Braided conductors and flat wires

Abstract

The objective is to provide a braided conductor that can be stably combined with shape-retaining members and the like while suppressing a decrease in flatness and flexibility. [Solution] In a braided conductor formed by weaving together linear conductors, the linear conductors are woven together as diagonal threads of the braided conductor, and a separate linear body is woven together as warp threads. The linear material used should be capable of plastic deformation and possess sufficient rigidity to resist the elastic restoring force of the linear conductor after plastic deformation, or it should have higher tensile strength characteristics than the linear conductor, or its hardness should be less than or equal to that of the linear conductor.

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, through which high voltage and large current flow, for example, in switchboards, control panels, storage batteries, control circuit wiring used inside vehicles, etc.

Background Art

[0002] As wiring materials for high voltage, there are known plate-like conductors made of copper, aluminum, etc. called busbars, and flat wires such as braided conductors formed by braiding a plurality of metal strands.

[0003] Patent Documents 1 and 2 describe a braided conductor obtained by flattening a braided conductor formed in a cylindrical shape by braiding a plurality of linear conductors. Such a braided conductor may be used in combination with members for the purpose of shape retention and deformation suppression.

[0004] Patent Document 1 describes a braided conductor using a shape retention member for at least a part of the linear material constituting the braided conductor.

[0005] However, in the structure described in Patent Document 1, when the cylindrical braided conductor is flattened, the shape retention members overlap each other, so there are problems such that the dimensional thickness increases at the overlapping part, resulting in a decrease in flatness or a decrease in flexibility.

[0006] Also, Patent Document 2 describes a flat conductor in which a tension member is inserted through a through hole of the flat conductor.

[0007] However, in the structure described in Patent Document 2, when the entire length of the flat conductor is long, the operation of inserting the tension member through the through hole becomes complicated, and there is a problem that it is difficult to insert the tension member so that it is stably positioned at a desired location inside the through hole.

Prior Art Documents

Patent Documents

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-75607 [Patent Document 2] Japanese Utility Model Publication No. 5-69818 [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a braided conductor that can be stably combined with shape-retaining members and the like while suppressing a decrease in flatness and flexibility. [Means for solving the problem]

[0010] As a result of diligent research into the shape of braided conductors, the inventors have found that in a braided conductor formed by braiding together linear conductors, the linear conductors are braided together as diagonal threads of the braided conductor, and a separate linear material is braided together as warp threads, thereby solving the above problem. [Brief explanation of the drawing]

[0011] [Figure 1] This is the basic structure of the braided conductor of the present invention. [Figure 2] This is an example of a braided conductor of the present invention, in which it is formed in a cylindrical shape. [Figure 3] This is an example of a braided conductor of the present invention, in which a tubular braided conductor is flattened into a flattened shape. [Figure 4] This invention relates to a flat electric wire using a braided conductor. [Figure 5] This is a schematic diagram of the bending resistance test. [Figure 6] This is the result of the bending resistance test. [Figure 7] This is a schematic diagram of the shape retention test. [Modes for carrying out the invention]

[0012] Hereinafter, the braided conductor of the present invention will be described with reference to the drawings.

[0013] As shown in FIG. 1, the braided conductor 1 of the present invention is formed by braiding linear conductors 10. The linear conductors 10 are braided as the diagonal threads of the braided conductor 1, and a strip body 20 different from the linear conductors 10 is braided as the vertical threads.

[0014] The strip body 20 is appropriately selected and used according to the desired characteristics and functions of the braided conductor 1, and mainly those that function as shape-retaining members or tension members are used.

[0015] Since the strip bodies 20 are braided as the vertical threads, the strip bodies 20 do not overlap each other in the braided conductor 1, so that an increase in the dimension in the thickness direction can be suppressed and flatness can be maintained, and it also contributes to maintaining the flexibility of the braided conductor 1.

[0016] In addition, since the strip body 20 is braided as the vertical threads, it can be braided simultaneously when braiding the linear conductors 10 which are the diagonal threads. Even when the total length of the braided conductor 1 becomes long, the strip body 20 can be easily provided, and the position where the strip body 20 is provided can be stabilized.

