INSULATED ELECTRICAL WIRE AND CABLING

Abstract

Insulated electrical wire (1), comprising: a conductor (2) in which a plurality of elementary wires (2a) made of a metal material are twisted together; and an insulation sheath (3) which encloses an outer circumference of the conductor (2), wherein the insulated electrical wire (1) comprises: an exposed portion (10) in which the insulation sheath (3) is removed from the outer periphery of the conductor (2); a covered portion (20) in which the insulation sheath (3) covers the outer periphery of the conductor (2), wherein the exposed portion (10) and the covered portion (20) are arranged adjacent to each other in a longitudinal axis direction of the insulated electric wire (1); and a water-stopping portion (4) in which a water-stopping agent (5) is arranged over the exposed portion (10) and a region of the sheathed portion (20) which adjoins the exposed portion (10), and the water-stopping section (4) has: a filled region (41) between the elementary wires (2), in which gaps between the elementary wires (2) in the exposed portion (10) are filled with the water-stopping agent (5); an outer peripheral region (42) of the exposed portion (10) in which the water-stopping agent (5) covers or surrounds or encases the outer periphery of the conductor (2) in the exposed portion (10); and an outer peripheral region (43) of the sheathed portion (20), in which the water-stopping agent (5) covers or surrounds or encloses an outer periphery of the insulation sheath (3) in the region of the sheathed portion (20), which adjoins the exposed section (10), wherein the filled region (41) between the elementary wires (2), the outer peripheral region (42) of the exposed portion (10) and the outer peripheral region (43) of the sheathed portion (20) are adjacent to one another, a layer thickness of the water-stopping agent (5) is greater in the outer peripheral region (42) of the exposed portion (10) than in the outer peripheral region (43) of the coated portion (20), the layer thickness of the water-stopping agent (5) in the outer peripheral region (43) of the sheathed portion (20) is smaller than a thickness of the insulation sheath (3), the water-stopping agent (5) has a higher modulus of elasticity than the insulation sheath (3), and the water-stopping agent (5) directly contacts a surface of the insulation sheath (3) in the sheathed portion (20) and a surface of the conductor (2) in the exposed portion (10), wherein the elastic modulus of the water-stopping agent (5) is not greater than twice the elastic modulus of the insulation sheath (3).

Description

Technical area

[0001] The present disclosure relates to an insulated electrical wire and to a wiring harness. State of the art

[0002] In some cases, a water-stopping treatment is applied to a portion of an insulated electric wire in the longitudinal axis direction of the wire. For example, Patent Document 1 discloses an electric wire having a water-stopping portion including a twisted conductor and an insulation cover, in which the twisted conductor is continuous in the longitudinal direction, while the insulation cover is cut by a corresponding length and is discontinuous in the longitudinal direction. In a portion in which the insulation cover is cut and the twisted conductor is exposed, the water-stopping portion is formed, in which gaps are formed.Spacings between elementary wires of the twisted conductor and gaps between the outer peripheral surface of the twisted conductor and cut surfaces of the insulation sheath are filled with a water-stopping resin or plastic, and the water-stopping resin is adhered to the cut surfaces of the insulation sheath. Literature listPatent document

[0003] Patent document 1: JP 2000 - 11 771 A

[0004] US 2008 / 0 283 268 A1 discloses a method for stopping water in grounding cables and ground wires. For a grounding cable attached to a wiring harness in a vehicle or the like, the objective is to perform an easy and simple sealing job. A first UV-curing type sealant has an acute contact angle with the bare conductor of the grounding cable and a viscosity of 15 to 500 mPas and is applied dropwise to the bare conductor. The first sealant is applied dropwise to a second sealant. The first and second sealants are irradiated with ultraviolet rays. This allows the first sealant to spontaneously decompress the interior of the grounding cable through capillary action without the need for suction.

[0005] MATWEB: Overview of materials for PVC, Wire and Cable Grade; url: [https: / / www.matweb.com / search / datasheet_print.aspx?matguid=400d17f8efc44e35b 1ca2532b01cb576] [accessed on October 4, 2024] discloses an overview of materials for PVC, wire and cable grade.

[0006] MATWEB: Overview of materials for Methacrylate Adhesive; url: https: / / www.matweb.com / search / datasheet_print.aspx?matguid=1351dacf63ae42078 cfec9ad1d1c9526 [accessed on October 4, 2024] discloses an overview of materials for methacrylate adhesive.

[0007] MATWEB: Overview of materials for Epoxy Adhesive; url: [https: / / www.matweb.com / search / datasheet_print. aspx?matguid=c1ec1ad603c74f62 8578663aaf44f261] [accessed on October 4, 2024] discloses an overview of materials for epoxy adhesives; MATWEB: Overview of materials for Low Density Polyethylene (LDPE), Wire / Cable Grade; url: [https: / / www.matweb.com / search / datasheet_print.aspx?matguid=67d08e5 0830a43daab7911ffc3ad3638] [accessed on October 4, 2024] discloses an overview of materials for LDPE polyethylene (Low Density Polyethylene). Summary of the inventionTechnical problem

[0008] In the configuration disclosed in Patent Document 1, when forming the water-stopping portion, the water-stopping resin is adhered to the cut surfaces of the insulation coating located on both sides of the portion where the twisted conductor is exposed, and the water-stopping portion is formed only in the portion where the twisted conductor is exposed. In this case, the mechanical strength of the water-stopping portion is low, and when a mechanical load, such as bending of an electric wire, is applied to the water-stopping portion or the vicinity thereof, there may be cases where sufficient water-stopping performance cannot be maintained. For example, when the electric wire is bent, the water-stopping resin may be damaged.the water-stopping resin may break or bend at a contact interface with the insulation jacket and the water-stopping performance may be impaired or deteriorated.

[0009] Thus, it is an object of the present invention to provide an insulated electric wire including a water-stopping portion whose water-stopping performance is unlikely to be affected by a mechanical stress, and a wiring including such an insulated electric wire. Solution to the problem

[0010] An insulated electric wire according to the present disclosure includes: a conductor in which a plurality of constituent wires made of a metal material are twisted together; and an insulation cover covering an outer periphery of the conductor, the insulated electric wire including: an exposed portion in which the insulation cover is removed from the outer periphery of the conductor; a covered portion in which the insulation cover covers the outer periphery of the conductor, the exposed portion and the covered portion being provided adjacent to each other in a longitudinal axis direction of the insulated electric wire; and a water-stopping portion in which a water-stopping agent is disposed over the exposed portion and a portion of the covered portion that is adjacent to the exposed portion.adjacent thereto, and the water-stopping portion includes: a filled region between the elementary wires, in which gaps between the elementary wires in the exposed portion are filled with the water-stopping agent; an outer peripheral region of the exposed portion, in which the water-stopping agent covers or surrounds or coats the outer periphery of the conductor in the exposed portion; and an outer peripheral region of the covered portion, in which the water-stopping agent covers or surrounds or coats an outer periphery of the insulation coating in the region of the covered portion that is continuous with the exposed portion, wherein the filled region between the elementary wires, the outer peripheral region of the exposed portion, and the outer peripheral region of the covered portion are continuous with each other.are continuous, and wherein a layer thickness of the water-stopping agent is greater in the outer peripheral region of the exposed portion than in the outer peripheral region of the covered portion, wherein the layer thickness of the water-stopping agent in the outer peripheral region of the covered portion is smaller than a thickness of the insulation coating, the water-stopping agent has a higher modulus of elasticity than the insulation coating, the water-stopping agent directly contacts a surface of the insulation coating in the covered portion and a surface of the conductor in the exposed portion, and the modulus of elasticity of the water-stopping agent is not greater than twice the modulus of elasticity of the insulation coating.

[0011] A wiring harness according to the present disclosure includes the insulated electrical wire described above. Advantageous effects of the invention

[0012] The insulated electric wire and the wiring according to the present disclosure each refer to an insulated electric wire including a water-stopping portion whose water-stopping performance is unlikely to be affected by a mechanical load, and a wiring including such an insulated electric wire. Short description of the drawings Fig. 1 is a side perspective view illustrating an insulated electric wire according to an embodiment of the present invention. Fig. Figure 2 is a side perspective view illustrating the size and shape of a water-stopping section, highlighting a preferred configuration. An illustration of elementary wires constituting a conductor is omitted. Fig. 3 is a cross-sectional view illustrating an example of a cross-sectional state of the water-stopping portion. Fig. 4 is a schematic side view illustrating a wiring harness according to an embodiment of the present invention, along with devices connected to both ends of the wiring harness. Fig. 5 is a flowchart illustrating steps for manufacturing the insulated electric wire according to the embodiment. Fig. 6A to 6C are cross-sectional views of the insulated electric wire, illustrating steps for manufacturing the insulated electric wire. Fig. 6A illustrates the wire before a water-stopping portion is formed, Fig. Figure 6B illustrates a step of partial exposure and Fig. Figure 6C illustrates a step of tightening. Fig. 7A to 7C are cross-sectional views of the insulated electric wire, illustrating steps for manufacturing the insulated electric wire. Fig. 7A illustrates a step of loosening, Fig. 7B illustrates a step of filling and Fig. Figure 7C illustrates a recommitment step. Fig. 8A and Fig. 8B are cross-sectional views of the insulated electric wire illustrating steps for manufacturing the insulated electric wire. Fig. 8A illustrates one step of movement of the sheath and Fig. Figure 8B illustrates a step of curing. Description of Embodiments[Description of Embodiments of the Present Disclosure]

[0013] First, embodiments of the present disclosure will be listed and described.

[0014] An insulated electric wire according to the present disclosure includes: a conductor in which a plurality of elementary wires made of a metal material are twisted together; and an insulation cover covering an outer periphery of the conductor, the insulated electric wire including: an exposed portion in which the insulation cover is removed from the outer periphery of the conductor; a covered portion in which the insulation cover covers the outer periphery of the conductor, the exposed portion and the covered portion being provided adjacent to each other in a direction of a longitudinal axis of the insulated electric wire; and a water-stopping portion in which a water-stopping agent is provided over the exposed portion and a region of the covered portion.covered portion which is continuous with the exposed portion, and the water-stopping portion includes: a filled region between the elementary wires, in which gaps between the elementary wires in the exposed portion are filled with the water-stopping agent; an outer peripheral region of the exposed portion, in which the water-stopping agent covers the outer periphery of the conductor in the exposed portion; and an outer peripheral region of the covered portion, in which the water-stopping agent covers an outer periphery of the insulation sheath in the region of the covered portion which is continuous with the exposed portion, wherein the filled region between the elementary wires, the outer peripheral region of the exposed portion, and the outer peripheral region of the covered portion are continuous with each other.are continuous, and wherein a layer thickness of the water-stopping agent is greater in the outer peripheral region of the exposed portion than in the outer peripheral region of the coated portion.

