JPS59177876A - Method of forming cable connector - 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 The present invention relates to a method for forming a connection part of a cable, particularly a crosslinked polyethylene insulated vinyl sheathed cable (hereinafter referred to as a C■ cable).

The 4-connection part of the aV cable is manufactured using a molding method using IF IJ olefin insulator, which is the same material as the cable insulator, from the viewpoint of improving electrical characteristics and axis stability for ultra-high voltage power transmission systems with 154KV lines or higher. It is common that This molding method requires heat and pressure crosslinking using polyolefin Teso laminated winding, polyolefin block or polyolefin extrusion. On the other hand, the connection part using the polyolefin extrusion molding P is a method that introduces the manufacturing technology of the cable body into the field, and is the most excellent method compared to other methods. In order to form a connection part using such an extrusion mold, it is extremely important to stably cool and shrink the polyolefin insulator filled in the mold from the viewpoint of the electrical properties of the connection part.

An object of the present invention is to provide a method for forming a CV cable connection part, which is characterized by stably shrinking a polyolefin insulator filled in a mold during cooling.

According to the present invention, the above object is achieved by crosslinking only the outer portion of the polyolefin insulator filled in the mold, that is, the portion near the inner surface of the mold, and shrinking it by cooling. Hereinafter, the present invention will be explained in detail based on the equipment for carrying out the method of the present invention shown in the drawings.

In Fig. 1, the conductor is exposed by pen/ring processing the Cv cable l, and the conductor connecting tube 6 is connected to the cable body.
After the connection is made, the internal semiconducting layer 4 is formed. The internal semiconducting layer 4 is conventionally applied using a semiconducting polymer, a 4-refin heat shrink tube or a semiconducting rubber molding.

4 & place the part to be continued in the mold 7 and heat it 1-1
Inject and fill the polyolefin insulation from step 8.

After removing a predetermined number of polyolefin insulators 2 filled in the mold 7 from the O-S-Flo hole 5, the insulator is closed and the heater 3 of the mold 7 is heated to 180°C to 230°C.
Raise the temperature to the s9 lyolefin crosslinking temperature of ℃, and
Comparative degrees, such as 30 minutes - 6 hours! After maintaining for 112 hours, heating was stopped and the mixture was cooled.

At the start of cooling, the pressure device 9 is connected to the pressure []1o provided in the mold 7. When the polyolefin insulator 2 contracts due to cooling and a gap is created between the mold 7 and the polyolefin insulator 2, the pressurizing device 9 is activated and a gas such as air, nitrogen gas, S dross gas, etc. is activated. The gas is sent through a pressurized 010, for example 0.5 K7/lyi? 0-1. O
Cooling is continued while pressurizing at a predetermined pressure such as K9/cri G.

By doing so, since only the outer portion of the polyolefin insulator 2 is crosslinked, this portion becomes the outer skin, and the shrinkage upon cooling becomes uniform.

That is, the inner semiconducting layer 4 side of the polyolefin insulator 2 is not crosslinked, so uniform shrinkage occurs.

As described above, the present invention has 1. d Liorefui/
Only the outer 1Ulj of the insulator is crosslinked and cooled, so
There is no significant increase in operating time, and there is no need for replenishment rams, which were previously required for shrinkage of uncrosslinked insulation.

[Brief explanation of drawings]

FIG. 1 is a schematic, partially sectional view of an apparatus for carrying out the method of the invention. 1...Cv cable, 2...polyolefin insulator,
3. Heater, 4.. Internal semiconductive layer, 5. Overflow hole, 6. Conductor connection tube, 7.. Mold, 8. Insulator injection hole, 9.. Pressurizing device, 10. Pressurizing port. 〇Figure 1

Claims (1)

[Claims] The insulation is peeled off to expose the conductors, and the properly connected cable connection part is placed in the mold, and the polyolefin insulator is filled in the mold. Immediately after filling, the mold temperature is adjusted to the temperature of the polyolefin insulator. Forming a cable connection part characterized by raising the temperature to a crosslinking temperature, maintaining this temperature for a relatively short time to crosslink the outer layer of the insulator, and then cooling the mold while pressurizing the inside of the mold with gas. Method.