JP2012248527A - Wire harness and method of manufacturing the same - Google Patents

Abstract

[PROBLEMS] To prevent the occurrence of a lateral flow of a water-stopping agent and reliably fill the water-stopping portion without any defects during the water-stopping treatment of exposed conductors between multiple wires of a wire harness. In addition, a wire harness that can reliably fill a narrow gap between electric wires or between stranded wires inside the electric wire, and can exhibit good water-stopping performance, A manufacturing method thereof is provided.
SOLUTION: A cured product of a curable resin composition having fluidity that can be supplied to the water-stopping portion in an uncured state as a water-stopping agent 40 and having photo-curing property and thermosetting property. Using the water-stopper 40 in the state of supplying and holding the water-stopper 10 to form a surface layer by photocuring the surface of the water-stopper, and then heating the water-stopper 10 to keep the water-stopper inside 40 was infiltrated, and the inner water blocking agent 40 was cured to form an inner layer portion.
[Selection] Figure 1

Description

  TECHNICAL FIELD The present invention relates to a wire harness and a method for manufacturing the same, and more specifically, an intermediate splice portion of an electric wire or shielded wire used in an automobile wire harness or the like, a water stopping method for an intermediate coating removal portion or a terminal portion of the electric wire, etc. The present invention relates to a wire harness that is suitably used for the manufacturing method and a manufacturing method thereof.

  Conventionally, various methods are known as water stopping methods for intermediate splice parts such as automobile wire harnesses (see, for example, Patent Documents 1 to 10).

  In the method described in Patent Document 1, an insulating sheet is wound so as to cover the conductor of the splice part and the connection terminal, and a sealing material such as butyl rubber or silicone is filled and sealed.

  The method described in Patent Document 2 uses a pressure difference to infiltrate a water-stopping material such as a photo-curable silicone resin into the inside of a coating material (insulator) and perform tape winding.

  In the method described in Patent Document 3, a silicone water-stopping material is applied to an adhesive tape, and on the other hand, a splice portion is placed on the surface of the foam sheet, and the foam sheet is wound around the splice portion together with the adhesive tape. This is a method of covering the exposed wire portion.

  In the method described in Patent Document 4, a splice portion coated with an adhesive material of an insulating resin sheet is placed, a low-viscosity photocurable silicone resin having a viscosity of about 10 Pa · s to 100 Pa · s is applied, and the insulating resin is applied. This is a method in which a sheet is wound around a splice portion to cure a silicone resin.

  In the waterproof structure described in Patent Document 5, the wire connection portion is placed between waterproof insulating sealing films obtained by vertically polymerizing, and embedded in a sealing layer made of a waterproof insulating adhesive that is semi-solidified in the air and sealed. It has a structure consisting of a sealing part.

  In the waterproofing method described in Patent Document 6, a splice portion is accommodated in a cavity of a case that is partly light transmissive, and a photocurable silicone resin is injected into the cavity, followed by light irradiation to light cure. This is a method of curing a functional silicone resin.

  The method described in Patent Document 7 is a method of covering a wire connecting portion with a resin case, filling the inside of the resin case with an ultraviolet curable adhesive, and curing by irradiation with ultraviolet rays to form a waterproof treatment layer. .

  In the method described in Patent Document 8, a wire connection portion is set in a mold having an open upper surface, a hot melted polyamide resin is poured into the mold, and it is cooled and cured to perform waterproofing.

  In the method described in Patent Document 9, the sheath of the shielded electric wire is peeled off, the adhesive is infiltrated into the exposed shield member, and the heat shrinkable tube is covered thereon via hot melt, and both ends of the heat shrinkable tube are covered. The heat shrinkable tube is heat-shrinked in a state of overlapping the outer periphery of the sheath.

  In the method described in Patent Document 10, a first sealing agent having an ultraviolet curable viscosity of 15 to 500 mPa · s is dropped onto a conductor to penetrate into the conductor, and the second sealing agent has a higher viscosity than the first sealing agent. The first sealing agent and the second sealing agent are cured by irradiating with ultraviolet rays after dripping and coating the first sealing agent.

JP 7-37692 A JP 2008-123712 A JP 2009-1167 A JP 2009-136039 A Utility Model Registration No. 2593163 JP 2009-130981 A Japanese Utility Model Publication No. 4-111110 JP-A-7-263106 JP 2007-250404 A International Publication No. 2007/013589 Pamphlet

  In the conventional water stop method, it is extremely difficult to reliably fill the resin composition of the water stop agent between the twisted wires of the wire and to block the leak path between the plurality of wires of the wire harness. It was.

  Therefore, in order to infiltrate the water-stopper into the space between the stranded wires, for example, a low-viscosity resin with a low contact angle with respect to the wire coating or conductor, or decompression, pressurization, or inclination It was necessary to use special means such as.

  However, when the resin composition used as a water-stopping agent for the intermediate splice part, the intermediate wire covering removal part, and the terminal part has a relatively low viscosity, for example, less than 10 Pa · s, when the resin composition is applied, There has been a problem that a so-called lateral flow phenomenon that flows out from the water-stopped portion to the outside occurs, resulting in a resin deficiency from the water-stopped portion.

  On the other hand, when a relatively high viscosity composition of about 10 to 100 Pa · s is used as the resin composition, it is possible to prevent the occurrence of the transverse flow, but in a narrow gap between wires or between stranded wires inside the wires. There is a possibility that the resin cannot be filled, and there is a problem that a desired water stopping performance may not be obtained.

  An object of the present invention is to solve the above-described problems of the prior art, and prevents the occurrence of a lateral flow of a water-stopping agent during the water-stopping treatment of a conductor exposed portion between a plurality of wires of a wire harness. It is possible to reliably fill the water-stopping part with no water loss and to reliably fill the narrow gaps between the wires and between the strands inside the wire. An object of the present invention is to provide a wire harness and a method for manufacturing the same that can exhibit good water stopping performance.

