JP5428722B2 - Water stop structure of electric wire and method of forming the water stop structure - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a water-stop structure for an electric wire and a method for forming the water-stop structure, and more specifically, a water-stop structure that prevents inundation from occurring inside the electric wire from the terminal crimping portion of the electric wire whose core wire is covered with an insulating coating layer. And a method for forming the water-stop structure.

  When connecting a crimp terminal to the wire terminal of a wire harness of an automobile or a motorcycle, the core wire is exposed by peeling the insulation coating layer of the wire, and the core wire barrel of the crimp terminal is crimped and crimped to the core wire exposed portion. The terminal is electrically connected.

  For example, an earth terminal that is crimped to an electric wire terminal for earthing may be bolted to a vehicle body or an engine case in an engine room or the like that is a flooded area of an automobile to achieve earth connection. In that case, the connection portion between the ground terminal and the electric wire, that is, the exposed portion of the core wire is also easily wetted. When the core wire of the electric wire is exposed to water in this way, the core wire is corroded, or water penetrates between a number of strands constituting the core wire due to a capillary phenomenon or a pressure difference. There is also a problem in that the inundation occurs in the connected electronic device and has an adverse effect. A similar problem also occurs at the connection point with the ground terminal of the electric wire routed in the motorcycle.

Conventionally, various water stop structures have been proposed for water immersion from the terminal connection portion of the terminal of the covered electric wire.
For example, in Japanese Patent Application Laid-Open No. 2001-167821 (Patent Document 1), as shown in FIG. 8, a core wire exposed portion where a terminal is crimped and crimped is resin-molded. Specifically, the terminal connection portion formed by crimping the terminal 3 to the core wire exposed portion 2 at the tip end portion of the covered electric wire 1 is covered with the shield resin 4 on both side surfaces and the upper surface except for the bottom surface. . Accordingly, it is possible to prevent water from being exposed from the front surface side, and when the bolt is fixed to the body of the automobile and connected to the ground, the connection surface on the bottom surface side is brought into a close state, and electrical conduction can be achieved. .

  However, the water-stopping structure requires a mold for molding, and requires different dedicated dies depending on the type and shape of the terminal to be used and the wire diameter. There is.

  As another example of the water stop structure, the present applicant has proposed a structure in which a water stop agent is infiltrated into an electric wire in Japanese Patent Application Laid-Open No. 2004-355851 (Patent Document 2). As shown in FIG. 9, the water stop structure supplies a water stop agent having fluidity to the side where the terminal 6 is crimped to the core wire exposed portion 5 a on one end side of the covered electric wire 5. From the terminal, air inside the insulating coating layer 5b is sucked and depressurized, so that the water-stopping agent penetrates inside the insulating coating layer 5b to form a water-stopping structure.

  In the suction process, the suction process is often performed simultaneously on the plurality of electric wires 5 in order to increase the efficiency of the water stop treatment. Specifically, as shown in FIG. 10, the other end of the plurality of electric wires 5 is inserted and connected to a common electric wire connecting device 7, and the electric wire connecting device 7 is connected to the suction pump 9 via the pressure control panel 8. This is done by connecting to the inlet. The electric wire connecting device 7 includes a housing 7a whose inside is sealed, and a front wall of the housing 7a includes a plurality of through holes 7c and a cylindrical rubber plug 7d attached to the inside of the through hole 7c. The provided electric wire holding plate 7b is provided, and the rubber plug 7d is brought into pressure contact with the surface of the insulating coating material 5b of the electric wire 5 inserted into each rubber plug 7d. I keep it.

  However, this water stop structure needs to prepare an electric wire holding plate 7b having a through hole 7c and a rubber plug 7d corresponding to the diameter of the electric wire used in the suction step, and also in the water stopping agent supply step. Therefore, a terminal holding base corresponding to the type and shape of the terminal to be used is required, which also increases the equipment cost, and there is room for improvement in this respect.

