stranded wire 10 of the embodiment in which the copper alloy wire 1 is a strand is also excellent in electrical conductivity and strength, and also in impact resistance.
Since the coated electric wire 3 of the embodiment includes the copper alloy stranded wire 10 of the embodiment in which the copper alloy wire 1 of the embodiment is a strand, the coated electric wire 3 is excellent in conductivity and strength as well as impact resistance. Further, the coated electric wire 3 can firmly fix the terminal 5 when the terminal 5 such as a crimp terminal is crimped, and also has excellent impact resistance in the mounted state of the terminal 5.
Since the electric wire 4 with a terminal of the embodiment includes the coated electric wire 3 of the embodiment, it is excellent in conductivity and strength as well as impact resistance. Further, the electric wire 4 with a terminal can firmly fix the terminal 5 and is also excellent in impact resistance when the terminal 5 is attached.
These effects will be specifically described with reference to Test Examples 1 and 2.

[Production method]
The copper alloy wire 1, the copper alloy stranded wire 10, the coated electric wire 3, and the electric wire with terminals 4 of the embodiment can be manufactured by, for example, a manufacturing method including the following steps. The outline of each process is listed below.

(Copper alloy wire)
<Continuous casting process> A cast material is manufactured by continuously casting a molten copper alloy having the above-mentioned specific composition.
<Wire drawing process> The cast material or a processed material obtained by processing the cast material is subjected to wire drawing to produce a wire drawing material.
<Heat treatment step> The above-mentioned wire drawing material is heat-treated to produce a heat-treated material.
This heat treatment is typically performed by artificial aging for precipitating precipitates containing Fe and P from a copper alloy in which Fe and P are in a solid solution state, and work-hardened wire drawing to the final wire diameter. It shall include softening to improve elongation. Hereinafter, this heat treatment is referred to as aging / softening treatment.

The following solution heat treatment can be included as the heat treatment other than the aging / softening treatment.
The solution heat treatment is a heat treatment for the purpose of forming a supersaturated solid solution, and can be applied at any time after the continuous casting step and before the aging / softening treatment.

(Copper alloy stranded wire)
When the copper alloy stranded wire 10 is manufactured, the following stranded wire step is provided in addition to the above-mentioned <continuous casting step>, <wire drawing step>, and <heat treatment step>. In the case of a compression stranded wire, the following compression steps are further provided.
<Twisting process> A stranded wire is manufactured by twisting a plurality of the above-mentioned wire drawing materials. Alternatively, a plurality of the above heat-treated materials are twisted together to produce a stranded wire.
<Compression step> The stranded wire is compression-molded into a predetermined shape to produce a compressed stranded wire.
When the above <twisted wire step> and <compression step> are provided, in the above <heat treatment step>, the aging / softening heat treatment may be applied to the stranded wire or the compressed stranded wire. When the stranded wire or the compression stranded wire of the heat-treated material is used, a second heat treatment step of further aging / softening the stranded wire or the compression stranded wire may be provided, or the second heat treatment step may be omitted. You may. When the aging / softening heat treatment is performed a plurality of times, the heat treatment conditions can be adjusted so that the above-mentioned characteristic parameters satisfy a specific range. By adjusting the heat treatment conditions, for example, it is easy to suppress the growth of crystal grains to obtain a fine crystal structure, and it is easy to have high strength and high elongation.

(Covered wire)
When manufacturing a coated wire including a coated wire 3 or a single copper alloy wire 1, the copper alloy wire manufactured by the above-mentioned method for manufacturing a copper alloy wire (copper alloy wire 1 of the embodiment) or the above-mentioned copper A coating step of forming an insulating coating layer on the outer periphery of the copper alloy stranded wire (copper alloy stranded wire 10 of the embodiment) manufactured by the method for producing an alloy stranded wire is provided. As a method for forming the insulating coating layer, a known method such as extrusion coating or powder coating can be used.

(Electric wire with terminal)
When the electric wire 4 with a terminal is manufactured, the terminal is attached to the exposed conductor by removing the insulating coating layer at the end of the coated electric wire (such as the coated electric wire 3 of the embodiment) manufactured by the above-mentioned manufacturing method of the coated electric wire. Equipped with a crimping process to attach.

