Preparation method of high-strength and high-toughness coating rod type insulator for high-speed rail overhead line system

Abstract

The invention relates to a preparation method of a high-strength and high-toughness coating rod type insulator for a high-speed rail contact net, and relates to the field of electrified traffic of high-speed railways. The high-strength and high-toughness coating rod type insulator comprises a porcelain insulator main body and an integrated metal flange body formed by an ETV coating and the porcelain insulator main body, the porcelain insulator main body is prepared by mixing calcined high bauxite, feldspar, kaolin, zirconite, quartz, cordierite, ceramic short fibers, clay and the like, adding the mixture into a ball mill, uniformly mixing to form slurry, sieving to remove iron, squeezing the slurry, pugging the slurry, performing high-pressure vacuum treatment, mechanically pressing to form a blank, cutting, drying, glazing, and firing at a high temperature of 1250 DEG C. The porcelain insulator main body is prepared by the steps of appearance detection, good quality detection and the like. By adopting a zirconium-aluminum composite ceramic matrix preparation technology, the composite material has the characteristics of high density, high strength, good toughness and small dispersity, the bending load tolerance strength is greater than or equal to 25KN / cm < 2 >, the torque load is greater than or equal to 15KN. M, and the composite material can completely meet the technical requirements of use of porcelain insulators in high-voltage power transmission grids of high-speed railways.

Description

Technical Field

[0001] The invention relates to the field of high-speed railway electrification transportation, and in particular to a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network. Background Art

[0002] With the vigorous advancement of railway electrification construction, the railway system has ushered in unprecedented rapid development, and electrification technology has become the core trend leading the upgrade of railway traction power. Looking forward to the next few years, the operating speed of high-speed railways is expected to jump from 250 kilometers to 350 kilometers, and even move towards a maximum speed of 400 kilometers. This speed increase has put forward higher requirements for the safe and stable operation of electric locomotives, especially the tension of the contact line needs to be increased accordingly to ensure stable power supply for trains during high-speed operation.

[0003] In this context, the performance standards of rod-type porcelain insulators, as key components in railway electrical systems, are also facing severe challenges. In order to meet the safety requirements of high-speed railways after the speed increase, rod-type porcelain insulators must have excellent strength, toughness and bending resistance, especially the bending strength must reach or exceed 16KN to adapt to higher mechanical stress.

[0004] However, the bending strength of most railway rod porcelain insulators in the current domestic market is still in the range of 8KN to 12KN, and is mainly concentrated in products with umbrella diameters of 178mm and 205mm. Although many companies have adopted high-strength porcelain formulas in material selection, they still generally use traditional methods in the glazing process of insulators, resulting in insufficient glue strength and difficulty in making the product's bending strength exceed the 16KN mark, thus limiting the wide application of these insulators in high-speed electrified railways.

[0005] Therefore, technological innovation and process upgrades are urgently needed to break through existing bottlenecks, promote the performance leap of rod-type porcelain insulators, and meet the new requirements of high-speed railway development. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network.

[0007] The present invention provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network, the method comprising a porcelain processing step and a porcelain assembly step; the porcelain processing step sequentially comprises ball milling of raw materials to form slurry, sieving the slurry to obtain raw material slurry, stirring the raw material slurry with recycled blanks to obtain mixed slurry, removing iron from the mixed slurry, aging, machine blank shaping, glazing and roasting, ETV coating, and machine blank shaping of the recycled blanks;

[0008] The weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥250 mesh.

[0009] Furthermore, the production process includes selecting ingredients, quantifying, ball milling, iron removal, screening, pumping, squeezing mud, kneading mud, high-pressure vacuum, forming, drying, glazing, kiln entry, roasting, inspection, polymer coating, side inspection, packaging, and warehousing.

[0010] Furthermore, the weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥250 mesh.

[0011] Furthermore, the raw material slurry and the recycled material are mixed and stirred in a mass ratio of 1:3 to 4 to obtain a mixed slurry.

[0012] Furthermore, before gluing the porcelain parts, a layer of asphalt paint is evenly applied inside the connecting steel caps to be connected to form a buffer layer; when gluing, the porcelain parts are placed upright, the connecting steel caps are placed at the lower ends of the porcelain parts, the coaxiality of the connecting steel caps and the porcelain parts is controlled, and the porcelain parts are vertically inserted from above into the connecting steel caps containing a proper amount of adhesive, and vibrated while being inserted to expel the gas in the porcelain parts, steel caps and adhesive.

[0013] Furthermore, the coaxiality of the porcelain component and the connecting steel caps at both ends is <1, and the coaxiality of the porcelain component and the connecting steel cap at one end is <0.5.

