JP4799956B2 - In-vehicle electric wire and waterproofing method thereof - Google Patents

Description

  The present invention relates to a technique for waterproofing an in-vehicle electric wire mounted on a vehicle.

  Some of the on-vehicle electric wires are required to have high waterproof properties. For example, a grounding wire for connecting an electric circuit provided in a vehicle or the like to a grounding terminal is connected to a suitable grounding part (for example, a vehicle body) with the grounding terminal fixed to the terminal exposed to the outside. Therefore, moisture easily enters from the terminal, and if the moisture enters the circuit through the inside of the covering material, there is a possibility that normal operation of the circuit is hindered.

Therefore, as a technique for providing a waterproof function to an in-vehicle electric wire including such an electric wire for grounding, a water-stopping agent having fluidity is supplied to one terminal of the in-vehicle electric wire in Patent Document 1 below. In addition, a technique is disclosed in which the other end is sucked to draw the water-stopping agent into the gap between the conductor of the in-vehicle electric wire and the covering material.
JP 2004-355851 A

  However, in a vehicle-mounted electric wire filled with a water-stopping agent so as to fill the gap between the conductor and the covering material as described above, the flexibility of the electric wire is reduced by the presence of the water-stopping agent, and the wiring work There was a risk that it would be difficult. Of course, if a relatively flexible material is used as the water-stopping agent, the flexibility of the wire will not be greatly reduced, but even in that case, the flexibility is higher than that in which the gap is secured. Slightly inferior.

  In addition, as described above, the method of drawing the water-stopping agent having fluidity supplied to one end of the in-vehicle electric wire into the electric wire requires a step of sucking the other end of the in-vehicle electric wire. . On the other hand, if such a process is not required and the waterproofing can be performed on the in-vehicle electric wire more easily, the manufacturing efficiency is improved.

  In view of such circumstances, the present invention provides an in-vehicle electric wire and a waterproof treatment method thereof that can effectively suppress the intrusion of moisture from an electric wire terminal with a simpler structure while maintaining good flexibility. The purpose is to provide.

  As means for solving the above-mentioned problems, the present invention provides an in-vehicle electric wire that is mounted on a vehicle having a coating material on the outside of a conductor, and the outer peripheral surface of the conductor and the inner peripheral surface of the coating material are Further, it is characterized by being covered with a water-repellent coating over a predetermined length from at least one terminal (claim 1).

  According to this in-vehicle electric wire, the outer peripheral surface of the conductor and the inner peripheral surface of the covering material are covered with a water-repellent coating at at least one end thereof, so that water droplets adhering to the end are separated by gaps between the conductors. In addition, even if an attempt is made to enter the inside of the electric wire through the gap between the covering material and the conductor, the penetration is inhibited by the action of the water-repellent coating covering the surface forming the gap, so that moisture enters from the terminal. Can be effectively suppressed. And the vehicle-mounted electric wire provided with the waterproof structure by such a water-repellent coating can suppress the intrusion of moisture in a state where the gap between the covering material and the conductor is not blocked (while the gap is secured inside the electric wire). Therefore, the flexibility is maintained well as compared with the conventional in-vehicle electric wire filled with a water-stopper inside the electric wire, and the wiring workability is further improved.

  The vehicle-mounted electric wire is preferably a vehicle-mounted electric wire with a terminal in which a terminal is connected to the terminal in advance for facilitating wiring work (Claim 2).

  In this in-vehicle electric cable with a terminal, moisture may adhere to the exposed conductor part and the terminal connected to the terminal, but even in that case, the water-repellent coating prevents the moisture from entering the inside of the electric wire. It can be effectively suppressed.

  In addition, although the use of this vehicle-mounted electric wire with a terminal is not particularly limited, it can be suitably used as an electric wire for grounding in which the terminal is connected to an earthing site provided at a predetermined location of a vehicle (claim) Item 3).

  According to this configuration, since the grounding wire can be waterproofed, it is generally opposite to the end of the grounding wire connected to a grounding part (for example, the vehicle body) that is generally susceptible to the external environment of the vehicle. It is possible to prevent moisture from entering the terminal.

  However, the in-vehicle electric wire according to the present invention is not limited to such a grounding electric wire, and can be used for various in-vehicle electric wires that require waterproofness. For example, even if the electric wire is connected to a connector having a waterproof function, the in-vehicle electric wire according to the present invention can be suitably used as long as the electric wire is connected to a circuit that requires particularly high waterproofness. .

