Electric wire with terminal

Abstract

To provide an electric wire with a terminal that achieves satisfactory electrical conduction between element wires at a crimped part of a core wire without excessively deforming a crimped part of the terminal and has excellent electrical characteristics.SOLUTION: An electric wire 1 with a terminal includes an electric wire 10 having a core wire 12 composed of a plurality of element wires 11 and an insulating coating 13, and a terminal 20 crimped to the core wire 12 exposed from an end part of the electric wire 10, and is resistance-welded by applying current while sandwiching the terminal 20 crimped to the core wire 12 between a pair of electrodes 101 and 101 from the outside. The terminal 20 has a bottomed cylindrical core wire crimping part 23 that extends in an extending direction of the electric wire 10 and into which the exposed core wire 12 is inserted, and a bottom wall 23a is provided with a protruding part 24 that extends into a cylindrical hole and is inserted into the inserted core wire 12.SELECTED DRAWING: Figure 6

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] Patent Document 1 discloses an electric wire with a terminal in which the exposed conductor of the electric wire is inserted into a tubular portion of the terminal (hereinafter also referred to as the "crimping portion") and the crimping portion is crimped to the exposed conductor by resistance welding, thereby connecting the electric wire and the terminal. The electric wire with terminal disclosed in Patent Document 1 is configured such that, in the process of crimping the electric wire and the terminal, the crimping portion is clamped between a pair of electrodes and pressed so as to reduce its dimension in the clamping direction, and when the pair of electrodes come into contact with each other, current flows between the contact portions of the pair of electrodes without flowing through the terminal, and heating is stopped when the crimping portion assumes a desired shape. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6569345 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the case of the electric wire with terminal disclosed in Patent Document 1, when the electric wire size is large, the pair of electrodes must apply excessive pressure to the crimping portion in order to sufficiently melt the central wire of the exposed conductor inserted into the crimping portion, which may result in excessive deformation of the crimping portion, which is inconvenient.

[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 has excellent electrical properties and achieves good conduction between the wires at the crimped portion of the core wire without excessively deforming the crimped portion of the 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 has a bottomed, cylindrical crimping portion extending in the extending direction of the electric wire and into which the exposed core wire is inserted, a protrusion provided on a cylindrical bottom of the crimping portion so as to be inserted into the core wire inserted into the crimping portion; The wire must have a terminal. [Effects of the Invention]

[0009] According to the present invention, the protrusions provided on the cylindrical bottom of the crimping portion are inserted into the core wire inserted into the crimping portion, thereby allowing heat to be transferred via the protrusions to the center of the core wire, which is normally difficult to transfer heat and melt. This makes it easy to melt the center of the core wire. Therefore, according to the present invention, better electrical conductivity between the wires is achieved in the crimped portion of the core wire (i.e., the portion inserted into the crimping portion) without excessively deforming the crimping portion of the terminal compared to conventional methods, resulting in excellent electrical properties.

[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 schematic cross-sectional view of the terminal-attached electric wire shown in FIG. [Figure 3] FIG. 3 is a schematic diagram showing a manufacturing apparatus for an electric wire with a terminal. [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. 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 and a terminal 20.

[0014] 2, 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 etc., the terminal 20 is configured to have a connection portion 21, a linking portion 22, and a core wire crimping portion 23. The connection portion 21, the linking portion 22, and the core wire crimping portion 23 are arranged in a line in this order from one end side to the other end side along the extending direction of the electric wire 10 (hereinafter also simply referred to as the "extending direction").

[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 generally rod-like shape that extends in the extension direction. The connecting portion 21 is connected to the core wire crimping portion 23 via the linking portion 22.

[0018] The core wire crimping portion 23 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. 2 etc., the core wire crimping portion 23 is formed in a cylindrical shape with a bottom. More specifically, the core wire crimping portion 23 extends in the extension direction, has a bottom wall 23a on one end side in the extension direction (left side in Fig. 2), and is formed so as to be open on the other end side in the extension direction (right side in Fig. 2).

