JP5158874B2 - Aluminum wire and terminal crimping method for aluminum wire - Google Patents

Description

  The present invention relates to an aluminum electric wire used for, for example, a vehicle wiring harness and a terminal crimping method for the aluminum electric wire.

  In recent years, for example, wire harnesses made of aluminum wires instead of copper wires have been used in vehicles. This is because, firstly, the aluminum wire is lighter than the copper wire, so that the weight of the vehicle can be reduced, and the workability when assembling the wire harness and the attachment of the wire harness to the vehicle are improved. There is. Second, when the vehicle is recycled, the conventional copper wire remains in the body, making it difficult to separate the copper and iron, but by using an aluminum wire instead of the copper wire, aluminum remains in the vehicle. Since it becomes easy to separate iron and aluminum during recycling, it is excellent in recyclability. Third, aluminum wires are cheaper than copper wires.

  On the other hand, since an aluminum wire tends to form an oxide film on a conductor, when the connection terminal is crimped, the metallic connection between the conductor and the terminal or between the strands of the stranded wire constituting the conductor becomes incomplete. Cheap. If an environmental change such as a temperature cycle is given in this state, the electrical resistance of the terminal crimping part increases, and the electrical characteristics at the terminal crimping part cannot be maintained. In order to prevent this and maintain stable electrical characteristics of the terminal crimping part of the aluminum wire, the compression ratio of the aluminum wire conductor part is the cross-sectional area of the aluminum wire conductor part of the crimped part / the cross-sectional area of the aluminum wire conductor part before crimping. Has been disclosed (see, for example, Patent Document 1).

  FIGS. 9A and 9B are a plan view (FIG. 9A) and a side view (FIG. 9B) showing a state where the terminal 200 is crimped to the conventional aluminum electric wire 10 '. FIG. 10A is a crimping sectional view of the aluminum electric wire with a terminal in a state where the terminal 200 is crimped to the aluminum electric wire 10 'as described above. FIG. 10B is a cross-sectional view of a crimped state in which the terminal 200 is crimped to the copper electric wire 20.

  Here, the crimping height of the terminal 200 is called a crimp height value, and the crimp compression rate (area reduction) between the terminal 200 and the electric wires 10 ′ and 20 is generally shown in FIG. 10 as the crimp height values Ha and Hb. Therefore, it is managed by this crimp height value.

  And the thing with a small crimp height value like the cross-sectional example A shown to Fig.10 (a) has a small conductor cross-sectional area, and is crimped | bonded by the highly compressed state. On the other hand, the one with a large crimp height value such as the cross-sectional example B shown in FIG. 10B has a large conductor cross-sectional area and is crimped in a low compression state.

  For example, when the compression rate in the cross-section example A with a small crimp height value is 70%, the cross-section example A corresponds to a terminal crimp structure having mechanical and electrical characteristics preferable as a terminal crimp structure to the aluminum electric wire 10 ′. . On the other hand, in the cross-sectional example B where the crimp height value (conductor cross-sectional area) is larger than that in the cross-sectional example A, the compressibility is larger than 70%, and the cross-sectional example B corresponds to a terminal crimping structure to a normal copper wire 20.

  That is, the compression ratio refers to a surface area reduction ratio when the cross-sectional area of the electric wire conductor before terminal crimping is 100%, and the smaller the crimp height value and the conductor cross-sectional area after crimping, the higher the compression. And the higher the compression, the smaller the compression rate.

  The conventional terminal crimping structure to the copper wire 20 is actually managed by the crimp height value that is the target compression rate, but the crimp compression rate is approximately 75 to 95 as a result, although it varies slightly depending on the type of terminal and the wire diameter. % Is managed within the range.

On the other hand, when the aluminum wire 10 ′ is crimped at the current control value, an increase in resistance value occurs in an environmental test that requires high or low temperature, and stable electrical connection cannot be maintained. However, in the embodiment of Patent Document 1, it is possible to clear an environmental test and achieve stable electrical connection by specifying an optimal management value in the range of 50 to 70% only for the aluminum electric wire 10 ′. It is described in detail.
Japanese Unexamined Patent Publication No. 2005-174896 (paragraph (0029), FIG. 4)

  Here, when the terminal 200 is crimped to the aluminum electric wire 10 ′, when the compression rate is 50 to 70% and the deformation of the aluminum electric wire 10 ′ is increased, the portion indicated by the dotted line P in FIGS. 11A and 11A As shown in FIG. 11 (b), the local deformation of the strand of the aluminum electric wire 10 ′ increases particularly near the bell mouth portion 211 of the terminal 200, and the strand is likely to break. . Here, the bell mouth portion 211 is an end portion on the electric wire side of the wire barrel 210 as shown in FIG. 11B, and a portion that does not exist before terminal crimping but has a tapered shape in side view after terminal crimping. Point to.

