JP2015135742A - Terminal and electrical wire connection method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal having excellent connection reliability with a core wire of an electrical wire.SOLUTION: In a terminal having an electric contact part on a front side in a longitudinal direction of a substrate consisting of a conductive metal plate and an electrical wire connection part on a rear side, the electrical wire connection part is provided with a core wire welding part consisting of the planar substrate and an insulation coating stationary part on the rear end of the substrate, the core wire welding part is provided with protrusions extending in the width direction over the whole length at two positions with an interval in the front-back direction, and a core wire consisting of a plurality of element wires exposed on the electrical wire terminal is welded with an ultrasonic wave in the state in which there is no gap in the element wires adjacent in the width direction and in the vertical space between the element wires and the terminal in the state in which the core wire is pressed against the upper surfaces of the protrusions at the two front and back positions.

Description

  The present invention relates to a terminal and a wire connecting method for the terminal, and more particularly to a method for connecting a core wire exposed at a wire terminal to a terminal by ultrasonic welding.

  Conventionally, as shown in FIG. 6, a terminal 100 made of a copper-based metal plate connected to a wire terminal has a wire connecting portion 101 on one side in the length direction and an electric contact portion 102 on the other side. The connection portion 101 is provided with an insulation coating barrel 103 and a core wire barrel 104, and the electrical contact portion 102 is a tab-shaped male terminal or a box-shaped female terminal having a flat plate shape as shown in the figure. The core wire 201 exposed at the end of the electric wire 200 is crimped and crimped to the terminal 100 by the core wire barrel 104, and the insulation coating layer 202 is crimped and crimped by the insulation coating barrel 103.

  On the other hand, as shown in FIGS. 7 (A) to 7 (D) in Japanese Patent Application Laid-Open No. 2004-127582 (Patent Document 1), a core wire 251 of an electric wire (hereinafter referred to as an aluminum electric wire) 250 made of an aluminum material is used. A pressing piece (insulation coating barrel) 303 set on the wire connection portion 302 of the terminal 300, resistance welded by the upper and lower electrodes 308 and 309 to weld the core wire 251 and protruding from the rear end side of the wire connection portion 302. A terminal for crimping and crimping the insulating coating 252 of the electric wire 250 is provided. As described above, the core wire 251 of the aluminum electric wire 250 is welded to the copper-based metal terminal 300 and the insulation coating 252 is crimped and crimped by the insulation coating barrel 303 because the core wire 251 made of aluminum-based metal and the copper-based metal are bonded. This is to increase the reliability of electrical connection between different types of metal with the terminal 300 and to prevent the occurrence of corrosion by preventing the adhesion of moisture to the connecting portion.

  Specifically, the terminal 300 disclosed in Patent Document 1 is provided with side walls 302b erected along both side edges in the width direction of the bottom wall 302a of the wire connection portion 302, and a gap is formed between the side walls 302b on both sides. A plurality of convex portions 305 inclined in the longitudinal direction are projected in parallel at the center portion of the bottom wall 302a, and the core wire 251 of the electric wire 250 is placed on the convex portions 305 for resistance welding.

JP 2004-127582 A

  In the terminal of Patent Document 1, a core wire 251 made of an aluminum-based metal of the electric wire 250 is resistance-welded to the terminal 300. However, the aluminum material of the core wire 251 has a melting point as compared with a copper-based metal of a widely used copper wire. In order to melt the core wire by resistance welding, it is necessary to heat at a high temperature. However, there is a problem that resistance welding is not suitable for the core wire welding of an aluminum electric wire because there is a risk of causing heat deterioration of the resin of the insulation coating of the electric wire when heated at a high temperature.

In addition, since there is a gap C1 between the convex portion 305 and the side wall 302b of the bottom wall 302a, which is a welded portion of the terminal 300, as shown in an enlarged view in FIGS. The core wires 251se on both sides in the width direction are likely to enter among the many strands 251s constituting the wire. The upper electrode 308 for resistance welding is inserted between the side walls 302b with a gap therebetween and is welded in contact with the core wire 251 on the convex portion 305, but the element that has fallen into the gap C1. The wire 251se is not in contact with the upper electrode 308, and as a result, there is a core wire 251se that is not welded to the wire connecting portion of the terminal 300. This is because the width of the upper electrode 308 of resistance welding is narrower than the width that allows the core wire 251 to be inserted.
As described above, when a part of the wire 251se of the core wire 251 is not welded and the gap C2 in the length direction of the electric wire is generated with the bottom wall 302a of the terminal 300, the gap C2 becomes a flooded path, and the dissimilar metal Corrosion occurs due to water immersion between the core wire 251 and the terminal 300. When this corrosion progresses, an electrical contact failure between the core wire 251 and the terminal 300 occurs.

