JPS5861512A - Movable high frequency coaxial cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] tsu? The present invention relates to a novel mobile high frequency transmission.

More specifically, the present invention relates to a mobile high-frequency coaxial cable with excellent bending resistance and flexibility.Recently, industrial televisions for remote monitoring have become widespread, and various industrial televisions are commercially available. In such industrial televisions, a detection section such as a television camera and a monitoring section such as a receiver are usually connected through a high frequency coaxial cable, and information is transmitted from the detection section to the monitoring section.

In the case where the position of the detection part is fixed, the high frequency coaxial cable may have an outer periphery of an inner conductor made of annealed copper wire or twisted copper wire, as specified in J.O.6501. A coaxial cable is used, which is formed by concentrically covering polyethylene as an insulator, and then sequentially concentrically applying a braid of soft #74 wire and a polyvinyl chloride sheath.

However, if the TV camera of the detection unit is attached to a moving part of the machine, for example, it may be attached to a moving lane in a factory or an unloader at a port to remotely monitor loading operations. In such a case, the running lane or unloader will be rolled out over a wide range, or bent or bent.

Recently, as a new use for industrial televisions, there has been a strong desire to install monitoring television cameras in elevators in order to prevent crime in elevators in high-rise buildings and high-rise residences. In that case, the high-frequency coaxial cable that connects the television camera in the elevator and the receiver in the control room must be able to withstand severe bending and bending due to the constant lifting and lowering of the elevator. Furthermore, even in industrial equipment, a television camera is sometimes installed on the movable part of the four-bot, and in such cases, the high frequency coaxial cable is also required to have bending resistance and flexibility.

However, the above-mentioned high-frequency coaxial cable has a drawback in that it has poor bending resistance and flexibility, and cannot withstand the above-mentioned uses.

Therefore, in order to improve the bending resistance, it is possible to use a flexible stranded wire for the internal conductor, but even if this alone will improve the bending resistance somewhat, using a thermoplastic resin such as polyvinyl chloride for the sheath However, it has the disadvantage that it has poor flexibility and is difficult to handle, especially as it becomes harder at lower temperatures.

Furthermore, it is also possible to form the sheath with a synthetic rubber material such as chlorprene, but in this case, the normal vulcanization temperature (
(approximately 140 to 150 degrees O), the insulating polyethylene undergoes thermal deformation during vulcanization of the sheath, so vulcanization must be performed at low temperatures for a long time, resulting in extremely low productivity and high costs. There is a problem.

The present invention has been completed in order to eliminate the above-mentioned problems and provide a mobile high frequency coaxial cable that has excellent transmission characteristics, and has excellent bending resistance and flexibility.
The gist is that in a high-frequency coaxial cable in which an insulator layer, an outer conductor layer, and a sheath layer are sequentially provided around an inner conductor, the inner conductor is a 1 m stranded wire, the insulator layer is made of olefin thermoplastic elastomer, A mobile high-frequency coaxial cable (hereinafter referred to as coaxial cable) with excellent bending resistance and flexibility, characterized in that the outer conductor layer is made of metal wire braid and the sheath layer is made of synthetic rubber.

The coaxial cable of the present invention uses, as an internal conductor, a flexible stranded wire in which fine mild steel wires or thin tin-plated mild steel wires are twisted around reinforcing wires, or twisted without reinforcing wires, and the sheath has flexibility. Polyethylene-insulated coaxial cables are made of synthetic rubber with excellent flexibility, and the insulator is a thermoplastic polyolefin elastomer with a low dielectric constant and excellent insulation and flexibility. It has almost the same transmission characteristics as , and also has excellent bending resistance and flexibility. Therefore, in addition to remote monitoring of moving machines such as lanes and unmadas as mentioned above, it is also useful for remote monitoring of elevators and in-machine wiring of industrial robots, which require particularly high bending resistance and flexibility. It has the remarkable effect that it can be suitably employed as a coaxial cable for use in other applications.

Furthermore, in the coaxial cable of the present invention, the polyolein thermoplastic elastomer used as the insulator does not require vulcanization itself and has excellent heat resistance, so even if the synthetic rubber sheath is vulcanized at normal vulcanization temperatures. Another advantage is that the insulator does not undergo thermal deformation and can be manufactured at low cost.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The coaxial cable of the present invention will be described below with reference to the drawings.

In Fig. 1, (1) is an internal conductor, and the internal conductor (1) is a twisted wire (ro) made by twisting thin mild steel wires or thin tin-plated mild steel wires around the reinforcing wire αυ and the reinforcing wire (b). ).

An insulator layer (2) is placed concentrically on the outer periphery of this internal conductor (1).
) is coated, and further an outer conductor layer (8) and a sheath layer (4) are applied in this order on the insulator layer (2) to obtain a coaxial couple.

