Electrically conductive part, wire harness, and method for manufacturing electrically conductive part

Abstract

The object of the present invention is to provide an electrically conductive part having excellent water-blocking properties within a conductor bundle. [Solution] The electrically conductive component of the present invention comprises a wire bundle having a plurality of wires, a first resin attached to the wires, and an injection-molded product that seals the wire bundle and contains a second resin, wherein in a cross section perpendicular to the axial direction of the wire bundle, the wires and the first resin are present in the inner region of the outermost tangent of the wire bundle, and the total area ratio of cavities in the inner region is 20% or less.

Description

[Technical field]

[0001] The present invention relates to an electrical conductive component and a wire harness. [Background technology]

[0002] Conventionally, vehicles such as motorcycles and automobiles are equipped with wire harnesses having insulated wires. In order to bundle a plurality of insulated wire bundles, the insulating layer of the insulated wires may be partially stripped to expose the conductors, and the exposed conductors may be joined by welding, crimping, or the like. In other cases, the exposed conductors may be joined to metal terminals. In such cases, there are problems such as water entering the insulated wires from the exposed conductors or electric leakage. To solve these problems, a technology is known in which the exposed conductors are sealed with resin.

[0003] Patent Document 1 discloses a wire harness in which the connection between the insulated electric wire and the metal terminal is embedded inside a molded resin, and a waterproof layer made of a silicone-based adhesive is formed on the connection to prevent water from entering the inside of the electric wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-126981 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a waterproof layer made of a silicone-based adhesive is formed at the connection between the insulated electric wire and the metal terminal, but no consideration has been given to the waterproofing of water that flows through the internal cavity of the wire bundle. Therefore, it cannot be said that this is sufficient to stop water from seeping into the wire bundle due to deterioration of the molded part or waterproof layer, for example.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrical conductive part having excellent water blocking properties within a conductor bundle. [Means for solving the problem]

[0007] The present invention is configured as follows. [1] An electrically conductive component comprising a wire bundle having a plurality of wires, a first resin attached to the wires, and a second resin sealing the wire bundle, wherein in a cross section perpendicular to the axial direction of the wire bundle, the wires and the first resin are present in an inner region of an outermost tangent of the wire bundle, and the total area ratio of cavities in the inner region is 20% or less. [2] The electrically conductive component according to [1] above, wherein the total area ratio of the conductors in the inner region is 80% or less. [3] An electrically conductive component according to [1] or [2] above, wherein the first resin has a maximum thickness outside the outermost tangent of 0.1 mm or less. [4] The electrically conductive part according to any one of the above [1] to [3], further comprising an insulating third resin covering at least a partial section of the conductive wire bundle. [5] An electrically conductive component as described in [4] above, wherein the maximum thickness of the first resin from the outermost tangent is smaller than the thickness of the third resin. [6] The electrically conductive component according to any one of the above [1] to [5], wherein at least some of the conductive wires are joined to each other. [7] The electrically conductive part according to any one of the above [1] to [6], wherein the first resin is at least one selected from the group consisting of polyester-based resins, urethane-based resins, epoxy-based resins, and acrylic-based resins. [8] The electrically conductive component according to any one of [1] to [7], wherein the second resin is at least one selected from the group consisting of polyester-based resins, polyamide-based resins, and polyolefin-based resins. [9] A wire harness having the electrically conductive part according to any one of [1] to [8] above. Effect of the Invention

[0008] According to the present invention, the above-mentioned configuration makes it possible to provide an electrically conductive component having excellent water blocking properties within a conductor bundle. [Brief description of the drawings]

