Flat wire

Abstract

To provide a flat wire capable of utilizing a connection terminal constituted to suit a conductor and electric wire having circular cross-section when providing a connection terminal to an end portion of the flat wire and easy to bend and wire in the neighborhood of the connection terminal.SOLUTION: A flat wire conductor uses as a conductor a belt-like conductor, which can be restored to a circular cross-section, and at least one end of the belt-like conductor is provided as a circular restoration section that has been restored to a circular cross-section, and a terminal is installed on the circular restoration section. As the belt-like conductor that can be restored to a circular cross-section, it is preferable to use the belt-like one by crushing a tubular braided conductor made by braiding linear conductors.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flat electric wire used for various applications, for example, a flat electric wire that is suitably used as a high-voltage wiring material through which a high-voltage and large current flows, such as in distribution boards, control boards, storage batteries, and control circuit wiring used inside vehicles. [Background technology]

[0002] Known high-voltage wiring materials include flat electric wires that use plate-shaped conductors called bus bars made of copper or aluminum, and ribbon-shaped conductors made by braiding multiple metal wires. These conductors and electric wires generally have a flat shape, and connection terminals that correspond to the flat shape are also used.

[0003] Known examples of a flat conductor / wire provided with a connection terminal include those described in Patent Documents 1 and 2.

[0004] In Patent Document 1, the bus bar and the conductor device are pressed against each other by a clip element, thereby achieving a mechanical connection between them.

[0005] Patent Document 2 discloses an electric wire with a crimp terminal in which an exposed conductor portion of a flat covered electric wire is rounded and crimped for connection.

[0006] The structures disclosed in Patent Documents 1 and 2 use connection terminals configured to fit flat conductors and electric wires, but there is a problem in that waterproofing, anti-corrosion structures, etc. used in connection terminals configured to fit general conductors and electric wires with circular cross-sections cannot be directly applied to such connection terminals.

[0007] Furthermore, for convenience in conductor wiring, the conductor may be bent near the connection terminal. However, while flat conductors and wires can be bent in the thickness direction, it is very difficult to bend them in the width direction, which can cause problems in wiring.

[0008] In Patent Document 3, a twisted portion is provided in the bus bar terminal that electrically connects the conductor and the terminal block, thereby alleviating stress while wiring. However, since the bus bar terminal is bent into a predetermined shape in advance, there is little freedom in the connection work. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2021-51999 [Patent Document 2] JP 2022-86674 A [Patent Document 3] JP 2017-139060 A Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a flat electric wire which, when providing a connection terminal at the end of the flat electric wire, can utilize a connection terminal which is configured to fit a conductor / electric wire having a circular cross section, and which is easy to bend and wire in the vicinity of the connection terminal. [Means for solving the problem]

[0011] As a result of thorough consideration of the shape of the flat electric wire, the inventors have found that the above-mentioned problem can be solved by using a band-shaped conductor that can be restored to a circular cross-section as the conductor used in the flat electric wire, and by forming at least one end of the band-shaped conductor as a circular restoration portion that is restored to a circular cross-section. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram of a flat electric wire of the present invention having a circular restoration portion with a small diameter. [Diagram 2] FIG. 2 is a schematic diagram of a flat electric wire according to the present invention in which a circular restoration portion has a large diameter. [Diagram 3] 4 is an example of a cross-sectional shape of a flat portion of a flat electric wire. [Figure 4]2 is an example of a strip conductor used in the present invention. [Diagram 5] This is an example in which a circular restoration portion is formed using a shape-retaining member. [Figure 6] This is an example of a flat wire using a supplementary insulator. [Figure 7] 1 is a modified example of the flat electric wire of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the flat electric wire of the present invention will be described with reference to the drawings.

[0014] As shown in Fig. 1, the flat electric wire 1 of the present invention is characterized in that a strip-shaped conductor 10 is used as the conductor, and at least one end of the strip-shaped conductor 10 is restored to a circular cross-sectional shape to form a circular restored portion 11. Fig. 1 shows a case where one end of the strip-shaped conductor 10 is the circular restored portion 11, but both ends of the strip-shaped conductor 10 may be the circular restored portion 11.

