Stretchable wire

Abstract

To provide a wire capable of being sufficiently deformed and having durability.SOLUTION: A stretchable wire comprises: an electric conductive body having conductivity formed so as to be stretchable in a stretching direction; and a flexible body continuously formed so as to be elastically deformed and having a first junction to which the electric conductive body is connected and a second junction separated from the first junction in the stretching direction and to which the electric conductive body is connected. The first shortest length along the electric conductive body from the first junction to the second junction is longer than the second shortest length along the flexible body from the first junction to the second junction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This relates to an expandable electric wire that can be easily deformed. [Background technology]

[0002] Stretchable electric wires are used for wiring various devices having moving parts, such as robots. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2008 / 078780 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-266401 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-229568 Summary of the Invention [Problem to be solved by the invention]

[0004] Stretchable electric wires are used for wiring various devices having movable parts. For this reason, the stretchable electric wires must be able to deform in accordance with various movements of the movable part while maintaining electrical connection. The movement of the movable part is often repeated, and the stretchable electric wires must be able to deform repeatedly in accordance with the movement of the movable part.

[0005] The present invention has been made in view of the above points, and an object of the present invention is to provide an electric wire that can be sufficiently deformed and has durability. [Means for solving the problem]

[0006] The stretchable electric wire according to the present invention is characterized by the following features: a conductor that is a metal fiber structure that is electrically conductive and stretchable in the stretching direction, has a width in a direction different from the stretching direction, has bonding parts where metal fibers are physically fixed to each other, and has voids formed between the metal fibers; a flexible body that is continuously formed so as to be elastically deformable, and has a first junction at which the conductor is joined, and a second junction at which the conductor is joined and that is spaced apart from the first junction in the extension / contraction direction, A first shortest length along the conductor from the first junction to the second junction is longer than a second shortest length along the flexible body from the first junction to the second junction. [Effects of the Invention]

[0007] It is sufficiently deformable and durable. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a laminated structure of an expandable electric wire 10-1 according to a first embodiment. FIG. [Figure 2] 1A is a cross-sectional view showing a cross section of an expandable electric wire 10-1 according to a first embodiment, and FIG. 1B is a plan view showing a plane of the expandable electric wire 10-1. [Figure 3] 10A is a cross-sectional view showing a cross section of an expandable electric wire 10-2 according to a second embodiment, and FIG. 10B is a plan view showing a plane of the expandable electric wire 10-2. [Figure 4] 10A is a cross-sectional view showing a cross section of an expandable electric wire 10-3 according to a third embodiment, and FIG. 10B is a plan view showing a plane of the expandable electric wire 10-3. [Figure 5] 10A is a cross-sectional view showing a cross section of an expandable electric wire 10-4 according to a fourth embodiment, and FIG. 10B is a plan view showing a plane of the expandable electric wire 10-4. [Figure 6] 10A is a cross-sectional view showing a cross section of an expandable electric wire 10-5 according to a fifth embodiment, and FIG. 10B is a plan view showing a plane of the expandable electric wire 10-5. [Figure 7] 13A is a cross-sectional view showing a cross section of an expandable electric wire 10-6 according to a sixth embodiment, and FIG. 13B is a plan view showing a plane of the expandable electric wire 10-6. [Figure 8] 13A is a cross-sectional view showing a cross section of an expandable electric wire 10-7 according to a seventh embodiment, and FIG. 13B is a plan view showing the plan view thereof. [Figure 9]13A is a cross-sectional view showing a cross section of an expandable electric wire 10-8 according to an eighth embodiment before assembly, and FIG. 13B is a cross-sectional view showing a cross section after assembly. [Figure 10A] 1 is a table showing an example. [Figure 10B] 1 is a table showing examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0009] <<<<<Outline of this embodiment>>>> <<First embodiment>> a conductive body formed to be stretchable in the stretching direction and having conductivity; a flexible body that is continuously formed so as to be elastically deformable, and has a first junction at which the conductor is joined, and a second junction at which the conductor is joined and that is spaced apart from the first junction in the extension / contraction direction, A stretchable electric wire is provided, wherein a first shortest length along the conductor from the first junction to the second junction is greater than a second shortest length along the flexible body from the first junction to the second junction.

[0010] The stretchable wire includes a conductor and a flexible body.

[0011] The conductor is conductive. The conductor may be any medium through which an electric current flows. The conductor is formed to be stretchable in the stretching direction. The conductor may be stretchable, for example, made of fibers or a continuous body such as a foil, film, or wire. Furthermore, the conductor does not need to be entirely conductive, and only a portion of it may be conductive. For example, the conductor may be made of a resin as a base material and the surface thereof may be coated with a conductive substance. The conductor is preferably a metal fiber structure.

[0012] The flexible body is formed continuously so as to be elastically deformable. "Continuous" means that any part of the flexible body is connected or connected and continuous, and does not have to be entirely or entirely continuous. For example, even if the flexible body is made of fibers or a mesh, it is sufficient as long as any part is connected or connected.

[0013] The flexible body has a first junction point and a second junction point. The first junction point is a first location where the flexible body and the conductor are joined. The second junction point is a second location that is spaced apart from the first junction point in the direction of expansion and contraction. The second junction point is a second location where the flexible body and the conductor are joined.

[0014] Note that bonding is different from contact. Bonding is a state of being joined together, while contact is close and touching. Bonding maintains a state of being joined together permanently or semi-permanently. Contact is when two objects move relative to each other and only come close and touch temporarily, and is assumed to come apart. After the first and second bonding points are formed, if a flexible body and a conductor come close and temporarily touch, it is not a bonding point.

[0015] There is no other joint between the first joint and the second joint, and even if there is temporary or accidental contact between the first joint and the second joint during the process of expansion and contraction, there is no other joint.

[0016] The length from the first junction point to the second junction point is divided into two types: the first length along the conductor and the second length along the flexible body. The shortest length among the first lengths is called the first shortest length. The shortest length among the second lengths is called the second shortest length. The first shortest length is longer than the second shortest length. The shortest length is the shortest length of the curve connecting two points. If the conductor has a shape that takes a detour around the flexible body, the first shortest length is longer than the second shortest length.

[0017] With this configuration, the conductor can also deform as the flexible body undergoes elastic deformation, expansion and contraction deformation, etc. Since only a portion of the conductor is joined to the flexible body, the degree of freedom of deformation of the conductor can be increased when the flexible body deforms.

[0018] <<Second embodiment>> The second embodiment is the same as the first embodiment, except that: The conductor has at least one of a curved portion that curves or a bent portion that bends (for example, a protrusion 110 and a groove 120 described later) between the first junction point and the second junction point.

[0019] The conductor can expand and contract as the curved or bent parts expand and contract. The conductor can deform smoothly as the flexible body deforms. The curved or bent parts provide room or margin (stretchability) for deformation.

[0020] There is at least one curved or bent portion between the first and second junctions, and there may be multiple curved or bent portions between the first and second junctions.

[0021] <<Third embodiment>> The third embodiment is the same as the second embodiment, except that: The curved portion curves in a direction perpendicular to the extension / contraction direction, The bending portion bends in a direction perpendicular to the extension / contraction direction.

[0022] The curved or bent portion is deformed to be convex or concave in a direction perpendicular to the direction of expansion and contraction. By changing the degree of concavity or convexity depending on the expansion and contraction, the curved or bent portion can widen or narrow, allowing the conductor to expand and contract smoothly.

[0023] <<Fourth embodiment>> The fourth embodiment is the same as the first embodiment, The stretchable member has a plurality of unit stretchable portions in the stretching direction, with the portion from the first joint point to the second joint point being a unit stretchable portion.

[0024] By having a plurality of unit stretchable portions, it becomes possible for the entire garment to stretch greatly.