[0015] The above-described insulated electric wire includes, as a continuous water-stopping portion, three areas: the filled area between the elementary wires in which the gaps between the elementary wires of the conductor exposed in the exposed portion are filled with the water-stopping agent, the outer peripheral area of the exposed portion in which the water-stopping agent covers the outer periphery of the conductor in the exposed portion, and the outer peripheral area of the covered portion in which the water-stopping agent covers an end portion of the covered portion. Since, in the outer peripheral area of the covered portion, the water-stopping agent is in contact with the outer peripheral surface of the insulation covering,-coating and covering it, the water-stopping portion is likely to be firmly held to the covered electric wire, compared with a case where a water-stopping portion includes only a filled region between the elementary wires and an outer peripheral region of the exposed portion, and even if a mechanical load such as bending is applied to the electric wire, the water-stopping portion is likely to maintain its water-stopping performance. Moreover, since the layer thickness of the water-stopping agent is greater in the outer peripheral region of the exposed portion than in the outer peripheral region of the covered portion, the layer of the water-stopping agent constituting the outer peripheral region of the exposed portion has high strength.Strength, and even if a mechanical load is applied, the load is unlikely to be transmitted to the outer peripheral region of the exposed portion or the filled region between the elementary wires, and the exposed portion is likely to maintain better water-stopping performance. For example, when the insulated electric wire is bent, the bending is unlikely to be added to a position of the exposed portion due to the presence of a thick layer of the water-stopping agent in the outer peripheral region of the exposed portion. As a result, it is possible to prevent a reduction in water-stopping performance in the exposed portion, which may occur due to the effect of bending.

[0016] Here, according to the invention, the layer thickness of the water-stopping agent in the outer peripheral region of the covered portion is smaller than a thickness of the insulation coating. With this arrangement, the covered portion is maintained bendable without interfering with the layer of the water-stopping agent, making it easy to maintain a state in which, when the insulated electric wire is bent in the water-stopping portion or the vicinity thereof, the bending will be absorbed by the covered portion and cannot be applied to the exposed portion. As a result, it is possible to maintain the water-stopping performance of the exposed portion high.

[0017] According to the invention, the water-stopping agent has a higher elastic modulus than that of the insulation covering. If the water-stopping agent has a high elastic modulus, it means that the material constituting the water-stopping portion is hard and unlikely to be subjected to mechanical deformation such as bending. Accordingly, when the insulated electric wire is bent in the water-stopping portion or the vicinity thereof, the covered portion is preferentially bent, and the exposed portion is likely to be maintained unbent. As a result, the exposed portion is likely to maintain better water-stopping performance.

[0018] According to the invention, the elastic modulus of the water-stopping agent is not greater than twice the elastic modulus of the insulation sheath. With this arrangement, it is easy to avoid situations where the insulated electrical wire as a whole is mishandled or mishandled due to an excessively high elastic modulus of the water-stopping agent, and where, during application of bending or the like, damage may occur at an interface between the water-stopping agent and the insulation sheath due to an excessive difference in elastic modulus between the water-stopping agent and the insulation sheath.

[0019] Preferably, the water-stopping portion has, at one end of the outer peripheral region of the covered portion, a tapered structure in which a layer of the water-stopping agent becomes thinner toward the outside in the longitudinal axis direction, at one end of the outer peripheral region of the covered portion, which corresponds to one end of the entire water-stopping portion in the longitudinal axis direction. With this arrangement, even if a mechanical load such as bending is applied to the insulated electric wire, stress is unlikely to concentrate at the end of the water-stopping portion, making it easy to maintain a state in which the water-stopping agent adheres to the insulation cover. As a result, better water-stopping performance is likely to be maintained.

[0020] Preferably, an outer peripheral surface of the water-stopping portion, except for end portions in the longitudinal axis direction, has no difference in height equal to or greater than the film thickness of the water-stopping agent in the outer peripheral region of the covered portion. With this arrangement, the outer peripheral surface of the water-stopping portion has a linear structure rather than a steeply inclined structure or a recess / projection structure. As a result, even if a mechanical load is applied to the water-stopping portion, a large load will not concentrate at a specific position, and the water-stopping portion as a whole is likely to maintain better water-stopping performance.

[0021] A wiring harness according to the present disclosure includes the above-described insulated electric wire. The wiring according to the present disclosure includes the insulated electric wire whose water-stopping performance is unlikely to be deteriorated by a mechanical load as described above, and the wiring as a whole can maintain better water-stopping performance even in a situation where a mechanical load such as bending is applied. [Details of Embodiments of the Present Disclosure]

[0022] A detailed description of an insulated electrical wire and wiring according to an embodiment of the present disclosure will now be provided with reference to the drawings. [Configuration of an insulated electrical wire]Overview of an insulated electrical wire

[0023] Fig. 1 illustrates an overview of an insulated electrical wire 1 according to an embodiment of the present disclosure. Fig. Figure 2 shows a water-stopping portion 4 of the insulated electrical wire 1 with an emphasis on a preferred configuration. Fig. 3 shows an example of a cross section of the water-stopping portion 4 taken normal to an axial direction of the insulated electric wire 1.

[0024] The insulated electric wire 1 according to an embodiment of the present disclosure includes a conductor 2 obtained by twisting a plurality of elementary wires 2a made of a metal material together, and an insulation coating 3 covering the outer periphery of the conductor 2. A water-stopping portion 4 is formed in a central portion of the insulated electric wire 1 in a longitudinal axis direction thereof.

[0025] The elementary wires 2a constituting the conductor 2 can be made of any type of metal material, and metal materials such as copper, aluminum, magnesium, and iron can be used. The metal material can be an alloy. Examples of added metal elements that can be used to form an alloy include iron, nickel, magnesium, silicon, and combinations thereof. All of the elementary wires 2a can be made of the same material, or elementary wires 2a made of multiple metal materials can be mixed in combination.

[0026] There is no particular limitation on the twisting structure of the elementary wires 2a of the conductor 2, but a simple twisting structure is preferable from the viewpoint of, for example, slightly increasing the distances between the elementary wires 2a when forming the water-stopping portion 4. For example, a twisting structure in which the elementary wires 2a are collectively twisted together is preferable rather than a master-slave twisting structure in which a plurality of strands each including a plurality of twisted elementary wires 2a are gathered and further twisted. Also, there is no particular limitation on the diameter of the entire conductor 2 and the diameter of each elementary wire 2a. However, the effect and significance of filling small gaps are limited.Distances between the elementary wires 2a in the water-stopping portion 4 with the water-stopping agent 5, in order to improve reliability of the water-stopping feature, are larger as the diameters of the entire conductor 2 and each elementary wire 2a are smaller, and it is preferable that the cross section of the conductor is about 8 mm. 2 or smaller and the diameter of individual elementary wires is about 0.45 mm or smaller.

[0027] There is no particular limitation on the material constituting the insulation sheath 3, as long as it is an insulating polymer material. Examples of such materials include a polyvinyl chloride (PVC) resin and an olefin-based resin. In addition to the polymer material, a filler or an additive may be appropriately included. Furthermore, the polymer material may be crosslinked.

[0028] The water-stopping portion 4 includes an exposed portion 10 in which the insulation coating 3 is removed from the outer periphery of the conductor 2. In the exposed portion 10, gaps between the elementary wires 2a constituting the conductor 2 are filled with the water-stopping agent 5, and a filled region 41 is formed between the elementary wires.

[0029] Furthermore, the water-stopping portion 4 includes an exposed portion outer peripheral region 42 in which the water-stopping agent 5 covers the outer periphery of the conductor 2 in the exposed portion 10 continuously from the inter-elementary-wire filled region 41 in which the gaps between the elementary wires 2a in the exposed portion 10 are filled with the water-stopping agent 5. In addition, the water-stopping portion 4 includes covered portion outer peripheral regions 43 that are continuous with the inter-elementary-wire filled region 41 and the exposed portion outer peripheral region 42. The covered portion outer peripheral regions 43 are continuous with the inter-elementary-wire filled region 41 and the exposed portion outer peripheral region 42.are obtained by the water-stopping agent 5 covering or covering the outer peripheries of end portions of sheathed portions 20 adjacent to both sides of the exposed portion 10, i.e., the water-stopping agent 5 covers areas or surfaces which are adjacent to or adjacent to the exposed portion 10 and in which the insulation sheath 3 covers or covers the outer periphery of the conductor 2. That is, in the water-stopping portion 4, the water-stopping agent 5 continuously covers the outer periphery, preferably the entire outer periphery, of an area extending from a part of the end portion of the sheathed portion 20, which is arranged on one side of the exposed portion 10, to a part of the end portion of the sheathed portion 20, which is arranged on the other side.Furthermore, the water-stopping agent 5 continuously fills the spaces between the elemental wires 2a in the exposed portion 10 from this outer peripheral portion. The structure of the water-stopping portion 4 will be described in detail later.

[0030] There is no particular limitation on the constituent material of the water-stopping agent 5, as long as it is an insulating material through which a fluid such as water is unlikely to permeate and which can exhibit water-stopping performance. However, the water-stopping agent 5 is preferably made of an insulating resin composition, specifically a thermoplastic resin composition or a curable resin composition, in view of ease in filling the gaps between the elemental wires 2a in a state of high fluidity, etc. By disposing such a resin composition,By applying the resin composition in a high-flow state between the elemental wires 2a and on the outer peripheries of the exposed portion 10 and the end portions of the covered portions 20, and then bringing the resin composition to a low-flow state, it is possible to reliably form a water-stopping portion 4 having superior water-stopping performance. A preferred embodiment of the constituent material of the water-stopping agent 5 will be described later.

