阅读说明：本技术 电线的芯线露出部的防水结构 (Waterproof structure for exposed core wire portion of electric wire ) 是由 福田隆夫 高田崇志 伊藤健二 前田悠作 于 2019-06-12 设计创作，主要内容包括：以即使在过度的冷热环境下等也能抑制内部防水部的开裂为目的。电线的芯线露出部的防水结构(20)具备：电线(10),其具有芯线露出部(12a)；内部防水部(21),其以覆盖芯线露出部(12a)的周围的方式设置,对芯线露出部(12a)进行防水；以及外装构件(30),其在内部防水部(21)的周围形成与外部空间分隔的空间(S)。(The purpose is to suppress cracking of an internal waterproof section even in an excessively cold/hot environment or the like. A waterproof structure (20) for a core wire exposed portion of an electric wire is provided with: an electric wire (10) having a core wire exposure portion (12 a); an internal waterproof section (21) which is provided so as to cover the periphery of the core wire exposed section (12a) and which waterproofs the core wire exposed section (12 a); and an exterior member (30) that forms a space (S) that is separated from the external space around the internal waterproof section (21).)

1. A waterproof structure for a core wire exposed portion of an electric wire is provided with:

an electric wire having a core wire exposed portion;

an internal waterproof section provided so as to cover a periphery of the core wire exposed section, the internal waterproof section waterproofing the core wire exposed section; and

and an exterior member that forms a space separated from an external space around the internal waterproof portion.

2. The waterproof structure of the core wire exposed portion of the electric wire according to claim 1,

the exterior member is a member that surrounds the outer peripheral surface of the internal waterproof portion with a space therebetween and forms a cylindrical space on the outer peripheral side of the internal waterproof portion.

3. The waterproof structure of the core wire exposed portion of the electric wire according to claim 2,

the gap including the space is a portion of 1mm or more.

4. The waterproof structure of the core wire exposed portion of the electric wire according to any one of claim 1 to claim 3,

the thickness of the exterior member is 1mm or more.

5. The waterproof structure of the core wire exposed portion of the electric wire according to any one of claim 1 to claim 4,

the exterior member is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin.

6. The waterproof structure of the core wire exposed portion of the electric wire according to any one of claim 1 to claim 4,

the exterior member is formed of metal.

7. The waterproof structure of the core wire exposed portion of the electric wire according to any one of claim 1 to claim 6,

the core wire exposed portion is provided at an end portion of the electric wire,

the inner waterproof portion includes an inner cap in which the core wire exposed portion is housed and a water stopping agent filled and solidified in the inner cap.

8. The waterproof structure of the core wire exposed portion of the electric wire of claim 7,

the solidified liquid level of the water-stopping agent in the inner cap is located on the inner side of the opening edge of the inner cap.

9. The waterproof structure of the core wire exposed portion of the electric wire according to claim 7 or claim 8, wherein,

the exterior member includes an outer cap that surrounds an outer peripheral surface of the inner cap with a space therebetween.

10. The waterproof structure of the core wire exposed portion of the electric wire according to claim 9,

the opening-side end portion of the outer cap includes a portion having an inner diameter smaller than an inner diameter of a portion surrounding the core wire exposed portion.

11. The waterproof structure of the core wire exposed portion of the electric wire according to claim 10,

the opening-side end portion of the outer cap is formed in a shape including a plurality of annular protrusions protruding toward an inner circumferential side.

12. The waterproof structure of the core wire exposed portion of the electric wire according to any one of claims 9 to 11,

the opening edge of the outer cap coincides with the opening edge of the inner cap.

Technical Field

The present invention relates to a technique for waterproofing an exposed portion of a core wire of an electric wire in a vehicle, a ship, an aircraft, a mechanical device, or the like.

Background

Patent document 1 discloses a resin-made protective cap having a cylindrical shape with one end closed and one end open, a terminal collective joint portion being inserted inside and a sealant being filled. In patent document 1, a small diameter portion is provided on the opening side of the protective cap, and a diameter-expanding portion is provided at the middle in the axial direction, so that the liquid surface of the sealant is positioned at the middle in the axial direction. The following settings are made: the terminal concentrated joint part and the wire group inserted into the protective cap are separated from the inner peripheral surface of the middle diameter-enlarged part by a required gap in a state of contacting with the inner peripheral surface of the small diameter part on the opening side.

Disclosure of Invention

Problems to be solved by the invention

However, the sealant cured in the protective cap may be broken in an excessively cold and hot environment.

Therefore, the present invention aims to suppress cracking of the inner waterproof portion even in an excessively cold and hot environment or the like.

Means for solving the problems

In order to solve the above problem, a waterproof structure for a core wire exposed portion of an electric wire according to claim 1 includes: an electric wire having a core wire exposed portion; an internal waterproof section provided so as to cover a periphery of the core wire exposed section, the internal waterproof section waterproofing the core wire exposed section; and an exterior member that forms a space separated from an external space around the internal waterproof portion.

The 2 nd aspect is the waterproof structure for the exposed portion of the core wire of the electric wire of the 1 st aspect, wherein the exterior member is a member that surrounds an outer peripheral surface of the internal waterproof portion with a space therebetween and forms a cylindrical space on an outer peripheral side of the internal waterproof portion.

