Electric wire with terminal and method for manufacturing the same

Abstract

To provide an electric wire with a terminal and a method for manufacturing the same that can suppress the transfer of excessive heat associated with resistance welding to an insulating coating of the electric wire and prevent carbonization of the insulating coating.SOLUTION: An electric wire with a terminal 1 includes an electric wire 10 and a terminal 20. The terminal 20 includes a core wire crimping portion 22 crimped to an exposed core wire 12, a coating crimping portion 24 crimped to an insulating coating 13, and a cooling structure 23 located between the core wire crimping portion 22 and the coating crimping portion 24 in the electric wire extension direction. The cooling structure 23 includes a base 231 that extends in the electric wire extension direction and on which the exposed core wire 12 is placed, a pair of extension pieces 232 extending from both widthwise end portions of the base 231 so as to rise in the clamping direction of the pair of electrodes, and a flange portion 234 formed such that a part of the extension piece 232 extends from the base 231 along the width direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric wire with a terminal and a method for manufacturing 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 process as electrodes, but this method can cause variations in the electrical heating and does not necessarily result in satisfactory conductivity.

[0004] Patent Document 1 discloses an electric wire with a terminal in which, at the connection portion between the terminal and the electric wire, a convex portion consisting of a convex strip is provided on the smooth surface of the bottom wall of the terminal at an angle to the longitudinal axis of the electric wire, and this convex portion is directly connected to the conductor at the end of the electric wire by resistance welding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4158889 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the electric wire with terminal disclosed in Patent Document 1, resistance welding is used to ensure electrical continuity between the wires at the crimped portion of the core wire that is crimped to the terminal. However, excessive heat from the resistance welding may be transferred to the insulating coating of the electric wire via the core wire or the terminal, which may cause partial carbonization of the insulating coating.

[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 can suppress the transfer of excessive heat associated with resistance welding to the insulating coating of the electric wire and prevent carbonization of the insulating coating, and a method for manufacturing an electric wire with a terminal. [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 is a core wire crimping portion that is crimped to the exposed core wire; a coating crimping portion that is crimped to the insulating coating; a cooling structure portion located between the core wire crimping portion and the coating crimping portion in the electric wire extending direction, The cooling structure includes: a base portion extending in the electric wire extending direction and on which the exposed core wire is placed; a pair of extension pieces extending from both widthwise end portions of the base portion so as to rise in a direction in which the pair of electrodes are sandwiched; A flange portion is formed so that a portion of the extension piece extends from the base portion along the width direction.

[0009] In order to achieve the above-mentioned object, a method for manufacturing an electric wire with a terminal according to the present invention comprises: The method for manufacturing the electric wire with terminal comprises: a crimping step of crimping the exposed core wire to the core wire crimping portion and crimping the insulation coating to the coating crimping portion; a welding step of, after the crimping step, sandwiching the core wire crimping portion from outside with the pair of electrodes while applying pressure to the core wire crimping portion in a state in which the cooling structure portion and the coating crimping portion are placed on a cooling device, and passing a current between the pair of electrodes to weld the exposed core wire and the core wire crimping portion by electrical heating, The flange portion is brought into surface contact with the cooling device during the welding process. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an electric wire with terminal that can suppress the transfer of excess heat associated with resistance welding to the insulating coating of the electric wire and prevent carbonization of the insulating coating, and a method for manufacturing the electric wire with terminal.

[0011] 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]

[0012] [Figure 1] FIG. 1 is a schematic side view of an electric wire with a terminal according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic top view of the electric wire with terminal shown in FIG. [Figure 3] FIG. 3 is a schematic development view of the terminal shown in FIG. [Figure 4] FIG. 4 is a schematic side view for explaining a method for manufacturing an electric wire with a terminal according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic top view of FIG. [Figure 6] FIG. 6 is a schematic top view showing a modified example of the electric wire with terminal shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a method for manufacturing an electric wire with a terminal according to one embodiment of the present invention will be described with reference to the drawings. The electric wire with terminal 1 manufactured according to this embodiment can be used to be routed between various devices such as a battery, inverter, and motor of an electric vehicle, for example.

[0014] [Outline of terminal-attached wire configuration] Hereinafter, an example of the schematic configuration of an electric wire with terminal manufactured by the manufacturing method of an electric wire with terminal according to the present embodiment will be described. As shown in FIG. 1 and other figures, the electric wire with terminal 1 includes an electric wire 10 and a terminal 20.

[0015] 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.

[0016] 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.

[0017] 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, a cooling structure portion 23, a third connecting portion 20c, and a coating crimping portion 24. The connecting portion 21, the first connecting portion 20a, the core wire crimping portion 22, the second connecting portion 20b, the cooling structure portion 23, the third connecting portion 20c, and the coating crimping portion 24 are arranged in a line in this order from one terminal side to the other terminal side along the extending direction of the electric wire 10.

