JP5686084B2 - Insulated wire manufacturing method and cable manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an insulated wire and a method for manufacturing a cable.

  As a conventional technique, there is known a method for manufacturing a conductor in which a copper alloy rough wire is drawn to a predetermined diameter to produce a hard copper wire, and the annealed hard copper wire is annealed to produce a soft copper wire. (For example, refer to Patent Document 1).

JP 11-224538 A

  The conventional method for producing a conductor requires an annealing process to obtain an annealed copper wire, and the hardness of the conductor is determined by this annealing process. In addition, in the conventional conductor manufacturing method, in the stranded wire process for producing a stranded wire from a plurality of conductors and in the unloading process after the annealing process, the curing of the conductor proceeds and the conductor of the produced cable has a desired hardness. There was a problem that the conductor was hardened.

  Accordingly, an object of the present invention is to provide a method of manufacturing an insulated wire and a method of manufacturing a cable that have high productivity, excellent softening temperature, and excellent flexibility with little work hardening when the cable is completed. It is in.

  In order to achieve the above object, the present invention adds copper containing inevitable impurities, oxygen in an amount exceeding 2 mass ppm, and at least one addition of Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr. Prepare a plurality of hard copper wires and twist them together by preparing a hard copper wire by drawing a dilute copper alloy wire containing the element to the final wire diameter. Insulation including a stranded wire production process for producing a stranded wire, a preheating process for pretreating the stranded wire to transform the hard copper wire into an annealed copper wire, and a coating step for coating the outer periphery of the annealed copper wire with a resin A method of manufacturing an electric wire is provided.

  Moreover, the manufacturing method of said insulated wire may contain 2 mass ppm or more and 12 mass ppm or less of sulfur, 2 mass ppm or more and 30 mass ppm or less of oxygen, and 4 mass ppm or more and 55 mass ppm or less of titanium. preferable.

  In addition, the above-described method for manufacturing an insulated wire includes a SCR continuous casting and rolling to produce a dilute copper alloy material as a molten metal at a molten copper temperature of 1100 ° C. or higher and 1320 ° C. or lower, and hot dilute the dilute copper alloy material to obtain diluted copper It is preferable to include the process of producing an alloy wire.

  Moreover, it is preferable that the manufacturing method of said insulated wire performs the process which produces a dilute copper alloy wire at the temperature of the rolling roll in a hot rolling process at 880 degrees C or less and 550 degrees C or more.

  Moreover, the manufacturing method of the cable containing the sheath coating | coated process which coat | covers a sheath to the insulated wire produced by any one of the manufacturing methods of said insulated wire.

  According to the insulated wire manufacturing method and cable manufacturing method according to the present invention, the productivity of the insulated wire is high, the softening temperature is excellent, and the flexibility of the work is low when the cable is completed. Methods and cable manufacturing methods can be provided.

FIG. 1 is a view showing an SEM image of TiS particles. FIG. 2 is a diagram showing the analysis result of FIG. FIG. 3 is a view showing an SEM image of TiO ₂ particles. FIG. 4 is a diagram showing the analysis result of FIG. FIG. 5 is a diagram showing an SEM image of Ti—O—S particles. FIG. 6 is a diagram showing the analysis result of FIG. FIG. 7 is a schematic diagram of a cable according to the fifth embodiment.

[Embodiment]
(Configuration of insulated wire)
The insulated wire according to the present embodiment is more thermally conductive than aluminum (Al), for example, from the viewpoint of miniaturization of a power module used in an automobile and / or an increase in current density of current supplied to the power module. It is made of copper (Cu), which is a high-rate material.

For example, the conductor of the insulated wire according to the present embodiment has a conductivity of 98% IACS (International Standard Copper Standard or higher) and a resistivity of 1.7241 × 10 ⁻⁸ Ωm as 100%. ), Preferably 100% IACS or more, and more preferably, a soft dilute copper alloy material as a soft copper material satisfying 102% IACS or more.

  Moreover, the conductor of the insulated wire which concerns on this Embodiment uses an SCR (Southwire Continuous Rod) continuous casting installation, there are few surface scratches, a manufacturing range is wide, and stable production is possible. The wire rod is made of a material having a softening temperature of 148 ° C. or less at a processing degree of 90% (for example, processing from φ8 mm to φ2.6 mm wire).

Moreover, the conductor of the insulated wire which concerns on this Embodiment is 2 mass ppm or more of sulfur (S) of 12 mass ppm or less, oxygen (O) of 2 mass ppm or more and 30 mass ppm or less, and titanium (4 mass ppm or more and 55 mass ppm or less). Ti). Furthermore, sulfur (S) and titanium (Ti) is, TiO, agglomeration of TiO _2, TiS, or a compound having a TiO-S bond or TiO, TiO _2, TiS, or a compound having a TiO-S bond The remaining Ti and S are included in the conductor of the insulated wire as a solid solution. In this embodiment, so-called low oxygen copper (LOC) is targeted because it contains oxygen exceeding 2 mass ppm and not more than 30 mass ppm.

