JP2011090804A - Electric wire with terminal fitting and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire with a terminal fitting and its manufacturing method, having low electric resistance between a core wire and a terminal fitting of the electric wire, without breaking strands, and with low manufacturing cost. <P>SOLUTION: The method of manufacturing an electric wire 10 with a terminal fitting, equipped with an electric wire 11 with a core wire 12 made of a plurality of strands, and a terminal fitting 20 having a crimp part 27 crimped to the core wire 12 exposed from the wire 11, carries out a process for exposing the core wire 12 by peeling off an insulation coating 13 covering an outer peripheral surface of the core wire 12, a process for forming a welding area 26 with strands to be welded with each other so as to have nearly the same shape as the core wire 12 after crimping the crimp part 27 by pinching the exposed core wire 12 with a pair of jigs and giving ultrasonic vibration to the core wire 12 by the jigs, and a process for crimping the crimp part 27 by winding it around an area containing the welded area 26 of the core wire 12 from outside. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electric wire with a terminal fitting and a method for manufacturing an electric wire with a terminal fitting.

  2. Description of the Related Art Conventionally, an electric wire with a terminal fitting is known in which a crimping portion of a terminal fitting is crimped around a core wire exposed from the electric wire from the outside.

  According to said structure, the core wire and the crimping | compression-bonding part are electrically connected because the outer peripheral surface of a core wire and the inner surface of a crimping | compression-bonding part contact. At this time, when a film having a relatively high electrical resistance such as an oxide film is formed on the surface of the element wire constituting the core wire, there is a concern that the elements cannot be sufficiently electrically connected to each other by the film. Is done. Then, only the strands that are located on the radially outer side of the core wire and contact the inner surface of the crimped portion contribute to the electrical connection between the core wire and the crimped portion, and are located on the radially inner side of the core wire. There is a concern that the strands do not contribute to the electrical connection with the crimping portion. As a result, there is a concern that the electrical resistance between the electric wire and the terminal fitting is increased.

  In order to keep the electrical resistance low, it is conceivable to crimp the crimping portion with a high pressure against the core wire. As a result, the oxide film formed on the surface of the strand was torn and the new surface was exposed, and it was expected that the electrical resistance would be reduced by contacting the strands.

  However, according to the above method, the cross-sectional area of the core wire is greatly reduced, so that the mechanical strength (more specifically, the strength with which the crimping portion holds the core wire) is lowered. In particular, when the core wire is made of aluminum, it is known that in order to break the oxide film on the surface of the wire, it must be crimped with a higher compression than the copper core wire. There is a problem of wire breakage, and in order to prevent the wire breakage, it is desirable to perform pressure bonding with as low compression as possible.

  Thus, in order to keep the electric resistance of the crimping part of the electric wire low, it is desirable to connect the crimping part with high compression, while on the other hand, low compression is good for maintaining mechanical strength and preventing strand breakage. There are conflicting requests.

  On the other hand, an electric wire with a terminal fitting formed by electrically connecting a core wire exposed from an electric wire and a terminal fitting by ultrasonic welding is also known. For example, in Patent Document 1, a conductor portion (core wire) of an electric wire is set on a welding portion of a terminal substrate portion, and an ultrasonic vibration is applied by pressing a vibration horn against the core wire, thereby welding the electric wire (core wire) and a terminal. Technology is disclosed. The strands are also welded together by this ultrasonic wave. Patent Document 2 discloses a technique for preventing loosening of the wire of the welded portion by crimping the welded portion with a wire barrel after ultrasonically welding the electric wire and the terminal.

  However, in general, as a terminal for an automobile, metal plating such as tin is applied to a copper / copper alloy which is a base material. In the case of such a terminal, there exists a situation that an electric wire and a terminal cannot be ultrasonically welded. Therefore, when ultrasonic welding is actually performed between the electric wire and the terminal, a terminal that is not subjected to metal plating, a terminal that is not subjected to plating only at the welded portion, or a terminal that is plated at the welded portion must be prepared. However, there is a problem that it leads to cost increase.

JP 2003-338328 A JP 2003-338327 A

  The present invention has been completed based on the above-described circumstances, and has a low electric resistance between the electric wire (core wire) and the terminal fitting, no wire breakage, and low manufacturing cost. And it aims at providing the manufacturing method of an electric wire with a terminal metal fitting.

  The present invention made in order to solve the above-mentioned problems is provided with a terminal fitting comprising: an electric wire having a core wire composed of a plurality of strands; and a terminal fitting having a crimping portion that is crimped to the core wire exposed from the electric wire. A method of manufacturing an electric wire, comprising: peeling an insulating coating covering an outer peripheral surface of the core wire to expose the core wire; sandwiching the exposed core wire with a pair of jigs; Forming a welded region in which the strands are welded to each other so as to be substantially the same shape as the shape of the core wire after crimping the crimped portion by applying sonic vibration; and And a step of crimping the crimping portion so as to be wound around the region including the outer side.