[0018] 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.

[0019] 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. 3, the core wire crimping portion 22 has a base 22a and a pair of crimping pieces 22b. The base 22a 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 (not shown). The core wire crimping portion 22 is connected to the cooling structure 23 via the second connecting portion 20b.

[0020] The cooling structure 23 is a part for preventing carbonization of the insulating coating 13 in a welding process described below, i.e., for preventing excessive heat transfer to the insulating coating 13 during the welding process described below. The cooling structure 23 will be described using the expanded state of the terminal 20 (the state shown in FIG. 3) as an example. The cooling structure 23 has a base 231, a pair of extension pieces 232, and a flange 234. The cooling structure 23 is connected to the coating crimping portion 24 via the third connecting portion 20c.

[0021] The base 231 has a substantially flat plate shape and extends in the extending direction of the electric wire 10. The base 231 is brought into surface contact with the cooling device 103 in a welding process described later (see FIG. 4). The pair of extension pieces 232 extend along the width direction from a pair of widthwise ends of the base 22a, and in the completed state of the electric wire with terminal 1, they stand upright from the base 231 (see FIG. 1, etc.).

[0022] A slit 233 is provided in each of the pair of extending pieces 232, and the slit 233 is formed in a substantially rectangular U-shape including a pair of first portions 233a extending in the width direction from an end portion on the inner side in the width direction (on the base 231 side) of the extending piece 232 and spaced apart in the extension direction of the electric wire 10, and a second portion 233b connecting ends of the pair of first portions 233a on the outer side in the width direction (on the opposite side from the base 231). As a result, a flange portion 234 is formed in each of the pair of extending pieces 232, extending short along the width direction from a pair of ends in the width direction of the base 231.

[0023] In the completed state of the electric wire with terminal 1, the flange portion 234 extends in the width direction and has a brim-like configuration (see FIG. 2 etc.) in which its lower surface (the surface in contact with the cooling device 103) is substantially flush with the lower surface (the surface in contact with the cooling device 103) of the base portion 231. Therefore, the flange portion 234 comes into surface contact with the cooling device 103 in a welding step described later.

[0024] The coating crimping portion 24 is a portion that is crimped to an end portion of the insulating coating 13 of the electric wire 10. As shown in Fig. 3, the coating crimping portion 24 has a base 24a and a pair of crimping pieces 24b. The base 24a has a pair of crimping pieces 24b extending in the extension direction of the electric wire 10. Similar to the pair of crimping pieces 22b, the pair of crimping pieces 24b of the base 24a are formed in the shape of arms that extend upward from a pair of ends in the width direction of the base 24a, and extend upward while inclining outward in the width direction before being crimped to the core wire 12 (not shown).

[0025] [Manufacturing equipment for electric wires with terminals] An example of an apparatus for manufacturing an electric wire with terminal used in the method for manufacturing an electric wire with terminal according to this embodiment will be described below. The manufacturing apparatus 100 for an electric wire with terminal has a pair of electrodes 101, 102 (see FIGS. 4 and 5). In addition, in this example, the manufacturing apparatus 100 for an electric wire with terminal has a cooling device 103.

[0026] The pair of electrodes 101, 102 are processing tools that sandwich the core wire crimping portion 22 from the outside and apply pressure while passing current through them to resistance weld the core wire 12 and the core wire crimping portion 22. The pair of electrodes 101, 102 may be, for example, an anvil-type electrode or a crimper-type electrode, but there are no particular limitations on the configuration, shape, etc., as long as they can perform the welding process described below.

[0027] The cooling device 103 is a device (or equipment) for preventing carbonization of the insulating coating 13 in the welding process described below, i.e., for preventing excessive heat transfer to the insulating coating 13 during the welding process. The cooling device 103 may be a device (or equipment) equipped with various cooling mechanisms, such as a water-cooled type using a chiller, a Peltier element, or a heat pump type, but the configuration, shape, etc. are not particularly limited as long as the present invention can be implemented.

[0028] In addition to the above, the manufacturing apparatus 100 for an electric wire with terminal further includes processing tools (anvil, crimper, etc.) not shown that are used in a core wire crimping step described later, and processing tools (anvil, crimper, etc.) not shown that are used in a coating crimping step described later. These are, for example, well-known tools, and there are no particular limitations on the configuration, shape, etc., as long as they can perform each of the steps described later.

[0029] [Manufacturing method for electric wire with terminal] An example of the method for manufacturing the electric wire with terminal according to this embodiment will be described below. However, the method for manufacturing the electric wire with terminal is not limited to the following method.

