JP2010020949A - Expansive electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expansive electric wire which is superior in extensibility and extension recovery rate, and low in manufacturing cost although it is thin and compact. <P>SOLUTION: In the expansive electric wire having a fibrous structure in which a conductive wire is spirally wound in either one direction of Z twist or S twist, and in the opposite direction, other fibers are spirally wound around and restrains the conductive wire while going through inside and outside of the conductive wire, the fibrous structure includes at least an elastic long fiber spirally wound around, and does not have a core part independent from the fibrous structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stretchable electric wire having elasticity, and more particularly to a thin, compact and inexpensive production wire that is suitable for robots and wearable electronic devices.

In recent years, the development of robots has been remarkable, and robots with various movements are appearing. In addition, various types of wearable electronic devices that can be worn on the human body and clothes have been developed. Many electric wires for power and signal transmission are used in these robots and wearable electronic devices. However, in general, an electric wire has a structure in which a copper wire is a core and an outer periphery thereof is covered with an insulator, and has almost no elasticity. For this reason, it is necessary to wire the electric wires with a large margin so as not to hinder the movement of the robot or the human body, and this often becomes an obstacle in device design and practical use.
Especially in the state-of-the-art humanoid robots and power assist devices that are attached to the human body to assist muscle strength, electric wires for moving the motor at the end via a multi-degree-of-freedom joint, and various sensors equipped at the end There are a number of electric wires for transmitting signals from the cable, and there is a need to give the wires elasticity in order to increase the degree of freedom of the wiring in the multi-degree-of-freedom joint.

In robots, etc., power cables for motors and cables for sensors tend to increase. On the other hand, robots are becoming more and more miniaturized. Has become important. At the same time, in order to minimize energy loss and prevent the movement of the body from being obstructed by wearable electronic devices, etc., it can be stretched with as little force as possible, and the stretched wires will sag. It is also desired that the material has excellent stretch recovery properties so that it does not occur.
A typical example of a stretchable electric wire is a curled cord that can be expanded and contracted by making the electric wire into a coil shape, and is used in fixed telephones, etc., but is generally thick and heavy. This is not suitable for humanoid robots and power assist devices that use many wires.
On the other hand, as a technique related to an expandable electric wire having elasticity in the electric wire itself, for example, in Patent Document 1, an outer periphery of a core yarn formed by winding an inelastic yarn in a state where the elastic yarn is stretched about twice, An expandable electric wire in which a copper foil is spirally wound is disclosed.

Further, in Patent Document 2, an elastic fiber filament yarn is used as a core, and a fiber bundle is wound or arranged around an elastic fiber filament yarn stretched 1.5 to 3.5 times. A metal wire composite elastic yarn in which a metal wire is spirally wound is disclosed, and there is a description that the diameter of the elastic fiber filament yarn needs to be three times or more the diameter of the metal wire.
Furthermore, Patent Document 3 discloses an expandable electric wire in which a plurality of core wires each having a conductive wire disposed on the outer periphery of a core material made of elastic elastic yarns are covered with false twisted yarns.
As described above, in general, a conventional expandable electric wire is manufactured by using an elastic thread as a core material, winding an inelastic thread around the outer periphery of the core material, and winding a metal wire around the outer periphery. The core material was an essential component. Moreover, as described in Patent Document 2, since the elastic yarn as the core material needs to be thicker than a certain degree in order to wind the metal wire, the thickness of the expandable electric wire must be increased. It was unsuitable for internal wiring of robots.

In order to make a conventional stretchable electric wire thin, a method of thinning a core material or winding a metal wire wound around the core material more conceivably can be considered. However, if the core material is thinned, the stretch recovery property is reduced, and if the metal wire is tightly wound, the stretchability of the core material is hindered and the extensibility itself is lowered. It was impossible to make it thin while having the properties and stretch recovery properties.
In addition, a conventional stretchable electric wire requires a minimum of layers such as a core material made of elastic yarn, an inelastic yarn coated on the core material, a metal wire, and an outer periphery coating. Since this process is necessary, there is a problem that the manufacturing cost is high, and the need for a cheaper extension wire is increasing.

JP 61-290603 A Japanese Patent Publication No. 64-3967 JP 2004-134313 A

  An object of the present invention is to provide a stretchable electric wire that is thin and compact, has excellent stretchability and stretch recovery, and is inexpensive to manufacture.

In order to solve the above-mentioned problems, the present inventors have focused on the structure of the stretchable electric wire, eliminated the core portion made of elastic yarn, and formed a fiber structure in which both the conductor wire and the elastic long fiber are spirally wound. The present inventors have found that the above problems can be solved and have reached the present invention.
That is, the present invention is as follows.
1. The conductor wire is spirally wound in one direction of either Z-twisting or S-twisting, and in the opposite direction, other fibers pass through the inside and outside of the conductor wire and spirally wound to restrain the conductor wire. An expandable electric wire having a fiber structure, wherein the fiber structure contains at least elastic long fibers wound in a spiral shape, and does not have a core independent of the fiber structure. .
2. 2. The expandable electric wire according to 1 above, wherein the other fibers wound in the direction opposite to the conductor wire are elastic long fibers and / or insulating fibers.
3. 3. The expandable electric wire according to 1 or 2 above, wherein the fiber structure has a braided structure containing elastic long fibers and conductor wires.
4). The expansion / contraction electric wire according to any one of the above items 1 to 3, wherein the expansion / contraction electric wire has a covering portion on an outer periphery thereof.

