JP5287322B2 - Shield wire terminal water-stop method and shield wire with terminal water-stop portion - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a shield wire terminal waterproofing method and a shield wire provided with a terminal waterproof portion, and in particular, in a shield wire wired in a waterproof region such as an engine room of a vehicle, a sheath of the shield wire from the end of the shield wire. Inundation is prevented from occurring in the gap between the drain wire and the core wire.

Among electric wires routed in automobiles, shielded electric wires are used particularly in wiring areas where shielding against noise is required. As this shielded electric wire 1, for example, as shown in FIG. 5 (A), a core wire 2 made of an insulation-coated electric wire to be a plurality of signal wires and a drain wire 3 for grounding are made of a metal foil, a metal mesh tube or the like. A shield layer 4 is used, and the shield layer 4 is sequentially covered with a sheath 5 made of an insulating resin material (see JP 2002-208321 A).
The drain wire 3 is composed of a large number of conductive strands, is not covered with insulation, and is in contact with the shield layer 4.

  In order to attach a terminal to such a terminal of the shielded electric wire 1 and connect the connector housing, as shown in FIG. Skinning is performed, and the exposed end of the core wire 2 is further peeled to crimp the terminal fitting. Similarly, terminals are connected to the drain wire 3 by crimping, and each terminal is inserted into the connector housing to enable mechanical connection with the counterpart device.

In the shield wire 1, a gap exists between the sheath 5 and the shield layer 4, and between the shield layer 4 and the core wire 2 and the drain wire 3, and water is likely to be generated from the peeled end surface of the terminal. It is necessary to provide a water stop at the end of line 1.
Therefore, conventionally, at the peeled end portion of the end of the shield wire, a water-stop material made of paste-like butyl rubber or silicone is attached from the end surface of the sheath 5 to the outer peripheral surface of the core wire 2 and the drain wire 3 to stop the water. In many cases, it prevents water from being peeled off.

  For example, in the shielded wire disclosed in Japanese Patent Application Laid-Open No. 2007-109684 (Patent Document 2), as shown in FIG. 6, the ground wire 7 is connected to the drain wire 3 drawn from the terminal peeling position of the shielded wire 1, The drain wire 3 and the ground wire 7 and the core wire 2 are covered with a shield material 8 made of butyl rubber having a conductive filler, and an outer sheath 9 having further conductivity is wound around the outer periphery of the shield material 8 to provide a shielding property. To keep water and stop water.

  However, due to the difference in thermal contraction rate between the core wire 2 and the sheath 5, the sheath 5 is more easily contracted than the core wire 2 at the terminal, and a deviation is likely to occur between the core wire 2 and the sheath 5. For example, in the thermal shock test in which the temperature is raised or lowered from 50 ° C. to 120 ° C., the sheath 5 is contracted by 10 mm from the core wire 2. The gap between the core wire 2 and the sheath 5 causes separation between the water-stopping material made of butyl rubber or the like and the sheath 5 to form a gap, and the gap exists on the inner peripheral surface side of the sheath 5 from the gap. There is a problem that flooding is likely to occur.

  Furthermore, when the shield material 8 made of butyl rubber filled with a conductive filler is wound around the terminal peeling position of the shield wire with the outer cover 9 as in Patent Document 2, the outer diameter is enlarged at the terminal position. There's a problem. In this way, when the wire harness that has a large number of shielded wires overlaps with the end of the shielded wire, the wire harness that does not fit in the tube when sheathed with a tube such as a corrugated tube Occurs.

JP 2002-208321 A JP 2007-109684 A

  The present invention has been made in view of the above-mentioned problems. The thermal shock prevents the separation between the sheath and the water-stopping material so as to improve the water-stopping performance and enlarge the water-stop processing section. The challenge is to suppress it.

In order to solve the above problems, as a first invention,
Peel the sheath of the end of the shielded wire, expose the core wire and drain wire from the end, pull out,
After wrapping the waterproof sheet soaked with the melted water-stopping agent in the foamed rubber sheet, the outer peripheral surface of the sheath and the exposed core wire and the outer periphery of the drain wire are tightly wound across the peeled point of the sheath,
Strongly wrap the adhesive tape on the outer peripheral surface of the foam rubber sheet with a half wrap, hold in this state in the horizontal direction,
The waterproofing agent soaked in the foamed rubber sheet is filled in the exposed gap between the core wire and the drain wire by the winding force of the adhesive tape, and is allowed to flow into the gap between the inner peripheral surface of the sheath and the core wire and the drain wire. Furthermore, a water-stopping agent is oozed out on the outer peripheral surface of the sheath,
In this state, the water-stopping agent is cured, and the hardened water-stopping agent is continuously fixed from the outer peripheral surface of the core wire and drain wire drawn out from the sheath terminal to the outer peripheral surface and the peeled end surface of the sheath. The terminal water stop method of the shield wire characterized by this is provided.

