CN218548099U - Hollow insulating tube and composite insulator - Google Patents

Abstract

The application discloses hollow insulating tube includes interior axial layer, hoop layer and the outer axial layer that sets gradually by inside to outside, and interior axial layer and outer axial layer all include a plurality of axial fiber yarn, and the hoop layer includes a plurality of hoop fiber yarn, and the winding angle on hoop layer is 85 ~ 90. The hollow insulating pipe greatly improves the circumferential strength and the axial strength of the hollow insulating pipe through the structural design of the circumferential layer, the inner axial layer and the outer axial layer; in addition, the winding angle of the circumferential layer of the hollow insulating pipe is set to be 85-90 degrees, and better circumferential strength can be provided for the hollow insulating pipe under the condition that the thickness of the circumferential layer is the same. The application also discloses a composite insulator.

Description

Hollow insulating tube and composite insulator

Technical Field

The application relates to the technical field of power transmission insulating equipment, in particular to a hollow insulating tube and a composite insulator.

Background

Most of the existing composite insulators are hollow insulating pipes formed by wet winding or pultrusion, the layering structures of the hollow insulating pipes formed by wet winding are formed by circumferential winding, the yarn layering is concentrated in circumferential direction, the tension action of axial yarns is avoided, and finally the bearing capacity of circumferential acting force (internal pressure or external pressure) of the hollow insulating pipes is large and the bearing capacity of axial acting force (bending stress or compressive stress) is small; the layer structure of the pultruded hollow insulation pipe is formed by axial pultrusion, tension action of annular yarns is avoided, and finally the bearing capacity of annular acting force (internal pressure or external pressure) of the hollow insulation pipe is smaller and the bearing capacity of axial acting force (bending stress or compressive stress) is larger.

The hollow insulating pipe formed by the two process methods cannot balance the circumferential acting force and the axial acting force, cannot enable the bearing capacity of the hollow insulating pipe in two directions to reach the best, and is limited in application range. In order to improve the axial bearing capacity of the hollow insulating pipe formed by wet winding, the wall thickness of the hollow insulating pipe needs to be greatly improved, and the problem of higher manufacturing cost exists; the hollow insulating tube wound by the wet method needs to be soaked and wound on the surface of a core mold to form a winding tube prefabricated part, and then the winding tube prefabricated part is transferred into a curing oven to be cured, namely, the winding process and the curing process are carried out step by step, so that the production period of the product is long, the efficiency is low, the layout of a production line is dispersed, and the loss is large; and the circumferential pressure-bearing capacity of the hollow insulating pipe can not be obviously improved even if the wall thickness of the pipe is improved.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a hollow insulating tube to prior art's not enough, the purpose of this application is to provide one kind, can possess stronger hoop intensity and axial strength simultaneously to and make hollow insulating tube's production efficiency improve, preparation cost reduction.

In order to achieve the above purpose, the technical means adopted by the application are as follows: the utility model provides a hollow insulating tube, includes interior axial layer, hoop layer and the outer axial layer that sets gradually by inside to outside, and interior axial layer and outer axial layer all include a plurality of axial fiber yarn, and the hoop layer includes a plurality of hoop fiber yarn, and the winding angle on hoop layer is 85 ~ 90. The hollow insulating pipe achieves the mechanical strength required by the hollow insulating pipe through the structural design of the annular layer, the inner axial layer and the outer axial layer, namely the annular layer provides the hollow insulating pipe with the bearing capacity for annular acting force (internal pressure or external pressure), the inner axial layer and the outer axial layer simultaneously provide the hollow insulating pipe with the bearing capacity for axial acting force (bending stress or compressive stress), and the strength required by the hollow insulating pipe is achieved through the sequential design and the thickness design of the inner axial layer, the annular layer and the outer axial layer; in addition, the winding angle of the circumferential layer of the hollow insulating pipe is set to be 85-90 degrees, and under the condition that the thicknesses of the circumferential layers are the same, better circumferential strength can be provided for the hollow insulating pipe; the main structure of the hollow insulating tube is formed by curing and pultrusion through a curing mould in a direct contact heat transfer mode after yarn is dipped in glue, namely, the hollow insulating tube enters the curing mould for curing after a layering structure of the hollow insulating tube is formed, the production process of the product is compact, the layout of a production line is compact, the curing and forming efficiency can be greatly improved, the processing period of the product is shortened, and the production efficiency of the product is improved; and the layer structure of the hollow insulating pipe is reasonable in design, and the wall thickness of the hollow insulating pipe can be reduced, the material is saved, and the material cost is reduced under the condition of achieving the same performance.