[0009] [Figure 1] Fig. 1(a) shows a plan view of the electrical conductive component of the first embodiment. Fig. 1(b) shows the plan view of Fig. 1(a) with the second resin omitted and only the outline of the first resin shown. Fig. 1(c) shows a B-B cross-sectional view of Fig. 1(a). [Diagram 2] Fig. 2(a) shows a plan view of an electrically conductive component according to a second embodiment. Fig. 2(b) shows the plan view of Fig. 2(a) with the second resin omitted and only the outline of the first resin shown. Fig. 2(c) shows a side view of Fig. 2(b). Fig. 2(d) shows a B-B cross-sectional view of Fig. 2(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present inventors conducted extensive research to provide an electrically conductive component having excellent water blocking properties within a conductor bundle. As a result, they found that the desired object can be achieved by an electrically conductive component that includes a conductor bundle having a plurality of conductor wires, a first resin attached to the conductor wires, and a second resin sealing the conductor bundle, in which the conductor wires and the first resin are present in an inner region of an outermost tangent of the conductor bundle in a cross section perpendicular to the axial direction of the conductor bundle, and the total area ratio of cavities in the inner region is 20% or less, and thus completed the present invention.

[0011] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and it is possible to carry out the present invention by making appropriate modifications within the scope of the above and below-mentioned aims, and all such modifications are included in the technical scope of the present invention.

[0012] (First embodiment) Fig. 1(a) shows a plan view of an electrically conductive component according to a first embodiment. Fig. 1(b) shows the plan view of Fig. 1(a) in which the second resin is omitted and only the outline of the first resin is shown. Fig. 1(c) shows a cross-sectional view taken along line B--B of Fig. 1(a). The dashed lines in Fig. 1(c) indicate the outermost tangents of the conductor bundle.

[0013] 1(a) and (b), an electrically conductive component 10 has a conductor bundle 5 having a plurality of conductor wires 4, a first resin 1 attached to the conductor wires 4, and a second resin 2 sealing the conductor bundle 5. Furthermore, as shown in Fig. 1(a) and (c), in a cross section perpendicular to the axial direction A of the conductor bundle 5 (hereinafter sometimes referred to as a BB cross section), the conductor wires 4 and the first resin 1 are present in an inner region 7 (hereinafter sometimes referred to as the inner region 7) of the outermost tangent of the conductor bundle 5, and the total area ratio of cavities 6 in the inner region 7 is controlled to 20% or less.

[0014] The outermost tangent in the present invention refers to the shortest tangent that circumscribes the plurality of conductor wires 4 so as to surround them in a cross section perpendicular to the axial direction A of the conductor bundle 5.

[0015] The greatest feature of the present invention is that in the B-B cross section, the total area ratio of the cavities 6 in the inner region 7 relative to the inner region 7 is controlled to 20% or less. Normally, cavities exist between multiple conductors 4, but in the present invention, the first resin 1 is adhered between the conductors 4 to reduce the total area ratio of the cavities 6 to 20% or less. This makes it easier to stop water that has infiltrated into the conductor bundle 5. The total area ratio of the cavities 6 is preferably 9% or less, more preferably 5% or less, even more preferably 2% or less, even more preferably 1% or less, particularly preferably 0.1% or less, and most preferably 0%.

[0016] The total area ratio (%) of the cavities 6 in the inner region 7 is calculated by the following formula. Total area ratio (%) of the cavities 6 in the inner region 7 = Total area of ​​the cavities 6 in the inner region 7 / Area of ​​the inner region 7 Each total area can be determined, for example, by cutting the sealing portion 9 perpendicular to the axial direction A at a position 1 cm away from the end of the third resin 3 in the axial direction A of the wire bundle 5, polishing the cross section, observing the cross section under an optical microscope (magnification 50x), photographing it, and performing image analysis on the photograph.

[0017] In addition, in the B-B cross section, it is preferable that the total area ratio of the conductors 4 in the inner region 7 relative to the inner region 7 is 80% or less. By making the total area ratio of the conductors 4 80% or less, it is possible to increase the amount of the first resin 1 attached per conductor 4, making it easier to improve the water stopping performance. It is more preferable that it is 70% or less, and even more preferable that it is 60% or less. On the other hand, by making the total area ratio of the conductors 4 20% or more, it is easier to suppress the propagation of cracks when they occur in the first resin 1. It is preferably 20% or more, more preferably 40% or more, and even more preferably 50% or more.

