JPH07264743A - Method and structure for splicing wire harness - Google Patents

Abstract

PURPOSE:To make it possible to insulate an outer part of a splice unit surely at low cost without enlarging or putting on weight thereof. CONSTITUTION:At least a wire joining part of a wire harness(W/H) is covered with an insulating tape 8. After the wire harness(W/H) with a wire joining part (S) is put in a cavity of a mold 9, the cavity in the mold 9 is filled with resin 4. The resin is hardened, and a resin layer 4' and the wire harness(W/H) is taken out from the mold 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for splicing a wire harness and a splice structure formed by the method.

[0002]

2. Description of the Related Art Conventionally, the insulation coating of electric wires to be connected to each other is peeled off to expose a core wire, and at the electric wire joint where the exposed core wires are connected by an intermediate crimp terminal, water leakage from the electric wire joint is prevented. Therefore, a waterproof treatment is generally performed in which a core wire portion of an electric wire protruding from both sides of the electric wire joint portion and the intermediate terminal is insert-molded with a resin, and the outer periphery of the resin is surrounded by a sheet.

As the waterproof splicing method, a method using a mold 1 shown in FIG. 8 is provided. In this method, the wires W1 and W2 of the wire harness and the intermediate crimp terminal 2 are used.
The electric wire joint S composed of is placed in the cavity 1a of the mold 1, and the cavity 1a is filled with a thermoplastic resin (hot melt ... molten resin) 4 from the injection nozzle 3 and the resin 4
Is wrapped around the entire outer periphery of the electric wire joint portion S, the electric wire joint portion S and the exposed core wire are wrapped with the resin 4, left for curing, and taken out from the mold 1 after curing. The taken-out wire harness is as shown in FIG. 9, and is provided with a resin layer 4'for waterproofing and insulating by molding core wires protruding from the outer periphery of the electric wire joint S and both sides of the electric wire joint S.

The resin layer 4'surrounding the electric wire joint portion S needs to have a thickness of at least 1 mm in the entire outer peripheral portion in order to satisfy electric performance. Therefore, in the method of setting the wire bonding portion S of the wire harness in the cavity 1a of the mold 1 and filling the resin 4 in the horizontal direction shown in FIG. 10 (A) and also shown in FIG. 10 (B). Also in the vertical direction, it is necessary to leave a space of 1 mm between the mold surface 1b of the cavity 1a and the wire joining portion S.

However, when the wire joining portion S of the wire harness is set in the cavity 1a of the mold 1, the wire joining portion S is set in the hollow cavity 1a, so that the wire joining portion S is indicated by the one-dot chain line in FIG. 10 (B). It may hang down, and in this case, the gap G1 between the wire joining portion S and the mold surface 1b becomes 1 mm or less. Similarly, as shown by the alternate long and short dash line in FIG. 10 (A), when it is curved in the lateral direction, the gap G2 becomes 1 mm or less.

Therefore, conventionally, in consideration of the above-mentioned case, the cavity 1 is provided so that the resin layer 4'of 1 mm can be secured even if the resin layer 4'is set out of the regular setting position.
The size of a is set. That is, in the state where it is set in the regular position, the mold surface 1b of the cavity 1a and the wire joint S
Cavity 1 so that there is a gap of 1 mm or more between
a is set.

As a result, in the conventional method using the mold 1, the resin layer 4'has a thickness of 1 mm or more, which is an unnecessarily large thickness, and there is a drawback that the splice is enlarged, and the amount of resin used increases. However, there is a drawback that it becomes heavy and costly. In addition, the wire joint S is provided inside the hollow cavity 1a.
Since the stability of the wire harness is poor, the resin layer 4'formed on the outer peripheral surface of the wire joint S is consequently set.
The thickness is not constant and the quality is unstable.

Further, in the cavity 1a, it is necessary to pour the resin 4 into the lower part of the wire joint S to wrap the entire outer periphery of the wire joint S, but the fluidity of the resin 4 is poor and the wire joint is poor. The case where it does not go around the lower part of S occurs. In that case, a portion not covered with the resin layer 4'is produced.

Therefore, the applicant of the present invention has previously provided a splicing method capable of reliably enclosing the outer periphery of the splice portion with resin. In this method, as shown in FIG. 11, the wire joining portion S and the core wires protruding from both sides thereof are inserted into a resin mold 6 prepared in advance, and then the thermoplastic resin 4 is injected into the resin mold 6. The resin 4 wraps around the gap between the resin molds 6 and is filled without any gaps. Further, the injected resin 4 melts the inner surface of the resin mold 6, and the resin 4 is fixed integrally with the resin 4. When the resin 4 is poured and left as it is, the resin 4 is naturally cured while being integrated with the resin mold 6.