[0015] In the band-shaped conductor 10, the band-shaped portion is called the flat portion 13, and the portion between the circular restoration portion 11 and the flat portion 13 is called the transition portion 12. The length of the transition portion 12 can be set arbitrarily, and the length may be set to approximately 0. Alternatively, it is possible to select a mode in which the flat portion 13 and the circular restoration portion 11 are directly connected as shown in FIG. 2.

[0016] The flat electric wire 1 of the present invention can be installed even when a narrow passage is present in the installation path because the strip conductor 10 has the flat portion 13. The cross section of the strip conductor 10 at the flat portion 13 may be, but is not limited to, a substantially elliptical shape as shown in Fig. 3(a) or a substantially rectangular shape as shown in Fig. 3(b).

[0017] By forming the end of the strip-shaped conductor 10 into the circular restoration portion 11 having a circular cross section, the circular restoration portion 11 can be easily provided with a terminal 30 that is applicable to a general electric wire having a circular cross section.

[0018] One example of the terminal 30 is a crimp terminal as shown in FIG. 1, which has integrally a fixing portion 31 fixed to the circular restoration portion 11 of the strip conductor 10 by a fixing method such as crimping, and a flat connecting portion 32 for fixing to a connected member such as an electrode provided on a control panel, a battery, etc., by a bolt or the like.

[0019] 1 is formed in a cylindrical shape, and is fixed to the strip-shaped conductor 10 by crimping the fixing portion 31 with the circular restoring portion 11 inserted therein. The connecting portion 32 extends outward from the fixing portion 31 in the longitudinal direction of the strip-shaped conductor 10, and is formed in a flat plate shape with a through hole 32a provided in the center thereof for passing a bolt therethrough.

[0020] The terminal 30 may be fixed to the circular restoration portion 11 by a method other than crimping, and examples of the fixing method include welding, adhesion, solder fixing, ultrasonic bonding, etc. In addition, the terminal 30 is not limited to a crimp terminal, and can be appropriately selected and used depending on the application and desired performance of the flat electric wire 1. The terminal 30 can be selected from a wide range of options.

[0021] Since there are various types of terminals that can be applied to typical circular cross-sectional electric wires, in the present invention, which assumes that terminal 30 is fixed to circular restoration portion 11, terminal 30 can be selected from a wide range of options according to the application of flat electric wire 1 and the desired performance.

[0022] In addition, since the end portion of the flat electric wire 1 of the present invention is the circular restoration portion 11, it can be bent in any direction at the circular restoration portion 11 like a general electric wire having a circular cross section.

[0023] Normally, the flat portion 13 of the strip conductor 10 used in the present invention can be bent in the thickness direction, but it is very difficult to bend it in the width direction. However, the circular restoration portion 11 makes it possible to bend it in the width direction as well, which facilitates the wiring of the flat electric wire 1 and the connection of the terminal 30 to an electrode, etc.

[0024] In addition, the band-shaped conductor 10 used in the present invention that can be restored to a circular cross-section does not simply refer to a conductor whose flattened portion 13 can be deformed into a circular cross-section, but rather refers to a conductor that is originally formed with a circular cross-section and is formed by deforming it into a flattened shape.

[0025] Examples of such a band-shaped conductor 10 include a conductor that is flattened by crushing a typical conductor with a circular cross section as shown in Figure 4(a), a conductor that is flattened by crushing a tubular braided conductor formed by braiding multiple linear conductors as shown in Figure 4(b), and a conductor that is flattened by crushing a tubular conductor made by spirally winding a linear conductor.

[0026] Usually, the strip conductor 10 is covered with an insulator 20, and the circular restored portion 11 is formed by removing the insulator 20 to restore the exposed end of the strip conductor 10 to a circular cross section. Therefore, the circular restored portion 11 and the transition portion 12 are usually exposed from the end of the insulator 20.

[0027] Considering that the strip-shaped conductor 10 is bent at the circular restoration portion 11 and that the terminal 30 is provided therein, it is preferable that the circular restoration portion 11 has a certain length or more.

[0028] As mentioned above, the length of transition portion 12 can be set arbitrarily, including to be nearly zero. From the viewpoint of reducing the load on band-shaped conductor 10, it is desirable for the length of transition portion 12 to be a certain amount or more. However, if the effect of the load can be ignored or if it is desired to ensure the length of circular restoration portion 11, it may be set to nearly zero.

