Conductor connection structure and method for manufacturing the same

Abstract

To provide a conductor connection structure that prevents local heat generation on an abutting joint surface during laser welding to improve productivity, and a method for manufacturing the same.SOLUTION: A conductor connection structure 1 comprises an electric wire 10 having a plurality of element wires 22 and a plate-like conductor 30, and the electric wire 10 and the conductor 30 are connected to each other in the conductor connection structure 1. With the plurality of element wires 22 formed in a plate state, end faces 221 of the plurality of element wires and an end face 321 of the conductor are abutted and connected to each other. The end face 321 of the conductor is provided with conductor extension parts 31 projecting toward the direction of the electric wire 10 from both ends in the width direction of the conductor 30. A laser trace L2, which is caused by irradiation with a laser beam L, is formed between end faces 221 of the plurality of element wires and the end face 321 of the conductor.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present invention relates to a conductor connection structure and a method for manufacturing the same. [Background technology]

[0002] A wide variety of electronic devices are installed in automobiles, and wire harnesses are arranged to transmit power, control signals, etc. to the electronic devices. The wire harnesses include multiple electric wires and connectors, and are connected to the electronic devices or other wire harnesses by fitting the connectors to the connectors of the electronic devices or the connectors of other wire harnesses.

[0003] An electric wire with terminal (electric wire with conductor) that constitutes such a wire harness generally includes an electric wire and a terminal fitting (conductor) attached to the end of the electric wire (see Patent Document 1).

[0004] Patent Document 1 discloses an electric wire with terminal, which includes an electric wire in which a conductor made of a material primarily containing a first metal is coated with an insulating material, and a terminal made of a material primarily containing a second metal different from the first metal and connected to the conductor exposed at one end of the electric wire. The electric wire with terminal further includes an alloy layer containing the first metal and the second metal formed along the entire outer periphery of the contact portion between the conductor and the terminal, spanning the conductor and the terminal. Specifically, the conductor, which includes multiple strands, and the terminal are butted together, and the contact portion between the conductor and the terminal is joined using a laser welder. The resulting joint between the conductor and the terminal forms an alloy layer, establishing electrical continuity and a strong bond between them. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-190617 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the multiple core wires exposed by the stripping process are heated and pressurized to form the electric wire conductor into a desired shape (plate-like, cylindrical, etc.) so as to fit into a mating terminal, and then the electric wire conductor is butt-joined to the terminal by laser welding. If the electric wire conductor formed before welding has low strength, heat will concentrate at the end of the butt-joining surface during laser welding, causing local deformation and fraying of the electric wire, which may result in an unintended shape and raise concerns about a short circuit.

[0007] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a conductor connection structure and a method for manufacturing the same that can suppress localized heat generation at the butt joint surface during laser welding, thereby improving productivity. [Means for solving the problem]

[0008] A conductor connection structure according to one aspect of the present invention comprises an electric wire having a plurality of strands and a plate-shaped conductor, and is a conductor connection structure that connects the electric wire and the conductor, in which the plurality of strands are formed into a plate shape and the end faces of the plurality of strands and the end face of the conductor are butted against each other to connect them, and the end face of the conductor is provided with conductor extension portions that protrude from both ends of the conductor in the width direction toward the electric wire, and laser marks caused by irradiation with laser light are formed between the end faces of the plurality of strands and the end face of the conductor.

[0009] A manufacturing method of a conductor connection structure according to an embodiment of the present invention is a manufacturing method of a conductor connection structure comprising an electric wire having a plurality of wires and a plate-shaped conductor, and connecting the electric wire and the conductor, and includes the steps of: abutting the end faces of the plurality of wires formed in a plate shape against the end face of the conductor, which has conductor extensions that protrude from both ends of the conductor in the width direction toward the electric wire; and forming laser marks by irradiating laser light between the end faces of the plurality of wires and the end face of the conductor. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a conductor connection structure and a method for manufacturing the same, which improves productivity by suppressing localized heat generation at the butt joint surfaces during laser welding. [Brief explanation of the drawings]

[0011] [Figure 1A] 1 is a side view showing an example of a conductor connection structure according to an embodiment of the present invention. [Figure 1B] 1 is a plan view showing an example of a conductor connection structure according to an embodiment of the present invention. [Figure 1C] FIG. 1C is an enlarged view of the joint portion of FIG. 1B. [Figure 2] FIG. 2 is a plan view showing a state before laser welding in the conductor connection structure according to the present embodiment. [Figure 3] 3 is a plan view illustrating an example of a conductor in the conductor connection structure according to the embodiment. FIG. [Figure 4] 3 is a plan view illustrating an example of a conductor in the conductor connection structure according to the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The conductor connection structure and the manufacturing method thereof according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0013] [Conductor connection structure] 1A, an electric wire with conductor 1 to which the conductor connection structure according to this embodiment is applied includes an electric wire 10 and a conductor 30 connected to the tip of the electric wire 10. Specifically, the electric wire with conductor (conductor connection structure) 1 includes an electric wire 10 having a plurality of element wires 22 and a plate-shaped conductor 30, and the electric wire 10 and the conductor 30 are connected to each other.

