JP2010073346A - Terminal fitting and electric wire with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance electric performance of a terminal fitting by reducing a contact resistance between a core wire and a barrel while achieving a configuration in which an oxide layer can be broken by crimping with low compression. <P>SOLUTION: A female terminal fitting 20 includes a bottom plate 22, on which a terminal of an exposed core wire 11 in an aluminum wire 10 is arranged, and a wire barrel 25 having barrel pieces 25A respectively protruded in a direction intersecting with the axial direction of the core wire 11 from both side edges of the bottom plate 22. The female terminal fitting crimps the terminal of the core wire 11 so as to hold the terminal by the wire barrel 25. The wire barrel 25 includes a plurality of contact pieces 30R, 30L extended from a protruding end of at least one barrel piece 25A of both barrel pieces 25A. Each contact piece 30R, 30L is arranged so as not to be overlapped with each of the other contact pieces 30R, 30L during crimping while keeping an interval therebetween in the axial direction of the core wire 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

Conventionally, what was described in patent document 1, for example as a terminal metal fitting connected to the terminal of an electric wire is known. This terminal fitting has a structure in which a barrel that is crimped so as to be held in the end of the exposed core wire in the covered electric wire is provided behind the terminal connecting portion connected to the mating terminal fitting. Thus, the exposed core wire and the barrel are electrically connected.
Japanese Patent Laid-Open No. 7-14658

By the way, an oxide film may be formed on the surface of the core wire. When the barrel is pressure-bonded in this state, an oxide film is interposed between the core wire and the barrel, and there is a concern that the contact resistance between the core wire and the barrel increases. In particular, when the covered electric wire is an aluminum electric wire, there is a situation that an oxide film is easily formed firmly. In order to break such an oxide film, the barrel may be pressure-bonded with high compression. However, pressure bonding with high compression increases the possibility of the core wire breaking.
The present invention has been completed based on the above-described circumstances, and its object is to realize a reduction in contact resistance between the core wire and the barrel while maintaining a relatively low compression pressure bonding. .

The present invention comprises: a bottom plate on which an end of an exposed core wire in a covered electric wire is disposed; and a barrel having barrel pieces respectively protruding from both side edges of the bottom plate in a direction intersecting the axial direction of the core wire. A terminal fitting for crimping so as to embrace the end of the core wire, wherein the barrel includes a plurality of contact pieces extending from a protruding end of at least one of the barrel pieces, Each contact piece is characterized in that it is arranged so as not to overlap with other contact pieces at the time of the crimping while being spaced apart in the axial direction of the core wire.
In the electric wire with terminal fitting of the present invention, the terminal fitting specified above is crimped to the end of the core wire in the covered electric wire in which the core wire is covered with the covering.

When the barrel is pressure-bonded to the core wire of the electric wire, each contact piece is pressed against the surface of the core wire, and the core wire enters a gap formed between the contact pieces. Along with that, the oxide film formed on the surface of the core wire by the edge portion of the contact piece is broken and peeled off, and a new surface appears. In addition, the new surface of the core wire is pressed against the edge of the contact piece and adheres to each other. As a result, the contact resistance between the core wire and the barrel, that is, the electric wire and the terminal fitting, can be reduced, and the electrical performance. Can be enhanced.
In this way, a plurality of contact pieces spaced apart from each other can be crimped, and the edge of the contact piece can be used to promote breakage of the oxide film and adhesion between the new surface of the core wire. Even if crimping is performed with low compression, the contact resistance between the core wire and the barrel can be reduced. In other words, the electrical performance can be enhanced while ensuring a high fixing force without causing breakage of the core wire. Moreover, since the contact piece is extended in the direction which cross | intersects the axial direction of a core wire, when the contact piece is pressed on the surface of a core wire, the fall prevention of the core wire to the axial direction can also be anticipated.

