JP6688002B2 - Power supply cable for fixed wiring - Google Patents

Description

  The present invention relates to a fixed wiring power supply cable laid inside a large machine.

  Usually, in a large machine such as a shield machine, electric power is supplied through a fixed-wiring power supply cable laid inside the large machine (for example, see Patent Document 1). As its name implies, the power supply cable for fixed wiring is used as fixed wiring after laying, but since it is often bent when laying, it is considered in the field regarding flexibility during laying. A power supply cable for fixed wiring is desired.

JP, 2009-228261, A

  However, since the power supply cable for fixed wiring has been developed mainly for use as fixed wiring after laying, there is a fact that the flexibility during laying is neglected at the time of its development.

  For example, a conventional fixed wiring power supply cable uses a circular compressed conductor formed by circularly compressing a plurality of conductor wires for the purpose of saving space after installation. In the above, since the space existing between the conductor wires is crushed by circular compression processing, and the ratio of the space to the cross-sectional area is small, the conductor wires are bent when the power cable for fixed wiring is bent. By displacing the wires, it is difficult to cause the circular compressed conductor to follow the deformation of the fixed-wiring power supply cable due to bending, and there is a problem that the flexibility at the time of installation is poor.

  Furthermore, in the conventional fixed-wiring power supply cable, even when viewed from other configurations, an insulating paper that is hard enough to prevent bending of the fixed-wiring power supply cable is used as an intervening material, or when the fixed-wiring power supply cable is bent. It seems that the flexibility at the time of laying is neglected because the metal tape which is easily broken is used as the shield.

  Therefore, an object of the present invention is to provide a fixed-wiring power supply cable, which has been sufficiently considered in terms of flexibility during laying, and which allows the laying work to be performed more easily than before.

The present invention devised to achieve this object includes a twisted electric wire formed by twisting three insulated electric wires, and a shield covering the outer circumference of the twisted electric wire via an interposition. And a jacket covering the outer periphery of the shield, and a fixed wiring power supply cable, wherein the insulated wire is a plurality of twisted conductors formed by twisting a plurality of conductor wires. And a parent twisted conductor formed by further twisting a plurality of child twisted conductors, and a space existing between a plurality of adjacent child twisted conductors or between a plurality of the conductor strands. And an insulator covered on the outer periphery of the parent twisted conductor, wherein the interposition is made of a plurality of fiber threads twisted together with the three insulated wires, and the shield is Formed by braiding multiple braided wires That is a power supply cable for fixed wiring made of braided shield.

  It is preferable that the insulator is made of a crosslinked polyethylene resin, the fiber thread is made of a polypropylene resin, and the jacket is made of a polyvinyl chloride resin.

  The twisted electric wire preferably has a ratio of twist pitch to twist outer diameter of 20 or less.

  According to the present invention, it is possible to provide a power supply cable for fixed wiring in which flexibility in laying is sufficiently taken into consideration and laying work can be performed more easily than before.

It is a cross-sectional schematic diagram which shows the electric power feeding cable for fixed wiring which concerns on this invention. It is explanatory drawing explaining the method of comparing flexibility. It is explanatory drawing explaining the result of having compared flexibility. It is explanatory drawing explaining the result of having compared flexibility.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, a power supply cable 100 for fixed wiring according to a preferred embodiment of the present invention includes a twisted electric wire 102 formed by twisting a plurality of insulated electric wires 101, and an outer circumference of the twisted electric wire 102. And a jacket 105 that covers the outer circumference of the shield 104.

  The insulated wire 101 is formed of a parent twisted conductor 107 formed by further twisting a plurality of child twisted conductors 106, a cross-linked polyethylene resin having high flexibility, and the outer circumference of the parent twisted conductor 107. The child twisted conductor 106 is formed by twisting a plurality of conductor wires 109 made of copper or a copper alloy having high conductivity. That is, the insulated wire 101 is formed by twisting a plurality of conductor wires 109 in multiple layers.

  Therefore, in the parent-twisted conductor 107, the space 110 existing between the plurality of conductor element wires 109 is expanded as compared with an aggregate conductor formed by simply assembling a plurality of conductor element wires 109. Since the space 110 occupies a large portion of the cross-sectional area thereof, the parent twisted conductor 107 of the fixed wiring power supply cable 100 is moved by shifting the position of the plurality of conductor wires 109 when the fixed wiring power supply cable 100 is bent. It becomes easy to follow the deformation caused by bending, and it becomes possible to improve the flexibility at the time of installation as compared with the conventional one.

  The twisted electric wire 102 preferably has a ratio (P / Pd) of the twist pitch (P) to the twist outer diameter (Pd) of 20 or less. When the ratio (P / Pd) of the twist pitch (P) to the twist outer diameter (Pd) in the twisted electric wire 102 is more than 20, the positional relationship of the plurality of insulated electric wires 101 is close to the vertically installed structure. This is because stress may be locally concentrated when the power cable 100 for fixed wiring is bent, and the insulated wire 101 may be broken.

  The interposition 103 is composed of a plurality of fiber threads 111 that are twisted together with a plurality of insulated electric wires 101, and the fiber threads 111 are made of polypropylene resin.