  The stretchable wire of the present invention is a stretchable wire that is thin and compact because it has no core, and at the same time has excellent stretchability and stretch recovery properties. Further, since the manufacturing process can be shortened, it can be manufactured at low cost.

The present invention will be specifically described below.
In the stretchable electric wire of the present invention, the conductor wire is spirally wound in one direction of Z-strand or S-strand. Since the conductor wire is generally made of a metal wire such as copper or aluminum, the conductor wire itself does not have elasticity, but the conductor wire is spirally wound to give the wire an extensibility. Can do.
In the expandable electric wire of the present invention, the conductor wire is spirally wound in one direction of Z-strand or S-strand, and in the opposite direction, other fibers are spirally wound while passing through the inside and outside of the conductor wire. And has a fiber structure in which conductor wires are constrained. Other fibers wound in the opposite direction to the conductor wire are wound spirally while passing through the inside and outside of the conductor wire to restrain the conductor wire, thereby forming a fiber structure without having a core portion. And a thin and compact telescopic wire can be obtained. Furthermore, since the conductor wire is constrained by other fibers, changes in the spacing between the conductor wires due to repeated expansion and contraction and bending operations involving expansion and contraction are suppressed, and signal transmission is possible when the conductor wire is used as a signal line. Deterioration can be suppressed.

The conductor wire is preferably constrained by one or more places per winding, and is constrained by other fibers wound in the direction opposite to the conductor wire, and the constraining part is more preferably two or more per turn. 4 or more are more preferable, and 8 or more are particularly preferable. The yarn that constrains the conductor wire may be an elastic long fiber or another fiber, but in any case, it is preferably an insulator.
The expandable electric wire of the present invention needs to have a structure that does not have a core part independent of the fiber structure. The core part independent of the fiber structure is structurally independent from the conductor wires, elastic long fibers and / or other fibers constituting the fiber structure, without crossing or entanglement or forming a knitted structure. It means the core part.

The stretchable electric wire of the present invention needs to contain at least elastic long fibers wound in a spiral as the fibers constituting the fiber structure. Elastic long fibers spirally wound in the fiber structure form the fiber structure while intersecting the conductor wire, so that it does not have a core like a conventional expandable electric wire. The electric wire which has is obtained.
Conventional stretchable electric wires generally have a structure in which a conductor wire is wound around a core mainly composed of elastic long fibers, and the core and the conductor are crossed or entangled or knitted. Is not knitted and has an independent core. And as a method of making the thickness of an electric wire thinner than before, for example, there is a method of making the elastic yarn of the core part thinner, but if so, the stretch recovery property is hindered. In addition, as another method, there is a method of winding the conductor wire around the elastic yarn of the core part by increasing the winding tension, etc. It will be disturbed.

The stretchable electric wire of the present invention is characterized in that it does not have an independent core as in a conventional stretchable wire, and this makes it possible to reduce the length of the elastic long fiber or tightly wrap the conductor wire. Since a telescopic electric wire that is thinner and more compact than an extensible electric wire having a conventional core portion can be obtained, the electric wire can be thinned without impairing the stretchability and the stretch recovery property.
In addition, the conventional expandable electric wires need to be prepared in advance with a core material that constitutes the core portion, and in many cases, are mainly composed of insulating fibers around the core material in order to facilitate winding of the conductor wire. A coating layer is provided. The expandable electric wire of the present invention does not have a core part independent of the fiber structure and can omit the step of providing a coating layer on the core material, so that the manufacturing cost can be reduced.

As a method of manufacturing a fiber structure in which a conductor wire and other fibers are spirally wound in opposite directions without having a core, and the other fibers pass through the inside and outside of the conductor wire, for example, S In a method for manufacturing a braided string-like material by winding yarns in the twisting direction and Z-twisting direction, there is a method of using a conductor wire and other fibers as the yarn to be wound.
Particularly, those using elastic long fibers as other fibers wound in the opposite direction to the conductor wires, that is, only from the conductor wires and elastic long fibers (including conductor wires covered with insulating fibers and elastic long fibers). The stretchable electric wire having the fiber structure becomes the thinnest and compact stretchable wire, which is preferable. In addition, the elastic long fiber is wound in the same direction as the conductor wire, and a third fiber such as an insulating fiber is wound in the opposite direction, or the elastic long fiber is wound in both the same direction and the opposite direction of the conductor wire. It can also be turned into a fiber structure. However, since an elastic wire wound with elastic long fibers only in one direction may have a large residual torque, in that case before winding the elastic long fibers in the opposite direction or covering the outer circumference It is preferable to turn off the torque by rotating the telescopic wire in the residual torque direction.

As a form when the conductor wire and the elastic long fiber are spirally wound together, the elastic long fiber and the conductor wire are individually wound in a spiral form, or the elastic long fiber and the conductor wire are aligned. There are a form in which the filament is wound in a spiral form, or a form in which a thread obtained by winding a conductor wire on the elastic long fiber with a covering device or the like is spirally wound. However, in order to wind the conductor wire without bending the elastic long fiber, it is necessary that the thickness of the elastic long fiber is larger than the thickness of the thin wire constituting the conductor wire. In order to obtain a thin stretchable electric wire, a form in which the elastic long fibers and the conductor wires are aligned and wound in a spiral shape is preferable, and a form in which the elastic long fibers and the conductor wires are individually wound in a spiral shape is most preferable.