[0025] <<Other Aspects>> The conductor preferably includes at least a metal fiber structure having electrical conductivity. That is, the conductor can be configured not only to include only a metal fiber structure, but also to include a metal fiber structure and other structures. The other structures may or may not be electrically conductive. By using the conductor in combination with a conductive structure, it is possible to increase the electrical conductivity and adjust the thermal conductivity. Specifically, it is possible to obtain a structure in which the metal fiber structure is laminated with metal foil, or a structure in which metal foil is partially overlapped on the metal fiber structure. In addition to metal foil, the conductor can be used in combination with other electrical conductors. Furthermore, when a non-conductive structure is used in combination, it is possible to further increase the strength and improve the insulation properties.

[0026] Preferably, the flexible body is silicone.

[0027] It is preferable that the device further comprises a bonding member for bonding the conductor and the flexible member.

[0028] The bonding material is preferably rubber.

[0029] The bonding material is preferably silicone rubber.

[0030] The ratio of the area occupied by the bonded body in the thickness direction is preferably 1% to 70%.

[0031] The ratio of the area occupied by the bonded body is preferably 10% to 80% in the expansion / contraction direction.

[0032] <<<<<Details of this embodiment>>>> The first to eighth embodiments will be described below with reference to the drawings. First, the configurations and definitions common to the first to eighth embodiments will be described. FIG. 1 is a perspective view showing an overview of the stretchable electric wires 10-1 to 10-8 showing the configuration common to the first to eighth embodiments. The stretchable electric wire 10-1 according to the first embodiment to the stretchable electric wire 10-8 according to the eighth embodiment have a conductor 100 and an elastic flexible body 200 in common. The conductor 100 and the elastic flexible body 200 have common configurations and functions in the stretchable electric wire 10-1 according to the first embodiment to the stretchable electric wire 10-8 according to the eighth embodiment. Note that, for clarity, the elastic joint bodies 300-1 to 300-8 are omitted in FIG. 1.

[0033] As will be described later, the expandable electric wire 10-1 according to the first embodiment has an elastic joint member 300-1, the expandable electric wire 10-2 according to the second embodiment has an elastic joint member 300-2, the expandable electric wire 10-3 according to the third embodiment has an elastic joint member 300-3, the expandable electric wire 10-4 according to the fourth embodiment has an elastic joint member 300-4, the expandable electric wire 10-5 according to the fifth embodiment has an elastic joint member 300-5, the expandable electric wire 10-6 according to the sixth embodiment has an elastic joint member 300-6, the expandable electric wire 10-7 according to the seventh embodiment has an elastic joint member 300-7, and the expandable electric wire 10-8 according to the eighth embodiment has an elastic joint member 300-8. In the first to eighth embodiments, the joining modes of the elastic joint members 300-1 to 300-8 are different from one another. Hereinafter, when there is no need to distinguish between the stretchable electric wires 10-1 to 10-8, they will be simply referred to as the stretchable electric wire 10 for convenience. When there is no need to distinguish between the elastic joined bodies 300-1 to 300-8, they will be simply referred to as the elastic joined body 300 for convenience.

[0034] <<<Conductor 100>>> The conductor 100 functions as a conductor (electric wire) that transmits various electrical signals. The electrical signals include control signals and drive signals. The electrical signals can be DC, AC, or pulse signals, and can be signals with any desired waveform. The conductor 100 may also function as a heating element that generates heat when a current is passed through it. The use of the conductor 100 can be determined appropriately depending on the resistance value of the conductor 100, etc.

[0035] <Shape of the conductor 100>

[0036] The conductor 100 has a flat, thin, or foil shape and is made of a flexible conductive material. The conductor 100 may be made of a conductive material that can deform while maintaining electrical connection. In particular, the conductor 100 is preferably made of a conductive material that can easily deform while maintaining electrical connection. The deformation of the conductor 100 may be plastic or elastic, as long as it deforms while maintaining electrical connection. The electrical connection is formed without interruption in any of the following states: before deformation, during deformation, and after deformation.

[0037] Furthermore, the conductor 100 is preferably made of a conductive material that can be repeatedly deformed, such as by expansion and contraction, while maintaining electrical connection. For example, the conductor 100 can be made of a metal fiber structure. Details of the metal fiber structure will be described later. The thickness of the conductor 100 may be any thickness as long as it can be deformed while maintaining electrical connection.

[0038] The conductor 100 has a long shape. The conductor 100 can function as a conductive wire such as a so-called shielded cable. When the conductor 100 is used in a shielded cable, the conductor 100 may be used as either an inner conductor or an outer conductor.

[0039] As shown in FIG. 1 and other figures, the conductor 100 has a pre-curved or bent shape. "Pre-curved" refers to the natural or initial state in which the stretchable electric wire 10-1 or the like is not stretched, bent, or otherwise deformed. The conductor 100 has a shape that is periodically curved or bent. For example, the conductor 100 has a pre-corrugated or bellows-like shape. A corrugated shape is a shape in which the cross-sectional shape is formed in a wave-like shape. A bellows-like shape has a structure in which mountain folds and valley folds are repeatedly formed.

[0040] The shape of the conductor 100 is not limited to a corrugated shape or an accordion-like shape. The conductor 100 may have a shape in which the protrusions 110 and the grooves 120 are adjacent to each other and repeat. The protrusions 110 have a shape such as a protruding stripe or a ridge, and have a convex cross section. The grooves 120 have a concave cross section. For example, the protrusions 110 have a cross section that is in an inverted U-shape, an inverted V-shape, an inverted horseshoe shape, or an inverted Ω-shape. The grooves 120 have a cross section that is in a U-shape, a V-shape, a horseshoe shape, or an Ω-shape. The inverted Ω-shape and Ω-shape refer to curved lines such as circular arcs or elliptical arcs with a central angle greater than 180 degrees.

[0041] In particular, by making the cross-sectional shape of the protrusion 110 an inverted horseshoe shape or an inverted Ω shape and by making the cross-sectional shape of the groove 120 a horseshoe shape or an Ω shape, the conductor 100 can be curved or bent not only in the longitudinal direction (described later) but also in the thickness direction (described later). This makes it possible to lengthen the length along the conductor 100 (the length of the conductor 100 itself). By providing room for the conductor 100 to stretch, the degree of stretchability of the conductor 100 can be increased, and the stretchable electric wire 10-1 can be stretched longer. Furthermore, it has excellent durability against stretching and contracting operations.

[0042] The wavelength (period) of the repetition of the ridges 110 and grooves 120 may be constant, irregular, or gradually changing. The wavelength may be the length connecting the apexes of two adjacent ridges 110 or the length connecting the bottoms of two adjacent grooves 120. The amplitude of the ridges 110 and grooves 120 may also be constant, irregular, or gradually changing. The amplitude may be the difference between the apex of adjacent ridges 110 and the bottom of adjacent grooves 120.

[0043] The grooves 120 are regions that are displaced in a direction toward the elastic flexible body 200, which will be described later. The protrusions 110 are regions that are displaced in a direction away from the elastic flexible body 200.

[0044] <<Direction definition>> <Wavelength direction WL (mainly the stretchable direction)> The direction in which the protrusions 110 and grooves 120 are repeated (arrow WL in FIG. 1) is referred to as the wavelength direction. The conductor 100 can expand and contract along the direction in which the protrusions 110 and grooves 120 are repeated, and the wavelength direction can also be referred to as the expansion / contraction direction or the longitudinal direction. The conductor 100 extends along the wavelength direction. The conductor 100 has a wavy shape in which the protrusions 110 and grooves 120 are repeatedly formed along the wavelength direction.

[0045] <Wave surface direction WS> The direction (arrow WS shown in FIG. 1) formed by connecting the protrusions 110 and grooves 120 that are in the same phase (same height or same depth) is referred to as the wave front direction. The wave front direction can also be referred to as the non-stretch direction, short side direction, or width direction. The lengths of the protrusions 110 and grooves 120 along the wave front direction can be determined appropriately. They may be determined to suit the general shapes of various cables, etc.

