JP7412127B2 - Flexible insulated wire - Google Patents

Description

The present invention relates to a bend-resistant insulated wire. More specifically, the present invention relates to a bend-resistant insulated wire that has excellent flexibility and is lightweight, and is particularly suitable for automotive wiring.

In recent years, as automobiles, industrial robots, electrical equipment, thermal equipment, etc. have become more sophisticated, the number of wiring locations has increased. The reliability required for the electric wires used for such wiring is also increasing. Furthermore, due to the demand for energy saving and compactness, there is also a demand for lighter weight electric wires themselves.

In response to these demands, for example, Patent Document 1 proposes an electric wire conductor for harnesses in which a stranded wire consisting of an aramid fiber bundle or string at the center and copper wires arranged around it is compressed and heat treated. . Further, Patent Document 2 relates to an overhead power transmission line, and a stranded conductor consisting of a tension member made of aramid fiber, glass fiber, etc. is arranged in the center, and a plurality of annealed copper wires are twisted on the outside thereof. An insulated wire has been proposed in which an insulated wire is provided with an insulating coating on the outside. Further, Patent Document 3 describes a structure in which a plurality of organic fibers having a maximum elongation of 10% or more are twisted around a center line made of copper or copper alloy formed to have a maximum elongation of 10% or more. , a small-diameter electric wire for a wire harness has been proposed in which the weight ratio of organic fiber to copper or copper alloy and the cross-sectional area of the thickness are specified.

Japanese Patent Application Publication No. 2008-91214 Japanese Patent Application Publication No. 4-138616 Japanese Patent Application Publication No. 2003-123542

Each of the electric wires of the above-mentioned prior art has a fiber in the center, a metal wire around the outer periphery, and an insulator around the outer periphery. However, in these electric wires, some of the fibers tend to protrude from between the metal wires, which tends to deteriorate the appearance of the electric wires. Further, moisture or oil may adhere to the fibers, and the moisture or the like adhering to the fibers causes foaming or rough skin of the insulator when the insulator is provided around the outer periphery of the metal wire. Deterioration of the appearance of the electric wire, foaming of the insulator, and roughening of the surface of the wire cause local non-uniformity and reduce the bending life.

Further, in Patent Document 1, since the fiber core comes into contact with the extruded resin when covering the insulator, the fiber core may be affected by heat and may not be able to perform its function as a fiber core. Such a phenomenon is more likely to occur when the extrusion temperature is high, causing a decrease in the flex life.

The present invention has been made to solve the above problems. The purpose is to provide a bend-resistant insulated wire that has excellent flexibility and is lightweight, and is particularly suitable for automotive wiring.

The bend-resistant insulated wire according to the present invention is made by twisting a twisted core formed by twisting a fiber thread and a first metal wire, and a plurality of second metal wires provided around the outer periphery of the twisted core. It has a stranded conductor and an insulator provided on the outer periphery of the stranded conductor, and is characterized in that the twist pitch of the stranded core is different from the twist pitch of the stranded conductor.

According to this invention, since the twisting pitches of the twisted core and the twisted wire conductor are different, it is possible to obtain a flexible, bend-resistant insulated wire that is not stiffer than when both have the same twisting pitch. Further, the twisted core having the first metal strands has a certain degree of strength, and since the twist pitch of the twisted core and the twisted wire conductor are different, the twisted core is difficult to follow the twist of the twisted wire conductor and meander. As a result, the center position of the stranded core and the center position of the stranded wire conductor are less likely to deviate from each other and are less likely to become flattened. If the flatness is large, it becomes difficult to process the terminals, but in this invention, the center position of the stranded core and the center position of the stranded wire conductor do not easily shift, and there is no flatness or there is no flatness, so it is easy to process the terminals. It can be a bent insulated wire. That is, the wire can be flexibly deformed by the stress applied during bending, resulting in a bend-resistant insulated wire with good bending resistance.

In the bend-resistant insulated wire according to the present invention, the difference (P1/P2 or P2/P1) between the twist pitch P1 of the twisted core and the twist pitch P2 of the twisted wire conductor is 1.5 to 5 times. According to this invention, since the difference between P1 and P2 is more than double, the twist state of one is less likely to affect the twist state of the other, meandering that affects the mutual twist states is less likely to occur, and the center position of the twisted core and the twist The center position of the wire conductor is difficult to shift, and it is difficult to flatten.