When spirally winding a yarn in which elastic long fibers and conductor wires are aligned, or a yarn in which conductor wires are wound around elastic long fibers, the elastic long fibers and conductor wires are wound in the same direction. Is done. When the elastic long fiber and the conductor wire are each wound spirally, the elastic long fiber and the conductor wire can be selected in either the same direction or the opposite direction. However, when the elastic long fiber and the conductor wire are spirally wound in the same direction, the elastic long fiber and / or the third fiber may be wound in the opposite direction in order to maintain the form of the stretchable electric wire. is necessary.
The stretchable wire of the present invention is a third wire other than the conductor wire and the elastic long fiber for the purpose of limiting the stretchability of the stretchable wire, increasing the breaking strength, or ensuring the spacing between the plurality of conductor wires. The fibers may be spirally wound at the same time. The third fiber wound at the same time is preferably an insulating fiber, and is preferably a crimped yarn such as false twisted yarn or latent crimped composite fiber in order not to inhibit stretchability, A fiber thinner than the conductor wire is preferable.

In a telescopic electric wire having a plurality of conductor wires, there are cases where two signal wires and two power wires are used. In this case, if the distance between the signal lines is not uniform, there is a problem that the characteristic impedance between the signal lines becomes non-uniform and the transmission loss becomes large (especially at a high frequency). A wire braided by winding a plurality of conductor wires in one direction is particularly preferable because of low transmission loss. At this time, in order to make the interval between the signal lines more uniform, the elastic long fibers or the insulating fibers are arranged in the same direction between the plurality of conductor lines, and the elastic long fibers or the insulating fibers are arranged in the opposite direction to be braided. Is preferred. At this time, in order to make the interval between the signal lines more uniform, the elastic long fibers or insulating fibers arranged in the direction opposite to the conductor lines are compared with the elastic long fibers or insulating fibers arranged in the same direction as the conductor lines. And finer is preferable, and fineness of 1/2 to 1/10 is more preferable.
As the insulating fibers, known insulating fibers such as fluorine fibers, polyester fibers, nylon fibers, polypropylene fibers, vinyl chloride fibers, saran fibers, glass fibers and polyurethane fibers can be used.

The elastic long fiber used in the stretchable electric wire of the present invention is not particularly limited as long as it is a stretchable long fiber, but is made of a thermoplastic elastomer such as polyurethane elastomer, polyester elastomer, polyamide elastomer, or the like, silicone Examples thereof include synthetic rubber-based long fibers such as rubber, ethylene propylene rubber, chloroprene rubber, and butyl rubber, or natural rubber-based long fibers.
In the stretchable electric wire of the present invention, it is necessary to wind the elastic long fiber spirally together with the conductor wire. Therefore, in order to obtain a thinner elastic wire, the elastic long fiber is preferably flexible, such as polyurethane elastomer or silicone rubber. An elastic long fiber made of is more preferable. Moreover, the thing made porous by a foaming agent etc. and the hollow elastic long fiber which has at least 1 or more hollow part continued in the longitudinal direction of the elastic long fiber are also preferable from a softness | flexibility point.

The elastic long fiber may be a monofilament or a multifilament. The elastic long fiber that is difficult to be continuously spun, such as melt spinning, may be a so-called slit yarn in which an elastic body is formed into a sheet, and then cut and divided at an arbitrary width. The preferred fineness of the elastic long fiber is preferably 10 to 5000 dtex, more preferably 30 to 2000 dtex.
The elastic long fiber preferably has a 50% elongation stress of 1 to 200 cN / mm ² , more preferably 5 to 100 cN / mm ² , and particularly preferably 10 to 50 cN / mm ² . When the 50% elongation stress is in this range, an expandable electric wire that can be extended with a small force can be obtained, and an expandable electric wire suitable for applications using a large number of expandable wires, such as humanoid robots, power assist devices, wearable electronic devices, etc. It becomes.

The elastic long fiber preferably has a 50% elongation recovery rate of 80% or more, more preferably 85% or more, and still more preferably 90%. When the 50% elongation recovery rate is within this range, an expandable electric wire excellent in repeated elongation recovery can be obtained. The elongation at break of the elastic long fibers is preferably 100% or more, more preferably 150% or more, and further preferably 200% or more. When the breaking elongation is within this range, an expandable electric wire having high extensibility can be obtained. The 50% elongation recovery rate can be measured by the following method.
A sample was set on a tensile tester (manufactured by A & D Co., Ltd., Tensilon tester) at a grip interval of 100 mm, stretched at a pulling rate of 100 mm / min, deweighted immediately after stretching 50%, and recorded. The residual elongation x (mm) when the load became zero was obtained from the load-elongation curve, and the 50% elongation recovery rate was obtained by the following formula.
50% elongation recovery rate (%) = [(50−x) / 50] × 100

The stretchable wire of the present invention preferably has an elongation rate of 10% or more at 10 N load, more preferably 50% or more, and further preferably 70% or more. The load of 10N is equivalent to the load when a person pulls and stretches the expansion / contraction wire with his / her hand, and when a load higher than this is applied, the conductor wire is stretched and plastically deformed or partly disconnected. There is.
Moreover, it is preferable that the elongation recovery rate after applying 10N load 10 times repeatedly is 60% or more, 70% or more is more preferable, 75% or more is further more preferable.
As the force required to extend the expansion / contraction electric wire, it is desired that the necessary force is small in the range of the regularly used elongation, and specifically, the load at the time of 30% elongation is 3000 cN or less. Preferably, 1000 cN or less is more preferable, 500 cN or less is more preferable, and 300 cN or less is particularly preferable.

