JPS5823135Y2 - cab tire cable - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cabtire cable that is lightweight and has excellent mechanical strength such as impact resistance, bending resistance, and strain resistance.

Cabtire cables are used in mines and various construction sites to supply power to moving equipment or to control equipment, so they have various mechanical strengths such as impact resistance, bending resistance, and strain resistance. , compression resistance, abrasion resistance, etc. are required, and in order to facilitate handling, flexibility and light weight are required.

Therefore, cabtire cables, apart from vinyl cabtire cables that have conventionally been used for very light purposes, generally have an insulator made of natural rubber or butyl rubber, and a sheath made of natural rubber, chloroprene, chlorosulfonated polyethylene, etc. A material made of cabtyre rubber has been used.

These cables naturally satisfy many of the above conditions, but since the insulator must satisfy necessary electrical properties such as insulation resistance, it is necessary to mix carbon black etc. like the sheath and make it mechanically stable. Therefore, when a large external impact force is applied, there is a risk that the insulator will be damaged even if the cabtyre sheath is not damaged.

Furthermore, since both the insulator and sheath of conventional cabtire cables are made of rubber, both the insulator and sheath require a vulcanization process.

Next, conventional general-purpose products have a structure in which a cabtyre sheath is applied to fill the gap between twisted insulated wire cores, that is, a solid structure, in order to improve impact resistance, compression resistance, water resistance, etc. However, this structure has the disadvantage that it is heavier than the interposed type, and since the insulated wire core is tightly attached to the sheath, it cannot move freely inside the sheath, so it is susceptible to bending and tension. When external forces such as straining are applied repeatedly at the same time,
The wire core is drawn little by little to the part that has been bent and does not easily return to its original position, which often causes tension in the wire core and leads to wire breakage.

The purpose of the present invention is to eliminate these drawbacks and provide a cabtyre cable that is lightweight, has excellent mechanical strength such as impact resistance, bending resistance, and ironing resistance, and does not require the vulcanization process of the insulator. be.

Next, the configuration of the present invention will be explained based on the drawings. In FIGS. 1 to 4, a plurality of wire cores each consisting of a conductor 1 coated with an insulator 2 made of an olefinic thermoplastic elastomer are connected by a chute or a composite. A cable core is formed by winding a tape 5 around a central seat 3 consisting of a fiber cord, twisted together with an inter-core intermediary 4 also consisting of a jute or synthetic fiber cord, and on which at least cabtyre rubber or olefin is twisted. This cabtyre cable is coated with a sheath 6 including one or more layers made of a thermoplastic elastomer.

The seat floor 3 and the intervening material 4 are preferably made of a material having high tensile rigidity and a low coefficient of friction with the insulator 2, such as polypropylene string.

Further, the present invention includes the following configurations of the sheath 6, but is not limited thereto.

(a) As shown in Figure 1, a single layer made of cabtyre rubber or olefin thermoplastic elastomer.

(b) As shown in Figure 2, the inner sheath 6a and the outer sheath 6
b. The reinforcing layer 6C is removed, and both the inner and outer sheaths are made from cabtyre rubber, and the reinforcing layer is made from canvas.

(c) Similarly, in FIG. 3, the inner sheath 6d is made of olefin thermoplastic elastomer, the outer sheath 6e is made of cabtyre rubber, and the reinforcing layer 6f is made of cotton braid.

(d) As shown in FIG. 4, the surface of an inner sheath 6g made of an olefinic thermoplastic elastomer is formed into a pleated cylindrical shape, and an outer sheath 6h is tightly coated thereon.

Note that the shape of the pleats includes triangular waves, sine waves, rectangular waves, etc. formed along the circumference.

In the cabtire cable of this invention, the olefin thermoplastic elastomer that makes up the wire core insulation does not need to be vulcanized like conventional rubber, and can be easily extruded like thermoplastic resin. It is an elastomer with excellent electrical properties, heat resistance, and cold resistance, and has flexibility over a wide temperature range.In particular, it has a lower specific gravity of 0.88 than conventional rubber, and has high hardness and excellent impact resistance. The coefficient of friction with inclusions is also smaller than that of rubber.

Therefore, according to the present invention, the vulcanization process of the insulator is unnecessary, and even if the insulator is made thinner, the cab tire cable is lightweight and has mechanical and electrical properties equivalent to or better than cabtire cables using conventional rubber. Tire cable is obtained.

In addition, the cabtire cable of this invention uses an olefin-based thermoplastic elastomer as the insulator, and makes use of the space saved by making the insulator thinner than that of conventional products, and uses jute or synthetic fibers in the center of the cable core. The insulator itself has excellent impact resistance, and the core diameter is the same as that of conventional products.This seat acts as a buffer against impact loads, etc. In addition to this, it also has excellent impact resistance.