The 3 rd aspect is the waterproof structure for the exposed portion of the core wire of the electric wire of the 2 nd aspect, and includes a portion where the gap of the space is 1mm or more.

The 4 th aspect is the waterproof structure for the exposed core wire portion of the electric wire according to any one of the 1 st to 3 rd aspects, wherein the thickness of the exterior member is 1mm or more.

The 5 th aspect is the waterproof structure of the exposed core wire portion of the electric wire according to any one of the 1 st to 4 th aspects, wherein the exterior member is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin.

The 5 th aspect is the waterproof structure of the exposed core wire portion of the electric wire according to any one of the 1 st to 4 th aspects, wherein the exterior member is formed of a metal.

The 7 th aspect is the waterproof structure of the core wire exposed portion of the electric wire according to any one of the 1 st to 6 th aspects, the core wire exposed portion being provided at an end portion of the electric wire, the internal waterproof portion including an internal cap in which the core wire exposed portion is housed and a water stop agent that is filled and solidified in the internal cap.

An 8 th aspect is the waterproof structure for the exposed portion of the core wire of the electric wire according to the 7 th aspect, wherein a surface of the solidified liquid of the water-stopping agent in the inner cap is located on a further inner side than an opening edge portion of the inner cap.

A 9 th aspect is the waterproof structure for the exposed portion of the core wire of the electric wire according to the 7 th or 8 th aspect, wherein the exterior member includes an outer cap that surrounds an outer peripheral surface of the inner cap with a space therebetween.

A 10 th aspect is the waterproof structure for the exposed portion of the core wire of the electric wire of the 9 th aspect, wherein the opening-side end portion of the outer cap includes a portion having an inner diameter smaller than an inner diameter of a portion surrounding the exposed portion of the core wire.

An 11 th aspect is the waterproof structure of the core wire exposed portion of the electric wire of the 10 th aspect, wherein the opening side end portion of the outer cap is formed in a shape including a plurality of annular protrusions protruding toward an inner peripheral side.

A 12 th aspect is the 9 th aspect of the present invention, which is directed to the waterproof structure for the exposed portion of the core wire of the electric wire of the 11 th aspect, wherein an opening edge portion of the outer cap and an opening edge portion of the inner cap are aligned in position.

Effects of the invention

According to the first aspect, the space separated from the external space is formed around the internal waterproof portion by the exterior member. Ambient temperature changes are less likely to be transmitted to the interior waterproof portion, and cracking of the interior waterproof structure can be suppressed even in an excessively cold and hot environment or the like.

According to the second aspect, the external heat is less likely to be transmitted to the inner waterproof portion over the entire periphery of the inner waterproof portion, and cracking of the inner waterproof portion can be effectively suppressed.

According to the aspect 3, since the space including the portion where the gap is 1mm or more is formed around the inner waterproof portion, the ambient temperature change is less likely to be transmitted to the inner waterproof portion, and the crack of the inner waterproof structure can be more effectively suppressed.

According to the 4 th aspect, the exterior member is less likely to deform, and the thickness of the space is easily maintained.

According to the 5 th aspect, the exterior member can be easily formed.

According to the 6 th aspect, radiant heat is less likely to be reflected, and temperature change due to the influence of radiant heat can be suppressed.

According to the 7 th aspect, the core exposed portion of the end portion of the electric wire can be waterproofed by the inner cap and the water-stop agent filled and solidified in the inner cap.

According to the 8 th aspect, a space is easily secured in the inner cap above the surface of the curing liquid.

According to the 9 th aspect, the outer peripheral surface of the inner cap is surrounded by the outer cap with a space therebetween, whereby a space can be formed around the inner cap.

According to the 10 th aspect, the opening-side end portion of the outer cap includes the portion having the inner diameter smaller than the inner diameter of the portion surrounding the exposed portion of the core wire, and therefore a space is easily secured around the exposed portion of the core wire.

According to the 11 th aspect, a space can be formed between the plurality of annular protrusions, and the presence of this space makes it possible to prevent external heat from being easily transmitted to the core exposed portion.

According to the 12 th aspect, since the opening edge portion of the outer cap and the opening edge portion of the inner cap are aligned in position, a space is easily secured on the distal end side of the inner cap.

Drawings

Fig. 1 is a partial sectional view showing a waterproof structure of a core wire exposed portion of an electric wire of an embodiment.

Fig. 2 is an explanatory diagram illustrating an example of a method of manufacturing a waterproof structure of a core wire exposed portion of an electric wire.

Fig. 3 is an explanatory diagram illustrating an example of a method of manufacturing a waterproof structure of a core wire exposed portion of an electric wire.

Fig. 4 is an explanatory diagram illustrating an example of a method of manufacturing a waterproof structure of a core wire exposed portion of an electric wire.

Fig. 5 is a partially cut-away view showing a waterproof structure of a core wire exposed portion of an electric wire of modification 1.

Fig. 6 is a partially cut-away view showing a waterproof structure of a core wire exposed portion of an electric wire of modification 2.