In order to solve the above problems, the wire harness of the present invention is
A wire harness having a water stop portion in which a conductor exposed portion in which an insulator of an electric wire bundle composed of a plurality of insulated wires is removed and an internal conductor is exposed is covered with a water stop agent,
The water-stopping agent has a fluidity that can be supplied to the water-stopping portion in an uncured state, and consists of a cured product of a curable resin composition having photocurability and thermosetting property,
The gist of the water-stopping agent is that it has a surface layer portion that is photocured by light irradiation and an inner layer portion that is cured while being penetrated into the waterstop portion by heating.

  The said wire harness WHEREIN: It is preferable that the surface of the said water stop agent is coat | covered with the light-transmitting protective sheet.

  In the wire harness, the water stop portion can be formed in an intermediate splice portion.

  The said wire harness WHEREIN: It is preferable that the said water stop part has coat | covered the surface of the insulator adjacent to the conductor exposed part of an insulated wire.

The manufacturing method of the wire harness of the present invention is as follows:
A method of manufacturing a wire harness having a water stop portion in which a conductor exposed portion in which an insulator of an electric wire bundle composed of a plurality of insulated wires is removed and an internal conductor is exposed is covered with a water stop agent,
As the water-stopping agent, it has a fluidity that can be supplied to the water-stopping portion in an uncured state, and uses a cured product of a curable resin composition having photocurability and thermosetting property,
In the state where the water-stopping agent is supplied to and held by the water-stopping portion, the front water-stopping portion is irradiated with light to photocur the surface of the water-stopping agent to form a surface layer portion, and the water-stopping portion After preventing the water stop agent from flowing out of the water stop portion, the water stop portion is heated to infiltrate the water stop agent into the water stop portion, and the inner water stop agent is cured to form an inner layer portion. Is a summary.

  In the method of manufacturing the wire harness, the water-stopping portion supplied with the water-stopping agent is covered using a light-transmitting protective sheet, and the surface of the water-stopping agent is covered with the protective sheet. It is preferable to form a surface layer portion by irradiating and curing the surface of the water-stopping agent.

  In the manufacturing method of the wire harness, the protective sheet is wound around the surface of the water stopping agent, and the surface layer portion is cured by irradiating light in a state where the water stopping portion is pressed from the outside of the protective sheet. Is preferred.

  In the method of manufacturing the wire harness, it is preferable that the water stopping agent has an uncured viscosity at 25 ° C. in a range of 10 to 100 Pa · s.

  In the manufacturing method of the wire harness, when the water stop agent is infiltrated into the water stop portion, the water stop portion is heated to a temperature at which the viscosity of the water stop agent is within a range of 1 to 500 mPa · s. It is preferable to do.

  In the manufacturing method of the wire harness, after the water stop portion is heated to a predetermined temperature and the water stop agent is permeated therein, the temperature is increased and the water stop agent is cured at a temperature higher than the predetermined temperature. It is preferable to carry out. .

  The wire harness of the present invention is a cured product of a curable resin composition having fluidity that the waterstop agent can be supplied to the waterstop portion in an uncured state and having photocurability and thermosetting properties. And by having a surface layer portion photocured by light irradiation and an inner layer portion cured in a state of permeating into the water stop portion by heating, compared to a conventional wire harness, the conductor exposed portion It is possible to prevent the occurrence of a lateral flow of the water-stopping agent during the water-stopping treatment, and the water-stopping portion can be reliably filled with the water-stopping portion to obtain a water-stopping portion having no defect.

  Furthermore, since the wire harness of the present invention has an inner layer portion cured in a state where it penetrates into the water stop portion by heating, the water stop agent is surely provided in a narrow gap between the wires and between the stranded wires inside the wire. It is possible to demonstrate good water stop performance

  The manufacturing method of the wire harness of the present invention has a fluidity that can be supplied to the waterstop portion in an uncured state as a waterstop agent, and has a photocurable property and a thermosetting property. Using a cured product of the product, in the state where the water-stop agent is supplied to and held by the water-stop portion, the front water-stop portion is irradiated with light to photo-harden the surface of the water-stop agent to form a surface layer portion Then, after preventing the water-stopping agent from flowing out from the water-stopping portion, the water-stopping portion is heated to infiltrate the water-stopping agent into the water-stopping portion and harden the water-stopping agent inside. By adopting the method of forming the inner layer part, it is possible to prevent the occurrence of lateral flow of the water-stopping agent. A water stop with no loss due to outflow is obtained.

  Furthermore, in the production method of the present invention, after forming the surface layer portion, when the water stop portion is heated, the water stop agent composed of the curable resin composition of the water stop portion is reduced in viscosity by heating, so that it penetrates into a narrow space. The water stop part which has the outstanding water stop performance can be obtained.

FIG. 1 is a perspective view showing an appearance of an example of a wire harness according to the present invention in the vicinity of an intermediate splice portion. It is sectional drawing of FIG. (A)-(c) shows an example of the manufacturing method of the wire harness of this invention, and is explanatory drawing which shows the manufacturing process of a water stop middle splice part. (D)-(f) shows an example of the manufacturing method of the wire harness of this invention, and is explanatory drawing which shows the manufacturing process of a water stop middle splice part. (A)-(e) is explanatory drawing which shows the manufacturing process of the other example of a water stop middle splice part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of the vicinity of an intermediate splice part of an example of the wire harness of the present invention, and FIG. 2 is a cross-sectional view of FIG. As shown in FIGS. 1 and 2, the wire harness 1 of the present invention has a plurality of insulated wires 4 (four in the example of FIGS. 1 and 2) in which the periphery of a conductor 2 made of a core wire is covered with an insulator 3. Insulated wire) It is composed of bundled wires.