[0014] Furthermore, the adhesive is formed by mixing and stirring quartz sand, cement and water.

[0015] Furthermore, after the new rod insulator with high-strength and high-toughness coating passes the inspection, ETV liquid high-temperature silicone rubber is used to automatically coat the surface of the shed.

[0016] Furthermore, the property parameters of the high-strength and high-toughness coated rod insulator for high-speed railway contact network include: bending strength 25KN, compressive strength 386KPa, impact strength 204MPa, creepage distance ≧1600mm, shed diameter Small skirt diameter

[0017] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0018] The embodiment of the present invention provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network, which mainly includes a porcelain insulator body and an ETV coating, and a metal flange body formed as an integral whole with the porcelain insulator body. The porcelain insulator body is made of calcined high-alumina bauxite, feldspar, kaolin, zircon, quartz, cordierite, ceramic short fiber, clay, etc., mixed and added to a ball mill to evenly mix to form a slurry, sieved to remove iron, squeezed mud, kneaded mud, high-pressure vacuum, machine pressed into a blank, cut, dried, glazed, and fired at a high temperature of 1250°C. The appearance and inspection are good, and the shed skirt is The upper surface is coated with ETV liquid phase, and the flange body and the two ends of the adhesive surface are sealed with cement adhesive to form a rod-shaped porcelain insulator. The zirconium-aluminum composite ceramic base preparation technology is adopted, which has the characteristics of fine grains, high density, high strength, good toughness and low dispersion. Its bending load resistance strength can reach 25KN / cm 2 The torque load of more than 15KN·m can fully meet the technical requirements for the use of porcelain insulators in high-speed railway high-voltage transmission grids. Specifically:

[0019] 1. A technical route that uses alumina fiber and zirconia to reinforce and toughen composite structural ceramic materials with high strength and high toughness;

[0020] 2. The bending load strength is ≧25KN / cm2, the impact force is 2.5 tons, and the travel speed is 100 km / h for every 4,000 Nt, which meets the demand for the electrified high-speed rail to increase its speed by 400-450 km / h;

[0021] 3. Innovation in technology integration of diversified and novel materials, material grading, molding process and sintering system;

[0022] 4. The optimized structural design of material particle size distribution reduces the weight of a single piece from 48.5Kg to 30.2Kg, a decrease of 38%. Reduce to Reduce by 23% to ensure the lightweight of rod-type porcelain insulators

[0023] 5. After optimizing the matching value of the shed coating, the surface is smooth, durable, waterproof and has outstanding anti-fouling effects.

[0024] 6. Structure height is 790mm, climbing distance ≧1600mm, large shed diameter Small umbrella skirt diameter The unit weight is reduced by 38% to ensure lightweight.

[0025] Bending load strength ≧25KN / cm 2 , torque load ≧15KN·m, impact force 2.5 tons, 100 km / h per 4000 Nt; fracture toughness: 8.6MPa*m 1 / 2、Elastic modulus: ≥300MPa, compressive strength 486MPa, hardness: grade 8.4, impact strength 204MPa.

[0026] The speed of electrified high-speed railways has been increased to 400-450 km / h. The shed has a smooth surface after coating, and is durable, waterproof and has outstanding anti-fouling effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 A simplified schematic flow chart of a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network provided in an embodiment of the present invention.

[0030] Figure 2 A simplified schematic flow chart of a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0033] In order to solve the shortcomings of the original traditional technology, the research on the technology of special insulation devices for electrified high-speed railways has not stopped so far. It has always remained on the basis of the existing application of 8-12KN bending load strength, and the speed of running at an increase of 250-350 kilometers per hour, which cannot meet the national railway bending strength requirements of more than 16KN, limiting the application and speed increase of high-speed electrified railways. Therefore, this technology adopts the technical route of reinforced and toughened composite structural ceramic materials based on the combination of alumina fiber and zirconia, the technical integration of diversified and novel materials, optimized structural design and innovative technical processes, innovations in molding processes and sintering systems, and innovations in material grading, to achieve the development of toughened high-strength coated rod-type porcelain insulators; the structure height is 790mm, the creepage distance is ≧1600mm, and the large skirt diameter is Small umbrella skirt diameter The weight of a single piece was originally 48.5Kg and was reduced to 30.2Kg, a decrease of 38%. Reduce to Reduce by 23% to ensure the lightweight of rod-type porcelain insulators. After inspection by the National Railway Product Quality Supervision and Certification Inspection Center, the bending load resistance strength is ≧25KN / cm 2 , with the characteristics of high strength and high toughness, it has achieved the demand for electrified high-speed rail to increase its speed by 400--450 km / h. The surface of the shed is smooth after coating, and it has excellent durability, good waterproofness and anti-fouling effect, which will accelerate the construction and transformation of railway electrification and will continue to accelerate the stability and reliable guarantee of safe driving.