Fig. 7 is a partially cut-away view showing a waterproof structure of a core wire exposed portion of an electric wire of modification 3.

Detailed Description

Hereinafter, a waterproof structure of a core wire exposed portion of an electric wire according to an embodiment will be described. Fig. 1 is a partial sectional view showing a waterproof structure 20 of a core wire exposed portion of an electric wire of an embodiment. Fig. 2 to 4 are explanatory views showing an example of a method of manufacturing the waterproof structure 20 of the core wire exposed portion of the electric wire.

The waterproof structure 20 of the exposed core wire portion of the electric wire includes the electric wire 10, an internal waterproof portion 21, and an exterior member 30.

Here, the waterproof structure 20 includes a plurality of electric wires 10. The electric wire 10 includes a core wire 12 and a coating layer 14.

The core wire 12 is formed of a conductive material such as copper, copper alloy, aluminum alloy, or the like. The core wire 12 is composed of 1 or more wires. When the number of the wires 10 is plural, the types of the core wires 12 of the plural wires 10 may be the same or different.

The coating layer 14 is formed by extrusion molding or the like of an insulating material such as resin around the core wire 12.

The electric wire 10 includes a core wire exposure portion 12 a. Here, the coating layer 14 at the end of the electric wire 10 is removed, and thus a core exposed portion 12a in which the core 12 is exposed is formed at the end of the electric wire 10.

The core exposed portions 12a of the end portions of the plurality of wires 10 are joined to each other to form a joint portion 16. The core wire exposed portions 12a are joined to each other by welding such as resistance welding or ultrasonic welding, crimping of terminals, or soldering, for example.

The internal waterproof portion 21 is provided so as to cover the periphery of the core wire exposed portion 12a, and is a portion that waterproofs the core wire exposed portion 12 a.

Here, the inner waterproof portion 21 includes an inner cap 22 and a water stopper 26.

The inner cap 22 is a cylindrical member having one end open and the other end closed. The inner diameter Φ 0 of the inner cap 22 is set to a size that can accommodate the core wire exposed portion 12a of the end portion of the electric wire 10, the joint portion 16 of the core wire exposed portions 12a of the plurality of electric wires 10 in this case, and a gap can be provided between the entire periphery of the joint portion 16 and the inner cap 22 in the accommodated state.

More specifically, a cylindrical shape in which the same diameter portion is continuous is formed from one end of the inner cap 22 to the extending direction intermediate portion. The other end of the inner cap 22 is formed in a shape of a hemispherical bulge toward the outside. The inner diameter Φ 0 of the one end and the extending direction intermediate portion of the inner cap 22 is set larger than the diameter of the outer diameter of the electric wire 10, here, the diameter of a circle circumscribing the portion bundling the plurality of electric wires 10 and surrounding the portion. The length L1 of the inner cap 22 is set to be larger than the length of the joint 16 and the core wire exposing portion 12 a.

Therefore, the portion where the plurality of electric wires 10 are bundled and the joint portion 16 can be housed in the inner cap 22, and in this housed state, the joint portion 16 and the plurality of electric wires 10 can be spaced from the inner peripheral surface of the inner cap 22 over the entire periphery thereof.

The inner cap 22 may also be formed by dip molding, and may also be formed by injection molding.

The inner cap 22 need not be of the shape described above. The inner cap may be formed in a spindle shape that becomes thickest at the extending direction intermediate portion. The extending direction intermediate portion of the inner cap does not necessarily have to be cylindrical, and may be formed in a polygonal cylinder such as a triangular cylinder or a rectangular cylinder, in addition to an elliptical cylinder.

The inner cap 22 is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin. Examples of the elastomer include urethane rubber, silicone rubber, fluororubber, and synthetic rubber. Examples of the thermoplastic resin include polyethylene, polypropylene, polyvinyl chloride, and acrylic resin. Examples of the thermosetting resin include phenol resins and epoxy resins.

The core wire exposed portion 12a (here, the portion of the joint portion 16 and the covering layer 14 close to the joint portion 16) is housed in the inner cap 22. The water stop agent 26 is filled in the inner cap 22 and cured. The water-stopping agent 26 is cured in the inner cap 22 in a state where a gap between the core wire exposed portion 12a and the inner peripheral surface of the inner cap 22, more specifically, a gap between the joint portion 16 and the inner peripheral surface of the inner cap 22 and the end portion of the coating layer 14 close to the joint portion 16, is filled.

As the water-stopping agent 26, a liquid water-stopping agent containing a main agent and a curing agent can be used, which is poured into the inner cap 22 housing the core wire exposed portion 12a and cured in the inner cap 22. Epoxy resin, acrylic resin, or the like can be used as the water-stopping agent 26. As the water-stopping agent 26, various curing type water-stopping agents such as a two-component curing type, a moisture curing type, and a photo-curing type can be used. The water-stopping agent 26 may be a mixture of rubber modifiers such as PBA (polybutyl acrylate) and the like, or impact-resistant resins such as PMMA (polymethyl methacrylate) and the like. However, as described later, in the present waterproof structure 20, since the influence of heat from the outside can be alleviated by the space S, even if the resin for preventing the cracking as described above is not used, the cracking of the resin can be suppressed, which contributes to cost reduction.

