Cable

Abstract

To provide a cable which prevents deterioration of transmission characteristics even when being wired to a movable part, and has high resistance against operation such as bending.SOLUTION: A cable 1 includes an aggregate core 4 constituted by twisting a plurality of pairs of coaxial wires 2 while being multilayered, a press-winding tape 5 wound around the aggregate core 4, and a sheath 6 covering the periphery of the press-winding tape 5, wherein the coaxial wire 2 has a conductor 21, an insulator 22 which covers the periphery of the conductor 21, and is composed of a resin composition containing a polypropylene resin or a foam polypropylene resin as a main component, a shield layer 23 covering the periphery of the insulator 22, and a jacket 24 which covers the periphery of the shield layer 23, and is composed of a non-fluorine resin having hardness equivalent to or greater than that of the insulator 22, and the aggregate core 4 has a fiber interposition 3 which is filled between the center of the cable, and respective layers 4a and 4b, and between the adjacent coaxial wires 2 of the outer layer 4b as the outermost layer and the press-winding tape 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to cables. [Background technology]

[0002] BACKGROUND ART Known conventional cables include, for example, multi-core cables in which coaxial wires are stacked in two or more layers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-207658 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for cables using multiple coaxial wires for transmitting image signals and the like to be routed through movable parts that are subjected to bending, twisting, swinging, and other movements (hereinafter referred to as bending and other movements). However, when conventional cables such as those disclosed in Patent Document 1 are used for such purposes, there is a problem that the transmission characteristics are likely to deteriorate at the movable parts. Furthermore, when the cable is subjected to repeated bending and other movements, the coaxial wires may rub against each other, causing the cable to break.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cable that is resistant to deterioration in transmission characteristics even when wired to a movable part and has high resistance to movements such as bending. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a cable comprising: an aggregate core formed by twisting together multiple pairs of coaxial wires in multiple layers; a pressure winding tape wound around the aggregate core; and a sheath covering the pressure winding tape, wherein the coaxial wires have conductors, an insulator covering the conductors and made of a resin composition mainly composed of polypropylene resin or foamed polypropylene resin, a shielding layer covering the insulator, and a jacket covering the shielding layer and made of a non-fluorine resin having a hardness equal to or greater than that of the insulator, and the aggregate core has fiber filler filled at the center of the cable, between each layer, and between adjacent coaxial wires and the pressure winding tape in the outermost layer. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a cable that is resistant to deterioration in transmission characteristics even when wired to a movable part and has high resistance to movements such as bending. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable according to an embodiment of the present invention. [Figure 2] 10(a) and 10(b) are cross-sectional views showing a modified example of a coaxial line. [Figure 3] FIG. 10 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment Mode] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] 1 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of cable 1 according to this embodiment. Cable 1 is used, for example, as internal wiring in equipment such as industrial robots, and is routed through a movable part that repeatedly undergoes movements such as bending, twisting, and swinging (hereinafter referred to as movements such as bending). Cable 1 is also used primarily for signal transmission, such as transmitting image signals from a camera.

[0011] The cable 1 includes an assembled core 4 formed by twisting together multiple pairs of coaxial wires 2 in multiple layers, a pressure winding tape 5 wound around the assembled core 4, and a sheath 6 that covers the pressure winding tape 5. Each part will be described in detail below.

[0012] (Coaxial line 2) The coaxial cable 2 includes a conductor 21, an insulator 22 that covers the conductor 21, a shield layer 23 that covers the insulator 22, and a jacket 24 that covers the shield layer 23. The conductor 21 is a stranded conductor formed by twisting together a plurality of metal wires. The metal wires that make up the conductor 21 are made of copper or a copper alloy, and may be plated with tin, silver, or the like. In this example, tin-plated annealed copper wires are used as the metal wires that make up the conductor 21. The conductor 21 may be compressed so that its outer shape is circular.

