JP2011255414A - Joining structure of wiring material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining structure of a wiring material capable of acquiring a large welding area, while securing an initial resistance value necessary for welding.SOLUTION: In this joining structure of the wiring material 19, a joining surface 13b of a second joining conductor 15 is resistance-welded on a flat joining surface 13a of a first joining conductor 11 through a projection 17 formed on the joining surface 13b. In the projection 17, a first stage projection 23 forming a skirt 21 is set with a radius R1 for securing the welding area, and a second stage projection 27 forming a center summit 25 is set with a smaller radius than the first stage projection 23 and projected inside a virtual contour 29 of the first stage projection 23, and melt formed when the second stage projection 27 is brought into contact with the flat joining surface 13a of the first joining conductor 11 and melted is filled into a gap surrounded by the flat joining surface 13a, the first stage projection 23, and a residue of the second stage projection 27.

Description

  The present invention relates to a connecting structure for a wiring material in which a joint surface is resistance-welded via a convex portion.

  For example, in the electrical wiring of an automobile, it may be necessary to connect an FFC (Flexible Flat Cable), which is a wiring material, and a mating connector. In this case, as shown in FIG. 3, a flat conductor 501 is exposed in an opening formed by peeling an insulator (not shown) of the FFC 500, and the connector terminal 503 is connected to the exposed flat conductor 501 by resistance. Connect by welding. For connection by resistance welding, it is important to manage the initial resistance value of the workpiece to be welded at the start of energization. In particular, when welding a rectangular conductor (copper) having a small specific resistance and a connector terminal (copper), an indent 505 that is a convex portion is added to the connector terminal 503 (see, for example, FIG. 7 of Patent Document 1), and an initial resistance is obtained. It is necessary to increase the value (decrease the contact area) and improve the heat generation.

JP 2002-15792 A

  However, since the initial resistance value is determined by the radius (R) of the indent 505 formed in the connector terminal 503 as shown in FIG. 4, the initial resistance value necessary for welding is secured, and the welding area N is set as follows. It was difficult to enlarge. That is, if the initial resistance value was ensured, the welding area N was reduced, and if the welding area N was increased, the initial resistance value was reduced (heat generation was reduced).

  This invention is made | formed in view of the said condition, The objective is to provide the joining structure of the wiring material which can obtain a big welding area, after ensuring the initial stage resistance value required for welding.

The above object of the present invention is achieved by the following configuration.
(1) A connecting structure of a routing material that is resistance-welded to a flat joint surface of a first joint conductor via a convex portion formed on the joint surface of the second joint conductor, wherein the convex portion , The first step convex portion serving as the skirt is set to a radius that secures a welding area, the second step convex portion serving as the center apex is set to a radius smaller than the first step convex portion, and the virtual of the first step convex portion A melt that protrudes inward from the contour line, and the second-stage convex portion is in contact with the flat joint surface of the first joint conductor, melts into the flat joint surface, the first-stage convex portion, and the second A connecting structure for routing members, which is filled in a gap surrounded by the remainder of the stepped convex portion.

  According to the connecting structure of the routing member, the convex shape that is indented is formed in a state where the second-stage convex portion protrudes from the tip of the first-stage convex portion. The front end surface of the first-stage convex part where the second-stage convex part is formed is a flat surface with a flared skirt or a horizontal plane (a surface orthogonal to the joining center axis). Since the second-stage convex portion has a small radius, the contact area at the time of melting is small, the resistance value is high, and the heat generation is good. This makes it possible to secure an initial resistance value necessary for welding. The melt of the second stage convex part gradually melted from the tip flows into the periphery of the second stage convex part (that is, the tip surface of the first stage convex part), the flat joint surface of the first joint conductor, the first stage convex part The space surrounded by the tip surface of the part and the remaining part of the second-stage convex part is filled. Simultaneously with the completion of the filling, the first joining conductor and the second joining conductor are joined together with the sum (large welding area) of the tip end surface of the second-stage convex portion after melting and the contact surface through the melt. In addition, the energy that was originally required to melt the volume corresponding to the voids becomes unnecessary due to the inflow of the melt. At the same time, the deformation amount of the entire convex portion can be reduced.