The solidified liquid surface 26F of the water-stopping agent 26 in the inner cap 22 may be located further to the back side than the opening edge portion of the inner cap 22 (see fig. 3). The solidified liquid surface 26F is a liquid surface of the liquid water-stopping agent 26 in a state where the liquid water-stopping agent 26 is poured into the inner cap 22, and then, the solidified liquid surface 26F is formed by solidifying the liquid water-stopping agent 26. The solidification liquid surface 26F may be located above the core wire exposure portion 12a and on the back side of the opening edge portion of the inner cap 22. For example, the entire length L1 of the inner cap 22 may be 40mm, and the distance L2 of the liquid curing surface 26F from the bottom of the inner cap 22 may be 30 to 35mm (see FIG. 3).

In the inner cap 22, the distal end portion of the core wire exposed portion 12a (the joint portion 16) may be in contact with the bottom of the inner cap 22 or may be present at a position apart from the bottom.

In the present embodiment, the internal waterproof portion 21 is described by an example including the internal cap 22 and the water-stopping agent 26, but such a configuration is not necessarily required.

For example, the internal waterproof portion 21 may be formed by molding a resin so as to cover the core wire exposed portion 12a (the joint portion 16). The internal waterproof portion 21 may be configured such that the core exposed portion 12a (joint portion 16) is covered with a heat shrinkable tube in which a water-stopping agent such as a hot melt adhesive is provided, the heat shrinkable tube is heat-shrunk, and the water-stopping agent is filled and disposed between the heat shrinkable tube and the core exposed portion 12a (joint portion 16). The internal waterproof portion 21 may be configured to cover the periphery of the core wire exposed portion 12a (joint portion 16) in a state of being in direct contact with the core wire exposed portion 12a (joint portion 16).

The exterior member 30 is a member in which a space S is formed around the interior waterproof portion 21 to be separated from the external space. The space S formed by the exterior member 30 may be separated from the external space to such an extent that air in the external space is not easily circulated, and it is not necessary to completely separate the space S so that air leakage does not occur. The space S may be a space filled with air or a space decompressed.

Here, the exterior member 30 is a member that surrounds the inner peripheral surface of the inner waterproof portion 21 with a space therebetween with respect to the outer peripheral surface thereof, and forms a cylindrical space S on the outer peripheral side of the inner waterproof portion 21. Here, the space S is also formed between the bottom of the interior of the exterior member 30 and the bottom of the inner cap 22. That is, the space S includes a portion that forms a cylindrical shape around the inner waterproof portion 21 and a portion that continues to the lower side of the portion and extends to the outside of the bottom of the inner waterproof portion 21, and forms a bottom cylindrical space as a whole.

More specifically, the exterior member 30 includes a cylindrical outer cap 32 having one end open and the other end closed. The outer cap 32 is a member that surrounds the outer peripheral surface of the inner cap 22 with a space therebetween. That is, the outer cap 32 is larger than the inner cap 22, and the space S can be provided between the inner cap 22 and the outer cap 32 in a state where the inner cap 22 is disposed inside the outer cap 32.

More specifically, the extending direction intermediate portion of the outer cap 32 is formed in a spindle shape that gradually becomes thicker from both end sides toward the extending direction intermediate position of the outer cap 32. For example, the length L4 of the outer cap 32 is 60mm, and the position where the distance L3 from the opening edge portion on one end side is 30mm, that is, the center position in the extending direction of the outer cap 32 is the thickest part.

The inner diameter Φ 2 of the portion where the intermediate portion in the extending direction of the outer cap 32 becomes thickest is formed larger than the outer diameter Φ 1 of the inner cap 22, and is formed to be the same as or larger than the outer diameter Φ 1 of the inner cap 22 plus 2mm, for example. For example, the outer diameter Φ 1 of the inner cap 22 may be set to 8mm, and the inner diameter Φ 2 of the thickest part of the outer cap 32 may be set to 10 mm. Therefore, in a state where the inner cap 22 is housed in the outer cap 32, the space S between the outer peripheral surface of the inner cap 22 and the inner peripheral surface of the outer cap 32 includes a portion where the interval t1 is 1mm or more. The upper limit of the interval t1 of the space S around the outer periphery of the inner cap 22 is set to, for example, 10mm or less.

The opening-side end 33 of the outer cap 32 on one end side includes a portion having an inner diameter Φ 3 smaller than the inner diameter of the portion surrounding the core wire exposed portion 12a (joint portion 16). Here, the extending direction intermediate portion of the outer cap 32 is formed in a spindle shape tapered toward both sides of the thickest portion where the inner diameter Φ 2 becomes 10mm, and an opening side end portion 33 is formed continuously with this spindle-shaped portion. The opening-side end 33 is formed in a shape including a plurality of annular protrusions 33p protruding toward the inner circumferential side. More specifically, the opening-side end 33 is formed in a cylindrical shape, and a plurality of annular protrusions 33p are formed by forming portions that are reduced in an annular shape from the outer circumferential side toward the inner circumferential side at intervals along the extending direction thereof. The annular projection 33p projects annularly on the inner circumferential side than the portion adjacent in the extending direction of the opening-side end 33. The annular protrusion 33p is a portion having an inner diameter Φ 3 smaller than the inner diameter of the portion surrounding the core exposed portion 12a (joint portion 16). For example, when Φ 2 is 10mm, the inner diameter Φ 3 of the annular projection 33p may be 8mm, for example.