  Furthermore, the vehicle-mounted electric wire according to the present invention can be used even when a terminal is not connected to the terminal. In addition, when actually wiring such an electric wire, it is necessary to cut off an excess portion of the electric wire or to remove the covering material of the terminal portion to expose the conductor. If the wire is cut or the covering material is removed in the region where the water-repellent film is formed (within a predetermined length from the terminal), the repellent even after the cutting or the like is performed. Since the water-based film can remain in the electric wire, the waterproof function is not impaired.

  The water-repellent film is preferably made of a water-repellent material having a contact angle of 90 degrees or more with respect to water (claim 4).

  According to this configuration, even if water droplets try to enter the gap between the conductors and the gap between the covering material and the conductor, the surface tension of the water acts in a direction to push it back. Can be prevented from entering.

  In addition, as said water-repellent material, a fluororesin or a silicone resin is suitable, for example (Claim 5).

  The present invention is also a method for waterproofing at least one terminal of an in-vehicle electric wire that has a coating material on the outside of a conductor and is mounted on a vehicle, the terminal being repelled by a volatile solvent. Supplying a water-repellent solution in which an aqueous material is dissolved, and supplying the water-repellent solution into the interior of the in-vehicle electric wire from the gap between the conductor and the gap between the covering material and the conductor; After the water-repellent solution supplying step, the volatile solvent is evaporated to leave the water-repellent material dissolved in the solvent, thereby forming a water-repellent coating on the outer peripheral surface of the conductor and the inner peripheral surface of the covering material. And a solvent evaporation step to be formed (claim 6).

  According to this method for waterproofing an in-vehicle electric wire, after supplying a water-repellent solution obtained by dissolving a water-repellent material in a volatile solvent to the electric wire terminal and infiltrating the solution into the electric wire (water repellent solution supply) Step), a water-repellent film can be formed on the outer peripheral surface of the conductor and the inner peripheral surface of the covering material by a simple method of evaporating the volatile solvent (solvent evaporation step). In addition, the solution supplied to the wire terminal in the water-repellent solution supplying step permeates the inside of the wire through the gap between the conductors and the gap between the covering material and the conductor by capillary action, so that the water-repellent solution is infiltrated. Therefore, it is not necessary to suck the other end of the electric wire as in the prior art. In addition, since a volatile solvent is used as a solvent for dissolving the water repellent material, the volatile solvent naturally evaporates in the solvent evaporation step, and thus the electric wire is heated to evaporate the solvent. There is no need to perform the process.

  In the water repellent solution supplying step, for example, the conductor is exposed in advance by removing the covering material of the end portion by a predetermined length, and the water repellent solution is dropped in the vicinity of the base end portion of the exposed conductor. (Claim 7).

  In this case, the dripping of the water repellent solution is a method in which a terminal is connected in advance to the exposed conductor of the terminal portion, and the water repellent solution is dripped so as to collect the water repellent solution in the vicinity of the conductor connecting portion on the terminal. It is preferable that it is present (claim 8).

  Thus, by using the terminal as a receptacle for the water-repellent solution, the water-repellent solution can be stably supplied.

  On the other hand, the water-repellent solution supplying step may be performed by immersing at least one terminal of the in-vehicle electric wire in the water-repellent solution (claim 9).

  According to this configuration, for example, a dispenser or the like is not required for dripping the water repellent solution, so that the in-vehicle electric wire can be waterproofed at a lower cost.

  As described above, according to the present invention, an in-vehicle electric wire that can effectively suppress the intrusion of moisture from the electric wire terminal with a simpler structure while maintaining good flexibility, and a waterproofing method thereof Can be provided.

  A preferred embodiment of the present invention will be described with reference to the drawings.

  In addition, although this embodiment demonstrates the method of water-stop-processing to the electric wire for earth | ground for connecting the circuit mounted in the vehicle to earth | ground, this invention is not limited to this, Various vehicle-mounted by which waterproofness is calculated | required It can also be applied to industrial wires.

  The ground wire according to the present embodiment can be manufactured by the following manufacturing method.

1) Terminal crimping process This process is a process of crimping and fixing the ground connection terminal 20 to one end of the grounding electric wire 10 as shown in FIGS.

  As the grounding wire 10, an insulated wire having a covering 14 around the conductor 12 is used. Then, the covering material 14 at one end is removed by a predetermined length to expose the conductor 12.

