JP2007250393A - Terminal crimping method of aluminum wire, and aluminum wire with terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a terminal crimping method of an aluminum wire capable of keeping conductivity, and of sufficiently ensuring mechanical (strong) connection. <P>SOLUTION: The cross-sectional shape of a conductor end 7 exposed by peeling an insulating material 3 at one end of an aluminum wire 1 and formed of multiple strands 2 made of aluminum or an aluminum alloy is preliminarily formed to set it nearly equal to the cross-sectional surface shape of a terminal 4 after crimping and plastic deformation thereof. Next, an extensible metallic material 11 is attached to the conductor end 7 after the preliminary formation. The terminal 4 is crimped and held to the conductor end 7 by plastically deforming it. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a terminal crimping method for an aluminum electric wire and an aluminum electric wire with a terminal.

Conventionally, conductors (copper) made of copper or copper alloy were mainly used for automotive wire harnesses, but in recent years, conductors have been changed from copper or other materials to aluminum or aluminum alloys to reduce the weight of the vehicle body. The proportion of using aluminum wires is increasing.
Aluminum wires and in-vehicle electrical equipment are connected via connection terminals. As a conventional connection method between aluminum wires and connection terminals, the insulation of one end of the aluminum wires is peeled off and exposed to the end of the wire. There is a method of crimping and holding the terminals by crimping (see, for example, Patent Document 1 and Patent Document 2).
JP 2005-327690 A JP 2005-174896 A

  However, conventional conductors made of copper or the like could be sufficiently conducted (conducted) just by caulking the terminals (coking). However, in the conductor made of aluminum or aluminum alloy, an oxide film is formed on the surface. Since it is formed, there is a drawback that it is difficult to conduct (it is difficult to ensure electrical connection) due to an increase in contact resistance between the conductor and the terminal.

  Then, an object of this invention is to provide the terminal crimping method of the aluminum electric wire which can maintain electrical conductivity and can ensure sufficient mechanical (strength) connection.

  In order to achieve the above object, a terminal crimping method for an aluminum electric wire according to the present invention is a conductive wire comprising a plurality of strands made of aluminum or aluminum alloy in which an insulator at one end of an aluminum electric wire is peeled and exposed. Preliminarily mold the cross-sectional shape of the end portion so that it is substantially the same as the cross-sectional shape after crimping plastic deformation of the terminal, and attach a metal material rich in extensibility to the end portion of the conductive wire after pre-molding, The terminal is plastically deformed and held at the end.

At the same time as or after the preforming of the conductor end, the strands of the conductor end are welded together to form a smooth surface portion on the outer peripheral surface of the conductor end, and extend to the smooth surface of the conductor end. A metal material rich in properties may be attached, and the terminal may be plastically deformed and held by crimping at the end of the conductor.
Moreover, the aluminum electric wire with a terminal which concerns on this invention is produced by the said crimping | compression-bonding method.

The present invention has the following remarkable effects.
According to the terminal crimping method of the aluminum electric wire according to the present invention, the conductive wire end portion and the terminal can be mechanically and firmly connected via the metal material, and the metal material prevents the formation of the oxide film of the element wire. It can be connected with sufficient electrical conductivity (preventing increasing the contact resistance). In particular, even an aluminum electric wire made of a thin aluminum or aluminum alloy conductor having a large surface area can be connected well, so that an aluminum electric wire with a terminal that can be bent more easily than an aluminum electric wire having the same cross-sectional area can be obtained.
Specifically, it is suitable for an automobile battery cable using an aluminum electric wire with a terminal having a large cross-sectional area (38 mm ^{2 to} 60 mm ² ).
In addition, it is possible to easily arrange an aluminum electric wire as a battery cable for a motorcycle or a light vehicle body in which the arrangement space is limited.
In addition, it is also suitable as an aluminum electric wire between the battery and inverter of a hybrid vehicle or an electric vehicle, and an aluminum electric wire between the inverter and the motor, which makes it possible to reduce the weight of the entire vehicle body and greatly improve fuel efficiency.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
In FIG. 1 (a), 1 is an aluminum electric wire used for a wire harness for automobiles, and the aluminum electric wire 1 is a conductive wire (twisted wire) formed by twisting a large number of strands 2 made of aluminum or aluminum alloy. ) 70 is coated with an insulator 3.