  Furthermore, the wire harness 1 has a conductor exposed portion 5 in which the insulated wires 3 of the bundle of wires are peeled off and the internal conductor 2 is exposed. The conductor exposed portion 5 has an intermediate splice portion 20 where the conductors are joined. In the intermediate splice unit 20, the conductors 2, 2, 2, 2 of the plurality of insulated wires 4, 4, 4, 4 are electrically connected.

The wire harness 1 is configured as a water-stop intermediate splice portion 10 (hereinafter sometimes simply referred to as the water-stop portion 10) by surrounding the intermediate splice portion 20 with a protective sheet 30 and a water-stop agent 40. The water stop part 10 has a surface layer part formed by curing the surface by light irradiation and an inner layer part formed by curing the inside by heat. The inner layer portion of the water stop portion 10 is hardened with the water stop agent 140 penetrating into the inside.

The insulated wire 4 uses, for example, a single wire or stranded wire of copper, copper alloy, aluminum or the like as the conductor 2 and uses a thermoplastic resin such as polyvinyl chloride or olefin resin as the insulator 3. A normal covered electric wire that is cross-linked or cross-linked can be used.

The intermediate splice part 20 is a part in which the insulator 3 is partially removed at the intermediate part in the longitudinal direction of the insulated wire 4 to expose the conductor 2, and the conductor 2 of another insulated wire 4 is joined to the conductor 2. is there. The conductor 2 of the other insulated wire 4 may be exposed at the intermediate portion in the longitudinal direction of the insulated wire 4 or may be exposed at the end of the insulated wire 4. . Here, the latter example will be described. Moreover, in the wire harness 1, the insulated wire 4 is not limited to four, What is necessary is just two or more, and the number of insulated wires is not specifically limited.

In the intermediate splice portion 20, the conductors 2 can be joined to each other by means such as welding by resistance welding, ultrasonic welding, laser welding, or the like. The conductor 2 in the splice part 20 may be joined by a method in which a component such as an intermediate crimp terminal is crimped to the joint part.

The water stop part 10 including the intermediate splice part 20 is filled with a water stop agent 40, and the outside of the water stop agent 40 is covered with a light-transmitting protective sheet 30. The said light transmittance is the light permeability at the time of hardening the curable resin composition of the water stopping agent 40.

The water stopping agent 40 covers the outer peripheral surface of the conductor 2 exposed to the intermediate splice part 20 and the surface of the insulator 3 adjacent to the conductor exposed part in the longitudinal direction of the insulated wire 4. That is, the water stop part 10 is formed so that the water stop agent 40 covers the covering parts 6 before and after the conductor adjacent to the conductor exposed part of the insulated electric wire 4. As described above, since the water-stopping agent 40 covers the covering portion 6, it is possible to further prevent moisture from entering from the gap between the insulator 3 and the conductor 2.

The water stop agent 40 has fluidity in an uncured state, and can be supplied to the water stop portion 10 and filled. Furthermore, the water-stopping agent 40 is made of a cured product of a curable resin composition having photo-curing property and thermosetting property, and can be cured after being filled in the water-stopping portion 10 to exhibit waterproof performance.

The surface layer portion of the water stop portion 10 is formed by photocuring the surface layer by light irradiation after filling the water stop agent 40. The surface layer portion holds the composition filled in the water stop portion 10 so as not to flow out. The inner layer part of the water stop part 10 heats the water stop part 10, reduces the viscosity of the water stop agent 40, and is completely cured in a state where it penetrates into gaps such as between conductor wires or between electric wires. Is formed.

The curable resin composition used as the water-stopping agent 40 is not particularly limited as long as it has the above characteristics. For example, (1) an ultraviolet curable resin imparted with thermosetting property, (2) Visible light curable resin imparted with thermosetting, (3) Resin in which active species are generated by ultraviolet irradiation, and cationic polymerization or anionic polymerization is accelerated by heat with time delay, (4) Active by ultraviolet irradiation Resin composition in which seeds are generated, a great amount of heat is generated during the polymerization reaction, and the active site radical site moves, so that curing proceeds even at a site where ultraviolet rays do not reach, (5) UV curable property Moisture-curing silicone resin or the like can be used.

In order to impart thermosetting properties to the ultraviolet curable resin, for example, a thermal radical polymerization initiator is added to the ultraviolet curable resin composition. Specifically, this composition contains a polymerizable compound, a photopolymerization initiator, and a thermal radical polymerization initiator.

As the polymerizable compound, a combination of a chain acrylate monomer and a cyclic acrylate monomer and / or a cyclic N-vinyl monomer is used to adjust resin viscosity, curing speed, hardness, Young's modulus, elongation at break, adhesion, and the like. It is preferable from the viewpoint of ease. In particular, polar monomers containing a cyclic structure contribute to improving the adhesion between the cured resin and the substrate.

The content of the polymerizable compound in the composition can be appropriately set according to the viscosity of the composition.

The acrylate compound is preferably a combination of a urethane acrylate oligomer and an acrylate monomer.

As the urethane acrylate oligomer, urethane acrylate obtained by reacting bisphenol A / ethylene oxide addition diol, tolylene diisocyanate and hydroxyethyl acrylate; urethane obtained by reacting polytetramethylene glycol, tolylene diisocyanate and hydroxyethyl acrylate Acrylate: Urethane acrylate obtained by reacting tolylene diisocyanate and hydroxyethyl acrylate. These oligomers may be used alone or in combination of two or more.

