CN113421728B - Preparation method of hard material sheath composite insulator with bird droppings prevention pressure equalizing cover - Google Patents

Abstract

A method for preparing a hard material sheathed composite insulator with an anti-guano voltage equalizing cover. The preparation method includes the following steps: inserting an insulating core rod into the center hole of the hardware, and then forming it into one by crimping or gluing; Put the two ends of the insulating mandrel-metal tool composite into the mold respectively, and integrally form a hard material sheath and an anti-guano pressure equalizing cover on the outer surface of the upper end of the mandrel, and on the outer surface of the lower end of the mandrel. A hard material sheath of hard material is formed; a silicone rubber sheath and silicone rubber shed are formed on the outside of the insulating mandrel-fitting complex with the hard material sheath and bird droppings equalizing cover. By wrapping the upper and lower ends of the insulator core rod with hard material sheaths, and installing an anti-bird droppings pressure equalizing cover between the upper end of the core rod and the upper end hardware, it has high hardness, corrosion resistance, bird pecking resistance, and bird droppings resistance. and other characteristics, improve the hard material and the preparation method of the entire composite insulator, and further improve the performance of the composite insulator.

Description

Preparation method of hard material sheathed composite insulator with anti-guano voltage equalizing cover

Technical field

The invention belongs to the technical field of insulator manufacturing, and specifically relates to a method for preparing a hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover.

Background technique

Composite insulators are widely used in power systems due to their small size, light weight, and high resistance to pollution and lightning voltage. With the widespread use of composite insulators, composite insulators on transmission lines are often eaten by birds and contaminated by bird droppings. Birds pecking at composite insulators will cause damage to the composite insulators, and bird droppings contaminating the insulators will increase the risk of insulator flashover. The main parts where birds peck at composite insulators are the sheds and sheaths at the upper and lower ends of the composite insulators. Birds pecking at the composite insulator shed will cause through holes or local tears in the shed, reducing the creepage distance of the composite insulator and affecting the external insulation performance of the composite insulator; birds pecking at the composite insulator sheath will cause The sheath is worn and the mandrel is exposed, which in turn causes the end seal to be damaged. Under high-humidity weather conditions such as rainy days and foggy days, local arc discharge is likely to occur between the exposed mandrel and the damp sheath interface, causing the mandrel to undergo an electrochemical reaction. . Under more severe conditions, insulators that are eaten by birds may suffer from brittle fracture and other serious accidents.

Based on the problem that traditional composite insulators cannot prevent bird pecks and bird droppings, the present invention provides a method for preparing a hard material sheathed composite insulator with a bird droppings proof voltage equalizing cover.

Contents of the invention

In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing a new type of hard material sheathed composite insulator with an anti-guano voltage equalizing cover, by wrapping hard materials on the upper and lower ends of the insulator core rod. material sheath, and an anti-bird droppings pressure equalizing cover is installed between the upper end of the mandrel and the upper end hardware to make it have high hardness, corrosion resistance, bird pecking resistance, bird droppings resistance, etc., to prevent bird droppings contamination and avoid mandrel Exposed to further avoid accidents such as flashover. Furthermore, the present invention improves the hard material and the preparation method of the entire composite insulator, further improving the performance of the composite insulator.

A method for preparing a hard material sheathed composite insulator with an anti-guano voltage equalizing cover. The composite insulator includes a silicone rubber shed (1), a silicone rubber sheath (2), a core rod (3), and hardware ( 5) and hard material sheath (4) and anti-guano pressure equalizing cover (6);

The core rod is located at the innermost part of the insulator; the upper and lower ends of the core rod are wrapped with hard material sheaths; the anti-guano voltage equalizing cover and the hard material sheath are integrally formed between the upper end of the core rod and the upper end fittings ; The silicone rubber sheath wraps the hard material sheath and the outside of the core rod, and the silicone rubber shed is arranged on the outside of the silicone rubber sheath; the hardware is located at both ends of the composite insulator, and the The mandrel is located in the center hole of the hardware;