[0013] In order to improve the transmission characteristics of high-speed signals, it is desirable to use a material with a low dielectric constant (preferably, a dielectric constant of 3 or less) for the insulator 22. Furthermore, in recent years, the use of fluororesins has been discouraged to reduce environmental impact. From the perspective of reducing environmental impact, it is more preferable to use a non-fluororesin, such as a polyolefin resin, for the insulator 22. Furthermore, it is more desirable for the specific gravity of the insulator 22 to be 1.0 or less. This reduces the weight of the coaxial line 2 and the weight of the cable 1, thereby further reducing friction with surrounding components of the cable 1. Furthermore, it is desirable for the insulator 22 to be made of a material that is relatively hard and resistant to deformation so as not to be crushed when subjected to bending or other movements. Therefore, in this embodiment, the insulator 22 is made of a resin composition mainly composed of polypropylene resin (hereinafter, PP) or foamed PP. PP may be irradiated and cross-linked. The insulator 22 may have a multilayer structure, or may have a structure in which non-foamed PP and foamed PP are laminated. The outer diameter of the insulator 22 is 1.0 mm or less.

[0014] The shield layer 23 is a horizontally wound shield in which a plurality of metal wires are spirally wound around the insulator 22. The metal wires that make up the shield layer 23 are made of copper or a copper alloy, and their surfaces may be plated with tin, silver, or the like.

[0015] The jacket 24 is the outermost layer of the coaxial cable 2. Like the insulator 22, the jacket 24 is preferably made of a non-fluorine resin from the viewpoint of reducing environmental impact. The jacket 24 is also preferably made of a material that is relatively hard and resistant to deformation so as not to be crushed when subjected to bending or other movements, and is made of a non-fluorine resin having a hardness equal to or greater than that of the insulator 22. Specifically, the jacket 24 is preferably made of nylon resin or PP. The outer diameter of the jacket 24, i.e., the outer diameter of the coaxial cable 2, is 2.0 mm or less.

[0016] Alternatively, the jacket 24 may be formed by wrapping a tape member such as nylon tape (a tape member made of a resin composition primarily composed of nylon resin) around the shielding layer 23. In this case, the jacket 24 may be formed by spirally wrapping the tape member so that portions of the tape member overlap in the width direction. For example, if the jacket 24 is formed of a material with low slipperiness such as polyvinyl chloride resin (PVC), measures such as applying talc (lubricant) to suppress wear are necessary. However, applying talc generates dust when the cable is repeatedly bent. By forming the jacket 24 from a tape member such as nylon tape, it is possible to suppress the generation of such dust. Furthermore, by forming the jacket 24 from a tape member, it is possible to suppress the generation of gaps between the metal wires in the shielding layer 23, which is made of a spirally wound shield, and thus to suppress degradation of transmission characteristics due to disorder of the metal wires.

[0017] In this embodiment, the coaxial lines 2 are used for transmitting differential signals. Therefore, the cable 1 is provided with multiple pairs of coaxial lines 2, i.e., an even number of two or more coaxial lines 2. Here, a case where 12 coaxial lines 2 are used will be described, but the number of coaxial lines 2 is not limited to this.

[0018] Although not shown, the coaxial cable 2 may also have a conductive tape between the insulator 22 and the shielding layer 23, which is a cross-wound shield. The conductive tape may be spirally wound so that a portion of the tape overlaps the other in the width direction. The conductive tape includes a substrate and a conductive layer made of a conductive resin disposed on the substrate. The substrate is formed in a long strip shape using a resin such as a polyolefin-based resin as the base resin. The conductive layer is made of a conductive resin having a polyolefin-based resin as the base resin and conductive particles dispersed in the base resin. The base resins constituting the substrate and the conductive layer may contain additives such as a crosslinking agent, a crosslinking catalyst, an antioxidant, a plasticizer, a lubricant, a filler, a flame retardant, a stabilizer, and a colorant. The substrate may also be conductive. The conductive tape protects the insulator 22 and enhances the shielding effect. In particular, when the insulator 22 is made of a foamed resin, using a conductive tape for protection is preferable.