In the bend-resistant insulated wire according to the present invention, the difference between the center position of the twisted core and the center position of the twisted wire conductor is less than 0.3 mm. According to this invention, since the difference between the center positions of the twisted core and the twisted wire conductor is less than 0.3 mm, there is no flatness or small flatness. As a result, a bend-resistant insulated wire with flexibility and easy terminal processing can be obtained. Note that the center position is a center position calculated from the outline of the cross section of the twisted core, and a center position calculated from the outline of the cross section of the twisted wire conductor. The misalignment causes a flattened shape, and the flattened shape may act to prevent stress from concentrating on a specific region, thereby improving the bending characteristics. However, there are some difficulties in terms of terminal processing. This invention improves both bending properties and end processability.

In the bend-resistant insulated wire according to the present invention, it is preferable that the twisting pitch P1 of the twisted core and the twisting pitch P2 of the twisted wire conductor are 5 to 15 times the outer diameter of the twisted wire conductor. According to this invention, each twist pitch and the outer diameter of the stranded wire conductor have the above relationship, so the difference between the center positions of the stranded core and the stranded wire conductor is small, and there is no flatness or small flatness. As a result, a bend-resistant insulated wire with flexibility and easy terminal processing can be obtained.

In the bend-resistant insulated wire according to the present invention, the first metal wire and the second metal wire have the same outer diameter. According to this invention, since metal wires having the same outer diameter are used, the twisted core and twisted wire conductor can be made smaller in diameter, and the entire insulated wire can be made smaller in diameter, lighter, and more flexible.

In the bend-resistant insulated wire according to the present invention, the stranded conductor has an outer diameter of 1.6 mm or less. According to this invention, the stranded wire conductor having the above-described outer diameter can realize a thinner insulated wire with excellent bending resistance, and can achieve weight reduction.

According to the present invention, it is possible to provide a bend-resistant insulated wire that has excellent flexibility, is lightweight, and is particularly suitable for wiring for automobiles. In particular, since the twisting pitches of the twisted core and the twisted wire conductor are different, the wire is less stiff than when both have the same twisting pitch, and a flexible, bend-resistant insulated wire can be obtained. Further, the twisted core having the first metal strands has a certain degree of strength, and since the twist pitch of the twisted core and the twisted wire conductor are different, the twisted core is difficult to follow the twist of the twisted wire conductor and meander. As a result, the center position of the stranded core and the center position of the stranded wire conductor are less likely to deviate from each other and are less likely to become flattened.

1 is a schematic explanatory diagram showing an example of a bend-resistant insulated wire according to the present invention. FIG. 3 is an explanatory diagram of each dimension constituting the bend-resistant insulated wire. FIG. 3 is an explanatory diagram of a twisted state of a twisted wire conductor. FIG. 3 is an explanatory diagram showing an aspect of a bending test.

Hereinafter, the bend-resistant insulated wire according to the present invention will be explained with reference to the drawings. Note that the present invention is not limited to the illustrated embodiment.

[Bending-resistant insulated wire]
As shown in FIGS. 1 and 2, the bend-resistant insulated wire 10 (hereinafter also referred to as "insulated wire 10") according to the present invention is a twisted wire formed by twisting a fiber thread 1a and a first metal wire 1b. It has a core 1, a stranded conductor 2 formed by twisting a plurality of second metal wires 3 provided on the outer periphery of the stranded core 1, and an insulator 4 provided on the outer periphery of the stranded conductor 2. , the twist pitch P1 of the twisted core 1 and the twist pitch P2 of the twisted wire conductor 2 are different. Note that "having" means that other configurations may be included as long as they do not impede the effects of the present invention. This means that plating or an insulating coating layer may be provided on the surface of the metal wire 3, and a fusion layer or the like may be provided on the outer periphery of the insulator 4.

Since the twisting pitches P1 and P2 of the twisted core 1 and the twisted wire conductor 2 are different, this bending-resistant insulated wire 10 is not stiffer than when both have the same twisting pitch, and is a flexible bending-resistant insulated wire 10. can do. Further, the twisted core 1 having the first metal wire 1b has a certain degree of strength, and the twisting pitches P1 and P2 of the twisted wire conductor 2 are different, so that the twisted core 1 has a certain degree of strength. It follows and is difficult to meander. As a result, the center position C1 of the stranded core 1 and the center position C2 of the stranded wire conductor 2 are difficult to deviate from each other, and it is difficult to flatten the wire. If the flatness is large, it becomes difficult to process the terminals, but in this bend-resistant insulated wire 10, the center position C1 of the stranded core 1 and the center position C2 of the stranded wire conductor 2 are difficult to shift, and there is no or small flatness, so it is difficult to process the terminals. The flexible insulated wire 10 can be easily bent. That is, the wire can be flexibly deformed by the stress applied during bending, resulting in a bend-resistant insulated wire with good bending resistance.

