Wire

Abstract

To provide a wire that can be made smaller in size while ensuring its strength, flexibility, electrical conductivity, and current carry capacity.SOLUTION: A wire includes: a steel wire conductor (10) including a steel wire (11) and a copper layer (12) wrapped around an outside of steel wire (11); and an insulation layer (14) wrapped around an outside of steel wire conductor (10). In the present invention, the steel wire of the steel wire conductor has high strength and flexibility, and the copper layer of the steel wire conductor has high conductivity and current carrying capacity. Therefore, the present invention can reduce the size of wire while ensuring its strength, flexibility, conductivity, and current carrying capacity.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Chinese Patent Application No. CN202410238915.X, filed with the State Intellectual Property Office of China on March 1, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a steel wire conductor for wire and a wire comprising a steel wire conductor. [Background technology]

[0003] In the past, smaller and lighter automotive wire harness products have become one of the development trends of automotive technology. Smaller and lighter wires not only reduce costs, but also reduce the overall weight of the vehicle and reduce energy consumption. Therefore, smaller and lighter automotive wire harnesses will become the development trend in the future.

[0004] Currently, signal wires in automotive wiring harnesses are generally 0.35 mm 2 or 0.5 mm 2 The signal wire has a small current and low wire utilization rate, but the strength of the soft copper is weak. If the cross-sectional area of ​​the signal wire becomes smaller, the strength of the signal wire will not meet the application requirements.

[0005] In the prior art, in order to reduce the size of the signal wire, 2 or 0.5 mm 2 Instead of soft copper wire with a cross-sectional area of ​​0.13 mm 2 Copper alloy wires having a cross-sectional area of ​​1000 mm or less are used. Copper alloy wires have high strength, but poor flexibility and are prone to breakage during assembly and application. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made to overcome or mitigate at least one aspect of the above-mentioned disadvantages. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a wire comprising a steel wire conductor and an insulating layer, the steel wire conductor including a steel wire and a copper layer wrapped around the steel wire, and the insulating layer wrapped around the steel wire conductor.

[0008] According to an exemplary embodiment of the present invention, the wire includes a plurality of steel wire conductors, and any two adjacent steel wire conductors of the plurality of steel wire conductors are in contact with each other.

[0009] According to another exemplary embodiment of the present invention, one steel wire conductor among the plurality of steel wire conductors is located at the center of the wire, and the other steel wire conductors among the plurality of steel wire conductors other than the one steel wire conductor located at the center of the wire are arranged around the one steel wire conductor located at the center of the wire.

[0010] According to another exemplary embodiment of the present invention, the steel conductors of the wire have the same diameter and are twisted together.

[0011] According to another exemplary embodiment of the present invention, the diameters of the steel wire conductors other than the one steel wire conductor located at the center of the wire are different from the diameter of the one steel wire conductor located at the center of the wire.

[0012] According to another exemplary embodiment of the present invention, the diameters of the steel wire conductors other than one steel wire conductor located at the center of the wire are smaller than the diameter of the one steel wire conductor located at the center of the wire.

[0013] According to another exemplary embodiment of the present invention, the steel wire conductors other than one steel wire conductor located at the center of the wire among the plurality of steel wire conductors have the same diameter as each other.

[0014] According to another exemplary embodiment of the present invention, the wire comprises seven steel wire conductors, the diameters of the seven steel wire conductors are the same as each other, and the diameters of the steel wires of the seven steel wire conductors are the same as each other.

[0015] According to another exemplary embodiment of the present invention, the diameter of the steel wire conductor is 0.25 mm and the thickness of the copper layer is 3-5 μm.

[0016] According to another exemplary embodiment of the present invention, the wire comprises a single steel wire conductor, the single steel wire conductor being located in the center of the wire.

[0017] According to another exemplary embodiment of the present invention, the wire further comprises a plurality of copper wires disposed around the single steel wire conductor, the single steel wire conductor and the plurality of copper wires being covered with an insulating layer.

[0018] According to another exemplary embodiment of the present invention, the multiple copper wires are twisted around the single steel wire conductor such that the multiple copper wires contact the single steel wire conductor and any two adjacent copper wires in the multiple copper wires contact each other.

[0019] According to another exemplary embodiment of the present invention, the diameter of the steel wire in the single steel wire conductor is larger than the diameter of the copper wire.

