CN114188896A

CN114188896A - Manufacturing process of insulation shielding isolation insulation joint of crosslinked cable

Info

Publication number: CN114188896A
Application number: CN202111310334.5A
Authority: CN
Inventors: 吕殿泉; 罗继宏; 夏鑫
Original assignee: Ruibang Power Technology Co ltd
Current assignee: Ruibang Power Technology Co ltd
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2022-03-15
Anticipated expiration: 2041-11-05
Also published as: CN114188896B

Abstract

The invention discloses a manufacturing process of a cross-linked cable insulation shielding isolation insulation joint, which comprises a wire stripping step, a die preparation step, a conductor welding step, an inner shielding recovery step, an insulation adding step and an outer shielding treatment step. In the double-cylinder curved end stress control body, the inner cylinder and the outer cylinder are in a straight cylinder shape, the isolation joint is small in size, the outer cylinder is connected with the inner cylinder through a stress control arc, the stress control arc is an arc and disperses and homogenizes a possible electric field, the rear end of the joint outer shielding layer surrounds the outer cylinder and is spaced from the outer cylinder, and the dispersed and homogenized electric field cannot be distorted. The inner shielding layer of the connector and the inner shielding layer of the cable can be obtained by clamping and holding the two half-and-half heating cross-linking molds, the transition between the inner shielding layer of the connector and the inner shielding layer of the cable is smooth, the outer peripheral wall of the inner shielding layer of the connector is smooth, the inner shielding layer of the connector stably plays a shielding role, and the cable connector is reliable; the pressure detection and the pressurization extrusion are not required to be set, and the structural form of the die is restrained to give a better insulating extrusion pressure.

Description

Manufacturing process of insulation shielding isolation insulation joint of crosslinked cable

Technical Field

The invention relates to a power cable, in particular to a manufacturing process of a cross-linked cable insulation shielding isolation insulation joint.

Background

The cross-linked power cable is an important component of a power grid system, and is sequentially provided with a cable conductor, a cable inner shielding layer, a cable insulating layer, a cable outer shielding layer, a metal sheath and an outer protective layer from inside to outside. In the cross-linked power cable, the outer protective layer protects the metal sheath, the metal sheath has shielding and waterproof functions, and when a cable conductor passes through current, the metal sheath generates induced voltage.

Generally, a high-voltage cross-linked cable is a single core, eddy current heating of a metal sheath is caused by induced voltage of the metal sheath, and the current-carrying capacity is influenced by a cable conductor along with the heating; furthermore, the induced voltage may penetrate the outer protective layer to threaten the safety of the approaching personnel.

Therefore, the cross-linked power cable is necessary to be provided with an insulating isolation joint at certain intervals, and the grounding wires of the external shields of the adjacent three sections of cables are cross-connected with each other, so that the induced voltage is controlled within a specified range.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a manufacturing process of a cross-linked cable insulation shielding isolation insulation joint, which can disperse and homogenize a possibly occurring electric field, and the dispersed and homogenized electric field can not generate electric field distortion.

According to the first aspect of the invention, the manufacturing process of the insulation shielding isolation insulation joint of the cross-linked cable comprises a wire stripping step, a die preparation step, a conductor welding step, an inner shielding recovery step, an insulation adding step and an outer shielding treatment step;

stripping the wires to expose the cable conductor, the cable inner shielding layer, the cable insulating layer and the cable outer shielding layer in a step-shaped distribution manner;

preparing a die, wherein a constraint die and a double-barrel curved end stress control body are sleeved on a cable in advance, the constraint die is made of silica gel, the double-barrel curved end stress control body comprises an inner barrel, a stress control arc and an outer barrel, the outer barrel is connected with the inner barrel through the stress control arc, and the stress control arc is an arc;

welding the conductors, and welding the two cable conductors in series to obtain a joint conductor;

the inner shielding is recovered, the outer peripheral wall of the joint conductor is firstly wrapped with a semi-conductive cloth belt, then a semi-conductive pipe, a semi-conductive cylinder, a semi-conductive belt, a semi-conductive sheet or a semi-sleeve shaped semi-conductive shielding material is attached, two semi-conductive cross-linking molds clamp the semi-conductive shielding material together, and the two ends of the semi-conductive cross-linking molds extend towards the corresponding inner shielding layers of the cable respectively, a demolding layer is arranged on the inner wall of the semi-conductive cross-linking mold, after the semi-conductive cross-linking molds are heated to a first preheating temperature, the two semi-conductive cross-linking molds are tightened to be meshed, in the tightening process, the redundant semi-conductive shielding material overflows towards the peripheral side of the semi-conductive cross-linking mold and/or overflows towards the inner shielding layers of the cable, the two semi-conductive cross-linking molds keep meshed for a certain time according to the first cross-linking temperature, cooling is carried out after cross-linking, and the redundant semi-conductive shielding material on the inner shielding layers of the cable is removed after cooling, obtaining a joint inner shielding layer;

adding insulation, wherein the restraint mold is sleeved towards the joint, so that the joint inner shielding layer corresponds to the middle part of the restraint mold, two ends of the restraint mold respectively extend towards the corresponding cable insulation layers, one end of the restraint mold is sleeved with a discharge end of a current divider, the other end of the restraint mold is sleeved with the outer barrel, one end of a support heating mold is inserted into a socket of the double-barrel curved end stress control body, the restraint mold is positioned in a forming mold, one end of the forming mold surrounds the one end of the restraint mold, the other end of the forming mold is closed by the support heating mold, after the current divider, the forming mold and the support heating mold are heated to a second preheating temperature, the current divider extrudes and injects insulation rubber material to the restraint mold, and when the insulation rubber material overflows between the inner wall of the support heating mold and the outer wall of the cable insulation layer, stopping the shunt, heating the shunt, the forming die and the supporting and heating die to a second crosslinking temperature, keeping crosslinking for a certain time, cooling after crosslinking, and cooling to obtain an additional insulation, wherein the additional insulation covers the outer peripheral wall of the outer cylinder;

and (2) performing external shielding treatment, namely modifying the added insulation to enable two ends of the added insulation to be in smooth transition with a cable insulation layer, coating semi-conducting paint on the outer peripheral wall of the added insulation, then winding a joint outer shielding belt and a transition outer shielding belt, wherein the joint outer shielding belt extends to the corresponding cable outer shielding layer, the double-cylinder curved end stress control body is connected with the corresponding cable outer shielding layer through the transition outer shielding belt to obtain the joint outer shielding layer and the transition outer shielding layer, and one end of the joint outer shielding layer surrounds the outer cylinder.

