JP5267104B2 - Electric wire with terminal bracket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire with a terminal metal fitting superior in mechanical strength even while securing superior electric performance by lowering contact resistance between the wire and the terminal fitting. <P>SOLUTION: The electric wire 10 with the terminal metal fitting is equipped with an electric wire 12 in which a core wire 11 is applied with an insulation coating, and the terminal fitting 13 crimped at the core wire 11 exposed from the end part of the electric wire 12. The terminal fitting 13 is equipped with a wire barrel 16 crimped to the core wire 11 so as to be wound around it, and a connection part 17 extended from the wire barrel 16 and connected to the counter side terminal. As for the core wire 11 exposed from the end part of the electric wire 12, a folded part 11A of which the end part is folded to the insulation coating 14 side of the electric wire 12, and a base part 11B exposed and positioned from the folded part 11A to the insulation coating 14 side of the electric wire 12 are formed, and the wire barrel 16 is crimped so that it is extended over both of the folded part 11A and the base part 11B of the core wire 11. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to 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 barrel formed on a terminal fitting is crimped to a core wire exposed from the electric wire with a mold.

  When an oxide film is formed on the surface of the core wire, there is a concern that the contact resistance between the electric wire and the terminal fitting increases. In order to reduce the contact resistance, it is conceivable that the barrel is crimped to the core wire with a large pressure by reducing the height of the barrel after crimping (crimping height). As a result, it was expected that the oxide film formed on the surface of the core wire was broken to expose the new surface of the core wire, and that the new surface and the terminal fitting were in contact with each other to reduce the contact resistance.

  However, according to the above method, since the cross-sectional area of the core wire is greatly reduced, the mechanical strength, particularly the tensile strength against an impact load (more specifically, the strength with which the crimp terminal holds the electric wire) is lowered.

In order to solve the above problem, Patent Document 1 has a configuration in which a plating layer having higher hardness and higher conductivity than an oxide film formed on the surface of the core wire is provided on the inner surface of the barrel with which the core wire contacts. A technique is disclosed in which a good connection state is formed by destroying the oxide film of the core wire when the barrel is pressure-bonded. Patent Document 2 discloses a technique for stabilizing electrical performance by increasing the contact area between the core wire and the terminal fitting by interposing a conductive crimp member between the barrel and the core wire. .
JP 2004-193073 A JP 2005-302475 A

  However, the above-described conventional technology has a situation that it is difficult to put it to practical use due to problems such as increased labor and cost.

  The present invention has been completed based on the above circumstances, and has excellent mechanical strength while ensuring good electrical performance by reducing the contact resistance between the electric wire and the terminal fitting. It aims at providing the electric wire with a terminal metal fitting.

The present invention is an electric wire with a terminal fitting comprising: an electric wire formed by insulatingly covering a core wire; and a terminal fitting that is crimped to the core wire exposed from an end of the electric wire, wherein the terminal fitting is A barrel that is crimped so as to be wound around the core wire, and a connecting portion that extends from the barrel and is connected to the counterpart terminal, and the core wire exposed from the end portion of the electric wire has the end portion of the electric wire A folded portion formed by folding back to the insulating coating side and a base portion located on the insulating coating side of the electric wire from the folded portion are formed , and the length of the folded portion and the base portion is determined. The ratio is 1: 1, and the barrel is crimped so as to extend over both the folded portion and the base portion of the core wire.

  The core wire may be made of aluminum or an aluminum alloy.

  According to the present invention, the folded portion and the base portion of the core wire are collectively crimped by the barrel of the terminal fitting, so that the tip end side in the length direction of the core wire of the crimped portion is the high compression portion and the insulation coating side is the low compression portion. Part. Since the core wire is sufficiently crushed and the oxide film is broken in the high compression portion, the terminal fitting and the core wire are in a good electrical connection state, and the mechanical strength can be secured in the low compression portion. Therefore, the electric wire with a terminal metal fitting excellent in both the electrical characteristics and the mechanical strength can be obtained.

