JP5391613B2 - How to shut off shield wire - Google Patents

Description

  The present invention relates to a method for waterproofing a shielded wire, and more specifically, when a core wire and a drain wire of a shielded wire terminal are connected by a connector, the drain wire is easily and reliably waterproofed.

Conventionally, a shield wire has been provided with a shield layer in which a core wire made of a plurality of or one insulation-coated wire is passed through a braided tube made of metal fiber, or a metal foil is vertically attached to the core wire, Is covered with a sheath made of an insulating resin layer.
For the ground connection of the shield layer, for example, the end of the sheath is removed to expose the shield layer, the metal braid of the shield layer is turned into a drain wire, and the ground terminal is connected to the drain wire.
In place of a drain wire formed by rolling a metal braid, a drain wire made of a bare conductor without insulation coating is wired together with a core wire to provide a shield layer and a shield wire made of a metal braid or metal foil and a shield wire. Has been.
In the shielded wire, it is only necessary to pull out the drain wire and connect the ground terminal to the end of the drain wire. Compared with the case where the drain wire is formed by winding the metal braid, the ground connection of the shield layer is easily performed. be able to.

When the ground terminal connected to the terminal of the drain wire is connected to the waterproof connector together with the terminal connected to the terminal of the core wire, the drain wire is not covered with an insulating material and needs to be waterproofed.
As a measure against waterproofing of this drain wire, as shown in FIG. 6, in Japanese Patent Laid-Open No. 2000-323201 (Patent Document 1), a metal braid 100 is pulled out from a sheath 101, and a conductor composed of a single core wire is attached to the pulled out metal braid 100. A drain wire 102 coated with insulation is spliced and a ground terminal 103 is connected to the end of the drain wire 102. In addition, the connection portion between the metal braid 100 and the drain wire 102 is surrounded by a heat shrinkable tube 104 to stop water.

  As described above, the conductor of the drain wire 102 is not a twisted wire but a single core wire so that water does not enter the conductor, and the connection portion between the metal braid 100 and the drain wire 102 is covered with the heat shrinkable tube 104. This prevents the occurrence of flooding from the connection.

JP 2000-323201 A

  When a single-core wire is used as the drain wire 102, the single-core wire is less likely to bend than a twisted wire, and thus there is a problem in terms of electrical connection reliability at a crimp connection portion with a ground terminal. In addition, when the splice between the drain wire 102 and the metal braid 100 is performed using a crimp terminal, the number of work steps and the number of parts increase. Further, since the splice portion is arranged on the outer periphery of the sheath of the shield wire and the splice portion is covered with the heat shrink tube 104 together with the sheath, there is a problem that the end of the shield wire is enlarged and the work man-hours and the number of parts are increased. .

  The present invention has been made in view of the above problems, and uses a twisted wire having high electrical connection reliability with a crimp terminal as a drain wire, and can reliably stop the drain wire made of a twisted wire. It is an object of the present invention to provide a shield water-stopping method that can reduce the number of work steps and the number of parts without enlarging the water-stop portion.

In order to solve the above-mentioned problems, the present invention provides a shield layer made of a metal braid or a metal foil, comprising a core wire made of a plurality of wires or one insulated wire and a drain wire made of a stranded wire conductor that is not insulated. A shield wire waterproofing method in which the outer periphery is covered with a sheath made of an insulating resin layer,
In connector side terminal of the shielded wire, the drain wire drawn out from the sheath, covered with a heat shrinkable tube from the terminal connection side of the distal end to a position a gap between the sheath end,
The heat-shrinkable tube is partially heated from the terminal connection side to heat the required area first, and is heat-shrinked first to adhere to the outer periphery of the drain wire,
Then, by supplying the thermosetting resin solids in which from the distal end opening of the sheath side of the unshrunk of the heat shrinkable tube with powder or rod-shaped gap of the outer peripheral surface of the drain wire and the inner peripheral surface of the heat shrinkable tube,
Then, together with the the unshrunk side heating of the heat shrinkable tube, it is filled in the gap between the strands and between the drain line of the drain wire by melting the thermosetting resin inner circumferential surface of the heat shrinkable tube, provides a method for stopping water shield wire for a vehicle-installing, characterized in that it the heat shrinkable tube is brought into close contact with the outer peripheral surface of the drain wire by heat shrinkage.