According to the manufacturing process of the insulation shielding isolation insulation joint of the crosslinked cable, the manufacturing process has at least the following beneficial effects: the double-cylinder curved end stress control body comprises an inner cylinder, a stress control arc and an outer cylinder, wherein the inner cylinder and the outer cylinder are in a straight cylinder shape, and the manufactured isolation joint is small in size; the stress control arc is a circular arc, and effectively disperses and homogenizes the electric field which possibly occurs, so that the electric field distortion is avoided; the inner shielding layer of the connector and the inner shielding layer of the cable can be obtained by clamping and holding the two half-and-half heating cross-linking molds, the transition between the inner shielding layer of the connector and the inner shielding layer of the cable is smooth, the outer peripheral wall of the inner shielding layer of the connector is smooth, the inner shielding layer of the connector stably plays a shielding role, the electric field distortion is not easy to occur, the inner shielding layer of the connector is reliable, the quality is good, and the cable connector is reliable; the insulating rubber material flows and expands along the axial direction and the radial direction of the constraint mould according to the pressure given by the structure of the constraint mould in the extrusion process, the insulating rubber material expands to constrain the mould and flows towards the rubber outlet, the insulating rubber material in the constraint mould is kept at proper pressure all the time, and the excessive rubber between the inner wall of the supporting and heating mould and the outer wall of the cable insulating layer indicates that the constraint mould is expanded in place.

According to some embodiments of the invention, the stress control arc is a circular arc with a radius R, 3.2mm < R <7 mm.

According to some embodiments of the present invention, in the inner shield recovering step, the first preheating temperature T1, the two half-heated cross-linking molds are kept at the first cross-linking temperature T2 for a bite time T1, 120 ℃ < T1<160 ℃, 190 ℃ < T2<230 ℃, 25min < T1<60 min; in the insulation adding step, the second preheating temperature T3 is kept for crosslinking time T2, 120 ℃ and < T3<160 ℃, 180 ℃ and < T4<230 ℃, and 15min and < T2<50min according to the second crosslinking temperature T4.

According to some embodiments of the invention, the second preheating temperature T3, 120 ℃ < T3<160 ℃, the inner wall of the supporting heating die and the cable insulation layer have a predetermined glue-out gap D2, 2mm < D2<6 mm.

According to some embodiments of the present invention, an end surface of the other end of the restraint mold abuts against the support heating mold or has a predetermined interval from the support heating mold, the support heating mold is provided with a shear rubber flange, and the end surface of the other end of the restraint mold corresponds to the shear rubber flange.

According to some embodiments of the invention, the constraining mold is made of silicone rubber.

According to some embodiments of the invention, an outer metal shielding net is laid on the outer peripheral wall of the joint outer shielding layer and used for connecting a metal sheath at one end, and a stress control body metal shielding net is laid on the outer peripheral wall of the double-cylinder curved end stress control body and extends into the socket of the double-cylinder curved end stress control body and is used for connecting a metal sheath at the other end.

According to some embodiments of the invention, at least one of the mold halves is provided with an overflow glue shearing blade for meshing.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic structural view of a cross-linked cable according to an embodiment of the present invention after stripping;

FIG. 2 is a schematic structural diagram of an insulation shield and isolation insulation joint of a cross-linked cable according to an embodiment of the present invention;

FIG. 3a is a front part of a process for manufacturing a cross-linked cable insulation shield isolation insulation joint according to an embodiment of the present invention;

FIG. 3b is a rear part of a process for manufacturing a cross-linked cable insulation shield isolation insulation joint according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a crosslinked cable according to an embodiment of the present invention when molds are prepared in an insulation adding process;

FIG. 5 is a cross-sectional view of a flow diverter according to an embodiment of the present invention;

FIG. 6 is an exploded perspective view of a diverter according to an embodiment of the present invention;

FIG. 7 is a cross-sectional view of an embodiment of the present invention supporting a heated mold;

FIG. 8 is a cross-sectional view of a constraining mold according to an embodiment of the present invention;

FIG. 9 is a cross-sectional view of a dual barrel curved end stress control body according to an embodiment of the present invention;

fig. 10 is a first schematic structural perspective view of a stress control body at a curved end of a double tube according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a stereoscopic view angle of a double-cylinder curved-end stress control body according to an embodiment of the invention;

FIG. 12 is a front view of a heated cross-linking mold closed in half according to an embodiment of the present invention;

FIG. 13 is a schematic perspective view of a mold for thermal crosslinking according to an embodiment of the present invention.

The cable comprises a cable conductor 110, a cable inner shielding layer 120, a cable insulating layer 130, a cable outer shielding layer 141, a joint outer shielding layer 142, a transition outer shielding layer 143, a double-cylinder curved end stress control body 144, an inner cylinder 144a, a stress control arc 144b, an outer cylinder 144c, an outer metal shielding net 151, a stress control body metal shielding net 152, a metal sheath 160 and additional insulation 170;

a constraint mold 200, a first insulation counterpart 210, an inner shield counterpart 220, a second insulation counterpart 230, a stress control body counterpart 240;

the semi-heated cross-linking mold 300, the heating mold body 310, the cross-linking molding cavity 320, the overflow glue shearing knife 321, the guide post 330, the guide hole 340, the connector lug 350 and the overflow glue vacancy 360;

a flow divider 400, a half inner mold 410, and a half outer mold 420;

supporting the heating mold 500, the glue cutting flange 510;

the mold 600 is formed.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and more than, less than, more than, etc. are understood as excluding the present number, and more than, less than, etc. are understood as including the present number. If any, the description to the first and second is only for the purpose of distinguishing technical features, and is not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Crosslinking is a structural change, the microstructure of the material changes, and the linear structure changes into a network structure. The material after cross-linking modification is tougher and resistant to high temperature, and still keeps the shape under the condition of heating to be transparent.

