JPH07263106A - Wire harness branch line junction part water-proofing method and machining device therefor - Google Patents

Abstract

PURPOSE:To improve the insulation strength and water-proofing performance. CONSTITUTION:A wire harness main 10 to which a branch 16 is connected in a connecting process is set in a forming die 40 with the upper face open in a setting process. In the setting process, the wire harness main 10 and the branch 16 are being set in a female mold 46, a main holddown 44A and a wire holddown 44B are turned down to the female mold 46 side and the wire harness main 10 and the branch 16 are fixed thereto. In a molding process, hot-melted polyamide resin 22 is poured from the nozzle 62A of a hot-melted dispenser 62 into a resin-poured recess 48 in the forming die 40, in which the wire harness main 10 and the branch 16 are fixed, at 210 deg.C or higher and cooled and hardened at a room temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproofing method for a branching portion of a wire harness branch line for branching a branch line from a main line of a wiring harness for a vehicle, and a processing apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, various methods for waterproofing a branch portion of a wire harness branch line for branching a branch line from a main line of a wiring harness for a vehicle have been considered. Examples thereof are Japanese Patent Publication No. 4-47432 and Japanese Patent Publication No. 4-47433.
The methods disclosed in these publications will be described below.

As shown in FIG. 19, Japanese Patent Publication No. 4-47.
In the method disclosed in Japanese Patent No. 432, the joint portion 104 between the electric wire 100 and the electric wire 102 is covered with a covering material 106, and the covering material 106 is a releasable support made of a plastic molding capable of transmitting ultraviolet rays. Inside the body 108,
It holds the sealing agent 110 which is solidified in the form of jelly. Note that FIG. 19 shows a state in which the support 108 is opened. Further, the sealing agent 110 is an ultraviolet curable resin composition, and after filling the inside of the support 108 with the sealing agent 110, the support 108 is closed and ultraviolet rays are radiated from the outside to seal the sealing agent. 110
Is being cured.

Further, in the method disclosed in Japanese Patent Publication No. 4-47433, a foam hot melt agent is used in place of the UV-curable resin composition as the sealant 110.

[0005]

However, in these methods, after the support 108 is filled with the sealing agent 110 composed of the ultraviolet curable resin composition or the hot melt agent, the support 108 is sealed and irradiated with ultraviolet rays. Alternatively, the sealant 110 is hardened by cooling. Therefore, when the sealing agent 110 hardens, a negative pressure is generated in the support 108 due to the volume contraction of the sealing agent 110, and the electric wires 100, 1
Air may enter the joint 104 from between the core wire of 02 and the coating. For this reason, the insulation strength and the waterproof performance may be reduced, and in the method of using the ultraviolet curable resin composition, the material cost and the equipment cost are expensive.

In view of the above facts, an object of the present invention is to provide a waterproof treatment method for a branch portion of a wire harness branch and a processing apparatus therefor capable of improving insulation strength and waterproof performance.

[0007]

According to a first aspect of the present invention, there is provided a waterproofing method for a branch portion of a wire harness branch line, which comprises a step of connecting a main wire and a branch wire of a wire harness covered with an insulating coating material. A setting step of setting the wire harness in a mold having an open upper surface, and a molding step of pouring hot-melted polyamide resin into the mold in which the wire harness is set and cooling and curing at room temperature. I am trying.

According to a second aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first aspect of the present invention, wherein the polyamide resin has a softening point (JIS). K2207) 150 °
C or higher, hardness at room temperature (JIS C hardness tester) 60-1
00, 30~70P _S, water absorption 0 in melt viscosity 190 °.
6% / day or less, insulation resistance at saturated water absorption of 100 M ohm or more, shear strength of 490 to 640 N / _cm ² , molecular weight of 7,000 to 9000, amide bond is about 35% in terms of molecular weight ratio, and wettability is JISK6768. It is characterized in that it has characteristics such that the prescribed test method gives a rate of 48 dyne / cm or more.

A waterproof treatment method for a branch portion of a wire harness branch line according to the present invention is defined by claim 1 or claim 2.
In the waterproof treatment method for the branch portion of the wire harness branch line described above, the molding die is made of resin.

According to a fourth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the third aspect of the present invention. It is characterized by using a resin mold.

According to a fifth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the present invention.
In the waterproofing method for the branch portion of the wire harness branch line described above, the molding die is made of metal, and the molding die is preheated when the resin is poured.

According to a sixth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the present invention.
In the method for waterproofing a wire harness branch line branching part according to the description, in the molding die, a resin injecting recess formed in a central part into which resin is poured, and a wire harness main line formed at one edge of the resin injecting recess The main line holding part in which the main line holding part is set, the main line holding part which holds down the wire harness main line by the main line holding part, and the wire harness main line and the wire harness branch line formed at the other edge of the resin injecting concave portion are separated by a predetermined distance. It is characterized in that it has a plurality of electric wire holding portions that are opened and set, and an electric wire retainer that presses the wire harness main line and the wire harness branch line with the electric wire retaining portions.

According to a seventh aspect of the present invention, there is provided a waterproofing device for a branch portion of a wire harness branch line, a forming die for holding an electric wire in a fixed position, a conveying device for moving the forming die to a resin injecting portion, and an electric wire. And a hot melt dispenser having a nozzle movable in the axial direction.