When the outer circumference of the elastic long fiber used in the stretchable wire of the present invention is covered with a synthetic fiber such as polyester or nylon (preferably a crimped yarn such as false twisted yarn) is covered, the friction on the surface of the elastic long fiber Is preferable because it is easy to wind in a spiral shape. Moreover, it is more preferable to apply a smoothing agent such as a silicone resin to the surface of the synthetic fiber because friction with the conductor wire can be further reduced.
The fineness of the synthetic fiber to be coated is preferably smaller than the fineness of the elastic long fiber, more preferably 1/5 or less of the elastic long fiber. When covering the synthetic fiber, in order not to inhibit the stretchability of the elastic long fiber, the synthetic fiber is covered with a covering machine or the like in a state of being stretched about 1.5 to 6 times within the range of the breaking elongation of the elastic long fiber. It is preferable to wind.

The conductor wire used for the expandable electric wire of the present invention may be a single wire or an aggregated wire of fine wires, but is preferably an aggregated wire of at least two or more fine wires. By using the aggregated wires of the thin wires, the flexibility of the conductor wires is increased and it becomes difficult to inhibit the stretchability, so that a thinner stretchable electric wire can be easily obtained.
Various methods are known for assembling thin lines, and any method known in the present invention may be used. However, since it is difficult to wind the wire simply by aligning it straight, it is preferable to use a stranded wire. Moreover, in order to exhibit flexibility, what gathered the assembly line with the insulating fiber can also be used.
The diameter of the thin wire constituting the conductor wire is preferably 1 mm or less, more preferably 0.1 mm or less, particularly preferably 0.08 mm or less, and most preferably 0.05 mm or less. If the diameter of the thin wire is within this range, the flexibility of the conductor wire is increased, the stretchability is hardly hindered, the disconnection due to the stretch is less likely to occur, and a thinner stretchable electric wire is easily obtained. Since it will be easy to disconnect at the time of a process when too thin, 0.01 mm or more is preferable.

When the conductor wire is used as an aggregate wire of thin wires, the converted diameter of the conductor wire obtained by the following formula is preferably 2 mm or less, more preferably 1 mm or less, and further preferably 0.5 mm or less.
Equivalent diameter of conductor wire = 2 × √ ((π × (Lt / 2) × (Lt / 2) × n) / π)
= Lt × √n
Lt: Diameter of the fine wire constituting the conductor wire n: Number of aggregates of the fine wire constituting the conductor wire If the converted diameter of the conductor wire is within this range, the flexibility is good and the wire can be wound stably. Moreover, from the point of workability | operativity at the time of winding, 0.01 mm or more is preferable and, as for the conversion diameter of a conductor wire, 0.02 mm or more is more preferable.

The conductor wire preferably has a specific resistance of 10 ⁻⁴ Ω · cm or less, and more preferably 10 ⁻⁵ Ω · cm or less. The conductor wire is preferably a copper wire made of copper by 80 wt% or more, or an aluminum wire made of aluminum by 80% or more. Copper wire is most preferred because it is relatively inexpensive and has low electrical resistance. Aluminum wires are preferred after copper wires because they are lightweight. Copper wire is generally annealed copper wire or tin-copper alloy wire, but strong copper alloy with enhanced strength (eg, oxygen-free copper added with iron, phosphorus, indium, etc.) without significantly reducing electrical conductivity ), Tin, gold, silver, platinum or the like plated to prevent oxidation, or those treated with gold or other elements to improve the electrical signal transmission characteristics can also be used.

The conductor wires can be used one by one covered with an insulator, or a set of fine wires can be covered together with an insulator. The thickness of the insulator to be coated is preferably 2 mm or less, more preferably 1 mm or less, and still more preferably 0.1 mm or less. If the thickness of the insulator to be covered is within this range, the insulated conductor wire is flexible and has a small outer diameter.
As the type of the insulator to be coated, any one of the well-known insulating resins that meets the above-described purpose can be arbitrarily selected. When resin coating is applied to each conductor wire, for example, as a so-called enamel coating used in general magnet wires, polyurethane coating, polyurethane-nylon coating, polyester coating, polyester-nylon coating, polyester-imide coating and polyesterimide- Polyamideimide coating etc. are mentioned. In the case where the resin coating is performed after forming the assembly line, a vinyl chloride resin, a polyolefin resin, a fluororesin, a urethane resin, an ester resin, or the like can be used. For identification, each conductor wire can be color-coded in advance.