In addition, it is good also as following structures.
The contact pieces include a plurality of first contact pieces extending from the protruding end of one barrel piece and a plurality of second contact pieces extending from the protruding end of the other barrel piece. The first contact pieces and the second contact pieces are alternately arranged in the axial direction of the core wire. If it does in this way, if it is the composition which arranges the 1st contact piece and the 2nd contact piece by turns, both contact pieces will be pressed against a core line by the balance in the direction of an axis alternately at the time of fixation. For this reason, when the core wire receives external force, the external force can be dispersed and pressed down by both contact pieces. For this reason, a higher fixing effect can be expected.

  The core wire of the covered electric wire is formed of a plurality of aluminum strands made of aluminum or an aluminum alloy. This is particularly useful for aluminum wires that can easily form oxide films.

  According to the present invention, it is possible to improve the electrical performance of the terminal fitting by reducing the contact resistance between the core wire and the barrel with a configuration capable of breaking the oxide film without causing breakage of the core wire by crimping at low compression. it can.

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
Drawing 1 is a side view showing electric wire 1 with a terminal metal fitting of this embodiment. The electric wire 1 with a terminal fitting includes an aluminum electric wire 10 and a female terminal fitting connected to the terminal (hereinafter referred to as a female terminal fitting 20, in this embodiment, an example of a “terminal fitting” in the claims). It has. The aluminum electric wire 10 has a structure in which a core wire 11 is formed by a stranded wire obtained by twisting a plurality of strands 12 made of aluminum or an aluminum alloy, and the periphery of the core wire 11 is covered with an insulating coating 13 made of a synthetic resin. . The aluminum electric wire 10 is an example of the “covered electric wire” recited in the claims in the present embodiment.

  FIG. 2 is a perspective view showing the female terminal fitting 20. The female terminal fitting 20 is formed by pressing a metal plate excellent in conductivity, for example, a plate material made of a copper alloy and plated with Sn (tin), and a mating male terminal fitting (not shown). A wire barrel 25 and an insulation barrel 26 are provided behind a terminal connecting portion 21 having a substantially rectangular tube shape that is electrically connected to the insulation barrel 26.

  An elastic contact piece 23 is provided inside the terminal connection portion 21 so as to be folded back from the front edge of the bottom plate 22, and the tab of the mating male terminal fitting is inserted into the terminal connection portion 21 from the front. The male terminal fitting and the female terminal fitting 20 are electrically connected by elastically contacting the elastic contact piece 23.

  The insulation barrel 26 is an open barrel type, and is formed so that a pair of left and right barrel pieces 26 </ b> A are opposed to each other from the left and right side edges of the bottom plate 22. The insulation barrel 26 is caulked and crimped to the end of the insulating coating 13 of the aluminum electric wire 10. For example, both barrel pieces 26 </ b> A overlap the protruding ends of the two ends of the insulation coating 13, and It can be squeezed from both the left and right sides.

FIG. 3 is a plan view showing a state where the barrel of the female terminal fitting 20 is developed, and FIG. 4 is a plan view showing a state where the barrel of the female terminal fitting 20 is crimped.
The wire barrel 25 is an open barrel type, and a pair of barrel pieces 25 </ b> A are formed to protrude from the left and right side edges of the bottom plate 22. Both barrel pieces 25A are formed so as to protrude in a direction intersecting the axial direction of the core wire 11, and when the female terminal fitting 20 is completed, the pair of left and right barrel pieces 25A are connected to each other from the left and right side edges of the bottom plate 22. It becomes the form which stood up so as to oppose. The wire barrel 25 is crimped and crimped so as to hold the end of the core wire 11 of the aluminum electric wire 10 described above. In this embodiment, the wire barrel 25 is an example of a “barrel” described in the claims.

  Now, from each protruding end of both barrel pieces 25 </ b> A, a plurality (three in the figure) of contact pieces 30 extend in the direction intersecting the axial direction of the core wire 11 with the same length. Each contact piece 30 has a long rectangular shape in the extending direction. Moreover, the cross-sectional shape of each contact piece 30 is rectangular, and the four corners of the cross-section are edge portions 30A.