Japanese Patent Laid-Open No. 2001-167821 JP 2004-355851 A

  The present invention has been made in view of the above problems, and in the water-stopping structure of the electric wire that prevents water from entering the electric wire from the terminal connection portion of the electric wire terminal and the method of forming the water-stopping structure, the type and shape of the terminal Therefore, there is no need to prepare different molds or facilities depending on the difference in size and wire diameter, and it is an object to achieve reliable water stop at low cost.

In order to solve the above-mentioned problems, the present invention creates water in the electric wire in which a core wire composed of a plurality of strands is covered with an insulating coating layer from a connection portion with a crimp terminal on the terminal side of the electric wire. It is a water stop structure for electric wires to prevent this,
A plurality of strands of said exposed by removing the insulating coating layer of the wire end core wires are integral reduction has been the core wire weld by ultrasonic welding or resistance welding, the core wire weld wire of the distal side or the It is installed at a position between the core wire barrel of the crimp terminal and the insulation coating barrel,
The core wire barrel of the crimp terminal is crimped and crimped to the core wire or the core wire welded portion, and the insulation coating barrel of the crimp terminal is crimped and crimped to the insulation coating layer of the wire, and
A region of the core wire welded portion that is past the crimping position of the insulation coating barrel is covered with a heat shrinkable tube filled with a water-stopping agent , and the tip of the heat shrinkable tube is crimped to the core wire welded portion. A water-stopping structure for an electric wire is provided, wherein the water-stopping structure is positioned in close contact with an outer periphery or an outer periphery of a core wire welded portion between the core wire barrel and the insulating coating barrel .

According to this water stop structure, since the core wire welded portion in which the core wire is welded and integrated with the exposed portion of the core wire on the terminal crimping side of the electric wire is formed, a gap between the strands is eliminated. It is possible to prevent water from entering the capillarity through the gap between the core wires. In addition, the core wire barrel of the crimp terminal is crimped and crimped to the outer peripheral surface of the exposed portion of the core wire, and the heat shrinkable tube in which the water-stopper is sealed is directly adhered to the outer peripheral surface by heat shrinkage. Thereby, even if the terminal connection part of the terminal of the one end side of the said electric wire exists in a to-be-watered area | region, the core wire welding part and the water-stopping agent immerse the gap between the strands of the core wire, and inside the electric wire passing through the gap. Can be prevented, and it is possible to reliably prevent water from passing through the inside of the electric wire and into the electric wire terminal on the other end side.
Therefore, inundation occurs in the inside of the wire from the end of the ground wire connected to the vehicle body panel in the flooded region, and it is possible to reliably prevent water from entering the connector connected to the other end of the ground wire.

  Furthermore, the water stop structure can cope with the difference in terminal type, shape, size and wire diameter because a heat-shrinkable tube is used. It can be handled simply by changing the size of the shrinkable tube. Therefore, unlike the above-described conventional example, it is not necessary to use various types of expensive dies or to prepare a plurality of facilities with different sizes, so that the cost can be reduced.

The core wire welded portion is preferably formed by welding a core wire exposed from the removal surface of the insulating coating layer at a position spaced from the removal surface by a set dimension.
This is because it is difficult to weld at the position in contact with the removal surface of the insulating coating layer when the core wire is ultrasonically welded or resistance welded. In addition, by leaving a set dimension from the removal surface of the insulation coating layer and leaving a flexible portion of the core wire that is not integrally cured, during crimping and crimping of the terminal core barrel and the insulation coating barrel to the wire end This makes it easier to crimp.

The said core wire welding part is made into appropriate shapes, such as a cross-sectional rectangular shape, a lower surface circular arc shape, or a cross-sectional circle shape.
The core wire welded portion preferably has a shape that allows the core wire barrel to be in close contact with the outer peripheral surface of the core wire welded portion when the terminal core barrel is crimped. Therefore, the shape of the bottom surface side of the core wire welded part is made to correspond to the surface shape of the substrate part of the crimp terminal that the bottom surface side contacts, and the core wire welded part is temporarily held in a stable posture on the terminal when the terminal is crimped. Thus, the crimping operation can be performed in the posture, and the positional displacement of the terminal at the time of crimping can be prevented.