In this case, when the inner cap 22 is housed in the outer cap 32 such that the opening-side end portion of the inner cap 22 is disposed in the opening-side end portion 33 of the outer cap 32, a portion of the inner cap 22 surrounding the core wire exposed portion 12a (the joint portion 16) is disposed in the extending-direction intermediate portion of the outer cap 32. In this state, an annular space S is formed between the outer peripheral surface of the portion of the inner cap 22 surrounding the core wire exposed portion 12a (the joint portion 16) and the inner peripheral surface of the outer cap 32 at substantially equal intervals in the circumferential direction. Therefore, the space S is easily secured around the entire periphery of the inner cap 22.

In order to stably arrange the portion of the inner cap 22 surrounding the core wire exposed portion 12a (the joint portion 16) at the position of the extending direction intermediate portion of the outer cap 32, the opening edge portion of the outer cap 32 preferably coincides with the opening edge portion of the inner cap 22 (see fig. 4).

Further, an annular recessed portion 33q recessed annularly as viewed from the inner peripheral side is formed adjacent to the annular projection 33p at the opening side end portion 33 of the outer cap 32. The inner peripheral surface of the annular recess 33q is disposed at a distance from the outer peripheral surface of the opening-side end of the inner cap 22. Therefore, in a state where the inner cap 22 is disposed in the outer cap 32, an annular space T is formed between the outer peripheral surface of the opening-side end portion of the inner cap 22 and the inner peripheral surface of the annular recess 33q and the two annular protrusions 33p (see fig. 4).

The other end of the outer cap 32 is formed in a shape bulging in a half-ball shape toward the outside. The length dimension L4 of the outer cap 32 is preferably greater than the length dimension L1 of the inner cap 22 to the extent that the top end of the inner cap 22 and the top end of the outer cap 32 can be separated. For example, when the length L of the inner cap 22 is set to 40mm, the length L4 of the outer cap 32 may be set to 60 mm.

However, the space S may be formed around the inner cap 22 and no space may be formed at the distal end of the inner cap 22, and in this case, the distal end of the inner cap 22 may be in contact with the distal end of the outer cap 32.

The thickness t2 of the outer cap 32 is preferably large enough to maintain the shape of the outer cap 32 to a certain extent, and the thickness t2 of the outer cap 32 may be 1mm or more, for example. The thickness t2 of the outer cap 32 may be 5mm or less.

The outer cap 32 may be formed by dip molding or injection molding.

It is not necessary that the outer cap 32 be of the shape described above. The extending direction intermediate portion of the outer cap 32 may have a cylindrical shape continuous with the same inner diameter. The extending direction intermediate portion of the outer cap is not necessarily cylindrical, and may be polygonal cylindrical such as triangular cylindrical or rectangular cylindrical, in addition to the elliptical cylindrical shape.

The outer cap 32 is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin. Examples of the elastomer include urethane rubber, silicone rubber, fluororubber, and synthetic rubber. Examples of the thermoplastic resin include polyethylene, polypropylene, polyvinyl chloride, and acrylic resin. Examples of the thermosetting resin include phenol resins and epoxy resins.

The outer cap 32 is fixed to the inner waterproof portion 21 or the electric wire 10 in a state where the inner waterproof portion 21 is housed in the outer cap 32. Here, in a state where the edge on the opening side of the outer cap 32 and the edge on the opening side of the inner cap 22 are aligned, the adhesive tape 40 is wound around a portion from the opening-side end 33 of the outer cap 32 to the electric wire 10 (here, the bundle of the electric wires 10) extending from the opening-side end 33, whereby the outer cap 32 is fixed to the electric wire 10. Further, since the opening of the inner cap 22 is closed by the tape 40, a space separated from the external space is also formed above the curing liquid surface 26F in the inner cap 22. Since the waterproof structure 20 can be manufactured by fitting the outer cap 32 around the inner waterproof portion 21 in this manner, the waterproof structure 20 can be obtained at low cost with excellent workability.

The constitution for fitting the outer cap 32 is not limited to the above example. For example, when the opening-side end of the inner cap 22 extends from the opening of the outer cap 32, an adhesive tape may be wound around a portion extending from the opening-side end 33 of the outer cap 32 to the opening-side end of the inner cap 22 extending from the opening-side end 33, and the outer cap 32 may be fixed to the inner cap 22.

In addition, the open-end portion 33 of the outer cap 32 may be fastened and fixed to the inner wire 10 or the inner cap 22 with a binding tape or the like. The outer cap 32 may be fixed to the electric wire 10 or the inner cap 22 using an adhesive or the like. Further, an insertion portion may be formed at an end portion of the covering layer 14 of the electric wire 10 or an opening-side end portion of the inner waterproof portion 21, the insertion portion being inserted into the opening-side end portion 33 of the outer cap 32, and the opening-side end portion 33 of the outer cap 32 being externally inserted into the insertion portion.

