Waterproof structure of covered electric wire

Abstract

To provide a waterproofing structure of a coated electric wire having one end arranged under a negative-pressure environment and the other end arranged under a watery environment, and capable of facilitating a waterproofing process.SOLUTION: A waterproofing structure 1 of a coated electric wire 2 has one end arranged under a negative pressure environment and the other end arranged under a watery environment. An air suction part 23 formed by opening a hole in an insulation coat 22 is formed in an intermediate part 2c of the coated electric wire 2. The intermediate part 2c is stored inside a sealed space 53c of a case 5. When a negative pressure is generated on one end side of the coated electric wire 2, air inside the sealed space 53c is sucked into the insulation coat 22 from the air suction part 23. Thus, air and water can be prevented from being sucked from the other end side of the coated electric wire 2.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a waterproof structure for a covered electric wire. [Background technology]

[0002] Wire harnesses installed in automobiles include covered electric wires, connectors in which terminal fittings connected to the ends of the electric wires are housed in a connector housing, etc. Waterproof connectors with a sealed structure are sometimes used to connect wire harnesses. In waterproof connectors, the gap between the connector housing and the covered electric wires is sealed with a rubber plug or filler.

[0003] Some wire harnesses are routed between the passenger compartment and the engine compartment. When a waterproof connector is attached to the engine compartment end of this wire harness, the air inside the waterproof connector expands and contracts as the temperature in the engine compartment changes due to the engine being running and stopped, creating a negative pressure inside the waterproof connector during contraction. This causes air to be sucked into the insulating sheath from the passenger compartment end of the wire harness, and this air flows into the engine compartment through the gaps between the strands of the core wire. In this case, if the passenger compartment end of the wire harness becomes wet for some reason, such as if a passenger spills a drink, water can seep into the insulating sheath.

[0004] To address this problem, Patent Document 1 discloses a water-stopping structure for electric wires in which the insulating coating of a coated electric wire is stripped in the middle to expose the core wire, and the multiple strands of the core wire in the exposed part are welded together, and then the exposed core wire including the welded part is covered with tape or a heat-shrinkable tube, thereby blocking water that has entered the insulating coating at the welded part. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-72943 Summary of the Invention [Problem to be solved by the invention]

[0006] The waterproof structure for electric wire disclosed in the above Patent Document 1 required complicated processes such as welding the core wires together, wrapping the welded portion with tape, and covering it with a heat-shrinkable tube and heating it.

[0007] Therefore, an object of the present invention is to provide a waterproof structure for a coated electric wire in which one end is placed in a negative pressure environment and the other end is placed in a water-exposed environment, and which can facilitate the waterproofing process. [Means for solving the problem]

[0008] The present invention provides a waterproof structure for a covered electric wire, one end of which is placed in a negative pressure environment and the other end of which is placed in a water-exposed environment, the waterproof structure comprising: Absolute An air intake section is formed by opening a hole in the edge coating, and the middle section is housed within the sealed space of the case. When negative pressure occurs on one end side of the insulated electric wire, air in the sealed space is sucked into the insulating coating through the air intake section, thereby preventing water from being sucked in from the other end side of the insulated electric wire. [Effects of the Invention]

[0009] According to the present invention, the waterproofing process for a covered electric wire can be facilitated. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a waterproof structure for a covered electric wire according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view of the case of FIG. 1. [Figure 3] FIG. 2 is a side view of the case of FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] FIG. 4 is a cross-sectional view taken along line BB in FIG. [Figure 6]FIG. 6 is a cross-sectional view of a main part of a waterproof structure for a covered electric wire according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a main part of a waterproof structure for a covered electric wire according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A "waterproof structure for a covered electric wire" according to a first embodiment of the present invention will be described with reference to FIGS.

[0012] The waterproof structure 1 for a covered electric wire 2 shown in Fig. 1 is a waterproof structure for a covered electric wire 2 in which one end 2a is placed in a negative pressure environment and the other end 2b is placed in a water-exposed environment. In this specification, a "negative pressure environment" is defined as an environment in which negative pressure may occur. Also, a "water-exposed environment" is defined as an environment in which water or other liquids may splash on the covered electric wire.