  The said crimp terminal is applied to the crimp terminal of the electric wire terminal arrange | positioned in the inundation area | region of a motor vehicle, and the earthing terminal connected to the vehicle body panel of an inundation area | region is used suitably. In addition, it is used suitably also for the terminal of the electric wire terminal inserted and latched not only in a ground terminal but in the connector arrange | positioned in a flooded area | region.

Further, the present invention provides a method for forming the water stop structure of the electric wire,
Exposing the core wire from the end of the wire,
The exposed core wire is ultrasonically welded or resistance welded to provide the core wire welded portion,
The core wire barrel of the crimp terminal and the insulation coating barrel to the insulation coating layer are crimped to the core wire of the electric wire terminal, and then the distal end side of the heat shrinkable tube coated with a water-stopping agent is crimped to the core wire welded portion . is positioned on the outer periphery of the core wire weld between the outer peripheral or core wire barrel and an insulating coating barrels of the core wire barrel, the cover toward the outer periphery of the insulating coating layer beyond the crimping position of the tip side or we said insulating coating barrel,
Was heated at shrinkage temperature of the heat shrinkable tube, the water stopping structure of the wire that is in close contact with the outer peripheral surface of the crimp connection of the said crimp terminal to contract the heat shrinkable tube wire causes melting the waterproofing agent A forming method is provided.

  As described above, according to the present invention, a core wire welded portion in which a plurality of strands are integrated without gaps is formed on at least a part of the core wire exposed portion of the electric wire terminal, and the core wire of the crimp terminal is formed on the core wire exposed portion. The barrel is caulked, and further, the heat-shrinkable tube in which the water-stopping agent is sealed is covered from the core wire welding part to the insulating coating layer of the electric wire. Thereby, at the front end side of the part covered with the heat shrinkable tube, the core wire is stopped between the water and the core wire and the core wire barrel, the core wire barrel and the heat shrinkable tube are in close contact with each other, or the core wire and the heat shrinkable tube, respectively. Since the heat-shrinkable tube and the insulating coating layer of the electric wire are in close contact with each other directly through the water-stopping agent, the water-tightness inside the heat-shrinkable tube can be secured and Infiltration of water from the exposed core wire exposed portion into the insulating coating layer can be reliably prevented.

  In addition, there is no need for a mold or special equipment to form the water-stopping structure, and even when the type, size, and shape of the terminals used are different, or when the diameter of the wires used is different, the heat shrinkage of different diameters The cost can be reduced because the tube can be used properly.

(A)-(C) are perspective views explaining the formation method of the water stop structure of the electric wire which concerns on 1st embodiment of this invention. (A) is the IIA-IIA sectional view taken on the line of FIG.1 (C), (B) is the IIB-IIB sectional view taken on the line of FIG.1 (C). It is a perspective view which shows the example of another earthing terminal. The modification of 1st Embodiment is shown, (A) is a perspective view which shows the core wire welding part of the modification 1, (B) is a perspective view which shows the core wire welding part of the modification 2, (C) is the modification 3 It is a perspective view which shows a core wire welding part. It is a front view explaining the state which temporarily placed the core wire welding part of the electric wire of modification 1 on the earth terminal. (A)-(C) are perspective views explaining the formation method of the water stop structure of the electric wire which concerns on 2nd embodiment of this invention. It is the VII-VII sectional view taken on the line of FIG. It is a figure which shows a prior art example. It is a figure which shows another prior art example. It is a figure explaining the attraction | suction process in the prior art example shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment, in which a ground terminal 20 having a bolt hole 21 is connected to a terminal of a covered electric wire 10 constituting a wire harness routed in an automobile, and the ground terminal 20 is connected to an engine room of the automobile. It is supposed to be bolted to the car body inside.