It is also possible to use a conductor wire that has been previously coated by winding and / or braiding insulating fibers, which is preferable because the insulating resin layer on the surface of the thin wire is not easily broken during processing.
In the stretchable electric wire of the present invention, it is preferable that at least an elastic long fiber and a conductor wire are spirally wound to form an intermediate body of the stretchable wire, and then a covering portion is formed on the outer periphery thereof. Usually, the outer periphery covering portion is required to protect the inner conductor wire without hindering the stretchability. For this reason, it is preferable that the outer periphery covering portion is formed of an insulating fiber braid and / or an elastic tubular material of insulating resin having an elongation of 50% or more.

In the stretchable electric wire of the present invention, in particular, when the elastic long fiber has a form wound at least in the direction opposite to the conductor wire, it has a structure in which a part of the conductor wire enters the inside of the elastic long fiber, The thickness of the outer peripheral covering portion can be reduced, and a thinner and more compact stretchable electric wire can be obtained, and at the same time, an effect that high stretchability can be maintained is also obtained.
As the insulating fiber covering the outer periphery, a multifilament or a spun yarn can be used, and it can be arbitrarily selected from known insulating fibers according to the use of the expandable electric wire and the assumed use conditions. The insulating fiber may be a raw yarn, but an original yarn or a pre-dyed yarn can also be used from the viewpoint of design properties and prevention of deterioration. In addition, the finish processing can improve flexibility and friction resistance. In addition, handling of known fibers such as flame retardant processing, water repellent processing, oil repellent processing, antifouling processing, antibacterial processing, antibacterial processing, and deodorizing processing can also improve handling in practical use. it can.

In particular, it is preferable to apply a smoothing agent such as a silicone resin to the surface of the insulating fiber because the friction coefficient on the surface of the stretchable electric wire can be further reduced. In addition, when used for the skin wiring of a humanoid robot, it is preferable to apply a water repellent treatment to the outer peripheral covering portion so that the resin constituting the skin does not penetrate into the inside of the stretchable electric wire and impair the stretchability.
Examples of insulating fibers that achieve both heat resistance and wear resistance include aramid fibers, polysulfone fibers, and fluorine fibers. From the viewpoint of fire resistance, glass fiber, flame-resistant acrylic fiber, fluorine fiber and saran fiber are mentioned, and from the viewpoint of wear resistance and strength, high-strength polyethylene fiber and polyketone fiber are mentioned. From the viewpoint of cost and heat resistance, there are polyester fiber, nylon fiber and acrylic fiber. Also suitable are flame retardant polyester fiber, flame retardant nylon fiber, flame retardant acrylic fiber (modacrylic fiber) and the like imparted with flame retardancy.

For local deterioration due to frictional heat, it is preferable to use non-melted fibers. Examples thereof include aramid fibers, polysulfone fibers, cotton, rayon, cupra, wool, silk and acrylic fibers. When emphasizing strength, examples include high-strength polyethylene fiber, aramid fiber, and polyphenylene sulfide fiber. When importance is attached to frictional properties, examples thereof include fluorine fibers, nylon fibers, and polyester fibers. When emphasizing design properties, acrylic fibers with good color can be used. Furthermore, when importance is attached to the tactile sensation due to human contact, cellulosic fibers such as cupra, acetate, cotton, and rayon, and silk or synthetic fibers with fine fineness can be used.
When it is desired to improve the coating property from the liquid, an elastic resin elastic tube-like material can be suitably used as the outer coating. The insulating resin can be arbitrarily selected from various elastic insulating resins, and can be selected in consideration of compatibility with other insulating fibers used for the extension wire and the internal structure of the extension wire.

Performances that should be considered include elasticity, abrasion resistance, heat resistance, and chemical resistance. Synthetic rubber-based elastic materials are examples of those that are excellent in these performances, such as fluorine rubber, silicone rubber, and ethylene. Propylene rubber, chloroprene rubber and butyl rubber are preferred.
The outer coating layer made of an insulating material can be a combination of a coating braided with insulating fibers and an elastic tubular material. In many cases, the expansion / contraction electric wire is desired to be expanded / contracted with a small force. However, when the elastic wire is covered only with an elastic tube-like material, it is necessary to increase the thickness of the elastic tube, and the force necessary for expansion / contraction tends to increase. In such a case, it is possible to achieve both coverage and stretchability by combining a thin tube and a braid made of insulating fibers.

Next, the typical manufacturing method of the expansion-contraction electric wire of this invention is demonstrated. In addition, the expansion / contraction electric wire of this invention is not limited to the following manufacturing methods.
As a typical manufacturing method of the expandable electric wire of the present invention, a yarn to be wound in a method of manufacturing a braided string-like material, that is, a so-called braid by winding the yarn in the S twist direction and the Z twist direction, respectively. As a method, a method using an elastic long fiber and a conductor wire can be mentioned. An apparatus for manufacturing a braid includes a braiding machine (a braiding machine), but any machine can be used as long as it can manufacture a braid having a similar braided structure.

There are round braids, flat braids, square braids, etc., depending on the shape of the braid. In the stretchable electric wire of the present invention, round braids are preferred because the conductor wires are easy to be wound without being bent. Further, depending on the number of yarns to be wound, there are a four-ply braid, an eight-pipe braid, a sixteen-punch braid, and the like, which may be appropriately adopted depending on the number of conductor wires to be wound. Preferably, a braid comprising at least twice the number of conductor wires to be wound is preferable. For example, when four conductor wires are wound, an eight-strand braid or 16-strand braid is preferable. In addition, in 4-strand braids and 8-strand braids, the stretchable electric wires in which the conductor wires are wound only in one direction have a substantially elliptical cross-section (a shape in which the conductor wires protrude slightly outward). The 16-piece assembly has a substantially round cross section or a substantially square cross section.

