WO2004061870A1

WO2004061870A1 - Electric wire coating device and electric wire

Info

Publication number: WO2004061870A1
Application number: PCT/JP2003/016707
Authority: WO
Inventors: Takeshi Kamata; Shigeharu Suzuki; Keigo Sugimura
Original assignee: Yazaki Corporation
Priority date: 2002-12-27
Filing date: 2003-12-25
Publication date: 2004-07-22
Also published as: AU2003296107A1; JPWO2004061870A1; JP4431053B2

Abstract

An electric wire coating device of low coating cost and an electric wire not discoloring are disclosed. The coating device (1) forms a coating layer on the outer surface of an electric wire (2). The coating device (1) comprises a bath (10) and a guide mechanism (11). The bath (10) contains a coating solution (C) and is closed. The coating solution (C) comprises a methacrylic resin and a solvent for dissolving the methacrylic resin. The guide mechanism (11) has a pair of squeegees (14, 15) and rollers (16a, 16b). The squeegee (14) guides the electric wire (2) into the bath (10). The rollers (16a, 16b) dip the electric wire (2) in the coating solution (C). The squeegee (15) removes the excess of the coating solution (C) from the outer surface of the electric wire (2) and guides the electric wire (2) out of the bath (10). The thickness of the coating layer ranges from 68 to 126 μm.

Description

Wire coating equipment and wires

Technical field

The present invention relates to an outer appearance of a covering portion made of a synthetic resin such as a polychlorinated vinyl for an electric wire.

The present invention relates to an electric wire coating device whose surface is coated with an acrylic resin or the like, and an electric wire.

Field background technology

Various electronic devices are mounted on automobiles and the like as moving bodies. For this reason, the above-mentioned automobiles and the like are provided with a wire harness in order to transmit power from a power supply or the like or control signals from a computer or the like to the electronic device. The wire harness includes a plurality of wires and a connector attached to an end of the wire or the like.

The electric wire includes a conductive core wire and a coating made of an insulating synthetic resin that covers the core wire. The electric wire is a so-called covered electric wire. The connector includes a conductive terminal fitting and an insulating connector housing. The terminal fitting is attached to the end of the electric wire and electrically connected to the core wire of the electric wire. The connector housing is formed in a box shape and accommodates terminal fittings.

When assembling the wire harness, first, the wire is cut into a predetermined length, and then a terminal fitting is attached to an end of the wire. Connect the wires as needed. Then, insert the terminal fitting into the connector housing. Thus, the above-described harness is assembled.

For the wires of the above-mentioned wire harness, it is necessary to identify the size of the core wire, the material of the sheath (change of material due to heat resistance, etc.), and the purpose of use. The intended use is, for example, an airbag, a control signal such as an ABS (Antilock Brake System) or vehicle speed information, or an automobile system (system) using electric wires such as a power transmission system. In order to identify the purpose of use (system) described above, for example, the wires of the wire harness have been formed in a stripe pattern with two different colors on the outer surface, for example. Therefore, conventionally, when a synthetic resin is extruded around a core wire to form a coating, a colorant of a desired color is first mixed into the synthetic resin constituting the coating. Then, a coloring agent having a different color from the coloring agent is applied to a part of the synthetic resin covering the core wire, that is, a part of the outer surface of the covering portion. In this way, a part of the outer surface of the coating has been colored, and the electric wire has been colored in a stripe pattern.

On the other hand, automobiles are used for a long period of time, for example, several years to over ten years. In addition, vehicles are used in cold and hot regions. For this reason, in the electric wires used in automobiles described above, if they are formed in a stripe pattern as described above, the colorant applied later particularly tends to fall from the outer surface of the electric wires with the passage of time.

In addition, since automobiles are used for a long time as described above, new electronic devices may be added during use. For this reason, if the colorant on the outer surface drops as described above, it becomes difficult to identify the electric wires, and it becomes difficult to electrically connect a desired electric wire to an additional electronic device. For this reason, in particular, it is desired that the color of the outer surface of an electric wire used for an automobile does not fade for a long period of time in a severe environment. In order to solve this kind of problem, the applicant of the present invention proposes to coat the surface of the coating with a methacrylic resin or an acrylic resin dissolved in an organic solvent. When coating the outer surface of the covering portion of the electric wire with methacrylic resin or acryl resin, it is conceivable to immerse the electric wire in an organic solvent in which the methacrylic resin or acrylic resin is dissolved. At this time, since the organic solvent evaporates even at room temperature, it is desirable to provide an exhaust device and maintain a good working environment for workers. In addition, when the organic solvent evaporates, the concentration of the methacrylic resin or the acrylic resin changes, and it may be difficult to coat the methacrylic resin or the acrylic resin with a predetermined thickness. For this reason, it is necessary to keep the concentration of the methacrylic resin or the acrylic resin constant.

As described above, when immersing electric wires in an organic solvent in which methacrylic or acrylic resin is dissolved, an exhaust device and a mechanism for keeping the concentration constant are required, and the equipment is large. The tendency was to rise in cost as the product became more compact. This, of course, increases the cost of the wires themselves.

Further, it is desirable that the methacrylic resin or acrylic resin which coats the outer surface of the electric wire has such a thickness that the coloring agent which colored the electric wire adheres to the outer surface of the electric wire and drops.

Therefore, a first object of the present invention is to provide an electric wire coating apparatus that can achieve cost reduction. A second object of the present invention is to provide an electric wire capable of preventing discoloration. Disclosure of the invention

In order to achieve the first object, an electric wire coating apparatus according to the present invention according to claim 1, comprising: an electric wire coating apparatus for coating an outer surface of a covering portion made of a synthetic resin of an electric wire with methacrylic resin or acryl resin. A storage tank that is hermetically sealed and contains a coating liquid containing a methacrylic resin or an acrylic resin, and a solvent that dissolves the methacrylic resin or the acrylic resin; Guide means for immersing the electric wire immersed in the coating liquid out of the storage tank, wherein the guide means removes excess coating liquid attached to the outer surface of the electric wire, and The coating liquid is characterized in that the coating liquid is prevented from leaking outside. According to this, a storage tank that stores a coating liquid composed of a methacrylic resin or an acrylic resin and a solvent that dissolves the methacrylic resin or the ataryl resin is closed. In addition, a guiding means for guiding the electric wire into the storage tank and immersing it in the coating liquid, and then guiding the wire out of the storage tank prevents the coating liquid from leaking out of the storage tank. For this reason, the coating liquid is confined in the storage tank.