[0020] According to another exemplary embodiment of the present invention, the wire comprises eight copper wires, the diameters of the eight copper wires being the same as each other, and the diameters of the eight copper wires being smaller than the diameters of the steel wires in the single steel wire conductor.

[0021] According to another exemplary embodiment of the present invention, the diameter of the steel wire conductor is 0.25 mm, the thickness of the copper layer is 3-5 μm, and the diameter of the copper wire is 0.15 mm.

[0022] According to another exemplary embodiment of the present invention, the thickness of the copper layer is less than 10% of the diameter of the steel wire and greater than 1% of the diameter of the steel wire.

[0023] According to another exemplary embodiment of the present invention, the steel wire is made of low carbon steel with a carbon content of 0.1% or less.

[0024] According to another exemplary embodiment of the present invention, the strength of the steel wire is equal to or greater than 1200 MPa.

[0025] According to another aspect of the present invention, there is provided a wire comprising a single steel wire conductor including a steel wire and a copper layer wrapped around the steel wire, a plurality of copper wires disposed around the single steel wire conductor, and an insulating layer wrapped around the plurality of copper wires.

[0026] In the exemplary embodiment of the present invention described above, the steel wire of the steel wire conductor has high strength and flexibility, and the copper layer of the steel wire conductor has high conductivity and current-carrying capacity. Therefore, the present invention can reduce the size of the wire while ensuring the strength, flexibility, conductivity, and current-carrying capacity of the wire.

[0027] The above and other features of the present invention will become more apparent from the detailed description of illustrative embodiments thereof, taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is an exemplary diagram of a wire according to a first embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of a wire according to a first embodiment of the present invention. [Figure 3] 1 is an exemplary perspective view of a steel wire conductor for wire according to a first embodiment of the present invention; FIG. [Figure 4] 4A and 4B are exemplary diagrams of a wire according to a second embodiment of the present invention; [Figure 5] FIG. 4 is a cross-sectional view of a wire according to a second embodiment of the present invention. [Figure 6] FIG. 10 is an exemplary perspective view of a steel wire conductor for wire according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Like reference numerals refer to like elements. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

[0030] In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are diagrammatically shown to simplify the drawings.

[0031] According to a general aspect of the present invention, there is provided a wire comprising a steel wire conductor and an insulating layer, the steel wire conductor including a steel wire and a copper layer wrapped around the steel wire, and an insulating layer wrapped around the steel wire conductor.

[0032] According to another general aspect of the present invention, there is provided a wire comprising a single steel wire conductor including a steel wire and a copper layer wrapped around the steel wire, a plurality of copper wires disposed around the single steel wire conductor, and an insulating layer wrapped around the plurality of copper wires.

[0033] According to another general aspect of the present invention, there is provided a steel wire conductor for wire, the steel wire conductor comprising a steel wire and a copper layer wrapped around the steel wire.

[0034] First embodiment 1 to 3 show a first embodiment according to the present invention. Among them, Fig. 1 shows an exemplary view of a wire 1 according to the first embodiment of the present invention. Fig. 2 shows a cross-sectional view of the wire 1 according to the first embodiment of the present invention. Fig. 3 shows an exemplary perspective view of a steel wire conductor 10 for the wire 1 according to the first embodiment of the present invention.

[0035] As shown in Figures 1 to 3, an exemplary embodiment of the present invention discloses a wire 1. The wire 1 includes a steel wire conductor 10 and an insulating layer 14. The steel wire conductor 10 is covered with the insulating layer 14. The steel wire conductor 10 includes a steel wire 11 and a copper layer 12. The copper layer 12 covers the outside of the steel wire 11.

[0036] 1 to 3, in the illustrated embodiment, the steel wire 11 of the steel wire conductor 10 has high strength and flexibility, and the copper layer 12 of the steel wire conductor 10 has high conductivity and current-carrying capacity. Therefore, the present invention can reduce the size of the wire 1 while ensuring the strength, flexibility, conductivity, and current-carrying capacity of the wire 1.

[0037] As shown in Figures 1 to 3, in the illustrated embodiment, the wire includes a plurality of steel wire conductors 10, and of the plurality of steel wire conductors 10, any two adjacent steel wire conductors 10 are in contact with each other.