  The shield water-stopping method of the present invention uses a thermosetting resin that is solidly used as a water-stopping agent, in which a heat-shrinkable tube is coated in a stepwise manner by covering a drain wire and forming a pseudo-covered electric wire. It is characterized by being. As the heat-shrinkable tube, Sumitomo Electric Fine Polymer's Sumitube (registered trademark) and Raychem's shrinkable tube are preferably used.

In the shielded wire that connects the electrical connection box and the electronic control unit with the connector, the terminal for connector connection is crimped to the core wire of the shielded wire and the end of the drain wire. In order to prevent water from entering the connector through the terminal, water is applied to the drain wire.
As described above, the water-stopping treatment is a pseudo-covered electric wire coated with a heat-shrinkable tube on the drain wire drawn from the tip of the shielded wire and insulated similarly to the core wire, and the drain wire made of stranded wire is submerged. This prevents water from entering the terminal side through the gap between the stranded wires.

In addition, in order to prevent water from being generated at the portion where the drain wire is pulled out from the sheath and entering the terminal side through the twisted wire of the drain wire, the terminal connection side of the heat shrinkable tube is heated first. On the other hand, the sheath does not heat the heat-shrinkable tube, and a gap is formed between the stranded wire and the stranded wire. A thermosetting resin in the form of powder or rod is supplied from the opening end on the sheath side of the gap.
Thus, by partially shrinking the terminal connection side of the heat-shrinkable tube first, a filling region of the water-stopping agent made of the thermosetting resin is defined, and the filled water-stopping agent reaches the terminal side. It can be prevented from flowing. In addition, since it is only necessary to fill the gap between the uncontracted portions with the water-stopping agent, the amount of the water-stopping agent supplied can be quantified to a small amount.

In addition, since the water-stopping agent is in the form of a powder or rod made of a thermosetting resin, the water-stopping agent does not sag at the time of supply compared to the case where a viscous water-stopping agent is supplied. Handling becomes easy. In addition, since a thermosetting resin is used as the water-stopping agent, it is cured by heating to the melting temperature of the water-stopping agent and then melting, and then heating to a room temperature. Compared with moisture-curing silicone or the like, the time until curing can be greatly shortened. Specifically, when silicone is used as a water-stop agent, it takes about 8 hours to cure, whereas a water-stop agent made of a thermosetting resin can be cured in 1 minute or less. At the same time as the shrinkage of the shrinkable tube, the hardening of the water stop agent is finished.
Thus, since the time until curing can be greatly shortened, the work space of the factory (work in process place) can be greatly reduced.

In addition, a twisted drain wire is covered with a heat-shrinkable tube to create a pseudo electric wire, and the place where the water-stopper is filled is limited to the sheath side. Therefore, the outer diameter of the drain wire is about the same as the outer diameter of the core wire, the shield wire by the water stop treatment can be slimmed, and enlargement can be prevented.
In particular, the terminal crimping side is not filled with a water-stopping agent between the drain wire stranded wire and the heat-shrinkable tube, so that the drain wire can have a smaller diameter and retain flexibility as compared to the sheath side. it can. Since the portion close to the crimping portion with the terminal is a base portion drawn out from the terminal accommodating chamber of the connector, the workability of connecting with the connector is not affected by maintaining a small diameter and flexibility.

The heat-shrinkable tube covered with the drain wire opens a gap of 5 mm to 10 mm between the distal end of the sheath, and the thermosetting resin is inserted through the gap from the tip opening of the non-shrinkable heat-shrinkable tube.
After the heat shrinkage, it is preferable that a protective tape is wound around the exposed portion of the drain wire between the tip of the heat shrinkable tube and the sheath.

