JP2007311369A - Connection structure between wire and terminal fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure capable of connecting a wire to a terminal fitting inexpensively even when the wire and the terminal fitting are formed of metals different from each other. <P>SOLUTION: A core wire made of, for instance, aluminum exposed by removing an insulation layer of an end part of a wire is covered with an intermediate cap made of, for instance, a copper alloy, and a crimp piece of an open barrel type terminal fitting made of, for instance, a copper alloy is crimped to surround the intermediate cap. Since the intermediate cap is formed of the same kind of metal as that of the terminal fitting, even if the connection part between the intermediate cap and the terminal fitting is exposed to the outside, electrolytic corrosion never occurs between both of them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a connection structure between an electric wire and a terminal fitting.

  For example, in order to reduce the weight of a power wire used in an electric vehicle, it is considered to use an aluminum core wire instead of a conventional copper alloy core wire.

  By the way, when the electric wire is connected to the terminal fitting in a conductive manner, when the core wire of the electric wire and the terminal fitting are formed of different kinds of metals, both the metals are dissolved as ions in the water when moisture is present in the connection portion between them. It is known that electrolytic corrosion occurs where corrosion proceeds due to an electrochemical reaction.

  On the other hand, as the terminal fitting to be connected to the electric wire, it is preferable to use an open barrel type in which the electric wire connecting portion is raised from the both side edges of the bottom plate in terms of cost.

  Then, when using an aluminum core wire, it is most preferable to use an aluminum open barrel type terminal fitting, but the aluminum open barrel type terminal fitting has sufficient strength of the caulking piece. However, it is not practical. However, when the conventional open-alloy type metal fitting made of copper alloy is used, there is a problem that electrolytic corrosion occurs as described above. For this reason, until now, when using an aluminum core wire, it has been necessary to use a closed barrel type terminal fitting with a cylindrical connection part covering the entire core wire part as the terminal fitting, and its high production I was troubled by the cost.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a connection structure between an electric wire and a terminal fitting that can be connected at low cost even if the electric wire and the terminal fitting are made of different metals. It is.

  In order to solve the above-mentioned problems, the invention of claim 1 is characterized in that an electric wire formed by coating a core wire with an insulating layer, and an electric wire having an open barrel shape, wherein the core wire is formed of a dissimilar metal and has a crimping piece. A connection structure with a terminal fitting having a connection portion, wherein an intermediate cap is covered on the core wire exposed by removing an insulating layer of a terminal portion of the electric wire, and the crimping is performed so as to surround the intermediate cap. A feature is that a piece is crimped and the intermediate cap is formed of a material that does not cause electrolytic corrosion between the terminal fitting and the terminal fitting such as the same kind of metal.

  The invention according to claim 2 is the connection structure between the electric wire and the terminal fitting according to claim 1, characterized in that a waterproof filler is filled between the core wire and the intermediate cap. Have.

  The invention of claim 3 is a connection structure between the electric wire and the terminal fitting according to claim 2, and is characterized in that metal powder is mixed in the filler.

  Invention of Claim 4 is a connection structure of the electric wire and terminal metal fitting in any one of Claim 1 thru | or 3, Comprising: A waterproof elastic member is externally fitted to the terminal part of the said insulating layer, The The elastic member is characterized in that the open end of the intermediate cap is externally fitted.

  According to the first aspect of the invention, first, the core wire exposed at the terminal portion of the electric wire is covered with the intermediate cap, and the core wire and the intermediate cap are conductively connected, and then the intermediate cap and the terminal fitting are conductively connected. Thus, the electric wire and the terminal fitting are connected in a conductive manner. At this time, the core wire and the intermediate cap are formed of different kinds of metals or the like. However, since the connection portion between the two is not exposed to the outside, no electrolytic corrosion occurs due to moisture. In addition, since the intermediate cap and the terminal fitting are formed of the same type of metal or the like, even if the connecting portion of both is exposed to the outside and is exposed to moisture, no electrolytic corrosion occurs between them. Therefore, it is possible to use an open barrel type terminal fitting, and there is an effect that the cost can be reduced as compared with the case of using a closed barrel terminal as in the prior art.

  According to the invention of claim 2, since the waterproof filler is filled between the core wire and the intermediate cap, moisture can be reliably prevented from entering between the two.

  Furthermore, according to the invention of claim 3, since the filler is configured to be mixed with metal powder, even when the filler is interposed between the intermediate cap and the core wire, the electrical continuity between the two is ensured. can do.

  Further, as in the invention of claim 4, a waterproof elastic member is externally fitted to the terminal portion of the insulating layer, and the opening end of the intermediate cap is externally fitted to the elastic member, so that there is no gap between the core wire and the intermediate cap. It is also possible to adopt a configuration that prevents moisture from entering.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. In this embodiment, an example of a connection structure in the case of connecting an electric wire formed by insulating coating an aluminum core wire and a terminal fitting made of a copper alloy is shown.

  As shown in FIG. 1, the electric wire 10 is obtained by covering a core wire 11 formed by twisting a plurality of thin aluminum wires with a resin insulating layer 12, and the insulating layer 12 is peeled off at the terminal portion. The core wire 11 is exposed.

  On the other hand, as shown in FIG. 2, the terminal fitting 20 is made of a thick copper alloy plate material and has an elongated shape in the front-rear direction as a whole. A front end portion (left side in FIG. 2) of the terminal fitting 20 is a flat plate-like device connection portion 21, and a connection hole 22 is formed in the device connection portion 21. At the rear end portion of the terminal fitting 20, an electric wire crimping portion 25 having an open barrel shape, that is, a pair of caulking pieces 24, 24 raised from the left and right side edges of the bottom plate 23 (the electric wire which is a constituent of the present invention) Connecting portion) is formed.