  First, a method for crimping the aluminum electric wire 1 to the terminal 4 shown in FIG. Note that the terminal 4 shown in FIG. 18 (a) will be described. This terminal 4 is obtained by punching a metal plate into a predetermined shape and pressing it, and is connected to a terminal or the like of an electric device outside the figure. A connecting portion 12 and a wire connecting portion 13 formed by integrally connecting a pair of crimping pieces 14 and 14 with a connecting portion 15 are provided.

As shown to Fig.1 (a), the insulator 3 of the one end part of the aluminum electric wire 1 is peeled first, and the conducting wire end part 7 is exposed. FIG. 1B is a cross-sectional explanatory view of the exposed conductor end portion 7.
Next, as shown in FIGS. 2 (a) and 2 (b), the cross-sectional shape of the conductive wire end portion 7 is substantially the same as the cross-sectional shape after crimping plastic deformation of the terminal 4 (see FIG. 5 (b)). Pre-mold as follows. Specifically, as shown in FIG. 2B, the cross-sectional shape of the conductive wire end portion 7 is formed in a substantially concave shape.

In FIG. 3 (a), reference numeral 8 denotes a container containing a metal material 11 rich in spreadability. The metal material 11 is, for example, aluminum solder and is put in the container 8 in a molten state. Then, the preliminarily formed conductor end 7 is immersed in the molten metal material 11 and pulled out to adhere the metal material 11 to the conductor end 7. Thereafter, the adhered molten metal material 11 is solidified.
As shown in FIG. 3B, the solidified metal material 11 adheres so as to cover (at least) the outer periphery of the conductor end 7. And in the state which the molten metal material 11 solidified, the cross-sectional shape of the outer peripheral surface of the metal material 11 is substantially concave shape.

  As shown in FIGS. 4 (a) and 4 (b), the preformed portion of the conductor end portion 7 is disposed between the crimping pieces 14, 14 of the terminal 4. More specifically, as shown in FIG. 4 (b), the conductor end portion 7 to which the metal material 11 is attached is brought into contact with the connecting portion 15 of the terminal 4, and the substantially concave portion of the conductor end portion 7 is formed. It arrange | positions so that the front end side of the crimping pieces 14 and 14 may face.

Then, as shown in FIGS. 5A and 5B, the terminal 4 is plastically deformed and held by crimping on the conductive wire end 7 to which the metal material 11 is attached.
Specifically, the terminal 4 is plastically deformed (by a press machine or the like) along the outer peripheral surface of the metal material 11 covering the outer surface of the conductor end portion 7. That is, the crimping pieces 14, 14 of the terminal 4 are bent toward each other, and the tips thereof enter into the recesses on the outer peripheral surface of the metal material 11. Further, the terminal 4 (crimp pieces 14, 14 / connecting portion 15) and the outer peripheral surface of the metal material 11 are in close contact with each other, and the substantially concave cross-sectional shape of the conductor end 7 after the terminal 4 is crimped is 4 is substantially the same as the state before pressure bonding (see FIG. 4B).
After the terminal 4 is crimped, the terminal 4 is electrically connected to the inner surface of the terminal 4 through the conductive coating layer 6 attached to the outer surface of the conductor end 7.

  FIG. 6 to FIG. 9 show another embodiment of the terminal crimping method of the aluminum electric wire according to the present invention, that is, the aluminum electric wire 1 shown in FIG. 1 (a) is shown in FIG. 18 (b). This is a method of crimping to the terminal 4. The terminal 4 shown in FIG. 18 (b) will be described. The terminal 4 is connected to a terminal or the like of an electric device not shown in the figure, and the electric wire connecting portion 17 is formed of a cylindrical portion 18.

First, the insulator 3 at one end of the aluminum electric wire 1 is peeled off to expose the conductor end 7 (see FIG. 1A).
Then, as shown in FIG. 6, the cross-sectional shape of the conductive wire end portion 7 is preformed so as to be substantially the same as the cross-sectional shape after crimping plastic deformation of the terminal 4 (see FIG. 9). Specifically, the cross-sectional shape of the conducting wire end portion 7 is formed in a substantially horizontal crescent shape (having a small ridge portion at the center of the concave surface).