[0013] The coated electric wire 2 is an electric wire with a circular cross section, in which a core wire 21 is covered with an insulating coating 22. The core wire 21 is formed by twisting a plurality of strands of wire. The strands are made of aluminum or an aluminum alloy. The coated electric wire 2 of this example has a waterproof connector 3 attached to one end 2a and a non-waterproof connector 4 attached to the other end 2b, thereby constituting a vehicle wire harness.

[0014] The waterproof connector 3 includes a terminal fitting connected to one end 2a of the insulated electric wire 2, a connector housing that accommodates the terminal fitting, and a seal member that seals the gap between the insulated electric wire 2 and the connector housing. The waterproof connector 3 is disposed in the engine compartment R1 of the vehicle. Therefore, negative pressure may be generated inside the waterproof connector 3 due to a drop in temperature in the engine compartment R1 when the engine is stopped. In other words, the inside of the waterproof connector 3 is in a negative pressure environment.

[0015] The non-waterproof connector 4 has a terminal fitting connected to the other end 2b of the insulated electric wire 2 and a connector housing that accommodates the terminal fitting. The non-waterproof connector 4 is disposed in the vehicle interior R2. The non-waterproof connector 4 may become wet due to some unintentional cause, such as an occupant spilling a drink. In other words, the inside of the non-waterproof connector 4 is a wet environment.

[0016] The terminal fittings of the waterproof connector 3 and the non-waterproof connector 4 are made of copper or copper alloy. If water seeps into the connection between these terminal fittings and the core wire 21, electrolytic corrosion will occur, which is undesirable. One of the purposes of the present waterproof structure 1 is to prevent this electrolytic corrosion.

[0017] 2 to 5 is attached to the middle portion 2c of the coated wire 2. This case 5 is made up of a first case 51 and a second case 52 that are assembled together with the middle portion 2c positioned therebetween. The first case 51 and the second case 52 are made of synthetic resin.

[0018] The first case 51 is formed in a flat plate shape and is provided with a groove 53a for positioning the middle portion 2c of the covered electric wire 2. The groove 53a has a semicircular cross section that matches the shape of the covered electric wire 2 and extends over the entire length of the first case 51. A pair of protrusions 54 are provided on both widthwise ends of the first case 51.

[0019] The second case 52 is formed in a flat plate shape and is provided with a groove 53b for positioning the middle portion 2c of the covered electric wire 2. The groove 53b has a semicircular cross section that matches the shape of the covered electric wire 2 and extends over the entire length of the second case 52. A pair of engaging portions 55 that engage with the protruding portions 54 of the first case 51 is provided on both widthwise ends of the second case 52. The first case 51 and the second case 52 are assembled together by the engagement of these protruding portions 54 and the engaging portions 55.

[0020] The grooves 53a and 53b form a space slightly larger than the insulated electric wire 2 when the first case 51 and the second case 52 are assembled together. The middle portion 2c of the insulated electric wire 2 is positioned in the space formed by the grooves 53a and 53b. The first case 51 and the second case 52 each have a packing 6 attached thereto to make the central portion of the space in the wire longitudinal direction an airtight space 53c.

[0021] Each packing 6 is formed in a rectangular frame shape in a plan view, and is attached to the mating surfaces of the first case 51 and the second case 52. A portion of the packing 6 is located on the inner surface of the grooves 53a, 53b and is in close contact with the insulated electric wire 2. These packings 6 maintain a watertight seal between the first case 51 and the second case 52, and between each case 51, 52 and the insulated electric wire 2.

[0022] 4, a needle portion 56 is provided in the portion of the grooves 53a, 53b that forms the sealed space 53c. The needle portion 56 penetrates the intermediate portion 2c when the first case 51 and the second case 52 are assembled together, thereby opening a hole in the insulating coating 22. As a result, the air intake portion 23 is formed in the portion of the intermediate portion 2c that is accommodated in the sealed space 53c by the needle portion 56 penetrating the portion and opening a hole in the insulating coating 22.

[0023] Furthermore, the volume of the space between the inner surface of the case and the coated wire 2 in the sealed space 53c is larger than the volume of the space inside the waterproof connector 3.

[0024] In the water stopping structure 1 of this example, when negative pressure occurs on the one end 2a side of the insulated electric wire 2, i.e., inside the waterproof connector 3, air in the sealed space 53c is sucked into the insulating coating 22 through the air intake portion 23. This makes it possible to prevent air and water from being sucked in from the other end 2b side of the insulated electric wire 2, i.e., the non-waterproof connector 4 side. The water stopping process of this water stopping structure 1 is very easy, as it simply requires attaching the case 5 to the middle portion 2c of the insulated electric wire 2.

