JP5196562B2 - Connection method of aluminum wire and copper wire and connection body thereof - Google Patents

Description

  The present invention relates to a method for connecting an aluminum electric wire and a copper electric wire for ultrasonic welding of a coated copper electric wire and a coated aluminum electric wire having a lower tensile strength than the coated copper electric wire, and a connection body thereof.

  In general automobiles, in particular, electric vehicles and fuel cell vehicles that have been in widespread use in recent years, the on-board batteries and fuel cells themselves are heavy, and therefore it is desired to reduce the weight of the vehicle as much as possible. As part of such weight reduction, a coated aluminum electric wire using aluminum, which has a density of about one third (2.70 / 8.96) as compared with copper, as an aluminum element wire has been attracting attention.

  Since a coated copper electric wire using a copper element wire as a wire conductor is generally used for a vehicle-mounted electrical component, connection with the coated copper electric wire is required when a coated aluminum electric wire is used. For connecting the coated copper wire and the coated aluminum wire, for example, as shown in Patent Document 1, an electric wire conductor made of a copper wire is inserted from one end of a cylindrical connection sleeve made of copper, and an aluminum wire is made from the other end. A wire conductor made of is inserted and crimped at the conductor insertion portions at both ends. Since the wire conductor of the coated aluminum electric wire is soft, it cannot be connected sufficiently only by crimping. Therefore, the crimping of the coated aluminum wire to the connection sleeve is made semi-crimped, and the connecting portion is soldered with aluminum.

However, with such a connection configuration, the connection portion becomes thicker due to the use of the connection sleeve, and the work of aluminum solder is required in addition to crimping and semi-crimping, resulting in a large number of connection man-hours. is there. Then, the connection method which directly ultrasonically welds the wire conductors of a covering aluminum electric wire and a covering copper electric wire is tried. As shown in FIG. 6, this aluminum electric wire and copper electric wire are connected by pressing a welding horn 501 of an ultrasonic welding machine from one side of the stacked electric wire conductors 503 and 505, and applying vibration by the welding horn 501. As a result, atomic diffusion is induced and bonding is performed by atomic bonding of mutual metals. In the figure, reference numeral 507 denotes a covering, and 509 denotes an electric wire fixing jig.
JP 2000-208245 A

However, when the aluminum wire and the copper wire are ultrasonically welded, for example, when the wire conductor 505 of the coated aluminum wire 511 is arranged on the welding horn 501 side, the wire conductor 505 of the coated aluminum wire 511 is shown in FIG. The aluminum strand 505a has a problem of causing damage such as thinning 513 or cut 515 due to metal fatigue or “scraping” due to stress concentration. On the other hand, if the ultrasonic force is reduced, a sufficient fixing force cannot be obtained on the wire conductor 503 of the coated copper wire. Moreover, the tensile strength was low and the soft aluminum strand 505a was arrange | positioned on the outer side, and it became the connection part which is easy to be damaged.
The present invention has been made in view of the above circumstances, and its purpose is to reduce the damage such as thinning and cutting of the aluminum conductor without reducing the ultrasonic force, and to achieve high adhesion between the aluminum wire and the copper wire. It is providing the connection method of the aluminum electric wire and copper wire which can be connected by, and its connection body.

The above object of the present invention is achieved by the following configuration.
(1) A method of connecting an aluminum electric wire and a copper electric wire for connecting a coated aluminum electric wire coated with an aluminum conductor and a coated copper electric wire coated with a plurality of copper conductors,
After inserting the aluminum conductor of the coated aluminum wire between the copper conductors of the coated copper wire,
A method of connecting an aluminum wire and a copper wire, wherein the copper conductor and the aluminum conductor are ultrasonically welded with a welding horn of an ultrasonic welding machine with the copper conductor interposed.

  According to this connection method of the aluminum electric wire and the copper electric wire, the aluminum conductor does not directly touch the welding horn, the copper conductor having high tensile strength that comes into contact with the welding horn mainly vibrates, and the joining surface with the aluminum conductor is ultrasonic. Welded.

(2) (1) A method for connecting an aluminum wire and a copper wire,
A method of connecting an aluminum wire and a copper wire, wherein the aluminum conductor of the coated aluminum wire is surrounded and inserted into a plurality of copper conductors of the coated copper wire.

  According to this method for connecting an aluminum wire and a copper wire, the entire circumference of the outer periphery of the connection portion of the aluminum conductor of the coated aluminum wire is covered with the copper conductor of the coated copper wire and is not exposed to the outside. In addition, ultrasonic welding can be performed in any direction in the circumferential direction of the copper conductor of the coated copper wire.