Each component of the bend-resistant insulated wire will be explained in detail below.

(Twisted core)
The twisted core 1 is an essential component located at the center of the bend-resistant insulated wire 10, and is preferably a high-tensile body that functions as a winding core. The twisted core 1 is made by twisting a fiber thread 1a and a first metal wire 1b.

The fiber yarn 1a is a fiber yarn consisting of a plurality of fibers. The fibers constituting the fiber thread 1a may have strength and heat resistance. Examples include polyester fibers such as Tetron (registered trademark), wholly aromatic polyamide fibers such as Kevlar (registered trademark), polyarylate fibers such as Vectran (registered trademark), and glass fibers. The fiber threads 1a may be made of the same material, may be made of different materials, or may be an arbitrary composite of fiber threads with different outer diameters.

The fiber yarn 1a is usually expressed in fineness (dtex) expressed in terms of weight, and 1 dtex is 1 g at a length of 10,000 m. The dtex range of the fiber yarn 1a in the present invention is preferably 110 to 2000 dtex. The fiber thread 1a may be made of a single fiber thread or may be made of two or more types of fiber threads. When using fiber yarns made of two or more types of fiber yarns, the total dtex may be within the above range. If it is less than 110 dtex, durability tends to be insufficient. On the other hand, if it exceeds 2000 dtex, the outer diameter becomes large, which tends to affect workability and processability.

The first metal wire 1b has the same material and wire diameter as the second metal wire 3 described later. By making the first metal wire 1b and the second metal wire 3 the same, the wires can be easily prepared and manufacturing costs can be reduced. The number of first metal wires 1b is also not particularly limited, but it is preferably the same number as the second metal wires 3.

The twisted core 1 has a concentric (perfectly circular) or substantially concentric cross section by twisting the fiber threads 1a and the first metal wires 1b so that they are not biased. The twisting pitch P1 is preferably 5 to 15 times the outer diameter D2 of the stranded wire conductor 2, which will be described later. By doing so, the difference between the center positions C1 and C2 of the twisted core 1 and the twisted wire conductor 2 is small, and there is no or small flatness. As a result, the bend-resistant insulated wire 10 can be made flexible and easy to process at the end.

The twisted core 1 is provided at the center of the cross section of the bend-resistant insulated wire 10. "Center" means that the center position C1 of the stranded core 1 is not deviated from the center position of the cross section of the bend-resistant insulated wire 10 (specifically, the center position C2 of the cross section of the stranded wire conductor 2), and the center position of the stranded core 1 is This means that the position C1 and the center position C2 of the stranded conductor 2 coincide. The center position C1 of the twisted core 1 is a position calculated from the contour of the cross section of the twisted core 1, and means the so-called center of gravity position of the contour. The above-mentioned "coincidence" means that the difference between the center position C1 of the stranded core 1 and the center position C2 calculated from the cross-sectional contour of the stranded wire conductor 2, which will be described later, is 0 or less than 0.3 mm. There is. This difference can be realized by twisting the twisted core 1 and the twisted wire conductor 2 so that the twisting pitches P1 and P2 are different. The reason for this is that the stranded core 1 having the first metal wire 1b has a certain degree of strength, and the twisting pitches P1 and P2 of the stranded core 1 and the stranded conductor 2 are different. This is because it follows the twist and becomes difficult to meander. When the difference is within the above range, a flexible, bend-resistant insulated wire that can be easily processed at the end can be obtained. That is, the wire can be flexibly deformed by the stress applied during bending, resulting in a bend-resistant insulated wire with good bending resistance.

The outer diameter of the twisted core 1 is not particularly limited, but may be in the range of 0.1 to 1.0 mm, for example. The twisted core 1 made of the fiber thread 1a and the first metal wire 1b is flexible and easily deformed, but since it is a twisted wire that includes the first metal wire 1b, it is a twisted core made only of the fiber thread 1a. It tends to form concentric circles or approximately concentric circles that are harder and stronger than the above. In addition, the outer diameter of the twisted core 1 is the outer diameter if the twisted core 1 is a perfect circle, and if the twisted core 1 is slightly flat, the outer diameter is the outer diameter converted from the cross-sectional area of the twisted core 1 to the cross-sectional area of a perfect circle. Evaluate as diameter.