The linear density of the inner axial layer, the annular layer and the outer axial layer is sequentially increased progressively, so that the preparation cost of the hollow insulating tube can be properly reduced.

The linear density of the inner axial layer is 400-2400 tex, the linear density of the annular layer is 1200-9600 tex, and the linear density of the outer axial layer is 4800-19200 tex, so that the overall performance of the hollow insulating pipe is ensured.

Wherein, a plurality of axial fiber yarns of the inner axial layer are polyester fibers. The chemical property of the polyester fiber is superior to that of glass fiber, the polyester fiber is corrosion resistant, and a polyester lining does not need to be arranged on the inner wall of the hollow insulating pipe, so that the processing difficulty and the material cost can be reduced.

The hollow insulating tube further comprises an inner liner layer, wherein the inner liner layer is made of fiber felt and arranged on the inner side of the inner axial layer. The inner liner can be polyester felt, glass fiber felt, composite felt or polyester cloth, fiber cloth and the like, the process forming of the inner wall is better, the spreading layer structure is uniform, resin is uniformly distributed, and the special function requirements (HF resistance, electric arc resistance and the like) of the product can be met aiming at the polyester material.

Wherein the roughness of the outer surface of the inner liner is greater than the roughness of the inner surface. The roughness of the outer surface of the inner liner layer is slightly larger, so that the interface connection strength between the inner liner layer and the inner axial layer can be enhanced.

The hollow insulating pipe further comprises an outer felt layer, wherein the outer felt layer is a fiber felt and is arranged on the outer side of the outer axial layer. The outer felt layer is the glass fiber felt, can play the effect of cladding axial fiber yarn, keeps apart the inner wall of axial fiber yarn and mould, avoids direct contact, ensures axial fiber yarn and resin evenly distributed simultaneously, and the technology formability is better.

Wherein the roughness of the outer surface of the outer felt layer is less than the roughness of the inner surface. The contact surface of the outer felt layer and the inner wall of the forming die is set to be smooth, the advancing resistance in the forming process can be reduced, and the process stability of the hollow insulating tube is ensured.

The diameters of the fiber yarns of each of the inner axial layer, the annular layer and the outer axial layer are uniform, so that calculation and design in a layering design stage are facilitated.

In view of the shortcomings of the prior art, it is another object of the present application to provide a composite insulator comprising any one of the hollow insulating tubes described above.

The beneficial effect of this application is: be different from prior art's condition, this application adopts and includes interior axial layer, the hollow insulation pipe who encircles layer and outer axial layer spreads the layer structure, wherein the hoop layer provides the bearing capacity to hoop effort (internal pressure or external pressure) for hollow insulation pipe, interior axial layer and outer axial layer provide the bearing capacity to axial effort (bending stress or compressive stress) simultaneously for hollow insulation pipe, whole mechanical strength is high, and the winding angle on the hoop layer of hollow insulation pipe sets up to 85 ~ 90, under the condition that the hoop layer thickness is the same, can provide better hoop intensity for hollow insulation pipe. Meanwhile, the forming process of the layer laying structure is simple and convenient, the production line is reasonable in layout, the production efficiency can be greatly improved, and the overall preparation cost is low.