  According to the present invention, by applying ultrasonic vibration to the exposed core wire of the electric wire by the pair of jigs, the oxide film formed on the surface of the strand is broken and the strands are welded to each other. Thereby, the electrical resistance between strands falls. In addition, at this time, the core wire is welded by a pair of jigs so that the crimped portion of the terminal is almost the same as the shape after crimping. In order to crimp the crimped portion of the terminal to the core wire, There is no need for excessively high compression, and it is only necessary to perform pressure bonding at such a low compression that the crimping portion and the core wire are electrically connected. Therefore, the cross-sectional area of the core wire is not significantly reduced. As described above, according to the present invention, it is possible to obtain an electric wire with a terminal fitting that has a low electrical resistance between the electric wire (core wire) and the terminal fitting, and that does not have a break in the strands. Moreover, since a general-purpose terminal plated with metal can be used as the terminal, the manufacturing cost can be suppressed.

The perspective view of the electric wire with a terminal metal fitting of one embodiment of the present invention Exploded perspective view of electric wire with terminal fittings Sectional drawing which shows the case where the core wire of an electric wire is also pinched | interposed with an anvil and a horn Cross-sectional view of the same core wire welded and formed into a flat heart shape Sectional view showing the case of crimping electric wires and terminal fittings Sectional view showing the case where the terminal fitting is crimped to the wire

An embodiment of the present invention will be described with reference to FIGS.
The electric wire 10 with a terminal metal fitting of this embodiment is wired between apparatuses (not shown), such as a battery, an inverter, and a motor, which constitute a power source for traveling in an electric vehicle, for example.

  FIG. 1 is a perspective view of an electric wire 10 with terminal fittings according to the present embodiment. As shown in the figure, an electric wire 11 is made of a synthetic resin covering a core wire 12 composed of a plurality of strands 14 and an outer periphery of the core wire 12. And an insulating coating 13. The core wire 12 can use arbitrary metals as needed, such as aluminum, an aluminum alloy, copper, a copper alloy. In this embodiment, aluminum or an aluminum alloy is used.

  On the other hand, the terminal fitting 20 is generally used and is formed by pressing a metal plate material into a predetermined shape. As the metal plate material, any metal such as copper or copper alloy can be used as necessary. In this embodiment, copper or a copper alloy is used. Further, the metal plate material may be plated with an arbitrary metal such as tin or nickel. In this embodiment, tin plating is applied.

  As shown in FIG. 2, the terminal fitting 20 includes a bottom plate 21 on which the core wire 12 exposed on the end side of the electric wire 11 is placed, and a generally rectangular shape extending from both the left and right sides of the bottom plate 21 and rising up. A pair of wire barrels 22 having a shape, and mounting holes 23 for inserting mounting bolts (not shown) provided alongside the bottom plate 21 along the axial direction of the electric wires 11 and having threads on the outer peripheral surface. And a flat plate-like connecting portion 24 having a substantially annular shape. In addition, the bottom plate 21 and the wire barrel 22 are formed with a plurality of recesses 25 extending in a direction orthogonal to the axial direction of the electric wire 11 (the direction in which the electric wire 11 extends) side by side in the axial direction of the electric wire 11. Yes. The bottom plate 21 and the wire barrel 22 serve as a crimping portion 27 that is crimped to the core wire 12.

  The end portion of the core wire 12 is formed into a heart shape having a flat cross section in the length direction, and a welding region 26 in which the strands 14 are welded to each other is formed. As shown in FIG. 3, the welding region 26 includes an anvil 30 having a concave portion 31 having a semicircular cross section, and a horn 40 having a concave portion 41 having a width equal to that of the concave portion 31 of the anvil 30 and having a cross section having a double mountain shape. And pressurizing between them and applying ultrasonic vibration to form such a shape.

  The bottom plate 21 and the wire barrel 22 described above are pressure-bonded so as to be wound from the outside around the core wire 12 including the welded region 26.

  Next, the manufacturing method of the electric wire 10 with a terminal metal fitting of this embodiment is demonstrated. First, the insulation coating 13 at the end of the electric wire 11 is peeled off to expose the core wire 12. Next, the core wire 12 is positioned in the concave portion 31 of the anvil 30 described above, and the horn 40 disposed above is lowered to sandwich the core wire 12. And ultrasonic vibration is given and the strands 14 of the core wire 12 are welded. Thereby, the welding region 26 is welded and formed so that the cross section in the length direction of the core wire 12 becomes a flat heart shape (see FIG. 3).

