JP2019109970A - Multicore cable - Google Patents

Abstract

To provide a multicore cable that has improved flexibility and can be made finer and be reduced in weight.SOLUTION: A multicore cable 1 has at least partially a press winding tape layer. The press winding tape 7 has a winding pitch more than 1 time as large as the tape width and equal to or less than 5 times as large as the tape width.SELECTED DRAWING: Figure 1

Description

The present invention relates to a multicore cable used for various service robots such as humanoid and movable parts such as assist suits.

In recent years, in multi-core cables used for movable parts of service robots and the like, improvement in flexibility is required. In addition, with the space saving accompanying the miniaturization of robots, and the expansion of applications such as assist suits worn by humans, thinning and weight reduction of multi-core cables are also required.

As an example of a multi-core cable excellent in flexibility, there is a structure having a press-wound tape closely wound around a stranded wire core obtained by twisting a plurality of wire cores together (for example, Patent Document 1) .
The press-winding tape is wound around the stranded wire core so that the tapes overlap. In the case of a structure in which the tapes have an overlap, the pressing effect on the stranded core is enhanced, but friction between the tapes occurs and the resistance to bending of the tapes increases, so that the flexibility of the entire cable decreases. is there.

Unexamined-Japanese-Patent No. 2017-079140

An object of the present invention is to provide a multi-core cable which can be thinned and reduced in weight while improving its flexibility.

The gist of the present invention is as follows.

(1) In a core wire comprising a plurality of electric wires twisted together and a multicore cable in which a press-winding tape layer is provided at least in part on the core wire,
The winding pitch of the press-winding tape is characterized by being larger than one time of the width of the tape and not more than five times the width of the tape.
(2) A core wire comprising a structure in which a stranded wire obtained by twisting a plurality of wires is further twisted together, and a multi-core cable in which at least a part of the press-winding tape layer is provided on the core wire
The winding pitch of the press-winding tape is characterized by being larger than one time of the width of the tape and not more than five times the width of the tape.
(3) A multi-core cable in which a press-winding tape layer is applied to at least a part of a core wire made of a structure in which both a plurality of electric wires and a stranded wire obtained by twisting a plurality of electric wires are further twisted together ,
The winding pitch of the press-winding tape is characterized by being larger than one time of the width of the tape and not more than five times the width of the tape.
(4) It is preferable that the pitch which twists an electric wire is 10 to 30 times the outer diameter of an electric wire.
(5) It is preferable that the width | variety of a holding-up tape is 1-3 times the outer diameter of a core wire.
(6) When the outer conductor is provided on the outer periphery of the press-winding tape, it is preferable that the outer conductor has a structure using a wire in which a conductive member is wound around the outer periphery of the center yarn.
(7) When a sheath is provided on the outer periphery of the press-winding tape, it is preferable to have an air gap between the press-winding tape and the sheath.
(8) When a sheath is provided on the outer periphery of the outer conductor, it is preferable to have an air gap between the outer conductor and the sheath.
(9) It is preferable to use a fluorine resin as a material of the insulator used for the electric wire.

According to the present invention, the following excellent effects can be expected.

(1) Since the winding pitch of the press-winding tape is greater than one time of the width of the tape and five times or less of the width of the tape, there is no overlap of the tapes, and the friction between the tapes and the resistance to bend the tapes are reduced. it can. As a result, the flexibility of the multicore cable against bending and twisting is improved.
(2) When the pitch which twists an electric wire is 10 to 30 times the outer diameter of an electric wire, the softness | flexibility with respect to bending improves.
(3) When the width of the press-winding tape is 1 to 3 times the outer diameter of the core wire, the workability of the tape winding and the flexibility for bending are improved.
(4) In the case where the outer conductor has a structure using a strand in which a conductive member is wound around the outer periphery of the center yarn, the flexibility of the multicore cable is improved, and the weight reduction of the multicore cable becomes possible.
(5) When there is an air gap between the holding tape and the sheath or between the outer conductor and the sheath, the flexibility of the multicore cable against bending and twisting is improved.
(6) When a fluorine resin is used as the material of the insulator used for the electric wire, it becomes possible to make the electric wire thin.
(7) The multi-core cable of the present invention combining the core wire, the press-winding tape, the outer conductor, and the sheath not only improves the shielding characteristics but also improves the flexibility, thinning and weight by the synergetic effect in each structure. Produces the greatest effect of all.

An example of sectional drawing in the multicore cable of this invention is shown. The other example of sectional drawing in the multi-core cable of this invention is shown. The schematic of the structure of the holding-up tape in this invention is shown. The schematic showing the twist pitch of a core wire is shown. Fig. 2 shows a schematic diagram representing the flexibility testing method in the present invention.