Further, a compound or aggregate in the form of TiO, TiO ₂ , TiS, Ti—O—S is distributed inside the crystal grains constituting the conductor of the insulated wire, and TiO has a size of 200 nm or less, TiO ₂ has a size of 1000 nm or less, TiS has a size of 200 nm or less, and a compound or aggregate in the form of Ti—O—S has a size of 300 nm or less. Furthermore, the conductor of the insulated wire according to the present embodiment includes 90% or more of particles of 500 nm or less. Here, the “size” is the size of the compound, and means the size of the major axis of the diameter and minor axis of the shape of the compound. The “particles” refer to the TiO, TiO ₂ , TiS, and Ti—O—S. “90%” indicates the ratio of the number of corresponding particles to the total number of particles.

(Manufacturing method of conductor of insulated wire)
The method for manufacturing an insulated wire according to the present embodiment is as follows. First, the manufacturing method of the conductor of an insulated wire is demonstrated. A soft diluted copper alloy material containing titanium (Ti) as a raw material of the conductor is prepared (raw material preparation step). Next, this soft dilute copper alloy material is made into a molten metal at a molten copper temperature of 1100 ° C. or higher and 1320 ° C. or lower (melt manufacturing process). Next, a wire rod is produced from the molten metal (wire rod production process). Subsequently, the wire rod is subjected to hot rolling using a rolling roll at a temperature of 880 ° C. or lower and 550 ° C. or higher (hot rolling step). Further, the wire rod that has undergone the hot rolling process is subjected to a drawing process (drawing process). Thereby, the conductor of the insulated wire which concerns on this Embodiment is manufactured.

  In addition, for the production of a conductor of an insulated wire, sulfur (S) of 2 mass ppm or more and 12 mass ppm or less, oxygen (O) of more than 2 mass ppm and 30 mass ppm or less, titanium (Ti) of 4 mass ppm or more and 55 mass ppm or less, and A soft dilute copper alloy material containing is used. Specifically, a soft dilute copper alloy material having a softening temperature of 130 ° C. or more and 148 ° C. or less with a size of φ2.6 mm is used.

  Hereinafter, the contents studied by the present inventors in the realization of the conductor of the insulated wire according to the present embodiment will be described.

  First, high-purity copper having a purity of 6N (that is, 99.9999%) has a softening temperature of 130 ° C. at a workability of 90%. Therefore, the present inventor has a soft material having a softening temperature of 130 ° C. or higher and 148 ° C. or lower that enables stable production, and the conductivity of the soft material is 98% IACS or higher, preferably 100% IACS or higher, more preferably 102% IACS or higher. A soft dilute copper alloy material capable of stably producing soft copper and a method for producing the soft dilute copper alloy material were studied.

  Here, high-purity copper (4N) having an oxygen concentration of 1 to 2 mass ppm was prepared, and a small continuous casting machine (small continuous casting machine) installed in a laboratory was used. ). And several mass ppm of titanium (Ti) was added to this molten metal. Subsequently, a φ8 mm wire rod was manufactured from the molten metal to which titanium (Ti) was added. Next, a φ8 mm wire rod was processed to φ2.6 mm (that is, the processing degree was 90%). The softening temperature of the φ2.6 mm wire rod was 160 ° C. to 168 ° C., and the softening temperature was not lower than this temperature. The conductivity of the φ2.6 mm wire rod was about 101.7% IACS. In other words, the oxygen concentration contained in the wire rod is reduced, and even if titanium (Ti) is added to the molten metal, the softening temperature of the wire rod cannot be lowered, and the conductivity of Cu (6N) is 102.8% from IACS. The inventor has also found that the electrical conductivity is low.

  The reason why the softening temperature cannot be lowered and the conductivity is lower than that of 6N high-purity copper (Cu) includes sulfur (S) of several mass ppm or more as an inevitable impurity during the production of the molten metal. It was speculated that it was caused by that. That is, it was speculated that the softening temperature of the wire rod does not decrease due to insufficient formation of sulfides such as TiS between sulfur (S) and titanium (Ti) contained in the molten metal. .

  Therefore, the present inventor has studied the following two measures in order to realize a decrease in the softening temperature of the conductor of the insulated wire and an improvement in the conductivity of the conductor of the insulated wire. And the insulated wire which concerns on this Embodiment was obtained by using together the following two measures for manufacture of the conductor of an insulated wire.

