JP2009099346A - Wire end connection structure and connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve connection reliability between terminals of a plurality of electric wires 10 by a simple structure. <P>SOLUTION: Each electric wire 10 has a conductor 12 and an insulated film 14, and the conductor 12 is exposed to the outside at its terminal. The electric wires are bundled to make the exposed conductors 12 uniform one another, and a common connection section 18 is formed by integrating the conductors 12 by melting and welding. Further, a constraint member 16 is integrated with the common connection section 18 by using the melted welding. The constraint member 16 constrains a change of an angle of each conductor 12 to the common connection section 18 by constraining the bundle of the electric wires from the outside at a range from the common connection section 18 to the insulated film 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for electrically connecting terminals of a plurality of electric wires wired to an automobile or the like.

  Conventionally, what is described in FIG.5 and FIG.6 of patent document 1 is known as a method for connecting the terminals of the above electric wires. This method consists of the following steps.

  1) The terminal of the conductor (core wire) in each electric wire is exposed, and these terminals are joined together by resistance welding or ultrasonic welding.

2) Cover the joint with a protective cap made of insulating resin, and fix the wire group on the tongue protruding from the protective cap by tape winding.
JP 2002-15784 A

  The resistance welding or ultrasonic welding described in Patent Document 1 is only for joining the surfaces of the ends of the conductors, and a dramatic improvement in the connection reliability is hardly desired. Further, in this method, in order to prevent a mechanical load from acting on the connection part by welding and causing the part to break, a tongue piece is extended from a protective cap for covering the welding part, and the tongue piece is applied to the tongue piece. It is necessary to fix the wire group by tape winding. This complicates the overall structure and requires a cumbersome tape winding operation. Moreover, the improvement of the reliability of fixation of the said electric wire group is also a subject.

  In view of such circumstances, an object of the present invention is to provide a structure capable of improving the connection reliability between terminals of electric wires with a simple structure and a method capable of performing the connection with a small number of man-hours. To do.

  In order to increase the connection reliability, the present inventors have conceived that the ends of the conductors of each electric wire are connected by fusion welding. The fusion welding here is a method of joining by melting of materials without requiring the addition of mechanical pressure, such as various types of arc welding such as TIG welding and submerged arc welding and some gas welding. It is a generic name (JIS Z 3001), and the fusion welding can drastically improve the connection reliability by mixing materials constituting the conductor.

  However, it has been found that in such a conductor connection portion by fusion welding, the breaking load is greatly reduced depending on the direction of the tension acting on the electric wire, and the breaking occurs even at a relatively low tension. This is because when a tension that greatly changes the angle between the common connection portion formed by melting by the fusion welding and the conductor of the electric wire connected thereto acts on the electric wire, the common connection portion and the electric wire It is considered that a bending load acts between the conductor and the shearing force due to the bending load causes the breakage.

  The present invention has been made from such a background, and is an electric wire terminal connection structure in which terminals of a plurality of electric wires are electrically connected to each other, and each electric wire has a conductor and an insulating coating covering the conductor. And the conductor is exposed at the terminal, the electric wires are bundled so that the exposed conductors are aligned with each other, and the conductors are integrated by fusion welding to form a common connection portion, Further, the bundle of electric wires is restrained from changing the angle of the conductor of each electric wire with respect to the common connection portion by constraining the bundle of electric wires from the outside in a region from the common connection portion to the insulating coating. A constraining member is provided around the at least one end of the constraining member, and at least an end of the constraining member is made of a metal material that can be melt-welded. In which is integrated with the common connection portion is.

