JPH0722088A - Structure and method for waterproof wire connection - Google Patents

Abstract

PURPOSE:To ensure that an electrical connection is waterproof without being enlarged and to simplify operations while reducing cost. CONSTITUTION:A wire connection 4 to which the exposed conductors 1a, 2a of plural wires 1, 2 are connected is covered with a coating 5 formed by the application and drying of a liquid coating material such as a one-liquid coating material comprising an acrylic or an urethane emulsified and dispersed in water, or a one-liquid coating material comprising solids dissolved in an organic solvent such as toluene. A tape 6 is wrapped around the outer peripheral surface of the coating. A protective coating formed by the application and cooling of a molten resin may be used in place of the tape to cover the outer peripheral surface of the coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure of a wire connecting portion in which conductors exposed by partially removing coatings of a plurality of wires are connected by connecting terminals, and a waterproofing method thereof.

[0002]

2. Description of the Related Art Conventionally, various waterproof measures for an electric wire connecting portion in which an exposed conductor of this kind is connected by a connection terminal have been provided, and there are mainly the following four waterproof measures. First
Is to be molded, arrange the wire connection part in the mold, press fit the waterproof material such as melted rubber or plastic,
The insulator which is solidified by cooling is molded, and the electric wire connecting portion is embedded in the insulator to perform waterproofing treatment. (JP-A-6
4-6307)

The second is to coat with a butyl pad,
Wrap the wire connection part with butyl rubber and tape it over, or sandwich the wire connection part with butyl rubber, pressurize it with a press machine, and tape it over it for waterproofing. ing. (Japanese Patent Publication No. 59-35510)
issue)

Thirdly, a heat-shrinkable tube is used for coating. The electric wire connecting portion is passed through the heat-shrinkable tube to be heated, and the shrinkage of the tube is used for waterproofing. (Actual No. 61-62376)

The fourth is a combination of an adhesive and a tape winding. After the electric wire connecting portion is pushed into the adhesive on the film, the film is folded in two and adhered to seal the electric wire connecting portion. , A tape is wrapped around the outer periphery to perform waterproofing. (Actual development number 62-123072)

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Each of the waterproof treatment measures had the following problems. That is, when the first molding process is performed, a mold is required depending on the size of the electric wire and the branch shape of the electric wire, resulting in high equipment cost and poor workability.

When the second butyl pad is used, since the butyl rubber is rolled in, the diameter of the electric wire connecting portion is increased and the weight is increased. In particular, if the outer diameter becomes large, wiring may not be possible. When the third heat-shrinkable tube is used, it is very difficult to pass an electric wire through the heat-shrinkable tube in advance, which is not practical, and even if it is put into practical use, workability becomes extremely poor.

The fourth method of combining the adhesive and the tape winding is related to the application of the present applicant.
Compared with the waterproofing measure, the diameter of the electric wire bonding portion does not become large and the workability is excellent. However,
With this fourth waterproofing measure, the cost of the adhesive is high,
In addition, a dispenser is required to supply the adhesive onto the film, which has a drawback of increasing equipment cost. In particular, since the amount of adhesive applied has a great influence on the waterproof performance, it is necessary to accurately control the dispenser, as well as the temperature of the adhesive and the temperature of the work place. Furthermore, since the adhesive requires a long time to cure, it is necessary to leave it after processing, which requires a long working time.
If the tape is wound and pressure is applied even before the adhesive is hardened in order to shorten the work time, the adhesive overflows from both ends of the tape winding, and the waterproof performance deteriorates. There is a drawback that the electric wires are adhered to each other by the adhesive.

The present invention solves the above-mentioned conventional problems,
Waterproofing can be performed very easily without increasing the cost, and the outer diameter of the wire connection part is not enlarged.
It is an object of the present invention to provide a waterproof structure and a waterproofing method for an electric wire connecting portion having excellent waterproofing performance.

[0010]

In order to achieve the above object, the present invention provides a coating film formed by applying a liquid coating material to an electric wire connecting portion for connecting exposed conductors of a plurality of electric wires. The present invention provides a waterproof structure for an electric wire connecting portion.

Further, the outer peripheral surface of the coating film is wrapped with a tape, or is covered with a protective film formed by applying and cooling a molten resin.

According to the present invention, in order to obtain the above-mentioned waterproof structure, after the electric wire connecting portion for connecting the conductors in which a plurality of electric wires are exposed is immersed in the liquid tank in which the liquid coating material is stored, The present invention provides a waterproofing method for an electric wire connecting portion which is taken out from a liquid tank and dried to coat the electric wire connecting portion with a coating film. A liquid coating material may be applied instead of dipping in the liquid tank described above.