FIG. 1 is an SEM (Scanning Electron Microscope) image of TiS particles, and FIG. 2 shows the analysis result of FIG. FIG. 3 is an SEM image of TiO ₂ particles, and FIG. 4 shows the analysis result of FIG. 5 is an SEM image of Ti—O—S particles, and FIG. 6 shows the analysis result of FIG. In the SEM image, each particle is shown near the center of the figure. 1 to 6 are SEM observation and EDX analysis of a cross section of a φ8 mm copper wire (wire rod) having oxygen concentration, sulfur concentration, and Ti concentration shown in the third row from the top in Example 1 of Table 1. It has been evaluated. The observation conditions were an acceleration voltage of 15 KeV and an emission current of 10 μA.

First, the first policy is to prepare a molten copper (Cu) in a state where titanium (Ti) is added to copper (Cu) having an oxygen concentration exceeding 2 mass ppm. In this molten metal, it is considered that oxides of TiS and titanium (Ti) (for example, TiO ₂ ) and Ti—O—S particles are formed. This is a consideration from the SEM image of FIG. 1 and the analysis result of FIG. 2, and the SEM image of FIG. 3 and the analysis result of FIG. 2, 4, and 6, platinum (Pt) and palladium (Pd) are metal elements that are vapor-deposited on an observation object when SEM observation is performed.

Next, the second strategy is to introduce a dislocation into copper (Cu) to facilitate the precipitation of sulfur (S), and to set the temperature in the hot rolling step under the normal copper production conditions. It is to set temperature (880 degreeC-550 degreeC) lower than temperature (namely, 950 degreeC-600 degreeC). With such a temperature setting, sulfur (S) can be deposited on the dislocations, or sulfur (S) can be deposited using titanium (Ti) oxide (for example, TiO ₂ ) as a nucleus. As an example, as shown in FIGS. 5 and 6, Ti—O—S particles and the like are formed together with molten copper.

  By the above first and second measures, sulfur (S) contained in copper (Cu) crystallizes and precipitates, so that a copper wire rod having a desired softening temperature and a desired conductivity is cooled. It can be obtained after wire drawing.

  Moreover, the conductor of the insulated wire which concerns on this Embodiment is manufactured using SCR continuous casting equipment. Here, the following three conditions were provided as limitations on the manufacturing conditions when using the SCR continuous casting equipment.

(1) About composition When obtaining a soft copper material having an electrical conductivity of 98% IACS or more, as pure copper (base material) containing inevitable impurities, 3-12 mass ppm of sulfur (S), and more than 2 and less than 30 mass ppm A soft dilute copper alloy material containing oxygen (O) and 4-55 mass ppm titanium (Ti) is used, and a wire rod (rough drawn wire) is produced from the soft dilute copper alloy material.

  Here, when obtaining a soft copper material having an electrical conductivity of 100% IACS or more, as pure copper (base material) containing inevitable impurities, 2 to 12 mass ppm of sulfur (S) and more than 2 to 30 mass ppm or less. A soft dilute copper alloy material containing oxygen (O) and 4-37 mass ppm titanium (Ti) is used. Further, when obtaining a soft copper material having an electrical conductivity of 102% IACS or more, as pure copper (base material) containing inevitable impurities, 3-12 mass ppm of sulfur (S) and oxygen of more than 2 and less than 30 mass ppm. A soft dilute copper alloy material containing (O) and 4 to 25 mass ppm of titanium (Ti) is used.

  Usually, in the industrial production of pure copper, since sulfur (S) is taken into copper (Cu) when producing electrolytic copper, it is difficult to reduce sulfur (S) to 3 mass ppm or less. The upper limit of the sulfur concentration of general-purpose electrolytic copper is 12 mass ppm.

  When the oxygen concentration is low, the softening temperature of the conductor of the insulated wire is difficult to decrease, so the oxygen concentration is controlled to an amount exceeding 2 mass ppm. Further, when the oxygen concentration is high, the surface of the conductor of the insulated wire is likely to be damaged in the hot rolling step, and therefore, the oxygen concentration is controlled to 30 mass ppm or less.

(2) About dispersed substances It is preferable that the size of the dispersed particles dispersed in the conductor of the insulated wire is small, and it is preferable that many dispersed particles are dispersed in the conductor of the insulated wire. This is because the dispersed particles have a function as a precipitation site of sulfur (S), and the precipitation site is required to have a small size and a large number.

Sulfur contained in the conductor of the insulated wire (S) and titanium (Ti) is, TiO, TiO _2, TiS, or compounds or TiO having TiO-S bond, TiO _2, TiS, or TiO-S bond The remaining Ti and S are included as a solid solution. As a soft dilute copper alloy material that is a raw material of a conductor of an insulated wire, TiO has a size of 200 nm or less, TiO ₂ has a size of 1000 nm or less, TiS has a size of 200 nm or less, and Ti—O A soft dilute copper alloy material in which the compound in the form of -S has a size of 300 nm or less and these are distributed in the crystal grains is used.