(Twisted conductor)
The stranded wire conductor 2 is an essential component provided on the outer periphery of the stranded core 1, and is a stranded wire formed by twisting a large number of second metal wires 3, as shown in FIG. The term "second" is used to distinguish it from the first metal wire 1b constituting the twisted core 1. The type of the second metal wire 3 is not particularly limited as long as it is a good conductive metal, but it can be made of a good conductive metal conductor such as a copper wire, a copper alloy wire, an aluminum wire, an aluminum alloy wire, a copper-aluminum composite wire, etc. Or those whose surfaces are coated with a plating layer can be preferably mentioned. Copper wire and copper alloy wire are particularly preferred. As the plating layer, a solder plating layer, a tin plating layer, a gold plating layer, a silver plating layer, a nickel plating layer, etc. are preferable. An insulating film (not shown) may be provided on the surface of the second metal wire 3 if necessary. The type of insulating film is not particularly limited, but examples include common enamel films, such as urethane, polyester, polyesterimide (PEI), polyimide (PI), polyamideimide (PAI), and the like. The thickness is not particularly limited, but may be of type 1, type 2, or type 3 according to the general Japanese Industrial Standards (JIS C 3202:2014).

The outer diameter of the second metal wire 3 is preferably in the range of 0.02 mm or more and 0.2 mm or less. By doing this, a large number of thin second metal wires 3 are twisted together to form the stranded wire conductor 2, so the diameter of the stranded wire conductor 2 can be reduced, and the entire insulated wire can be made smaller in diameter, lighter, and more flexible. realizable. As a result, it is possible to reduce stress concentration with a large number of second metal wires 3 and improve tensile strength and bending properties. If the outer diameter of the second metal wire 3 is less than 0.02 mm, the metal wire itself becomes thinner in diameter, a large number of wires are required, and the absolute value of the single wire strength becomes small. On the other hand, if the outer diameter of the second metal wire 3 exceeds 0.2 mm, surface irregularities will become large.

The number of second metal wires 3 is not particularly limited, but is preferably the same as the number of first metal wires 1b. The number of wires is preferably about 50 to 150 including the first metal wires. By selecting the number from the above range based on the outer diameter of the second metal wire 3 described above, the diameter and weight of the stranded wire conductor 2 can be reduced. If the total number of first metal wires 1b and second metal wires 3 is less than 50, durability may be insufficient. On the other hand, if the total number of first metal wires 1b and second metal wires 3 exceeds 150, it may not be possible to achieve a reduction in diameter and weight, depending on the wire diameter of the second metal wires 3. be.

The twisting direction of the stranded wire conductor 2 and the twisting direction of the stranded core 1 may be the same direction or different directions, and are not particularly limited. preferable.

The stranded conductor 2 is twisted at a twisting pitch P2 that is different from the twisting pitch P1 of the twisted core 1. Since the twisting pitches P1 and P2 of the twisted core 1 and the twisted wire conductor 2 are different, the bend-resistant insulated wire 10 is not stiffer than when both have the same twisting pitches P1 and P2, and is flexible. The difference (P1/P2 or P2/P1) between the twist pitch P1 of the twisted core 1 and the twist pitch P2 of the twisted wire conductor 2 is 1.5 to 5 times. By setting the difference between P1 and P2 to 1.5 to 5 times, the twist state of one is less likely to affect the twist state of the other, meandering that affects the mutual twist states is less likely to occur, and the center position C1 of the twisted core 1 is and the center position C2 of the stranded wire conductor 2 are difficult to shift, and it is difficult to flatten.

The relationship between the twist pitch P2 of the second metal wire 3 and the outer diameter D2 of the stranded wire conductor 2 is 5 times "twist pitch P2 (mm)" ÷ "outer diameter D2 (mm) of the stranded wire conductor" A range of 25 times is preferred. By setting it within this range, untwisting can be suppressed, variations in bending properties can be reduced, and the cross section can be easily rounded, so that good appearance and durability can be obtained. If this value is less than 5 times, the second metal wire 3 will be wound tightly, so the stranded conductor 2 will tend to overlap more, and the second metal wire 3 may float. As a result, the cross section may not be round, may become stiff and may not satisfy the bending characteristics, or may vary. On the other hand, if this value exceeds 25 times, the twist becomes loose and the threads may pop out, causing the thread to unravel during work. As a result, the cross section may not be round, and the bending properties may vary.