An example of a method of manufacturing the waterproof structure 20 of the exposed core wire portion of the electric wire will be described.

First, as shown in fig. 2, the electric wire 10 including the core wire exposed portion 12a is prepared. Here, a plurality of wires 10 are prepared, and core exposed portions 12a are joined to form a joint portion 16. Then, the joint portion 16 and the end portion of the covering layer 14 connected to the joint portion 16 are put into the inner cap 22. Before or after this, a liquid water-stop agent 26B is injected into the inner cap 22 from the nozzle 26N or the like. In this case, the liquid water-stop agent 26B may be injected into the inner cap 22 to such an extent that the liquid surface of the liquid water-stop agent 26B is located on the back side of the edge of the opening side. Then, the liquid water-stop agent 26B is cured. Thereby, the water-stop agent 26 cured in the inner cap 22 is formed, and the inner waterproof portion 21 is formed at the end of the electric wire.

Next, as shown in fig. 3 and 4, the inner waterproof portion 21 is put into the outer cap 32. At this time, the edge of the inner cap 22 on the opening side and the edge of the outer cap 32 on the opening side are aligned, and the end of the inner cap 22 on the opening side is positioned inside the end 33 on the opening side of the outer cap 32. Then, the annular projection 33p contacts the periphery of the opening-side end of the inner cap 22. Since the annular projection 33p projects inward from the extending direction intermediate portion of the outer cap 32, the inner peripheral surface of the extending direction intermediate portion of the outer cap 32 and the outer peripheral surface of the inner cap 22 can be separated by the projecting dimension of the annular projection 33p in the extending direction intermediate portion of the outer cap 32. This enables an annular space S to be formed around the inner cap 22. Further, since the inner cap 22 is separated from the distal end portion of the outer cap 32, the space S can be provided also on the distal end side of the inner cap 22.

Then, the outer cap 32 is fixed to the inner cap 22 or the electric wire 10 with an adhesive tape 40 or the like. Thereby, the waterproof structure 20 of the core wire exposed portion of the electric wire can be manufactured.

According to the present embodiment, the exterior member 30 can form the space S separated from the external space around the internal waterproof portion 21. Therefore, the ambient temperature change is not easily transmitted to the interior waterproof portion 21, and the interior waterproof structure can be prevented from cracking even in an excessively cold and hot environment.

Here, as a problem of waterproofing regarding the core wire exposed portion 12a, the following phenomenon is assumed: since the inner waterproof portion 21 is cracked around the core wire exposed portion 12a or around the end portion of the coating layer 14, water from the outside enters the core wire exposed portion 12a through the cracking. In the present embodiment, the internal waterproof portion 21 is less likely to change in temperature, and the internal waterproof portion 21, for example, the water stopper 26 is less likely to crack due to linear expansion or the like, so that the waterproof property is easily maintained.

Further, the core exposed portion 12a also has a problem with water stopping. The water stop includes the above-described water prevention (water intrusion from the outside) and also includes a problem of water circulation between the electric wires 10. That is, when the core exposed portions 12a of the plurality of electric wires 10 are joined to each other at the joint portion 16, water that has entered 1 electric wire 10 may be transmitted to another electric wire 10 via another joint portion 16, and it is desirable to suppress this. Normally, the water-stopping agent 26 is cured in a state of being filled between the wires of the core wire exposed portion 12a, and therefore, water stopping between the wires is also achieved. However, if the water-stopping agent 26 between the wires is cracked due to linear expansion or the like, the water stopping between the wires is broken. In the present embodiment, a temperature change is less likely to occur in the internal waterproof portion 21, and cracking of the water-stopping agent 26 between the wires due to linear expansion or the like can be suppressed, so that the water-stopping property can be easily maintained.

The exterior member 30 surrounds the outer peripheral surface of the inner waterproof portion 21 with a space therebetween, and forms a cylindrical space S on the outer peripheral side of the inner waterproof portion 21. Therefore, the external heat is not easily transmitted to the inner waterproof portion 21 around the entire periphery of the inner waterproof portion 21, and the inner waterproof portion 21 can be effectively prevented from being cracked.

In addition, if the space S formed around the inner waterproof portion 21 includes portions having an interval of 1mm or more, external heat is less likely to be transmitted to the inner waterproof portion 21, and cracking of the inner waterproof portion 21 can be effectively suppressed.

When the thickness t2 of the exterior member 30 is 1mm or more, the exterior member 30 is less likely to be deformed by heat or the like, and the space S is easily ensured between the internal waterproof portion 21 and the exterior member 30. This makes it easy to maintain a state in which external heat is not easily transmitted to the inner waterproof portion 21, and can effectively suppress cracking of the inner waterproof portion 21. In particular, when the outer cap 32 is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin, the thickness t2 of the exterior member 30 may be 1mm or more in order to suppress deformation of the exterior member 30.

In addition, when the exterior member 30 is formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin, the exterior member 30 can be easily formed. In addition, since the space S may be formed by the exterior member 30 around the internal waterproof portion 21, the material forming the exterior member 30 is not particularly considered in this point.