  In this structure, the fusion welding for joining the conductors is a method of mixing the materials constituting the conductors, so that the connection reliability at the common connection portion formed by the fusion welding is high. Furthermore, since the wire bundle is restrained from the outside by the restraining member in the region from the common connection portion to the insulation coating, the change in the angle of the conductor with respect to the common connection portion is suppressed, so that the tension acting on each wire is reduced. Regardless of the direction, it is possible to effectively suppress the bending load from acting on the connection portion between the common connection portion and the conductor or in the vicinity thereof, and as a result, the durability of the connection portion is enhanced. In addition, since the restraint member is integrated with the common connection portion by the fusion welding, the restraint by the restraint member is reliably maintained.

  Preferably, the restraining member is a restraining sleeve made of the metal material that can be melt welded, and the bundle of wires is inserted inside the restraining member. Use of such a restraining sleeve makes it possible to reliably restrain the wire bundle from the outside with a simple structure having a small number of parts.

  In the restraining sleeve, it is more preferable to configure a diameter-expanded portion whose diameter increases as the end opposite to the common connection portion approaches the end. Such a diameter-expanded portion causes damage to the electric wire when the electric wire and the end of the restricting sleeve are pressed against each other when tension in a direction different from the axial direction of the restricting sleeve is applied to the electric wire. Can be effectively suppressed.

  The structure according to the present invention preferably includes a protective cap made of an insulating material and having a shape capable of covering the common connection portion and the restraining sleeve. In this case, the protective cap is engaged with the enlarged diameter portion of the restraining sleeve from the side opposite to the common connection portion to prevent the restraining sleeve from being detached from the protective cap. If it has a stop part, it is possible to detach | leave the said restraining sleeve with the simple structure using the shape of the said enlarged diameter part.

  In the restraining member, it is preferable that at least an end portion on the common connection portion side is made of copper or a copper alloy. Since the copper or copper alloy has a high electrical conductivity, even if it is mixed with the common connection by the fusion welding, the electric resistance value of the common connection is hardly increased. On the other hand, since the fusion welding is not subject to restrictions on the material to be welded, the application range is wide. For example, the present invention can be applied even when the conductor of the electric wire is aluminum or an aluminum alloy.

  The present invention is also an electric wire terminal connection method for electrically connecting the terminals of a plurality of electric wires, each of which has a conductor and an insulating coating covering the conductor, and an end of the conductor is exposed. The wires are bundled together so that the ends of the conductors are aligned with each other, and at the periphery of these wires, a restraint member made of a metal that can be melt-welded at least at the end of the conductor is arranged and The conductors are electrically connected to each other by integrating the disposing step of projecting the end of the conductor from the end and the end of each conductor and the end of the restraining member by the fusion welding. And a welding step of forming the common connection portion and fixing the restraining sleeve at a position where the bundle of the wires is restrained from the outside in the region from the common connection portion to the insulation coating of each electric wire. It is intended.

  According to this method, the highly reliable connection structure can be constructed with less man-hours. That is, in this method, the restraint member is fixed using fusion welding for connecting the conductors, that is, the restraint member and the common connection portion are integrated. A terminal connection structure can be manufactured.

  In the arranging step, a restraining sleeve made of the melt-weldable metal (more preferably, copper or a copper alloy) is used as the restraining member, and the bundle of wires is inserted inside the restraining sleeve. preferable.

  As described above, according to the present invention, by integrating the ends of the conductors of the electric wires and the restraining members for restraining the ends of these electric wires from the outside, the structure is simplified, and The connection reliability between the wires can be increased with a small number of man-hours.

  Preferred embodiments of the present invention will be described with reference to the drawings. In addition, although embodiment shown below bundles the three electric wires 10 as shown in FIG.1 and FIG.2 and mutually connects these, this invention is limited about the number of the electric wires connected mutually. Not.

  In this embodiment, the electric wires 10 are connected to each other through the following steps.

1) Terminal processing process In this process, the terminal processing of each said electric wire 10 is performed. Specifically, each electric wire 10 includes a conductor 12 including one or a plurality of strands and an insulating coating 14 covering the conductor 12, of which the terminal of the conductor 12 is partially removed by the terminal of the insulating coating 14. Only the exposure process is performed.

