JP2015153622A - Terminal connection structure for aluminum-based wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply achieve waterproof between an aluminum wire and a terminal made of a copper-based metal plate.SOLUTION: On the terminal side, insulation coating is peeled off to expose an aluminum core wire, the aluminum core wire is welded to a terminal made of a copper-based metal plate, the insulation coating adjacent to the skin-peeled end is caulked and crimped by an insulation coating barrel provided in the terminal, and an aluminum core wire exposure part between the rear end of a welding part of the aluminum core wire and the skin-peeled end of a wire is covered with at least a covering material.

Description

  The present invention relates to a terminal connection structure for an aluminum-based electric wire, and more particularly to a connection structure for welding as an aluminum-based electric wire arranged in a vehicle and a terminal.

Recently, as an electric wire to be wired to a vehicle, an aluminum electric wire (hereinafter abbreviated as an aluminum electric wire) in which an aluminum core wire twisted with an aluminum metal wire is covered with an insulating resin is used for reasons such as light weight. Yes. In a thick electric wire used as a power line or the like when the core cross-sectional area of the aluminum electric wire is 8 mm ² or more, the aluminum core wire is welded to the terminal from the viewpoint of improving the reliability of electrical connection with the terminal.

  That is, as shown in FIG. 9, the aluminum core wire 101 exposed from the insulating coating 102 at the end of the aluminum electric wire 100 is welded to the substrate 121 of the terminal 120 made of a copper-based metal plate. The insulation coating 102 continuous with the aluminum core wire 101 is crimped and crimped by an insulation coating barrel 122 protruding from the substrate 121 of the terminal 120.

  Since the terminal 120 is formed by processing a copper-based metal plate, the contact between the substrate 121 of the terminal 120 and the aluminum core wire 101 becomes a dissimilar metal contact between copper and aluminum, and a snow melting agent or a battery is applied to the contact portion. Galvanic corrosion occurs when water containing electrolyte, salt, or dissolved oxygen contained in the solution adheres. In the region A shown in FIG. 10 (A), the corrosion hardly prevents the electrolytic solution and water from being immersed in the welded portion between the aluminum core wire 101 and the substrate 121 of the terminal 120 because there is almost no gap. However, the aluminum core wire 101 cannot be welded to the boundary position of the peeled end 102e of the insulating coating 102 of the aluminum electric wire 100. Therefore, as shown to FIG. 10 (A), the core wire exposure part 105 which cannot be welded exists in the B area | region between the welding area A of the aluminum core wire 101, and the peeling end 102e. As shown in FIG. 10B, gaps C are generated between the strands 101 a of the aluminum core wire of the core wire exposed portion 105 and between the strand 101 a and the substrate 121 of the terminal 120. If water is generated in the gap C between the strand 101a and the substrate 121 through the gap between the strands 101a, the substrate 121 is corroded, and there is a problem that the corrosion spreads to the area of the core wire weld.

  In order to solve the above problem, Japanese Patent Application Laid-Open No. 2013-62206 provides a connection structure for amyl electric wires shown in FIG. In the terminal 200, long barrels 203 and 204 that continue from the front part to the rear end of the board of the electric wire connection part 201 are projected from both sides in the board width direction. After the aluminum core wire 101 of the aluminum electric wire 100 is welded to the substrate, the barrels 203 and 204 are continuously crimped and crimped to the aluminum core wire 101 and the insulating coating 102, and the stacked barrels 203 and 204 are welded and the front end is The front end face is also sealed by pressing toward the terminal board, and the aluminum core wire 101 connected to the terminal 200 is covered and sealed with barrels 203 and 204.

JP2013-62206A

  When a long barrel protrudes from both sides in the width direction of the terminal and is crimped and crimped with a barrel continuous to both the core wire and the insulation coating as in Patent Document 1, the outer diameters of the core wire and the insulation coating are different. Various problems occur. That is, if the core wire is crimped, the barrel may dig deeply into the insulating coating, and the insulating coating may be damaged. On the other hand, when caulking so as to be in close contact with the insulating coating, a gap is generated on the outer periphery of the core wire. Furthermore, it is necessary to press the front end of the barrel until it comes into contact with the terminal board. Therefore, it is necessary to change the pressing force applied to the barrel in the length direction, but in this case, there is a problem that the configuration of the crimping apparatus becomes very complicated.