[0014] The electric wire 10 is a coated electric wire having a plurality of wires 22 and an insulating sheath 21 that covers the plurality of wires 22. The plurality of wires 22 may be made of a conductive metal material such as copper, a copper alloy, aluminum, or an aluminum alloy. The insulating sheath 21 is made of a resin material that is flexible and electrically insulating. The structure of the plurality of wires 22 (electric wire conductor) is not limited to a twisted wire in which a plurality of core wires are twisted together, and may be other forms (single-core wire, braided wire, etc.). At one end of the electric wire 10, the insulating sheath 21 is removed to expose a portion of the plurality of wires 22.

[0015] The exposed wires 22 are formed into a substantially rectangular shape in plan view, with end surfaces 221 of the wires formed on the conductor 30 side for butt-joining. The wires 22 and end surfaces 221 are formed into a plate shape before welding. The wires 22 may be formed by ultrasonic welding, resistance welding, heat welding, or other methods. The shape of the wires 22 may be any shape that fits the mating conductor 30, and may be flat or cylindrical.

[0016] The conductor 30 is formed as a flat conductor body 32, and has an end surface 321 of the conductor for butt-joining on the side of the electric wire 10. Conductor end surface 321 is provided with conductor extension portions 31 that protrude from both ends of the conductor 30 in the width direction toward the electric wire 10. The conductor 30 may be a substantially rectangular parallelepiped plate-like member, a bus bar, or a laminated thin plate.

[0017] The conductor 30 is made of a conductive metal, and at least the end portion and the end surface 321 of the conductor are plate-shaped components. The conductor 30 is formed by processing a plate made of a conductive metal material such as copper, a copper alloy, aluminum, or an aluminum alloy. The conductor 30 may be made of a single-layer metal plate, or may be made of a laminated plate made by stacking multiple thin metal plates. The surface of the conductor 30 may also be subjected to a surface treatment such as plating.

[0018] In this embodiment, the thickness of the conductor 30 is approximately the same as the thickness of the plurality of wires 22. The thickness of the conductor 30 is not particularly limited, but can be, for example, 3 mm to 6 mm.

[0019] The conductor 30 (conductor body 32) may have a hole penetrating the front and back surfaces of the conductor body 32. A fastening member such as a bolt or a screw may be inserted into this hole, and the conductor 30 may be fastened to a connected portion of various devices, etc., for fixed and electrically connected. Furthermore, the conductor 30 may be formed with a leaf spring or a protrusion to prevent it from coming loose when inserted into a connector, etc.

[0020] 1B, in the conductor-equipped electric wire 1, a plurality of element wires 22 are formed into a plate shape, and end faces 221 of the element wires are butted against an end face 321 of the conductor to be connected to each other. Conductor extensions 31 are provided on the end face 321 of the conductor, protruding from both ends of the conductor 30 in the width direction toward the electric wire 10.

[0021] 2, the gap a formed between the side surface 311 of the conductor extension 31 and the side surface 222 of the plurality of strands 22 is preferably 0 mm or more and 0.8 mm or less, and more preferably 0 mm. A gap a of 0 mm indicates that no gap is formed between the conductor extension 31 and the plurality of strands 22, and the conductor extension 31 and the plurality of strands 22 are in contact with each other. By setting the gap a within the above range, it is possible to suppress localized heat generation at the end of the butt joint surface, as described below.

[0022] 3, the width b of the conductor extension 31 is preferably 2 mm or more and 5 mm or less. Furthermore, the length c of the conductor extension 31 is preferably 2 mm or more and 4 mm or less. By setting the width b and length c of the conductor extension 31 within the above ranges, it is possible to suppress localized heat generation at the end of the butt joint surface, as will be described later.

[0023] The shape of the conductor extension 31 may be symmetrical as shown in FIG. 3, or asymmetrical as shown in FIG.