[0038] As shown in Figures 1 to 3, in the illustrated embodiment, one steel wire conductor 10 among the multiple steel wire conductors 10 is located at the center of the wire 1, and the steel wire conductors 10 other than the one steel wire conductor 10 located at the center of the wire 1 are arranged around the one steel wire conductor 10 located at the center of the wire 1.

[0039] As shown in FIGS. 1 to 3, in the illustrated embodiment, the plurality of steel wire conductors 10 in the wire 1 have the same diameter and are twisted together.

[0040] The present invention is not limited to the embodiments shown in Figures 1 to 3. For example, in another exemplary embodiment of the present invention, the diameters of the steel wire conductors 10 other than the one steel wire conductor 10 located at the center of the wire 1 are different from the diameter of the one steel wire conductor 10 located at the center of the wire 1.

[0041] The present invention is not limited to the embodiments shown in Figures 1 to 3. For example, in another exemplary embodiment of the present invention, the diameters of the steel wire conductors 10 other than the one steel wire conductor 10 located at the center of the wire 1 are smaller than the diameter of the one steel wire conductor 10 located at the center of the wire 1.

[0042] The present invention is not limited to the embodiments shown in Figures 1 to 3. For example, in another exemplary embodiment of the present invention, the diameters of the steel wire conductors 10 other than one steel wire conductor 10 located at the center of the wire 1 are the same as each other.

[0043] 1 to 3, in the illustrated embodiment, the wire 1 includes seven steel wire conductors 10, the seven steel wire conductors 10 have the same diameter, and the steel wires 11 of the seven steel wire conductors 10 have the same diameter. However, the present invention is not limited to the embodiment shown in FIGS. 1 to 3. For example, in another exemplary embodiment of the present invention, the wire 1 may include two, three, four, five, six, eight, or more steel wire conductors 10.

[0044] 1 to 3, in the illustrated embodiment, the thickness of the copper layer 12 of the steel wire conductor 10 is less than 10% of the diameter of the steel wire 11 of the steel wire conductor 10 and is greater than 1% of the diameter of the steel wire 11. For example, in the embodiment shown in FIGS. 1 to 3, the thickness of the copper layer 12 may be 3 to 5 μm. However, the present invention is not limited thereto, and for example, the cross section of the copper layer 12 of each steel wire conductor 10 may occupy 40% of the total cross section of each steel wire conductor 10.

[0045] As shown in Figures 1 to 3, another exemplary embodiment of the present invention also discloses a steel wire conductor 10 for a wire 1. The steel wire conductor 10 includes a steel wire 11 and a copper layer 12. The copper layer 12 covers the outside of the steel wire 11.

[0046] As shown in Figures 1 to 3, in the illustrated embodiment, the wire 1 includes seven steel wire conductors 10 having a diameter of 0.25 mm and an insulating layer 14 having a diameter of 1.2 to 1.4 mm. The cross-sectional area of ​​the steel wires 11 in the seven steel wire conductors 10 is approximately 0.35 mm.2 The cross-sectional area of ​​the copper layer 12 in the seven steel wire conductors 10 is about 0.13 mm 2 is.

[0047] 1 to 3, in the illustrated embodiment, the steel wire 11 in the steel wire conductor 10 functions as a strength reinforcing structure to increase the strength of the wire 1, and the copper layer 12 in the steel wire conductor 10 functions as an excellent conductive medium, resulting in stable conductivity of the wire and reliable terminal crimping performance. The insulating layer 14 of the wire 1 can be made of insulating materials such as PVC, XLPE, or FEP depending on various application environments.

[0048] As shown in FIGS. 1-3 , in the illustrated embodiment, to achieve an electrical connection between a terminal (not shown) and a wire 1, the terminal is typically crimped onto one end of the wire 1. The terminal crimp area has a concave-convex sawtooth structure. During the terminal crimping process, as the crimp height decreases, the deformation of the steel wire conductor 10 in the crimp area increases. Within a certain crimp height range, the crimp height decreases, and the greater the deformation of the steel wire, the greater the terminal crimp retention force. Therefore, the steel wire conductor 10 can increase the pressure retention force between the wire 1 and the terminal.