  As a result, the plurality of fiber threads 111 can be displaced when the power cable 100 for fixed wiring is bent, and the interposition 103 can be made to follow the deformation accompanying the bending of the power cable 100 for fixed wiring. That is, in the fixed wiring power supply cable 100, the bending is not hindered by the interposition 103.

  The shield 104 includes a braided shield 112 formed by braiding a plurality of braided wires (not shown).

  As a result, the plurality of braided wires can be displaced when the power cable 100 for fixed wiring is bent, and the shield 104 can be made to follow the deformation accompanying the bending of the power cable 100 for fixed wiring. That is, in the fixed wiring power supply cable 100, the bending does not break the shield 104.

  The jacket 105 is made of polyvinyl chloride resin that is inexpensive and has high insulation and water resistance, and reduces the price of the fixed wiring power supply cable 100.

  In consideration of flexibility during installation, it is possible to use a cabtire cable that is used as a movable wiring that is repeatedly bent, but a cabtire cable is required to have flexibility only during installation. It has an excessive performance as a fixed wiring, and has a larger outer diameter and a higher price than the fixed wiring power supply cable 100.

  On the other hand, the fixed-wiring power supply cable 100 has flexibility that is about the middle of that of the conventional fixed-wiring power supply cable and the cabtire cable, but also compared with the conventional fixed-wiring power supply cable. Outer diameter and price are almost unchanged.

  As described above, according to the present invention, it is possible to provide the fixed-wiring power supply cable 100 in which the flexibility at the time of laying is sufficiently taken into consideration and the laying work can be performed more easily than before. .

  Next, a specific example of the present invention will be described.

  Here, the insulated wire of the present invention that employs the parent twist conductor and the conventional insulated wire that employs the circular compressed conductor are compared in terms of flexibility.

  In the embodiment, a child twisted conductor formed by twisting 34 conductor wires each having an outer diameter of 0.45 mm is used, and 27 child twisted conductors are further twisted and formed. By creating a parent-twisted conductor having an outer diameter of 18.7 mm, and forming an insulator formed of cross-linked polyethylene resin with a thickness of 2.0 mm on the outer circumference of the parent-twisted conductor, the rated temperature is increased. Of 90 ° C. and a rated voltage of 600 V were produced.

  In the comparative example, 37 conductor wires each having an outer diameter of 2.3 mm are circularly compressed to form a circular compressed conductor having an outer diameter of 14.7 mm, and the circular compressed conductor is formed. An insulated wire having a rated temperature of 90 ° C. and a rated voltage of 600 V was manufactured by forming an insulator having a thickness of 2.0 mm formed of a cross-linked polyethylene resin on the outer periphery of the insulated wire.

  Then, as shown in FIG. 2, these insulated electric wires 201 are made horizontal, one end 202 is fixed, and a weight 204 having a load of 2 kg or 4 kg is hung on the other end 203 from the horizontal position A to the descending position B at that time. The descent distance L was measured, and the descent distance L from the horizontal position A to the descent position B when the load was removed was measured.

  As shown in FIGS. 3 and 4, the insulated wire according to the embodiment has a descent distance L from the horizontal position A to the descent position B when the weight is hanging down and a descent distance L from the horizontal position A to the descent position B when the weight is removed. It is found that both are longer than the insulated wire according to the comparative example, and have higher flexibility at the time of installation and smaller repulsive force at the time of bending as compared with the insulated wire according to the comparative example.

  As described above, it has been proved that the adoption of the parent twisted conductor in the power supply cable for fixed wiring significantly improves the flexibility during installation.

100 Power Supply Cable for Fixed Wiring 101 Insulated Electric Wire 102 Twisted Electric Wire 103 Interposition 104 Shield 105 Jacket 106 Child Twisted Conductor 107 Parent Twisted Conductor 108 Insulator 109 Conductor Element Wire 110 Space 111 Fiber Yarn 112 Braided Shield

Claims (3)

A twisted electric wire formed by twisting three insulated electric wires;
A shield which is coated on the outer periphery of the twisted electric wire via an interposition,
A jacket coated on the outer periphery of the shield,
In the fixed wiring power supply cable equipped with
The insulated electric wire is adjacent to a plurality of child twisted conductors formed by twisting a plurality of conductor element wires and a parent twisted conductor formed by further twisting the plurality of child twisted conductors. Between a plurality of the child twisted conductors , or a space present between a plurality of the conductor strands, and an insulator covered on the outer periphery of the parent twisted conductor,
The interposition includes a plurality of fiber yarns twisted together with the three insulated wires, and the shield includes a braided shield formed by braiding a plurality of braided wires. Power supply cable for fixed wiring. The insulator is made of cross-linked polyethylene resin,
The fiber yarn is formed of polypropylene resin,
The power supply cable for fixed wiring according to claim 1, wherein the jacket is made of polyvinyl chloride resin.   The power supply cable for fixed wiring according to claim 1 or 2, wherein the twisted electric wire has a ratio of a twist pitch to a twisted outer diameter of 20 or less.