[0017] In addition, since the load and behavior when the braided conductor 1 is pulled in the length direction are different between the linear conductor 10 which is the diagonal thread and the strip body 20 which is the vertical thread, it also contributes to protecting the linear conductor 1 against external forces such as tension.

[0018] Examples of the aspect of the braided conductor 1 of the present invention include a flat one and a cylindrical one shown in FIG. 2. As the flat one, there are those in the aspect shown in FIG. 1 in which the linear conductor 10 and the strip body 20 are braided flat from the beginning, and those in the aspect shown in FIG. 3 in which the linear conductor 10 and the strip body 20 are braided cylindrically and then crushed to form a flat shape.

[0019] " From the perspective of enhancing the flexibility of the linear conductor 10, an embodiment in which the tubular braided conductor 100 formed by braiding the linear conductor 10 and the strip conductor 20 in a tubular shape is crushed and formed into a flat shape can be preferably used.

[0020] The braided structure of the tubular braided conductor 100 is not particularly limited, but the number of braids is preferably 12 to 96. When the length direction of the tubular braided conductor 100 is 0°, the braiding angle is preferably 5° to 54°, more preferably 5° to 30°, and most preferably 10° to 30° in consideration of flexibility.

[0021] Also, considering the maintenance of the flat state when crushed and formed into a flat shape, the braiding density is preferably 60 to 100%, more preferably 80 to 100%, and most preferably 90 to 100%.

[0022] The ratio of the width H to the thickness t when the braided conductor 1 is formed into a flat shape is not particularly limited. As an example of the ratio range, an embodiment in which the ratio of the thickness t:width H is in the range of 1:4 to 1:16 according to the standard JCS1236 of the plain weave wire can be cited.

[0023] When the ratio of the thickness t:width H is in the range of 1:8 to 1:16, the braided conductor 1 has excellent bending properties in the thickness direction and also has excellent heat dissipation properties because the surface area is large.

[0024] The ratio of the thickness t:width H does not necessarily have to conform to the standard JCS1236, and an embodiment in which the ratio of the thickness t:width H is in the range of 1:2 to 1:4 can also be selected. When set within this range, in addition to the bending properties in the thickness direction, the bending properties in the width direction can also be obtained, which contributes to improving the wiring freedom of the braided conductor 1.

[0025] In the case of the embodiment in which the braided conductor 1 described later is coated with the insulating coating 30, it is preferable that the ratio including the insulating coating 30 is within the above-mentioned range.

[0026] In the braided conductor 1 of the present invention, the location and number of the strip conductors 20 serving as the warp threads are not particularly limited and can be appropriately selected according to the desired characteristics and functions of the braided conductor 1.

[0027] A typical way to install the linear elements 20 is to install them along the ends of the braided conductor 1 in the width direction, as shown in Figure 1. Although Figure 1 shows the configuration with the elements installed along both ends in the width direction, it is also possible to install them along only one end.

[0028] Furthermore, the position of the linear body 20 does not necessarily have to coincide with the end in the width direction; it may be located near the end, even if it is offset towards the center in the width direction from the end.

[0029] By providing the linear elements 20 along the ends in the width direction, the dimensions in the thickness direction are suppressed, which contributes to maintaining flatness.

[0030] In particular, when the filamentous bodies 20 are provided along both ends in the width direction, the shape stability of the braided conductor 1 is increased, and stable production becomes possible.

[0031] To flatten the tubular braided conductor 100, a tubular braided conductor 100 (see Figure 2) is formed by braiding the filamentous bodies 20 as warp threads so that they are symmetrically positioned with respect to the center of the circle. Then, the tubular braided conductor 100 is flattened so that the filamentous bodies 20 are located at the ends (see Figure 3), thereby obtaining a braided conductor 1 with filamentous bodies 20 along both ends in the width direction.

[0032] The linear conductors 10 that form the diagonal threads of the braided conductor 1 may be single-wire or stranded. From the viewpoint of improving the flexibility and bending resistance of the braided conductor 1, a stranded linear conductor 10 is preferably used.