A waterproofing device for a branch portion of a wire harness branch line according to the present invention is a molding die for holding an electric wire in a fixed position, a transfer device for moving the molding die to a resin filling portion, and an electric wire. And a hot melt dispenser having a nozzle provided with a plurality of holes in the axial direction.

According to a ninth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the second aspect, which is the waterproof treatment method for a branch portion of a wire harness branch line according to the present invention. It features a wedge shape.

According to a tenth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first aspect of the present invention, which is the waterproof treatment method for a branch portion of the wire harness branch line according to the first aspect. The lower mold is composed of an upper mold and a lower mold connected to each other, and the lower mold has a resin injection recess formed in the center thereof, and a main wire holding portion formed on one edge of the resin injection recess for setting a wire harness main line. And a plurality of electric wire holding portions which are formed on the other edge of the resin injecting concave portion and in which the wire harness main line and the wire harness branch line are set at a predetermined interval, and the upper mold has It is characterized in that the central portion is provided with a window portion that is smaller in the longitudinal direction than the resin injection recess.

According to the eleventh aspect of the present invention, there is provided a waterproofing method for a branch portion of a wire harness branch line, which comprises a step of connecting a main wire and a branch wire of a wire harness covered with an insulating coating material, and molding the wire harness. Mold setting step of setting in mold, injection step of pouring hot-melt polyamide resin, pressurized gas blowing step of blowing pressurized gas such as compressed air into the injection-molded mold, and cooling and curing at normal temperature And a cooling step.

According to a twelfth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the eleventh aspect of the waterproof treatment method for a branch portion of a wire harness branch line according to the present invention. It consists of an upper mold and a lower mold connected via a joint, and the lower mold has a resin injection recess formed in its center and a wire harness main line formed on one edge of the resin injection recess. A main wire holding portion, and a plurality of electric wire holding portions that are formed on the other edge of the resin injecting concave portion and a wire harness main wire and a wire harness branch line are set at a predetermined interval,
The upper mold is characterized in that a central portion thereof is provided with a recess facing the resin injection recess and an air hole for blowing a pressurized gas.

According to a thirteenth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the eleventh aspect, which is a waterproof treatment method for a branch portion of a wire harness branch line according to the present invention. A resin injection recess formed in the central portion, a main line holding portion formed on one edge of the resin injection recess for setting the wire harness main line, and a wire harness formed on the other edge of the resin injection recess From a lower mold provided with a plurality of electric wire holding portions in which the main wire and the wire harness branch wires are set with a predetermined gap, and an upper mold that also serves as a compressed air duct that covers the resin injection recess from above. It is characterized by being formed.

[0020]

According to the method of waterproofing a branch portion of a wire harness branch wire according to the present invention as set forth in claim 1, in the connection step, the main wire and the branch wire of the wire harness covered with an insulating coating material are connected, and in the setting step, The wire harness is set in a mold having an open upper surface, and in the molding step, hot-melted polyamide resin is poured into the mold in which the wire harness is set and cooled and cured at room temperature. At this time,
Since the adhesion between the polyamide resin and the insulation coating material of the wire harness is good, it is possible to improve the insulation strength and waterproof performance of the branch portion of the wire harness branch line.

Further, since the molding die has a large air-opening surface, a difference in curing speed between the resin surface and the inside is small during cooling and curing, and no negative pressure is generated in the molding die, so that air bubbles are generated around the wire. It's hard to do. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials. Further, since there is no special constraint condition on the amount of the material and the amount of the material is easily controlled, the yield of the material is good. Also, because of the easy processing method, no skill is required,
Easy to automate. Furthermore, the material color of the polyamide resin is dark brown and transparent, and the inside can be seen, so that the quality of the connection shape and the resin mold attachment can be visually confirmed.

According to a second aspect of the present invention, there is provided a waterproof treatment method for a branched portion of a wire harness branch line according to the first aspect of the present invention, wherein the polyamide resin has a softening point of 150 ° C. Above, hardness at room temperature 60
~100, 30~70P _S, water absorption 0.6% / day or less, insulation resistance 100M at saturation water in melt viscosity 190 °
A molecular weight of 7,000 to 9000, a amide bond of about 35% in terms of molecular weight ratio, and a wettability of 48 dyne / cm or more by the test method specified by JISK6768 so that the shear strength is 490 or more and the shear strength is 490 to 640 N / _cm ^2. Since the characteristics are provided, the adhesion between the polyamide resin and the insulating coating material of the wire harness is improved, and the insulation strength and the waterproof performance of the branch portion of the wire harness branch line can be improved.

According to a third aspect of the present invention, there is provided a method for waterproofing a wire harness branch line branching portion according to the present invention, wherein the molding die is made of resin. Therefore, as compared with the conventional metal mold, the cooling and curing speed of the resin material can be suppressed. Therefore, at the time of cooling and hardening, a difference in hardening speed between the resin surface and the inside is small and a negative pressure is not generated in the molding die, so that bubbles are less likely to be generated around the electric wire. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials.

According to a fourth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the third aspect of the present invention. Since the resin mold is used, it is not necessary to apply a release agent to the mold. For this reason,
It is possible to prevent the insulation strength and the waterproof performance of the branch portion of the wire harness branch line from being deteriorated due to the surrounding of the release agent.

According to a fifth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first or second aspect, which is a waterproof treatment method for a branch portion of the wire harness branch line. In addition, since the mold is preheated when the resin is poured, the cooling and hardening rate of the metal mold can be suppressed. Therefore, at the time of cooling and hardening, a difference in hardening speed between the resin surface and the inside is small and a negative pressure is not generated in the molding die, so that bubbles are less likely to be generated around the electric wire. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials.