Hereinafter, the continuous casting process, the wire drawing process, and the heat treatment process will be described in detail.
<Continuous casting process>
In this step, a molten metal of a copper alloy having a specific composition containing the above-mentioned Fe, P, Sn in a specific range is continuously cast to produce a cast material. Here, if the atmosphere at the time of dissolution is a vacuum atmosphere, oxidation of Fe, P, Sn and the like can be prevented. On the other hand, if the atmosphere at the time of melting is the atmosphere atmosphere, the atmosphere control is unnecessary and the productivity can be improved. In this case, it is preferable to use the above-mentioned C, Mn, Si (deoxidizer element) in order to prevent the above-mentioned element from being oxidized by oxygen in the atmosphere.

Examples of the method for adding C (carbon) include covering the surface of the molten metal with charcoal pieces, charcoal powder, or the like. In this case, C can be supplied into the molten metal from charcoal pieces or charcoal powder near the surface of the molten metal.
For Mn and Si, a raw material containing them may be prepared separately and mixed in the molten metal. In this case, even if a portion exposed from a gap formed by charcoal pieces or charcoal powder on the surface of the molten metal comes into contact with oxygen in the atmosphere, oxidation in the vicinity of the surface of the molten metal can be suppressed. Examples of the raw material include simple substances of Mn and Si, alloys of Mn and Si and Fe, and the like.

In addition to the above-mentioned addition of the deoxidizing agent element, it is preferable to use a crucible or a mold made of high-purity carbon having few impurities because impurities are less likely to be mixed in the molten metal.

Here, in the copper alloy wire 1 of the embodiment, Fe and P are typically present as precipitates, and Sn is present as a solid solution. Therefore, it is preferable to include a process of forming a supersaturated solid solution in the manufacturing process of the copper alloy wire 1. For example, a solution step for performing the solution process can be separately provided. In this case, a supersaturated solid solution can be formed at any time. On the other hand, if a supersaturated solid solution casting material is produced by increasing the cooling rate in the case of continuous casting, the coated electric wire is finally excellent in electrical and mechanical properties without a separate solution step. A copper alloy wire 1 suitable for a conductor such as 3 can be manufactured. Therefore, as a method for manufacturing the copper alloy wire 1, it is proposed to perform continuous casting, particularly to increase the cooling rate in the cooling process and quench the copper alloy wire 1.

As the continuous casting method, various methods such as a belt-and-wheel method, a double belt method, and an upcast method can be used. In particular, the upcast method is preferable because it can reduce impurities such as oxygen and easily prevent oxidation of Cu, Fe, P, Sn and the like. The cooling rate in the cooling process is preferably more than 5 ° C./sec, more preferably more than 10 ° C./sec, and more preferably 15 ° C./sec or more.

The cast material can be subjected to various plastic working, cutting and other processing. Examples of plastic working include conform extrusion and rolling (hot, warm, cold) and the like. The cutting process includes peeling and the like. By performing these processes, surface defects of the cast material can be reduced, disconnection and the like can be reduced during wire drawing, and productivity can be improved. In particular, it is difficult for the upcast material to break if these processes are applied.

<Wire drawing process>
In this step, the cast material, the processed material obtained by processing the cast material, and the like are subjected to wire drawing (cold) of at least one pass, typically a plurality of passes, to obtain a predetermined final wire diameter. Make a wire wire. When performing a plurality of passes, the degree of processing for each pass may be appropriately adjusted according to the composition, the final wire diameter, and the like. When intermediate heat treatment is performed before wire drawing, or when a plurality of passes are performed, intermediate heat treatment can be performed between the passes to improve workability. The conditions of this intermediate heat treatment can be appropriately selected so as to obtain desired processability.

<Heat treatment process>
In this step, as described above, aging / softening treatment for the purpose of artificial aging and softening is performed. By this aging / softening treatment, the effect of improving the strength by strengthening the precipitation of the above-mentioned precipitates and the effect of maintaining high conductivity by reducing the solid solubility in Cu can be satisfactorily achieved, and copper having excellent conductivity and strength can be satisfactorily achieved. The alloy wire 1 and the copper alloy stranded wire 10 can be obtained. Further, by the aging / softening treatment, toughness such as elongation can be improved while maintaining high strength, and a copper alloy wire 1 or a copper alloy stranded wire 10 having excellent toughness can be obtained.