[0018] The first resin 1 is not particularly limited as long as it can be attached to the conductor, and examples thereof include one or more types selected from the group consisting of polyester resins, urethane resins, epoxy resins, and acrylic resins. These are preferred because they tend to improve adhesion to the second resin 2 used for sealing. Of these, polyester resins are more preferred.

[0019] The polyester resin is formed by reacting a carboxylic acid component with a hydroxyl group component. Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, and naphthalenedicarboxylic acid. Examples of the hydroxyl group component include ethylene glycol, 1,4-butanediol, diethylene glycol, neopentyl glycol, and cyclohexanedimethanol.

[0020] The urethane resin is formed by reacting a hydroxyl group component (prepolymer) with an isocyanate compound (curing agent). Examples of the hydroxyl group component include polyester polyol, polycaprolactone polyol, polyether polyol, polyalkylene polyol, and polycarbonate polyol. Examples of the isocyanate compound include diisocyanates such as trimethylene diisocyanate (TDI), hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), and xylylene diisocyanate (XDI).

[0021] Epoxy resins are formed by reacting a prepolymer having two or more epoxy groups in one molecule with various curing agents. Examples of prepolymers include glycidyl ether type epoxy resins, hydrogenated bisphenol A type epoxy resins, glycidyl ester type epoxy resins, glycidyl ether type epoxy resins, alicyclic epoxy resins, modified epoxy resins obtained by modifying these with alkylphenols or fatty acids, and novolac type epoxy resins. Examples of curing agents include phenolic compounds, aliphatic amines, alicyclic amines, aromatic polyamines, polyamides, aliphatic acid anhydrides, alicyclic acid anhydrides, aromatic acid anhydrides, dicyandiamide, organic acid dihydrazides, boron trifluoride amine complexes, imidazoles, and tertiary amines.

[0022] The acrylic resin is formed by polymerizing an acrylic monomer. Examples of the acrylic monomer include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-hexyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 4-hydroxybutyl acrylate, hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, and hydroxypropyl methacrylate.

[0023] The first resin 1 may contain a curing catalyst, for example, tin, amine, bismuth, or the like.

[0024] The first resin 1 preferably has a maximum thickness (hereinafter referred to as the maximum thickness of the first resin 1) of 0.1 mm or less outside the outermost tangent of the conductor bundle 5. By making the maximum thickness of the first resin 1 0.1 mm or less, the contact area between the first resin 1 and the second resin 2 can be reduced, and it is easy to prevent the occurrence of voids at the contact surface. The maximum thickness of the first resin 1 is more preferably 0.08 mm or less, and even more preferably 0.05 mm or less. On the other hand, by making the maximum thickness of the first resin 1 0.001 mm or more, it is easy to prevent the intrusion of water from the outside of the conductor bundle 5. The maximum thickness of the first resin 1 is more preferably 0.01 mm or more, and even more preferably 0.02 mm or more.

[0025] The second resin 2 seals the conductor bundle 5. This makes it easier to prevent water from entering the conductor bundle 5. The second resin 2 is not particularly limited as long as it can seal the conductor bundle 5 by injection molding or the like, and both thermoplastic resins and thermosetting resins can be used. In consideration of the adhesiveness to the first resin 1, the second resin 2 is preferably one or more types selected from the group consisting of polyester-based resins, polyamide-based resins, and polyolefin-based resins. Of these, polyester-based resins are more preferable.

[0026] The polyester resin is formed by reacting a carboxylic acid component with a hydroxyl group component as described above. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and poly(1,4-cyclohexanedimethylene terephthalate). Commercially available products include Viroshot (registered trademark, manufactured by Toyobo Co., Ltd.). Viroshot can be injected even at low pressure, making it easier to suppress damage to the conductor bundle 5 during injection molding. For this reason, Viroshot is particularly preferred. Examples of Viroshot include Viroshot (registered trademark) GM-955 series and GM-960 series.

[0027] Polyamide resins are polymers that have amide bonds in the molecule. Examples of polyamide resins include nylon 6,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 6, nylon 12, nylon 11, and nylon 4,6.