Such a problem occurs because the portion of the conductor corresponding to the bell mouth portion 211 becomes a transition portion between a portion deformed by crimping and a portion not subjected to deformation, so that the local deformation such as the strand is strongly stretched locally. If the compression deformation is large, it is considered that the wire is easily broken at the bell mouth portion 211.

  Further, not only when the terminal 200 is crimped to the aluminum electric wire 10 ′, but particularly when this aluminum electric wire 10 ′ is used as a vibration part of the wire harness of the vehicle, the aluminum electric wire 10 ′ is constantly vibrated during traveling of the vehicle. Breakage at the bell mouth portion is likely to occur.

  An object of the present invention is to provide an aluminum wire excellent in durability in which a strand is not easily broken at a bell mouth portion of a crimped terminal, and a terminal crimping method of the aluminum wire.

In order to solve the above-mentioned problem, an aluminum electric wire according to claim 1 of the present invention is
An aluminum electric wire with a connection terminal crimped to a conductor,
Solder is applied to a predetermined part in the longitudinal direction of the conductor over the entire circumference,
The portion to which the solder is applied is in contact with a bell mouth portion of a connection terminal crimped to the conductor.

  According to the aluminum electric wire according to the first aspect, since the conductor is reinforced by the solder in the bell mouth portion, the conductor is hardly broken in the bell mouth portion. This is not only due to the fact that the cross-sectional area of the conductor and the solder is simply increased by the application of solder, but also because the strands are joined together by solder so that the tensile stress at the time of deformation of the conductor is adjacent to the element. This is considered to be because the conductor of the bell mouth portion is reinforced by a mechanism such as sharing between the wires or a compressive stress being applied to the surface of the strand by solder.

An aluminum electric wire according to claim 2 of the present invention is the aluminum electric wire according to claim 1,
The conductor is covered with a covering portion made of an insulating material, and the covering portion is removed at the end of the wire,
Solder is applied over the entire circumference in a predetermined part of the conductor in the longitudinal direction of the exposed portion where the covering portion is removed,
The portion to which the solder is applied is in contact with a bell mouth portion of a connection terminal crimped to the conductor.

  According to the aluminum electric wire which concerns on Claim 2, even if it is a covered wire with which the aluminum electric wire was insulation-coated, the effect | action similar to Claim 1 is acquired when a terminal is crimped | bonded to the part which remove | eliminated the edge part of the coating | cover.

Moreover, the terminal crimping method of the aluminum electric wire which concerns on Claim 3 of this invention is the following.
A method for crimping an aluminum wire by crimping a connection terminal on the aluminum wire,
Apply solder flux to a predetermined part in the longitudinal direction of the conductor over the entire circumference.
Dipping at least a portion of the conductor to which the solder flux has been applied in molten solder, and applying the solder to the portion to which the solder flux has been applied,
The connecting terminal is crimped so that the soldered portion is in contact with the wire side end of the wire barrel of the connecting terminal to be crimped to the conductor.

  According to the terminal crimping method for an aluminum electric wire according to claim 3, it is possible to easily manufacture an aluminum electric wire with a crimping terminal that does not easily break the conductor portion corresponding to the bell mouth portion of the terminal as in claims 1 and 2. Become.

  According to the present invention, when an aluminum wire is crimped to a terminal, the compression rate is reduced to achieve stable electrical connection, and the wire is not easily broken at the bell mouth portion of the crimped terminal and has excellent durability. And the terminal crimping method of an aluminum electric wire can be provided.

  Hereinafter, an aluminum electric wire and an aluminum electric wire terminal crimping method according to an embodiment of the present invention will be described in detail based on the drawings. First, an aluminum electric wire according to an embodiment of the present invention will be described.

  FIG. 1 is a side view showing an aluminum electric wire 10 according to an embodiment of the present invention. 2 is a plan view (FIG. 2 (a)) and a side view (side view) showing a state in which a connection terminal (hereinafter simply referred to as “terminal”) 100 is crimped to an aluminum electric wire 10 according to an embodiment of the present invention. FIG. 2 (b)). FIG. 3 is a side view partially enlarged showing only the vicinity of the bell mouth portion of the terminal 100 in FIG. FIG. 4 is a plan view (FIG. 4A) and a side view (FIG. 4B) of the terminal 100 before being crimped to the aluminum electric wire 10.