[0031] As described above, since the water-stopping agent 5 is disposed in the gaps between the elementary wires 2a in the exposed portion 10 to constitute the filled region 41 between the elementary wires 2a, water-stopping is realized at the regions between the elementary wires 2a, and fluid such as water is prevented from entering the regions between the elementary wires 2a from the outside. Also, even if water enters a gap between the elementary wires 2a in one portion of the insulated electric wire 1, the water is prevented from moving to another portion of the insulated electric wire 1 along the elementary wires 2a.For example, water adhering to one end of the insulated electric wire 1 can be prevented from moving toward the other end of the insulated electric wire 1 through a gap between the elementary wires 2a.

[0032] The outer peripheral region 42 of the exposed portion, in which the water-stopping agent 5 covers the outer peripheral region of the conductor 2 in the exposed portion 10, plays a role of physically protecting the exposed portion 10. In addition, when the water-stopping agent 5 is made of an insulating material, the outer peripheral region 42 of the exposed portion plays a role of insulating the conductor 2 in the exposed portion 10 from the outside. Also, when the water-stopping portion 4 includes the covered portion outer peripheral regions 43 in which the water-stopping agent 5 also covers the outer peripheries of the end portions of the covered portions 20 adjacent to the exposed portion 10 as one piece, water-stopping is possible between the insulating sheath 3 and the conductor 2. That is,, a fluid such as water is prevented from entering the gap between the insulation cover 3 and the conductor 2 from the outside. Also, even if water enters a gap between the insulation cover 3 and the conductor 2 in one portion of the insulated electric wire 1, the water is prevented from moving to another portion of the insulated electric wire 1 through the gap between the insulation cover 3 and the conductor 2. For example, water adhering to one end of the insulated electric wire 1 can be prevented from moving toward the other end of the insulated electric wire 1 through the gap between the insulation cover 3 and the conductor 2.Since the water-stopping portion 4 includes the outer peripheral regions 43 of the covered portion that are continuous with the filled region 41 between the elemental wires and the outer peripheral region 42 of the exposed portion, the water-stopping portion 4 as a whole can have high mechanical strength, and the insulated electric wire 1 can easily and reliably have a water-stopping structure using the water-stopping portion 4. As a result, even if a mechanical load such as bending is applied to the insulated electric wire 1, the water-stopping structure of the water-stopping portion 4 can be firmly maintained.

[0033] In the present embodiment, the water-stopping portion 4 is provided at a middle portion of the insulated electric wire 1 in the longitudinal axis direction thereof in view of the size of a request, ease in increasing the distances between the elemental wires 2a, and the like. However, the same water-stopping portion 4 may also be provided at an end portion of the insulated electric wire 1 in the longitudinal axis direction thereof. In this case, another member such as a terminal may be connected to the end portion of the insulated electric wire 1, or no member may be connected thereto. The water-stopping portion 4 covered with the water-stopping agent 5 may include, in addition to the conductor 2 and the insulation sheath 3, another member such as a connecting member.Examples of the case where the water-stopping portion 4 includes another member include a case where the water-stopping portion 4 includes a splicing portion in which a plurality of insulated electric wires 1 are connected to each other.

[0034] A protective member, such as a tube or a band made of a resin material, may also be provided on the outer periphery of the water-stopping portion 4. By providing the protective member, it is possible to protect the water-stopping portion 4 from physical irritation such as contact with an external object. Also, when the water-stopping agent 5 is made of, for example, a curable resin, the water-stopping agent 5 is subject to aging and may be damaged when the water-stopping portion 4 is bent or vibrated. However, if a protective member is provided on the outer periphery of the water-stopping portion 4, such damage can be reduced. In view of effectively reducing the effects of bending or vibration,To prevent vibration from being applied to the water-stopping portion 4, the protective member is preferably made of a material having at least higher rigidity than that of the water-stopping agent 5 constituting the water-stopping portion 4. The protective member can be arranged, for example, by winding a tape material having an adhesive layer around the outer periphery of the insulated electric wire 1 including the water-stopping portion 4 in a spiral shape. Building material of the water-stopping agent

[0035] As described above, in the insulated electric wire 1 according to the present embodiment, the water-stopping agent 5 constituting the water-stopping portion 4 is preferably made of a curable resin composition. A curable resin composition is a resin composition having one or more types of curability, such as heat curability, light curability, moisture curability, two-component curability, and anaerobic curability. In view of an excellent property in rapid curability or the like, the water-stopping agent 5 has light curability or anaerobic curability, and more preferably has both of these types of curability.

[0036] There is no particular limitation on the specific type of resin constituting the water-stopping agent 5. Examples of the resin include a silicone resin, an acrylic resin, an epoxy resin, and a urethane resin. Various types of additives can be appropriately added to the resin material as long as the properties of the resin material as the water-stopping agent 5 are not deteriorated. Also, only one type of water-stopping agent 5 is preferably used in view of simplicity of configuration, but two or more types of water-stopping agents 5 may also be appropriately mixed or stacked in combination, for example.

[0037] It is preferable that the water-stopping agent 5 be a resin composition having a viscosity of 4,000 mPa s or higher, more preferably 5,000 mPa s or higher, even more preferably 10,000 mPa s or higher at the time of filling. This is because, when the water-stopping agent 5 is disposed on the areas between the elemental wires 2a and on the outer peripheral portions, particularly on the outer peripheral portions, the water-stopping agent 5 hardly drips or flows and is likely to remain in these areas with high uniformity. On the other hand, it is preferable that the viscosity of the water-stopping agent 5 at the time of filling be kept at 200,000 mPa s or lower. This is because if the viscosity is too high, the water-stopping agent 5 is unlikely to penetrate sufficiently into the areas between the elementary wires 2a.

[0038] Also, the water-stopping agent 5 in its hardened state preferably has a higher elastic modulus than the insulation sheath 3. If the water-stopping agent 5 has a high elastic modulus, this means that the water-stopping agent 5 is hard and unlikely to deform mechanically. Accordingly, by providing the water-stopping agent 5 with a higher elastic modulus than that of the insulation sheath 3, when a mechanical load is applied to the insulated electric wire 1, the load is unlikely to be transmitted to the water-stopping portion 4, and the water-stopping portion 4 is likely to maintain its water-stopping performance. For example,When the insulated electric wire 1 is bent near the water-stopping portion 4, the water-stopping portion 4 is not bent, but the covered portions 20 not covered by the water-stopping agent 5 are likely to be bent. Here, the elastic moduli of the water-stopping agent 5 and the insulation sheath 3 can be evaluated as bending elastic moduli and can be measured, for example, by a bending test according to JIS K 7171:2016.

[0039] More preferably, the elastic modulus of the water-stopping agent 5 is at least 1.2 times that of the insulation sheath. There is no particular limitation on the specific elastic modulus of the water-stopping agent 5, but the flexural elastic modulus at room temperature may preferably be 200 MPa or higher, and more preferably 220 MPa or higher.

[0040] The harder the water-stopping agent 5 is, the more likely the effect of a mechanical load on the water-stopping performance is reduced, and there is no particular upper limit regarding the elastic modulus of the water-stopping agent 5. However, if the water-stopping agent 5 is too hard, the handling of the insulation sheath 3 as a whole when the insulated electric wire is bent and laid, for example, may be reduced, and damage such as cracking or bending is more likely to occur at an interface with the insulation sheath 3 or the vicinity thereof, and it is therefore preferable that the elastic modulus of the water-stopping agent 5 be maintained at a value not greater than twice the elastic modulus of the insulation sheath 3.Also, it is preferable that the elastic modulus of the water-stopping agent 5 can be maintained such that the flexural elastic modulus at room temperature is about 300 MPa or lower. Configuration of the water-stopping section

[0041] The following will describe a configuration of the water-stopping portion 4 based on a preferred embodiment. (1) External shape and thickness of an outer peripheral area

[0042] First, a preferred embodiment will be described with respect to the outer shape of the water-stopping portion 4 as a whole, and layer thicknesses of the water-stopping portion 5 in the outer peripheral region 42 of the exposed portion and the outer peripheral regions 43 of the covered portion with reference to Fig. 2 are described.

[0043] In the water-stopping portion 4 of the insulated electric wire 1 according to the present embodiment, a layer thickness La of the water-stopping agent 5 in the outer peripheral region 42 of the exposed portion is greater than a layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the covered portion (La>Lb). The greater the layer thickness of the water-stopping agent 5, the higher the material strength of the layer of the water-stopping agent 5. Thus, a mechanical load such as bending is unlikely to be applied to the water-stopping portion 4, and even if a mechanical load is applied, the effect thereof can be suppressed.Accordingly, since the layer thickness of the water-stopping agent 5 is greater in the outer peripheral region 42 of the exposed portion than in the outer peripheral regions 43 of the covered portion, the water-stopping performance of the water-stopping portion 4 is unlikely to be affected by a mechanical load at a position in the exposed portion 10. For example, when bending is applied to the water-stopping portion 4 or a region near it, the portion of the water-stopping portion 4 corresponding to the exposed portion 10 is less likely to be bent.

[0044] As a result, the water-stopping agent 5 constituting the filled region 41 between the elemental wires or the outer peripheral region 42 of the exposed portion is unlikely to be subjected to damage such as cracking due to bending stress, and improved water-stopping performance is maintained. Even if bending is applied to portions of the water-stopping portion 4 corresponding to the covered portions 20 and the water-stopping agent 5 is damaged in the corresponding portions, the water-stopping performance of the water-stopping portion 4 may not be greatly impaired. However, if bending is applied to the water-stopping portion 4 at a position of the exposed portion 10, the water-stopping performance may be improved.is applied, and the water-stopping agent 5, which constitutes the filled region 41 between the elementary wires and the outer peripheral region 42 of the exposed portion, is damaged, it will be difficult to sufficiently prevent water from entering the gaps between the elementary wires 2a, and the water-stopping performance of the water-stopping portion 4 is likely to be severely deteriorated. Therefore, by setting the layer thickness of the water-stopping agent 5 to be larger in the outer peripheral region 42 of the exposed portion than in the outer peripheral regions 43 of the covered portion, it is possible to preferentially position the exposed portion 10 at which the water-stopping performance is more seriously affected by a mechanical load such as bending, against exertion.Application of such a mechanical load. It is further preferred that the layer thickness La of the water-stopping agent 5 in the outer peripheral region 42 of the exposed portion be at least 1.5 times the layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the coated portion.