  As shown in FIG. 8, a molten metal material 11 is attached to the preliminarily formed conductor end 7 as shown in FIG. The metal material 11 is attached and solidified so as to cover the (at least) outer periphery of the conductor end 7. In a state where the molten metal material 11 is solidified, the cross-sectional shape of the outer peripheral surface of the metal material 11 is a substantially crescent crescent shape (having a small ridge at the center of the concave surface). In this way, the conductive coating layer 6 is formed on the outer peripheral surface.

Then, as shown in FIG. 8, the conducting wire end 7 preliminarily molded and attached with the metal material 11 is inserted into the cylindrical portion 18 of the terminal 4, and then the terminal 4 is connected to the conducting wire end 7 as shown in FIG. Is plastically deformed and pressed and held through the conductive coating layer 6.
Specifically, the cylindrical portion 18 is plastically deformed along the outer peripheral surface of the metal material 11 (after solidification) attached to the conductive wire end portion 7. That is, the inner peripheral surface of the cylindrical portion 18 is in close contact with the conductive coating layer 6 of the metal material 11 and is formed in a substantially crescent crescent shape. And the cross-sectional shape of the substantially horizontal crescent shape of the conducting wire end 7 after the terminal 4 is crimped is substantially the same as the state before the terminal 4 is crimped (see FIG. 8).

  10 to 17 show still another embodiment of the present invention. Here, an aluminum electric wire 1 having a large number of thin wires 2 is used. That is, the diameter size of the strand 2 of the aluminum wire 1 shown in FIG. 1B is set to about 0.8 to 1.2 mm, whereas the diameter size of the strand 2 of the aluminum wire 1 shown in FIG. For example, it is a thin one set to 0.32 mm. Moreover, the conducting wire 70 of the aluminum electric wire 1 shown in FIG. 10 exemplifies a rope stranded wire by twisting a plurality of bundles (19 bundles) of strands 9 obtained by twisting a plurality of (19) strands 2. In addition, what is shown in FIG. 10 is the cross-sectional explanatory drawing of the conducting wire end part 7 which peeled and exposed the insulator 3 of the one end part of the aluminum electric wire 1. FIG.

  The terminal 4 to be crimped uses the one shown in FIG. The terminal 4 in FIG. 18 (c) includes a terminal connection portion 19 connected to a terminal or the like of an electric device not shown, and an electric wire connection portion 20 including a bottomed cylindrical portion 21.

First, the insulator 3 of the aluminum electric wire 1 is peeled to expose the conductor end 7 (see FIG. 10).
Next, as shown in FIG. 11, the cross-sectional shape of the conductive wire end portion 7 is preformed into a lemon shape so as to be substantially the same as the cross-sectional shape after crimping plastic deformation of the terminal 4 (see FIG. 14), Simultaneously with the preliminary molding, the strands 2 of the conductor end 7 are welded together to form the smooth surface portion 5 on the outer peripheral surface of the conductor end 7.

  The preforming and the welding are simultaneously performed using an ultrasonic welding apparatus including a pair of horns 22 and 23 shown by a two-dot chain line in FIG. 11, and the conductor end portion 7 is sandwiched between the pair of horns 22 and 23. Apply pressure, apply ultrasonic vibration to the conductor end 7 while applying pressure (preliminary molding), and perform welding.

  15 and 16, which are enlarged cross-sectional views of the end portion 7 of the conducting wire, will be described in more detail. As shown in FIG. 15, the strands 2 before preforming / welding are bundled and are in contact with each other or close to each other. The strand 2 has a circular cross section. The strands 2 (at least along the outer peripheral surface) after preforming and welding shown in FIG. 16 are welded to each other. In particular, the strands 2 a on the outer peripheral surface side of the conducting wire end portion 7 are crushed by the horns 22 and 23 and welded together to form the smooth surface portion 5 on the outer circumferential surface of the conducting wire end portion 7. That is, in FIG. 15, since each strand 2 is circular, the outer periphery of the strand bundle 9 in which the strands 2 are bundled has a fine concavo-convex surface in which arcs are continuously arranged. In FIG. On the outer peripheral surface of the end portion 7, a smooth surface portion 5 is formed by smoothing the uneven surface of the strand 9 shown in FIG.

