JPS63304586A - Forming method for power cable insulating connection part - Google Patents

Abstract

PURPOSE:To make collective molding of an insulating connection part formable stably by covering an edge-cut part with inner and outer external semiconductive layers and forming a tip part of the inner semiconductive layer to be not contractible or almost not contractible. CONSTITUTION:A conductor connection part 10 is covered with a reinforced insulation layer 16, and its outside is covered with an inner semiconductive layer 18 and an outer semiconductive layer 22, with an edge-cut insulation layer 20 in between. A tip part 32 of the inner semiconductive layer is made of a material which is not contractible or almost not contractible, and the other part is made of a heatcontractible material. The outer semiconductive layer 22 is also formed to be heat-contractible. The reinforced insulation layer 16 and the edge-cut insulation layer 20 are made of the same species or groups of materials, and they are closely adhered to each other. Since the tip part 32 is not almost deformed upon the collective molding formation of this insulating connection part, the part 32 does not penetrate into the reinforced insulation layer 16, and also continuous formation of the insulation layer is enabled collectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of forming an insulating connection part of a rubber 9 plastic electrical cable, and particularly relates to forming an insulating layer of an edge cut part.

Then, collectively mold the ■reinforcing insulating layer, ■edge-cut insulating layer, and ■external semiconducting layer (hereinafter simply referred to as bulk molding).
It is related to a method that makes it possible.

[About insulated connections] An example is shown in FIG.

10 is a conductor connection part; 12 is a cable insulation layer; 14 is a cable outer semiconducting layer; 16 is a reinforcing insulating layer.

Reference numeral 18 denotes an outer semiconductive layer (hereinafter referred to as inner semiconducting layer) inside the edge cut portion provided directly above the reinforcing insulating layer 16; 20 refers to the edge cut portion insulating layer; 22 refers to the edge cut portion provided on the edge cut portion insulating layer 20; This is an outer semiconducting layer (hereinafter referred to as an outer semiconducting layer) on the outside of the .

[Prior Art and Problems: Part 1] The following methods are available for manufacturing the above-mentioned insulated connection portions by batch molding.

That is, (1) the reinforcing insulating layer 16 is made of uncrosslinked PE, (2) the inner semiconducting layer 18 is made of shrunk semiconductive heat shrink tube, and (2) the edge insulating layer 20 is made of uncrosslinked PE. (2) The outer semiconducting layer 22 is made of a shrunken semiconductive heat shrink tube, and is then molded all at once.

・Circular interpolation: As shown in FIG. 7, the end portion 19 (inner electrode portion) of the inner semiconducting layer 18 falls in the direction of the conductor, and the electrical performance of the connection portion deteriorates.

[Prior Art and Problems: Part 2] A method of heat-shrinking a heat-shrinkable tube for an external semiconducting layer with an insulating layer at an edge cut portion onto the reinforcing insulating layer 16, and then molding it all at once is also being considered.

・Length: (1) The thickness of the insulating layer (6 to 7 inches) at the edge and edge cut is much thicker than the outer semiconducting layer tube (approximately 1 mm), making it difficult to heat shrink. ,it takes time.

(2) Moreover, since the boundary between the reinforcing insulating layer 16 and the edge-cutting insulating layer 20 is not completely fused, there remains a concern.

[Means for Solving the Problems] The present invention uses a semiconductive partial heat shrinkable tube 180 in which only the tip portion 32 does not shrink or hardly shrinks, as shown in FIG. 1, to form the inner semiconductive layer 18. The above-mentioned problem is solved by forming the above-mentioned structure.

[Description] [l] About the semiconductive partial heat shrink tube 180: As shown in FIG. 1, it consists of a thick portion 26, a tapered portion 28, and a thin portion 30, and the entire tube is made of, for example, semiconductive cross-linked PE. Constructed from polyolefin materials such as

The thick portion 26 and the tapered portion 28 are made of heat shrink tubing.