Examples of the acrylate monomer include a chain acrylate monomer and a cyclic acrylate monomer. The cyclic acrylate monomer is an acrylate monomer having a cyclic structure such as an alicyclic ring or an aromatic ring. Examples of the cyclic acrylate monomer include isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and dicyclohexane. Examples include alicyclic structure-containing (meth) acrylates such as pentanyl (meth) acrylate; benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, and acryloylmorpholine. As the cyclic acrylate monomer, isobornyl (meth) acrylate is preferable. As the cyclic acrylate monomer, IBXA (manufactured by Osaka Organic Chemical), Aronix M-111, M-113, M-114, M-117, TO-1210 (above, manufactured by Toagosei Co., Ltd.) can be used. In this specification, the chain acrylate monomer is a linear or branched acrylate monomer that does not contain a cyclic structure. Examples of chain acrylate monomers include neopentyl glycol diacrylate, 3-methyl-1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, and 2-butyl-2ethyl-1,3-propanediol. Diacrylate, 2,4-diethyl-1,5-pentanediol diacrylate, 2-methyl-1,8-octanediol diacrylate, 1,9-nonanediol diacrylate, phenoxyhexaethylene glycol acetate, hydroxypivalate neo Pentyl glycol acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, dipentaerythritol Lumpur hexaacrylate, and the like.

A methacrylate compound may be used together with the acrylate compound. Examples of the methacrylate compound include di-2-methacryloxyethyl phosphate, mono [2- (meth) acryloyloxyethyl] phosphate, mono [2- (meth) acryloyloxyethyl] diphenyl phosphate, and mono [2- (meta ) Acryloyloxyethyl] phosphate, bis [2- (meth) acryloyloxypropyl] phosphate, tris [2- (meth) acryloyloxyethyl] phosphate, and O = P (-R1) in JP-A-11-100414 -R2) (-R3) and the like.

The said cyclic N-vinyl monomer is a vinyl monomer which has cyclic structures, such as an aromatic ring and an alicyclic ring, and contains a nitrogen atom. Examples of the cyclic N-vinyl monomer include N-vinyl pyrrolidone (manufactured by Nippon Shokubai), N-vinyl caprolactam, vinyl imidazole, vinyl pyridine and the like.

Examples of the photopolymerization initiator include benzophenone derivatives such as benzophenone, methyl orthobenzoin benzoate, 4-benzoyl-4′-methyldiphenyl sulfide, thioxanthone and derivatives thereof, 2-methyl-1- [4- (methylthio). ) Phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin derivative, benzyldimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, acylphosphine oxide, Examples include monoacylphosphine oxide, bisacylphosphine oxide, acrylphenylglyoxylate, diethoxyacetophenone, and titanocene compounds. The photopolymerization initiator can be appropriately selected in consideration of the curing speed, yellowing and the like. A photoinitiator may be used independently and may be used in combination of 2 or more type.

Specific combinations of photopolymerization initiators include, for example, Lucilin TPO (BASF Japan) and Irgacure 184 (Ciba Specialty Chemicals), Lucirin TPO (BASF Japan) and Irgacure 651 (Ciba Specialty). Chemicals), Lucyrin TPO (BASF Japan) and Irgacure 907 (Ciba Specialty Chemicals), Irgacure 184 and Irgacure 907 (both manufactured by Ciba Specialty Chemicals), and the like.

The content of the photopolymerization initiator in the composition liquid is preferably in the range of 0.1 to 5% by mass, more preferably in the range of 0.3 to 2% by mass. If the content of the photopolymerization initiator is reduced and it is less than 0.1% by mass, it may not be photocured even at a location where it is sufficiently exposed to light. When it exceeds, many unreacted photoinitiators will remain easily. The remaining photopolymerization initiator is activated by heat, light, and the like, discolors the sealed portion after curing, and may cause physical properties such as an increase in Young's modulus and a decrease in elongation due to the reaction.

As the thermal radical polymerization initiator, azoisobutyl, tolyl (AIBN), benzoyl peroxide (BPO), lauroyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, di-tert-butyl peroxide, Examples thereof include peracid compounds such as tert-butyl perbenzoate and cyclohexanone peroxide.

In addition to the polymerizable compound, photopolymerization initiator, and thermal radical polymerization initiator, other additives may be added to the curable resin composition. Examples of such additives include antioxidants, coloring materials, ultraviolet absorbers, light stabilizers, silane or titanium-based coupling agents, antifoaming materials, curing accelerators, thiol compounds, phosphate esters, and the like. Adhesive aids, leveling agents, surfactants, storage stabilizers, polymerization inhibitors, plasticizers, lubricants, fillers, anti-aging agents, wettability improvers, coating film improvers, and the like.

Moreover, as said curable resin composition, the composition which added the radical polymerization initiator to the commercially available ultraviolet curable resin etc., the composition which prepared the viscosity of the commercially available ultraviolet-ray and thermosetting resin, etc. can be used. . Specific examples of such combinations include the following materials.

The above (1) includes an acrylic rubber polymer (manufactured by Three Bond, trade name “3013Q”, viscosity at 25 ° C .: 23 Pa · s) and a thermal radical polymerizer.

Examples of (2) include urethane acrylate (trade name “3170D” manufactured by ThreeBond Co., Ltd., viscosity at 25 ° C .: 37 Pa · s) and a thermal radical initiator.

Examples of the above (3) include those prepared by adjusting the viscosity of a cationic polymerizable ultraviolet curable resin (manufactured by DIC, trade name “Tyforth Series”) to 10 Pa · s (25 ° C.) or more.

Examples of the above (5) include those prepared by preparing a UV curable silicone (trade name “5773”, manufactured by LOCKTITE Co., Ltd.) having a moisture curable property with a viscosity of 10 Pa · s (25 ° C.) or more.