  An aluminum wire 10 according to an embodiment of the present invention is an aluminum wire in which a terminal 100 is crimped to a conductor portion 11 of the aluminum wire 10 shown in FIG. 1, and the conductor portion 11 is covered with a covering portion 12 made of an insulating material. In addition, the covering portion 12 is removed at the end of the aluminum electric wire 10. Then, solder 15 is applied to a predetermined part in the longitudinal direction of the conductor portion 11 at the exposed portion where the covering portion 12 is removed, over the entire circumference. And the part which this solder | pewter 15 was apply | coated exists in the bell mouth part of the terminal 100 crimped | bonded to the conductor part 11 as shown in FIG.2 and FIG.3 (the electric wire side edge part of a wire barrel, before terminal crimping) However, after the terminal is crimped, it comes into contact with a portion 111 having a tapered shape in a side view.

  As shown in FIGS. 2 and 4, the terminal 100 includes an electric wire connecting portion 100A and a terminal connecting portion 100B. And 100 A of electric wire connection parts are comprised by the insulation barrel 120 which crimps | bonds the aluminum electric wire 10 with the resin coating | cover with the wire barrel 110 which crimps | bonds the conductor part 11. FIG. The wire barrel 110 has a substantially U-shaped cross section and forms a so-called open barrel type terminal.

  Then, the terminal crimping method to the aluminum electric wire mentioned above is demonstrated. FIG. 5 is a process diagram showing a general aluminum soldering method in which solder is entirely applied to a conductor portion of an aluminum electric wire. FIG. 6 is a process diagram showing a state before and after the conductor portion of the aluminum electric wire is immersed in a solder bath without using a flux. 5 and 6 that the solder is applied only to the portion where the solder flux is applied to the conductor portion of the aluminum electric wire. FIG. 7 is a process diagram for explaining a method of applying solder to an aluminum electric wire according to an embodiment of the present invention.

  First, the conductor portion 11 is covered with a covering portion 12 made of an insulating material, and the aluminum wire 10 is prepared in which the covering portion 12 is removed at the end of the aluminum wire 10 and the conductor portion 11 is exposed.

  Next, as shown in FIG. 7A, a solder flux 15a is applied to a predetermined part in the longitudinal direction of the aluminum electric wire 10 over the entire circumference. Here, the solder flux 15a may be any solder flux applicable to aluminum or an aluminum alloy, and is not limited to a specific solder flux.

  Next, as shown in FIG. 7B, at least a portion of the conductor portion 11 to which the solder flux 15a is applied is immersed in a molten solder solution 50.

  As a result, as shown in FIG. 7C, the solder 15 is applied only to the portion of the aluminum electric wire 10 where the solder flux 15a is applied.

  And the terminal 100 is crimped | bonded to the conductor part 11 so that the part to which the solder | pewter 15 was apply | coated contacts the bellmouth part 111 of the terminal 100 crimped | bonded to the conductor part 11. FIG.

  Below, the terminal crimping | compression-bonding process to this aluminum electric wire is demonstrated. FIG. 8 is a process diagram showing, in order from (a) to (d), a state before crimping a terminal to an aluminum electric wire according to an embodiment of the present invention, and a state after crimping the terminal. The right side when viewed from the side shows the aluminum wire as viewed from the direction of the covering portion.

  First, as shown in FIG. 8A, the terminal 100 is fixed to the base 80, and the aluminum electric wire 10 is positioned at an appropriate position of the terminal 100. That is, the conductor portion 11 of the aluminum electric wire 10 is positioned in the region sandwiched between the wire barrels 110 and the covering portion 12 is positioned in the region sandwiched between the insulation barrels 120. At this time, positioning is performed so that the above-described solder 15 of the aluminum electric wire 10 contacts the electric wire side end portion of the wire barrel 110 formed as the bell mouth portion 111 after the terminal of the wire barrel 110 to be crimped to the aluminum electric wire 10 is crimped.

  In this state, the crimping jig 90 having a specially shaped crimping groove as viewed in the terminal longitudinal direction is approached from above the terminal 100 (see arrow X indicating the terminal crimping direction in FIG. 8A). The crimping jig 90 is formed with crimping portions corresponding to the wire barrel 110 and the insulation barrel 120 to be crimped. That is, a terminal crimping portion 91 is formed at a position corresponding to the wire barrel 110 of the terminal 100, and a terminal crimping portion 92 is formed at a position corresponding to the insulation barrel 120 of the terminal 100. Here, the crimping jig 90 is lowered toward the terminal side by an actuator (not shown) (see FIG. 8B). By this descending operation, the end portions of the barrels 110 and 120 are gradually bent along the crimping grooves of the crimping portion of the crimping jig 90. It deforms (curls) in the direction of the central axis (see FIG. 8C).

