JP2010067577A - Terminal fitting, and electric cable with terminal fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce contact resistance by conducting to a metal strand wire inside the electric cable in diameter direction. <P>SOLUTION: A terminal fitting 10 is crimped to the terminal of a core wire 42 in a covered cable 40 in which the core wire 42 is covered. The terminal fitting is provided with a crimping part 30 which crimps the terminal of the core wire 42 exposed at the front end of the covered cable 40 and from which the covered cable 40 is extracted to the rear side and a contact part 34 which contacts the interior of a bundle of the metal strand wire 41 constituting the core wire 42 by being extended to the rear through the inside of the crimping part 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a terminal fitting that is crimped to the end of a core wire in a covered electric wire that covers a core wire, and 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 terminal fitting that is crimped to the end of a core wire in a covered electric wire that covers the core wire, the end of the core wire exposed at the front end of the covered electric wire is crimped, and the covered electric wire is moved backward from the crimped portion. It is characterized in that it has a configuration including a crimping portion to be drawn out and a contact portion that contacts the inside of a bundle of metal strands constituting the core wire by extending backward through the inside of the crimping portion.

  In such a configuration, when the end of the core wire is placed in the crimping part and crimped, the contact part scrapes the coating inside the bundle of metal strands, and the metal strand from which the coating is scraped and the contact part can conduct. Contact. 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.
A pair of caulking pieces rising from both side edges of the bottom wall on which the core wire is disposed may be provided, and the contact portion may be bent from the front edge of one caulking piece to the other caulking piece side and extended backward. .
According to such a structure, a contact part can be moved to the inside of the bundle | flux of a metal strand in connection with the operation | movement which crimps a pair of crimping piece. Therefore, even when the compressibility of the crimping portion is increased and the cross-sectional area of the bundle of metal strands is reduced, the contact portion can always be disposed inside the bundle of metal strands.

It is good also as a structure provided in the front of the crimping | compression-bonding part, and having the standing wall which stands | starts up from the front edge of the bottom wall in which a core wire is arrange | positioned, and the contact part is extended back from the side edge in a standing wall.
According to such a configuration, since the contact portion can be provided to extend to the side of the standing wall in the expanded state of the terminal fitting, the contact portion can be formed longer in accordance with the longitudinal dimension of the crimping portion. Therefore, the contact area of a metal strand and a contact part can be earned.

A pair of contact portions may be provided, and the pair of contact portions may be arranged to face each other.
According to such a structure, it becomes easy for a pair of contact part to enter the inside of the bundle | flux of a metal strand with crimping | compression-bonding.

As a configuration in which one of the terminal fittings is crimped to the end of the core wire in the covered electric wire in which the core wire is covered with a coating, and the contact portion is in contact with the inside of the bundle of metal wires constituting the core wire Also good.
At that time, the core wire may be made of aluminum or an aluminum alloy.

  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. As shown in FIG. 2, the terminal fitting 10 is crimped to the end of the covered electric wire 40 by a crimping portion 30. In other words, the covered electric wire 40 is drawn backward from the crimping portion with 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 . 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 rising 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. Although not shown, serrations may be provided by, for example, forming a groove in the crimping surface of the wire barrel 31 where the core wire 42 is crimped.

  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 this respect, in the present embodiment, the coating is scraped off to establish conduction by setting the compression rate higher than that in the case of using a core wire made of a copper alloy.

  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, a contact portion 34 that extends rearward from the front edge of both the caulking pieces 31A through the inside of the crimping portion 30 is provided. The contact portion 34 is bent from the front edge of one caulking piece 31A to the other caulking piece 31A and extends rearward, and is bent from the front edge of the other caulking piece 31A to one caulking piece 31A. By extending backward, a pair is provided in an opposing state. Both contact portions 34 are configured to contact the inside of a bundle of metal strands 41 constituting the core wire 42 in a state where both the caulking pieces 31A are caulked. Note that the front end position of the bundle of the metal strands 41 is a position that is substantially aligned with the front edges of the both crimping pieces 31 </ b> A so as not to interfere with the bent portions of the both contact portions 34.

  Further, both contact portions 34 are provided in a form protruding forward from the front edges of the both caulking pieces 31A as shown in FIG. The front end positions of both contact portions 34 are positions that do not interfere with the main body portion 20. As shown in FIG. 4, the first bent edge 34 </ b> A and the second bent edge 34 </ b> B are set in the both contact portions 34 in order from the front edge side of the both caulking pieces 31 </ b> A. As shown in FIG. 5, the two contact portions 34 are bent at the first bent edge 34A as shown in FIG. 6 after the leading ends of both contact portions 34 are bent upward at the second bent edge 34B. This is done by bending the tip ends of both contact portions 34 upward so that the tips of both contact portions 34 face rearward. Thereafter, both the caulking pieces 31A are bent upward until they are in the facing state shown in FIG.