The uncured curable resin composition only needs to have fluidity that can be supplied to the intermediate splice unit 20 at normal temperature to cover the part. The curable resin composition preferably has an uncured viscosity at room temperature (25 ° C.) in the range of 10 to 100 Pa · s, and more preferably in the range of 20 to 50 Pa · s. The viscosity is a value measured with a B-type viscometer in accordance with JIS-K7117-D. If the viscosity of the curable resin composition is less than 10 Pa · s, there is a possibility that it cannot flow out and be retained from the water stop, and if the viscosity exceeds 100 Pa · s, it may be difficult to supply the composition to the water stop. is there.

Further, when the curable resin composition is heated, it penetrates into the intermediate splice part 20, and the gap between the insulators 3 of the insulated wire 4, between the strands constituting the conductor 2, between the conductors 2, and the like. It has fluidity that can fill the gap. Specifically, it is preferable to control the heating temperature so that the viscosity of the curable resin composition of the water stop portion 10 when infiltrated by heating is in the range of 1 to 500 mPa · s. More preferably, the heating temperature of the curable resin composition of the water stop portion 10 is controlled so that the viscosity is in the range of 1 to 100 mPa · s.

When the curable resin composition is infiltrated into the water-stopping portion 10, if the viscosity of the curable resin composition is less than 1 mPa · s, the volatile component at the time of curing of the curable resin is increased, and a foaming site is generated and filling is performed. If it exceeds 500 mPa · s, there is a possibility that the penetration into details may be insufficient.

In the curable resin composition after curing, the cured product is preferably flexible and has appropriate rubber elasticity. As specific physical properties of the cured product, the elongation of the cured product is preferably 50% or more at room temperature, and more preferably 100% or more. The cured product preferably has a low temperature (−50 ° C.) elongation of 10% or more, and more preferably 20% or more. When the cured product is flexible and has an appropriate rubber elasticity, it is difficult to cause damage such as cracks and breaks when the water-stopping portion 10 is subjected to a cold heat cycle, an external tensile force, a bending stress, or the like. The measurement of the elongation at break (%) of the cured product was carried out using a tensile tester (AGS, manufactured by Shimadzu Corporation) using a film in which a curable resin composition was formed to a thickness of 200 μm in accordance with JIS-K7113. It can be measured by doing.

The curable resin composition preferably has a peel adhesive strength of 100 N / m or more, more preferably 300 N / m or more, for the cured product conductor or insulator. When the peel adhesive strength is in the above range, the waterproof performance of the water stop portion by the water stop agent can be surely exhibited. The peel adhesive strength is a 90 ° peel test or JIS- based on JIS-Z0237 using a resin film obtained by curing the curable resin composition with a thickness of 500 μm on a base made of copper / PVC. It is determined by performing a 180 ° peel test or a T peel test in accordance with K6854.

Moreover, it is preferable that the adhesive force with respect to the shear stress of hardened | cured material is 1 MPa or more, and, more preferably, the curable resin composition is 3 MPa or more. If the adhesive strength against the shear stress of the cured product is in the above range, it has a resistance to the shear stress with the base material caused by the difference in linear expansion coefficient with the base material, so that the waterproof performance of the water stop part is surely exhibited. be able to. The base in this case is a conductor metal (copper, aluminum, tin-plated copper, etc.) or an insulating resin (PVC, olefin resin, etc.). The adhesive force with respect to the shear stress of the cured product can be measured by a test method of JIS-K6850.

The protective sheet 30 covers the surface of the water-stopping agent 40 in a state of being in close contact with the surface of the water-stopping agent 40. As the protective sheet 30, a sheet that has a light-transmitting property capable of transmitting light that cures the water-stopping agent 40 and that can hold the water-stopping agent 40 in an uncured state is used.

Regarding the light transmittance of the protective sheet 30, for example, when the water-stopping agent 40 uses an ultraviolet curable resin, the ultraviolet transmittance is preferably 50% or more, and more preferably 90% or more.

As the protective sheet 30, a wrap sheet of olefin resin such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and polyvinylidene fluoride, or a wrap sheet of general-purpose resin such as polyester, polyethylene terephthalate, and nylon can be used. . The protective sheet 30 is preferably a sheet of polyvinyl chloride resin, polyvinylidene chloride resin, or polyvinylidene fluoride resin that has particularly good self-adhesion (adhesion).

The thickness of the protective sheet 30 is preferably 100 μm or less, more preferably 5 to 50 μm.

The protective sheet 30 has a Young's modulus (value at room temperature in the measurement direction according to JIS-K7113) in the range of 50 to 500 MPa when the thickness is less than 50 μm, and 10 to 100 MPa when the thickness is 50 μm to 100 μm. When the thickness exceeds 100 μm, it is preferably less than 10 MPa. Further, the protective sheet 30 has an elongation at break of preferably 20% or more, more preferably 50% or more.

The protective sheet 30 preferably has a self-adhesion strength in a range of 0.5 to 10 N / m expressed by peel adhesive strength (value at room temperature in a measurement method according to JIS-Z0237 or JIS-K6854). The water-stopping part 10 follows the deformation of the surface of the water-stopping agent 40, the protective sheet 30 is deformed, and the water-stopping agent 40 is cured in a state where the surface of the water-stopping agent 40 and the protective sheet 30 are in close contact with each other. . When the protective sheet 30 has a high self-adhesive force, when the protective sheet 30 is wound around the intermediate splice portion 20 and the water-stopping agent 40, the protective sheet 30 is easily covered and has excellent workability.

Further, a pressure-sensitive adhesive layer made of a weak pressure-sensitive adhesive having a thickness of 10 μm or less may be formed on the surface of the protective sheet 30. The thickness of the pressure-sensitive adhesive layer is preferably 5 μm or less.