[0019] As shown in Fig. 2 and other figures, a protrusion 24 is provided on the bottom wall 23a of the core wire crimping portion 23, protruding toward the other end side within the core wire crimping portion 23. The length of the protrusion 24 is preferably formed to be at least half the length of the core wire crimping portion 23, and in this example, it is approximately half the length of the core wire crimping portion 23. The protrusion 24 is formed, for example, in a conical shape with a tapered protruding end, and when the exposed core wire 12 is inserted into the core wire crimping portion 23, the protrusion 24 is inserted into the inside of the core wire 12, i.e., between the plurality of wires 11 (see Fig. 2 and other figures).

[0020] [Manufacturing equipment for electric wires with terminals] An example of a manufacturing apparatus for an electric wire with terminal will be described below. 3 and other figures, the manufacturing apparatus 100 for an electric wire with terminal has a pair of electrodes 101, 101. The pair of electrodes 101, 101 are electrodes for performing resistance welding.

[0021] The lower electrode 101 of the pair of electrodes 101, 101 is a fixed mold and has a function of supporting the terminal 20. The upper electrode 101 of the pair of electrodes 101, 101 is a movable mold located above the lower electrode 101 and is movable relative to the lower electrode 101 in the up-and-down direction (the direction perpendicular to the extension direction of the electric wire 10).

[0022] Each of the pair of electrodes 101 has a thickness in the extension direction of the electric wire 10, and a pressing portion 102 is formed in the widthwise center of the end surface of the paired electrode 101 side, recessed in a substantially rectangular shape so as to be spaced apart from the paired electrode 101. That is, the pressing portion 102 is formed such that the widthwise center of the upper surface of the lower electrode 101 is recessed downward in a substantially rectangular shape, and the widthwise center of the lower surface of the upper electrode 101 is recessed upward in a substantially rectangular shape. As a result, when the pair of electrodes 101 come into contact with each other, a substantially rectangular cylindrical space is defined by the pressing portions 102. Therefore, the core wire crimping portion 23 pressed by the pair of electrodes 101 has the same shape as the space defined by the pressing portions 102. The pressing portion 102 is formed to crimp the core wire crimping portion 23 to the core wire 12 inserted therein.

[0023] The bottom surfaces of the pressure applying portions 102, 102 are each provided with a pressure applying rib 103 that protrudes toward the paired electrode 101. That is, the pressure applying rib 103 of the lower electrode 101 protrudes downward from the surface located above the pressure applying portion 102, and the pressure applying rib 103 of the upper electrode 101 protrudes upward from the surface located below the pressure applying portion 102. The pressure applying rib 103 is formed to more firmly crimp the core wire crimping portion 23 to the core wire 12 inserted therein.

[0024] [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.

[0025] First, the exposed core wire 12 of the electric wire 10 is inserted into the core wire crimping portion 23 of the terminal 20 (see FIG. 4). At this time, as the insertion of the core wire 12 into the core wire crimping portion 23 progresses, the protrusions 24 of the terminal 20 are inserted into the core wire 12 from one end side. As a result, when the insertion of the core wire 12 into the core wire crimping portion 23 is completed, the protrusions 24 are positioned inside the core wire 12, i.e., between the plurality of element wires 11.

[0026] As a preparation for this step, terminal treatment of the electric wire 10 is performed by removing the insulating coating 13 at one end of the electric wire 10 to expose the core wire 12 by a predetermined length.

[0027] Next, the core wire crimping portion 23 with the exposed core wire 12 inserted therein is placed on the pressure portion 102 of the lower electrode 101 (see FIG. 5). As a result, the core wire crimping portion 23 is placed on the pressure rib 103 of the lower electrode 101.

[0028] Next, the upper electrode 101 is moved downward relative to the lower electrode 101, and the core wire crimping portion 23 is sandwiched and pressurized in the vertical direction between the pair of electrodes 101, 101, and current is passed between the pair of electrodes 101, 101 to electrically heat the core wire crimping portion 23 (see Figure 6).

[0029] Then, when the pair of electrodes 101, 101 are electrically heated, the core wire 12 generates heat via the core wire crimping portion 23, melting and softening it. At this time, heat is also transferred to the center of the core wire 12 via the protrusions 24, so that the center of the core wire 12, which is normally difficult to melt, can easily melt.