  The present invention has been made in view of the above problems, and in a terminal for welding and connecting an aluminum core wire of an aluminum electric wire to a terminal made of a copper-based metal, adhesion of moisture while maintaining electrical connection reliability between the electric wire and the terminal. The problem is to suppress the corrosion that occurs.

In order to solve the above-mentioned problems, the present invention provides an aluminum core wire in which an aluminum core wire formed by twisting an aluminum-based metal strand is covered with an insulating resin insulation coating, and the insulation coating is peeled off at the terminal side. Is exposed, and the aluminum core wire is welded to a terminal made of a copper-based metal plate, and the insulation coating adjacent to the peeled end is crimped and crimped with an insulation coating barrel provided on the terminal,
An aluminum electric wire terminal connection structure is provided in which an exposed portion of an aluminum core wire between a rear end of a welded portion of the aluminum core wire and a peeled end of the electric wire is covered with a covering material.

The covering material is made of an insulating resin tape, and the insulating resin tape is wrapped around the exposed portion of the aluminum core wire.
Or the said coating | covering material consists of an insulating heat contraction tube, and the said aluminum core wire exposed part is enclosed with this insulating heat contraction tube.
Alternatively, the covering material is a barrel projecting from both sides of the terminal of the terminal in the width direction, and the barrel is a short barrel separated from the insulating coating barrel, and the barrel exposes the aluminum core wire exposed portion. It is crimped to surround.

In the case of the aluminum wire terminal connection structure shown in FIG. 9 of the conventional example, the present inventor observed the corrosion state of the terminal through a salt spray test.
As a result, almost no corrosion occurred at the interface between the welded portion of the aluminum core wire and the terminal in the section taken along the line II in FIG. 10A. On the other hand, corrosion has occurred in the exposed portion of the aluminum core wire in which the aluminum core wire in the section II-II in FIG. 10A is not welded to the terminal. This corrosion is only at the outer periphery because the aluminum core wire is a stranded wire. It was corroded to the center of the aluminum core wire.
From the test results, in the region A where the aluminum core wire was welded to the substrate, no gap was generated by welding, so that no water was transmitted through the gap. Therefore, even if moisture adheres to the outer surface of the aluminum core wire, corrosion does not occur at the welded portion interface between the aluminum core wire and the terminal. Therefore, it has been confirmed that the core wire welded portion need not be covered with a barrel or the like for waterproofing.
On the other hand, in the region where there is an unweldable aluminum core wire exposed portion in the region B between the rear end and the peeled end of the welded portion, there is a gap between the strands of the aluminum core wire, resulting in flooding.
As described above, since it is the aluminum core wire exposed portion that is not welded to the terminal that is likely to cause corrosion in the terminal due to water immersion, the aluminum core wire exposed portion is configured to be waterproof.

  In the present invention, as described above, the exposed portion of the aluminum core wire between the rear end of the welded portion of the aluminum core wire and the peeled end of the wire is covered with a covering material made of an adhesive tape, a heat-shrinkable tube, or a barrel for waterproofing. doing. When covering with the adhesive tape or the heat shrinkable tube, it is preferable to cover from the rear end of the welded portion of the aluminum core wire to the outer peripheral surface of the insulating coating of the electric wire beyond the crimped portion by the insulating coating barrel.

The aluminum electric wire used in the present invention is an electric wire that is routed in a vehicle, and is suitably used as an aluminum electric wire that is a thick electric wire having a core wire cross-sectional area of 8 mm ² or more and is used as a power line or an earth line. This is because a thick aluminum electric wire used as a power supply line or the like can improve electrical connection reliability by welding a core wire to a terminal. In addition, as described above, in an aluminum wire, corrosion due to contact with a dissimilar metal with a terminal made of a copper metal of a dissimilar metal is likely to occur. Therefore, in order to prevent the corrosion, the thick aluminum wire and the terminal are welded. Because it is often required to connect with.

  The shape of the electrical contact portion of the terminal may be any shape such as a tab-shaped male type, a box-shaped female type, or a bolt tightening type provided with a bolt hole.