In the present invention, a water-stopping agent made of a solid thermosetting resin is supplied from the distal end opening of the heat-shrinkable tube of the non-shrinkable portion. Therefore, it is necessary to secure a space for supplying the water-stopping agent, and as described above, a gap of 5 mm to 10 mm is provided between the heat-shrinkable tube and the distal end of the sheath.
Since the gap is thus formed, a protective tape is wound between the heat-shrinkable tube and the sheath after shrinkage in order to protect the drain wire. Even if water is generated from the gap without wrapping the protective tape, it is possible to prevent water from entering the terminal connection side at the tip at the filling portion of the water-stopping agent. However, in order to protect the drain wire from the gap, it is preferable to wind the protective tape.

  Specifically, the core wire and the drain wire are drawn from 40 mm to 80 mm from the distal end of the sheath, and the heat shrinkable tube in the region of 20 mm to 50 mm from the terminal crimping portion of the drain wire is first heat-shrinked, and the unshrinked 15 mm to 25 mm It is preferable that the heat-shrinkable tube is heat-shrinked later. That is, the terminal connection side, which is about half of the length of the drain line drawn out, is thermally contracted first.

As mentioned above, the filling area of the water-stopping agent is as narrow as 15 to 25 mm, but the water-stopping agent is surely filled between the gap between the twisted wires of the drain wire and between the stranded wire and the inner peripheral surface of the heat-shrinkable tube. If there is a portion to be used, it is possible to reliably prevent the water immersed in the portion from entering the terminal side.
Before supplying the solid thermosetting resin in the form of a powder or rod, unwinding the twisted drain wire can increase the permeability of the molten thermosetting resin, ensuring that the void Occurrence can be prevented.

As the thermosetting resin used as the water-stopping agent, an epoxy resin is preferably used.
Epoxy resins are inexpensive and have a melting point below the shrink temperature of the heat shrink tube. Therefore, it can be melted from a solid powder or rod-like body at the shrinkage temperature of the heat-shrinkable tube, and it is not necessary to heat the heat-shrinkable tube excessively in order to melt the water-stopping agent. Adverse effects can be prevented.

  Crimp terminals are crimped and connected to the core wire of the core wire and the end of the drain wire. Since the drain wire is formed from a stranded wire to enhance the crimping performance with the crimp terminal, the electrical connection reliability can be improved as compared with the case where the single core wire of Patent Document 1 is used.

  Preferably, the waterproof rubber plug is simultaneously crimped and crimped with a barrel of a crimp terminal that is crimp-connected to the core wire of the shield wire and the end of the drain wire. Thereby, it is possible to more reliably prevent water from entering the connector.

  In this way, the connector that inserts and locks the drain terminal of the shielded wire and the terminal of the core wire that has been reliably water-stopped can be suitably used particularly for connection to the electronic control unit. .

As described above, in the waterproofing method of the shield wire of the present invention, a drain wire made of a stranded wire conductor that is not covered with insulation, out of the core wire and the drain wire that is pulled out from the sheath on the connector connection side and connects the terminal to the terminal. On the other hand, the heat-shrinkable tube is covered to form a pseudo-covered electric wire.
In particular, the present invention is characterized in that the heat-shrinkable tube, which is a pseudo-covered electric wire covered with the drain wire, is heated stepwise, and a solid thermosetting resin is used as a water-stopping agent. By heating the heat-shrinkable tube stepwise and first heating the region on the terminal connection side, it is possible to prevent the water-stopping agent filling the unshrinked portion from flowing to the terminal side, The amount of water-stopping agent supplied can be quantified by defining the filling area. In addition, the sheath-side heat-shrinkable tube is post-heated, so that the solid water-stopping agent can be melted and the heat-shrinkable tube can be simultaneously heat-shrinked. In addition, by using a solid thermosetting resin as the water-stopping agent, the filling operation becomes easy and the curing time can be greatly shortened, and the work space of the factory (work-in-place storage area) can be greatly reduced. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment.
The shield wire 1 shown in FIG. 1 and FIG. 2 is a shield wire after water stop treatment.
The shield wire 1 is routed in an engine room which is a wet area of the automobile, a connector 30 is connected to the tip of the shield wire 1, and an electronic control unit (not shown) for mounting the connector 30 in the engine room It fits into the connector housing part.