[0033] The diameter of the linear conductor 10 used in the braided conductor 1 is not particularly limited, but it is preferable to use a small diameter from the viewpoint of obtaining flexibility for the braided conductor 1. When the linear conductor 10 has a single-wire structure, it is set to, for example, about 0.5 to 2.5 mm.

[0034] When the linear conductor 10 has a stranded wire structure, flexibility is obtained due to the stranded structure, which allows for a larger diameter of the linear conductor 10 compared to the case of a single-wire structure. Increasing the diameter of the linear conductor 10 allows for a larger conductor cross-sectional area, which reduces conductor resistance and contributes to suppressing heat generation in the linear conductor 10.

[0035] When the linear conductor 10 is made into a stranded wire structure, it is preferable to twist together multiple conductor strands with a diameter of about 0.05 to 0.5 mm to form a stranded wire with a diameter of about 0.5 mm to 2.5 mm.

[0036] The specific form of the stranded linear conductor 10 is not particularly limited, and can be selected from a bundled stranded structure in which multiple conductor strands are bundled and twisted in the same direction, a composite stranded structure in which multiple bundles of bundled conductor strands are further bundled and twisted, or a concentric stranded structure. From the viewpoint of obtaining flexibility for the braided conductor 1, a bundled stranded structure is preferably used.

[0037] When a stranded wire structure is used as the linear conductor 10, the twist pitch of the conductor strands is not particularly limited, but is preferably 10 to 100 times the outer diameter of the linear conductor 10. When considering the maintenance of flexibility and flatness of the braided conductor 1, a particularly preferred twist pitch is 30 to 80 times, and when considering mechanical strength against vibration, etc., a particularly preferred twist pitch is 15 to 35 times.

[0038] The material of the linear conductor 10 is not particularly limited, and metal wires made of copper, copper alloys, aluminum, aluminum alloys, etc., or metal wires that have been plated with tin, silver, nickel, etc., can be used. In addition, metal foil threads in which metal foil is spirally wrapped around a tensile strength wire can also be used.

[0039] When forming the braided conductor 1, in addition to using a uniform configuration for all the linear conductors 10, the braided conductor 1 may also be constructed by combining different types of linear conductors 10, such as by braiding together a first linear conductor made of aluminum or an aluminum alloy and a second linear conductor made of copper or a copper alloy so that they intersect.

[0040] As mentioned above, the filament 20 can be appropriately selected and used in accordance with the desired characteristics and functions of the braided conductor 1. One example is the filament 20 used to impart shape retention to the braided conductor 1.

[0041] Braided conductors 1 and flat electric wires 200 using them, as in the present invention, may be installed in a state where they are bent at a predetermined angle or curved at a predetermined bending radius. However, an elastic restoring force acts to return them to their original straight state, making it difficult to maintain the desired bent or curved state.

[0042] To address these challenges, weaving together shape-retaining filaments 20 as warp threads helps maintain the desired bent or curved state, making it easier to achieve the desired arrangement.

[0043] In addition, it is possible to fine-tune the bending or curvature of the structure, which is expected to improve the efficiency of the installation work.

[0044] When the purpose is to maintain the shape, the wire 20 is preferably made of a material that can undergo plastic deformation and exhibits sufficient rigidity after plastic deformation to resist the elastic restoring force of the braided conductor 1. Examples include metal wires such as steel, stainless steel, nickel, nickel alloys (Alumel, Chromel), copper, and aluminum, and plating with tin or the like may be applied as needed.

[0045] In addition to metal wires, resin compositions and rubber materials can also be used as the filament 20. When using a resin composition, the shape can be set by heating and cooling it in the desired bending state, thereby promoting shape stability.

[0046] For the purpose of maintaining shape, the filament 20 can be a single wire or stranded wire with an outer diameter of about 0.6 to 2.6 mm, but a single wire is preferable because it can secure a large shape-retaining force with a smaller diameter.

