JP2016177966A - Wire connection structure of crimping terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire connection structure in which the reliability of a waterproof coating for preventing corrosion at the crimp joint of a terminal of dissimilar metal and a wire is enhanced.SOLUTION: In the wire connection structure of a crimping terminal 1, a core wire 11 at the tip of a wire 10 is pulled into the coating 12 of the wire, the opening at the tip of the coating 12 is closed by a welded portion 14a, the wire at a part covered with the coating is crimped by caulking a pair of crimping pieces 3a, 3b erected from both ends of the crimping terminal 1 in the longitudinal direction, and a protrusion 6a formed on a crimping auxiliary piece 6 connected electrically with the crimping pieces 3a, 3b or the tip of any one of the crimping pieces 3a, 3b breaks through the coating 12 and is connected electrically with the core wire 11.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wire connection structure of a crimp terminal, and more particularly to a wire connection structure of a crimp terminal suitable when the core wire and the terminal of the wire crimped to the terminal are made of different metals.

  For example, in order to improve the fuel efficiency of an automobile, the core wire of an electric wire used in a wire harness in the automobile is lighter than copper or copper alloy (hereinafter abbreviated as copper) or aluminum alloy (hereinafter abbreviated as aluminum). To reduce the weight of the vehicle. On the other hand, a copper terminal is suitable as a terminal to be crimped (clamped) to an aluminum electric wire in view of mechanical characteristics.

  By the way, in the crimping | compression-bonding part which connects an aluminum electric wire to a terminal, it becomes dissimilar metal joining of the core wire and copper of an aluminum electric wire. If moisture or the like adheres to the joint portion of such a different metal, the joint portion may be cracked or have poor contact due to corrosion due to electrolytic corrosion. In order to cope with such a problem, for example, Patent Documents 1 to 4 propose various wire connection structures of crimp terminals suitable for joining different kinds of metals.

  In Patent Document 1, a crimping portion of a terminal is formed as a hollow cylindrical body whose tip is sealed, and a core wire portion of an electric wire is inserted into the hollow cylindrical body to be crimped. An electric wire connection structure that prevents water from penetrating has been proposed.

  Patent Document 2 proposes a wire connection structure that prevents water from entering the crimping joint by covering the entire crimped portion of the aluminum core wire and terminal and the tip of the coating of the aluminum wire with a resin coating. .

  In Patent Document 3, after removing the coating of the portion connected to the terminal, leaving a resin coating at the tip portion of the core wire of the electric wire, after crimping the crimp terminal to the exposed portion of the core wire, Fold the resin coating part at the tip to the part, melt the resin coating part folded by ultrasonic welding, etc., and melt the whole of the aluminum core wire and terminal crimping part and the aluminum resin resin coating tip part with molten resin An electric wire connection structure has been proposed that prevents water from entering the crimp joint by covering.

  Patent Document 4 discloses an electric wire connection structure that prevents water from entering the crimp joint portion by injecting resin into the entire crimp portion of the aluminum core wire and terminal and the tip portion of the resin coating of the aluminum electric wire. Proposed

JP 2014-187015 A JP 2014-107072 A JP 2013-219877 A JP 2013-214477 A

  According to the electric wire connection structures described in Patent Documents 1 to 4, since water can be prevented from entering into the crimp joint of different metals, corrosion due to electrolytic corrosion of terminals and electric wires can be prevented, and the crimp joint can be cracked or contacted. The possibility of causing defects or the like can be avoided. However, according to the electric wire connection structure described in Patent Document 1, since the hollow cylinder is formed by laser welding or the like, in addition to the problem that work man-hours are required, it is necessary to insert the tip of the electric wire into the hollow cylinder. Equipment change is required.

  According to the electric wire connection structure described in Patent Document 2, there is a possibility that the coating resin may be peeled off due to expansion and contraction of a terminal fitting or the like accompanying a temperature change, and there is a problem in waterproof reliability. According to the electric wire connection structure described in Patent Literature 3, the amount of resin for covering the entire electric wire connection portion may be insufficient with only the coating resin at the tip of the electric wire, which causes a problem in waterproof reliability.