As shown in FIG. 3, the shield wire 1 is composed of a core wire 2 made up of a plurality of (two in this embodiment) insulated wires and a drain wire 3 made only of stranded wire conductors that are not covered with insulation. It is covered with a shield layer made of foil 4 and covered with a sheath 5 made of an insulating resin layer of the metal foil 4.
The shield wire 1 is an end portion on the connection side with the connector 30, and the metal foil 4 and the sheath 5 are removed from the tip by 40 mm to 80 mm (the shortest 40 mm in this embodiment), and the core wire 2 and the drain wire 3. And pulls out.

  At the tip of the drawn core wire 2, the insulation coating layer 2a is further peeled to expose the core wire 2b of the core wire 2, and the crimp terminal 6 for connector connection is crimped and connected to the end of the drain wire 3. The crimp terminal 6 is crimped and connected. The crimp terminal 6 is a female terminal having a box-shaped female terminal portion 6a, a core wire barrel 6b, and an insulation coating barrel 6c. When the crimping terminal 6 is crimped and connected to the core wire 2 b and the drain wire 3 of the core wire 2, the waterproof rubber plug 7 is simultaneously crimped and crimped by the insulating coating barrel 6 c of the crimping terminal 6.

  Since the drain wire 3 is composed only of a stranded wire conductor and does not have an insulation coating layer, the heat shrinkage from the terminal crimping position P1 between the female terminal portion 6a of the crimp terminal 6 and the core wire barrel 6b to the position P2 near the cut end surface of the sheath 5 It passes through the tube 10. The heat-shrinkable tube 10 is heat-shrinked to be brought into close contact with the outer peripheral surface of the drain wire 3, and the drain wire 3 drawn from the sheath 5 is covered with the heat-shrinkable tube 10, thereby forming the pseudo covered electric wire 11.

In the quasi-covered electric wire 11 in which the drain wire 3 is covered with the heat shrinkable tube 10, a water-stopping agent is filled in a region L 1 that is approximately ½ of the entire length from the position P 1 in contact with the terminal crimping position to the other end P 2. The remaining sheath-side region L2 is filled with a water-stopping agent 13 made of a thermosetting epoxy resin. The water-stopping agent 13 is also filled in the gap between the stranded wires of the drain wire 3 and the gap between the stranded wire and the inner peripheral surface of the heat-shrinkable tube 10, and the water-blocking agent is filled to block water from reaching the crimp terminal 6. doing.
A gap S of 5 mm to 10 mm (10 mm in the present embodiment) is formed between the sheath-side distal end position P2 of the heat-shrinkable tube 10 and the cut end 5a of the sheath 5, and a protective tape 14 is wound around the gap S. ing.

Next, a water stopping method for the shield wire 1 will be described.
In the first step, the sheath 5 and the metal foil 4 of the shield wire 1 are removed at the end of the shield wire 1 connected to the connector 30, and the core wire 2 and the drain wire 3 are 40 mm to 80 mm (this embodiment) Pull out 40 mm).
In the second step, the insulation coating 2a at the tip of the core wire 2 is peeled off to expose the core wire 2b.
In the third step, the core wire 2b and the crimp terminal 6 are crimped and connected. The core wire 2b of the core wire 2 and the twisted wire of the drain wire 3 are crimped and crimped by the core wire barrel 6b of the crimp terminal 6 and crimped and crimped to the outer peripheral surface of the waterproof rubber plug 7 by the insulation coating barrel 6c.