  Then, by further lowering the crimping jig 90, the tip of the wire barrel is pushed between the strands of the conductor portion 11 of the aluminum electric wire 10. At the same time, the insulation barrel 120 is also crimped to the covering portion 12 of the aluminum electric wire 10. Under the present circumstances, it crimps | bonds so that the solder 15 of the aluminum electric wire 10 mentioned above may contact the bellmouth part 111 of the wire barrel 110 crimped | bonded to an aluminum electric wire.

  Further, when the terminal 100 is crimped to the conductor portion 11 of the aluminum electric wire 10 in this way, the compression ratio of the aluminum electric wire conductor portion defined by the cross-sectional area of the aluminum electric wire conductor portion of the crimped portion / the cross-sectional area of the aluminum electric wire conductor portion before the crimping. The terminal 100 is crimped to the aluminum electric wire 10 so that the (area reduction) is in the range of 50 to 70%. When this terminal crimping operation is finished, the crimping jig 90 is raised to complete the terminal crimping operation (see FIG. 8D).

  In the aluminum electric wire 10 with a terminal crimped in this way, the conductor portion 11 is reinforced by the solder 15 at the bell mouth portion 111, so that the conductor portion 11 in the bell mouth portion 111 of the terminal 100 is hardly broken. . This is not only because the cross-sectional area of the conductor portion 11 and the solder 15 is simply increased by the application of the solder 15, but also because the wires are joined together by the solder 15. This is because the conductor portion 11 of the bell mouth portion 111 is reinforced by a mechanism such as sharing the tensile stress at the time between adjacent strands or applying a compressive stress to the surface of the strand by the solder 15. it is conceivable that.

  Hereinafter, since the terminal 100 was actually crimped | bonded to the aluminum electric wire 10 using such a terminal crimping method of the aluminum electric wire 10, the result is demonstrated as an Example.

  Specifically, the conductor 12 was partially removed from the covering 12 at the end of the aluminum electric wire 10 made of aluminum or an aluminum alloy. And solder flux was apply | coated with the brush near the base of the conductor part 11 from which the coating | coated part 12 was removed (refer Fig.7 (a)). At this time, the solder flux 15a is applied in a short range in the longitudinal direction of the coating removal portion, and is applied to the entire circumference in the circumferential direction. Was applied once in a strip shape.

  Then, the conductor part 11 which is a coating removal part was immersed in the solder liquid of a solder tank (refer FIG.7 (b)). As a result, the oxide film only on the portion where the solder flux 15a was applied was removed, and the solder 15 adhered. Moreover, since the aluminum oxide film remained on the surface of the conductor part 11 in the part other than that, the solder 15 did not adhere and it remained with the strand. As a result, the aluminum electric wire 10 with the solder 15 attached in a headband shape near the base of the conductor portion 11 was obtained (see FIG. 7C).

  The aluminum electric wire 10 was set together with the terminal 100 in a die of a crimping machine. Here, the position in the longitudinal direction of the aluminum electric wire 10 was determined with respect to the terminal 100 such that the solder 15 was placed on the bell mouth portion 111 of the wire barrel 110.

  Subsequently, the terminal 100 was crimped | bonded to the aluminum electric wire 10 with the crimping method mentioned above. At this time, even if the wire barrel 110 of the terminal 100 was crimped to the aluminum electric wire 10 at a compression rate of 50 to 70%, the core wire did not break at the bell mouth portion 111. In addition, the electrical connectivity was good and stable conduction was shown by a reliability test.

  In carrying out the present invention, the connection terminal may be a terminal that is electrically and mechanically connected by crimping an electric wire, and the shape of the terminal is not limited. Moreover, although the wire barrel was an open barrel in the above-described embodiment, the shape of the barrel portion where the terminal caulks the conductor may be a closed barrel instead. In the above-described embodiment, the terminal is provided with the insulation barrel, but the insulation barrel is not necessarily provided in the terminal. In addition, the type of the aluminum electric wire is not limited as long as the conductor is aluminum or an aluminum alloy. Moreover, the kind of solder will not be limited if it can be soldered to aluminum or an aluminum alloy.

