JP2021190329A - cable - Google Patents

Abstract

To enhance reliability of a cable from the viewpoint that connected railway vehicles relatively move in a longitudinal direction of a train, therefore, there is a risk of breakage of an internal conductor and an insulation layer (sheath) constituting a cable connected between the vehicles, and at this time, hanging of the broken cable and contact of a cable breakable part with a vehicle are prevented.SOLUTION: A cable has an internal conductor 1, a first insulation layer 2 covering the internal conductor 1, a braid 3 which covers the first insulation layer 2 and is composed of a resin, and a second insulation layer 4 covering the braid 3. Tensile strength of the braid 3 is higher than tensile strength of the internal conductor 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cable.

It is known to use flexible cables (crossover cables, jumper cables, jumper wires) for transmitting high voltage between railway vehicles. Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-328603) describes that a material having excellent mechanical strength is used as the sheath material of the crossover cable.

Japanese Unexamined Patent Publication No. 2006-328603

Since the connected railroad cars (hereinafter, sometimes simply referred to as rolling stocks) move relatively in the front-rear direction of the train, the transmission cable connected between the cars has flexibility and tensile strength. Is required. However, it is conceivable that the cable will be damaged and broken as a result of repeated fluctuations in the distance between vehicles during vehicle operation. At this time, the broken cable may hang down and the broken portion of the cable may touch the vehicle body. From the viewpoint of preventing the broken crossover cable from hanging down and the broken crossover cable from touching the vehicle, it is necessary to improve the reliability of the crossover cable for railway vehicles.

An object of the present invention is to improve the reliability of a cable.

Other objectives and novel features will become apparent from the description and accompanying drawings herein.

A brief description of typical embodiments disclosed in the present application is as follows.

The cable according to one embodiment includes an inner conductor, a first insulating layer that covers the inner conductor, a braid that covers the first insulating layer and is made of resin, and a second insulating layer that covers the braid. , And the tensile strength of the braid is higher than the tensile strength of the internal conductor.

According to one embodiment disclosed in the present application, the reliability of the cable can be improved.

It is sectional drawing of the cable which is an embodiment. It is a side view which shows by breaking a part of the cable which is an embodiment. It is a graph which shows the relationship between the strength and strain of each of a fiber material and a steel wire. It is a schematic side view which shows the structure which connected the cable which is an embodiment to a railroad vehicle. It is sectional drawing of the cable which is a comparative example.

Hereinafter, embodiments will be described in detail with reference to the drawings. In all the drawings for explaining the embodiment, the members having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted. Further, in the following embodiments, the same or similar parts will not be repeated in principle unless it is particularly necessary.

(Embodiment)
The cable of the present embodiment includes a braid made of resin between the first insulating layer and the second insulating layer that sequentially cover the outer periphery of the inner conductor, whereby the inner conductor, the first insulating layer and the second insulating layer are provided. It prevents the cable from touching the railroad vehicle when the cable breaks.

<Manufacturing method of cables and composite stranded wires>
Hereinafter, a railroad vehicle crossover cable will be described as the cable of the present embodiment with reference to FIGS. 1 to 4. FIG. 1 is a cross-sectional view of the cable of the present embodiment. FIG. 2 is a side view showing a partially broken cable of the present embodiment. FIG. 3 is a graph showing the relationship between the strength and strain of each of the fiber material and the steel wire. FIG. 4 is a schematic side view showing a structure in which the cable of the present embodiment is connected to a railroad vehicle.

1 and 2 show the cable of this embodiment. The cable of the present embodiment is a cable used as a crossing cable for a railroad vehicle provided for transmitting a high voltage between two railroad vehicles connected to each other, and is a cable such as a jumper cable or a jumper wire. Called.

As shown in FIG. 1, an internal conductor 1 which is a core wire exists at the center of the cable (crossover cable) 5. The inner conductor 1 is a stranded wire formed by twisting a plurality of wire rods 1a. The wire rod 1a has, for example, a structure in which seven twisted wires formed by twisting 29 strands having a diameter of about 0.2 mm are twisted together. The strand is made of, for example, copper (Cu). The inner conductor 1 has, for example, a structure in which 19 wires 1a are twisted together. That is, the internal conductor 1 is composed of, for example, about 3800 strands.