2) Arrangement Step In this step, as shown in FIG. 1A, the ends of the electric wires 10 are bundled together, and the electric wire bundle is inserted into a common restraining sleeve 16. As a result, the restraining sleeve 16 projects the end of each conductor 12 from one end of the restraining sleeve 16 as shown in FIG. The conductor 12 and the end portion of the insulating coating 14 are disposed at a position so as to cover the terminal portion.

  The material of the restraining sleeve 16 may be a metal material that can be melt welded. For example, aluminum, aluminum alloy, and stainless steel can be applied. However, as described later, a material having a particularly high conductivity, such as copper or a copper alloy, is more preferable.

3) Connection process In this process, the restraining sleeve 16 and the end of each conductor 12 projecting from one end of the restraining sleeve 16 are joined by fusion welding. In this fusion welding, the conductors 12 are fused together to form a common connection part 18 (spherical in the illustrated example), and in addition to the common connection part 18 and the common connection part 18. And unite.

  Since the common connection portion 18 is a material in which the material constituting the terminal of each conductor 12 is once melted and mixed together, its connection reliability is extremely high. For example, even if the surface of the end of each conductor 12 is covered with a relatively high resistance film such as an oxide film before welding, the film disappears due to the high heat generated by the fusion welding. In addition, since the fusion welding is less subject to material restrictions than resistance welding and ultrasonic welding, the scope of application of the present invention is wide. Therefore, according to the present invention, the conductors 12 can be electrically connected to each other with high connection reliability even if the conductors 12 are made of a metal material such as aluminum or an aluminum alloy that is easy to form an oxide film on the surface. Is possible.

  The restraining sleeve 16 only restrains the electric wire 10 from the outside in the region from the common connecting portion 18 to the terminal of the insulating coating 14. However, the restraint serves to protect the common connecting portion 18. Significantly contributes. If the restraining sleeve 16 is omitted, depending on the direction of the tension acting on the electric wire 10, the connection portion between the common connection portion 18 and the conductor 12 or a portion in the vicinity thereof is broken with a relatively low tension. There is a fear. This is because the nature of the load applied to the part differs depending on the direction of the tension.

  Specifically, as indicated by an arrow A in FIG. 2, most of the tension in the direction that does not change the angle formed by the common connecting portion 18 and the conductor 12 connected thereto acts only as a tensile load. . The durability of the connecting portion against this tensile load is high. On the other hand, as shown by the arrow B in FIG. 2, the tension in the direction that significantly changes the angle formed by the common connecting portion 18 and the conductor 12 connected to the common connecting portion 18 (changes approximately 90 ° in the figure) is Acts as a bending load. Even if the bending load is low, the shearing force generated at the connection site by this bending load may cause the connection site or its vicinity to break (shear).

  The restraining sleeve 16 restrains a change in the angle of each conductor 12 with respect to the common connection portion 18 by restraining the bundle of wires from the outside in a region from the common connection portion 18 to the insulating coating 14. In order to suppress, regardless of the direction of the tension acting on each electric wire 10, it is possible to limit the load generated at the connection portion between the common connection portion 18 and the conductor 12 due to the tension to almost only the tensile load. It is. This dramatically improves the mechanical durability of the connection site.

  In addition, since the restraining sleeve 16 is integrated with the common connection portion 18 by the fusion welding, the restraining sleeve 16 has extremely high fixing strength and restraint reliability. Further, since it is not necessary to perform a separate process from the connection between the conductors 12 for fixing the restraining sleeve 16, the highly reliable connection structure can be obtained with a small number of man-hours.

  Although the constituent material of the restraining sleeve 16 is mixed with the constituent material of the conductor 12 by the fusion welding, the restraining sleeve 16 is made of a material having high conductivity such as copper or a copper alloy. If so, it is possible to effectively suppress an increase in the electrical resistance value due to the mixing of the materials.