[0028] The polyolefin resin is a homopolymer or copolymer of olefins such as ethylene, propylene, butene, or a copolymer of these olefins and a monomer component copolymerizable therewith. Examples of the polyolefin resin include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-α-olefin copolymer, ethylene-propylene copolymer, and ethylene-butene copolymer.

[0029] Conventional additives can be added to the second resin 2 within a range that does not impair the properties of the second resin 2. Examples of additives include fillers such as silica and talc; flame retardants such as antimony oxide, aluminum hydroxide, and magnesium hydroxide; plasticizers such as phthalates and adipates; release agents such as polyethylene wax and silicone oil; and hydrolysis inhibitors such as carbodiimides. These additives may be used alone or in combination of two or more. The content of the additive is preferably about 0.1 parts by mass or more and 50 parts by mass or less in 100 parts by mass of the second resin 2. More preferably, it is 1 part by mass or more and 30 parts by mass or less, and even more preferably, it is 5 parts by mass or more and 20 parts by mass or less.

[0030] 1(a) and 1(c), in the first embodiment, the shape of the sealing portion 9 sealed by the second resin 2 is cylindrical, but the shape is not particularly limited. Examples of the shape of the sealing portion 9 in a cross section perpendicular to the axial direction A of the conductor bundle 5 include a circle, an ellipse, and a polygon such as a triangle or a rectangle. The cross-sectional shape of the sealing portion 9 in the axial direction A may also be different. Since the sealing portion 9 has a variety of shapes, it can be accommodated in a variety of locations.

[0031] As shown in Fig. 1(b), it is preferable that parts of the conductive wires 4 are joined to each other to form a joint 11. This allows electrical continuity to be achieved. The joining may be performed by a known method such as welding or crimping.

[0032] The electrically conductive component 10 preferably has an insulating third resin 3 covering at least a partial section of the conductive wire bundle 5. By covering the conductive wire bundle 5 with the insulating third resin 3, an insulated wire can be formed.

[0033] The third resin 3 is not particularly limited as long as it is an insulating resin, but is preferably one or more resins selected from the group consisting of polyvinyl chloride, polyethylene, and polypropylene, which are used for the insulating layer of an insulated electric wire. Of these, polyvinyl chloride is more preferable.

[0034] When the third resin 3 is included, the maximum thickness of the first resin 1 is preferably smaller than the thickness of the third resin 3. This makes it easier to reduce the size of the sealing portion 9 sealed with the second resin 2.

[0035] The thickness of the third resin 3 is preferably 0.2 mm or more and 5.0 mm or less. By making it 0.2 mm or more, it is possible to easily prevent electric leakage. It is more preferable that it is 0.5 mm or more, and even more preferable that it is 0.8 mm or more. On the other hand, by making it 5.0 mm or less, it is possible to reduce the contact area with the first resin 1 and the second resin 2, and it is possible to easily prevent the occurrence of voids at the contact surface. It is more preferable that it is 2.0 mm or less.

[0036] The material of the conductor 4 is not particularly limited, but examples thereof include copper, copper alloy, aluminum, silver, and gold- or tin-plated versions of these materials.

[0037] Second Embodiment Fig. 2(a) shows a plan view of the electrical conductive part of the second embodiment. Fig. 2(b) shows the plan view of Fig. 2(a) in which the second resin is omitted and only the outline of the first resin is shown. Fig. 2(c) shows a side view of Fig. 2(b). Fig. 2(d) shows a B-B cross-sectional view of Fig. 2(a). Note that the same components as those of the electrical conductive part of the first embodiment are given the same numbers and their explanations are omitted.

[0038] As shown in Figs. 2(b) and (c), the conductor bundle 5 may be connected to a metal terminal 8. The shape of the metal terminal 8 is not particularly limited, but may have a ring-shaped portion 8a, a protrusion 8b, and a main body 8c as shown in Figs. 2(b) and (c). The ring-shaped portion 8a is formed in a ring shape, the protrusion 8b is formed in a U-shape, and the main body 8c is formed in a rectangular parallelepiped shape. By connecting such a metal terminal 8 and the conductor bundle 5, it is possible to easily fix the electrically conductive component 10 at a desired location. Also, the shape of the metal terminal 8 or the second resin 2 may be changed to form a connector.

