JP2000341841A - Method and structure for cutting off water for electric cable terminal connecting part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably cut water for an electric cable terminal connecting part with high performance. SOLUTION: An electric wire connecting part 3 connected with the terminal core wires 2 of a plurality of electric cables 1 is covered with an insulated covering material 10 whose both ends are open, and is immersed in a thermoplastic insulating resin melting tank 13 under this condition. The surface of the insulated covering material is coated with the melting resin. The melting resin is charged into its inside from the front end opening of the insulated covering material, and it is raised from the melting tank to harden the melting resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire terminal connecting portion in which cores exposed by stripping the insulation coating of the ends of a plurality of wires are integrally fixed and connected by resistance welding or ultrasonic welding. TECHNICAL FIELD The present invention relates to a water stopping method and a water stopping structure formed by the method, and is particularly preferably applied to electric wires routed in a water-covered area of an automobile.

[0002]

2. Description of the Related Art Conventionally, as a method of splicing between electric wires, as shown in FIG. A method is used in which the wire terminal connection portion 3 is integrally fixed by welding to form a wire end connection portion 3.

[0003] In order to stop the water at the wire terminal connecting portion 3,
Normally, as shown in FIG. 6, the electric wire terminal connection portion 3 is covered with a cap 4 having a closed end made of an insulating resin, and the cap 4 is filled with a sealant 6 so as to stop water. (JP-A-8-130045).

[0004] Alternatively, as shown in FIG. 7, a tube 7 coated with a hot-melt adhesive on its inner surface is connected to a wire terminal connecting portion 3.
The tube 7 is heated to melt the hot-melt adhesive to integrate the wire terminal connection portion 3 with the tube 7 and to penetrate and fill the space between the core wires and between the wires, and at the tip of the wire terminal connection portion. (See Japanese Patent Application Laid-Open No. 10-108345).

[0005]

In the method shown in FIG. 6, the sealing agent filled in the cap 4 is hardened by 10-1.
Since it takes 5 minutes and the productivity is very poor, it is necessary to fill the cap 4 with the sealing agent 6, insert the electric wire connection part into the cap 4, and hold it for a long time after the insertion as described above. It was difficult to perform in the assembly work line. Similarly, it is difficult to perform the method of FIG. 7 during the assembly work of the wire harness because it is necessary to cover the wire connection portion with a tube, inject hot melt into the tip thereof, and heat the tube using a heating means. In any case, there was a problem that the so-called in-line water stopping operation could not be performed, resulting in poor productivity.

[0006] Both of the water-stop structures shown in Figs. 6 and 7 have a problem in that the water-stop performance is not sufficient when the water-stop structure is installed in a water-receiving area such as an engine room of an automobile. That is, when the sealing agent 6 is filled in the cap 4 of FIG. 6, if the outer diameter of the electric wire is large, the sealing agent 6 may not be reliably filled between the inner peripheral surface of the cap 4 and the outer peripheral surface of the electric wire 1. There is a possibility that this will occur, and stable water stopping performance cannot be ensured, and it is not easy to adjust the filling amount of the sealant into the cap 4. When the heat-shrinkable tube 7 of FIG. 7 is used, the penetration of the resin between the core wires and between the electric wires is often insufficient.
Also in this case, stable water stopping performance cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made to provide a water-stopping operation that can be performed in-line, and has a high and stable water-stopping performance at a terminal portion of an electric wire. The challenge is to do.

[0008]

In order to solve the above-mentioned problems, the present invention covers an electric wire connecting portion to which terminal wires of a plurality of electric wires are connected with an insulating covering material having openings at both ends. It is immersed in a melting tank of resin (hot melt) to coat the surface of the insulating coating material with the molten resin, fill the inside of the insulating coating material with the molten resin through the opening at the tip, and pull up from the melting tank to cure the molten resin. The present invention provides a method for stopping water at a terminal portion of an electric wire, wherein

[0009] The melting tank of the thermoplastic insulating resin is installed on an assembly line of a wire harness, and the terminal end of the electric wire covered with the insulating coating material is immersed in the melting tank. The water can be stopped in-line to cure. Further, when immersed in the melting bath, the insulating resin can be attached also to the outer peripheral surface of the insulating coating material and the outer peripheral surface of the electric wire drawn from the insulating coating material. In addition, the molten resin flows into the inside of the insulating covering material from both sides of the front end opening and the rear end opening of the insulating covering material, and the resin is securely applied to the inner peripheral surface of the insulating covering material, the connection portion, the outer peripheral surface of the core wire and the electric wire. The resin can be filled, and the resin can penetrate into the gaps between the core wires and between the electric wires.

[0010] The present invention provides a water-stop structure for a wire terminal connection manufactured by the above method, wherein the water-stop structure is such that the insulating coating material extends from the bundled wire side to a position beyond the terminal connection. In addition, the insulating resin is filled in the gap between the wires, the gap between the core wires, and the outer periphery of the wire terminal connecting portion inside the insulating coating material, and the outer peripheral surface of the insulating coating material is also coated with the insulating resin. Have been.