  In addition, since the particle size formed in a crystal grain changes according to the holding | maintenance time of molten copper at the time of casting, and cooling conditions, it is necessary to set casting conditions appropriately.

(3) Casting conditions By SCR continuous casting and rolling, wire rods are produced with an ingot rod working degree of 90% (30 mm) to 99.8% (5 mm). As an example, a condition for manufacturing a wire rod of φ8 mm with a processing degree of 99.3% is adopted. Hereinafter, casting conditions (a) to (c) will be described.

[Casting conditions (a)]
The molten copper temperature in the melting furnace is controlled to 1100 ° C. or higher and 1320 ° C. or lower. When the temperature of the molten copper is high, blowholes increase, and scratches are generated and the particle size tends to increase, so the temperature is controlled to 1320 ° C. or lower. The reason why the temperature is controlled to 1100 ° C. or higher is that copper (Cu) tends to harden and the production is not stable, but the molten copper temperature is preferably as low as possible.

[Casting conditions (b)]
As for the temperature of the hot rolling process, the temperature in the first rolling roll is controlled to 880 ° C. or lower, and the temperature in the final rolling roll is controlled to 550 ° C. or higher.

  Unlike normal pure copper production conditions, for the purpose of further reducing the solid solubility limit, which is the driving force for crystallization of sulfur (S) in molten copper and precipitation of sulfur (S) during hot rolling, It is preferable to set the molten copper temperature and the hot rolling temperature to the conditions described in “Casting Condition (a)” and “Casting Condition (b)”.

  Further, the temperature in the normal hot rolling process is 950 ° C. or less in the first rolling roll and 600 ° C. or more in the final rolling roll, but for the purpose of reducing the solid solution limit, The first rolling roll is set to 880 ° C. or lower, and the final rolling roll is set to 550 ° C. or higher.

  In addition, the reason for setting the temperature in the final rolling roll to 550 ° C. or higher is that the wire rod has many scratches at temperatures lower than 550 ° C., and the manufactured insulated wire cannot be handled as a product. The temperature in the hot rolling process is preferably as low as possible while controlling the temperature to 880 ° C. or lower in the first rolling roll and 550 ° C. or higher in the final rolling roll. By setting such a temperature, the softening temperature of the conductor of the insulated wire (softening temperature after being processed to φ8 to φ2.6 mm) is set to the softening temperature of 6N high-purity copper (Cu) (that is, 130 ° C.). Can be approached.

[Casting conditions (c)]
The conductivity of oxygen-free copper is about 101.7% IACS, and the conductivity of 6N high purity copper (Cu) is 102.8% IACS. In the present embodiment, for example, the conductivity of a wire rod having a diameter of φ8 mm is 98% IACS or more, preferably 100% IACS or more, more preferably 102% IACS or more. In the present embodiment, a soft dilute copper alloy in which the softening temperature of the wire rod of the wire rod (for example, φ2.6 mm) after cold drawing is 130 ° C. or higher and 148 ° C. is manufactured, and this soft dilute copper is manufactured. Alloys are used in the manufacture of insulated wire conductors.

  In order to use industrially, the electrical conductivity of 98% IACS or more is requested | required as electrical conductivity of the soft copper wire of the purity utilized industrially manufactured from electrolytic copper. Further, the softening temperature is 148 ° C. or less judging from industrial value. Since the softening temperature of 6N copper (Cu) is 127 ° C to 130 ° C, the upper limit value of the softening temperature is set to 130 ° C from the obtained data. This slight difference is due to the presence of inevitable impurities not contained in 6N copper (Cu).

  After copper (Cu) is melted in the shaft furnace, it is preferable to flow it in the reduced state. That is, in a reducing gas (for example, CO) atmosphere, the wire rod is stably manufactured by casting while controlling the sulfur concentration, titanium concentration, and oxygen concentration of the dilute alloy and rolling the material. It is preferable. In addition, that copper oxide mixes and / or that a particle size is larger than predetermined size will reduce the quality of the insulated wire manufactured.

Note that the additive element added to the pure copper may include at least one of Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr. The reason why the elements selected from the group consisting of Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr are selected as the additive elements is that these elements are active elements that are easily combined with other elements. This is because S can be trapped because it is easily combined with S, and the copper base material (matrix) can be highly purified. One or more additive elements may be included. Also, other elements and impurities that do not adversely affect the properties of the alloy can be included in the alloy.
Further, in the preferred embodiment described below, it is described that the oxygen content is more than 2 and not more than 30 mass ppm, but depending on the addition amount of the additive element and the S content, In the range having the property of, it is possible to include more than 2 and 400 mass ppm.