[0039] The method for joining the conductor bundle 5 and the metal terminal 8 is not particularly limited, and may be a known method such as welding, crimping, etc. Although not shown, the conductor bundle 5 may be fixed by crimping the main body 8c of the metal terminal 8.

[0040] As shown in FIGS. 2(a) to (d), the electrically conductive component 10 does not necessarily have to have a plurality of conductor bundles 5, and may have only one conductor bundle 5.

[0041] Furthermore, the shape of the sealing portion sealed with the second resin 2 shown in FIGS. 2(a) and 2(d) is a combination of hexagonal columns of different sizes, but the sealing portion may be formed into a complex shape like this.

[0042] The electrically conductive part 10 can be used, for example, as a bundling part or a connector of a wire harness. That is, the present invention also includes a wire harness having the electrically conductive part.

[0043] Next, a method for producing an electrical conductive part according to an embodiment of the present invention will be described.

[0044] In the first embodiment, a portion of the insulating film (third resin 3) of the insulated wire is removed, a first resin 1 is adhered to the exposed conductor wire 4, and then the conductor wire bundle 5 is sealed with a second resin 2 to obtain an electrically conductive component 10.

[0045] In the second embodiment, a portion of the insulating film (third resin 3) of the insulated wire is removed, the conductor wire 4 and the metal terminal 8 are joined, the first resin 1 is then adhered to the conductor wire 4, and the conductor bundle 5 is then sealed with the second resin 2 to obtain the electrically conductive component 10.

[0046] The method of adhering the first resin 1 to the conductive wire 4 is not particularly limited, but examples include a method of applying a liquid first resin 1, or a liquid containing a monomer, prepolymer, and, if necessary, a curing agent, a curing catalyst, etc. that form the first resin 1 (hereinafter referred to as a treatment liquid) to the conductive wire 4, or a method of immersing the conductive wire 4 in the treatment liquid.

[0047] The viscosity of the treatment liquid at 23°C is preferably 0.1 poise or more and 300 poise or less. By setting the viscosity of the treatment liquid to 300 poise or less, the first resin 1 can be easily filled into the conductor bundle 5, and the total area ratio of the cavities 6 can be easily controlled to 20% or less. More preferably, it is 50 poise or less, and even more preferably, it is 30 poise or less. On the other hand, by setting the viscosity to 0.1 poise or more, it can be easily attached to the conductor 4. More preferably, it is 1 poise or more, and even more preferably, it is 10 poise or more. The viscosity can be measured based on the method described in, for example, JIS K7117-1.

[0048] The treatment liquid may be a commonly used low-boiling solvent, such as methyl ethyl ketone, toluene, etc. After treatment, the solvent may be evaporated by natural drying, air drying, a dryer, an oven, etc.

[0049] The conductor bundle 5 may be sealed with the second resin 2 by, for example, injection molding. Specifically, the conductor 4 to which the first resin 1 is attached may be placed in a metal mold, and molten resin may be injected into the metal mold to perform injection molding. An example of an injection molding machine that may be used is the THX5S1VN injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd.

[0050] The injection molding temperature (nozzle temperature) is preferably 180°C or higher and 230°C or lower. By setting the temperature at 180°C or higher, it becomes easier to inject the molten resin. Furthermore, this makes it easier to harden the first resin 1 when the first resin 1 is a thermosetting resin. On the other hand, by setting the molding temperature at 230°C or lower, it becomes easier to suppress decomposition and discoloration of the molten resin.

[0051] The injection pressure is preferably 0.05 MPa or more and 50 MPa or less. By setting the pressure to 50 MPa or less, the movement of the conductor bundle 5 during injection can be suppressed, making it easier to suppress damage. On the other hand, by setting the injection pressure to 0.05 MPa or more, it is easier to fill the molten resin. When Vyroshot is used as the molten resin, molding can be performed at a low injection pressure of 0.1 MPa or more and 30 MPa or less.

