JP2020037745A - Covered electric wire, terminal-equipped electric wire, copper alloy wire, and copper alloy stranded wire - Google Patents

Abstract

To provide a covered electric wire, a terminal-equipped electric wire, a copper alloy wire and a copper alloy stranded wire which are excellent in shock resistance as well as in conductivity and strength.SOLUTION: A covered electric wire comprises a conductor and an insulative covering layer provided on the outside of the conductor. The conductor is made of a copper alloy which contains Fe in an amount of 0.2 or more and 1.6 mass% or less, P in an amount of 0.05 or more and 0.4 mass% or less, and Sn in an amount of 0.05 or more and 0.7 mass% or less, with the balance of Cu and impurities, and with a Fe/P mass ratio being 4.0 or more. The covered electric wire is a stranded wire obtained by twisting together a plurality of copper alloy wires having diameters of 0.5 mm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a covered electric wire, an electric wire with a terminal, a copper alloy wire, and a copper alloy stranded wire.

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

JP 2014-156617 A

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

  2. Description of the Related Art In recent years, various kinds of electric devices and control devices mounted on a vehicle have been increasing with the advancement of high performance and high functionality of a vehicle, and electric wires used for these devices are also increasing. Accordingly, the weight of the electric wire also tends to increase. On the other hand, for the purpose of environmental protection, it is desired to reduce the weight of electric wires for the purpose of improving fuel efficiency of automobiles. The wire made of the copper-based material described above tends to have high conductivity, but tends to be heavy. For example, when 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, a thin wire rod has a small cross-sectional area, and when subjected to an impact, the force of receiving the impact is likely to be small. Therefore, a copper-based wire rod having excellent impact resistance even if it is thin as described above is desired.

  As described above, in an electric wire used in a state in which a terminal such as a crimp terminal is attached, the cross-sectional area of a terminal-attached portion of the conductor to which compression processing has been applied is the other portion (hereinafter, may be referred to as a main line portion). ) Is smaller than the cross-sectional area. For this reason, the terminal attachment portion of the conductor is likely to be a portion that is easily broken when subjected to an impact. Therefore, it is desired that even the thin copper-based wire as described above does not easily break in the vicinity of the terminal mounting portion when subjected to an impact, that is, has excellent impact resistance in the terminal mounted state.

  Further, in the case of electric wires for use in vehicles, it is conceivable that the electric wires may be pulled, bent or twisted, or vibrated during use when arranging or connecting to a connector housing. It is conceivable that an electric wire for a robot or the like may be bent or twisted during use. An electric wire which is hardly broken even by such repeated bending and twisting operations and has excellent fatigue resistance, and an electric wire which is excellent in adhesion to a terminal such as a crimp terminal as described above, are more preferable.

  Therefore, an object is to provide a covered electric wire, an electric wire with a terminal, a copper alloy wire, and a copper alloy stranded wire which are excellent in conductivity and strength and also excellent in impact resistance.

A covered electric wire according to one embodiment of the present invention,
A conductor, a coated electric wire including an insulating coating layer provided outside the conductor,
The conductor is
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
It is a stranded wire formed by twisting a plurality of copper alloy wires having a wire diameter of 0.5 mm or less.

An electric wire with a terminal according to one embodiment of the present invention,
The insulated wire according to the above aspect is provided with a terminal attached to an end of the insulated wire.

Copper alloy wire according to one embodiment of the present invention,
A copper alloy wire used for a conductor,
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
The wire diameter is 0.5 mm or less.

Copper alloy stranded wire according to one embodiment of the present invention,
A plurality of the copper alloy wires according to the above aspect are twisted.

  The above-mentioned covered electric wire, electric wire with terminal, copper alloy wire, and copper alloy stranded wire are excellent not only in conductivity and strength but also in impact resistance.

It is an outline perspective view showing the covered electric wire of an embodiment. It is an outline side view showing the neighborhood of a terminal about an electric wire with a terminal of an embodiment. FIG. 3 is a cross-sectional view of the electric wire with terminal shown in FIG. 2 taken along a cutting line (III)-(III). It is explanatory drawing explaining the measuring method of "the impact energy of the terminal mounting state" measured in the test examples 1 and 2.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
(1) A covered electric wire according to one embodiment of the present invention is:
A conductor, a coated electric wire including an insulating coating layer provided outside the conductor,
The conductor is
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
It is a stranded wire formed by twisting a plurality of copper alloy wires having a wire diameter of 0.5 mm or less.
The above-mentioned stranded wire includes a so-called compression stranded wire, which is formed by simply twisting a plurality of copper alloy wires and compression-formed after twisting. The same applies to the copper alloy twisted wire of (10) described later. A typical twisting method is concentric twisting.
The wire diameter is a diameter when the copper alloy wire is a round wire, and is a diameter of a circle having an equivalent area in a cross section when the cross section is a wire material other than a circle.

Since the above-mentioned covered electric wire is provided with a conductor having a small diameter (copper alloy wire) made of a copper-based material, it is excellent in conductivity and strength and light in weight. Since this copper alloy wire is composed of a copper alloy having a specific composition, the above-described coated electric wire is excellent in conductivity and strength and also excellent in impact resistance, as described below. In the above copper alloy, Fe and P are typically present in the parent phase (Cu) as precipitates or crystallizations containing Fe or P, such as compounds such as Fe ₂ P, and the effect of strengthening the precipitation and Cu And has the effect of maintaining high electrical conductivity by reducing solid solution into the alloy. In particular, since Fe is contained in excess of P, Fe and P easily form a compound without excess or deficiency, and it is possible to effectively prevent the excess P from forming a solid solution in the matrix and lowering the conductivity. . From this point, it is easier to maintain the high conductivity of Cu. In addition, since Sn is contained in a specific range, a further effect of improving the strength by solid solution strengthening of Sn can be obtained. Since it has high strength by the above-described precipitation strengthening and solid solution strengthening, it has high strength, high toughness, and excellent impact resistance even when elongation or the like is increased by heat treatment. Such a covered wire, a copper alloy stranded wire constituting a conductor of the covered wire, and a copper alloy wire as each element of the copper alloy stranded wire are provided with high conductivity, high strength, and high toughness in a well-balanced manner. It can be said that.