According to a sixth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first or second aspect, which is a waterproof treatment method for a branch portion of the wire harness branch line. Since it has a main wire presser for pressing the wire harness main wire with the holding portion and an electric wire presser for pressing the wire harness main wire and the wire harness branch wire with the electric wire holding portion, between the main wire and the branch wire, or the branch wire. When there are multiple lines, a gap is secured between adjacent branch lines,
It is possible to reliably pour the polyamide resin between the wires to ensure high insulation performance.

In the waterproof treatment device for the branch portion of the wire harness branch line according to the present invention as defined in claim 7, the mold holding the electric wire in a fixed position is moved to the resin injection part by the carrying device.
The hot melt dispenser moves a nozzle in the axial direction of the electric wire, and pours the polyamide resin into the entire region of the mold for resin injection. Therefore, it is possible to efficiently flow the polyamide resin into the resin injection concave portion, and it is possible to significantly improve the productivity. In addition, the equipment configuration is simple, so it is inexpensive. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

In the waterproof treatment device for the branch portion of the wire harness branch line according to the present invention as defined in claim 8, the mold holding the electric wire in a fixed position is moved to the resin injection part by the conveying device. In a hot melt dispenser, a polyamide resin is poured into a resin injection recess of a molding die from a nozzle provided with a plurality of holes in the axial direction of an electric wire. Therefore, it is possible to efficiently flow the polyamide resin into the resin injection concave portion, and it is possible to significantly improve the productivity. In addition, the equipment configuration is simple, so it is inexpensive. Furthermore, because of the easy processing method,
It does not require skill and is easy to automate.

According to a ninth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the second aspect of the present invention. The shape of the polyamide resin makes it difficult for water to collect on the surface, which is advantageous for waterproofness.

In the waterproof treatment method for the branch portion of the wire harness branch line according to the present invention, the polyamide resin, which has begun to solidify at the edge of the window of the upper mold, is pushed down to the lower mold side. It easily flows into the gap between them, and the adhesion between the electric wire coating portion and the polyamide resin is increased, so that excellent waterproof performance is obtained. Moreover, even if the temperature of the polyamide resin is set low by pressing the polyamide resin,
Since the polyamide resin can be sufficiently filled in the gap between the electric wires, the cooling time can be shortened and the polyamide resin can be prevented from being deteriorated due to oxidation at high temperature.

Further, when the upper and lower molds are closed, the polyamide resin rises from the window portion, so that even if sink marks occur during cooling and curing, the connecting portion of the electric wire is not exposed. In addition, since the difference in curing speed between the resin surface and the inside is small and no negative pressure is generated in the molding die during cooling and curing due to the window portion,
Bubbles are less likely to occur around the wires. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials. Also, because there are no special restrictions on the amount of material, and it is easy to control the amount of material,
The material yield is also good. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

In the waterproof treatment method of the branch portion of the wire harness branch line according to the present invention, the pressurized gas such as compressed air is injected into the mold in which the polyamide resin has been injected in the pressurized gas blowing step. Since the polyamide resin is blown in, the polyamide resin easily flows into the gap between the electric wires, and the adhesiveness between the electric wire coating portion and the polyamide resin is increased, so that excellent waterproof performance is obtained. Further, since the polyamide resin and the upper mold are not in contact with each other, sink marks occur on the entire upper surface of the polyamide resin. For this reason, no negative pressure is generated in the mold during cooling and curing, and bubbles are less likely to be generated around the electric wire.

In the waterproofing method of the branch portion of the wire harness branch line according to the present invention, the pressurized gas is blown from the air holes of the upper mold into the mold in which the polyamide resin has been completely injected. Easily flows into the gap between the electric wires, and the adhesiveness between the electric wire coating portion and the polyamide resin increases, so that excellent waterproof performance can be obtained. Further, since the polyamide resin and the upper mold are not in contact with each other, sink marks occur on the entire upper surface of the polyamide resin. For this reason, no negative pressure is generated in the mold during cooling and curing, and bubbles are less likely to be generated around the electric wire.

In the waterproof treatment method of the branch portion of the wire harness branch line according to the present invention, the pressurized gas is blown into the molding die in which the injection of the polyamide resin is completed from the upper die which also serves as the pressurized gas duct. The polyamide resin easily flows into the gap between the electric wires, and the adhesiveness between the electric wire coating portion and the polyamide resin is increased, so that excellent waterproof performance is obtained. Further, since the polyamide resin and the upper mold are not in contact with each other, sink marks occur on the entire upper surface of the polyamide resin. For this reason,
Since there is no negative pressure in the mold during cooling and curing,
Bubbles are less likely to occur around the wires.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a waterproofing method for a branch portion of a wire harness branch line according to the present invention will be described with reference to FIGS.

As shown in FIG. 1A, in the wire harness waterproofing method of the first embodiment, the branch wire 16 is connected to the main wire 10 of the wire harness by thermocompression bonding or metal tube caulking in the wire connecting step. In the setting step, the mold is set in the mold 40 having an open upper surface.

As shown in FIG. 4, the main wire 10 and the branch wire 16 of the wire harness are composed of a copper electric wire 14 having a coating 12 made of vinyl chloride.

