JPS5919109A - Connecting method of lead laminate tape - Google Patents

Abstract

PURPOSE:To obtain a water-screening and chemical-resistant electric cable comprising lead laminate tapes, by removing part of the plastic layer of each of lead laminate tapes to expose each of the lead surfaces, overlapping the exposed parts of the lead surfaces, subjecting said parts to ultrasonic vibrations to weld said exposed parts together readily and positively. CONSTITUTION:The plastic film layers 3, 3' on the lead laminate tapes 1, 1' where connection should be done are peeled and removed, opposite plastic film alyers are peeled and turned back, and the thus exposed lead tapes 10, 10' are overlapped. Ultrasonic vibrations are applied onto the overlapped parts to produce frictional heat to the interface of the lead tapes so as to weld them, and after that, if required, the turned back plastic layers 2, 2' are restored to the original positions and fused to complete the connection.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for connecting a lead laminated tape made by laminating a plastic film on one or both sides of a lead or lead alloy foil, particularly when manufacturing water-shielding and/or chemical-resistant electric cables using lead laminated tape. This article relates to a method for connecting lead laminated tape.

In general, rubber for high voltage use where the working voltage is 3.300V or higher.
Glasstic power pulls have an internal semiconducting layer on top of the conductor,
It has a structure in which a crosslinked polyethylene insulating layer, an external semiconductive layer, an electrostatic shielding layer made of copper tape, etc., and a protective cylindrical layer made of vinyl chloride resin, etc. are provided in this order.

In power cables with such a structure, it is difficult for the protective sheath to completely block water from entering the inside of the cable, and with protective sheaths made of vinyl chloride resin, polyethylene, rubber, etc., moisture gradually enters the inside. It is something that penetrates.

The moisture that has gradually penetrated into the protective sheath reaches the cable core and finally diffuses into the outer semiconducting layer and then into the insulating layer, thereby creating a so-called water tree in the insulating layer. This was a serious cause of deterioration of electrical properties such as insulation performance of capeple.

Not only high-voltage electrical cables but also low-voltage electrical cables are still being used.
Even for communication cables for pull and various signals, electrical cables installed at petrochemical plants etc. are installed in soil contaminated with benzene, xylene, oil, chemicals, etc., so they must be covered with a protective sheath. are severely attacked by these contaminants, so electrical cables that are chemically resistant as well as waterproof are required.

For this reason, the present inventor proposed a water-shielding and chemical-resistant electrical cable that can prevent moisture and contaminants from entering the cable core, and has achieved great results. Namely, there are a number of improved electrical cable structures in which a lead-glass laminate tape (also referred to as lead laminate tape) is longitudinally arranged on the cable core, or a lead laminate tape is arranged longitudinally on the inner surface of the protective sheath. has been proposed and has achieved great results.

By the way, in order to reduce cable weight and cost, this lead laminate tape has a lead foil thickness of 0.02 to 0.
．． An extremely thin one is used. In addition, after the lead laminated tape 0 is vertically attached to the cable core, a thermoplastic film (thickness 002~
0.5 tram) is laminated so that heat fusion can be performed when joining the seams.

In recent years, there has been an increasing demand for longer cable lengths, and a single length of lead-lined laminate cable is too short to manufacture a long cable, so another new lead-lined laminate cable is needed in the middle. I had to connect to 0.

Until now, the following methods have been used to connect lead laminate tapes.

(1) Overlapping heat fusion method (heat sealing method) This is a method in which the connecting ends of lead-plated laminated tapes are nailed together, and that part is heated and pressurized to a temperature higher than the melting point of the laminated plastic to heat-seal the connection. Although it is simple, it has the fatal drawback that complete water shielding cannot be expected because it is a thermal fusion method using glass glue and the lead is not directly bonded to each other, and electrical connection between the leads cannot be obtained.

(2) - Solder connection method: After peeling off the lead laminate tape's silky layer and joining the lead tapes together with solder, the solder layers are heat-sealed to each other. This provides both water barrier properties and electrical connection. However, since the temperature is raised above the melting point of lead tape, the metal crystal structure of the lead tape becomes coarse and its strength, fatigue properties, etc. deteriorate. Furthermore, as the lead tape gets into the interface, the thickness of the connection increases, and at the same time, the flexibility of this part decreases significantly.
Since the conductor has a cast structure and is brittle, various stresses and strains tend to concentrate in this part, which has the disadvantage of causing breakage and damage at the connection part during cable manufacturing and cable installation.

The present invention has been made in view of these shortcomings, and provides a simple and reliable method for connecting low-strength lead laminated Tesos to each other, allowing strong direct bonding of the lead to each other without using a conductor. The purpose is to provide a high-quality subjunctive method.

That is, in the present invention, when connecting lead laminated tags in which a plastic film is laminated on one or both sides of a lead foil, after peeling off the plastic film, the lead surfaces are overlapped with each other, and the overlapping portion is treated with ultrasonic waves. This is a method for connecting lead epsilon tape, which is characterized by welding.

In the present invention, when R11< shown in FIG. , q , , v'TV connection area was peeled off and both ships' tape 10. The stern surfaces of the IQ' are stacked so that they are in direct contact with each other, and then placed on a flat plate 4 as shown in Figure 2, and ultrasonic waves are applied in a direction square to the lead tape surface while applying static pressure from above. Gives vibration. Then,
Friction occurs at the interface between two stacked lead tapes, and the frictional heat causes the very thin lead at the interface to reach its melting point and weld. Thereafter, the folded plastic film layer 2.2' is returned to its original position and fused. FIG. 3 shows the state in which the connection has been completed. In addition, in FIG. 2, 5 is a horn attached to the tip of the ultrasonic vibrator 6, 7 is a tip attached to the tip of the horn 6, and 8 is an arrow indicating the direction of applying static pressure. and 9 are bidirectional arrows indicating the direction of vibration of the thousand tubes 7.