In order to achieve the second object, an electric wire according to the present invention according to claim 2 includes a conductive core wire, a covering portion covering the core wire and made of a synthetic resin, and an outer surface of the covering portion. And a coating layer to be coated, wherein the coating layer is made of methacrylic resin, and the thickness of the coating layer is 68 m or more and 126 μΐη or less. According to this, since the thickness of the coating layer made of methacrylic resin is at least 68 πι and at most 126 μπι, the coating layer can reliably prevent color fading of the electric wire.

The methacrylic resin described in the present specification is a resin obtained by polymerizing methacrylic acid or methacrylic acid ester. In particular, methyl methacrylate polymer is the best among all plastics in terms of transparency and weather resistance, and is widely used in construction, lighting, signboards, sundries, and other industrial parts. In addition, demands for various methacrylates, for example, ethyl methacrylate, n-butyl, iso-butynole, hexyl, laurinole, and the like are increasing as paints, adhesives, and for finishing textiles, leather, and paper. Furthermore, when methacrylic acid is copolymerized to introduce a power poxyl group into the polymer, properties such as improved adhesiveness, water solubility, and cross-linking property are imparted, so that it is widely used.

According to a third aspect of the present invention, in the electric wire according to the second aspect, the thickness of the coating layer is not less than 87 // m and not more than 126 μπι. .

According to this, since the thickness of the coating layer made of methacrylic resin is not less than 87 μm and not more than 126 μηι, the coating layer can more reliably prevent color fading of the electric wire.

The electric wire according to the present invention according to claim 4 is the electric wire according to claim 2, wherein the thickness of the coating layer is not less than 107 / zm and not more than 126 ^ m. I have.

According to this, since the thickness of the coating layer made of methacrylic resin is not less than 107 μm and not more than 126 / m, the color loss of the electric wire can be more reliably prevented by the coating layer.

In order to achieve the second object, an electric wire according to the present invention according to claim 5 includes a conductive core wire, a covering portion covering the core wire and made of a synthetic resin, and an outer surface of the covering portion. And a coating layer to be coated, wherein the coating layer is made of acrylic resin, and the thickness of the coating layer is not less than 45.5 μπι and not more than 85 μm. I have.

According to this, the thickness of the coating layer made of atari resin is 45.5 μm. Since it is not less than m and not more than 85 μπι, the coating layer can surely prevent discoloration of the electric wire.

The acrylic resin described in this specification is a resin obtained by polymerizing acrylic acid and its derivatives. Polymers and copolymers such as acrylic acid, acrylic acid ester, acrylamide, atalylonitrile, methacrylic acid, and methacrylic acid ester are included. Of these, acrylic acid ester polymers are widely used as adhesives and paints, and methyl methacrylate polymers are widely used as transparent molding materials.

The electric wire of the present invention according to claim 6 is the electric wire according to claim 5, wherein the thickness of the coating layer is not less than 59 Atm and not more than 85 Im.

According to this, since the thickness of the coating layer made of the acrylic resin is not less than 59 // m and not more than 85 μπι, the coating layer can more reliably prevent discoloration of the electric wire.

The electric wire of the present invention according to claim 7 is the electric wire according to claim 5, wherein the thickness of the coating layer is 72 or more and 85 m or less.

According to this, since the thickness of the coating layer made of an acrylic resin is not less than 72 μπι and not more than 85 μπι, the coating layer can more reliably prevent color fading of the electric wire. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram showing a configuration of an electric wire coating apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a wire on which a coating layer has been formed by the wire coating apparatus of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is an explanatory diagram showing a configuration of an electric wire coating apparatus according to a second embodiment of the present invention. FIG. 5 is an explanatory diagram showing a change in the degree of discoloration with respect to the thickness of a coating layer formed on a sheet material of the same material as the covering portion of the electric wire shown in FIG. FIG. 6 is an explanatory diagram showing conditions and the like when the degree of discoloration is measured. (A) is a diagram schematically showing conditions and the like when the degree of discoloration shown in FIG. 5 is measured. FIG. 5B is a plan view showing the sheet material used in FIG. 5A and a sheet material to be compared. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an electric wire coating apparatus and an electric wire according to a first embodiment of the present invention will be described with reference to FIG. 1 to FIG. An electric wire coating device (hereinafter simply referred to as a coating device) 1 shown in FIG. 1 according to the first embodiment of the present invention is an outer surface 3 a of a coating portion 3 of the electric wire 2 shown in FIGS. 2 and 3. Then, a coating layer 4 is formed.

The electric wire 2 forms a wire harness that is routed to a vehicle or the like as a moving body. The electric wire 2 includes a conductive core wire 5 and an insulating coating 3 as shown in FIGS. The core wire 5 is formed by twisting a plurality of strands. The wires constituting the core wire 5 are made of a conductive metal. Further, the core wire 5 may be composed of a single wire.

The coating part 3 is made of polyvinyl chloride (PVC) as a synthetic resin. The covering part 3 covers the core wire 5. The electric wire 2 is formed in a round shape in cross section by the core wire 5 and the covering portion 3 covering the core wire 5. The coating layer 4 is formed on the outer surface 3 a of the covering portion 3.