[0046] <Layer direction ML (thickness direction)> As will be described later, the stretchable electric wire 10-1 and the like are configured by stacking a conductor 100 and an elastic flexible body 200. The stacking direction (arrow ML shown in FIG. 1) is referred to as the stacking direction. In addition, since the stacking direction is the direction of the thickness of the stretchable electric wire 10-1, the elastic flexible body 200, and the like, it can also be referred to as the thickness direction.

[0047] <Material of Conductor 100> The material of the conductor 100 may be appropriately determined depending on various electrical properties such as required resistivity, withstand voltage, withstand current, etc. The conductor 100 may be made of a material that is deformable and conductive, and conventionally known electric wires, metal foils, etc. may be used, but it is preferable that the conductor 100 has a conductive structure including a metal fiber body.

[0048] The conductor 100 having a conductive structure including a metal fiber body will be described in detail below. The metal fiber body may be in the following form, or may be used as part of the conductor.

[0049] The conductor 100 may be made of metal fibers of a single composition, or may be made of a combination of two or more types of metal fibers, or may be made of metal-coated fibers in which organic fibers are coated with metal, or a structure containing metal-coated fibers.

[0050] The metal-coated fibers may be prepared by making a paper from metal-coated organic fibers and then fusing the fibers together, or by making a paper from organic fibers and then coating them with metal.

[0051] In the present invention, "metal fiber" means a fiber whose main component is metal. For example, "copper fiber" means a fiber whose main component is copper. "Mainly composed of copper" means that a certain amount of other components, including unavoidable impurities, may be contained as long as the effects of the present invention are not impaired.

[0052] Examples of metal components constituting the metal fibers include, but are not limited to, copper, stainless steel, iron, aluminum, nickel, and chromium. The metal components may be precious metals such as gold, platinum, silver, palladium, rhodium, iridium, ruthenium, and osmium. Among these, copper, stainless steel, and aluminum are preferred as metal components constituting the metal fibers. Copper fibers are particularly preferred because they have an excellent balance between rigidity and plastic deformability.

[0053] Examples of components other than metals include polyethylene terephthalate (PET) resin, polyvinyl alcohol (PVA), polyethylene, polypropylene, and other polyolefins, polyvinyl chloride resin, aramid resin, nylon, acrylic resin, and organic materials having binding and supporting properties, such as fibrous materials thereof. These organic materials can be used, for example, to assist and improve shape retention and functionality when producing the conductor 100.

[0054] The metal fibers constituting the conductor 100 are partially bonded. Bonding of the metal fibers means that the metal fibers are physically fixed to each other and form bonded portions. In the conductor 100, the metal fibers may be directly fixed to each other at the bonded portions, or some of the metal fibers may be indirectly fixed to each other via a component other than the above-mentioned metal component.

[0055] For example, when the metal fibers are sintered and bonded together, the thermal conductivity and homogeneity of the conductor 100 become stable, and it becomes easier to obtain excellent flexibility and resistance to disconnection.

[0056] When multiple metal fibers are bonded together, voids may be formed between the metal fibers. By providing the conductor 100 with multiple fixed portions formed by bonding and the voids, the metal fibers that make up the conductor 100 are deformed, which allows the stretchable electric wire 10-1 itself to deform, contract, or extend, thereby achieving excellent flexibility.

[0057] The sheet resistivity of the conductor 100 is designed depending on the energization conditions of the stretchable electric wire 10-1, and is not limited, but is preferably 100 mΩ / □ or less, more preferably 50 mΩ / □ or less, even more preferably 30 mΩ / □ or less, and most preferably 10 mΩ / □ or less. If the sheet resistivity of the conductive structure is 100 mΩ / □ or less, it is easy to suppress heat generation when energizing the stretchable electric wire 10-1.

[0058] The conductor 100 preferably has a strip-like structure. For example, the strip-like conductor 100 may be a nonwoven fabric in which metal fibers are randomly bonded, a woven fabric having a regular pattern, or a mesh material. The surface of the conductor 100 may be flat or may be corrugated or otherwise roughened, and is not particularly limited.

[0059] Furthermore, the vertical thickness of the conductor 100 is preferably in the range of 0.005 mm to 10 mm, more preferably 5 mm or less, even more preferably 1 mm or less, and most preferably 0.5 mm or less. If the thickness of the conductor 100 is 0.005 mm or more, the expandable electric wire 10-1 is less likely to break even when it is deformed. If the thickness of the conductor 100 is 10 mm or less, excellent flexibility is easily obtained.

[0060] The thickness of the conductor 100 can be adjusted appropriately in a pressing process described below.

[0061] The basis weight of the conductor 100 is 10 g / m 2 ~1,000g / m 2 The basis weight of the conductor 100 is preferably in the range of 10 g / m 2 If the basis weight of the conductor 100 is 1,000 g / m or more, a predetermined thickness can be obtained and the conductor 100 is less likely to break. 2 If it is below this, it is easy to reduce the weight of the conductor 100, and therefore it is easy to reduce the weight of the expandable electric wire 10-1.

[0062] The average fiber diameter of the metal fibers can be set arbitrarily as long as it does not impair the effects of the present invention. The average fiber diameter of the metal fibers is preferably 0.1 μm to 100 μm, more preferably 0.5 μm to 50 μm, and even more preferably 1 to 30 μm. If the average fiber diameter of the metal fibers is 0.1 μm or more, the conductive metal fibers can have an appropriate rigidity, making it difficult for so-called lumps to form when manufacturing the conductor 100. If lumps do not form, the homogeneity of the conductor 100 can be easily stabilized. This makes it easy to obtain excellent flexibility and breakage resistance. If the average fiber diameter of the metal fibers is 30 μm or less, the metal fibers can have an appropriate rigidity, making it difficult for the fibers to become entangled.

[0063] The cross section of the metal fiber perpendicular to the longitudinal direction may have any shape, such as a circle, an ellipse, a substantially square, or an irregular shape.

[0064] The average fiber length of the metal fibers can be set arbitrarily as long as it does not impair the effects of the present invention. The average fiber length of the metal fibers is preferably in the range of 0.1 mm to 10 mm, more preferably in the range of 0.3 mm to 5 mm, and even more preferably in the range of 0.5 to 3 mm. If the average fiber length of the metal fibers is in the range of 0.1 mm to 10 mm, the conductor 100 tends to have stable homogeneity even when obtained by papermaking.

[0065] The aspect ratio of the metal fibers is preferably 10 to 10,000. If the aspect ratio is 10 or more, the metal fibers can be easily partially bonded together, and the stretchable electric wire 10-1 can maintain an appropriate strength. On the other hand, if the aspect ratio is 10,000 or less, it is easy to obtain excellent uniformity of the conductor 100, and therefore excellent flexibility.

[0066] The space factor of the conductor 100 is preferably 70% or less, more preferably 50% or less, and even more preferably 30% or less. If the space factor is 70% or less, the flexibility of the conductor 100 can be maintained.

[0067] 1cm of conductor 100 2 The coefficient of variation (CV value) of basis weight defined in JIS Z8101 per unit volume is preferably 10% or less. Since basis weight is an index showing weight per unit volume, a coefficient of variation of basis weight of a certain value or less can be said to be a stable value for the space factor of the conductor 100. In other words, if the coefficient of variation of the basis weight of the conductor 100 is 10% or less, clumps of extremely large sizes and voids are unlikely to exist in the conductor 100, the conductor 100 has excellent homogeneity, and the expandable electric wire 10-1 is likely to have excellent bending properties and breakage resistance.