  As shown in FIG. 1A, the covered electric wire 10 is formed by covering the outer periphery of a core wire 12 composed of a plurality of strands 11 with an insulating coating layer 13. The strand 11 is made of a copper-based metal wire, and a number of strands 11 are twisted to form a core wire 12, and the insulating resin layer 13 is formed of an insulating resin such as vinyl chloride.

  As shown in FIG. 1B, the ground terminal 20 connected to one end of the covered electric wire 10 includes a round electric contact portion 22 having a bolt hole 21 and a substrate portion 23 continuous with the electric contact portion 22. A core wire barrel 24 for crimping the core wire and an insulating coating barrel 25 for crimping the insulating coating layer are projected from the both sides in the width direction on the substrate portion 23. In the first embodiment, as the ground terminal 20, the substrate portion 23 has a flat plate shape.

First, the formation method of the water stop structure of an electric wire is demonstrated using FIG. 1 (A)-(C).
The insulation coating layer 13 at the end of the covered wire 10 on the side to which the ground terminal 20 is crimped is removed to form a core wire exposed portion A where the core wire 12 is exposed.
Next, as shown in FIG. 1A, a core wire welded portion B in which the strands 11 are integrated by ultrasonic welding (or resistance welding) is formed on the distal end side of the core wire exposed portion A. At this time, the cross-sectional shape of the core wire welding portion B is a rectangular shape in which the lower surface side is flattened so as to correspond to the shape of the substrate portion 23 of the ground terminal 20. In addition, the rear end of the core wire weld B is set at a position that is a required dimension L away from the removal surface 13 a of the insulating coating layer 13.

Next, the terminal of the covered electric wire 10 is placed on the ground terminal 20 set on the mounting table of the crimping apparatus (not shown), and the core wire weld B is aligned with the position of the core wire barrel 24 of the ground terminal 20. At the same time, the insulating coating layer 13 at a position close to the skinning position is aligned with the position of the insulating coating barrel 25, and the ground terminal 20 is crimped.
1B, the core wire barrel 24 of the ground terminal 20 is crimped and crimped to the outer peripheral surface of the core wire welded portion B, and the ground terminal 20 is connected to the outer peripheral surface of the insulating coating layer 13 of the electric wire 10. The insulation coating barrel 25 is crimped and crimped.

Next, as shown by a dotted line in FIG. 1B, the insulation coating layer 13 of the electric wire 10 extends from the outer circumference of the core wire barrel 24 crimped to the outer circumference of the core wire welded portion B beyond the crimping position of the insulation coating barrel 25. A heat-shrinkable tube 30 coated with a water stop agent 31 is placed on the inner peripheral surface.
The heat-shrinkable tube 30 is heated at a heat-shrinkable temperature, and the heat-shrinkable tube 30 is shrunk as shown in FIG. 1 (C) to bring the heat-shrinkable tube 30 into close contact with the outer peripheral surface of the core wire welded portion B and from the insulating coating barrel. The insulating coating layer 13 is closely attached to the outer peripheral surface. In addition, the melted water-stopping agent 31 is a gap between the inner peripheral surface of the heat-shrinkable tube 30 and the outer peripheral surface of the core wire welded portion B, a portion sandwiched between the core wire barrel 24 and the insulating coating barrel 25, and the insulating coating barrel 25 and the insulation. The space between the outer peripheral surface of the covering layer 13 and the inner peripheral surface of the heat shrinkable tube 30 is filled, and the portion covered with the heat shrinkable tube 30 has no voids.