[0030] First, the terminal 20 is crimped to the electric wire 10. As a preparation for this step, the insulating coating 13 is removed from one end of the electric wire 10 to expose a predetermined length of the core wire 12. In this example, since the terminal 20 has the cooling structure 23, the predetermined length of the exposed core wire 12 is longer than when the terminal 20 does not have the cooling structure 23 (conventional).

[0031] Next, the terminal 20 is placed on an anvil (not shown), 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 24a of the coating crimping portion 24.

[0032] Next, a crimper (not shown) is moved downward relative to the anvil on which the terminal 20 is placed, thereby crimping the pair of crimping pieces 22b of the core wire crimping portion 22 to the core wire 12 (this step is also referred to as the "core wire crimping step"). At this time, the crimper crimps the pair of crimping pieces 22b so that they surround the core wire 12 and bite into the upper part of the core wire 12 while the pair of downward-facing tips abut against each other. Similarly, an anvil and crimper (not shown) crimp the pair of crimping pieces 24b of the insulation crimping portion 24 to the insulating coating 13 (this step is also referred to as the "covering crimping step"). This completes the crimping of the terminal 20 to the electric wire 10. The core wire crimping step and the covering crimping step may be performed together or sequentially.

[0033] Next, the core wire 12 and the core wire crimping portion 22 are welded (this step is also referred to as the "welding step"). In performing this step, the terminal 20 crimped to the electric wire 10 is arranged so that the core wire crimping portion 22 is located on the electrode 101 and the cooling structure portion 23 and the insulation crimping portion 24 are located on the cooling device 103 (see FIGS. 4 and 5). In this state, the base portion 231 and the flange portion 234 are in surface contact with the cooling device 103. At this time, it is preferable that the base portion 24a of the insulation crimping portion 24 is also in surface contact with the cooling device 103.

[0034] Next, electrode 102 is moved downward relative to electrode 101, and while pressing core wire crimping portion 22, electricity is applied between the pair of electrodes 101, 102 to heat them (see FIGS. 4 and 5). As a result, the crimped portion of core wire 12 generates heat via core wire crimping portion 22, melting and softening it. Thereafter, the crimped portion of core wire 12 solidifies, thereby integrating the multiple element wires 11 in the crimped portion and welding the outer periphery of the crimped portion to core wire crimping portion 22, thereby completing electric wire with terminal 1.

[0035] After the electrical heating, electrode 102 is moved upward relative to electrode 101, completing the production of electric wire with terminal 1. The best method for producing an electric wire with terminal described above can be selected as appropriate.

[0036] [Example of effect] As described above, according to this embodiment, the cooling structure 23 is provided between the core wire crimping portion 22 and the coating crimping portion 24, thereby ensuring a longer gap between the crimped portion of the core wire 12 (the portion resistance-welded to the core wire crimping portion 22) and the insulating coating 13, thereby improving heat dissipation. In addition, the flange portion 234 is provided in the cooling structure 23, so that not only the base portion 231 and the pair of extension pieces 232 but also the flange portion 234 serve as a heat transfer path (i.e., a heat dissipation path) in the cooling structure 23, thereby further improving heat dissipation. This makes it possible to suppress excessive heat transfer to the insulating coating 13 due to resistance welding. As a result, according to this embodiment, carbonization of the insulating coating 13 due to resistance welding can be suppressed.

[0037] Furthermore, according to this embodiment, in the welding process, the cooling structure 23 and the coating crimping portion 24 are placed on the cooling device 103, thereby suppressing excessive heat transfer to the insulating coating 13 due to resistance welding. In addition, the flange portion 234 is in surface contact with the cooling device 103, which increases the contact area between the cooling structure 23 and the cooling device 103, thereby more appropriately suppressing excessive heat transfer to the insulating coating 13 due to resistance welding.

[0038] [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.

[0039] In the above embodiment, in the cooling structure 23 of the terminal 20, the pair of extension pieces 232 rise upward from the base 231 (see FIG. 1, etc.), and the flange portions 234 have a brim-like configuration extending along the width direction (see FIG. 2, etc.). However, for example, as shown in FIG. 6, the pair of extension pieces 232 and the flange portions 234 may be crimped to the exposed core wire 12. In this case, after the above-mentioned welding step, the pair of extension pieces 232 and the flange portions 234 may be crimped to the exposed core wire 12 using processing tools (anvil, a crimper, etc.) not shown. By crimping the pair of extension pieces 232 and the flange portions 234 to the core wire 12 in this way, the outer dimensions of the electric wire with terminal 1 can be made smaller than when the pair of extension pieces 232 and the flange portions 234 are not crimped to the core wire 12.

[0040] [Features of the embodiment] Hereinafter, features of the embodiments of the electric wire with terminal and the method for manufacturing the electric wire with terminal according to the present invention will be briefly summarized and listed.