[0029] The material for the insulator 20 can be appropriately selected from various resin compositions such as polyethylene, polyvinyl chloride, polyester, polyamide, and fluororesin, and various rubber materials such as silicone rubber, fluororubber, and EPDM (ethylene propylene diene rubber).

[0030] Specifically, fluororesin is preferable from the viewpoint of thinning the diameter, and silicone rubber is preferable from the viewpoint of flexibility as the material of the insulator 20. In this embodiment, silicone rubber is used.

[0031] The thickness of the insulator 20 is not particularly limited and may be determined in consideration of the insulating properties, mechanical strength, and flexibility, but is preferably 0.08 mm or more. In the case of silicone rubber used in this embodiment, the thickness is preferably 0.25 mm or more and 5 mm or less, and is set to 2 mm in this embodiment.

[0032] The insulator 20 is usually formed by extruding a resin composition or a rubber material around the strip conductor 10, but the method of forming the insulator 20 is not particularly limited, and a method of wrapping an insulating tape around the strip conductor 10 can also be selected.

[0033] When the insulator 20 is formed by extrusion coating, the flexibility of the flat electric wire 1 can be adjusted by adjusting the adhesive strength between the insulator 20 and the strip-shaped conductor 10 .

[0034] If it is desired to make the flat electric wire 1 easier to bend, it is preferable to extrude the insulator 20 so that the adhesion strength is such that the strip-shaped conductor 10 can move within the insulator 20 when the flat electric wire 1 is bent. Providing room for the strip-shaped conductor 10 to move within the insulator 20 makes it easier to bend the flat electric wire 1.

[0035] On the other hand, when it is desired to make the flat electric wire 1 difficult to bend, the insulator 20 is extrusion coated so as to have an adhesive strength that prevents the strip-shaped conductor 10 from moving within the insulator 20.

[0036] It is not necessary to provide the insulator 20, and depending on the usage environment of the flat electric wire 1, the strip conductor 10 may be exposed over the entire length of the flat electric wire 1, or only a portion of the strip conductor 10 may be covered with the insulator 20.

[0037] In the present invention, a conductor obtained by flattening a cylindrical braided conductor formed by braiding a plurality of linear conductors as shown in FIG. 4( b ) can be preferably used as the band-shaped conductor 10 .

[0038] A tubular braided conductor is a conductor with a circular cross section, and because it has a hollow portion, it is easy to crush and flatten, and can also be easily restored to a circular cross section.

[0039] Furthermore, from the viewpoint of providing the circular restoration portion 11 with a terminal 30 that is applicable to a typical circular cross-sectional electric wire, it is necessary to maintain the circular cross-sectional shape of the circular restoration portion 11. However, in the present invention, the strip conductor 10, which has once been deformed into a flattened shape, is restored to a circular shape, and therefore it may be difficult to maintain the circular cross-sectional shape.

[0040] If the band-shaped conductor 10 is a flattened tubular braided conductor, a hollow portion will be formed again when forming the circular restoration portion 11. However, by inserting a shape-retaining member 40 into the hollow portion as shown in Figure 5, the circular cross-sectional shape can be easily maintained.

[0041] In addition, since there is some room for reducing or expanding the outer diameter of the tubular braided conductor, it is possible to adjust the outer diameter of the circular restoration portion 11 to a conductor diameter suitable for the terminal 30 to be connected, providing more room for selecting a terminal 30 according to the application of the flat electric wire 1 and the desired performance.

[0042] Furthermore, when the flat electric wire 1 is arranged in an apparatus or the like, even if there is a narrow passage in the arrangement path whose diameter is smaller than the width of the flat portion 13 and through which the flat portion 13 cannot be inserted, there is room to insert the circular restoration portion 11, the outer diameter of which can be adjusted, into the narrow passage, thereby increasing the degree of freedom in arranging the flat electric wire 1 in a narrow space.

[0043] There is no particular limitation on the material of the linear conductor used in the strip conductor 10, and it is possible to use metal wires made of copper, copper alloys, aluminum, aluminum alloys, etc., or metal wires plated with tin, silver, nickel, etc., or metal foil threads in which metal foil is wound helically around a tensile strength wire. In this embodiment, tin-plated annealed copper wire is used.

