JP4844541B2 - Splice part waterproofing method and wire harness having waterproof splice part - Google Patents

Description

  The present invention relates to a method for waterproofing a splice part and a wire harness provided with the waterproof splice part, and more specifically, when the waterproof process is performed by infiltrating the splice part with a sealant, the leakage of the sealant is prevented and the waterproof process workability It is what raises.

  Conventionally, when it is necessary to connect each other at the splices of a plurality of electric wires in a wire harness, the core wire is exposed by stripping the middle portion of each electric wire, and the core wires are bundled together with a joint terminal. Electrical continuity is obtained by means of pressure bonding, resistance welding, ultrasonic welding, or the like. When the wire harness provided with the splice portion is disposed in the flooded region, the joint terminal is corroded when the splice portion is flooded, so that the splice portion is waterproofed.

  As shown in FIGS. 5 (A) and 5 (B) disclosed in the conventional example of Japanese Patent Laid-Open No. 2006-318716, a waterproof region including the splice portion 1 of the wire harness W / H is used as the waterproof treatment structure of the splice portion. Cover the outer peripheral surface of the electric wire group at both ends with the adhesive tape 2, place the foam sheet 4 coated with the low-viscosity sealing agent 3 on the inner surface of the adhesive tape 2, and penetrate the sealing agent 3 to the details of the splice part 1 By doing so, the splice part is often waterproofed by being covered with the sealant 3.

  According to the waterproof structure, the sealant 3 can be permeated to the details of the splice part 1 by the action of the low-viscosity sealant 3 having high fluidity, but it adheres to the splice part 1 while the sealant 3 is not solidified. Tape 2 must be wound. However, the sealing agent 3 is likely to leak from both sides of the pressure-sensitive adhesive tape 2 due to the pressure action caused by the winding of the pressure-sensitive adhesive tape 2, and in such a situation, there is a possibility that a sufficient waterproof function in the splice portion 1 cannot be exhibited.

JP 2006-318716 A

  The present invention has been made in view of the above-mentioned problems, and prevents leakage of the sealing agent during waterproofing, ensures penetration of the gap between the core wires of the splice portion with the sealing agent, and ensures the outer peripheral surface of the splice portion with the sealing material. It is an object to cover it with a high waterproof function.

In order to solve the above-mentioned problem, the present invention is a method for waterproofing a splice part that peels off a part of an insulation coating of a plurality of electric wires and connects exposed core wires,
A case made of a resin molded product comprising a lower case and an upper case and having a cavity inside, the upper and lower walls and the peripheral walls on both the left and right sides, which are the lead-out side of the case, are transparent parts for light transmission, The central part sandwiched between the transparent parts on both the left and right sides is a colored part for light impermeability, and the right and left side walls are provided with wire outlets, and the upper wall or peripheral wall is provided with a resin inlet,
In the cavity of the lower case, the splice portion, the core wire exposed portions on both sides of the splice portion, and the insulation coating portions of the electric wires adjacent to the core wire exposure portions are accommodated, and the insulation coating portions are formed in the left and right transparent portions. And the splice part and the core wire exposed part are located in a central colored part, and the electric wire continuous to the insulating coating part is drawn out from the electric wire outlet,
Next, the upper case is covered with the lower case, and uncured photocurable silicone resin is injected into the cavity from the resin injection port,
Immediately after the resin injection, the case is irradiated with light to cure the photocurable silicone resin on the outer periphery of the insulating coating portion located in the transparent portion, and the colored portion of the photocurable silicone resin is naturally cured. A method for waterproofing a splice part is provided.

  According to the waterproofing method, the photocurable silicone resin on the outer periphery of the insulating coating portion located in the transparent portion is first cured by receiving light irradiation, and between the wire outlets on both sides of the case and the outer periphery of the wire. The gap can be closed. Therefore, while preventing the uncured silicone resin from leaking out from these gaps, the central colored portion delays the curing of the silicone resin to maintain fluidity, and the silicone resin is placed on both sides of the splice portion and the splice portion. The core wire exposed portion can be surely penetrated into the gap between the strands.

  In particular, since the photocurable silicone resin disposed on the insulating coating portion of the electric wire is cured immediately upon receiving light irradiation regardless of the viscosity, it is not necessary to set the uncured viscosity of the silicone resin high. Therefore, it becomes possible to use a resin having low viscosity and high fluidity, and the silicone resin can be infiltrated into the gaps between the core wires, including the gaps between the wires of the insulating coating portion.

  Further, when the photocurable silicone resin on the outer periphery of the insulating coating portion located in the transparent portion is cured by light irradiation and the silicone resin is continuously injected into the cavity, the silicone resin with the outlet blocked. Can surely penetrate into the details. Further, since the injection pressure of the resin increases when the resin is completely filled in the cavity, it can be recognized that the waterproof treatment has been reliably performed by increasing the injection pressure to a certain set pressure. Therefore, the conventionally required waterproof seal test becomes unnecessary, and workability is improved.

