Electric wire with terminal

Abstract

To provide an electric wire with a terminal excellent in electrical characteristics by attaining good conduction between element wires in a crimp portion of a core wire crimped to the terminal.SOLUTION: An electric wire 1 with a terminal includes an electric wire 10 and a terminal 20, and is resistance-welded by sandwiching the terminal 20 crimped to a core wire 12 of the electric wire 10 by a pair of electrodes from the outside and energizing the pair of electrodes, and further includes auxiliary electrodes 30 that are inserted from the outside of the terminals 20 along a sandwiching direction of the pair of electrodes to the terminals 20 and are entered into gaps between a plurality of element wires 11 with respect to a crimped portion 12a of the core wire 12 to which the terminal 20 is crimped.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric wire with a terminal. [Background technology]

[0002] Electric wires with terminals have been proposed in the past, in which a terminal is crimped onto a core wire exposed from an electric wire. This type of electric wire with terminals may be used, for example, as a power electric wire for use in electric vehicles. In this case, the number of element wires constituting the core wire is large, and when a terminal is crimped onto the core wire, the element wires in the radial center portion are less likely to undergo plastic deformation. This prevents the oxide film on the surface of the element wires from being destroyed, making it difficult to achieve electrical continuity, particularly between the element wires. In addition, this increases the electrical resistance of the core wire crimped portion, which can cause heat generation problems when current is applied.

[0003] To address this problem, one method is to melt the wires in the core wire crimped portion by resistance welding using the processing tools (so-called anvil and crimper) used during the crimping as electrodes, but this can cause variations in electrical heating and does not necessarily result in satisfactory conductivity.

[0004] To address the above problem, Patent Document 1 discloses a method in which a rectangular U-shaped auxiliary electrode is inserted into the tip of the exposed core wire, and current is also passed through the auxiliary electrode during the crimping process, thereby destroying the oxide film on the wire and achieving conductivity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-176880 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the method disclosed in Patent Document 1, when inserting the auxiliary electrode into the tip of the exposed core wire, some of the wires may be pushed inward (on the side opposite the tip), causing the wires to become uneven in parts. This may cause the current path in the core wire crimped portion to be partially narrowed, potentially causing molten metal to splash (explode) due to excessive heat generation. As such, there is room for improvement in conventional electric wires with terminals.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide an electric wire with a terminal that achieves good conduction between the wires at the crimped portion of the core wire that is crimped to the terminal, and has excellent electrical properties. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the electric wire with terminal according to the present invention comprises: An electric wire with terminal, comprising: an electric wire having a core wire made of a plurality of wires and an insulating coating covering the core wire; and a terminal crimped onto the core wire exposed at an end of the electric wire, the terminal crimped onto the core wire being resistance-welded by sandwiching the terminal crimped onto the core wire from the outside between a pair of electrodes and passing current therethrough, The terminal further includes an auxiliary electrode that is inserted from the outside of the terminal along the clamping direction of the pair of electrodes to the crimped portion of the core wire to which the terminal is crimped, and that fits between the multiple wires. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an electric wire with a terminal that has excellent electrical properties and that ensures good electrical continuity between the wires at the crimped portion of the core wire that is crimped to the terminal.

[0010] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic side view showing an electric wire with a terminal according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the auxiliary electrode shown in FIG. 2 before the core wire is inserted into the crimped portion. [Figure 4] FIG. 4 is a first schematic diagram for explaining the method for manufacturing an electric wire with a terminal. [Figure 5] FIG. 5 is a second schematic view for explaining the method for manufacturing an electric wire with a terminal. [Figure 6] FIG. 6 is a third schematic view for explaining the method for manufacturing an electric wire with a terminal. [Figure 7] FIG. 7 is a fourth schematic view for explaining the method for manufacturing an electric wire with a terminal. [Figure 8] FIG. 8 is a fourth schematic view for explaining the method for manufacturing an electric wire with a terminal. [Figure 9] FIG. 9 shows a modified example of the terminal. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an electric wire with terminal 1 according to one embodiment of the present invention will be described with reference to the drawings. The electric wire with terminal 1 can be used to be routed between various devices such as a battery, an inverter, and a motor of an electric vehicle, for example.