The internal waterproof portion 21 can be waterproofed by an internal cap 22 in which the core wire exposed portion 12a is housed and a water-stopping agent 26 which is filled and cured in the internal cap 22. As such a configuration, a configuration that has been used in the past can be used.

Further, since the solidification liquid surface 26F of the water-stopping agent 26 in the inner cap 22 is located further to the back side than the opening edge portion of the inner cap 22, a space for suppressing heat transfer is easily secured in the inner cap 22 also at a position above the solidification liquid surface 26F. This can effectively suppress cracking of the inner waterproof portion 21.

Further, since the exterior member 30 includes the outer cap 32 surrounding the outer peripheral surface of the inner cap 22 with a space therebetween, the space S can be formed around the inner cap 22 by the outer cap 32. In addition, since such an outer cap 32 is formed to be larger than the inner cap 22, it is easy to use the apparatus for manufacturing the inner cap 22, and the outer cap 32 can be easily manufactured.

Further, since the opening-side end portion 33 of the outer cap 32 includes a portion having an inner diameter Φ 3 smaller than the inner diameter of the extending-direction intermediate portion, which surrounds the core-wire exposed portion 12a, the space S is easily secured around the portion of the inner cap 22 surrounding the core-wire exposed portion 12 a.

The inner diameter Φ 3 of the opening-side end 33 is an inner diameter into which the opening-side end of the inner cap 22 is fitted without rattling. Here, the inner diameter Φ 3 of the opening-side end 33 is the same as the outer diameter Φ 1 of the inner cap 22. Therefore, the opening-side end portion of the inner cap 22 can be stably inserted and held in the opening-side end portion 33 of the outer cap 32, and the space S can be easily stably secured around the inner cap 22.

Further, since the opening-side end portion 33 of the outer cap 32 is formed in a shape including the plurality of annular protrusions 33p protruding toward the inner circumferential side, a space can be formed between the plurality of annular protrusions 33p, and external heat can be hardly transmitted to the core wire exposing portion 12a due to the presence of the space.

The plurality of annular protrusions 33p facilitate stable holding of the opening-side end of the inner cap 22 in a fixed posture.

In addition, since the opening edge portion of the outer cap 32 coincides with the position of the opening edge portion of the inner cap 22, the position of the outer cap 32 and the position of the inner cap 22 can be stably aligned in the extending direction of the outer cap 32, so that a space is easily and stably secured on the tip end side of the inner cap 22.

The waterproof structure 20 of the exposed core wire portion of the electric wire can be widely used in various forms in a vehicle, a ship, an aircraft, a mechanical device, and the like, in a place where water may be submerged. For example, a part near a heat source such as an engine of an automobile is submerged. In the case where a plurality of sensors are provided at such a portion and the ground circuits and the like are connected in parallel, the waterproof structure 20 using the exposed core wire portion of the present electric wire can be configured to connect the ground circuits to the ground portion in one parallel, and thus the wiring connection work of the equipment and the like can be easily performed.

In practice, a sample was prepared using a bisphenol a epoxy resin as the water-stopping agent 26, and a cold thermal shock test was performed using a test apparatus having a temperature recovery time of 5 minutes or less.

In the cold thermal shock test, the sample was exposed to an environment of 1000 cycles with one cycle of exposing the sample to an environment of-40 ℃ for 30 minutes and 120 ℃ for 30 minutes. The samples exposed to the cold and hot environments were subjected to a test of applying an air pressure of 200hPa to the wire 10 to determine whether air leakage occurred, a test of determining whether or not insulation performance equal to or higher than lloomq was secured between the core wire exposed portion 12a and the outside, and a test of determining whether or not leakage current exceeded lOO μ a under predetermined voltage application conditions.

As sample a, the following samples were prepared: the inner waterproof portion 21 is formed at the end of the electric wire 10, but the exterior member 30 is not provided, and the test result is not satisfactory.

As sample B, a sample in which the exterior member 30 was formed on the sample a was prepared. The dimensions of each portion are set to values or ranges exemplified in the above embodiments.

In this case, in sample B in which the exterior member 30 was provided for sample a that failed the test result, the test result was confirmed to be acceptable.

From the results, it is found that: by providing the space S with the exterior member 30, the waterproof property is improved.

In addition, in sample C using bisphenol a type epoxy resin as the water-stopping agent 26, a sample was prepared in which the interval t1, which is the maximum gap of the surrounding space of the inner waterproof portion 21, was 1 mm. The sample C was heated at a high temperature of 130 ℃ to saturate the humidity of the sample C at 130 ℃ and then taken out, and the sample C was quenched with water at 10 ℃ to measure the time until the temperature of the sample C was lowered to 40 ℃.

In this case, it is understood that the time required for the sample to fall to 40 ℃ is 2 times or more the time required for the sample without the exterior member 30 to fall to 40 ℃ under the same conditions. Therefore, the following can be known: when the gap t1 of the space S is set to 1mm or more, the temperature change can be effectively suppressed.

{ modification example }

Various modifications will be described.

In the above embodiment, the outer cap 32 is described as being formed of at least one of an elastomer, a thermoplastic resin, and a thermosetting resin, but the material of the outer cap 32 is not particularly limited.