Drawings

FIG. 1 is a partial cross-sectional view of a hollow insulating tube 100 according to an embodiment of the present application;

fig. 2 is a schematic winding angle diagram of the hollow insulating tube 100 according to an embodiment of the present application;

FIG. 3 is a partial cross-sectional view of a hollow insulating tube 200 according to an embodiment of the present application;

FIG. 4 is a partial cross-sectional view of a hollow insulating tube 300 according to an embodiment of the present application;

FIG. 5 is a partial cross-sectional view of a hollow insulating tube 400 according to an embodiment of the present application;

fig. 6 is a schematic structural view of a composite insulator 1000 according to an embodiment of the present application.

Detailed Description

As required, detailed embodiments of the present application are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the application and that they may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present application in virtually any appropriately detailed manner, including employing various features disclosed herein in connection with which such features may not be explicitly disclosed.

In one embodiment, as shown in fig. 1, the hollow insulating tube 100 includes an inner axial layer 110, a circumferential layer 120, and an outer axial layer 130 sequentially arranged from inside to outside along a radial direction of the hollow insulating tube, and the inner axial layer 110 and the outer axial layer 130 include a plurality of axial fiber yarns and are formed by pultrusion, wherein the axial direction is along the axial direction of the hollow insulating tube 100. The hoop layer 120 includes a plurality of hoop fiber yarns and is formed by winding, wherein the hoop direction is a hoop direction along the hollow insulation pipe 100. And after the resin glue solution infiltrates the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130, the resin glue solution is cured to form the hollow insulating tube 100.

Wherein the winding direction of the circumferential layer 120 is set at an angle of preferably 45 to 90 ° (including 45 ° and 90 °, the same applies hereinafter) to the axial direction of the hollow insulating tube 100 to provide the circumferential strength of the hollow insulating tube 100. The winding process with the winding angle smaller than 45 degrees belongs to small-angle winding, the process forming difficulty is high, the efficiency is low, the winding speed needs to be reduced to keep the matching with the pultrusion speed mainly due to the small-angle winding, and the phenomena of pause and the like can occur when the speed is too low to influence the forming process. Therefore, the winding angle is selected from 45 degrees to 90 degrees, which is beneficial to processing and forming and can improve the efficiency.

Specifically, an inner axial layer 110 is formed by sequentially pultrusion of the impregnated axial fiber yarns, a circumferential layer 120 is formed by winding the impregnated circumferential fiber yarns outside the inner axial layer 110, and an outer axial layer 130 is formed outside the circumferential layer 120 by pultrusion of the impregnated axial fiber yarns, so that a preform of the hollow insulating tube 100 is formed, and the preform passes through a curing mold for heating and molding, and finally the hollow insulating tube 100 is obtained. Of course, in other embodiments, the inner axial layer, the circumferential layer, and the outer axial layer may be formed by pultrusion and winding fiber yarns layer by layer, and then the inner axial layer, the circumferential layer, and the outer axial layer are dipped in glue and then cured and formed, which is not limited in this regard.

The hollow insulating tube 100 formed by the stretch-wrap process achieves the required mechanical strength of the hollow insulating tube 100 by sequentially designing the structures of the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130. Wherein, the circumferential layer 120 provides the hollow insulating pipe 100 with a bearing capacity for a circumferential acting force (internal pressure or external pressure), i.e. provides the hollow insulating pipe 100 with a circumferential strength, and avoids the hollow insulating pipe 100 from being damaged by bearing a circumferential internal load or external load; the inner axial layer 110 and the outer axial layer 130 can provide the hollow insulating tube 100 with bearing capacity for axial acting force (bending stress or compressive stress), namely, provide axial strength for the hollow insulating tube 100, and avoid the hollow insulating tube 100 from being damaged due to bearing axial tensile load or compressive load, so that compared with a wound tube and a pultruded tube, the hollow insulating tube 100 can balance the circumferential acting force and the axial acting force, and can enable the bearing capacity of the hollow insulating tube 100 in two directions to reach the best, the performance is good, and the application range is wide. In addition, the main structure of the hollow insulating tube 100 is a product formed by directly transferring heat and curing through a curing mold after yarn is dipped in glue solution, namely, the hollow insulating tube 100 enters the curing mold for curing after being formed in a layering structure, so that the production process of the product is compact, and the layout of a production line is compact; the inner axial layer 110 can replace the traditional composite felt liner, namely the step of arranging the composite felt liner on the inner wall of the hollow insulating pipe can be eliminated, and the forming process of the hollow insulating pipe 100 is simplified, so that the curing forming efficiency can be greatly improved, the product processing period is shortened, and the product production efficiency is improved; meanwhile, the layer structure of the hollow insulating tube 100 is reasonable in design, the wall thickness of the hollow insulating tube 100 can be reduced under the condition that the same performance is achieved, materials are saved, and the material cost is reduced.