  A ground connection terminal 20 as shown in FIGS. 1A and 1B is fixed to the end of the ground wire 10 by pressure. The illustrated ground connection terminal 20 is formed of a single metal plate, and integrally includes a ground connection portion 21 connected to a vehicle body ground, a conductor barrel 22 and an insulation barrel 24. The ground connection portion 21 is provided with a bolt insertion hole 21a through which a not-illustrated bolt can be inserted, and the ground connection portion 21 is fastened to the vehicle body by the bolt to be electrically connected to the body. (Ie connected to the body ground).

  In a state where both the barrels 22 and 24 of the ground connection terminal 20 are opened, the end of the grounding wire 10 from which the covering material 14 has been removed as described above is set, and then the conductor barrel 22 and the insulation barrel 24. Are closed and fixed to the conductor 12 and the covering material 14 by crimping.

2) Water-repellent solution supplying step This step is a step of supplying a water-repellent solution to one terminal of the grounding electric wire 10 (the terminal on the side to which the ground connection terminal 20 is fixed). Specifically, the water repellent solution is dropped by a dispenser (not shown) at the dropping position A shown in FIGS. 1A and 1B, that is, near the base end of the exposed portion of the conductor 12. Thus, the water repellent solution is stored between the conductor barrel 22 and the insulation barrel 24 of the ground connection terminal 20 (while the ground connection terminal 20 is used as a receiver of the water repellent solution), and the water repellent solution is stably repelled. An aqueous solution can be supplied. In addition, what is necessary is just to set this dripping position suitably according to a terminal structure. Further, the dropping amount of the water repellent solution and the number of times of dropping should be set as appropriate. However, when the dropping amount is large, it is desirable to drop the water repellent solution in a plurality of times.

  This water-repellent solution is constituted by dissolving a water-repellent material having a contact angle of 90 degrees or more with respect to water, such as a fluororesin or a silicone resin, in a volatile solvent. In addition, as a volatile solvent for dissolving such a water-repellent material, for example, a fluorine-based solvent, an alcohol-based solvent, silicone oil, benzene, toluene, xylene, or the like can be used.

  The water-repellent solution dripped onto the terminal on the side of the ground connection terminal 20 penetrates into the ground wire 10 from the gap between the conductors 12 and the gap between the covering material 14 and the conductor 12 due to a capillary phenomenon. Specifically, as shown in FIG. 2 which is an enlarged cross-sectional view of the terminal portion, the water-repellent solution dropped at the dropping position A is a gap B between the conductor wires 12a constituting the conductor 12, and Through the gap C between the conductor 12 and the covering material 14, it penetrates into the inner side (right side in FIG. 2) of the electric wire by capillary action.

3) Solvent evaporation step As described above, this step is performed inside the electric wire through the gap between the conductors 12 of the grounding wire 10 (the gap between the conductor strands 12a) B and the gap C between the covering material 14 and the conductor 12. This is a step of evaporating the solvent of the permeated water repellent solution. However, since the solvent has volatility and evaporates spontaneously, it is actually only necessary to leave the in-vehicle electric wire 10 for a while.

  Then, when the volatile solvent evaporates in this manner, the water-repellent material dissolved in the solvent remains, and as shown in FIG. 3A, the conductor 12 (each conductor strand 12a ) And the inner peripheral surface of the covering material 14 are formed with a water-repellent coating 30.

  In FIG. 3A, a region where the water-repellent coating 30 is formed is shown as a region D. The length of the film forming region D is determined by the penetration depth of the water repellent solution. Accordingly, the length of the film forming region D can be adjusted by increasing or decreasing the amount of the water repellent solution dropped in the water repellent solution supplying step. Becomes longer.

  Further, the thickness of the water-repellent coating 30 can be adjusted by the concentration of the water-repellent material in the water-repellent solution, and the thickness of the water-repellent coating 30 increases as the concentration of the water-repellent material increases. . If the thickness of the water-repellent coating 30 is set such that the gap B between the conductors 12 and the gap C between the covering material 14 and the conductor 12 are not completely blocked by the coating 30, Since a gap is secured inside the film formation region D), the flexibility of the electric wire can be maintained well. Therefore, the concentration of the water-repellent material is preferably set to an appropriate value that does not become too thick so that the thickness of the water-repellent coating 30 is smaller than the size of the gaps B and C.