[0047] The cross-sectional shape of the wire body 20 may be circular, elliptical, rectangular, or the like. The outer diameter of the wire body 20 is preferably within the range of 0.8 to 1.2 times the outer diameter of the linear conductor 10, considering shape stability and appearance.

[0048] Another example of the filament 20 is a filament 20 used to enhance the durability of the braided conductor 1.

[0049] From the standpoint of improving the durability of the braided conductor 1, a wire 20 having higher tensile strength characteristics than the linear conductor 10 is preferably used. Specifically, synthetic fibers such as polyester fibers and polyamide fibers, as well as carbon fibers and glass fibers, can be used.

[0050] By weaving together filaments 20 with tensile strength as warp threads, the tensile strength of the braided conductor 1 can be increased, contributing to improved durability of the braided conductor 1.

[0051] In addition, from the viewpoint of improving the bending resistance of the braided conductor 1, it is preferable that the hardness of the filament 20 be less than or equal to the hardness of the linear conductor 10.

[0052] When the linear conductor 10 and the filament 20 come into contact and slide against each other at bends, the material with lower hardness wears more quickly. Therefore, by making the hardness of the filament 20 less than or equal to that of the linear conductor 10, wear and breakage of the linear conductor 10 during bending are suppressed, contributing to improved bending resistance of the braided conductor 1.

[0053] Furthermore, resin-based tensile strength bodies often have lower hardness compared to metals. When they come into contact with and slide against metal, the tensile strength body wears down first, which in turn suppresses metal wear.

[0054] The aforementioned synthetic fibers, such as polyester fibers and polyamide fibers, have lower hardness than copper, copper alloys, aluminum, and aluminum alloys, which are often used as linear conductors 10, and are therefore preferable to use.

[0055] In addition to being used in a state where the conductor is exposed, the braided conductor 1 of the present invention can also be used as a flat electric wire 200 with an insulating coating 30 provided on the outer circumference of the braided conductor 1, as shown in Figure 4.

[0056] The insulating coating 30 can be appropriately selected from various resin compositions such as polyethylene, polyvinyl chloride, polyester, polyamide, and fluororesin, as well as various rubber materials such as silicone rubber, fluororubber, and EPDM (ethylene propylene diene rubber).

[0057] As for the specific material of the insulating coating 30, fluororesin is preferable from the viewpoint of reducing the diameter by thinning the wall, and silicone rubber is preferable from the viewpoint of flexibility.

[0058] The thickness of the insulating coating 30 is not particularly limited and should be determined considering insulation properties, mechanical strength, and flexibility, but it is desirable to have a thickness of 0.08 mm or more.

[0059] The insulating coating 30 is usually formed by extruding a resin composition or rubber material around the braided conductor 1, but the method of forming the insulating coating 30 is not particularly limited, and methods such as winding insulating tape around the braided conductor 1 can also be selected.

[0060] When the insulating coating 30 is formed by extrusion coating, the flexibility of the flat wire 200 can be adjusted by adjusting the adhesion strength between the insulating coating 30 and the braided conductor 1.

[0061] To make the flat wire 200 easier to bend, it is desirable to extrude the insulating coating 30 so that the braided conductor 1 can move within the insulating coating 30 when the flat wire 200 is bent. Having room for the braided conductor 1 to move within the insulating coating 30 makes the flat wire 200 easier to bend.

[0062] Conversely, if you want to make the flat wire 200 less flexible, you can extrude the insulating coating 30 to achieve a tight seal that prevents the braided conductor 1 from moving within the insulating coating 30. [Examples]

[0063] The following are examples of the present invention.

[0064] [Example 1] The braided conductor 1-1 of Example 1 uses a filament 20 primarily for shape retention. Two single-core copper wires with a diameter of 0.6 mm are used as the filament 20, and they are braided together as warp threads of the tubular braided conductor 100 so that the filament 20 is present along both ends in the width direction when the conductor is flattened.

