JP2010073345A - Connection structure of terminal metal fitting, electric wire with terminal metal fitting, and manufacturing method of electric wire with terminal metal fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alleviate contact resistance by making connection with a metal strand at the inside in a radial direction. <P>SOLUTION: The connection structure of the terminal metal fitting 10 connected to a terminal of a core wire 42 in a coated wire 40 made by coating the core wire 42 is provided with a crimping part 30 crimping the terminal of the core wire 42, and a conductive member 35 fitted separately from the crimping part 30 and conductively connecting an inside of a bundle of metal strands 41 and an inner periphery of the crimping part 30 by being plugged into, and crimped to, the inside of the bundle of the metal strands 41 constituting the core wire 42. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection structure of a terminal fitting connected to a terminal of a core wire in a covered electric wire coated with a core wire, 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, for example, a terminal fitting described in Patent Document 1 below is known as a terminal fitting for a wire harness of an automobile. The terminal fitting is configured to include a crimping portion that crimps a terminal end of a core wire in a covered electric wire that covers the core wire. By the way, if an insulating coating is formed on the surface of the core wire during crimping, this coating becomes an insulating layer, and there is a problem that conduction cannot be established between the core wire and the crimping portion. Therefore, it is considered that the film is scraped off to achieve electrical continuity by crimping at a compression rate as high as possible.
JP 2003-249284 A

  However, when a thick coated electric wire is used, the number of metal strands constituting the core wire increases, so that the pressure from the crimping portion is easily dispersed. For this reason, the film remains on the radially inner metal wire that does not contact the crimping portion, and the contact resistance increases because conduction cannot be achieved.

  This invention is completed based on the above situations, Comprising: It aims at reducing contact resistance by taking conduction | electrical_connection with respect to the metal strand of a radial inside.

  The present invention is a connection structure of a terminal fitting connected to a terminal end of a core wire in a covered electric wire covering a core wire, the crimping part for crimping the terminal end of the core wire, and provided separately from the crimping part. Characterized by a configuration comprising a conductive member that connects the inside of the bundle of metal strands and the inner periphery of the crimping portion so as to be conductive by being inserted into and crimped to the bundle of metal strands to be configured Have

  According to such a configuration, by inserting the conducting member into the bundle of metal strands and placing the terminal end of the core wire in the crimping portion and crimping, the conducting member scrapes the coating inside the bundle of metal strands, The metal strand from which the coating has been removed comes into contact with the conductive member so as to be conductive. Therefore, the contact resistance can be reduced by taking electrical continuity with the radially inner metal strand that does not contact the crimping portion.

The following configuration is preferable as an embodiment of the present invention.
The conducting member is a conductive metal flat plate that is opposed to the bottom wall and inserted into a bundle of metal strands and crimped so that both side edges of the conducting member are on the inner periphery of the crimping portion. It is good also as a structure which contacts.
According to such a configuration, the conducting member can be easily inserted into the bundle of metal strands, and both side edges of the conducting member can be brought into contact with the inner periphery of the crimping portion.

The crimping portion includes a bottom wall on which the end of the core wire is disposed and a pair of caulking pieces rising from both side edges of the bottom wall, and a pair of caulking pieces that have entered the inside of the bundle of metal strands by crimping. It is good also as a structure which a front-end | tip part contacts the center part of a conduction member.
According to such a structure, the front-end | tip part of both crimping pieces can be made to contact the center part of a conduction | electrical_connection member.

It is good also as a structure by which the several recessed part which a core wire cuts in by crimping | compression-bonding is formed in the crimping | compression-bonding surface where the terminal of the core wire in a crimping | compression-bonding part is crimped | bonded.
Moreover, it is good also as a structure by which the several recessed part is given to the front and back both sides in a conduction | electrical_connection member.
According to such a configuration, the core wire can bite into the concave portion by pressure bonding, and the opening edge portion of the concave portion can scrape off the coating film of the core wire to make conduction.

It is good also as an electric wire with a terminal metal fitting by which the terminal metal fitting is connected to the terminal of the core wire in the covered electric wire in which a core wire is covered with the covering, and the terminal metal fitting is connected.
At that time, the core wire may be made of aluminum or an aluminum alloy.