  Next, as shown in FIG. 4, the core wire 12 is placed on the bottom plate 21 of the terminal fitting 20 so that the two peaks of the welding region 26 face upward. Then, the terminal fitting 20 is positioned on the anvil 50 of the crimping device, the crimper 60 disposed above the terminal fitting 20 is lowered, and the wire barrel 22 is bent so as to be wound around the core wire 12. Then, the wire barrel 22 is pressed so as to closely follow the two ridges of the core wire 12, and the core wire 12 is slightly compressed (see FIG. 5). As a result, the height of the core wire 12 is compressed and slightly reduced, and the width is increased and slightly increased.

  In addition, the 1st height dimension H1 which is the height dimension of the welding area | region 26 before crimping the terminal metal fitting 20 becomes a little higher than the 2nd height dimension H2 which is the height dimension of the welding area | region 26 after crimping | compression-bonding. Is set to In addition, the first width dimension W1 that is the width dimension of the welded region 26 before crimping the terminal fitting 20 is equal to or less than the second width dimension W2 that is the width dimension of the welded region 26 after crimping. Is set to In the welding region 26, the shapes of the anvil 30 of the ultrasonic device and the concave portions 31 and 41 of the horn 40 are set in advance, and the shapes of the anvil 50 and the crimper 60 of the crimping device are set in advance. Each height dimension H1, H2 and each width dimension W1, W2 have the relative magnitude relationship described above.

  Thus, according to this embodiment, since the core wire 12 is ultrasonically welded in advance before the terminal fitting 20 is crimped to the core wire 12 of the electric wire 11, the electrical connection between the strands 14 is ensured. The electrical resistance can be reduced. Further, during the ultrasonic welding, the shape of the core wire 12 is formed so as to be substantially the same as the shape of the core wire 12 after the terminal fitting 20 is crimped, so that the terminal fitting 20 is crimped to the core wire 12. It is not necessary to crimp with a large force, and it is only necessary to perform crimping with low compression to such an extent that the terminal fitting 20 and the core wire 12 are electrically and mechanically connected.

In addition, according to such a method of manufacturing an electric wire with terminal fittings, a commonly used terminal fitting with metal plating can be used as it is, so that the manufacturing cost can be reduced.
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) About the material, form, etc. of a terminal metal fitting or a core wire, it is not limited to the said embodiment. For example, as the terminal fitting, any terminal fitting such as a male terminal fitting, a female terminal fitting, or a splice terminal can be used as necessary.

  (2) The shape of the core wire before crimping the terminal fitting can be exactly the same as the shape of the core wire after crimping the terminal fitting.

DESCRIPTION OF SYMBOLS 10 ... Electric wire 11 with a terminal metal fitting ... Electric wire 12 ... Core wire 13 ... Insulation coating 14 ... Elementary wire 20 ... Terminal metal fitting 21 ... Bottom plate part (crimp part)
22 ... Wire barrel (crimp part)
24 ... terminal connection part 26 ... welding area 27 ... pressure bonding part H1 ... first height dimension H2 ... second height dimension W1 ... first width dimension W2 ... second width dimension

Claims (5)

A method of manufacturing an electric wire with a terminal fitting, comprising: an electric wire having a core wire composed of a plurality of strands; and a terminal fitting having a crimping portion to be crimped to the core wire exposed from the electric wire,
Peeling the insulation coating covering the outer peripheral surface of the core wire to expose the core wire;
By sandwiching the exposed core wire between a pair of jigs and applying ultrasonic vibrations to the core wire with the jig, the wire is formed so that the crimped portion has substantially the same shape as the core wire after being crimped. Forming a weld region welded together;
And a step of crimping the crimping portion so as to be wound around an area including the welded region of the core wire from the outside. The first width dimension that is the width dimension of the welded region before the crimping portion is crimped is set to be equal to or less than the second width dimension that is the width dimension of the welded region after the crimping portion is crimped. In addition, the first height dimension that is the height dimension of the welded region before the crimping part is crimped is the second height dimension that is the height dimension of the welded region after the crimping part is crimped. The manufacturing method of the electric wire with a terminal metal fitting of Claim 1 set higher than this. The method of manufacturing an electric wire with terminal fitting according to claim 1 or 2, wherein the element wire is made of aluminum or an aluminum alloy. An electric wire with a terminal fitting comprising: an electric wire including a core wire composed of a plurality of strands; and a terminal fitting having a crimping portion to be crimped to the core wire exposed from the electric wire,
The strands are welded to each other by applying ultrasonic vibration to the core wire exposed from the electric wire, and the crimping portion is outside the region including the welded region in which the strands are welded to each other. An electric wire with a terminal fitting, characterized by being crimped so as to be wound around. The electric wire with terminal fitting according to claim 4, wherein the element wire is made of aluminum or an aluminum alloy.

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