[0045] Furthermore, it is preferable that the layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the covered portion is smaller than a thickness Lc of the insulation covering 3 (Lb <Lc). Je kleiner die Schichtdicke des wasserstoppenden Mittels 5 ist, umso wahrscheinlicher ist es, dass der isolierte elektrische Draht 1 an der entsprechenden Position gebogen wird. Derart ist es, wenn die Lage bzw. Schicht des wasserstoppenden Mittels 5, welche auf dem äußeren Umfang der Isolationsummantelung 3 in jedem der Außenumfangsbereiche 43 des ummantelten Abschnitts vorgesehen ist, derart ausgebildet ist, um dünner als die Schicht der Isolationsummantelung 3 zu sein, für die Schicht des wasserstoppenden Mittels 5 unwahrscheinlich, die Flexibilität der Isolationsummantelung 3 zu beeinflussen, und derart ist es für den wasserstoppenden Abschnitt 4 wahrscheinlich, sich in den Bereich der entsprechenden ummantelten Abschnitte 20 zu biegen.Based on the effect, together with the above-described effect that the film thickness of the water-stopping agent 5 is larger in the outer peripheral region 42 of the exposed portion than in the outer peripheral regions 43 of the covered portion (La>Lb), when bending is applied to the insulated electric wire 1 at a position of the water-stopping portion 4, the water-stopping portion 4 is likely to bend in the covered portions 20 rather than in the exposed portion 10. In this way, with this configuration in which bending applied to the water-stopping portion 4 is absorbed by the outer peripheral regions 43 of the covered portion, it is possible to bend the water-stopping portion 4 more easily.is incorporated so that the filled region 41 between the elementary wires and the outer peripheral region 42 of the exposed portion is unlikely to bend, it is easy to prevent a situation where damage such as a crack due to bending occurs in the water-stopping agent 5 in the filled region 41 between the elementary wires and the outer peripheral region 42 of the exposed portion, which have the most essential functions in water-stopping for the conductor 2, and sufficient water-stopping performance cannot be maintained. It is further preferable that the layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the covered portion be 80% or less of the thickness Lc of the insulation cover 3.

[0046] As the overall shape of the water-stopping portion 4, the water-stopping portion 4 preferably has tapered portions 44 at both ends in the longitudinal axis direction. That is, the water-stopping portion 4 preferably has, at the ends of the outer peripheral regions 43 of the covered portion, which correspond to the ends of the entire water-stopping portion 4, a tapered structure in which the layer of the water-stopping agent 5 is thinner toward the outside in the longitudinal axis direction (opposite to the exposed portion 10). When such tapered portions 44 are formed, the water-stopping agent 5 constituting the water-stopping portion 4 is likely to firmly adhere to the outer peripheral surface of the insulation sheath 3. Accordingly, it is preferable for the state in which the water-stopping portion 4 has a betterhigher water-stopping performance, it is likely to be maintained. Specifically, even if a mechanical load such as bending is applied to the insulated electric wire 1 at the water-stopping portion 4 or the vicinity thereof, stress is unlikely to concentrate at the ends of the water-stopping portion 4 due to the presence of the tapered portions 44, and the layers of the outer peripheral regions 43 of the covered portion are unlikely to be removed from the surface of the insulation cover 3. As a result, it is possible to prevent a reduction in water-stopping performance due to an effect of the load.

[0047] Furthermore, the water-stopping portion 4 preferably has a linear shape in the longitudinal axis direction except for a partial area at the ends in the longitudinal axis direction, such as the tapered portions 44. That is, an outer surface shape of the water-stopping portion 4 may be approximate to a straight pipe. As a result of the water-stopping portion 4 having a linear shape, it is easy to avoid a situation where a mechanical load concentrates at a specific position of the water-stopping portion 4 and damage such as a crack starts or progresses from this position. Accordingly, the water-stopping portion 4 as a whole is likely to maintain better water-stopping performance.An example of a preferable indicator for the water-stopping portion 4 having a linear shape is such that the outer peripheral surface of the water-stopping portion 4 does not have a structural difference in height equal to or greater than the layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the coated portion. Examples of structures that can cause a difference in height of the outer peripheral surface of the water-stopping portion 4 may include structures with recesses / projections and structures of an inclined surface. If none of such structures are formed or a difference in height is suppressed, concentrated application of mechanical loads is likely to be avoided.Preferably, no difference is formed in a height which is greater than or equal to 20% of the layer thickness Lb of the water-stopping agent 5 in the outer peripheral regions 43 of the coated portion. (2) Condition of a conductor in the water-stopping section

[0048] The following will describe a preferred embodiment concerning the conductor 2 surrounded by the water-stopping agent 5 in the water-stopping portion 4. As described above, in the water-stopping portion 4 of the insulated electric wire 1 according to the present embodiment, the water-stopping agent 5 passes between the constituent wires 2a of the conductor 2 exposed as the exposed portion 10 and is cured. The state of the conductor 2 constituting the exposed portion 10 may be the same as the state of the conductor 2 in the covered portions 20 covered by the insulation sheath 3, but it is preferable that the states be different from each other to allow the water-stopping agent 5 to pass through and remain between the constituent wires 2a.

[0049] First, in the insulated electric wire 1, preferably, the density of the metal material per unit length (per unit length of the insulated electric wire 1 in the longitudinal axis) is non-uniform and has a non-uniform distribution. Each of the elementary wires 2a is defined as a wire having a substantially uniform diameter continuously along the entire longitudinal axis of the insulated electric wire 1. In the present specification, the state where the density of the metal material per unit length is different between regions is defined as a state where the diameter and number of the elementary wires 2a are constant, but the state of assembly of the elementary wires 2a, such as the state of twisting of the elementary wires 2a, is different.

[0050] Specifically, it is preferable that the density of the metal material of the conductor 2 per unit length is higher in the exposed portion 10 than in the covered portions 20. However, the density of the metal material per unit length may be partially lower in adjacent or contiguous regions 21 of the covered portions 20, which are directly contiguous to the exposed portion 10, than in the exposed portion 10. In other words, the density of the metal material per unit length is higher in the exposed portion 10 than at least in remote regions 22 of the covered portions 20 other than the adjacent or contiguous regions 21. In the remote regions 22, the state of the conductor 2, such as the density of the metal material per unit length, is substantially the same as the state of the insulated electric wire 1 in which no water-stopping portion 4 is formed.Possible reasons why the density of the metal material in the adjacent regions 21 may be reduced include that the metal material is shifted to the exposed portion 10 and that the conductor 2 is deformed to ensure continuity between the exposed portion 10 and the sheathed portions 20.

[0051] Fig. Fig. 8B schematically illustrates a state of the conductor 2 having the density distribution of the metal material as described above. In Fig. 6A to 8B, the area inside the conductor 2 is hatched, and the higher the density of the hatching, the smaller the twist pitch of the elementary wires 2a, that is, the smaller the distances between the elementary wires 2a. Furthermore, the larger the width (vertical length) of the area representing the conductor 2, the larger the diameter of the conductor 2. These parameters in the drawings only schematically show the relative relationship of the sizes between the areas and are not proportional to the twist pitch of the elementary wires 2a or to the diameter of the conductor 2. Moreover, the parameters in the drawings are discontinuous between different regions, but in the actual insulated electric wire 1, the state of the conductor 2 changes continuously between these regions.

[0052] By increasing the density of the metal material per unit length in the exposed portion 10 and the actual length of the elementary wires 2a included per unit length, it is possible to realize a state in which the elementary wires 2a are loosened, the distances between the elementary wires 2a are increased, and large gaps between the elementary wires 2a are ensured, and thus the water-stopping agent 5 can penetrate the gaps between the elementary wires 2a in this state, as will be described later in detail as a method for manufacturing the insulated electric wire 1. As a result, the water-stopping agent 5 is more likely to penetrate between the gaps between the elementary wires 2a.to penetrate them, and thus each part of the exposed section 10 can be easily and very uniformly filled with the water-stopping agent 5. In . Fig. 8B, for facilitating an understanding of a change in the density of the metal material, a state in which the diameter of the conductor 2 is larger in the exposed portion 10 than in the removed areas 22 of the covered portions 20 is shown, however, the conductor diameter in the exposed portion 10 is not necessarily large, and it is rather preferable that the conductor diameter in the exposed portion 10 is the same as the conductor diameter in the covered portions 20 in view of downsizing the water-stopping portion 4, as shown in Fig. 2 is shown.

[0053] Furthermore, it is preferable that the twist pitch of the elementary wires 2a is smaller in the exposed portion 10 than the twist pitch in the remote areas 22 of the covered portions 20, in addition to the density of the metal material per unit length being higher in the exposed portion 10 than in the remote areas 22 of the covered portions 20. This is because the fact that the twist pitch of the elementary wires 2a is smaller in the exposed portion 10 and the distances between the elementary wires 2a are smaller in the exposed portion 10 also brings about an effect of improving the water-stopping performance. That is,When the distances between the elementary wires 2a are reduced during formation of the water-stopping portion 4 in which the gaps between the elementary wires 2a are filled with the water-stopping agent 5 in a liquid state, the water-stopping agent 5 is likely to remain in the gaps between the elementary wires 2a uniformly without dripping or flowing. When the water-stopping agent 5 is cured from this state, better water-stopping performance can be obtained in the exposed portion 10. Also, as a result of the twist pitch being smaller in the exposed portion 10 than in the removed regions 22, it is possible to suppress the conductor diameter in the exposed portion 10.to reduce so as not to become too large compared with the conductor diameter of the removed regions 22, even if the density of the metal material per unit length is higher in the exposed portion 10 than in the removed regions 22. Accordingly, the outer diameter of the entire water-stopping portion 4 can be made substantially the same as the outer diameter of the insulated electric wire 1 in the removed regions 22, or can be suppressed or reduced so as not to be much larger than that in the removed regions 22. (3) Condition of the cross-section of the water-stopping section in the exposed section

[0054] The following will describe a preferred embodiment of a cross-sectional structure of a portion of the water-stopping portion 4 corresponding to the exposed portion 10. As described above, the water-stopping portion 4 of the insulated electric wire 1 according to the present embodiment includes the inter-constituent wire filled portion 41 in which the water-stopping agent 5 is disposed in the gaps between the constituent wires 2a constituting the conductor 2 in the exposed portion 10, and the exposed portion outer peripheral portion 42 in which the water-stopping agent 5 covers the outer periphery of the conductor 2, and thus the exposed portion 10 has superior water-stopping performance.The water-stopping performance can be further improved by controlling the state of a cross section of the water-stopping portion 4 in the exposed portion 10. The following will describe a preferable state of a cross section of the water-stopping portion 4 in the exposed portion 10.