In an implementation scenario, as shown in table 1, a hollow insulating pipe with an axial bending strength of 400MPa and an internal pressure bearing strength of 4.24MPa is designed, and a hollow insulating pipe molded by using a wet-process winding and layering structure is used as a comparative example, and the hollow insulating pipe of the comparative example should be designed to have an inner diameter of 230mm and an outer diameter of 248mm, that is, a wall thickness of 9mm, according to the strength requirement of the hollow insulating pipe; when the same mechanical performance requirements are met, by using the layering structure of the hollow insulating pipe 100 of the embodiment, the hollow insulating pipe 100 only needs to be designed to have an inner diameter of 230mm and an outer diameter of 242mm, namely, the wall thickness is 6mm, so that the production and manufacturing cost can be greatly reduced; in addition, the hollow insulating pipe with the inner diameter of 230mm, the outer diameter of 248mm and the length of 1000mm is formed by wet winding, the curing and forming time is at least 16h, while the hollow insulating pipe (with the inner diameter of 230mm, the outer diameter of 242mm and the length of 1000 mm) in the embodiment only needs 0.5h, so that the production efficiency of the hollow insulating pipe can be greatly improved by adopting the layer laying structure in the embodiment.

TABLE 1 comparison of parameters between the present example and the comparative example

In addition, if the hollow insulating pipe is formed by pultrusion, the wall thickness of the hollow insulating pipe needs to be set larger to meet the circumferential strength of the hollow insulating pipe while meeting the axial strength of the hollow insulating pipe; and possess the hollow insulating tube 100 of axial strength and hoop strength simultaneously in this application, its wall thickness only need according to axial and hoop intensity design can, need not to satisfy hollow insulating tube 100's strength requirement through increasing the wall thickness.

Therefore, compared with a winding-formed hollow insulating tube or a pultrusion-formed hollow insulating tube, the hollow insulating tube 100 of the present embodiment can reduce the wall thickness of the hollow insulating tube 100 and save materials, thereby reducing the cost, under the condition of achieving the same performance.

In addition, the hollow insulating tube with the same mechanical property is prepared, two different forming processes, namely a stretch-wrap forming process and a wet-process wrap forming process are compared, and the cost reduction rate of the stretch-wrap forming process can reach over 40% only by comparing the three aspects of materials, labor and energy consumption.

Furthermore, the economic advantages of the stretch-wrap forming process are also shown in the fixed asset investment, the core mould tools, hot air drying ovens, winding machines, demoulding machines, cutting machines, lathes, traveling cranes, logistics transport vehicles and the like with different specifications need to be input in the wet-process stretch-wrap forming process from the fixed asset and management cost investment angle for comparative analysis, the requirements of various types of equipment are integrated, meanwhile, due to the multi-process circulation, products and equipment also occupy more production plants, and the investment of a single production line is estimated preliminarily to be nearly ten million; however, the stretch wrap forming process only needs a forming die and traction equipment, equipment requirements are few, equipment asset investment is greatly reduced, in addition, because the production line is compact and regular, the circulation among product processes is reduced, the occupied area requirement of a workshop is reduced, and compared with the production requirement of the same product, the input of the stretch wrap forming process production line is estimated to be about millions. Therefore, the hollow insulation tube 100 formed by the stretch-wrap forming process of the present application has great advantages, both from a technical level and an economic level.

