Twisted pair wires, communication wires and wire harnesses

Abstract

To suppress variations in characteristic impedance even when a temperature changes.SOLUTION: A wire 1A for communication includes insulated wires 11A and 11B having conductors 111 which are composed of a single wire or a twisted wire, and have tensile strengths of 600 MPa or more and elongations at break of 1% or more and less than 7%, and cross-sectional areas of 0.35 mm2 or less, and insulated films 112 that cover the outer peripheries of the conductors and are formed of a polyolefin-based resin, wherein the insulated wires 11A and 11B constitute a twisted pair 2. The twisted pair 2 is covered with a sheath 12A formed of a polyolefin-based resin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a twisted pair wire, a communication wire, and a wire harness. [Background technology]

[0002] Inventions of electric wires used for communication inside an automobile include, for example, electric wires disclosed in Patent Documents 1 to 11. Patent Documents 1 to 10 disclose communication electric wires having a characteristic impedance in the range of 100Ω±10Ω, which are formed by twisting together electric wires including conductors having a tensile strength of 400 MPa or more and a breaking elongation of 7% or more and an insulating coating that covers the conductor. Patent Document 11 discloses an electric wire for transmitting information inside a vehicle, which is formed by twisting together conductors that are Sn-Cu alloys and have a tin content of 0.2 to 1.5 wt%. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6108057 [Patent Document 2] Patent No. 6164382 [Patent Document 3] Patent No. 6274346 [Patent Document 4] Patent No. 6447756 [Patent Document 5] JP 2019-33101 A [Patent Document 6] JP 2017-188431 A [Patent Document 7] Patent No. 6485591 [Patent Document 8] International Publication No. 2018 / 117204 [Patent Document 9] International Publication No. 2018 / 143350 [Patent Document 10] JP 2019-114548 A [Patent Document 11] JP 2009-245742 A Summary of the Invention [Problem to be solved by the invention]

[0004] Strict control of characteristic impedance is required for wires used for high-speed communication inside automobiles. For example, 100BASE-T1, which is the in-vehicle Ethernet (registered trademark), specifies a characteristic impedance of 100Ω±10Ω. In addition, 100BASE-T1 requires that the characteristic impedance be within the range of 100Ω±10Ω over the entire operating temperature range.

[0005] However, when the temperature of an electric wire installed inside an automobile rises, the dielectric constant of the insulating coating changes, causing the characteristic impedance to change. If the change in the characteristic impedance is large, there is a risk that the characteristic impedance will fall outside the range of 100Ω±10Ω.

[0006] The present invention has been made in view of the above, and has an object to provide a technique for suppressing fluctuations in characteristic impedance even when temperature changes. [Means for solving the problem]

[0007] In order to solve the above problems and achieve the object, a twisted pair wire according to one aspect of the present invention is made of a single wire or a twisted wire, has a tensile strength of 600 MPa or more, a breaking elongation of 1% or more and less than 7%, and a cross-sectional area of ​​0.35 mm 2 The present invention is characterized in that it comprises an electric wire having a conductor as described below and an insulating coating formed of a polyolefin resin that covers the outer periphery of the conductor, and the electric wire is twisted in pairs.

[0008] A communication electric wire according to one aspect of the present invention includes the twisted pair wire described above, and a sheath made of a polyolefin resin that covers an outer periphery of the twisted pair wire.

[0009] A wire harness according to one aspect of the present invention includes the twisted pair wire or the communication wire, and is arranged in an automobile. Effect of the Invention

[0010] According to the present invention, there is an advantage that the fluctuation of the characteristic impedance is suppressed even when the temperature changes. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a communication electric wire having a pipe-shaped sheath. [Diagram 2] FIG. 2 is a cross-sectional view of a communication wire having a solid sheath. [Diagram 3] FIG. 3 is a diagram showing how to twist a twisted pair of wires. [Figure 4] FIG. 4 is a plan view showing a schematic diagram of the wiring of communication wires in an automobile. [Diagram 5] FIG. 5 is a cross-sectional view of a communication wire according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment described below. In addition, in the description of the drawings, the same or corresponding elements are appropriately assigned the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationship of each element may differ from the actual one. There may also be parts in which the dimensional relationship and ratio are different between the drawings.