  The present invention is also a method for manufacturing an electric wire with a terminal fitting in which a terminal fitting is connected to an end of a core wire in a covered electric wire covering the core wire, and is provided separately from a crimping portion for crimping the end of the core wire. The inside of the bundle of metal strands and the inner periphery of the crimping part are inserted into the bundle of metal wires constituting the core wire at the end of the core wire, and the end of the core wire into which the conduction member is inserted is crimped. It is good also as a manufacturing method of the electric wire with a terminal metal fitting connected so that conduction | electrical_connection is possible by a conduction member.

  According to the present invention, the contact resistance can be reduced by conducting to the radially inner metal strand.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to the drawings of FIGS. As shown in FIG. 1, the terminal fitting 10 in the present embodiment includes a main body portion 20 having a rectangular tube shape and a crimping portion 30 formed at the rear of the main body portion 20. The terminal fitting 10 is crimped to the end of the covered electric wire 40 by the crimping portion 30. The terminal fitting 10 is formed by punching a metal flat plate made of a copper alloy into a predetermined shape with a die to form the terminal fitting 10 in an unfolded state, and then bending the terminal fitting 10 in the unfolded state. ing. In the present embodiment, the female terminal fitting having the main body portion 20 is illustrated as the terminal fitting 10, but according to the present invention, a male terminal fitting having a tab shape may be used.

The covered electric wire 40 is an aluminum electric wire, and has a configuration in which a core wire 42 made of a plurality of metal wires 41 is covered with a covering 43 made of an insulating synthetic resin. The covered electric wire 40 of the present embodiment is a thick covered electric wire, which is a bundle of 37 metal strands 41, and the total sectional area of the bundle of these metal strands 41 is 3 mm ² . For simplification of the drawings, in FIGS. 1 to 3, the total number of metal wires 41 is drawn smaller than the actual number (37). The metal element wire 41 can use any metal such as copper, copper alloy, aluminum, or aluminum alloy. In addition, the metal strand 41 of this embodiment is comprised with the aluminum alloy.

  The main body 20 is formed by bending the bottom part 22, the pair of side parts 23 rising from both side edges of the bottom part 22, and the two side parts 23 by bending each other from the upper edge of one side part 23 toward the upper edge of the other side part 23. The ceiling part 24 formed in heavy is provided.

  An elastic contact piece 21 that can be elastically displaced is formed inside the main body portion 20 by folding back from the front edge of the bottom surface portion 22 of the main body portion 20. A mating conductor (not shown) in the form of a tab can be inserted between the opposing surface (the lower surface of the ceiling portion 24) facing the elastic contact piece 21 and the elastic contact piece 21 inside the main body 20. ing.

  The distance between the elastic contact piece 21 in the natural state and the opposing surface is set to be smaller than the plate thickness of the counterpart conductor. For this reason, when the counterpart conductor is inserted between the opposing surfaces while bending the elastic contact piece 21, the counterpart conductor and the elastic contact piece 21 are elastically contacted and electrically connected.

  The crimping portion 30 includes a wire barrel portion 31 and an insulation barrel portion 32 disposed behind the wire barrel portion 31. The crimping portion 30 has a bottom wall 33 that extends in the front-rear direction (the axial direction of the core wire 42) continuously with the bottom surface portion 22 of the main body portion 20.

  The wire barrel portion 31 includes a bottom wall 33 and a pair of caulking pieces 31 </ b> A that rise in an opposed state from both side edges of the bottom wall 33. The wire barrel portion 31 can crimp the core wire 42 by arranging the end of the core wire 42 along the front-rear direction on the bottom wall 33 and caulking the end of the core wire 42 with both caulking pieces 31A.

  The insulation barrel portion 32 includes a bottom wall 33 and a pair of caulking pieces 32 </ b> A that rise in an opposed state from both side edges of the bottom wall 33. The insulation barrel portion 32 is capable of crimping the coating 43 and the core wire 42 by arranging a portion of the coating 43 on the bottom wall 33 and caulking the portion of the coating 43 with both caulking pieces 32A.

