CN104242174A - Manufacturing method of intermediate cable joint - Google Patents

Abstract

The invention provides a manufacturing method of an intermediate cable joint, and belongs to the technical field of cable connection. According to the technical scheme, the manufacturing method comprises the steps of straightening and wiping a cable, stripping off an outer sheath from an installation position to a wiring terminal, binding a steel armor through a constant-force spring along the steel armor, and then forming an annular gash in the binding direction of the steel armor in a sawing mode; winding two layers of filling adhesives around the part from the position 50 mm below a fracture and the whole constant-force spring, the steel armor and an inner protection layer, winding three layers of filling adhesives around a divergence part, and fixing a ground wire with one end divided into three strands to a three-phase copper shield through three small constant-force springs; winding a layer of black self-adhesive tape around the filling adhesives and the small constant-force springs, winding a PVC belt around the part within 100 mm above the end of a fingerstall after a shielding layer is cleaned, measuring the length of a crimping core wire of the wiring terminal, stripping off a main insulating layer according to the size, and crimping the wiring terminal; sleeving cable cores with the tail ends of cold contraction tubes, aligning the cold contraction tubes with a limiting line, and winding conductor self-adhesive tape around all the cold contraction tubes and the end of the cold contraction fingerstall respectively after contraction.

Description

The manufacture method of cable intermediate joint

Technical field

The invention belongs to technical field of cable connection, particularly relate to a kind of manufacture method of cable intermediate joint.

Background technology

Cable terminal is the parts be connected with other electric equipments by cable, and cable intermediate joint is the parts coupled together by two cables, and cable terminal and transition joint are referred to as electric cable accessories.Electric cable accessories should equally with cable body can long-term safety run, and has the useful life identical with cable.Good electric cable accessories should have following performance:

Core is connected: mainly connection electrical resistance is little and connect stable, can stand the impact of fault current; After long-time running, its contact resistance should not be greater than cable core body with 1.2 times of length resistance; Certain mechanical strength, vibration resistance, decay resistance should be had; Answer that volume is little, cost is low, be convenient to in-site installation in addition.

Good insulation preformance: the insulation property of electric cable accessories should be not less than cable body, and the dielectric loss of insulating material used is low, the sudden change structurally tackling electric field in electric cable accessories can improve process, the measure of the Electric Field Distribution that changes.

Summary of the invention

The invention provides a kind of manufacture method of cable intermediate joint, the present invention is realized by following technical proposals:

(1) cable alignment, to clean, peel off the oversheath from installation site to binding post, along steel armour, steel armour is tied with constant force spring, then pack tightly direction along steel armour and saw an annular gash;

(2) below fracture, 50mm is to whole constant force spring, steel armour and sheath, and be wound around two-layer with filling glue, junctions place twines one deck more, and ground wire one end being divided into three strands is fixed in three-phase copper shield with three little constant force springs respectively;

(3) outside filling glue and little constant force spring, twine one deck black self-adhesive tape, after clean screen, within fingerstall termination up 100mm, be wound around PVC band, measure the length of binding post crimping heart yearn, peel off main insulating layer by size, compression bonded line terminal;

(4) cold shrink tube terminal be inserted in cable core and align with spacing line, the port of each phase cold shrink tube and shrinkage fingerstall holds semiconductor self-adhesive tape after shrinking respectively.

Embodiment

Below by specific embodiment, the present invention is further illustrated.

1, oversheath is shelled: by cable alignment, clean, peel off the oversheath (by constant force spring temporarily around oversheath cut-off part, oversheath can be peelled off to facilitate) from installation site to binding post;

2, steel armour is sawed: steel armour ties along steel armour by temporary constant force spring, then pack tightly direction along steel armour and saw an annular gash, (not sawed-off second layer steel armour, prevent from hurting cable), lever up (disconnection of steel armour limit) with straight screwdriver, leave behind with pliers again and turn Song Gangkai, deviating from steel armour band, handle the burr at sawed-off place well.Whole process all will pack tightly direction along steel armour, and the steel armour on cable can not be allowed to get loose;

3, shell inner sheath: key point, prevent from scratching copper shield.Stay steel armour 30mm, inner sheath 10mm, and be wound around steel armour with loosening with tied silk or PVC band.PVC band in copper shield termination tightly wraps, with loosening and scuffing cold shrink tube;

4, install steel armour earth connection: delta-ring cone is firmly filled in cable turnoff, paint, iron rust on removing steel armour, be fixed on steel armour ground wire on steel armour with large constant force spring.For fixation, ground wire should reserve 10 ~ 20mm, and constant force spring reserved part reflexed, then is wound around with constant force spring after being wound around a circle;