[0013] [Outline of terminal-attached wire configuration] The general configuration of the terminal-attached wire will be described below. As shown in FIG. 1 and other figures, the electric wire with terminal 1 includes an electric wire 10, a terminal 20, and an auxiliary electrode 30.

[0014] 1, the electric wire 10 includes a core wire 12 made up of a plurality of wires 11 and an insulating coating 13 covering the core wire. In this example, the wires 11 are made of, for example, aluminum or an aluminum alloy. The insulating coating 13 is made of an insulating resin.

[0015] The terminal 20 is formed by pressing and bending a metal plate into a predetermined shape. In this example, the metal plate is made of, for example, copper or a copper alloy.

[0016] 1, the terminal 20 is configured to have a connecting portion 21, a first connecting portion 20a, a core wire crimping portion 22, a second connecting portion 20b, and a coating crimping portion 23. The connecting portion 21, the first connecting portion 20a, the core wire crimping portion 22, the second connecting portion 20b, and the coating crimping portion 23 are arranged in a line in this order along the extending direction of the electric wire 10 from one terminal side to the other terminal side.

[0017] The connecting portion 21 is a portion of the terminal 20 that is connected to a mating terminal. In this example, the connecting portion 21 is formed in a substantially rectangular tubular shape that extends in the extension direction of the electric wire 10. The connecting portion 21 is connected to the core wire crimping portion 22 via the first coupling portion 20a.

[0018] The core wire crimping portion 22 is a portion that is crimped to the core wire 12 exposed at one end portion of the electric wire 10. As shown in Fig. 4, the core wire crimping portion 22 has a base 22a and a pair of crimping pieces 22b. The base 22a has a generally U-shaped cross section and extends in the extension direction of the electric wire 10. The pair of crimping pieces 22b are formed in the shape of arms that extend upward from a pair of widthwise ends of the base 22a, and extend upward while inclining outward in the widthwise direction before being crimped to the core wire 12. The core wire crimping portion 22 is connected to the coating crimping portion 23 via the second connecting portion 20b.

[0019] The coating crimping portion 23 is a portion that is crimped to an end portion of the insulating coating 13 of the electric wire 10. As shown in Fig. 1, the coating crimping portion 23 has a base 23a and a pair of crimping pieces 23b. Similar to the base 22a, the base 23a has a generally U-shaped cross section and extends in the extension direction of the electric wire 10 (not shown). Similar to the pair of crimping pieces 22b, the pair of crimping pieces 23b are formed in arm shapes that extend upward from a pair of ends in the width direction of the base 23a, and extend upward while inclining outward in the width direction before being crimped to the core wire 12 (not shown).

[0020] The auxiliary electrode 30 is made of aluminum, an aluminum alloy, copper, a copper alloy, or any other metal as required, and preferably has a higher resistance than the element wires 11. As shown in Fig. 2 , the auxiliary electrode 30 is inserted into the crimped portion 12a of the core wire 12 from the outside of the core wire crimping portion 22 so as to get between the plurality of element wires 11.

[0021] The auxiliary electrode 30 includes a head 31 disposed outside the core wire crimping portion 22, and a plurality of foot portions 32 extending from the head 31 to enter between the wires 11. Before being inserted into the crimping part 12a, the foot portions 32 extend linearly from the head 31, as shown in Fig. 3, with their tips 32a inclined so as to approach the head 31 from the radially outer side toward the radially inner side.

[0022] [Manufacturing equipment for electric wires with terminals] An example of a manufacturing apparatus for an electric wire with terminal will be described below. The manufacturing apparatus 100 for an electric wire with terminal has an anvil-type electrode 101 (see Figures 4 to 8), a crimper-type electrode 102 (see Figures 4 to 8), an auxiliary electrode inserting tool 103 (see Figures 6 to 7), and an electrode for an auxiliary electrode 104 (see Figure 8).

[0023] The anvil electrode 101 is a fixed mold and has a function of supporting the terminal 20. The anvil electrode 101 is one of the electrodes used for resistance welding.

