JP2010165630A - Electric wire with terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire with a terminal in which a shape of the terminal is not complicated, which facilitates connection between the terminal and electric wire, has a good waterproof property of a connection part, and secures reliable connection between the electric wire and terminal for a long period of time. <P>SOLUTION: The electric wire with a terminal 1 is structured by connecting the electric wire 2, of which a conductor 21 is coated with a coating member 22, to the connector terminal 3 having a contact part 31, a wire barrel part 32, and an intermediate connection part 33; including a conductor connection part 5 formed by fixing the conductor 21 on the wire barrel part 32; covering the conductor connection part 5 with a waterproof tube 4 using a heat-shrinkable tube; and tightly covering a periphery of the intermediate connection part 33 with a terminal side end part 41 of the waterproof tube 4. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a terminal-attached electric wire having a waterproof structure in which a connection terminal is provided at an electric wire terminal and a connection portion between the electric wire and the connection terminal is covered.

  2. Description of the Related Art Conventionally, copper alloy connector terminals (connection terminals) and the like that are excellent in electrical conductivity and spring properties are connected to terminals of electric wires such as automobile wire harnesses by crimping. In general, copper conductor wires have been used for automobile wires, but in recent years, it has been desired to use aluminum wires. Compared to copper wires, aluminum wires contribute to weight reduction to improve fuel efficiency as a measure against global warming and as crude oil prices rise due to tight supply and demand. Aluminum is also advantageous for recycling automobile scraps because it can be easily separated from iron. Furthermore, aluminum has the advantage of abundant resources.

  For example, as described in Patent Document 1, a connection terminal crimping structure made of an aluminum electric wire and a copper alloy is known. Patent Document 1 describes a terminal crimping structure in which the upper limit of the compressibility of the wire conductor part defined by the ratio of the cross-sectional area of the wire conductor part of the crimped part / the cross-sectional area of the aluminum conductor part before crimping is defined as 70%. . In the case of such an open barrel structure, the connection portion between the terminal and the electric wire and the end of the electric wire core wire are exposed to the outside. Therefore, moisture easily enters the inside of the electric wire due to condensation. In particular, when the electric wire is an aluminum electric wire, corrosion easily proceeds when water enters the inside of the electric wire.

  In general, the surface of a connection terminal such as a copper alloy is plated with tin or precious metal in order to improve the reliability of electrical contacts. Aluminum is a base metal having a large ionization tendency compared to the metal on the connection terminal side. For this reason, when an aluminum electric wire is connected to a connection terminal plated with a copper alloy or a noble metal, corrosion tends to proceed at a joint portion of different metals. That is, when a dissimilar metal comes into contact, electrons move from a base metal having a large ionization tendency such as aluminum to a noble metal. When an electrolyte such as water is present outside the joint between the aluminum wire and the terminal and an ion path is established, a current circuit is locally connected, and dissolved oxygen, hydrogen ions, etc. at the interface between the noble metal and the electrolyte Robbed of electrons. Correspondingly, the base metal is eluted as a cation in the electrolyte, and the contact corrosion of different metals proceeds. As a result, the contact resistance of the electric wire crimping portion increases, and in some cases, the aluminum electric wire may break.

  Moreover, a flexible twisted wire is used as a core wire for the electric wire of the automobile wire harness. However, when a flexible stranded wire is used, water is more likely to enter the gap in the wire. If water enters the device connected to the wire through the wire, an electrical short circuit is caused and the electronic device is broken. Furthermore, the supply of oxygen is insufficient for water that has entered the gaps in the wires. Then, when the electric wire is an aluminum electric wire, the passive oxide film on the surface may become unstable and corrosion may proceed.

  In the connection structure of the open barrel structure as described in Patent Document 1, it is possible to avoid water intrusion to some extent by applying rust preventive grease or the like to the exposed part. However, there is a possibility that the waterproof performance may be reduced due to deterioration or detachment of grease. Therefore, it is difficult to maintain the waterproof performance for a long time, and the reliability is insufficient. In addition, it is a very time-consuming operation to apply the grease sufficiently and uniformly.

  On the other hand, the connection that can prevent the corrosion of the electric wire and the malfunction or failure of the electronic equipment connected to the electric wire by preventing water from entering the electric wire from the connection part between the electric wire of the wire harness and the connector terminal. Electric wires with terminals are known (see, for example, Patent Documents 2 to 4).