  The water stop structure formed by the above method is covered with the heat shrinkable tube 30 from the outer periphery of the core wire welding portion B to the outer periphery of the insulating coating layer 13 in the connection portion between the covered electric wire 10 and the ground terminal 20. As shown in FIG. 2 (A), at the tip end side of the heat-shrinkable tube 30, the strands 11 are integrated by the core wire welded portion B without any gaps, so that the water between the strands is stopped and the core wire welded portion. The outer peripheral surface of B is deformed and adhered to the substrate portion 23 of the ground terminal 20 and the inner peripheral surface of the core wire barrel 24 by caulking. In addition, between the outer peripheral surface of the ground terminal 20 and the inner peripheral surface of the heat shrinkable tube 30, the heat shrinkable tube 30 contracted by heating is provided on the outer peripheral surface of the core wire barrel 24 and the substrate portion 23 of the ground terminal 20. It adheres without gap through.

  In addition, on the rear end side of the heat shrinkable tube 30, as shown in FIG. 2B, the heat shrinkable tube 30 that is shrunk by heating has a gap between the outer peripheral surface of the insulating coating layer 13 of the electric wire 10 via a water stop agent 31. There is no close contact.

  Therefore, the connection portion between the ground terminal 20 and the covered electric wire 10 is stopped without gaps at both ends of the portion covered with the heat shrinkable tube 30, and the water tightness in the heat shrinkable tube 30 can be ensured. Therefore, even if the tip portion not covered with the heat-shrinkable tube 30 in the exposed portion A of the core wire is covered with water, water can enter the electric wire from the gap between the strands 11 and the gap between the core wire 12 and the terminal 20. Can be prevented. And even if the insulating coating layer 13 is flooded, it is possible to reliably prevent water from entering inside along the surface of the insulating coating layer 13.

  In addition, according to the method for forming the water stop structure, since a mold and special equipment are not required, even if the type, shape, and size of the terminal used are different, or the wire diameter used is different, This can be dealt with only by changing the diameter of the heat-shrinkable tube 30, and the cost can be reduced.

  Furthermore, since the cross-sectional shape of the core wire welded portion B is rectangular, the core wire welded portion B is stable when temporarily placed on the flat substrate portion 23 of the ground terminal 20, and the electric wire 10 is not glazed. Therefore, the workability of crimping the ground terminal 20 is improved, and the displacement of the ground terminal 20 can be prevented.

In addition, as shown in FIG. 3, when using what the board | substrate part 23 curved in circular arc shape as the earthing terminal 20 crimped | bonded to the covered electric wire 10, like the modification 1 shown to FIG. 4 (A), The cross-sectional shape of the core wire weld B is a semicircular shape. Or the cross-sectional shape of the core wire welding part B is made into substantially elliptical shape like the modification 2 shown to FIG. 4 (B). Alternatively, as in Modification 3 shown in FIG. 4C, the cross-sectional shape of the core wire welded portion B is a perfect circle shape, and the lower surface side of the core wire welded portion B is an arc shape along the inner surface shape of the substrate portion 23. It is preferable to do.
As a result, as shown in FIG. 5 (illustration shows an example in which the core wire welded portion has a semicircular cross section), the core wire welded portion B is stable on the substrate portion 23 without blur when the electric wire 10 is set to the ground terminal 20. Can be temporarily placed in a posture.

6 and 7 show a second embodiment of the present invention.
In 2nd Embodiment, as shown to FIG. 6 (A), the core wire welding part B of the covered electric wire 10 is partially formed in the rear end side near the insulation coating layer 13 instead of the front end side of the core wire exposure part A. Yes.
Next, as shown in FIG. 6 (B), the core wire barrel 24 of the ground terminal 20 is crimped and crimped to the tip-side core wire exposed portion C of the core wire exposed portion A where the core wire welded portion B is not formed, and insulation is performed. An insulation coating barrel 25 is pressure-bonded to the outer periphery of the coating layer 13, and the core wire weld B is disposed between the core wire barrel 24 and the insulation coating barrel 25.
Next, as shown in FIG. 6 (C), a heat shrinkable tube 30 enclosing a water-stopping agent 31 is put on the outer periphery of the insulating coating layer 13 beyond the insulating coating barrel 25 from the outer periphery of the core wire welded portion B, and the required temperature. The heat-shrinkable tube 30 is contracted by heating.