  Here, the reason for adding titanium (Ti) as an additive element to the conductor of the insulated wire is as follows. That is, (a) titanium (Ti) is likely to be a compound by combining with sulfur (S) in molten copper, and (b) easy to process and handle compared to other additive metals such as zirconium (Zr). This is because (c) it is cheaper than niobium (Nb) and the like, and (d) it is easy to deposit with oxide as a nucleus.

  From the above, it can be used as molten solder plating material (wire, board, foil), enameled wire, soft pure copper, high conductivity copper, soft copper wire, energy during annealing can be reduced, productivity is high, conductivity A practical soft dilute copper alloy material excellent in softening temperature and surface quality can be obtained as a raw material for the conductor of the insulated wire according to the present embodiment. A plating layer can also be formed on the surface of the soft dilute copper alloy material. For the plating layer, for example, a material mainly containing tin (Sn), nickel (Ni), silver (Ag), or Pb-free plating can be used. Further, the shape of the soft dilute copper alloy material is not particularly limited, and can be a round cross-section, a rod shape, or a flat conductor.

  In the present embodiment, the wire rod is manufactured by the SCR continuous casting rolling method and the soft material is manufactured by hot rolling. However, the twin roll type continuous casting rolling method or the Properti type continuous casting rolling method is adopted. You can also.

(Effect of embodiment)
The insulated wire according to the present embodiment has high productivity, excellent softening temperature, and excellent flexibility with little work hardening when the cable is completed. Moreover, since the insulated wire according to the present embodiment can omit the annealing process of the conductor, energy costs such as electric power consumed in the annealing process, equipment costs of the annealing process, equipment maintenance costs, time required for the annealing process In addition, labor costs can be reduced. Below, the Example of the conductor of the insulated wire produced by said manufacturing method is described.

  Table 1 shows the experimental conditions and results.

  First, as an experimental material, a φ8 mm copper wire (wire rod, workability 99.3%) having the oxygen concentration, sulfur concentration, and titanium concentration shown in Table 1 was prepared. The φ8 mm copper wire is hot-rolled by SCR continuous casting and rolling. Ti flows the molten copper melted in the shaft furnace into the reed in the reducing gas atmosphere, guides the molten copper flowing in the reed to the casting pot of the same reducing gas atmosphere, and after adding Ti in this casting pot, An ingot rod was made with a mold formed between the cast ring and the endless belt through the nozzle. This ingot rod is hot-rolled to produce a φ8 mm copper wire. Next, cold drawing was applied to each experimental material. Thus, a copper wire having a size of φ2.6 mm was produced. And while measuring the semi-softening temperature and electrical conductivity of a copper wire of φ 2.6 mm size, the dispersed particle size in the copper wire of φ 8 mm was evaluated.

  The oxygen concentration was measured with an oxygen analyzer (Leco (registered trademark) oxygen analyzer), and the concentrations of sulfur and titanium were analyzed by ICP emission spectroscopic analysis.

  The measurement of the semi-softening temperature in the φ2.6 mm size was obtained from the result of quenching in water after holding each temperature at 400 ° C. or lower for 1 hour and conducting a tensile test. The value obtained by using the result of the tensile test at room temperature and the result of the tensile test of the soft copper wire heat-treated at 400 ° C. for 1 hour, and adding the tensile strengths of the two tensile tests and dividing by two. The temperature corresponding to the strength was determined as the semi-softening temperature.

  As described above, it is preferable that the size of the dispersed particles dispersed in the conductor of the insulated wire is small, and it is preferable that many dispersed particles are dispersed in the conductor of the insulated wire. Therefore, the case where the number of dispersed particles having a diameter of 500 nm or less is 90% or more was determined to be acceptable.

  In Table 1, Comparative Example 1 is a result of trial production of a copper wire having a diameter of 8 mm in an argon (Ar) atmosphere in a laboratory, and 0 to 18 mass ppm of titanium (Ti) was added. While the semi-softening temperature of the copper wire not added with titanium (Ti) was 215 ° C., the softening temperature of the copper wire added with 13 mass ppm of titanium (Ti) decreased to 160 ° C. Is the minimum temperature.) As shown in Table 1, as the Ti concentration increased to 15 mass ppm and 18 mass ppm, the semi-softening temperature also increased, and the required softening temperature of 148 ° C. or lower could not be realized. Moreover, although the electrical conductivity requested | required industrially was 98% IACS or more, comprehensive evaluation was disqualified (henceforth, a disqualification is represented as "x").

  Therefore, as Comparative Example 2, a Φ8 mm copper wire (wire rod) having an oxygen concentration adjusted to 7 to 8 mass ppm was prototyped using the SCR continuous casting and rolling method.