Hereinafter, the manufacturing method of the wire harness of FIG. 1 will be described. FIGS. 3A to 3C and FIGS. 4D to 4F are explanatory views showing an example of the method for manufacturing the wire harness of the present invention and showing the manufacturing process of the water stop intermediate splice portion. In this embodiment, an ultraviolet curable resin imparted with thermosetting property is used as the water-stopping agent 40, and a sheet having appropriate flexibility, self-adhesiveness, stretchability, ultraviolet transparency, and the like is used as the protective sheet 30.

A wire bundle in which the intermediate splice portion 20 is formed in advance using a plurality of insulated wires is prepared. The wire bundle 7 has a conductor exposed portion 5 in which the insulator 3 of the insulated wire 4 is removed and the internal conductor 3 is exposed (see FIG. 3B).

First, as shown in FIG. 3A, the water-stopping agent 40 is supplied to the surface of the protective sheet 30 that is large enough to cover the intermediate splice part 20. The water-stopping agent 40 is discharged to the central portion of the protective sheet 30 from the nozzle 60 of the discharge device by a predetermined amount.

Next, as shown in FIG. 3B, the intermediate splice portion 20 of the wire bundle is placed on the water stopping agent 40 discharged on the protective sheet 30. The water stopping agent 40 is supplied to the intermediate splice unit 20. Further, as shown in FIG. 2C, the water-stopping agent 40 can be supplied by placing the intermediate splice portion 20 on the protective sheet 30 and discharging the water-stopping agent 40 from the nozzle 60 thereon. Good. Supply of the water stopping agent 40 to the water stopping portion is performed at room temperature.

Next, as shown in FIG. 4 (d), the folded portion side of the protective sheet 30 is wound around the intermediate splice portion 20 and the water stopping agent 40, and the overlapping portion where the protective sheets overlap each other in the portion without the intermediate splice portion 20. Bend it to 32. The overlapping portion 32 of the protective sheet 30 is maintained in an overlapped state by the self-adhesiveness of the protective sheet 30.

Next, the protective sheet 30 is wound around the surface of the water-stopping agent 40 of the intermediate splice unit 20 so that the water-stopping agent 40 is filled in the protective sheet 30. As shown in FIG. 4D, after the protective sheet 30 is folded in half, the overlapping portion of the protective sheet 30 is rubbed with a roll 51, and the water stopping agent 40 of the overlapping portion 32 is placed in the intermediate splice portion. Push toward 20. The overlapping portion 32 of the protective sheet 30 is wound around the water stop portion 10 to be in close contact therewith.

Next, as shown in FIG. 4E, the overlapping portion of the protective sheet 30 is wound around the intermediate splice portion 20 and the water stopping agent 40. When the protective sheet 30 is wound in a state where a tensile tension is applied, the protective sheet 30 is wound around the intermediate splice part 20 and the water-stopping agent 40 in a state where the water-stop part 10 is pressed from the outside of the protective sheet 30. As a result, the water-stopping agent 40 existing locally around the intermediate splice part 20 is extruded and passes between the outer peripheral part of the intermediate splice part 20 and the protective sheet 30. The water stopping agent 40 can cover the entire outer periphery of the intermediate splice part 20.

The protection sheet 30 is maintained in a state of being wound around the water stop portion 10 by self-adhesion. Further, the water stop portion 10 is also maintained in a state where it is pressed from the outside of the protective sheet 30.

Next, as shown in FIG. 4 (e), the intermediate splice unit 20 is wrapped around the outer periphery of the intermediate splice unit 20 and the water-stopping agent 40 using the ultraviolet irradiation device 52. The surface of the water-stopping agent 40 is cured by irradiating with ultraviolet rays 53 to form a surface layer portion.

The ultraviolet rays 53 irradiated to the intermediate splice part 20 pass through the protective sheet 30 and are irradiated to the water stop agent 40. At this time, the ultraviolet irradiation is performed under irradiation conditions such that only the surface of the ultraviolet curable resin composition of the water-stopping agent 40 is cured. Since the surface of the water stopping agent 40 in contact with the protective sheet 30 is cured, the water stopping agent 40 can be prevented from flowing out from the end 33 of the protective sheet 30 to the outside.

The ultraviolet irradiation time is preferably in the range of 0.1 to 3 seconds, since it is easy to keep only the surface without curing the internal water-stopping agent.

At this stage, the water stop agent 40 inside the water stop portion 10 is in an uncured state. When the water-stopping agent 40 has an uncured viscosity at 25 ° C. in the range of 10 to 100 Pa · s, the water-stopper can be reliably supplied and filled.

In order to cure only the surface of the ultraviolet curable composition, the ultraviolet irradiation time, the intensity of irradiation light, and the like may be appropriately selected according to the composition of the ultraviolet curable resin composition used as a water-stopping agent.

As the ultraviolet irradiation device, a light source such as a bulb-type UV lamp or an LED-UV lamp in which Hg, Hg / Xe, a metal halide compound or the like is enclosed can be used. Further, the ultraviolet irradiation device may use a condensing UV irradiation device that collects and irradiates light from the light source with a reflection mirror.

Next, as shown in FIG. 4 (f), the intermediate splice unit 20 is heated by the heating device 70, and the water stop agent 40 inside the water stop unit 10 is heated to a predetermined temperature. In addition, FIG.4 (f) has shown the cross section of the transversal direction of a wire harness. When the water stopping agent 40 is heated, the viscosity decreases. The water-stopping agent 40 having a reduced viscosity penetrates and fills the gaps between the strands of the conductor 3 and the gaps between the electric wires. It is preferable to heat the water-stopping agent at this time so that the viscosity of the uncured water-stopping agent 40 is 1 to 500 mPa · s. When the viscosity of the water-stopping agent 40 is in the above range, it is possible to reliably penetrate the details of the water-stopping agent 40 in a short time.