[0013] 1 is a cross-sectional view of a communication electric wire 1A according to one embodiment of the present invention. The communication electric wire 1A has a characteristic impedance in the range of 100Ω±10Ω. The communication electric wire 1A is wired, for example, in an automobile and used for communication in the automobile in accordance with the Ethernet (registered trademark) standard.

[0014] The communication electric wire 1A is composed of an insulated electric wire 11A, an insulated electric wire 11B, and a sheath 12A. The insulated electric wire 11A and the insulated electric wire 11B are twisted together to form a twisted pair wire 2, and the twisted pair wire 2 is covered with a sheath 12A.

[0015] (sheath) The sheath 12A contributes to protecting the twisted pairs 2, stabilizing the twisting of the twisted pairs 2, and ensuring the distance between the twisted pairs 2 and the surrounding environment. The sheath 12A is preferably formed of a resin based on a polyolefin resin. In this embodiment, the sheath 12A is formed of a halogen-free material based on a polyolefin resin to which a flame retardant and an antioxidant are added. The shape of the sheath 12A is a hollow pipe type, with a radial cross-sectional thickness of 0.75 mm and an outer diameter of 3.2 mm.

[0016] Regarding the hardness of the sheath 12A, if it is too soft, problems such as wear and deformation may occur, whereas if it is too hard, the twisted pairs 2 will not open when the temperature rises, so there is a desirable range of hardness. In this embodiment, the hardness of the sheath 12A is preferably within the range of D25 to D70, and more preferably within the range of D40 to D60, when measured with a type D durometer according to JIS K 6253-3.

[0017] The sheath protecting the twisted pair wires 2 may be a solid sheath that is not hollow, instead of the pipe-type sheath 12A shown in Fig. 1. Fig. 2 is a cross-sectional view of a communication electric wire 1B having a solid sheath 12B. A tape or the like may be interposed between the twisted pair wires 2 and the sheaths 12A and 12B. When the sheath is the solid sheath 12B, the hardness of the sheath 12B is preferably within the range of D30 to D40 when measured with a type D durometer according to JIS K 6253-3.

[0018] (Insulated Wire) The insulated wire 11A is composed of a conductor 111 and an insulating coating 112. The conductor 111 is an annealed compressed conductor formed by compressing seven S-twisted wires 1111. The conductor 111 is an example of a twisted wire. It is preferable to anneal this compressed conductor by setting the heating temperature, heating time, temperature holding time after heating, and cooling time so that the tensile strength of the compressed conductor is in the range of 600 MPa to 1200 MPa and the breaking elongation is 1% or more and less than 7%. In this embodiment, the annealed conductor 111 has a tensile strength of 800 MPa and a breaking elongation of 2.5%. The radial cross-sectional area of ​​the conductor 111 is 0.05 mm in order to set the characteristic impedance to 100 Ω±10 Ω. 2 (0.05sq) or more and 0.35mm 2 From the viewpoint of reducing weight and diameter when wired in an automobile, the cross-sectional area of ​​the conductor 111 in the radial direction is preferably 0.22 mm 2 (0.22sq), preferably less than 0.13mm 2 It is more preferable that the thickness of the wires 1111 is (0.13 sq.). The number of wires 1111 constituting the conductor 111, which is a twisted wire, is not limited to seven, and may be other numbers. Also, the conductor 111 may be a solid wire instead of a twisted wire.

[0019] The wire 1111 is made of a copper alloy with a tin concentration of 0.7 mass%. The tin concentration in the wire 1111 is preferably 0.4 mass% or more and 0.8 mass% or less, and more preferably 0.6 mass% or more and 0.8 mass% or less. The wire 1111 may also be made of a copper alloy with a silver concentration of 1 mass% or more and 4 mass% or less. The insulated wire 11B has the same configuration as the insulated wire 11A, and therefore a description thereof will be omitted.