The hard material of the hard material layer includes the following components by weight: 100 parts of alicyclic epoxy resin, 25 to 40 parts of plastic, 15 to 35 parts of methylhexahydrophthalic anhydride curing agent, and aluminum trihydrate 8 to 12 parts of micro-powder flame retardant, 1 to 2 parts of silanized coupling agent, 1 to 3 parts of light stabilizer;

The preparation method includes the following steps:

Step 1: Insert the insulating core rod into the center hole of the hardware, and then form it into one by crimping or gluing to obtain the insulating core rod-fitting tool composite;

Step 2: Put the two ends of the insulating mandrel-hardware composite obtained in step 1 into the mold respectively, and integrally form a hard material sheath and an anti-guano pressure equalizing cover on the outer surface of the upper end of the mandrel. , forming a hard material sheath of hard material on the outer surface of the lower end of the mandrel;

Step 3: Form a silicone rubber sheath and silicone rubber shed on the outside of the insulating mandrel-fitting complex with a hard material sheath and an anti-guano voltage equalizing cover.

Preferably, step 2 further includes, step 2-1, weighing the raw materials of the hard material layer according to the following weight ratio: 100 parts of alicyclic epoxy resin, 25 to 40 parts of plastic, and 15 to 15 parts of methylhexahydrophthalic anhydride curing agent. 35 parts, 8-12 parts of aluminum trihydrate micro-powder flame retardant, 1-2 parts of silanized coupling agent, 1-3 parts of light stabilizer, put them into a vacuum stirring tank for stirring and degassing, the vacuum degree is less than 0.5kPa , the mixing temperature is 30~40℃, the stirring and degassing time is 120min, and the mixed gel is obtained;

Step 2-2: Keep the mold temperature at 110~130℃ and the vacuum in the mold cavity less than 0.1kPa. Inject the mixed gel into the mold cavity at a fixed pressure of 0.3~0.5MPa. The injection pressure holding time is 30~45min and the curing time is 30min. ;

Step 2-3, demould, remove flash, and obtain an insulating core rod-fitting complex with a hard material sheath and an anti-guano pressure equalizing cover on the upper outer surface of the core rod and a hard material sheath on the lower outer surface. .

Preferably, step 3 further includes,

Step 3-1: Polish the surfaces of the hard material sheaths at both ends of the insulating mandrel-fitting complex in Step 2 and the surface of the mandrel in the middle, apply adhesive, and place them in an oven to preheat. The preheating temperature is 60 to 80°C. , preheating time 45~60min;

Step 3-2: Put the insulating mandrel-hardware complex with a hard material sheath and an anti-guano pressure equalizing cover that was preheated in step 3-1 into the mold, and inject and plasticize the silicone rubber raw material. , the plasticizing temperature is 150~250℃, the injection pressure is 15~80MPa, and the mold is demoulded to form a silicone rubber sheath and a silicone rubber shed, thereby obtaining a hard material sheathed composite insulator with an anti-guano pressure equalizing cover.

Preferably, the diameter of the anti-guano pressure equalizing cover is 1.5 to 2 times that of the silicone rubber shed.

Preferably, the plastic includes one or more of polyethylene, polypropylene, polystyrene, polyamide, and polycarbonate.

Preferably, the aluminum trihydrate micropowder includes 60% to 70% by weight of aluminum oxide and 30% to 40% by weight of titanium dioxide.

Preferably, the core rod is made of glass fiber and epoxy resin.

Preferably, the silicone rubber sheath and silicone rubber shed are made of silicone rubber material, and the silicone rubber sheath and silicone rubber shed are wrapped outside the hard material layer through one-time injection molding.

Preferably, the silicone rubber shed has an equal-diameter shed structure, one large shed structure and one small shed structure, one large shed structure and two small shed skirts, or one large shed structure, one in the middle and one small shed structure.

Preferably, the hard material sheaths at the upper and lower ends of the mandrel respectively cover 15% to 20% of the total length of the mandrel.

