Braided conductor

Abstract

To provide a braided conductor that can be used as a high-voltage wiring material through which a large high-voltage current flows, has excellent heat dissipation property, flexibility (versatility) and insulation property, and can save space.SOLUTION: The braided conductor is a conductor that braids a plurality of linear material having conductivity into a tube-shape, and the linear material is characterized by having a twisted wire structure in which a plurality of wires are twisted together. Further, it is preferable that the shape of the braided conductor comprises a flat-shape and the twisted wire structure of the linear material is a collective twisted structure.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a braided conductor used for various applications, and is suitably used as a wiring material for high voltage where high voltage and large current flow, for example, in distribution boards, control panels, storage batteries, control circuit wiring used inside vehicles, etc.

Background Art

[0002] As a general wiring material, a plate-shaped conductor made of copper, aluminum, etc. called a bus bar (busbar) is known. Since the shape of the bus bar cannot be easily deformed, it is necessary to manufacture a new bus bar according to the place of use, and it has poor versatility.

[0003] In addition, when used in high voltage applications or in narrow spaces, insulation is required, and an insulating coating may be necessary. Although it can be substituted with a general electric wire, there is a problem that it is not suitable for space saving compared to a plate shape like a bus bar.

[0004] As a wiring material for high voltage using a braided conductor, Patent Document 1 describes a braided wire (braided conductor) as a flexible bus bar for vehicles. The braided wire has a structure in which tinned copper wires are flat-braided. Compared with a plate-shaped bus bar, it is not limited to the place of use, has excellent versatility, and is excellent in flexibility and stretchability. On the other hand, there is a problem with insulation.

[0005] In recent years, as a wiring material for high voltage used under high voltage and large current, such as in vehicle applications such as electric vehicles, hybrid vehicles, and railways, heat generation of the wiring material for high voltage has become a problem, and further flexibility (versatility), insulation, and space saving are required.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] The object of the present invention is to provide a braided conductor that can be used as a high-voltage wiring material for high voltage and high current, has excellent heat dissipation, flexibility (versatility), and insulation properties, and can also be made into a space-saving design. [Means for solving the problem]

[0008] The gist of this invention is as follows:

[0009] (1) A conductor comprising a braid of multiple conductive linear materials, wherein the linear material is characterized by having a stranded structure formed by twisting together multiple strands. (2) The braided conductor is preferably in the shape of a tube. (3) The braided conductor has a flattened shape, and the ratio of the major axis to the minor axis is preferably 8:1 to 2:1. (4) The stranded wire structure is preferably a bundled stranded structure. (5) In the case of a bundled twisted structure, the twist pitch is preferably 10 to 100 times the outer diameter of the linear material. (6) The diameter of the individual wires constituting the linear material is preferably 0.05 mm or more and 2.5 mm or less. (7) The braiding angle is preferably 5° or more and 54° or less. (8) It is preferable that the conductor is formed such that the rate of temperature rise on the surface of the conductor during the energization test is smaller than that of a round conductor with the same cross-sectional area as a braided conductor. (9) The braided conductor preferably has an outer sheath, and the material of the outer sheath preferably has a continuous operating temperature of 90°C or higher. (10) Preferably used as a wiring material for high voltage. (11) It is preferable that at least a portion of the linear material has a shape-retaining member. [Effects of the Invention]

[0010] According to the braided conductor of the present invention, since the linear material constituting the braid has a stranded structure, it has excellent flexibility (versatility) and bendability. Furthermore, because the conductor cross-sectional area is larger compared to general braided conductors, the conductor resistance is reduced, and heat generation is suppressed. Since the temperature rise during energization can be suppressed, it contributes to preventing failure of connected electronic equipment and reducing the risk of burns to workers. In addition, because the thickness of the braided conductor is increased and the edges are eliminated, it can be used stably as a high-voltage wiring material under higher voltage and higher current conditions. [Brief explanation of the drawing]

[0011] [Figure 1] This is an example of a braided conductor according to the present invention. [Figure 2] This is another example of a braided conductor according to the present invention (an example using a shape-retaining member). [Figure 3] This is an example of a conventional braided conductor. [Figure 4] These are the measured values ​​of current and temperature rise obtained from an energizing test of a braided conductor according to the present invention. [Modes for carrying out the invention]

[0012] In Figure 1, the braided conductor 1 of the present invention is a conductor formed by braiding together a plurality of conductive linear materials 2. While braided conductors 1 can be flat-braided or tubular (hollow), a tubular shape is preferred from the viewpoint of high-voltage applications and productivity.