As shown in FIGS. 1 and 2, the outer periphery of the inner conductor 1 is covered with the inner conductor 1 and a first insulating layer (inner layer) 2 made of an insulator is provided. A braid (braided tube) 3 made of a resin is provided on the outer periphery of the first insulating layer 2 by covering the first insulating layer 2. A second insulating layer (outer layer) 4 which covers the braid 3 and is made of an insulator is provided on the outer periphery of the braid 3. As described above, the cable 5 includes an inner conductor 1, a first insulating layer 2, a braid 3, and a second insulating layer 4 that sequentially cover the outer periphery of the inner conductor 1. In other words, the inner conductor 1 is doubly covered with the first insulating layer 2 and the second insulating layer 4, and the braid 3 is interposed between the first insulating layer 2 and the second insulating layer 4. There is.

The first insulating layer 2 is made of, for example, urethane. The second insulating layer 4 comprises, for example, a mixture of polybutylene terephthalate (PBT) and a silicone elastomer.

The braid 3 is knitted by combining a plurality of fibers (threads) made of a resin which is an insulator. Here, the braid 3 is formed by weaving a plurality of single wires (resin fibers) 3a. Braid 3 is, for example, a cross braid. That is, for example, as shown in FIG. 2, four single wires 3a arranged side by side are used as a set of fibers, and a plurality of the set of fibers are crossed and knitted. Since FIG. 1 does not show a portion where the single wires 3a overlap and intersect with each other, the distance between the first insulating layer 2 and the second insulating layer 4 is only about the diameter of one single wire 3a. However, at the location where the single wires 3a overlap and intersect each other, the distance between the first insulating layer 2 and the second insulating layer 4 has a size of about twice the diameter of one single wire 3a.

The diameter of the single wire 3a is 0.1 to 0.25 mm. That is, if the diameter of the single wire 3a is less than 0.1 mm, the braid 3 cannot maintain the desired tensile strength. Further, if the diameter of the single wire 3a is larger than 0.25 mm, the braid 3 becomes excessively hard and the flexibility of the braid 3 decreases. That is, when the diameter of the single wire 3a is outside the range of 0.1 to 0.25 mm, the braid 3 may be more easily broken than the inner conductor 1, the first insulating layer 2 or the second insulating layer 4. .. Therefore, from the viewpoint of preventing breakage of the braid 3, the diameter of the single wire 3a is preferably 0.1 to 0.25 mm.

Here, the case where the braid 3 is composed of the braid of the single wire 3a has been described, but when the diameter of the yarn constituting the braid 3 is within the range of 0.1 to 0.25 mm, the yarn is a plurality of resins. It may be a stranded wire made of fibers.

Here, as the material of the braid 3, that is, the material of the single wire 3a, a resin having a higher tensile strength than the material (metal) constituting the internal conductor 1 is used. Further, the tensile strength of the material of the braid 3 is higher than any of the tensile strengths of the first insulating layer 2 and the second insulating layer 4. That is, the tensile strength of the material constituting the braid 3 is higher than the tensile strength of any of the materials constituting the inner conductor 1, the first insulating layer 2, and the second insulating layer 4. In the present embodiment, the tensile strength of the material of the braid 3 (material of the single wire 3a) is, for example, 3000 MPa or more.

In this embodiment, for example, para-aramid is used as the material of the braid 3. In this case, the single wire 3a is a para-aramid fiber. Para-aramid is a material with relatively high tensile strength. This is shown in FIG. FIG. 3 is a graph showing strain on the horizontal axis and strength (tensile strength) on the vertical axis. That is, the graph shown in FIG. 3 is a stress-strain curve of fibers and steel wires.

In FIG. 3, the para-aramid fiber graph 1A is shown by a solid line, the steel wire graph 1B is shown by a broken line, the polyethylene terephthalate fiber graph 1C is shown by a alternate long and short dash line, and the polyamide synthetic resin (nylon) fiber graph 1D is shown by two. It is shown by a dotted line, and Graph 1E of the meta-aramid fiber is shown by a three-dot chain line. Para-aramid, polyethylene terephthalate, polyamide synthetic resin (nylon) and meta-aramid are each materials used for fibers for industrial materials, for example. As shown in FIG. 3, the para-aramid has a higher tensile strength than any of steel wire, polyethylene terephthalate, polyamide synthetic resin (nylon) and meta-aramid.

In the present embodiment, the use of para-aramid as an example of the material of the braid 3 shown in FIG. 1 will be described, but the tensile strength constitutes each of the inner conductor 1, the first insulating layer 2, and the second insulating layer 4. A material other than para-aramid may be used for the braid 3 as long as the material has a higher tensile strength than any of the materials to be used. In this case, it is desirable that the tensile strength of the material of the braid 3 is 3000 MPa or more.