[0068] <<<Elastic flexible body 200>>> The elastic flexible body 200 has an elastic modulus (elastic modulus) that allows for large elastic deformation. Furthermore, the elastic flexible body 200 preferably has high bondability with the elastic joined body 300. For example, the elastic flexible body 200 preferably has high wettability and affinity with the elastic joined body 300 in a liquid state. The elastic joined body 300 preferably has an elastic modulus (elastic modulus) that provides low rubber hardness and excellent compressibility after curing. The elastic joined body 300 preferably has high bondability with the elastic flexible body 200 and with the conductor 100. The stretchable electric wire 10 elastically deforms and bends. The various elastic moduli (elastic moduli), such as the tensile modulus, shear modulus, and bulk modulus, of the elastic flexible body 200 and the elastic joined body 300 can be appropriately determined depending on the degree and tendency of the elastic deformation and bending of the stretchable electric wire 10. The manufacturing process of the stretchable electric wire 10 will be described in detail later.

[0069] The elastically flexible body 200 and the elastic joined body 300 have flexibility and elasticity. The entire stretchable electric wire 10 can be elastically deformed or bent. Since the entire stretchable electric wire 10 can be elastically deformed, it can be stretched and deformed. Furthermore, since the entire stretchable electric wire 10 can bend, it can bend and bend as a whole.

[0070] The elastic flexible body 200 and the elastic joint body 300 are non-conductive (dielectric, insulating). The conductor 100 is held in a state of being joined to the elastic flexible body 200 by the elastic joint body 300 (see FIGS. 1 and 2). The manner of joining by the elastic joint body 300 will be described in detail later.

[0071] <Configuration of Elastic Flexible Body 200> The elastic flexible body 200 functions as a lower layer or base in the manufacturing process. The elastic flexible body 200 preferably has a thin film or plate shape in its natural state. The elastic flexible body 200 may have a rectangular parallelepiped or quadrangular prism shape in its natural state. When joined by the elastic joining body 300, the elastic flexible body 200 functions as a holding member that stably holds the conductor 100. Furthermore, the expansion and contraction state of the conductor 100 is determined according to the expansion and contraction of the elastic flexible body 200, and the elastic flexible body 200 functions as an expansion and contraction control member.

[0072] <<<Elastic Joint 300>>> In the manufacturing process, the elastic bonding body 300 functions as an adhesive when in a molten state, and when hardened, it bonds the conductor 100 and the elastic flexible body 200 together and holds the conductor 100 in place.

[0073] <Materials of the Elastic Flexible Body 200 and the Elastic Joint Body 300> The elastic flexible body 200 and the elastic bonded body 300 may be made of a known resin material that is insulating and flexible.

[0074] Examples of the resin include polyacrylic acid resins such as polymethacrylic acid and polycyanoacrylic acid (polycyanoacrylate); polyvinylpyrrolidone resin; polyester resins such as polyethylene terephthalate; polypropylene resin; fluororesin such as polytetrafluoroethylene; polyimide resin; polyamide resins including aramid; polyparaphenylene benzobisoxazole resin, silicone resin, silicone rubber, fluororubber, acrylic rubber, etc. These resins can be used alone or in combination of two or more.

[0075] Among these, silicone, fluorine-based resin, acrylic rubber, or the like is preferable in consideration of the ability to follow the deformation of the conductor 100.

[0076] The elastic flexible body 200 and the elastic joining body 300 may be made of different materials, or two or more or all of them may be made of the same material.

[0077] <<<Arrangement of the conductor 100 and production of the stretchable electric wire 10>>> The conductor 100 is disposed on the elastic flexible body 200. The conductor 100 and the elastic flexible body 200 have an elongated shape. The conductor 100 is disposed so that the longitudinal direction of the conductor 100 coincides with the longitudinal direction of the elastic flexible body 200.

[0078] The conductor 100 has a shape that repeatedly curves and bends along the wavelength direction WL. The conductor 100 approaches and moves away from the elastic flexible body 200. The conductor 100 and the elastic flexible body 200 are joined by an elastic joining body 300 at the closest part where the conductor 100 is closest to the elastic flexible body 200. By joining the conductor 100 to the elastic flexible body 200, the conductor 100 can expand and contract in accordance with the expansion and contraction of the elastic flexible body 200.

[0079] Specifically, first, the elastic flexible body 200 is stretched to a certain extent to put it in a stretched state. Next, the elastic bonded body 300 in a liquid state is attached to the surface of the elastic flexible body 200. Next, the conductor 100 in its natural state is placed on the elastic bonded body 300 in a liquid state. Next, the elastic bonded body 300 is hardened to fix the closest portion of the conductor 100 to the elastic flexible body 200. Finally, the elastic flexible body 200 is returned from the stretched state to its natural state. In this way, a stretchable electric wire 10 can be produced in which the conductor 100 stretches and contracts as the elastic flexible body 200 stretches and contracts.

[0080] In the following, first to eighth embodiments will be described according to the form of the elastic joined body 300 and the like.

[0081] <<<First embodiment>>> 2A is a cross-sectional view showing a cross section of an expandable electric wire 10-1 according to the first embodiment, and FIG. 2B is a plan view showing a plane of the expandable electric wire 10-1 according to the first embodiment. The expandable electric wire 10-1 according to the first embodiment has a conductor 100, an elastic flexible body 200, and elastic joined bodies 310A1 to An (elastic joined bodies 310). n is a value of 1 or more, and is an appropriate value depending on the longitudinal length, flexibility, and degree of freedom of deformation of the conductor 100, and the longitudinal length and elastic modulus of the elastic flexible body 200, etc. The expandable electric wire 10-1 has a long shape.

[0082] <<Overview of the joining process>> A plurality of elastic joint bodies 310A1-An are arranged at a plurality of positions along the wavelength direction WL of the elastic flexible body 200. The elastic joint bodies 310A1-An are in a liquid state at the beginning of the joining process, and the liquid elastic joint bodies 310A1-An are applied onto the elastic flexible body 200. When the conductor 100 is arranged on the elastic flexible body 200 via the elastic joint bodies 310A1-An, the elastic joint bodies 310A1-An are hardened. The arrangement of the conductor 100 and the positions of the elastic joint bodies 310A1-An will be described later.

[0083] <Hardening of Elastic Joints 310A1 to 310An> The elastic joint members 310A1-An have a thin film-like shape when hardened. The elastic joint members 310A1-An have elasticity and flexibility when hardened. When the elastic joint members 310A1-An harden, the conductor 100 is joined to the elastic flexible body 200. When hardened, the elastic joint members 310A1-An can deform in accordance with the deformation of the elastic flexible body 200. When the elastic flexible body 200 and the elastic joint members 310A1-An expand and contract, the conductor 100 can expand and contract.

[0084] <<Arrangement positions of elastic joining bodies 310A1 to 310An>> The elastic joint members 310A1 to An are arranged at a plurality of positions (arrangement positions LP1 to LPn) spaced apart from one another along the wavelength direction WL of the elastic flexible body 200. The i-th elastic joint member 310Ai (i = 1 to n) is positioned at the i-th arrangement position LPi (i = 1 to n). The plurality of arrangement positions LP1 to LPn are equally spaced. The lengths of the adjacent two i-th arrangement positions LPi (i = 1 to n) and the i+1-th arrangement position LPi+1 (i = 1 to n-1) are equal.

[0085] <<Shapes of the elastic joining bodies 310A1 to An>> The elastic joints 310A1 to 310An extend continuously along the wavefront direction WS at each of the arrangement positions LP1 to LPn. The elastic joints 310 at each of the arrangement positions LP1 to LPn have an elongated shape extending in the wavefront direction WS. The length of each of the elastic joints 310A1 to 310An in the longitudinal direction (wavefront direction WS) at each of the arrangement positions LP1 to LPn is the same. The length of the elastic joints 310A1 to 310A1 is preferably longer than the width of the conductor 100 (length in the wavefront direction WS). The elastic joints 310 at each of the arrangement positions LP1 to LPn are parallel to each other.