  In addition, since the above-mentioned coated electric wire is made of a stranded wire of a high-strength, high-toughness copper alloy wire as a conductor as described above, a conductor (twisted wire) is used as compared with a case where a single wire having the same cross-sectional area is used as a conductor. As a whole, it tends to be superior due to mechanical properties such as flexibility and torsion, and has excellent fatigue resistance. Furthermore, the stranded wire or the copper alloy wire tends to be hardened when subjected to plastic working such as compression working with a reduced cross section. Therefore, when a terminal such as a crimp terminal is fixed, the above-mentioned coated electric wire can firmly fix the terminal by work hardening, and is excellent in adhesion to the terminal. By this work hardening, the strength of the terminal connection portion in the conductor (twisted wire) can be increased. Therefore, it is hard to be broken at the terminal connection part when receiving an impact, and the above-mentioned coated electric wire is also excellent in the impact resistance in the terminal mounted state.

(2) As an example of the above-mentioned covered electric wire,
Examples of the copper alloy include a form in which at least one element selected from C, Si, and Mn is contained in a mass ratio of 10 ppm or more and 500 ppm or less.

  By containing C, Si, and Mn in a specific range, they function as deoxidizing agents such as Fe, P, and Sn, reduce and prevent oxidation of these elements, and provide high conductivity due to the inclusion of these elements. The effect of the property and high strength can be obtained appropriately. In addition, the above-described embodiment 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 embodiment is more excellent in conductivity and strength.

(3) As an example of the above-mentioned covered electric wire,
The copper alloy wire may have an elongation at break of 5% or more.

  In the above embodiment, since the conductor is provided with a copper alloy wire having a high breaking elongation, the conductor is excellent in impact resistance, hardly broken by bending or twisting, and excellent in flexibility and twisting.

(4) As an example of the above-mentioned covered electric wire,
The copper alloy wire may have a conductivity of 60% IACS or more and a tensile strength of 400 MPa or more.

  In the above embodiment, since the conductor is provided with a copper alloy wire having high conductivity and high tensile strength, the conductivity and strength are excellent.

(5) As an example of the above-mentioned covered electric wire,
An embodiment in which the terminal fixing force is 45 N or more is given.
The method for measuring the terminal fixing force, the (6), (11) impact energy when the terminal is attached, and the (7), (12) impact energy measurement methods described later will be described later (see Test Examples 1 and 2).

  In the above-described embodiment, when a terminal such as a crimp terminal is attached, the terminal can be firmly fixed, and the fixing property with the terminal is excellent. Therefore, the above-described embodiment is excellent in conductivity, strength, and impact resistance, and also has excellent terminal fixing properties, and can be suitably used for the above-described electric wire with terminal.

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

  In the above embodiment, the impact energy is high when the terminal such as the crimped terminal is crimped and the terminal is in a state where the terminal is crimped. Therefore, the above-described embodiment is excellent in conductivity, strength, and impact resistance, and also excellent in impact resistance in a terminal mounted state, and can be suitably used for the above-described electric wire with terminal.

(7) As an example of the above-mentioned covered electric wire,
A form in which the impact energy of only the covered electric wire is 6 J / m or more is exemplified.

  In the above embodiment, the coated wire itself has high impact energy, is hardly broken even when subjected to an impact, and is excellent in impact resistance.

(8) The electric wire with terminal according to one embodiment of the present invention,
The insulated wire according to any one of the above (1) to (7), and a terminal attached to an end of the insulated wire.

  Since the above-mentioned electric wire with a terminal is provided with the above-mentioned covered electric wire, it is excellent not only in conductivity and strength as described above, but also in impact resistance. In addition, since the above-mentioned electric wire with terminal is provided with the above-mentioned covered electric wire, as described above, it is also excellent in fatigue resistance, adhesion to a terminal such as a crimp terminal, and impact resistance in a terminal mounted state.

(9) The copper alloy wire according to one embodiment of the present invention includes:
A copper alloy wire used for a conductor,
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
The wire diameter is 0.5 mm or less.

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

(10) The copper alloy stranded wire according to one embodiment of the present invention includes:
A plurality of the copper alloy wires described in the above (9) are twisted.

  The above-described 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 and also excellent in impact resistance. Therefore, by using the above copper alloy stranded wire as a conductor of the wire, the wire is excellent in conductivity and strength and also excellent in impact resistance, furthermore, fatigue resistance, adhesion to terminals such as crimp terminals, It is possible to construct an electric wire that is also excellent in impact resistance when terminals are installed.

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

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

(12) As an example of the above copper alloy stranded wire,
A form in which the impact energy of only the copper alloy stranded wire is 4 J / m or more is exemplified.

  In the above embodiment, the impact energy of the copper alloy stranded wire itself is high. By using the copper alloy stranded wire of the above-described embodiment as a conductor and a coated electric wire having an insulating coating layer, it is possible to construct a coated electric wire having higher impact energy, typically, the above-described coated electric wire (7). Therefore, the above-mentioned embodiment can be suitably used for a conductor such as a covered electric wire or a terminal-attached electric wire which is excellent in conductivity and strength and also excellent in impact resistance.

[Details of Embodiment of the Present Invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings, the same reference numerals indicate the same names. The content of the element is defined as a mass ratio (% by mass or ppm by mass) 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 covered electric wire 3 (FIG. 1), and is made of a copper alloy containing a specific additive element in a specific range. The copper alloy contains 0.2% or more and 1.6% or less of Fe, 0.05% or more and 0.4% or less of P, and 0.05% or more and 0.7% or less of Sn. It is an Fe-P-Sn-Cu alloy composed of impurities. In particular, in the copper alloy, the ratio Fe / P of the content of Fe to the content of P is 4.0 or more in terms of mass ratio. The above impurities are mainly unavoidable. Hereinafter, each element will be described in detail.