In the water-stop structure formed by the above-described method, the inter-strand water can be stopped by the core wire weld B as shown in FIG. Further, the gap between the lower outer peripheral surface of the core wire welded portion B and the substrate portion 23 of the ground terminal 20 and the gap between the upper outer peripheral surface of the core wire welded portion B and the heat shrinkable tube 30 are caused by contraction of the heat shrinkable tube 30. The core wire welding part B before hardening deform | transforms, and the core wire welding part B, the board | substrate part 23, and the heat-shrinkable tube 30 can be closely_contact | adhered integrally without a gap.
The point that the outer peripheral surface of the insulating coating layer 13 and the inner peripheral surface of the heat shrinkable tube 30 are in close contact with each other through the water stop agent 31 on the rear end side of the heat shrinkable tube 30 is the same as that in the first embodiment.

  Therefore, also in this embodiment, water can be stopped at both the front and rear ends of the heat-shrinkable tube 30, and water tightness inside the heat-shrinkable tube 30 can be secured. Can be effectively prevented from entering.

10 Covered Wire 11 Elementary Wire 12 Core Wire 13 Insulation Covering Layer 20 Grounding Terminal (Crimp Terminal)
24 core wire barrel 25 insulation coating barrel 30 heat shrinkable tube 31 water stop agent A core wire exposed part B core wire welded part C tip side core wire exposed part

Claims (5)

A wire waterproof structure that prevents water from being generated from a connecting portion with a crimping terminal on the terminal side of the electric wire, in which the core wire composed of a plurality of strands is covered with an insulating coating layer. ,
A plurality of strands of said exposed by removing the insulating coating layer of the wire end core wires are integral reduction has been the core wire weld by ultrasonic welding or resistance welding, the core wire weld wire of the distal side or the It is installed at a position between the core wire barrel of the crimp terminal and the insulation coating barrel,
The core wire barrel of the crimp terminal is crimped and crimped to the core wire or the core wire welded portion, and the insulation coating barrel of the crimp terminal is crimped and crimped to the insulation coating layer of the wire, and
A region of the core wire welded portion that is past the crimping position of the insulation coating barrel is covered with a heat shrinkable tube filled with a water-stopping agent , and the tip of the heat shrinkable tube is crimped to the core wire welded portion. A water-stopping structure for an electric wire, wherein the water-stopping structure is positioned in close contact with an outer periphery or an outer periphery of a core wire welded portion between the core wire barrel and the insulating coating barrel .   The said core wire welding part is the water stop structure of the electric wire of Claim 1 in which the core wire exposed from the removal surface of the said insulation coating layer is welded and formed in the position which opened the set dimension from the said removal surface.   The water stop structure for an electric wire according to any one of claims 1 and 2, wherein the core wire welded portion has a rectangular cross section, a bottom arc shape, or a circular cross section.   The water stop structure for an electric wire according to any one of claims 1 to 3, wherein the crimp terminal is a ground terminal. A method for forming a water stop structure for an electric wire according to any one of claims 1 to 4,
Exposing the core wire from the end of the wire,
The exposed core wire is ultrasonically welded or resistance welded to provide the core wire welded portion,
The core wire barrel of the crimp terminal and the insulation coating barrel to the insulation coating layer are crimped to the core wire of the electric wire terminal, and then the distal end side of the heat shrinkable tube coated with a water-stopping agent is crimped to the core wire welded portion . is positioned on the outer periphery of the core wire weld between the outer peripheral or core wire barrel and an insulating coating barrels of the core wire barrel, the cover toward the outer periphery of the insulating coating layer beyond the crimping position of the tip side or we said insulating coating barrel,
Was heated at shrinkage temperature of the heat shrinkable tube, the water stopping structure of the wire that is in close contact with the outer peripheral surface of the crimp connection of the said crimp terminal to contract the heat shrinkable tube wire causes melting the waterproofing agent Forming method.