JPS63268407A - Manufacture of extrusion molded joint of insulated cable - Google Patents

Abstract

PURPOSE:To eliminate an irregular thickness of an extruded resin by providing a cable supporting base having a plurality of guide rollers at both ends of an extrusion metal mold. CONSTITUTION:Two series of parallel crosslike rollers 5 made or 4 guide rollers are disposed at upper and lower, and right and left sides as a supporting base to support a CV cable 1 at both ends of a metal mold 3. Thus, the extension of the cable 1 from the mold 3 can be escaped in a longitudinal direction at its supporting point, but a bending moment is not generated at a fulcrum, no eccentricity occurs in the mold, and the extension of the cable due to temperature rise can be absorbed at a cable offset. Thus, an eccentricity of an extruded resin is eliminated at the extrusion molded joint of an insulated cable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing an extrusion mold joint hem of an insulated cable.

[Prior Art] FIG. 2 shows the arrangement of a mold and an insulated cable, as well as the method of supporting the cable, when extruding a conventional extrusion mold joint of this type. The insulated cable 1 is not supported by the mold 3 but is supported by a support frame 4 provided outside the mold 3. This support point usually simply supports gravity.

[Problems to be Solved by the Invention] However, in the extrusion process, the cable length of about 2 m (between fulcrums) is heated to about 100'C. 17 in °C
You will only need x10-6x100x2000=3.4(m). If the fulcrum in Fig. 2 is a fixed fulcrum that allows only the bending moment, an eccentricity of 50 m will occur at the center of the mold.

In reality, since the fulcrum is not completely fixed, deviations in the length direction occur, and such eccentricity would never occur.

However, when the conductor size is large, bending is more likely to occur than a longitudinal shift at the fulcrum, such as when the cable is bent from the beginning. Therefore, with such a fulcrum, it is difficult to completely prevent eccentricity during the extrusion process.

The biggest problem with extrusion work is uneven thickness of the extruded resin. Causes of this include: ■ bending during sleeve compression, ■ bending of the cable itself, ■ improper setting before extrusion, and ■ movement of the cable due to heating.

Regarding items 2 to 3, it is possible to prevent uneven thickness to some extent by paying sufficient attention when setting. ③ is a problem, and the current situation is that there are no clear countermeasures. In particular, when there are ■ and ■, it is thought that ■ is likely to occur, and there has been a demand for a working method that does not cause uneven thickness even if the cable moves due to heating.

An object of the present invention is to provide a working method in which uneven thickness does not occur in the extruded resin even if the cable moves due to heating during extrusion work and heating/pressure/crosslinking work.

[Means for Solving the Problems] That is, the gist of the present invention is that a cable support frame having a plurality of guide rollers is provided at both ends of an extrusion mold. That is, the present invention provides support for supporting an insulated cable from the top, bottom, right and left on both ends of the mold with a support stand made up of a plurality of guide rolls outside both ends of the mold during extrusion work and/or heating/pressure/crosslinking work at the extrusion mold joint part. This method of manufacturing an extrusion mold joint part of an insulated cable is characterized in that the above operations and/or heating, pressurizing, and crosslinking operations are performed while holding the cable in the center of a mold.

Note that the plurality of guide rollers may be of any structure as long as they have a mechanism that controls vertical and horizontal bending and reliably supports the insulated cable without swinging horizontally or horizontally. For example, a combination of two sets of #finger-like objects may be mentioned.

[Function] The present invention is capable of extruding resin while holding the cable in the center of the mold using a support frame that supports the insulated cable from the top, bottom, left and right with a plurality of guide rolls outside both ends of the mold. (or) By heating, pressurizing, and cross-linking, the cable joint can be positioned correctly in the mold, and at the same time, the expansion of the insulated cable due to heating can be prevented by supporting guide rolls that move the cable further away from the mold. It was communicated until
As a result, the cable within the mold remains in its correct position, eliminating the risk of uneven resin thickness.

[Example] FIG. 1 shows one embodiment of the present invention.

As a support frame, two #finger-shaped rollers 5 each consisting of four guide rollers are arranged vertically, horizontally, and horizontally.
The CV cable 1 was supported outside both ends of the mold 3, respectively. As a result, when the cable extends from inside the mold 3, it is allowed to escape in the length direction at the support point, but a bending moment is not generated at the support point, and eccentricity does not occur within the mold, causing elongation due to temperature rise. The amount was absorbed by the cable offset section.

Even if sleeve 2 is bent, the distance between the fulcrums is approximately 2
If the bending moment is not allowed at the fulcrum at m, the bending of the cable within the mold will not be promoted because the bending rigidity of the cable is large.

[Effects of the Invention] According to the present invention, there is no eccentricity of the extruded resin at the extrusion mold joint portion of the insulated cable, thereby greatly improving the quality of a part of the extrusion mold joint 1.

[Brief explanation of the drawing]

FIG. 1 is a side view illustrating an embodiment of the method for manufacturing extrusion mold joints 1 to 1 of an insulated cable according to the present invention, and FIG. 2 is a diagram illustrating a conventional method for manufacturing an extrusion mold joint portion of an insulated cable. It is. DESCRIPTION OF SYMBOLS 1...CV cable, 2...Sleeve, 3...Mold, 4...Support frame, 5...#finger-shaped guide roller.

Claims (1)

[Claims] When extruding the insulated cable extrusion mold joint part and/or heating, pressurizing, and cross-linking the insulated cable, the insulated cable is supported from the top, bottom, left and right on a support stand consisting of a plurality of guide rolls outside both ends of the mold. While holding the insulated cable in the center of the mold, the extrusion process and/or heating/
A method for manufacturing an extrusion mold joint part of an insulated cable, which is characterized by performing pressurization and crosslinking work.