[0034] The technical solution of the present invention is as follows:

[0035] The present invention provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network, the method comprising a porcelain processing step and a porcelain assembly step; the porcelain processing step sequentially comprises ball milling of raw materials to form slurry, sieving the slurry to obtain raw material slurry, stirring the raw material slurry with recycled blanks to obtain mixed slurry, removing iron from the mixed slurry, aging, machine blank shaping, glazing and roasting, ETV coating, and machine blank shaping of the recycled blanks;

[0036] The weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥250 mesh.

[0037] The embodiment of the present invention provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network, which mainly includes a porcelain insulator body and an ETV coating, and a metal flange body formed as an integral whole with the porcelain insulator body. The porcelain insulator body is made of calcined high-alumina bauxite, feldspar, kaolin, zircon, quartz, cordierite, ceramic short fiber, clay, etc., mixed and added to a ball mill to evenly mix to form a slurry, sieved to remove iron, squeezed mud, kneaded mud, high-pressure vacuum, machine pressed into a blank, cut, dried, glazed, and fired at a high temperature of 1250°C. The appearance and inspection are good, and the shed skirt is The upper surface is coated with ETV liquid phase, and the flange body and the two ends of the adhesive surface are sealed with cement adhesive to form a rod-shaped porcelain insulator. The zirconium-aluminum composite ceramic base preparation technology is adopted, which has the characteristics of fine grains, high density, high strength, good toughness and low dispersion. Its bending load resistance strength can reach 25KN / cm 2 The torque load reaches more than 15KN·m; the impact force is 2.5 tons, and the travel speed is 100 kilometers per hour for every 4000 Newtons; it can fully meet the technical requirements for the use of porcelain insulators in high-speed railway high-voltage transmission power grids.

[0038] In some specific embodiments, a flow chart of a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network provided by an embodiment of the present invention is as follows: Figure 1 shown.

[0039] In some specific embodiments, the production process includes selecting ingredients, quantifying, ball milling, iron removal, screening, pumping, squeezing mud, kneading mud, high-pressure vacuum, forming, drying, glazing, kiln entry, roasting, inspection, polymer coating, inspection, packaging, and warehousing.

[0040] In some specific embodiments, the weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥ 250 mesh.

[0041] In some specific embodiments, the raw material slurry and the recycled material are mixed and stirred in a mass ratio of 1:3 to 4 to obtain a mixed slurry.

[0042] In some specific embodiments, before gluing the porcelain parts, a layer of asphalt paint is evenly applied inside the connecting steel caps to be connected to form a buffer layer; when gluing, the porcelain parts are placed upright, the connecting steel caps are placed at the lower ends of the porcelain parts, the coaxiality of the connecting steel caps and the porcelain parts is controlled, and the porcelain parts are vertically inserted from top to bottom into the connecting steel caps containing a proper amount of adhesive, and vibrated while being inserted to expel the gas inside the porcelain parts, steel caps and adhesive.

[0043] In some specific embodiments, the coaxiality between the porcelain component and the connecting steel caps at both ends is <1, and the coaxiality between the porcelain component and the connecting steel cap at one end is <0.5.

[0044] In some specific embodiments, the adhesive is formed by mixing and stirring quartz sand, cement, and water.

[0045] In some specific embodiments, after the new rod-type insulator with high-strength and high-toughness coating passes the inspection, RT and liquid ETV high-temperature silicone rubber are automatically coated on the shed surface.

[0046] In some specific embodiments, the property parameters of the high-strength and high-toughness coated rod insulator for high-speed railway contact network include: bending strength 25KN, compressive strength 386KPa, impact strength 164MPa, creepage distance ≧1600mm, shed diameter Small skirt diameter

[0047] It should be noted that in the method for preparing high-strength and high-toughness coated rod insulators for high-speed railway contact networks provided in the embodiment of the present invention, the raw materials involved, unless otherwise specified or restricted, can all be commercially available products; at the same time, the process steps and parameters involved can all be carried out in accordance with existing preparation processes or using existing equipment in conventional operating methods, and the present invention document will not describe them one by one.