[0049] As shown in Figures 1 to 3, in the illustrated embodiment, the steel wire conductor 10 plays a role in ensuring the strength of the wire structure. The elongation of the steel wire 11 decreases as the strength increases, but the hardness increases. The steel wire 11 undergoes appropriate deformation during the terminal crimping process to ensure reliable crimp retention. At the same time, a low-carbon steel material with a C content of 0.1% is selected, which has excellent compressive toughness and impact toughness. If a high-carbon steel wire 11 is selected, it will be more susceptible to brittle fracture during the terminal crimping process.

[0050] As shown in Figures 1 to 3, in the illustrated embodiment, after the wire 1 is crimped to the terminal, the surface coating of the wire 11 must form a stable and reliable friction force with the terminal to prevent the wire 1 from easily slipping out of the crimped area of ​​the terminal, thereby ensuring a terminal crimp retention force of more than 50 N. By comparatively testing different coatings (zinc, tin, and copper) on the surface of the steel wire 11, it was found that the best crimp retention performance was achieved when there was a copper layer on the surface of the steel wire 11. Experimental testing showed that good crimp retention could be achieved by achieving a copper layer of 3 to 5 μm on the surface of the steel wire 11.

[0051] 1 to 3, in the illustrated embodiment, after a plurality of steel wire conductors 10 are twisted together to form a wire 1, the surface of the steel wire conductor is rounded and has high concentricity. Finally, after the outer insulating layer 14 is extruded, the surface of the wire 1 is rounded and smooth.

[0052] Second embodiment 4 to 6 show a second embodiment of the present invention. Among them, Fig. 4 shows an exemplary view of a wire 1 according to the second embodiment of the present invention. Fig. 5 shows a cross-sectional view of the wire 1 according to the second embodiment of the present invention. Fig. 6 shows an exemplary perspective view of a steel wire conductor 10 for the wire 1 according to the second embodiment of the present invention.

[0053] As shown in Figures 4 to 6, an exemplary embodiment of the present invention discloses a wire 1. The wire 1 includes a single steel wire conductor 10, a plurality of copper wires 13, and an insulating layer 14. The single steel wire conductor 10 is located at the center of the wire 1. The plurality of copper wires 13 are arranged around the single steel wire conductor 10. The single steel wire conductor 10 and the plurality of copper wires 13 are covered with an insulating layer 14.

[0054] 4 to 6, in the illustrated embodiment, the steel wire 11 of the steel wire conductor 10 has high strength and flexibility, and the copper layer 12 of the steel wire conductor 10 has high conductivity and current-carrying capacity. Therefore, the present invention can reduce the size of the wire 1 while ensuring the strength, flexibility, conductivity, and current-carrying capacity of the wire 1.

[0055] As shown in Figures 4 to 6, in the illustrated embodiment, multiple copper wires 13 are twisted around a single steel wire conductor 10 so that the multiple copper wires 13 are in contact with the single steel wire conductor 10 and so that any two adjacent copper wires 13 in the multiple copper wires 13 are in contact with each other.

[0056] As shown in FIGS. 4 to 6, in the illustrated embodiment, the diameter of the steel wire 11 in the single steel wire conductor 10 is larger than the diameter of the copper wire 13.

[0057] 4 to 6, in the illustrated embodiment, the wire 1 includes eight copper wires 13, and the diameters of the eight copper wires 13 are the same as each other and are smaller than the diameter of the steel wires 11 in the single steel wire conductor 10. However, the present invention is not limited to the embodiment shown in FIGS. 4 to 6. For example, in other exemplary embodiments of the present invention, the wire 1 may include four, six, ten, or more copper wires 13.

[0058] 4 to 6, in the illustrated embodiment, the thickness of the copper layer 12 of the steel wire conductor 10 is less than 10% of the diameter of the steel wire 11 of the steel wire conductor 10 and is greater than 1% of the diameter of the steel wire 11. For example, in the embodiment shown in FIGS. 4 to 6, the thickness of the copper layer 12 may be 3 to 5 μm.

[0059] As shown in Figures 4 to 6, another exemplary embodiment of the present invention also discloses a steel wire conductor 10 for a wire 1. The steel wire conductor 10 includes a steel wire 11 and a copper layer 12. The copper layer 12 covers the outside of the steel wire 11.