In this way, the lead in the very thin part only at the contact interface of the lead tape reaches its melting point and is welded, so a strong bond can be obtained even though the lead tape in the entire overlap group does not deform or melt. Therefore, the effect of heat on the lead tape is limited to only the very thin part at the interface, and the lead tape in the entire overlap group is not affected by heat, so there is no change in the metal structure of lead in this part, and therefore mechanical There is no decrease in strength. Therefore, the present invention does not require solder or flux, does not require external heating, and the working time is extremely short at 1 to 3 seconds. Because of this strong bond, the mechanical properties of the lead tape in the bonded area are practically the same as those of the lead tape itself in the non-bonded area.

Next, the present invention will be explained with examples.

(Example 1) In the connection of a lead-laminated Teso in which a 50-μm-thick polyethylene film (hereinafter referred to as PE) was laminated on both sides of a lead plate 7' (50 μm thick), after removing the pg at the overlapping part, A static pressure of 6.5 kg was applied from above and a frequency of 28 kHz.

The lead tapes were joined together using ultrasonic welding with an amplitude of 2.4 μm for a welding time of 3 seconds. Thereafter, pg was fused to the joint.

Next, in manufacturing the 5 KVCE cable, the above lead laminate tape (P
E/Pb/Pg) was applied vertically, and the vertically applied lap part was heat-sealed, and then a polyethylene sheath was extruded and covered, and this vertically applied layer was removed, and the water-blocking layer and sheath were fused and integrated. Ta. Note that one tape connection was included for each 3 m cable length.

(Example 2) In the connection of a lead laminated tag made by laminating a 100 μm thick polyvinyl chloride resin film (hereinafter referred to as PVC) on both sides of a lead wire f (50 μm thick), the PVC at the overlapped portion was removed. Ultrasonic welding was performed under the same conditions as in Example 1, and then PvC was fused to this joint.

Next, in the manufacture of 6 KVCV cables, the above-mentioned lead laminated tag (P) is attached to the outside of the cable core.
VC/Pb/PVC) were longitudinally attached and the longitudinally attached wrap portion was heat-sealed, and then a vinyl chloride resin sheath was extruded and covered, and the lead tape longitudinally attached layer and sheath were fused and integrated. still,
One tape connection was included for each 3m cable length.

(Example 3) When connecting a lead laminate tape made by laminating a 150 μm thick conductive PK (PE containing carbon black) on both sides of a lead tape (100 μm), the following was carried out after removing the conductive PG at the overlapping part. Connection was made in the same manner as in Example 1.

Next, in manufacturing the 6KvCv cable, the above-mentioned lead laminate tag (conductive PE/Pb/conductive PE) that has been connected is placed vertically on the cable insulator, and after being closely integrated with the insulator, Copper tape shielding and vinyl chloride resin anti-corrosion layer were applied respectively. Tape connection is cable length 3
One location is included for +n.

Comparative Example Using the same lead laminate tape as used in Example 1, one side of the PI'C where the connection is to be made is peeled and folded back, and the other side is removed.
- Coat the lead tape with the lead tape, and then put the folded PE back on top of the overlapped part of the lead tape. Joined each other and 7.

Next 6! (V(di): The cable was manufactured in the same manner as in Example 1. The tape connection was made at one point per 3 m of cable length.

Next, the tensile strength of the connection portion of each lead laminate tape obtained in Examples 1, 2.3 and Comparative Example above is shown.

The properties of elongation and repeated bending are shown in Table 1 as relative values when each property of the lead-filled laminate Teso before connection is taken as 1.

In addition, Table 2 shows the results of the bend test (bending at a diameter 10 times the outside diameter of the cable 10 times, then disassembling it and observing it) conducted on each of the cables obtained in Examples 1, 2.3 and Comparative Examples. Indicated.

Table 1 Table 2 Note that the lead structure in the vicinity of the joint of the lead laminate tape in the comparative example that was soldered was coarsened, and various mechanical property tests also showed that it was difficult to assemble the tape vertically into the cable. Even in the cable pend test in the open state, the laminate Teso's
On the other hand, in the lead laminated tags connected according to the present invention, the fractures occurred randomly both at the joints and at other positions, and there was no tendency for the joints to be particularly prone to fractures.

As described above, the lead laminate tape connected according to the present invention does not suffer from any thermal deterioration of the lead at the connection part, so it has mechanical properties equivalent to parts other than the connection part, and it can be easily integrated into the cable. In this case, not only water-shielding properties and electrical properties, but also various cable properties including pend properties are virtually unchanged from other parts than the connection part, and have practically good properties.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the overlapping part showing the state of connection of the lead laminated tag according to the present invention, FIG. 2 is a schematic explanatory diagram of the ultrasonic welding device according to the present invention, and FIG. FIG. 3 is a cross-sectional view of a connecting portion where two lead laminate tapes are connected to each other. 1.1'...lead laminate teno, 2.2', 1゜3'...plasti, kufilm layer, 4...flat plate, 5
... Ultrasonic vibrator, 6... Horn, 7... Chip, 8... Arrow indicating direction of static pressure, 9... Bidirectional arrow indicating vibration direction, 10.10'--・Lead tape. Applicant's agent Patent attorney Takehiko Suzue 1 figure 2 figures 3 F'J

Claims (1)

[Claims] When connecting lead-plated tenos in which a glass film is laminated on one or both sides of lead foil, the plastic film is peeled off, the lead surfaces are overlapped, and the overlapping portion is welded using ultrasonic waves. How to connect lead laminated tags.