[0044] When forming the tubular braided conductor that becomes the band conductor 10, in addition to a mode in which all linear conductors are used, the braided conductor may be formed by combining different types of linear conductors, such as by interweaving a first linear conductor made of aluminum or an aluminum alloy with a second linear conductor made of copper or a copper alloy to form a braided conductor.

[0045] The linear conductor used to form the tubular braided conductor that becomes the band conductor 10 may have a twisted structure in addition to a single wire structure. From the viewpoint of improving the flexibility and bending resistance of the flat electric wire 1, a twisted linear conductor can be preferably used.

[0046] The diameter of the linear conductor used in the band conductor 10 is not particularly limited, but is preferably small in order to obtain flexibility of the flat electric wire 1. When the linear conductor has a single wire structure, it is set to, for example, about 0.5 to 2.5 mm.

[0047] When the linear conductor has a stranded structure, the flexibility resulting from the stranded structure is available, and this allows the diameter of the linear conductor to be made larger than in the case of a solid wire structure. Increasing the diameter of the linear conductor allows the conductor cross-sectional area to be increased, which reduces the conductor resistance and contributes to suppressing heat generation in the flat electric wire 1.

[0048] When the linear conductor has a stranded wire structure, it is preferable to strand a plurality of conductor wires each having a diameter of about 0.05 to 0.5 mm to form a stranded wire having a diameter of about 0.5 mm to 2.5 mm.

[0049] The specific form of the linear conductor having a stranded wire structure is not particularly limited, and may be selected from a bunched stranded structure in which a plurality of conductor wires are bundled and twisted in the same direction, a composite stranded structure in which a plurality of bundled and twisted conductor wires are further bundled and twisted, a concentric stranded structure, etc. From the viewpoint of obtaining flexibility of the flat electric wire 1, a bunched stranded structure can be preferably used.

[0050] When a stranded linear conductor is used, the twist pitch of the conductor wires is not particularly limited, but is preferably 10 to 100 times the outer diameter of the linear conductor. When considering the flexibility of the strip conductor 1 and the maintenance of the shape of the flat portion 13, the particularly preferred twist pitch is 30 to 80 times, and when considering the mechanical strength against vibration, etc., the particularly preferred twist pitch is 15 to 35 times.

[0051] As shown in FIG. 4, the flat portion 13 of the strip-shaped conductor 10 has a cross-sectional shape in which the width H is larger than the thickness t. The ratio of the width H to the thickness t in the flat portion 13 is not particularly limited, but is preferably in the range of 1:2 to 1:8, and more preferably in the range of 1:2 to 1:4.

[0052] When the ratio of thickness t:width H is 1:8, the bendability in the thickness direction is excellent, and the surface area is large, resulting in excellent heat dissipation. When the ratio of thickness t:width H is in the range of 1:2 to 1:4, the bendability in the width direction as well as the bendability in the thickness direction can be obtained, which contributes to improving the degree of freedom in wiring of the flat electric wire 1. In the portion where the flat portion 13 is covered with the insulator 20, it is preferable that the ratio including the insulator 20 is in the above-mentioned range.

[0053] The braiding configuration of the tubular braided conductor is not particularly limited, but the number of strands is preferably 12 to 96. When the longitudinal direction of the braided conductor is taken as 0°, the braiding angle is preferably 5° to 54°, and in consideration of flexibility, it is more preferably 5° to 30°, and most preferably 10° to 30°.

[0054] In addition, in consideration of maintaining the shape of the flat portion 13, the braid density is preferably 60 to 100%, more preferably 80 to 100%, and most preferably 90 to 100%.

[0055] When the tubular braided conductor is constructed using linear conductors with a bundled twist structure, the combination of the twist pitch and braid angle of the linear conductor is not particularly limited, but a combination of a twist pitch of 30 to 80 times and a braid angle of 5° to 54°, particularly 5° to 30°, is preferred. Reducing the braid angle contributes to a reduction in the conductor resistance and a reduction in the weight of the strip conductor 10.

[0056] In addition, in consideration of the shape stability of the wiring state when the flat electric wire 1 is wired, a shape-stable linear member may be used as a part of the linear conductor constituting the belt-shaped conductor 10.