As shown in FIG. 4, the cable 5 is connected between two railroad vehicles 9. That is, one end of the cable 5 is fixed to one of the two railcars 9, and the other end of the cable 5 is fixed to the other of the two railcars 9. Specifically, each of both ends of the cable 5 is connected to a separate railroad vehicle 9 via a terminal 6 and an insulator 7 in order.

The cable 5 is used to transmit a voltage of, for example, about 26 kV between the railway vehicles 9. The cable 5 has a spiral shape (spring shape) in order to cope with fluctuations in the distance between the railroad vehicles 9. That is, the cable 5 deforms the spiral shape to enhance the elasticity and flexibility of the cable 5. This prevents the cable 5 from being damaged due to the repeated fluctuations in the distance between the railroad vehicles 9.

<Effect of embodiment>
Since the connected railroad cars move relatively in the front-rear direction of the train, the transmission cable (crossover cable) connected across the cars is required to have flexibility and tensile strength. However, it is conceivable that the cable will be damaged and broken as a result of repeated fluctuations in the distance between vehicles during vehicle operation. At this time, the broken cable may hang down and the broken portion of the cable may touch the vehicle body.

FIG. 5 shows a cross-sectional view of a cable as a comparative example. As shown in FIG. 5, the cable (crossover cable) 15 of the comparative example has the same structure as the cable 5 shown in FIG. 1 except that it does not have the braid 3. That is, the cable 15 includes an inner conductor 1 and a first insulating layer 2 and a second insulating layer 4 that sequentially cover the inner conductor 1.

As a result of using such a cable 15 connected between vehicles and repeatedly expanding and contracting between the vehicles, it is conceivable that all of the internal conductor 1, the first insulating layer 2 and the second insulating layer 4 are broken. .. The fact that all of the inner conductor 1, the first insulating layer 2 and the second insulating layer 4 are broken means that the entire cable 15 is broken. In this case, since there is nothing to support the broken portion of the cable 15, the broken cable 15 may hang down and the cable may touch the vehicle as described above.

On the other hand, the cable 5 of the present embodiment shown in FIG. 1 includes an inner conductor 1, a first insulating layer 2 that covers the inner conductor 1, and a braid 3 that covers the first insulating layer 2 and is made of resin. The braid 3 has a second insulating layer 4 that covers the braid 3, and the tensile strength of the braid 3 is higher than that of the inner conductor 1.

As described above, as one of the main features of the present embodiment, the braid 3 is provided between the first insulating layer 2 and the second insulating layer 4. Since the braid 3 has a higher tensile strength than the other portions constituting the cable 5, it is more difficult to break than any of the inner conductor 1, the first insulating layer 2, and the second insulating layer 4. Therefore, even if any of the internal conductor 1, the first insulating layer 2, and the second insulating layer 4 is broken as a result of the cable 5 repeatedly expanding and contracting between the vehicles, the braid 3 is not broken and the broken portion of the cable 5 is broken. It can prevent it from hanging down. That is, it is possible to secure a separation distance between the vehicle body and the fractured portion.

Further, since the braid 3 functions as a reinforcing layer of the cable 5, in the present embodiment, the internal conductor 1, the first insulating layer 2 and the second insulating layer 4 are broken as compared with the comparative example having no braid 3. You can also get the effect of making it difficult.

From the above, according to the present embodiment, the reliability of the cable can be improved.

Although the invention made by the present inventors has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment and can be variously modified without departing from the gist thereof. Needless to say.

1 Internal conductor 1a Wire rod 2 First insulating layer 3 Braided 3a Single wire 4 Second insulating layer 5, 15 Cable

Claims (8)

With the inner conductor,
The first insulating layer covering the inner conductor and
A braid made of a resin covering the first insulating layer and
A second insulating layer covering the braid and
Have,
A cable in which the tensile strength of the braid is higher than the tensile strength of the internal conductor. In the cable according to claim 1,
A cable having a tensile strength of 3000 MPa or more. In the cable according to claim 1 or 2.
The braid density of the braid is 50-70%, cable. In the cable according to any one of claims 1 to 3.
The resin is a cable made of para-aramid. In the cable according to any one of claims 1 to 4.
A cable with a spiral shape. In the cable according to any one of claims 1 to 5.
The braid is a cable composed of a plurality of single wires woven together. In the cable according to claim 6,
A cable having a diameter of the single wire of 0.1 to 0.25 mm. In the cable according to any one of claims 1 to 7.
A cable used as a crossover cable for railroad vehicles.

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