The beneficial effect of the present invention is that compared with the existing technology,

(1) The method of the present invention to install the hard sheath between the core rod and the silicone rubber sheath at both ends of the insulator avoids the direct exposure of the core rod through the high-strength, corrosion-resistant hard sheath, which greatly improves the efficiency of the insulator. The operation stability of composite insulators is improved. At the same time, the invention adopts a silicone rubber material sheath and umbrella group with the best hydrophobicity and hydrophobic migration, so that the composite insulator with a hard material layer reinforced core rod has both excellent anti-fouling flashover ability and anti-bird pecking performance. ;

(2) In the present invention, an anti-guano pressure equalizing cover made of hard material is installed on the upper end of the insulator, that is, the hanging end. The diameter of the equalizing cover is 1.5 to 2 times the diameter of the insulator shed, which prevents bird droppings from contaminating the surface of the shed. Or bridge the insulator shed, and at the same time avoid the bird droppings falling too close to the insulator, greatly reducing the probability of bird droppings flashover. The integrated molding of the bird droppings-proof pressure equalizing cover and the hard sheath further strengthens the structural stability and bird droppings and bird peck-proofing capabilities.

(3) The hard material of the present invention uses alicyclic epoxy resin, which has better dielectric properties, weather resistance and ultraviolet radiation resistance than traditional bisphenol A epoxy resin; by adding polyolefin, etc. Plastic raw materials, compared with traditional epoxy resin formulas, greatly reduce the proportion of inorganic fillers in the mixture; by adding methyl hexahydrophthalic anhydride as a curing agent, the alicyclic epoxy resin can be fully cured in an acid anhydride system. At the same time, the use of highly toxic and volatile amine curing agents can be avoided; the hard material mixture of the present invention has the advantages of easy stirring, uniform material curing, and short curing time;

(4) The preparation process of the present invention is simple, the hard material sheath and the anti-guano pressure equalizing cover are integrally formed, and the preparation process greatly improves the compactness of the internal structure of the hard material, reduces internal stress, and improves the insulation performance. Mechanical strength, dimensional accuracy and uniformity of parts, as well as the short gel curing time, greatly improve the utilization rate of the mold, shorten the production cycle, have high production efficiency, low product cost and low labor intensity.

Description of the drawings

Figure 1 is a schematic diagram of the specific structure of the hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover of the present invention.

Figure 2 is a schematic diagram of the shed structure of the hard material sheathed composite insulator with an anti-guano pressure equalizing cover of the present invention, in which 2-1 is an equal-diameter shed knot, and 2-2 is a large and small shed structure. 2-3 is a structure with one large umbrella and two small umbrellas, and 2-4 is a structure with one large, one in the middle and one small umbrella.

Figure 3 is a flow chart of the preparation method of the hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover according to the present invention.

Detailed ways

The present application will be further described below in conjunction with the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention, but cannot be used to limit the protection scope of the present application.

As shown in Figure 1, the hard material sheathed composite insulator with an anti-guano voltage equalizing cover of the present invention includes a silicone rubber shed 1, a silicone rubber sheath 2, a core rod 3, a hard material sheath 4, and hardware 5 And anti-guano pressure equalizing cover 6.

The core rod 3 is located at the innermost part of the composite insulator, and its upper and lower ends are wrapped with hard material sheaths 4. The core rod 3 is the mechanical load-bearing component of the composite insulator and the main part of the internal insulation. It is made of glass fiber, epoxy resin and other materials and has excellent mechanical strength, insulation performance and long-term stability.

The hard material sheath 4 wraps the upper and lower ends of the core rod 3 to insulate and seal and strengthen the core rod. The hard material of the hard material sheath 4 is based on alicyclic epoxy resin and plastic materials, supplemented by methyl hexahydrophthalic anhydride curing agent, aluminum trihydrate micropowder flame retardant, silanized coupling agent, and light stabilizer , has the characteristics of high hardness, impact resistance, arc resistance, and bird peck resistance. It can prevent the core rod from being exposed after the end sheath of the composite insulator is eaten by birds, further avoiding accidents such as flashover. Preferably, the hard material sheaths at the upper and lower ends of the core rod respectively cover 15% to 20% of the total length of the core rod to protect key parts of the insulator from bird pecks.