After forming the above coating film, the coating film is wrapped in multiple wraps with tape, or the electric wire connecting portion coated with the coating film is dipped in a liquid tank containing a molten resin, and then taken out from the liquid tank and dried. ,
The coating film is covered with a protective film. The above-mentioned tape winding may be performed without being dried immediately after being dipped in a liquid bath of the coating material and pulled up, or immediately after applying the coating material.

As the liquid coating material for forming the coating film, a one-liquid coating material in which an acrylic substance or a urethane substance is dispersed in water as an emulsion is used. Alternatively, a one-component coating material in which solid content is dissolved in an organic solvent such as toluene is used.

A vinyl chloride tape is preferably used as the tape for winding the tape, and molten vinyl chloride (PVC) is preferably used as the molten resin to form the protective film.

The application and drying of the above liquid coating material may be carried out as many times as necessary, and may be repeated until a required film thickness is obtained.

[0017]

[Function] The formation of the coating film on the electric wire connecting portion is
All you have to do is to immerse the wire connection part in a liquid tank that stores the liquid coating material, then take it out and dry it, or apply the liquid coating material and dry it. In operation, the wire connection part can be covered with the coating film layer. Since the coating film layer uses the liquid coating material, the gap between the conductors is filled without leakage, and the conductor and the insulating coating terminal portion where the conductors are exposed can be reliably covered with the liquid coating material. It is possible to achieve reliable waterproofing. Moreover, since it is liquid, the film thickness does not increase, and the outer diameter of the electric wire connecting portion can be prevented from increasing.

Further, when the outer peripheral surface of the coating film layer is wound with a tape and the tape winding is a multi-wrap winding, reliable waterproofing is achieved even in this tape winding portion, and the thickness is not large. It is possible to suppress enlargement of the electric wire connecting portion. When a protective film is provided by immersing in a molten vinyl chloride liquid tank instead of the above tape winding, it is enough to immerse it in the liquid tank, take it out and cool it, so that anyone can do it and workability is good. A protective film can be formed. Further, the protective film also does not have a large thickness, and it is possible to suppress enlargement of the electric wire connecting portion.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 1 and 2 show a waterproof structure of an electric wire connecting portion according to a first embodiment of the present invention, in which a conductor 1a is exposed by peeling off an insulating coating of an intermediate portion of the covered electric wire 1 and a tip of the covered electric wire 2. The conductor 2a is exposed by peeling off the insulating coating on a part, and the exposed conductors 1a and 2a are crimped and crimped by the connection terminal 3.

In the electric wire connecting portion 4 in which the conductors 1a and 2a are crimped with the connecting terminal 3, the whole outer surface of the conductors 1a and 2a and the metallic connecting terminal 3 and the insulating coating near the exposed conductor portions of the covered electric wires 1 and 2 are covered. The entire outer surface of 1b and 2b is covered with a coating film 5 having a waterproof property without leakage. The coating film 5 is formed by applying a one-component coating material in which an acrylic substance or a urethane substance is dispersed in water as an emulsion and then drying. As the one-component coating material, for example, HUX-232 manufactured by Asahi Denka Kogyo Co., Ltd., or NANOCRYL manufactured by Toyo Ink Mfg. Co., Ltd. is used.

Instead of the above liquid coating material, a one-liquid coating material in which a solid content is dissolved in an organic solvent such as toluene may be used. For example, Cemedine 240 manufactured by Cemedine Co., Ltd. is preferably used. To be

On the outer peripheral surface of the coating film layer 5,
2 pieces of vinyl chloride tape 6 with adhesive on the back
It is wrapped in heavy wrap.

As described above, in the electric wire connecting portion 4, the entire surface of the insulating coating near the conductor, the connecting terminal and the exposed conductor portion is covered with the coating film 5, and the outer peripheral surface of the coating film is wrapped with the tape 6. It is protected by the formed protective layer.

Next, a waterproof method for forming the waterproof structure will be described. As shown in FIG. 3, first, the covered electric wire 1
The required portions 2 and 2 are peeled off to expose the conductors 1a and 2a from the insulating coatings 1b and 2b. In the embodiment, the coated electric wires 1 and 2 having a cross-sectional area of 0.5 mm ² are used, and the conductors 1a and 2a are connected to the U-shaped metal connecting terminal 3
Crimp and crimp.

After that, the electric wire connecting portion 4 is immersed in the liquid tank 10 storing the one-liquid coating material for about 1 second. After the immersion, it is taken out of the liquid tank 10 and naturally dried. In order to shorten the drying time, it is preferable to add alcohol in the water-dispersed coating material, in which case,
It can be dried in 40 seconds. When the liquid coating material is dried, it solidifies to form a film, forming a coating film 5.