[0024] The crimper electrode 102 is a movable die located above the anvil electrode 101 and is movable relative to the anvil electrode 101 in the vertical direction (the direction perpendicular to the direction in which the electric wire 10 extends). The crimper electrode 102 is one of the electrodes used for resistance welding. As shown in FIG. 4, the crimper electrode 102 has a thickness in the direction in which the electric wire 10 extends, and a crimping surface 102a that is recessed upward is formed in the center of the width direction of the lower surface. The crimping surface 102a is formed to crimp while guiding a pair of crimping pieces 22b of the core wire crimping portion 22 of the terminal 20.

[0025] The auxiliary electrode inserting tool 103 is a tool for inserting the auxiliary electrode 30 into the crimped portion 12a from outside the core wire crimping portion 22. As shown in Figures 6 and 7, the auxiliary electrode inserting tool 103 is inserted into a hole 102b provided in the crimper electrode 102 and is movable in the vertical direction relative to the anvil electrode 101. The auxiliary electrode inserting tool 103 has, for example, a punch 103a that inserts the auxiliary electrode 30 into the crimped portion 12a from outside the core wire crimping portion 22, and a catcher 103b that holds the auxiliary electrode 30.

[0026] The electrode 104 for the auxiliary electrode is an electrode that applies current to the auxiliary electrode 30. As shown in Fig. 8, the electrode 104 for the auxiliary electrode is inserted into a hole 102b provided in the crimper-type electrode 102, and is movable relative to the anvil-type electrode 101 in the up-down direction.

[0027] [Manufacturing method for electric wire with terminal] An example of a method for manufacturing an electric wire with a terminal will be described below. However, the method for manufacturing the electric wire with terminal is not limited to the following method.

[0028] First, the terminal 20 is crimped onto the electric wire 10. As a preparation for this step, the electric wire 10 is subjected to end treatment in which the insulating coating 13 is removed from one end of the electric wire 10 to expose a predetermined length of the core wire 12.

[0029] Next, the terminal 20 is placed on the anvil-type electrode 101, and then the electric wire 10 is placed on the terminal 20 so that the exposed core wire 12 is positioned at the base 22a of the core wire crimping portion 22 and the terminal portion of the insulating coating 13 is positioned at the base 23a of the coating crimping portion 23 (see Figure 4).

[0030] Next, the crimper-type electrode 102 is moved downward relative to the anvil-type electrode 101, and the pair of crimping pieces 22b of the core wire crimping portion 22 is crimped to the core wire 12 (see FIG. 5). At this time, the pair of crimping pieces 22b are crimped by the crimping surface 102a of the crimper-type electrode 102 so as to surround the core wire 12 and so as to bite into the upper part of the core wire 12 while the pair of downward-facing tips abut against each other. Similarly, the pair of crimping pieces 23b of the cover crimping portion 23 is crimped to the insulating cover 13 by a processing tool (a so-called anvil and crimper) not shown. This completes the crimping of the terminal 20 to the electric wire 10. Note that the process of crimping the core wire crimping portion 22 to the core wire 12 and the process of crimping the cover crimping portion 23 to the insulating cover 13 may be performed simultaneously or sequentially.

[0031] Next, the auxiliary electrode 30 is inserted into the crimped portion 12a of the core wire 12. As a preparation for this step, the auxiliary electrode 30 is held by the auxiliary electrode inserting tool 103, that is, in this example, the tip (lower side in FIG. 6) of the punch 103a and the catcher 103b.

[0032] Next, the auxiliary electrode inserter 103 is inserted through the hole 102b of the crimper electrode 102 and moved downward relative to the anvil electrode 101 (see FIG. 6), and the auxiliary electrode 30 is inserted into the crimped portion 12a of the core wire 12 from the outside of the terminal 20 (see FIG. 7). At this time, when the punch 103a is operated, the catcher 103b is released and the auxiliary electrode 30 is inserted into the crimped portion 12a.

[0033] As a result, the head 31 of the auxiliary electrode 30 comes into contact with the core wire crimping portion 22, and the multiple feet 32 ​​of the auxiliary electrode 30 penetrate the core wire crimping portion 22 and enter between the multiple strands 11. At this time, because the tips 32a of the feet 32 ​​are formed at an angle, as the feet 32 ​​are inserted, the tips 32a spread radially outward relative to the central axis of the auxiliary electrode 30, that is, the tips 32a enter between the multiple strands 11 so as to move away from each other. This completes the insertion of the auxiliary electrode 30 into the crimped portion 12a of the core wire 12. After the auxiliary electrode 30 has been inserted, the auxiliary electrode inserting tool 103 is moved upward relative to the anvil electrode 101, and is moved out of the hole 102b.