・ Fe
Fe is present mainly as a precipitate in Cu, which is a parent phase, and contributes to improvement in strength such as tensile strength.
When Fe is contained in an amount of 0.2% or more, a precipitate containing Fe and P can be favorably formed, and the copper alloy wire 1 having excellent strength by precipitation strengthening can be obtained. Moreover, the solid solution of P into the mother phase is suppressed by the above-mentioned precipitation, and the copper alloy wire 1 having high conductivity can be obtained. Although depending on the amount of P and the manufacturing conditions, the strength of the copper alloy wire 1 tends to increase as the Fe content increases. If higher strength is desired, the Fe content can be made more than 0.35%, further 0.4% or more, and 0.45% or more.
When Fe is contained in a range of 1.6% or less, it is easy to suppress coarsening of precipitates containing Fe and the like. As a result, fractures originating from coarse precipitates can be reduced, and the strength is excellent. In addition, in the manufacturing process, the wire is hardly broken at the time of wire drawing, and the productivity is excellent. Although it depends on the amount of P and the manufacturing conditions, the smaller the Fe content, the easier it is to suppress the above-mentioned coarsening of precipitates. When the suppression of coarsening of precipitates (reduction of breakage and disconnection) is desired, the content of Fe is 1.5% or less, further 1.2% or less, 1.0% or less, and less than 0.9%. It can be.

・ P
In the copper alloy wire 1, P mainly exists as a precipitate together with Fe and contributes to improvement in 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, a precipitate containing Fe and P can be favorably formed, and the copper alloy wire 1 having excellent strength by precipitation strengthening can be obtained. The strength of the copper alloy wire 1 tends to increase as the content of P increases, depending on the amount of Fe and the manufacturing conditions. If higher strength is desired, the content of P can be set to more than 0.1%, further 0.11% or more, 0.12% or more. In addition, a part of the contained P functions as a deoxidizing agent, and permits to exist in the parent phase as an oxide.
When P is contained in a 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 depending on the amount of Fe and the production conditions, the smaller the P content, the easier it is to suppress the above coarsening. In the case where suppression of coarsening of precipitates (reduction of breakage and disconnection) is desired, the P content can be made 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 ranges, if Fe is appropriately contained in P, particularly if Fe is equivalent to or more than P, Fe and P are present as compounds. easy. As a result, the effect of improving the strength by precipitation strengthening can be appropriately obtained, and the effect of maintaining a high conductivity of the mother phase by reducing the solid solution of excess P can be appropriately achieved. The copper alloy wire 1 can be used.
When Fe / P is 4.0 or more, it has excellent conductivity and high strength as described above. The larger the Fe / P, the better the conductivity tends to be, and the Fe / P can be more than 4.0, and more preferably 4.1 or more. Fe / P can be selected, for example, in the range of 30 or less, but if it is 20 or less, and more preferably 10 or less, coarsening of precipitates due to excessive Fe is easily suppressed.

・ Sn
Sn mainly exists as a solid solution in Cu, which is a parent phase, and contributes to improvement in strength such as tensile strength, that is, mainly functions as a solid solution strengthening element.
When the content of Sn is 0.05% or more, the copper alloy wire 1 having more excellent strength can be obtained. As the Sn content increases, the strength tends to increase. If higher 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 a range of 0.7% or less, a decrease in conductivity due to excessive solid solution of Sn in Cu can be suppressed, and the copper alloy wire 1 having high conductivity can be obtained. In addition, a decrease in workability due to excessive solid solution of Sn is suppressed, plastic working such as wire drawing is easily performed, and the productivity is excellent. When high conductivity and good workability are desired, the Sn content can be set to 0.6% or less, further 0.55% or less, and 0.5% or less.

  The copper alloy wire 1 of the embodiment has high strength due to precipitation strengthening of Fe and P and solid solution strengthening 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 elongation, etc., and having high strength and high toughness can be obtained.

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

  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 or the like cannot be appropriately formed, or cannot be dissolved in the matrix, and the high conductivity and high strength due to the inclusion of Fe and P, and the inclusion of Sn There is a possibility that the effect of solid solution strengthening due to the above may not be obtained properly. These oxides may serve as starting points of breakage during wire drawing or the like, which may cause a decrease in productivity. At least one element of C, Mn, and Si, preferably two elements (in this case, preferably C and Mn or C and Si), more preferably all three elements in a specific range. Thus, precipitation strengthening by precipitation of Fe and P and securing of high conductivity and solid solution strengthening of Sn can be more reliably achieved, and the copper alloy wire 1 having excellent conductivity and high strength can be obtained.

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 more easily the antioxidant effect can be obtained, and the content can be set to 20 ppm or more, and more preferably 30 ppm or more.
When the above total content is 500 ppm or less, a decrease in conductivity due to an excessive content of these deoxidizing elements hardly occurs, and the conductivity is excellent. The lower the total content is, the easier it is to suppress the decrease in conductivity, and thus the content can be 300 ppm or less, further 200 ppm or less, or 150 ppm or less.

The content of only C is preferably from 10 ppm to 300 ppm, more preferably from 10 ppm to 200 ppm, particularly preferably from 30 ppm to 150 ppm.
The content of only Mn or the content of only Si 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, more preferably more than 10 ppm and 100 ppm or less.
When each of C, Mn, and Si is contained in the above-mentioned range, the effect of preventing the above-mentioned elements such as Fe from being oxidized easily can be easily obtained. For example, the content of oxygen 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 crystallized substances containing Fe and P are dispersed. By having a dispersed structure such as precipitates, preferably a structure in which fine precipitates are uniformly dispersed, it is expected to increase strength by precipitation strengthening and to secure high conductivity by reducing solid solution of Cu such as P. it can.

  Furthermore, a fine crystal structure is mentioned as a structure of the copper alloy. In this case, the above-mentioned precipitates and the like are likely to be uniformly dispersed and exist, and further higher strength can be expected. In addition, since there are few coarse crystal grains which can be a starting point of fracture and it is difficult to fracture, it is likely that toughness such as elongation is easily increased and it is expected to be more excellent in impact resistance. Furthermore, in this case, when the copper alloy wire 1 of the embodiment is used as a conductor of an electric wire such as the covered electric wire 3 and a terminal such as a crimp terminal is attached to the 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-described effect is easily obtained, and the average crystal grain size can be 7 μm or less, and further 5 μm or less. The crystal grain size can be adjusted, for example, by adjusting the production conditions (such as workability and heat treatment temperature, etc.) according to the composition (Fe, P, Sn content, Fe / P value, etc.). It can be of 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, taking the observation range of a predetermined area S _0, examine all crystalline number N present in the observation area. The area (S ₀ / N) obtained by dividing the area S ₀ by the number N of crystals is defined as the area Sg of each crystal grain, and the diameter of a 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 can be the range where the number n of crystals is 50 or more, or the entire cross section. Thus the observation range that sufficiently large, can be sufficiently reduced errors due to something other than crystals which may be present in the area S ₀ (like precipitates).