  Then, the conducting wire end 7 that has been preformed and welded is immersed in a molten metal material (aluminum solder) 11 (see FIG. 3 (a)), and as shown in FIG. A metal material 11 is adhered (applied) to the surface portion (outer peripheral surface) 5 to form the conductive coating layer 6. Thereafter, the outer peripheral surface of the metal material 11 is formed in a lemon shape with the metal material 11 solidified. Further, as shown in FIG. 17 which is a partially enlarged view of FIG. 12, the metal material 11 is securely attached to the smooth surface portion 5 of the conductor end portion 7.

As shown in FIG. 13, the conducting wire end 7 to which the metal material 11 is adhered is inserted into the bottomed cylindrical portion 21 of the terminal 4, and then the terminal 4 is plastically deformed to the conducting wire end 7 as shown in FIG. And press-fit.
Specifically, the bottomed cylindrical portion 21 is plastically deformed along the outer peripheral surface of the conductive coating layer 6 of the metal material 11 (after solidification) attached to the conducting wire end portion 7. That is, when the bottomed cylindrical portion 21 is subjected to plastic deformation with a reduced diameter by pinching 180 ° symmetrical positions on the outer peripheral surface of the bottomed cylindrical portion 21, the inner peripheral surface of the bottomed cylindrical portion 21 is the outer peripheral surface of the metal material 11. To form a lemon shape. And the lemon-shaped cross-sectional shape of the conducting wire end part 7 after the terminal 4 is crimped is substantially the same as the state before the terminal 4 is crimped (see FIG. 13).
In this way, the conductive coating layer 6 made of the metal material 11 is interposed between the smooth surface portion 5 of the conductive wire end 7 after crimping the terminal 4 and the inner peripheral surface of the terminal 4.

  Further, the preforming and welding may not be performed at the same time, but only the preforming may be performed first, and then welding may be performed. Further, the welding is not limited to ultrasonic welding, and may be performed by a resistance welding apparatus including a pair of electrodes.

  Moreover, the terminal crimping method of the aluminum electric wire of the present invention can be freely changed in design, and the pre-shaped cross-sectional shape of the conductor end 7 is not limited to the above-described embodiment, but can be freely selected according to the shape of the terminal 4 to be connected. It is possible to change to Moreover, the conducting wire 70 of the aluminum electric wire 1 may be a stranded wire, a rope twisted wire, or a bundled wire.

19 and 20 show a comparative example with the present invention. First, the comparative example shown in FIG. 19 will be described.
The aluminum electric wire 1 used here is an aluminum electric wire 1 having an element wire 2 having the same large diameter as shown in FIG. As the terminal 4 connected to the aluminum electric wire 1, one having a bottomed cylindrical portion 21 shown in FIG.

  As shown in FIG. 19A, the insulator 3 at one end of the aluminum electric wire 1 is peeled off to expose the conductor end 7. Then, without conducting the preforming of the conductive wire end portion 7, the molten metal material 11 is attached without changing the conductive wire end portion 7 as it is, that is, while the cross sectional shape of the entire conductive wire end portion 7 is substantially circular. As shown in FIG. 19 (b), the shape of the conductive coating layer 6 of the deposited metal material 11 is circular.

After the metal material 11 adhering to the conductive wire end 7 is solidified, the conductive wire end 7 is inserted into the bottomed cylindrical portion 21 of the terminal 4, and the terminal 4 is reduced in plasticity as shown in FIG. 19 (c). Deform and hold with pressure. Due to the reduced diameter plastic deformation of the terminal 4, the conductive wire end 7 is crushed together with the metal material 11 from a circle to a lemon shape, and the element wire 2 is also compressed and deformed.
Then, the conductive coating layer 6 made of the metal material 11 covering the conductive wire end portion 7 is broken or broken down into powders along with the plastic deformation from FIG. To do.

Next, another comparative example shown in FIG. 20 will be described.
The aluminum electric wire 1 used here is an aluminum electric wire 1 having a strand 2 having the same thin diameter as shown in FIG. Further, as the terminal 4 connected to the aluminum electric wire 1, one having a pair of crimping pieces 14 and 14 shown in FIG.