[0030] During electrical heating, the pair of electrodes 101, 101 applies pressure to the core wire crimping portion 23, thereby crimping the core wire 12. At this time, as described above, the center of the core wire 12 is heated (melted), so there is no need to excessively deform the core wire crimping portion 23. Furthermore, the pressure ribs 103 apply stronger pressure to the core wire crimping portion 23 at locations 25 (see FIG. 6, etc.) corresponding to the pressure ribs 103, 103 than to other locations, so that even the center of the core wire 12, which is normally less susceptible to plastic deformation, can easily undergo plastic deformation.

[0031] Thereafter, the melted and softened core wire 12 solidifies, integrating the plurality of wires 11, and welding the outer periphery of the core wire 12 to the core wire crimping portion 23, thereby completing the electric wire with terminal 1. After the electrical heating, the upper electrode 101 is moved upward relative to the lower electrode 101, thereby completing the production of the electric wire with terminal 1.

[0032] [Example of effect] As described above, according to this embodiment, the protrusions 24 provided on the bottom wall 23a of the core wire crimping portion 23 are inserted into the core wire 12 inserted in the core wire crimping portion 23, thereby allowing heat to be transferred via the protrusions 24 to the center of the core wire 12, which is normally difficult for heat to transfer and melt. This makes it easy to melt the center of the core wire 12. Therefore, according to this embodiment, compared to conventional terminals, good conductivity between the wires 11 is achieved in the crimped portion of the core wire 12 (i.e., the portion inserted into the core wire crimping portion 23) without excessively deforming the core wire crimping portion 23 of the terminal 20, resulting in excellent electrical characteristics.

[0033] Furthermore, according to this embodiment, the length of the protrusions 24 in the extending direction is formed to be at least half the length of the core wire crimping portion 23, thereby enabling more effective heat transfer to the center of the core wire 12 via the protrusions 24. This allows the center of the core wire 12 to melt more easily.

[0034] [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.

[0035] [Features of the embodiment] Here, the features of the embodiments of the electric wire with terminal according to the present invention described above will be briefly summarized and listed below in [1] to [2].

[0036] [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, 101) and passing current through the terminal, The terminal (20) has a bottomed, cylindrical crimping portion (core wire crimping portion 23) that extends in the extending direction of the electric wire (10) and into which the exposed core wire (12) is inserted, A protrusion (24) is provided on a cylindrical bottom (bottom wall 23a) of the crimping portion (core wire crimping portion 23) so as to protrude into the core wire (12) inserted into the crimping portion (core wire crimping portion 23). Wire with terminal (1).

[0037] According to the configuration [1] above, the protrusions provided on the cylindrical bottom of the crimping portion are inserted into the core wire inserted into the crimping portion, thereby allowing heat to be transferred via the protrusions to the center of the core wire, which is normally difficult to transfer heat and melt. This makes it easy to melt the center of the core wire. Therefore, this configuration achieves good electrical conductivity between the wires at the crimped portion of the core wire (i.e., the portion inserted into the crimping portion) without excessively deforming the crimping portion of the terminal compared to conventional configurations, resulting in excellent electrical characteristics.

[0038] [2] The terminal-attached electric wire (1) described in [1] above, The protrusion (24) protrudes in the extending direction so that the length of the protrusion (24) is equal to or greater than half the length of the crimping portion (core wire crimping portion 23). Wire with terminal (1).

[0039] According to the above configuration [2], the length of the protrusion in the extension direction is formed to be at least half the length of the crimping portion, so that heat can be more effectively transferred to the center of the core wire via the protrusion, thereby making it easier to melt the center of the core wire. [Explanation of symbols]

[0040] 1 electric wire 10 Electric wire 11 Wire 12 core wire 13 Insulation coating 20 terminals 21 Connection 22 Connecting part 23 Core wire crimping part 23a Bottom wall 24 Protrusion 25 locations 101 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 has a bottomed, cylindrical crimping portion extending in the extending direction of the electric wire and into which the exposed core wire is inserted, a protrusion provided on a cylindrical bottom of the crimping portion so as to be inserted into the core wire inserted into the crimping portion; Wire with terminals.

2. The electric wire with terminal according to claim 1, The protrusion protrudes in the extension direction so that the length of the protrusion is equal to or greater than half the length of the crimping portion. Wire with terminals.

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