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JP-7856177-B2 - Electric wire conductors and insulated wires

JP7856177B2JP 7856177 B2JP7856177 B2JP 7856177B2JP-7856177-B2

Inventors

  • 前嶋 悠佑
  • 大塚 保之
  • 今里 文敏

Assignees

  • 株式会社オートネットワーク技術研究所
  • 住友電装株式会社
  • 住友電気工業株式会社

Dates

Publication Date
20260511
Application Date
20250131

Claims (8)

  1. A single-strand core wire made of stainless steel, It has a copper coating layer made of copper or a copper alloy that covers the outer circumference of the core wire, The conductor cross-sectional area is less than 0.13 mm² . The Young's modulus is less than 1.1 × 10⁵ MPa. The tensile strength is 1080 MPa or less. A wire conductor used in a single-strand configuration.
  2. The electric wire conductor according to claim 1, wherein the Young's modulus of the core wire is 1.2 × 10⁵ MPa or more.
  3. A wire conductor according to claim 1 or claim 2, having a tensile strength of 950 MPa or more.
  4. The electric wire conductor according to any one of claims 1 to 3, wherein the stainless steel constituting the core wire is SUS 304H.
  5. A wire conductor according to any one of claims 1 to 4, wherein the copper coating layer is formed on the surface of the core wire and then subjected to heat treatment at a temperature of 100°C to 400°C.
  6. A wire conductor according to any one of claims 1 to 5, An insulated wire having an insulating coating that covers the outer circumference of one of the aforementioned wire conductors.
  7. The aforementioned electric wire conductors are arranged in parallel in multiples, Each outer circumference of the aforementioned wire conductor is covered with the insulating coating, thereby forming a covered portion. The insulated wire according to claim 6, wherein the spaces between the covering portions are connected by connecting portions that are integrated with the insulating covering of the covering portions.
  8. The insulated wire according to claim 7, wherein the distance between at least one pair of adjacent conductors is 0.2 mm or more and 1.2 mm or less.

Description

This disclosure relates to electric wire conductors and insulated electric wires. In automobiles, communication wires are connected to various communication devices via connectors. As devices become smaller, connectors are also being made smaller and lighter. When connectors become smaller, the communication wires connected to them also need to be thinner. For example, Patent Document 1 describes a stranded conductor using strands of a Cu alloy containing Fe, with a conductor cross-sectional area reduced to 0.13 mm² . Japanese Patent Publication No. 2018-085344Japanese Patent Publication No. 2018-37324 Figure 1 is a cross-sectional view showing a single-wire insulated electric wire according to one embodiment of the present disclosure.Figures 2A and 2B are cross-sectional views showing flat wires. Figures 2A and 2B show different configurations.Figures 3A and 3B are side views illustrating the buckling of a wire, with Figure 3A showing the state before buckling and Figure 3B showing the state after buckling.Figure 4 shows the buckling force measurement results for insulated wires with three types of conductors.Figures 5A to 5C are photographs of insulated wires with three types of conductors after buckling. Figure 5A shows a copper-clad stainless steel wire after softening, Figure 5B shows a copper-clad stainless steel wire without softening, and Figure 5C shows a Cu-Sn alloy wire. All figures are shown for a test distance of 2.0 mm.Figure 6 shows the measurement results of buckling for insulated wires with three types of conductors.Figure 7 shows the evaluation results regarding the relationship between the tensile strength and buckling amount of an electric wire conductor.Figures 8A and 8B show the evaluation results regarding the relationship between the tensile strength and crimping strength of electric wire conductors. Figure 8A shows the case of low compression, and Figure 8B shows the case of high compression. [Description of Embodiments in this Disclosure] First, embodiments of this disclosure will be listed and described. The electric wire conductor according to this disclosure comprises a single core wire made of stainless steel and a copper coating layer made of copper or a copper alloy that covers the outer circumference of the core wire, has a conductor cross-sectional area of less than 0.13 mm² and a Young's modulus of less than 1.1 × 10⁵ MPa, and is used in a single-wire state. The above-mentioned electric wire conductor has a structure in which a copper coating layer is provided on the outer circumference of a stainless steel core wire. Despite having a small conductor cross-sectional area of less than 0.13 mm² , it possesses high material strength and is less prone to buckling when the electric wire conductor is inserted into a connector terminal. In other words, because a copper coating layer made of a low-rigidity material is placed on the outer circumference of a highly rigid stainless steel core wire, even if the electric wire conductor is deformed when inserted into a connector terminal, the deformation is easily resolved, making it less likely to lead to irreversible buckling. Due to the presence of the low-rigidity copper coating layer, the Young's modulus of the electric wire conductor as a whole is a small value of less than 1.1 × 10⁵ MPa, resulting in a smaller buckling force than materials with an even higher Young's modulus. Therefore, although buckling is more likely to occur even with a small force when inserted into a connector terminal, the effect of the copper coating layer in promoting the resolution of deformation during buckling reduces the amount of deformation of the electric wire conductor due to buckling. As a result, the impact of buckling when inserted into a connector terminal is reduced. Here, the Young's modulus of the core wire is preferably 1.2 × 10⁵ MPa or higher. This high Young's modulus of the core wire enhances the reduction of buckling force and deformation of the wire conductor due to buckling, thereby increasing the effectiveness of reducing the effects of buckling. The aforementioned wire conductor should preferably have a tensile strength of 950 MPa or higher. This increases the strength of the wire conductor, making it less prone to buckling when inserted into the connector terminal. Furthermore, when the connector terminal is inserted into the wire conductor and crimped, high strength is achieved at the crimped portion. A wire conductor with such tensile strength can be suitably manufactured through heat treatment. The stainless steel constituting the core wire is preferably SUS 304H. SUS 304H is a material that exhibits high Young's modulus, tensile strength, and elongation at break, making it suitable for use as a core wire component. The insulated wire according to this disclosure comprises a wire conductor and an insulating coating that covers the outer circumference of one of the wire conductors. This insulated wire has a small conductor cross