Then, a vinyl chloride tape 6 having a back surface coated with an adhesive material is wound around the outer peripheral surface of the insulating coating 1b in the vicinity of the exposed conductor on one side of the coated electric wire 1 and then wound around the outer peripheral surface of the coating film 5. Then, it is wound around the outer peripheral surfaces of the covered electric wires 1b and 2b in the vicinity of the exposed conductor portion of the other side of the integrated covered electric wire 1 and in the exposed conductor portion of the covered electric wire 2.

The waterproof performance of the electrical connecting portion having the waterproof structure of the first embodiment was 0.3 kgf / cm ² as a result of a measurement experiment. The waterproof performance is a numerical value in which the air pressure is applied from the end of the electric wire and the coating film 5 has holes due to the pressure. Therefore, the larger the measured value, the less likely the holes are formed in the coating film, indicating that the waterproof performance is high.

In the first embodiment, the liquid coating tank 10 is immersed once, and the coating film 5 is formed by drying after the immersion. However, the liquid coating material is immersed in the liquid tank 10. -By repeating drying a plurality of times, the film thickness of the coating film 5 can be increased and the waterproof performance can be improved.

As a modified example 1 of the first embodiment, the above liquid tank 1
The process of immersing in 0, then pulling out from the liquid tank and drying was repeated twice. In this case, the waterproof performance is 0.45kgf
It became / cm ² . Also, when it was repeated 4 times, the waterproof performance was 0.8 kgf / cm ² . Incidentally, the film thickness of the coating film is 30 to 50 when the immersion in the liquid tank and the drying are performed once.
μm was 80 to 100 μm when it was repeated twice, and 180 to 200 μm when it was repeated 4 times.

In the first embodiment, the liquid coating material is pulled out of the liquid tank 10 and then naturally dried, but it may be heated and forcedly dried. In this case, the formation time of the coating film 5 can be shortened. As a modified example 2 of the first embodiment, forced drying by the above heating was performed. That is, after pulling up from the liquid tank 10, hot air at 80 ° C. was applied to form the coating film 5 in a short time. The forced drying time was 10 seconds when the liquid coating material was a water dispersion coating material and 5 seconds when it was an organic solvent coating material. After the forced drying by the heating of the modified example 2 and the winding of the tape 6 to complete the completion, the waterproof performance was measured and it was about the same as the first embodiment.

In the first embodiment described above, the electrical connection portion 4 at room temperature is used.
Is immersed in a liquid tank of liquid coating material at room temperature melted with water or an organic solvent, and after pulling out of the liquid tank, the coating material is solidified by evaporating water or organic solvent by drying to form a film. Is forming. Therefore, the thickness of the coating film formed in one step cannot be set to a certain value or more. On the other hand, when the electrical connection part 4 is immersed in a liquid tank while being heated, water or an organic solvent can be evaporated to form a coating film in the liquid tank, and the coating material further melted on the surface of the coating film. Since it can be attached, the thickness of the coating film can be increased in one step. Further, even if the electric connection part 4 is heated and immersed in the liquid tank and pulled up immediately after the immersion, a thin coating film can be formed, and the time for forming the coating film can be shortened.

Therefore, as a modified example 3 of the first embodiment, the heated electrical connection portion 4 was immersed in the liquid tank 10 and pulled up immediately after the immersion to form a thin coating film 5. Even in the case where the coating film 5 formed by the method of this modification 3 was applied to the electrical connection portion 4, the waterproof performance of 0.15 kghf / cm ² was obtained. Needless to say, the waterproof performance can be improved by performing the above steps multiple times to increase the thickness of the thin coating film.

In the liquid coating material of the first embodiment described above, the solid content ratio is 20 to 40%, and a coating film having a thickness of 100 μm or less is formed in one step. When the viscosity of the liquid is reduced by increasing it to 50 to 70%, the thickness of the coating film 5 can be increased to about 200 μm in one step, and the waterproof performance can be improved.

Therefore, as a modified example 4 of the first embodiment, the solid content ratio of the liquid coating material is 50 to 70%, and
The coating film 5 having a thickness of about 200 μm was formed in the same process. According to the modification 4, if the film thickness is increased in one step, the tape winding process applied to the surface of the coating film 5 can be unnecessary by repeating this step a plurality of times.

4 and 5 show a second embodiment of the present invention. In the first embodiment and the modified examples 1 to 4 thereof, after the coating film 5 is formed, the surface is subjected to tape winding treatment for waterproof protection, but in the second example, it is replaced with tape winding. Then, in the same manner as the coating film forming method, the electrical connection portion 4 provided with the coating film 5 is immersed in a liquid tank in which the molten resin is stored, and after a lapse of a required time, the electric connection part 4 is pulled out from the liquid tank and cooled to form the protective film
Is formed.