[0086] <<Method of joining the conductor 100 and the elastic flexible body 200>> The electrical conductor 100 has a plurality of closest portions CP1 to CPn that are closest to the elastic flexible body 200. The i-th closest portion CPi of the electrical conductor 100 corresponds to the i-th elastic joint body 310Ai. The i-th closest portion CPi of the electrical conductor 100 is positioned at the arrangement position LPi of the i-th elastic joint body 310Ai. The closest portions CP1 to CPn of the electrical conductor 100 are positioned at the arrangement positions LP1 to LPn of the corresponding elastic joint bodies 310A1 to An and joined to the elastic flexible body 200.

[0087] Each of the closest portions CP1 to CPn of the conductor 100 extends in the wavefront direction WS. Each of the closest portions CP1 to CPn of the conductor 100 has an elongated shape extending in the wavefront direction WS. For example, each of the closest portions CP1 to CPn of the conductor 100 has a linear or elongated rectangular shape along the wavefront direction WS. Each of the closest portions CP1 to CPn of the conductor 100 is thinner than the elastic connector 310. Each of the closest portions CP1 to CPn of the conductor 100 at least partially overlaps with the elastic connectors 310A1 to An. Each of the closest portions CP1 to CPn of the conductor 100 has an elongated shape and may be arranged so as to at least partially overlap with the region in which the elastic connectors 310A1 to An extend.

[0088] <<Formation of the stretchable electric wire 10-1>> The elastic joints 310A1-An in a liquid state are applied to the elastic flexible body 200 at the corresponding placement positions LP1-LPn. The closest portions CP1-CPn of the conductor 100 are positioned so as to overlap the corresponding elastic joints 310A1-An, and the entire conductor 100 is placed on the elastic flexible body 200. The elastic joints 310A1-An are cured. As a result of the curing, the closest portions CP1-CPn of the conductor 100 are bonded to the elastic flexible body 200. The elastic joints 310A1-An can integrate the conductor 100 and the elastic flexible body 200.

[0089] By hardening, the elastic joint members 310A1-An have elasticity and flexibility. When the elastic flexible body 200 expands or contracts, the elastic joint members 310A1-An also expand or contract. In response to the expansion or contraction of the elastic joint members 310A1-An, the closest portions CP1-CPn of the conductor 100 are displaced. In response to the displacement of the closest portions CP1-CPn, the entire conductor 100 can expand or contract. Therefore, the entire stretchable electric wire 10-1 can expand or contract.

[0090] The conductor 100 has two longitudinal ends 130a and 130b. The ends 130a and 130b function as terminals for establishing an electrical connection with other electrical components such as electric wires. The ends 130a and 130b of the conductor 100 are not joined to the elastic flexible body 200 and are configured to be able to be separated to a certain extent from the elastic flexible body 200. This facilitates the process of establishing an electrical connection with other electrical components such as other electric wires. The length of the longitudinal direction WL of the ends 130a and 130b can be determined appropriately depending on the size, shape, and number of the components to be connected.

[0091] <<Unit expansion section>> By configuring in this manner, the stretchable electric wire 10-1 has a plurality of unit stretchable parts such as arrangement positions LP1 to LPn and nearest parts CP1 to CPn in the stretching direction (wavelength direction WL), with arrangement positions LPi to LPi+1 and nearest parts CPi to CPi+1 being unit stretchable parts.

[0092] <<Separation and bypass between the conductor 100 and the elastic flexible body 200>> The length CLi (shortest length (shortest path)) along the conductor 100 from the arrangement position LPi to LPi+1 is longer than the length FLi (shortest length (shortest path)) along the elastic flexible body 200 from the arrangement position LPi to LPi+1. The shortest length is the shortest curve connecting two points.

[0093] The conductor 100 is curved and bent from the arrangement position LPi to LPi+1. Therefore, the conductor 100 makes a detour (including a long detour, a long route, a roundabout route, etc.) from the arrangement position LPi to LPi+1 around the elastic flexible body 200. Due to the detour of the conductor 100, the length CLi becomes longer than the length FLi. Due to the detour of the conductor 100, the conductor 100 is separated from the elastic flexible body 200. If the conductor 100 has a configuration in which the conductor 100 is separated from the elastic flexible body 200 due to the detour, it is included in the concept of the stretchable electric wire 10-1 according to the first embodiment.

[0094] <<Temporary contact or contact due to changes over time>> As the elastic flexible body 200 expands and contracts, the conductor 100 also expands and contracts. For this reason, in the process of expansion and contraction, in a contracted state, or in an extended state, there may be a location between arrangement positions LPi and LPi+1 where the conductor 100 comes into contact with the elastic flexible body 200 and does not separate from the elastic flexible body 200.

[0095] Furthermore, repeated expansion and contraction deformation may cause partial changes over time in the conductor 100. For example, parts of the conductor 100 may become frayed or partially break.

[0096] However, this is not a permanent contact due to bonding or the like, but rather a temporary contact or contact due to changes over time, and if the stretchable electric wire 10-1 can return to its natural state, its initial state when manufactured, its shipping state, etc., the state in which the conductor 100 is separated from the elastic flexible body 200 will be reproduced.

[0097] Even if temporary contact or contact due to a change over time occurs, the fact remains that the conductor 100 is bypassing the elastic flexible body 200 between the arrangement positions LPi and LPi+1, which are the junction points. Regardless of whether there is temporary contact or contact due to a change over time, an expandable electric wire in which the conductor 100 is bypassing the elastic flexible body 200 between the arrangement positions LPi and LPi+1, which are the junction points, is included in the concept of the expandable electric wire 10-1 according to the first embodiment.

[0098] 2(b), the length of the elastic bonding bodies 310A1 to 310An in the wavefront direction WS is shown shorter than the width of the conductor 100 in the wavefront direction WS, but it may be the same as or longer than the width. This increases the contact area with the conductor 100, allowing the conductor 100 to be accurately bonded to the elastic flexible body 200.

[0099] <<<Second embodiment>>> FIG. 3(a) is a cross-sectional view showing a cross section of an expandable electric wire 10-2 according to the second embodiment, and FIG. 3(b) is a plan view showing a plane of the expandable electric wire 10-2.

[0100] The stretchable electric wire 10-2 has a conductor 100, an elastic flexible body 200, and an elastic joint body 320 (320A11, A12, A13 to An1, An2, An3). The elastic joint body 320 has the same function and action as the elastic joint body 310 of the first embodiment.

[0101] The elastic joint bodies 320A11, A12, A13 to An1, An2, and An3 are arranged in a matrix in the elastic flexible body 200, as shown in FIG. 3(a). Specifically, the elastic joint bodies 320Aij (i = 1 to n, j = 1 to 3) are arranged at 1 to n positions along the wavelength direction WL and at multiple positions, for example, three positions (j = 1, 2, and 3), along the wavefront direction WS. The number of positions along the wavefront direction WS is not limited to three, and may be determined appropriately depending on the length (width) of the electrical conductor 100 and the elastic flexible body 200 in the wavefront direction WS.

[0102] Each of the elastic joint members 320Aij (i = 1 to n, j = 1 to 3) has a substantially rectangular shape. The shape may be a circle, an ellipse, or the like. The shape and size of each of the elastic joint members 320Aij (i = 1 to n, j = 1 to 3) may be determined appropriately depending on the material and hardness of the conductor 100 and the elastic flexible body 200. The spacing, number, and positions of the elastic joint members 320Aij along the wavefront direction WS may be determined appropriately depending on the length of the conductor 100 and the elastic flexible body 200 along the wavefront direction WS and the size of the elastic joint members 320Aij. The spacing, number, and positions of the elastic joint members 320Aij along the wavefront direction WS do not need to be the same for each arrangement position LPi and may be different.

[0103] The elastic joint bodies 320Aij (i = 1 to n, j = 1 to 3) may be arranged separately and dispersed along a first direction and a second direction different from the first direction in the plane in which the elastic flexible body 200 extends. The first direction and the second direction do not necessarily have to be orthogonal to each other.