  It is preferable to use foamed urethane rubber having a porosity of 30 to 70% as the foamed rubber sheet, and silicone as a molten water-stopping agent soaked into the pores of the foamed urethane rubber. The thickness of the urethane foam rubber is 2.8 to 2.2 mm, which is relatively thin.

  As described above, in the present invention, the pores of the foam rubber sheet such as foamed urethane rubber are soaked and filled with a water-stopping agent such as silicone in a molten state, and the foam rubber sheet is sandwiched between the terminal peeling positions. Winding is performed from the outer peripheral surface of the drawn core wire and drain wire to the outer peripheral surface of the sheath, and immediately after the foamed rubber sheet is wound, the adhesive tape is half-wrapped around the outer peripheral surface of the foamed rubber sheet and strongly wound. As a result, the water-stopping agent filled in the pores of the foamed rubber sheet oozes out and stops on the outer periphery of the drawn core wire and drain wire, the gap between the drain wire strands, and the outer peripheral surface of the sheath. The liquid agent is applied, and in this state, the water stop agent is cured by standing for a required time.

As a second invention, the sheath of the end of the shield wire is peeled off, and the core wire and the drain wire are exposed from the end and drawn out,
After wrapping the waterproof sheet soaked with the melted water-stopping agent in the foamed rubber sheet, the outer peripheral surface of the sheath and the exposed core wire and the outer periphery of the drain wire are tightly wound across the peeled point of the sheath,
Cover the outer peripheral surface of the foam rubber sheet with a heat shrinkable tube,
The heat-shrinkable tube is heated and shrunk, tightly adhered to the outer peripheral surface of the foamed rubber sheet, and held in this state in a horizontal direction to be stationary,
The waterproofing agent soaked in the foam rubber sheet is filled in the exposed gap between the core wire and the drain wire by the shrinkage force of the heat shrinkable tube, and flows into the gap between the inner peripheral surface of the sheath and the core wire and the drain wire. Furthermore, a water-stopping agent is oozed out on the outer peripheral surface of the sheath,
In this state, the water-stopping agent is cured, and the hardened water-stopping agent is continuously fixed from the outer peripheral surface of the core wire and drain wire drawn out from the sheath terminal to the outer peripheral surface and the peeled end surface of the sheath. The terminal water stop method of the shield wire characterized by this is provided.

In the second invention, in the first invention, instead of the method in which the outer peripheral surface of the foamed rubber sheet is strongly wound with an adhesive tape by half-wrapping, the heat-shrinkable tube is covered with the foamed rubber sheet, and the heat-shrinkable tube is heated. It shrinks and adheres strongly to the foamed rubber sheet. By controlling the shrinkage rate of the heat-shrinkable tube and adjusting the pressure applied to the foamed rubber sheet, it is possible to reliably fill the gap between the core wire and the drain wire with the water stop agent soaked in the foamed rubber sheet. .
As the heat-shrinkable tube, “Sumitube” manufactured by Sumitomo Electric Fine Polymer is preferably used.

In the terminal water stop part formed as described above, the hardened water stop agent is continuously fixed from the outer peripheral surface of the drawn core wire and drain wire to the outer peripheral surface of the sheath. Therefore, the core wire and the sheath are continuously provided from the outer peripheral surface of the core wire drawn out to the outer peripheral surface of the sheath, even if the sheath contracts due to thermal shock and the deviation occurs. It is possible to prevent peeling between the water-stopping agent and the peeled end surface of the sheath. As a result, water can be prevented from being generated from the peeled portion, and the water stop performance can be maintained.
Further, since the foamed rubber sheet is strongly half-wrapped with an adhesive tape or pressed strongly with a heat-shrinkable tube, the foamed rubber sheet can be thinned and its outer diameter is not enlarged. Therefore, for example, the diameter can be reduced by about 30% as compared with the case where the butyl rubber and the outer skin described in Patent Document 2 are coated. Thus, since the enlargement of the terminal water stop part of a shield wire can be suppressed, the wire harness in which the several shield wire was converged can be accommodated in a corrugated tube.