  Patent Document 2 describes a closed barrel terminal formed by crimping a cylindrical crimping portion including a cylindrical lining having a large number of holes with a specially shaped tool. According to this structure, it is possible to form a metal bond by cold welding between the strands and between the electric wire and the terminal. As a result, there is an advantage that the connection reliability is excellent, and the dissimilar metal contact portion between the terminal and the electric wire and the end of the core wire can be covered.

  In Patent Document 3, after supplying a water-stopping agent having fluidity to a grounding wire terminal with a crimped connection terminal, the air is stopped by sucking air from the other side of the wire and reducing the pressure. A method for infiltrating a liquid agent into the inside of an electric wire covering material is disclosed.

  Patent Document 4 discloses a grounding terminal fitting that is waterproofed by a heat-shrinkable tube provided with an adhesive layer.

JP 2005-174896 A US Pat. No. 3,955,044 JP 2008-177171 A Japanese Patent No. 3214393

  As described in Patent Document 2, in the case of a closed barrel terminal, there is a problem that many special parts and tools are required when the terminal and the electric wire are joined. Moreover, the workability of component insertion is poor, which is disadvantageous in terms of cost.

  In addition, as described in Patent Document 3, the method of infiltrating the water-stopping agent inside the wire covering material requires time for equipment such as decompression and pressurization and hardening of the water-stopping agent, Not convenient. In addition, as long as an open barrel structure is used, there is a problem that it is impossible to avoid exposure of the dissimilar metal contact portion between the terminal and the electric wire and the end of the electric wire core wire.

  In addition, as described in Patent Document 4, when waterproofing is performed using a heat-shrinkable tube provided with an adhesive layer, it is difficult to cover the wire core end surface with only the tube. For this reason, it is necessary to increase the application quantity of the adhesive agent in a tube terminal. Furthermore, it is necessary to provide the terminal with a special structure (inflow restricting means) for preventing the adhesive from excessively flowing out to the terminal body side. Therefore, there is a problem that the shape of the terminal becomes complicated and the manufacturing cost of the terminal increases.

  The problem to be solved by the present invention is to solve the above problems, the shape of the terminal is not complicated, the connection between the terminal and the electric wire is easy, and the waterproofness of the connection part is good. An object of the present invention is to provide a terminal-attached electric wire capable of ensuring a reliable connection between an electric wire and a terminal over a long period of time.

  In order to solve the above-mentioned problems, an electric wire with a terminal according to the present invention is connected to a terminal including a contact portion and a wire barrel portion, and an electric wire whose conductor is covered with an insulator, and the wire barrel portion of the terminal is connected to the wire In the electric wire with a terminal having a conductor connection part to which a conductor is connected, an intermediate connection part is provided between the contact part of the terminal and the wire barrel part, and the conductor connection part is formed of a heat-shrinkable tube. It is covered by the waterproof tube used, and the terminal side end of the waterproof tube covers the periphery of the intermediate connection portion of the terminal without any gap.

  The terminal-attached electric wire according to the present invention employs the above-described configuration, so that the waterproof property of the connection portion between the terminal and the electric wire is good, the shape of the terminal is not complicated, and the connection between the terminal and the electric wire is easy. Furthermore, since the electric wire with a terminal of the present invention has a good waterproof property, it is possible to ensure a reliable connection between the electric wire and the terminal over a long period of time.

FIG. 1 is an external perspective view showing a terminal portion of an electric wire with a terminal according to an example of the present invention. FIG. 2 is a longitudinal sectional view taken along line BB in FIG. FIG. 3 is an external perspective view showing a state in which the waterproof tube of the electric wire with terminal of another example of the present invention is removed. FIG. 4 is an external perspective view showing a terminal-attached electric wire of another example of the present invention. 5 (a) to 5 (c) are cross-sectional views of the intermediate connection portion showing an aspect of the terminal used in the electric wire with terminal of the present invention. FIG. 6 is a cross-sectional view of the intermediate connection portion showing a part of the manufacturing process of the electric wire with terminal of FIG. FIG. 7 is a perspective view showing an appearance of an example of a female terminal used in the electric wire with terminal of the present invention. FIG. 8 is a perspective view showing an appearance of an example of a mail terminal used in the electric wire with terminal of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view showing a terminal portion of an example of a terminal-attached electric wire, and FIG. 2 is a cross-sectional view taken along line BB in FIG. In the electric wire with terminal 1 shown in FIG. 1, a connector terminal 3 is connected as a terminal to the end of the electric wire 2. In the terminal-attached electric wire 1, a conductor connecting portion 5 (see FIG. 2) that is a connecting portion between the electric wire 2 and the connector terminal 3 is covered with a waterproof tube 4 using a heat-shrinkable tube.