[0104] By distributing multiple elastic joint bodies 320i1, i2, i3 (i = 1 to n) in the wavefront direction WS, the material can be easily curved or bent not only in the wavelength direction WL but also in the wavefront direction WS, and can accommodate various expansion and contraction deformations.

[0105] <<<Third embodiment>>> FIG. 4(a) is a cross-sectional view showing a cross section of an expandable electric wire 10-3 according to a third embodiment, and FIG. 4(b) is a plan view showing a plane of the expandable electric wire 10-3.

[0106] The stretchable electric wire 10-3 has a conductor 100, an elastic flexible body 200, and an elastic joint body 330. The elastic joint body 330 has the same functions and actions as the elastic joint body 310 of the first embodiment.

[0107] The elastic joint member 330 is arranged differently from the elastic joint member 310 of the first embodiment. As shown in FIG. 4(a), the elastic joint member 330 is a single member that extends entirely in both the wavelength direction WL and the wavefront direction WS of the elastic flexible body 200. The elastic joint member 330 has a long rectangular shape. The longitudinal direction of the elastic joint member 330 is the same as the longitudinal direction of the elastic flexible body 200.

[0108] The length of the elastic joint body 330 in the wavelength direction WL and the length in the wavefront direction WS may be determined appropriately depending on the size of the conductor 100 and the elastic flexible body 200, etc.

[0109] By using a single elastic joint body 330, it is possible to easily apply the liquid elastic joint body 330 without increasing the precision of the position of the elastic joint body 330. By making the elastic joint body 330 extend over the entire elastic flexible body 200, it is possible to place the closest portions CP1 to CPn of the conductor 100 on the elastic joint body 330 without adjusting the positions of each of the closest portions CP1 to CPn, and the stretchable electric wire 10-3 can be easily formed.

[0110] 4(b), the length of the elastic bonding body 330 in the wavefront direction WS is shown shorter than the width of the conductor 100 in the wavefront direction WS, but it may be the same as or longer than the width. This increases the contact area with the conductor 100, allowing the conductor 100 to be accurately bonded to the elastic flexible body 200.

[0111] <<<Fourth embodiment>>> FIG. 5(a) is a cross-sectional view showing a cross section of an expandable electric wire 10-4 according to a fourth embodiment, and FIG. 5(b) is a plan view showing a plane of the expandable electric wire 10-4.

[0112] The stretchable electric wire 10-4 has a conductor 100, an elastic flexible body 200, and elastic joint members 340 (340A1 to A3). The elastic joint members 340 have the same functions and actions as the elastic joint members 310 of the first embodiment.

[0113] The three elastic joint bodies 340A1 to A3 have an elongated shape. The longitudinal direction of the elastic joint bodies 340A1 to A3 is the wavelength direction WL. The three elastic joint bodies 340A1 to A3 are arranged parallel to each other and spaced apart in the wavefront direction WS. The elastic joint bodies 340A1 to A3 extend in the wavelength direction WL of the elastic flexible body 200.

[0114] The amount of the elastic joint bodies 340A1-A3 can be reduced compared to the third embodiment 330, thereby reducing costs. By extending in the longitudinal direction of the elastic flexible body 200, similar to the third embodiment 330, the electric conductor 100 can be placed on the elastic joint bodies 340A1-A3 without adjusting the positions of the closest portions CP1-CPn of the electric conductor 100, and the stretchable electric wire 10-4 can be easily formed.

[0115] 5(b), three elastic joint bodies 340A1-A3 are shown, but the number and width of the elastic joint bodies 340 can be determined depending on the width of the conductor 100 in the wavefront direction WS, etc. Furthermore, although an example has been shown in which each of the three elastic joint bodies 340A1-A3 is integrally formed along the wavelength direction WL, each may be divided into multiple bodies depending on the length of the elastic flexible body 200 in the wavelength direction WL, etc. Dividing each into multiple bodies makes it easier to arrange the elastic joint bodies 340 on the elastic flexible body 200.

[0116] <<<Fifth embodiment>>> 6A is a cross-sectional view showing a cross section of an expandable electric wire 10-5 according to a fifth embodiment, and FIG. 6B is a plan view showing a plan view thereof. In FIG. 6B, for clarity, the elastic joint members 310A1 to 310An and the closest parts CP1 to CPn are shown by solid lines.

[0117] The stretchable electric wire 10-5 has a conductor 100, an elastic flexible body 200, an elastic joint body 310, and an insulating covering body 410. The stretchable electric wire 10-5 has the elastic joint bodies 310A1 to An of the first embodiment. In other words, the stretchable electric wire 10-5 according to the fifth embodiment is the stretchable electric wire 10-1 of the first embodiment provided with an insulating covering body 410.

[0118] The insulating cover 410 has insulating properties and is in the form of a thin film. The insulating cover 410 has an elongated shape. The longitudinal direction of the insulating cover 410 is the same as the longitudinal direction of the conductor 100. The insulating cover 410 has elasticity and flexibility.

[0119] The insulating cover 410 covers the entire conductor 100 except for both longitudinal ends 130a and 130b of the conductor 100. The ends 130a and 130b of the conductor 100 are exposed. The ends 130a and 130b are kept exposed in order to form an electrical connection with other electrical components such as electrical wires.

[0120] As described above, the insulating covering 410 has elasticity and flexibility, and can expand and contract in accordance with the expansion and contraction of the conductor 100 and the elastic flexible body 200. Therefore, the covering state of the conductor 100 is maintained even during expansion and contraction, and accurate insulation can be achieved.

[0121] 6(b), the length of the insulating cover 410 in the wavefront direction WS is shown shorter than the width of the elastic flexible body 200 in the wavefront direction WS, but it may be the same as or longer than the width. The insulating cover 410 can cover the conductor 100 accurately.

[0122] <<<Sixth embodiment>>> 7A is a cross-sectional view showing a cross section of an expandable electric wire 10-6 according to a sixth embodiment, and FIG. 7B is a plan view showing a plan view thereof. In FIG. 7B, for clarity, the elastic joint members 310A1 to 310An and the nearest neighbor portions CP1 to CPn are shown by solid lines.

[0123] The stretchable electric wire 10-6 has a conductor 100, an elastic flexible body 200, an elastic joint body 310, and an insulating cover body 420. The stretchable electric wire 10-6 has the elastic joint bodies 310A1 to An of the first embodiment. In other words, the stretchable electric wire 10-6 according to the sixth embodiment is the stretchable electric wire 10-1 of the first embodiment provided with an insulating cover body 420.

[0124] The insulating coating 420 is similar to the insulating coating 410. The insulating coating 420 has insulating properties and is in the form of a thin film. The insulating coating 420 has an elongated shape. The longitudinal direction of the insulating coating 420 is the same as the longitudinal direction of the conductor 100. The insulating coating 420 has elasticity and flexibility.

[0125] The insulating cover 420 covers the entire conductor 100 except for both longitudinal ends 130a and 130b of the conductor 100. The ends 130a and 130b of the conductor 100 are exposed. The ends 130a and 130b are kept exposed in order to form an electrical connection with other electrical components such as electrical wires.

[0126] The insulating cover 420 has a curved gap 422 between two adjacent ridges 110 of the conductor 100 that curves toward the groove 120 of the conductor 100 .

[0127] As described above, the insulating covering 420 has elasticity and flexibility, and can expand and contract in accordance with the expansion and contraction of the conductor 100 and the elastic flexible body 200. Furthermore, by providing the curved gap 422, when the degree of extension of the conductor 100 and the elastic flexible body 200 is small, the curved gap 422 can be released from the curve without being stretched, and can approach a tensioned state. Furthermore, when the degree of extension of the conductor 100 and the elastic flexible body 200 becomes large to a certain extent, the curved gap 422 transitions from a tensioned state to an extended state. In this way, the curved gap 422 can provide a margin for extension, and it is possible to provide an expandable electric wire 10-6 that can maintain an insulating state even at high extension.