(2) The wiring structure joining structure according to (1), wherein the first step convex portion and the second step convex portion are spherical surfaces whose centers are located on the joint central axis of the second step convex portion. A connecting structure of wiring members, characterized in that the wiring member is formed to have a part.

  According to the connecting structure of the routing material, the first-stage convex portion and the second-stage convex portion are concentric, and the melt is filled in an annular shape around the second-stage convex portion. As a result, the melt is restrained by surface tension or the like, and there is little flow deformation, and stable welding is possible.

  According to the joining structure of the routing material according to the present invention, it is possible to obtain a large welding area while securing an initial resistance value necessary for welding.

It is a principal part expanded sectional view of the junction structure of the wiring material which concerns on this invention. (A) is the principal part expanded sectional view before welding, (b) is the principal part expanded sectional view after welding. It is a perspective view of the junction structure of the conventional wiring material. It is AA sectional drawing of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an enlarged cross-sectional view of a main part of a connecting structure for wiring members according to the present invention.
The connecting structure of the routing material according to the present embodiment is suitably used for connecting, for example, a routing material (FFC) used as an electrical wiring of an automobile and a connector terminal of a mating connector.

  As for the 1st junction conductor 11 which is a flat rectangular conductor of FFC, the junction surface 13 (13a) becomes flat. On the other hand, the convex part 17 is formed in the joining surface 13 (13b) of the 2nd joining conductor 15 which is a connector terminal. In the bonding structure of the wiring member 19, resistance welding is performed on the flat bonding surface 13 a of the first bonding conductor 11 via the convex portion 17 formed on the bonding surface 13 b of the second bonding conductor 15.

  In resistance welding, current is passed through the first joining conductor 11 and the second joining conductor 15 that are base materials to generate Joule heat, and at the same time, the base materials are joined together. In welding between irons or between aluminums, a melt (nugget) is usually formed on the joint surface. The nugget is a maximum melted portion generated in the joint portion, and exhibits a meteorite-like shape around the joint center axis 37. The periphery of the nugget becomes a portion (corona bond) that has undergone metallurgical transformation and is pressed in a high temperature range. This corona bond is not melted. In the case of bonding between copper, bonding immediately before the start of melting is performed, and bonding is performed by so-called diffusion. In the present embodiment, the diffusion bonding is also performed by increasing the temperature to the molten state. The bonding in this specification may be a bonding in which any of these nuggets, diffusions, and corona bonds is combined. Diffusion bonding is solid-phase bonding, and is performed using various diffusion bonding apparatuses. The temperature range where the temperature of the bonding interface is below the melting point of the base material to be bonded and the diffusion of atoms is active due to energization or the like. It is done at.

  As for the convex part 17, the 1st step | paragraph convex part 23 used as the skirt 21 is set to radius R1 which ensures a welding area. Further, the convex portion 17 has a second-stage convex portion 27 which is the central apex 25 set to a radius R2 smaller than that of the first-stage convex portion 23 and protrudes inside the virtual contour line 29 of the first-stage convex portion 23. It becomes. The virtual contour line 29 is a contour line of the first stage convex part 23 when the second stage convex part 27 is not formed. Actually, the second-step convex portion 27 is formed, and the first-step convex portion 23 is not formed at that portion, so that it does not represent the actual contour.

  Inside the virtual contour line 29, a space 41 surrounded by the virtual contour line 29, the first-stage convex part 23, and the second-stage convex part 27 is formed. This space portion 41 becomes a notch space generated by forming the second-stage convex portion 27 on the first-stage convex portion 23.

  In the present embodiment, the first-stage convex part 23 and the second-stage convex part 27 are a part of the spherical surface 39 (39a, 39b) in which the centers P1, P2 are located on the joint center axis 37 of the second-stage convex part 27. It is formed. These first-stage convex part 23 and second-stage convex part 27 can be provided by press molding on the second bonding conductor 15. For example, a die (not shown) having a shape similar to that of the convex portion 17 is arranged on the protruding surface 15a side of the convex portion 17, and is pressed with a punch (not shown) from the surface 15b opposite to the protruding surface of the convex portion 17. Thus, the protrusion 17 can be extruded and formed.