  According to the electric wire connection structure described in Patent Document 4, the reliability of waterproofing of the electric wire connection portion is high, but a mold for resin coating molding is required every time the shape of the terminal or electric wire connection portion is different. There's a problem.

  The problem to be solved by the present invention is to provide an electric wire connection structure in which the reliability of a waterproof coating that prevents corrosion of a crimped joint between a different metal terminal and an electric wire is improved.

  In order to solve the above-described problems, the first aspect of the crimp terminal electric wire connection structure according to the present invention is such that the core wire at the tip of the electric wire is drawn into the sheath of the electric wire, and the tip opening of the sheath is closed by welding. The portion of the electric wire covered with the coating is crimped by crimping a pair of crimping pieces raised from both longitudinal edges of the crimping terminal, and formed into a crimping auxiliary piece electrically connected to the crimping piece. One end of either the projected protrusion or the crimping piece is formed by breaking through the coating and electrically connected to the core wire.

  Since the core wire of the electric wire of the crimping connection portion is configured as described above, the tip opening is closed by welding and sealed inside the coating, so that it is possible to prevent water from entering the crimping connection portion. In addition, the protrusion formed on the crimping auxiliary piece electrically connected to the crimping piece provided on the terminal fitting or the tip of the crimping piece penetrates the coating and is connected to the internal core wire. As a result, the entire crimp-bonding portion between the different metal terminal and the electric wire is sealed with the electric wire coating, and the connection between the terminal and the core wire is ensured by the protrusion formed on the crimping auxiliary piece or the tip of the crimping piece. As a result, it is possible to improve the reliability of the waterproof coating that prevents corrosion of the joint between the different metal terminal and the electric wire.

  According to a second aspect of the present invention, the pressure-bonding auxiliary piece is a plate material that is bent and attached from the inner bottom surface to the both side surfaces of the pair of pressure-bonding pieces, and a plurality of protrusions are formed at the bending tip of the plate material. It is characterized by becoming. In this case, the plurality of protrusions are preferably protrusions with sharp tips. According to this, in the process of crimping a pair of crimping pieces, by first crimping the crimping auxiliary piece, the plurality of protrusions at the tip of the crimping auxiliary piece break through the coating and are electrically connected to the internal core wire. The Next, the entire outer peripheral surface of the crimping auxiliary piece is crimped by the pair of crimping pieces by crimping the pair of crimping pieces on the outer circumferential surface of the crimping auxiliary piece after the crimping. As a result, since the whole of the crimp joint of the different metal terminal and the wire is covered with the coating resin of the electric wire, the waterproofing reliability of the crimp joint can be improved, and the electrical connection between the terminal and the core wire is a crimping aid. A plurality of protrusions at the tip of the piece are connected to the core wire in the sheath, and the connection between the terminal and the core wire is ensured.

  According to a third aspect of the present invention, the pressure-bonding auxiliary piece is a plate material bent from the inner bottom surface to the both side surfaces of the pair of pressure-bonding pieces, and the plate material has a plurality of protrusions cut and raised by a punch. It is characterized by. Thereby, there can exist an effect equivalent to a 2nd aspect, and also in a same crimping process, a pair of crimping piece and a crimping auxiliary piece can be crimped | bonded at once.

  According to a fourth aspect of the present invention, in the first aspect, the tip of any one of the crimping pieces is a tip of a bent portion obtained by folding the tip of the one crimping piece inward, and the other crimping piece. It is preferable that the front-end | tip part is crimped | superposed on the outer surface of said one crimping piece. Thereby, at the time of crimping | bonding a pair of crimping | compression-bonding piece, the front-end | tip of the bending part of one crimping | crimping piece penetrates a coating | cover first, and it penetrates into an internal core wire, and electrical connection with a terminal and a core wire is made. Next, the other crimping piece is crimped to the one crimping piece so as to overlap the outer peripheral surface. Accordingly, it is possible to prevent water from penetrating into the crimping joint portion through the tip protrusion of the bent portion that has penetrated through the coating.