[0020] The insulating coating 112 is preferably made of a resin with a low dielectric constant, and is formed of a resin based on a polyolefin resin such as PE (polyethylene), EVA (ethylene vinyl acetate), or PP (polypropylene). In this embodiment, the insulating coating 112 is formed of a halogen-free material based on PP with added flame retardants and antioxidants.

[0021] In this embodiment, the thickness of the insulating coating 112 is set to 0.2 mm in combination with the diameter of the conductor 111 and the thickness of a sheath 12A described later, so that the characteristic impedance of the communication electric cable 1A is 100Ω±10Ω.

[0022] The hardness of the insulating coating 112 is preferably such that it does not cause plastic deformation when the communication electric wires 1A, 1B are installed in an automobile and the temperature rises, and for example, in the communication electric wire 1A having the pipe-type sheath 12A, the hardness of the insulating coating 112 is preferably equal to that of the sheath 12A. In the communication electric wire 1B having the solid sheath 12B, the hardness of the insulating coating 112 is preferably equal to that of the sheath 12B.

[0023] (twisted pair wire) 3 is a diagram showing a method of twisting the twisted pair wire 2. The twisted pair wire 2 is a twisted wire obtained by twisting the insulated electric wires 11A and 11B with a double twist buncher type twisting machine. In this embodiment, the twisted pair wire 2 has a pitch of 20 mm and is twisted with a Z twist.

[0024] However, when insulated electric wires 11A and 11B are simply twisted together, insulated electric wires 11A and 11B are twisted when they are twisted together, and this twist creates an untwisting force, making twisted pair 2 prone to coming apart.

[0025] Therefore, in this embodiment, while insulated electric wires 11A and 11B are twisted and rotated together in a direction opposite to the rotational direction of the twisting (i.e., a rotational direction that reduces the twisting of insulated electric wires 11A and 11B due to the twisting), a so-called twist-back is performed to prevent twisting.

[0026] Here, the ratio Y / X of the twisting rotation angle X to the twisting rotation angle Y is called the twisting ratio. That is, when the insulated electric wires 11A and 11B are not twisted at all and the insulated electric wires 11A and 11B are in a twisted state, the twisting ratio is 0%, and when the insulated electric wires 11A and 11B are twisted at all and the insulated electric wires 11A and 11B are not twisted at all, the twisting ratio is 100%. In this embodiment, the twisting ratio of the twisted pair wire 2 is 100%. By setting the twisting ratio to 100%, the insulated electric wires 11A and 11B are less likely to come apart.

[0027] (Functions and Effects of Telecommunication Cables) When the temperature of the communication electric wires 1A, 1B rises, the dielectric constant of the sheaths 12A, 12B and the insulating coating 112 increases, so that the sheaths 12A, 12B and the insulating coating 112 act to reduce the characteristic impedance of the communication electric wires 1A, 1B.

[0028] On the other hand, in the twisted pair wire 2, when the temperature rises, the insulated wires 11A, 11B expand. When the insulated wires 11A, 11B expand, the gap between the twisted pair of insulated wires 11A, 11B opens against the pressure of the sheaths 12A, 12B because the tensile strength of the insulated wires 11A, 11B is as hard as 600 MPa or more. This gap between the wires of the twisted pair wire 2 acts to increase the characteristic impedance of the communication wires 1A, 1B.

[0029] In this way, in the communication cables 1A and 1B, an increase in temperature causes both a decrease and an increase in the characteristic impedance, and one effect cancels out the other, thereby suppressing changes in the characteristic impedance due to an increase in temperature.

[0030] (evaluation) The change in characteristic impedance due to temperature rise was evaluated for the above-mentioned communication electric wires 1A and 1B. For this evaluation, Examples 1 and 2 having the configuration of communication electric wire 1A were created, and Examples 3 and 4 having the configuration of communication electric wire 1B were created. In addition, Comparative Examples 1, 2, and 5 were created for comparison with Examples 1 and 2, and Comparative Examples 3 and 4 were created for comparison with Examples 3 and 4.