[0057] The shape-stable linear member is a conductive linear member, and may be a solid wire or a stranded wire having an outer diameter of 0.6 to 2.6 mm. The cross-sectional shape of the shape-stable linear member may be circular, elliptical, rectangular, etc. In consideration of shape stability and appearance, the outer diameter of the shape-stable linear member is preferably within a range of 0.8 to 1.2 times the outer diameter of the other linear conductors.

[0058] The material of the shape-stable linear member is not particularly limited, but examples include steel, stainless steel, nickel, nickel alloys (alumel, chromel), copper, aluminum, etc., and may be plated with tin or the like as necessary. From the viewpoint of electrical properties, the same materials as the other linear conductors can be preferably used. When electrical properties do not need to be considered, resin compositions, rubber materials, etc. can also be used as the shape-stable linear member, and when a resin composition is used, it is possible to heat and cool the material in a desired bent state to give it a shape and promote shape stability.

[0059] The number of shape-stable linear members used is not particularly limited, but when the band-shaped conductor 10 is formed using a tubular braided conductor, it is preferable that the number of shape-stable linear members is about 5 to 20% of the number of strands.

[0060] The shape-stable linear member does not necessarily have to be incorporated into the braid, and may be structured so as to be vertically attached in contact with the strip-shaped conductor 10. In this case, it is easy to implement an embodiment in which the shape-stable linear member is provided only in desired locations, such as providing the shape-stable linear member only in the flat portion 13.

[0061] In this embodiment, a bunched twisted wire made by twisting together 150 soft copper wires with a diameter of 0.08 mm to a diameter of 1 mm is used as a linear conductor, and a cylindrical braid with 48 strands is formed, which is then flattened to a thickness t:width H ratio of 1:5 to form the band-shaped conductor 10. The twist pitch of the bunched twist is set to 30 times the outer diameter of the linear conductor, the braid pitch of the cylindrical braid is 170 mm, and the braid angle is 15 degrees. The conductor cross-sectional area is equivalent to 35 sq.

[0062] The cross-sectional shape of the shape-retaining member 40 to be inserted into the hollow portion of the circular restoration portion 11 is not particularly limited as long as it can keep the circular restoration portion 11 in a circular cross section, and a circular cross section or a polygonal cross section can be used.

[0063] From the viewpoint of reliably maintaining the circular restoration portion 11 in a circular cross section, it is particularly preferable to use a shape-retaining member 40 having a substantially circular cross section, such as a cylindrical shape or a tubular shape. From the viewpoint of promoting weight reduction of the flat electric wire 1, it is preferable to use a cylindrical shape-retaining member having a hollow interior.

[0064] Examples of cylindrical shape-retaining members include those in the form of a tube or a pipe, and when it is desired to increase the flexibility of the circular restoration portion 11, a spiral tube-like member can also be used.

[0065] The shape-retaining member 40 may have a constant outer diameter along its length, or may have a tapered shape in which the outer diameter changes along its length.

[0066] When using a tapered shape-retaining member 40, it is usually sufficient to use one in which the outer diameter increases from the flat portion 13 toward the circular restoration portion 11. However, depending on the specifications of the terminal 30 to be connected to the circular restoration portion 11 and the desired performance of the flat electric wire 1, it is also possible to use one in which the outer diameter first increases from the flat portion 13 toward the circular restoration portion 11 and then decreases again.

[0067] The outer diameter of the shape-retaining member 40 is not particularly limited, and may be set to a value that provides the desired outer diameter of the circular restoring portion 11. When there is no particular limit to the outer diameter of the circular restoring portion 11, the outer diameter of the shape-retaining member 40 may be approximately the same as the inner diameter of the tubular braided conductor that constitutes the band-shaped conductor 10.

[0068] The length of the shape-retaining member 40 is not particularly limited, and may be set according to the desired lengths of the circular restoration portion 11 and the transition portion 12. Although the shape-retaining member 40 is usually present in the circular restoration portion 11 of the strip-shaped conductor 10, a part of the shape-retaining member 40 may be present in the transition portion 12 and the flat portion 13. For example, when the shape-retaining member 40 has a tapered shape in which the outer diameter increases from the flat portion 13 toward the circular restoration portion 11, a tapered portion at the tip of the taper may be inserted into the flat portion 13, and the transition portion 12 may be formed along the tapered portion.

[0069] The material of the shape-retaining member 40 is not particularly limited, and can be appropriately selected depending on the function desired for the circular restoration portion 11 and the terminal 30 to be connected.