Hereinafter, as an example of the multi-core cable of the present invention, a basic configuration will be described with reference to the drawings.

The multicore cable 1 of FIG. 1 is provided with a core wire 5 in which a plurality of electric wires 4 are twisted, an interposition 6, a holding winding tape 7, and a sheath 9.

The electric wire 4 is comprised by the conductor 2 which each consists of a material which has electroconductivity, and the insulator 3 which carries out the insulation coating of the conductor.
The material of the conductor 2 is not particularly limited as long as it has conductivity. For example, a metal wire such as copper or aluminum or an alloy wire obtained by adding tin, iron, zinc, nickel or the like to them is used. Used as a line. The surface of the metal wire may be plated with silver, tin or the like.
The configuration of the conductor 2 is not particularly limited, but in consideration of flexibility against bending, wire thinning and the like, a stranded wire structure formed by bundling and twisting a plurality of metal wires is preferable.
The material of the insulator 3 is not particularly limited as long as it is a material having electrical insulation, but, for example, thermoplastic resin such as fluorocarbon resin or polyolefin, silicone rubber, fluororubber, polyvinyl chloride (PVC), polyurethane, etc. It can be mentioned.
Preferably, a thermoplastic resin such as fluorocarbon resin or polyolefin is used. Thermoplastic resins such as polyolefin are excellent in flexibility, extrusion moldability and the like.
More preferably, it is a fluorine resin, and has a low dielectric constant, a high volume resistivity, and a high insulation property as compared with other resins, so it is suitable for making the electric wire thin.

The press-winding tape 7 is configured to be wound on the core wire 5. A schematic view of the structure of the press-winding tape in the present invention is shown in FIG.
The present invention is characterized in that the winding pitch of the press-winding tape 7 is greater than 1 time of the width of the press-winding tape 7 and not more than 5 times the width of the press-winding tape 7.
When the winding pitch of the press-winding tape 7 is larger than 1 time of the width of the press-winding tape 7, there is no overlapping of the tapes, and the contact between the tapes can be minimized. The friction between the tapes and the resistance to bend the tapes can be reduced. As a result, the flexibility of the multicore cable 1 against bending is improved.
On the other hand, when the winding pitch of the press-winding tape 7 is five times or less the width of the press-winding tape 7, the pressing effect on the core wire 5 can be maintained.
Preferably, the winding pitch of the press-winding tape 7 is greater than one time of the width of the press-winding tape 7 and not more than three times the width of the press-winding tape 7.
More preferably, the winding pitch of the press-winding tape 7 is greater than one time of the width of the press-winding tape 7 and not more than twice the width of the press-winding tape 7 in that the flexibility and the pressing effect are compatible. is there.

The core wire 5 is formed by twisting a plurality of electric wires 4.
The pitch of the core wire 5 is preferably 10 to 30 times the outer diameter of the wire 4. The schematic showing the twist pitch of a core wire is shown in FIG.
When the pitch of the core wire 5 is 10 times or more of the outer diameter of the electric wire 4, the flexibility to twisting is improved. This is because, in the case where the pitch of the core wire 5 is maintained at a certain level or more, even if twisting is performed in the same direction as the twisting direction of the core wire 5, flexibility against twisting can be secured.
Moreover, when the pitch of the core wire 5 is 30 times or less of the outer diameter of the electric wire 4, the softness | flexibility with respect to a bending | flexion improves. This is because, in the core wire 5, the flexibility against bending can be secured in the case where the number of nodes formed by the pitch is secured at a certain level or more. The smaller the pitch value, the greater the number of nodes formed by the pitch.
More preferably, the pitch of the core wire 5 is 10 to 20 times the outer diameter of the wire 4.

In FIG. 1, core wire 5 is formed by twisting three electric wires 4, but it is not particularly limited. It may be configured to have two or four or more electric wires 4.

The winding direction of the press-winding tape 7 is not particularly limited, but is preferably the same direction as the twisting direction of the core wire 5 because the flexibility to bending and twisting can be further improved.

The width of the press-winding tape 7 is preferably 1 to 3 times the outer diameter of the core wire 5.
When the width of the press-winding tape 7 is 1 or more times the outer diameter of the core wire 5, the pressing effect on the core wire 5 and the workability of the tape winding are improved.
In addition, when the width of the press-winding tape 7 is not more than three times the outer diameter of the core wire 5, the pressing effect of the press-winding tape 7 on the core wire 5 can be maintained.
More preferably, the width of the press-winding tape 7 is 1 to 2 times the outer diameter of the core wire 5.