As shown in FIG. 2, the molding die 40 is made of Teflon (registered trademark of DuPont) resin mixed with a fluorine resin having good water repellency, and is connected to the upper die 44 through a joint 42. It is composed of a lower mold 46.
The lower mold 46 has a wedge-shaped resin injection recess 48 formed in the center thereof, and a groove as a main line holding portion formed on one longitudinal edge 40A of the resin injection recess 48 for setting the wire harness main line. 50 and two grooves 52, 54 as electric wire holding portions, which are formed on the other edge 40B in the longitudinal direction of the resin injecting recess 48 and in which the wire harness main line and the wire harness branch line are set with a predetermined gap therebetween. And are equipped with. In addition, the upper die 44 includes a main line retainer 44A for retaining the wire harness main line with the groove 50, and the grooves 52, 54.
And an electric wire retainer 44B for pressing the wire harness main line and the wire harness branch line with each other. The main wire retainer 44A is provided with a protrusion 56 that enters the groove 50 and contacts the wire harness main line.
The protrusions 58 and 60 that enter the grooves 52 and 54 and contact the wire harness main line and the wire harness branch line are formed in the.

The grooves 50, 52 and 54 are set so that the gap between the electric wires and the gap between the electric wire and the mold are about 1.5 mm, respectively. When used, it is possible to secure the surrounding property of a predetermined resin and the insulation performance of the product.

As shown in FIG. 1B, in the setting step of the waterproofing method for the wire harness of the first embodiment, with the main wire 10 and the branch wire 16 of the wire harness set in the lower mold 46, The main wire retainer 44A and the electric wire retainer 44B are tilted in the direction of the lower mold 46 (direction of arrow A in FIG. 1B) to fix the main line 10 and the branch line 16 of the wire harness.

As shown in FIG. 1C, in the molding step, the nozzle 62A of the hot melt dispenser 62 is placed in the resin injection recess 48 of the molding die 40 to which the main wire 10 and the branch wire 16 of the wire harness are fixed. From 200 ° C to 2
The polyamide resin 22 hot melted at 20 ° C. is poured and cooled and cured at room temperature. The viscosity of the polyamide resin 22 as, for hot melt to 200 ° C~220 ° C was shown in FIG. 10 has a 30P _S weak.

As shown in FIG. 3, the hot melt dispenser 62 comprises a nozzle 62A, a heater 64, a cylinder sleeve 66, a piston 67, and a cassette holder 68, and a tablet-shaped polyamide resin 70 loaded in the cassette holder 68. It is sent to the cylinder sleeve 66 and pushed into the heater 64 by the piston 67. The tablet-shaped polyamide resin 70 is melted by the heater 64, and the nozzle 62A
The molten polyamide resin 22 is discharged into the resin injection recess 48 of the molding die 40.

Also, the hot melt dispenser 62
Is fixed to the arm 72A of the drive device 72, and is moved integrally with the arm 72A by the piston 74, so that the nozzle 62A is set in the molding die 40 in the axial direction of the wire harness main line 10 (see FIG. ) Arrow F
Direction). Therefore, the polyamide resin 22 is made to flow evenly into the resin injection recess 48 of the molding die 40.

Further, the molding die 40 is cooled by the carrying device 82 having the drive motor 76, the gear 78 and the carrying belt 80, and the cooling stage 8 provided downstream of the nozzle 62A.
It is conveyed to No. 4 and cooled here.

When the above-mentioned polyamide resin is poured into the Teflon resin molding die 40 and cooled in the atmosphere at 20 ° C., it takes 40 seconds or more. Therefore, the cooling stage 8
It is preferable that two or more 4 are provided.

As shown in FIG. 4, the product 86 taken out from the mold after cooling and hardening is the main wire 10 of the wire harness.
A polyamide resin 22 covers a connecting portion 20 between the branch wire 16 and the branch wire 16. Further, the polyamide resin 22 of the product 86 has a wedge shape with no unevenness on the surface, so that the water can be immediately cut off even if it is covered with water. Further, the polyamide resin 22 of the product 86 has a wall thickness A of about 1.5 mm all around the electric wire,
The sealing length B of each electric wire is about 5 mm, and the gap C between the electric wires is about 1.5 mm. The outer diameter of the wire is 2 mm.

Further, the product 86, after the temperature and humidity stress is added,
Insulation resistance 100M ohm or more at room temperature, tensile strength 6
0N above, has a sealing pressure 50KP _a more properties.

As shown in FIGS. 5 and 6, the temperature stress and the humidity stress are assumed to be used in an environment where there is a possibility of rainwater in the engine room of the automobile. In addition, the performance standard is a value based on the following evaluation method in consideration of general use conditions of the automobile and durability when the wire harness is assembled to the vehicle body.

As shown in FIG. 7, for insulation resistance, a metal foil 28 is wound around the waterproofing portion 26 of the wire harness 24, and DC 5 is applied between the copper wire 30 and the metal foil 28 of the wire harness 24.
The value is measured with an insulation resistance meter of 00V.

As shown in FIG. 8, the tensile strength is 100 in the axial direction of the electric wire (direction of arrow C in FIG. 8) while fixing one end 24A of the wire harness 24, grasping the waterproofing processing portion 26.
It is pulled at a constant speed of mm / min, and the load is applied when the waterproofing portion 26 is pulled out or peeled from the wire harness 24.