  In Comparative Example 2, it was a copper wire having a minimum Ti concentration (that is, 0 mass ppm, 2 mass ppm) among the prototype manufactured by the SCR continuous casting and rolling method, and the conductivity was 102% IACS or more, but the semi-softening temperature. Was 164 ° C. and 157 ° C., and was not less than the required 148 ° C., so the overall evaluation was “x”.

  In Example 1, the oxygen concentration and the sulfur concentration substantially coincide (that is, the oxygen concentration: 7 to 8 mass ppm, the sulfur concentration: 5 mass ppm), and different copper wires are used within the range of the Ti concentration of 4 to 55 mass ppm. Prototype.

  When the Ti concentration is in the range of 4 to 55 mass ppm, the softening temperature is 148 ° C. or lower, the conductivity is 98% IACS or higher and 102% IACS or higher, and the dispersed particle size is 90% or higher for particles of 500 nm or less. there were. Moreover, since the surface of the wire rod was also clean (that is, the surface was smooth) and all satisfied the product performance, the comprehensive evaluation was a pass (hereinafter, the pass was expressed as “◯”).

  Here, the copper wire satisfying an electrical conductivity of 100% IACS or more was a case where the Ti concentration was 4 to 37 mass ppm, and the copper wire satisfying the 102% IACS or more was a case where the Ti concentration was 4 to 25 mass ppm. When the Ti concentration was 13 mass ppm, the conductivity showed a maximum value of 102.4% IACS, and the conductivity was slightly lower around this concentration. This is because, when the Ti concentration is 13 mass ppm, by capturing the sulfur content in copper (Cu) as a compound, the conductivity is close to that of high-purity copper (6N).

  Therefore, both the semi-softening temperature and the conductivity can be satisfied by increasing the oxygen concentration and adding titanium (Ti).

  In Comparative Example 3, a copper wire having a Ti concentration of 60 mass ppm was prototyped. Although the copper wire which concerns on the comparative example 3 satisfy | fills a request | requirement, semi-softening temperature is 148 degreeC or more, and did not satisfy | fill product performance. Furthermore, there are many scratches on the surface of the wire rod, making it difficult to adopt as a product. Therefore, it was shown that the addition amount of titanium (Ti) is preferably less than 60 mass ppm.

  In the copper wire which concerns on Example 2, while setting sulfur concentration to 5 mass ppm and controlling Ti concentration in the range of 13-10 mass ppm, the influence of oxygen concentration was examined by changing oxygen concentration.

  Regarding the oxygen concentration, copper wires having greatly different concentrations from 2 mass ppm to 30 mass ppm were prepared. However, since copper wires with an oxygen concentration of less than 2 mass ppm are difficult to produce and cannot be stably manufactured, the overall evaluation is “△” (“△” is an intermediate evaluation between “○” and “×”) .) Further, even when the oxygen concentration was 30 mass ppm, both the semi-softening temperature and the conductivity met the requirements.

  In Comparative Example 4, when the oxygen concentration was 40 mass ppm, there were many scratches on the surface of the wire rod, and the product could not be used as a product.

  Therefore, by setting the oxygen concentration in the range of more than 2 and 30 mass ppm or less, all the characteristics of the semi-softening temperature, the electrical conductivity of 102% IACS or more, and the dispersed particle size can be satisfied. It was shown to be clean and satisfy product performance.

  Example 3 is a copper wire in which the oxygen concentration and the Ti concentration are set close to each other and the sulfur concentration is changed within a range of 4 to 20 mass ppm. In Example 3, a copper wire having a sulfur concentration of less than 2 mass ppm could not be realized due to restrictions on raw materials. However, by controlling the Ti concentration and the sulfur concentration, the requirements for both the semi-softening temperature and the conductivity could be satisfied.

  In Comparative Example 5, when the sulfur concentration was 18 mass ppm and the Ti concentration was 13 mass ppm, the semi-softening temperature was as high as 162 ° C., and the required characteristics were not satisfied. In particular, the surface quality of the wire rod was poor and it was difficult to produce a product.

  From the above, when the sulfur concentration is in the range of 2 to 12 mass ppm, the semi-softening temperature, the conductivity of 102% IACS or more, and the dispersed particle size can be satisfied, and the surface of the wire rod is also clean. It was shown that the product performance can be satisfied.

  Comparative Example 6 is a copper wire using 6N Cu. In the copper wire according to Comparative Example 6, a particle having a semi-softening temperature of 127 ° C. to 130 ° C., a conductivity of 102.8% IACS, and a dispersed particle size of 500 μm or less was not observed at all.

  Table 2 shows the temperature of molten copper and the rolling temperature as production conditions.

  In Comparative Example 7, a wire rod having a molten copper temperature of 1330 ° C. to 1350 ° C. and a rolling temperature of 950 to 600 ° C. and a diameter of 8 mm was produced. Although the wire rod according to Comparative Example 7 satisfies the requirements for the semi-softening temperature and the electrical conductivity, there are about 1000 nm of particles with respect to the dispersed particle size, and more than 10% of the particles are over 500 nm. . Therefore, the wire rod according to Example 7 was determined to be inappropriate.