That is, the width of the upper electrode 308 for resistance welding is narrower than the width of the portion into which the core wire 251 of the welded portion of the terminal is inserted, and the strands on both sides in the width direction of the core wire 251 placed on the bottom wall of the welded portion. The above-mentioned problem arises because the wire is not welded to the terminal.
In addition, in the case of ultrasonic welding instead of resistance welding, as shown in FIG. 9, ultrasonic welding couples metals by applying parallel vibration while applying pressure to the terminal 300 and the strand 251 s of the core wire 251. Therefore, the deformation of the element 251s having a circular cross section is small, and the gap C3 is easily generated in the length direction of the electric wire between the adjacent elements 251s and between the element 251s and the terminal 300. Therefore, this gap C3 becomes an inundation path, and inundation occurs at the connection portion between the core wire 251 and the terminal 300, which may cause corrosion.

  The present invention has been made in view of the above problems, and a plurality of strands constituting a core wire of an electric wire are welded to a terminal without a gap between adjacent strands, between a strand and a terminal. It is an object of the present invention to eliminate the generation of gaps and prevent water from being generated between the core wire and the terminal.

In order to solve the above problems, the present invention provides:
In the terminal provided with the electric contact part on the front side in the length direction of the substrate made of the conductive metal plate and the electric wire connection part on the rear side,
In the wire connection portion, a core wire welded portion made of the flat substrate, and an insulating coating fixing portion at the rear end of the substrate,
The core wire welded portion is provided with protrusions extending in the entire length in the width direction at two places spaced in the front-rear direction,
A core wire composed of a plurality of strands exposed at the end of the electric wire is pressed against the upper surfaces of the two front and rear projections, and between the strands adjacent in the width direction and between the strands and the terminals. A terminal that is configured to be ultrasonically welded without a gap is provided.

It is preferable that the insulation coating fixing portion provided behind the core wire welding portion is provided with an insulation coating barrel projecting from both sides in the width direction of the substrate, and the insulation coating barrel is crimped and crimped to the insulation coating of the electric wire.
Note that the insulating coating fixing portion is not limited to crimping crimping by a barrel, and may be configured, for example, in a U-shape by pressing the insulating coating from the side and fixing.

The height of the protrusion is not less than the radius of the wire and not more than the diameter, and the protrusion is provided at a right angle to the length direction of the terminal,
Of the protrusions provided at the two front and rear positions, one protrusion on the front is provided on the front end side of the core wire welded portion continuous with the electric contact portion, and one protrusion on the rear end is provided on the rear side close to the insulating coating barrel. It is preferable that the distance between the front and rear protrusions is increased at the rear end of the core wire weld.
That is, two protrusions at the front and rear are provided at positions corresponding to both ends in the front-rear direction of the horn of the ultrasonic welder, and the range of the protrusions can be widened to expand the range of the wire connection portion that can be reliably waterproofed.

  When the height of the protrusion is equal to or greater than the radius of the strand, the lower side portion can be crushed and brought into close contact with the core wire welded portion on the lower surface where the lowermost strand is in contact. On the other hand, by making it below the diameter, it is possible to smoothly apply ultrasonic vibrations without overloading the strands.

In addition, it is preferable that the protrusions provided at the two front and rear positions are provided at right angles to the length direction of the terminal.
That is, by providing the projections at the two front and rear portions in parallel with each other and in the direction perpendicular to the length direction of the core wire to be welded, the distance between the two front and rear projections can be widened to ensure waterproofing. The range of the wire connection part can be expanded.

The terminal of the present invention is an electric wire routed in a vehicle, with respect to a thick electric wire having a core wire cross-sectional area of 8 mm ² or more, and an aluminum electric wire whose core wire is made of an aluminum-based metal (hereinafter abbreviated as an aluminum electric wire). Preferably used.
This is because, in the case of a thick wire, the electrical connection reliability can be increased by welding the core wire to the terminal. Also, with aluminum wires, corrosion due to moisture is likely to occur on the contact surface with a terminal made of a dissimilar copper-based metal. Therefore, the terminal and core wire are connected by welding to prevent the occurrence of corrosion. Reliability can be increased.