When making the water stop agent penetrate | infiltrate at this time, it is preferable that it is the predetermined temperature which a water stop agent does not thermoset. By heating the water-stopping agent 40 to penetrate the water-stopping portion to a temperature at which the water-stopping agent does not thermally cure, the internal water-stopping agent 40 is cured in a state that does not sufficiently penetrate the gap between the water-stopping portions. Therefore, it is possible to prevent the water-stopping portion from being damaged and to exhibit a better waterproof performance.

Next, with the water-stopping agent 40 penetrating into the water-stopping portion 10, the intermediate splice portion is further heated to bring the temperature of the water-stopping agent 40 to a temperature higher than the penetration temperature of the water-stopping agent, The uncured water stopping agent 40 is cured. Heating is performed for a predetermined time to completely cure the water stop agent 40 on the inner side of the water stop portion 10. The inner layer of the water stop part 10 is formed.

The heating for thermosetting the internal water-stopping agent is preferably 80 ° C. or higher in order to obtain a viscosity of 500 mPa · s or lower. In addition, the heating is preferably performed at 150 ° C. or lower in order to efficiently perform thermosetting and at the same time not damage the electric wire coating. In particular, the heating of the water-stopping agent is preferably performed within the range of 100 to 140 ° C. for the reason of achieving both resin penetration and curing. Further, the heating temperature is preferably selected as appropriate in consideration of the decomposition temperature of the thermal radical polymerization initiator.

Said heating apparatus 70 will not be specifically limited if it is an apparatus which can heat the water stop agent of the water stop part 10, Various heating apparatuses can be used. Examples of the heating device include a ceramic heater, a hot air jet heater, a pipe electromagnetic heater, a halogen lamp heater, and a contact rubber heater.

  FIGS. 5A to 5E are explanatory views showing manufacturing steps of another example of the water stop intermediate splice part. As a method of winding the protective sheet 30 around the intermediate splice portion 20, a method of winding the protective sheet 30 with a pair of rollers 110 as described below may be used.

As shown in FIGS. 5A to 5E, the winding device is disposed so that the pair of rollers 110 are in contact with each other. When the electric wires at both ends of the intermediate splice portion 20 are moved downward along the pair of side grooves, the intermediate splice portion 20 is sandwiched by the pair of rollers 110 and rotates the pair of rollers 110. And move downward.

First, as shown in FIG. 5A, the protective sheet 30 is placed on the top plate portion, the water-stopping agent 40 is supplied onto the protective sheet 30, and the intermediate splice portion 20 is placed.

Next, as shown in FIG. 5B, the wire bundle is moved downward along the lateral groove. The intermediate splice part 20 is sandwiched between the pair of rollers 110 while being sandwiched by the protective sheet 30.

Next, as shown in the figure, the pair of roller portions 110 sandwich the intermediate splice portion 20, the water-stopping agent 40 and the protective sheet 30 while elastically deforming according to the shape of the peripheral portion of the intermediate splice portion 20. Thereby, the protective sheet 30 is wound around the intermediate splice part 20 and the water-stopping agent 40 while force is applied from around (see FIG. 5C).

Next, as shown in FIG. 5 (d), the rod-shaped member 120 is moved toward the intermediate splice portion 20 with the intermediate splice portion 20 being sandwiched between the pair of rod-shaped members 120. As shown in FIG. 5E, the protection sheet 30 is wound around the surface of the water stopping agent 40 in a state where the water stopping portion is pressed from the outside of the protection sheet 30.

Examples of the present invention and comparative examples are shown below. The present invention is not limited to the examples.

Example 1 <Water stop intermediate splice part> (Workpiece) An outer diameter of 2.6 mm in which a copper strand wire obtained by twisting a 26 μm copper strand in a 1-6-12-18 array is coated with polyvinyl chloride (PVC). The PVC coating on the ends of the 10 PVC wires was removed, and an intermediate splice work was prepared by resistance welding the copper stranded wire portions of two sets of wire bundles bundled in groups of five.

(Water Resistant Curable Resin Composition) For 100 parts by mass of UV curable resin mainly composed of urethane acrylate oligomer and acrylate monomer, trade name “Irgacure” manufactured by Ciba Specialty Chemicals Co., Ltd. as a photo radical polymerization initiator. 1 part by weight of 184 ”, 0.3 part by weight of the product name“ Lucirin TPO ”manufactured by BASF Japan Ltd., and 1 part by weight of cumene hydroperoxide as a thermal radical polymerization initiator. A resin prepared with a viscosity of 20 Pa · s (25 ° C.) was used.

(Filling with water-stopping agent and maintaining shape) A PVC wrap film (width 100 mm x length 80 mm x thickness 20 µm, self-adhesive strength 0.8 N / m) is used as a protective sheet, and the above water-stop is provided at the center of the wrap film. 0.84 g of the agent is dropped, and after placing the intermediate splice work from above, the PVC wrap film is folded back in the direction perpendicular to the longitudinal direction of the work, and the water-stopping agent covers the peripheral part of the intermediate splice part of the work The portion of the PVC wrap film that was not wrapped with the water-stopping agent was attached.

Furthermore, it passes between the two rubber sponges and is narrowed down by a narrowing device with a mechanism that narrows the part pasted from the pasted ends with two round bars toward the workpiece, and the periphery of the intermediate splice part is cleanly cylindrical with the electric wire. Wrapped to become. The outer diameter of the portion of the water stop portion encased in a cylindrical shape was 7 mmφ.

At this time, the water stop agent flowed and spread from the center of the splice part in the longitudinal direction of the electric wire and the circumferential direction of the work by the above-mentioned squeezing force, and was able to fill the water stop part. The excess portion of the PVC wrap film was inserted into a sheet winding machine having a brush and wound around the work. The above-described winding was performed while maintaining the workpiece in a horizontal state. As a result, the water-stopping agent did not cause a lateral flow and could be maintained in a state where the water-stopping agent was held in the water-stopping portion without flowing out from the end of the wrap film.