  The elastic long fiber to be wound is one whose outer periphery is coated with a synthetic fiber such as polyester or nylon (crimped yarn such as false twisted yarn is preferable) in order to prevent damage or breakage due to friction with the yarn weight. preferable. In order to ensure high extensibility of the elastic long fibers, it is preferable to coat the synthetic fibers while elongating the elastic long fibers at as high a magnification as possible during the coating process. Specifically, it is preferably stretched by about 1.5 to 6 times, more preferably 3 to 6 times within the range of the elongation at break of the elastic long fibers.

  When winding the elastic long fibers and the conductor wires individually in a spiral using a string making machine, first, the elastic long fibers and the conductor wires are separately wound around the bobbin for the string making machine, and the bobbin is Set up a braiding machine and braid. At this time, a tension is applied to the yarn to be braided by the thread weight, but it is preferable to apply the tension to the elastic long fiber by the heaviest weight thread as long as it does not break. By doing so, the elastic long fiber is stretched and braided with the conductor wire to form an intermediate body of the stretchable electric wire, and the intermediate body that has exited the exit side roll of the stringing machine is relaxed and the elastic long fiber is contracted. , An intermediate having elasticity. The tension applied to the conductor wire is preferably such that the conductor wire is not loosened during braiding so that the conductor wire is not damaged or broken.

  When spirally winding a yarn in which elastic long fibers and conductor wires are aligned, first, the elastic long fibers and conductor wires are aligned and wound on a bobbin for a string making machine, and the bobbin is then wound on a string. Braided on the machine. When braiding, tension is applied by the thread weight, but the elastic long fibers are aligned with the conductor wires having a remarkably high elastic modulus (that is, difficult to stretch), so the length that the elastic long fibers are stretched is the conductor wire. Limited by. Accordingly, when the elastic long fiber and the conductor wire are aligned and wound on a bobbin for a string making machine, the elastic long fiber is about 1.2 to 6 times, preferably 1.5 to 5 within the range of elongation at break. It is preferable that the elastic long fiber is stretched around the conductor wire while being stretched and wound around the bobbin by about twice, more preferably about 2 to 4 times.

The elastic long fibers can be stretched by applying tension with a tension washer or the like, or by making the yarn feeding speed slower than the bobbin winder winding speed through the yarn feeding roll, keeping the stretching ratio constant. Although there is a method of feeding yarn, the latter method is preferable in that variation in stretchability of the stretchable electric wire can be reduced.
In the case of spirally winding a thread obtained by winding a conductor wire on an elastic long fiber with a covering device or the like, during the covering process, the elastic long fiber Within the range of breaking elongation, it is preferable to wind the conductor wire while stretching the elastic fiber, about 1.2 to 6 times, preferably about 1.5 to 5 times, more preferably about 2 to 4 times. .

  In the stretchable electric wire of the present invention, the winding angle of the conductor wire is preferably in the range of 30 degrees to 80 degrees. If the winding angle is within this range, the stretchability is easily developed. The winding angle is more preferably 35 ° to 75 °, and particularly preferably 40 ° to 70 °. The winding angle of the conductor wire may be controlled by adjusting the ratio of the winding speed of the braid to the speed at which the bobbin goes around the braid at the time of braiding, the expansion ratio of the elastic long fiber, and the like. In the present invention, the winding angle is an angle formed between the length direction (axial direction) of the telescopic electric wire and the conductor wire when the telescopic electric wire is viewed from the side, and refers to an angle when the telescopic electric wire is in a relaxed state. . The winding angle can be obtained by using an inverse trigonometric function by cutting a loose stretchable electric wire for a certain length, unwinding the wound conductor wire, measuring the length thereof, and then winding the wound wire.

It is preferable that the elastic long fiber and the conductor wire are spirally wound to form an intermediate body of the stretchable electric wire, and then a covering portion is formed on the outer periphery of the elastic fiber braid and / or an insulating resin elastic tube.
When the outer periphery covering portion is formed by braiding insulating fibers, the intermediate body in which the elastic long fibers and the conductor wires are spirally wound is again placed on a stringing machine or the like, and the intermediate body is stretched on the outer periphery. A method of braiding insulating fibers is preferred, and the final shape of the braid may be a round string or a narrow tape. In addition, a plurality of the intermediates may be collected and the outer periphery thereof may be coated with insulating fibers, or a plurality of the intermediates previously coated with insulating fibers may be combined and the outer periphery may be further coated with insulating fibers. Also good. Preferably, the one in which the outer periphery of the intermediate body consisting only of the elastic long fiber and the conductor wire is covered with the insulating fiber can be most compact.