[0070] One example of the shape-retaining member 40 is one in which the shape-retaining member 40 is formed from the conductive material that constitutes the strip-shaped conductor 10. When the shape-retaining member 40 is formed from the conductive material that constitutes the strip-shaped conductor 10, it is possible to provide the same strength as the strip-shaped conductor 10, and since the shape-retaining member 40 also functions as a conductor, the conductor cross-sectional area in the circular restoration portion 11 increases, the conductor resistance decreases, and this contributes to suppressing heat generation in the circular restoration portion 11.

[0071] Considering the compatibility between ensuring the conductor cross-sectional area and flexibility, when using the conductive material constituting the strip conductor 10 as the material for the shape-retaining member 40, a twisted conductor made by twisting together the linear conductors constituting the strip conductor 10 can be preferably used as the shape-retaining member 40.

[0072] When a stranded conductor obtained by twisting together the linear conductors constituting the strip conductor 10 is used as the shape-retaining member 40, the specific form is not particularly limited, and a structure selected appropriately from a set twist structure, a composite twist structure, a concentric twist structure, etc. The linear conductor may have a single wire structure or a twisted wire structure, and the diameter of the conductor wires constituting the linear conductor may be the same as that of the conductor wires constituting the strip conductor 10, or may be smaller or larger.

[0073] Another example of the shape-retaining member 40 is one in which the shape-retaining member 40 is formed from the resin composition or rubber material that constitutes the insulator 20. When the shape-retaining member 40 is formed from the material that constitutes the insulator 20, there is an advantage that the physical properties can be made equivalent to those of the insulator 20, and the heat resistance of the circular restoration portion 11 and the flat portion 13 can be made to be approximately the same.

[0074] In addition, since the circular restoration portion 11 is formed relatively flexibly, it is possible to bend the circular restoration portion 11 in any direction, and it is expected that the installation work of the flat electric wire 1 will be facilitated.

[0075] Considering compatibility between heat resistance and flexibility, when the material constituting the insulator 20 is used as the material for the shape-retaining member 40, it is preferable to use silicone rubber or fluororubber as the material for both.

[0076] Furthermore, in the case where the shape-retaining member 40 is an elastic body such as a rubber material, when a mode is selected in which the terminal 30 is crimped to the circular restoration portion 11, a repulsive force is generated due to the elasticity of the shape-retaining member 40 at the crimp fixing portion, and an improvement in the strength of the crimp fixing can be expected.

[0077] As described above, since the circular restoration portion 11 is usually exposed from the insulator 20, it may be covered with an auxiliary insulator 25 as necessary as shown in Fig. 6. The auxiliary insulator 25 has a role of covering and insulating the periphery of the exposed strip-shaped conductor 10 and a role of preventing moisture and foreign matter from penetrating into the flat electric wire 1. When providing the auxiliary insulator 25, it is provided between the end of the insulator 20 and the terminal 30 so as to cover the strip-shaped conductor 10 exposed from the insulator 20.

[0078] Typically, the auxiliary insulator 25 is provided between the end of the insulator 20 and the terminal 30 so as to cover the entire length of the strip conductor 10 exposed from the insulator 20, but if necessary, it may be provided so as to cover only a portion of the strip conductor 10 exposed from the insulator 20.

[0079] When the auxiliary insulator 25 is provided so as to cover the entire length of the strip-shaped conductor 10 exposed from the insulator 20, it may be provided so as to cover the end of the insulator 20 and the fixing portion 31 of the terminal 30 together.

[0080] The auxiliary insulator 25 may be formed by wrapping an insulating tape around the exposed portion of the strip-shaped conductor 10, by covering the exposed portion with a heat shrink tube, or by molding the exposed portion with a resin composition.

[0081] It is preferable to use the same material for the auxiliary insulator 25 as for the insulator 20, but since the auxiliary insulator 25 will be installed later to cover the strip conductor 10 exposed from the insulator 20, the material may be selected with priority given to workability when installing the auxiliary insulator 25.

[0082] In addition, in consideration of bending the strip-shaped conductor 10 at the circular restoration portion 11, it is preferable that the auxiliary insulator 25 is made of a material having excellent flexibility.