[0019] As shown in FIGS. 2(a) and 2(b), the coaxial cable 2 may have a metal-evaporated tape 25 between the insulator 22 and the shield layer 23 (see FIG. 2(a)) consisting of a horizontally wound shield, or between the shield layer 23 and the jacket 24 (see FIG. 2(b)). The metal-evaporated tape 25 is preferably wound spirally so that a portion of the tape overlaps the other tape in the width direction. The metal-evaporated tape 25 has a substrate made of a polyester resin such as polyethylene terephthalate and a metal layer formed by vapor deposition on the surface of the substrate. The metal-evaporated tape 25 is preferably wound spirally in the same direction as the horizontally wound shield, with the metal layer in contact with the horizontally wound shield that constitutes the shield layer 23. This prevents the occurrence of suckout in the frequency band used when transmitting signals over distances of 5 m or more. The metal layer of the metal-evaporated tape 25 is made of, for example, copper. The thickness of the metal layer is preferably 0.3 μm or more and 3.0 μm or less. This prevents the metal layer of the metal vapor deposition tape 25 from being lost when the cable 1 is bent into a U-shape or the like and subjected to repeated sliding motions, and also prevents the cable 1 from becoming hard, maintaining the ease of bending (flexibility) of the cable 1. The thickness of the base material of the metal vapor deposition tape 25 is preferably, for example, 4.0 μm or more and 10 μm or less. This prevents the metal vapor deposition tape 25 from being torn and the cable 1 from becoming hard, when the cable 1 is bent into a U-shape or the like and subjected to repeated sliding motions.

[0020] (Power line 7, signal line 8) In addition to multiple coaxial wires 2, cable 1 may also include one or more pairs of insulated wires or sub-stranded wires formed by twisting multiple insulated wires together. In this embodiment, in addition to twelve coaxial wires 2, cable 1 includes two power wires 7 used for power supply and four signal wires 8 used for transmitting low-speed signals such as control signals. Power wires 7 and signal wires 8 are insulated wires each having conductors 71 and 81 made of a stranded conductor formed by twisting together metal wires such as tin-plated annealed copper wires, and insulators 72 and 82 covering the conductors 71 and 81. The insulators 72 and 82 are made of a non-fluorine resin such as PP or foamed PP. The outer diameter of power wire 7 is larger than that of signal wire 8. That is, cable 1 may include insulated wires with different outer diameters. The outer diameters of power wires 7 and signal wires 8 are adjusted so that the outer diameters of sub-stranded wires 7a and 8a (described later) are equal to the outer diameter of coaxial wire 2. The outer diameters of the power line 7 and the signal line 8 are, for example, 0.5 mm or more and 1.0 mm or less. The outer diameter of the power line 7 is preferably 1.0 times or more and 1.5 times or less the outer diameter of the signal line 8. This makes it easy to make the outer diameter of the child stranded wires 7a, 8a equal to the outer diameter of the coaxial wire 2. If the outer diameter of the child stranded wires 7a, 8a is equal to the outer diameter of the coaxial wire 2, the positions of the multiple coaxial wires 2 are less likely to shift circumferentially or radially when the cable 1 is repeatedly bent or otherwise subjected to other operations, and therefore the transmission characteristics are less likely to deteriorate.

[0021] In this embodiment, two power wires 7 are twisted together to form a first child strand 7a. Four signal wires 8 are twisted together to form a second child strand 8a. The outer diameter of the child strands 7a, 8a is equal to the outer diameter of the coaxial wire 2 (for example, 0.9 to 1.1 times the outer diameter of the coaxial wire 2). The number of power wires 7 and signal wires 8 constituting each child strand 7a, 8a may be two or more.

[0022] (4 aggregate cores, 3 fiber intercalated) The assembly core 4 is constructed by twisting together 12 coaxial wires 2 and two child strands 7a, 8a. Here, the assembly core 4 has a two-layer structure, with an inner layer 4a made up of four coaxial wires 2 twisted together and an outer layer 4b made up of eight coaxial wires 2 and two child strands 7a, 8a twisted together.

[0023] The collective core 4 has fiber fillers 3 filled at the cable center, between each layer 4a, 4b, and between adjacent coaxial wires 2 and the pressure winding tape 5 in the outermost layer (here, outer layer 4b). The fiber fillers 3 are filled so as to fill all gaps formed between the coaxial wires 2 and the child strands 7a, 8a in the space surrounded by the pressure winding tape 5. The fiber fillers 3 serve to separate adjacent coaxial wires 2 and child strands 7a, 8a to prevent friction, and also to prevent misalignment of the coaxial wires 2 and child strands 7a, 8a, so that the uniformity of their arrangement does not collapse when the cable 1 is subjected to bending or other operations.