5, twine filling glue: 50mm is to whole constant force spring, steel armour and sheath below fracture, be wound around two-layer with filling glue, junctions place twines one deck more, and the shrinkage fingerstall made like this is full to be enriched;

6, fixed copper bonding line: ground wire one end being divided into three strands is fixed in three-phase copper shield with three little constant force springs respectively, twines and spring is pushed away inward afterwards as far as possible.Steel armour ground wire is separated with copper shield ground wire, not short circuit;

7, shrinkage 3 core branch is installed: undertaken by the requirement of electric cable accessories specification;

8, be set with shrinkage protecting pipe: outside filling glue and little constant force spring, twine one deck black self-adhesive tape, make the plastic strip in shrinkage fingerstall be easy to extract out.Three of finger tip little stay pipes are extracted a bit (see from inner and refer to that root aligns) slightly, then fingerstall is inserted in presses down as far as possible, plastic strip will be held to extract out counterclockwise.After clean screen, PVC band is wound around within fingerstall termination up 100mm, by shrinkage pipe box to fingerstall root, counterclockwise extraction plastic strip, with hand steered cold shrink tube end when taking out, unclamp behind location, do not hold the cold shrink tube of not shrinking always, excise according to the distance of cold shrink tube termination to binding post or lengthen cold shrink tube or excise unnecessary core;

9, copper shield is shelled: carry out form and aspect mark at cable core crotch, by electric cable accessories specification, correct measurement good copper shield cut-off part position, (wrap with PVC band, prevent copper shield from unclamping), or tighten with copper wire inside cut-off part, tighten direction along copper strips and (note scratching semiconductor layer along the standardized shallow trace of copper wire cutter! ), slowly torn by copper shield band, last suitable copper strips is tightened direction and is taken off copper wire;

10, shell outer semiconducting layer: be outer semiconducting layer fracture from copper strips fracture 10-20mm place (being as the criterion with specification given size), wrap a circle adhesive tape inside fracture and mark.1. peelable release outer semiconducting layer processing method, in predetermined semi-conductive layer stripping place (outside adhesive tape), with the standardized annellation of cutter, draw two perpendicular traces from annellation to end, spacing is about 10mm.Then by a little bar shaped semi-conductive layer from end tear to annular trace direction (note, can not semi-conductive layer inside pull-up annellation! ), do not answer Damage to insulation layer with during cutter cut, semi-conductive layer fracture should be neat.Check that main insulating layer surface is with or without tool marks and residual semiconductive material, if any cleaning out.2. can not exfoliated outer semiconducting layer processing method, from heart yearn end, wipe semi-conductive layer (also available dedicated cutter) off with glass, scrape a slope at incision position, fracture wants neat, semiconductive material should not be stayed in main insulating layer surface, and surface should adopt belt sanding smooth.(external shield of 35kV cable mostly is can not be exfoliated)

11, binding post is installed: measured cable fixed position and each phase terminal Len req, amputated unnecessary lead-in wire.Measure the length of binding post crimping heart yearn, peel off main insulating layer by size, compression bonded line terminal.File except binding post crimping burr, corner angle, and cleans up;

12, clean main insulating layer surface: the dirt cleaning main insulation surface with cleaner special, notes time clean to wipe outside semiconductive layer end from insulating end, does not generally oppositely wipe, in order to avoid take semiconducting species to main insulating layer surface;

13, shrink cable termination pipe is installed: twine flat with filling glue by the gap at terminal compression joint position and impression.Cold shrink tube terminal be inserted in cable core and align with spacing line, pulling support bar gently, cold shrink tube is shunk;

14, sealed port: the port of each phase cold shrink tube and shrinkage fingerstall holds semiconductor self-adhesive tape after shrinking respectively.Like this, cold shrink tube outer semiconductor layer and cable outer semiconductor screen good contact can be made, axially waterproof and dampproof effect can be played again.

Make shrinkage cable end points for attention:

1, the making of cold-shrink cable terminal must be carried out in fine, air dried situation.Construction site should be cleaned, without the dust flown upward or paper scrap.Standard GB/T 50168-92 " cable line construction and acceptance specification " 6.1.3 article of regulation: " when manufacturing plastic insulating power cable terminal and joint, dust should be prevented, foreign material fall in insulation.Forbid at mist or construct in the rain ".If on the make do not note the impact of environmental factor, air gap will be formed owing to entering dust, impurity etc. in cable end insulation, and under strong electric field partial discharge occur, then develop into insulation breakdown, cause the fault that cable end punctures.If made in a humid environment, then cable easily makes moist and integral insulation level is declined, and also easily enters moisture in addition and forms air gap and occur partial discharge;