(Wire diameter)
The copper alloy wire 1 of the embodiment can have a predetermined wire diameter by adjusting the degree of work (cross-section reduction rate) during 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 whose weight is desired to be reduced, for example, a conductor for an electric wire wired in an automobile. The wire diameter can be 0.35 mm or less, and further 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 a die used for wire drawing, or the shape of a forming die when the copper alloy wire 1 is a compression twisted wire. The copper alloy wire 1 can be, for example, a square wire having a rectangular cross-section such as a rectangle, a polygonal wire such as a hexagon, or an irregular wire such as an elliptical wire. The copper alloy wire 1 constituting the compression stranded wire is typically a deformed wire whose cross-sectional shape is irregular.

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

When higher strength is desired, the tensile strength can be set to 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 greater than or equal to 62% IACS, greater than or equal to 63% IACS, and even greater than or equal to 65% IACS.

-Work hardening index As an example of the copper alloy wire 1 of the embodiment, there is a copper alloy wire having a work hardening index of 0.1 or more.
The work hardening coefficient, the formula σ = C × ε ⁿ of the true stress sigma of the plastic strain region when the test force is applied to the uniaxial direction of the tensile tests and true strain epsilon, defined as an index n of true strain epsilon Is done. In the above equation, C is an intensity constant.
The above-mentioned index n can be obtained by conducting 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 is, the easier the work hardening is, and in the processed portion, the effect of improving the strength by the work hardening can be obtained. For example, when a copper alloy wire 1 is used for a conductor of an electric wire such as a covered electric wire 3 and a terminal such as a crimp terminal is attached to the conductor by crimping or the like, the terminal mounting portion of the conductor is subjected to plastic working such as compression working. It becomes the processed part. Although this processed portion has been subjected to plastic working such as compression working with a reduction in cross section, it is harder than before the plastic working and has increased strength. Therefore, it is possible to reduce the strength of the processed portion, that is, the terminal mounting portion of the conductor and its vicinity, which is a weak point. When the work hardening index is 0.11 or more, further 0.12 or more, 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 portion of the conductor will maintain the same strength as the main line portion of the conductor. Since the work hardening index varies depending on the composition and manufacturing conditions, the upper limit is not particularly defined.

  The tensile strength, elongation at break, electrical conductivity, and work hardening index can be set to predetermined values by adjusting the composition and manufacturing conditions. For example, when Fe, P, and Sn are increased or the degree of wire drawing is increased (narrowed), the tensile strength tends to increase. For example, when the heat treatment temperature is increased in the case of performing the heat treatment after drawing, 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 to take a branch from the conductor, the welding portion is hardly broken, and the welding strength is reduced. Is high.

[Copper alloy stranded wire]
The stranded copper alloy wire 10 of the embodiment uses the copper alloy wire 1 of the embodiment as a strand, and is formed by twisting a plurality of copper alloy wires 1. The copper alloy stranded wire 10 substantially maintains the composition, structure, and characteristics of the copper alloy wire 1 which is a strand, and the cross-sectional area of the copper alloy strand 1 is likely to be larger than that of a single strand of copper. The force which can be received sometimes can be increased, and it is superior in impact resistance. In addition, the copper alloy stranded wire 10 is easier to bend or twist, and is superior in bendability and twistability as compared with a single wire having the same cross-sectional area. It is hard to be broken by repeated bending. Furthermore, as described above, the copper alloy stranded wire 10 includes a plurality of copper alloy wires 1 that are easily work-hardened, and thus the copper alloy stranded wire 10 is used as a conductor of an electric wire such as the covered electric wire 3. When a terminal such as a crimp terminal is attached, the terminal can be more firmly fixed. In FIG. 1, seven concentric twisted copper alloy strands 10 are illustrated, but the number of twists and the twisting method can be changed as appropriate.

  The copper alloy twisted wire 10 can be a compression twisted wire (not shown) that is compression-molded after twisting. Since the compression stranded wire is excellent in the stability of the twisted state, when the compression stranded wire is used as a conductor of an electric wire such as the coated electric wire 3, the insulating coating layer 2 and the like are easily formed on the outer periphery of the conductor. In addition, the compression twisted wire tends to have better mechanical properties than a simple twisted wire, and can have a smaller diameter.

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 twists, and the like of the copper alloy wire 1.
If 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. In addition, when the copper alloy stranded wire 10 is used as a conductor of an electric wire such as the covered electric wire 3 and a terminal such as a crimp terminal is attached to the 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 stranded copper alloy wire 10, and the shock resistance when the terminal is mounted is 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 twisted wire 10 is, for example, 10 mm or more, even if the strand (copper alloy wire 1) is a thin wire of 0.5 mm or less, it is easy to twist, and the productivity of the copper alloy twisted wire 10 is reduced. Excellent. When the twist pitch is, for example, 20 mm or less, the twist is not loosened even when bending is performed, and the bendability is excellent.

-Impact energy in a terminal mounted state The copper alloy stranded wire 10 of the embodiment is used for a conductor such as a covered electric wire because the copper alloy wire 1 composed of a specific copper alloy is used as a strand as described above. Therefore, when a terminal such as a crimp terminal is attached to the end of the conductor and subjected to an impact, it is difficult to break near the terminal attachment portion. Quantitatively, in the stranded copper alloy wire 10, the impact energy when the terminal is attached (impact energy when the terminal is attached) is 1.5 J / m or more. The greater the impact energy in the terminal mounting state, the more difficult it is to break near the above-mentioned terminal mounting portion when receiving an impact. If such a copper alloy stranded wire 10 is used as a conductor, it is possible to construct a covered electric wire or the like having excellent impact resistance in a terminal mounted state. The impact 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 defined.

-Impact energy Since the copper alloy stranded wire 10 of the embodiment uses the copper alloy wire 1 made of a specific copper alloy as a strand as described above, it is not easily broken when subjected to an impact or the like. Quantitatively, the impact energy of only the copper alloy stranded wire 10 is 4 J / m or more. As the impact energy is larger, the copper alloy stranded wire 10 itself is less likely to break when subjected to an impact. If such a copper alloy stranded wire 10 is used as a conductor, a covered electric wire having excellent impact resistance can be constructed. The impact energy of the stranded copper alloy 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.