Furthermore, since we placed an interposition made of jute or synthetic fiber string in the gap between the wire cores, this serves as a tension member together with the seat floor, preventing large tensile loads from being applied to the conductor, and also acts as an insulator. Since the coefficient of friction with the seat floor and inclusions is small, the insulated wire core can move relatively freely within the cable core even when external forces such as straining are applied repeatedly, resulting in high bending and straining resistance. You will get an excellent cable.

Next, as shown in Figures 3 and 4, the sheath consists of two layers,
The inner sheath is made of olefin-based thermoplastic elastomer and the outer sheath is made of cabtire rubber, as shown in Figure 2. Both layers are made of cabtire rubber, and it is lighter than the one with canvas interposed in the middle, and has the same mechanical strength. However, as shown in Figure 4, by forming the interface between the inner sheath and the outer sheath into a pleated cylindrical shape, the contact area between the two can be increased and the mutual frictional force can be increased. It is possible to improve the adhesion and further improve the mechanical strength.

Further, when the two layers are formed in a cylindrical shape, the mechanical strength of the sheath can be reinforced by applying a cotton braid on the inner sheath as shown in FIG.

Cabtire cables used for applications such as submersible pumps must be watertight, so they must be solid. In this case, the central seat and the intervening wire cores should be made of olefin-based thermoplastic elastomer. A similar structure would accomplish the purpose and would be lightweight and have good compression resistance.

Next, in order to confirm the above-mentioned effects, we investigated the weight of a JIS C3311-compliant type 3 chloroprene cabtyre cable (hereinafter referred to as 3RNCT) having the structure shown in Table 1 and an example of the present invention designed to have the same core diameter. Tables 2 and 3 show comparisons of various mechanical properties tested under the same test conditions.

The test method for impact resistance is based on JISC3004, the weight is 20 kg, and the fall height at which damage occurs is measured.

In the bending resistance test, as shown in FIG. 5, one end of the sample was fixed to the fixing part 11, a tension of 3 kg was applied by the spring 13 attached to the other end of the sample, and the sample was guided by a 25 mmφ guide rod. The conductor is repeatedly bent at a rate of 30 times/minute, and the number of times it takes for the conductor to break is measured, with 90 degrees left and right being swung as one time.

In addition, the straining resistance test was conducted at 20 m as shown in Figure 6.
The wire is bent by the mφ pulley 21 and the lQQmmφ guide 22, and the winder is moved back and forth from side to side while applying a tension of 50 kg by the winder 23, and this is repeated until the wire breaks. Measure the number of times.

As is clear from Table 2, the weight of the product of the present invention is 13% lighter in Example 1 and 19% lighter in Example 2 than the conventional product.

Furthermore, as shown in Table 3, the test results show that the products of the present invention are superior to the conventional products in impact resistance, bending resistance, and ironing resistance in all examples.

As illustrated by the above results, the cabtire cable of the present invention is lighter than conventional products with the same core diameter and the same outer diameter, and has better mechanical strength such as impact resistance, strain resistance, and bending resistance. In addition to being excellent, it has many other effects such as eliminating the need for a vulcanization process for the insulator.

[Brief explanation of drawings]

FIGS. 1 to 4 are cross-sectional views showing an embodiment of the present invention, FIG. 5 is a bending test, and FIG. 6 is a ladder test. 1...Conductor, 2...Insulator, 3...
...Central seat, 4...Interposition between wire cores, 5...
...Tape, 6...Sheath, 6 a, 6
d. 6g...Inner sheath, 6b, 6e, 6h...
...External sheath, 6C...Reinforced canvas, 6F.
... Reinforcement wire braid, 11 ... Fixed part, 12
...Guide roll, 13 ...Spring, 2
1... Pulley, 22... Guide roll, 23... Winding machine.

Claims (1)

[Scope of utility model registration request] 1. A cable core is formed by twisting multiple wire cores made by covering a conductor with an insulator made of olefinic thermoplastic elastomer along with a central seat made of jute or synthetic fiber string and an inter-core intervening material, and then wrapping tape around the cable core. form,
A cabtire cable comprising a sheath comprising at least one layer made of cabtire rubber or an olefinic thermoplastic elastomer thereon. 2. The cabtire cable according to claim 1, wherein the central seat and the intervening wire cores are made of polypropylene string. 3. The cabtire cable according to claim 2, wherein the sheath is formed by applying a canvas over an inner sheath made of cabtire rubber and then covering it with an outer sheath. 4. Request for registration of a utility model characterized in that the sheath consists of an inner sheath made of an olefinic thermoplastic elastomer covered with an outer sheath made of cabtyre rubber with or without a reinforcing layer such as cotton braid. range 2nd
Cabtire cable as described in section. 5. The cabtire cable according to claim 4, wherein the inner sheath is formed into a pleated cylindrical surface and the outer sheath is tightly coated thereon.