[0034] Next, the auxiliary electrode 30 is heated by passing electricity through it. The electrode 104 for the auxiliary electrode is inserted through the hole 102b of the crimper-type electrode 102 and moved downward relative to the anvil-type electrode 101 until the electrode 104 for the auxiliary electrode is brought into contact with the head 31.

[0035] Next, while the auxiliary electrode 30 is pressed downward by the electrode 104 for the auxiliary electrode, a current is passed between the anvil electrode 101 and the electrode 104 for the auxiliary electrode (see FIG. 8). As a result, the crimped portion 12a is heated via the auxiliary electrode 30, and melts and softens. After heating by the current, the electrode 104 for the auxiliary electrode is moved upward relative to the anvil electrode 101, and is moved out of the hole 102b.

[0036] Next, the anvil-type electrode 101 and the crimper-type electrode 102 apply current to the crimped portion 12a from outside the core wire crimping portion 22 to heat it (see FIG. 2). As a result, the crimped portion 12a generates heat via the core wire crimping portion 22, melting and softening it. Thereafter, the crimped portion 12a solidifies, thereby integrating the plurality of elemental wires 11 in the crimped portion 12a and welding the outer periphery of the crimped portion 12a to the core wire crimping portion 22, thereby completing the electric wire with terminal 1.

[0037] After the electrical heating, the crimper electrode 102 is moved upward relative to the anvil electrode 101, completing the production of the electric wire with terminal 1. The order of the electrical heating process using the auxiliary electrode 104 (and the anvil electrode 101) and the electrical heating process using the anvil electrode 101 and the crimper electrode 102 may be reversed, or may be performed together.

[0038] [Example of effect] According to this embodiment, the auxiliary electrode 30 penetrates between the plurality of element wires 11, thereby promoting plastic deformation between the plurality of element wires 11, and the electrical heating of the auxiliary electrode 30 causes the crimped portion 12a of the core wire 12 to melt and soften in a concentrated manner. This ensures good electrical continuity between the plurality of element wires 11, and also ensures that the crimped portion 12a is heated by electrical heating between the anvil-type electrode 101 and the crimper-type electrode 102 via a path separate from that of the auxiliary electrode 30, thereby heating the entire crimped portion 12a and ensuring even better electrical continuity between the plurality of element wires 11. In other words, according to this embodiment, better electrical continuity between the element wires 11 can be achieved at the crimped portion 12a of the core wire 12 than in the conventional case, resulting in superior electrical characteristics.

[0039] Furthermore, according to this embodiment, the auxiliary electrode 30 has a head portion 31 and a foot portion 32, so that when the auxiliary electrode is heated by electrical current, heat is transferred from the head portion 31 to the foot portion 32, thereby melting and softening the crimped portion 12a of the core wire 12 in a concentrated manner.

[0040] Furthermore, according to this embodiment, the tip portions 32a of the multiple leg portions 32 extend away from each other, so that when the auxiliary electrode 30 is heated by electrical current, the crimped portion 12a of the core wire 12 can be melted and softened in a concentrated and more efficient manner.

[0041] [Other embodiments] The present invention is not limited to the above-described embodiments, and can be appropriately modified, improved, etc. Furthermore, the material, shape, size, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as they can achieve the present invention.

[0042] 9, the terminal 20 may be provided with an insertion hole 24 through which the leg portion 32 of the auxiliary electrode 30 is inserted. This makes it easier to insert the auxiliary electrode 30 (leg portion 32) into the crimped portion 12a of the core wire 12.

[0043] Furthermore, for example, a rivet may be used as the auxiliary electrode 30. As the rivet, various types of rivets such as a self-piercing rivet, a blind rivet, and a split rivet may be used.

[0044] [Features of the embodiment] The features of the above-described embodiment of the electric wire with terminal according to the present invention will be briefly summarized below.