The conditions for the aging / softening treatment include, for example, the following in the case of batch processing.
(Heat treatment temperature) 350 ° C. or higher and 550 ° C. or lower, preferably 400 ° C. or higher and 500 ° C. or lower (retention time) 1 hour or longer and 40 hours or lower, preferably 3 hours or longer and 20 hours or lower, depending on the composition, processing state, etc. It is good to select. As a specific example, it is advisable to refer to Test Examples 1 and 2 described later. In addition, continuous processing such as a furnace type or an energization type may be used.

When the heat treatment temperature is high in the above range in the case of the same composition, the conductivity, the elongation at break, the impact resistance energy in the terminal mounted state, and the impact resistance energy of the main line tend to be improved. When the heat treatment temperature is low, the growth of crystal grains can be suppressed and the tensile strength tends to be improved. When the above-mentioned precipitates are sufficiently precipitated, the strength tends to be high and the conductivity tends to be improved.

In addition, the aging treatment can be mainly performed during the wire drawing, and the final stranded wire can be mainly softened. The aging treatment conditions and the softening treatment conditions may be selected from the above-mentioned aging / softening treatment conditions.

[Test Example 1]
Copper alloy wires having various compositions and coated electric wires using the obtained copper alloy wires as conductors were manufactured under various manufacturing conditions, and their characteristics were investigated.

The copper alloy wire was manufactured according to any of the manufacturing patterns (A) to (C) shown in Table 1 (final wire diameter φ0.35 mm or φ0.16 mm). The covered electric wire was manufactured according to any of the manufacturing patterns (a) to (c) shown in Table 1.

The following cast materials were prepared for each production pattern.
(Casting material)
An electrolytic copper (purity of 99.99% or more) and a mother alloy containing each element shown in Table 2 or a simple substance of the element were prepared as raw materials. The prepared raw material was melted in the atmosphere using a crucible made of high-purity carbon (with an impurity content of 20 mass ppm or less) to prepare a molten copper alloy. The composition of the copper alloy (remaining Cu and impurities) is shown in Table 2.

Using the above-mentioned molten copper alloy and a high-purity carbon mold (impurity amount is 20 mass ppm or less), a continuous cast material with a circular cross section (wire diameter φ12.5 mm or φ9.5 mm) is used by the upcast method. Was produced. The cooling rate was over 10 ° C./sec.

In the manufacturing patterns (a) to (c), a wire drawing material having a wire diameter of φ0.16 mm is produced in the same manner as in the steps shown in the copper alloy wire manufacturing patterns (A) to (C), and seven wire drawing materials are formed. After twisting, compression molding was performed to prepare a compression stranded wire having a cross-sectional area of 0.13 mm ² (0.13 sq), and heat treatment (aging / softening treatment) was performed under the conditions shown in Table 2. Polyvinyl chloride (PVC) or polypropylene (PP) is extruded to a predetermined thickness (selected from 0.1 mm to 0.3 mm) on the outer periphery of the obtained heat-treated material to form an insulating coating layer, and the heat-treated material is used as a conductor. A covered electric wire was manufactured.

(Measurement of characteristics)
For the copper alloy wire (φ0.35 mm or φ0.16 mm) manufactured according to the manufacturing patterns (A) to (C), the tensile strength (MPa), elongation at break (%), conductivity (% IACS), and work hardening index are calculated. Examined. The results are shown in Table 3.

Conductivity (% IACS) was measured by the bridge method. Tensile strength (MPa), elongation at break (%), and work hardening index were measured using a general-purpose tensile tester in accordance with JIS Z 2241 (Metallic Material Tensile Test Method, 1998).

For the coated electric wire (conductor cross-sectional area 0.13 mm ² ) manufactured according to the manufacturing patterns (a) to (c), the terminal fixing force (N), the impact resistance energy (J / m, terminal mounting impact resistance) when the conductor is mounted. E), the impact resistance energy (J / m, impact resistance E) of the conductor was investigated. The results are shown in Table 3.