This invention provides the shield wire provided with the terminal water stop part formed by the said method.
The shield wire is preferably arranged in a wet area including an engine room of an automobile.
The shielded wire wired in the flooded area has a terminal connected to the terminal of the drain line, and together with the terminal connected to the core line terminal drawn out from the terminal of the shielded cable, connected to the equipment arranged in the flooded area Is done.
For example, the terminal of the drain wire terminal is inserted and locked into the waterproof connector together with the terminal connected to the terminal of the other core wire, and the waterproof connector is fitted into the connector fitting portion of the ECU mounted in the engine room. ing.

As described above, in the terminal water stop part of the shield wire of the present invention, the water stop agent continuously cured from the outer peripheral surface of the drawn core wire and drain wire to the outer peripheral surface of the sheath with the peeled point of the sheath interposed therebetween Is fixed. Therefore, even if there is a gap between the core wire and the sheath due to a thermal shock in which the heat changes abruptly, it is possible to prevent separation between the water-stopping agent and the sheath, and the reliability of the water-stopping performance Can be increased.
In addition, at the terminal waterstop, the adhesive tape is strongly half-wrapped around the outer peripheral surface of the foam rubber sheet, or the heat shrink tube is heated after being covered with the heat shrink tube, and the heat shrink tube is shrunk to add the foam rubber sheet from the outer periphery. Since the thickness is reduced by pressing, it is possible to suppress the enlargement of the outer diameter at the terminal water stop portion.

The shield wire provided with the terminal water stop part of the first embodiment of the present invention is shown, (A) is a partially sectional front view, (B) is a sectional view taken along line BB of (A), (C) is ( (A) CC sectional view taken on the line, (D) is DD sectional view taken on the line (A). (A)-(D) are drawings which show the formation process of a water stop part. It is an expanded sectional view showing the state where the foamed urethane sheet was soaked with silicone. (A) (B) is drawing which shows 2nd embodiment. (A) (B) is drawing which shows a shield wire. It is drawing which shows a prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The shield wire 10 in any of the first embodiment shown in FIGS. 1 to 3 and the second embodiment shown in FIG. 4 is wired in a waterproof region of an automobile engine room, and the terminal of the shield wire 10 is connected to a connector. The connector is fitted in a connector housing portion of an ECU (not shown) which is disposed in the waterproof region. The shield wire 10 is provided with a water stop 20 at the terminal position.

As shown in FIG. 1, in this embodiment, the shield wire 10 is formed by surrounding a core wire 12 made of an insulation-coated electric wire serving as two signal wires and a single drain wire 11 with a shield layer 13. The outer periphery of the layer 13 is covered with a sheath 14 made of an insulating coating material, and the drain wire 11 is brought into contact with the shield layer 13 to conduct.
The drain wire 11 is made of a metal strand and does not have a coating layer. The shield layer 13 is formed by winding a metal foil tape. A metal wire braided tube may be used.

  The shield wire 10 cuts and peels off the sheath 14 and the shield layer 13 at a peel point P having a shortest dimension L1 of about 100 mm from the tip, and draws the drain wire 11 and the core wire 12. A terminal (not shown) inserted into and locked to the connector is crimped to the end of each core wire 12 and drain wire 11.

The water stop portion 20 is provided with the water stop region S from the position of the dimension L2 (about 45 mm) in the skin peeling direction to the dimension L3 (about 45 mm) in the opposite direction across the skin peel point P of the shield wire 10. .
That is, the water stop 20 is provided on the outer periphery of the drain wire 11 and the core wire 12 drawn at the position of the dimension L2, and on the outer periphery of the sheath 14 at the position of the dimension L3.

  In the water stop part 20, as shown in FIGS. 1C and 1D, the outer periphery of the drain wire 11 and the core wire 12 drawn out in a state where the silicone 21 used as the water stop agent is cured in a gel state (21g) To the outer periphery of the sheath 14 and further to the peeled end surface 14a of the sheath 14 in a continuous state. The outer peripheral surface of the cured silicone 21 is surrounded by a foamed urethane sheet 22 used as a foamed rubber sheet, and the outer peripheral surface of the foamed urethane sheet 22 is half-wrapped with an adhesive tape 23.

The formation method of the water stop part 20 of the terminal of the said shield wire 10 is demonstrated below with reference to FIG. 2 (A)-(D) and FIG.
First, the sheath 14 and the shield layer 13 are peeled off at the end of the shield wire 10 with the dimension L1, and the core wire 12 and the drain wire 11 are pulled out from the peeled point P of the sheath 14 that has been cut.

