JP7337135B2 - cable - Google Patents

Description

The present invention relates to cables.

As a cable for moving parts used in moving parts such as robots, a shield layer is provided around an assembly of multiple twisted pair wires, and a power line for driving a motor is provided around it. (See Patent Document 1, for example).

JP 2016-129924 A

However, in the above-mentioned conventional cables for movable parts, all of the twisted pair wires consisting of a large number of wires are collectively arranged in the central part of the cable, so the outer diameter of the cable is difficult to decrease, and further reduction in diameter is required. need to be improved. In response to such a problem, for example, when the number of power lines arranged around the twisted pair wires arranged in the central portion of the above-described conventional cable for the movable part is increased while the number of power lines arranged around it is reduced. However, since the power lines are arranged at wider intervals in the circumferential direction, a large amount of space is wasted, and the outer diameter of the cable cannot be reduced. 2. Description of the Related Art In recent years, robots and the like have been required to reduce wiring space for electric wires and cables due to their miniaturization. Further, in the conventional cables for movable parts, improvements are required to reduce the influence of external noise at the end of the cable and the influence of low-frequency noise on power lines.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a cable that can be reduced in diameter while suppressing the influence of noise.

In order to solve the above problems, the present invention has a first substrate connected to terminal portions of inner-layer twisted pair wires constituting a twisted pair assembly provided at the center of a cable, wherein the twisted pair A cable is provided in which a second substrate different from the first substrate is connected to an end portion of an outer layer twisted pair wire provided on the outer periphery of a wire assembly via a braided shield layer.

ADVANTAGE OF THE INVENTION According to this invention, the cable which can be thinned can be provided, suppressing the influence of a noise.

1 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable for a movable part according to one embodiment of the present invention; FIG. FIG. 3 is a side view showing a terminal portion of the cable for the movable portion of FIG. 1;

[Embodiment]
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of the cable for movable part according to the present embodiment. FIG. 2 is a side view showing the terminal portion of the cable for the movable portion.

As shown in FIGS. 1 and 2, the cable 1 for movable part has a plurality of twisted pair wires 2 for signal transmission and a plurality of power wires 3 for signal transmission. The movable part cable 1 is used, for example, as wiring for a movable part of an industrial robot such as a robot arm.

The twisted pair wire 2 is composed of ETFE (tetrafluoroethylene-ethylene copolymer) around a twisted wire conductor 2a in which strands of electric conductors such as copper (for example, strands having an outer diameter of 0.1 mm or less) are twisted together. ), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer) or other fluororesin insulator 2b is twisted two insulated wires 2c configured together. The twisted pair 2 transmits control signals and the like used for controlling various devices such as control of an air injector. Here, the case of using eight twisted pair wires 2 is shown, but the number of twisted pair wires 2 is not limited to this.

The power supply wire 3 is composed of ETFE (tetrafluoroethylene-ethylene copolymer ), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), or the like. The power line 3 is used, for example, to transmit a power signal such as supplying a drive current for driving a motor (for example, an actuator or the like). Here, the case of using nine power lines 3 is shown, but the number of power lines 3 is not limited to this.

A cable 1 for a movable part according to the present embodiment includes a twisted wire pair assembly 4 in which a plurality of inner layer twisted wire pairs 21 for signal transmission are twisted together, and a twisted pair wire assembly 4 provided around the twisted wire pair assembly 4. A single braided shield layer 5, a plurality of power supply wires 3 for power supply, and one or more outer layer twisted pair wires 22 for signal transmission are helically twisted around the outer periphery of the first braided shield layer 5. and a second braided shield layer 7 provided around the outer wire layer 6 .

In the cable 1 for the movable part, some of the twisted pairs 2 (6 out of 8) are arranged inside the first braided shield layer 5 as the inner layer twisted pair 21, and the twisted pair 2 (two out of eight wires) are arranged outside the first braided shield layer 5 together with the power wire 3 as an outer layer twisted pair wire 22 .

When all the twisted pair wires 2 are used to form the twisted pair wire assembly 4, the outer diameter of the twisted pair wire assembly 4 is increased. In addition, if the number of power wires 3 constituting the outer wire layer 6 is small, there will be wasted space between the power wires 3, resulting in an increase in the overall size of the cable. In the present embodiment, by including part of the twisted pair wires 2 in the outer wire layer 6, the outer diameter of the twisted pair wire assembly 4 is reduced and the number of wires in the outer wire layer 6 is increased. By reducing the wasted space, the diameter of the cable 1 for the movable part is reduced. As the outer layer twisted wire pair 22 used for the outer wire layer 6 , it is preferable to use a wire that is not affected by noise from the power supply wire 3 .