The reinforcing wire (b) in the internal conductor (1) is a twisted wire (b)
This reinforcing wire is provided in order to impart appropriate tensile strength to the inner conductor (1) without impairing its bending resistance and flexibility, but the flexible twisted wire in the present invention does not have such reinforcing wire. Things are also tll. The reinforcing wire (b) is 1, for example piano wire 1.7 specified in XX8 G 5502.
511505 and IXB Glu50
Hard steel wires specified in 6 are tin-plated or galvanized, and stainless steel wires stranded as specified in 7XB G4609 are used.

In addition, the diameter of the thin soft copper wire or tinned annealed copper wire forming the thin wire (b) is usually 0.18 to 0.4.
5 Arrondissements are used. It is preferable to use tin-plated mild steel wire to prevent corrosion and discoloration caused by components in the insulator.

The insulating layer (2) is formed by extruding a polyolein thermoplastic elastomer onto the internal conductor (1) using an extruder.

Thermoplastic elastomers generally exhibit rubber elasticity at room temperature,
It is plasticized and behaves at high temperatures, and can be used as a material for extrusion molding in the same way as ordinary thermoplastic resins, and has the advantage of not requiring a vulcanization process. Diolefin-based thermoplastic elastomers have the advantages of such thermoplastic elastomers, and have superior electrical properties (insulating properties) compared to other thermoplastic elastomers (e.g., polystyrene-based, polyurethane-based, polyester-based, etc.). Combined with its high bending resistance and flexibility, it is suitable for use as an insulator material for mobile coaxial cables. In other words, the dielectric constant of polyolefin thermoplastic elastomer is almost the same as that of polyethylene, which is conventionally used as an insulator material (A8TM D 15G, 1kl).
ls of 2.1 to 2.3), and therefore has a low open capacitance and high characteristic impedance with approximately the same thickness as the insulating layer of a normal coaxial cable, and also has an attenuation level that is comparable to that of the industrial industry. The distance used for commercial televisions is sufficient. Therefore, the diolefin-based thermoplastic neelastomer of the present invention can be said to be extremely preferable for use as an insulating material, since it has excellent electrical properties in addition to flexibility.

Such a polyolefin-based thermoplastic elastomer is manufactured by mixing a polyolefin-based rubber such as ethylene-propylene rubber with a thermoplastic resin such as polyethylene or polypyrene, and partially crosslinking the mixture as necessary. Examples of commercially available diolefin thermoplastic elastomers include "Sumitomo TPIJ" manufactured by Sumitomo Chemical Co., Ltd., and "TPR" manufactured by Eisato Iyal Co., Ltd.
, and DuPont's ``TFI J.''

Polyolefin thermoplastic elastomer in the present invention! - may be suitably used, but it goes without saying that the am ratio, #4 electric loss tangent, bending rigidity, and torsional rigidity may be as small as possible.

The thickness of the insulator layer obtained using meliolefin thermoplastic □lastomer is IXB O! If you make sure that the diameter ratio is in accordance with the diameter ratio of the inner and outer conductors of high frequency coaxial cables specified in $501 (6.0 to 6.3,500 series for 7611 series and 6.25 to 3.45 for 3,500 series). good.

As the outer conductor (8), a braid of ordinary fine mild steel wire or tin-plated fine mild steel wire (according to the coaxial cable specified in IXB 03501) is used, and this wire is closely spaced on the insulating layer (2). Applied evenly. Similarly to the case of the internal conductor, it is preferable to use tin-plated annealed copper wire for the braided wire.

The sheath (4) is made of synthetic rubber such as viaprene or chlorosulfonated polyethylene, which is applied uniformly and closely on the outer conductor (8), and the sheath (4) has a wall thickness of IXB O3501. It is determined according to the coaxial cable stipulated in . If this synthetic rubber sheath is used, it not only has better flexibility than a pre-vinyl chloride sheath, but also eliminates problems such as deterioration of damping characteristics due to migration of plasticizer to the insulator.

Next, the coaxial cable of the present invention will be explained with reference to Examples and Comparative Examples.

Examples 1-4 Tin-plated mild steel fine wires were stranded around stainless steel strands, as shown in the following table, or stranded alone as internal conductors.

As an insulating layer, "Sumitomo l!lpx" manufactured by Sumitomo Chemical Co., Ltd.
5260 J was used to extrude and coat the inner conductor. Furthermore, each coaxial cable was obtained by applying an outer conductor and a sheath as shown in the following table. At that time, 1212 prene was extruded as a sheath onto the outer conductor and vulcanized at 140'O for 60 minutes, but the insulation No physical abnormalities (fever symptoms such as fatigue) were observed.

Comparative Examples 1 to 4 100- of coaxial cable specified in J Engineering 805501
In 27 and 5D-2V, each coaxial cable was obtained by using as an inner conductor a thin mild steel wire twisted together or a thin mild steel wire twisted around stainless steel aSS as shown in the following table.