  As shown in FIG. 20A, the insulator 3 at one end of the aluminum electric wire 1 is peeled off to expose the conductor end 7. Then, as shown in FIG. 20 (b), the conducting wire end portion 7 is formed into a substantially quadrangular shape (with rounded corners), and at the same time, ultrasonic welding is performed to form the smooth surface portion 5 on the outer peripheral surface of the conducting wire end portion 7. In this case, the conducting wire end portion 7 is not preformed so as to be substantially the same (substantially concave shape) as the cross-sectional shape of the terminal 4 after the crimping plastic deformation.

  As shown in FIG. 20 (c), the conductive coating layer 6 of the molten metal material 11 is formed on the conductive wire end portion 7 (smooth surface portion 5). After the conductive coating layer 6 of the metal material 11 is solidified, as shown in FIG. 20 (d), the terminal 4 is plastically deformed and held by crimping on the conductor end portion 7. Due to the plastic deformation of the terminal 4, the crimping pieces 14, 14 are bent toward each other and their tips bite into the conductor end 7, so that the cross-sectional shape of the conductor end 7 is substantially square to substantially concave. Transformed into In particular, the portion where the tips of the crimping pieces 14 and 14 of the conductive wire end 7 bite is greatly compressed and deformed. Therefore, the conductive coating layer 6 covering the conductive wire end 7 is crushed and broken or powdered and destroyed. The Therefore, the conductivity with the terminal 4 is lowered.

As described above, the terminal crimping method of the aluminum electric wire according to the present invention is an end of a conductive wire composed of a large number of strands 2 made of aluminum or aluminum alloy which is exposed by peeling off the insulator 3 at one end of the aluminum electric wire 1. The cross-sectional shape of the portion 7 is preformed so as to be substantially the same as the cross-sectional shape after crimping plastic deformation of the terminal 4, and a metal material 11 having excellent extensibility is attached to the conductor wire end portion 7 after the pre-molding, Since the terminal 4 is plastically deformed and held by crimping to the conductive wire end 7, the conductive wire end 7 and the terminal 4 can be mechanically and firmly connected via the metal material 11, and the metal material 11 is made of the element wire 2. The formation of an oxide film can be prevented (the contact resistance can be prevented from increasing), and the connection can be ensured with sufficient conductivity.
That is, the conductor end portion 7 is preformed corresponding to the cross-sectional shape of the terminal 4 to be connected after the crimping plastic deformation, so that when the terminal 4 is plastically deformed and crimped to the conductor end portion 7, the conductor end portion 7 can be prevented from being greatly deformed. This prevents the metal material 11 attached to the conductor end 7 from being crushed and broken or powdered, and preventing an oxide film from being formed on the conductor end 7 made of aluminum or aluminum alloy. Can do. In addition, the aluminum electric wire 1 can be connected to the terminals 4 having various shapes with good electrical conductivity and sufficient mechanical connection strength.