  In Example 4, the molten copper temperature was controlled in the temperature range of 1200 ° C. to 1320 ° C., and the rolling temperature was controlled in the temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Example 4 had good wire rod surface quality and dispersed particle size, and the overall evaluation was “◯”.

  In Comparative Example 8, the molten copper temperature was controlled to 1100 ° C., and the rolling temperature was controlled to a temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 8 was not suitable as a product because there were many scratches on the surface of the wire rod because the molten copper temperature was low. This is because, since the molten copper temperature is low, scratches are likely to occur during rolling.

  In Comparative Example 9, the molten copper temperature was controlled to 1300 ° C. and the rolling temperature was controlled to a temperature range of 950 ° C. to 600 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 9 has a high quality in the surface of the wire rod because the temperature in the hot rolling process is high, but the dispersed particle size includes a large size, and the overall evaluation is “x”. It was.

  In Comparative Example 10, the molten copper temperature was controlled to 1350 ° C., and the rolling temperature was controlled to a temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 10 had a large dispersed particle size due to the high molten copper temperature, and the overall evaluation was “x”.

(Configuration of cable 1)
FIG. 7 is a schematic diagram of a cable according to the fifth embodiment. A cable 1 according to the present embodiment covers, for example, an insulated wire 4 having an insulator 3 covering a conductor 2 and a stranded wire formed from a plurality of conductors 2 as shown in FIG. And a sheath 5. In addition, the cable 1 which concerns on Example 5-Example 7 shown below shall have the structure shown in FIG. 7, and shall use the code | symbol of a present Example for the code | symbol.

(Method for manufacturing cable 1)
The manufacturing method of the cable 1 according to the present embodiment is as follows. First, copper containing inevitable impurities, oxygen in an amount exceeding 2 mass ppm, and at least Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr. A dilute copper alloy wire containing a kind of additive element is drawn to a final wire diameter to produce a hard copper wire (hard copper wire production step). Next, the outer periphery of the hard copper wire is coated with a resin, and the hard copper wire is transformed into an annealed copper wire by the amount of heat at the time of the coating (coating process). Thereby, the insulated wire 4 of the cable 1 which concerns on a present Example is produced.

  Specifically, first, a wire rod (for example, φ8) is manufactured using the third material from the top in Example 1 of Table 1. Next, the wire rod is drawn to obtain a final wire diameter (for example, φ3.55), and then, for example, seven stranded wires are created and finished to a predetermined size. Next, the stranded wire is covered with a resin to form the insulator 3 (covering step).

  This coating step is performed, for example, by extrusion coating polyethylene. At the time of this extrusion coating, the conductor 2 is heated at an extrusion resin temperature (180 ° C. to 200 ° C.). As shown in the above embodiment and Examples 1 to 4, since a material having a low semi-softening temperature is used as the conductor 2, heat is transferred to the conductor 2 by the heating temperature of the resin during this extrusion coating. The conductor 2 is softened.

  Since the conductor 2 is softened by the heating temperature of the resin during the extrusion coating, it is not necessary to subject the wire drawing material to an annealing process. Next, a cable (insulated cable) 1 is produced by extrusion coating a sheath 5 (for example, a vinyl sheath, a polyethylene sheath, a flame resistant polyethylene sheath). The cable manufacturing method of the present embodiment is not limited to a stranded single-core insulated cable, but is an insulated cable produced by twisting a plurality of insulated wires and further extruding a sheath. May be.

(Method for manufacturing cable 1)
The manufacturing method of the cable 1 according to the present embodiment is as follows. First, copper containing inevitable impurities, oxygen in an amount exceeding 2 mass ppm, and at least Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr. A dilute copper alloy wire containing a kind of additive element is drawn to a final wire diameter to produce a hard copper wire (hard copper wire production step). Next, a resin is coated on the outer periphery of the hard copper wire (coating process). Next, the coated resin is subjected to a crosslinking treatment, and the hard copper wire is transformed into an annealed copper wire by the amount of heat during the crosslinking treatment (crosslinking step). Thereby, the insulated wire 4 of the cable 1 which concerns on a present Example is produced.

  Specifically, the process up to the manufacturing process of the stranded wire is the same as that of the fifth embodiment. Next, after the resin (for example, silane-grafted polyethylene) is extrusion coated on the stranded wire, heat (for example, 130 ° C. to 150 ° C.) is insulated with a heater (heat source) in order to crosslink the coated resin. Give to 4. As shown in the above embodiment and Examples 1 to 4, since a material having a low semi-softening temperature is used as the conductor 2, the conductor 2 is softened by the heat treatment in this crosslinking step.