[0031] In Examples 1 to 4, the wire 1111 was made of a copper alloy with a tin concentration of 0.7 mass %, and the conductor 111 was annealed to have a tensile strength of 800 MPa and a breaking elongation of 2.5%. In Examples 1 to 4, the cross-sectional area of ​​the conductor 111 in the radial direction was 0.13 mm 2 The insulating coating 112 in Examples 1 to 4 was made of a halogen-free material based on PP (polypropylene) with added flame retardant and antioxidant, and had a radial thickness of 0.2 mm.

[0032] The sheaths 12A and 12B according to Examples 1 to 4 were formed of a halogen-free material based on a polyolefin resin, and had a radial thickness of 0.75 mm. Regarding the outer diameter and hardness of the sheaths 12A and 12B according to Examples 1 to 4, the sheath 12A of Example 1 had an outer diameter of 3.2 mm and a hardness measured by a durometer (HDD) of D55. The sheath 12A of Example 2 had an outer diameter of 2.5 mm and a hardness measured by a durometer (HDD) of D55. The sheath 12B of Example 3 had an outer diameter of 3.2 mm and a hardness measured by a durometer (HDD) of D45, which was softer than those of Examples 1 and 2. The sheath 12B of Example 4 had an outer diameter of 2.5 mm and a hardness measured by a durometer (HDD) of D45, which was softer than those of Examples 1 and 2.

[0033] In Comparative Examples 1 to 4, the wire 1111 was made of tough pitch copper, and the conductor 111 was annealed to have a tensile strength of 200 MPa and a breaking elongation of 20%.2 The insulating coating 112 in Comparative Examples 1 to 4 was made of a halogen-free material based on PP (polypropylene) with added flame retardant and antioxidant, and had a radial thickness of 0.2 mm.

[0034] The sheaths 12A and 12B according to Comparative Examples 1 to 4 were formed of a halogen-free material based on a polyolefin resin, as in Examples 1 to 4, and had a radial thickness of 0.75 mm. Regarding the outer diameter and hardness of the sheaths 12A and 12B according to Comparative Examples 1 to 5, the sheath 12A of Comparative Example 1 had an outer diameter of 3.2 mm and a hardness measured by a durometer (HDD) of D55. The sheath 12A of Comparative Example 2 had an outer diameter of 2.5 mm and a hardness measured by a durometer (HDD) of D55. The sheath 12B of Comparative Example 3 had an outer diameter of 3.2 mm and a hardness of Dyy. The sheath 12B of Comparative Example 4 had an outer diameter of 2.5 mm and a hardness measured by a durometer (HDD) of D45.

[0035] In Comparative Example 5, the wire 1111 was made of a copper alloy containing 0.7 mass % tin, and the conductor 111 was annealed to have a tensile strength of 450 MPa and a breaking elongation of 3%. 2 The thickness of the insulating coating 112 in Comparative Example 5 was 0.13 sq. The insulating coating 112 in Comparative Example 5 was made of a halogen-free material based on PP (polypropylene) to which a flame retardant and an antioxidant were added, and had a radial thickness of 0.2 mm. The sheath 12A in Comparative Example 5 was made of a halogen-free material based on polyolefin resin, had a radial thickness of 0.75 mm, an outer diameter of 3.2 mm, and a hardness measured with a durometer (HDD) of D55.

[0036] The characteristic impedance of each of Examples 1 to 4 and Comparative Examples 1 to 5 was measured by TDR (Time Domain Reflectometry) using an E5071C ENA vector network analyzer manufactured by Keysight Technologies, Inc. For the measurement by TDR, the rise time of the pulse signal used for the measurement was set to 700 ps, ​​and the average of the central 8 m of the 10 m was used as the characteristic impedance for each of Examples 1 to 4 and Comparative Examples 1 to 5. In addition, in order to observe the change in characteristic impedance due to temperature change, the characteristic impedance was measured for each of Examples 1 to 4 and Comparative Examples 1 to 5 at room temperature (23°C), -40°C, and 105°C.