[0024] By placing the fiber filler 3 between adjacent coaxial wires 2 or child wires 7a, 8a, surface contact (contact in a crushed state) between the adjacent coaxial wires 2 or child wires 7a, 8a is prevented, and point contact or non-contact is achieved, making it possible to reduce friction when the cable 1 is bent or otherwise subjected to motion. As a result, loss of alignment due to bending or other such factors is prevented, and deterioration of transmission characteristics can be suppressed, while resistance to motion such as bending can also be improved. Fibers made of nylon, polypropylene, staple fiber, etc. can be used as the fiber filler 3, but it is preferable to use one with higher cushioning properties, and staple fiber is the most preferred.

[0025] The amount of fiber interposition 3 disposed between the inner layer 4a and the outer layer 4b, and the amount of fiber interposition 3 disposed between adjacent coaxial wires 2 or child strands 7a, 8a in the outer layer 4b and the pressure winding tape 5 are greater than the amount of fiber interposition 3 disposed at the cable center. Furthermore, the amount of fiber interposition 3 disposed between adjacent coaxial wires 2 or child strands 7a, 8a in the outer layer 4b and the pressure winding tape 5 is greater than the amount of fiber interposition 3 disposed between the inner layer 4a and the outer layer 4b. For example, the total number of fiber interposition 3 disposed between the inner layer 4a and the outer layer 4b is between three and five times the number of fiber interposition 3 disposed at the cable center. Furthermore, the total number of fiber interposition 3 disposed between adjacent coaxial wires 2 or child strands 7a, 8a in the outer layer 4b and the pressure winding tape 5 is between six and nine times the number of fiber interposition 3 disposed at the cable center. This reduces damage to the multiple coaxial wires 2 when the cable 1 is repeatedly bent or otherwise subjected to other operations, and also makes it less likely that the positions of the multiple coaxial wires 2 (especially the positions of adjacent coaxial wires 2 in the cable circumferential direction) will shift circumferentially or radially, thereby suppressing deterioration of transmission characteristics. Note that the number of intervening fibers 3 refers to the number of threads made of fiber. The amount of intervening fibers 3 arranged between the inner layer 4a and the outer layer 4b is represented by the total number of intervening fibers 3 arranged in each of the valleys between the multiple coaxial wires 2 (four in FIG. 1 ) that make up the inner layer 4a. The amount of fiber intervening pieces 3 arranged between adjacent coaxial wires 2 or child strands 7a, 8a in the outer layer 4b and the pressure winding tape 5 is indicated by the total number of fiber intervening pieces 3 arranged in each of the multiple spaces surrounded by adjacent coaxial wires 2 or child strands 7a, 8a in the outer layer 4b and the pressure winding tape 5.

[0026] More specifically, in this embodiment, seven intervening fibers 3 are arranged in the center of the cable, seven intervening fibers are arranged in each of four valley portions between the four coaxial wires 2 constituting the inner layer 4a between the inner layer 4a and the outer layer 4b, and five intervening fibers 3 are arranged in each of ten locations in the outer layer 4b between adjacent coaxial wires 2 or child strands 7a, 8a and the pressure winding tape 5. That is, in this embodiment, seven intervening fibers 3 are arranged in the center of the cable, 28 intervening fibers 3 between the inner layer 4a and the outer layer 4b (four times the number of intervening fibers 3 arranged in the center of the cable), and 50 intervening fibers 3 between the outer layer 4b and the pressure winding tape 5 (approximately seven times the number of intervening fibers 3 arranged in the center of the cable). In this way, the number of fiber intervening pieces 3 (here, five) arranged per location between adjacent coaxial wires 2 or child twisted wires 7a, 8a in the outer layer 4b and the pressure winding tape 5 is less than the number of fiber intervening pieces 3 (here, seven) arranged at the center of the cable.

[0027] The set core 4 is configured by regularly arranging the coaxial wires 2 and the child strands 7a, 8a symmetrically. More specifically, the set core 4 is configured by regularly arranging the coaxial wires 2 and the child strands 7a, 8a rotationally symmetrically about the cable center by 180 degrees. Here, in the outer layer 4b, four coaxial wires 2 are arranged between each of the two child strands 7a, 8a, and the two child strands 7a, 8a are arranged opposite each other across the cable center. If the number of coaxial wires 2 in the inner layer 4a is n, the number of coaxial wires 2 in the outer layer 4b should be 2n or more. Furthermore, if the set core 4 is divided into two regions in a cross section of the cable 1 by a line A passing through the cable center, each of the two regions should contain n or more coaxial wires 2 in the outer layer 4b. Such a regular arrangement prevents the lengths of paired coaxial wires 2 from differing, suppressing skew and improving transmission characteristics.