[0060] As shown in Figures 4 to 6, in the illustrated embodiment, the wire 1 includes a steel wire conductor 10 having a diameter of 0.25 mm and eight copper wires 13 having a diameter of 0.15 mm. The cross-sectional area of ​​the copper layer 12 of the steel wire conductor 10 and the eight copper wires 13 is approximately 0.19 mm. 2 is.

[0061] As shown in Figures 4 to 6, in the illustrated embodiment, when the steel wire conductor 10 and copper wires 13 of the wire 1 are twisted together, the steel wire conductor 10 functions as a strength reinforcing structure located at the center of the wire 1, and the eight copper wires 13 are tightly twisted around the central steel wire conductor 10.

[0062] 4 to 6, in the illustrated embodiment, the copper layer of the steel wire conductor 10 functions as an excellent conductive medium, resulting in stable and reliable terminal crimping performance. The insulating layer 14 of the wire 1 can be made of insulating materials such as PVC, XLPE, or FEP depending on various application environments, and the outer diameter of the insulating layer 14 can be 1.1 to 1.2 mm.

[0063] As shown in FIGS. 4-6, in the illustrated embodiment, a terminal (not shown) is typically crimped onto one end of the wire 1 to achieve an electrical connection between the terminal and the wire 1. The terminal crimp area has a concave-convex sawtooth structure. During the terminal crimping process, as the crimp height decreases, deformation of the steel wire conductor 10 in the crimp area increases. Within a certain crimp height range, the greater the deformation of the steel wire as the crimp height decreases, the greater the terminal crimp retention force.

[0064] As shown in Figures 4 to 6, in the illustrated embodiment, the steel wire conductor 10 serves to ensure the strength of the wire structure. The diameter of the steel wire conductor 10 can be 0.25 mm, and the strength of the steel wire 11 is selected as 1200 MPa, which corresponds to a tensile force of 60 N. The tensile force of the eight copper wires 13 is 26 N. The final design tensile force of the wire 1 is 86 N, which has a certain design margin compared to the standard 50 N.

[0065] As shown in Figures 4 to 6, in the illustrated embodiment, the elongation of the steel wire 11 decreases as the strength increases, but the hardness increases. The steel wire 11 with a strength of 1200 MPa maintains good ductility and low hardness, undergoes appropriate deformation during terminal crimping, and achieves reliable crimp retention. At the same time, the steel wire 11 is made of a low-carbon steel material with a C content of 0.1%, which has excellent compressive toughness and impact toughness. Experimental verification has shown that selecting a high-carbon steel wire with a strength exceeding 2000 MPa for the steel wire 11 would result in brittle fracture during the terminal crimping process.

[0066] As shown in Figures 4 to 6, in the illustrated embodiment, after the wire 1 is crimped to the terminal, the surface coating of the steel wire 11 must create a stable and reliable friction force with the terminal to prevent the wire 1 from easily slipping out of the crimped area of ​​the terminal. Therefore, it is necessary to ensure that the terminal crimp retention force exceeds 50 N. By comparing and verifying different surface coatings (zinc, tin, and copper) of the steel wire 11, it was found that the best crimp retention performance was achieved when there was a copper layer on the surface of the steel wire 11. The copper layer on the surface of the steel wire 11 deformed together with the surrounding copper wire 13, resulting in a connection effect similar to that of cold welding. Experimental verification showed that a 3 to 5 μm copper layer on the surface of the steel wire 11 could achieve good crimp retention.

[0067] As shown in Figures 4 to 6, in the illustrated embodiment, the steel wire conductor 10 covered with the copper layer 12 may have an outer diameter of 0.25 mm, and the copper wire 13 may have an outer diameter of 0.15 mm. The size design of the steel wire conductor 10 and the copper wire 13 employs special stranding parameters and processes to ensure that the copper wire 13 completely covers the central steel wire conductor 10 after stranding. After stranding, the surfaces of the multiple copper wires 13 are rounded and have extremely high concentricity. Finally, the surface of the wire 1 after extrusion of the outer insulating layer 14 is rounded and smooth.

[0068] Those skilled in the art will appreciate that the above embodiments are intended to be illustrative and not limiting. For example, many modifications may be made to the above embodiments by those skilled in the art, and various features described in different embodiments may be freely combined with each other without causing any discrepancy in structure or principle.

[0069] While several exemplary embodiments have been shown and described, it will be appreciated by those skilled in the art that various modifications or variations may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined in the claims and their equivalents.