  In the method for connecting an aluminum electric wire and a terminal according to the present invention, the insulation coating is peeled off at the end of the aluminum electric wire to expose the aluminum core wire, and the exposed aluminum core wire is disposed on the core wire welding portion of the substrate of the electric wire connection portion of the terminal. Then, ultrasonically weld, and then crimp and crimp the insulation barrel to the insulation coating with a crimping device, and finally cover at least the exposed part of the aluminum core wire from the rear end of the weld that is not welded to the substrate The insulating resin tape is wound or covered with an insulating heat-shrinkable tube. In addition, when the terminal is provided with a barrel surrounding the aluminum core wire exposure as a coating material, the barrel surrounding the aluminum core wire exposed portion is simultaneously crimped and crimped at the time of crimping and crimping the insulation coating barrel, and the aluminum core wire exposed portion is Is covered.

As described above, the welding of the core wire to the terminal is preferably performed by ultrasonic welding.
As the welding method, resistance welding and ultrasonic welding can be used. However, in the case of an aluminum electric wire whose core is an aluminum-based metal, the melting point of the aluminum-based metal is high. This may cause thermal degradation of the insulation coating. Therefore, ultrasonic welding is preferably used for aluminum wires.

  In the aluminum-based electric wire terminal connection structure of the present invention, the aluminum core wire exposed portion where the core wire is exposed without being welded between the rear end of the welded portion of the aluminum core wire and the peeled end of the insulation coating of the electric wire is tape, heat shrinkable It is waterproofed by covering with a tube or barrel covering. Since this structure is adopted, it is possible to prevent water from being welded from a non-welded portion that occurs when the aluminum core wire is welded to the terminal, and corrosion at the dissimilar metal contact portion between the aluminum core wire and the copper-based terminal can be prevented and suppressed.

It is a perspective view of the terminal of the embodiment of the present invention. It is a front view of the electric wire connected to the said terminal. It is drawing which shows the ultrasonic connection method of the said terminal and an electric wire. The state which weld-connected the said terminal and the electric wire is shown, (A) is a front view, (B) is a top view. The state which wound the adhesive tape after the said terminal and an electric wire were wound is shown, (A) is sectional drawing, (B) is a partial front view, (C) is a top view. It is the schematic which shows 2nd Embodiment. A 3rd embodiment is shown, (A) is a schematic front view of a terminal, and (B) is a sectional view showing the state where a barrel was caulked to an aluminum core wire exposure part. It is a graph which shows a test result. It is drawing which shows a prior art example. (A) (B) is explanatory drawing of the problem of a prior art example. It is a perspective view which shows another prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 show a first embodiment.
The terminal 1 shown in FIG. 1 has the same shape as the conventional terminal 120 shown in FIG. That is, the copper-based metal plate is punched and then bent. The terminal 1 is provided with a wire connecting portion 3 on one side (rear side) in the length direction of the flat substrate 2 and an electric contact portion 4 on the other side (front side). The electrical contact portion 4 is for making electrical connection by contacting with an electrical contact portion of a mating terminal (not shown). In this embodiment, as shown in FIG. 1, since it is a bolt fastening terminal, the width | variety of the board | substrate 2a of the electrical contact part 4 is expanded, and the bolt hole 5 is provided in the center.
The wire connection portion 3 has a core wire welding portion 6 on the front upper surface of a rectangular flat substrate 2b. Insulation coating barrels 7 (7a, 7b) are projected from both side surfaces in the width direction of the substrate at the rear portion of the core wire welding portion 6.

An aluminum-based electric wire 10 (hereinafter abbreviated as “aluminum electric wire 10”) having aluminum or aluminum alloy as a core wire connected to the terminal 1 is an electric wire to be wired to a vehicle, and has a core wire cross-sectional area of 8 mm ² or more and a thick electric wire. Used as a power line or ground line. As shown in FIG. 2, in the electric wire 10, the insulation coating 12 is peeled off at a terminal, and an aluminum core wire 11 twisted with a wire 11 a made of an aluminum-based metal is protruded from a peeled end 12 e of the insulation coating 12.