That is, in the waterproof structure of the electric connection portion according to the second embodiment, the protective film 20 is formed by applying and cooling molten resin, in this embodiment, molten PVC (molten vinyl chloride) on the surface of the coating film 5. is doing.

As shown in FIG. 6, the protective film 20 is formed by forming the coating film 5 in the same process as in the first embodiment, immersing it in a molten PVC liquid tank 21, and after a required time elapses, A protective film 20 made of vinyl chloride is formed on the surface side of the coating film 5 with a required thickness by pulling it up from the tank 21 and cooling it. Since the other points of the second embodiment are the same as those of the above-mentioned first embodiment, the same elements are designated by the same reference numerals and the description thereof will be omitted.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the first and second embodiments, the liquid coating material is dipped in a liquid tank to form a coating film. Instead of this dipping method, the liquid coating material is sprayed or brushed electrically. You may apply to the connection part 4. However, from the viewpoint of the permeability of the liquid, it is preferable to immerse it in the liquid tank.

[0039]

As is apparent from the above description, in the waterproof structure of the electric connecting portion according to the present invention, the electric connecting portion in which the exposed conductor is connected by the connecting terminal is applied by immersing it in a liquid coating material or the like. Since this is dried and solidified to form a film, it is possible to coat the entire outer peripheral surface of the conductor, the connection terminal, the insulating coated terminal, and the like of the electrical connection portion with no leakage. Therefore, waterproofing can be surely achieved only by providing the coating film. Moreover,
If the surface of the coating film is wrapped with a tape or a protective film made of vinyl chloride resin is applied, the mechanical performance of the electrical connection portion can be further enhanced.

Further, since the electric connection portion is covered with the coating formed by applying and drying the liquid coating material and then solidifying the coating, it does not leak into the gap and the film thickness does not increase more than necessary. , No increase in weight. Therefore, the problem that the wiring becomes difficult due to the increase in the outer diameter does not occur.

Further, when the waterproofing method according to the present invention is used, only the liquid tank for immersion is required, no special equipment is required, and the waterproofing can be performed without increasing the cost. Moreover, since it is simply immersed in a liquid tank and pulled up after a required time to give an impression, or because only a liquid coating material is applied, the waterproofing work is extremely simple and can be performed by anyone. is there.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic view showing a work process of the first embodiment.

FIG. 4 is a partial sectional view showing a second embodiment of the present invention.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a schematic view showing a work process of the second embodiment.

[Explanation of symbols]

 1, 2 Coated electric wire 1a, 2a Conductor 3 Connection terminal 5 Coating film 6 Tape 10, 21 Liquid tank 20 Protective film

Claims (9)

[Claims] 1. A waterproof structure of an electric wire connecting portion in which an electric wire connecting portion connecting an exposed conductor of a plurality of electric wires is covered with a coating film formed by applying a liquid coating material. 2. The waterproof structure for an electric wire connecting portion according to claim 1, wherein an outer peripheral surface of the coating film is wound with a tape. 3. The waterproof structure for an electric wire connecting portion according to claim 1, wherein the outer peripheral surface of the coating film is covered with a protective film formed by applying and cooling molten resin. 4. The liquid coating material for forming the coating film layer is a one-liquid coating material in which an acrylic substance or a urethane substance is emulsified and dispersed in water, or a solid content in an organic solvent such as toluene. The electric wire waterproof structure according to claim 1, wherein a one-liquid coating material in which is dissolved is used. 5. A thermoplastic resin such as molten vinyl chloride is used as the molten resin forming the protective film.
Waterproof structure of the electric wire connection part. 6. An electric wire connecting part for connecting exposed conductors of a plurality of electric wires is dipped in a liquid tank storing a liquid coating material, then taken out from the liquid tank and dried, or , A method of waterproofing a wire connecting part in which a liquid coating material is applied and then dried to coat the wire connecting part with a coating film. 7. The waterproofing method for an electric wire connecting portion according to claim 6, wherein the outer peripheral surface of the coating film is wound in multiple wraps with a tape. 8. The coating film tank is covered with a protective film by immersing the electric wire connecting portion coated with the coating film in a liquid tank in which molten resin is stored, then taking out from the liquid tank and cooling it. How to waterproof the electric wire connection part. 9. The waterproofing method for an electric wire connecting portion according to claim 6, wherein the liquid coating material is applied and then dried, and the application and drying are performed a required number of times to form a coating film having a required thickness.