The terminal fixing force (N) is measured as follows. The insulating coating layer is peeled off at one end of the coated electric wire to expose the compressed stranded wire which is a conductor, and a terminal is attached to one end of the compressed stranded wire. Here, a commercially available crimp terminal is used as the terminal to crimp the compression stranded wire. Further, here, as shown in FIG. 3, the cross-sectional area of the terminal mounting portion 12 in the conductor (compressed stranded wire) is the value shown in Table 3 (residual conductor) with respect to the cross-sectional area of the main line portion other than the terminal mounting portion. The mounting height (crimp height C / H) was adjusted so that the rate was 70% or 80%).
Using a general-purpose tensile tester, the maximum load (N) at which the terminal did not come off when the terminal was pulled at 100 mm / min was measured. This maximum load is defined as the terminal fixing force.

The impact resistance energy (J / m or (N / m) / m) of the conductor is measured as follows. A weight is attached to the tip of the heat-treated material (conductor of compressed stranded wire) before extrusion of the insulating material, and the weight is lifted 1 m upward and then freely dropped. The weight (kg) of the maximum weight at which the conductor does not break is measured, and the product value of the gravitational acceleration (9.8 m / s ² ) and the fall distance divided by the fall distance ((weight weight x 9.). Let 8 × 1) / 1) be the impact resistance energy of the conductor.

The impact resistance energy (J / m or (N / m) / m) of the conductor with the terminal attached is measured as follows. Here, for the heat-treated material (conductor of compressed stranded wire) before extrusion of the insulating material, the sample S in which the terminal 5 (here, the crimp terminal) is attached to one end of the conductor 10 in the same manner as the above-mentioned measurement of the terminal fixing force. (Here, the length is 1 m) is prepared, and the terminal 5 is fixed by the jig J as shown in FIG. A weight W is attached to the other end of the sample S, the weight W is lifted to the fixed position of the terminal 5, and then the weight W is freely dropped. Similar to the impact resistance energy of the conductor described above, the weight of the maximum weight W at which the conductor 10 does not break is measured, and ((weight weight × 9.8 × 1) / 1) is used as the impact resistance energy in the terminal mounted state. ..

As shown in Table 3, the sample No. 1-1 to No. Sample Nos. 1-8 are all No. From 1-101 to No. It can be seen that the conductivity, strength, and impact resistance are superior to those of 1-104. Furthermore, the sample No. 1-1 to No. All of 1-8 are also excellent in impact resistance when the terminals are attached. Quantitatively, it is as follows.
Sample No. 1-1 to No. In each of 1-8, the tensile strength is 400 MPa or more, further 415 MPa or more, and there are many samples of 420 MPa or more.
Sample No. 1-1 to No. In each of 1-8, the conductivity is 60% IACS or more, 62% IACS or more, and there are many samples of 65% IACS or more and 68% IACS or more.
Sample No. 1-1 to No. In each of 1-8, the impact resistance energy of the conductor is 4 J / m or more, 4.5 J / m or more, and there are many samples of 5 J / m or more, and 6 J / m or more.
Sample No. 1-1 to No. In each of 1-8, the impact resistance energy of the conductor with the terminal attached is 1.5 J / m or more, 1.7 J / m or more, 2.5 J / m or more, and 3 J / m or more. many. Sample No. equipped with such a conductor. 1-1 to No. The 1-8 covered electric wire is expected to have higher impact resistance energy and impact resistance energy when the terminal is attached (see Test Example 2).

Furthermore, the sample No. 1-1 to No. It can be seen that all of 1-8 have high breaking elongation, high strength, high toughness, and high conductivity in a well-balanced manner. Quantitatively, the elongation at break is 5% or more, more than 7%, 8% or more, and there are many samples of 10% or more. In addition, sample No. 1-1 to No. It can be seen that in each of 1-8, the terminal fixing force is as large as 45 N or more, 50 N or more, and 55 N or more, and the terminals can be firmly fixed. Furthermore, the sample No. 1-1 to No. In each of 1-8, the work hardening index is as large as 0.1 or more, and most of the samples are 0.12 or more, further 0.13 or more, and it can be seen that the effect of improving the strength by work hardening can be easily obtained.