[0037] The configurations of Examples 1 to 4 and Comparative Examples 1 to 5 and the measurement results of the characteristic impedance are shown in Table 1. In addition, for Examples 1 to 4 and Comparative Examples 1 to 5, when the temperature rises, the degree of effect on the characteristic impedance of each of the following factors is shown in Table 2: the gap between the insulated wires 11A and 11B constituting the twisted pair wire 2, the holding of the insulated wires 11A and 11B by the sheaths 12A and 12B, the change in the dielectric constant of the sheaths 12A and 12B, and the change in the dielectric constant of the insulating coating 112. In Table 2, "+" indicates that the characteristic impedance is increased, and the more "+" there is, the greater the effect of increasing the characteristic impedance. In addition, in Table 2, "-" indicates that the characteristic impedance is decreased, and the more "-" there is, the greater the effect of decreasing the characteristic impedance.

[0038] [Table 1]

[0039] [Table 2]

[0040] In Table 1, regarding the suppression of change in characteristic impedance when the temperature is increased from room temperature to high temperature, when the change in characteristic impedance is -2Ω<change<+2Ω, it is rated as the best "◎", when 2Ω≦change, it is rated as the next best "○", when -4Ω<change≦-2Ω, it is rated as "△", which is worse than "◯", and when change≦-4Ω, it is rated as "×", which is worse than "△".

[0041] It is assumed that the communication electric wires 1A and 1B are used as wire harnesses for automobiles. When the communication electric wires 1A and 1B are used as wire harnesses for automobiles, other electric wires, exterior materials of the automobile, metal bodies of the automobiles, and the like are close to the communication electric wires 1A and 1B, and the characteristic impedance is reduced due to the influence of these. In addition to this reduction in characteristic impedance, a further reduction in characteristic impedance due to a temperature change to a high temperature further increases the amount of change in characteristic impedance. For this reason, in the evaluation of Examples 1 to 4 and Comparative Examples 1 to 5, the lower the characteristic impedance value is compared to that at room temperature, the worse the characteristic impedance is judged to be.

[0042] As shown in Table 1, in Examples 1 to 4, the change in characteristic impedance was small when the temperature was changed from room temperature to a high temperature (105°C), and all of them were given a good result of "◎" for suppression of the change in characteristic impedance. On the other hand, in Comparative Examples 1 to 5, the change in characteristic impedance was -3Ω or more when the temperature was changed from room temperature to a high temperature (105°C), and the suppression of the change in characteristic impedance was given a result of "△" or "×".

[0043] Next, the effect on the characteristic impedance when the temperature increases of each of the following will be described: the spacing between insulated wires 11A, 11B that make up twisted pair 2, the containment of insulated wires 11A, 11B by sheaths 12A, 12B, the change in the dielectric constant of sheaths 12A, 12B, and the change in the dielectric constant of insulating coating 112.

[0044] First, regarding the effect of increasing the characteristic impedance when the temperature rises, when the spacing between the insulated wires 11A, 11B constituting the twisted pair wire 2 is examined individually, it is "++++" as shown in Table 2, and the temperature rise acts to greatly increase the characteristic impedance in all of Examples 1 to 4 and Comparative Examples 1 to 5.

[0045] First, in Comparative Examples 1 to 5, the conductor 111 is tough pitch copper, and has a tensile strength of 200 MPa and a breaking elongation of 20%, which is softer than Examples 1 to 4. Therefore, even if the temperature rises, the sheaths 12A and 12B suppress the gap between the insulated wires 11A and 11B. By suppressing the gap between the insulated wires 11A and 11B, the increase in the characteristic impedance can be suppressed. In other words, the holding of the insulated wires 11A and 11B by the sheaths 12A and 12B has the effect of relatively lowering the characteristic impedance, and the degree of this effect is large, "---".