In one implementation scenario, the linear density of the inner axial layer 110, the hoop layer 120, and the outer axial layer 130 sequentially increases. The linear density is the mass of the yarn per unit length, and the smaller the linear density is, the better the wettability of the yarn is, and the better the mechanical properties of the hollow insulation tube 100 are.

In other implementation scenes, the linear density of the circumferential layer and the outer axial layer can be the same, so that the hollow insulating pipe is convenient to prepare, and the design scheme can be adjusted according to the performance requirement of the hollow insulating pipe.

Specifically, in this embodiment, the linear density of the inner axial layer 110 is 400tex to 2400tex, the linear density of the hoop layer 120 is 1200tex to 9600tex, and the linear density of the outer axial layer 130 is 4800tex to 19200tex. During use of the hollow insulating tube 100, since the inner wall of the hollow insulating tube 100 may be subjected to arc radiation and chemical corrosion, the yarns of the inner wall of the hollow insulating tube 100 are required to have optimal electrical and chemical resistance, while the yarns of the outer layer of the hollow insulating tube 100 mainly provide mechanical properties. The yarns with the linear density of 400 tex-2400 tex have good wettability, the cured inner axial layer 110 has good chemical corrosion resistance and electrical performance, the mechanical performance is also excellent, the requirements of the inner axial layer 110 are met, and any linear density of the yarns in the range can be met; the yarns with the linear density of 1200tex to 9600tex have good wettability, and under the condition that the performance requirement of the annular layer 120 is lower than that of the inner axial layer 110, the cost of the yarns with the linear density of 1200tex to 9600tex is lower, so that the requirements of the annular layer 120 are met, and any linear density of the yarns in the range can be used; the outer axial layer 130 has the lowest performance requirements for the yarns, so the linear density of the used yarns is the highest, the cost is the lowest, and the yarns with the linear density of 4800 tex-19200 tex are adopted, and the yarns with any linear density in the range can meet the requirements of the outer axial layer 130. Since the higher the linear density, the lower the wettability and the lower the yarn cost, the linear densities of the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130 are sequentially increased, so that the performance requirements of the hollow insulating tube 100 can be ensured, the cost can be appropriately reduced, and the preparation cost of the hollow insulating tube 100 can be optimized. In addition, it is preferable to keep the fiber yarn diameters of the layers uniform, facilitating calculation and design at the ply design stage. In general, it is sufficient if the sequentially increasing linear density rule of the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130 is satisfied. It is understood that in other embodiments, the linear density of the inner, hoop, and outer axial layers may be optional within their ranges.

In an implementation scenario, the hollow insulating tube 100 is made of glass fibers, that is, the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130 are all made of glass fibers, so that the condition that the interface connection of each layer structure of the hollow insulating tube 100 is not tight due to the fact that the layer structures are made of different materials is avoided, meanwhile, the glass fibers are common fibers which are most common in the current market and have the highest cost performance, the performance requirement of the hollow insulating tube 100 can be met, and the economic maximization of a product can be realized by controlling the material cost to the maximum extent.

In another implementation scenario, the hollow insulating tube 100 is made of polyester fibers, compared with glass fibers, the polyester fibers have stronger corrosion resistance and better electrical performance, and the inner axial layer 110 directly uses the polyester fibers, so that a polyester fiber lining layer can be prevented from being arranged on the inner wall of the hollow insulating tube 100. Of course, in other embodiments, the hollow insulating tube may also be made of aramid fiber or other types of fibers with good insulating properties and mechanical properties, and the type of the fiber yarn is determined according to the specific application scenario and working condition of the hollow insulating tube, as long as the requirements of the internal insulating properties of the hollow insulating tube and the mechanical properties of the whole hollow insulating tube can be met.