Comparative Examples 5 to 6; 10 of coaxial cables specified in JXB O5501
At 0-2V and 5D-2V, each coaxial cable was obtained by applying [Sumitomo rpm 5260 J] instead of polyethylene as the insulator.

Comparative Example 7 100 of coaxial cable specified in rXS O5501
-27 was created.

The bending resistance, characteristic impedance, and attenuation of each coaxial cable found in Examples 1 to 4 and Comparative Examples 1 to 7 were examined. The results are shown in the table below.

For the corrosion resistance test, one end of the sample coaxial cable (length approximately 400 mm) (+5) was fixed as shown in Figure 2.
Attach a spring (6) to the other end and apply a tension of 6kl.

Next, the sample was swung left and right at an angle of 90° using the guide handle (1) with a diameter of 25 mm as a fulcrum, and the sample was bent repeatedly at a speed of 50 times/minute, with one reciprocation being counted as one reciprocation, and the sample was bent repeatedly at a rate of 50 times/min. The number of times was measured.

The characteristic impedance was measured by the resonance method, and the attenuation was measured by the substitution method.

Furthermore, the flexibility of the coaxial cables obtained in Example 1 and Comparative Example 5 was investigated. The test was conducted using the sample coaxial cable (length 20
The amount of deflection (111111) of the coaxial cable was measured when one end of the coaxial cable (0111111) was fixed and held horizontally and a 200 g weight was suspended from the other end at room temperature. As a result, the coaxial cable of Example 1 had a deflection amount of 118 mm, while that of Comparative Example 5 had a deflection amount of 721111 mm.

From the above results, Examples 1 to 4 have the same structure of internal conductor and external conductor as Comparative Examples 1 to 4, but Examples 1 to 4 have better insulation than Comparative Examples 1 to 4. It can be seen that due to the difference in the materials of the body and the sheath, it can withstand bending resistance of 4,000 to -8,000 times or more.

When compared with Comparative Examples 5 to 7 in which the internal conductor is not a flexible twisted wire, the improvement in bending resistance is even more remarkable, and even in terms of the amount of deflection, which is a measure of flexibility, Example 1 is better than Comparative Example 5. The deflection was 1.64 times that of the previous model.

The characteristic impedance of each example fully satisfies the standard specified by IXB, and the attenuation is slightly inferior to that of polyethylene-insulated coaxial cables (Comparative Examples 1 to 4 and 7), but it is suitable for industrial televisions. There is no problem at all if it is used for short distances, and as mentioned above, since the sheath is made of synthetic rubber, there is no deterioration due to plasticizer migration like in the case of vinyl sheaths, and on the contrary, it will not deteriorate over the long term. do.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the coaxial cable of the present invention, and FIG. 2 is a schematic explanatory view showing a bending resistance test of the coaxial cable. (Main symbols in the drawing) (l): Internal conductor (2)! Insulator (3): Outer conductor (4) Nissin patent application - Person: Chugoku 1J1 Line Industry Co., Ltd. Patent attorney So Asahina A. ! 1 Figure 7, 1 72 18F November 1982! 4 Commissioner of the Japan Patent Office Shima 1) Mr. Haruki ■ Indication of the case 1982 Patent Application No. 16 No. 60 2 Name of the invention Mobile high frequency coaxial cable 3 Person making the amendment Relationship with the case Patent applicant 5 Subject of the amendment (1) Contents of the amendment to the "Detailed Description of the Invention" in the specification/book (1) As a result of intensive study, the amendment to "Completion J" in lines 1 and 2 of page 5 of the specification has been made. (2) "Vulcanization itself" on page 6, line 10 is corrected to "vulcanization of itself." (8) Correct "corrosion" on page 7, line 19 to "chemical corrosion". (4) On page 10, line 2, amend "If it is small" to "If it is fast." (6) On page 11, lines 8-9, “Tin plated J” is
and correct it. (6) “About 400!11nJ” at the end of page 12 of the same page.
Correct it to 02. (7) "(ta
s/br) J is corrected to "I C)". I”

Claims (1)

[Claims] 1. A high-frequency coaxial cable in which an insulator layer, an outer conductor layer, and a sheath layer are sequentially provided around an inner conductor, wherein the inner conductor is a flexible m-wire, the insulator layer is a polyolein thermoplastic elastomer, A high-frequency coaxial cable for transportation with excellent bending resistance and flexibility, characterized by an outer conductor layer made of braided metal wire and a rough sheath layer made of synthetic rubber. 2. The high-frequency coaxial cable for transportation according to claim 1, wherein the internal conductor is made of a flexible stranded wire in which mild steel II or tin-plated mild steel thin wires are twisted around a reinforcing wire.