When the resin mold 6 is used and the thickness of the resin mold 6 itself is set to 1 mm, the insulating thickness of 1 mm is ensured by inserting the resin mold 6 into the resin mold 6, and therefore the resin mold 6 is used. It is not necessary to provide a gap of 1 mm or more between the wire joining portion S and the wire joining portion S. Further, the resin 4 to be injected into the resin mold 6 is at least the electric wire joint portion S not surrounded by the resin mold 6.
It is sufficient to surround the upper part of the electric wire joint S with the resin mold 6 and to close the gap between the electric wire and the resin mold 6 on both sides. Even if it is not, since it is surrounded by the bottom surface of the resin mold 6, the amount of resin injected into the resin mold 6 can be made smaller than before.

[0011]

However, in the above-mentioned splicing method, the resin mold 6 has a wall thickness required to obtain at least the desired insulating property, and the wire joint S is housed inside. The resin 4 must be of a size that can be injected. Therefore, the molded resin layer S'becomes large, the weight increases accordingly, and a large and expensive mold is required to mold the resin mold 6. Moreover, in the above-mentioned splicing method, the resin cannot be injected at a high pressure, so in order to obtain a preferable filling state, for example, the resin to be filled is 3000 cps.
It was necessary to use a material with a low viscosity, and there were restrictions in terms of materials.

The present invention has been made to solve the above problems, and provides an inexpensive splicing method and structure for a wire harness capable of improving the insulation without increasing the volume and weight of the splice portion. That is the purpose.

[0013]

In order to achieve the above object, in the invention as set forth in claim 1, at least the wire joint portion of the wire harness is covered with an insulating tape, and the splice of the wire harness including the insulating tape. The parts are arranged in a cavity of a mold, a resin is filled in the cavity and cured to form a resin layer, and then the resin layer is taken out from the mold together with a wire harness.

According to a second aspect of the invention, the splice portion of the wire harness is entirely covered with the insulating tape.

According to the third aspect of the invention, after inserting the splice portion of the wire harness into the cavity of the lower mold of the mold, the upper mold is closed and the filling resin is injected under pressure. It is the one.

According to a fourth aspect of the present invention, there is provided a splice structure manufactured by the method for splicing a wire harness according to the first aspect of the present invention, wherein at least an electric wire joint portion of the wire harness is wound. The tape and the resin layer for molding the splice portion of the wire harness are provided.

In a fifth aspect of the invention, a thermoplastic resin is used as the filling resin. Also,
In the invention according to claim 6, a resin having an insulating property, a thermoplastic property, and an adhesive property with a filling resin is used as the insulating tape. Examples of the resin include polypropylene, polyamide, and vinyl chloride. To be

According to a seventh aspect of the invention, the insulating tape and the resin to be filled are made of the same material.
Materials that can be used include polypropylene, polyamide, vinyl chloride and the like. The heat-resistant temperature of polypropylene is 80 to 100 ° C, and when it is poured into the cavity of the mold, it is heated to 150 ° C to be in a molten state, and when pressure is injected into the mold, the inner and outer surfaces of the contacting insulating tape are melted and integrated. It sticks and hardens if left after injection. The heat-resistant temperature of polyamide is 120 to 140 ° C.
Therefore, at the time of injection into the cavity of the mold, it is heated to 200 ° C. to be in a molten state. As the resin to be injected, a two-component mixed adhesive (urethane or the like) or a one-component adhesive (silicone RTV or the like) may be used instead of using a resin which is heated and melted (hot melt).

[0019]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. In the splice structure shown in FIG. 1, the insulating tape 8 is wound around the splice portion SP of the wire harness W / H,
Further, it has a structure in which the periphery thereof is covered with a resin layer 4 '. It should be noted that parts having the same configurations and functions as those of the prior art shown in FIG.

Electric wire joint S of the wire harness W / H
As shown in FIG. 2, an intermediate crimping terminal 2 is provided with a core wire a in which the middle of the first electric wire W1 is peeled and exposed, and a core wire b in which the tip of the second electric wire W2 is peeled and exposed. It is connected by crimping.

A splice portion S including the electric wire joint portion S
P, that is, the intermediate portion of the first electric wire W1 and the second electric wire W2
Not only the exposed part of the core wire a by peeling off the tip of
As shown in FIG. 3, an insulating tape 8 is wound around the entire portion including a part of the insulating film adjacent to the core wire, and the winding thickness is a thickness for satisfying the electrical insulation performance. For example, it is set to 1 mm.