The material of the holding tape 7 is not particularly limited. For example, fluorine resin materials, polyethylene, nylon, paper and the like can be mentioned. In view of the coefficient of friction, flexibility and the like, a fluorine resin material is preferred.

The interposition 6 may be used between the core wire 5 and the press-winding tape 7. An air gap may be provided without using the interposition 6.
The material of the interposition 6 is not particularly limited. For example, various fibers such as cotton, polypropylene, polyester and the like can be mentioned.

The sheath 9 may be applied to the outer periphery of the multicore cable 1 of the present invention.
The material of the sheath 9 is not particularly limited, and examples thereof include polyvinyl chloride, polyurethane, polyethylene, fluorocarbon resin, polyamide resin, polyimide resin, and polyester elastomer.
Soft polyvinyl chloride is preferred in terms of flexibility and versatility.

Moreover, it is preferable that an air gap (not shown) be provided between the press-winding tape 7 and the sheath 9.
By providing the air gap, the load on the inside of the cable is relieved, and the flexibility of the multicore cable 1 against bending and twisting is improved.

Hereinafter, another example of the multicore cable of the present invention will be described with reference to FIG.
The multicore cable 1 of FIG. 2 includes a stranded wire 4 'obtained by twisting a plurality of electric wires 4; a core wire 5 obtained by further twisting a plurality of stranded wires 4'; an interposition 6; A conductor 8 and a sheath 9 are provided.

The twisting direction of the stranded wire 4 ′ is not particularly limited, but it is more preferable that the twisting direction is the same as the twisting direction of the core wire 5 because the flexibility against bending and twisting can be further improved.

In FIG. 2, the stranded wire 4 ′ is formed by twisting two electric wires 4, but is not particularly limited. It may be configured to have three or more electric wires 4. Further, the configuration of the stranded wire 4 'does not have to be the same.

In addition, as a mode different from FIGS. 1 and 2, core wire 5 may have a configuration in which both a plurality of electric wires and a stranded wire obtained by twisting a plurality of electric wires are further twisted (FIG. Not shown).
That is, the stranded wire 4 'constituting the core wire 5 may be a single wire like the electric wire 4 shown in FIG. 1 or may be a combination of these. For example, it may be a combination of different configurations of the single wire electric wire 4 and the stranded wire 4 '(two, three, etc.).

The twist pitch of the stranded wire 4 ′ is preferably 10 to 30 times the outer diameter of the wire 4.
When the pitch of the stranded wire 4 'is 10 times or more of the outer diameter of the electric wire 4, the flexibility to twisting is improved. This is because, in the case where the pitch of the stranded wire 4 'is maintained at a certain level or more, even if twisting is performed in the same direction as the twisting direction of the stranded wire 4', flexibility against twisting can be secured.
In addition, when the pitch of the stranded wire 4 'is 30 times or less of the outer diameter of the electric wire 4, the flexibility for bending is improved. This is because flexibility in bending can be secured in the case where the number of knots formed by the pitch in the stranded wire 4 ′ is maintained at a certain level or more. The smaller the pitch value, the greater the number of nodes formed by the pitch.

The twist pitch of the core wire 5 is not particularly limited, but preferably 40 or more times the outer diameter of the stranded wire 4 'in consideration of flexibility against twisting.
Since the combination of the twist pitch of the stranded wire 4 ′ and the twist pitch of the core wire 5 affects the flexibility of the multi-core cable 1, it is necessary to select an appropriate combination.

The outer conductor 8 is formed on the outer periphery of the holding tape 7.
The material of the outer conductor 8 is not particularly limited as long as it is a material having conductivity. For example, metal wires such as copper, alloy wires obtained by adding tin, iron, zinc, nickel or the like to them, or center yarns The wire etc. which wound the electrically-conductive member around outer periphery are used.
In consideration of the flexibility, weight reduction, and the like of the multi-core cable 1, it is preferable to use a wire in which a conductive member is wound around the outer periphery of the center yarn.
The material of the center yarn is not particularly limited, but in consideration of flexibility and the like, polyester, polyamide and the like are preferable.
The material of the conductive member is not particularly limited, but copper and aluminum are preferable in consideration of flexibility, conductivity, weight reduction and the like. The surface of the conductive member may be plated with silver, tin or the like.

The structure of the outer conductor 8 is not particularly limited. It is necessary to select an appropriate structure from the braided structure, the horizontal winding structure, etc. according to the application.
A braided structure is preferable in consideration of the shield characteristics. In consideration of the flexibility to twisting, a horizontal winding structure is preferred.

Hereinafter, although an example is given and explained concretely about multi core cable 1 (Drawing 1, Drawing 2) of the present invention, it is not limited about these about the range of the present invention.