[0041] [1] An electric wire (10) having 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 from an end of the electric wire (10), the terminal (20) being resistance-welded by sandwiching the terminal (20) crimped onto the core wire (12) from the outside between a pair of electrodes (101, 102) and passing current therethrough, The terminal (20) is a core wire crimping portion (22) that is crimped to the exposed core wire (12); a coating crimping portion (24) that is crimped onto the insulating coating (13); a cooling structure portion (23) located between the core wire crimping portion (22) and the coating crimping portion (24) in the extending direction of the electric wire, The cooling structure (23) is a base (231) extending in the electric wire extending direction and on which the exposed core wire (12) is placed; a pair of extension pieces (232) extending from both widthwise ends of the base (231) so as to rise in the clamping direction of the pair of electrodes; a flange portion (234) formed so that a part of the extension piece (232) extends from the base portion (231) along the width direction; Wire with terminal (1).

[0042] According to the configuration [1] above, by providing a cooling structure between the core wire crimping portion and the insulation crimping portion, a longer distance can be ensured between the crimped portion of the core wire (the portion resistance-welded to the core wire crimping portion) and the insulating coating, thereby improving heat dissipation. In addition, by providing a flange portion in the cooling structure, not only the base portion and the pair of extension pieces but also the flange portion become heat transfer paths (i.e., heat dissipation paths) in the cooling structure, further improving heat dissipation. This makes it possible to suppress excessive heat transfer to the insulating coating due to resistance welding. As a result, according to this embodiment, carbonization of the insulating coating due to resistance welding can be suppressed.

[0043] [2] A method for manufacturing an electric wire with terminal according to the above [1], a crimping step of crimping the exposed core wire (12) to the core wire crimping portion (22) and crimping the insulation coating (13) to the coating crimping portion (24); a welding step of, after the crimping step, sandwiching the core wire crimping portion (22) from outside with the pair of electrodes (101, 102) while applying pressure to the core wire crimping portion (22) in a state in which the cooling structure portion (23) and the coating crimping portion (24) are placed on a cooling device (103), and passing current between the pair of electrodes (101, 102) to weld the exposed core wire (12) and the core wire crimping portion (22) by electrical heating, The flange portion (234) is brought into surface contact with the cooling device (103) during the welding process. Manufacturing method of electric wire with terminal.

[0044] According to the configuration [2], in the welding process, the cooling structure and the coating crimping portion are placed on a cooling device, and at this time, the flange portion is in surface contact with the cooling device, thereby suppressing excessive heat transfer to the insulating coating due to resistance welding. As a result, this configuration can suppress carbonization of the insulating coating due to resistance welding.

[0045] [3] A method for manufacturing an electric wire with terminal according to the above [2], The method further includes a step of crimping the pair of extension pieces (232) and each of the flange portions (234) to the exposed core wire (12) after the welding step. Manufacturing method of electric wire with terminal.

[0046] According to the configuration [3] above, by crimping the pair of extension pieces and each flange portion to the core wire, the external dimensions of the terminal-attached wire can be made smaller than when the pair of extension pieces and each flange portion are not crimped to the core wire. [Explanation of symbols]

[0047] 1 Wire with terminal 10 Electric wire 11 Wire 12 core wire 13 Insulation coating 20 terminals 21 Connection 22 Core wire crimping part 23 Cooling structure 231 Base 232 Extension piece 233 Slit 233a Part 1 233b Part 2 234 Flange 24 Cover crimping part 100 Manufacturing equipment 101 Electrode 102 electrode 103 Cooling device

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 a core wire crimping portion that is crimped to the exposed core wire; a coating crimping portion that is crimped to the insulating coating; a cooling structure portion located between the core wire crimping portion and the coating crimping portion in the electric wire extending direction, The cooling structure includes: a base portion extending in the electric wire extending direction and on which the exposed core wire is placed; a pair of extension pieces extending from both widthwise end portions of the base portion so as to rise in a direction in which the pair of electrodes are sandwiched; a flange portion formed so that a part of the extension piece extends from the base portion along the width direction, Wire with terminals.

2. A method for manufacturing an electric wire with terminal according to claim 1, a crimping step of crimping the exposed core wire to the core wire crimping portion and crimping the insulation coating to the coating crimping portion; a welding step of, after the crimping step, sandwiching the core wire crimping portion from outside with the pair of electrodes while applying pressure to the core wire crimping portion in a state in which the cooling structure portion and the coating crimping portion are placed on a cooling device, and passing a current between the pair of electrodes to weld the exposed core wire and the core wire crimping portion by electrical heating, The flange portion is in surface contact with the cooling device in the welding process. Manufacturing method of electric wire with terminal.

3. A method for manufacturing an electric wire with a terminal according to claim 2, the step of crimping the pair of extension pieces and the flange portions to the exposed core wire after the welding step. Manufacturing method of electric wire with terminal.

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