By constructing the stranded conductor 2 in such a twisted state, the difference between the center position C1 of the stranded core 1 and the center position C2 of the stranded conductor 2 becomes less than 0.3 mm. This explanation is as described in the explanation column for twisted core 1.

The outer diameter D2 of the stranded wire conductor 2 is preferably 1.6 mm or less. By doing so, the stranded wire conductor 2 having the outer diameter D2 can realize a reduction in diameter of the insulated wire 10 having excellent bending resistance, and can achieve weight reduction. Note that the lower limit of the outer diameter of the stranded wire conductor 2 is not particularly limited, but can be set to 0.12 mm depending on the outer diameter of the stranded core 1 and the outer diameter and number of the second metal wires 3 described above.

(Insulator)
The insulator 4 is provided to cover the stranded conductor 2. For example, after the stranded wire conductor 2 is provided, it can be formed by resin extrusion or the like so as to cover the outer periphery thereof. The constituent material of the insulator 4 may be any insulating and heat-resistant resin material, such as polyimide resin, acrylic resin, polyvinyl chloride (PVC), polyamide resin, polyester resin, fluorine resin, etc. can be mentioned. The thickness of the insulator 4 may be approximately 0.05 mm or more and 1.0 mm or less, but the thicker the better in order to improve the bending characteristics, and preferably approximately 0.1 mm to 0.3 mm, for example.

The thickness of the insulator 4 is preferably within a range of 10 to 30% of the outer diameter of the stranded conductor 2 described above. That is, it is preferable that "the thickness of the insulator 4 (mm)"/"the outer diameter of the stranded wire conductor (mm)" is 10 to 30%. If this value is less than 10%, the thickness of the insulator may be insufficient, resulting in insufficient insulation performance and durability. On the other hand, if this value exceeds 30%, the insulator becomes too thick and may lack flexibility and flexibility.

Preferably, the thickness of the insulator 4 is uniform. However, since the insulator 4 is mainly formed by resin extrusion, the surface after the stranded conductor 2 is provided, which is a stage before resin extrusion, has small surface irregularities based on the second metal wire 3. It is preferable. In the present invention, since the stranded conductor 2 formed by twisting a large number of second metal wires 3 is provided so as to cover the stranded core 1, the unevenness on the surface of the stranded conductor 2 is reduced. Therefore, after the insulator 4 is formed on the outer periphery by resin extrusion, the surface unevenness of the outer diameter becomes small, and the thickness of the insulator 4 becomes uniform at each part. As a result, local stress concentration can be reduced and the bending life can be extended.

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that the present invention is not limited thereby.

[Example 1]
As the twisted core 1, a fiber thread (660 dtex, outer diameter approximately 0.245 mm) made of aramid (polyamide) fiber and a first metal wire 1b made of 50 annealed copper wires each having an outer diameter of 0.08 mm are used. Collective twisting was performed at a twisting pitch of P1. Around the outer periphery of the twisted core 1, a second metal wire 3 made of 50 annealed copper wires with the same outer diameter of 0.08 mm as the first metal wire 1b is attached with a 5 mm diameter in the opposite direction to the twisting direction of the twisted core 1. A twisted wire conductor 2 having an outer diameter of 0.97 mm was obtained by twisting at a twisting pitch P2. Next, an FEP resin (insulator 4) was formed with a thickness of 0.2 mm by melt extrusion, and an insulated wire 10 with an outer diameter of 1.4 mm was produced. Note that Tables 1 and 2 summarize the configuration of this bend-resistant insulated wire 10.

[Example 2]
The twist pitch P1 of the twisted core 1 was set to 5 mm, and the twist pitch P2 of the twisted wire conductor 2 was set to 5 mm. The rest was the same as in Example 1.

[Example 3]
As the first metal wire 1b and the second metal wire 3, 75 annealed copper wires each having an outer diameter of 0.05 mm were used. Furthermore, the twist pitch P1 of the twisted core 1 was set to 8 mm, and the twist pitch P2 of the twisted wire conductor 2 was set to 4 mm. The rest was the same as in Example 1.

[Example 4]
As the first metal wire 1b and the second metal wire 3, 75 annealed copper wires each having an outer diameter of 0.05 mm were used. Furthermore, the twist pitch P1 of the twisted core 1 was set to 3 mm, and the twist pitch P2 of the twisted wire conductor 2 was set to 11 mm. The rest was the same as in Example 1.