At least the outer surface 3a of the coating 3 is colored in a desired color. The outer surface 3a may be colored in a desired color by mixing a colorant of a desired color into the synthetic resin constituting the covering portion 3. A liquid colorant of a desired color may be applied to the outer surface 3a of the non-colored or white-colored coating portion 3 by, for example, being sprayed onto the outer surface 3a to be colored to a desired color.

By changing these colors to various colors, the electric wires 2 can be distinguished from each other. The above-mentioned colors indicate the wire type and system of wire 2 of the wire harness. Used to perform such things as: That is, the colors described above indicate the intended use of each wire 2 of the wire harness and are used to identify the intended use. The coloring material applied to the outer surface 3a is a liquid material in which a coloring material (an industrial organic substance) is dissolved or dispersed in water or another solvent. Organic substances include dyes and pigments (mostly organic substances and synthetic products), and sometimes dyes are used as pigments and pigments are used as dyes. As a more specific example, the coloring material in this specification indicates both a coloring liquid and a paint.

The term “colored liquid” refers to a substance in which a dye is dissolved or dispersed in a solvent, and the term “paint” refers to a substance in which a pigment is dispersed in a dispersion. Therefore, when the outer surface 3a of the electric wire 2 is colored with the coloring liquid, the dye penetrates into the coating portion 3, and when the outer surface 3a of the electric wire 2 is colored with paint, the pigment soaks into the coating portion 3. And adhere to outer surface 3a. That is, coloring the outer surface 3a of the electric wire 2 in this specification means that the entire or a part of the outer surface 3a of the electric wire 2 is dyed with a dye, and that the entire outer surface 3a of the electric wire 2 is entirely or partially colored. Indicates that the pigment is applied to the part.

Further, it is desirable that the solvent and the dispersion have an affinity with the synthetic resin constituting the covering portion 3 of the electric wire 2. In this case, the dye will surely penetrate into the coating portion 3, and the pigment will surely adhere to the outer surface 3a of the coating portion 3.

Further, the term “drip ejection” indicates that the liquid coloring material is urged and ejected toward the outer surface 3 a of the fixed amount of electric wire 2 in a state of a droplet, that is, a state of a droplet.

The coating layer 4 is made of methacrylic resin. In the illustrated example, the coating layer 4 is made of polymethylmethacrylate (PMMA). The methacrylic resin described in the present specification is a resin obtained by polymerizing methacrylic acid or methacrylic acid ester. In particular, methyl methacrylate polymer is the best among all plastics in terms of transparency and weather resistance, and is widely used in construction, lighting, signboards, sundries, and other industrial parts. In addition, demand for various methacrylates, for example, metatali / ethyl oleate, n-butynole, iso-butynole, hexinole, laurinole, etc. is increasing as a finish for paints, adhesives, fibers, leather and paper. . Furthermore, when methacrylic acid is copolymerized to introduce a power poxyl group into a polymer, properties such as improved adhesiveness, water solubility, and cross-linking property are imparted, so that it is widely used. The coating layer 4 covers the covering portion 3 of the electric wire 2 over the entire circumference. The thickness T (shown in FIG. 3) of the coating layer 4 is uniform. The thickness T of the coating layer 4 is not less than 68 μηι and not more than 126 μπι. For this reason, the cross section of the electric wire 2 and the coating layer 4 formed on the outer surface 3 a of the covering portion 3 of the electric wire 2 are formed in a round shape.

The electric wire 2 having the above-described configuration has the coating layer 4 formed on the outer surface 3a. For this reason, it is possible to prevent the plasticizer in the PVC constituting the covering portion 3 from migrating from the outer surface 3a of the electric wire 2 to the outside over time. Therefore, the electric wire 2 can prevent the coating portion 3 from deteriorating, and prevent the mechanical strength and the like from decreasing over time.

Further, since the coating layer 4 is formed on the outer surface 3a, it is possible to prevent the above-mentioned coloring agent or coloring material from migrating from the outer surface 3a of the electric wire 2 to the outside as time passes. Therefore, the wire 2 can prevent the coloring agent or the coloring material which colored the outer surface 3a of the covering portion 3 from dropping. That is, the electric wire 2 can prevent the outer surface 3a from discoloring.

As shown in FIG. 1, the coating apparatus 1 includes a storage tank 10 and a guide mechanism 11 as guide means. The storage tank 10 includes a lower case 12 and an upper case 13. The lower case 12 is formed in a box shape having an upper opening. The upper case 13 is formed in a box shape having an opening below. The lower case 12 and the upper case 13 are attached to each other with the openings facing each other. The space between the lower case 12 and the upper case 13 is kept watertight (liquid tight). When attached to each other, the outer walls of the lower case 12 and the upper case 13 are continuous with each other. When they are attached to each other, the space inside the lower case 12 and the upper case 13 is sealed. Thus, the inside space of the storage tank 10 is sealed.

The storage tank 10 stores a coating liquid C composed of a methacrylic resin and a solvent that dissolves the methacrylic resin. In the illustrated example, PMMA is used as the methacrylic resin. In addition, well-known alcohols, polyhydric alcohols, ketones, and esters can be used as the solvent. A solvent that evaporates at room temperature is desirable. In the illustrated example, acetone is used as an example of a ketone solvent. The guide mechanism 11 includes a pair of squeegees 14 and 15 and a plurality of rollers 16. The squeegees 14 and 15 are attached to the opposing peripheral walls of the cases 12 and 13 described above. The squeegees 14 and 15 are arranged above the level of the coating liquid C in the storage tank 10.

One of the pair of squeegees 14, 15 on the left side in FIG. 1 guides the electric wire 2 from outside the storage tank 10 into the storage tank 10. The squeegee 14 has a hole 17 through which the electric wire 2 can pass. The hole 17 passes through one squeegee 14 as a matter of course, and has a round planar shape. The inner diameter of the hole 17 is equal to the outer diameter of the electric wire 2. When the electric wire 2 is passed through the hole 17, the space between the squeegee 14 and the electric wire 2 becomes watertight (liquid tight). Therefore, when the electric wire 2 is passed through the hole 17, the coating liquid C in the storage tank 10 is prevented from leaking out of the storage tank 10 from between the one squeegee 14 and the electric wire 2.