One of the reasons for obtaining the above results is that it is composed of a copper alloy having a specific composition in which Fe, P, Sn are contained in the above-mentioned specific range and the mass ratio of Fe / P is 4.0 or more. By equipping the conductor with the copper alloy wire to be formed, the effect of improving the strength by strengthening the precipitation of Fe and P and strengthening the solid solution of Sn, and the high conductivity of Cu by reducing the solid solution of P etc. based on the appropriate precipitation of Fe and P. It is considered that this is because the maintenance effect of the rate was obtained well. Here, by appropriately containing C, Mn, and Si, these elements function as antioxidants to prevent the oxidation of Fe, P, and Sn, so that Fe and P can be appropriately precipitated and Sn is appropriately used. It is probable that it was able to dissolve in solid. Further, it is considered that the decrease in conductivity due to the inclusion of C, Mn, and Si could be suppressed. In this test, the content of C is 100 mass ppm or less, the total content of Mn and Si is 20 mass ppm or less, and the total content of these three elements is 150 mass ppm or less, especially 120 mass ppm or less. Therefore, it is considered that the above-mentioned antioxidant effect and effect of suppressing the decrease in conductivity were appropriately obtained. Further, it is considered that the impact resistance is also excellent because the strength is high, the elongation at break is high, the toughness is excellent, and the fracture is difficult even when an impact is applied. It is considered that the terminal mounting points on the conductor are also excellent in impact resistance in the terminal mounting state because the effect of improving the strength due to work hardening accompanying the compression process is satisfactorily obtained.

In addition, one of the reasons why the terminal fixing force is high is considered to be that the work hardening index is large and the strength improving effect by work hardening is obtained. For example, the sample No. which has a different work hardening index and the same terminal mounting conditions (conductor residual ratio). 1-1, No. Compare 1-101. Sample No. 1-1 is the sample No. Although the tensile strength is lower than that of 1-101, the terminal fixing force is about the same, and the impact resistance energy when the terminal is attached is significantly large. Sample No. In 1-1, it is considered that the small tensile strength was compensated by work hardening. Focusing on the tensile strength and the terminal fixing force in this test, it can be said that there is a correlation that the larger the tensile strength, the larger the terminal fixing force.

From this test, the copper alloy having a specific composition containing Fe, P, and Sn described above is subjected to plastic processing such as wire drawing and heat treatment such as aging and softening to provide conductivity and strength as described above. It was shown that copper alloy wires and copper alloy stranded wires, which are excellent in impact resistance as well as excellent in impact resistance, and coated electric wires and electric wires with terminals using these as conductors can be obtained. Further, it can be seen that even if the composition is the same, the tensile strength, conductivity, impact resistance energy, etc. can be made different by adjusting the heat treatment temperature (for example, Samples No. 1-2 and No. 1-3). Comparison of Samples No. 1-4 and No. 1-5, Comparison of Samples No. 1-7 and No. 1-8). When the heat treatment temperature is increased, the conductivity and the impact resistance energy of the conductor tend to be high. In addition, the higher the Sn content, the higher the tensile strength tends to be (for example, compare Samples No. 1-8, No. 1-4, No. 1-2).

[Test Example 2]
In the same manner as in Test Example 1, copper alloy wires having various compositions and coated electric wires using the obtained copper alloy wires as conductors were manufactured under various manufacturing conditions, and their characteristics were investigated.

In this test, a copper alloy wire (heat-treated material) having a wire diameter of 0.16 mm was produced according to the production pattern (B) of Test Example 1. The heat treatment conditions are shown in Table 4. Further, in the same manner as in Test Example 1, the conductivity (% IACS), tensile strength (MPa), breaking elongation (%), and work hardening index of the obtained copper alloy wire (0.16 mm) were examined. The results are shown in Table 4.

According to the production pattern (b) of Test Example 1, a wire drawing material having a wire diameter of 0.16 mm is produced, seven wire drawing materials are twisted together, and then compression molding is performed to produce a compression twisted wire having a cross-sectional area of 0.13 mm ² . Then, the heat treatment was performed under the conditions shown in Table 5. The insulating material (PVC or PP) shown in Table 5 is extruded to the thickness (0.20 mm or 0.23 mm) shown in Table 5 on the outer periphery of the obtained heat-treated material to form an insulating coating layer, and the heat-treated material is used as a conductor. A covered electric wire was manufactured.