  In addition, it is preferable that the single-layer copper alloy wire 1 also has the impact energy or the impact energy in the terminal mounted state satisfying the above range. The stranded copper alloy wire 10 of the embodiment tends to have higher impact energy and impact energy in a terminal mounted state than the single copper alloy wire 1.

[Coated wire]
The copper alloy wire 1 or the stranded copper alloy wire 10 of the embodiment can be used as a conductor as it is, but having an insulating coating layer on the outer periphery is excellent in insulation. The covered electric wire 3 of the embodiment includes a conductor and the insulating coating layer 2 provided outside the conductor, and the conductor is the copper alloy stranded wire 10 of the embodiment. As a covered electric wire of another embodiment, there is one in which the conductor is a copper alloy wire 1 (single wire). FIG. 1 illustrates a case where a conductor is provided with a copper alloy stranded wire 10.

Examples of the insulating material forming the insulating coating layer 2 include polyvinyl chloride (PVC), halogen-free 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 insulating strength, and is not particularly limited.

-Terminal fixing force Since the covered electric wire 3 of the embodiment is provided with the copper alloy stranded wire 10 having the copper alloy wire 1 made of a specific copper alloy as a strand as described above, the terminal such as a crimp terminal is used. The terminal can be firmly fixed in a state of being attached by crimping or the like. Quantitatively, the terminal fixing force is 45 N or more. The larger the terminal fixing force, the more firmly the terminal can be fixed, and the easier it is to maintain the connection state between the coated electric wire 3 (conductor) and the terminal, which is preferable. The terminal fixing force is preferably 50 N or more, more than 55 N, and more preferably 58 N or more, and the upper limit is not particularly defined.

-Impact energy in the mounted state of the terminal The impact energy in the terminal mounted state of the insulated wire 3 and the impact energy in the insulated wire 3 of the embodiment are the bare conductors not provided with the insulating coating layer 2, that is, of the embodiment. It tends to be higher than that of the copper alloy twisted wire 10. Depending on the constituent material and thickness of the insulating coating layer 2, the impact energy of the coated electric wire 3 in the terminal mounted state and the impact energy of only the coated electric wire 3 may be further increased as compared with the bare conductor. is there. Quantitatively, the impact 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 insulated wire 3 in the terminal mounting state is, the larger the impact energy is, the harder it is to break near the terminal mounting portion when receiving an impact, preferably 3.2 J / m or more, more preferably 3.5 J / m or more. Not specified.

-Impact energy In addition, quantitatively, the impact energy of only the covered electric wire 3 (hereinafter, sometimes referred to as the impact energy of the main wire) is 6 J / m or more. The larger the impact energy of the main wire, the more difficult it is to break when subjected to an impact, 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 defined.

  When the insulating coating layer 2 is removed from the coated electric wire 3 to obtain a state of only the conductor, that is, only the copper alloy stranded wire 10, and the impact energy and the impact energy of the conductor in the terminal mounted state are measured, It takes substantially the same value as the copper alloy stranded wire 10. Specifically, a form in which the impact resistance of the conductor provided in the insulated wire 3 in the terminal mounted state is 1.5 J / m or more, and a form in which the conductor in the insulated wire 3 has an impact resistance of 4 J / m or more. No.

  In the case of 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 energy when the terminal is mounted, and the impact energy of the main wire satisfy the above-mentioned range. The insulated wire 3 of the embodiment in which the conductor is the copper alloy stranded wire 10 is, compared to the insulated wire in which the single wire copper alloy wire 1 is used as the conductor, the terminal fixing force, the impact energy when the terminal is mounted, and the impact energy of the main wire. Tend to be higher.

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

[Wire with terminal]
As shown in FIG. 2, the terminal-equipped electric wire 4 includes the covered electric wire 3 of the embodiment and a terminal 5 attached to an end of the covered electric wire 3. Here, as the terminal 5, one end is provided with a female or male fitting portion 52, the other end is provided with an insulation barrel portion 54 for gripping the insulating coating layer 2, and a conductor (a copper alloy in FIG. The crimp terminal provided with the wire barrel part 50 which grips the stranded wire 10) is illustrated. The crimp terminal is crimped to the exposed end of the conductor from which the insulating coating layer 2 has been removed at the end of the covered electric wire 3, and is electrically and mechanically connected to the conductor. The terminal 5 may be a crimp type such as a crimp terminal, or a fusion type to which a molten conductor is connected. As another embodiment of the electric wire with terminal, there is an electric wire provided with a covered electric wire having the above-described copper alloy wire 1 (single wire) as a conductor.

  The terminal-attached electric wire 4 includes a form in which one terminal 5 is attached to each of the coated electric wires 3 as shown in FIG. That is, the terminal-attached electric wire 4 has a form including one covered wire 3 and one terminal 5, a form including a plurality of covered electric wires 3 and one terminal 5, and a form including a plurality of covered electric wires 3 and a plurality of terminals. 5 is provided. When a plurality of electric wires are provided, if the plurality of electric wires are bundled with a tying tool or the like, the electric wire with terminal 4 can be easily handled.

[Characteristics of copper alloy wire, copper alloy stranded wire, coated wire, 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 electric wire with terminal 4 are each composed of the copper alloy wire 1. Maintain or have comparable properties. Therefore, as an example of each of the above-mentioned 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. No.

  A terminal 5 such as a crimp terminal provided on the terminal-attached electric wire 4 itself can be used as a terminal used for measuring the terminal fixing force of the terminal-attached electric wire 4 and the impact energy resistance when the terminal is attached.

[Uses 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 insulated wire 3 of the embodiment is suitably used for applications in which the terminal 5 is attached to the end, for example, wiring of transport equipment such as automobiles and airplanes and control equipment such as industrial robots. it can. The electric wire with terminal 4 of the embodiment can be used for wiring of various electric devices such as the above-described transport device and control device. The covered electric wire 3 and the electric wire with terminal 4 of such an embodiment can be suitably used as constituent elements of various wire harnesses such as an automobile wire harness. The wire harness provided with the covered electric wire 3 and the electric wire with terminal 4 of the embodiment can easily maintain a good connection state with the terminal 5 and can enhance the reliability. The copper alloy wire 1 of the embodiment and the stranded copper alloy wire 10 of the embodiment can be used as conductors of electric wires such as the covered electric wire 3 and the electric wire 4 with a terminal.