For example, as in modification 1 shown in fig. 5, the exterior member 30 may include an outer cap 132 made of metal. As the metal, aluminum alloy, iron, stainless steel, or the like can be used. In addition, the opening-side end 133 of the outer cap 132 formed of metal may be fastened and fixed to the inner cap 22 or the electric wire 10 (bundle of electric wires 10) by being plastically deformed toward the inner cap 22 or the electric wire 10 (bundle of electric wires 10). Preferably, the structure is as follows: the fastening deformation is performed at a plurality of positions in the extending direction of the opening side end portion 133, and annular protrusions 133p similar to the annular protrusion 33p are formed. Of course, the outer cap 132 may be fixed with an adhesive tape or the like as in the above embodiment. In addition, the outer cap 132 may be fixed to the electric wire 10 or the inner cap 22 using an adhesive or the like. Further, an insertion portion may be formed at an end portion of the covering layer 14 of the electric wire 10 or an opening-side end portion of the inner waterproof portion 21, the insertion portion may be inserted into the opening-side end portion 33 of the outer cap 132, and the opening-side end portion 133 of the outer cap 132 may be externally inserted into the insertion portion.

According to modification 1, since the outer cap 132 formed of metal can reflect radiant heat, a change in humidity of the inner waterproof portion 21 due to the influence of radiant heat can be suppressed, and in this regard, cracking of the inner waterproof portion 21 can also be suppressed.

The present embodiment and each modification example are configured as follows: the inner cap 22 is put into the outer cap 32, and a space S is formed between the inner cap 22 and the outer cap 32. Such a space S may not be formed between the inner cap 22 and the outer cap 32.

For example, the inner waterproof portion 21 may be surrounded by a member having a space therein partitioned from the outside.

As such a member, a member containing space having a space separated from the outside in the inside thereof can be used. As the containing space member, for example, a foamed member such as a foamed resin, a bubble buffer in which air is sealed between 2 resin sheets or the like, and a fiber assembly member (nonwoven fabric, woven fabric or the like) formed of an assembly of fibers can be used. The foaming member can be considered to be a member having a plurality of spaces separated from the external space in its interior. The bubble buffer can be considered to be a member having a space separated from an external space in its own interior. The fiber assembly member is considered to be a member in which air in the space between fibers is not easily exchanged with outside air, and thus a space separated from the outside space is provided between fibers.

Therefore, when the interior waterproof portion 21 is surrounded by the above-described interior space member, a space separated from the external space can be formed around the interior waterproof portion 21.

As in modification 2 shown in fig. 6, the inclusion space member 230 may be configured as follows: the inner cap 22 is formed into a bottomed tubular shape having one end side open and the other end side closed by mold forming, heating compression molding, heating bonding, sewing, or the like, and is housed therein. In the case where the containing space member 230 is formed in a bottomed tubular shape, the containing space member 230 may be in contact with the outer peripheral surface of the inner waterproof portion 21 without a gap. A gap may be formed between the interior space member and the interior waterproof portion 21. Unlike the outer cap 32, the containing space member 230 is not necessarily hard enough to maintain its shape so as to form the space S.

As in modification 3 shown in fig. 7, the following configuration may be adopted: the interior space member 330 is formed in a sheet or a belt shape, is wound around the interior waterproof portion 21, and is maintained in the wound state by a double-sided tape, an adhesive, a tape, or the like (the tape 40 is illustrated in fig. 7). The interior space member 330 may be configured to cover the periphery of the interior waterproof portion 21 but not the distal end side, or may be configured to cover the periphery and the distal end side of the interior waterproof portion 21.

In the present embodiment and the above modifications, the end portion of the electric wire 10 is formed with the core wire exposed portion 12a, and the waterproof structure of the core wire exposed portion 12a at the end portion is described. However, when the core wire exposed portion is formed in the intermediate portion in the extending direction of the electric wire, the configuration described in the above embodiment and the like can be applied to a structure for waterproofing the core wire exposed portion 12 a. For example, the following configuration may be adopted: an exposed core wire portion at an intermediate portion in the extending direction of the electric wire is covered with a resin such as a photo-setting resin or a thermosetting resin, or a heat shrinkable tube to form an inner waterproof portion, and an exterior member forming a space separated from an external space is provided around the inner waterproof portion. As the exterior member in this case, the following configuration can be adopted: a structure in which a pipe member having both end portions narrower than an intermediate portion is used, tapes are wound around both end portions of the pipe member and the electric wire, and a space is provided between the pipe member and the inner waterproof portion; a structure of winding a foamed sheet, a foamed tape, and the like.

The respective configurations described in the above embodiments and modifications can be appropriately combined as long as they do not contradict each other. For example, a foamed resin or the like may be provided inside the metal cap.

As described above, the present invention has been described in detail, but the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that numerous modifications not illustrated can be devised without departing from the spirit of the invention.

Description of the reference numerals

10 electric wire

12a core wire exposed part

20 waterproof structure

21 inner waterproof part

22 inner cap

26 water-stopping agent

26F curing level

30 outer sheathing member

32. 132 outer cap

33. 133 open side end part

33p annular projection

33q annular recess

40 adhesive tape

230. 330 containing space component

S space

T space