Referring to fig. 3a and 3b, a manufacturing process of an insulation-shielding isolation insulation joint of a crosslinked cable according to an embodiment of the first aspect of the invention includes a wire stripping step, a mold preparation step, a conductor welding step, an inner shielding recovery step, an insulation adding step, and an outer shielding treatment step.

The cable is stripped, so that the cable conductor 110, the cable inner shield layer 120, the cable insulation layer 130 and the cable outer shield layer 141 are exposed in a step-like distribution (see fig. 1, see the second state diagram of fig. 3 a).

The method includes the steps of preparing a die, sleeving a restraining die 200 and a double-barrel curved end stress control body 144 on a cable in advance (the prepared restraining die 200 and the double-barrel curved end stress control body 144 are hidden in a second state diagram of fig. 3 a), wherein the restraining die 200 is made of silica gel, the double-barrel curved end stress control body 144 comprises an inner barrel 144a, a stress control arc 144b and an outer barrel 144c, the outer barrel 144c is connected with the inner barrel 144a through the stress control arc 144b, and the stress control arc 144b is an arc. The structure of double-barrel curved end stress control body 144 can be seen in fig. 4, 9-11. The stress control body is of a double-cylinder curved end structure, so that it can be understood that the inner cylinder 144a and the outer cylinder 144c are in a straight cylinder shape, the double-cylinder curved end stress control body 144 has a preset shape structure, and the outer cylinder 144c is in a structural shape of 'flanging' relative to the inner cylinder 144 a; the inner cylinder 144a and the outer cylinder 144c are transitionally connected by a stress control arc 144 b. Wherein 'out' is the corresponding understandable radially outward direction for articles in the form of inner cylinder 144 a.

In practice, the restraining die 200 is smaller than the outer diameter of the cable, so the restraining die 200 is expanded by an expanding tool, the expanded restraining die 200 is sleeved on the cable, and the expanding tool can be a spiral line framework or the like. The expanding tool is removed and the constraining die 200 and the double-barrel curved end stress control body 144 recover their shapes.

The dual-barrel curved end stress control body 144 is integrally formed, such as by injection molding/casting in a mold, such as 3D printing; referring to fig. 9, it will be appreciated that in some embodiments, the inner cylinder 144a has a slight draft for demolding, and the double cylinder curved end stress control body 144 can be released from the mold after extrusion/casting/3D printing.

In the conductor welding step, the two cable conductors 110 are welded in series to obtain a joint conductor (see the third state diagram of fig. 3 a).

The inner shielding is recovered, the outer peripheral wall of the joint conductor is firstly wrapped with a semi-conductive cloth belt, then a semi-conductive pipe, a semi-conductive cylinder, a semi-conductive belt, a semi-conductive sheet or a semi-sleeve shaped semi-conductive shielding material is attached, the two semi-heated cross-linking molds 300 clamp the semi-conductive shielding material together, two ends of the semi-heated cross-linking molds 300 respectively extend towards the corresponding cable inner shielding layers 120, the inner walls of the semi-heated cross-linking molds 300 are provided with demolding layers, after the semi-heated cross-linking molds 300 are heated to a first preheating temperature, the two semi-heated cross-linking molds 300 are tightened to be occluded, in the tightening process, the redundant semi-conductive shielding material overflows towards the peripheral sides of the semi-heated cross-linking molds 300 and/or overflows towards the cable inner shielding layers 120, the two semi-heated cross-linking molds 300 are kept occluded for a certain time according to the first cross-linking temperature, cooling is carried out after cross-linking, the redundant semi-conductive shielding material on the cable inner shielding layers 120 is removed after cooling, and obtaining the joint inner shielding layer.

Those skilled in the art will appreciate that the semiconductive tube, the semiconductive barrel, the semiconductive tape, and the semiconductive sheet are made of a shielding material for the cable. The semi-conductive cloth belt is a belt-shaped material mixed with cloth threads in the shielding material for the cable. The semi-conductive belt and the semi-conductive sheet are in a belt shape and are relatively similar in shape, the semi-conductive sheet is harder than the semi-conductive belt, and the semi-conductive belt and the semi-conductive sheet are attached to the semi-conductive cloth belt in a winding mode. The two semi-sleeve-shaped semi-conductive shielding materials can be spliced into a sleeve-shaped semi-conductive shielding material.

The structure of the mold 300 for half-heating crosslinking is shown in fig. 12 and 13. Since both ends of the half-and-half heated cross-linked mold 300 extend toward the corresponding cable inner shield layers 120, it can be understood that the half-and-half heated cross-linked mold 300 is longer than the joint conductor.

The mold is a half-and-half structure, and the half-and-half heated cross-linking mold 300 is used for clamping and receiving the semiconductive shielding material, so it can be understood that the inner wall surface of the half-and-half heated cross-linking mold 300 is a half of a cylindrical surface, and the inner peripheral wall of the half-and-half heated cross-linking mold 300 is a flat wall surface. According to the structure and the function of the semi-heating cross-linking mold 300, the joint inner shielding layer can be obtained by clamping and holding the two semi-heating cross-linking molds 300, the redundant semi-conductive shielding materials are cut by an overflow glue shearing knife or the end part overflows outwards, the joint inner shielding layer only needs to be slightly polished, and the joint inner shielding layer is directly a flattening piece which can reliably shield an electric field.