2, divest semiconductive shielding layer and remove clean: semiconductive shielding layer is a very important part of cable.Cable conductor forms by multiple conducting wires is stranded, and easily form air gap between it and insulating barrier, conductive surface is rough, and electric field can be caused to concentrate.Add the screen of one deck semiconductive material at conductive surface, the conductor equipotential of it and conductively-closed and with insulating barrier good contact, thus avoid, between conductor and insulating barrier, partial discharge occurs, this one deck is shielding for internal shield; Also gap may be there is equally at insulating surface and sheath contact position, it is the factor causing partial discharge, therefore the screen of one deck semiconductive material is added at surface of insulating layer, the insulating barrier of it and conductively-closed has good contact, with metallic sheath equipotential, thus avoid, between insulating barrier and sheath, partial discharge occurs, this one deck is shielding for outer shielding layer;

Semiconductive shielding layer mainly plays uniform electric field in the cable and eliminates air gap, reduces or eliminate the effect of partial discharge electricity.But must divest when making cable end and remove clean, its main purpose is used to guarantee high pressure creepage distance over the ground;

Standard GB/T 50168-92, " cable line construction and acceptance specification " 6.2.5 article regulation: " plastic insulated cable, when making terminals and joint, thoroughly should remove semiconductive shielding layer.If " do not divest semiconductive shielding layer or do not clean up, there is edge flashing because creepage distance is easy not at binding post place on the one hand, also easily produce air gap on the other hand and cause partial discharge;

3, should take to improve around semi-conductive tape etc. the measure that cable shield Analysis of End Electric Field concentrates: standard GB/T 50168-92 " cable line construction and acceptance specification " 6.2.3 article of regulation: " terminal of 6kV and above power cable and joint; still should be improved the effective measures that cable shield Analysis of End Electric Field is concentrated, and the alternate and distance to the ground of external insulation should be guaranteed." the copper shield incision position of cable terminal and binding post end, because electric field is concentrated, need to take to improve around semi-conductive tape etc. the measure that electric field concentrates.If do not take these measures, then can make to run cable and concentrate at screen incision position electric field, become weak link, easily cause cable insulation breakdown fault;

4, after completing, leak stopping, protection against the tide and seal approach should be taked: standard GB/T 50168-92, " cable line construction and acceptance specification " 6.2.11 article of regulation: " assembling, combination cable terminal and joint time, the cooperation between each parts or lap-joint must take leak stopping, protection against the tide and seal approach.Plastic cable should adopt the modes such as self-adhesive tape, adhesive tape, adhesive (PUR) to seal; Hacking is answered on plastic sheath surface, gluing of surfaces solvent-applied except degreasing, bonding should well ".After shrinkage manufacturing cable head completes, should respectively after shrinking the port of each phase cold shrink tube and shrinkage fingerstall hold semiconductor self-adhesive tape.Like this, cold shrink tube outer semiconductor layer and cable outer semiconductor screen good contact can be made, axially waterproof and dampproof effect can be played again.Holding self-adhesive tape, is the key link of shrinkage joint moisture seal, will hold, and then reserved packet is around to initiating terminal with half overlay method from joint one end to the other end.Every layer hold after, with the hands should hold successively, make it to bond better.Answer pulling force suitable when holding, accomplish to hold closed seamless gap.

If do not take these leak stopping, protection against the tide and seal approach, then cable end is in running, easily progressively infiltrates into moisture, impurity etc., causes cable end Fault of Insulating Breakdown.

In sum, shrinkage manufacturing cable head is a technical stronger job, needs the experienced technical staff of the ability of holding qualification to come.Every preparation should be fully carried out before making cable terminal.Should be specifically noted that in manufacturing process and keep clean, shorten Production Time as far as possible, reduce the possibility invading impurity, moisture, gas, dust etc.According to technological process, in accordance with technological standards, conscientiously complete the making of shrinkage cable end, thus stop or reduce cable end because making quality all kinds of faults that cause.

Claims (1)

1. a manufacture method for cable intermediate joint, is characterized in that comprising the following steps:

(1) cable alignment, to clean, peel off the oversheath from installation site to binding post, along steel armour, steel armour is tied with constant force spring, then pack tightly direction along steel armour and saw an annular gash;

(2) below fracture, 50mm is to whole constant force spring, steel armour and sheath, and be wound around two-layer with filling glue, junctions place twines one deck more, and ground wire one end being divided into three strands is fixed in three-phase copper shield with three little constant force springs respectively;

(3) outside filling glue and little constant force spring, twine one deck black self-adhesive tape, after clean screen, within fingerstall termination up 100mm, be wound around PVC band, measure the length of binding post crimping heart yearn, peel off main insulating layer by size, compression bonded line terminal;

(4) cold shrink tube terminal be inserted in cable core and align with spacing line, the port of each phase cold shrink tube and shrinkage fingerstall holds semiconductor self-adhesive tape after shrinking respectively.