The anti-guano pressure equalizing cover 6 is also made of the same hard material as the hard material sheath 4, is located between the upper end of the mandrel and the upper end hardware, and is integrally formed with the hard material sheath 4. The diameter of the anti-bird droppings pressure equalizing cover is 1.5 to 2 times the diameter of the silicone rubber. The large size pressure equalizing cover expands the protection range, increases the bird droppings shielding area, and hinders the falling of bird droppings to achieve the purpose of preventing bird droppings.

The silicone rubber sheath 2 and the silicone rubber shed 1 are located on the outside of the core rod 3, and are preferably formed on the outside of the core rod 3 and the hard material sheath 4 through one-time injection molding to further seal and insulate. The silicone rubber sheath 2 and the silicone rubber shed 1 are made of silicone rubber and other materials, and have the characteristics of strong hydrophobicity, pollution flashover resistance, and electric corrosion resistance. Further, the rubber is silicone rubber, including but not limited to methyl silicone rubber, methyl vinyl silicone rubber, methyl vinyl phenyl silicone rubber, fluorosilicone rubber, etc. As shown in Figure 2, the silicone rubber shed 1 adopts four shed structures, namely the equal diameter shed structure shown in Figure 2-1, the large and small shed structure shown in Figure 2-2, and the shed structure shown in Figure 2-3 The umbrella skirt structure shown in Figure 2-4 is one large, one middle and one small. Different shed structures have different external insulation properties, pollution flashover resistance and self-cleaning properties. According to the different environmental conditions of insulator installation and operation, insulators with different shed structures can be selected to meet actual needs.

The long-term operating experience of ordinary silicone rubber composite insulators shows that the main parts of composite insulators pecked by birds are at both ends of the insulator, and the electric field distortion of the insulator caused by damage to the silicone rubber sheath and shed is relatively weak and is not the main hazard caused by bird pecks. , the really serious situation is when the sheaths at both ends of the insulator are pecked by birds, causing the insulator core rod to be exposed. The interface between the exposed core rod and the damp sheath is prone to local arc discharge, causing the core rod to undergo an electrochemical reaction. Under more severe conditions, insulators that are pecked by birds may suffer from brittle fracture and other vicious accidents. Based on this, the present invention installs hard sheaths between the core rods and silicone rubber sheaths at both ends of the insulator. The high-strength, corrosion-resistant hard sheath avoids the direct exposure of the core rods and greatly improves the performance of the composite insulator. Operational stability, while using silicone rubber material sheaths and umbrella groups with the best hydrophobicity and hydrophobic migration, so that the composite insulator with a hard material layer reinforced core rod has both excellent anti-fouling flashover capabilities and bird pecking resistance performance.

Long-term operating experience of ordinary silicone rubber composite insulators shows that the harm of bird droppings to composite insulators is reflected in two aspects. First, bird droppings accumulate on the surface of the insulator shed, and even bridge multiple sheds of the insulator; second, bird droppings accumulate on the insulator. The nearby whereabouts caused a flashover accident. In the present invention, a bird droppings-proof voltage equalizing cover of hard material is installed on the upper end of the insulator, that is, the hanging end. The diameter of the voltage equalizing cover is 1.5 to 2 times the diameter of the insulator shed, which prevents bird droppings from contaminating the surface of the shed or bridging the insulator. The umbrella skirt also prevents bird droppings from falling too close to the insulator, greatly reducing the probability of bird droppings flashover. The integrated molding of the bird droppings-proof pressure equalizing cover and the hard sheath further strengthens the structural stability and bird droppings and bird peck-proofing capabilities.