[0052] The pressure retention time and mold temperature after injection of the second resin 2 vary depending on the type of mold and resin, and are not particularly limited, but are preferably at least 20 seconds and at most 5 minutes, and preferably at least 20°C and at most 230°C.

[0053] In the examples of Patent Document 1, the one-component heat-curing silicone adhesives "TSE322" and "TSE3212" manufactured by Momentive Corporation, which are used as adhesives for the waterproofing layer, have viscosities of 1100 poise and 2800 poise at 23°C, respectively, and it has been confirmed that when these are used, the total area ratio of cavities 6 within the inner region 7 of the outermost tangent of the wire bundle 5 exceeds 20%.

[0054] This application claims the benefit of priority based on Japanese Patent Application No. 2017-072383, filed on March 31, 2017. The entire content of the specification of Japanese Patent Application No. 2017-072383, filed on March 31, 2017, is incorporated herein by reference. [Explanation of symbols]

[0055] 1. First Resin 2. Second Resin 3. Third Resin 4 conductors 5 Conductor bundle 6 cavities 7 Inner area of ​​outermost tangent 8 Metal terminal 8a Ring-shaped part 8b Protrusion 8c Main body 9 Sealing part 10 Electrical Conductive Parts 11 Joint A axis direction

Claims

1. A conductor bundle having a plurality of conductors; A first resin attached to the conductive wire; an injection-molded product that encapsulates the conductor bundle and includes a second resin; and a third insulating resin covering the conductor bundle. the first resin is at least one selected from the group consisting of a polyester resin, a urethane resin, and an epoxy resin; the first resin is covered by the injection molding and is not exposed; the conductor bundle has an uncoated portion that is not coated with the third resin, the uncoated portion is not connected to another member, An electrically conductive component characterized in that, in a cross section perpendicular to the axial direction of the conductor bundle in the uncoated portion, the conductor and the first resin are present in an inner region of the outermost tangent of the conductor bundle, and the total area ratio of cavities in the inner region is 20% or less.

2. 2. The electrically conductive component according to claim 1, wherein a total area ratio of said conductors in said inner region is 80% or less.

3. 3. The electrically conductive part according to claim 1, wherein the first resin has a maximum thickness of 0.1 mm or less outside the outermost tangent line.

4. 4. The electrically conductive part according to claim 1, wherein a maximum thickness of the first resin from the outermost tangent is smaller than a thickness of the third resin.

5. 5. The electrically conductive part according to claim 1, wherein the third resin is at least one resin selected from the group consisting of polyvinyl chloride, polyethylene, and polypropylene.

6. 6. The electrically conductive part according to claim 1, wherein at least some of the conductive wires are joined to each other.

7. 7. The electrically conductive part according to claim 1, wherein the second resin is at least one resin selected from the group consisting of polyester-based resins, polyamide-based resins, and polyolefin-based resins.

8. A wire harness comprising the electrically conductive part according to any one of claims 1 to 7.

9. A wire bundle including a plurality of conductor wires coated with an insulating third resin, the wire bundle having an uncoated portion that is not coated with the third resin and is not connected to another member, and a step of attaching a first resin to at least the uncoated portion; a step of sealing the conductor bundle to which the first resin is attached by injection molding using a second resin so that the first resin is not exposed; the first resin is at least one selected from the group consisting of a polyester resin, a urethane resin, and an epoxy resin; A method for manufacturing an electrically conductive component, wherein in a cross section perpendicular to the axial direction of the conductor bundle after the sealing in the uncoated portion, the conductor and the first resin are present in an inner region of an outermost tangent to the conductor bundle, and a total area ratio of cavities in the inner region is 20% or less.

10. In the step of adhering the first resin, The method for producing an electrical conductive part according to claim 9, wherein the liquid containing the components forming the first resin has a viscosity at 23° C. of 0.1 poise or more and 300 poise or less.

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