  In order to make it easier for the resin to permeate between the wires of the insulating coating portion, it is preferable to form a positioning groove for each wire at the wire outlet to ensure a gap for resin permeation between the wires. .

The uncured photocurable silicone resin has a viscosity of 1 Pa.s. s-50 Pa. s, and the hardness after curing is preferably 30 degrees or less on Shore A.
This is because the viscosity is 1 pa. If it is less than s, the fluidity is too high and the resin leaks out from the wire outlet or the like before photocuring. If it exceeds s, the fluidity is so low that it is difficult to penetrate the resin into the details, and the waterproof sealability is also lowered.

  This invention also provides the wire harness provided with the waterproof splice part manufactured by the said method.

  As described above, according to the present invention, since the transparent portions are provided on both the left and right sides of the case on the wire drawing side, by irradiating the case with light, first, the transparent portions on both sides of the case are arranged. The photocurable silicone resin can be cured on the outer periphery of the insulating coating portion, and the gap between the wire outlet and the outer periphery of the wire can be filled to close the outlet of the silicone resin. Therefore, it is possible to prevent the uncured silicone resin from leaking out of the case and to allow the resin to penetrate into the details.

  Further, the exit of the silicone resin is not blocked by utilizing the high viscosity of the resin, but is blocked by photocuring of the photocurable silicone resin, so that the viscosity of the photocurable silicone resin can be set low. . As a result, the silicone resin before curing can be sufficiently permeated into the details of the gap between the wires in the insulation coating portions of the wires on both sides of the splice portion. It is possible to reliably prevent water from entering the part and to exhibit high waterproof performance.

  Furthermore, by continuing to inject the resin even after the transparent portion of the case is irradiated with light to cure the silicone resin in the portion, the injection pressure can be increased to ensure that the silicone resin penetrates into the details. In addition, since it is possible to confirm that the waterproofing treatment has been reliably performed by increasing the injection pressure to a certain set pressure, a waterproof seal test is not required, and workability can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a waterproofing method for a splice portion of a wire harness according to an embodiment of the present invention.
As shown in FIG. 1, the wire harness 10 peels the insulation coating 12 of the plurality of electric wires 11 at an intermediate portion to expose the core wire 13, and connects the core wires 13 by resistance welding to form a splice portion 14. ing.

A case 20 is used for waterproofing the splice portion 14.
As shown in FIG. 3, the case 20 has a rectangular parallelepiped shape surrounded by an upper wall 21, a bottom wall 22, left and right side walls 23, and front and rear side walls 24. As shown in FIG. 1, the case 20 is composed of a lower case 20A and an upper case 20B made of symmetrical halves, and one cavity is filled with the cavity 25A of the lower case 20A and the cavity 25B of the upper case 20B. The cavity 25 for use is formed inside.

The left and right side walls 23A located at both ends of the lower case 20A in the wiring direction are provided with a plurality of wire lead-out recesses 26A for accommodating the insulation coating portions 16 of the electric wires 11 one by one from the upper end with a required interval, A resin injection recess 27A communicating with the cavity 25A is provided from the upper end at the intermediate position in the wiring direction of the front side wall 24A parallel to the wiring direction.
Similarly, the upper case 20B is also provided with a wire drawing recess 26B from the lower end at a position facing the respective wire drawing recess 26A, and a resin injection recess 27B at a position facing the resin injection recess 27A from the lower end. It is recessed.
Thus, when the upper case 20B is put on the lower case 20A and the cavity 25 is closed, as shown in FIG. 3, a plurality of electric wire outlets 26 formed of round holes are formed by the upper and lower electric wire extraction recesses 26A and 26B. At the same time, one resin injection port 27 made of a round hole is formed by the upper and lower resin injection recesses 27A and 27B.

The left and right sides of the lower case 20A are respectively formed of a transparent portion 28A for light transmission with transparent resin, while the central portion sandwiched between the transparent portions 28A on both sides is formed with a colored portion 29A for light opaqueness with black resin. Forming. Similarly, transparent portions 28B are formed on both the left and right sides of the upper case 20B, and a colored portion 29B is formed at the center portion sandwiched between the transparent portions 28B on both sides.
Thus, when the upper case 20B is covered with the lower case 20A, as shown in FIG. 3, the transparent portion in which the upper wall 21, the bottom wall 22, and the left and right side walls 23, 24 are surrounded by the transparent resin on both the left and right sides. 28, and a colored portion 29 in which the upper wall 21, the bottom wall 22, and the front and rear side walls 24 are surrounded by a black resin is formed in the central portion sandwiched between the transparent portions 28 on both sides.

Next, a waterproofing method for the splice unit 14 using the case 20 will be described.
First, as shown in FIG. 2, the splice portion 14 and the core wire exposed portions 15 on both sides of the splice portion 14 are disposed in the region of the colored portion 29A in the cavity 25A of the lower case 20A. At this time, the insulation coating portions 16 of the electric wires 11 in the portions adjacent to the core wire exposed portions 15 on both sides are engaged with the wire drawing recesses 26A on the left and right sides one by one, and the splice portion 14 side end of the insulation coating portions 16 is engaged. Projecting into the region of the transparent portion 28A in the cavity 25A.