[0013] Furthermore, the linear material 2 is characterized by a stranded wire structure formed by twisting together multiple strands. Because the linear material 2 has a stranded wire structure, it has excellent flexibility (versatility) and bendability, and as shown in Figure 3, the conductor cross-sectional area is larger compared to conventional braided conductors, so the conductor resistance is reduced and heat generation is suppressed. In addition, because the thickness of the braided conductor 1 is increased and the edges are eliminated, it can be used stably as a high-voltage wiring material under higher voltage and higher current conditions.

[0014] The shape of the stranded conductor 1 is not particularly limited, but a flat shape is preferred. The flat shape is, for example, an elliptical shape or a rectangular shape, and particularly preferably a substantially rectangular shape.

[0015] The major axis and minor axis of the stranded conductor 1 are not particularly limited, but it is preferably closer to a square than at least 8:1, and particularly preferably 4:1 to 2:1. Regarding the definition of the major axis and minor axis, the maximum length among the diameters of the stranded conductor 1 is taken as the major axis, and the minimum length is taken as the minor axis. In the case of 8:1, in addition to excellent bendability in the minor axis direction, the surface area increases, so the heat dissipation performance is also improved. When it is 4:1 to 2:1, it is excellent in bendability in both the minor axis direction and the major axis direction, so the degree of freedom in wiring increases, which is preferable. The flat-shaped stranded conductor 1 with these ratios contributes to space saving, for example, by being stacked and installed so as to form a square. When an outer covering is provided on the stranded conductor 1, it is preferable that the ratio including the outer covering is as described above.

[0016] Regarding the ratio of the major and minor axes of the stranded conductor 1 in further detail, in the case of a two-conductor power line used for single-phase AC or DC, the ratio of the major axis to the minor axis is preferably 2:1. Also, in the case of a power line used for three-phase AC, it is preferably designed with a ratio of 3:1. When used as an earth wire, it is preferably designed with the ratio of the major axis to the minor axis at which the surface heat dissipation resistance (the thermal resistance corresponding to the temperature difference between the cable and the surrounding air) becomes the maximum value.

[0017] The stranding structure is not particularly limited, but a collective stranding structure in which a plurality of strands are bundled and stranded in the same direction is preferred. As another example, a composite stranding structure in which a plurality of conductors with a collective stranding structure are further bundled and stranded, or a concentric stranding structure or the like may also be used.

[0018] The stranding pitch of the conductor with a collective stranding structure is not particularly limited, but is preferably 10 times to 100 times the outer diameter of the wire rod 2. From the viewpoints of flexibility and maintaining the flat shape of the stranded conductor 1, it is particularly preferably 30 times to 80 times. Also, from the viewpoint of mechanical strength against vibrations and the like, it is preferably 15 times to 35 times.

[0019] The outer diameter of the linear material 2 (for example, a conductor having a stranded structure) is not particularly limited, but is φ0.50 mm to φ2.5 mm (equivalent to 0.15 sq to 3.0 sq), and the strand diameter constituting the linear material 2 is preferably φ0.05 mm to φ0.50 mm.

[0020] The material of the linear material 2 is a material having conductivity and is not particularly limited. For example, copper wire, alloy wire, aluminum wire, etc. may be mentioned, and preferably bare soft copper wire or aluminum wire. Appropriately, tin plating, silver plating, nickel plating may be applied to the surface. It is preferable that all of the linear materials 2 are materials having conductivity, but insulating materials such as inorganic fibers may be mixed as appropriate.

[0021] The braiding structure is not particularly limited, but the number of braids is preferably 12 to 96. When the axial direction is 0°, the braiding angle is preferably 5° to 54°, more preferably 5° to 30°, and most preferably 10° to 30° from the viewpoint of flexibility. From the viewpoint of maintaining the shape in a flat shape or the like, the braiding density is preferably 60% to 100%, more preferably 80% to 100%, and most preferably 90% to 100%.

[0022] The combination of the pitch of the twisted wire structure of the linear material 2 and the braiding angle is not particularly limited, but preferably, the pitch of the stranded structure is 30 to 80 times, and the braiding angle is 5° to 54°, preferably 5° to 30°. Since the conductor resistance and the weight become smaller as the braiding angle becomes smaller, it is particularly suitable as a high-voltage wiring material (power line) for transportation equipment.