The other squeegee 15 on the right side in FIG. 1 guides the electric wire 2 in the storage tank 10 out of the storage tank 10. The other squeegee 15 is provided with a hole 18 through which the electric wire 2 can pass. The hole 18, of course, penetrates the other squeegee 15, and has a round planar shape. The inner diameter of the hole 18 is equal to the sum of the outer diameter of the electric wire 2 and a value obtained by doubling the desired thickness T of the coating layer 4. Also, when the wire 2 having the coating liquid C adhered to the outer surface 3 a is passed through the hole 18, the coating liquid C having a desired thickness T or more is applied from the outer surface 3 a of the covering portion 3 of the wire 2. Remove.

Thus, the other squeegee 15 removes the excess coating liquid C adhered to the outer surface 3 a of the electric wire 2. Further, when the electric wire 2 is passed through the hole 18, the coating liquid C in the storage tank 10 is prevented from leaking out of the storage tank 10 from between the other squeegee 15 and the electric wire 2. The squeegees 14 and 15 are disposed above the level of the coating liquid C in the storage tank 10 and the inner diameters of the holes 17 and 18 are formed as described above. 1 is configured to prevent the coating liquid C from leaking out of the storage tank 10.

Further, the pair of squeegees 14 and 15 described above are made of synthetic rubber such as ethylene-propylene-diene three-dimensional assembly (Ethylene-Propylene-Diene Methylene Linkage: EPDM), silicone rubber, and urethane rubber. In the illustrated example, three rollers 16 are provided. These rollers 16 are accommodated in the storage tank 10 and are arranged in a direction from one squeegee 14 to the other squeegee 15. These rollers 16 are rotatably supported in the storage tank 10. The rotation centers of these rollers 16 are parallel to each other, and are orthogonal to the direction from one squeegee 14 to the other squeegee 15.

Of the three rollers 16, both ends (that is, located near the pair of squeegees 14 and 15) two rollers 16 (hereinafter denoted by reference numeral 16 a) are located above the liquid level S of the coating liquid C in the storage tank 10. positioned. Therefore, the coating liquid C does not adhere to the roller 16a. One of the rollers 16 (referred to below as 16b) located at the center of the three rollers 16 is partially immersed in the coating liquid C in the storage tank 10. Of course, the coating liquid C adheres to the roller 16b. The three rollers 16a and 16b described above rotate along arrows Ml, M2 and M3 in FIG. 1 in synchronization with each other, so that the rollers 17a and 16b enter the storage tank 10 from the hole 17 of one of the squeegees 14. The led electric wire 2 is moved toward the other squeegee 15. At this time, the electric wire and the electric wire 2 are passed above the two rollers 16a and below the central roller 16b. In this way, the rollers 16a and 16b immerse the electric wire 2 guided into the storage tank 10 through the hole 17 of one squeegee 14 in the coating liquid C in the storage tank 10, and then fix the other squeegee. It is led out of the storage tank 10 through the hole 18 of 15. The guide mechanism 11 configured as described above guides the electric wire 2 from the hole 17 of one squeegee 14 into the storage tank 10. Then, the electric wires 2 passed through the storage tank 10 are immersed in the coating liquid C by the rollers 16a and 16b. The guide mechanism 11 guides the electric wire 2 immersed in the coating liquid C to the outside of the storage tank 10 through the hole 18 of the other squeegee 15.

The inner diameters of the holes 17 and 18 of the pair of squeegees 14 and 15 are formed as described above, so that the guide mechanism 11 can remove excess coating liquid adhering to the outer surface 3 a of the electric wire 2. C is removed by the other squeegee 15 and the coating liquid C is prevented from leaking out of the storage tank 10. Thus, the coating apparatus 1 forms the coating layer 4 to have a thickness Τ of 68 μπι or more and 126 // m or less. When the coating layer 4 is formed on the outer surface 3a of the electric wire 2 using the coating apparatus 1 having the above-described configuration, the electric wire 2 is guided into the storage tank 10 through the hole 17 of one of the squeegees 14. . Then, after passing the electric wire 2 above the roller 16a near the one squeegee 14 and then below the roller 16b, the electric wire 2 passes above the roller 16a near the other squeegee 15 above. Let it through. Then, the electric wire 2 is guided to the outside of the storage tank 10 through the hole 18 of the other squeegee 15.

After that, the coating liquid C is stored in the storage tank 10. At this time, part of the central row La 1 6 b is dipped into the coating solution C, and the other roller 1 6 _a is a state away from the liquid surface S of the quotes queuing solution C. Then, the rollers 16a and 16b are synchronized, and rotate along arrows M1, M2 and M3 in FIG. The electric wire 2 is led into the storage tank 10 through the hole 17 of the one squeegee 14 and immersed in the coating liquid C in the storage tank 10, and then the storage tank is passed through the hole 18 of the other squeegee 15. Guide outside 10 Thus, the coating layer 4 is formed on the outer surface 3a of the electric wire 2.

According to the present embodiment, the storage tank 10 that stores the coating liquid C including the metharyl resin and the solvent that dissolves the metharyl resin is sealed. Further, the guide mechanism 11 for guiding the electric wire 2 into the storage tank 10 and immersing it in the coating liquid C, and then guiding the electric wire 2 out of the storage tank 10 prevents the coating liquid C from leaking out of the storage tank 10. Therefore, the coating liquid C is confined in the storage tank 10.

Therefore, it is possible to prevent the solvent of the coating liquid C from evaporating and coming out of the storage tank 10. Therefore, an exhaust device for exhausting the solvent is not required, and a mechanism for keeping the concentration of the coating liquid C in the storage tank 10 constant is not required. Therefore, the size and cost of the coating apparatus 1 itself can be reduced, and the cost of the electric wire 2 can be reduced.