  The terminal 1 is connected to the aluminum electric wire 10 by the method shown in FIG. 3, and the aluminum electric wire 10 is ultrasonically connected to the terminal 1 as shown in FIG. That is, the aluminum core wire 11 is ultrasonically welded onto the core wire welding portion 6 of the terminal 1, and the insulation coating 12 is crimped and crimped by the insulation coating barrel 7. In this state, there is an aluminum core wire exposed portion 15 which is not welded from the rear end of the welded portion X of the aluminum core wire 11 to the peeled end 12e of the insulating coating. As shown in FIG. 5, an adhesive tape made of an insulating resin such as vinyl chloride and coated with an adhesive is provided on the insulating coating 12 at a position beyond the crimping and crimping portion by the aluminum core wire exposed portion 15 and the insulating coating barrel 7. 8 (hereinafter abbreviated as “tape 8”) is wrapped with a half wrap and covered. That is, the aluminum core wire exposed portion 15 is covered with the covering material made of the tape 8.

A method for connecting the terminal 1 and the aluminum electric wire 10 will be described with reference to FIG.
The aluminum electric wire 10 with the aluminum core wire 11 exposed at the terminal is set on the terminal 1, the aluminum core wire 11 is positioned on the core wire welding portion 6 of the terminal 1, and the peeled end 12 e of the insulating coating 12 is slightly smaller than the insulating coating barrel 7. Position it forward. In this state, the terminal 1 is placed at a predetermined position of the fixing base (anvil) 31 of the ultrasonic welding apparatus 30, the ultrasonic electrode (horn) 32 is lowered from above, and the upper surface of the exposed aluminum core wire 11 is pressurized. . In this state, an ultrasonic wave is applied, and the aluminum core wire 11 is welded to the core wire welding portion 6 of the substrate 1.

  When the horn 32 is placed in contact with the peeled end 12e of the insulating coating 12, thermal damage occurs in the insulating coating 12, so that a gap Z is formed between the end surface 32a of the horn 32 and the peeled end 12e. Therefore, the unwelded aluminum core wire exposed portion 15 remains between the welded portion X of the aluminum core wire 11 welded to the terminal 1 by the horn 32 and the peeled end 12e. The Y region where the unwelded aluminum core wire exposed portion 15 exists exists in a state of being inclined upward from the rear end of the welded portion X to the peeled end 12e.

  The aluminum core wire exposed portion 15, the crimped crimping portion by the insulating coating barrel 7, and further to the insulating coating 12 portion of the aluminum electric wire 10 extending from the rear end 1 e of the terminal 1, that is, in the region including the range of the region Y The said tape 8 of a covering material is wound and covered. Specifically, as shown in FIG. 5, a tape 8 is wound around the upper surface side of the aluminum core wire exposed portion 15 on the upper surface side from the lower surface of the substrate 2 of the terminal 1 and the crimping and crimping portion by the insulating coating barrel 7. The tape 8 is continuously wound around the outer peripheral surface of the electric wire 10 extending from the rear end of the substrate 2 by half-wrapping.

  As described above, in the aluminum electric wire 10 connected to the terminal 1, the welded portion X is not covered with the covering material such as the tape 8 and the barrel, but the aluminum core wire exposed portion 15 on the rear end side of the welded portion X is not welded. The Y region where the water is present is covered with a covering material made of the tape 8, and is waterproofed so as not to be exposed to water.

FIG. 6 shows a second embodiment.
In the second embodiment, the range including the aluminum core wire exposed portion 15, the crimping and crimping portion by the insulating coating barrel 7, and the Y region to the portion of the insulating coating 12 of the electric wire 10 extending from the rear end 1 e of the terminal 1. In addition, instead of the tape as a covering material, it is covered with a heat shrinkable tube 20 made of an insulating resin.
That is, the heat-shrinkable tube 20 having a large inner diameter which is not heat-shrinked before heating is covered in the above range, and then the heat-shrinkable tube 20 is shrunk by heating at a required temperature, and the aluminum core wire exposed portion 15, the substrate 2, and the insulation coating The heat shrinkable tube 20 is brought into close contact with the outer peripheral surface of 12 so as to eliminate a gap serving as a water immersion path. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

FIG. 7 shows a third embodiment.
In the third embodiment, as a covering material for the aluminum core wire exposed portion 15, barrels 19 </ b> A and 19 </ b> B for crimping and crimping the aluminum core wire exposed portion 15 are provided at the rear portion of the core wire welded portion 6 of the wire connecting portion 3 of the terminal 1. Provided. The barrels 19A and 19B are provided separately from the insulating coating barrel 7 provided at the rear end with a slit-shaped gap.