Next, the effect | action of the joining structure of an above-described wiring material is demonstrated.
FIG. 2A is an enlarged cross-sectional view of a main part before welding, and FIG. 2B is an enlarged cross-sectional view of the main part after welding.
In the connecting structure of the routing members, the convex portion 17 is formed in a state where the second-stage convex portion 27 protrudes from the tip of the first-stage convex portion 23. The front end surface 23a of the first-stage convex part 23 where the second-stage convex part 27 is formed is a flat surface that spreads slowly at the bottom or a horizontal surface (a surface that is orthogonal to the joint center axis 37).

  Since the second-stage convex part 27 has a smaller radius than the first-stage convex part 23, as shown in FIG. 2A, the contact area at the time of melting is smaller than that of the first-stage convex part 23, and the resistance value is the first-stage convex part. Higher than 23, the exothermic property is good. This makes it possible to secure an initial resistance value necessary for welding. An electrode (not shown) is connected to each of the first bonding conductor 11 and the second bonding conductor 15. That is, the direct welding is performed in which the electrodes are arranged to face each other with the material to be joined.

  The first bonding conductor 11 and the second bonding conductor 15 cause a large current to flow between the electrodes for a short time while pressure is applied, and the convex portion 17 of the second bonding conductor 15 is formed on the bonding surface 13 a of the first bonding conductor 11. Press contact. Thereby, as for the convex part 17, the front-end | tip of the 2nd step | paragraph convex part 27 fuse | melts. As shown in FIG. 2B, the melt 31 in which the second-stage convex portion 27 is in contact with the flat joint surface 13 a of the first joint conductor 11 is melted into the flat joint surface 13 a, the first-stage convex portion 23, And the space | gap 35 enclosed by the remainder 33 of the 2nd step convex part 27 is filled.

  In the present embodiment, since the outer periphery of the first-stage convex part 23 and the second-stage convex part 27 is spherical, the melt 31 of the second-stage convex part 27 gradually melted from the tip is the second-stage convex part 27. (Ie, the front end surface 23a of the first-stage convex portion 23). The molten material 31 that has flowed in is filled into the gap 35 surrounded by the flat joint surface 13 a of the first joint conductor 11, the tip surface 23 a of the first-stage convex portion 23, and the remaining portion 33 of the second-stage convex portion 27.

  The melt 31 is filled with the first-stage convex part 23 and the second-stage convex part 27 concentrically, and in a ring shape around the second-stage convex part 27. Thereby, the melt 31 is restrained by the surface tension or the like, and there is little flow deformation and stable welding is possible. In addition, this space | gap 35 becomes small because the space part 41 shown in FIG.

  Simultaneously with the completion of the filling, the first joining conductor 11 and the second joining conductor 15 are joined by the sum (large welding area L) of the second-stage convex portion tip surface 27a after melting and the contact surface through the melt 31. Is done. In addition, the energy that was originally required to melt the volume corresponding to the gap 35 becomes unnecessary due to the inflow of the melt 31. At the same time, the amount of deformation of the entire convex portion 17 can be reduced, and welding with a low applied pressure is possible.

  Therefore, according to the wiring material joining structure according to the present embodiment, it is possible to obtain a large welding area L while securing an initial resistance value necessary for welding.

11 1st junction conductor 13a, 13b Joint surface 15 2nd junction conductor 17 Convex part 19 Arrangement material 21 Bottom 23 First step convex part 25 Top 27 Second stage convex part 29 Virtual outline 31 Melt 33 Remaining part 35 Air gap 37 Joining Central axis 39a, 39b Spherical surface

Claims (2)

It is a connecting structure of a routing material that is resistance-welded to the flat joint surface of the first joint conductor via a convex portion formed on the joint surface of the second joint conductor,
The convex portion is set to have a radius at which the first step convex portion serving as a skirt secures a welding area, the second step convex portion serving as a central apex is set to a radius smaller than the first step convex portion, and the first step convex portion. It protrudes inside the virtual contour line of the convex part,
The melt obtained by melting the second-stage convex portion in contact with the flat joint surface of the first joint conductor is surrounded by the flat joint surface, the first-stage convex portion, and the remainder of the second-stage convex portion. A wiring material joining structure characterized by being filled in a gap. It is a junction structure of wiring materials according to claim 1,
The routing material, wherein the first-stage convex part and the second-stage convex part have a part of a spherical surface whose center is located on the joint central axis of the second-stage convex part. Bonding structure.

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