In particular, from the viewpoint of increasing the reliability of electrical connection between a thick aluminum wire and a terminal, it is essential that the core wire of the thick aluminum wire be welded to the terminal.
The melting point of the aluminum-based metal of the aluminum wire is higher than that of the copper-based metal of the widely used copper wire. Therefore, when the aluminum wire is welded to the terminal by resistance welding, it is necessary to heat it at a high temperature. There is a risk of generating.
Therefore, the terminal of the present invention including welding with an aluminum electric wire is welded to the core wire of the electric wire not by resistance welding but by ultrasonic welding.

Furthermore, this invention provides the connection method of the said terminal and an electric wire.
In this method, the core wire exposed at the end of the electric wire is bridged and placed on the upper surface of the two protrusions of the core wire welding portion of the terminal, and the core wire of the terminal is placed on the anvil of the ultrasonic welding apparatus. Set a welded part, pressurize the wire with a horn of an ultrasonic welding device, and apply ultrasonic vibration in a state of pressing so as to crush the lower surface of the core wire that contacts the upper surface of the protrusion. And ultrasonic welding.

  As described above, when the horn above the ultrasonic welding apparatus is lowered and pressed, the strands are pressed and crushed more strongly than the other portions on the protrusions of the core wire welded portion, and adjacent strands And the lowermost element wire and the core wire welding part of a terminal will be in the state closely_contact | adhered. In this state, the strands of the core wires and the bottom strand and the terminal are welded by frictional heat due to the load of ultrasonic vibration. Therefore, it is possible to reliably eliminate the occurrence of gaps in the width direction between the core wires and between the wires and the terminals on the front and rear protrusions extending in the entire width direction of the terminals. As a result, water stoppage is reliably performed at the two front and rear projections, so that water is not applied to the contact portion between the core wire and the terminal at the portion sandwiched between the two front and rear projections, and corrosion is reliably generated. The electrical connection reliability between the core of the electric wire and the terminal can be improved.

In the present invention, in the terminal to which the core wire of the electric wire is welded and connected, protrusions are provided over the entire length in the width direction at two locations on both the front and rear sides of the core wire welded portion, and the front and rear wires 2 constituting the core wire exposed at the end of the electric wire. The place is set on the upper surface of the projection, and in this state, ultrasonic welding is performed by pressing the lower surface of the wire in contact with the upper surface of the projection with a horn above the ultrasonic welding machine. Therefore, the strands of the core wire can be welded on the projection without any gap, and the strands adjacent in the width direction on the projection can be welded in a state where the gap is crushed.
As a result, the wires can be welded without gaps in the width direction and without gaps in the length direction on the two front and rear projections, and a flooding prevention wall (barrier) can be formed on the two front and rear projections. Therefore, the portion sandwiched between the two protrusions at the front and rear can be held in the connection range between the electric wire and the terminal where no water is generated, and electrical connection reliability can be ensured.

The terminal of embodiment of this invention is shown, (A) is a perspective view, (B) is a front view, (C) is a partial top view. The electric wire connected to the said terminal is shown, (A) is a front view, (B) is a left view. It is a top view of the state which set the electric wire terminal to the said terminal. The state which ultrasonically welds the said terminal and the core wire of an electric wire is shown, (A) is sectional drawing of the protrusion part of a terminal, (B) is sectional drawing of a part without a protrusion, (C) is drawing which shows a comparative example. is there. The connection part of the said terminal and an electric wire is shown, (A) is a top view, (B) is a front view. (A) (B) is drawing which shows a prior art example. (A)-(D) are drawings which show another prior art example. (A) and (B) are drawings showing the problems of the conventional example of FIG. It is drawing which shows the problem in the case of ultrasonically welding a terminal and an electric wire.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a terminal 1 of the embodiment. The terminal 1 is formed by punching a copper metal plate and bending it. The terminal 1 is provided with a wire connecting portion 3 on one side (rear side) in the length direction of the 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).

  An electric wire 20 shown in FIG. 2 connected to the terminal 1 is an electric wire to be wired to a vehicle, and a core wire 21 formed by twisting a number of strands 22 made of aluminum metal is covered with an insulating coating 23 made of an insulating resin. doing. Since the strands 22 forming the core wire 21 are twisted with a circular cross section to form the core wire 21, there are minute gaps between the numerous strands 22 constituting the core wire 21.

The electric wire 20 of the present embodiment is a power supply line made of a thick aluminum electric wire having a core wire cross-sectional area of 20 mm ² . The electric wire 20 composed of the power supply line is provided with a bolt hole 5 in the substrate 2a of the electrical contact portion 4 of the terminal 1 for bolting connection with the power supply terminal.