In the thin portion 30, only the tip portion 32 is made of a non-shrinkable (or hardly shrinkable) tube, and the portion 34 is heat-shrinkable.

Note that the entire thin portion 30 may be non-shrinkable (or hardly shrinkable).

The inner diameter of the thin portion 30 is made equal to the outer diameter of the reinforcing insulating layer 16.

[2] Method for manufacturing semiconductive partially heat-shrinkable tube 180: As shown in FIG. 2, a mandrel 36 is used.

This outer shape is the same as the inner shape of the semiconductive partial heat shrink tube 180.

The tip portion 32 manufactured in advance is fitted onto the mandrel 36. Also, fit the other pieces of semiconductive heat shrink tubing.

Then, a semiconductive tape for molding 38 is sandwiched between the tip portion 32 and the heat-shrinkable portion 34, and the outside thereof is further wrapped with the semiconductive tape for molding 38, etc., and the two are fused together by applying pressure and heat. do.

[3] How to use semiconductive partially heat-shrinkable tube 180: (1) As shown in FIG. (the same diameter as the inner diameter), the above semiconductive partial heat shrink tube 180 is attached.

After determining the position of the tip portion 32, that is, the inner electrode, the remaining portion is heat-shrinked to form the inner semiconductive layer 18.

(2) Next, as shown in FIG. 4, the edge-cut insulating layer 20 is wound up with uncrosslinked PE tape, the outside of which is covered with a semiconductive heat-shrinkable tube 220, and the outside semiconducting tube is heated and shrunk. Construct layer 22 (FIG. 5).

(3) Then, the reinforcing insulating layer 16, the inner semiconducting layer 18,
The entire edge cutting portion insulating layer 20 and outer semiconductive layer 22 are collectively molded to complete the process.

[Function] During bulk molding, even if the reinforcing insulating layer 6 is softened by heating, the tip portion 32 of the semiconductive partially heat-shrinkable tube 180 does not shrink or hardly shrinks. No depression occurs.

[Effect of the Invention 1] Since the inner semiconductive layer 18 is constructed using the semiconductive partial heat shrinkable tube 180 that only the tip portion 32 does not shrink or hardly shrinks, (1) As described above, the edge cutting portion insulating layer 20 It is possible to create a stable molded insulated connection without the inner electrode falling in.

(2) Therefore, batch molding becomes possible.

(3) Since the interface between the reinforcing insulating layer 16 and the edge-cutting insulating layer 20 is formed of completely the same or very similar materials (for example, uncrosslinked extruded PE and uncrosslinked PE tape),
There is no need to worry about fusion properties.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a semiconductive partially heat-shrinkable tube 180 used in the present invention, FIG. 2 is an explanatory diagram of its manufacturing method, and FIGS. A step-by-step explanation of a method for forming an insulated connection part of a power cable according to the present invention using a partial heat shrink tube 180. FIG. 6 is a general illustration of an insulated connection part, and FIG. 7 is an explanation of problems in the prior art. figure. 10: Conductor connection portion 12: Cable insulating layer 14: Cable external semiconducting layer 16: Reinforcement insulating layer 18: External semiconducting layer inside edge cutting portion 20: Edge cutting portion insulating layer 22: External semiconducting layer outside edge cutting portion 26: Thick part 28: Tapered part 30: Thin part 32: Tip part 36: Mandrel

Claims (1)

[Claims] On the reinforcing insulating layer 16, the outer semiconducting layer 1 inside the edge cut portion.
8, the edge cut portion insulating layer 20, and the outer semiconductive layer 22 outside the edge cut portion to form an insulating connection portion, the outer semiconductive layer 18 inside the edge cut portion is
1. A method of forming an insulated power cable connection, characterized in that the second part of the power cable insulated connection is constructed using semiconductive partial heat shrink tubing 180 that does not shrink or hardly shrinks.