[0065] The tubular braided conductor 100-1 used in Example 1-1 was constructed by twisting together 40 strands of tinned soft copper wire with a diameter of 0.08 mm to form a bundled stranded wire with a diameter of 0.6 mm, which was used as the linear conductor 10. As described above, a tubular braided conductor with 32 strands was used, with two single-core copper wires braided as warp threads. The twist pitch of the bundled strand was set to 30 times the outer diameter of the linear conductor 10, and the braiding pitch of the tubular braided conductor 100-1 was set to 61 mm and the braiding angle to 15 degrees.

[0066] The above-mentioned tubular braided conductor 100-1 was flattened so that filaments 20 are present along both ends in the width direction and the ratio of thickness t to width H is 1:6, resulting in the braided conductor 1-1 of Example 1. The conductor cross-sectional area is equivalent to 7.5 sq.

[0067] [Example 2] The braided conductor 1-2 of Example 2 uses a filament 20 primarily for the purpose of improving the durability of the braided conductor 1. Two fiber threads with a diameter of 0.25 mm, made by twisting three strands of 200 denier aramid fiber together, are used as the filament 20, and are knitted as the warp threads of the tubular braided conductor 100 so that the filament 20 is present along both ends in the width direction when the conductor is flattened.

[0068] Except for the modification of the filament 20, the tubular braided conductor 100-2 used in Example 2 was constructed in the same manner as in Example 1, and the flattening was also carried out in the same manner as in Example 1 to obtain the braided conductor 1-2 of Example 2.

[0069] [Comparative Example] A braided conductor prepared in the same manner as braided conductor 1-1 of Example 1, without using the filament 20, was designated as comparative example braided conductor 1'.

[0070] The following tests were performed on the braided conductors of the examples and comparative examples prepared as described above.

[0071] (Flexural resistance test) The bending resistance of the braided conductor 1 was evaluated using the bending resistance test apparatus 500 shown in Figure 5. A braided conductor 1 with a length of 400 mm was used as the test subject. The braided conductor 1, with its upper end fixed by a fixing part 501 and a load of 1000 g attached to its lower end by a load 503, was lightly clamped from the thickness direction by a mandrel 502 with a radius of R20 mm and bent 90 degrees to the left and right at a speed of 60 times / minute. One bending cycle was defined as bending 90 degrees to the left and right, and the rate of increase in the conductor resistance value after 30,000 bending cycles was compared, with the conductor resistance value before bending set to 100%. The comparison results are shown in Figure 6.

[0072] In the comparative example, the braided conductor 1' experienced progressive breakage as the number of bends increased, and the conductor resistance value after the bending test rose to more than twice the value before the test, resulting in a state unsuitable for use as an electrical conductor.

[0073] On the other hand, although wire breakage occurred in the braided conductor 1 of Examples 1 and 2 due to bending, the conductor resistance value after the bending test was less than twice that before the bending test. This confirmed that the presence of the wire body 20 reduced the load on the linear conductor 10, and improved the bending resistance of the braided conductor 1.

[0074] In Example 1, the conductor resistance value after the bending test increased to more than 1.5 times the value before the bending test, whereas in Example 2, the increase was limited to about 1.3 times.

[0075] In Example 1, the filament 20 is a copper wire exhibiting a hardness similar to that of the linear conductor 10. In contrast, in Example 2, aramid fiber yarn, which has lower hardness and superior surface slipperiness compared to the linear conductor 10, was used as the filament 20. Therefore, the load on the linear conductor 10 was reduced compared to Example 1, and the improvement in bending resistance was enhanced.

[0076] (Shape retention test) A schematic diagram of the shape retention test is shown in Figure 7(a). The braided conductor 1 to be tested was wrapped in a U-shape around a mandrel 600 with a radius of R15 mm so that the flattened surface of the braided conductor 1 was in contact with the surface of the mandrel 600. The test was then conducted to see if the wrapped portion could maintain its U-shape after being removed from the mandrel 600. The shape retention test was performed on Example 1 and the comparative example.

[0077] As shown in Figure 7(b), the braided conductor 1-1 of Example 1 maintained its U-shape even after being removed from the mandrel 600, confirming the shape-retaining effect of the filament 20.