Furthermore, as for the hard materials used in the hard material sheath 4 and the anti-guano pressure equalizing cover 6, they use alicyclic epoxy resin, and the epoxy group is directly connected to the alicyclic ring, which can form a tight rigid molecule. Structure, after curing, the cross-linking density is high, so the heat deformation temperature is high, the heat resistance temperature of Martin reaches more than 190°C, and the thermal decomposition temperature is greater than 360°C. Therefore, it has small curing shrinkage, high tensile strength and good thermal stability. Since the synthesis process does not contain chlorine, sodium and other ions, the alicyclic epoxy resin has better dielectric properties. Both in terms of specific resistance and dielectric loss tangent value, it is better than the traditional bisphenol A-type epoxy resin. Oxygen resin is preferred. And unlike traditional bisphenol A-type epoxy resin, the molecular structure of alicyclic epoxy resin does not contain benzene rings, so it has better weather resistance and ultraviolet radiation resistance than bisphenol A-type epoxy resin.

Adding plastic raw materials such as polyolefin to hard materials greatly reduces the proportion of inorganic fillers in the mix compared to traditional epoxy resin formulas. Alicyclic epoxy resin is more reactive towards acid anhydrides than traditional amines. By adding methylhexahydrophthalic anhydride as a curing agent, the alicyclic epoxy resin can be fully cured in an acid anhydride system and can be Avoid using highly toxic and volatile amine curing agents.

The hard material specifically includes the following components by weight: 100 parts of alicyclic epoxy resin, 25 to 40 parts of plastic, 15 to 35 parts of methyl hexahydrophthalic anhydride curing agent, and 8 to 8 parts of aluminum trihydrate micropowder flame retardant. 12 parts, 1 to 2 parts of silanized coupling agent, 1 to 3 parts of light stabilizer.

When the curing agent content in the components increases, the initial viscosity of the mixture decreases and the fluidity becomes stronger, which facilitates mixing. However, if the curing agent content is too high, the viscosity will be too low, and the inorganic filler will settle and stratify, affecting the uniformity of the material after curing. sex. When the content of inorganic fillers in the components is too high, the mixture will be difficult to stir and degassed. Therefore, by controlling the proportions of each component in the raw material formula of hard materials, especially the proportions of alicyclic epoxy resin, plastics, curing agents, and aluminum trihydrate powder, the mixture has better performance in the stages of stirring, injection, and curing. Effect.

The alicyclic epoxy resin includes, but is not limited to, poly[(2-ethylene oxide)-1,2-cyclohexanediol]2-ethyl-2-(hydroxymethyl)-1,3- Propylene glycol ether has the advantages of good thermal stability, good weather resistance, good electrical insulation properties, and good process performance.

The plastic includes, but is not limited to, at least one of polyethylene, polypropylene, polycarbonate, polystyrene, and polyamide.

The methylhexahydrophthalic anhydride is a curing agent and has the advantages of low melting point, low viscosity of the complex formed with the alicyclic epoxy resin, long pot life, high heat resistance of the cured product, and good high-temperature electrical properties.

The aluminum trihydrate micropowder flame retardant contains 60% to 70% by weight of alumina and 30% to 40% by weight of titanium dioxide. The alumina is α-alumina and/or γ-alumina, and a preferred solution is composed of 50% by weight of α-alumina and 50% by weight of γ-alumina.

The silane coupling agent is a type of organosilicon compound that contains two different chemical properties at the same time, and is used to improve the actual bonding strength between polymers and inorganic substances. The amount of silicide coupling agent is related to the specific surface area of the filler. A preferred solution is that the mass of silicide coupling agent is 0.5% to 2% of the organic filler.

The light stabilizer is not particularly limited and can be added according to the desired type.

By wrapping the upper and lower ends of the mandrel with hard material sheaths and installing an anti-bird droppings pressure equalizing cover between the upper end of the mandrel and the upper hardware, it can prevent bird droppings from falling and avoid exposing the mandrel. , compared with the structure of traditional composite insulator core rods directly wrapped with silicone rubber sheaths, it has better sealing, temperature resistance and corrosion resistance, and has high hardness, impact resistance, bird pecking resistance, bird droppings resistance, etc. Features.