(3) (1) A method for connecting an aluminum wire and a copper wire,
A plurality of copper conductors of the coated copper wire is divided into two with the axis line in between,
A method of connecting an aluminum wire and a copper wire, wherein the aluminum conductor of the coated aluminum wire is inserted between the two divided copper conductors.

  According to this connection method of the aluminum electric wire and the copper electric wire, the copper conductor of the coated copper electric wire can be divided into two by the diametrical separation surface passing through the axis, so that the formation of the insertion space of the copper conductor for inserting the aluminum conductor can be achieved. Easy to do.

(4) A connection body of an aluminum wire and a copper wire in which a coated aluminum wire coated with an aluminum conductor and a coated copper wire coated with a plurality of copper conductors are connected,
The connection between the aluminum wire and the copper wire, wherein the aluminum conductor of the coated aluminum wire inserted between a plurality of copper conductors of the coated copper wire is ultrasonically welded via the copper conductor disposed on the outside body.

  According to the connection body of the aluminum electric wire and the copper electric wire, the aluminum conductor of the covered aluminum electric wire is inserted into the copper conductor of the covered copper electric wire, and the aluminum conductor is disposed on the inner side, and is covered with the copper conductor having high tensile strength.

  According to the method for connecting an aluminum wire and a copper wire according to the present invention, after inserting the aluminum conductor of the coated aluminum wire between the copper conductors of the coated copper wire, the copper conductor is interposed and the welding horn of the ultrasonic welding machine is used. Since copper conductor and aluminum conductor are ultrasonically welded, the aluminum conductor does not directly touch the welding horn, but the copper conductor with high tensile strength that comes in contact with the welding horn is mainly vibrated, and the joint surface with the aluminum conductor is ultrasonically welded. it can. As a result, it is possible to connect the aluminum electric wire and the copper electric wire with a high adhering force by reducing damage such as thinning or cutting of the aluminum conductor without reducing the ultrasonic force.

  According to the connection body of the aluminum electric wire and the copper electric wire according to the present invention, the aluminum conductor of the covered aluminum electric wire inserted between the copper conductors of the covered copper electric wire is ultrasonically welded via the copper conductor arranged on the outside. The aluminum conductor is covered with a copper conductor having a high tensile strength, so that a connection portion that is not easily damaged can be obtained.

Hereinafter, preferred embodiments of a method for connecting an aluminum electric wire and a copper electric wire according to the present invention and a connection body thereof will be described with reference to the drawings.
FIG. 1 is a perspective view of a connection body of an aluminum wire and a copper wire according to the present invention, FIG. 2 is a perspective view of a modification example of the connection body of the aluminum wire and the copper wire, and FIG. It is a side view which concerns on the modification connected by being pinched | interposed.
The connection body 100 of the aluminum electric wire and the copper electric wire according to the present embodiment has a copper element wire 3a in which the aluminum conductor 7 of the covered aluminum electric wire 5 inserted between the plurality of copper conductors 3 of the covered copper electric wire 1 is arranged on the outside. The connecting portion 9 is formed by ultrasonic welding. The aluminum conductor 7 of the covered aluminum electric wire 5 is inserted into the plurality of copper conductors 3 of the covered copper electric wire 1, and the aluminum element wire 7a is disposed on the inner side, and is covered with the copper element wire 3a having high tensile strength.

  The connecting body 100 is preferably inserted into the copper conductor 3 of the coated copper wire 1 so that the aluminum conductor 7 of the coated aluminum wire 5 is surrounded. The aluminum conductor 7 of the covered aluminum wire 5 can be inserted into an insertion space 11 formed by inserting a pointed tool (not shown) or the like into the copper conductor 3 from the direction of the axis G, for example. The coated copper wire 1 in which the aluminum conductor 7 is inserted is welded by an ultrasonic welding machine described later.

  In such a connection body 100 in which the cylindrical conductors 3 and 7 are coaxially inserted and ultrasonically welded, the entire outer periphery of the connection portion 9 of the aluminum conductor 7 of the coated aluminum wire 5 is the copper of the coated copper wire 1. It is covered with the conductor 3 and is not exposed to the outside. Moreover, ultrasonic welding in the arbitrary directions of the circumferential direction in the copper conductor 3 of the covering copper electric wire 1 is attained. That is, intermittent welding while rotating the coated copper electric wire 1 and the coated aluminum electric wire 5 around the axis G becomes possible.