  Next, as shown in FIG. 3, the upper case 20B is covered downward on the upper surface of the lower case 20A, and the cavity 25 is closed. Thereby, the splice part 14 and the core wire exposed parts 15 on both sides are arranged in the colored part 29, and the insulating coating part 16 is arranged in the transparent part 28. Further, each electric wire 11 continuous to the insulating coating portion 16 is drawn out from the electric wire outlet 26 on both the left and right sides of the case 20, and the electric wire outlet 26 is in close contact with the outer periphery of the insulating coating portion 16 of the electric wire 11.

Next, as shown in FIG. 4, after a resin injection nozzle 30 is connected to the resin injection port 27 and a photocurable silicone resin (not shown) is injected into the cavity 25 through the injection port 27. Immediately, the case 20 is irradiated with light from directly above the upper wall 21 vertically downward. The irradiated light does not pass through the colored part 29 but passes through only the transparent part 28, and cures the photocurable silicone resin injected into the transparent part 28.
Thereafter, the photocurable silicone resin is continuously injected, and when the injection pressure rises and reaches the set pressure, the injection is terminated, and the photocurable silicone resin injected into the colored portion 29 is naturally cured. Let

  The photocurable silicone resin has a viscosity of 5 Pa.s. s, and the hardness after curing is around 30 degrees on Shore A.

  According to the waterproof method, by injecting light after injecting the photocurable silicone resin, the resin is cured at the outer periphery of the insulating coating portion 16 located in the transparent portions 28 on both sides, and the outer periphery of the insulating coating portion 16 is Since the gap between the surface and the wire outlet 26 can be sealed, it is possible to prevent the resin in the cavity 25 from leaking out of the case 20 before curing.

  In addition, since the photocurable silicone resin cures in response to light regardless of the viscosity, it is possible to increase the fluidity by setting the viscosity low, and the photocurable silicone resin before curing can be applied to the insulating coating portion. The gap between the 16 electric wires can be sufficiently penetrated. Further, since the insulation coating portions 16 are arranged one by one in engagement with the wire lead-out recess 26A, it is possible to secure a gap for resin penetration between the wires. Accordingly, the resin can be sufficiently distributed to the outer peripheral surface of each electric wire 11 in the insulating coating portions 16 on both sides sandwiching the splice portion 14 and the core wire exposed portion 15, and the gap is surely sealed to provide high waterproofness. Can do.

  Further, by continuing the injection while the outlet of the resin is blocked, the injection pressure is increased and the resin can be sufficiently permeated into the details of the splice portion 14 and the core wire exposed portion 15. In addition, by confirming that the injection pressure is a constant set pressure, it can be easily determined that a certain waterproof treatment has been performed, so the conventional waterproof seal test is no longer required, thus improving workability. be able to.

  The resin injection port 27 may be provided on the upper wall 21 of the case 20.

It is a perspective view which shows the splice part and case of the wire harness before the waterproof process based on 1st embodiment of this invention. It is a top view which shows the state which has arrange | positioned the splice part of the wire harness to the lower case. It is a perspective view which shows the state which covered the upper case on the lower case shown in FIG. FIG. 4 is an explanatory perspective view illustrating a resin injection operation into the case illustrated in FIG. 3. It is a figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wire harness 14 Splice part 15 Core wire exposed part 16 Insulation coating | cover part 20 Case 20A Lower case 20B Upper case 25 Cavity 26 Electric wire outlet 27 Resin inlet 28 Transparent part 29 Middle part

Claims (3)

A method of waterproofing a splice part that peels off a part of the insulation coating of a plurality of electric wires and connects the exposed core wires,
A case made of a resin molded product comprising a lower case and an upper case and having a cavity inside, the upper and lower walls and the peripheral walls on both the left and right sides, which are the lead-out side of the case, are transparent parts for light transmission, The central part sandwiched between the transparent parts on both the left and right sides is a colored part for light impermeability, and the right and left side walls are provided with wire outlets, and the upper wall or peripheral wall is provided with a resin inlet,
In the cavity of the lower case, the splice portion, the core wire exposed portions on both sides of the splice portion, and the insulation coating portions of the electric wires adjacent to the core wire exposure portions are accommodated, and the insulation coating portions are formed in the left and right transparent portions. And the splice part and the core wire exposed part are located in a central colored part, and the electric wire continuous to the insulating coating part is drawn out from the electric wire outlet,
Next, the upper case is covered with the lower case, and uncured photocurable silicone resin is injected into the cavity from the resin injection port,
Immediately after the resin injection, the case is irradiated with light to cure the photocurable silicone resin on the outer periphery of the insulating coating portion located in the transparent portion, and the colored portion of the photocurable silicone resin is naturally cured. A method for waterproofing a splice part, characterized by that.   The uncured photocurable silicone resin has a viscosity of 1 Pa.s. s-50 Pa. The method for waterproofing a splice part according to claim 1, which is s.   The wire harness provided with the waterproof splice part manufactured by the method of Claim 1 or Claim 2.

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