  Here, an insulating coating (for example, aluminum hydroxide or aluminum oxide) is formed on the surface of the core wire 42 by reacting with water or oxygen in the air. And if both 42 and 31 are connected with the film interposed between the core wire 42 and the wire barrel portion 31, there is a problem that the contact resistance increases. In that respect, in this embodiment, the compression rate is set higher than when a core wire made of a copper alloy is used, and serrations (an example of the “concave portion” of the present invention) 34 are provided in the crimping surface of the wire barrel portion 31. Therefore, the coating is scraped off to make conduction. That is, the core wire 42 bites into the serration 34 by crimping, and the opening edge portion of the serration 34 scrapes off the film, thereby providing electrical continuity. The serration 34 has a net-like shape as a whole, and is configured by forming a groove obliquely with respect to the axial direction of the core wire 42 on the crimping surface to which the core wire 42 is crimped in the wire barrel portion 31.

  However, when a thick covered electric wire is used as in the present embodiment, the number of the metal strands 41 increases, so that the pressure from the caulking pieces 31A is easily dispersed. Therefore, the coating tends to remain on the radially inner metal wire 41 that does not come into contact with the caulking piece 31 </ b> A, and the contact resistance increases due to the inability to conduct. For this reason, in order to establish electrical continuity with the radially inner metal wire 41, it is necessary to remove the coating as a premise.

  Therefore, in the present embodiment, the conducting member 35 provided separately from the wire barrel portion 31 is inserted into the bundle of metal strands 41 constituting the core wire 42 at the end of the core wire 42, and the conducting wire 35 is inserted into the core wire. The end of 42 is crimped so that the inside of the bundle of metal strands 41 and the inner periphery of both the caulking pieces 31A are connected to each other by the conducting member 35 so as to be conductive.

  The conducting member 35 is configured by a conductive metal flat plate such as copper or a copper alloy. For this reason, it is easy to insert the conducting member 35 into the bundle of metal strands 41 at the end of the core wire 42.

  Serrations 36 having the same shape as the serrations 34 formed on the crimping surface of the wire barrel portion 31 are applied to both the front and back sides of the conducting member 35. Thereby, the metal element wire 41 bites into the serration 36 by crimping the bundle of the metal element wires 41 into which the conducting member 35 is inserted, and the opening edge portion of the serration 36 scrapes off the film to make the conduction. . Therefore, the metal wires 41 can be connected to each other by the conductive member 35 so as to be conductive.

  Further, as shown in FIG. 3, the conducting member 35 is inserted into the bundle of the metal strands 41 so as to face the bottom wall 33. Therefore, by caulking both the caulking pieces 31A, the end portions of the both caulking pieces 31A enter the bundle of the metal strands 41, and as shown in FIG. It contacts the central portion 35A. At this time, the central portion 35A of the conducting member 35 is pressed by the tip portions of the both caulking pieces 31A and deformed downward, and is connected to the tip portions of the both caulking pieces 31A so as to be conductive.

  On the other hand, the both side edge portions 35B of the conductive member 35 are brought into contact with the inner periphery of both the caulking pieces 31A by caulking both the caulking pieces 31A so that the interval between the both caulking pieces 31A is reduced. At this time, both side edge portions 35B of the conductive member 35 are deformed upward by receiving pressure from the inner periphery of the both caulking pieces 31A, and are connected to the inner periphery of the both caulking pieces 31A so as to be conductive. Therefore, the radially inner metal wire 41 is connected to the inner periphery and the tip of the caulking pieces 31A through the conductive member 35 so as to be conductive, so that a contact area with the core wire 42 can be gained and the contact resistance can be reduced. it can.