The inner shielding layer of the connector can be obtained by clamping and contracting the two half-and-half heating cross-linking molds 300, so that a person skilled in the art can understand that the forming channel defined by the half-and-half heating cross-linking molds 300 has the same diameter or slightly larger than the outer diameter of the inner shielding layer 120 of the cable; for cables with different sizes, the molding channels defined by the two half-and-half heating crosslinking molds 300 are of corresponding sizes, that is, the half-and-half heating crosslinking molds 300 are of corresponding specifications.

Referring to fig. 4, referring to the fifth state diagram of fig. 3a, during the insulation addition, the restraint mold 200 is fitted to the connector sleeve, so that the inner shielding layer of the connector corresponds to the middle of the restraint mold 200, two ends of the restraint mold 200 respectively extend to the corresponding cable insulation layers 130, one end of the restraint mold 200 is fitted to the discharge end of the shunt 400, the other end of the restraint mold 200 is fitted to the outer cylinder 144c of the dual-cylinder curved end stress control body 144, one end of the support heating mold 500 is inserted into the socket of the dual-cylinder curved end stress control body 144, the restraint mold 200 is located in the forming mold 600, one end of the forming mold 600 embraces one end of the restraint mold 200, the other end of the forming mold 600 is closed by the support heating mold 500, after the shunt 400, the forming mold 600 and the support heating mold 500 are heated to the second preheating temperature, the shunt 400 extrudes the insulation rubber material to the restraint mold 200, and when the insulation rubber material overflows between the inner wall of the support heating mold 500 and the outer wall of the cable insulation layers 130, the shunt 400 is stopped, the shunt 400, the molding die 600, and the support heating die 500 are heated to the second crosslinking temperature and are kept crosslinked for a certain time, cooling is performed after crosslinking, cooling is performed to obtain the additional insulation 170, and the additional insulation 170 covers the outer peripheral wall of the outer cylinder 144 c.

The added insulation 170 (joint insulation) is known to those skilled in the art as cable insulation.

Referring to fig. 4, the left end of the forming mold 600 surrounds the left end of the constraining mold 200, and the right end of the constraining mold 200 is sleeved with the outer cylinder 144 c. The flow divider 400, the forming mold 600, and the supporting heating mold 500 may perform heating, so it is understood that the flow divider 400, the forming mold 600, and the supporting heating mold 500 are all embedded with heating structures.

Since the additional insulation 170 covers the outer peripheral wall of the outer tube 144c, the rear end of the joint outer shield layer 142 surrounds the outer tube 144c after the joint outer shield layer 142 described below is added and attached with insulation.

In some embodiments of the present invention, the heating structure supporting the heating mold 500 is a stress control body heating structure that extends to the front end of the supporting heating mold 500, which may heat the stress control arc 144 b. In the insulating crosslinking, the stress control body heating structure provides a second crosslinking temperature for the stress control arc 144b, so that the insulating rubber material is firmly attached to the stress control arc 144b during crosslinking, the stress control arc 144b is tightly insulated and has no gap with the added insulation, and the homogenization control of the stress control arc 144b on an electric field is effectively ensured.

Referring to fig. 4, the middle portion of the constraint mold 200 is used for corresponding to the joint inner shielding layer, two ends of the constraint mold 200 respectively extend to the corresponding cable insulation layers 130, and one end of the constraint mold 200 is sleeved with the discharge end of the shunt 400. It can be understood that the constraining mold 200 includes the fixed end, the first insulation counterpart 210, the inner shield counterpart 220, the second insulation counterpart 230, and the stress controller counterpart 240, and the first insulation counterpart 210, the inner shield counterpart 220, the second insulation counterpart 230, and the stress controller counterpart 240 are sequentially disposed in the axial direction of the constraining mold 200. The shunt 400 and the molding die 600 together clamp the fixed end, and the stress control body corresponding portion 240 is fitted over the outer cylinder 144 c. Because the insulating rubber material has a certain melting degree, the restraint mold 200 is designed into a structure with a preset size, the insulating rubber material in the restraint mold 200 always keeps proper pressure, the added insulation 170 is tight and firm, and the added insulation 170 is tightly attached to the inner shield; during the crosslinking reaction, the firm additional insulation 170 is fully crosslinked and denatured, the additional insulation 170 during the crosslinking reaction is effectively integrated with the cable insulation, and the crosslinked and denatured additional insulation 170 is effectively and tightly attached to the inner shield.

And (3) performing external shielding treatment, namely modifying the additional insulation 170 to enable two ends of the additional insulation 170 to be in smooth transition with the cable insulation layer 130, coating semi-conducting paint on the outer peripheral wall of the additional insulation 170, then winding a joint external shielding tape and a transition external shielding tape, wherein the joint external shielding tape extends to the corresponding cable external shielding layer 141 (refer to fig. 2, the joint external shielding tape extends to the cable external shielding layer 141 on the front side), the double-cylinder curved-end stress controller 144 is connected with the corresponding cable external shielding layer 141 through the transition external shielding tape (refer to fig. 2, the double-cylinder curved-end stress controller 144 is connected with the cable external shielding layer 141 on the rear side through the transition external shielding tape) to obtain a joint external shielding layer 142 and a transition external shielding layer 143, one end of the joint external shielding layer 142 surrounds the outer cylinder 144c, and the transition external shielding layer 143 is used for smooth transition connection.