[0011] The insulating coating material is a tube, an adhesive sheet,
An adhesive tape is used. In the case of an adhesive sheet and an adhesive tape, the adhesive tape is wound around the electric wire, the core wire, and the outer peripheral surface of the electric wire connection portion, and the wound portion is projected from a tip end of the electric wire connection portion by a required dimension. A heat-shrinkable tube is most preferably used as the insulating coating material.

[0012] In the above-described water-stop structure of the wire terminal connection portion,
The outer peripheral surface of the insulating coating material is further coated with an insulating resin layer, so to speak, it is double coated, so it has abrasion resistance even when it comes in contact with an external interference material during use, and the wire terminal connection part can easily be connected to the outside. Not exposed to Further, even if the thickness of the insulating resin layer on the outer surface formed of the molten resin varies, the insulating coating material having a constant thickness is located in the inner layer, so that stable water stopping performance can be obtained. Also, because it is immersed in the melting tank,
The inner peripheral surface of the insulating coating material is filled with resin without generating a gap, and the gap between the outer peripheral surface of the wire connection portion, the core wire and the electric wire and the inner peripheral surface of the insulating coating material is securely filled with the resin. In addition, the resin penetrates and fills the gap between the core wire and the electric wire, and high water stopping performance can be stably obtained.

In particular, when a heat-shrinkable tube is used as the insulating coating material, the heat-shrinkable tube itself shrinks due to the heat of the molten resin, and adheres tightly to the wire connection portion, the core wire, and the outer peripheral surface of the wire. Can be even higher.

The wire terminal connecting portion may be one in which the core wires exposed from the wire terminals are integrally connected by resistance welding or ultrasonic welding, or one in which the core wires are caulked and crimped together with a crimp terminal. .

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In the first embodiment, as shown in FIG. 1, terminal core wires 2 of a large number of electric wires 1 are integrally fixed by resistance welding to form an electric wire terminal connecting portion 3. A heat-shrinkable tube 10 is put over the wire end connection portion 3 (hereinafter, abbreviated as the connection portion 3) to the core wire 2 and the wire 1, and has a constant thickness from the outer circumferential surface of the heat-shrinkable tube 10 to the outer circumferential surface of the wire 1. In addition to providing the insulating resin layer 11, a filled insulating resin portion 11 'is also provided inside the heat-shrinkable tube 10 without any gap.

The water stopping structure of the wire terminal connecting portion shown in FIG.
It is formed by a method shown in FIGS.

First, as shown in FIG.
A resin-made heat-shrinkable tube 10 having openings 10a and 10b is put on the ends of the electric wires. At this time, one end 10a of the tube 10
Extends from the tip of the connection portion 3 and has the other end 10
“b” extends a required dimension from the exposed portion of the core wire toward the electric wire 1.

Next, as shown in FIG. 2 (B), the terminal portion of the electric wire having the heat-shrinkable tube 10 covered in the melting tank 13 of the thermoplastic resin 12 installed on the wire harness assembling work line is raised. Immerse more. During this immersion, the part of the electric wire 1 drawn out of the heat-shrinkable tube 10 is also immersed.

As the thermoplastic resin 12 stored in the melting tank 12, polyamide or vinyl chloride having an adhesive property is used, and the viscosity is set to 2000 cps or less.

When immersed in the melting tank 13, FIG.
As shown in (C), the resin 12 melted with a constant thickness adheres to the outer peripheral surface of the heat-shrinkable tube 10 and the upper peripheral surface of the electric wire 1. At the same time, the resin 12 flows into the opening 10 a located at the lower end of the heat-shrinkable tube 10, and is filled between the outer peripheral surface of the connection portion 3, the core wire 2, the electric wire 1 and the inner peripheral surface of the heat-shrinkable tube 10. At the same time, a gap between adjacent core wires 2 and a gap between adjacent electric wires 1 penetrate and fill.
Similarly, the resin 12 flows from the upper opening 10b into the heat-shrinkable tube 10. And the heat-shrinkable tube 10
The resin itself is heated by the heat of the melted resin 11, contracts and adheres to the outer peripheral surfaces of the connection portion 3, the core wire 2, and the electric wire 1.

Next, as shown in FIG. 2 (D), the electric wire 1 is pulled up from the melting tank 12 and held for 5 to 10 seconds. The melted thermoplastic resin 11 hardens in 5 to 10 seconds, and forms the insulating resin layer 11 on the outer peripheral surface of the heat-shrinkable tube 10 and the filled insulating resin portion 11 'inside the tube 10 shown in FIG.

In the above waterproof structure, an insulating resin layer 11 is further provided on the outer peripheral surface of the heat-shrinkable tube 10 having a constant thickness.
Since the water stop is doubled on the outer peripheral surface of the wire end, stable water stop performance can be obtained, and wear resistance is provided even in the case of contact with an external interference material. Further, since the outer peripheral surface of the electric wire 1 drawn from the heat-shrinkable tube 10 is also covered with the insulating resin layer 11, the heat-shrinkable tube 10
Water can be prevented from being generated in the inside from the electric wire side. Further, also in the heat-shrinkable tube 10, the filling insulating resin portion 11 'is reliably provided between the inner surface thereof and the connecting portion 3, the core wire 2 and the outer peripheral surface of the electric wire, and further in the gap between the core wire 2 and the electric wire. Can be eliminated, and high water stopping performance can be stably obtained.