  As shown in FIGS. 1 and 2, in the electric wire 2, the periphery of the conductor 21 is covered with an insulating material 22 made of an insulating material such as synthetic resin. The conductor 21 is composed of a stranded wire in which strands made of a plurality of fine metal wires are twisted together. As the conductor 21, a conductive wire such as copper, copper alloy, aluminum, aluminum alloy, tin-plated copper, or the like is used. The conductor 21 is not limited to a stranded wire, and may be a single wire. The electric wire 2 of the electric wire 1 with a terminal shown in FIG. 1 is an electric wire having a substantially circular cross section. An aluminum electric wire using aluminum or an aluminum alloy as an electric wire has an advantage that it is lightweight, low-cost and easy to recycle.

  The connector terminal 3 is formed as a contact portion 31 whose tip opposite to the side to which the electric wire 2 is connected is connected to another terminal. The side of the connector terminal 3 to which the electric wire is connected is formed as a wire barrel portion 32. As shown in FIG. 2, the conductor 21 of the electric wire 2 is fixedly connected to the wire barrel portion 32 of the connector terminal 3 to form the conductor connection portion 5.

  Further, an intermediate connection portion 33 is provided between the contact portion 31 of the connector terminal 3 and the wire barrel portion 32, where the terminal side end portion 41 serving as one end portion of the waterproof tube 4 is located. The connector terminal 3 shown in FIG. 1 is formed as a flat plate in which the cross-sectional shape of the intermediate connection portion 33 is a simple square shape.

  As shown in FIGS. 1 and 2, in the terminal-attached electric wire 1, the terminal-side end portion 41 of the waterproof tube 4 is located at the intermediate connection portion 33 of the connector terminal, and a gap is formed around the intermediate connection portion 33 of the terminal. It is in close contact with the cover. Further, the wire-side end portion 42 of the waterproof tube 4 is located around the wire covering material 22 and is in close contact with the wire 2 so as to cover the periphery of the wire covering material 22 without any gap. Covered in an airtight state, the conductor connection portion 5 is shielded from the outside air. Further, the waterproof joint 4 reinforces the mechanical joint strength between the connector terminal 3 and the electric wire 2.

  The waterproof tube 4 is formed by heat shrinking using a heat shrinkable tube. As such a heat-shrinkable tube, for example, a tube in which an inner layer 44 made of a heat-meltable adhesive is provided inside an outer layer 43 made of a heat-shrinkable resin layer is preferable. As the outer layer 43, for example, an electron beam cross-linked semi-hard flame retardant polyolefin resin or the like is used. The shrinkage rate of the heat shrinkable tube is preferably 75% or more in terms of the inner diameter change rate. As the heat-shrinkable tube, for example, a commercial product such as “Sumitube SA2” manufactured by Sumitomo Electric Fine Polymer Co., Ltd. can be used.

  In order to form the waterproof tube 4 by covering the conductor connecting portion 5 with the heat shrinkable tube, the conductor 21 of the electric wire 2 is pressure-bonded and fixed to the wire barrel portion 32, and then the heat shrinkable tube is inserted from the electric wire side or the terminal side. Then, it is placed at a predetermined position and heated to shrink the heat shrinkable tube.

  Further, when the heat shrinkable tube is provided with the inner layer 44 made of a heat-meltable adhesive, the adhesive melts and fills the gap by heating during shrinkage, so that the airtightness can be further improved. .

  FIG. 3 is an external perspective view showing a state where the waterproof tube of the electric wire with terminal of another example of the present invention is removed, and FIG. 4 is a perspective view showing the electric wire with terminal of another example of the present invention. Fig.5 (a)-(c) shows the aspect of the terminal used for the electric wire with a terminal of this invention, and is sectional drawing of an intermediate | middle connection part. As shown to Fig.5 (a), the cross section of the intermediate connection part 33 of the connector terminal 3 is formed in flat form in the electric wire with a terminal of FIG.1 and FIG.2. In the present invention, the cross-sectional shape of the intermediate connection portion 33 is not limited to this shape, and when the waterproof tube 4 is formed by contraction using a heat-shrinkable tube, the terminal-side end portion 41 of the waterproof tube 4 is Any shape that can be in close contact with the intermediate connecting portion 33 without any gap is acceptable.