[0070] As used herein, an element referred to in the singular and preceded by the words "a" or "an" does not exclude a plurality of such elements or steps, unless expressly stated otherwise. Furthermore, references to "one embodiment" of the invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Also, unless expressly stated otherwise, embodiments "comprising" or "having" an element or elements having a particular characteristic may include additional such elements that do not have that characteristic.

Claims

1. Steel wire (11), and A copper layer (12) surrounding the steel wire (11) A steel wire conductor (10) comprising: an insulating layer (14) covering the steel wire conductor (10); A wire comprising:

2. The wire (1) according to claim 1, wherein the wire (1) comprises a plurality of steel wire conductors (10), and any two adjacent steel wire conductors (10) of the plurality of steel wire conductors (10) are in contact with each other.

3. 3. The wire according to claim 2, wherein one of the plurality of steel wire conductors is located at the center of the wire, and the other steel wire conductors other than the one steel wire conductor located at the center of the wire are arranged around the one steel wire conductor located at the center of the wire.

4. 4. The wire according to claim 3, wherein the steel wire conductors (10) in the wire (1) have the same diameter and are twisted together.

5. 4. The wire according to claim 3, wherein the diameters of the steel wire conductors (10) other than the one steel wire conductor (10) located at the center of the wire (1) are different from the diameter of the one steel wire conductor (10) located at the center of the wire (1).

6. 6. The wire according to claim 5, wherein the diameters of the steel wire conductors (10) other than the one steel wire conductor (10) located at the center of the wire (1) are smaller than the diameter of the one steel wire conductor (10) located at the center of the wire (1).

7. The wire according to claim 5, wherein the steel wire conductors (10) among the plurality of steel wire conductors (10) other than the one steel wire conductor (10) located at the center of the wire (1) have the same diameter as each other.

8. 4. The wire (1) according to claim 3, wherein the wire (1) comprises seven steel wire conductors (10), the diameters of the seven steel wire conductors (10) being the same as each other, and the diameters of the steel wires (11) of the seven steel wire conductors (10) being the same as each other.

9. The wire according to claim 8, wherein the diameter of the steel wire conductor (10) is 0.25 mm and the thickness of the copper layer (12) is 3 to 5 μm.

10. 2. The wire (1) according to claim 1, wherein the wire (1) comprises a single steel wire conductor (10), the single steel wire conductor (10) being located at the center of the wire (1).

11. Further comprising a plurality of copper wires (13) arranged around the single steel wire conductor (10); 11. The wire of claim 10, wherein the single steel wire conductor (10) and the plurality of copper wires (13) are covered with the insulating layer (14).

12. 12. The wire according to claim 11, wherein the plurality of copper wires (13) are twisted around the single steel wire conductor (10) such that the plurality of copper wires (13) are in contact with the single steel wire conductor (10) and any two adjacent copper wires (13) in the plurality of copper wires (13) are in contact with each other.

13. 12. The wire according to claim 11, wherein the diameter of the steel wire (11) in the single steel wire conductor (10) is greater than the diameter of the copper wire (13).

14. 12. The wire (1) according to claim 11, wherein the wire (1) comprises eight copper wires (13), the diameters of the eight copper wires (13) being the same as each other, and the diameters of the eight copper wires (13) being smaller than the diameter of the steel wire (11) in the single steel wire conductor (10).

15. 15. The wire according to claim 14, wherein the diameter of the steel wire conductor (10) is 0.25 mm, the thickness of the copper layer (12) is 3-5 μm, and the diameter of the copper wire (13) is 0.15 mm.

16. 16. The wire according to any one of the preceding claims, wherein the thickness of the copper layer (12) is less than 10% of the diameter of the steel wire (11) and more than 1% of the diameter of the steel wire (11).

17. 16. Wire according to any one of the preceding claims, wherein the steel wire (11) is made of low carbon steel with a carbon content of 0.1% or less.

18. 16. The wire according to any one of the preceding claims, wherein the strength of the steel wire (11) is 1200 MPa or more.

19. Steel wire (11), and A copper layer (12) surrounding the steel wire (11) a single steel wire conductor (10) including a plurality of copper wires (13) arranged around the single steel wire conductor (10); an insulating layer (14) covering the copper wires (13); A wire comprising:

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