[0128] 7(b), the length of the insulating cover 420 in the wavefront direction WS is shown shorter than the width of the elastic flexible body 200 in the wavefront direction WS, but it may be the same as or longer than the width. The insulating cover 420 can cover the conductor 100 accurately.

[0129] <<<Seventh embodiment>>> FIG. 8(a) is a cross-sectional view showing a cross section of an expandable electric wire 10-7 according to the seventh embodiment, and FIG. 8(b) is a plan view showing a plane of the expandable electric wire 10-7.

[0130] The stretchable electric wire 10-7 has a conductor 100, an elastic flexible body 200, an elastic joint body 310, and elastic joint bodies 370a and 370b. The stretchable electric wire 10-7 has the elastic joint bodies 310A1 to An of the first embodiment. In other words, the stretchable electric wire 10-7 according to the seventh embodiment is the stretchable electric wire 10-1 of the first embodiment provided with the elastic joint bodies 370a and 370b.

[0131] The conductor 100 has two longitudinal ends 130a and 130b, which are exposed and function as terminals for forming an electrical connection with other electrical components such as electrical wires.

[0132] The elastic connectors 370a and 370b are made of the same material as the elastic connector 310 and have the same functions and actions. The elastic connector 370a connects the end 130a to the elastic flexible body 200, and the elastic connector 370b connects the end 130b to the elastic flexible body 200. This not only keeps the ends 130a and 130b of the conductor 100 in a fixed position, but also increases the strength of the ends 130a and 130b.

[0133] 8(b), the elastic connector 370a is spaced apart from the connector 310A1, and the elastic connector 370b is spaced apart from the connector 310An. However, the elastic connector 370a may be integrated with the connector 310A1, and the elastic connector 370b may be integrated with the connector 310An, so that they are continuous. This increases the contact area, and allows both ends 130a and 130b of the conductor 100 to be accurately positioned on the elastic flexible body 200.

[0134] 8(b) shows the state in which the elastic connectors 370a and 370b are exposed from the conductor 100, but the elastic connectors 370a and 370b may be made smaller so that they are included in both ends 130a and 130b of the conductor 100. This not only reduces the amount of the elastic connectors 370a and 370b, but also prevents other members from adhering to the elastic connectors 370a and 370b.

[0135] <<<Eighth embodiment>>> FIG. 9 is a cross-sectional view (a) showing a cross section of an expandable electric wire 10-8 according to the eighth embodiment before assembly, and a cross-sectional view (b) showing a cross section after assembly.

[0136] The stretchable electric wire 10-8 has a conductor 100, an elastic flexible body 200, and an elastic joint body 310. The stretchable electric wire 10-8 has the elastic joint bodies 310A1 to An of the first embodiment. The stretchable electric wire 10-8 according to the eighth embodiment has the same configuration as the stretchable electric wire 10-1 of the first embodiment (see FIG. 2).

[0137] The stretchable electric wire 10-1 of the first embodiment has an overall long and flat shape. The stretchable electric wire 10-8 of the eighth embodiment has a cylindrical (tube-like) shape (Fig. 9(b)). By joining the two ends 280a and 280b in the wavefront direction WS of the elastic flexible body 200 of the stretchable electric wire 10-1 of the first embodiment (Fig. 9(a)), a cylindrical (tube-like) shape can be formed (Fig. 9(b)). The same material as the elastic joint body 310 can be used for the joint.

[0138] By forming it in this way, the entire body can be covered with the elastic flexible body 200, and it is possible to insulate and protect it.

[0139] Figure 9(b) shows a case where the shape is cylindrical (tube-like), but it can also be a cylindrical shape such as an elliptical cylinder or an elongated cylinder, as long as the elastic flexible body 200 surrounds the conductor 100.

[0140] <<<Example>>> Figures 10A and 10B are tables showing examples. Figures 10A and 10B show examples 1 to 9 and comparative examples 1 and 2. The numbers in parentheses in the column of shape (embodiment) indicate the first to eighth embodiments described above.

[0141] The wiring portion corresponds to the conductor 100. The rubber stretchable portion corresponds to the elastic flexible body 200. The rubber joint portions correspond to the elastic joint bodies 310-380.

[0142] <Wiring material> The material of the wiring portion is the same as that of the conductor 100. The material of the wiring portion in Examples 1 to 9 and Comparative Example 1 is a metal fiber structure. The material of the wiring portion in Comparative Example 2 is a metal foil.

[0143] <Wiring width> The width of the wiring portion is the length in the wavefront direction WS of the conductor 100. The width of the wiring portion in Examples 1 to 5, Examples 8 and 9, and Comparative Examples 1 and 2 is 10 mm. The width of the wiring portion in Examples 6 and 7 is 3 mm.

[0144] <Wiring length> The length of the wiring portion is the length in the wavelength direction WL of the unprocessed conductor 100 before the protrusions 110 and grooves 120 are formed on the conductor 100. The length of the wiring portion in Examples 1 to 9 and Comparative Examples 1 and 2 (all) is 100 mm.

[0145] <Wiring height> The height of the wiring portion is the height in the stacking direction ML when the protrusions 110 and grooves 120 are formed. The height of the wiring portion in Examples 1 to 5, Examples 8 and 9, and Comparative Examples 1 and 2 is 5 mm. The height of the wiring portion in Examples 6 and 7 is 2 mm.

[0146] <Wiring pitch> The pitch of the wiring portions is the distance between the apexes of two adjacent protrusions 110 or the distance between the bottoms of two adjacent grooves 120. The pitch of the wiring portions in Examples 1 to 5, Examples 8 and 9, and Comparative Examples 1 and 2 is 2 mm. The pitch of the wiring portions in Examples 6 and 7 is 1 mm.

[0147] <Wiring thickness> The thickness of the wiring portion is the thickness of the conductor 100. The thickness of the wiring portion of Example 1 is 200 μm. The thickness of the wiring portion of Example 2 is 203 μm. The thickness of the wiring portion of Example 3 is 199 μm. The thickness of the wiring portion of Example 4 is 195 μm. The thickness of the wiring portion of Example 5 is 198 μm. The thickness of the wiring portion of Example 6 is 98 μm. The thickness of the wiring portion of Example 7 is 103 μm. The thickness of the wiring portion of Example 8 is 208 μm. The thickness of the wiring portion of Example 9 is 205 μm. The thickness of the wiring portion of Comparative Example 1 is 197 μm. The thickness of the wiring portion of Comparative Example 2 is 201 μm.

[0148] In summary, the thickness of the wiring portion is approximately 200 μm in Examples 1 to 5, Examples 8 and 9, and Comparative Examples 1 and 2. The thickness of the wiring portion in Examples 6 and 7 is approximately 100 μm.

[0149] <Wiring space factor> The space factor of the wiring portion is the ratio of the area where metal fibers exist to the volume of the metal fiber body. When the metal fiber body is composed only of metal fibers, the space factor of the wiring portion is calculated using the following formula from the basis weight and thickness of the metal fiber body and the true density of the metal fibers. Space factor (%) = (basis weight of metal fiber body / (thickness of metal fiber body × true density of metal fiber) × 100

[0150] The space factor of the wiring portion of Example 1 is 15%. The space factor of the wiring portion of Example 2 is 21%. The space factor of the wiring portion of Example 3 is 10%. The space factor of the wiring portion of Example 4 is 11%. The space factor of the wiring portion of Example 5 is 29%. The space factor of the wiring portion of Example 6 is 36%. The space factor of the wiring portion of Example 7 is 34%. The space factor of the wiring portion of Example 8 is 13%. The space factor of the wiring portion of Example 9 is 14%. The space factor of the wiring portion of Comparative Example 1 is 14%. The space factor of the wiring portion of Comparative Example 2 is 100%.