  Each contact piece 30 is arranged at an interval in the axial direction of the core wire 11. Further, in the axial direction of the core wire 11, the left and right contact pieces 30 are alternately arranged. Specifically, in the upper barrel piece 25A (one barrel piece) in FIG. 3, the contact pieces 30 (first contact pieces 30R) having a predetermined width a are arranged at equal intervals with a predetermined interval b. ing. On the other hand, in the lower barrel piece 25A (the other barrel piece) in FIG. 3, the contact pieces 30 (second contact pieces 30L) having a predetermined width c are arranged at equal intervals with a predetermined interval d. Yes.

  Then, in the axial direction of the core wire 11 (left-right direction in FIG. 3), the second contact piece 30L is shifted from the first contact piece 30R to the right side in FIG. ing. Further, the interval b between the first contact pieces 30R is set larger than the width c of the second contact piece 30L, and the arrangement interval d between the second contact pieces 30R is larger than the width a of the first contact piece 30R. Is also set larger. For this reason, as shown in FIG. 4, in the state where the wire barrel 25 is crimped to the core wire 11, the contact pieces 30 </ b> R and 30 </ b> L do not overlap each other, and the other contact piece is disposed between the one contact pieces. It becomes the composition which is done. As a result, a square-wave-shaped gap 30B is formed between the first contact piece 30R and the second contact piece 30L.

The female terminal fitting 20 of the present embodiment has the above-described structure, and is connected to the end of the aluminum electric wire 10 as follows.
First, the end of the insulating coating 13 of the aluminum electric wire 10 is peeled off, and the end of the core wire 11 is exposed over a predetermined length. Next, the female terminal fitting 20 is crimped to the end of the aluminum electric wire 10 by a crimping device (not shown).

  The crimping will be specifically described. First, the exposed central portion of the end of the core wire 11 is set on the bottom plate 22 of the wire barrel 25 of the female terminal fitting 20. At the same time, the insulation barrel 26 is set with the remaining end of the insulation coating 13 disposed thereon.

  Next, both barrels 25 and 26 are clamped by being clamped between an anvil and a crimper installed in the crimping apparatus. As a result, the insulation barrel 26 is caulked with respect to the end of the insulating coating 13, and the wire barrel 25 is caulked with respect to the end of the core wire 11.

  By the way, the aluminum electric wire 10 has a characteristic that an oxide film is easily formed on the surface of the core wire 11 when the outside air touches the surface. In order to improve the electrical connection performance between the wire barrel 25 and the core wire 11, it is necessary to peel off this oxide film during caulking. This is because when an oxide film is interposed between the wire barrel 25 and the core wire 11, the contact resistance between the core wire 11 and the wire barrel 25 increases due to the oxide film.

  FIG. 5 is a cross-sectional view showing a state where the contact pieces 30R and 30L after crimping are in contact with the core wire 11. As shown in FIG. When the wire barrel 25 is caulked, the outer peripheral portion of the core wire 11 enters the gap 30B between the contact piece 30R and the contact piece 30L. Then, the edge portion 30 </ b> A is difficult to insert into the outer periphery of the core wire 11. Thereby, the oxide film formed on the outer peripheral surface of the core wire 11 is broken and peeled off, and a new surface appears. Further, the new surface of the core wire 11 comes into contact with the edge portion 30 </ b> A of the contact piece 30 while being pressed. As a result, Al (aluminum) on the new surface of the core wire 11 and Sn (tin) plated on each contact piece 30 adhere (bond at the atomic level and stick to each other), thereby improving the electrical connection performance. With the above operation, the operation of connecting the female terminal fitting 20 to the terminal of the aluminum electric wire 10 is completed. In addition, in FIG. 5, the cross section of the core wire 11 which consists of several aluminum strand 12 is typically shown typically as a whole.

  As described above, according to the present embodiment, the plurality of contact pieces 30 are formed on both the barrel pieces 25A of the wire barrel 25, and the edge portions 30A of the contact pieces 30 are inserted into the core wire 11 during caulking to break the oxide film. can do. For this reason, an oxide film can be fractured by caulking at a relatively low compression. That is, the electrical performance can be enhanced while ensuring a high fixing force without causing breakage of the core wire 11.