In Example 1, an insulator of a fluorine resin layer was coated on the outer periphery of a conductor having a structure in which tin-plated soft copper wires were twisted together to form a wire.
Next, two wires were twisted to form a twisted wire. The twist pitch of the stranded wire is 15 times the outer diameter of the wire.
Furthermore, three stranded wires were twisted to form a core wire. The twist pitch of the core wire is 40 times the outer diameter of the stranded wire.
Further, a fluorine resin holding tape was wound on the core wire. The winding pitch of the holding tape is twice the width of the holding tape. In addition, the width of the press-winding tape is 1.6 times the outer diameter of the core wire.
The interstices of cotton were filled in the gaps between the core wire and the press-winding tape.
Furthermore, an outer conductor was formed on the outer periphery of the holding tape. The material of the outer conductor is a copper foil, and the structure of the outer conductor is a braided structure.
Furthermore, a sheath was formed around the outer conductor. The material of the sheath is soft polyvinyl chloride. Also, an air gap is provided between the outer conductor and the sheath.
The specific configuration of Example 1 is shown in Table 1 below.

The specific configuration of the comparative example is shown in Table 1. The twist pitches of the stranded wire and the core wire, the structure of the press-winding tape, and the material of the outer conductor are different from those of the embodiment.

The tests described below were performed on each of the multicore cables created as described above, and various performances were evaluated and compared.

(Flexibility test method)
Schematics representing the flexibility testing method are shown in FIGS. 3 (a), (b).
FIG. 3A is a schematic view before the test. The sample length is 300 mm, the fixing distance is 150 mm, and a load is applied to 10 mm from the sample end.
FIG. 3 (b) is a schematic view after the test is performed. By applying a load at a point 10 mm from the sample end, the sample bends in a direction approximately parallel to the gravity.
Measure the distance between the bent sample and the fixed end of the sample in a direction perpendicular to gravity. The shorter the distance, the more flexible the sample.
In the process of making the multi-core cable, the flexibility test is performed on the structure at each stage, and the test results are compared. The higher the rate of increase in the test results, the greater the decrease in sample flexibility.

The test results of the above-mentioned flexibility test in Example 1 and Comparative Example are shown in Table 2. The difference in load value between "wires and strands" and "other structures" is to minimize the influence of the weight of the sample itself.

Table 2 below describes the difference in flexibility between Example 1 and Comparative Example.
When the test result of the electric wire and the test result of the twisted wire in which two electric wires are twisted are compared, Example 1 increases from 9 mm to 12 mm. The rate of increase is 33%. On the other hand, the comparative example is increasing from 9 mm to 15 mm. The rate of increase is 67%.
The higher the rate of increase in the test results, the greater the decrease in sample flexibility. Thus, it can be seen that the sample of Example 1 exhibits relatively higher flexibility than the sample of the Comparative Example.
It is considered that the difference in the twisting pitch of the stranded wire contributes to the improvement of the flexibility.

Moreover, Example 1 does not change with 7 mm from 7 mm, when the test result before and behind winding a holding-winding tape on a core wire is compared. On the other hand, the comparative example increases from 8 mm to 13 mm. The rate of increase is 63%.
The higher the rate of increase in the test results, the greater the decrease in sample flexibility. Thus, it can be seen that the sample of Example 1 exhibits relatively higher flexibility than the sample of the Comparative Example.
It is considered that the difference in the pitch of the tape winding and the difference in the width of the press-wound tape greatly contribute to the improvement of the flexibility.

Moreover, when the test result before and behind which forms an outer conductor is compared, Example 1 is increasing with 7 mm to 8 mm. The rate of increase is 14%. On the other hand, the comparative example increases from 13 mm to 18 mm. The rate of increase is 38%.
The higher the rate of increase in the test results, the greater the decrease in sample flexibility. Thus, it can be seen that the sample of Example 1 exhibits relatively higher flexibility than the sample of the Comparative Example.
It is considered that the difference in the material of the outer conductor contributes to the improvement of the flexibility.

Example 2 changes the twist pitch of a twisted wire, and describes it as "Example 2-1-2-3." The other configuration is the same as that of the first embodiment.

The test results of the above-mentioned flexibility test in Examples 2-1 to 2-3 are shown in Table 3.

From Table 3, the increase rate of a test result is high before and behind twisting a wire, so that the twist pitch of a twisted wire is large.
The higher the rate of increase in the test results, the greater the decrease in sample flexibility. Therefore, it can be seen that the greater the twist pitch of the stranded wire, the lower the flexibility.
When the twist pitch of the stranded wire is in the range of 10 to 30 times the outer diameter of the wire, a certain degree of flexibility can be secured. As mentioned above, flexibility against bending and twisting can also be ensured.