[0055] As this is Fig. 3, in a region enclosed by a surface 5a of the water-stopping agent 5 in the water-stopping portion 4, the surface of the elementary wires 2a is preferably in contact with the water-stopping agent 5 or another elementary wire 2a. In other words, preferably, the surface of each elementary wire 2a included in the conductor 2 is in contact with the water-stopping agent 5 or another elementary wire 2a adjacent to that elementary wire 2a, and is not in contact with any substance other than the water-stopping agent 5 and the constituent material of the elementary wires 2a, such as bubbles B filling a defect portion of the water-stopping agent 5 with air, and liquid bubbles formed as a result thereof.that a liquid such as water enters the bubble B. Preferably, the water-stopping agent 5 tightly fills the gaps between the elementary wires 2a and adheres to the surface of the elementary wires 2a without the interposition of any bubble B or the like.

[0056] For this configuration, it is unlikely to cause situations where water enters a region between the elementary wires 2a via a bubble B from the outside of the water-stopping portion 4, and where, for example, damage that may serve as an entry path of water occurs due to the bubble B when an external force is applied. Thus, in the water-stopping portion 4, the water-stopping agent 5 adhering to the surfaces of the elementary wires 2a can particularly effectively prevent water from entering a region between the elementary wires 2a.It is also possible to effectively prevent water that has entered a region between the elementary wires 2a in one portion of the insulated electric wire 1, such as a wire terminal, from moving to another portion of the insulated electric wire 1, such as the covered portion 20, along the elementary wires 2a. In this way, by eliminating bubbles B that are in contact with an elementary wire 2a, in addition to the effect that the layer thickness La of the outer peripheral portion 42 of the exposed portion is larger than the layer thickness Lb of the outer peripheral portions 43 of the covered portion, and the like, it is easy to prevent a reduction in water-stopping performance due to the application of mechanical loads.

[0057] Here, the surface of an elementary wire 2a may be in contact with the water-stopping agent 5 or another elementary wire 2a, but better water-stopping performance can be realized when the surface is in contact with the water-stopping agent 5, because by directly adhering to the elementary wire 2a, the water-stopping agent 5 particularly effectively prevents the elementary wire 2a from coming into contact with water. However, even when the surface of an elementary wire 2a is in contact with another elementary wire 2a, water cannot enter a contact interface between the two adjacent elementary wires 2a that are in contact with each other, and sufficiently good water-stopping performance can be ensured.Due to the absence of bubbles B in contact with the elementary wires 2a, the positional relationship between the adjacent elementary wires 2a hardly changes, and a state in which water cannot enter the contact interface between the adjacent elementary wires 2a is maintained.

[0058] The cross-section of the water-stopping portion 4 may contain bubbles B that are not in contact with any elementary wire 2a, but are surrounded over their entire circumference by the water-stopping agent 5, rather than bubbles B that are in contact with an elementary wire 2a. Ideally, it is preferred that no type of bubble B is included in the area enclosed by the surface 5a of the water-stopping agent 5, however, even if there is a bubble B, this will not significantly reduce the water-stopping performance of the water-stopping portion 4 as long as the bubble B is not in contact with an elementary wire 2a. For example, there may be bubbles B whose entire circumference is surrounded by the water-stopping agent 5 on the outer side of the area formed by the conductors 2. Also, in the configuration shown in Fig. 3, such a bladder B, the entire circumference of which is surrounded by the water-stopping means 5, on the outer side of the conductor 2.

[0059] It should be noted that, as described above, bubbles B in contact with an elementary wire 2a are a cause of a reduction in water-stopping performance. However, when, for example, the required level of water-stopping performance is low, the water-stopping performance and the waterproofing performance of the insulated electric wire 1 may not be greatly affected despite the presence of bubbles B in contact with an elementary wire 2a, as long as the amount or size of such bubbles B is small. For example, in a cross section of the water-stopping portion 4, it is preferable that the sum of the cross-sectional areas of bubbles B in contact with the elementary wires 2a be 5% or lower of the sum of the cross-sectional areas of the elementary wires 2a.It is also preferable that the cross-sectional area of each bubble B in contact with an elementary wire 2a be 80% or lower of the cross-sectional area of an elementary wire 2a. On the other hand, even bubbles B whose entire circumference is surrounded by the water-stopping agent 5 and which are not in contact with an elementary wire 2a may impair the water-stopping performance of the water-stopping portion 4 if they are arranged close to the elementary wires 2a. Accordingly, it is preferable that a bubble B and an elementary wire 2a be provided at a distance of 30% or more of the diameter of the elementary wire 2a, and the space therebetween be filled with the water-stopping agent 5.

[0060] Furthermore, it is preferable that, in a cross section of the water-stopping portion 4, the elementary wires 2a arranged in the outer peripheral portion of the conductor 2 have a more flattened shape than the elementary wires 2a arranged inwardly thereof. Fig. 3, elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 have a flattened and substantially elliptical cross-section. Elementary wires 2a2 arranged inward from the elementary wires 2a1 arranged in the outer peripheral portion 2 of the conductor have a less flattened cross-section. The cross-section, taken normal to the axial direction, of all elementary wires 2a is itself substantially circular, and thus, the flattened cross-sectional shape of the water-stopping portion 4 is obtained by the arrangement of the elementary wires 2a in the conductor 2, rather than by the cross-sectional shape of all elementary wires 2a themselves, as will be described below.

[0061] When the elementary wires 2a constituting the conductor 2 are twisted in a gentle spiral shape with a relatively small inclination angle, the axial direction of the elementary wires 2a is oriented in a direction close to the longitudinal axis direction of the insulated electric wire 1, and thus a cross section of the elementary wire 2a taken normal to the longitudinal axis direction of the insulated electric wire 1 has a shape which is substantially circular and less flattened.In contrast, when the elementary wires 2a constituting the conductor 2 are twisted in a steep spiral shape with a relatively large inclination angle, the axial direction of the elementary wires 2a is oriented in a direction that is greatly inclined relative to the longitudinal axis direction of the insulated electric wire 1, and thus, when an elementary wire 2a is cut normal to the longitudinal axis direction of the insulated electric wire 1, the elementary wire 2a will be cut at an angle relative to the axial direction of the elementary wire 2a. Accordingly, the cross section of the elementary wire 2a has a flattened shape that can be approximated to an ellipse.Thus, the above description of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 in the cross section of the water-stopping portion 4 having a more flattened shape than the elementary wires 2a2 arranged inward thereof means that the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 are twisted in a steep spiral shape with a large inclination angle compared to the spiral shape of the inner elementary wires 2a2.

[0062] As described above, the water-stopping portion 4 can be formed by filling the regions between the elementary wires 2a with the water-stopping agent 5 in a state of high fluidity and then lowering the fluidity, and by twisting the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 in a steep spiral state with a large inclination angle, with the regions between the elementary wires 2a being filled with the water-stopping agent 5 in a state of high fluidity, the water-stopping agent 5 filling the regions is unlikely to drip or flow to the outside of the conductor 2 and remains in the regions between the elementary wires 2a with high uniformity. As a result,the areas between the elementary wires 2a are filled with a sufficient amount of water-stopping agent 5, and a water-stopping portion 4 having superior water-stopping performance is easily formed. Specifically, as will be described later, as a method for manufacturing the insulated electric wire 1, a manufacturing method is used in which the distances between the elementary wires 2a in the exposed portion 10 are increased while the elementary wires 2a are untwisted from the covered portions 20 to the exposed portion 10, and in this state, the gaps are made smaller.Gaps between the elementary wires 2a are filled with the water-stopping agent 5, and after the filling step, the gaps between the elementary wires 2a in the exposed portion 10 are reduced to lower the twist pitch of the elementary wires 2a (re-tightening), for the cross-sectional shape of the elementary wires 2a1 in the outer peripheral portion of the conductor 2 is likely to be flattened, and is advantageous in that the water-stopping agent 5 is easily held in the gaps between the elementary wires 2a. Thus, the feature that the elementary wires 2a1 in the outer peripheral portion of the conductor 2 have a flattened cross-sectional shape is an indicator used when forming a water-stopping portion 4 having better water-stopping performance.

[0063] Ellipticity can be used as a specific indicator for judging the level of flatness of the cross-sectional shape of the elementary wires 2a. Ellipticity is obtained by dividing the length of the short axis (short diameter) of a cross-sectional shape by the length of the long axis (long diameter), i.e., (short diameter / long diameter). The smaller the value of ellipticity, the more flattened the cross-sectional shape. In a cross section of the water-stopping portion 4, the ellipticity of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 preferably has a value smaller than the value of the ellipticity of the elementary wires 2a2 arranged inward thereof. Furthermore, the ellipticity of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 is preferably 0.95 or less.This brings about an effect of configuring the water-stopping portion 4 in which a sufficient amount of water-stopping agent 5 is held between the elementary wires 2a, and exhibits better water-stopping performance. On the other hand, the ellipticity of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 is preferably 0.50 or higher. This makes it possible to suppress a difference in actual length between the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 and the elementary wires 2a2 arranged inward thereof to a range in which the above-described effect of improving water-stopping performance is not satisfied.

[0064] It is preferable that, in a cross section of the water-stopping portion 4, the ellipticity of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 is smaller than the ellipticity of the elementary wires 2a2 arranged inward therefrom, and the ellipticities of the elementary wires 2a1 and 2a2 in a cross section of the water-stopping portion 4, particularly, the ellipticity of the elementary wires 2a1 arranged in the outer peripheral portion, are smaller than the values of the ellipticities of the elementary wires 2a in a cross section of the covered portion 20 (specifically, the removed portion 22) taken normal to the longitudinal axis direction of the insulated electric wire 1. This means that the twist pitch of the elementary wires 2a is smaller in the exposed portion 10 constituting the water-stopping portion 4.than in the covered portions 20. As described above, in the production method in which the distances between the elementary wires 2a in the exposed portion 10 are increased, and in this state, the gaps between the elementary wires 2a are filled with the water-stopping agent 5, and after the filling step, the distances between the elementary wires 2a in the exposed portion 10 are reduced to lower the twist pitch of the elementary wires 2a (re-tightening), an advantageous effect of easily holding the water-stopping agent 5 in the gaps between the elementary wires 2a is realized. Also, by decreasingBy lowering the twist pitch of the elementary wires 2a in the exposed portion 10 relative to the twist pitch in the covered portions 20 in the re-tightening step, the effect of retaining the water-stopping agent 5 in the gaps between the elementary wires 2a is particularly improved. Accordingly, the feature that the ellipticity of the elementary wires 2a in a cross section is smaller in the exposed portion 10 than in the covered portion 20 functions as a good indicator for use when the water-stopping portion 4 having better water-stopping performance is formed.