  The restraining sleeve 16 may have a completely straight cylindrical shape, but as shown in FIGS. 3 and 4, the end of the restraining sleeve 16 opposite to the common connection portion 18 ( In FIG. 3, it is more preferable to configure the enlarged diameter portion 16a whose diameter is increased as the lower end portion is directed toward the end thereof. Such an enlarged diameter portion 16a facilitates the insertion of the wire bundle into the restraining sleeve 16, and when tension is applied to the wire 10 so as to greatly change its direction as shown in FIG. The bending load that acts locally on the electric wire 10 is effectively reduced.

  Further, when the protective cap 20 as shown in FIG. 4 is put on the common connection portion 18 and the restraining sleeve 16, the enlarged diameter portion 16 a is used to detach the restraining sleeve 16 from the protective cap 20. It is possible to prevent it. The protective cap 20 is for preventing the common connection portion 18 and the restraining sleeve 16 from coming into contact with other conductor portions and short-circuiting, and is formed of an insulating material such as a synthetic resin. An inward locking claw 22 as shown in the figure is formed on the periphery of the opening of the protective cap 20, for example, and this locking claw 22 is on the side opposite to the common connection portion 18 with respect to the enlarged diameter portion 16a ( If the protective cap 20 is formed so as to be engaged from the left side in FIG. 4, it is possible to effectively remove the restraining sleeve 16 from the protective cap 20 with a simple structure using the enlarged diameter portion 16a. It is possible to prevent it.

  Instead of or in addition to the formation of the enlarged diameter portion 16a, the inner edge of the end portion of the restraining sleeve 16 opposite to the end portion on the common connection portion 18 side may be chamfered.

  Further, the restraining member according to the present invention is not limited to a cylindrical member like the restraining sleeve 16. For example, it may be composed of a plurality of members arranged in the circumferential direction around the wire bundle, and these members may be integrated with the end of the conductor 12 by the fusion welding. However, as shown in the drawing, the constraining sleeve 16 that is continuous in the circumferential direction has a structure with a small number of parts and can restrain the wire bundle more reliably.

  Further, the entire restraining member does not necessarily need to be formed of a metal material that can be melt welded, and at least the end portion on the side of the common connection portion 18 only needs to be made of the metal material.

  Durability tests were conducted on the following examples and comparative examples.

1) Example: For a restraint made of a copper pipe having a diameter of 3 mm, each of which is a terminal treatment for three wires having a stainless steel conductor and a total cross-sectional area of 0.13 mm ² . It is inserted through the sleeve. And the terminal of the conductor of each electric wire and the said restraining sleeve are integrated by TIG welding, and the common connection part 18 is formed.

  2) Comparative example: Same as the above example except that the restraining sleeve is omitted.

  3) Contents of endurance test: An apparatus as shown in FIG. 5 is used. The device has a fixed clamp 30 and a movable clamp 32 that are spaced apart from each other. The fixed clamp 30 grips two wires other than the wire to be measured among the three wires 10. The movable clamp 32 grips the remaining electric wire to be measured and pulls it in a direction away from the fixed clamp 30, that is, in a direction opposite to the other two electric wires (a direction away from 180 °).

  In this durability test, in the structure according to the embodiment, since the restraining sleeve 16 restrains each electric wire from the outside, the tensile force of the movable clamp 32 is all connected to the common connecting portion 18 and the measurement target electric wire. Acts as a tensile load. On the other hand, in the comparative example, the tensile force of the movable clamp 32 causes a bending load at the connection portion between the common connection portion 18 and the measurement target wire, that is, the angle of the measurement target wire with respect to the common connection portion 18 is about 90 °. Acts as a changing load.

  The results of this durability test are shown in FIG. In the comparative example, the minimum value of the breaking load is 22.7N, the maximum value is 56.4N, and the average value is 43.4N, whereas in the example, the minimum value of the breaking load is 50N, the maximum value is 60N, The average value is 55.4N, and all the values are higher than those of the comparative example. In particular, the difference between the minimum values is significant, which clearly shows the high connection reliability of the structure according to the embodiment.