  As a modification of the connection body 100, as shown in FIG. 2, the plurality of copper conductors 3 of the coated copper wire 1 are divided into two parts with the axis G interposed therebetween, and the copper conductors 13 and 15 divided into two parts are covered. It is good also as the connection part 9A which inserts the aluminum conductor 7 of the aluminum electric wire 5. FIG. In the connecting portion 9A in which the aluminum conductor 7 of the coated aluminum wire 5 is sandwiched between the divided copper conductors 13 and 15, the copper conductor 3 of the coated copper wire 1 formed by bundling a plurality of copper strands 3a is separated in the diameter direction passing through the axis G. Since the surface 19 can be divided into two, the insertion space 21 for the copper conductor 3 for inserting the aluminum strand 7a can be easily formed.

  Furthermore, as a modified example of the connection body 100, as shown in FIG. 3, the copper conductors 3 and 3 of a pair of covered copper wires 1 and 1 are stacked on the straight line from opposite directions, and between these copper conductors 3 and 3, A connecting portion 9B that sandwiches the aluminum conductor 7 of the coated aluminum wire 5 inserted from either direction and ultrasonically welds the three conductors 3, 7, and 3 through the one copper conductor 3 may be used. In the figure, 31 indicates a welding horn, and 33 indicates an electric wire fixing jig.

  According to this connecting portion 9B, the aluminum conductor 7 of the coated aluminum wire 5 is sandwiched between the copper conductors 3 and 3 of the pair of coated copper wires 1 and 1, and hardly exposed to the outside. Moreover, the aluminum conductor 7 of the covering aluminum electric wire 5 can be easily covered without forming the insertion space 21 of the copper conductor 3 by using a special tool in the operation of sandwiching the pair of copper conductors 3 and 3.

Next, a method for connecting an aluminum wire and a copper wire will be described.
FIG. 4 is a front view from the conductor axis showing the welding situation by the welding horn of the ultrasonic welding machine, and FIG. 5 is an enlarged view of the copper strand and the aluminum strand at the end of the welding horn of the connection method according to the present invention. .
In order to connect the copper conductor 3 of the coated copper wire 1 and the aluminum conductor 7 of the coated aluminum wire 5 to form the connecting portion 9, first, the coated aluminum wire 5 is placed between the copper conductors 3 of the coated copper wire 1. The aluminum conductor 7 is inserted. As described above, the insertion space 11 of the copper conductor 3 can be formed by inserting a pointed tool (not shown) or the like from the direction of the axis G.

  The copper conductor 3 of the covered copper wire 1 with the aluminum conductor 7 inserted inward is placed on an anvil 35 formed in a concave shape, for example. The covered copper electric wire 1 and the covered aluminum electric wire 5 are fixed at the respective covered portions by an electric wire fixing jig 33 (see FIG. 3). Next, the welding horn 31 of the ultrasonic welding machine 37 is lowered and approached to the lower anvil 35, and the copper strand 3a and the aluminum strand are pressed while pressing the welding horn 31 with a predetermined pressing force with the copper strand 3a interposed. 7a is ultrasonically welded.

  In ultrasonic welding, vibration is applied while pressure is applied to the joint surface by the welding horn 31. In the present embodiment, the vibration is in the direction along the axis G of the conductors 3 and 7 (in the direction perpendicular to the plane of FIG. 4). A pressing force from the vertical direction (upward direction in FIG. 4) and vibration in a direction parallel to the bonding surface (perpendicular direction in FIG. 4) act on the metal bonding surface. Due to these pressing force and vibration shear force, a large internal stress is generated in the structure near the joint surface. The stress due to this oscillating shear force is reversed at a cycle of tens of thousands of times per second.

  If the stress exceeds the elastic limit of the metal, microscopic destruction (film destruction) occurs on the joint surface, atomic diffusion occurs, and recrystallization of a thin granular structure occurs on the joint surface. Thereby, the conductors 3 and 7 are welded. In the connection body 100 in which the cylindrical conductors 3 and 7 are coaxially inserted and ultrasonically welded, as described above, the coated copper electric wire 1 and the coated aluminum electric wire 5 are rotated in the circumferential direction while rotating around the axis G. Ultrasonic welding at an arbitrary position becomes possible. In this way, the aluminum strand 7a does not directly touch the welding horn 31, the high tensile strength copper strand 3a that contacts the welding horn 31 mainly vibrates, and the joint surface with the aluminum strand 7a is ultrasonic. Welded.