The twisted wire pair assembly 4 is configured by twisting six inner layer twisted wire pairs 21 together. The inner layer twisted wire pairs 21 forming the twisted wire pair assembly 4 are configured to have different twist pitches. This is to suppress crosstalk (noise) between the inner layer twisted pair wires 21 . The twist pitch of the inner layer twisted pair wire 21 is the interval along the longitudinal direction of the inner layer twisted pair wire 21 at points where the insulated wires 2c are at the same position in the inner layer twisted pair wire 21 in the circumferential direction. .

In addition, since stress concentrates at the center of the cable 1 for the movable part when it is bent, six inner layer twisted pair wires 21 are helically twisted around the interposition 8 in the present embodiment. A twisted pair wire assembly 4 was constructed. This makes it possible to suppress the deterioration of the transmission characteristics of the inner layer twisted pair wire 21 due to the concentration of the stress at the time of bending on the inner layer twisted pair wire 21 .

As the intervention 8, for example, filamentous bodies such as staple threads can be used. Staple yarn has an appropriate cushioning property and does not break even when bent, so it is suitable as the interposition 8 of the cable 1 for the movable part used in the movable part. The filamentous body used for the intervention 8 is not limited to staple thread, and may be made of, for example, string, paper, non-woven fabric, or the like. Further, the intervention 8 is not limited to a filamentous body, and for example, a band-shaped body can be used. By imparting cushioning properties, the interposition 8 disperses the stress applied to the inner layer twisted pair 21 during bending, and also plays a role of suppressing deterioration of the transmission characteristics of the inner layer twisted pair 21 .

The twisting direction of the inner layer twisted pair 21 is preferably opposite to the twisting direction of the twisted wire conductor 2 a of the inner layer twisted pair 21 and the twisted pair assembly 4 . The twist direction of the twisted wire conductor 2 a is the same as the twist direction of the twisted pair wire assembly 4 . This is because when the twisting direction of the inner layer twisted pair 21 is the same as the twisting direction of the twisted conductor 2a and the twisted pair assembly 4, the strands constituting the twisted conductor 2a are repeatedly twisted in the same direction. This is because there is a possibility that the wire may be squeezed out during bending or the like. By setting the twisting direction of the inner layer twisted wire pair 21 to be opposite to the twisting direction of the twisted wire conductor 2a and the twisted pair wire assembly 4, it is possible to suppress breakage of the strands and improve resistance to bending. become.

The twisting direction of the stranded conductor 2a is the direction in which the wires are rotated from the other end side to the one end side when viewed from the one end side of the insulated wire 2c. The twist direction of the inner layer twisted pair 21 is the direction in which the insulated wire 2c rotates from the other end side to the one end side when viewed from one end side of the inner layer twisted pair wire 21 . The twist direction of the twisted pair wire assembly 4 is the direction in which the inner layer twisted pair wire 21 rotates from the other end side to the one end side when viewed from one end side of the twisted pair wire assembly 4 . .

A first pressure winding tape 9 is spirally wound around the twisted pair wire assembly 4 . As the first pressing tape 9, a paper tape, a tape made of non-woven fabric, or the like can be used. The first pressing winding tape 9 is wound so as to have a substantially circular shape when viewed in cross section. Each of the six inner-layer twisted pair wires 21 forming the twisted pair assembly 4 is in contact with the inner peripheral surface of the first pressing tape 9 . A first braided shield layer 5 made of a braided shield in which metal wires are woven is provided around the first pressing winding tape 9 .

A resin tape 10 is spirally wound around the outer circumference of the first braided shield layer 5 . The resin tape 10 improves the slippage between the first braided shield layer 5 and the power supply wire 3 or the outer layer twisted pair wire 22 constituting the outer wire layer 6, and plays a role of suppressing wear due to repeated bending. . As the resin tape 10, it is preferable to use a material that is resistant to abrasion and has good slipperiness. Anything can be used.

An outer wire layer 6 is formed on the outer periphery of the resin tape 10 by spirally twisting nine power wires 3 and two outer layer twisted pair wires 22 . The power wire 3 and the outer twisted pair wire 22 have different outer diameters, and the outer twisted pair wire 22 has a larger outer diameter than the power wire 3 . Therefore, in order to prevent unevenness during twisting, the outer layer twisted wire pairs 22 are spaced apart in the circumferential direction so that the power wires 3 are arranged between the plurality of outer layer twisted wire pairs 22. It is desirable that they are arranged, and it is more desirable that they are arranged at approximately equal intervals in the circumferential direction. Note that the coaxial lines 3 do not have to be arranged at exactly equal intervals, and an error of about ±10° is allowed. In this embodiment, since nine power wires 3 are used, four power wires 3 are arranged on one side and five power wires 3 are arranged on the other side between the two outer layer twisted pair wires 22 in the circumferential direction. The wires 3 and the outer layer twisted pair wires 22 were arranged at substantially equal intervals in the circumferential direction.