The isolation joint made by the invention is shown in figure 2. A cross-linked cable insulation shielding isolation insulation joint is characterized in that a cable conductor, a cable inner shielding layer, a cable insulation layer and an outer shielding layer are sequentially arranged from inside to outside, the outer shielding layer is sequentially provided with a first cable outer shielding layer, a joint outer shielding layer, a double-drum curved end stress control body and a second cable outer shielding layer along the axial direction of the joint, the joint outer shielding layer is connected with the first cable outer shielding layer, the double-drum curved end stress control body comprises an inner drum, a stress control arc and an outer drum, the inner drum 144a is in a straight drum shape, the outer drum 144c is connected with the inner drum 144a through the stress control arc 144b, the stress control arc 144b is an arc, one end, far away from the first cable outer shielding layer, of the joint outer shielding layer surrounds the outer drum, and the second cable outer shielding layer is connected with the inner drum. Referring to fig. 2, the outer shielding layer is sequentially provided with a first cable outer shielding layer, a joint outer shielding layer, a double-cylinder curved end stress control body and a second cable outer shielding layer from front to back, the front end of the joint outer shielding layer is connected with the rear end of the first cable outer shielding layer, the rear end of the joint outer shielding layer surrounds the outer cylinder, and the front end of the second cable outer shielding layer is connected with the inner cylinder.

Referring to fig. 2, as can be known to those skilled in the art, the connection between the outer shielding layer 142 of the connector and the outer shielding layer of the first cable is a smooth transition connection, and the connection between the outer shielding layer of the second cable and the inner tube 144a is a smooth transition connection.

When the insulated joint is manufactured in a field environment, the semi-heated cross-linking mold 300, the shunt 400, the molding mold 600, the supporting heating mold 500, and the like may be supported by corresponding landing supports.

According to the manufacturing process of the insulation shielding isolation insulation joint of the crosslinked cable, the manufacturing process has at least the following beneficial effects: the double-cylinder curved end stress control body 144 comprises an inner cylinder 144a, a stress control arc 144b and an outer cylinder 144c, the inner cylinder 144a and the outer cylinder 144c are in a straight cylinder shape, and the manufactured isolation joint is small in size; stress control arc 144b is a circular arc, stress control arc 144b effectively homogenizes the electric field dispersion that may occur; the connector inner shielding layer can be obtained by clamping and holding the two half-and-half heating cross-linking molds 300, the connector inner shielding layer and the cable inner shielding layer 120 are in smooth transition, the outer peripheral wall of the connector inner shielding layer is smooth, the connector inner shielding layer stably plays a role in shielding, electric field distortion is not prone to occurring, the connector inner shielding layer is reliable and good in quality, and a cable connector is reliable; the insulating rubber material flows and expands along the axial direction and the radial direction of the constraint mould 200 according to the pressure given by the structure of the constraint mould 200 in the extrusion process, the insulating rubber material expands to constrain the mould 200 and flows towards the rubber outlet, the insulating rubber material in the constraint mould 200 always keeps proper pressure, and the excessive rubber between the inner wall of the supporting and heating mould 500 and the outer wall of the cable insulating layer 130 indicates that the constraint mould 200 is expanded to the position; the molding channel defined by the two half-heating crosslinking dies 300 has the same diameter or slightly larger than the outer diameter of the cable inner shielding layer 120.

The tightening and clamping of the two half-and-half heating cross-linking molds 300 is the clamping and clamping type, the diameters of the joint inner shielding layers limited by the two half-and-half heating cross-linking molds 300 and the cable shielding layers are equal (deviation is +/-1 mm), and the inner shielding layers are quickly recovered.

In some embodiments of the present invention, the stress control arc 144b is a circular arc with a radius R, 3.2mm < R <7mm, the stress control arc 144b works well for electric field dispersion equalization, while the volume of the isolated joint is relatively small. More preferably, 4mm < R <6 mm.

In some embodiments of the present invention, the inner shield recovery step, the first pre-heat temperature T1, the two heated cross-linking mold halves 300, maintains the bite time T1, 120 ℃ < T1<160 ℃, 190 ℃ < T2<230 ℃, 25min < T1<60min at the first cross-linking temperature T2. In the insulation adding step, the second preheating temperature T3 is kept for crosslinking time T2, 120 ℃ and < T3 and <160 ℃, 180 ℃ and < T4 and <230 ℃ and 15min and < T2 and <50min according to the second crosslinking temperature T4.

In some embodiments of the present invention, the second preheating temperature T3, 120 ℃ < T3<160 ℃, the inner wall of the support heating mold 500 and the cable insulation layer 130 have a predetermined glue-out gap D2, 2mm < D2<6 mm. The inner wall of the supporting heating mold 500 and the cable insulation layer 130 have a preset glue outlet gap D2, and the molding cavity can discharge internal gas to extrude into the insulation glue; in addition, 2mm < D2<6mm, a semi-solid effective trapped pressure is formed in the restraint mold, and the insulating rubber material at the second preheating temperature is in a melting state to a certain extent, so in the insulating extrusion process, the extruded insulating rubber material can give a stronger bulging pressure to the restraint mold 200, the restraint mold 200 can also reversely give a stronger tamping pressure, the filled added insulation 170 has better quality, no air bubbles exist, and the later-stage crosslinking is sufficient.

In some embodiments of the present invention, the width L1 of one end of the outer shield 142 corresponding to both the double-barrel curved-end stress control body 144 (i.e., the overlap width L1 of the outer shield 142 with the double-barrel curved-end stress control body 144 in radial projection), L1 > 5mm, and the effective distance D1 of one end of the outer shield 142 from the outer barrel 144c, 3mm < D1<5.5 mm. The effective space is used as an isolation space and is used for effectively limiting the homogenized and dispersed electric field, the homogenized and dispersed electric field cannot extend out of the joint, the voltage is below 1000kV, the insulation and isolation of the isolation joint are good, and the power cable is not easy to break down.

In some embodiments of the invention, 6mm < L1<12mm, 3.0mm < D1<5.5 mm.

Referring to fig. 8, in some embodiments of the present invention, the first insulation counterpart 210, the inner shield counterpart 220, and the second insulation counterpart 230 have the same thickness (deviation ± 0.4mm), the first insulation counterpart 210 and the second insulation counterpart 230 have the same inner diameter (deviation ± 0.4mm), the inner diameter of the inner shield counterpart 220 is smaller than the inner diameter of the insulation counterpart, the inner diameter of the insulation counterpart is smaller than the inner diameter of the stress controller counterpart 240, and the thickness of the stress controller counterpart 240 is 50% -80% of the thickness of the insulation counterpart.