The expandable electric wire thus obtained preferably has a resistance of 10 Ω / m or less in a relaxed state. In the case of more than this, even if a weak current can be supplied, it is not suitable for supplying a drive current. More preferably, it is 1 Ω / m or less.
A thin elastic tape shape incorporating a plurality of the stretchable wires of the present invention can also be made. In order to obtain a narrow elastic tape shape, it is preferable to use 2 to 100 stretchable electric wires that are pre-insulated. Although 3 to 5 general-purpose devices are used, there are cases where it is desired to wire a large number of motors and sensors from a power source to the end with a single tape, and a large number of telescopic wires can be formed into a tape. From the viewpoint of handleability, the width of the tape is preferably 20 cm or less, and more preferably 10 cm or less.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited only to these Examples. Moreover, in the Example and comparative example of this invention, in order to make it easier to compare the thickness of an electric wire, it evaluated by omitting outer periphery coating | cover.
The evaluation method used in the present invention is as follows.
(1) Wire thickness After leaving the sample in the standard state (temperature 20 ° C, relative humidity 65%) for 2 hours or more, the dimensions of the cross section (in the case of a substantially round cross section) so that the sample does not deform under the standard state. Is a diameter D (mm), a major axis D1 (mm), a minor axis D2 (mm) in the case of a substantially elliptical cross section, and a side square B1 (mm), B2 (mm) in the case of a substantially square cross section, The cross-sectional area A (mm ² ) was determined by the following formula.
For the substantially round ^{cross-section: A = π × D 2/} 4
In the case of a substantially elliptical cross section: A = π × D1 × D2 / 4
In the case of a substantially square cross section: A = B1 × B2

(2) Elongation rate at 10N load After leaving the sample in the standard state (temperature 20 ° C, relative humidity 65%) for 2 hours or more, under the standard state, a tensile tester (manufactured by A & D Co., Ltd., A sample is set at a gripping interval of 100 mm on a Tensilon tester, stretched at a pulling speed of 100 mm / min, and immediately after a load of 10 N is applied, the sample is deweighted at the same speed. The distance L1 (mm) between the chucks was obtained, and the elongation rate (%) at 10 N load was obtained by the following formula.
Elongation rate at 10N load = {(L1-100) / 100} × 100
(3) Tensile recovery rate after 10N load The 10N load extension test of (2) is repeated 10 times. From the 10th load-elongation curve, the distance L2 (mm) between chucks at 10N load and the load returns to 0. The distance L3 (mm) between the chucks was determined, and the elongation recovery rate (%) after 10 N load was determined by the following formula.
Elongation recovery rate after 10N load = {(L3-100) / (L2-100)} × 100

[Example 1]
940d using a double covering machine (made by Kataoka Techno Co., Ltd., SP-400 type)
While a tex / 72f polyurethane elastic long fiber (Asahi Kasei Fibers Co., Ltd., trade name: Leuka) is used as a core, a 155 dtex / 48f nylon false twisted yarn is twisted under 500 T / m while being stretched at a stretch ratio of 6 times ( S twist) and 332 T / m top twist (Z twist) to obtain a double cover yarn.
The obtained double cover yarn was placed on a bobbin winder for a string making machine with a yarn feeding roller (auto winder manufactured by Yoshida Seisakusho Co., Ltd.) and wound around the bobbin at an expansion ratio of 1.2. Moreover, as a conductor wire, a copper fine wire assembly wire (USTC manufactured by Tatsuno Electric Wire Co., Ltd., diameter 0.03 mm × 48 pieces) covered with polyester processed yarn was wound around a bobbin alone.
Using a 16-punch round stringing machine (manufactured by Sakurai Tekko Co., Ltd.), four bobbins each wound with a double cover yarn are arranged in the S twist direction every other bobbin 4 and each conductor wire is wound around the bobbin 4 The book was arranged every other Z-strand direction and subjected to braiding to obtain an expandable electric wire. As for the yarn weight at the time of the braiding process, 40 cm (about 150 g) was applied to the double cover yarn, and 20 cm (about 75 g) was applied to the conductor wire.
Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.

[Comparative Example 1]
As a core material, four double cover yarns similar to those in Example 1 were drawn and wound around a yarn tube separately.
Using a 16-punch round punching string machine (manufactured by Sakurai Tekko Co., Ltd.), the double cover thread wound around the thread tube is supplied to the core while being stretched 2.0 times. Four bobbins around which conductor wires have been wound are arranged in the Z twist direction, and four bobbins wound with nylon false twisted yarn (230 dtex / 72f × 2), which is an insulating fiber, are wound in the S twist direction. Placing every other piece and performing braiding processing gave a telescopic wire. As for the yarn weight at the time of the braiding process, the conductor wire was hung with 20 mm (about 75 g) and the nylon false twisted yarn with 15 mm (about 56 g).
Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.

[Comparative Example 2]
A stretchable electric wire was obtained in the same manner as in Comparative Example 1 except that two double cover yarns similar to those in Example 1 were used as the core material. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.