[0083] Specific examples of auxiliary insulator 25 include a PVC heat shrink tube, a silicone rubber heat shrink tube, a fluororesin heat shrink tube, and a fluororesin tape, and in this embodiment, a silicone rubber heat shrink tube is used.

[0084] As described above, when the flat electric wire 1 of the present invention is obtained using the strip conductor 10 covered with the insulator 20, the insulator 20 is removed to form the circular restoration portion 11. Therefore, when insulating the strip conductor 10 over the entire length of the flat electric wire 1, it is preferable to use the auxiliary insulator 25 in combination. However, as a variant, the strip conductor 10 can be insulated over the entire length of the flat electric wire 1 without using the auxiliary insulator 25.

[0085] (Variation 1) A circular restoration portion 11 is formed on the bare strip conductor 10 that is not covered with the insulator 20, and a terminal 30 is provided as necessary. Then, insulating tape is wound around the entire length of the strip conductor 10 as shown in FIG. 7 to form the insulator 20, so that the strip conductor 10 can be insulated over the entire length of the flat electric wire 1 without using an auxiliary insulator 25.

[0086] (Variation 2) Instead of using the insulating tape of variant example 1, the entire length of the strip conductor 10 can be covered with a heat shrink tube to form the insulator 20, thereby making it possible to insulate the strip conductor 10 over the entire length of the flat electric wire 1 without using an auxiliary insulator 25.

[0087] As an example of the embodiment of the circular restoration portion 11, there is an embodiment in which the outer diameter is smaller than the width of the flat portion 13 shown in Fig. 1. In the case of this embodiment, improvement in bending property can be expected due to the narrower diameter of the circular restoration portion 11, and the terminal 30 can be made smaller, so that it can be preferably used when the flat electric wire 1 is arranged in a narrow space.

[0088] When making the circular restoration portion 11 have an outer diameter smaller than the width of the flat portion 13, if the circular restoration portion 11 is formed by inserting a shape-retaining member 40 into the band-shaped conductor 10, the outer dimensions of the shape-retaining member 40 are also set small according to the desired dimensions of the circular restoration portion 11.

[0089] In addition, in the case of an embodiment in which the shape-retaining member 40 is inserted, the outer diameter of the circular restoration portion 11 may be equal to or larger than the width of the flattened portion 13 as shown in Fig. 2, so long as the shape-retaining member 40 has flexibility that does not impair the flexibility of the circular restoration portion 11. If the strip-shaped conductor 10 is a tubular braided conductor that has been flattened by crushing it, the flexibility of the strip-shaped conductor 10 itself in the circular restoration portion 11 can be improved by restoring the outer diameter to a large value. In addition, when it is desired to increase the conductor cross-sectional area in the circular restoration portion 11, an embodiment in which the outer diameter of the circular restoration portion 11 is equal to or larger than the width of the flattened portion 13 can be preferably used.

[0090] (Summary of the embodiment) The technical ideas grasped from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[0091] [1] A flat electric wire (1) having a band-shaped conductor (10) that can be restored to a circular cross-section, and at least one end of the band-shaped conductor (10) is a circular restored portion (11) that is restored to a circular cross-section.

[0092] [2] The flat electric wire (1) described in [1] above, characterized in that the strip conductor (10) is covered with an insulator (20), and the circular restoration portion (11) is exposed from an end of the insulator (20).

[0093] [3] The flat electric wire according to the above [1] or [2], characterized in that a terminal (30) is fixed to the circular restoration portion (11).

[0094] [4] The flat electric wire (1) according to the above-mentioned [3] citing the above-mentioned [2], characterized in that at least a part of the strip-shaped conductor (10) exposed from the insulator (20) is covered with an auxiliary insulator (25) between the end of the insulator (20) and the terminal (30).

[0095] [5] The flat electric wire (1) described in [1] above, characterized in that the band-shaped conductor (10) including the circular restoration portion (11) is covered with an insulator (20).

[0096] [6] The flat electric wire (1) according to the above [5], characterized in that a terminal (30) is fixed to the circular restoration portion (11).

[0097] [7] The flat electric wire (1) according to any one of the above [1] to [6], characterized in that the band-shaped conductor (10) is formed into a band-like shape by crushing a tubular braided conductor formed by interweaving linear conductors, and the circular restored portion (11) is restored to a tubular shape.