[0078] In the case of the comparative example braided conductor 1', as shown in Figure 7(c), when removed from the mandrel 600, the wound portion spread out in a roughly V-shape, indicating poor shape retention.

[0079] (Summary of the embodiments) The technical concept understood from the embodiments described above will be described using the reference numerals and other symbols from the embodiments. However, the reference numerals and other symbols in the following description are not limited to the components in the claims that are specifically shown in the embodiments.

[0080] [1] A braided conductor (1) formed by braiding together linear conductors (10), wherein the linear conductors (10) are braided together as diagonal threads of the braided conductor (1), and the filamentous bodies (20) are braided together as warp threads.

[0081] [2] The braided conductor (1) according to [1] above, characterized in that the braided conductor (1) is cylindrical.

[0082] [3] The braided conductor (1) according to [2] above, characterized in that the cylindrical braided conductor (1) is flattened to form a flat shape.

[0083] [4] The braided conductor (1) according to [3] above, characterized in that the linear body (20) is provided along the end in the width direction of the flattened braided conductor (1).

[0084] [5] The braided conductor (1) according to any one of [1] to [4] above, characterized in that the linear conductor (10) has a stranded structure formed by twisting together a plurality of conductor strands.

[0085] [6] The braided conductor (1) according to any one of [1] to [5] above, characterized in that the linear body (20) is capable of plastic deformation and exhibits sufficient rigidity to resist the elastic restoring force of the linear conductor (1) after plastic deformation.

[0086] [7] The braided conductor (1) according to any one of [1] to [6] above, characterized in that the linear body (20) has higher tensile strength characteristics than the linear conductor (10).

[0087] [8] A braided conductor (1) according to any one of [1] to [7] above, characterized in that the hardness of the filament (20) is less than or equal to the hardness of the linear conductor (10).

[0088] [9] An electric wire (200) characterized in that a braided conductor (1) described in any of [1] to [8] above is covered with an insulating coating (30).

[0089]

[10] The flat wire (200) described in [9] above, referencing [3] above.

[0090] Furthermore, configurations obtained by appropriately selecting and combining the configurations described in [1] to

[10] above also fall within the technical scope of this disclosure.

[0091] Although embodiments of the present invention have been described above, the embodiments described above do not limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. Moreover, the present invention can be implemented with appropriate modifications without departing from its spirit. [Industrial applicability]

[0092] The braided conductor of the present invention is suitably used in busbars and other applications where high voltage and high current flow in power distribution boards, control panels, storage batteries, and control circuit wiring used 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, and rapid charging cables, and can be used in a variety of applications. [Explanation of symbols]

[0093] 1. Braided conductor 10. Linear conductor 20. Striatum 30 Insulating coating 100 tubular braided conductor 200 Flat Electric Wire 500 Flexural resistance testing device 600 Mandrels

Claims

1. A braided conductor formed by weaving together linear conductors, The linear conductor is woven together as a diagonal thread of the braided conductor, A braided conductor characterized by having filaments woven together as warp threads.

2. The braided conductor according to claim 1, characterized in that the braided conductor is cylindrical.

3. The braided conductor according to claim 2, characterized in that the tubular braided conductor is flattened to form a flattened shape.

4. The braided conductor according to claim 3, characterized in that the wires are braided together as warp threads so as to be located at the ends in the width direction of the flattened braided conductor.

5. The braided conductor according to any one of claims 1 to 4, characterized in that the linear conductor has a stranded structure formed by twisting together a plurality of conductor strands.

6. The braided conductor according to any one of claims 1 to 4, characterized in that the wire is capable of plastic deformation and exhibits sufficient rigidity to resist the elastic restoring force of the linear conductor after plastic deformation.

7. The braided conductor according to any one of claims 1 to 4, characterized in that the wire has higher tensile strength characteristics than the linear conductor.

8. The braided conductor according to any one of claims 1 to 7, characterized in that the hardness of the wire body 20 is less than or equal to the hardness of the linear conductor 10.

9. A flat electric wire characterized by having a braided conductor as described in claim 3 or 4 covered with an insulating coating.

Images