With respect to the obtained heat-treated material (conductor of compressed wire material), the breaking load (N), breaking elongation (%), and electric resistance per 1 m (mΩ / m) were examined. In addition, the breaking load (N), breaking elongation (%), and impact resistance energy (J / m) of the main line were examined for the obtained coated electric wire. The results are shown in Table 5.

The breaking load (N) and breaking elongation (%) were measured using a general-purpose tensile tester in accordance with JIS Z 2241 (Metallic Material Tensile Test Method, 1998). For the electrical resistance, the resistance value at a length of 1 m was measured using a resistance measuring device of a 4-terminal method according to JASO D 618. The impact resistance energy of the main line was measured in the same manner as in Test Example 1 with the coated electric wire as the test target.

The impact resistance energy (J / m) of the obtained covered electric wire was measured in the state where the terminal was attached. The results are shown in Table 6. In this test, the insulating coating layer was peeled off at one end of the coated electric wire to expose the compressed stranded wire as a conductor, and a crimp terminal was attached to one end of the compressed stranded wire, and the measurement was performed in the same manner as in Test Example 1. As the crimp terminal, it is a crimp terminal formed by press-molding a metal plate (made of copper alloy) into a predetermined shape, and is a fitting portion 52, a wire barrel portion 50, and an insulation barrel portion 54 (over) as shown in FIG. I prepared the one equipped with the wrap type). Here, the thickness of the metal plate is the thickness (mm) shown in Table 6, and various types having the plating type (tin (Sn) or gold (Au)) shown in Table 6 applied to the surface thereof are prepared. Then, the mounting height (C / H (mm)) of the wire barrel portion 50 and the mounting height (V / H (mm)) of the insulation barrel portion 54 are as shown in Table 6. A crimp terminal was attached to the conductor of the covered wire.

As shown in Tables 4 and 5, the sample No. 2-11 ~ No. Sample Nos. 2-14 have the same wire diameter or the same conductor cross section. It can be seen that, as compared with 2-101, it has a good balance of conductivity, strength, and impact resistance. Further, as shown in Table 6, the sample No. 2-11 ~ No. Both 2-14 have excellent impact resistance when the terminals are attached. Quantitatively, it is as follows.
Sample No. 2-11 ~ No. Both 2-14 have a tensile strength of 400 MPa or more and further 450 MPa or more (Table 4).
Sample No. 2-11 ~ No. In each of 2-14, the conductivity is 60% IACS or more, and further 62% IACS or more (Table 4).
Sample No. 2-11 ~ No. In each of 2-14, the impact resistance energy is 9 J / m or more, and further 10 J / m or more (Table 5).
Sample No. 2-11 ~ No. In each of 2-14, the impact resistance energy when the terminal is attached is 3 J / m or more, 3.5 J / m or more, 3.8 J / m or more, and many samples are 4 J / m or more (Table 6). ..
In this test, even if the C / H and V / H are the same, it can be said that the impact resistance energy in the terminal mounted state may be further enhanced by differentizing the plating type, coating type, coating thickness, etc. of the terminal. (For example, compare condition No. 2 and condition No. 3 in Table 6). Further, in this test, even if the same crimp terminal is used, it can be said that the impact resistance energy in the terminal mounted state tends to be further enhanced by making the V / H different (here, the V / H is increased). (For example, refer to conditions No. 2, No. 4, No. 7 to No. 10 in Table 6 for comparison).

Further, as shown in Table 4, the sample No. 2-11 ~ No. It can be seen that each of 2-14 has a breaking elongation of 5% or more and further 10% or more, and has high strength, high toughness, and high conductivity in a well-balanced manner as in Test Example 1. Further, as shown in Table 5, it can be said that the compression stranded wire has a higher tensile strength (breaking load / cross-sectional area) than the single wire, and the coated electric wire provided with the insulating coating layer can improve the tensile strength as compared with the compression stranded wire. .. It can be said that the breaking elongation of a single wire can be substantially maintained even if it becomes a compression stranded wire (see Table 4), and that the coated electric wire provided with an insulating coating layer can improve the breaking elongation as compared with the compression stranded wire. It can be said that the coated electric wire provided with the insulating coating layer tends to have higher impact resistance energy and impact resistance energy in the terminal-mounted state than in the case of only the conductor shown in Test Example 1.
In addition, sample No. 2-11 ~ No. Both 2-14 have a work hardening index of 0.1 or more, and further have a work hardening index of 0.12 or more. Such sample No. 2-11 ~ No. Both 2-14 are considered to have excellent terminal stickiness.