[0046] In Comparative Examples 1 to 5, when the temperature rises, the dielectric constant of the sheaths 12A and 12B rises and the characteristic impedance falls. The degree of this effect is smaller than the effect of the suppression by the sheaths 12A and 12B, and the degree of the effect of lowering the characteristic impedance is "-". In Comparative Examples 1 to 5, when the temperature rises, the dielectric constant of the insulating coating 112 rises and the characteristic impedance falls. The degree of this effect is smaller than the effect of the suppression by the sheaths 12A and 12B and larger than the effect of the increase in the dielectric constant of the sheaths 12A and 12B, and the degree of the effect of lowering the characteristic impedance is "-".

[0047] Thus, in Comparative Examples 1 to 5, the sum of the extent of the "+" effect of increasing the characteristic impedance is 4, while the sum of the extent of the effect of decreasing the characteristic impedance is 7, so that the effect of decreasing the characteristic impedance is greater than the effect of increasing it, resulting in large fluctuations in the characteristic impedance.

[0048] On the other hand, in Examples 1 to 4, conductor 111 has a tensile strength of 800 MPa and a breaking elongation of 2.5%, which is harder than Comparative Examples 1 to 5. Therefore, the force exerted by insulated wires 11A, 11B to separate the wires is stronger than in Comparative Examples 1 to 5, and when the temperature rises, the wires of insulated wires 11A, 11B are opened more widely against the suppressing force of sheaths 12A, 12B than in Comparative Examples 1 to 5. The effect of the separation of insulated wires 11A, 11B causing a relative decrease in the characteristic impedance is "-", which is smaller than in Comparative Examples 1 to 5.

[0049] In addition, in Examples 1 to 4, as the temperature rises, the dielectric constant of the sheaths 12A and 12B rises and the characteristic impedance falls. The degree of this effect is smaller than the effect of the suppression by the sheaths 12A and 12B, and the degree of the effect of lowering the characteristic impedance is "-". In addition, in Examples 1 to 4, as the temperature rises, the dielectric constant of the insulating coating 112 rises and the characteristic impedance falls. The degree of this effect is smaller than the effect of the suppression by the sheaths 12A and 12B and larger than the effect of the increase in the dielectric constant of the sheaths 12A and 12B, and the degree of the effect of lowering the characteristic impedance is "-".

[0050] Thus, in Examples 1 to 4, the total degree of the "+" effect that increases the characteristic impedance is 4, while the total degree of the "-" effect that decreases the characteristic impedance is 4, so the effect that attempts to increase the characteristic impedance is offset by the effect that attempts to decrease it, and fluctuations in the characteristic impedance are suppressed.

[0051] (Wire harness) Next, an example of wiring the communication wires 1A and 1B in an automobile will be described. The communication wires 1A and 1B of the present invention can be used in combination with a normal wire harness, and can also be used in the examples described below. FIG. 4 is a plan view that shows a schematic diagram of wiring the communication wire 1A or the communication wire 1B according to the above-mentioned embodiment. The automobile 1000 shown in FIG. 4 is an automobile including, for example, a hybrid car, an electric car, or a fuel cell car. The automobile 1000 has a wiring structure 500 for a wire harness.

[0052] The wiring structure 500 is a system that supplies power from a secondary battery BAT possessed by an automobile 1000 to electrical equipment and relays signals exchanged between an ECU (Electronic Control Unit) 600 that controls the electrical equipment and the electrical equipment. The wiring structure 500 has a plurality of electric connection boxes and a plurality of cables. The secondary battery BAT is a secondary battery that can be repeatedly charged and discharged. The voltage of the secondary battery BAT is, for example, 12V, 24V, 48V, etc., and supplies power to a plurality of electrical equipment. The position of the secondary battery BAT is not limited to the position shown in the figure.

[0053] In order to avoid the drawing becoming too complicated, in FIG. 4, electrical components 7101 to 710 n (n is an integer of 2 or more) and Electrical Equipment 7201 to 720 m (m is an integer of 2 or more) is illustrated, and other electrical components are omitted. Note that FIG. 4 is a diagram showing wiring in schematic form, so that electrical components 7101 to 710 are illustrated. n and electrical equipment 7201-720 m Please note that the actual placement locations of do not necessarily match those shown in FIG.