[0025] (Second embodiment) A "waterstop structure for a covered electric wire" according to a second embodiment of the present invention will be described with reference to Fig. 6. In Fig. 6, the same components as those in the first embodiment described above are designated by the same reference numerals, and description thereof will be omitted.

[0026] 6, the waterproof structure 101 for a covered electric wire 2 does not have the needle portion 56 provided in the first case 151 and the second case 152 of the case 105 attached to the middle portion 2c of the covered electric wire 2. Therefore, an air intake portion 123 formed by removing a part of the insulating coating 22 is formed in advance in the middle portion 2c of the covered electric wire 2. The other configurations are the same as those of the waterproof structure 1 of the first embodiment.

[0027] The water stopping structure 101 of this example has the same effect as the water stopping structure 1 of the first embodiment, and when negative pressure is generated on the one end 2a side of the insulated electric wire 2, i.e., inside the waterproof connector 3, air in the sealed space 53c is sucked into the insulating coating 22 through the air intake portion 123. This makes it possible to prevent air and water from being sucked in from the other end 2b side of the insulated electric wire 2, i.e., the non-waterproof connector 4 side. The water stopping process of this water stopping structure 101 is very easy, as it simply involves removing a portion of the insulating coating 22 from the middle portion 2c of the insulated electric wire 2 to form the air intake portion 123, and then attaching the case 105 to this middle portion 2c.

[0028] (Third embodiment) A "waterstop structure for a covered electric wire" according to a third embodiment of the present invention will be described with reference to Fig. 7. In Fig. 7, the same components as those in the first and second embodiments described above are designated by the same reference numerals, and description thereof will be omitted.

[0029] 7, a water-stopping structure 201 for a covered electric wire 2 is applied with a water-stopping material 206 instead of the packing 6 (see FIG. 6) of the case 105 of the second embodiment to maintain watertightness between the first case 151 and the second case 152, and between each of the cases 151, 152 and the covered electric wire 2. The other configurations are the same as those of the water-stopping structure 101 of the second embodiment.

[0030] The water stopping structure 201 of this example has the same effects as the water stopping structures 1 and 101 of the first and second embodiments. The water stopping process of this water stopping structure 201 is very easy, as it simply involves removing a portion of the insulating coating 22 from the middle portion 2c of the insulated electric wire 2 to form the air intake portion 123, and then attaching the case 105 coated with the water stopping material 206 to this middle portion 2c.

[0031] In addition to using the packing 6 and the waterproofing material 206 described above, the case 5, 105 may be sealed together with a heat shrinkable tube.

[0032] In the above-described embodiment, the needle portion 56 is provided on both the first case 51 and the second case 52, but the needle portion 56 may be provided on at least one of the first case 51 and the second case 52. Also, a blade portion may be provided instead of the needle portion 56.

[0033] In the above-described embodiment, the waterproof connector 3 is attached to the one end 2a of the insulated electric wire 2. However, the present invention is not limited to a waterproof connector, and an electric junction box or other in-vehicle equipment may be attached to the one end of the insulated electric wire. In other words, it is sufficient that the one end of the insulated electric wire is placed in a negative pressure environment.

[0034] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still include the configuration of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0035] 1,101,201 Waterproof structure for coated electric wires 2. Insulated wire 5,105 cases 22 Insulation coating 23,123 Air intake 53b Confined space

Claims

1. A waterproof structure for a covered electric wire, one end of which is placed in a negative pressure environment and the other end of which is placed in a water-exposed environment, an air intake portion formed by opening a hole in the insulating coating at the intermediate portion of the insulated electric wire; The intermediate portion is accommodated in the sealed space of the case, When negative pressure occurs on the one end side of the insulated electric wire, air in the sealed space is sucked into the insulating coating through the air suction portion, thereby suppressing the suction of water from the other end side of the insulated electric wire. A waterproof structure for a covered electric wire.

2. the case is composed of a first case and a second case that are assembled to each other with the intermediate portion positioned therebetween, At least one of the first case and the second case is provided with a needle or blade that pierces the intermediate portion when the first case and the second case are assembled together to make a hole in the insulating coating. The waterproof structure for a covered electric wire according to claim 1 .

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