  The specific shape of the intermediate connection portion 33 of the connector terminal is erected on the flat plate portion 33a and both sides of the flat plate portion 33a as shown in FIGS. 3, 4, 5B, and 5C, for example. A concave cross section formed by the side wall portions 33b and 33c can be mentioned. The connector terminal 3 can improve the intensity | strength of the connector terminal 3 if the cross-sectional shape of the intermediate connection part 33 is formed in the above concave shape.

  As shown in FIGS. 4 and 5B and 5C, when the intermediate connection portion 33 of the connector terminal is formed to have a concave cross section, when the heat shrinkable tube is contracted, the heat shrinkable tube is connected to the connector terminal. It is preferable to make it adhere | attach along the shape of an intermediate | middle connection part. FIG. 6 is a cross-sectional view of the intermediate connection portion showing a part of the manufacturing process of the electric wire with terminal of FIG. As shown in FIG. 6, after covering the intermediate connection portion 33 with the heat shrink tube 45, the heat shrink tube 45 is pressed into the concave portion by pressing the die 6 corresponding to the shape of the intermediate connection portion 33 of the connector terminal. The heat-shrinkable tube is shrunk in a state of being in close contact with the inside. Thereafter, if the mold 6 is removed, as shown in FIG. 4, the waterproof tube 4 has a state in which the connector terminal side end portion 41 follows the shape of the intermediate connection portion 33 and is in close contact with the intermediate connection portion 33. can do.

  The intermediate connection portion 33 shown in FIGS. 1 and 2 or the flat plate portion (FIGS. 5 (b) and (c) 33a) of the intermediate connection portion 33 in FIGS. It has a rectangular cross-sectional shape. With such a shape, the connector terminal side end portion 41 of the heat-shrinkable tube can follow the shape of the periphery of the intermediate connection portion 33 and easily perform airtight coating. In addition, even if there are some protrusions or the like that are convex outward on the surface of the flat plate portion (33a) of the intermediate connection portion 33, if there is no concave fitting portion that is concave on the inside, just shrink the heat shrinkable tube, The waterproof tube 4 can be easily adhered to the shape around the intermediate connection portion 33.

  Further, there is no special unevenness between the intermediate connection portion 33 and the contact portion 31 and between the intermediate connection portion 33 and the wire barrel portion 32 as in the adhesive backflow prevention structure. The portions excluding the side wall portions 33b and 33c on the surface do not need to be particularly roughened and are formed in a flat shape similar to the intermediate connection portion 33.

  As a terminal used for the electric wire with a terminal of the present invention, it is not limited to the above-mentioned connector terminal, and various connector terminals etc. can be used. For example, the structure of the contact portion is not limited to the female type, and may be a mail type. FIG. 7 is a perspective view showing an example of a female terminal used in the electric wire with terminal of the present invention, and FIG. 8 is a perspective view showing an example of the mail terminal.

  As shown in FIG. 7, the female terminal 60 is provided with a contact portion 63 including an upper holder 61 and a spring tongue 62. Further, the female terminal 60 is provided with an intermediate connection portion 64, a wire barrel portion 65, and an insulation barrel 66 at the contact portion 63. When the electric wire is crimped, it is separated from the carrier 67.

  As shown in FIG. 8, the mail terminal 70 is provided with a contact portion 71 inserted into and electrically connected to the contact portion 63 of the female terminal 60 at one end. Further, the mail terminal 70 is configured such that a stabilizer 72, a lance hole 73, an intermediate connection portion 74, a wire barrel portion 75, an insulation barrel 76, and the like are sequentially provided on the contact portion 71. When the electric wire is crimped, it is separated from the carrier 77.

When the connector terminals shown in FIGS. 7 and 8 are used, the end portion of the waterproof tube 4 on the electric wire side is covered with the electric wire insulation coating resin that can ensure airtightness easily. However, if the insulation barrels 66 and 76 are tightly adhered to the electric wire insulation coating resin, if the conductor connecting portion 5 can be sealed by covering the periphery of the insulation barrels 66 and 76, then it will be done as such. good.