[0054] The wiring structure 500 has a plurality of cables, namely, cable BW1, cable BW2, cable RW, cable LW, cable RW1, cable LW1, cable RW11, and cable LW11. Among the cables RW, cable LW, cable RW1, cable LW1, cable RW11, and cable LW11, the cables used for communication between electrical components and an ECU are cables having the above-mentioned communication electric wire 1A or communication electric wire 1B, and are an example of a wire harness.

[0055] The wiring structure 500 has a plurality of electric junction boxes, including a distribution unit FM, an electric junction box FR, an electric junction box FL, an electric junction box MR, an electric junction box ML, an electric junction box RR, and an electric junction box RL. These electric junction boxes have terminals to which electric wires that connect electric components and the electric junction box to supply power to the electric components are connected, terminals to which communication wires 1A or 1B that connect the electric components and the electric junction box to transmit and receive signals between the electric components, a control unit that controls the power supply to the electric components, a relay circuit, a fuse, a switching circuit, a smoothing circuit, and the like.

[0056] The distribution unit FM is connected to the secondary battery BAT via a cable BW1, and is connected to the ECU 600 via a cable BW2. In addition, a cable RW and a cable LW are connected to the distribution unit FM. The cable RW is connected to an electric junction box FR. The cable RW supplies power to the electric junction box FR, and relays signals exchanged between the ECU 600 and the electrical equipment. The cable LW is connected to an electric junction box FL. The cable LW supplies power to the electric junction box FL, and relays signals exchanged between the ECU 600 and the electrical equipment. The distribution unit FM is preferably disposed in a position close to the secondary battery BAT.

[0057] The electric junction box FR is disposed on the front right side of the automobile 1000, and is connected to a cable RW. The electric junction box FR is connected to, for example, electrical equipment disposed in the front part of the automobile 1000, and supplies power supplied from the cable RW to the connected electrical equipment. The electric junction box FR also relays signals exchanged between the ECU 600 and the electrical equipment via the cable RW. Furthermore, a cable RW1 disposed on the right side of the automobile 1000 is connected to the electric junction box FR. The cable RW1 supplies power supplied from the electric junction box FR to the electric junction box MR, and relays signals exchanged between the ECU 600 and the electrical equipment.

[0058] The electric junction box FL is disposed on the front left side of the automobile 1000, and is connected to a cable LW. The electric junction box FL is connected to, for example, electrical equipment disposed on the front side of the automobile 1000, and supplies power supplied from the cable LW to the connected electrical equipment. The electric junction box FL also relays signals exchanged between the ECU 600 and the electrical equipment via the cable LW. Furthermore, a cable LW1 disposed on the left side of the automobile 1000 is connected to the electric junction box FL. The cable LW1 supplies power supplied from the electric junction box FL to the electric junction box ML, and relays signals exchanged between the ECU 600 and the electrical equipment.

[0059] The electric junction box MR is disposed near the cowl on the right side of the automobile 1000, and a cable RW1 is connected to the electric junction box MR. The electric junction box MR is connected to electrical equipment disposed, for example, near the cowl of the automobile 1000 or between the front and rear of the automobile 1000, and supplies power supplied from the cable RW1 to the connected electrical equipment. The electric junction box MR also relays signals exchanged between the ECU 600 and the electrical equipment via the cable RW, the electric junction box FR, and the cable RW1. A cable RW11 disposed on the right side of the automobile 1000 is further connected to the electric junction box MR. The cable RW11 supplies power supplied from the electric junction box MR to the electric junction box RR, and relays signals exchanged between the ECU 600 and the electrical equipment.

[0060] The electric junction box ML is disposed near the cowl on the left side of the automobile 1000, and a cable LW1 is connected to the electric junction box ML. The electric junction box ML is connected to electrical equipment disposed, for example, near the cowl of the automobile 1000 or between the front and rear of the automobile 1000, and supplies power supplied from the cable LW1 to the connected electrical equipment. The electric junction box ML also relays signals exchanged between the ECU 600 and the electrical equipment via the cable LW, the electric junction box FL, and the cable LW1. A cable LW11 disposed on the left side of the automobile 1000 is further connected to the electric junction box ML. The cable LW11 supplies power supplied from the electric junction box ML to the electric junction box RL, and relays signals exchanged between the ECU 600 and the electrical equipment.