[0028] The twist pitch of each layer in the assembled core 4 is preferably greater than 30 mm. This makes it difficult for the coaxial wires 2 to fall toward the center of the cable. Note that the twist pitch here refers to the distance along the cable longitudinal direction between points where any coaxial wires 2 or child strands 7a, 8a are positioned at the same circumferential position in the cable. Furthermore, the twist pitch of the outer layer 4b is preferably between two and four times the twist pitch of the inner layer 4a. This reduces damage to the coaxial wires 2 during twisting, thereby suppressing deterioration of transmission characteristics.

[0029] Furthermore, it is preferable that the twist direction of the assembly core 4 and the twist direction of the child strands 7a, 8a are different directions. This prevents the twist of the child strands 7a, 8a from becoming tighter when the assembly core 4 is twisted, which could cause breaks in the power line 7 or the signal line 8. The twist direction of the child strands 7a, 8a is the direction in which the power line 7 or the signal line 8 rotates from one end to the other when viewed from one end of the child strand 7a. The twist direction of the assembly core 4 is the direction in which the coaxial line 2 or the child strands 7a, 8a rotate from one end to the other when viewed from one end of the assembly core 4. The inner layer 4a and outer layer 4b of the assembly core 4 are twisted in the same direction.

[0030] (Pressing tape 5) The pressure winding tape 5 is spirally wound around the collective core 4 so that portions of the tape overlap in the width direction. To prevent friction with the coaxial wires 2 and the child strands 7a, 8a that constitute the outer layer 4b, it is desirable to use a material with high cushioning properties for the pressure winding tape 5, and it is more desirable to use a foamed resin tape or a nonwoven fabric tape. Examples of foamed resin tapes include foamed PP tape. If damage to the coaxial wires 2 due to friction with the pressure winding tape 5 is not a problem, it is desirable to use a material with as high strength as possible for the pressure winding tape 5 to prevent damage to the pressure winding tape 5. In this case, it is desirable to use nylon tape (a tape member made of a resin composition whose main component is nylon resin) as the pressure winding tape 5.

[0031] The winding direction of the pressure wrapping tape 5 is preferably the same as the twisting direction of the collective core 4. This makes it easier to bend the cable 1. The winding direction of the pressure wrapping tape 5 is the direction in which the pressure wrapping tape 5 rotates from one end to the other end of the cable 1, as viewed from one end of the cable 1.

[0032] (Sheath 6) The sheath 6 is provided so as to cover the periphery of the pressure wrapping tape 5. From the viewpoint of reducing the environmental impact, the sheath 6 is desirably made of a non-fluorine resin such as a polyolefin resin, for example, a resin composition containing PVC as a main component. The resin composition constituting the sheath 6 may contain additives such as a crosslinking agent, a crosslinking catalyst, an antioxidant, a plasticizer, a lubricant, a filler, a flame retardant, a stabilizer, and a colorant.

[0033] (Variation) The cable 1a shown in FIG. 3, like the cable 1 in FIG. 1, uses 12 coaxial wires 2, two power wires 7, and four signal wires 8 to form an assembled core 4, but the arrangement of the wires is different. In the cable 1a, four coaxial wires 2 are twisted together to form an inner layer 4a, and two twisted pairs 8b, each consisting of two power wires 7 and two signal wires 8, are twisted around the inner layer 4a to form an outer layer 4b. In the inner layer 4a, four coaxial wires 2 are configured to face each other across the center of the cable, and are arranged with 180-degree rotational symmetry about the center of the cable. In the outer layer 4b, eight coaxial wires 2 are configured to face each other across the center of the cable, two power wires 7 are configured to face each other, and two twisted pairs 8b are configured to face each other across the center of the cable, and are arranged with 180-degree rotational symmetry about the center of the cable. Two coaxial wires 2 are arranged between each of the power wires 7 and the twisted pairs 8b. In this case, a plurality of fiber fillers 3 (for example, five) are arranged in each of a plurality of spaces (12 spaces in FIG. 3) that exist between adjacent coaxial wires 2, twisted pair wires 8b, or power wires 7 in the outer layer 4b and the pressure winding tape 5. As shown in FIG. 3, the specific arrangement of the coaxial wires 2, power wires 7, and signal wires 8 can be changed as appropriate. However, in order to maintain regularity and improve transmission characteristics, it is advisable to arrange each wire so that it is 180-degree rotationally symmetrical about the center of the cable.