  In the fourth aspect, the fifth aspect of the present invention is preferably such that a plurality of protrusions are formed at the tip of the bent portion. Thereby, the front-end | tip of a bending part can break a coating | cover and can make it easy to approach. Furthermore, it is preferable that the width in the terminal axis direction of the valley portion of the bent portion is formed narrower on both sides than the width in the terminal axis direction of the crimping piece. As a result, when the tip of the bent portion or the plurality of protrusions that break through the coating are sufficiently inserted into the coating, the valley portions of the folded portion are positioned on both sides of the coating and the electric wire is crimped. It is possible to prevent water from penetrating into the crimp joint through the tip protrusion of the bent part that has entered.

  According to the present invention, it is possible to provide an electric wire connection structure in which the whole of a crimp joint of a dissimilar metal terminal and an electric wire can be enclosed in the sheath of the electric wire, and the waterproof reliability of the crimp joint is improved. Can do.

It is a figure explaining the electric wire connection structure of the crimp terminal of Example 1 of this invention, (a) is a perspective view of a terminal, (b) is a perspective view of a crimping auxiliary piece. It is a figure explaining the process of the preparation stage of the electric wire used for the electric wire connection structure of Example 1. FIG. It is a figure explaining the crimping | compression-bonding process for forming the electric wire connection structure of Example 1. FIG. It is a sectional side view of the electric wire connection structure of Example 1. It is a figure explaining the electric wire connection structure of the crimp terminal of Example 2 of this invention, (a) is a structure of the crimping auxiliary piece which concerns on the characteristic, (b) is a figure which shows the cross section of an electric wire connection structure. It is a perspective view of the terminal applied to the electric wire connection structure of the crimp terminal of Example 3 of this invention. It is a figure which shows the cross section of the electric wire connection structure of Example 3. FIG. It is a perspective view of the terminal applied to the electric wire connection structure of the crimp terminal of Example 4 of this invention.

  Hereinafter, the present invention will be described based on examples.

  With reference to FIGS. 1-4, the electric wire connection structure of the crimp terminal of Example 1 of this invention is demonstrated. FIG. 1A is a perspective view of a terminal fitting 1 constituting a terminal used in the first embodiment. A pair of crimping pieces 3a and 3b and a pair of electric wires are connected to a female terminal box 2 at the tip. The fastening pieces 4a, 4b are arranged in a row on the bottom plate 5 of the terminal fitting. FIG. 1B is a perspective view of the crimping auxiliary piece 6 that is disposed inside the pair of crimping pieces 3a and 3b and used for crimping connection of an electric wire (not shown). The crimping auxiliary piece 6 is bent so that the plate material can be arranged inside according to the shape of the pair of crimping pieces 3a, 3b, and each saw blade-like projection 6a is formed at the bent tip. The protrusion 6 a is formed sufficiently higher than the thickness of the resin coating 12. Further, the opposing protrusions 6 a at the tip of the crimping auxiliary piece 6 are formed so as to be displaced from each other in the axial direction of the terminal fitting 1.

  The terminal fitting 1 of the present embodiment is formed using copper or a copper alloy (hereinafter collectively referred to as copper), and further appropriately plated. Similarly, the crimping auxiliary piece 6 is further appropriately plated with copper. Further, as shown in FIG. 2, the electric wire 10 is formed by covering a core wire (for example, 7 cores) 11 of aluminum or an aluminum alloy (hereinafter abbreviated as aluminum) with a thermoplastic resin coating 12.