(Hardening only the surface layer portion by ultraviolet irradiation) Next, using a UV irradiation device, the workpiece is irradiated with ultraviolet rays from above the wrap film, and the surface of the water-stopping agent in contact with the wrap film is cured. Formed. Ultraviolet irradiation was performed for 1 second at an irradiation intensity of 400 mW / cm ² using an LED-UV lamp having a central wavelength of 385 nm.

(Penetration and hardening of the water-stopping agent by heating) Insert a work irradiated with ultraviolet light between two ceramic heater plates controlled at a space temperature of 120 ° C and hold it for 90 seconds. At the same time, the water-stopping agent inside was thermally cured to form an inner layer portion, thereby forming a water-stop intermediate splice portion.

(Water-stopping performance) Applying a pressure of 200 kPa from each of the 10 insulated wires at both ends of the intermediate splice work on which the water-stopping intermediate splice is formed, immersing the other 9 insulated wires in water It was observed whether air leaks from the stranded wire. As a result, no leak occurred in any of the electric wires. In addition, even when a pressure of 200 kPa was applied simultaneously to 10 insulated wires, no leakage occurred from the interface between the outside covered with the water-stopping agent and the insulator or from the splice portion.

(Observation) After the above water-stop test, in the water-spliced intermediate splice, the cross section of the copper strand near the end of the insulated wire on the splice side was cut and observed. Was nicely filled.

Comparative example 1 Except having made the ultraviolet irradiation time in Example 1 into 5 second or more, the same process was performed using the same material as Example 1, and the water stop part was formed. As a result, the water-stopping agent in the portion wrapped in a cylindrical shape with the wrap film was almost cured at the portion irradiated with ultraviolet rays. When the water stop test was carried out, 8 out of 10 insulated wires showed a leak path between the insulated wires at 50 kPa. Moreover, when the cross section near the insulated wire on the splice side was cut and observed, many portions not filled with resin were observed between the copper stranded wires as conductors.

In the above embodiment, the example in which the water-stopping portion is applied to the intermediate splice portion has been described. However, the present invention provides a water-stopping portion of the terminal splice obtained by filling a light-transmitting protective cap with a water-stopping agent. It can also be applied to a water stop portion of a ground terminal constituted by a crimp terminal, a water stop portion of a wire crimping terminal for inserting a connector, and the like.

DESCRIPTION OF SYMBOLS 1 Wire harness 2 Conductor 3 Insulator 4 Insulated electric wire 5 Conductor exposed part 6 Covering part before and behind a conductor 7 Wire bundle 10 Water stop middle splice part (water stop part)
20 Intermediate splice part 30 Protective sheet 40 Water stop agent

Claims (10)

A wire harness having a water stop portion in which a conductor exposed portion in which an insulator of an electric wire bundle composed of a plurality of insulated wires is removed and an internal conductor is exposed is covered with a water stop agent,
The water-stopping agent has a fluidity that can be supplied to the water-stopping portion in an uncured state, and consists of a cured product of a curable resin composition having photocurability and thermosetting property,
The said water stop agent has the surface layer part photocured by light irradiation, and the inner layer part hardened | cured in the state which osmose | permeated the inside of the said water stop part by heating, The wire harness characterized by the above-mentioned.   The wire harness according to claim 1, wherein a surface of the water blocking agent is covered with a light-transmitting protective sheet.   The wire harness according to claim 1 or 2, wherein the water stop portion is an intermediate splice portion.   The wire harness according to any one of claims 1 to 3, wherein the water stop portion covers a surface of an insulator adjacent to a conductor exposed portion of an insulated wire. A method of manufacturing a wire harness having a water stop portion in which a conductor exposed portion in which an insulator of an electric wire bundle composed of a plurality of insulated wires is removed and an internal conductor is exposed is covered with a water stop agent,
As the water-stopping agent, it has a fluidity that can be supplied to the water-stopping portion in an uncured state, and uses a cured product of a curable resin composition having photocurability and thermosetting property,
In the state where the water-stopping agent is supplied to and held by the water-stopping portion, the front water-stopping portion is irradiated with light to photocur the surface of the water-stopping agent to form a surface layer portion, and the water-stopping portion After preventing the water stop agent from flowing out of the water stop portion, the water stop portion is heated to infiltrate the water stop agent into the water stop portion, and the inner water stop agent is cured to form an inner layer portion. A method of manufacturing a wire harness.   Covering the water-stop part supplied with the water-stopping agent using a protective sheet having light permeability, and irradiating light in a state where the surface of the water-stopper is covered with the protective sheet, the water-stopper The method for manufacturing a wire harness according to claim 5, wherein the surface layer portion is formed by curing the surface of the wire harness.   The said protective sheet is wound around the surface of the said water stop agent, light irradiation is performed in the state in which the said water stop part was pressed from the outer side of the said protective sheet, and a surface layer part is hardened. Wire harness manufacturing method.   The method for producing a wire harness according to any one of claims 5 to 7, wherein the water-stopping agent has an uncured viscosity at 25 ° C in a range of 10 to 100 Pa · s. .   The water-stopping part is heated to a temperature at which the viscosity of the water-stopping agent is within a range of 1 to 500 mPa · s when the water-stopping agent is allowed to penetrate into the water-stopping part. The manufacturing method of the wire harness of any one of 5-8. The water-stopper is cured at a temperature higher than the predetermined temperature by raising the temperature after heating the water-stop part to a predetermined temperature and allowing the water-stopper to penetrate inside. The manufacturing method of the wire harness of any one of claim | item 5-9.

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