[0098] [8] The flat electric wire (1) according to the above [7], characterized in that in the circular restored portion (11) restored to the tubular shape, a shape-retaining member (40) is inserted into a hollow portion of the circular restored portion (11).

[0099] [9] The flat electric wire (1) according to the above [8], characterized in that the cross-sectional shape of the shape-retaining member (40) is substantially circular.

[0100]

[10] The flat electric wire (1) described in [8] or [9] above, wherein the shape-retaining member (40) is formed from the conductive material constituting the strip-shaped conductor (10).

[0101]

[11] The flat electric wire (1) according to [8] or [9] above, which cites [2] or [5] above, characterized in that the shape-retaining member is formed from a material constituting the insulator (20).

[0102]

[12] The flat electric wire according to any one of the above [1] to

[11] , wherein the outer diameter of the circular restoration portion (11) is smaller than the width of the strip-shaped conductor (10).

[0103]

[13] The flat electric wire (1) according to any one of the above [1] to

[11] , characterized in that the outer diameter of the circular restoration portion (11) is equal to or greater than the width of the strip-shaped conductor (10).

[0104]

[14] The flat electric wire according to any one of [1] to

[13] above, characterized in that the flat portion (13) of the strip-shaped conductor (10) is formed so that the ratio of thickness t:width H in a cross section perpendicular to the longitudinal direction is in the range of 1:2 to 1:8.

[0105] Additionally, configurations in which the configurations described in [1] to

[14] above are appropriately selected and combined also fall within the technical scope of the present disclosure.

[0106] Although the embodiment of the present invention has been described above, the invention according to the claims is not limited to the above-described embodiment. Furthermore, not all of the combinations of features described in the embodiment are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be modified appropriately without departing from the spirit of the invention. [Industrial Applicability]

[0107] The flat electric wire of the present invention is suitably used in bus bars through which high voltage and large current flows in wiring of control circuits used in switchboards, control panels, storage batteries, and inside vehicles, but is not limited thereto and can also be applied to earth wires, power wires for automobiles, high frequency power supply leads, quick charging cables, and the like, and is used in a variety of applications. [Explanation of symbols]

[0108] 1 Flat wire 10 Strip conductor 11 Circular restoration section 12 Transition 13 Flat part 20 Insulators 25 Auxiliary Insulator 30 Terminals 31 Fixed part 32 Connection 32a through hole 40 Shape retention member

Claims

1. A flat electric wire comprising a band-shaped conductor capable of being restored to a circular cross section, at least one end of the band-shaped conductor being a circular restored portion that is restored to a circular cross section.

2. 2. The flat electric wire according to claim 1, wherein the band-shaped conductor is covered with an insulator, and the circular restoration portion is exposed from an end of the insulator.

3. 3. The flat electric wire according to claim 2, wherein a terminal is fixed to the circular restoration portion.

4. 4. The flat electric wire according to claim 3, wherein at least a portion of the strip-shaped conductor exposed from the insulator is covered with an auxiliary insulator between the end of the insulator and the terminal.

5. The flat electric wire according to claim 1 , wherein the belt-shaped conductor, including the circular restoration portion, is covered with an insulator.

6. The flat electric wire according to claim 5, wherein a terminal is fixed to the circular restoration portion.

7. The flat electric wire according to any one of claims 1 to 6, characterized in that the band-shaped conductor is formed into a band-like shape by crushing a tubular braided conductor formed by braiding linear conductors together, and the circular restored portion is restored to a tubular shape.

8. The flat electric wire according to claim 7, wherein the flat portion of the belt-shaped conductor is formed such that a ratio of thickness t:width H in a cross section perpendicular to the longitudinal direction is in a range of 1:2 to 1:

8.

9. The flat electric wire according to claim 7, wherein a shape-retaining member is inserted into a hollow portion of the circular restored portion restored to the cylindrical shape.

10. 10. The flat electric wire according to claim 9, wherein the shape-retaining member is formed from a conductive material that constitutes the band-shaped conductor.

11. The flat electric wire according to claim 9, which relies on claim 2, wherein the shape-retaining member is formed from a material that constitutes the insulator.

12. The flat electric wire according to claim 9, which relies on claim 5, wherein the shape-retaining member is formed from a material that constitutes the insulator.

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