As shown in FIG. 9, the seal pressure is such that compressed air is sent from the copper wire of the wire harness 24 from the air source 34 via the air regulator 32, and air leaks from the waterproof processing portion 26 immersed in the water 36. The air pressure when it is generated.

Further, in order to satisfy each required performance of the product,
As a material of the waterproofing unit 26, a softening point (JIS K2
207) Hardness at room temperature (JIS C
Hardness meter) 60 to 100, melt viscosity at 190 ° C 30 to 7
0P _S (see FIG. 10), water absorption rate 0.6% / day or less (see FIG. 11, measured with a plate having a thickness of 3 mm), insulation resistance at saturated water absorption of 100 ohms or more (see FIG. 12, plate with a thickness of 3 mm) To have a shear strength of 490 to 690 N / cm ² , a molecular weight of 7,000 to 9000, an amide bond is about 35% in a molecular weight ratio, and the distribution of the amide bond in the molecule is unevenly distributed so that the molecule itself has electrical characteristics. Polyamide resin is used.

Next, the operation of the first embodiment will be described. In the waterproof treatment method for the branch portion of the wire harness branch line of the first embodiment, the branch line 16 is connected to the main line 10 of the wire harness in the connecting step, and the molding die 40 having an open upper surface is set in the setting step. set. Next, in the molding step, the hot-melted polyamide resin 22 is poured into the resin injection recess 48 of the molding die 40 in which the wire harness is set, and is cooled and cured at room temperature. At this time, the adhesion between the polyamide resin 22 and the insulation coating material 12 of the wire harness is good, so that the insulation strength and the waterproof performance of the branch portion of the wire harness branch line can be improved.

Further, since the upper die 44 of the molding die 40 is divided into the main line retainer 44A and the wire retainer 44B, the atmosphere open surface of the molding die 40 is wide. Therefore, at the time of cooling and hardening, a difference in hardening speed between the resin surface and the inside of the resin is small, and a negative pressure is not generated in the molding die 40, so that bubbles are less likely to be generated around the electric wire. For the same reason, internal stress is less likely to remain, and solvent stress cracks of the product 86 are less likely to occur even when contacting various oil materials.

Further, since there is no special restriction condition on the amount of the polyamide resin 22 and the amount of the polyamide resin 22 can be easily controlled, the yield of the polyamide resin 22 is good. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

Further, in the waterproof treatment method for the branch portion of the wire harness branch according to the first embodiment, the polyamide resin 22 used has a softening point of 150 ° C. or higher and a hardness of 60 to 60 at room temperature.
100, 30~70P _S, water absorption 0.6% / day or less, insulation resistance 100M at saturation water in melt viscosity 190 °
A molecular weight of 7,000 to 9000, a amide bond of about 35% in terms of molecular weight ratio, and a wettability of 48 dyne / cm or more by the test method specified by JISK6768 so that the shear strength is 490 or more and the shear strength is 490 to 640 N / _cm ^2. Because of the characteristics, the adhesiveness between the polyamide resin 22 and the insulating coating material 12 of the wire harness is improved, and the insulation strength and waterproof performance of the branch portion of the wire harness branch line can be further improved.

Further, since the material color of the polyamide resin 22 is dark brown and the inside can be seen, it is possible to visually check the quality such as the connection shape and the resin mold attachment condition.

Further, in the waterproofing method of the branch portion of the wire harness branch line according to the first embodiment, since the mold 40 is made of Teflon resin, the polyamide resin 22 is cooled more than the conventional metal mold. The curing speed can be suppressed.
Therefore, at the time of cooling and hardening, a difference in hardening speed between the resin surface and the inside is small and no negative pressure is generated in the molding die, so that bubbles are less likely to be generated around the electric wire. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials.

Further, since it is made of Teflon resin having good water repellency, it is not necessary to apply a mold release agent to the molding die. Therefore, it is possible to prevent the insulation strength and the waterproof performance of the branch portion of the wire harness branch line from being deteriorated due to the release agent getting around.

In the hot melt dispenser 62 of the first embodiment, the nozzle 62A is movable in the axial direction of the wire harness main line 10 set in the molding die 40. Therefore, the polyamide resin 22 evenly flows into the resin injection recess 48 of the molding die 40, and the molding die 40
It is possible to efficiently flow the polyamide resin into the resin injection recess 48, and it is possible to significantly improve the productivity. In addition, the equipment configuration is simple, so it is inexpensive. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

When the length of the polyamide resin 22 in the axial direction of the electric wire is 25 mm or more, when a single hole nozzle having a shaft diameter of about 1 mm is used, the resin injection recess 4 of the molding die 40 is used.
In order to uniformly fill the polyamide resin 22 in 8, the nozzle 62A requires a moving mechanism that allows the nozzle 62A to move in the axial direction of the wire harness main line 10 set in the molding die 40, but instead of this, As shown in FIG. 13, a nozzle 88 having a plurality of holes 88A formed along the axial direction of the wire harness main line 10 may be used.

Further, in the waterproof treatment method for the branch portion of the wire harness branch line of the first embodiment, since the polyamide resin 22 of the product 86 has a wedge shape without unevenness on the surface, it is difficult for water to collect on the surface of the polyamide resin. It is advantageous for waterproofing.

Next, a second embodiment of the waterproofing method for the branch portion of the wire harness branch line according to the present invention will be described with reference to FIGS. 14 and 15.