  In the fourth step, the length of the drain wire 3 from the position P1 between the female terminal portion 6a of the crimp terminal 6 and the core wire barrel 6b to the position P2 having a gap S between the cut end 5a of the sheath 5 and The heat-shrinkable tube 10 is put on.

  In the fifth step, the heat-shrinkable tube 10 is contracted by heating the region L1 (in this embodiment, 20 mm) from the position P1 on the terminal crimping side to the position of about ½ of the total length. The drain wire 30 is brought into close contact with the outer peripheral surface. At this time, the remaining sheath-side region L2 (20 mm in the present embodiment) is not heated, and the heat-shrinkable tube 10 is not shrunk, and there is a gap between the inner peripheral surface of the heat-shrinkable tube 10 and the outer peripheral surface of the drain wire 3. C is opened. As shown in FIG. 4, the tip opening 15 of the gap C is opened with the gap S facing the sheath cutting end 5a.

In the sixth step, as shown in FIG. 4 (B), a predetermined amount of epoxy resin powder 13A serving as the water-stopping agent 13 is supplied from the sheath-side tip opening 15 of the heat-shrinkable tube 10. Before supplying the epoxy resin powder 13A, the twist of the drain wire 3 made of a twisted wire is returned.
The supply amount of the epoxy resin powder 13A can be quantified from the length of the non-shrinkable portion of the heat shrinkable tube 10, the inner diameter of the heat shrinkable tube 10, and the outer diameter of the drain wire 3. The filling of the epoxy resin powder 13A can be easily performed, for example, by inserting a supply tube 16 into the tip opening 15 and pumping the epoxy resin powder through the supply tube. The epoxy resin powder preferably has an average particle size of 10 μm to 100 μm.

In the seventh step, the non-shrinkable region L2 of the heat shrinkable tube 10 is heated. Since the heat shrinkage starting temperature of the heat shrinkable tube 10 is lower than the melting point of the epoxy resin powder 13A, the waterstop 13 starts to melt while the heat shrinkable tube 10 is heated for shrinkage, and the drain wire 3 is twisted back to be parallel. It penetrates into the gaps between the strands and the outer peripheral surface of the strands and the inner peripheral surface of the heat-shrinkable tube 10, and can be filled without generating voids (voids).
In this way, the heat-stopping agent 13 is melted and the heat-shrinkable tube 10 is contracted simultaneously by the heating in the seventh step. The epoxy resin melted by heating is cured in 1 minute or less after the heating is stopped.
When the thermal contraction of the heat-shrinkable tube 10 is finished and the inner peripheral surface of the heat-shrinkable tube 10 is in close contact with the outer peripheral surface of the drain wire 3, the curing of the water-stopping agent 13 made of epoxy resin is also finished.

  In the eighth step, the exposed drain wire 3 is protected by wrapping the protective tape 14 around the gap S of about 10 mm between the distal end P2 of the heat-shrinkable tube 10 serving as the supply port for the epoxy resin powder and the sheath cut end 5a. To do. Next, after setting the waterproof rubber plug 7 to the end of the drain wire 3, the crimp terminal 6 is crimped and connected. The twisted wire of the drain wire 3 is crimped and crimped by the core wire barrel 6b of the crimp terminal 6 and crimped and crimped to the outer peripheral surface of the waterproof rubber plug 7 by the insulating coating barrel 6c.

  Finally, the crimping terminal 6 at the end of the core wire 2 of the shielded wire 1 and the drain wire 3 subjected to the water stop treatment is inserted and locked to the connector 30 respectively.