Wherein, because the layer structure of spreading of difference can be designed according to the requirement of the hoop mechanical properties and the axial mechanical properties of hollow insulating pipe, that is to say, design the conversion according to axial strength demand, the hoop strength demand of hollow insulating pipe, the thickness that each layer was spread to output hollow insulating pipe. Therefore, as described above, the inner axial layer 110, the circumferential layer 120 and the outer axial layer 130 have different performance requirements for yarns, generally, the yarn performance requirement of the inner axial layer 110 is the highest, the quality is the best, and the price is the highest, and the optimum yarn thickness ratio is obtained by designing and verifying that the yarn thickness ratio is the last of the circumferential layer 120 times and the outer axial layer 130, so that the production cost can be optimized on the premise of ensuring the performance of the hollow insulating tube 100.

In this embodiment, the resin solution may be any one of polyurethane resin, epoxy resin, vinyl resin, phenolic resin, and unsaturated polyester resin, and the prepared insulation product has stable mechanical properties and excellent electrical properties.

Further, as shown in fig. 2, the winding angle of the hoop layer 120 is represented by θ, which is an angle between the fiber yarn of the hoop layer 120 and the axial direction of the hollow insulating tube 100, and in the present application, θ is set in a range of 85 ° to 90 ° (including 90 ° and not including 85 °). At this time, the fiber yarn of the circumferential layer 120 is similar to pure circumferential winding, that is, the fiber yarn is close to perpendicular to the axial direction of the hollow insulating tube 100, and can provide better circumferential strength to the hollow insulating tube 100, because in the circumferential layer of the same thickness, the larger the winding angle of the circumferential layer is, the higher the circumferential strength of the hollow insulating tube 100 is. Meanwhile, the circumferential layer 120 only needs to be wound in one direction, and the process is simple and easy to operate.

According to the hollow insulating pipe 100 of the embodiment, through the structural design of the circumferential layer 120, the inner axial layer 110 and the outer axial layer 130, the circumferential layer 120 greatly improves the bearing capacity of the hollow insulating pipe 100 for a circumferential acting force (internal pressure or external pressure), and the inner axial layer 110 and the outer axial layer 130 improve the bearing capacity of the hollow insulating pipe 100 for an axial acting force (bending stress or compressive stress); in addition, the winding angle of the circumferential layer 120 of the hollow insulating pipe 100 is set to be 85-90 degrees, and under the condition that the thicknesses of the circumferential layers 120 are the same, better circumferential strength can be provided for the hollow insulating pipe 100; and the main structure of the hollow insulating tube 100 is a product formed by directly transferring heat and curing through a curing mold after yarn impregnation, that is, the hollow insulating tube 100 enters the curing mold for curing after layering structure forming, the product production process is compact, the production line layout is compact, the curing forming efficiency can be greatly improved, the product processing cycle is shortened, and the product production efficiency is improved.

In another embodiment, as shown in fig. 3, the hollow insulation tube 200 further comprises an outer felt layer 240, the outer felt layer 240 being a fiber felt, disposed outside the outer axial layer 230. The outer felt layer 240 is a glass fiber felt, and can play a role in coating the axial fiber yarns, isolate the axial fiber yarns from the inner wall of the mold, avoid direct contact between the axial fiber yarns and the inner wall of the mold, ensure uniform distribution of the axial fiber yarns and resin, and achieve better process formability.

In one implementation, the outer felt layer 240 has an outer surface with a roughness that is less than the roughness of its inner surface. The outer surface of the outer felt layer 240, that is, the surface contacting the inner wall of the forming mold, is set to be smooth, and in the process of guiding the outer felt layer 240 into the forming mold, since the outer felt layer 240 is not impregnated with resin, the outer surface of the outer felt layer 240 directly contacts the inner wall of the forming mold, the roughness of the outer surface of the outer felt layer 240 is reduced, the advancing resistance in the forming process can be reduced, and the process stability of the hollow insulating tube 200 is ensured. While setting the roughness of the inner surface of the outer felt layer 240 a little larger may enhance the interface connection strength between the outer felt layer 240 and the outer axial layer 230.