In some embodiments of the present invention, the first insulation counterpart 210 and the second insulation counterpart 230 are both spaced apart from the cable insulation 130 by a distance D4, D4 ≦ 18mm, and the inner shield counterpart 220 is spaced apart from the terminal inner shield by a distance D5, D5 ≦ 5 mm. And injecting an insulating glue material with a certain melting degree to the constraint mould 200 at a second preheating temperature, wherein D4 is less than or equal to 18mm, D5 is less than or equal to 5mm, the insulating glue material with a certain melting degree can better push the constraint mould 200, and the insulating glue material filled in the constraint mould 200 is firm and has no air bubbles. Pressure detection and pressurization work are eliminated without setting pressure detection and pressurization extrusion, and the structural form of the die is restrained to give better insulating extrusion pressure.

In some embodiments of the present invention, prior to the mold preparation step, the double-barreled curved end stress-controlling body 144 has been cross-linked, i.e., the microstructure of the double-barreled curved end stress-controlling body 144 has a linear structure that is wholly or partially reticulated.

Referring to FIG. 9, in some embodiments of the invention, the rear end edge of the outer barrel 144c is radiused

In some embodiments of the present invention, in the inner shield recovery step, the joint conductor is covered with the semi-conductive cloth tape, and then the semi-conductive tube, the semi-conductive tape, the semi-conductive sheet, or the semi-sleeve shaped semi-conductive shield material, i.e. the inner semi-conductive shield material and the outer semi-conductive shield material, is attached. The inner semi-conductive shielding material is a semi-conductive cloth belt winding layer, the semi-conductive cloth belt winding layer and the outer semi-conductive shielding material are combined into a whole joint inner shielding layer, and the semi-conductive cloth belt winding layer is derived into a stable substrate of the joint inner shielding layer. When the semi-conductive shielding materials are clamped and collected after the first preheating temperature, the two semi-conductive shielding materials are in a molten state to a certain degree, and the outer semi-conductive shielding materials are compacted inwards along the radial direction.

In the inner shielding recovery, after the two half-and-half heating crosslinking molds 300 are buckled to the semiconductive shielding material, the two half-and-half heating crosslinking molds 300 can be clamped by the clamp. Alternatively, the two mold halves 300 may be connected to corresponding tools/supports, respectively.

The semi-sleeve-shaped semi-conductive shielding material is generally obtained by splitting a semi-conductive pipe/semi-conductive cylinder manually or by equipment, and the semi-sleeve-shaped semi-conductive shielding material is not understood to be semi-sleeve-shaped with accurate size. Even the radian alpha of the semi-sleeve-shaped semi-conductive shielding material actually used,

the two semi-sleeve-shaped semi-conductive shielding materials are assembled to form a semi-conductive shielding cylinder with an overlap.

In some embodiments of the present invention, the end surface of the other end of the constraining mold 200 abuts against the supporting heating mold 500 or is at a predetermined interval from the supporting heating mold 500. Referring to fig. 4, the rear end surface of the restraint mold 200 abuts against or is spaced a predetermined distance from the support heating mold 500.

Referring to fig. 7, in some embodiments of the present invention, the supporting heating mold 500 is provided with a shear flange 510, and the end surface of the other end of the restraining mold 200 corresponds to the shear flange 510. Referring to fig. 4, the rear end of the restraint mold 200 corresponds to the glue shearing flange 510, in the process of extruding and injecting insulation, the insulation glue swells the restraint mold 200, and the rear end of the swelled restraint mold 200 is butted with the glue shearing flange 510. When the insulating glue is extruded to the connecting seam between the supporting heating mold 500 and the forming mold 600 through the glue shearing flange 510, the glue shearing flange 510 shears the part of the overflowed glue, and the supporting heating mold 500, the forming mold 600 and the restraining mold 200 can be detached relatively easily at the later stage.

Referring to fig. 12 and 13, in some embodiments of the invention, at least one of the mold halves 300 is provided with an overflow glue shearing blade 321, the overflow glue shearing blade 321 being for snap engagement. And (3) tightening the two half-and-half heating crosslinking dies 300 to occlusion, wherein in the tightening process, the redundant semi-conductive shielding materials overflow to the occlusion part or the end part of the half-and-half heating crosslinking dies 300, and the overflow glue shearing knife 321 cuts off the semi-conductive shielding materials overflowing from the occlusion part. The tightening process may be further tightening the hoop to complete the engagement of the two half-and-half heated cross-linking molds 300.

Referring to fig. 13, in some embodiments of the present invention, the semi-heated cross-linking mold 300 includes a heating mold body 310 and a cross-linking molding cavity 320 connected to the heating mold body 310, and an electrical heating tube is embedded in the heating mold body 310. When the two half-and-half heating crosslinking molds 300 are spliced, the two crosslinking molding cavities 320 are occluded, the two crosslinking molding cavities 320 clamp the semiconductive shielding material together, and at least one crosslinking molding cavity 320 is provided with an overflow glue shearing knife 321; the half-and-half heating crosslinking mold 300 is provided with an overflow vacancy 360, and the occlusion part of the two crosslinking molding cavities 320 corresponds to the overflow vacancy 360. In the process that the two half-and-half heating crosslinking molds 300 are tightened to be meshed, part of the insulating glue material overflows to the glue overflow vacant site 360, and the glue overflow shearing knife 321 shears the part of the glue overflow.

The heating mold body 310 and the cross-linking molding cavity 320 may be integrally molded or detachably connected.