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

[Production method]
The copper alloy wire 1, the copper alloy stranded wire 10, the covered wire 3, and the terminal-equipped wire 4 of the embodiment can be manufactured by, for example, a manufacturing method including the following steps. Hereinafter, the outline of each step is listed.

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

As a heat treatment other than the aging / softening treatment, the following solution treatment can be included.
The solution treatment is a heat treatment for the purpose of forming a supersaturated solid solution, and can be performed 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 process is provided in addition to the above-described <continuous casting process>, <drawing process>, and <heat treatment process>. In the case of using a compression stranded wire, the following compression step is further provided.
<Twisting step> A plurality of the above drawn materials are twisted to produce a stranded wire. Alternatively, a stranded wire is manufactured by twisting a plurality of the heat-treated materials.
<Compression step> The above stranded wire is compression molded into a predetermined shape to produce a compressed stranded wire.
When the above <Twisting step> and <Compression step> are provided, in the <Heat treatment step>, aging and softening heat treatment may be performed on the stranded wire or the compression stranded wire. When a stranded or compression stranded wire of the heat-treated material is used, the stranded wire or the compressed stranded wire may further include a second heat treatment step of performing aging / softening heat treatment, or the second heat treatment step may be omitted. May be. When the aging / softening heat treatment is performed a plurality of times, the heat treatment conditions can be adjusted so that the above-described 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 form a fine crystal structure, and to have high strength and high elongation.

(Coated wire)
When manufacturing a covered electric wire including the covered electric wire 3 or the single copper alloy wire 1, the copper alloy wire (the copper alloy wire 1 of the embodiment) manufactured by the above-described copper alloy wire manufacturing method, or the above-described copper The method includes a coating step of forming an insulating coating layer on the outer periphery of the copper alloy stranded wire (the copper alloy stranded wire 10 of the embodiment) manufactured by the method for manufacturing an alloy stranded wire. Known methods such as extrusion coating and powder coating can be used for forming the insulating coating layer.

(Wire with terminal)
When manufacturing the electric wire 4 with a terminal, at the end of the coated electric wire (such as the coated electric wire 3 of the embodiment) manufactured by the above-described method for manufacturing a coated electric wire, the terminal is connected to the conductor exposed by removing the insulating coating layer. And a crimping step for attaching

Hereinafter, the continuous casting step, the wire drawing step, and the heat treatment step will be described in detail.
<Continuous casting process>
In this step, a cast material is produced by continuously casting a melt of a copper alloy having a specific composition containing Fe, P, and Sn in the specific range described above. Here, if the atmosphere at the time of melting 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 an air atmosphere, atmosphere control is not required and productivity can be improved. In this case, it is preferable to use the above-mentioned C, Mn, Si (deoxidizing element) in order to prevent the oxidation of the element by oxygen in the atmosphere.

The method of adding C (carbon) includes, for example, covering the surface of the molten metal with a piece of charcoal or charcoal powder. In this case, C can be supplied into the molten metal from a piece of charcoal or charcoal powder near the surface of the molten metal.
Mn and Si may be prepared by separately preparing raw materials containing these and mixing them 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 contacts oxygen in the atmosphere, oxidation near the surface of the molten metal can be suppressed. Examples of the raw material include a simple substance of Mn or Si, an alloy of Mn or Si and Fe, and the like.

  In addition to the above-described addition of the deoxidizer element, it is preferable to use a high-purity carbon material having a small amount of impurities as a crucible or a mold because impurities are hardly mixed into the molten metal.

  Here, the copper alloy wire 1 of the embodiment typically has Fe and P present as precipitates and Sn as a solid solution. Therefore, it is preferable that the manufacturing process of the copper alloy wire 1 includes a process of forming a supersaturated solid solution. For example, a solution treatment step of performing a solution treatment can be separately provided. In this case, a supersaturated solid solution can be formed at any time. On the other hand, when performing a continuous casting, if the cooling rate is increased to produce a supersaturated solid solution casting material, it is possible to achieve excellent electrical and mechanical properties without providing a separate solution treatment 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, and particularly to increase the cooling rate in the cooling process and rapidly cool.

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

  Various processes such as plastic working and cutting can be applied to the cast material. Examples of the plastic working include conform extrusion, rolling (hot, warm, and cold). The cutting processing includes peeling and the like. By performing these processes, surface defects of the cast material can be reduced, and breakage during wire drawing can be reduced, and productivity can be improved. In particular, when these processes are performed on the up-cast material, it is difficult to break the wire.

<Wire drawing process>
In this step, at least one pass, typically a plurality of passes, of wire drawing (cold) is performed on the cast material or the processed material obtained by processing the cast material to obtain a predetermined final wire diameter. Produce a drawn wire. In the case of performing a plurality of passes, the working ratio of each pass may be appropriately adjusted according to the composition, the final wire diameter, and the like. In the case where an intermediate heat treatment is performed before wire drawing or a plurality of passes are performed, an intermediate heat treatment is performed between passes, so that workability can be improved. Conditions for this intermediate heat treatment can be appropriately selected so that desired workability is obtained.

<Heat treatment process>
In this step, the aging / softening treatment for the purpose of artificial aging and softening is performed as described above. By this aging / softening treatment, it is possible to improve the strength by precipitation strengthening of the above-mentioned precipitates and the effect of maintaining high conductivity by reducing the solid solution in Cu. The alloy wire 1 and the copper alloy stranded wire 10 are obtained. Further, by aging and softening treatment, it is possible to improve toughness such as elongation while maintaining high strength, and to obtain a copper alloy wire 1 and a copper alloy stranded wire 10 having excellent toughness.

The conditions of the aging / softening treatment are as follows, for example, in the case of batch treatment.
(Heat treatment temperature) 350 ° C. or more and 550 ° C. or less, preferably 400 ° C. or more and 500 ° C. or less (retention time) 1 hour or more and 40 hours or less, preferably 3 hours or more and 20 hours or less. It is better to select. As a specific example, Test Examples 1 and 2 described below may be referred to. Note that a continuous process such as a furnace type or an energization type may be used.

  When the heat treatment temperature is high within the above range in the case of the same composition, the electrical conductivity, the elongation at break, the impact energy when the terminal is mounted, and the impact energy of the main wire 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 precipitates described above are sufficiently precipitated, the strength tends to be high and the conductivity tends to be improved.