[0061] The electric connection box RR is disposed on the right rear side of the automobile 1000, and is connected to a cable RW11. The electric connection box RR is, for example, a box for storing n electric components 7101 to 710 arranged at the rear of the automobile 1000. n The electrical components 7101 to 710 are connected to the power supply RW11 through the cable EW1. n In addition, the electric junction box RR relays signals exchanged between the ECU 600 and the electrical components via the cable RW, the electric junction box FR, the cable RW1, the electric junction box MR, and the cable RW11. The cable EW1 is an example of a branch line.

[0062] The electric connection box RL is disposed on the left rear side of the automobile 1000, and the cable LW11 is connected to the electric connection box RL. The electric connection box RL is, for example, a box for connecting m electric components 7201 to 720 disposed in the rear of the automobile 1000. m Electrical components 7201 to 720 are connected to the power supply from the cable LW11. m Further, the electric junction box RL relays signals exchanged between the ECU 600 and the electrical components via the cable LW, the electric junction box FL, the cable LW1, the electric junction box ML, and the cable LW11. The cable EW2 is an example of a branch line.

[0063] According to the wiring structure 500, even when the wiring structure 500 is installed in an environment prone to high temperatures, such as an engine compartment or the back side of a roof lining, the variation in characteristic impedance of the communication wire 1A or the communication wire 1B connecting the ECU 600 and the electrical equipment can be suppressed, and communication in accordance with the Ethernet (registered trademark) standard can be performed between the ECU 600 and the electrical equipment.

[0064] [Variations] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment and can be implemented in various other forms. For example, the above-mentioned embodiment may be modified as follows to implement the present invention. The above-mentioned embodiment and the following modifications may be combined with each other. The present invention also includes a configuration in which the components of the above-mentioned embodiments and modifications are appropriately combined. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-mentioned embodiment and modifications, and various modifications are possible. For example, the effect of suppressing the fluctuation of the characteristic impedance in an environment that is prone to high temperatures (such as an engine room or the back side of a roof lining) can be achieved even in a structure other than the above-mentioned wiring structure.

[0065] Fig. 5 is a diagram showing a modified example of the communication electric wire. The communication electric wire 1C shown in Fig. 5 differs from the communication electric wire 1B in that it has an insulating coating 112A instead of the insulating coating 112. The insulating coating 112A is formed of a resin whose base material is a polyolefin resin. It differs in that the insulating coating 112 is a pipe type, whereas the insulating coating 112A is a solid type. [Explanation of symbols]

[0066] 1A, 1B communication wire 2 twisted pair 11A, 11B insulated wire 12A, 12B sheath 111 Conductor 112 Insulating coating 500 Cable Structure 600 ECU 7101~710 n , 7201~720 m Electrical Equipment 1000 Cars 1111 Wire BAT secondary battery BW1, BW2, EW1, EW2, RW1, LW1, RW11, LW11 cables FM distribution section FR, MR, RR, FL, ML, RL Electrical Junction Box

Claims

1. It is made of a single wire or a stranded wire, is made of a Cu-Sn alloy, has a tensile strength of 600 MPa or more, a breaking elongation of 1% or more and less than 7%, and has a cross-sectional area of ​​0.35 mm ２ The present invention provides an electric wire having a conductor as described below and an insulating coating formed of a polyolefin resin that covers the outer periphery of the conductor, A twisted pair wire in which the electric wires are twisted in pairs.

2. The twisted pair wire according to claim 1 ; a polyolefin resin sheath covering the outer periphery of the twisted pair wire; A communication cable comprising:

3. A wire harness comprising the twisted pair wire according to claim 1 or the communication wire according to claim 2, the wire harness being arranged in an automobile.

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