  The present embodiment is configured as described above, and its operation will be described subsequently. First, the covering 43 is peeled off at the end of the covered electric wire 40 to expose the core wire 42. Next, as shown in FIG. 3, the conducting member 35 is inserted into the bundle of metal strands 41, and the end of the core wire 42 into which the conducting member 35 is inserted is disposed on the bottom wall 33 of the wire barrel portion 31. The covering 43 is disposed on the bottom wall 33 of the insulation barrel portion 32. Thereafter, when crimping is performed by a crimping machine (not shown), the ends of the both caulking pieces 31A and 32A are brought into contact with the crimper (not shown) and bent inward. The tip ends of the two caulking pieces 31 </ b> A of the wire barrel part 31 divide the bundle of metal strands 41 and enter the inside, and the two caulking pieces 32 </ b> A of the insulation barrel part 32 are arranged along the outer periphery of the covering 43. When the crimper reaches the bottom dead center, the core wire 42 is crimped by the two caulking pieces 31A of the wire barrel portion 31, as shown in FIG. On the other hand, the covering 43 is pressure-bonded together with the core wire 42 by the both caulking pieces 32 </ b> A of the insulation barrel portion 32. At substantially the same time, the rear end of the bottom wall 33 is cut by a slide cutter (not shown) to complete an electric wire with terminal fittings.

  As a result of the above crimping, the radially outer metal element wire 41 in contact with both the caulking pieces 31A is scraped off by the serrations 34 and is electrically connected to both the caulking pieces 31A. On the other hand, the metal wire 41 on the radially inner side is scraped off by the serration 36 and is connected to the conductive member 35 so as to be conductive. Further, the central portion 35A of the conductive member 35 is connected to the tip portions of the both caulking pieces 31A so as to be conductive, and both side edge portions 35B of the conductive member 35 are connected to the inner periphery of the both caulking pieces 31A. Thus, the radially inner metal strands 41 are connected to each other through the conducting member 35 so that they can be conducted, and the radially inner metal strand 41 is conducted to the inner periphery and the distal end portion of both the caulking pieces 31A through the conducting member 35. Connected as possible. Therefore, it is possible to conduct not only the radially outer metal element wire 41 but also the radially inner metal element 41, increase the contact area with the core wire 42, and lower the contact resistance. .

As described above, in the present embodiment, when the end of the core wire 42 is crimped, the coating can be scraped off with the serration 36 on the radially inner metal wire 41 that does not contact the both caulking pieces 31A. And can be connected in a conductive manner. In particular, when a thick covered electric wire 40 having a cross-sectional area of 3 mm ² is used, the number of metal wires 41 increases, and the number of radially inner metal wires 41 that do not contribute to conduction also increases. However, in this embodiment, since the metal wire 41 on the radially inner side can contribute to conduction by the conducting member 35, the contact area of the metal wire 41 that can be conducted can be greatly increased, and the contact resistance can be reduced. Can be reduced.

  Further, the tip portions of the both caulking pieces 31A can be brought into contact with the central portion 35A of the conducting member 35, and the inner periphery of the both caulking pieces 31A and both side edge portions 35B of the conducting member 35 can be brought into contact with each other. Further, since the serrations 34 and 36 are provided, the coating film can be scraped off by the opening edges of the serrations 34 and 36.

<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) Although the conductive member 35 having a flat plate shape is used in this embodiment, according to the present invention, the contact area with the metal element wire 41 is further increased by using the conductive member 35 having a bellows shape. May be.

  (2) Although the metal conductive member 35 is used in the present embodiment, according to the present invention, a conductive member obtained by plating a conductive metal on the surface of the resin may be used. Alternatively, a conductive member in which a conductive metal is vapor-deposited may be used.

  (3) In this embodiment, although the conducting member 35 is in contact with the inner circumference of both the caulking pieces 31A, according to the present invention, the V-shaped conducting member is inserted into the bundle of metal wires 41 and V The folded end of the character may be brought into contact with the inner periphery of the bottom wall 33.

  (4) In the present embodiment, the leading end portions of the both caulking pieces 31A are pressed against the central portion 35A of the conducting member 35 to deform the conducting member 35. However, according to the present invention, the central portion 35A of the conducting member 35 is penetrated. A hole may be provided, and the leading end portions of the both caulking pieces 31A may be brought into non-contact with each other by inserting the leading end portions of the both caulking pieces 31A into the through holes.