As shown in Figure 3, the preparation method of a composite insulator with a hard material layer-reinforced core rod of the present invention includes the following steps:

Step 1: Insert the insulating core rod into the center hole of the hardware, and then form it into one body by crimping or gluing to obtain the insulating core rod-hardware composite.

Step 2: Put the two ends of the insulating mandrel-hardware composite obtained in step 1 into the mold respectively, and integrally form a hard material sheath and an anti-guano pressure equalizing cover on the outer surface of the upper end of the mandrel. , forming a hard material sheath of hard material on the outer surface of the lower end of the mandrel. Step 2 further includes:

Step 2-1, weigh the raw materials of the hard material layer according to the following weight ratio: 100 parts of alicyclic epoxy resin, 25 to 40 parts of plastic, 15 to 35 parts of methyl hexahydrophthalic anhydride curing agent, aluminum trihydrate micropowder resist Add 8 to 12 parts of fuel, 1 to 2 parts of silanized coupling agent, and 1 to 3 parts of light stabilizer into a vacuum stirring tank for stirring and degassing. The vacuum degree is less than 0.5kPa, and the mixing temperature is 30 to 40°C. , the stirring and degassing time is about 120 minutes, and the mixture gel is obtained;

Step 2-2: Keep the mold temperature at 110~130℃ and the vacuum in the mold cavity less than 0.1kPa. Inject the mixed gel into the mold cavity at a fixed pressure of 0.3~0.5MPa. The injection pressure holding time is 30~45min and the curing time is approximately 30min;

Step 2-3, demould, remove flash, and obtain an insulating core rod-fitting complex with a hard material sheath and an anti-guano pressure equalizing cover on the upper outer surface of the core rod and a hard material sheath on the lower outer surface. .

Further, before mixing in step 2-1, the raw materials of the hard material are pretreated to remove moisture, gas and volatile substances.

In step 2-2, the mixed gel temperature is injected into the mold cavity at room temperature. The mold temperature of the part is about 80 to 100°C higher than the temperature of the mixed system, so that the gel process of the curing reaction starts from the mold wall to the middle. The mixture spreads. During the entire punching process, a certain pressure is maintained on the mold cavity, so that the mixed material is squeezed into the mold cavity under a fixed pressure to supplement the voids formed by the volume shrinkage of the system during the gelling process, thus improving the density of the internal structure of the cured product. properties, reducing internal stress, improving insulation performance, mechanical strength, dimensional accuracy and uniformity of parts. The gel solidification time in the preparation process is short, which greatly improves the utilization rate of the mold, shortens the production cycle, has high production efficiency, low product cost and low labor intensity.

Step 3: Form a silicone rubber sheath and silicone rubber shed on the outside of the insulating mandrel-fitting complex with a hard material sheath and an anti-guano voltage equalizing cover. Step 3 further includes:

Step 3-1: Polish the surfaces of the hard material sheaths at both ends of the insulating mandrel-fitting complex in Step 2 and the surface of the mandrel in the middle, apply adhesive, and place them in an oven to preheat. The preheating temperature is 60 to 80°C. , preheating time is 45~60min.

Step 3-2: Put the insulating mandrel-hardware complex with a hard material sheath and an anti-guano pressure equalizing cover that was preheated in step 3-1 into the mold, and inject and plasticize the silicone rubber raw material. , the plasticizing temperature is 150~250℃, the injection pressure is 15~80MPa, and the mold is demoulded to form a silicone rubber sheath and a silicone rubber shed, thereby obtaining a hard material sheathed composite insulator with an anti-guano pressure equalizing cover.

Furthermore, the adhesives described in step 3-1 include but are not limited to silane adhesives, and mechanical rotational grinding is used to increase the contact area between the hard material layer and the adhesive and improve the bonding reactivity with the adhesive. Improve the wetting effect of the adhesive on the hard material layer through preheating, while controlling the preheating time and temperature to avoid adhesive failure.