[0065] Furthermore, a filling rate with the water-stopping agent can be used as an indicator for evaluating whether or not the gaps between elementary wires 2a in the filled area 41 between the elementary wires of the water-stopping portion 4 are filled with a sufficient amount of the water-stopping agent 5. A filling rate of the water-stopping agent is defined as a ratio of an area (A1) of a region between the elementary wires 2a filled with the water-stopping agent 5 to a sum (A0) of areas of a region formed by the conductor 2 and a region enclosed by the conductor 2 in a cross section of the water-stopping portion 4 (A1 / A0 × 100%). For example, in a cross section of the water-stopping portion 4, by calculating the area (A0) of the polygonal region formed by connecting the centers,Taking the center points of the elementary wires 2a1 arranged in the outer peripheral portion of the conductor 2 as a reference, a filling rate with the water-stopping agent can be calculated as a ratio of the area (A1) of the region filled with the water-stopping agent 5 to the area (A0). For example, when the filling rate with the water-stopping agent is 5% or higher, and specifically 10% or higher, it is conceivable that the gaps between the elementary wires 2a are filled with an amount of the water-stopping agent 5 sufficient to ensure better water-stopping performance. On the other hand, the filling rate with the water-stopping agent is preferably kept at 90% or lower from the viewpoint of avoiding the use of an excessive amount of the water-stopping agent 5.

[0066] Also, as described above, the surface of an elementary wire 2a is preferably not in contact with any bubble B. The surface of an elementary wire 2a may be in contact with the water-stopping agent 5 or may be in contact with another elementary wire 2a, but it is preferable that the surface be in contact only with the water-stopping agent 5 from the viewpoint of easily ensuring better water-stopping performance. Based on this view, in a cross section of the water-stopping portion 4, the sum of the lengths of the portions in the circumference of the elementary wires 2a that are not in contact with any bubble B or adjacent elementary wires 2a but are in contact with the water-stopping agent 5 is preferably 80% or higher of the sum of the circumferential lengths of all the elementary wires 2a.Also, since it is easier to fill a gap between elementary wires 2a with the water-stopping agent 5 when the distance between the adjacent elementary wires 2a is sufficiently large, it is preferable that a cross section of the water-stopping portion 4 includes a portion constituted by the water-stopping agent 5 and in which the distance between adjacent elementary wires 2a is 30% or higher of the outer diameter of the elementary wires 2a. [Configuration of a cabling]

[0067] A wiring harness 6 according to an embodiment of the present disclosure includes the above-described insulated electric wire 1 having the water-stopping portion 4 according to the embodiment of the present disclosure. Fig. 4 illustrates an example of the wiring harness 6 according to the present embodiment. The insulated electric wire 1 constituting the wiring 6 is provided at the respective ends thereof with electrical connections 61 and 63, such as connectors, capable of connecting to other devices U1 and U2. The wiring 6 may include another type of insulated electric wire (not shown) in addition to the above-described insulated electric wire 1 according to the embodiment.

[0068] The wiring 6 may employ any type of electrical connections 61 and 63 provided at the respective ends of the insulated electric wire 1, and any type of devices U1 and U2 to which the electrical connections 61 and 63 are connected, but a suitable insulated electric wire 1 is such that one end thereof is waterproof while the other end is not waterproof, in view of efficient use of the water-stopping performance of the water-stopping portion 4.

[0069] As such an embodiment, the first electrical connection 61 provided at one end of the insulated electric wire 1 includes a waterproof structure 62 as shown in Fig. 4. An example of the waterproof structure 62 is such that the connector constituting the first electrical connection 61 is provided with a rubber plug for sealing a space between a connector housing and a connector terminal. With the waterproof structure 62, even if water adheres to the surface or the like of the first electrical connection 61, the water is unlikely to enter the first electrical connection 61.

[0070] On the other hand, the second electrical connection 63 provided at the other end of the insulated electric wire 1 does not include a waterproof structure as included in the first electrical connection 61. Accordingly, when water adheres to the surface or the like of the second electrical connection 63, the water may enter the second electrical connection 63.

[0071] The exposed portion 10, in which the conductor 2 is exposed, is formed in a middle portion of the insulated electric wire 1 constituting the wiring 6, that is, at a position between the first electrical connection 61 and the second electrical connection 63, and in an area including this exposed portion 10, the water-stopping portion 4 filled with the water-stopping agent 5 is formed. There is no particular limitation on the specific position and number of the water-stopping portions 4, but at least one water-stopping portion 4 is preferably provided at a position closer to the first electrical connection 61 than to the second electrical connection 63 in order to effectively suppress the influence of water on the first electrical connection 61 having the waterproof structure 62.

[0072] The wiring 6, which includes electrical connections 61 and 63 at both ends of the insulated electric wire 1, can be used to electrically connect two devices U1 and U2. For example, the first device U1, to which the first electrical connection 61 having the waterproof structure 62 is connected, may be a device such as an electrical control unit (ECU) that requires waterproofing. On the other hand, the second device U2, to which the second electrical connection 63 is connected without any waterproof structure, may be a device that does not require waterproofing.

[0073] Since the insulated electric wire 1 constituting the wiring 6 includes the water-stopping portion 4, even if water that has entered the wiring 6 from the outside moves along the elementary wires 2a constituting the conductor 2, it is possible to suppress the movement of the water along the insulated electric wire 1 from progressing beyond the water-stopping portion 4. That is, it is possible to suppress external water from moving beyond the water-stopping portion 4, reaching the electrical connections 61 and 63 at both ends, and further entering the devices U1 and U2 connected to the electrical connections 61 and 63.For example, even if water adhering to the surface of the second electrical connection 63 without any waterproof structure enters the second electrical connection 63 and moves along the insulated electric wire 1 via the elementary wires 2a constituting the conductor 2, the movement of the water is stopped by the water-stopping agent 5 with which the water-stopping portion 4 is filled. As a result, the water cannot move to the side on which the first electrical connection 61 is provided beyond the water-stopping portion 4, and can neither reach the position of the first electrical connection 61 nor enter the first electrical connection 61 and the first device U1. By suppressing water movement by the water-stopping portion 4 in this way, it is possible to efficiently improve the waterproof characteristic.property of the waterproof structure 62 with respect to the first electrical connection 61 and the device U1.

[0074] The effect of suppressing water movement using the water-stopping portion 4 provided on the insulated electric wire 1 is realized regardless of the position where the water adheres, the reason therefor, the environment when the water adheres, or the situation after the water adheres. For example, when the wiring 6 is installed in a motor vehicle, water that has entered a portion of the insulated electric wire 1, such as a gap between the elementary wires 2a, from the non-waterproof second electrical connection 63 can be effectively prevented from entering the first electrical connection 61 having the waterproof structure 62 and the first device U1 due to capillary action or cold breathing.“Cold breathing” refers to a phenomenon in which, when the first electrical connection 61 having the waterproof structure 62 and the first device U1 are heated when, for example, the motor vehicle is driven and then heat is released, the pressure on the first electrical connection 61 side becomes lower and the pressure on the second electrical connection 63 side becomes relatively higher, so that a pressure difference occurs along the insulated electric wire 1 and water adhering to the second electrical connection 63 climbs toward the first electrical connection 61 and the first device U1. [Method for manufacturing the insulated electric wire]

[0075] The following will describe an example of a method for manufacturing the insulated electric wire 1 according to the above-described embodiment.

[0076] Fig. 5 schematically illustrates a manufacturing method according to the present disclosure. In this method, the water-stopping portion 4 is formed in a partial area of the insulated electric wire 1 in the longitudinal axis direction thereof by performing: (1) a partial exposure step; (2) a density modification step; (3) a filling step; (4) a re-tightening step; (5) a sheath movement step; and (6) a curing step in this order. The density modification step (2) may include: (2-1) a tightening step; and subsequently (2-2) a loosening step. The steps will be explained below. Next, a case where the water-stopping portion 4 is formed in a central portion of the insulated electric wire 1 will be described.However, specific operations in the steps and the order of the steps may be set appropriately in accordance with details of the configuration of a water-stopping portion 4 to be formed, such as a position at which the water-stopping portion 4 is to be formed. (1) Step of partial exposure

[0077] First, in the step of partial exposure, an exposed section 10 is formed as shown in Fig. 6B, in a continuous linear insulated electric wire 1 as shown in Fig. 6A. The covered portions 20 are provided adjacent to both sides of the exposed portion 10 in the longitudinal axis direction thereof.

[0078] In one example of the method for forming such an exposed portion 10, a substantially annular slit is formed in the outer periphery of the insulation coating 3 substantially at the center of the area where the exposed portion 10 is to be formed. Then, the regions of the insulation coating 3 located on both sides of the slit are held by their outer periphery and are pulled away from each other along the axial direction of the insulated electric wire 1 (movement M1). Along with this movement, the conductor 2 is exposed between the regions of the insulation coatings 3 on both sides. In this manner, the exposed portion 10 is formed adjacent to or adjacent to the covered portions 20. (2) Step of density modification

[0079] The filling step may be performed, and the gaps between the elementary wires 2a constituting the conductor 2 in the exposed portion 10 may be filled with the water-stopping agent 5 immediately after the exposed portion 10 in which the conductor 2 is exposed is formed in the partial exposure step. However, it is preferable to perform the density modification step before the filling step so that the gaps between the elementary wires 2a can be enlarged and filled with the water-stopping agent 5 with high uniformity.