  (5) Although the serrations 34 and 36 are provided on the crimping surface of the wire barrel portion 31 and the front and back sides of the conductive member 35 in the present embodiment, the serrations 34 and 36 are not necessarily provided according to the present invention. Only one of the two serrations 34 and 36 may be provided.

  (6) In this embodiment, one conductive member 35 is inserted into the bundle of metal strands 41, but according to the present invention, a plurality of conductive members 35 are inserted into the bundle of metal strands 41. But you can.

(7) Although this embodiment uses a thick covered electric wire 40 having a cross-sectional area of 3 mm ² , according to the present invention, the invention is not limited to this covered electric wire 40, and other cross-sectional areas are covered. An electric wire may be used. For example, the following covered electric wires are mentioned.
Aluminum electric wire 1 Size: 1.25mm ² (The number of metal wires 41 is 16)
Aluminum wire 2 Size: 2mm ² (19 metal strands 41)
Aluminum wire 3 Size: 2.5mm ² (19 metal strands 41)

Side view of electric wire with terminal fittings in this embodiment 1 is an exploded perspective view of the electric wire with terminal fitting in FIG. 1 before crimping. Sectional drawing which showed the state before a conduction | electrical_connection member was inserted and crimped | bonded inside the bundle | flux of a metal strand in this embodiment Sectional drawing which showed the state after the conduction | electrical_connection member was inserted and crimped | bonded inside the bundle | flux of a metal strand in this embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Terminal metal fitting 30 ... Crimp part 31A ... Caulking piece 33 ... Bottom wall 34 ... Serration (recessed part)
35 ... Conducting member 35A ... Central portion of conducting member 35B ... Both side edges of conducting member 36 ... Serration (recess)
40 ... Covered wire 41 ... Metal wire 42 ... Core wire

Claims (8)

It is a connection structure of a terminal fitting connected to the end of the core wire in a covered electric wire formed by covering the core wire,
A crimping portion for crimping the end of the core wire;
Provided separately from the crimping part and inserted into the bundle of metal strands constituting the core wire and crimped so that the inside of the bundle of metal strands and the inner periphery of the crimping part can be conducted. The connection structure of the terminal metal fitting provided with the conduction | electrical_connection member connected to. The conducting member is a conductive metal flat plate that is opposed to the bottom wall and is inserted into the bundle of metal wires to be crimped, whereby both side edges of the conducting member are crimped. The connection structure of the terminal metal fitting of Claim 1 which contacts the inner periphery of a part. The crimping portion is configured to include a bottom wall on which the end of the core wire is disposed and a pair of caulking pieces rising from both side edges of the bottom wall, and the crimping portion enters the bundle of the metal strands by crimping. The terminal metal fitting connection structure according to claim 1 or 2, wherein tip portions of the pair of caulking pieces contact a central portion of the conducting member. The terminal metal fitting connection structure according to any one of claims 1 to 3, wherein a plurality of recesses into which the core wire bites by crimping are formed on a crimping surface to which the end of the core wire is crimped in the crimping portion. . The terminal fitting connection structure according to claim 4, wherein the plurality of recesses are provided on both front and back sides of the conducting member. The terminal by which the terminal metal fitting is connected by applying the connection structure of the terminal metal fitting as described in any one of Claim 1 thru | or 5 to the terminal of the said core wire in the covered electric wire in which a core wire is coat | covered with covering. Wire with bracket. The said core wire consists of aluminum or aluminum alloy, The electric wire with a terminal metal fitting of Claim 6 characterized by the above-mentioned. A method of manufacturing an electric wire with a terminal fitting in which a terminal fitting is connected to a terminal of the core wire in a covered electric wire in which a core wire is covered with a coating,
The conducting member provided separately from the crimping portion for crimping the end of the core wire is inserted into a bundle of metal wires constituting the core wire at the end of the core wire, and the end of the core wire into which the conducting member is inserted A method of manufacturing an electric wire with a terminal fitting in which the inside of the bundle of metal strands and the inner periphery of the crimping portion are connected by the conducting member so as to be conducted by crimping.

Images