  As described above, according to the grounding electric wire 10 of the present embodiment, the outer peripheral surface of the conductor 12 (each conductor strand 12a) and the inner peripheral surface of the covering material 14 at the end on the side to which the ground connection terminal 20 is connected. Are covered with the water-repellent coating 30, so that water droplets attached to the terminal on the side of the ground connection terminal 20 connected to a ground part (for example, a vehicle body) that is generally susceptible to the external environment of the vehicle. Even if the gap between the conductors 12 (the gap between the conductor wires 12a) B and the gap C between the covering material 14 and the conductor 12 is to enter the opposite terminal, the surface forming these gaps B and C Since the intrusion is hindered by the action of the water-repellent coating film 30 to be covered, the intrusion of moisture from the terminal on the ground connection terminal 20 side can be effectively suppressed.

  Specifically, the water-repellent coating 30 that covers the outer peripheral surface of the conductor 12 (each conductor strand 12a) and the inner peripheral surface of the covering material 14 has a contact angle of 90 degrees or more with respect to water. 3B, when the water droplet 32 shown in FIG. 3B adheres to the end of the electric wire, the illustrated contact angle θ becomes an obtuse angle, so that the surface tension F of the water causes the water droplet 32 to move outside the electric wire. Since it acts in the direction of pushing back (left side in FIG. 3), it is possible to reliably prevent the water droplet 32 from entering the electric wire.

  Moreover, the grounding electric wire 10 having a waterproof structure with such a water-repellent coating 30 does not close the gap B between the conductors 12 and the gap C between the covering material 14 and the conductor 12 (no gaps are formed inside the electric wires). Because it can prevent the ingress of moisture (with assured), the flexibility of the wire is better maintained and the wiring workability is better than the conventional wire in which the gap in the covering material 14 is filled with a water-stopper. It becomes. In addition, because of the presence of the gaps B and C, the pressure inside the covering material 14 does not increase even under special circumstances such that the bending of the wire is excessively repeated or a rapid temperature change occurs. There is also an advantage that the durability of the covering material 14 is improved.

  Further, according to the waterproofing method for the grounding wire 10 in the present embodiment, a water repellent solution obtained by dissolving a water repellent material in a volatile solvent is supplied to the terminal on the ground connection terminal 20 side, and the water repellent solution is obtained. Is allowed to evaporate into the inside of the electric wire from the gap B between the conductors 12 and the gap C between the covering material 14 and the conductor 12 (water repellent solution supply step), and then the volatile solvent is evaporated (solvent evaporation step). The water repellent coating 30 can be formed on the outer peripheral surface of the conductor 12 (conductor strand 12a) and the inner peripheral surface of the covering material 14 by a simple method. In addition, since the solution supplied to the wire end in the water repellent solution supply step permeates the inside of the wire through the gaps B and C by capillary action, the wire repellent as in the prior art is used to permeate the water repellent solution. There is no need to suck the other terminal. In addition, since a volatile solvent is used as a solvent for dissolving the water repellent material, the volatile solvent naturally evaporates in the solvent evaporation step, and thus the electric wire is heated to evaporate the solvent. There is no need to perform the process.

  In this embodiment, the waterproof treatment is performed only on the terminal on the ground connection terminal 20 side, but the waterproof effect on the electric wire is further enhanced by performing the same waterproof treatment on the terminal on the opposite side. It may be.

  In the present embodiment, the water-repellent solution supplying step is performed after the terminal crimping step, but this can be performed before the terminal crimping step. However, in that case, there is no place where the water repellent solution can be held in a stable state, such as the dropping position A in the present embodiment, and therefore, the supply of the water repellent solution may become unstable. However, even in such a case, the water-repellent solution can be stably supplied by supplying the solution while attaching a jig (solution receiver) separately to the wire terminal.

  Furthermore, the water-repellent solution supplying step of the present embodiment is performed by dropping the water-repellent solution onto one terminal of the grounding wire 10. Instead of such a method, the one terminal is water-repellent. You may carry out by immersing in the solution (For example, the tank in which the water repellent solution was stored).

  Although the color of the water-repellent coating 30 was not particularly mentioned, a colored water-repellent coating 30 may be formed by mixing a colorant into the water-repellent solution. If it does in this way, it will become possible to discriminate | determine easily visually whether it is an electric wire with which the waterproof process was performed.