  In this facing state, both the caulking pieces 31A are opened as they go upward, and both the contact portions 34 are also inclined. However, both the caulking pieces 31A approach each other and the contact portions 34 gradually move along with the pressure bonding. It becomes a stubborn state. That is, both contact portions 34 can be moved into the bundle of metal strands 41 in conjunction with the caulking operation of both caulking pieces 31A. Therefore, even when the cross-sectional area of the bundle of the metal strands 41 is reduced by caulking both the caulking pieces 31A at a high compression rate, the both contact portions 34 can be reliably arranged inside the bundle of the metal strands 41.

  In addition, since both the contact portions 34 are arranged to face each other in a state of being vertically cut along with the caulking operation of both the caulking pieces 31A, it is easy to enter the inside while scraping the bundle of the metal strands 41. Then, when both the contact portions 34 are arranged inside the bundle of the metal strands 41, when both the caulking pieces 31A are caulked and the bundle of the metal strands 41 is crimped, as shown in FIG. However, the coating is scraped off inside the bundle of metal strands 41, and both contact portions 34 come into contact with the metal strand 41 from which the coating has been removed.

  The present embodiment is configured as described above, and its operation will be described subsequently. First, the covering 43 is peeled off at the front end portion of the covered electric wire 40 to expose the core wire 42. Next, the end of the core wire 42 is disposed on the bottom wall 33 of the wire barrel portion 31, and 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. Further, when the crimper is lowered, both contact portions 34 face each other and enter the inside while scraping the bundle of metal wires 41. When the crimper reaches the bottom dead center, the core wire 42 is crimped by the caulking piece 31A as shown in FIG. On the other hand, the covering 43 is crimped together with the core wire 42 by the caulking piece 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.

  By this crimping, the radially outer metal element wire 41 in contact with the caulking piece 31A is pressed against both the caulking pieces 31A to scrape the film and is connected to both the caulking pieces 31A in a conductive manner. On the other hand, the radially inner metal wire 41 is pressed against both contact portions 34 to scrape the coating and is connected to both contact portions 34 so as to be conductive. Therefore, since it is possible to conduct not only the radially outer metal element wire 41 but also the radially inner metal element wire 41, the contact resistance can be reduced.

As described above, in the present embodiment, when the end of the core wire 42 is crimped, the metal wire 41 on the radially inner side that does not come into contact with both the caulking pieces 31 </ b> A is pressed against both the contact portions 34 and scraped off the coating. Thus, the two contact portions 34 can be connected so as to be conductive. 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 contact portion 34, the contact area of the metal wire 41 that can be conducted can be greatly increased, and the contact resistance is reduced. Can be reduced.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to the drawings of FIGS. The terminal fitting 11 of the present embodiment is obtained by changing the configuration of the contact portion 34 in the first embodiment, and the same reference numerals are given to the configurations common to the first embodiment, and the same configurations as those in the first embodiment. The description of the function and effect is omitted.

  As shown in FIG. 8, the contact portion 35 in the present embodiment extends rearward from both side edges of the standing wall 36 that rises upward from the front edge of the bottom wall 33. The upper edge of the standing wall 36 is connected to the main body portion 20 via a connecting portion 37. The rear end of the contact portion 35 extends rearward from the rear end of the contact portion 34 of the first embodiment. For this reason, it is possible to earn the contact area with respect to the inside of the bundle | flux of the metal strand 41 rather than Embodiment 1. FIG.

  A first bent edge 36A is set between the both contact portions 35 and both side edges of the standing wall 36, and a second bent edge 36B is formed between the front edge of the bottom wall 33 and the lower edge of the standing wall 36. A third bent edge 36 </ b> C is set between the connecting portion 37 and the upper edge of the standing wall 36. In the expanded state shown in FIG. 9, the contact portion 35 bends both contact portions 35 upward at the first bending edge 36A, then bends the standing wall 36 upward at the second bending edge 36B and the third bending edge 36C. It is formed by bending the connecting portion 37 forward.