  The pressing pieces (not shown) of the crimping device for crimping and crimping the barrels 19A and 19B and the insulation coating barrel 7 are separated and simultaneously crimped and crimped, but the crimping and crimping operations are separate. As shown in FIG. 7B, the barrels 19A and 19B are arranged such that one barrel 19A is brought into close contact with the outer surface of the aluminum core wire exposed portion 15 and the tip side is folded, and the other barrel 19B is overlapped with the outer surface of the barrel 19A. Covered.

"Experimental example"
An aluminum electric wire terminal connection structure (Example) of the present invention in which an aluminum core wire exposed portion is covered with the heat shrinkable tube 20 of the second embodiment using an aluminum electric wire, and an aluminum electric wire not covered with the heat shrinkable tube 20 For the connection structure (conventional example) shown in FIG. 9, the presence or absence of a voltage drop due to corrosion was measured while spraying with salt water.
As a result, as shown in FIG. 8, in the example, there was no voltage drop even after 96 hours. On the other hand, in the conventional example, a voltage drop occurred after 24 hours.

  As described above, even if the welded portion X of the aluminum core wire is not covered, the occurrence of corrosion can be prevented or suppressed only by covering the unwelded aluminum core wire exposed portion 15. Therefore, even if there is a gap between the strands 11a of the aluminum core wire exposed portion 15 and corrosion occurs due to the presence of dissolved oxygen, the aluminum core wire exposed portion is covered with the covering material, so that dissolved dissolved in the air It was confirmed that the supply of oxygen can be delayed, and as a result, the progress of corrosion can be significantly delayed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, the terminal may be replaced with a bolted terminal, and the electrical contact portion may be a tab-shaped male terminal, or a box-shaped female terminal.

DESCRIPTION OF SYMBOLS 1 Terminal 2 Board | substrate 3 Electric wire connection part 4 Electrical contact part 6 Core wire welding part 7 Insulation coating barrel 8 Tape 10 Electric wire 11 Aluminum core wire 12 Insulation coating 12e Skinned end 15 Aluminum core wire exposed part 20 Heat shrinkable tube

Claims (5)

A terminal made of a copper-based metal plate, with an aluminum core wire formed by twisting an aluminum-based metal strand covered with an insulating resin insulation coating, stripping the insulation coating on the terminal side to expose the aluminum core wire The aluminum core wire is welded, and the insulation coating adjacent to the peeled end is crimped and crimped with an insulation coating barrel provided on the terminal,
The terminal connection structure of the aluminum-type electric wire which has covered the aluminum core wire exposed part between the rear end of the welding part of the said aluminum core wire, and the peeled end of the said electric wire at least with the coating | covering material.   2. The terminal connection structure for an aluminum-based electric wire according to claim 1, wherein the covering material is made of an insulating resin tape, and the insulating resin tape is wrapped around and covered with the exposed portion of the aluminum core wire.   2. The terminal connection structure for an aluminum-based electric wire according to claim 1, wherein the covering material is an insulating heat-shrinkable tube, and the exposed portion of the aluminum core wire is surrounded by the insulating heat-shrinkable tube.   The coating material is a barrel projecting from both sides of the terminal of the terminal in the width direction, and the barrel is a short barrel separated from the insulating coating barrel, and the barrel surrounds the exposed portion of the aluminum core wire. The terminal connection structure of the aluminum-type electric wire of Claim 1 currently crimped to. 5. The aluminum wire according to claim 1, wherein the aluminum-based electric wire is an electric wire arranged in a vehicle, and is used as a power supply line and a grounding wire with a thick wire having a core wire cross-sectional area of 8 mm ² or more. The terminal connection structure of the aluminum-type electric wire of description.

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