Further, since the thickness T of the coating layer 4 made of the methacrylic resin of the electric wire 2 described above is 68 μππ or more and 126 μπι or less, the color loss of the electric wire 2 can be reliably prevented by the coating layer 4. . In particular, in the electric wire 2 for automobiles, the coating layer 4 is made of methacrylic resin and formed to the thickness Τ described above, so that it does not discolor even when used in a severe environment for a long time. it can.

Next, an electric wire coating apparatus according to a second embodiment of the present invention (hereinafter simply referred to as “ This will be described with reference to FIG. Also in this embodiment, the coating apparatus 20 forms the coating layer 4 on the outer surface 3a of the electric wire 2 shown in FIG. 2 described in the first embodiment. Also in the present embodiment, the coating layer 4 is made of a methacrylic resin, and has a thickness T of 68 μηι or more and 126 μιη or less.

As shown in FIG. 4, the coating apparatus 20 includes a storage tank 21 and a pair of squeegee members 22 and 23 as guide means. The storage tank 21 includes a pair of case members 24. The case member 24 is formed in a box shape with one wall 25 and a plurality of peripheral walls 26 connected to the outer edge of the wall 25. An edge of the plurality of peripheral walls 26 on a side away from the one wall 25 forms an opening 27. Thus, case member 24 is formed in a box shape having opening 27 in one direction. The pair of case members 24 are arranged with the openings 27 facing each other with a space therebetween.In addition, a pipe 28 is connected to one of the case members 24 located at the top in FIG. ing. The pipe 28 guides the coating liquid C between the pair of case members 24. The coating liquid C includes a methacrylic resin and a solvent for dissolving the methacrylic resin, as in the first embodiment described above.

In the storage tank 21 having the above-described configuration, a pair of squeegee members 22 and 23 are attached to a pair of case members 24 as described later, and are surrounded by the case member 24 and the squeegee members 22 and 23. Space is sealed. The storage tank 21 stores the coating liquid C supplied through the pipe 28 in the space, and also prevents the coating liquid C from leaking from the space to the outside.

The pair of squeegee members 22 and 23 are housed in a housing tank 21. One squeegee member 22 of the pair of squeegee members 22 and 23 is formed in a truncated cone shape. One of the squeegee members 22 is attached to both of the pair of case members 24 in such a manner that the bottom surface is overlapped with the inner surfaces of the peripheral walls 26 of the pair of case members 24 facing each other. The space between one squeegee member 22 and the pair of case members 24 is water-tight (liquid-tight). A hole 29 is provided at the center of one squeegee member 22. The hole 29, of course, penetrates the squeegee member 22. The hole 29 has a round planar shape. The inner diameter of the hole 29 is substantially equal to the outer diameter of the electric wire 2. When one squeegee member 22 is attached to the pair of case members 24, the hole 29 communicates the inside and outside of the pair of case members 24. The hole 29 allows the electric wire 2 to pass therethrough. Further, when the electric wire 2 is passed through the hole 29, the space between the squeegee member 22 and the electric wire 2 becomes water-tight (liquid-tight). For this reason, when the electric wire 2 is passed through the hole 29, the coating liquid C in the storage tank 21 is prevented from leaking out of the storage tank 21 from between the one squeegee member 22 and the electric wire 2.

The other squeegee member 23 is formed in a disk shape. The other squeegee member 23 is formed such that the thickness T gradually decreases from the outer edge toward the center. The outer edge of the other squeegee member 23 is fixed to the inner surface of one wall 25 of both the pair of case members 24. The space between the other squeegee member 23 and the pair of case members 24 is water-tight (liquid-tight).

A hole 30 is formed at the center of the other squeegee member 23. The hole 30 has a round planar shape. The hole 30 faces the hole 29 of the squeegee member 22. The inner diameter of the hole 30 is equal to the sum of the outer diameter of the electric wire 2 and twice the thickness T of the coating layer 4. The other squeegee member 23 is a pair of case members

When attached to 24, hole 30 communicates the inside and outside of the pair of case members 24. When the wire 2 having the coating liquid C adhered to the outer surface 3 a is passed through the hole 30, the coating liquid C having a desired thickness T or more is applied to the outer surface of the coating portion 3 of the wire 2.

3 Remove from a.

Thus, the other squeegee member 23 removes excess coating liquid C attached to the outer surface 3a of the electric wire 2. When the electric wire 2 is passed through the hole 30, the coating liquid C in the storage tank 21 is prevented from leaking out of the storage tank 21 from between the other squeegee member 23 and the electric wire 2. By forming the inner diameters of the holes 29 and 30 as described above, the pair of squeegee members 22 and 23 are configured to prevent the coating liquid C from leaking out of the storage tank 21. . Thus, the coating apparatus 20 forms the coating layer 4 to a thickness 厚 of 68 μπι or more and 126 μm or less. The pair of squeegee members 22, 23 configured as described above guide the electric wire 2 into the storage tank 21 through the hole 29 of one squeegee member 22. Connect the led wire 2 to the cord in the space. After being immersed in the squeezing liquid C, the squeegee member 23 is led out of the storage tank 21 through the hole 30 of the other squeegee member 23. Further, in the squeegee members 22 and 23 described above, at least the inner surfaces of the holes 29 and 30 are made of diamond or ceramics. For this reason, even when the electric wire 2 is passed through the holes 29 and 30, the pair of squeegee members 22 and 23 are hardly worn.

When the coating layer 4 is formed on the outer surface 3a of the electric wire 2 by using the coating apparatus 20 having the above-described configuration, the electric wire 2 is passed through the hole 29 of the one squeegee member 2 Lead inside. Then, the electric wire 2 is guided to the outside of the storage tank 21 through the hole 30 of the other squeegee member 23.