As shown in FIG. 2A, a foamed urethane sheet 22 cut into a rectangular shape is prepared, and the foamed urethane sheet 22 is soaked with molten sol-like silicone 21s.
Specifically, as shown in FIG. 3, the urethane foam sheet 22 has pores 22a that are open on the surface, and is a continuous foam in which the pores 22a are three-dimensionally continuous. About%. The thickness (t) of the foamed urethane sheet 22 is about 2.2 mm to 2.8 mm.
The foamed urethane sheet 22 is placed on a base (not shown), melted silicone 21 is applied to the central portion of the upper surface thereof, and silicone 21 s is filled in the pores 22 a of the foamed urethane sheet 22.

As shown in FIG. 2B, the water stop area S of the end of the shield wire 10 is placed on the surface of the foamed urethane sheet 22 in which the molten silicone 21s is soaked into the air holes 22a.
The sol-like silicone 21s has a viscosity of about 5 Pa.s. The fluidity is assumed to be about s.

Next, as shown in FIG. 2C, the urethane foam sheet 22 is wound around the water stop region S of the shield wire 10 with the application side of the silicone 21s as the inner surface.
Immediately after the urethane foam sheet 22 is wound and before the silicone 21 is cured, the adhesive tape 23 is strongly wound around the outer peripheral surface of the foamed urethane sheet 22 by half-wrapping as shown in FIG.

  In this state, the shield wire 10 including the water stop region S around which the foamed urethane sheet 22 and the adhesive tape 23 are wound is held in a horizontal state and kept stationary. The resting time is until the silicone 21 is cured in a gel form.

The melted silicone 21s filled in the pores 22a of the foamed urethane sheet 22 while being stationary in the horizontal state is strongly wound around the foamed urethane sheet 22 by the adhesive tape 23. Exudes from the inner surface. The exuded silicone 21s flows so as to adhere to the drawn core wire 12, the outer peripheral surface of the drain wire 11, the gap between the strands of the drain wire 11, the outer peripheral surface of the sheath 14, and the peeled end surface 14a of the sheath 14. To do.
After the required time has elapsed, the silicone 21 is cured in a gel form, and the cured silicone 21g is the core wire 12, the outer peripheral surface of the drain wire 11, the gap between the strands of the drain wire 11, the outer peripheral surface of the sheath 14, It adheres to the peeled end surface 14a of the sheath 14 in a continuous state.

  As described above, after the silicone 21g is cured, when the silicone 21 protrudes from both ends of the foamed urethane sheet 22 and the adhesive tape 23 in the length direction, the adhesive tape is wound around both ends.

  Thus, since the water stop part 20 is formed at the end of the shielded wire 10, the cured silicone 21g can be tightly fixed from the outer peripheral surface of the sheath 14 to the peeled end surface 14a, and the silicone 21g Silicone 21g which can be tightly fixed to the outer peripheral surfaces of the drawn core wire 12 and drain wire 11 and is cured with the peel point P interposed therebetween can be made continuous.

As described above, in the water stop portion 20 provided at the end of the shield wire 10, the outer periphery of the core wire 12 and the drain wire 11 is continuously extended from the outer peripheral surface of the sheath 14 with the peel point P of the sheath 14 interposed therebetween. 21 g of cured silicone is fixed. Therefore, even if a deviation occurs between the core wire 12 and the sheath 14 due to a thermal shock in which the heat changes abruptly, it is possible to prevent the separation between the silicone 21g and the sheath 14 and to prevent water stoppage. Reliability can be increased.
And in the water stop part 20, since the adhesive tape 23 is strongly half-wrapped around the outer peripheral surface of the foamed urethane sheet 22 to reduce the thickness of the foamed urethane sheet 22, the outer diameter of the water stop part 20 is enlarged. Can be suppressed. As a result, even if the corrugated tube is externally mounted on the wire harness in which a plurality of shielded wires 10 each having the water stop portion 20 are converged at the terminal, the shield wire 10 having the water stop portion 20 is accommodated in the corrugated tube. be able to.

4A and 4B show a second embodiment.
In 2nd embodiment, after winding the foaming urethane sheet 22 which apply | coated the silicone 21 used as a water-stopping agent around the water-stopping area | region S of the shield wire 10, before the silicone hardens | cures, the heat-shrinkable tube 30 of the foaming urethane sheet 22 is carried out. After covering the outer periphery, the heat shrinkable tube 30 is heated and contracted to adhere to the outer peripheral surface of the urethane foam sheet 22.
When the heat-shrinkable tube 30 is contracted by heating, the heating temperature is controlled so that the contracted heat-shrinkable tube 30 strongly presses the outer peripheral surface of the foamed urethane sheet 22.