  Here, the detail of the electric wire connection structure of the crimp terminal of the present embodiment will be described according to the manufacturing procedure. As shown in FIG. 2A, the electric wire 10 applied to the present embodiment draws the core wire 11 of the electric wire 10 in the direction of the arrow 13 and draws the core wire 11 at the tip portion into the resin coating 12 by a set dimension. The air core part 14 is formed. Next, as shown in FIG. 2 (b), the resin coating 12 of the air core portion 14 is melted and the tip opening of the coating is welded to form a welded portion 14a. Thereby, the tip of the core wire 11 is sealed with the resin coating 12.

  Thus, the process which crimp-connects the electric wire 10 by which the front-end | tip was sealed by the resin coating 12 to the terminal metal fitting 1 is performed. First, the crimping auxiliary piece 6 is attached to the outer periphery of the tip end portion of the core wire 11 in the resin coating 12 excluding the air core portion 14 of the electric wire 10. And as shown to Fig.3 (a), it mounts on the hollow receiving surface formed in the crimper 21 of the crimping machine, and the anvil 22 is lowered | hung in the direction of the arrow 23 shown in figure. As a result, as shown in FIG. 2B, the pair of protrusions 6 a of the crimping auxiliary piece 6 are guided by the receiving surface of the crimping auxiliary piece 6 formed on the anvil 22 and bent while breaking through the resin coating 12. Then, it enters between the strands of the core wire 11 and the crimping auxiliary piece 6 comes into contact with the core wire 11.

  Next, the electric wire 10 with the crimping auxiliary piece 6 crimped thereon is placed and crimped inside the pair of crimping pieces 3a and 3b and the wire crimping pieces 4a and 4b of the terminal fitting 1. At this time, the portion where the crimping auxiliary piece 6 is crimped is positioned in the pair of crimping pieces 3a and 3b, and the crimping pieces 3a and 3b are formed in the crimper 24 of the crimping machine as shown in FIG. Place it on a concave receiving surface. Although not shown in the figure, the wire crimping pieces 4a and 4b are similarly placed on a recessed receiving surface formed in the crimper 24 of the crimping machine. Next, when the anvil 25 is lowered in the direction of the arrow 26, as shown in FIG. 2 (d), a pair of crimping pieces 3a and 3b are crimped and crimped to the outer peripheral surface of the electric wire 10 to which the crimping auxiliary piece 6 is crimped. Is done. At this time, the distal end portion of the lower crimping piece 3a or 3b is bent slightly inward so that the distal end portions of the pair of crimping pieces 3a and 3b overlap and are crimped, or the curvature of the receiving surface 27 of the anvil 25 Make a difference.

  By such a crimping process, as shown in FIG. 4, a wire-bonding structure of a crimping terminal having a cross section taken along line IV-IV in FIG. That is, the electric wire 10 is crimped and fixed to the terminal fitting 1 by the crimping pieces 3a and 3b and the wire crimping pieces 4a and 4b. The crimping auxiliary piece 6 is crimped to the tip end portion of the electric wire 10 by the crimping pieces 3a and 3b, and the projection 6a penetrates the resin coating 12 and enters the core wire 11 to contact the element wire. As a result, the terminal fitting 1 is electrically connected to the core wire 11 via the crimping pieces 3 a and 3 b and the crimping auxiliary piece 6.

  As a result, as shown in FIG. 4, in the wire connection structure of the crimp terminal, the crimp connection portion between the terminal fitting 1 and the core wire 11 is sealed in the resin coating 12 with the tip opening closed by the welded portion 14 a. That is, the entire crimp-bonded joint between the dissimilar metal terminal fitting 1 and the electric wire 10 can be sealed and sealed in the resin coating 12 of the electric wire 10. Moreover, the connection between the terminal fitting 1 and the core wire 11 is ensured by the tip of the protrusion 6 a formed on the crimping auxiliary piece 6. Further, according to this embodiment, the resin coating 12 is melted only at the welded portion 14a at the tip, and the resin coating for waterproofing is the resin coating 12 of the original electric wire 10, so that the terminal fitting 1 Even if the resin expands and contracts with the change, the coating resin 12 is not likely to be peeled off. Therefore, according to the present embodiment, it is possible to improve the waterproof reliability of the crimping joint, and it is possible to prevent corrosion of the connection portion between the terminal metal 1 and the core wire 11 which are different metals.