[0034] Furthermore, the cable 1a includes an ensemble shield layer 9 between the pressure wrapping tape 5 and the sheath 6. The ensemble shield layer 9 is made of a horizontally wound shield in which a plurality of metal wires are wound in a spiral shape. However, the ensemble shield layer 9 is not limited to this, and may be a braided shield in which metal wires are braided, or may be configured by winding a metal tape. In this way, the ensemble shield layer 9 may be provided so as to cover the periphery of the collective core 4. This can enhance the noise suppression effect.

[0035] (Actions and Effects of the Embodiments) As described above, the cable 1 according to this embodiment comprises an aggregate core 4 formed by twisting together multiple pairs of coaxial wires 2 in multiple layers, a pressure winding tape 5 wound around the aggregate core 4, and a sheath 6 covering the pressure winding tape 5. The coaxial wires 2 have conductors 21, an insulator 22 covering the conductors 21 and made of a resin composition mainly composed of polypropylene resin or foamed polypropylene resin, a shielding layer 23 covering the insulator 22, and a jacket 24 covering the shielding layer 23 and made of a non-fluorine resin having a hardness equal to or greater than that of the insulator 22. The aggregate core 4 has fiber fillers 3 filled at the center of the cable, between each layer (here, between the inner layer 4a and the outer layer 4b), and between adjacent coaxial wires 2 and the pressure winding tape 5 in the outermost layer (here, the outer layer 4b).

[0036] By constructing the insulator 22 of the coaxial wire 2 from a resin composition primarily composed of PP or foamed PP and the jacket 24 from a harder non-fluororesin, the use of fluororesin is reduced, reducing the environmental impact, while the insulator 22 and jacket 24 are less likely to collapse when subjected to bending or other movements, thereby suppressing deterioration of transmission characteristics in moving parts. Furthermore, by filling the gaps between the coaxial wires 2 in the assembled core 4 with fiber fillers 3, it is possible to prevent adjacent coaxial wires 2 from coming into close contact with each other, suppressing friction, and suppress misalignment of the coaxial wires 2, thereby maintaining uniformity in their arrangement. As a result, it is possible to improve resistance to movements such as bending and suppress deterioration of transmission characteristics due to misalignment of the coaxial wires 2. According to the cable 1 of this embodiment, when the cable 1 is bent into a U-shape and fixed at one end, and the other end is slid along the longitudinal direction, repeatedly performing a U-shaped sliding motion, the cable does not break even after tens of millions of U-shaped sliding motions.

[0037] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[0038] [1] A cable (1) comprising: an aggregate core (4) formed by twisting together multiple pairs of coaxial wires (2), a pressure winding tape (5) wound around the aggregate core (4), and a sheath (6) covering the pressure winding tape (5); the coaxial wires (2) have conductors (21), an insulator (22) covering the conductors (21) and made of a resin composition mainly composed of polypropylene resin or foamed polypropylene resin, a shielding layer (23) covering the insulator (22), and a jacket (24) covering the shielding layer (23) and made of a non-fluorine resin having hardness equal to or greater than that of the insulator (22); the aggregate core (4) has fiber fillers (3) filled at the cable center, between each layer (inner layer 4a, outer layer 4b), and between adjacent coaxial wires 2 and the pressure winding tape (5) in the outermost layer (outer layer 4b).

[0039] [2] The cable (1) described in [1], wherein the collective core (4) is configured by regularly arranging a plurality of the coaxial wires (2) so as to be rotationally symmetrical by 180 degrees about the center of the cable.

[0040] [3] The cable (1) according to [1], wherein the fiber filler (3) is made of staple fiber.

[0041] [4] The cable (1) according to [1], wherein the pressure wrapping tape (5) is a foamed resin tape made of a foamed resin or a nonwoven fabric tape.