[Comparative Example 3]
In Comparative Example 1, the stretchable electric wire was formed in the same manner as in Comparative Example 1 except that the yarn weight at the time of braiding was twisted tightly by winding 40 mm (about 150 g) of both conductor wire and nylon false twisted yarn. Obtained. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.
In Example 1 and Comparative Example 1, the same elastic long fibers and conductor wires were used, and the stretchable wires were manufactured using the same stringing machine. In Comparative Example 1, the elastic long fibers were in the core. Since the conductor wire is not restrained, the insulating fiber is wound in the opposite direction to the conductor wire in order to maintain the shape of the electric wire.
The stretchable wire obtained in Example 1 has an elongation rate and elongation recovery rate equivalent to those of the stretchable wire obtained in Comparative Example 1, with a wire diameter of about 20% and a cross-sectional area of about 40% smaller. It was a very thin and compact telescopic wire. In addition, at least the cost of arranging the core material and the cost of the insulating fiber could be reduced.
The stretchable wire obtained in Comparative Example 1 had the same elongation rate and stretch recovery rate as the wire of Example 1, but was too thick to meet the purpose of the present invention.
Comparative Example 2 is obtained by thinning the elastic long fiber of the core part of Comparative Example 1, and although the diameter of the electric wire is slightly reduced, it is still thicker than the electric wire of Example 1, and the elongation recovery rate is greatly reduced. It was insufficient as a telescopic wire.
In Comparative Example 3, the conductor wire and the insulating fiber were wound more tightly than in Comparative Example 1, and although the thickness of the electric wire was reduced to a thickness close to that of the electric wire of Example 1, both the elongation rate and the elongation recovery rate were Was greatly reduced, and it was insufficient as an expandable electric wire.

[Example 2]
An expandable electric wire was obtained in the same manner as in Example 1 except that four bobbins around which the double cover yarn was wound were arranged every other bobbin in the Z twist direction. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.
The obtained expandable electric wire has a substantially square cross section, and the cross-sectional area is almost the same as that of the expandable electric wire of Example 1 although the elastic long fiber is used twice as compared with Example 1. It was a very thin and compact telescopic wire.

[Example 3]
For the purpose of making the distance between the conductor wires more uniform, the same procedure as in Example 1 was conducted except that four bobbins each wound with the same nylon false twisted yarn as in Comparative Example 1 were arranged in the Z twist direction. An elastic wire was obtained. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.

[Comparative Example 4]
In order to make the spacing between the conductor wires more uniform, the same procedure as in Comparative Example 1 was conducted except that four bobbins each wound with the same nylon false twisted yarn as in Comparative Example 1 were arranged in the Z twist direction. An elastic wire was obtained. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.
In Example 3 and Comparative Example 4, the same elastic fiber and conductor wire were used, and the telescopic wire was manufactured using the same stringing machine. Comparative Example 4 was for maintaining the shape of the wire. Insulating fiber is wound in the opposite direction to the conductor wire. The expandable electric wire obtained in Example 3 is very thin and compact compared with the expandable electric wire obtained in Comparative Example 4 with the same extensibility, approximately 15% smaller in diameter and 30% smaller in cross-sectional area. It was a flexible telescopic wire. In addition, at least the cost of arranging the core material and the cost of the insulating fiber could be reduced.

[Example 4]
Using an 8-round stringing machine (manufactured by Sakurai Tekko Co., Ltd.), 4 bobbins wound with double cover yarn are placed in the S twist direction, and 4 bobbins wound with conductor wires are Z twisted. The wire was placed in the direction and braided to obtain an expandable electric wire. As for the yarn weight at the time of the braiding process, 40 cm (about 150 g) was applied to the double cover yarn, and 20 cm (about 75 g) was applied to the conductor wire. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.
The obtained expandable electric wire has a substantially elliptical cross section, a smaller cross-sectional area than the expandable electric wire of Example 1, and an elongation at constant load greater than that of Example 1. It was an excellent extension wire.

[Example 5]
When the same conductor wire as in Example 1 was wound around the bobbin for a stringing machine, the covering yarn similar to that in Example 1 was drawn and aligned on the same bobbin at an expansion ratio of 2.0.
Comparative Example 1 using a 16-punch round stringing machine (manufactured by Sakurai Tekko Co., Ltd.) and arranging four bobbins each having a conductor wire and covering yarn aligned and wound in the Z twist direction. Four bobbins each wound with the same nylon false twisted yarn were arranged every other in the S twist direction and subjected to braiding to obtain an expandable electric wire. The yarn weight at the time of braiding was 20 kg (about 75 g) when the conductor wire and covering yarn were aligned, and 15 kg (about 56 g) of the nylon false twisted yarn. Table 1 shows the evaluation results of the thickness of the obtained elastic wire and the elongation at 10N load and the elongation recovery rate after 10N load.
Shown in

  The expandable electric wire of the present invention is suitable for wiring of devices having bending portions such as bending devices such as body wearing devices and clothes wearing devices in the robot field, and particularly, humanoid robots (internal wiring and skin wiring). It is suitable for power assist devices, wearable electronic devices and the like. Other robots (industrial robots, home robots, hobby robots, etc.), rehabilitation aids, vital data measurement equipment, motion capture, protective clothing with electronic equipment, game controllers (including human-mounted type), microphones, It can be suitably used in the field of headphones and the like.

Claims (4)

  The conductor wire is spirally wound in one direction of either Z-twisting or S-twisting, and in the opposite direction, other fibers pass through the inside and outside of the conductor wire and spirally wound to restrain the conductor wire. An expandable electric wire having a fiber structure, wherein the fiber structure contains at least elastic long fibers wound in a spiral shape, and does not have a core independent of the fiber structure. .   The stretchable electric wire according to claim 1, wherein the other fibers wound in the direction opposite to the conductor wire are elastic long fibers and / or insulating fibers.   The stretchable electric wire according to claim 1 or 2, wherein the fiber structure is a braided structure containing elastic long fibers and conductor wires.   The stretchable electric wire according to any one of claims 1 to 3, wherein the stretchable electric wire has a covering portion on an outer periphery thereof.