The beneficial effects of the present invention are that, compared with the prior art:

(1) The method of the present invention to install the hard sheath between the core rod and the silicone rubber sheath at both ends of the insulator avoids the direct exposure of the core rod through the high-strength, corrosion-resistant hard sheath, which greatly improves the efficiency of the insulator. The operation stability of composite insulators is improved. At the same time, the invention adopts a silicone rubber material sheath and umbrella group with the best hydrophobicity and hydrophobic migration, so that the composite insulator with a hard material layer reinforced core rod has both excellent anti-fouling flashover ability and anti-bird pecking performance. ;

(2) In the present invention, an anti-guano pressure equalizing cover made of hard material is installed on the upper end of the insulator, that is, the hanging end. The diameter of the equalizing cover is 1.5 to 2 times the diameter of the insulator shed, which prevents bird droppings from contaminating the surface of the shed. Or bridge the insulator shed, and at the same time avoid the bird droppings falling too close to the insulator, greatly reducing the probability of bird droppings flashover. The integrated molding of the bird droppings-proof pressure equalizing cover and the hard sheath further strengthens the structural stability and bird droppings and bird peck-proofing capabilities.

(3) The hard material of the present invention uses alicyclic epoxy resin, which has better dielectric properties, weather resistance and ultraviolet radiation resistance than traditional bisphenol A epoxy resin; by adding polyolefin, etc. Plastic raw materials, compared with traditional epoxy resin formulas, greatly reduce the proportion of inorganic fillers in the mixture; by adding methyl hexahydrophthalic anhydride as a curing agent, the alicyclic epoxy resin can be fully cured in an acid anhydride system. At the same time, the use of highly toxic and volatile amine curing agents can be avoided; the hard material mixture of the present invention has the advantages of easy stirring, uniform material curing, and short curing time;

(4) The preparation process of the present invention is simple, the hard material sheath and the anti-guano pressure equalizing cover are integrally formed, and the preparation process greatly improves the compactness of the internal structure of the hard material, reduces internal stress, and improves the insulation performance. Mechanical strength, dimensional accuracy and uniformity of parts, as well as the short gel curing time, greatly improve the utilization rate of the mold, shorten the production cycle, have high production efficiency, low product cost and low labor intensity.

The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above implementation examples are only preferred embodiments of the present invention, and the detailed description is only to help readers better understand the present invention. It is not intended to limit the protection scope of the present invention. On the contrary, any improvements or modifications made based on the inventive spirit of the present invention should fall within the protection scope of the present invention.

Claims (9)