  Moreover, in this embodiment, since the contact piece 30 is extended in the direction which cross | intersects the axial direction of the core wire 11, when the contact piece 30 is pressed on the surface of a core wire, the removal | extraction to the axial direction of the core wire 11 is carried out. Prevention can also be expected.

  In the present embodiment, the right and left contact pieces 30R and 30L are alternately arranged during caulking. In this way, the left and right contact pieces 30R, 30L are pressed against the core wire 11 alternately in a balanced manner in the axial direction at the time of fixing. For this reason, when the core wire 11 receives an external force, the external force can be dispersed and pressed down by the contact pieces 30R and 30L. For this reason, a higher fixing effect can be expected.

  In the present embodiment, the core wire 11 of the covered electric wire is formed of an aluminum element wire 12 made of aluminum or an aluminum alloy. For the aluminum electric wire 10 that can easily form an oxide film, a configuration that can break the oxide film with low compression caulking is particularly effective.

<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) In the above embodiment, each contact piece 30R, 30L has the same width and length, but is not limited to this, and the width, length, number, etc. of each contact piece 30R, 30L are different values. It may be set.

  (2) In the above embodiment, the left and right contact pieces 30R and 30L are alternately arranged. However, the contact pieces may not be arranged alternately. Further, the contact piece may be formed only on one side barrel piece 25A.

  (3) In the said embodiment, although the female terminal metal fitting 20 was illustrated as a terminal metal fitting connected to the terminal of an aluminum electric wire, other terminals, such as the male terminal metal fitting provided with the male tab, or the LA terminal which has a centerpiece-shaped connection part. It may be a terminal fitting.

  (4) The present invention can be applied to other electric wires such as copper electric wires in addition to the aluminum electric wires 10 exemplified in the above embodiment.

  (5) In the said embodiment, although the aluminum electric wire 10 was formed with the strand wire which twisted the strand 12 in multiple numbers, a single core wire may be sufficient.

The side view which shows the terminal metal fitting to which this invention is applied. The perspective view which shows a female terminal metal fitting. The top view which shows the state which expand | deployed the barrel of the female terminal metal fitting. The top view which shows the state which crimped the barrel of the female terminal metal fitting. Sectional drawing which shows the state which the contact piece after crimping contacted the core wire.

Explanation of symbols

10 ... Aluminum electric wire (in this embodiment, an example of "covered electric wire" described in the claims)
DESCRIPTION OF SYMBOLS 11 ... Core wire 20 ... Female terminal metal fitting (In this embodiment, an example of the "terminal metal fitting" described in a claim)
22 ... bottom plate 25 ... wire barrel (in this embodiment, an example of "barrel" described in claims)
25A ... barrel piece 30R ... first contact piece 30L ... second contact piece

Claims (4)

A bottom plate on which an end of an exposed core wire in the covered electric wire is disposed, and a barrel having barrel pieces respectively protruding from both side edges of the bottom plate in a direction intersecting the axial direction of the core wire, and the core wire by the barrel It is a terminal fitting that crimps so as to embrace the terminal of
The barrel includes a plurality of contact pieces extending from a protruding end of at least one of the barrel pieces.
Each said contact piece is arrange | positioned so that it may not overlap with another contact piece at the time of the said crimping | compression-bonding, opening the space | interval in the axial direction of the said core wire. The terminal fitting according to claim 1,
The contact piece includes a plurality of first contact pieces extending from a protruding end of one of the barrel pieces,
A plurality of second contact pieces extending from the protruding end of the other barrel piece;
With
The terminal fitting, wherein the first contact piece and the second contact piece are alternately arranged in the axial direction of the core wire. An electric wire with terminal fitting, wherein the terminal fitting according to claim 1 or 2 is crimped to an end of the core wire in a covered electric wire having a core wire covered with a coating. It is an electric wire with a terminal metal fitting according to claim 3,
An electric wire with terminal fitting, wherein the core wire of the covered electric wire is formed of aluminum or an aluminum alloy.

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