JPH0530006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a self-supporting cable.

BACKGROUND OF THE INVENTION Self-supporting cables are shown in FIGS. 3 and 4. As shown in the figure, a self-supporting cable consists of a cable core 1, a metal laminate tape 2 that wraps it, a hanging wire 3, and a plastic sheath 4 that covers all of these in a streamlined shape to prevent snow from accreting. It is configured. Incidentally, a hollow part 5 is provided between the cable core 1 and the hanging wire 3 so that it can be easily torn when the hanging wire part is separated.

Traditionally, this self-supporting cable was manufactured as shown in FIGS. 5 and 6. The cable core 1, on which the metal laminate tape 2 is formed, and the hanging wire 3 are arranged side by side and reach an extruder crosshead 6. In the extruder crosshead 6, the plastic jacket 4 is applied by means of a streamlined extrusion die 7. After that, it is cooled in a cooling water tank.

[Problem that the invention attempts to solve] The above conventional technology has the following problems.

(1) Due to side-by-side extrusion, a deformation 4a is created in the plastic jacket 4, as shown in FIG. This is a problem in terms of snow accretion and appearance.

(2) Also, as shown in Figure 7, the empty space 5
is empty. A deformed portion 5a is generated and is deformed as shown by the solid line. This makes it difficult to tear when separating the hanging wire parts.

(3) Because it is extruded horizontally, water does not catch on the bottom side easily.

(4) Since no external pressure is applied in this method, the adhesion between the metal laminate tape 2 and the plastic jacket 4 is weak.

The present invention has been made in view of the above points,
The object of the present invention is to provide a method for manufacturing a self-supporting cable that has a beautiful shape, has a hanging wire part that is easy to tear, and can improve the adhesion of metal laminate tapes.

[Means for Solving the Problems] The above purpose is to arrange the hanging wire and the cable core vertically, extrude them with an extruder crosshead with a cavity formed between the hanging wire and the cable core, and then extrude the suspended wire and the cable core. This is accomplished by applying external pressure to the plastic jacket and cooling it while applying internal pressure to the cavity.

[Function] Since the hanging wire and the cable core are extruded vertically, the hanging wire and the cable core are extruded vertically, which improves water coverage. In addition, since the plastic jacket was cooled while applying external pressure to the entire plastic jacket, the plastic jacket was cooled while applying external pressure, and the adhesion between the metal laminate tape and the plastic jacket and the connection between the hanging wire and the plastic jacket were improved. Improves adhesion. Furthermore, since internal pressure is applied to the hollow part during manufacturing, internal pressure can be applied to the hollow part, a hollow part without deformed parts is created, and the tearability of the hanging wire part is improved.

[Example] The present invention will be described below based on the illustrated example. An embodiment of the invention is shown in FIGS. 1 and 2. FIG. Note that parts that are the same as those in the conventional system are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the hanging wire 3 and the cable core 1 are arranged vertically, and are extruded by an extruder crosshead 6 with a hollow part 5 formed between the hanging wire 3 and the cable core 1, and then the plastic covered during extrusion is extruded. The outer cover 4 is cooled while applying external pressure, and the inner pressure is applied to the hollow part 5 during manufacturing. By doing this, the hanging wire 3 and the cable core 1 are arranged vertically, and this is extruded by the extruder crosshead 6 with a hollow part 5 formed between the hanging wire 3 and the cable core 1, and then during this extrusion, While the coated plastic jacket 4 is cooled under external pressure, the cavity 5 is produced under internal pressure. Therefore, the plastic sheath 4, the metal laminate tape 2, and the hanging wire 3 are well bonded to each other, and the hollow part 5 without any deformed parts is created, and the shape is beautiful and the hanging wire part is easy to tear. Metal laminated tape 2
It is possible to obtain a method for manufacturing a self-supporting cable that makes it possible to improve the adhesiveness of the cable.

That is, the cable core 1 formed with the metal laminated tape 2 and the suspension wire 3 are arranged vertically in a line,
reach of the extruder crosshead 6. In the extruder crosshead 6, an extrusion die 7 forms a cavity 5 and a plastic jacket 4 is applied. The plastic jacket 4 is cooled while applying pressure in a pressure water bath 9 attached to the extruder crosshead 6 via a packing 8. That is, cooling water is supplied from a cooling water pipe 10 provided in the pressure water tank 9 to cool the cable, and compressed air is supplied from an external pressure pipe 11 provided in the pressure water tank 9 to apply pressure to the plastic jacket 4. and extruder crosshead 6
Compressed air was supplied to the hollow part 15 from an internal pressure pipe 12 provided inside the hollow part 5, and internal pressure was applied to the hollow part 5 to keep the dimensions of the hollow part 5 appropriate. By doing so, the following effects can be achieved.

(1) Since the hanging wire 3 and the cable core 1 are extruded vertically side by side, there is no deformation of the shape, and it is possible to manufacture a cable with a beautiful shape that is symmetrical from side to side.

(2) Since external pressure is applied to the entire plastic sheath 4, the adhesiveness of the metal laminate tape 2 and the adhesion of the hanging wire 3 are improved.

(3) Since internal pressure is applied to the hollow part 5 and balanced with the external pressure, the dimensions and shape of the hollow part 5 can be controlled, the shape is beautiful, and the tearability of the hanging wire part can be improved.

[Effects of the Invention] As described above, the present invention has a beautiful shape, the hanging wire part is easy to tear, and the adhesiveness of the metal laminate tape is improved. A method for manufacturing a self-supporting cable that enables improved adhesiveness can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the manufacturing state according to an embodiment of the method for manufacturing a self-supporting cable of the present invention, FIG. 2 is a longitudinal sectional side view showing the manufacturing state according to the same embodiment, and FIG. Figure 4 is a side view of the self-supporting cable, Figure 5 is a plan view showing the state of the self-supporting cable when it is manufactured using a conventional manufacturing method, and Figure 6 is a side view of the self-supporting cable. FIG. 5 is a sectional view taken along line A-A in FIG. 5, and FIG. 7 is a longitudinal sectional side view of a self-supporting cable produced by a conventional method for manufacturing a self-supporting cable. 1: Cable core, 2: Metal laminate tape, 3: Hanging wire, 4: Plastic jacket, 5: Sky
Part, 6: Extruder crosshead, 8: Packing,
9: Pressure water tank, 10: Cooling water pipe, 11: External pressure pipe, 12: Internal pressure pipe.

Claims (1)

[Scope of Claims] 1. Equipped with an extruder crosshead, a suspension line, an empty space,
In the method of manufacturing a self-supporting cable having a cable core provided with a metal laminate tape and a plastic jacket, the suspension wire and the cable core are arranged vertically, and the suspension wire and the cable core are arranged vertically in the extruder crosshead between the suspension wire and the cable core. Forming a cavity and extruding, then cooling while applying external pressure to the plastic jacket coated during extrusion,
A method for producing a self-supporting cable, characterized in that the production is carried out by applying internal pressure to the hollow part. 2. a pressure water tank in which the plastic jacket is attached to the extruder crosshead via a packing;
A method of manufacturing a self-supporting cable according to claim 1, wherein the cable is cooled while applying external pressure. 3. The method of manufacturing a self-supporting cable according to claim 1, wherein the hollow portion is an internal pressure pipe provided inside the extruder crosshead to which internal pressure is applied.