The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 14, a window 92 is formed in the center of the upper die 90 of the molding die 40 of the second embodiment. The length L1 of the window portion 92 along the longitudinal direction of the upper die 90 is smaller than the length L2 of the resin injection recess 48, and the pressing portion 90 is provided on both edges of the window portion of the upper die 90.
A and 90B are formed.

Therefore, as shown in FIG.
Is closed, the pressing portions 90A, 90 formed on the upper die 90 are closed.
B lowers the polyamide resin 22 which has begun to solidify (see FIG. 15).
Polyamide resin 22
Easily flows into the gap between the electric wires, and the adhesiveness between the electric wire coating portion and the polyamide resin increases, so that excellent waterproof performance can be obtained. Further, by pressing the polyamide resin 22, even if the temperature of the polyamide resin 22 is set low, the polyamide resin 22 can be sufficiently filled in the gap between the electric wires, so that the cooling time can be shortened.

Further, when the upper mold 90 is closed, the polyamide resin 22 rises from the window 92 as shown by the imaginary line in FIG. 15, so that even if sink marks occur during cooling and curing, the connecting portion of the wire is exposed. There is nothing to do. Further, due to the window portion 92, a difference in curing speed between the resin surface and the inside is small during cooling and curing, and a negative pressure is not generated in the molding die 40. For this reason, bubbles are less likely to be generated around the electric wire. For the same reason, internal stress is less likely to remain, and solvent stress cracks are less likely to occur when contacting various oil materials. Further, since there is no special constraint condition on the amount of the material and the amount of the material is easily controlled, the yield of the material is good. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

Next, a third embodiment of the waterproofing method for the branch portion of the wire harness branch line of the present invention will be described with reference to FIGS.

The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 16, in the upper mold 94 of the molding die 40 of the third embodiment, a concave portion 96 facing the resin injection concave portion 48 of the lower mold 46 is communicated with the concave portion 96 at the central portion. An air hole 98 is formed to blow the pressurized gas into the recess 96.

Therefore, as shown in FIG. 17, in the pressurized gas blowing step, a pressurized gas such as compressed air is blown into the molding die 40 in which the injection of the polyamide resin 22 is completed through the air holes 98. Therefore, due to this atmospheric pressure, the polyamide resin 22 easily flows into the gap between the electric wires, and the adhesion between the electric wire coating portion and the polyamide resin 22 is increased, so that excellent waterproof performance is obtained. Further, since the polyamide resin 22 and the ceiling portion 96A of the recess 96 of the upper mold 94 are not in contact with each other, the polyamide resin 22 is cooled and cured from a raised position as shown by an imaginary line in FIG.
Sinking occurs on the entire upper surface. Therefore, no negative pressure is generated in the molding die 40 during cooling and curing, and bubbles are less likely to be generated around the electric wire.

For the same reason, it becomes difficult for internal stress to remain,
Solvent stress cracks are less likely to occur when contacting various oil materials. Also, there are no special restrictions on the amount of material,
The yield of the material is good because it is easy to control the amount of the material. Furthermore, since it is an easy processing method, no skill is required and it is easy to automate.

Instead of the upper mold 94, as shown in FIG. 18, an upper mold 99 which also serves as a compressed air duct for covering the resin injection recess 48 of the lower mold 46 from above may be used.

[0074]

According to the method of waterproofing a branch portion of a wire harness branch line according to the present invention, a molding step of pouring hot-melted polyamide resin into a mold in which the wire harness is set and cooling and hardening at room temperature is performed. As a result, it has an excellent effect that the insulation strength and the waterproof performance can be improved.

According to a second aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the present invention, which is the same as the waterproof treatment method for a branch portion of the wire harness branch line according to the first aspect, in which the polyamide resin has a softening point (JIS K2207). ) 150 ° C or higher, normal temperature hardness (JIS C hardness meter) 60 to 100,
30~70P _S, water absorption of 0.6% in melt viscosity 190 ° /
day or less, insulation resistance at saturated water absorption of 100 M ohms or more, and shear strength of 490 to 640 N / _cm ² , a molecular weight of 7,000 to 9000, and an amide bond in a molecular weight ratio of about 3
Since the wettability is 5% and the wettability is 48 dyne / cm or more according to the test method defined by JISK6768, the adhesion between the polyamide resin and the insulation coating material of the wire harness is improved, and the wire harness branch line is improved. It has an excellent effect that the insulation strength and the waterproof performance of the branch portion can be improved.

According to a third aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first aspect of the present invention. Therefore, when cooling and curing, the difference in curing speed between the resin surface and the inside is small and there is no negative pressure in the mold, so it is difficult for bubbles to form around the wire and when it contacts various oil materials. It has an excellent effect that the solvent stress crack of (3) is unlikely to occur.

In the waterproof treatment method for a wire harness branch line branch portion according to the present invention as defined in claim 4, in the waterproof treatment method for a wire harness branch line branch portion according to claim 3, a water-repellent fluorine resin is blended. Since a resin mold is used, it is not necessary to apply a mold release agent to the mold, so it is possible to prevent deterioration of the insulation strength and waterproof performance of the wire harness branch line branch part due to the surrounding of the mold release agent. Have an effect.