1. A method for preparing a hard material sheathed composite insulator with an anti-guano voltage equalizing cover. The composite insulator includes a silicone rubber shed (1), a silicone rubber sheath (2), a core rod (3), Hardware (5), hard material sheath (4) and anti-guano pressure equalizing cover (6); The core rod is located at the innermost part of the insulator; the upper and lower ends of the core rod are wrapped with hard material sheaths, and the hard material sheaths on the upper and lower ends of the core rod respectively cover 15% to 20% of the total length of the core rod; so The anti-guano pressure equalizing cover and the hard material sheath are integrally formed between the upper end of the mandrel and the upper end hardware; the silicone rubber sheath wraps the hard material sheath and the outside of the mandrel, and the silicon rubber sheath wraps the hard material sheath and the outside of the mandrel. The rubber shed is arranged outside the silicone rubber sheath; the hardware is located at both ends of the composite insulator, and the core rod is located in the center hole of the hardware; The hard material of the hard material sheath includes the following components by weight: 100 parts of alicyclic epoxy resin, 25-40 parts of plastic, 15-35 parts of methylhexahydrophthalic anhydride curing agent, trihydrate 8 to 12 parts of aluminum micropowder flame retardant, 1 to 2 parts of silanized coupling agent, 1 to 3 parts of light stabilizer; It is characterized in that the preparation method includes the following steps: Step 1: Insert the insulating core rod into the center hole of the hardware, and then form it into one by crimping or gluing to obtain the insulating core rod-fitting tool composite; Step 2: Put both ends of the insulating mandrel-fitting composite obtained in step 1 into the mold respectively. During the production process, keep the mold temperature at 110-130°C and the vacuum in the mold cavity less than 0.1kPa. Mix the materials. The gel is injected into the mold cavity at a fixed pressure of 0.3~0.5MPa, the injection pressure holding time is 30~45min, and the curing time is 30min. A hard material sheath of hard material and anti-bird droppings are integrally formed on the outer surface of the mandrel to equalize the pressure. Cover, a hard material sheath formed of hard material on the outer surface of the lower end of the mandrel; Step 3: Form a silicone rubber sheath and silicone rubber shed on the outside of the insulating mandrel-fitting complex with a hard material sheath and an anti-guano voltage equalizing cover. 2. The method for preparing a hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized in that: Step 2 further includes, Step 2-1, weigh the raw materials of the hard material layer according to the following weight ratio: 100 parts of alicyclic epoxy resin, 25 to 40 parts of plastic, 15 to 35 parts of methyl hexahydrophthalic anhydride curing agent, aluminum trihydrate micropowder resist 8 to 12 parts of fuel, 1 to 2 parts of silanized coupling agent, and 1 to 3 parts of light stabilizer are put into a vacuum stirring tank for stirring and degassing. The vacuum degree is less than 0.5kPa, and the mixing temperature is 30 to 40°C. , stirring and degassing time 120min, to obtain the mixture gel; Step 2-2: Keep the mold temperature at 110~130℃ and the vacuum in the mold cavity less than 0.1kPa. Inject the mixed gel into the mold cavity at a fixed pressure of 0.3~0.5MPa. The injection pressure holding time is 30~45min and the curing time is 30min. ; Step 2-3, demould, remove flash, and obtain an insulating core rod-fitting complex with a hard material sheath and an anti-guano pressure equalizing cover on the upper outer surface of the core rod and a hard material sheath on the lower outer surface. . 3. The method for preparing a hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized in that: Step 3 further includes, Step 3-1: Polish the surfaces of the hard material sheaths at both ends of the insulating mandrel-fitting complex in Step 2 and the surface of the mandrel in the middle, apply adhesive, and place them in an oven to preheat. The preheating temperature is 60 to 80°C. , preheating time 45~60min; Step 3-2: Put the insulating mandrel-hardware complex with a hard material sheath and an anti-guano pressure equalizing cover that was preheated in step 3-1 into the mold, and inject and plasticize the silicone rubber raw material. , the plasticizing temperature is 150~250℃, the injection pressure is 15~80MPa, and the mold is demoulded to form a silicone rubber sheath and a silicone rubber shed, thereby obtaining a hard material sheathed composite insulator with an anti-guano pressure equalizing cover. 4. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The diameter of the anti-guano pressure equalizing cover is 1.5 to 2 times that of the silicone rubber shed. 5. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The plastic includes one or more of polyethylene, polypropylene, polystyrene, polyamide, and polycarbonate. 6. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The aluminum trihydrate micropowder includes the aluminum trihydrate micropowder including 60% to 70% by weight of alumina and 30% to 40% by weight of titanium dioxide. 7. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The core rod is made of fiberglass and epoxy resin. 8. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The silicone rubber sheath and the silicone rubber shed are made of silicone rubber material, and the silicone rubber sheath and the silicone rubber shed are wrapped around the outside of the hard material layer through one-time injection molding. 9. The hard material sheathed composite insulator with a bird droppings-proof voltage equalizing cover as claimed in claim 1, characterized by: The silicone rubber shed has an equal diameter shed structure, one large shed structure and one small shed structure, one large shed structure and two small shed skirts, or one large shed structure, one in the middle and one small shed structure.