[Comparative example 1]
As the twisted core 1, a fiber yarn (660 dtex, outer diameter of about 0.245 mm) made of aramid (polyamide) fiber was used. On this twisted core 1, 100 annealed copper wires each having an outer diameter of 0.08 mm were twisted together at a twisting pitch of 15 mm to form a stranded conductor 2 having an outer diameter of 0.97 mm. Next, an FEP resin (insulator 4) was formed with a thickness of 0.2 mm by melt extrusion, and an insulated wire 10 with an outer diameter of 1.4 mm was produced.

[Comparative example 2]
150 annealed copper wires each having an outer diameter of 0.05 mm were used as the stranded conductor, and the twisting pitch was 11 mm. The rest was the same as Comparative Example 1.

[Comparative example 3]
Fifty annealed copper wires with an outer diameter of 0.08 mm were used as the stranded conductors, and the twist pitch was 11 mm. The rest was the same as Comparative Example 1.

[Bending test]
A bending test was conducted for each Example and Comparative Example by the method shown in FIG. In the bending test, as shown in FIG. 4, the insulated wire 10 with a length of 1000 mm produced in each example and comparative example is sandwiched between mandrels 42 and 42 with a radius of 5 mm, and a load 41 is applied to the lower end of the insulated wire 10. was attached, and the number of bends was measured in the direction perpendicular to the mandrel 42 at a rate of 30 times per minute, with one bend being 90 degrees on each side. The number of times of bending was evaluated as the number of times until the resistance value of the insulated wire 10 increased by 10%. The insulated wires of Examples 1 to 4 and Comparative Examples 1 to 3 were all bent more than 20,000 times, and the measurement was terminated when the bending number was exceeded. In addition, in Table 2, all are represented by "○".

[Terminal processability]
Regarding the end processability, in Examples 1 to 5, the twisted cores 1 are all located at the center position (L=0), so they are less likely to come apart and the wires are less likely to be damaged during strip processing. As a result, the reliability of the terminal section can be improved. The end portion after strip processing was observed with an optical microscope, and cases where no defects such as scratches had occurred were indicated by "○", and cases where defects such as scratches had occurred were indicated by "△".

[Misalignment of center position]
The obtained bend-resistant insulated wire 10 was cured in a resin, a cross section was cut out, polished and observed under a microscope, and the distance L between the center position C1 of the stranded core 1 and the center position C2 of the stranded wire conductor 2 was measured. .

1 Twisted core 1a Fiber thread 1b First metal strand 2 Twisted conductor 3 Second metal strand 4 Insulator 10 Flexible insulated wire D1 Outer diameter of stranded core D2 Outer diameter of stranded conductor D3 Outer of flexed insulated wire Diameter d1 Outer diameter of the first metal wire d2 Outer diameter of the second metal wire C1 Center position of the stranded conductor C2 Center position of the stranded conductor L Distance between C1 and C2 P1 Twisting pitch of the stranded core P2 of the stranded conductor Twisting pitch T Insulator thickness

Claims (5)

A twisted core with an outer diameter of 0.1 to 1.0 mm made by twisting fiber threads and a first metal wire, and a plurality of second metal wires provided around the outer periphery of the twisted core are twisted. It has a stranded conductor with an outer diameter of 1.6 mm or less and an insulator provided on the outer periphery of the stranded conductor, and the twisting direction of the stranded conductor and the twisting direction of the stranded core are different directions, A bend-resistant insulated wire characterized in that the twist pitch P1 of the twisted core is different from the twist pitch P2 of the twisted wire conductor, and P1/P2 or P2/P1 is 1.5 to 5 times . The bend-resistant insulated wire according to claim 1 , wherein the difference between the center position of the twisted core and the center position of the twisted wire conductor is less than 0.3 mm. A twisting pitch P1 of the twisted core is 5 to 15 times the outer diameter of the twisted core, and a twisting pitch P2 of the stranded wire conductor is 5 to 15 times the outer diameter of the stranded wire conductor . 2. The bend-resistant insulated wire according to 2 . The bend-resistant insulated wire according to any one of claims 1 to 3 , wherein the first metal wire and the second metal wire have the same outer diameter. The bend-resistant insulated wire according to any one of claims 1 to 4 , wherein the number of the first metal strands and the second metal strands are the same .

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