Thereafter, the coating liquid C is supplied to the space in the storage tank 21 through the pipe 28. At this time, the space is filled with the coating liquid C. Then, the electric wire 2 is moved from one squeegee member 22 to the other squeegee member 23 along the arrow N. The electric wire 2 is guided into the storage tank 21 through the hole 29 of the one squeegee member 22, is immersed in the coating liquid C in the storage tank 21, and then is stored through the hole 30 of the other squeegee member 23. 2 1 lead outside. Thus, the coating layer 4 is formed on the outer surface 3a of the electric wire 2.

According to the present embodiment, the storage tank 21 for storing the coating liquid C composed of metharyl resin and a solvent for dissolving the methacryl resin is sealed. Also, after the electric wire 2 is led into the storage tank 21 and dipped in the coating liquid C, the pair of squeegee members 2 and 2 3 guided to the outside of the storage tank 21 leak the coating liquid C out of the storage tank 21. To prevent that. Thus, the coating liquid C is confined in the storage tank 21.

Therefore, it is possible to prevent the solvent of the coating liquid C from evaporating and coming out of the storage tank 21. Therefore, an exhaust device for exhausting the solvent is not required, and a mechanism for keeping the concentration of the coating liquid C in the storage tank 21 constant is not required. Therefore, the size and cost of the coating apparatus 20 itself can be reduced, and the cost of the electric wire 2 can be reduced.

Further, also in the present embodiment, since the thickness T of the coating layer 4 made of methacrylic resin of the electric wire 2 is not less than 68 and not more than 126 m, the color of the electric wire 2 is Falling can be reliably prevented. In particular, electric wires for automobiles In the case of 2, since the coating layer 4 is made of methacrylic resin and has the thickness T described above, it is possible to prevent discoloration even when used in a severe environment for a long time.

In the first and second embodiments described above, the coating liquid C contained in the storage tanks 10 and 21 is composed of a methacrylic resin and a solvent that dissolves the methacrylic resin, and the coating layer 4 is composed of the methacrylic resin. Become. However, in the present invention, the coating liquid C contained in the storage tanks 10 and 21 may be composed of an acrylic resin and a solvent for dissolving the acrylic resin, and the coating layer 4 may be composed of the acrylic resin.

When the coating layer 4 is made of an acrylic resin, the thickness T is set to be equal to or more than 45.5 μτη and equal to or less than 85 μπι. At this time, the inner diameters of the holes 17 and 18 of the squeegees 14 and 15 and the inner diameters of the holes 29 and 30 of the squeegee members 22 and 23 are set so that the thickness of the coating layer 4 is 45.5 μm. The dimensions are not less than πι and not more than 85 μm. The coating liquid C is composed of an attaryl resin and a solvent for dissolving the acryl resin. The coating layer 4 is composed of an acrylic resin, and the thickness 1: of the coating layer 4 is set to 45.5 μπι or more and 85 In the following cases, the coating layer 4 can reliably prevent the wire 2 from discoloring. In particular, in the electric wire 2 for automobiles, the coating layer 4 is made of ataryl resin and has the thickness T described above, so that even if used in a severe environment for a long period of time, discoloration will not occur. Can be prevented.

Next, the inventors of the present invention formed a plurality of coating layers 4 having different thicknesses T in order to confirm the effect of the coating layer 4 of the electric wire 2 of the present invention. The plurality of coating layers 4 are made of the same material as the covering portion 3 of the electric wire 2, and the outer surface of the sheet material 100 a (shown in FIG. 6) in which the outer surface 3 a of the electric wire 2 is similarly colored. Formed. As the present invention product 1 and the present invention product 2, a plurality of sheet materials 100a having different thicknesses T of the coating layer 4 made of methacrylic resin or acryl resin were prepared. Further, as a comparative example, a sheet material having the same material and color as the sheet material 100a and having no coating layer 4 was prepared.

Thus, the product 1 of the present invention, in which the coating layer 4 indicated by the solid line in FIG. 5 is made of methacrylic resin-based PMMA as a methacrylic resin, and the coating layer indicated by the solid line in FIG. Inventive product 2 in which the coating layer 4 is made of thermoplastic acrylic bead resin using various homopolymers and copolymers produced using acrylic resin and methacrylic resin-based monomers as in the case of PMMA as acrylic resin, The comparative example in which the coating layer 4 indicated by the two-dot chain line in the figure was not formed was used.

In this experiment, as shown in Fig. 6 (a), the sheet material 100a or the colored sheet material without the coating layer 4 was uncolored and coated with a coating layer.

4 is not formed and overlaps with a sheet material 100 c made of the same material as that of the covering portion 3. These sheet materials 100a and 100c are formed by a pair of members made of glass or the like.

A pressure P (for example, 140 kgf / cm ² ) was applied between the sheets 101 so that the sheet materials 100 a and 100 c approached each other.

Then, it was left for 24 hours in a room or the like heated to 80 ° C. with the pressure P applied. After standing for 24 hours, the color of the outer surface of the sheet material 100c was compared with the color of the outer surface of the uncolored sheet material 100b like the sheet material 100c. The color loss of the sheet material 100 a or the colored sheet material on which the coating layer 4 is not formed, ie, from the sheet material 100 a or the sheet material on which the coating layer 4 is not formed, to the sheet material 100 The degree of color that moved (moved) to 0c was measured. Figure 5 shows the results.

The color difference (ΔΕ) on the vertical axis in FIG. 5 refers to the sheet material 10 Ob (shown in FIG. 6 (b)) as a reference in the present invention product 1 and the present invention product 2 as a reference. The degree of color in which the coloring material under the coating layer 4 of the sheet material 100a has moved (transferred) to the sheet material 100c after 24 hours has elapsed under the conditions shown in FIG. 6 (a) is shown. . That is, the coating of the sheet material 100a after 24 hours has passed under the conditions shown in FIG. 6 (a) based on the sheet material 100b (shown in FIG. 6 (b)) as a reference. The degree to which the coloring material under layer 4 has fallen from the outer surface (hereinafter referred to as color fading) is shown.