  Moreover, although the water repellent material of this embodiment was comprised with the material which has a contact angle of 90 degree | times or more with respect to water like a fluororesin or a silicone resin, even if it is less than 90 degree | times, the conductor 12 and the coating | covering material 14 As long as it has a larger contact angle, it is possible to suppress the intrusion of moisture to some extent. Accordingly, an acrylic resin or an epoxy resin may be used as the water repellent material.

  1A and 1B, the water repellent solution is dropped at the dropping position A (between the conductor barrel 22 and the insulation barrel 24 of the ground connection terminal 20) by the following method. Waterproofing was performed under the conditions of

Water repellent material… Fluororesin “Durasurf DS-5320Z” (manufactured by Harves Co., Ltd.)
Concentration of water repellent material ... 2% (estimated film thickness 0.5-1.0 μm)
Water repellent solution dripping amount ... 5mg
Cross-sectional area / length of wire ... 3mm ² / 1m
Standing time to evaporate the solvent ... 30 seconds

  After the waterproof treatment was performed under the above conditions, the wire end was immersed in a water tank, and it was confirmed that there was no water intrusion in the wire. In addition, when air is blown from the terminal on the opposite side while the terminal is immersed in the water tank, generation of bubbles in the water tank is confirmed, and as a result, it can be confirmed that the wire terminal is not blocked. did it.

(A) is a top view which shows the structure which crimped-fixed the ground connection terminal to one terminal of the electric wire for earth | ground concerning embodiment of this invention, (b) is the front view. It is an expanded sectional view of the terminal part of the electric wire for earthing. (A) is a figure which shows the condition where the water-repellent film was formed in the terminal part shown in FIG. 2, (b) is a figure which shows the condition where the water droplet adhered to the said terminal.

Explanation of symbols

10 Grounding wire (wire for automotive use)
12 Conductor 12a Conductor Wire 14 Coating Material 20 Ground Connection Terminal (Terminal)
30 Water repellent coating B B Gap between conductors (gap between conductor wires)
C Clearance between the coating material and the conductor

Claims (9)

An in-vehicle electric wire that is mounted on a vehicle with a covering material outside the conductor,
An in-vehicle electric wire, wherein an outer peripheral surface of the conductor and an inner peripheral surface of a covering material are covered with a water-repellent coating over a predetermined length from at least one end.   The in-vehicle electric wire according to claim 1, wherein the in-vehicle electric wire is an in-vehicle electric wire with a terminal having a terminal connected to the terminal.   The in-vehicle electric wire according to claim 2, wherein the in-vehicle electric wire with a terminal is an earth electric wire in which the terminal is connected to an earth portion provided at a predetermined location of a vehicle. The in-vehicle electric wire according to any one of claims 1 to 3,
The in-vehicle electric wire, wherein the water-repellent coating is made of a water-repellent material having a contact angle of 90 degrees or more with respect to water. The in-vehicle electric wire according to claim 4,
The in-vehicle electric wire, wherein the water repellent material is a fluororesin or a silicone resin. A method for waterproofing at least one terminal of a vehicle-mounted electric wire mounted on a vehicle having a coating on the outside of a conductor,
A water repellent solution in which a water repellent material is dissolved in a volatile solvent is supplied to the terminal, and the water repellent solution is introduced into the interior of the in-vehicle electric wire from the gap between the conductors and the gap between the covering material and the conductor. A water-repellent solution supplying step for permeation;
After the water-repellent solution supplying step, the water-repellent coating is formed on the outer peripheral surface of the conductor and the inner peripheral surface of the covering material by evaporating the volatile solvent and leaving the water-repellent material dissolved in the solvent. And a solvent evaporation process for forming a vehicle. The waterproofing method for an in-vehicle electric wire according to claim 6,
The water-repellent solution supplying step is a step in which a conductor is exposed in advance by removing a predetermined length of the covering material of the terminal portion, and the water-repellent solution is dropped near the base end portion of the exposed conductor. A waterproofing method for an in-vehicle electric wire, characterized in that: The waterproofing method for an in-vehicle electric wire according to claim 7,
The water-repellent solution supplying step is a step in which a terminal is connected to the exposed conductor of the terminal portion in advance, and the water-repellent solution is dripped so as to collect the water-repellent solution in the vicinity of the conductor connecting portion on the terminal. A waterproofing method for an in-vehicle electric wire characterized by the above. A waterproof treatment method for an in-vehicle electric wire according to claim 6,
The water-repellent solution supplying step is a step of immersing at least one end of the vehicle-mounted electric wire in the water-repellent solution.

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