  In addition, the connector terminal of the aspect shown in FIG. 1 is not provided with an insulation barrel. In the embodiment of FIG. 1, the wire-side end portion 42 of the waterproof tube 4 covers and closely contacts the wire covering material 22. In the present invention, since the waterproof tube 4 can also function as an insulation barrel, the insulation barrel of the connector terminal may be omitted as shown in FIG. If the insulation barrel of the connector terminal 3 is omitted, the total length of the waterproof tube 4 can be shortened. Also, if there is no insulation barrel, the outer diameter of the part does not increase, so the change in the cross-sectional area of the waterproof tube can be reduced, and when using a heat shrinkable tube, the inner diameter shrinkage rate may be small, Airtight coating of the waterproof tube can be easily performed.

  1, the conductor 21 of the electric wire 2 is fixed to the wire barrel 32 of the connector terminal 3 by crimping. In the present invention, the fixing of the conductor 21 to the wire barrel 32 is not limited to crimping, and various fixing methods can be used. Examples of the fixing method include a welding method such as ultrasonic welding and a soldering method such as soldering.

  Moreover, although the heat shrinkable tube used for the waterproof tube 4 of the aspect of FIG. 1 is formed in the same diameter from an edge part to an edge part, you may make it a heat shrinkable tube from which the opening diameters of both ends differ. Moreover, the waterproof tube 4 is good also as a laminated structure by several heat shrinkable tubes using several heat shrinkable tubes from which a diameter differs. In short, it suffices if both ends of the waterproof tube are in close contact with the electric wire or the terminal and can be covered in an airtight manner.

  The electric wire with a terminal of the present invention is used for various electric wires with a connecting terminal having a waterproof structure in which a connecting terminal is provided at an electric wire terminal and the connecting portion of the electric wire and the connecting terminal is covered in addition to the electric wire and the connector terminal described above. can do. In particular, a flexible stranded wire is used as the core wire, and can be suitably used for an automobile wire harness used in a humid environment or the like. Moreover, it can use suitably for the aluminum electric wire etc. which a corrosion progresses easily when a water | moisture content penetrate | invades inside as an electric wire.

1 Electric wire with terminal 2 Electric wire 21 Conductor 22 Coating material (insulator)
DESCRIPTION OF SYMBOLS 3 Connector terminal 31 Contact part 32 Wire barrel part 33 Intermediate connection part 4 Waterproof tube 41 Terminal side end part 42 of waterproof tube Terminal side end part 5 of waterproof tube Conductor connection part

Claims (7)

In a terminal-equipped electric wire having a conductor connecting portion in which an electric wire whose conductor is covered with an insulator is connected to a terminal including a contact portion and a wire barrel portion, and the conductor of the electric wire is fixed to the wire barrel portion of the terminal ,
An intermediate connection portion is provided between the contact portion of the terminal and the wire barrel portion,
The conductor connection part is covered with a waterproof tube using a heat-shrinkable tube, and the terminal side end of the waterproof tube covers the periphery of the intermediate connection part of the terminal without a gap. With electric wire.   The electric wire with a terminal according to claim 1, wherein an end portion of the waterproof tube on the electric wire side covers the periphery of the insulator of the electric wire without a gap.   The electric wire with a terminal according to claim 1 or 2, wherein the conductor is made of aluminum or an aluminum alloy.   The cross-sectional shape of the intermediate connection part of the said terminal is flat form, The electric wire with a terminal of any one of Claims 1-3 characterized by the above-mentioned.   The cross-sectional shape of the intermediate connection part of the said terminal is provided with the side wall for reinforcement in the side, The electric wire with a terminal of any one of Claims 1-4 characterized by the above-mentioned.   The electric wire with a terminal according to any one of claims 1 to 5, wherein the waterproof tube uses a flame-retardant heat-shrinkable tube made of an electron beam cross-linked semi-rigid flame-retardant polyolefin resin. .   The heat-shrinkable tube according to any one of claims 1 to 6, wherein the waterproof tube uses a heat-shrinkable tube in which an inner layer made of a heat-meltable adhesive is provided inside a heat-shrinkable outer layer. The electric wire with a terminal given in the paragraph.

Images