[0023] In current-conducting tests, it is preferable that the braided conductor 1 is formed such that the rate of increase in surface temperature is smaller than that of a round conductor with the same cross-sectional area as the braided conductor 1. When the surface temperature of the braided conductor 1 is measured during current application and plotted with the current value (squared) [A] on the horizontal axis and the temperature rise [°C] on the vertical axis, a proportional relationship is obtained. The slope of the braided conductor 1 is smaller than that of the round conductor, indicating that the braided conductor 1 has a smaller rate of increase in surface temperature during current-conducting tests (see Figure 4). The more the wire material 2 has a stranded structure and is also flatter, the larger the surface area of ​​the braided conductor becomes, and therefore the rate of temperature rise can be kept small due to the heat dissipation effect.

[0024] Furthermore, as shown in Figure 2, shape retention can be provided to at least a portion of the linear material 2 in the braided conductor 1 of the present invention by using a shape-retaining member 3. From the viewpoint of bending resistance, it is preferable that the shape-retaining member 3 is braided together with the other linear material 2. By weaving it into the braided conductor 1, shape retention can be obtained with a relatively simple manufacturing method.

[0025] The shape-retaining member 3 is a conductive wire, preferably a single wire or stranded wire with an outer diameter of φ0.6 mm to φ2.6 mm. The cross-sectional shape of the single wire or stranded wire may be circular, elliptical, rectangular, or the like. The ratio of the outer diameter of the shape-retaining member 3 to the outer diameter of the other wire 2 is preferably equal to ±20% from the viewpoint of shape retention and appearance.

[0026] The material of the shape-retaining member 3 is not particularly limited, but examples include steel, stainless steel, nickel, nickel alloys (Alumel, Chromel), copper, aluminum, etc., and plating with tin or the like may be applied as needed. From the viewpoint of electrical properties, it is preferable that it be made of the same material as the other linear material 2. If electrical properties are not considered, plastic can also be suitably used. Plastic can be shaped and retained by heating and cooling it in the desired bent state.

[0027] The number of shape-retaining members 3 used is not particularly limited, but it is preferable that they be applied in a number of approximately 5 to 20% of the total number of strokes.

[0028] The shape-retaining member 3 does not necessarily have to be incorporated into the braid; for example, it may be attached longitudinally in contact with the inside of the braided conductor 1. In this case, it is strong against tension in the longitudinal direction, and the effect of suppressing the expansion and contraction of the braided structure is obtained, making it difficult for the diameter to change.

[0029] Furthermore, it is preferable to apply an outer sheath around the braided conductor 1 from the viewpoint of improving insulation. The material of the outer sheath is not particularly limited, but it is preferable that the continuous use temperature is 90°C or higher. Here, the continuous use temperature is the temperature at which the physical properties of the material deteriorate by 50% from their initial values ​​when the material is left in the atmosphere at a constant temperature for 40,000 hours. The braided conductor 1 of the present invention has an excellent heat generation suppression effect and can be used with insulating materials at relatively low temperatures. Fluororesin is preferred in terms of thinning the wall and reducing the diameter, and silicone rubber is preferred in terms of flexibility. Other examples include polyethylene, PVC, fluororubber, polyester, nylon, EPDM (ethylene propylene diene rubber), and polyethylene blends including crosslinking.

[0030] Its applications are not particularly limited, and it can be used in a variety of applications as a high-voltage wiring material. Here, high voltage refers to AC 30V or higher or DC 60V or higher. From the viewpoint of improving heat dissipation due to the increased surface area of ​​the covering, it is preferable to use it as a ground wire for high currents. Furthermore, if the braided conductor 1 has a rectangular structure composed of multiple stranded wires, it has a larger surface area compared to a round conductor, and is therefore also preferable to use as a lead wire for high-frequency power supplies.

[0031] The braided conductor 1 of the present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. [Examples]

[0032] The examples are braided conductor 1 of the present invention, and are Examples 1 to 7. Details of the specifications are shown in Table 1.

[0033] Examples 1 to 3 use a twisted structure as the linear material 2, and each has a different braiding pitch (braiding angle). The shape of the braided conductor 1 is a flattened shape that is roughly rectangular, with a ratio of major axis to minor axis of 2:1.