According to a fifth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the first aspect of the present invention. In addition, since the mold heats up when the resin is poured, there is little difference in the curing speed between the resin surface and the interior during cooling and curing, and there is no negative pressure inside the mold, so air bubbles form around the wire. It has an excellent effect that it is difficult to generate solvent stress cracks when it comes into contact with various oil materials. In the waterproof treatment method for a wire harness branch line branch portion according to the present invention according to claim 6, in the waterproof treatment method for a wire harness branch line branch portion according to claim 1 or 2, the molding die is a main line holding portion. Since it has a main wire retainer that holds down the wire harness main wire with and a wire retainer that holds down the wire harness main wire and the wire harness branch line with the wire holding part, the polyamide resin flows securely between the wires. It has an excellent effect that it is possible to secure high insulation performance.

In the waterproof treatment device for the branch portion of the wire harness according to the present invention as defined in claim 7, the hot melt dispenser has a nozzle movable in the axial direction of the electric wire, and the polyamide resin is applied to the entire area of the resin injection recess of the molding die. Because of the pouring configuration, the polyamide resin can be efficiently flowed into the resin injecting recess, and the productivity can be significantly improved. In addition, the equipment configuration is simple, so it is inexpensive. Further, since it is an easy processing method, it has an excellent effect that it requires no skill and is easy to automate.

In the waterproofing device for branching the wire harness branch line according to the present invention as defined in claim 8, the hot melt dispenser is provided with a plurality of holes in the axial direction of the electric wire, from the nozzle provided with a plurality of holes to the resin injection concave portion of the molding die. Since the polyamide resin is poured into the resin injection mold, it is possible to efficiently flow the polyamide resin into the resin injection recess, and it is possible to significantly improve the productivity. In addition, the equipment configuration is simple, so it is inexpensive. Further, since it is an easy processing method, it has an excellent effect that it requires no skill and is easy to automate.

According to a ninth aspect of the present invention, there is provided a waterproof treatment method for a branch portion of a wire harness branch line according to the second aspect of the present invention, which is a waterproof treatment method for a branch portion of a wire harness branch line, wherein the polyamide resin is a wedge having no irregularities on its surface. Because of the shape, the polyamide resin has an excellent effect that it is difficult for water to collect on the surface and is advantageous in waterproofness.

In the waterproof treatment method for the branch portion of the wire harness branch line according to the present invention as defined in claim 10, since the polyamide resin which has started to solidify at the edge of the window of the upper mold is pushed down to the lower mold side, the insulation strength and the It has an excellent effect that the waterproof performance can be improved. Moreover, even if the temperature of the polyamide resin is set low by pressing the polyamide resin,
Since the polyamide resin can be sufficiently filled in the gap between the electric wires, there is an excellent effect that the cooling time can be shortened.

In the waterproof treatment method of the branch portion of the wire harness branch line according to the present invention, the pressurized gas such as compressed air is injected into the mold in which the polyamide resin has been injected in the pressurized gas blowing step. Since it blows in, it has an excellent effect that the insulation strength and the waterproof performance can be improved.

In the waterproofing method of the branch portion of the wire harness branch line according to the present invention, the pressurized gas is blown from the air holes of the upper die into the molding die in which the polyamide resin has been completely injected. It also has an excellent effect that the waterproof performance can be improved.

In the waterproofing method for the branch portion of the wire harness branch line according to the present invention, the pressurized gas is blown into the molding die in which the injection of the polyamide resin is completed from the upper die which also serves as the pressurized gas duct. It has an excellent effect that the insulation strength and the waterproof performance can be improved.

[Brief description of drawings]

1A to 1C are explanatory views showing a waterproof treatment method for a wire harness branch line branch portion according to a first embodiment of the present invention.

FIG. 2 is a three-sided view showing a molding die of the waterproof processing apparatus for the wire harness branch line branching portion according to the first embodiment of the present invention.

FIG. 3 is a schematic view showing a waterproof processing device for a branch portion of a wire harness branch line according to the first embodiment of the present invention.

FIG. 4 is a three-sided view showing a product manufactured by the waterproofing method for the branch portion of the wire harness branch line according to the first embodiment of the present invention.

FIG. 5 is a graph showing temperature stress of a product manufactured by the waterproof treatment method for the wire harness branch portion according to the first embodiment of the present invention.

FIG. 6 is a graph showing humidity stress of a product manufactured by the waterproofing method for the branch portion of the wire harness branch according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of an insulation resistance measuring method.

FIG. 8 is an explanatory diagram of a tensile strength measuring method.

FIG. 9 is an explanatory diagram of a seal pressure measuring method.

FIG. 10 is a graph showing melt viscosity of polyamide resin.

FIG. 11 is a graph showing the water absorption rate of a polyamide resin.

FIG. 12 is a graph showing a relationship between a water absorption rate of a polyamide resin and an insulation resistance value.

FIG. 13 is a perspective view showing another example of the nozzle of the waterproof processing device for the wire harness branch line branch portion according to the first example of the present invention.

FIG. 14 is a perspective view showing a molding die of the waterproof processing apparatus for the wire harness branch line branching portion according to the second embodiment of the present invention.

FIG. 15 is a side sectional view showing a molding die of the waterproof processing apparatus for the wire harness branch line branching portion according to the second embodiment of the present invention.

FIG. 16 is a perspective view showing a molding die of a waterproof processing device for a branch portion of a wire harness branch line according to a third embodiment of the present invention.

FIG. 17 is a side sectional view showing a molding die of the waterproof processing apparatus for the wire harness branch line branching portion according to the third embodiment of the present invention.