[0080] In the density modification step, a non-uniform density distribution of the metal material is formed among the exposed portion 10, the adjacent region 21, and the distal region 22 of the covered portion 20, and the intervals between the elementary wires 2a of the conductor 2 in the exposed portion 10 are increased. Specifically, the non-uniform density distribution of the metal material is formed such that the density of the metal material per unit length is higher in the exposed portion 10 than in the distal regions 22. Such a density distribution can be formed at the same time as increasing the intervals between the elementary wires 2a in the exposed portion 10 in the tightening step and the subsequent loosening step. (2-1) Step of dressing

[0081] As this is Fig. 6C, in the tightening step, the twist of the elementary wires 2a in the exposed portion 10 is temporarily tightened relative to the original state. Specifically, the insulated electric wire 1 is twisted and rotated in the twist direction of the elementary wires 2a so that the twist is further tightened (movement M2). Thus, the twist pitch of the elementary wires 2a in the exposed portion 10 is reduced, and the intervals between the elementary wires 2a are reduced.

[0082] During this process, if the covered portions 20 arranged on both sides of the exposed portion 10 are held from the outside at portions adjacent to the exposed portion 10, and the conductor 2 is twisted so that the holding portions (i.e., holding portions 30) are rotated in mutually opposite directions, the conductor 2 can be wound from the holding portions 30 toward the exposed portion 10. As a result of the winding of the conductor 2, the twisting pitch of the elementary wires 2a in the holding portions 30 is increased relative to the original pitch, and the density of the metal material per unit length is reduced from the original density, as shown in Fig. 6C. Accordingly, a portion of the metal material originally disposed in the holding portions 30 is shifted toward the exposed portion 10, and the twisting pitch of the elementary wires 2a in the exposed portion 10 is reduced by this shift. Also, the density of the metal material per unit length in the exposed portion 10 is increased. It is preferable that a force for holding the insulated electric wire 1 in the holding portions 30 from the outer peripheral side is sufficiently suppressed to allow the relative movement of the conductor 2 relative to the insulation cover 3 with a view to smoothly winding the conductor 2 from the holding portions 30 toward the exposed portion 10. (2-2) Step of loosening

[0083] Afterwards, as described in Fig. 7A, in the loosening step, the twist of the elementary wires 2a in the exposed portion 10 is again loosened from the state where the twist was tightened in the tightening step. The twist can be loosened by simply releasing the grip of the gripping portions 30, or by holding the gripping portions 30 and twisting and rotating the gripping portions 30 in the direction opposite to the tightening direction of the tightening step, that is, the direction opposite to the twisting direction of the conductor 2 (movement M3).

[0084] During the process, the portions of the conductor 2 wound by the holding portions 30 arranged on both sides of the exposed portion 10 in the tightening step do not completely return to the areas covered with the insulation sheath 3 due to the rigidity of the conductor 2, and remain at least partially in the exposed portion 10. As a result, the twist of the elementary wires 2a of the conductor 2 is loosened, the conductor 2 is wound to the exposed portion 10, and thus a state is realized in which the elementary wires 2a, whose actual length is greater than the length before the tightening step is performed, are bent and arranged in the exposed portion 10. That is, as shown in Fig. 7A, in the exposed portion 10, the diameter of the area completely formed by the conductor 2 is larger than the diameter before the tightening step is performed (in Fig. 6B), and the density of the metal material per unit length is increased. The twist pitch of the elementary wires 2a in the exposed portion 10 is at least larger than the twist pitch in the state where the twist is tightened in the tightening step and is larger than the twist pitch before the tightening step is performed, depending on the degree of loosening. In view of increasing the distances between the elementary wires 2a, the twist pitch of the elementary wires 2a in the exposed portion 10 is preferably larger than the twist pitch before the tightening step is performed.

[0085] After the loosening step, the holding portions 30 of the covered portions 20 where the insulation cover 3 was held from the outside in the tightening step will serve as the adjacent regions 21 in which the density of the metal material per unit length is lower than that in the exposed portion 10, and also lower than that in the state before the tightening step is performed. The regions of the covered portions 20 that did not function as the holding portions 30 in the tightening step, that is, the regions spaced apart from the exposed portion 10, will be defined as the removed regions 22.In the removed regions 22, the states of the conductor 2, such as the density of the metal material per unit length and the twist pitch of the elementary wires 2a, do not change significantly from the states before the tightening step is performed. The proportion of the metal material in the adjacent regions 21, which was obtained as a result of the reduction in the density per unit length, is shifted to the exposed portion 10 and contributes to an increase in the density of the metal material per unit length in the exposed portion 10. As a result, the exposed portion 10 has the highest density of the metal material per unit length, the removed regions 22 have the next highest density, and the adjacent regions 21 have the lowest density. (3) Step of filling

[0086] Next, in the filling step, the gaps between the elementary wires 2a in the exposed portion 10 are filled with the uncured water-stopping agent 5 as shown in Fig. 7B. The filling process with the water-stopping agent 5 can be performed by injecting a liquid resin composition into the gaps between the elemental wires 2a using an appropriate method such as application, dipping, dropping, and injection, which corresponds to such properties of the water-stopping agent 5 as viscosity.

[0087] In the filling step, in addition to filling the gaps between the elementary wires 2a with the water-stopping agent 5, the water-stopping agent 5 is also disposed on the outer periphery of the conductor 2 in the exposed portion 10. For this purpose, for example, the amount of the water-stopping agent 5 to be introduced into the exposed portion 10 only needs to be adjusted such that the water-stopping agent 5 remains even after the gaps between the elementary wires 2a are filled. In this case, the water-stopping agent 5 may be disposed on the outer peripheral portion of the insulation covering 3 at the end portions of the covered portions 20, in addition to the outer periphery of the exposed portion 10.However, when the sheath moving step is performed after the filling step, the water-stopping agent 5 introduced into the exposed portion 10 may be partially moved onto the outer peripheral portion of the insulation sheath 3 in the covered portions 20 in the sheath moving step. Accordingly, it is sufficient that the water-stopping agent 5 be disposed on the outer periphery of the exposed portion 10 in addition to the gaps between the elementary wires 2a. By adjusting the amount of the water-stopping agent 5 to be disposed on the outer periphery of the conductor 2 in the exposed portion 10 in the filling step, the layer thickness La in the outer peripheral region 42 of the exposed portion and the layer thickness Lb in the outer peripheral region 42 of the exposed portion can be adjusted.Outer peripheral area 43 of the covered portion of the water-stopping portion 4 to be formed can be controlled, and thus it is possible to maintain the predetermined relationships (such as La>Lb and Lb <Lc) zu realisieren.

[0088] Since the distances between the elementary wires 2a in the exposed portion 10 are increased in the density modification step, and then the water-stopping agent 5 is introduced into the exposed portion 10 in the filling step, the water-stopping agent 5 easily penetrates the expanded spaces between the elementary wires 2a. Accordingly, the water-stopping agent 5 can easily penetrate every part of the exposed portion 10 evenly with high uniformity. Accordingly, after the water-stopping agent 5 is cured, a reliable water-stopping portion 4 exhibiting excellent water-stopping performance can be formed.Also, even if the water-stopping agent 5 has a relatively high viscosity such as 4 Pa s or higher, the water-stopping agent 5 can penetrate the gaps between the elementary wires 2a with high uniformity by sufficiently increasing the gaps between the elementary wires 2a.

[0089] As described above, a predetermined portion of the insulated electric wire 1, such as a region between the elemental wires 2a, can be filled with the water-stopping agent 5 by any method such as application or immersion. However, the portion is preferably filled with the water-stopping agent 5 by immersion, from the viewpoint of improving uniformity in filling with the water-stopping agent 5 or handleability when forming water-stopping portions 4 in a plurality of insulated electric wires 1.

[0090] For example, a spray device for spraying the water-stopping agent 5 is preferably used to immerse the predetermined portion of the insulated electric wire 1 in the water-stopping agent 5. In this case, it is also possible to bring the insulated electric wire 1 into contact with the spray of the water-stopping agent 5 while the insulated electric wire rotates around its axis to arrange the water-stopping agent 5 with high uniformity. (4) Step of re-dressing

[0091] After the completion of the filling step, the re-tightening step is carried out as described in Fig. 7C, and the distances between the elementary wires 2a in the exposed portion 10 are reduced in the state where the gaps between the elementary wires 2a are filled with the water-stopping agent 5. Similar to the above-mentioned tightening step, for example, the density modification step, this step may be performed such that the covered portions 20 located on both sides of the exposed portion 10 are held at the adjacent areas 21 outside of the insulation cover 3, and the conductor 2 is twisted and rotated in the direction of twisting of the elementary wires 2a so that the twisting of the elementary wires 2a is tightened (movement M4).Unlike the tightening step, an operation of winding the conductor 2 to the exposed portion 10 is not performed in the re-tightening step.

[0092] When the gaps between the elementary wires 2a in the exposed portion 10 are narrowed in the re-tightening step, the water-stopping agent 5 is confined in the narrowed gaps. Thus, the water-stopping agent 5 is likely to remain in the gaps between the elementary wires 2a without flowing or dripping until the flowability of the water-stopping agent 5 is sufficiently lowered due to curing or the like. Accordingly, after the water-stopping agent 5 is cured, a reliable water-stopping portion 4 having excellent water-stopping performance is easily formed. To enhance the effect, it is preferable that the twist pitch of the elementary wires 2a in the exposed portion 10 be reduced in the re-tightening step.For example, it is preferable that in the re-tightening step, the twist pitch of the elementary wires 2a is smaller in the exposed portion 10 than in the adjacent regions 21 as well as in the removed regions 22. It is also preferable that after the re-tightening step, the exposed portion 10 has the same outer diameter as that of the covered portions 20.

[0093] The retightening step is preferably performed while the water-stopping agent 5 filling the gaps between the elementary wires 2a is flowable, ie, before the water-stopping agent 5 is cured or during the curing process. Accordingly, the retightening process is unlikely to be hindered or affected by the water-stopping agent 5.