It is process drawing which shows the electric wire terminal connection method which concerns on embodiment of this invention, (a) is the state before an electric wire bundle is inserted in a restraining sleeve, (b) is the said electric wire bundle in the said restraining sleeve. The inserted state, (c) shows a state in which the common connection portion is formed by fusion welding after the insertion. It is a perspective view which shows the direction of the tension | tensile_strength which can act on each conductor connected to the said common connection part. It is a partial cross section perspective view which shows the suitable example of the said sleeve for restraint. It is sectional drawing which shows the example of the cap for protection covered on the said sleeve for restraint. It is a perspective view which shows the apparatus used for the endurance test of the Example which concerns on this invention, and a comparative example. It is a graph which shows the result of the said endurance test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric wire 12 Conductor 14 Insulation coating 16 Restraint sleeve 16a Diameter expansion part 18 Common connection part 20 Protection cap 22 Locking claw

Claims (8)

A wire terminal connection structure in which terminals of a plurality of wires are electrically connected to each other,
Each electric wire has a conductor and an insulating coating covering the conductor, and the conductor is exposed at the end thereof, and the electric wires are bundled so that the exposed conductors are aligned with each other, and the conductors are melt-welded. A common connection part is formed by being integrated by
Further, the bundle of electric wires is restrained from changing the angle of the conductor of each electric wire with respect to the common connection portion by constraining the bundle of electric wires from the outside in a region from the common connection portion to the insulating coating. A restraining member is provided around the
At least an end of the constraining member on the side of the common connection is made of a metal material that can be melt-welded, and the end is melt-welded together with the conductor and integrated with the common connection. Wire terminal connection structure. In the electric wire terminal connection structure according to claim 1,
The wire terminal connection structure, wherein the restraining member is a restraining sleeve made of the metal material that can be melt welded, and the bundle of wires is inserted inside the restraining member. In the electric wire terminal connection structure according to claim 2,
The electric wire terminal connection structure characterized by comprising the diameter expansion part which diameter-expands as the edge part on the opposite side to the said common connection part goes to the terminal end among the said restraining sleeves. In the electric wire terminal connection structure according to claim 3,
A protective cap made of an insulating material and having a shape capable of covering the common connection portion and the restraining sleeve, the protective cap being connected to the enlarged diameter portion of the restraining sleeve. An electric wire terminal connection structure comprising a locking portion that prevents the restraining sleeve from being detached from the protective cap by engaging from the opposite side. In the electric wire terminal connection structure in any one of Claims 1-4,
The electric wire terminal connection structure characterized in that at least an end portion on the common connection portion side of the restraining member is made of copper or a copper alloy. A wire terminal connection method for electrically connecting the terminals of a plurality of electric wires, each of which has a conductor and an insulating coating covering the conductor, and the terminal of the conductor is exposed,
The electric wires are bundled so that the ends of the conductors are aligned with each other, and at the end of the electric wires, at least an end portion on the end side of the conductor is arranged by a metal that can be melt welded, and from the end portion An arrangement step for projecting the end of the conductor; and
By integrating the ends of the conductors and the end portions of the restraining members by the fusion welding, a common connection part for electrically connecting the conductors to each other is formed, and from the common connection part, the electric wires And a welding step of fixing the restraining sleeve at a position where the bundle of wires is restrained from the outside in a region up to the insulation coating. In the electric wire terminal connection method according to claim 6,
In the arranging step, a constraining sleeve made of the metal that can be melt welded is used as the constraining member, and the bundle of electric wires is inserted inside the constraining sleeve. In the electric wire terminal connection method according to claim 7,
An electric wire terminal connection method using a restraining sleeve made of copper or a copper alloy as the restraining member.

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