FIG. 18 is a perspective view showing a modified example of the molding die of the waterproof processing apparatus for the wire harness branch line branch portion according to the third example of the present invention.

FIG. 19 is a perspective view showing a waterproofing method for a branch portion of a wire harness branch line according to a conventional example.

[Explanation of symbols]

 10 wire harness main wire 12 coating 16 branch wire 20 connection portion 22 polyamide resin 40 molding die 42 joint 44 upper die 44A main wire retainer 44B electric wire retainer 46 lower die 48 resin injection recess 50 groove (main wire retaining portion) 52 groove (electric wire retaining) 54 groove (electric wire holding part) 62 hot melt dispenser 62A nozzle 72 drive device 84 cooling stage 86 product 88 nozzle 88A hole 90 upper mold 90A pressing part 90B pressing part 92 window part 94 upper mold 96 concave part 98 air hole 99 upper mold

Claims (13)

[Claims] 1. A wire connecting step of connecting a main wire and a branch wire of a wire harness coated with an insulating coating material, a setting step of setting the wire harness in a mold having an open upper surface, and the wire harness being set. And a molding step of pouring hot-melted polyamide resin into a molding die and cooling and hardening at room temperature. 2. The softening point (JIS
K2207) Hardness at room temperature (JIS)
C hardness meter) 60 to 100, melt viscosity 30 at 190 °
～70P _S, water absorption 0.6% / day or less, when the saturated water absorption insulation resistance 100M Ohm or more, the shear strength 490-64
As will be 0N / _cm ^2, molecular weight 7000 to 9000,
The amide bond is about 35% in terms of molecular weight, and the wettability is JIS
2. The waterproof treatment method for a branch portion of a wire harness branch line according to claim 1, wherein the test method defined by K6768 is provided with a property of 48 dyne / cm or more. 3. The waterproof treatment method for a branch portion of a wire harness branch line according to claim 1, wherein the molding die is made of resin. 4. The waterproofing method for a branch portion of a wire harness branch line according to claim 3, wherein a resin molding die containing a fluorine resin having good water repellency is used. 5. The waterproof treatment method for a branch portion of a wire harness branch line according to claim 1, wherein the molding die is made of metal and the molding die is preheated when the resin is poured. 6. The molding die comprises: a resin injection recess formed in a central portion into which a resin is poured; and a main wire holding portion formed on one edge of the resin injection recess for setting a wire harness main line. A main wire retainer for pressing the wire harness main wire with the main wire holding portion, and a plurality of wire harness main wires formed on the other edge of the resin injection recess and wire harness branch wires are set at a predetermined interval. The wire harness branching part according to claim 1 or 2, further comprising: a wire holding part; and a wire holding part for holding the wire harness main line and the wire harness branch line by the wire holding part. Waterproof treatment method. 7. A molding die for holding an electric wire in a fixed position, a conveying device for moving the molding die to a resin filling portion, and a hot melt dispenser having a nozzle movable in an axial direction of the electric wire. A featured waterproofing device for the branch part of the wire harness branch line. 8. A molding die for holding an electric wire in a fixed position, a conveying device for moving the molding die to a resin filling portion, a hot melt dispenser having a nozzle having a plurality of holes in the axial direction of the electric wire, A waterproofing device for a branch portion of a wire harness branch line, comprising: 9. The waterproof treatment method for a branch portion of a wire harness branch line according to claim 2, wherein the polyamide resin has a wedge shape with no surface irregularities. 10. The molding die comprises an upper die and a lower die which are connected via a joint, and the lower die has a resin injecting recess formed in the center thereof and one of the resin injecting recesses. A main wire holding portion formed on the edge and on which the wire harness main wire is set, and a plurality of electric wires formed on the other edge of the resin injecting recess and on which the wire harness main wire and the wire harness branch line are set with a predetermined gap. 2. The wire harness branch wire branching part according to claim 1, further comprising a holding part, wherein the upper mold part is provided with a window part which is smaller in a longitudinal direction than the resin injecting recess part in a central part thereof. Waterproof treatment method. 11. A wire connecting step of connecting a main wire and a branch wire of a wire harness coated with an insulating coating material, a mold setting step of setting the wire harness in a mold, and a pouring step of pouring a hot-melt polyamide resin. And waterproofing of the wire harness branch line branching part, which includes a step of blowing a pressurized gas such as compressed air into the injection-molded mold and a cooling step of cooling and hardening at room temperature. Processing method. 12. The molding die comprises an upper die and a lower die connected to each other through a joint, the lower die having a resin injection recess formed in the center thereof and one of the resin injection recesses. A main line holding portion formed on an edge and on which the wire harness main line is set, and a plurality of wire harness main lines formed on the other edge of the resin injecting recess and a wire harness branch line are set at a predetermined interval. An electric wire holding part is provided, and the upper mold part is provided with a concave part facing the resin injecting concave part and an air hole for blowing a pressurized gas in a central part thereof. A method for waterproofing a branched portion of a wire harness branch described. 13. The molding die includes a resin injection recess formed in a central portion, and a main wire holding portion formed on one edge of the resin injection recess for setting a wire harness main line.
A lower mold provided with a plurality of electric wire holding portions formed on the other edge of the resin injecting recess and having a wire harness main line and a wire harness branch line set at predetermined intervals, and a resin injecting recess The method of waterproofing a branch portion of a wire harness branch line according to claim 11, further comprising: an upper mold that also serves as a compressed air duct that covers the above from above.