  Since the conductor 2 is softened by the heat treatment in this cross-linking step, it is not necessary to perform an annealing step on the wire drawing material. Next, a stranded wire is produced by the conductor 2, and the insulated wire 4 is produced by extrusion-coating the resin on the stranded wire. Next, the cable 1 is produced by extruding the sheath 5 on the insulated wire 4.

(effect)
According to said Example 5 and Example 6, the annealing process (annealing) after a wire drawing process can be skipped. As a result, the cost of electricity can be reduced. At the same time, in the covering step or the bridging step, the conductor 2 is softened by applying heat to the conductor 2, whereby the cable 1 having a small influence of work hardening can be produced.

  The present embodiment is different from the above-described Embodiment 5 and Embodiment 6 in that the conductor is not softened by the coating process but preheating (130 ° C. to 150 ° C.) is given to the conductor 2 before the coating process. .

(Method for manufacturing cable 1)
The manufacturing method of the cable 1 according to the present embodiment is as follows. First, copper containing inevitable impurities, oxygen in an amount exceeding 2 mass ppm, and at least Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr. A dilute copper alloy wire containing a kind of additive element is drawn to a final wire diameter to produce a hard copper wire (hard copper wire production step). Next, a plurality of hard copper wires are prepared, and twisted wires are prepared by twisting them together (twisted wire manufacturing step). Next, pre-heat treatment is performed on the stranded wire to transform the hard copper wire into an annealed copper wire (preheating step). Next, a resin is coated on the outer periphery of the annealed copper wire (coating process). Thereby, the insulated wire 4 of the cable 1 which concerns on a present Example is produced.

  Specifically, the process up to the manufacturing process of the stranded wire is the same as that of the fifth embodiment. Next, in order to preheat this stranded wire, heat (for example, 130 ° C. to 150 ° C.) is applied to the insulated wire 4 with a heater (heat source). As shown in the above embodiment and Examples 1 to 4, since a material having a low semi-softening temperature is used as the conductor 2, the conductor 2 is softened by the heat treatment in the preheating step.

  Since the conductor 2 is softened by the heat treatment in the preheating step, it is not necessary to perform the annealing step on the wire drawing material. Next, a stranded wire is produced by the conductor 2, and the insulated wire 4 is produced by extrusion-coating the resin on the stranded wire. Next, the cable 1 is produced by extruding the sheath 5 on the insulated wire 4.

(effect)
According to the method for manufacturing the cable 1 according to the present embodiment, the conductor 2 can be softened by the pre-heat treatment performed on the conductor 2 before the covering step, so that a large annealing apparatus for the annealing step is not necessary. . Therefore, it is possible to apply heat to the conductor 2 with a low-cost facility, and the conductor 2 is softened by the applied preheating, so that a cable with less influence of work hardening can be produced.

  As mentioned above, although embodiment of this invention and its Example were demonstrated, embodiment and Example described above do not limit the invention which concerns on a claim. It should be noted that not all combinations of features described in the embodiments and examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 ... Cable 2 ... Conductor 3 ... Insulator 4 ... Insulated electric wire 5 ... Sheath

Claims (5)

A dilute copper alloy wire containing copper containing inevitable impurities, oxygen in an amount exceeding 2 mass ppm, and at least one additive element of Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, Cr, A hard copper wire production process for producing a hard copper wire by performing wire drawing so as to be the final wire diameter,
Preparing a plurality of the hard copper wires and twisting them together to produce a stranded wire; and
A preheating step of subjecting the stranded wire to a pre-heat treatment to transform the hard copper wire into an annealed copper wire;
A coating step of coating the outer periphery of the annealed copper wire with a resin;
The manufacturing method of the insulated wire containing this. 2. The method of manufacturing an insulated wire according to claim 1 , wherein the additive element includes sulfur of 2 mass ppm or more and 12 mass ppm or less, oxygen of more than 2 mass ppm and 30 mass ppm or less, and titanium of 4 mass ppm or more and 55 mass ppm or less. . A method comprising producing a diluted copper alloy material as a molten metal at a molten copper temperature of 1100 ° C. or higher and 1320 ° C. or lower by SCR continuous casting and rolling, and hot rolling the diluted copper alloy material to produce a diluted copper alloy wire. A method for producing an insulated wire according to 1 or 2 . The manufacturing method of the insulated wire of Claim 3 with which the process of producing the said dilute copper alloy wire is performed at the temperature of the rolling roll in a hot rolling process at 880 degrees C or less and 550 degrees C or more. The manufacturing method of the cable including the sheath coating | coated process which coat | covers a sheath to the insulated wire produced by the manufacturing method of the insulated wire of any one of Claim 1 thru | or 4 .