  Insulation coating in which a wire connecting portion 3 of the terminal 1 is provided with a core wire welded portion 10 and an insulation coating barrel 12 provided on the rear side of the core wire welded portion 10 in a region extending from the boundary 4e with the front electrical contact portion 4 to the rear end. A caulking portion 11 is provided. As shown in FIG. 1C, the core wire welded portion 10 is made of a rectangular flat plate having the same width X1 in the longitudinal direction and the length dimension Y1, and the insulation coating crimped portion 11 is formed at the rear end of the substrate 2. An insulation coating barrel 12 projects from the side edge in the width direction.

  The core wire welded portion 10 is an element of the core wire 21 exposed at the end of the electric wire 20 between the anvil 30 disposed below the welded portion of the ultrasonic welding apparatus shown in FIG. This is a portion where the wire 22 is ultrasonically welded. The width X1 and length Y1 of the core wire weld 10 are less than the width and length of the anvil 30. In the present embodiment, the width X1 of the core wire welded portion 10 is 5 mm, the length Y1 is 30 mm, and the plate thickness t is 2 mm.

  Linear protrusions 15 and 16 are provided at two positions in the front-rear direction near the front end and the rear end in the length direction of the core wire welded portion 10 so as to protrude upward in the entire width direction. The protrusions 15 and 16 are provided in parallel to each other at right angles to the length direction. The protrusion height h of the protrusions 15 and 16 is greater than or equal to the radius of the core wire 21 and less than or equal to the diameter. In the present embodiment, the height h is 0.2 mm.

Next, a method for connecting the terminal 1 to the electric wire 20 will be described with reference to FIGS.
In order to weld the core wire 21 exposed at the end of the electric wire 20 to the core wire welded portion 10 of the terminal 1, the tips of the multiple strands 22 of the core wire 21 are positioned at the front end of the core wire welded portion 10, and the front projection 15 It is placed on top and placed on the rear projection 16 in a bridging manner. In this state, the peeled end 23 s of the insulating coating 23 is positioned behind the protrusion 16 and in front of the insulating coating barrel 12 of the insulating coating crimping portion 11.

  As shown in FIGS. 4A and 4B, the strands 22 of the core wire 21 are stacked in the vertical direction in a scattered state in the width direction X, and the strands 22 protrude from both end edges in the width direction of the core wire welded portion 10. Set so that it does not. In this state, the lower surface of the core wire welding portion 10 of the terminal 1 is set on the anvil 30 of the ultrasonic welding apparatus.

  Next, the horn 31 of the ultrasonic welding apparatus is lowered to the core wire 21 set on the core wire weld 10. Before the ultrasonic vibration is generated, the strand 22 of the core wire 21 set on the core wire welded portion 10 is pressurized from the upper surface. With this pressurization, the lower surface of the core wire 21 spanned between the front and rear projections 15 and 16 is pressed against the upper surface of the core wire welded portion 10 as shown in FIG. Of the strands 22 stacked in the vertical direction, the lower strand 22d extends in the width direction from the middle strand 22m, the middle strand 22m extends in the width direction from the upper strand 22u, and the strand 22 is trapezoidal. Pressure.

In particular, the pressurization is strongly applied to the strands 22 placed on the protrusions 15 and 16 at the two front and rear positions protruding on the core wire welding portion 10. Since the protrusions 15 and 16 are provided over the entire length in the width direction of the core wire welded portion 10, the strands 22 do not protrude at positions outside the both ends of the core wire welded portion 10 in the width direction.
In addition, if the protrusions 15 and 16 are not provided on the entire length in the width direction of the terminal 1 and the protrusions 50 are provided with gaps on both sides in the width direction as shown in FIG. The strands 22 fall outward, and gaps C <b> 5 are generated between the strands 22 on the top surface of the terminal core wire weld 10 and between the top and bottom strands 22.

  Since the height of the projections 15 and 16 is equal to or greater than the radius of the strand 22, the lower side of the lower strand 22 d is crushed on the projections 15 and 16 as shown in FIG. The gap C3 shown in FIG. 4B disappears between the lower strand 22d contacting the upper surface of the welded portion 10. In addition, there is no gap C2 between the adjacent strands 22 in the width direction on the protrusions 15 and 16 and between the adjacent strands 22 in the vertical direction.