  In FIG. 5, the block diagram of the crimping | compression-bonding auxiliary piece 31 which is the principal part of Example 2 of this invention, and sectional drawing of a crimping connection part are shown. The difference of the present embodiment from the first embodiment is the configuration of the pressure-bonding auxiliary piece 31, and the other points are the same as those of the first embodiment. Therefore, only the differences will be described, and the other description will be omitted.

  In the crimping auxiliary piece 31 of this embodiment, a plurality of triangular projections 33 cut and raised by a punch (not shown) are formed on the same flat plate 32 as the crimping auxiliary piece of the first embodiment. The protrusion 33 is formed sufficiently higher than the thickness of the resin coating 12. Then, similarly to the first embodiment, the flat plate 32 is bent with the projections 33 on the inside in accordance with the shape extending from the bottom surface inside the pair of crimping pieces 3a, 3b to both side surfaces. And it mounts inside the crimping | compression-bonding pieces 3a and 3b of the terminal metal fitting 1 of FIG. Next, as in the first embodiment, the electric wire 10 processed as shown in FIG. 2B is placed on the terminal fitting 1, and the crimping auxiliary piece 31 is connected to the crimping auxiliary piece 31 together with the pair of crimping pieces 3a and 3b by a crimping machine (not shown). Clamp to 10. Thereby, the triangular protrusion 33 of the crimping auxiliary piece 31 breaks through the resin coating 12 and enters between the strands of the core wire 11 to form a terminal crimping portion having the cross-sectional structure shown in FIG.

  According to this embodiment, since the pair of crimping pieces 3a and 3b and the crimping auxiliary piece 31 can be crimped to the electric wire 10 at a time in the same crimping process, workability is good.

  In FIG. 6, the perspective view of the terminal metal fitting 41 of Example 3 of this invention is shown. This embodiment differs from the terminal fitting 1 of the first embodiment in the shape of one end portion of the pair of crimping pieces 43a and 43b of the terminal fitting 41. In addition, although the female terminal box 42, the wire crimping pieces 44a and 44b, and the bottom surface bottom plate 45 are slightly different from each other, they do not substantially affect the features of the present invention, and thus the description thereof is omitted.

  In the present embodiment, a bent portion 46 is formed by bending the tip end portion of one crimping piece 43b inward. The width in the terminal axis direction of the bent portion 46 is formed narrower from both sides than the width in the terminal axis direction of the valley portion of the bent portion of the bent portion 46, but is equal to the width in the terminal axis direction of the crimping piece 43b. It doesn't matter. Moreover, the plate | board thickness of the front-end | tip of the bending part 46 is formed in the taper shape.

  Similarly to the first embodiment, the terminal fitting 41 formed in this way has a pair of crimping pieces 43a and 43b and a pair of electric wire crimping pieces 44a and 44b inside the pair of electric wires 10 formed as shown in FIG. Place the crimp connection at the tip. And a pair of wire crimping pieces 44a and 44b are crimped together with a pair of crimping pieces 43a and 43b by a crimping machine (not shown). Thereby, the tip of the bent portion 46 of the crimping piece 43b breaks through the resin coating 12 and enters between the strands of the core wire 11 to form a terminal crimping portion having the cross-sectional structure shown in FIG. That is, when crimping the pair of crimping pieces 43a and 43b, the tip of the bent portion 46 of the one crimping piece 43b first breaks through the resin coating 12 and enters between the strands of the inner core wire 11, and the terminal fitting 1 and Electrical connection with the core wire 11 is made.

  On the other hand, the tip of the crimping piece 43a is crimped so as to overlap the outer peripheral surface of the crimping piece 43b. This overlap length (wrap amount) can prevent water from entering from the overlapping portion of the pair of pressure-bonding pieces 43a and 43b, thereby ensuring the reliability of waterproofing.