  In addition, such electric wires with terminal fittings can be used in the same way as conventional terminal fittings by simply performing a simple operation of turning the core wires before the terminal fittings are crimped to the core wires. There is an effect that there is very little labor and cost burden.

An embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, an electric wire 10 with a terminal metal fitting according to the present embodiment includes an electric wire 12 including a core wire 11 and a female terminal metal fitting 13 that is crimped to the core wire 11 exposed from the end of the electric wire 12. (Corresponding to the terminal fitting described in 1).

  The electric wire 12 includes a core wire 11 formed by twisting a plurality of fine metal wires and an insulating coating 14 made of a synthetic resin that covers the outer periphery of the core wire 11. The core wire 11 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.

  The female terminal fitting 13 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. 1, the female terminal fitting 13 is a wire barrel 16 having a generally rectangular shape that is caulked so as to be wound around the core wire 11 exposed on the end side of the electric wire 12 (on the barrel described in the claims). And a connecting portion 17 that extends from the wire barrel 16 in the length direction of the electric wire 12 and is connected to a male terminal fitting (not shown) (corresponding to a counterpart terminal described in claims).

  The connecting portion 17 has a rectangular tube shape, and a male terminal fitting can be inserted. An elastic contact piece 18 that is elastically deformable is formed inside the connecting portion 17, and the elastic contact piece 18 elastically contacts the male terminal fitting, whereby the male terminal fitting and the female terminal fitting 13 are electrically connected. Connected.

  Next, the manufacturing method of the electric wire 10 with a terminal metal fitting of this embodiment is demonstrated. First, as shown in FIG. 2, the exposed end portion of the core wire 11 is folded back to the insulating coating 14 side of the electric wire 12, and the core wire 11 is overlapped (hereinafter, the folded portion is referred to as a folded portion 11A). To do). At this time, in the exposed core wire 11, a portion where the folded core wire 11 is not overlapped (hereinafter referred to as a base portion 11 </ b> B) is left in a portion located on the insulating coating 14 side of the electric wire 12. . In the present embodiment, the ratio of the length dimension of the folded portion 11A and the base portion 11B is set to be about 1: 1.

  Next, the core wire 11 of the electric wire 12 is placed on the wire barrel 16 of the terminal fitting 13. At this time, it mounts so that the boundary part of 11 A of fold over parts and the base 11B may become center vicinity of the width direction of the wire barrel 16 (dimension of the direction in which the electric wire 12 of the wire barrel 16 extends). And it is hold | maintained by curving so that the wire barrel 16 may be wound around the core wire 11 side, and the electric wire 12 (core wire 11) may not be detached or displaced. The wire barrel 16 is crimped so as to extend over both the folded portion 11A and the base portion 11B of the core wire 11. In other words, both the folded portion 11 </ b> A and the base portion 11 </ b> B of the core wire 11 are collectively crimped by the wire barrel 16.

  Thus, in the state where the female terminal fitting 13 is crimped to the electric wire 12, as shown in FIG. 3, the height dimension H (crimping height) after the crimping of the wire barrel 16 is the direction in which the electric wire 12 extends (see FIG. 3 (the direction indicated by the arrow A in FIG. 3). “Substantially the same” includes the case where the crimping height is the same, and also includes the case where the crimping heights are close enough to be considered substantially the same even if the crimping heights are different.

  That is, as shown in FIG. 3, the folded portion 11A side of the core wire 11 is highly compressed compared to the base portion 11B side. As a result, on the folded portion 11A side, the oxide film formed on the surface of the core wire 11 is broken and the new surface of the core wire 11 is exposed, the electrical connection between the core wires 11 is ensured, and the contact resistance is low and good. Electrical performance can be ensured.

  Further, since the new surface of the core wire 11 made of aluminum or an aluminum alloy and the tin plating layer formed on the surface of the female terminal fitting 13 are slid in contact with pressure, an alloy layer is formed. The contact resistance between 12 and the female terminal fitting 13 can be further reduced.