In the water-stop treatment method for the drain wire 3 drawn out for connecting the shield wire 1 to the connector, the heat-shrinkable tube 10 is heat-shrinked in stages, so that the terminal-side region L1 that is not filled with the water-stopping agent 13 is stopped. A sheath side region L2 filled with the liquid medicine 13 can be provided. Therefore, the filled water-stopping agent 13 can be reliably prevented from flowing to the crimp terminal 6.
Moreover, since the epoxy resin powder is used instead of the liquid silicone resin conventionally used as a water-stopping agent, handling at the time of filling becomes easy. In addition, when silicone resin is used as a water-stopping agent, it takes about 8 hours to cure, but since a thermosetting epoxy resin is used, it can be cured in about 1 minute after heating is stopped. And the curing time can be dramatically shortened.

FIG. 5 shows a second embodiment.
In the second embodiment, as the water-stopping agent, instead of the epoxy resin powder, four rod-shaped epoxy resin solids 13B are used. Thus, when the rod-shaped solid material 13B is used, it becomes easy to make the supply amount constant, and the rod-shaped solid material 13B may be simply filled at 90 degrees from the tip opening 15 of the heat shrinkable tube 10 and filled easily. be able to.
Since the other steps and the form of the shield wire subjected to the water stop treatment are the same as those in the first embodiment, the same reference numerals are given and the description thereof is omitted.

It is a top view of the shield line of 1st Embodiment water-stop-processed with the water stop method of this invention. (A) and (B) are the partial expanded sectional views of FIG. It is a perspective view of a shield wire. (A) is a partial cross-sectional top view in the process of the water stop method, (B) is a principal part expanded sectional view. It is sectional drawing which shows 2nd Embodiment. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield wire 2 Core wire 3 Drain wire 4 Metal foil 5 Sheath 6 Crimp terminal 13 Water stop agent 13A Epoxy resin powder 14 Protection tape 30 Connector L1 Area | region which is not filled with a water stop agent L2 Area | region where a water stop agent is filled

Claims (4)

A core wire made of a plurality of wires or one insulated wire and a drain wire made of a stranded wire conductor that is not insulated are covered with a shield layer made of metal braid or metal foil, and the outer periphery is made of an insulating resin layer. A method for water-stopping a shielded wire covered with a sheath,
In connector side terminal of the shielded wire, the drain wire drawn out from the sheath, covered with a heat shrinkable tube from the terminal connection side of the distal end to a position a gap between the sheath end,
The heat-shrinkable tube is partially heated from the terminal connection side to heat the required area first, and is heat-shrinked first to adhere to the outer periphery of the drain wire,
Then, by supplying the thermosetting resin solids in which from the distal end opening of the sheath side of the unshrunk of the heat shrinkable tube with powder or rod-shaped gap of the outer peripheral surface of the drain wire and the inner peripheral surface of the heat shrinkable tube,
Then, together with the the unshrunk side heating of the heat shrinkable tube, it is filled in the gap between the strands and between the drain line of the drain wire by melting the thermosetting resin inner circumferential surface of the heat shrinkable tube, method for stopping water shield wire for a vehicle-installing, characterized in that it the heat shrinkable tube is brought into close contact with the outer peripheral surface of the drain wire by heat shrinkage.   The water stopping method for a shield wire for vehicle wiring according to claim 1, wherein an epoxy resin is used as the thermosetting resin. The heat shrinkable tube covering the drain line, a gap of 5mm~10mm between the tip of the sheath, and inserting the thermosetting resin from the distal end opening of the unshrunk of the heat shrinkable tube from the gap ,
The shield wire for vehicle wiring according to claim 1 or 2, wherein a protective tape is wound around an exposed portion of the drain wire between the tip of the heat shrink tube and the sheath after the heat shrinkage. Water stop method. It said core wire and said drain wire is pulled out 40mm~80mm from the distal end of the sheath,
The crimp terminal crimped connection to the terminal of the core wire and the drain wire of the core wire,
The heat-shrinkable tube in the region of 20 mm to 50 mm from the terminal crimping portion of the drain wire is first heat-shrinked, and the non-shrinkable heat-shrinkable tube of 15 mm to 25 mm is heat-shrinked later. The water stop method of the shield wire for vehicle routing as described in 2.

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