[0024] In this embodiment, end faces 221 of the multiple wires and end face 321 of the conductor are butted against each other and connected. Specifically, end faces 221 of the multiple wires and end face 321 of the conductor are welded and electrically connected by irradiation with laser light. As shown by the thick lines in FIGS. 1B and 1C , laser marks L2 are formed between end faces 221 of the multiple wires and end face 321 of the conductor due to the irradiation of laser light L.

[0025] In conventional methods using laser beam welding, if the strength of the shaped electric wire conductor is low before welding, heat concentrates at the end of the butt joint surface during laser welding, making it difficult for the heat to escape from the electric wire. This can lead to localized deformation and fraying of the electric wire, potentially resulting in an unintended shape and raising concerns about short circuits. In the conductor connection structure of this embodiment, heat is transferred to the conductor extension 31 during laser welding, suppressing localized heating at the end surfaces 221 of the multiple wires, particularly at the end of the butt joint surface. This reduces the likelihood of localized deformation and melting of the multiple wires 22. Even if deformation and fraying occur in the multiple wires 22, these are prevented by the conductor extension 31, preventing unintended shape formation and unintended short circuits. Therefore, the conductor connection structure of this embodiment can improve productivity by reducing electric wire defects.

[0026] Furthermore, as described above, the conductor connection structure of this embodiment can be welded even when the strength of the electric wire conductor (plurality of elemental wires 22) is low. Therefore, there is no need to form the electric wire 10 (plurality of elemental wires 22) firmly before welding, and therefore welding is possible even when the electric wire is formed using relatively low-power equipment such as ultrasonic welding. Furthermore, even during laser welding, localized heat generation in the electric wire 10 (plurality of elemental wires 22) is suppressed, so the laser irradiation conditions can be relaxed. Therefore, the conductor connection structure of this embodiment can improve productivity by relaxing the welding conditions.

[0027] As described above, the conductor connection structure of this embodiment is a conductor connection structure 1 that includes an electric wire 10 having a plurality of element wires 22 and a plate-like conductor 30, and that connects the electric wire 10 and the conductor 30. Then, with the plurality of element wires 22 formed into a plate shape, end faces 221 of the plurality of element wires and an end face 321 of the conductor are butted against each other and connected. The end face 321 of the conductor is provided with conductor extension portions 31 that protrude from both ends of the conductor 30 in the width direction toward the electric wire 10. Furthermore, laser marks L2 caused by irradiation with laser light L are formed between the end faces 221 of the plurality of element wires and the end face 321 of the conductor.

[0028] In the above-described conductor connection structure, localized heat generation at the end surfaces 221 of the plurality of wires is suppressed, making it difficult for localized deformation and melting damage to occur in the plurality of wires 22. This makes it possible to prevent the electric wire 10 (the plurality of wires 22) from taking on an unintended shape or the occurrence of an unintended circuit short. Furthermore, the above-described conductor connection structure eliminates the need to firmly shape the electric wire 10 (the plurality of wires 22) before welding, and can alleviate the laser irradiation conditions even during laser welding. From the above, the conductor connection structure of this embodiment can provide a conductor connection structure that suppresses localized heat generation at the butt joint surfaces during laser welding, thereby improving productivity.

[0029] [Method of manufacturing conductor connection structure] Next, a description will be given of a method for manufacturing the conductor-equipped electric wire (conductor connection structure) 1 according to this embodiment. The method for manufacturing the conductor-equipped electric wire 1 is a method for manufacturing a conductor connection structure 1 that includes an electric wire 10 having a plurality of element wires 22 and a plate-shaped conductor 30, and that connects the electric wire 10 and the conductor 30.

[0030] The manufacturing method of the conductor-attached electric wire 1 includes a step of butting end faces 221 of a plurality of wires formed in a plate shape against an end face 321 of the conductor having conductor extensions 31 protruding from both ends of the conductor in the width direction toward the electric wire 10. This step is a preparation step before welding the end faces 221 of the plurality of wires and the end face 321 of the conductor by irradiating a laser beam.

[0031] The method for manufacturing the conductor-equipped electric wire 1 includes a step of forming laser marks L2 by irradiating laser light L between end faces 221 of the plurality of wires and end face 321 of the conductor. This step is a step of welding between end faces 221 of the plurality of wires and end face 321 of the conductor by irradiating laser light.

[0032] The laser light L may be scanned along the width direction L1 of the electric wire 10, that is, along the direction of the arrow pointing from top to bottom in Figures 1B and 1C. Specifically, the laser light L may be scanned along the width direction L1 of the electric wire 10, with one end of the end faces 221 of the multiple wires as a scanning start position L3 and the other end of the end faces 221 of the multiple wires as a scanning end position L4.