The same material as the resin 4 is used for the insulating tape 8 which is wound around the intermediate crimp terminal 2 in advance.
According to this, since the resin 4 is heated and injected into the mold in a molten state, the heat melts the insulating tape 8, and the both cover the splice portion SP integrally.

The resin layer 4'of the splice portion SP is shown in FIG.
It is formed by the mold 9 shown in FIG. The lower mold 9B of the mold 9 is
The lower mold 9B has a triangular cavity 9b having an open upper surface, and a front wall 9c of the lower mold 9B is formed with a half-shaped wire insertion groove 9d in which the first wire W1 is located. The wall 9e is formed with similarly-divided wire insertion grooves 9f and 9g in which the first and second electric wires W1 and W2 are located, respectively.

On the other hand, the upper die 9A of the die 9 has a triangular cavity 9a whose lower surface is substantially the same shape as the cavity 9b of the lower die 9B, and the front wall 9h and the rear wall 9i have the above-mentioned shape. An electric wire insertion groove 9j (the other two are not shown) is formed which forms an electric wire insertion hole with each electric wire insertion groove 9d, 9f, 9g. By covering the lower mold 9B with the upper mold 9A, the cavity 9a is aligned with the cavity 9b of the lower mold 9B. On the upper wall 9h of the upper mold 9A,
An injection port 9i into which the resin injection nozzle 3 is fitted is formed. However, the injection port 9i may be formed at two positions in the electric wire direction, and the resin injection nozzle 3 may be fitted into each of the injection ports 9i.

The resin 4 injected into the mold 9 is a thermoplastic resin such as PP (polypropylene), PA.
(Polyethylene), PBT (polybutylene terephthalate), PVC (polyvinyl chloride), etc. are used. In this embodiment, since the resin 4 can be injected into the mold at high pressure by the injection nozzle 3, the viscosity is 15000.
It can be used up to high cps. On the other hand, in the conventional resin mold 6 shown in FIG. 8, since the resin 4 was simply poured from above, a resin having a low viscosity of about 3000 cps was used.

In the above structure, when performing the splicing work, first, as shown in FIG. 3, the insulating tape 8 is previously wound and covered on the entire splice portion, and the lower mold 9B of the mold 9 is covered.
After being inserted into the cavity 9b formed in the above from above, the lower mold 9B is covered with the upper mold 9A as shown in FIG.

Subsequently, as shown in FIG. 7, the resin injection nozzle 3 fills the cavities 9a and 9b with the thermoplastic resin (hot melt ... Molten resin) 4 under pressure. The insulating resin 8 is melted by the injected resin 4 and the injected resin 4
And cover the splice portion 8 integrally.

When the resin 4 is injected and left for a certain period of time, the resin 4 is naturally cured while being integrated with the insulating tape 8. In this case, in order to improve the processing efficiency, the mold 9
Cooling water may be circulated therein for forced cooling. Thereafter, the upper mold 9A is removed, and the cured resin layer 4'is taken out from the lower mold 9B together with the wire harness, whereby the splice portion is completed as shown in FIG.

In the above-mentioned processing step, since the electric wire joint portion S to be inserted into the insulating tape 8 is covered with the insulating tape 8 at its periphery, the insulating property is guaranteed regardless of the filled state of the resin 4. .

The thickness of the resin 4 filled around the electric wire joint S depending on the winding thickness of the insulating tape 8 may be 1 mm or less, which is the conventional required thickness.
The amount of resin injected into a and 9b can be made smaller than before.

In the above embodiment, the first electric wire W1 having the intermediate stripped is joined to the second electric wire W2 having the distal stripped, and the electric wire joint S is composed of two electric wires.
It goes without saying that the present invention can also be applied to the splice of the electric wire joint portion S in which two or more electric wires are joined.

In the above embodiment, the insulating tape is wound around the entire splice portion, but as shown in the figure, only the intermediate crimp portion S may be wound. In this case, the insulating tape is wound near the inner surface of the cavity of the mold and is wound around the intermediate pressure-bonding portion S that is most flexible when the resin is filled, so that the minimum dimension required to obtain the desired insulating performance is obtained. Since the above is ensured, a desired insulating property can be obtained at the splice portion in combination with the resin to be filled. Further, in the above embodiment, the insulating tape 8
Although the same material is used as the material of the resin 4 and the material of the resin 4 to be injected, different materials may be used.

[0033]

As is apparent from the above description, according to the first aspect of the present invention, the wire joining portion of the wire harness is covered with the insulating tape in advance, and the splice portion together with the insulating tape forms the cavity of the mold. Since the resin is injected inside the cavity and hardened by injecting the resin into the cavity, the insulation property of the electric wire joint portion is secured by the insulating tape itself. Therefore,
It is not always necessary to fill the outer periphery of the electric wire joint portion with a resin having a thickness capable of ensuring insulation. In addition, there is no problem even if the set position of the wire joining portion arranged in the molding die is slightly displaced, and the workability is improved.