One of the reasons for obtaining the above results is that, as in Test Example 1, Fe and P are provided with a copper alloy wire composed of a copper alloy having a specific composition including Fe, P, Sn in the conductor. It is considered that this is because the effect of improving the strength by strengthening the precipitation and strengthening the solid solution of Sn and the effect of maintaining the high conductivity of Cu by reducing the solid solution of P and the like were obtained satisfactorily. In particular, as in Test Example 1, the proper inclusion of C, Mn, and Si provided the antioxidant effect of Fe, P, and Sn, and the inclusion of the deoxidizing agent element such as C provided the effect of suppressing the decrease in conductivity. it is conceivable that. Further, it is considered that the strength is high and the toughness is excellent, and the impact resistance and the impact resistance when the terminal is attached are also excellent.

The present invention is not limited to these examples, and is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.
For example, the composition of the copper alloys of Test Examples 1 and 2, the wire diameter of the copper alloy wire, the number of twisted wires, the heat treatment conditions, and the like can be appropriately changed.

1 Copper alloy wire 10 Copper alloy stranded wire (conductor) 3 Coated wire 4 Wire with terminal 12 Terminal mounting location 2 Insulation coating layer 5 Terminal 50 Wire barrel part 52 Fitting part 54 Insulation barrel part S Sample J Jig W weight

Claims (3)

A method for manufacturing a coated electric wire, which comprises a conductor and an insulating coated layer provided on the outside of the conductor.
The process of manufacturing copper alloy wire and
A process of manufacturing a stranded wire to be a conductor by twisting a plurality of the copper alloy wires together.
A step of forming the insulating coating layer on the outer periphery of the stranded wire is provided.
The process of manufacturing the copper alloy wire is
The process of continuously casting molten copper alloy to manufacture cast materials,
A process of manufacturing a wire drawing material having a wire diameter of 0.5 mm or less by wire drawing a processed material obtained by subjecting the cast material to conform extrusion.
The wire drawing material is provided with a step of heat-treating the wire drawing material to manufacture the heat-treated material.
The copper alloy is
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
Fe / P is 4.0 or more by mass ratio ,
The conditions of the heat treatment are
The heat treatment temperature is 400 ° C or higher and 500 ° C or lower.
A method for manufacturing a coated electric wire, which has a holding time of 3 hours or more and 20 hours or less . It is a manufacturing method of copper alloy wire.
The process of continuously casting molten copper alloy to manufacture cast materials,
A process of manufacturing a wire drawing material having a wire diameter of 0.5 mm or less by wire drawing a processed material obtained by subjecting the cast material to conform extrusion.
The wire drawing material is provided with a step of heat-treating the wire drawing material to manufacture the heat-treated material.
The copper alloy is
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
Fe / P is 4.0 or more by mass ratio ,
The conditions of the heat treatment are
The heat treatment temperature is 400 ° C or higher and 500 ° C or lower.
A method for manufacturing a copper alloy wire having a holding time of 3 hours or more and 20 hours or less . It is a manufacturing method of copper alloy stranded wire.
The process of manufacturing copper alloy wire and
It is provided with a process of manufacturing a stranded wire by twisting a plurality of the copper alloy wires.
The process of manufacturing the copper alloy wire is
The process of continuously casting molten copper alloy to manufacture cast materials,
A process of manufacturing a wire drawing material having a wire diameter of 0.5 mm or less by wire drawing a processed material obtained by subjecting the cast material to conform extrusion.
The wire drawing material is provided with a step of heat-treating the wire drawing material to manufacture the heat-treated material.
The copper alloy is
Fe is 0.2% by mass or more and 1.6% by mass or less,
P is 0.05% by mass or more and 0.4% by mass or less,
Containing Sn in an amount of 0.05% by mass or more and 0.7% by mass or less,
The rest consists of Cu and impurities
Fe / P is 4.0 or more by mass ratio ,
The conditions of the heat treatment are
The heat treatment temperature is 400 ° C or higher and 500 ° C or lower.
A method for manufacturing a copper alloy stranded wire having a holding time of 3 hours or more and 20 hours or less .

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