[0048] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0049] Example

[0050] This example provides a method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network. Figure 1 and Figure 2 As shown, the production process includes selecting ingredients, quantifying, ball milling, iron removal, screening, paddle pumping, mud squeezing, mud kneading, high-pressure vacuum, forming, drying, glazing, kiln entry, roasting, inspection, polymer coating, inspection, packaging, and warehousing; the preparation method of high-strength and high-toughness coated rod insulators for high-speed rail contact network includes a porcelain processing step and a porcelain assembly step; the porcelain processing steps include, in order, ball milling of raw materials to form mud, sieving of mud to obtain raw material slurry, stirring of raw material slurry and returned blanks to obtain mixed mud, iron removal of mixed mud, aging, machine blank forming, glazing and roasting, ETV coating, and machine blank forming of returned blanks;

[0051] The weight percentage of each raw material in the ball mill is as follows: calcined high-alumina bauxite 33%; kaolin 28%; zircon 12%; clay 5%; feldspar 4%; calcined cordierite 13%; ceramic short fiber 14%; quartz 4%; fineness ≥ 250 mesh;

[0052] The raw material slurry and the recycled material are mixed and stirred in a mass ratio of 1:3.5 to obtain a mixed slurry;

[0053] Before gluing the porcelain parts, evenly apply a layer of asphalt paint inside the connecting steel caps to be connected to form a buffer layer; when gluing, stand the porcelain parts upright, place the connecting steel caps at the lower end of the porcelain parts, control the coaxiality of the connecting steel caps and the porcelain parts, and vertically insert the porcelain parts from the top into the connecting steel caps containing a proper amount of adhesive, while vibrating to discharge the gas in the porcelain parts, steel caps and adhesive;

[0054] The coaxiality of the porcelain part and the connecting steel caps at both ends is <1, and the coaxiality of the porcelain part and the connecting steel cap at one end is <0.5;

[0055] The adhesive is formed by mixing and stirring quartz sand, cement and water;

[0056] After the new rod-type insulator with high strength and high toughness coating passes the inspection, ETV liquid high temperature silicone rubber is used to automatically coat the shed surface;

[0057] The property parameters of the high-strength and high-toughness coated rod insulator for high-speed railway contact network include: bending strength 25KN, compressive strength 386KPa, impact strength 164MPa, creepage distance ≧1600mm, shed diameter Small skirt diameter Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0058] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a high-strength and high-toughness coated rod insulator for a high-speed railway contact network, characterized in that: The method for preparing high-strength and high-toughness coated rod insulators for high-speed railway contact network comprises a porcelain processing step and a porcelain assembly step; the porcelain processing step comprises, in order, ball milling of raw materials to form slurry, sieving of slurry to obtain raw material slurry, stirring of raw material slurry and recycled blank material to obtain mixed slurry, iron removal of mixed slurry, aging, machine blank shaping, glazing and firing, and ETV coating; The weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥250 mesh.

2. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: The production process includes selection of ingredients, quantification, ball milling, iron removal, screening, pumping, mud squeezing, mud kneading, high-pressure vacuum, forming, drying, glazing, kiln entry, roasting, inspection, polymer coating, side inspection, packaging, and warehousing.

3. The method for preparing high-strength and high-toughness coated rod insulators for high-speed railway contact network according to claim 1, characterized in that: The weight percentage of each raw material in the ball mill to the total amount of raw materials is as follows: calcined high-alumina bauxite 30-35%; kaolin 25-30%; zircon 10-15%; clay 14-16%; feldspar 3-5%; calcined cordierite 10-15%; ceramic short fiber 13-18%; quartz 3-5%; fineness ≥250 mesh.

4. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: The raw material slurry and the recycled material are mixed and stirred in a mass ratio of 1:3 to 4 to obtain mixed mud.

5. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: Before gluing the porcelain parts, evenly apply a layer of asphalt paint inside the connecting steel caps that need to be connected to form a buffer layer; when gluing, stand the porcelain parts upright, place the connecting steel caps at the lower end of the porcelain parts, control the coaxiality of the connecting steel caps and the porcelain parts, insert the porcelain parts vertically from the top into the connecting steel caps filled with an appropriate amount of adhesive, and vibrate while inserting to expel the gas in the porcelain parts, steel caps and adhesive.

6. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: The coaxiality of the porcelain component and the connecting steel caps at both ends is <1, and the coaxiality of the porcelain component and the connecting steel cap at one end is <0.

5.

7. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: The adhesive is formed by mixing and stirring quartz sand, cement and water.

8. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: After the new rod-type insulator with high-strength and high-toughness coating passes the inspection, ETV liquid high-temperature silicone rubber is used to automatically coat the surface of the shed.

9. The method for preparing high-strength and high-toughness coated rod insulator for high-speed railway contact network according to claim 1, characterized in that: The property parameters of the high-strength and high-toughness coated rod insulator for high-speed railway contact network include: bending load strength 25KN, compressive strength 386KPa, impact strength 204MPa, creepage distance ≧1600mm, shed diameter Small skirt diameter

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