In the above embodiment, the heat-shrinkable tube 10 is used as the insulating coating material, but a tube having no heat-shrinkability may be used. Also, instead of the tube 10,
As shown in FIG. 3A, an adhesive sheet 20 having an adhesive applied to the inner surface may be used, and the adhesive sheet 20 may be wound around the connecting portion 3 of the terminal of the electric wire, the core wire 2 and the electric wire 1 to be fixed. Further, as shown in FIG. 3 (B), an adhesive tape 21 having an adhesive applied to the inner surface is used, and the adhesive tape 21 is wound around the electric wire 1, the core wire 2, and the connection portion 3, and the required dimension is further extended from the connection portion 3. The windings may be formed in the presence of the windings. Further, as shown in FIG. 3 (C), after the cap 4 similar to that shown in FIG. 6 is used and fixed to the electric wire by tape winding, the closed end of the cap 4 may be cut and used. In any case, after attaching these insulating coating materials, they are immersed in a thermoplastic resin melting tank as in the first embodiment.

FIG. 4 shows a second embodiment. The difference from the first embodiment is that the core wires 2 exposed from the ends of the plurality of electric wires 1 are shown.
Is crimped and crimped by a crimp terminal 30 to form an electric wire terminal connecting portion 3 ′ integrally connected. The other configuration is the same as that of the first embodiment. The insulating coating material made of the tube 10 is covered and immersed in a molten resin bath to form a water-stop structure similar to that of the first embodiment. The description is omitted by attaching reference numerals.

[0025]

As is apparent from the above description, according to the present invention, after covering the terminal end portion of the electric wire with an insulating coating material such as a tube having both ends opened, it is immersed in a melting bath of a thermoplastic resin. Since the molten resin flows into the insulation coating material and fills it, the molten resin is surely penetrated into the gap between the insulation coating material and the connection portion, the core wire and the outer peripheral surface of the wire, and further into the gap between the core wire and the wire. can do. In addition, since an insulating resin layer can be further formed on the outer peripheral surface of the insulating coating material and can be double-coated with the insulating resin material, a stable water-blocking structure and a water-resistant material having wear resistance can be obtained. It can improve the water stopping performance.

Further, it is immersed in a thermoplastic resin melting tank,
In order to set the wire harness in a work line for assembling the wire harness in order to set the wire harness in 5 seconds to 10 seconds after being pulled out of the melt bath, the water stopping operation can be performed in the assembly line (inline). Therefore, water can be stopped efficiently,
Productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a water stop structure according to a first embodiment.

FIGS. 2A to 2D are views showing a method of forming the water-stop structure.

FIGS. 3A to 3C are diagrams showing other insulating coating materials.

FIG. 4 is a drawing showing a water stop structure of a second embodiment.

FIG. 5 is a front view showing an electric wire group provided with electric wire terminal connecting portions.

FIG. 6 is a sectional view showing a conventional water blocking structure.

FIG. 7 is a sectional view showing another conventional water blocking structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric wire 2 Core wire 3 and 3 'Electric wire terminal connection part 10 Heat-shrinkable tube (insulating coating material) 11, 11' Insulating resin tank 12 Melted thermoplastic resin 13 Melting tank 20 Adhesive sheet 21 Adhesive tape 30 Crimp terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E085 BB01 CC03 DD03 HH13 JJ13 JJ38 5G375 AA02 BA09 BA15 BA26 BB43 BB45 BB48 BB81 CA02 CA12 CA13 CB04 CB08 CB10 CB21 CD17 DB33 EA17

Claims (4)

[Claims] An electric wire connecting portion to which terminal wires of a plurality of electric wires are connected is covered with an insulating coating material having openings at both ends. In this state, the insulating coating material is immersed in a melting tank of a thermoplastic insulating resin, and the surface of the insulating coating material is coated. A method of stopping water at a wire terminal connection portion, wherein a molten resin is coated, the inside of the insulating coating material is filled with the molten resin from an opening at a front end thereof, and the molten resin is pulled up from a melting tank to cure the molten resin. 2. A water stopping structure for an electric wire terminal connection manufactured by the method according to claim 1, wherein the insulating coating material is covered from the bundled electric wire side to a position beyond the terminal connection. Together with the gap between the electric wires inside the insulating coating material,
Insulation resin is filled in the gap between the core wires and the outer periphery of the wire terminal connecting portion, and the outer peripheral surface of the insulating coating material is also covered with the insulating resin, and the water stopping structure of the wire terminal connecting portion. 3. The water stopping structure for an electric wire terminal connecting part according to claim 2, wherein the insulating covering material comprises a tube, an adhesive sheet, and an adhesive tape. 4. The water stopping structure according to claim 3, wherein the tube is a heat-shrinkable tube.