In order to suppress crosstalk, it is desirable that the two outer layer twisted pair wires 22 have different twisting pitches. Moreover, it is desirable that the twist pitch of the inner layer twisted pair wire 21 is equal to or less than the twist pitch of the two outer layer twisted pair wires 22 . This is because the inner layer twisted pair 21, which is arranged closer to the center of the cable, is more likely to be subjected to stress during bending than the outer layer twisted pair 22, so it is necessary to make the twist finer to improve resistance to bending. is desired.

Further, in the present embodiment, the outer wire layer 6 is formed by twisting the interposer 11 together with the power source wire 3 and the outer layer twisted pair wire 22 . The interposition 11 has a function of shaping the outer shape of the cable 1 for the movable part into a circular shape, and a function of interposing between the electric wires constituting the outer electric wire layer 6 and suppressing abrasion of the electric wires when the electric wires are bent or the like. fulfill In the present embodiment, in the outer wire layer 6, adjacent power wires 3 and adjacent power wires 3 and outer layer twisted pair wires 22 are not in contact with each other. As the intervening material 11 used in the outer wire layer 6, staple thread or the like can be used, like the intervening material 8 used in the assembly 4 of twisted pair wires.

A second pressure winding tape 12 made of paper tape or non-woven fabric is spirally wound around the outer wire layer 6 . The second press winding tape 12 is wound so as to have a substantially circular cross-sectional view by appropriately adjusting the amount and arrangement of the interventions 11 . All the electric wires forming the outer electric wire layer 6 , that is, the nine power wires 3 and the two outer layer twisted pair wires 22 are in contact with the inner peripheral surface of the second pressing tape 12 . Further, the outer layer twisted pair wires 22 are in contact with the outer peripheral surface of the resin tape 10 . Since the power wire 3 has an outer diameter smaller than that of the twisted pair wire 22 for outer layer, the power wire 3 is not in contact with the outer peripheral surface of the resin tape 10 .

A second braided shield layer 7 made of a braided shield in which metal wires are woven is provided around the second pressing winding tape 12 . The second braided shield layer 7 is covered with a jacket 13 made of an insulator. As the jacket 13, for example, a material made of polyvinyl chloride (PVC) resin, polyurethane (PU) resin, or the like can be used so as to protect the cable 1 for the movable part from external force.

As shown in FIG. 2, the jacket 13 is removed from the end portion of the cable 1 for the movable portion to expose the second braided shield layer 7, and the gap between the metal wires of the second braided shield layer 7 is widened. (spreading the stitches), the twisted pair wire assembly 4 covered with the first braided shield layer 5 is pulled out from the widened gap.

In the illustrated example, the inner layer twisted pair 21 constituting the twisted pair assembly 4 is connected to the first substrate 14, one outer layer twisted pair 22 is connected to the second substrate 15, and the other outer layer twisted pair is connected to the second substrate 15. The line 22 is connected to the third board 16 and the power line 3 is connected to the fourth board 17 . However, for example, the inner layer twisted pair 21 and the outer layer twisted pair 22 may be mounted on a common substrate, and the specific configuration of the substrate to be connected is not limited to that illustrated.

By configuring the terminal portion of the cable 1 for the movable part as shown in FIG. It is possible to prevent the line 21 from being affected by external noise at the terminal portion. Similarly, the power wires 3 and the outer layer twisted pair wires 22 constituting the outer wire layer 6 are also covered with the second braided shield layer 7 up to the immediate vicinity of the second to fourth substrates 15 to 17, can suppress the influence of external noise.

In order to pull out the twisted pair wire assembly 4 covered with the first braided shield layer 5 at the terminal portion of the cable 1 for the movable part, the second braided shield layer 7 has a mesh that can be easily expanded. desirable. Therefore, it is desirable that the braid angle of the second braided shield layer 7 be as small as possible. On the other hand, since stress is applied to the first braided shield layer 5 when it is bent, it may break if the braid angle is too small. Therefore, in order to improve the workability of terminal processing while suppressing the influence of noise at the terminal portion and to sufficiently maintain resistance to bending, the braid angle of the first braided shield layer 5 is set to the second braid It is desirable to make it larger than the braid angle of the shield layer 7 . The braid angle is the angle between the longitudinal direction of the cable and the longitudinal direction of the metal strands forming the braided shield.