  As described above, ultrasonic vibration is applied in a state where the horn 30 is lowered to press the strands 22 of the core wire 21, and contact friction is generated between adjacent strands and between the strands 22 and the core wire welded portion 10, The contact surface is melted and welded by frictional heat. Thereby, in the waterproof region Z of the core wire welded portion 10 between the protrusions 15 and 16 shown in FIG. 5B, the lower wire 22d is welded to the upper surface of the core wire welded portion 10, and the lower wire 22d, The middle strand 22m and the upper strand 22u are welded up and down, and the strands adjacent to each other in the width direction are welded, and the terminal 1 and the core 21 of the electric wire are electrically connected.

  The strands 22 on the projections 15 and 16 are fixedly welded to the core wire welded portion 10 of the terminal 1 in the state shown in FIG. 4 (A), and the lower strand 22d and the middle strand adjacent to each other in the vertical direction. 22m and upper wire 22u are welded together. And it is welded without the gap on either side between the strands 22 adjacent on the protrusions 15 and 16 in the width direction. In addition, since the protrusions 15 and 16 are provided over the entire length in the width direction of the core wire welded portion 10 on the flat plate, the strands 22 are welded without gaps over the entire length in the width direction and serve as a waterproof weir. Therefore, it is possible to reliably prevent water from entering the core wire welded portion 10 in the waterproof region Z between the protrusions 15 and 16.

  As described above, after the core wire 21 is ultrasonically welded to the core wire welded portion 10 of the terminal 1, the terminal insulation coating barrel 12 is crimped and crimped to the insulation coating 23 of the electric wire 20.

  As described above, the wire 22 of the core wire 21 is ultrasonically welded to the core wire welded portion 10 of the terminal, and the insulation coating 23 is crimped and crimped by the insulation coating barrel 12 of the insulation coating crimping portion 11 so that the terminal 1 and the electric wire are connected. 20 is connected. Thus, the core wire 21 and the terminal 1 of the electric wire 20 are welded by ultrasonic welding, and the insulation coating 23 is crimped and crimped, so that the electric wire 20 and the terminal 1 can be connected in a state where the electrical connection reliability is improved. Moreover, by forming a waterproof weir that can reliably prevent flooding by the protrusions 15 and 16 on the front and rear sides of the core wire connecting portion 10, it is possible to prevent corrosion between the wire 22 and the core wire welded portion of the terminal 1. it can.

  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, a copper wire may be connected to the terminal instead of the aluminum wire. Moreover, the shape of the electrical contact portion of the terminal may be changed to a bolt hole and 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 10 Core wire welding part 11 Insulation coating crimping part 12 Insulation coating barrel 15, 16 Protrusion 20 Electric wire 21 Core wire 22 Wire 23 Insulation coating 30 Anvil 31 Horn

Claims (5)

In the terminal provided with the electric contact part on the front side in the length direction of the substrate made of the conductive metal plate and the electric wire connection part on the rear side,
In the wire connection portion, a core wire welded portion made of the flat substrate, and an insulating coating fixing portion at the rear end of the substrate,
The core wire welded portion is provided with protrusions extending in the entire length in the width direction at two places spaced in the front-rear direction,
A core wire composed of a plurality of strands exposed at the end of the electric wire is pressed against the upper surfaces of the two front and rear projections, and between the strands adjacent in the width direction and between the strands and the terminals. A terminal characterized in that ultrasonic welding is performed in a state where there is no gap.   The terminal according to claim 1, wherein the insulating coating fixing portion is provided with an insulating coating barrel as an insulating coating caulking portion. The height of the protrusion is not less than the radius of the wire and not more than the diameter, and the protrusion is provided at a right angle to the length direction of the terminal,
Of the protrusions provided at the two front and rear positions, one protrusion on the front is provided on the front end side of the core wire welded portion continuous with the electric contact portion, and one protrusion on the rear end is provided on the rear side close to the insulating coating barrel. The terminal according to claim 1 or 2, wherein the terminal is provided at a rear end of the core wire welded portion, and the width of the front and rear projections is expanded. The terminal according to any one of claims 1 to 3, wherein the electric wire is an electric wire to be wired to a vehicle, and is used for connecting a thick electric wire and an aluminum electric wire having a core wire diameter of 8 mm ² or more. A method of connecting a core wire exposed at an electric wire terminal to the terminal according to any one of claims 1 to 4,
The core wire exposed at the end of the wire is bridged and placed on the upper surface of the two protrusions of the core wire weld of the terminal, and the core wire weld of the terminal is set on the anvil of the ultrasonic welding apparatus Then, ultrasonic welding is performed by applying ultrasonic vibration in a state where the wire is pressed with a horn of an ultrasonic welding apparatus and pressed so as to crush the lower surface of the wire contacting the upper surface of the protrusion. How to connect the terminals and wires.

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