  An intermediate cap 30 made of the same kind of copper alloy as that of the terminal fitting 20 is coated on the core wire of the terminal portion of the electric wire. As shown in FIG. 1, the intermediate cap 30 has a cylindrical shape with one side closed, and has a length so that it can cover from the core wire 11 of the terminal portion of the electric wire 10 to the tip of the insulating layer 12. A step portion 31 is formed in the middle of the direction, and the end side thereof has a large diameter.

  In this embodiment, when connecting the electric wire 10 and the terminal fitting 20, first, the filler 40 is applied to the terminal portion of the electric wire 10 and the inner wall of the intermediate cap 30. The filler 40 is made of a waterproof synthetic resin, and a metal powder such as zinc is mixed in advance in the resin. And as shown in FIG. 3, the intermediate | middle cap 30 is coat | covered so that the core wire 11 and the insulating layer 12 of the terminal part of the electric wire 10 may be covered. Then, the filler 40 is thinly spread between the core wire 11 of the electric wire 10 and the intermediate cap 30, and the gap between the two is embedded. This reliably prevents moisture from entering between the electric wire 10 and the intermediate cap 30. Moreover, electrical conduction between the core wire 11 and the intermediate cap 30 is ensured by the metal powder in the filler.

  Next, the terminal portion of the electric wire 10 covered with the intermediate cap 30 is placed on the bottom plate 23 of the terminal fitting 20, and the crimping piece 24 is crimped and fixed so as to surround the intermediate cap 30 (FIG. 4). reference). Then, as shown in FIG. 5, the core wire 11 of the electric wire 10 and the terminal fitting 20 are electrically connected via the filler 40 and the intermediate cap 30, and thereby the electric wire 10 and the terminal fitting 20 are connected. Connection is complete.

  In the above connection state, since the space between the core wire 11 and the intermediate cap 30 of the electric wire 10 is completely embedded by the filler 40, even if both are dissimilar metals, moisture enters and electrolytic corrosion occurs. Is prevented. In addition, the intermediate cap 30 and the terminal fitting 20 are in a state where the connection portions are exposed, but since both are formed of the same kind of metal, even if they are exposed to moisture, no electrolytic corrosion occurs.

  As described above, according to the present embodiment, even when the core wire of the electric wire and the terminal fitting are formed of different kinds of metals, the open barrel is formed by covering the core wire with the intermediate cap made of the same metal as the terminal fitting. It has become possible to use type terminals. Therefore, the cost can be reduced as compared with the case of using a closed barrel type terminal fitting.

<Other embodiments>
The present invention is not limited to the embodiment 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, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In the above embodiment, the intermediate cap has a shape that covers the core wire and the terminal portion of the insulating layer in a lump, but may have a shape that covers only the core wire. Moreover, it is good also as a shape which coat | covers a part of core wire, and what is necessary is just to set it as the form which protects the exposed part of a core wire with another protection means.

  (2) The filler is not always necessary. For example, as shown in FIG. 6, for example, an O-ring 50 is fitted on the end portion of the insulating layer 12, and the open end of the intermediate cap 30 is fitted on the outer periphery of the O-ring 50. By combining, waterproofness may be improved. Furthermore, the boundary between the intermediate cap and the electric wire may be sealed with a sealant or the like, or the intermediate cap may be in close contact with the resin layer of the electric wire and waterproofed.

  (3) In the above embodiment, the intermediate cap is made of the same type of metal as the terminal fitting. However, the invention is not limited to this, and the intermediate cap may be formed from an alloy that is difficult to ionize in water, such as a conductive resin or conductive rubber. .

The perspective view of the electric wire and middle cap of one embodiment of the present invention Perspective view of open barrel type terminal fitting The perspective view which shows the state before connecting an electric wire to a terminal metal fitting The perspective view which shows the state which connected the electric wire to the terminal metal fitting Cross section The perspective view of the electric wire and intermediate cap of other embodiments

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electric wire 11 ... Core wire 12 ... Insulating layer 20 ... Terminal metal fitting 24 ... Crimp piece 25 ... Electric wire crimping part (electric wire connection part)
30 ... Intermediate cap 40 ... Filler 50 ... O-ring (elastic member)

Claims (4)

An electric wire formed by coating an insulating layer on a core wire, and the core wire is formed of a dissimilar metal, and has a connection structure with a terminal fitting having an electric wire connecting portion having an open barrel shape provided with caulking pieces,
The core wire exposed by removing the insulating layer of the terminal portion of the electric wire is covered with an intermediate cap, the crimping piece is crimped so as to surround the intermediate cap, and the intermediate cap is the same type as the terminal fitting. A connection structure between an electric wire and a terminal fitting, which is formed of a material that does not cause electrolytic corrosion with the terminal fitting such as metal. The connection structure between the electric wire and the terminal fitting according to claim 1, wherein a waterproof filler is filled between the core wire and the intermediate cap. The connection structure between the electric wire and the terminal fitting according to claim 2, wherein metal powder is mixed in the filler. The electric wire according to any one of claims 1 to 3, wherein a waterproof elastic member is externally fitted to a terminal portion of the insulating layer, and an open end of the intermediate cap is externally fitted to the elastic member. And connection structure of terminal fittings.

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