Referring to fig. 13, in the two mold halves 300, one of which is provided with a guide post 330 and the other of which is provided with a guide hole 340 for connecting the guide post 330, the two mold halves 300 are engaged in a guide direction of the guide post 330. The two half-and-half heating cross-linking molds 300 are stably tightened, when the two half-and-half heating cross-linking molds 300 are meshed, a more accurate forming channel is defined, the semi-conductive shielding material is cross-linked and shaped according to the more accurate forming channel, the outer peripheral wall of the joint inner shielding layer is smooth, the joint inner shielding layer stably plays a shielding role, electric field distortion is not easy to occur, the joint inner shielding layer is reliable and good in quality, and a cable joint is reliable; the peripheral wall of the shield layer in the molded joint may not even be polished.

In some embodiments of the present invention, the semi-heated cross-linking mold 300 is made of one of aircraft aluminum, titanium alloy and aluminum alloy, and the electric heating tube is embedded in the semi-heated cross-linking mold 300. The semi-heated cross-linking mold 300 has higher strength and smaller weight, the semi-heated cross-linking mold 300 conducts heat more uniformly, and the heated cross-linking molding cavity 320 enables the semi-conductive shielding material to be heated uniformly. The semi-conductive shielding material is used as a main heat absorption medium, heat conduction of the semi-heating crosslinking mold 300 is uniform, and heat emitted by the electric heating tube can be absorbed more.

In some embodiments of the invention, the release layer is a polytetrafluoro layer or a high temperature resistant release layer.

Referring to fig. 12 and 13, in some embodiments of the present invention, a connector 350 is connected to the heating mold body 310, and the cable of the electrothermal tube extends to the connector 350. The external power connector can be directly connected with the connector 350, so that the electric heating tube can be connected with a power supply quickly, and the complexity of manufacturing a high-voltage cable connector on site is reduced. The semi-heated cross-linked mold 300 is heated by the electric heating tube, and has higher heating effect compared with electric heating tiles and the like.

In some embodiments of the present invention, the heating mold body 310 is provided with a hole for assembling the electric heating tube, and the heating mold body 310 is connected with an end cap for sealing and covering the hole.

In some embodiments of the present invention, the heating mold body 310 is detachably connected to the cross-linking molding cavity 320, the end cap is screwed to the heating mold body 310, and the end cap is further fastened to the cross-linking molding cavity 320.

In some embodiments of the present invention, at least one of the mold halves 300 is embedded with a temperature sensor.

In some embodiments of the present invention, the sensing end of the temperature sensor abuts against the corresponding cross-linking cavity 320, and the temperature sensor can sense the temperature of the semi-conductive material more quickly and accurately.

Referring to FIG. 4, in some embodiments of the invention, the inner wall of the shunt 400 is a predetermined distance D3, 3mm < D3<5.5mm, from the cable insulation 130.

In some embodiments of the present invention, the constraining mold 200 is made of silicone rubber.

Referring to fig. 6, in some embodiments of the invention, the flow divider 400 is provided with an extrusion port for docking the extruder, a runner, and a discharge runner, which is a sleeve-like runner with one end docking the runner and the other end serving as the discharge end of the docking confinement mold 200. The shunt is used for transforming the insulating rubber material introduced by the extrusion injection port into an annular rubber channel, and the gap between the inner wall of the constraint mould 200 and the outer wall of the cable inner shielding layer is introduced into the insulating rubber material through the annular rubber channel. Therefore, the insulating rubber material is uniformly introduced into the restraint mold 200, and the pressure uniformity of the insulating rubber material is effectively ensured.

Referring to fig. 5 and 6, in some embodiments of the present invention, the flow divider 400 includes an inner mold composed of two inner mold halves 410 and an outer mold half composed of two outer mold halves 420, an outer wall of one inner mold half 410 is connected to an inner wall of the corresponding outer mold half 420 by screws, and the two outer mold halves 420 are assembled by screws.

In some embodiments of the present invention, in the external shielding processing step, the outer circumferential wall of the additional insulation 170 is coated with the semi-conductive paint, and then the joint external shielding tape and the transition external shielding tape are wound, so that the joint external shielding tape and the transition external shielding tape can be tightly attached to the additional insulation 170, and the joint external shielding layer 142 and the additional insulation 170, and the transition external shielding layer 143 and the additional insulation 170 are tight and seamless, so as to avoid electric field distortion.

In some embodiments of the present invention, an outer metal shielding mesh 151 is laid on the outer peripheral wall of the outer shielding layer 142 of the connector, the outer metal shielding mesh 151 is used for connecting a metal sheath 160 at one end, and the metal sheath 160 is suitable for connecting a ground wire. Referring to fig. 1, an outer metallic shielding mesh 151 is used to connect a metallic sheath 160 of the front end of the cable.

Referring to fig. 2, in some embodiments of the invention, the peripheral wall of the double-barrel curved end stress control body 144 is provided with a stress control body metal shielding mesh 152, the stress control body metal shielding mesh 152 extends into the socket of the double-barrel curved end stress control body 144, and the stress control body metal shielding mesh 152 is used for connecting with the other end metal sheath 160. Referring to fig. 1, a stress control body metallic shielding mesh 152 is used to connect the metallic sheath 160 of the cable back end. The stress control body metal shielding mesh 152 effectively absorbs the electric field of the double-cylinder curved end stress control body 144, weakens the electric field which is possibly generated, and the weakened electric field is less likely to be distorted, so that the safety of the cable isolation joint is ensured. The metal sheath 160 is suitable for being connected with a grounding wire, and the cable outer shielding layer 141 is not easy to generate eddy heat and works in a good state, so that the electric power current-carrying capacity is effectively ensured.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. A manufacturing process of a cross-linked cable insulation shielding isolation insulation joint is characterized by comprising the following steps:

stripping the wires to expose the cable conductor (110), the cable inner shielding layer (120), the cable insulating layer (130) and the cable outer shielding layer (141) according to a step-shaped distribution mode;

preparing a die, wherein a constraint die (200) and a double-barrel curved end stress control body (144) are sleeved on a cable in advance, the constraint die (200) is made of silica gel, the double-barrel curved end stress control body (144) comprises an inner barrel (144a), a stress control arc (144b) and an outer barrel (144c), the outer barrel (144c) is connected with the inner barrel (144a) through the stress control arc (144b), and the stress control arc (144b) is an arc;