  That is, both contact portions 35 in the deployed state are configured to extend sideways from both side edges of the standing wall 36 between the caulking pieces 31 </ b> A and the main body portion 20, and thus interfere with the main body portion 20. There is no. Therefore, by extending both contact portions 35 in the unfolded state further to the side, the rear ends of both contact portions 35 after the bending process can be set to a position aligned with the rear ends of both the caulking pieces 31A.

  Moreover, both the contact parts 35 are always in a standing state irrespective of the caulking operation of both the caulking pieces 31A. For this reason, when the terminal of the core wire 42 is arranged on the bottom wall 33, both the contact portions 35 can be arranged inside the bundle of metal strands 41. Then, when both the contact portions 35 are disposed inside the bundle of the metal strands 41, both the caulking pieces 31A are caulked and the bundle of the metal strands 41 is crimped, as shown in FIG. However, the coating is scraped off inside the bundle of metal strands 41, and both contact portions 35 come into contact with the metal strand 41 from which the coating has been removed.

  As described above, in the present embodiment, both contact portions 35 are deeper in the front-rear direction with respect to the bundle of metal strands 41 than in Embodiment 1, so that the contact area with respect to the inside of the bundle of metal strands 41 can be gained. . Therefore, the contact resistance can be reduced as compared with the first embodiment.

<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 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)

  (2) In the present embodiment, the contact portion is formed in a flat plate shape. However, according to the present invention, for example, the contact portion has a bellows shape and extends rearward so that the metal strand 41 is formed. You may make it earn a contact area with the inside of a bundle of.

  (3) Although a pair of contact portions is provided in this embodiment, according to the present invention, only one contact portion may be provided, or three or more contact portions may be provided.

  (4) Although the contact portion 34 extends backward by performing right angle bending twice from the front edge of the caulking piece 31A in the first embodiment, according to the present invention, the contact portion 34 extends from the front edge of the caulking piece 31A. It may be folded back into a substantially U shape and extend backward.

  (5) Although the standing wall 36 rises upward from the front edge of the bottom wall 33 in the second embodiment, according to the present invention, the standing wall 36 may rise obliquely forward from the front edge of the bottom wall 33. In that case, what is necessary is just to make the both contact parts 35 in the expansion | deployment state into the form extended diagonally back from the both-sides edge of the standing wall 36. FIG.

The side view of the electric wire with a terminal metal fitting in Embodiment 1 AA line sectional view in FIG. The top view which showed the contact part in the unfolded state in Embodiment 1. The top view which expanded and showed the contact part in FIG. The top view which showed the state which bent the 1st bending edge in FIG. The top view which showed the state which bent the 2nd bending edge in FIG. Sectional drawing which showed the contact part before crimping in Embodiment 1. The perspective view of the contact part in Embodiment 2. The top view which showed the contact part in the unfolded state in Embodiment 2. Sectional drawing which showed the cross section in the position which crosses a contact part in the electric wire with a terminal metal fitting in Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,11 ... Terminal metal fitting 30 ... Crimp part 31A ... Caulking piece 33 ... Bottom wall 34, 35 ... Contact part 36 ... Standing wall 40 ... Covered electric wire 41 ... Metal wire 42 ... Core wire 43 ... Covering

Claims (6)

A terminal fitting that is crimped to the end of the core wire in a covered electric wire that covers the core wire,
Crimping the end of the core wire exposed at the front end of the covered electric wire, and a crimping portion from which the covered electric wire is drawn backward from the crimped portion;
A terminal fitting provided with a contact portion that extends rearward through the inside of the crimp portion and contacts the inside of a bundle of metal strands constituting the core wire. A pair of caulking pieces rising from both side edges of the bottom wall on which the core wire is disposed;
The terminal fitting according to claim 1, wherein the contact portion is bent backward from a front edge of one of the caulking pieces to the other caulking piece side. A standing wall that is provided in front of the crimping portion and rises upward from a front edge of a bottom wall on which the core wire is disposed;
The terminal fitting according to claim 1, wherein the contact portion extends rearward from a side edge of the standing wall. 4. The terminal fitting according to claim 2, wherein a pair of the contact portions are provided, and the pair of contact portions are arranged to face each other. The terminal fitting as described in any one of Claim 1 thru | or 4 is crimped | bonded to the terminal of the said core wire in the covered electric wire formed by a core wire being coat | covered, and the said contact part comprises the said core wire. An electric wire with terminal fittings in contact with the inside of a bundle of metal wires. The said core wire consists of aluminum or aluminum alloy, The electric wire with a terminal metal fitting of Claim 5 characterized by the above-mentioned.

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