Simultaneously with or after the preforming of the conductive wire end 7, the strands 2 of the conductive wire end 7 are welded together to form the smooth surface portion 5 on the outer peripheral surface of the conductive wire end portion 7, and the smooth surface portion of the conductive wire end portion 7. Since a metal material 11 rich in extensibility is attached to 5 and the terminal 4 is plastically deformed and held by crimping on the end 7 of the conductor, even if the strand 2 of the aluminum wire 1 such as rope twist is thin, the conductor The metal material 11 can be reliably attached to the end portion 7. The conductor end 7 and the terminal 4 can be mechanically and firmly connected via the metal material 11, and the metal material 11 prevents the formation of an oxide film on the element wire 2 (increases contact resistance). Can be connected with sufficient electrical conductivity.
That is, when the wire 2 of the aluminum electric wire 1 is thin, there is a fine uneven surface with circular arcs arranged continuously on the outer periphery of the conductor end 7 (see FIG. 15), so a metal material with a large surface tension (aluminum solder) 11 is difficult to enter the concave portion of the concavo-convex surface and hardly adhere to the conductive wire end portion 7, but the smooth surface portion 5 can be formed by smoothing the concavo-convex surface by welding the strands 2 to each other. The metal material 11 can be reliably attached to the metal (see FIGS. 16 and 17).
As a result, when the aluminum electric wire 1 is required to be flexible, the aluminum electric wire 1 using the thin wire 2 (for example, a wire having a diameter of 0.5 mm or less) can be obtained with good electrical conductivity and sufficient machine. Connection strength can be obtained and connected to the terminal 4.
Moreover, since the aluminum electric wire with a terminal manufactured by the above-mentioned method preforms the conducting wire end 7 corresponding to the cross-sectional shape after the crimping plastic deformation of the terminal 4 to be connected, the terminal 4 is plastically deformed. It is possible to prevent the cross-sectional shape of the conductive wire end portion 7 from being greatly deformed when crimping to the conductive wire end portion 7. This prevents the metal material 11 attached to the conductor end 7 from being crushed and broken or powdered, and preventing an oxide film from being formed on the conductor end 7 made of aluminum or aluminum alloy. Can do. In addition, the aluminum electric wire 1 can be connected to the terminals 4 having various shapes with good electrical conductivity and sufficient mechanical connection strength.
Furthermore, it is suitable for a battery cable of an automobile having a large cross-sectional area (38 mm ^{2 to} 60 mm ² ).
Further, it is preferable as a battery cable for a motorcycle or a light automobile body in which a wiring space is limited (easy wiring). In addition, it can be suitably used between a battery and an inverter of a hybrid vehicle or an electric vehicle, and greatly helps to reduce the weight of the entire vehicle body and further improve fuel efficiency.

It is explanatory drawing which shows one Embodiment of the terminal crimping method of the aluminum electric wire which concerns on this invention, Comprising: (a) is side surface explanatory drawing, (b) is a cross-sectional explanatory drawing. It is explanatory drawing, Comprising: (a) is side surface explanatory drawing, (b) is a cross-sectional explanatory drawing. It is explanatory drawing, Comprising: (a) is side surface explanatory drawing, (b) is a cross-sectional explanatory drawing. It is explanatory drawing, Comprising: (a) is side surface explanatory drawing, (b) is a cross-sectional explanatory drawing. It is explanatory drawing, Comprising: (a) is side surface explanatory drawing, (b) is a cross-sectional explanatory drawing. It is transverse cross-sectional explanatory drawing which shows other embodiment of this invention. FIG. FIG. FIG. It is a cross-sectional explanatory drawing which shows another embodiment of this invention. FIG. FIG. FIG. FIG. It is a partial enlarged view. It is a partial enlarged view. It is a partial enlarged view. It is a perspective view of a terminal, (A) is a perspective view showing one form of a terminal, (B) is a perspective view showing another form of the terminal, and (C) is a perspective view showing still another form of the terminal. is there. It is a cross-sectional explanatory drawing which shows a comparative example. It is a cross-sectional explanatory drawing which shows another comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum electric wire 2 Elementary wire 3 Insulator 4 Terminal 5 Smooth surface part 7 Conductor end part
11 Metal

Claims (3)

  The cross-sectional shape of the conductive wire end (7) composed of a large number of strands (2) made of aluminum or aluminum alloy, which is exposed by peeling off the insulator (3) at one end of the aluminum wire (1), Preliminarily molded so that the cross-sectional shape after crimping plastic deformation of the terminal (4) is substantially the same, and a metal material (11) rich in extensibility is attached to the conductive wire end (7) after the preforming, A terminal crimping method for an aluminum electric wire, characterized in that the terminal (4) is plastically deformed and held by crimping on an end portion (7) of a conducting wire.   Simultaneously with or after the preforming of the conducting wire end (7), the strands (2) of the conducting wire end (7) are welded together to form a smooth surface portion (5) on the outer peripheral surface of the conducting wire end (7). Formed, adheres a metal material (11) rich in extensibility to the smooth surface portion (5) of the conductor end (7), and plastically deforms the terminal (4) to the conductor end (7) to hold it by pressure bonding. The terminal crimping method of the aluminum electric wire of Claim 1.   The aluminum electric wire with a terminal produced by the terminal crimping method of the aluminum electric wire of Claim 1 or 2.

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