Further, in the comparative example, based on the sheet material 100b as a reference, the coloring material of the sheet material having not been formed with the coating layer 4 having passed for 24 hours under the conditions shown in FIG. 6 (a). Indicates the degree of color transferred (shifted) to the sheet material 100c. That is, the coloring of the sheet material without the coating layer 4 having passed for 24 hours under the conditions shown in Fig. 6 (a) with reference to the sheet material 100b as the reference object. It indicates the degree to which the material has fallen from the outer surface (hereinafter referred to as discoloration). The sheet material 100b is non-colored and does not have the coating layer 4 and is made of the same material as the covering portion 3 similarly to the sheet material 100c, and is not subjected to the above-described pressurization and heating. .

FIG. 5 shows that when the color difference (ΔΕ) increases, that is, when the discoloration increases, the coloring material falls more from the outer surface, and the effect of the coating layer 4 decreases. Further, it shows that when the color difference (ΔΕ) is small, that is, the color fading is small, the coloring material is less likely to fall off the outer surface, and the effect of the coating layer 4 is increased.

In the comparative example indicated by the two-dot chain line in FIG. 5, the color difference (ΔΕ) is 65. Therefore, when the color difference (ΔΕ) exceeds 65, the color loss is larger than that in the case where the coating layer 4 is not formed. Therefore, when the color difference (ΔΕ) exceeds 65, it indicates that the effect of the coating layer 4 is completely absent.

According to FIG. 5, it was clear that the color difference (ΔΕ) of the product 1 of the present invention was less than 30 when the thickness T of the coating layer 4 was 68 μπι or more and 126 μπι or less. For this reason, when the thickness の of the coating layer 4 is 68 / im or more and 126 m or less, the color difference (ΔE), that is, the degree of color fading, is lower than that of the case where the coating layer 4 is not provided. It became clear that it was less than half.

In addition, in the product 1 of the present invention, when the thickness T of the coating layer 4 was 87 μηι or more and 126 μπι or less, it was found that the color difference (ΔΕ) was less than 20. For this reason, when the thickness の of the coating layer 4 is 87 / m or more and 126 / m or less, the color difference (ΔΕ), that is, the degree of color fading, is lower than that of the case where the coating layer 4 is not provided. It became clear that it was less than one third.

Further, in the product 1 of the present invention, when the thickness T of the coating layer 4 was not less than 107 / ίΐη and not more than 126 im, it was clear that the color difference (ΔΕ) was less than 10. Therefore, when the thickness T of the coating layer 4 is 107 μηι or more and 126 m or less, the color difference (ΔΕ), that is, the degree of color fading is about 6 minutes compared to the case where the coating layer 4 is not provided. It became clear that it became 1 or less.

According to FIG. 5, in the product 2 of the present invention, the thickness T of the coating layer 4 is 45. It was clear that the color difference (ΔΕ) was less than 30 when the above and below 85 μπι. For this reason, the thickness の of the coating layer 4 is 45.

When it was 85 μπι or less, it became clear that the color difference (ΔΕ), that is, the degree of discoloration, was about half or less as compared with the case where the coating layer 4 was not provided. In addition, it was revealed that the color difference (ΔΕ) of the product 1 of the present invention was less than 20 when the thickness の of the coating layer 4 was 59 μπι or more and 85 μπι or less. For this reason, when the thickness の of the coating layer 4 is 59 m or more and 85 μπι or less, the color difference (ΔΕ), that is, the degree of color loss is about 3 minutes compared to the case where the coating layer 4 is not provided. It became clear that it became 1 or less.

Furthermore, it was found that the color difference (ΔΕ) of the product 1 of the present invention was less than 10 when the thickness の of the coating layer 4 was not less than 72 μπι and not more than 85 μΐη. Therefore, if the thickness の of the coating layer 4 is not less than 72 / zm and not more than 85 / m, the color difference (Δ), that is, the degree of discoloration, is lower than that of the case where the coating layer 4 is not provided. It became clear that it was about 1/6 or less.

Therefore, in the first and second embodiments described above, the thickness T of the coating layer 4 made of a methacrylic resin is set to 68 μπι or more and 126 μιη or less. Therefore, it has been clarified that the coating layer 4 can reliably prevent the wire 2 from discoloring. In particular, it has been clarified that the electric wire 2 for automobiles can prevent discoloration even when used in a severe environment for a long time.

In the first and second embodiments described above, the thickness の of the coating layer 4 made of an acrylic resin is 45.5 μπι or more and 85 μΐη or less. For this reason, it became clear that the coating layer 4 can surely prevent discoloration of the electric wire 2. In particular, it has been clarified that the electric wire 2 for automobiles can prevent discoloration even when used in a severe environment for a long time.

In the first and second embodiments described above, the thickness コーティング of the coating layer 4 made of a methacrylic resin is 68 μπι or more and 126 / zm or less. However, in the present invention, the thickness T of the coating layer 4 made of a methacrylic resin may be 8 or more and 126 / zm or less.

In this case, as shown in Fig. 5, the color difference (ΔΕ) does not exceed 20. However, it became clear that the coating layer 4 can more reliably prevent the color fading of the electric wire 2. In particular, it has been clarified that the electric wire 2 for automobiles can be prevented from being discolored even when used in a severe environment for a long time.

Further, in the present invention, the thickness T of the coating layer 4 made of a methacrylic resin may be not less than 107 / zm and not more than 126 / xm. In this case, as shown in FIG. 5, the color difference (ΔΕ) did not exceed 10 and it became clear that the coating layer 4 could more reliably prevent the wire 2 from discoloring. In particular, it has become clear that the electric wire 2 for automobiles can more reliably prevent discoloration even when used in a severe environment for a long time.

In the first and second embodiments described above, the thickness T of the coating layer 4 made of an acrylic resin is not less than 45.5 m and not more than 85 / xm. However, in the present invention, the thickness T of the coating layer 4 made of an acrylic resin may be not less than 59 μπι and not more than 85 μπι.