According to the second aspect of the invention, since the splice portion is completely covered with the insulating tape in advance, the resin coating the periphery of the splice portion may be defectively filled, or the resin layer may be used during use. Even if cracks or the like occur on the splice, insulation at the splice portion can be reliably achieved. And since the insulating tape can be easily wound around the wire joining portion in advance, it is not necessary to use a mold for a molding die as in the conventional case.
Cost can be reduced.

Further, according to the invention of claim 3, since the resin can be filled at a high pressure, even a material having a high viscosity can be used, and the applicable range of the used material or its state, etc. Spreads.

Further, in the splice structure according to the fourth aspect, since the insulation property can be ensured by the insulating tape itself, even if the electric wire joint portion bends and approaches the mold cavity surface during molding, the electric wire joint portion can be formed as in the conventional case. Does not deteriorate the insulation.

Further, in claim 5, since the thermoplastic resin is used as the resin to be filled in the die and the resin is injected under pressure into the die in a molten state, the resin has good permeability and after the resin is injected, It can be cured by leaving it alone and can be welded together with the insulating tape.

Further, according to claim 6, since the material forming the insulating tape is one having insulation, thermoplasticity and adhesiveness, it is possible to surely insulate the electric wire joint portion. The resin to be injected into the mold can be securely bonded and integrated.

In particular, if the same material as the filling resin to be injected into the mold is used as the material forming the above-mentioned insulating tape as claimed in claim 7, structural defects such as cracks resulting from the difference in material after molding. It is good without causing When polypropylene, polyamide, or vinyl chloride is used as the resin, the processing temperature (melting temperature) is not so high, the workability is good, and the insulating and adhesive properties are excellent, and the economical efficiency is high. preferable.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wire harness portion of the present invention.

FIG. 2 is a perspective view showing an electric wire joining portion of the wire harness shown in FIG.

3 is a perspective view showing a state in which a wire harness portion of the wire harness of FIG. 1 is covered with an insulating tape.

FIG. 4 is a perspective view of another embodiment showing a state where the wire harness portion of the wire harness of FIG. 1 is covered with an insulating tape.

5 is a perspective view showing a state before setting the wire harness portion of FIG. 1 in a molding die. FIG.

6 is a sectional view of a molding die in which the wire harness portion of FIG. 1 is set.

7 is a cross-sectional view showing a state where resin is filled in the cavity of the molding die of FIG.

FIG. 8 is a perspective view of a conventional molding die.

FIG. 9 is a perspective view of a resin layer of a conventional wire harness.

FIG. 10A is a plan view showing a state where the electric wire joint portion is displaced in the horizontal direction, and FIG. 10B is a sectional view showing a state where the electric wire joint portion is displaced in the vertical direction.

FIG. 11 is a splice structure using a resin mold,
(A) is a perspective view of the resin mold, (B) is a plan sectional view of the resin mold filled with the resin, and (C) is a side sectional view of the resin mold filled with the resin.

[Explanation of symbols]

 2 Crimping terminal 3 Injection nozzle 4 Resin 4'Resin layer 8 Insulating tape 8a Bottom part 8b Both sides 9 (A, B) Mold 9a, 9b Cavity S Wire joint W / H Wire harness W1 First wire W2 Second wire

Claims (7)

[Claims] 1. A wire harness in which at least an electric wire joining portion is covered with an insulating tape, a splice portion of the wire harness including the insulating tape is disposed in a cavity of a mold, and the cavity is filled with a resin to cure the resin. A method for splicing a wire harness, comprising forming a resin layer by carrying out the above, and taking out the resin layer together with the wire harness from a mold. 2. The method of splicing a wire harness according to claim 1, wherein the insulating tape covers the entire splice portion of the wire harness. 3. The splicing method according to claim 1, wherein after the splice portion of the wire harness is inserted into the cavity of the mold, the filling resin is injected under pressure. 4. A splice structure for a wire harness, comprising: an insulating tape that winds at least an electric wire joint portion of the wire harness; and a resin layer that molds a splice portion of the wire harness. 5. The splice structure for a wire harness according to claim 4, wherein a thermoplastic resin is used as the filling resin. 6. The splice structure for a wire harness according to claim 4, wherein the insulating tape is made of a resin having an insulating property, a thermoplastic property, and an adhesive property with a filling resin. 7. The splice structure for a wire harness according to claim 4, 5 or 6, wherein the insulating tape and the resin to be filled are made of the same material.