[0042] [5] The cable (1) described in [1], wherein the assembly core (4) has one or more pairs of insulated wires (power wires 7, signal wires 8) or sub-stranded wires (7a, 8a) formed by twisting together a plurality of the insulated wires (power wires 7, signal wires 8), and the insulated wires (power wires 7, signal wires 8) or the sub-stranded wires (7a, 8a) are arranged in 180-degree rotational symmetry about the center of the cable.

[0043] [6] The cable (1) according to [1], wherein the jacket (24) is configured by wrapping a tape member around the shielding layer (23).

[0044] [7] The cable (1) according to [1], wherein each pair of the coaxial lines (2) is used for transmitting differential signals.

[0045] [8] The cable (1) described in [1], wherein the total number of the fiber intervening pieces (3) arranged between each layer (inner layer 4a, outer layer 4b) and the total number of the fiber intervening pieces (3) arranged between adjacent coaxial wires (2) and the pressure winding tape (5) in the outermost layer (outer layer 4b) are greater than the number of the fiber intervening pieces (3) arranged at the center of the cable.

[0046] [9] The cable (1) described in [1], wherein the total number of the fiber intervening pieces (3) arranged between the adjacent coaxial wires (2) and the pressure winding tape (5) in the outermost layer (outer layer 4b) is greater than the total number of the fiber intervening pieces (3) arranged between each of the layers (inner layer 4a, outer layer 4b).

[0047]

[10] The cable (1) described in [1], wherein the number of the fiber intervening pieces (3) arranged per location between the adjacent coaxial wires (2) and the pressure winding tape (5) in the outermost layer (outer layer 4b) is less than the number of the fiber intervening pieces (3) arranged at the center of the cable.

[0048] (Addendum) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be appropriately modified and implemented within the scope of its spirit. [Explanation of symbols]

[0049] 1...Cable 2…Coaxial line 3...Fiber interposition 4...Collective Core 4a...inner layer 4b…outer layer 5...Press and wrap tape 6...Sheath 7…Power line 7a…First child stranded wire 8...Signal line 8a…Second child stranded wire 9...Bulk shield layer 21...conductor 22...Insulator 23...Shield layer 24...Jacket 25...Metal vapor deposition tape

Claims

1. an aggregate core formed by twisting together multiple pairs of coaxial wires in multiple layers; a pressure winding tape wound around the collective core; a sheath that covers the surrounding of the pressure wrapping tape, The coaxial cable includes a conductor, an insulator covering the conductor and made of a resin composition containing polypropylene resin or foamed polypropylene resin as a main component, a shielding layer covering the insulator, and a jacket covering the shielding layer and made of a non-fluorine resin having a hardness equal to or greater than that of the insulator, The aggregate core has fiber fillers filled in the cable center, between each layer, and between adjacent coaxial wires and the pressure winding tape in the outermost layer. cable.

2. The collective core is configured by regularly arranging the plurality of coaxial wires so as to be rotationally symmetrical by 180 degrees about the center of the cable. The cable of claim 1 .

3. The fiber filler is made of staple fiber. The cable of claim 1 .

4. The pressure wrapping tape is a foamed resin tape made of a foamed resin or a nonwoven fabric tape. The cable of claim 1 .

5. The core assembly has one or more pairs of insulated wires or child strands formed by twisting together a plurality of the insulated wires, and is configured such that the insulated wires or the child strands are arranged in 180-degree rotational symmetry with respect to the center of the cable. The cable of claim 1 .

6. The jacket is configured by wrapping a tape member around the shielding layer. The cable of claim 1 .

7. Each pair of coaxial lines is used to transmit a differential signal. The cable of claim 1 .

8. the total number of the intervening fibers arranged between the layers and the total number of the intervening fibers arranged between the adjacent coaxial wires and the pressure winding tape in the outermost layer is greater than the number of the intervening fibers arranged in the center of the cable; The cable of claim 1 .

9. the total number of the intervening fibers disposed between the adjacent coaxial cables and the presser winding tape in the outermost layer is greater than the total number of the intervening fibers disposed between the respective layers; The cable of claim 1 .

10. the number of the intervening fibers arranged at one location between the adjacent coaxial wires and the pressure winding tape in the outermost layer is less than the number of the intervening fibers arranged at the center of the cable; The cable of claim 1 .

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