[0151] <Material of rubber elastic part> The material of the rubber stretchable portion is the same as the material of the elastic flexible body 200. The material of the rubber stretchable portion in Examples 1 to 5, Examples 8 and 9 and Comparative Examples 1 and 2 is silicone. The material of the rubber stretchable portion in Examples 6 and 7 is elastomer.

[0152] <Thickness of elastic rubber part> The thickness of the rubber stretchable portion is the thickness of the elastic flexible body 200. The thickness of the rubber stretchable portion in Examples 1 to 9 is approximately 500 μm. The thickness of the rubber stretchable portion in Comparative Examples 1 and 2 is approximately 6 mm.

[0153] <Pre-stretching of elastic elastic parts> The pre-stretching of the rubber stretchable portion is the pre-stretching of the elastic flexible body 200. This means that the conductor 100 is joined to the elastic flexible body 200 in a pre-stretched state. Pre-stretching is performed in all of Examples 1 to 9 and Comparative Examples 1 and 2.

[0154] <Rubber joint material> The material of the rubber joints is the same as the material of the elastic joints 310 to 380. The material of the rubber joints in Examples 1 to 5, Examples 8 and 9, and Comparative Examples 1 and 2 is silicone. The material of the rubber joints in Examples 6 and 7 is elastomer.

[0155] <Shape of partial covering of rubber joint> The shape of the partial covering of the rubber joints is the same as that of the elastic joints 310 to 380. This is as explained in the first to eighth embodiments. The shape of the partial covering of the rubber joints in Examples 1, 3, 4 and 6 to 9 is dot-shaped. The shape of the partial covering of the rubber joints in Examples 2 and 5 is line-shaped.

[0156] <Ratio of rubber joint area across width> The widthwise area ratio of the rubber joint is the ratio of the area of ​​the elastic joints 310-380 to the area of ​​the stretchable region. Specifically, it is the ratio of the area where the elastic joints 310-380 are provided to the area DS of the stretchable region (see FIG. 2). The stretchable region is the region where the protrusions 110 and grooves 120 are present. The area DS of the stretchable region is the area along the wavelength direction. In other words, the area DS of the stretchable region is the area along the elastic flexible body 200, not the area along the conductor 100. The area where the protrusions 110 and grooves 120 are present may be considered as the area projected onto the elastic flexible body 200. The area of ​​the elastic joints 310-380 is the total area where only the elastic joints 310-380 are present.

[0157] The width direction area of ​​the rubber joint in Example 1 is 23%. The width direction area of ​​the rubber joint in Example 2 is 78%. The width direction area of ​​the rubber joint in Example 3 is 11%. The width direction area of ​​the rubber joint in Example 4 is 75%. The width direction area of ​​the rubber joint in Example 5 is 56%. The width direction area of ​​the rubber joint in Example 6 is 38%. The width direction area of ​​the rubber joint in Example 7 is 12%. The width direction area of ​​the rubber joint in Example 8 is 21%. The width direction area of ​​the rubber joint in Example 9 is 86%. The width direction area of ​​the rubber joint in Comparative Example 1 is 100%. The width direction area of ​​the rubber joint in Comparative Example 2 is 100%.

[0158] From the above, the area ratio of the rubber joint in the width direction is preferably 10% to 86%, more preferably 10% to 80%, and even more preferably 11% to 78%.

[0159] <Area ratio of rubber joint in thickness direction> The area ratio of the rubber joint in the thickness direction is the height of the rubber joint (height ET of the elastic joints 310 to 380 (see FIG. 2)) relative to the height PT of the wiring portion (see FIG. 2).

[0160] The area of ​​the rubber joint in the thickness direction of Example 1 is 15%. The area of ​​the rubber joint in the thickness direction of Example 2 is 32%. The area of ​​the rubber joint in the thickness direction of Example 3 is 3%. The area of ​​the rubber joint in the thickness direction of Example 4 is 3%. The area of ​​the rubber joint in the thickness direction of Example 5 is 47%. The area of ​​the rubber joint in the thickness direction of Example 6 is 65%. The area of ​​the rubber joint in the thickness direction of Example 7 is 68%. The area of ​​the rubber joint in the thickness direction of Example 8 is 74%. The area of ​​the rubber joint in the thickness direction of Example 9 is 14%. The area of ​​the rubber joint in the thickness direction of Comparative Example 1 is 100%. The area of ​​the rubber joint in the thickness direction of Comparative Example 2 is 100%.

[0161] From the above, the area ratio of the rubber joint in the thickness direction is preferably 1% to 74%, more preferably 1% to 70%, and even more preferably 3% to 68%.

[0162] <Stretching durability> The stretch durability is that the resistance change is less than 10% when stretched repeatedly by 50%, and no breakage or cracking occurs. The stretch amount is 50%, the number of stretches is 1,000, and a 90-degree twist is applied during stretching. The even-numbered stretches were twisted +90 degrees, and the odd-numbered stretches were twisted -90 degrees.

[0163] <Resistance change> The resistance change was the result of applying a voltage of 30 V and a current of 250 mA to both ends 130a and 130b of the conductor 100. Examples 1 to 9 were good. Comparative Examples 1 and 2 were bad.

[0164] <Appearance changes> Changes in appearance were confirmed by visual inspection. Examples 1 to 9 were good, while Comparative Examples 1 and 2 were poor.

[0165] <<<<<Scope of embodiment>>>> As described above, the first to eighth embodiments have been described, but the descriptions and drawings that form part of this disclosure should not be understood as limiting, and various embodiments not described herein are also included.

[0166] <<<<<Modifications>>>> In the first to eighth embodiments described above, examples have been shown in which the conductor 100 is made of a metal fiber structure, but the conductor 100 may be made of a continuous body such as a foil, film, or wire. Furthermore, the entire conductor does not need to be conductive, and only a portion of the conductor may be conductive. For example, the conductor may be made of a resin base material whose surface is coated with a conductive substance. In other words, the conductor 100 of the stretchable electric wires 10-1 to 10-8 of the first to eighth embodiments may be made of a metal made of a continuous body such as a foil or film. [Explanation of symbols]

[0167] 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7, 10-8 stretchable wire 100 Conductors 200 Elastic flexible body 300-1, 300-2, 300-3, 300-4, 300-5, 300-6, 300-7, 300-8 Elastic joints

Claims

1. a conductor that is a metal fiber structure that is electrically conductive and stretchable in the stretching direction, has a width in a direction different from the stretching direction, has bonding parts where metal fibers are physically fixed to each other, and has voids formed between the metal fibers; a flexible body that is continuously formed so as to be elastically deformable, and has a first junction at which the conductor is joined, and a second junction at which the conductor is joined and that is spaced apart from the first junction in the extension / contraction direction, a first shortest length along the conductor from the first junction to the second junction that is longer than a second shortest length along the flexible body from the first junction to the second junction.

2. The stretchable electric wire according to claim 1 , wherein the voids allow the metal fibers to deform, and the conductor itself to deform, contract, or extend.

3. The flexible body may further include a joining member that joins the conductor and the flexible body made of the same material as the conductor, The expandable electric wire according to claim 1 , wherein the bonding material functions as an adhesive when in a molten state, and bonds the conductor and the flexible body when the bonding material hardens.

4. the conductor has a plurality of nearest neighbor portions that are closest to the flexible body; The stretchable cord of claim 1 , wherein each of the nearest neighbor portions extends perpendicular to the stretch direction.

5. The stretchable cord according to claim 1 , wherein the conductor has at least one of a curved portion or a bent portion between the first junction and the second junction.

6. The curved portion curves in a direction perpendicular to the extension / contraction direction, The expandable electric wire according to claim 5 , wherein the bent portion bends in a direction perpendicular to the expansion and contraction direction.

7. The expandable electric wire according to claim 1 , wherein a unit stretchable portion extends from the first joint point to the second joint point, and the expandable electric wire has a plurality of unit stretchable portions in the expansion / contraction direction.

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