  In the present invention, the solder is applied to a predetermined part in the longitudinal direction of the conductor portion of the aluminum electric wire and applied to the entire circumference in the circumferential direction, which means that the solder is applied in a headband shape in a narrow sense. However, it is not limited to applying the solder to the narrow band shape of the aluminum electric wire as in the above-described embodiment, and any form as long as it is a part of the length of the conductor part and the entire circumference in the circumferential direction. There may be.

  The reason why the conductor portion is limited to a part in the longitudinal direction is that the solder is applied to the entire region of the aluminum electric wire that crimps the wire barrel of the terminal (that is, at least over the entire length of the portion deformed by crimping). This is because the deformation is restrained in the longitudinal direction between the strands at the deformed portion, the behavior during compression becomes unstable, and stable crimping cannot be performed. Moreover, since the cross-sectional area increases in the entire deformed portion, the crimping force is increased.

  It should be noted that the degree of reinforcement described above can be adjusted by the thickness to which the solder is applied. Further, in this embodiment, the solder flux is applied by applying a brush or a nozzle to only a part of the longitudinal direction of the electric wire while rotating the electric wire as in the above-described example. The method is not limited. Moreover, you may add vibrations, such as an ultrasonic wave, at the time of the immersion to the solder tank of the conductor part of an aluminum electric wire.

It is a side view which shows the aluminum electric wire which concerns on one Embodiment of this invention. It is a top view (Drawing 2 (a)) and a side view (Drawing 2 (b)) which show the state where a terminal was crimped to an aluminum electric wire concerning one embodiment of the present invention. It is a side view which expands and shows only the bellmouth part vicinity of the terminal in FIG. It is the top view (Drawing 4 (a)) and side view (Drawing 4 (b)) which show the terminal before crimping to the aluminum electric wire concerning one embodiment of the present invention. It is process drawing which shows the method of soldering the whole aluminum wire in order of (a)-(c). It is process drawing which shows the state before and behind immersing this aluminum electric wire in a solder tank in the state which does not apply | coat a flux to an aluminum electric wire in order of (a)-(b). It is process drawing which shows the application | coating method of the solder to the aluminum electric wire which concerns on one Embodiment of this invention in order of (a)-(c). It is process drawing which shows from the state before terminal crimping to the state after terminal crimping to the aluminum electric wire which concerns on one Embodiment of this invention to the state after terminal crimping in order of (a)-(d), The state which looked at the terminal from the left side The right side shows the aluminum wire as viewed from the direction of the covering. It is the top view (Drawing 9 (a)) and the side view (Drawing 9 (b)) which show the state where a terminal was crimped to the conventional aluminum electric wire. In sectional drawing (FIG. 10 (a)) of the terminal crimping part in the state which crimped the terminal to the conventional aluminum electric wire, and sectional drawing (FIG.10 (b)) of the terminal crimping part in the state which crimped the terminal to the conventional copper electric wire. is there. A side view (FIG. 11 (a)) and a partially enlarged view (FIG. 11 (b)) enlarging a portion indicated by a dotted line P in FIG. ).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10 'Aluminum electric wire 11 Conductor part 12 Covering part 15 Solder 15a Solder flux 20 Copper electric wire 50 Solder liquid 80 Base 90 Crimping jig 91,92 Terminal crimping part 100 (Connection) terminal 100A Wire connection part 100B Terminal connection part 110 Wire barrel 111 Bell mouth part 120 Insulation barrel 200 Terminal 210 Wire barrel 211 Bell mouth part Ha, Hb Crimp height value

Claims (3)

An aluminum electric wire with a connection terminal crimped to a conductor,
Solder is applied to a predetermined part in the longitudinal direction of the conductor over the entire circumference,
An aluminum electric wire characterized in that a portion to which the solder is applied is in contact with a bell mouth portion of a connection terminal crimped to the conductor. The conductor is covered with a covering portion made of an insulating material, and the covering portion is removed at the end of the wire,
Solder is applied over the entire circumference in a predetermined part of the conductor in the longitudinal direction of the exposed portion where the covering portion is removed,
The aluminum wire according to claim 1, wherein the soldered portion is in contact with a bell mouth portion of a connection terminal that is crimped to the conductor. A method for crimping an aluminum wire by crimping a connection terminal on the aluminum wire,
Apply solder flux to a predetermined part in the longitudinal direction of the conductor over the entire circumference.
Dipping at least a portion of the conductor to which the solder flux has been applied in molten solder, and applying the solder to the portion to which the solder flux has been applied,
A terminal crimping method for an aluminum electric wire, characterized in that the connection terminal is crimped so that a portion to which the solder is applied is in contact with an end of the wire barrel of the connection terminal crimped to the conductor.

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