[0034] Example 4 is a braided conductor 1 that uses a linear material 2 consisting of a composite twisted structure of the same size as in Examples 1 to 3.

[0035] Example 5 has a different braided structure from Examples 1 to 3, but the braided conductor 1 is of the same size, and the ratio of the major axis to the minor axis is 3:1.

[0036] Examples 6 and 7 are linear materials 2 with a larger diameter than those in Examples 1-5. Both have a twisted structure, with a ratio of major axis to minor axis of 3:1 and 4:1, respectively.

[0037] The conventional example is a general circular conductor, and its size is the same as in Examples 6 and 7.

[0038] Conductor resistance was measured for the examples, and the results are shown in Table 1. The measurement method was based on JIS C 2525, using the double bridge method to measure conductor resistance [Ω / km]. The measurement length was 1m.

[0039] Furthermore, Figure 4 shows the measurement results of the surface temperature rise rate of the braided conductor during the energization test for Examples 6 and 7 and the Conventional Example. The surface temperature of the braided conductor 1 was measured for each current value during energization, and the graph shows the current value (squared) [A] on the horizontal axis and the temperature rise [°C] on the vertical axis (ambient temperature 20°C).

[0040] [Table 1]

[0041] Examples 1-3 show that stable conductor resistance can be obtained when the braiding angle is between 5° and 30°, and that the smaller the braiding angle, the lower the conductor resistance. Because the conductor resistance is low, heat generation can be suppressed, making it suitable for high-voltage wiring materials. The composite twisted structure of Example 4 and the braided conductor 1 of Example 5, which has a major-to-minor-major ratio of 3:1, also have low conductor resistance and can be stably used as high-voltage wiring materials. In particular, Example 5 is preferable because its large surface area is expected to have a heat dissipation effect.

[0042] The results of the power-on test (Figure 4) show that the temperature rise rate in Examples 6 and 7 is smaller than that of conventional examples, indicating superior heat dissipation. [Industrial applicability]

[0043] The braided conductor of the present invention can suppress the temperature rise of the conductor surface when energized, and is therefore suitable for use in busbars and other applications where high voltage and high current flow in control circuit wiring used in distribution boards, control panels, storage batteries, and inside vehicles. However, it is not limited to these applications and can also be applied to ground wires, automotive power wires, high-frequency power lead wires, rapid charging cables, inlet harnesses, drone wires, and other applications, and can be used in a variety of uses. [Explanation of Symbols]

[0044] 1. 10 Braided Conductor 2, 20 wire material 3. Shape-retaining member

Claims

1. A braided conductor formed by braiding together multiple conductive linear materials, The braided conductor is made by braiding the wire material into a tube shape and then flattening it. The wire material is characterized by a braided conductor having a stranded structure formed by twisting together multiple strands.

2. The braided conductor according to claim 1, characterized in that the ratio of the major axis to the minor axis of the braided conductor is 8:1 to 2:

1.

3. The stranded structure of the linear material is characterized by being a bundled twist structure. The braided conductor according to claim 1 or 2.

4. The twist pitch of the bundled twist structure is characterized by being 10 to 100 times the outer diameter of the linear material. The braided conductor according to claim 3.

5. The wire diameter of the strands constituting the linear material is 0.05 mm or more and 2.5 mm or less. A braided conductor according to any one of claims 1 to 4.

6. The braiding angle is characterized by being between 5° and 54°. A braided conductor according to any one of claims 1 to 5.

7. The braiding angle is characterized to be 5° or more and 30° or less. The braided conductor according to claim 6.

8. The conductor is characterized in that the rate of temperature rise on the conductor surface during an electrical current test is smaller than that of a round conductor with the same cross-sectional area as the braided conductor. A braided conductor according to any one of claims 1 to 7.

9. Characterized by having an outer covering, A braided conductor according to any one of claims 1 to 8.

10. The material of the outer covering is characterized by having a continuous operating temperature of 90°C or higher. The braided conductor according to claim 9.

11. Characterized by being used as a high-voltage wiring material, A braided conductor according to any one of claims 1 to 10.

12. The linear material is characterized by having a shape-retaining member in at least a portion of it. Braided conductor according to claims 1 to 11.

13. The shape-retaining member is a conductive wire, characterized in that it is a single wire or stranded wire with an outer diameter of φ0.6 mm or more. The braided conductor according to claim 12.

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