[0033] As shown in FIG. 1C , the wires 22 each have a side surface 222 of the wires on the conductor extension 31 side. Meanwhile, the conductor extension 31 each has a side surface 311 of the conductor extension on the wires 22 side. The scanning start position L3 is a corner of the wires 22 where the end surface 221 intersects with one side surface 222 (the upper side surface in FIG. 1C ), and is a portion in contact with the end surface 321 of the conductor. Meanwhile, the scanning end position L4 is a corner of the wires 22 where the end surface 221 intersects with the other side surface 222 (the lower side surface in FIG. 1C ), and is a portion in contact with the end surface 321 of the conductor. The laser beam L is scanned from the scanning start position L3 to the scanning end position L4 along the width direction L1 of the electric wire 10, thereby welding the butt joint surfaces.

[0034] In addition, in Figures 1B and 1C, the positions of the scanning start position L3 and the scanning end position L4 may be reversed, in which case the laser light L may be scanned in the width direction of the conductor end face 321, that is, from bottom to top in Figures 1B and 1C.

[0035] When laser beams are scanned from the scanning start position L3 to the scanning end position L4 during laser welding, conventional methods have a problem of localized heating due to heat concentration at the scanning start position L3 and the scanning end position L4. In the manufacturing method of a conductor connection structure of this embodiment, the conductor extension 31 is provided on the end surface 321 of the conductor, allowing heat to be transferred from the scanning start position L3 and the scanning end position L4 to the conductor extension 31, facilitating heat dissipation. This suppresses localized heating at the end surfaces 221 of the wires, particularly at the ends of the butt joint surfaces, reducing the likelihood of localized deformation and melting of the wires 22. Even if deformation or fraying occurs in the wires 22, this is prevented by the conductor extension 31, preventing unintended shapes and unintended circuit shorts. Therefore, the manufacturing method of a conductor connection structure of this embodiment can improve productivity by reducing wire defects.

[0036] Furthermore, the manufacturing method of the conductor connection structure of this embodiment eliminates the need to firmly shape the electric wire 10 (plurality of element wires 22) before welding as described above, and can relax the laser irradiation conditions even during laser welding. Therefore, the manufacturing method of the conductor connection structure of this embodiment can improve productivity by relaxing the welding conditions.

[0037] As described above, the manufacturing method of a conductor connection structure according to this embodiment is a manufacturing method of a conductor connection structure 1 including an electric wire 10 having a plurality of wires 22 and a plate-like conductor 30, and connecting the electric wire 10 and the conductor 30. The manufacturing method includes a step of butting the end faces 221 of the plurality of wires 22 formed in a plate shape against an end face 321 of the conductor, which has conductor extension portions 31 protruding from both widthwise ends of the conductor 30 toward the electric wire 10. The manufacturing method also includes a step of forming laser marks L2 by irradiating laser light L between the end faces 221 of the plurality of wires and the end face 321 of the conductor. Therefore, the manufacturing method of a conductor connection structure according to this embodiment can provide a manufacturing method of a conductor connection structure that improves productivity by suppressing localized heating of the butt joint surfaces during laser welding.

[0038] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0039] 1 Conductor-attached wire (conductor connection structure) 10 Electric wire 22 Multiple wires 30 Conductors 31 Conductor extension 221 End faces of multiple wires 321 Conductor end face L laser light L1 Wire width direction L2 laser mark L3 Scan start position L4 Scan end position

Claims

1. A conductor connection structure comprising an electric wire having a plurality of wires and a plate-shaped conductor, the electric wire and the conductor being connected together, The plurality of wires are formed into a plate shape, and end faces of the plurality of wires and an end face of the conductor are butted against each other and connected to each other, The end surfaces of the conductor are provided with conductor extensions that protrude from both ends of the conductor in the width direction toward the electric wire, A conductor connection structure in which laser marks are formed between the end faces of the plurality of wires and the end face of the conductor by irradiating them with laser light.

2. A method for manufacturing a conductor connection structure comprising an electric wire having a plurality of wires and a plate-shaped conductor, the electric wire and the conductor being connected, a step of butting end faces of the plurality of wires formed in a plate shape against end faces of the conductor, the end faces having conductor extensions that protrude from both ends of the conductor in a width direction toward the electric wire; forming laser marks between end faces of the plurality of wires and an end face of the conductor by irradiating the end face with laser light; A method for manufacturing a conductor connection structure comprising:

3. 3. The method for manufacturing a conductor connection structure according to claim 2, wherein the laser light is scanned along the width direction of the electric wire, with one end of the end faces of the plurality of wires as the scanning start position and the other end of the end faces of the plurality of wires as the scanning end position.

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