In addition, since low-frequency noise is likely to occur in the motor or the like to which the power line 3 is connected, the second braided shield layer 7 covering the power line 3 has an increased outer diameter of the metal wire to increase noise resistance. is desired. On the other hand, in the first braided shield layer 5, if the outer diameter of the metal wire is increased, it becomes difficult to bend it. desired. Therefore, in order to reduce the influence of noise generated by a motor or the like on the power supply line 3 and to make the cable 1 for a movable part easy to bend, the metal wires constituting the first braided shield layer 5 are replaced by the second braided It is desirable to make the outer diameter smaller than that of the metal wires forming the shield layer 7 . More specifically, the outer diameter of the metal wire forming the second braided shield layer 7 is 1.2 to 1.5 times the outer diameter of the metal wire forming the first braided shield layer 5. do it. Here, the outer diameter of the metal wires forming the first braided shield layer 5 was set to 0.08 mm, and the outer diameter of the metal wires forming the second braided shield layer 7 was set to 0.10 mm.

(Actions and effects of the embodiment)
As described above, in the cable for movable part 1 according to the present embodiment, the twisted pair wire assembly 4 obtained by twisting a plurality of inner layer twisted wire pairs 21 for signal transmission and the twisted wire pair assembly 4 A first braided shield layer 5 provided around, a plurality of power supply wires 3 for power supply, and one or more outer layer twisted pair wires 22 for signal transmission are spirally wound around the outer periphery of the first braided shield layer 5. and a second braided shield layer 7 provided around the outer wire layer 6 .

By including part of the twisted pair 2 (for applications that are not easily affected by noise) in the outer wire layer 6, the number of twisted pair wires 2 included in the twisted pair assembly 4 is reduced and the twisted pair It is possible to reduce the outer diameter of the assembly 4 and reduce the unnecessary gaps formed between the wires in the outer wire layer 6, so that the movable part can be made thinner while suppressing the influence of noise. can realize the cable 1 for

(Summary of embodiment)
Next, technical ideas understood from the embodiments described above will be described with reference to the reference numerals and the like in the embodiments. However, each reference numeral and the like in the following description do not limit the constituent elements in the claims to the members and the like specifically shown in the embodiment.

[1] A twisted wire pair assembly (4) obtained by twisting a plurality of inner layer twisted wire pairs (21) for signal transmission, and a first braided shield provided around the twisted wire pair assembly (4) A layer (5), a plurality of power supply wires (3) for power supply, and one or more outer layer twisted pair wires (22) for signal transmission are spirally formed around the outer circumference of the first shield layer (5) A cable (1) for a moving part, comprising an outer wire layer (6) twisted together and a second braided shield layer (7) provided around the outer wire layer (6).

[2] The cable for movable part (1) according to [1], wherein the braid angle of the first braided shield layer (5) is larger than the braid angle of the second braided shield layer (7).

[3] According to [1] or [2], the strands constituting the first braided shield layer (5) have a smaller outer diameter than the strands constituting the second braided shield layer (7). Cable for moving parts (1).

[4] The outer wire layer (6) has a plurality of outer layer twisted wire pairs (22), and the outer layer twisted wire pairs (22) are spaced apart in the circumferential direction. , a cable for a movable part (1) according to any one of [1] to [3].

[5] The twisted pair assembly (4) is configured by spirally twisting the plurality of inner layer twisted pair wires (21) around an intermediate (8), [1] to [4 ], the cable for a movable part (1) according to any one of the above items.

[6] Any one of [1] to [5], wherein the plurality of inner layer twisted pair wires (21) constituting the twisted pair assembly (4) are configured to have different twist pitches. 2. Cable for movable part (1) according to item 1.

[7] Each of the inner layer twisted pair wires (21) constituting the twisted pair assembly (4) is an insulated wire ( 2c) are twisted together, and the twisting direction of the inner layer twisted pair (21) is opposite to the twisting direction of the twisted conductor (2a) and the twisted pair assembly (4). The movable part cable (1) according to any one of [1] to [6], wherein:

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the scope of claims. Also, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention. Moreover, the present invention can be modified appropriately without departing from the gist thereof.

Reference Signs List 1 Cable for movable part 2 Twisted wire pair 2a Twisted wire conductor 2b Insulator 2c Insulated wire 21 Twisted wire pair for inner layer 22 Twisted wire pair for outer layer 3 Power supply wire 4 Twisted wire assembly 5 ... First braided shield layer 6 ... Outer wire layer 7 ... Second braided shield layer 8 ... Interposition 10 ... Resin tape

Claims (1)

A first substrate is connected to terminal portions of a plurality of inner layer twisted pair wires constituting a twisted pair wire assembly provided in the center of the cable,
A second substrate different from the first substrate is attached to the terminal portion of the outer-layer twisted pair wire, which is smaller in number than the plurality of inner-layer twisted-pair wires, provided on the outer periphery of the above-mentioned twisted-pair assembly via a braided shield layer. 2 boards are connected,
an outer wire layer including a power wire and the twisted pair wire for the outer layer is provided outside the braided shield layer,
The twist pitch of the twisted pair wire for the inner layer is equal to or less than the twist pitch of the twisted pair wire for the outer layer.
cable.