In other embodiments, the roughness of the outer and inner surfaces of the outer felt layer may be different, and is not particularly limited herein.

In another implementation scenario, the outer felt layer 240 is formed by guiding a fiber felt to cover the outer side of the outer axial layer 230 through a felt guide, infiltrating the outer felt layer 240 together with glue solution infiltrated on the outer surface of the outer axial layer 230, and heating the outer felt layer and the outer axial layer through a forming mold to be cured into a whole.

The hollow insulating tube 200 of this embodiment can play the effect of cladding axial fiber yarn owing to include outer felt layer 240, keeps apart the inner wall of axial fiber yarn and mould and avoids the two direct contact, ensures axial fiber yarn and resin evenly distributed simultaneously, and pultrusion technology formability is better.

In another embodiment, as shown in fig. 4, the hollow insulating tube 300 further includes an inner liner 350, the inner liner 350 is a fiber mat and is disposed inside the inner axial layer 310, similarly, the inner liner 350 is formed inside the inner axial layer 310 by introducing and coating the fiber mat on a core mold through a mat guide, and the inner liner 350 is impregnated together with glue solution impregnated on the inner surface of the inner axial layer 310 and is heated by a forming mold and then cured into a whole.

Wherein the roughness of the outer surface of the liner layer 350, i.e., the surface of the liner layer 350 in contact with the inner axial layer 310, is greater than the roughness of the inner surface thereof, i.e., the surface of the liner layer 350 in contact with the mandrel. The inner surface of the lining layer 350 is directly contacted with the outer wall of the core mold, the roughness of the inner surface of the lining layer 350 is reduced, the advancing resistance in the forming process can be reduced, and the process stability of the hollow insulating tube 300 is ensured. Setting the roughness of the outer surface of the inner liner 350 a little larger at the same time may enhance the interface connection strength between the inner liner 350 and the inner axial layer 310.

The inner liner 350 can be polyester felt, glass fiber felt, composite felt or polyester cloth, fiber cloth and the like, so that the inner wall of the hollow insulating tube 300 is better formed by a process, the paving structure is uniform, the resin is uniformly distributed, and meanwhile, different material types can meet different special function requirements (HF resistance, electric arc resistance and the like) of products, namely, the use requirements of different application scenes of the hollow insulating tube 300 are met.

The hollow insulating tube 300 of this embodiment is better because including the inner liner 350, the inner wall technology formability of guarantee hollow insulating tube 300, and the layer structure is even, the resin distributes evenly, and the selection of different materials can satisfy the different special function demands of product simultaneously.

In another embodiment, as shown in fig. 5, the hollow insulation pipe 400 comprises both the outer felt layer 440 and the inner liner layer 450, which can further stabilize the performance of both the inner and outer walls of the hollow insulation pipe 400, preventing the inner and outer walls from being defective, and especially being more advantageous in the production of large-diameter hollow insulation pipes. Specifically, the structure, material and forming manner of the outer felt layer 440 are the same as those of the outer felt layer 240, and the structure, material and forming manner of the inner liner layer 450 are the same as those of the inner liner layer 350, which are not described herein again.

In another embodiment, as shown in fig. 6, the composite insulator 1000 includes a flange 600 and an insulating shed 700, and further includes the hollow insulating tube 100, the flange 600 is fixedly sleeved at both ends of the hollow insulating tube 100, and the insulating shed 700 covers the outer circumference of the hollow insulating tube 100.

In an implementation scenario, the flange 600 and the hollow insulating tube 100 are sealed and fixed by means of a glue connection. In other implementation scenarios, the flange and the hollow insulating pipe may be fixed in other manners such as interference fit.

In yet another implementation scenario, the insulating shed 700 is a high temperature vulcanized silicone rubber shed, and is injected to the outer circumference of the hollow insulating tube 100 by high temperature injection. In other implementation scenarios, the insulating shed may be made of other types of rubber materials or hard plastic materials.