In this case, as shown in FIG. 5, the color difference (ΔΕ) did not exceed 20 and it became clear that the coating layer 4 could more reliably prevent the color loss of the electric wire 2. In particular, it has been clarified that the electric wire 2 for automobiles can be prevented from being discolored even when used in a severe environment for a long time.

In the present invention, the thickness の of the coating layer 4 made of an acrylic resin may be not less than 72 μm and not more than 85 μππ. In this case, as shown in FIG. 5, the color difference (ΔΕ) did not exceed 10 and it became clear that the coating layer 4 could more reliably prevent the color drop of the electric wire 2. In particular, it has been clarified that the electric wire 2 for automobiles can more reliably prevent discoloration even when used in a severe environment for a long time. .

Further, in the above-described embodiment, the electric wire 2 constituting the wire harness arranged in the vehicle is described. However, the electric wire 2 manufactured by the manufacturing apparatus 1 of the present invention is not limited to an automobile, but may be used for various electronic devices such as a portable computer and various electric machines.

Industrial applicability

As described above, the present invention described in claim 1 is based on metharyl resin or acryl. A storage tank for storing a coating liquid composed of a resin and a solvent that dissolves a methacrylic resin or an acrylyl resin is sealed. In addition, a guiding means for guiding the electric wire into the coating tank and dipping the wire into the coating liquid, and then guiding the wire out of the storage tank prevents the coating liquid from leaking out of the storage tank. Therefore, the coating liquid is confined in the storage tank.

Therefore, it is possible to prevent the solvent of the coating liquid from evaporating and coming out of the storage tank. Therefore, an exhaust device for exhausting the solvent is not required, and a mechanism for maintaining a constant concentration of the coating solution in the storage tank is not required. Therefore, the size and cost of the wire coating device itself can be reduced, and the cost of the wire can be reduced.

According to the second aspect of the present invention, since the thickness of the coating layer made of methacrylic resin is 68 m or more and 126 / m or less, the color loss of the electric wire can be reliably prevented by the coating layer. In particular, in automotive wires, the coating layer is made of methacrylic resin and has the thickness described above, so that it is possible to prevent discoloration even when used in a harsh environment for a long time. '' According to the third aspect of the present invention, since the thickness of the coating layer made of methacrylic resin is 87 μππ or more and 126 μm or less, the coating layer more reliably prevents discoloration of electric wires. it can. In particular, in automotive wires, the coating layer is made of methacrylic resin and has the thickness described above, so even if used in a harsh environment for a long period of time, it will further prevent discoloration. it can.

According to the fourth aspect of the present invention, since the thickness of the coating layer made of methacrylic resin is not less than 107 // m and not more than 126 μπι, the discoloration of the electric wire is further ensured by the coating layer. Can be prevented. In particular, in the case of electric wires for automobiles, the coating layer is made of metharyl resin and formed to the above-mentioned thickness, so that even if used in a severe environment for a long time, it is possible to further prevent discoloration. . According to the fifth aspect of the present invention, since the thickness of the coating layer made of an acrylic resin is 45.5 or more and 85 Azm or less, the color loss of the electric wire can be reliably prevented by the coating layer. In particular, in the case of electric wires for automobiles, the coating layer is made of acryl resin and formed to the above-mentioned thickness. Even when used for environmental protection, it is possible to prevent color fading.

According to the sixth aspect of the present invention, since the thickness of the coating layer made of an acrylic resin is not less than 59 μηι and not more than 85 μηι, the coating layer can more reliably prevent color fading of the electric wire. In particular, in automotive electric wires, the coating layer is made of acryl resin and is formed to the above-mentioned thickness, so even if it is used in a severe environment for a long time, it will not discolor. More can be prevented.

According to the present invention described in claim 7, since the thickness of the coating layer made of an acrylic resin is not less than 72 μπι and not more than 85, color fading of the electric wire can be more reliably prevented by the coating layer. In particular, in electric wires for automobiles, the coating layer is made of acrylic resin and formed to the above-mentioned thickness, so that even if used in a harsh environment for a long period of time, discoloration is further prevented. it can.

Claims

The scope of the claims

1. In an electric wire coating apparatus for coating the outer surface of a covering portion made of a synthetic resin of an electric wire with methacrylic resin or acryl resin,

A storage tank which is hermetically sealed and stores a coating liquid comprising a methacrylic resin or an acrylic resin and a solvent for dissolving the methacrylic resin or the acrylic resin; and passing the electric wire through the storing tank 內 and dipping the electric wire in the coating liquid A guiding means for guiding the electric wire immersed in the coating liquid to the outside of the storage tank; and- the guiding means removes excess coating liquid adhering to the outer surface of the electric wire; An electric wire coating apparatus, wherein the coating liquid is prevented from leaking.

2. An electric wire comprising: a conductive core wire; a covering portion covering the core wire and made of a synthetic resin; and a coating layer covering an outer surface of the covering portion.

The electric wire, wherein the coating layer is made of a metharyl resin, and the thickness of the coating layer is 68 μπα or more and 126 μm or less.

3. The electric wire according to claim 2, wherein the thickness of the coating layer is not less than 87 / m and not more than 126.

3. The electric wire according to claim 2, wherein the thickness of the coating layer is not less than 107 tm and not more than 126 iz m.

5. An electric wire comprising: a conductive core wire; a covering portion covering the core wire and made of a synthetic resin; and a coating layer covering an outer surface of the covering portion.

The electric wire, wherein the coating layer is made of an attaryl resin, and the thickness of the coating layer is 45.5 μ 5η or more and 85 μm or less.

6. The electric wire according to claim 5, wherein the thickness of the coating layer is not less than 59 μπι and not more than 85 μπι.

7. The electric wire according to claim 5, wherein the thickness of the coating layer is 72 μπι or more and 85 / zm or less.