  In the case of the aluminum strand 7a, since it is softer and has a lower tensile strength than the copper strand 3a, problems such as breakage of the aluminum strand 7a occur when excessive pressing is performed. In the connection method of the aluminum electric wire and the copper electric wire according to the present embodiment, as shown in FIG. 5, the aluminum strand 7a is pressed by the welding horn 31 via the copper strand 3a, so that the copper strand 3a Even if the necessary pressing force is applied, the pressing force is partially absorbed by the deformation of the copper element wire 3a to protect the aluminum element wire 7a. That is, the copper wire 3a exhibits a function as a cushion. Thereby, generation | occurrence | production of the thinning 513, the piece 515, etc. which were shown in FIG. 7 is prevented.

  Therefore, according to the connection method of the aluminum electric wire and the copper electric wire according to the present embodiment, after inserting the aluminum conductor 7 of the coated aluminum electric wire 5 between the copper conductors 3 of the coated copper electric wire 1, the copper strand 3a is interposed. Since the copper strand 3a and the aluminum strand 7a are ultrasonically welded by the welding horn 31 of the ultrasonic welder 37, the aluminum strand 7a does not directly touch the welding horn 31, but has a high tensile strength in contact with the welding horn 31. It is possible to ultrasonically weld the joint surface with the aluminum strand 7a by mainly vibrating the copper strand 3a. As a result, it is possible to connect the aluminum electric wire and the copper electric wire with a high adhering force by reducing damage such as thinning or cutting of the aluminum wire 7a without reducing the ultrasonic force.

  In addition, according to the above-described connection body 100, 100A, 100B of the aluminum electric wire and the copper electric wire, the aluminum conductor 7 of the coated aluminum electric wire 5 inserted between the copper conductors 3 of the coated copper electric wire 1 is disposed outside. Since the ultrasonic welding is performed through the strand 3a, the aluminum strand 7a is covered with the copper strand 3a having a high tensile strength, and the connecting portions 9, 9A, 9B that are not easily damaged can be obtained.

  In the above-described embodiment, the coated copper electric wire 1 and the coated aluminum electric wire 5 are both stranded wires in which the copper conductor 3 and the aluminum conductor 7 are twisted from a plurality of strands. However, the present invention is not limited to this, and a plurality of copper conductors or a single aluminum conductor may be used.

It is a perspective view of the connection body of the aluminum electric wire and copper electric wire which concern on this invention. It is a perspective view which concerns on the modification of the connection body of an aluminum electric wire and a copper electric wire. It is a side view which concerns on the modification which an aluminum electric wire is pinched | interposed and connected to two copper electric wires. It is a front view from the conductor axis showing the welding situation by the welding horn of an ultrasonic welding machine. It is an enlarged view of the copper strand and the aluminum strand in the welding horn end part of the connection method concerning the present invention. It is explanatory drawing which shows the connection method of the conventional aluminum electric wire and copper electric wire. It is an enlarged view of the aluminum strand in the welding horn end part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coated copper electric wire 3 Copper conductor 7 Aluminum conductor 3a Copper element wire 5 Coated aluminum electric wire 7a Aluminum element wire 31 Welding horn of ultrasonic welding machine 100 Connection body of aluminum electric wire and copper electric wire G Wire conductor axis

Claims (4)

A method of connecting an aluminum electric wire and a copper electric wire for connecting a coated aluminum electric wire coated with an aluminum conductor and a coated copper electric wire coated with a plurality of copper conductors,
After inserting the aluminum conductor of the coated aluminum wire between the copper conductors of the coated copper wire,
A method of connecting an aluminum wire and a copper wire, wherein the copper conductor and the aluminum conductor are ultrasonically welded with a welding horn of an ultrasonic welding machine with the copper conductor interposed. A method for connecting an aluminum electric wire and a copper electric wire according to claim 1,
A method of connecting an aluminum wire and a copper wire, wherein the aluminum conductor of the coated aluminum wire is surrounded and inserted into a plurality of copper conductors of the coated copper wire. A method for connecting an aluminum electric wire and a copper electric wire according to claim 1,
A plurality of copper conductors of the coated copper wire is divided into two with the axis line in between,
A method of connecting an aluminum wire and a copper wire, wherein the aluminum conductor of the coated aluminum wire is inserted between the two divided copper conductors. A connection body of an aluminum wire and a copper wire in which a coated aluminum wire coated with an aluminum conductor and a coated copper wire coated with a plurality of copper conductors are connected,
The connection between the aluminum wire and the copper wire, wherein the aluminum conductor of the coated aluminum wire inserted between a plurality of copper conductors of the coated copper wire is ultrasonically welded via the copper conductor disposed on the outside body.

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