the conductors are welded, and the two cable conductors (110) are welded in series to obtain a joint conductor;

the inner shielding is recovered, the semi-conductive cloth belt is wrapped on the outer peripheral wall of the joint conductor firstly, then a semi-conductive pipe, a semi-conductive cylinder, a semi-conductive belt, a semi-conductive sheet or a semi-sleeve-shaped semi-conductive shielding material is attached, two semi-conductive shielding materials are clamped and embraced by the semi-heating cross-linking mold (300) together, the two ends of the semi-heating cross-linking mold (300) extend towards the corresponding cable inner shielding layer (120) respectively, a demolding layer is arranged on the inner wall of the semi-heating cross-linking mold (300), after the semi-heating cross-linking mold (300) is heated to a first preheating temperature, the semi-heating cross-linking mold (300) is tightened to be meshed, in the tightening process, the redundant semi-conductive shielding materials overflow to the peripheral side of the semi-heating cross-linking mold (300) and/or overflow to the cable inner shielding layer (120), and the semi-heating cross-linking mold (300) is kept for a certain time according to the first cross-linking temperature, cooling is carried out after cross-linking, and redundant semiconductive shielding materials on the cable inner shielding layer (120) are removed after cooling, so that a joint inner shielding layer is obtained;

adding insulation, wherein the restraint mold (200) extends towards a joint sleeve to enable the joint inner shielding layer to correspond to the middle of the restraint mold (200), two ends of the restraint mold (200) respectively extend towards the corresponding cable insulation layers (130), one end of the restraint mold (200) is sleeved with a discharge end of a shunt (400), the other end of the restraint mold (200) is sleeved with the outer cylinder (144c), one end of a supporting heating mold (500) is inserted into a socket of the double-cylinder curved-end stress control body (144), the restraint mold (200) is located in a forming mold (600), one end of the forming mold (600) surrounds the one end of the restraint mold (200), the other end of the forming mold (600) is closed by the supporting heating mold (500), and after the shunt (400), the forming mold (600) and the supporting heating mold (500) are heated to a second preheating temperature, the shunt (400) extrudes insulating rubber material to the restraint mold (200), when the insulating rubber material overflows between the inner wall of the support heating mold (500) and the outer wall of the cable insulating layer (130), the shunt (400) is stopped, the shunt (400), the forming mold (600) and the support heating mold (500) are heated to a second crosslinking temperature and are kept crosslinked for a certain time, cooling is performed after crosslinking, additional insulation (170) is obtained after cooling, and the additional insulation (170) covers the outer peripheral wall of the outer cylinder (144 c);

and (2) performing external shielding treatment, namely modifying the additional insulation (170) to enable two ends of the additional insulation (170) to be in smooth transition with the cable insulation layer (130), coating semi-conductive paint on the outer peripheral wall of the additional insulation (170), then winding a joint external shielding tape and a transition external shielding tape, wherein the joint external shielding tape extends to the corresponding cable external shielding layer (141), the double-barrel curved end stress control body (144) is connected with the corresponding cable external shielding layer (141) through the transition external shielding tape to obtain a joint external shielding layer (142) and a transition external shielding layer (143), and one end of the joint external shielding layer (142) surrounds the outer barrel (144 c).

2. The process for making a cross-linked cable insulation shield isolation insulation joint as claimed in claim 1, wherein said stress control arc (144b) is an arc of radius R, 3.2mm < R <7 mm.

3. The process for manufacturing the insulation shield isolation insulation joint of the crosslinked cable according to claim 1, wherein in the step of recovering the inner shield, the first preheating temperature T1, the two half-heated crosslinking dies (300) are kept at the first crosslinking temperature T2 for a bite time T1, 120 ℃ < T1<160 ℃, 190 ℃ < T2<230 ℃, 25min < T1<60 min;

in the insulation adding step, the second preheating temperature T3 is kept for crosslinking time T2, 120 ℃ and < T3<160 ℃, 180 ℃ and < T4<230 ℃, and 15min and < T2<50min according to the second crosslinking temperature T4.

4. The process for manufacturing the insulation shield isolation insulation joint of the crosslinked cable according to claim 1, wherein the second preheating temperature T3, 120 ℃ < T3<160 ℃, the inner wall of the supporting and heating mold (500) and the cable insulation layer (130) have a predetermined glue-out gap D2, 2mm < D2<6 mm.

5. Process for making a cross-linked cable insulation shield insulation joint according to any one of claims 1 to 4, characterized in that the end face of the other end of the constraining mold (200) abuts against the supporting heating mold (500) or is at a predetermined distance from the supporting heating mold (500), characterized in that the supporting heating mold (500) is provided with a shear-gluing flange (510), the end face of the other end of the constraining mold (200) corresponding to the shear-gluing flange (510).

6. Process for making a cross-linked cable insulation shield insulation joint according to any one of claims 1 to 4, characterized in that said constraining mold (200) is made of silicone rubber.

7. The process for manufacturing the insulated joint of the crosslinked cable according to any one of claims 1 to 4, wherein an outer metal shielding net (151) is laid on the outer peripheral wall of the joint outer shielding layer (142), the outer metal shielding net (151) is used for connecting one end metal sheath (160), a stress control body metal shielding net (152) is laid on the outer peripheral wall of the double-cylinder curved end stress control body (144), the stress control body metal shielding net (152) extends into a socket of the double-cylinder curved end stress control body (144), and the stress control body metal shielding net (152) is used for connecting the other end metal sheath (160).

8. Process for manufacturing a cross-linked cable insulation shield insulation joint according to any one of claims 1 to 4, characterized in that at least one of said pair of half-heated cross-linking molds (300) is provided with an overflow glue shearing blade (321), said overflow glue shearing blade (321) being adapted to engage.