In other embodiments, the composite insulator may be any one of the hollow insulating pipes in the above embodiments.

The composite insulator 1000 of the embodiment adopts the hollow insulating tube 100, so that the mechanical property and the electrical property of the composite insulator 1000 are more excellent, and meanwhile, the labor cost and the material cost of the composite insulator 1000 are lower.

The beneficial effect of this application is: different from the prior art's condition, this application adopts the hollow insulating pipe that includes interior axial layer, hoop layer and outer axial layer to spread the layer structure, and wherein the hoop layer provides the bearing capacity to the hoop effort (internal pressure or external pressure) for hollow insulating pipe, and interior axial layer and outer axial layer provide the bearing capacity to axial effort (bending stress or compressive stress) for hollow insulating pipe simultaneously, and whole mechanical strength is high. In addition, the winding angle of the circumferential layer of the hollow insulating pipe is set to be 85-90 degrees, and under the condition that the thicknesses of the circumferential layers are the same, better circumferential strength can be provided for the hollow insulating pipe.

Meanwhile, the main structure of the hollow insulating tube is a product formed by directly transferring heat and curing through a curing mold after yarn is impregnated with glue solution, namely, the hollow insulating tube enters the curing mold for curing after a layering structure of the hollow insulating tube is formed, the production process of the product is compact, and the layout of a production line is compact; and the inner axial layer can replace the traditional composite felt lining, namely the step of arranging the composite felt lining on the inner wall of the hollow insulating pipe can be eliminated, and the forming process of the hollow insulating pipe is simplified, so that the curing forming efficiency can be greatly improved, the product processing period is shortened, and the product production efficiency is improved.

In addition, the layer structure design of the hollow insulating tube is reasonable, the wall thickness of the hollow insulating tube can be reduced under the condition of reaching the same performance, materials are saved, and the material cost is reduced.

While the specification and features of the present application have been described above, it will be understood that various changes and modifications in the above-described constructions and materials, including combinations of features disclosed herein either individually or in any combination, will be apparent to those skilled in the art upon studying the disclosure. Such modifications and/or combinations are within the skill of the art to which this application pertains and are within the scope of the claims of this application.

Claims (10)

1. A hollow insulating tube is characterized in that: including interior axial layer, hoop layer and the outer axial layer that sets gradually by interior to exterior, interior axial layer with outer axial layer all includes a plurality of axial fiber yarn, the hoop layer includes a plurality of hoop fiber yarn, the winding angle on hoop layer is 85 ~ 90.

2. The hollow insulating tube of claim 1, wherein: the linear densities of the inner axial layer, the annular layer and the outer axial layer are sequentially increased progressively.

3. The hollow insulating tube of claim 1, wherein: the linear density of the inner axial layer is 400tex to 2400tex, the linear density of the annular layer is 1200tex to 9600tex, and the linear density of the outer axial layer is 4800tex to 19200tex.

4. The hollow insulating tube of claim 1, wherein: the plurality of axial fiber yarns of the inner axial layer are polyester fibers.

5. The hollow insulating tube of claim 1, wherein: the inner liner is a fiber felt and is arranged on the inner side of the inner axial layer.

6. The hollow insulating tube of claim 5, wherein: the roughness of the outer surface of the inner liner layer is larger than that of the inner surface.

7. The hollow insulating tube of claim 1, wherein: the composite material also comprises an outer felt layer which is a fiber felt and is arranged on the outer side of the outer axial layer.

8. The hollow insulating tube of claim 7, wherein: the roughness of the outer surface of the outer felt layer is less than the roughness of the inner surface.

9. The hollow insulating tube of claim 1, wherein: the fiber yarn diameter of each of the inner axial layer, the hoop layer and the outer axial layer is uniform.

10. A composite insulator is characterized in that: comprising a hollow insulating tube according to any of claims 1 to 9.

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