  On the other hand, the base portion 11B side of the core wire 11 is compressed lower than the folded portion 11A side, so that the mechanical strength, particularly the tensile strength against impact load (more specifically, the crimp terminal is the electric wire). Strength to hold 12) is ensured.

Thus, according to this embodiment, even if the wire barrel 16 is crimped to the core wire 11 with a uniform crimping height H over the direction in which the electric wire 12 extends (the direction of the arrow A in FIG. 3), the core wire In the region where the 11 is folded and overlapped (the folded portion 11A), the core wire 11 is highly compressed compared to the other region (the base portion 11B). For this reason, the compression rate (the ratio of the cross-sectional area of the core wire 11 after crimping to the cross-sectional area of the core wire 11 before crimping) on the distal end side of the electric wire 12 is lower than the compression rate on the base side of the electric wire 12. Thereby, the crimping by the high compression in the front end side portion of the core wire 11 effectively reduces the contact resistance between the core wire 11 and the wire barrel 16, while the terminal metal fitting is suppressed by the suppressed compression on the base side of the core wire 11. The tensile strength of the attached electric wire 10, more specifically, the holding strength of the core wire 11 by the wire barrel 16 can be ensured high. That is, it is possible to achieve both reduction in contact resistance and securing high mechanical strength.
In order to achieve both electrical characteristics and mechanical strength, it is effective to set the ratio of the folded portion 11A and the base portion 11B to 1: 1.

  In the present embodiment, the core wire 11 is made of aluminum or an aluminum alloy. Thus, when the core wire 11 is made of aluminum or an aluminum alloy, an oxide film is easily formed on the surface of the core wire 11. The present invention is effective when an oxide film is easily formed on the surface of the core wire 11.

<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.

  (2) In the above embodiment, the tip end portion of the core wire 11 is folded back in one direction. However, the present invention is not limited to this. For example, the core wire 11 is untwisted and divided into a plurality of directions. It is also possible to fold over the circumferential direction.

  (3) Although the terminal fitting 13 of the present embodiment has only the wire barrel 16, it is of course applicable to a terminal fitting having an insulation barrel.

  (4) In the present embodiment, the terminal fitting is the female terminal fitting 13 having the rectangular tube-shaped connecting portion 17, but is not limited thereto, and may be a male terminal fitting having a male tab, or a metal plate material. A so-called LA terminal in which a through hole is formed may be used, and a terminal fitting having an arbitrary shape may be used as necessary.

  (5) In the present embodiment, the electric wire 12 is a covered electric wire that covers the outer periphery of the core wire 11 with the insulating coating 14, but is not limited thereto, and any electric wire such as a shielded electric wire can be used as necessary. . The core wire 11 may be a single core wire.

Sectional side view of the electric wire with terminal fitting of one embodiment of the present invention Similarly, side view of electric wire Similarly, a partially enlarged sectional view of the caulking portion

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electric wire 11 with a terminal metal fitting ... Core wire 11A ... Folding part 11B ... Base 12 ... Electric wire 13 ... Terminal metal fitting 14 ... Insulation coating 16 ... Wire barrel 17 ... Connection part

Claims (2)

An electric wire with a terminal fitting comprising: an electric wire formed by insulatingly covering a core wire; and a terminal fitting that is crimped to the core wire exposed from an end of the electric wire,
The terminal fitting includes a barrel that is crimped so as to wrap around the core wire, and a connection portion that extends from the barrel and is connected to a counterpart terminal,
The core wire exposed from the end portion of the electric wire has a folded portion formed by folding the end portion toward the insulating coating side of the electric wire, and a base portion located exposed to the insulating coating side of the electric wire from the folded portion. And the ratio of the length dimension of the folded part and the base part is 1: 1 ,
An electric wire with a terminal fitting, wherein the barrel is crimped so as to extend over both the folded portion and the base portion of the core wire. The electric wire with a terminal fitting according to claim 1, wherein the core wire is made of aluminum or an aluminum alloy .

Images