  In FIG. 8, the perspective view of the terminal metal fitting 51 which concerns on Example 4 of this invention is shown. The present embodiment is a modification of the third embodiment. As shown in the figure, this embodiment is characterized in that a plurality of protrusions 57 are formed at the ends of the bent portions 56 of the pair of crimping pieces 53a and 53b. Since other configurations are the same as those of the third embodiment, the same reference numerals are given and the description thereof is omitted. The plurality of protrusions 57 are formed in a tapered shape, and the height thereof is sufficiently longer than the thickness of the resin coating 12. Further, the width in the terminal axis direction of the valley portion of the bent portion 56 is formed so that both sides are narrower than the width in the terminal axis direction of the crimping piece 43b, as in the third embodiment.

  By mounting and crimping the tip end of the electric wire 10 on the terminal fitting 51 of the fourth embodiment as in the fourth embodiment, as shown in the cross-sectional view shown in FIG. The protrusion 57 breaks the resin coating 12 of the electric wire and easily enters between the strands of the core wire 11. Other technical effects are the same as those of the third embodiment.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited thereto, and can be implemented in a form that is modified or changed within the scope of the gist of the present invention. It will be apparent to those skilled in the art that such variations or modifications are within the scope of the claims.

  For example, the terminal fitting is not limited to a female terminal, and it is apparent that the present invention can be applied to a male terminal. Further, the shape of the pair of crimping pieces and the crimping auxiliary piece is not limited to the embodiment. The point is that the projection formed on a part of the crimping piece or the projection formed on the crimping piece belongs to the present invention as long as it has a shape that penetrates the resin coating and is electrically connected to the core wire during crimping. In addition, if it has a pair of crimping pieces, a crimping auxiliary piece, and an air core at the tip of the electric wire, it belongs to the present invention. As the configuration of the terminal fitting other than these characteristic configurations, a publicly known and well-known configuration can be adopted.

DESCRIPTION OF SYMBOLS 1 Terminal metal fitting 3a, 3b Crimping piece 5 Bottom plate 6 Crimping auxiliary piece 10 Electric wire 11 Core wire 12 Resin coating 14 Air core part 14a Welding part

Claims (6)

  The core wire at the tip of the electric wire was drawn into the coating of the electric wire, the opening at the tip of the coating was closed by welding, and the electric wire in the portion covered with the coating was raised from both edges in the longitudinal direction of the crimp terminal A pair of crimping pieces are crimped and crimped, and either a protrusion formed on a crimping auxiliary piece electrically connected to the crimping piece or the tip of the crimping piece breaks through the coating to electrically connect to the core wire. Wire connection structure of crimp terminals that are connected to each other.   The crimping auxiliary piece is a plate member that is bent and mounted from the inner bottom surface of the pair of crimping pieces to both side surfaces, and a plurality of protrusions are formed at the front ends of the both side surfaces of the plate member. The electric wire connection structure of the crimp terminal according to claim 1.   The crimping auxiliary piece is a plate member that is bent and mounted from the inner bottom surface to the both side surfaces of the pair of crimping pieces, and the plate member is formed with a plurality of protrusions cut and raised by a punch. The electric wire connection structure of the crimp terminal according to claim 1.   The tip of one of the crimping pieces is the tip of a bent portion obtained by bending the tip of the one crimping piece inward, and the tip of the other crimping piece is overlapped with the outer surface of the one crimping piece. The wire connection structure for a crimp terminal according to claim 1, wherein the wire connection structure is crimped.   The wire connection structure for a crimp terminal according to claim 4, wherein a plurality of protrusions are formed at the tip of the bent portion.   The wire connection of a crimp terminal according to claim 4 or 5, wherein a width in the terminal axis direction of the valley portion of the bent portion is formed narrower on both sides than a width in the terminal axis direction of the crimp piece. Construction.

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