[0045] [1] An electric wire (10) includes a core wire (12) made of a plurality of wires (11) and an insulating coating (13) covering the core wire (12), and a terminal (20) crimped onto the core wire (12) exposed at an end of the electric wire (10), and the terminal (20) is resistance-welded by clamping the terminal (20) crimped onto the core wire (12) from the outside between a pair of electrodes (anvil-type electrode 101 and a crimper-type electrode 102) and passing current through the terminal, The crimping device further includes an auxiliary electrode (30) that is inserted from the outside of the terminal (20) along the clamping direction of the pair of electrodes (anvil-type electrode 101 and crimper-type electrode 102) to the terminal (20) relative to the crimping portion (12a) of the core wire (12) to which the terminal (20) is crimped, and that fits between the plurality of element wires (11). Wire with terminal (1).

[0046] According to the configuration [1] above, the auxiliary electrode penetrates between the multiple strands, promoting plastic deformation between the multiple strands, and the electrical heating of the auxiliary electrode causes concentrated melting and softening of the crimped portion of the core wire. This ensures good electrical continuity between the multiple strands, and because the electrical heating of the pair of electrodes heats the crimped portion via a route separate from the auxiliary electrode, the entire crimped portion is heated, resulting in even better electrical continuity between the multiple strands. In other words, this configuration provides better electrical continuity between the strands at the crimped portion of the core wire than conventional configurations, resulting in superior electrical characteristics.

[0047] [2] The terminal-attached wire (1) according to the above [1], The auxiliary electrode (30) has a head (31) located on the outer side of the terminal (20) and a foot (32) extending from the head (31) so as to enter between the plurality of wires (11). Wire with terminal (1).

[0048] According to the configuration [2] above, the auxiliary electrode has a head and a foot, so that when the auxiliary electrode is heated by electrical current, heat is transferred from the head to the foot, thereby melting and softening the crimped portion of the core wire in a concentrated manner.

[0049] [3] The electric wire with terminal (1) described in [2] above, The auxiliary electrode (30) has a plurality of the legs (32), The plurality of foot portions (32) extend such that the insertion tip portions (32a) are spaced apart from each other. Wire with terminal (1).

[0050] According to the configuration [3] above, the insertion tip ends of the multiple legs extend away from each other, so that when the auxiliary electrode is heated by electrical current, the crimped portion of the core wire can be melted and softened in a concentrated and more efficient manner.

[0051] [4] The electric wire with terminal (1) according to any one of [1] to [3] above, The terminal (20) is provided with an insertion hole (24) into which the auxiliary electrode (30) is inserted. Wire with terminal (1).

[0052] According to the configuration [4] above, the terminal is provided with an insertion hole into which the auxiliary electrode is inserted, which makes it easy to insert the auxiliary electrode into the crimped portion of the core wire. [Explanation of symbols]

[0053] 1 Wire with terminal 10 Electric wire 11 Wire 12 core wire 12a Crimped part 13 Insulation coating 20 terminals 22 Core wire crimping part 24 Insertion hole 30 Auxiliary electrode 31 Head 32 Foot 32a Tip 100 Manufacturing equipment 101 Anvil-type electrode 102 Crimper-type electrode 103 Auxiliary electrode insertion tool 104 Electrode for auxiliary electrode

Claims

1. An electric wire with terminal, comprising: an electric wire having a core wire made of a plurality of wires and an insulating coating covering the core wire; and a terminal crimped onto the core wire exposed at an end of the electric wire, the terminal crimped onto the core wire being resistance-welded by sandwiching the terminal crimped onto the core wire from the outside between a pair of electrodes and passing current therethrough, the terminal is crimped to the core wire at a crimping portion thereof, and the crimping portion is inserted from the outside of the terminal along a clamping direction of the pair of electrodes to the terminal, and is inserted between the plurality of wires. Wire with terminals.

2. The electric wire with terminal according to claim 1, The auxiliary electrode has a head portion located on the outer side of the terminal, and a foot portion extending from the head portion so as to enter between the plurality of wires. Wire with terminals.

3. The electric wire with terminal according to claim 2, the auxiliary electrode has a plurality of the legs, The plurality of foot portions extend such that the insertion tip portions are spaced apart from each other. Wire with terminals.

4. The electric wire with terminal according to any one of claims 1 to 3, The terminal has an insertion hole into which the auxiliary electrode is inserted. Wire with terminals.

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