  In addition, aging treatment is mainly performed during drawing, and softening treatment is mainly performed on the final twisted wire. The condition of the aging treatment and the condition of the softening treatment may be selected from the above-mentioned conditions of the aging and softening treatment.

[Test Example 1]
Copper alloy wires of various compositions and coated electric wires using the obtained copper alloy wires as conductors were produced under various manufacturing conditions, and the characteristics were examined.

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

In each of the production patterns, the following cast materials were prepared.
(Cast material)
Electrolytic copper (purity of 99.99% or more) and a master alloy containing each element shown in Table 2 or an element simple substance were prepared as raw materials. The prepared raw material was melted in the air using a high-purity carbon crucible (impurity amount: 20 mass ppm or less) to prepare a molten copper alloy. Table 2 shows the composition of the copper alloy (remainder Cu and impurities).

  Using a copper alloy melt and a high-purity carbon mold (impurity amount is 20 mass ppm or less), a continuous cast material having a circular cross section (wire diameter φ12.5 mm or φ9.5 mm) by an up-cast method. Was prepared. The cooling rate was higher than 10 ° C./sec.

In the production patterns (a) to (c), in the same manner as in the steps shown in the production patterns (A) to (C) for the copper alloy wire, a drawn wire having a wire diameter of 0.16 mm was prepared, and seven drawn wires were used. After twisting, compression molding was performed to produce a compression stranded wire having a cross-sectional area of 0.13 mm ² (0.13 sq), and subjected to heat treatment (aging / softening treatment) under the conditions shown in Table 2. Polyvinyl chloride (PVC) or polypropylene (PP) is extruded to a predetermined thickness (select from 0.1 mm to 0.3 mm) on the outer periphery of the obtained heat-treated material to form an insulating coating layer. Was produced.

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

  The conductivity (% IACS) was measured by the bridge method. The tensile strength (MPa), elongation at break (%), and work hardening index were measured using a general-purpose tensile tester according to JIS Z 2241 (metallic material tensile test method, 1998).

For the covered electric wires (conductor cross-sectional area: 0.13 mm ² ) manufactured according to the manufacturing patterns (a) to (c), the terminal fixing force (N), the impact energy in the state where the conductor is mounted (J / m, the terminal mounting shock resistance) E) and impact resistance (J / m, impact resistance E) of the conductor were examined. Table 3 shows the results.

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

The impact 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 (compressed stranded wire conductor) before extruding the insulating material, and the weight is lifted 1 m upward and then dropped freely. The weight (kg) of the maximum weight at which the conductor was not disconnected was measured, and the product of the product of the gravitational acceleration (9.8 m / s ² ) and the falling distance divided by the falling distance ((weight × 9. 8 × 1) / 1) is defined as the impact energy of the conductor.

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

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

  Further, the sample No. 1-1. It can be seen that each of Examples 1-8 has a high elongation at break and a high balance of high strength, high toughness, and high electrical conductivity. Quantitatively, the elongation at break is 5% or more, more than 7%, 8% or more, and many samples have 10% or more. In addition, the sample No. 1-1. In each of Examples 1-8, the terminal fixing force is as large as 45 N or more, more than 50 N or more, and more than 55 N, and it can be seen that the terminal can be firmly fixed. Further, the sample No. 1-1. All of the samples 1-8 have a large work hardening index of 0.1 or more, and many samples have a work hardening index of 0.12 or more, and more preferably 0.13 or more.

  One of the reasons for obtaining the above results is that a copper alloy containing Fe, P, and Sn in the above specific range and having a specific composition in which the mass ratio of Fe / P is 4.0 or more is included. By providing a copper alloy wire to the conductor, the effect of strengthening the precipitation 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 and the like based on the proper precipitation of Fe and P It is considered that the effect of maintaining the rate was obtained favorably. Here, by appropriately containing C, Mn, and Si, these elements functioned as an antioxidant to prevent oxidation of Fe, P, and Sn, so that Fe, P could be appropriately precipitated, and Sn was appropriately contained. It is considered that the solid solution was formed. It is also considered that the decrease in conductivity due to the inclusion of C, Mn, and Si was 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, particularly 120 mass ppm or less. Thus, it is considered that the above-described antioxidant effect and the effect of suppressing a decrease in conductivity were appropriately obtained. Further, it is considered that, since it has high strength, it has high elongation at break and excellent toughness, and hardly breaks even when subjected to an impact, so that it has excellent impact resistance. It is considered that, since the strength improvement effect by the work hardening accompanying the compression working was favorably obtained at the terminal mounting portion in the conductor, the impact resistance in the terminal mounting state was also excellent.

  In addition, one of the reasons why the terminal fixing force is high is considered that the work hardening index is large and the strength improving effect by the work hardening was obtained. For example, the sample Nos. Having different work hardening indices and having the same terminal mounting conditions (residual conductor ratio) were used. 1-1, No. Compare 1-101. Sample No. 1-1 is sample No. 1. Although the tensile strength is lower than that of 1-101, the terminal fixing force is almost the same and the impact energy in the terminal mounted state is significantly large. Sample No. It is considered that 1-1 compensated for the low tensile strength by work hardening. In this test, when focusing on the tensile strength and the terminal fixing force, it can be said that there is a correlation that the terminal fixing force increases as the tensile strength increases.

  According to this test, the copper alloy having the specific composition including Fe, P, and Sn described above is subjected to plastic working such as wire drawing and heat treatment such as aging and softening, thereby obtaining conductivity and strength as described above. It was shown that a copper alloy wire and a copper alloy stranded wire excellent in impact resistance as well as a coated wire and a terminal-attached wire using these as conductors can be obtained. Further, it can be seen that, even with the same composition, by adjusting the heat treatment temperature, the tensile strength, the electrical conductivity, the impact energy, and the like can be changed (for example, the sample No. 1-2 and the sample No. 1-3 have different properties). , Comparison between Sample Nos. 1-4 and No. 1-5, and comparison between Samples No. 1-7 and No. 1-8). Increasing the heat treatment temperature tends to increase the electrical conductivity and the impact energy of the conductor. In addition, the higher the Sn content, the higher the tensile strength tends to be (for example, see the comparison of Sample Nos. 1-8, No. 1-4, and No. 1-2).

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

  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. Table 4 shows the heat treatment conditions. Further, in the same manner as in Test Example 1, the obtained copper alloy wire (0.16 mm) was examined for electrical conductivity (% IACS), tensile strength (MPa), elongation at break (%), and work hardening index. Table 4 shows the results.