Example 3 changes the winding pitch of a press-winding tape, and describes it as "Example 3-1-3-4." The other configuration is the same as that of the first embodiment.

The test results of the above-mentioned flexibility test in Examples 3-1 to 3-4 are shown in Table 4.

From Table 4, when the winding pitch of the press-winding tape is 1 and 7 times, the test results increase before and after winding the press-winding tape on the core wire.
The higher the rate of increase in the test results, the greater the decrease in sample flexibility. Therefore, in Example 3, when the winding pitch of a press-winding tape is 1 time and 7 times, it turns out that a softness falls.
When the winding pitch of the press-winding tape is 1 time, it is difficult to reduce the friction between the tapes and the resistance for bending the tapes because the tapes are in contact with each other. As a result, it is considered that the flexibility is reduced.
In the case where the winding pitch of the press-winding tape is 5 times or less, in the press-winding tape, the number of nodes formed by the pitch is maintained at a certain level or more, so flexibility against bending can be secured. The smaller the pitch value, the greater the number of nodes formed by the pitch.
When the winding pitch of the press-winding tape is greater than one and not more than five, the friction between the tapes and the resistance to bending the tapes can be reduced because there is no overlapping of the tapes. As a result, it is thought that it contributes to the improvement of the flexibility of the sample.

Example 4 changes the tape width of a press-winding tape, and describes it as "Examples 4-1 to 4-4." The other configuration is the same as that of the first embodiment.
In all the examples 4, the winding pitch of the press-winding tape is adjusted according to the change of the tape width of the press-winding tape so that the winding pitch of the press-winding tape is twice the width of the press-winding tape. The

The test results of the above-mentioned flexibility test in Examples 4-1 to 4-4 are shown in Table 5.

From Table 5, as the tape width of the press-wound tape is wider, the increase rate of the test result is higher before and after the press-wound tape is wound on the core wire.
The lower the rate of increase in test results, the better the flexibility of the sample can be maintained. Therefore, it is understood that the flexibility can be maintained as the tape width of the press-winding tape is narrower with respect to the outer diameter of the core wire.

The multicore cable of the present invention can improve the flexibility and the flexibility against bending and can be made thin and light, so it is particularly useful in coaxial cables and the like used for movable parts such as service robots. However, the application is not limited.

Reference Signs List 1 multi-core cable 2 conductor 3 insulator 4 electric wire 4 'twisted wire 5 core wire 6 interposition 7 holding winding tape 8 outer conductor 9 sheath

Claims (9)

In a core wire rod having a configuration in which a plurality of electric wires are twisted together, and a multicore cable in which a press-winding tape layer is provided on at least a part of the core wire rod,
A multi-core cable characterized in that a winding pitch of the press-winding tape is greater than one time of the width of the tape and not more than five times of the width of the tape. In a core wire rod having a configuration in which a plurality of stranded wires are further twisted together and a multicore cable in which a pressing winding tape layer is applied to at least a part of the core wire rod, winding pitch of the pressing winding tape A multi-core cable characterized in that it is more than 1 times the width of the tape and not more than 5 times the width of the tape. A core wire comprising a plurality of electric wires and a stranded wire obtained by twisting a plurality of electric wires together and further twisted together, and a multi-core in which a press-winding tape layer is applied to at least a part of the core wire. In the cable
A multi-core cable characterized in that a winding pitch of the press-winding tape is greater than one time of the width of the tape and not more than five times of the width of the tape. In the multicore cable, the pitch at which the wires are twisted is 10 to 30 times the outer diameter of the wires.
The multicore cable according to any one of claims 1 to 3. In the multicore cable, the width of the press-wrapping tape is 1 to 3 times the outer diameter of the core wire.
The multicore cable according to any one of claims 1 to 4. In a multicore cable in which an outer conductor is provided on the outer periphery of the press-wound tape,
The outer conductor is a structure using a wire in which a conductive member is wound around the center yarn.
The multicore cable according to any one of claims 1 to 5. In a multi-core cable in which a sheath is provided on the outer periphery of the holding winding tape,
There is an air gap between the holding tape and the sheath,
The multicore cable according to any one of claims 1 to 6. In a multicore cable in which a sheath is provided on the outer periphery of the outer conductor,
There is an air gap between the outer conductor and the sheath,
The multicore cable according to claim 6. In the multicore cable, a fluorine resin is used as a material of the insulator used for the electric wire,
The multicore cable according to any one of claims 1 to 8.

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