JPH046098Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a heat-resistant moving coaxial cable having a ring-shaped corrugated metal sheath.

[Prior Art] As an example of a coaxial cable used for transmitting large amounts of power, there is one in which an outer conductor is made of a metal sheath in order to increase the transmission capacity of the outer conductor. In order to withstand the heat generated by the transmitted power, the insulating layer is made of heat-resistant tetrafluoroethylene resin or
There are those coated with fluorinated ethylene resin or the like in solid form, and it is also possible to coat polyethylene on the center conductor and then crosslink it.

However, the coaxial cable configured as described above has a drawback of poor flexibility. In particular, when a coaxial cable is used as a so-called moving cable, in which the coaxial cable is once installed and then wound around a drum and recovered, it is extremely difficult to handle. This tendency becomes even stronger as the cable size increases.

[Purpose and summary of the invention] The heat-resistant corrugated metal sheathed coaxial cable of the invention solves the above-mentioned problems, and has a
A heat-resistant insulating layer, an outer conductor made of a ring-shaped corrugated metal sheath, and an outer jacket are sequentially provided, and the heat-resistant insulating layer is a tube-shaped insulating layer made of tetrafluoroethylene resin or hexafluoroethylene resin. 3 parts
It has ~4 spirally wound layers spirally wound on the center conductor.

[Example] Hereinafter, the heat-resistant corrugated metal sheath coaxial cable of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.
In the figure, 1 is a center conductor, 2 is a heat-resistant insulating layer, and the insulating layer 2 is made of tetrafluoroethylene resin or 6
Tube-shaped insulating members 20, 20... formed of fluoroethylene resin are arranged around the outer periphery of the central conductor 1.
4 pieces (4 pieces in the drawing), arranged at equal intervals from each other,
Each is spirally wound. After covering the outer periphery of the insulating layer 2 with a metal tape lengthwise, the edges of the metal tape are joined to form a tube, and this is corrugated to form a ring shape with the same cross section to form the outer conductor 3. The inner circumferential surface of the outer conductor 3 presses the insulating layer 2 and the insulating member 20 is slightly deformed, and the center conductor 1 and the outer conductor 3 engage with each other through the insulating layer 2, and these become relative to each other. It is prevented from moving.

It is preferable to use a tube-shaped member as the insulating layer in order to improve the flexibility of the cable, and the effective dielectric constant of the insulating layer can be reduced. When winding a cord, a larger number of cords can be wound than a cord-like member. (For example, when using a tube with a cross-sectional area factor of 50%, where only two strings can be wound, the tube can be wound with four.) As a result, when comparing the cable cross-sections,
In the case of a tube, the center conductor and the outer conductor engage with each other via the tube at more locations, and can have more stable strength than in the case of a string.

Furthermore, since the outer conductor is processed with ring-shaped corrugations, in combination with the tube-shaped insulating member, the repulsive force of the tube acts on the center conductor and outer conductor in the cross section where the ring is narrowed, so the insulating member The position of the center conductor becomes stable and the center conductor can be held at the center of the cable in a well-balanced manner.

The number of tube-shaped insulating members 20 and the spiral winding pitch are determined by taking into consideration the flexibility, strength, electrical characteristics, etc. necessary for the mobile cable. Outer diameter of inner conductor 1 +
If the diameter is 4 to 8 times the outer diameter of the insulating member 20, the coaxial cable can achieve the object of the present invention.

4 is an outer covering, the material of which is determined by the temperature of the outer conductor 3 or the temperature of the surrounding atmosphere;
If the temperature does not exceed 60℃ on the outer circumferential surface of the outer conductor 3, general cable covering materials such as vinyl or polyethylene can be used, and if the temperature exceeds 60℃, heat-resistant vinyl or chloroprene rubber can also be used. .

[Effects] As mentioned above, the heat-resistant corrugated metal sheathed coaxial cable of the present invention has extremely excellent heat resistance because the insulation layer is made of tetrafluoroethylene resin or hexafluoroethylene resin. The outer conductor is a ring-shaped corrugated metal sheath that is wound 3 to 4 times spirally around the center conductor so that its inner circumferential surface presses against the insulating layer, making it more flexible than a solid insulating layer. Since the insulating layer is tube-shaped, it has more stable strength than that of a string-shaped insulating layer. With this combination, the center conductor and outer conductor engage with each other via the tube in the narrow cross section of the ring, and the repulsive force of the tube stabilizes the position of the insulating member and maintains the center conductor at the center of the cable in a well-balanced manner. It works to bend the coaxial cable,
Even if the temperature of the coaxial cable increases, its structure remains stable, and therefore it is suitable as a mobile coaxial cable that transmits large amounts of power.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of an embodiment of the present invention. In the figure, 1 is a center conductor, 2 is an insulating layer, 3 is an outer conductor, and 4 is an outer cover.

Claims (1)

[Scope of utility model registration request] A heat-resistant insulating layer, an outer conductor consisting of a ring-shaped corrugated metal sheath, and an outer jacket are sequentially provided on the center conductor, and the heat-resistant insulating layer is made of tetrafluoroethylene resin or hexafluoroethylene resin. A heat-resistant corrugated metal sheathed coaxial cable, characterized in that it has a spirally wound layer in which three to four tube-shaped insulating members are spirally wound on the central conductor.