After shrinking the heat shrinkable tube 30, the shield wire 10 including the water stop region S to which the foamed urethane sheet 22 and the heat shrinkable tube 30 are attached is held in a horizontal state and kept stationary. The resting time is until the silicone 21 is cured in a gel form.
When the heat shrinkable tube 30 is used instead of the adhesive tape, and the heat shrinkable tube 30 is covered with the outer peripheral surface of the foamed urethane sheet, the foamed urethane sheet is contracted by the heat shrinkable tube 30 as in the first embodiment. By compressing, the silicone impregnated into the urethane foam sheet oozes out from the surface, and the core wire 12, the outer peripheral surface of the drain wire 11, the gap between the strands of the drain wire 11, the outer peripheral surface of the sheath 14, and the sheath 14 It flows so as to adhere to the peeled end surface 14a.
After the required time has elapsed, the silicone 21 is cured in a gel state, and the cured silicone 21g is used for the core wire 12, the outer peripheral surface of the drain wire 11, the gap between the strands of the drain wire 11, the outer peripheral surface of the sheath 14, It can be fixed to the peeled end surface 14a of the sheath 14 in a continuous state.

  In this way, using a heat-shrinkable tube instead of half-wrapping with an adhesive tape has the advantage that a uniform force can be applied to the foamed urethane sheet rather than tape winding that depends on skill, and workability is improved. is there.

DESCRIPTION OF SYMBOLS 10 Shield wire 11 Drain wire 12 Core wire 13 Shield layer 14 Sheath 20 Water stop part 21 Silicone 21s Silicone with fluidity in sol form 21g Silicone cured in gel form 22 Foamed urethane sheet 23 Adhesive tape 30 Heat shrinkable tube P Peel point
S Water stoppage area

Claims (5)

Peel the sheath of the end of the shielded wire, expose the core wire and drain wire from the end, pull out,
After wrapping the waterproof sheet soaked with the melted water-stopping agent in the foamed rubber sheet, the outer peripheral surface of the sheath and the exposed core wire and the outer periphery of the drain wire are tightly wound across the peeled point of the sheath,
Strongly wrap the adhesive tape on the outer peripheral surface of the foam rubber sheet with a half wrap, hold in this state in the horizontal direction,
The waterproofing agent soaked in the foamed rubber sheet is filled in the exposed gap between the core wire and the drain wire by the winding force of the adhesive tape, and is allowed to flow into the gap between the inner peripheral surface of the sheath and the core wire and the drain wire. Furthermore, a water-stopping agent is oozed out on the outer peripheral surface of the sheath,
In this state, the water-stopping agent is cured, and the hardened water-stopping agent is continuously fixed from the outer peripheral surface of the core wire and drain wire drawn out from the sheath terminal to the outer peripheral surface and the peeled end surface of the sheath. A method for shutting off a terminal of a shielded wire, characterized by that. Peel the sheath of the end of the shielded wire, expose the core wire and drain wire from the end, pull out,
After wrapping the waterproof sheet soaked with the melted water-stopping agent in the foamed rubber sheet, the outer peripheral surface of the sheath and the exposed core wire and the outer periphery of the drain wire are tightly wound across the peeled point of the sheath,
Cover the outer peripheral surface of the foam rubber sheet with a heat shrinkable tube,
The heat-shrinkable tube is heated and shrunk, tightly adhered to the outer peripheral surface of the foamed rubber sheet, and held in this state in a horizontal direction to be stationary,
The waterproofing agent soaked in the foam rubber sheet is filled in the exposed gap between the core wire and the drain wire by the shrinkage force of the heat shrinkable tube, and flows into the gap between the inner peripheral surface of the sheath and the core wire and the drain wire. Furthermore, a water-stopping agent is oozed out on the outer peripheral surface of the sheath,
In this state, the water-stopping agent is cured, and the hardened water-stopping agent is continuously fixed from the outer peripheral surface of the core wire and drain wire drawn out from the sheath terminal to the outer peripheral surface and the peeled end surface of the sheath. A method for shutting off a terminal of a shielded wire, characterized by that.   The foamed rubber sheet is made of urethane foam rubber having a porosity of 30 to 70%, and silicone is used as a molten water-stopping agent soaked into the pores of the foamed urethane rubber. Terminal water stop method of the shield wire.   The shield wire provided with the terminal water stop part formed by the method of Claim 1 or Claim 2.   The shield wire provided with the terminal water stop part of Claim 4 arranged in the to-be-watered area | region containing the engine room of a motor vehicle.

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