According to the production pattern (b) of Test Example 1, a drawn wire having a wire diameter of 0.16 mm is produced, and seven drawn wires are twisted and then compression molded to produce a compressed stranded wire having a cross-sectional area of 0.13 mm ^2. Then, heat treatment was performed under the conditions shown in Table 5. An insulating material (PVC or PP) shown in Table 5 was 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. Was produced.

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

  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). The electric resistance was measured at a length of 1 m using a four-terminal resistance measuring apparatus according to JASO D618. The impact energy of the main wire was measured in the same manner as in Test Example 1 using the covered electric wire as a test object.

  About the obtained covered electric wire, the impact energy (J / m) in the state where the terminal was attached was measured. Table 6 shows the results. In this test, the insulation coating layer was peeled off at one end of the covered electric wire to expose the compression stranded wire as a conductor, and a crimp terminal was attached to one end of the compression stranded wire, and the measurement was performed in the same manner as in Test Example 1. The crimp terminal is a crimp terminal formed by press-molding a metal plate (made of copper alloy) into a predetermined shape. The crimp terminal includes a fitting portion 52, a wire barrel portion 50, and an insulation barrel portion 54 (as shown in FIG. 2). (Wrap type). Here, the thickness of the metal plate is the thickness (mm) shown in Table 6, and various kinds of the metal plate having the plating type (tin (Sn) or gold (Au)) shown in Table 6 are prepared. Then, the mounting height (C / H (mm)) in the wire barrel portion 50 and the mounting height (V / H (mm)) in the insulation barrel portion 54 have the sizes shown in Table 6, and thus each sample was measured. A crimp terminal was attached to the conductor of the covered electric wire.

As shown in Tables 4 and 5, sample no. 2-11-No. Sample Nos. 2 to 14 all have the same wire diameter or the same conductor cross-sectional area. Compared with 2-101, it is understood that the three components of conductivity, strength, and impact resistance are provided in a well-balanced manner. Further, as shown in Table 6, the sample No. 2-11-No. Each of 2-14 is also excellent in impact resistance in a terminal mounted state. Quantitatively, it is as follows.
Sample No. 2-11-No. Each of 2-14 has a tensile strength of 400 MPa or more, and more preferably 450 MPa or more (Table 4).
Sample No. 2-11-No. Each of 2-14 has an electrical conductivity of 60% IACS or more, and furthermore, 62% IACS or more (Table 4).
Sample No. 2-11-No. 2-14 all have an impact resistance of 9 J / m or more, and more preferably 10 J / m or more (Table 5).
Sample No. 2-11-No. Each of the samples 2-14 has an impact energy of 3 J / m or more, more preferably 3.5 J / m or more, and 3.8 J / m or more in the terminal mounted state, and many samples have 4 J / m or more (Table 6). .
In this test, it can be said that, even if C / H and V / H are the same, by changing the plating type, coating type, coating thickness, etc. of the terminals, the impact energy in the terminal mounted state may be further increased. (For example, see the comparison between 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 by making V / H different (here, V / H is increased), the impact energy in the terminal mounted state tends to be further increased. (For example, see the comparison of conditions No. 2, No. 4, No. 7 to No. 10 in Table 6).

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

  One of the reasons that the above results were obtained is that, as in Test Example 1, by providing a conductor with a copper alloy wire made of a copper alloy having a specific composition including Fe, P, and Sn, Fe and P It is considered that the effect of improving the strength by precipitation strengthening of Sn and the solid solution strengthening of Sn and the effect of maintaining the high conductivity of Cu by reducing the solid solution of P and the like were favorably obtained. In particular, as in Test Example 1, by appropriately containing C, Mn, and Si, an effect of preventing oxidation of Fe, P, and Sn and an effect of suppressing a decrease in conductivity due to the inclusion of a deoxidizing element such as C were obtained. it is conceivable that. Furthermore, it is considered that it is excellent in toughness in spite of being high strength, and also excellent in impact resistance and impact resistance in a terminal mounted state.

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

DESCRIPTION OF SYMBOLS 1 Copper alloy wire 10 Copper alloy stranded wire (conductor) 3 Insulated wire 4 Wire with terminal 12 Terminal attachment location 2 Insulating coating layer 5 Terminal 50 Wire barrel 52 Fitting 54 Insulation barrel S Sample J Jig W Weight

Claims (12)

A conductor, a coated electric wire including an insulating coating layer provided outside the conductor,
The conductor is
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
A covered electric wire which is a stranded wire formed by twisting a plurality of copper alloy wires having a wire diameter of 0.5 mm or less.   The covered electric wire according to claim 1, wherein the copper alloy contains at least one element selected from C, Si, and Mn in a mass ratio of 10 ppm or more and 500 ppm or less in total.   The coated electric wire according to claim 1 or 2, wherein a breaking elongation of the copper alloy wire is 5% or more.   4. The coated electric wire according to claim 1, wherein the copper alloy wire has a conductivity of 60% IACS or more and a tensile strength of 400 MPa or more. 5.   The insulated wire according to any one of claims 1 to 4, wherein the terminal fixing force is 45N or more.   The coated electric wire according to any one of claims 1 to 5, wherein impact resistance in a state where the terminal is attached is 3 J / m or more.   The coated electric wire according to any one of claims 1 to 6, wherein the impact energy of only the coated electric wire is 6 J / m or more.   An electric wire with a terminal, comprising: the covered electric wire according to any one of claims 1 to 7; and a terminal attached to an end of the covered electric wire. A copper alloy wire used for a conductor,
Fe of 0.2% by mass to 1.6% by mass,
P is not less than 0.05% by mass and not more than 0.4% by mass,
Containing 0.05% by mass or more and 0.7% by mass or less of Sn;
The balance consists of Cu and impurities,
It is composed of a copper alloy having a mass ratio of Fe / P of 4.0 or more,
A copper alloy wire having a wire diameter of 0.5 mm or less.   A copper alloy twisted wire obtained by twisting a plurality of the copper alloy wires according to claim 9.   The copper alloy stranded wire according to claim 10, wherein impact energy in a state where the terminal is attached is 1.5 J / m or more.   The copper alloy stranded wire according to claim 10 or 11, wherein the impact energy of only the copper alloy stranded wire is 4 J / m or more.

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