[0094] Specifically, when the above-mentioned filling step is performed by immersing the insulated electric wire 1 in the water-stopping agent 5 using the spray device or the like, the re-tightening step is preferably performed with the insulated electric wire 1 immersed in the water-stopping agent 5. This can easily avoid a situation where the water-stopping agent 5 drips out and is removed from the gaps of the constituent wires 2a due to the re-tightening process itself. For example, it is preferable to do this after the predetermined portion of the insulated electric wire 1 including the exposed portion 10 is brought into contact with the spray of the water-stopping agent 5 and the water-stopping agent 5 is deposited in the gaps between the constituent wires 2a or the like.in the step of filling, the step of retightening is carried out by twisting and rotating the conductor 2 (movement M4) while the insulated electric wire 1 is in contact with the spray jet or stream. (5) Step of movement of the sheath

[0095] Next, in the step of moving the sheath as shown in Fig. 8A, the regions of the insulation covering 3 located in the covered portions 20 on both sides of the exposed portion 10 are moved toward the exposed portion 10, approaching each other (movement M5). Similar to the re-tightening step, the covering moving step is preferably performed while the water-stopping agent 5 filling the exposed portion 10 is flowable, that is, before the water-stopping agent 5 is cured, or during the curing process. The covering moving step and the re-tightening step may also be performed substantially in a single operation. As described above, when the filling step is performed by immersing the insulated electric wire 1 in the water-stopping agent 5 using the spray device or the like.is carried out, and the step of re-tightening is carried out in this state, preferably the step of moving the sheath is also carried out in the state in which the insulated electric wire 1 is immersed in the water-stopping agent 5.

[0096] Even if there is an area where the gaps between the elementary wires 2a cannot be filled with the sufficient amount of the water-stopping agent 5 in the step of filling at one end of the exposed portion 10 or the like, the water-stopping agent 5 will reach such an area in the step of moving the covering, and a state will be realized in which the gaps between the elementary wires 2a are filled with the water-stopping agent 5 in the entire exposed portion 10 in which the conductor 2 is exposed. Moreover, a part of the water-stopping agent 5 disposed on the outer periphery of the conductor 2 in the exposed portion 10 can be moved to the outer periphery of the insulation covering 3 in the covered portions 20. Thus, the water-stopping agent 5 is continuously supplied.arranged continuously over three areas, namely, or in particular, the gaps between the elementary wires 2a in the exposed portion 10, the outer periphery of the conductor 2 in the exposed portion 10, and the outer peripheries of the parts of the insulation sheath 3 at the ends of the sheathed portions 20.

[0097] Since the water-stopping agent 5 is disposed over the three regions, it is possible, after the subsequent curing step, to form a water-stopping portion 4 in which the filled region 41 between the elementary wires, the outer peripheral region 42 of the exposed portion, and the outer peripheral regions 43 of the covered portion are continuous with each other. That is, after the subsequent curing step, it is possible to form a water-stopping portion 4 that has excellent water-stopping performance in the regions between the elementary wires 2a, has an outer periphery that is physically protected and electrically insulated, and has excellent water-stopping performance between the conductor 2 and the insulation covering 3, using the same material at the same time.The step of moving the sheath may be omitted if, in the step of filling, a sufficient amount of water-stopping agent 5 can be introduced into an area extending over the entire exposed portion 10 and further, for example, to an area including the end portions of the sheathed portions 20 arranged on both sides of the exposed portion 10. (6) Step of hardening

[0098] Finally, the water-stopping agent 5 is cured in the curing step. At this time, only a curing method corresponding to the type of curability of the water-stopping agent 5 needs to be used. For example, if the water-stopping agent 5 has heat curability, it can be cured by heating; if the water-stopping agent 5 has light curability, it can be cured by light irradiation; and if the water-stopping agent 5 has moisture curability, it can be cured by humidification, e.g., while being placed in the atmosphere.

[0099] In the step of hardening, as described in Fig.8B, the insulated electric wire 1 is preferably rotated around its axis (movement M6) until the water-stopping agent 5 is completely cured. If the water-stopping agent 5 is cured without rotating the insulated electric wire 1, that is, while the insulated electric wire 1 remains stationary, the uncured water-stopping agent 5 will drip due to gravity, and the water-stopping agent 5 will be cured in a state in which a thicker layer of the water-stopping agent 5 is formed at a lower position in the direction of gravity than at a higher position.Thus, after curing the water-stopping agent 5, the conductor 2 will be eccentric in the water-stopping portion 4, and there is a possibility that non-uniformity may occur in the water-stopping performance or physical characteristics along the circumferential direction of the insulated electric wire 1. For example, the material strength or water-stopping performance of the water-stopping agent 5 may be impaired in a portion where the layer thickness of the water-stopping agent 5 is reduced, while the water-stopping agent 5 is likely to be damaged when it comes into contact with an external object in a portion where the layer thickness of the water-stopping agent 5 is increased.

[0100] Accordingly, by performing the hardening step while rotating the insulated electric wire 1 around its axis, the unhardened water-stopping agent 5 is unlikely to remain at one position in the circumferential direction of the insulated electric wire 1, and the layers of the water-stopping agent 5 are likely to have a very high uniform thickness around the entire circumference. Thus, a water-stopping portion 4 having a linear shape is easily obtained, and the eccentricity of the conductor 2 in the water-stopping portion 4 is reduced, making it possible to realize a water-stopping portion 4 having very good uniform water-stopping performance and physical properties.Moreover, when the water-stopping agent 5 has light-curability, performing the curing step while rotating the insulated electric wire 1 around its axis makes it possible to irradiate the entire insulated electric wire 1 in the circumferential direction with the light L from the light source 80, and thus the light-curing of the water-stopping agent 5 can proceed uniformly over the entire circumference.When, after the completion of the filling step, the re-tightening step, and the sheath moving step, time is required to move the insulated electric wire 1, for example, between processing devices before the curing step is started, it is preferable to keep the insulated electric wire 1 rotated about its axis even during such a period of time so that the water-stopping agent 5 is prevented from dripping at a specific position in the circumferential direction.

[0101] Embodiments of the present disclosure have been described in detail, but the present invention is by no means limited to the above-described embodiments and can be variously modified within a range without departing from the spirit of the present invention. List of reference symbols 1 insulated electrical wire 2 conductors 2a elementary wire 2a1 elementary wire arranged on an outer peripheral portion of the conductor 2a2 elementary wire arranged inward from the elementary wire 2a1 3 Insulation sheath or coating 4 water-stopping section 5 water-stopping agent 5a Surface of the water-stopping agent 6 Wiring or wiring harness 10 exposed section 20 sheathed or coated section 21 adjacent or neighbouring area 22 remote area 30 stopping or holding section 41 filled area between the elementary wires 42 outer or outer peripheral area of the exposed section 43 outer or outer peripheral area of the sheathed section 44 tapered section 61 first electrical connection 62 waterproof structure 63 second electrical connection 80 light source B Bladder L Light La layer thickness of the water-stopping agent in the outer peripheral area of the exposed portion Lb Layer thickness of the water-stopping agent in the outer peripheral area of the coated portion Lc Thickness of the insulation sheath M1 to M6 movement

Claims

[1] Insulated electrical wire (1), comprising: a conductor (2) in which a plurality of elementary wires (2a) made of a metal material are twisted together; and an insulation sheath (3) which encloses an outer circumference of the conductor (2), wherein the insulated electrical wire (1) comprises: an exposed portion (10) in which the insulation sheath (3) is removed from the outer periphery of the conductor (2); a covered portion (20) in which the insulation sheath (3) covers the outer circumference of the conductor (2), wherein the exposed portion (10) and the covered portion (20) are arranged adjacent to each other in a longitudinal axis direction of the insulated electric wire (1); and a water-stopping portion (4) in which a water-stopping agent (5) is arranged over the exposed portion (10) and a region of the sheathed portion (20) which adjoins the exposed portion (10), and the water-stopping section (4) has: a filled region (41) between the elementary wires (2), in which gaps between the elementary wires (2) in the exposed portion (10) are filled with the water-stopping agent (5); an outer peripheral region (42) of the exposed portion (10) in which the water-stopping agent (5) covers or surrounds or encloses the outer periphery of the conductor (2) in the exposed portion (10); and an outer peripheral region (43) of the sheathed portion (20), in which the water-stopping agent (5) covers or surrounds or encloses an outer periphery of the insulation sheath (3) in the region of the sheathed portion (20), which adjoins the exposed section (10), wherein the filled region (41) between the elementary wires (2), the outer peripheral region (42) of the exposed portion (10) and the outer peripheral region (43) of the sheathed portion (20) are adjacent to one another, a layer thickness of the water-stopping agent (5) is greater in the outer peripheral region (42) of the exposed portion (10) than in the outer peripheral region (43) of the coated portion (20), the layer thickness of the water-stopping agent (5) in the outer peripheral region (43) of the sheathed portion (20) is smaller than a thickness of the insulation sheath (3), the water-stopping agent (5) has a higher modulus of elasticity than the insulation sheath (3), and the water-stopping agent (5) directly contacts a surface of the insulation sheath (3) in the sheathed portion (20) and a surface of the conductor (2) in the exposed portion (10), wherein the elastic modulus of the water-stopping agent (5) is not greater than twice the elastic modulus of the insulation sheath (3). [2] The insulated electric wire (1) according to claim 1, wherein the water-stopping portion (4) at one end of the outer peripheral region (43) of the covered portion (20) which corresponds to one end of the entire water-stopping portion (4) in the longitudinal axis direction has a tapered structure in which a layer of the water-stopping agent (5) becomes thinner outward in the longitudinal axis direction. [3] The insulated electric wire (1) according to any one of claims 1 to 2, wherein an outer peripheral surface of the water-stopping portion (4) except for end portions in the longitudinal axis direction has no difference in a height which is equal to or greater than the layer thickness of the water-stopping agent (5) in the outer peripheral region (43) of the covered portion (20). [4] The insulated electric wire (1) according to claim 3, wherein the outer peripheral surface of the water-stopping portion (4) except for the end portions in the longitudinal axis direction has no difference in a height which is equal to or greater than 20% of the layer thickness of the water-stopping agent (5) in the outer peripheral region (43) of the covered portion (20). [5] An insulated electric wire (1) according to any one of claims 1 to 4, wherein the water-stopping agent (5) has a flexural modulus at room temperature of 300 MPa or lower. [6] An insulated electric wire (1) according to any one of claims 1 to 5, wherein a twist pitch of the elementary wires (2a) of the conductor (2) is smaller in the exposed portion (10) than at least in a remote region (22) which is a region of the covered portion (20) except for a region adjacent to the exposed portion (10). [7] The insulated electric wire (1) according to any one of claims 1 to 6, wherein ellipticities of the elementary wires (2a) in a cross section of the water-stopping portion (4) taken normal to the longitudinal axis direction of the insulated electric wire (2a) are smaller than ellipticities of the elementary wires (2a) in a cross section of the covered portion (20) taken normal to the longitudinal axis direction of the insulated electric wire (1). [8] Wiring comprising the insulated electric wire (1) according to any one of claims 1 to 7.

Images