CN103177825B - A kind of support insulator - Google Patents

Abstract

The present invention relates to a kind of support insulator, including insulator body and by fixing with insulator body root and the top respectively cast iron seat of cement fixed bed, described insulator body is included micron zirconia ceramic layer, transition zone and conventional ceramic layer successively by root to top；In described transition zone, micron zirconia ceramic content is gradually lowered, and conventional ceramic content is gradually increased.The present invention can prevent insulator root from crackle, fracture effective prolongation insulator service life occur.

Description

a post insulator

technical field

The invention relates to a post insulator.

Background technique

The accidents caused by the breakage of porcelain bottles seriously affect the safe operation of the power system. According to the statistics of relevant departments, the main part of the breakage of the pillar porcelain insulator is at the junction of the cast iron flange and the porcelain insulator, that is, the cast iron flange is exposed about 10mm to the inside of the cast iron flange. In the range of about 20mm, this is a basic feature of the fracture of domestic porcelain bottles. There are two main reasons for cracks: one is that the thermal expansion coefficient of ceramics is small and the expansion coefficient of cast iron is relatively large. When the temperature drops suddenly, the cast iron seat forms an excessive clamping force on the ceramic insulator, thus forming cracks; the other is Porcelain pillar insulators are electric porcelain products sintered at high temperature. They are brittle materials. If the material is not uniform enough, or the force is uneven during processing and use, it will cause extremely small holes or cracks, which will become the source of fracture.

Contents of the invention

The technical problem to be solved by the present invention is to provide a post insulator that can effectively reduce the probability of cracks and breakage at the root of the insulator and effectively prolong the service life of the insulator.

The present invention adopts following technical scheme:

A post insulator, which is characterized in that it includes an insulator body and cast iron seats fixed to the root and top of the insulator body through a cement fixing layer, and the insulator body includes a micron zirconia ceramic layer, a transition layer and a common Ceramic layer: the content of micron zirconia ceramics in the transition layer gradually decreases from bottom to top, and the content of ordinary ceramics gradually increases.

The thickness of the micron zirconia ceramic layer is 10mm higher than the cast iron seat at the root, and the thickness of the transition layer is not less than 20% of the distance between the micron zirconia ceramic layer and the first shed (1-4) on the insulator body.

In the mud sintering manufacturing process, the transition layer is formed by the green sheet lamination method, and the specific steps are:

(1) A series of green sheets with different composition ratios are prepared by casting method. The mass or volume ratio of micron zirconia in the green sheets changes in a gradient from 95% to 5%, and the gradient of each layer should not exceed 5% %, the thickness of the single-layer blank is determined according to the thickness H of the transition layer. The specific steps include: mixing materials, preparing slurry, casting and drying. The solid material content in the dried green sheet should be consistent with the solid material content in the insulator mud body within the allowable error range, so as to ensure consistent deformation during sintering.

(2) Cutting and lamination—cut the prepared blanks into blanks of corresponding sizes according to the diameter of the insulator root, stack the blanks together in sequence according to the composition gradient and press them appropriately to form a transition layer .

Combining the micron zirconia ceramic layer, the transition layer and the ordinary ceramic layer and adopting an appropriate method to closely combine the three before sintering and forming.

Beneficial effects of the present invention: (1) The root of the cast iron flange glued with the present invention adopts high-strength micron zirconia ceramics, the purity and density of the root are much higher than that of the main body of the insulator, and the original defects such as small holes or cracks are reduced. (2) The thermal expansion coefficient and elastic modulus of the high-strength micron zirconia ceramic layer (expansion coefficient: 9.4×10 ^-6 /°C, elastic modulus: 190GPa) at the root of the insulator of the present invention are the same as those of cast iron (expansion coefficient: 10.4×10 ^-6 /℃, elastic modulus: 120GPa), which effectively reduces the clamping force caused by the cast iron seat to the root of the ceramic insulator, thereby improving the stress state at the joint between the post insulator and the cast iron seat, and avoiding the expansion of the cast iron seat and the root of the insulator. The coefficient difference is too large to cause cracks in the insulator and prolong the service life of the insulator; (3) In the transition layer between the high-strength micron zirconia ceramic layer and the ordinary ceramic layer of the insulator, the micron zirconia ceramic changes in a gradient from 95% to 5%. , and the change gradient of each layer does not exceed 5%, which reduces the stress concentration between the main body and the root of the insulator due to the difference in chemical composition, and the mechanical strength is effectively guaranteed.

Description of drawings

Fig. 1 is a structural representation of the present invention;

In the accompanying drawings: 1-1 micron zirconia ceramic layer, 1-2 transition layer, 1-3 ordinary ceramic layer, 1-4 first shed, 2 cast iron seat, 3 fixed layer.

detailed description

As shown in Figure 1, the present invention includes an insulator main body and a cast iron base 2 fixed to the root and top of the insulator main body through a cement fixing layer 3, and the insulator main body includes a micron zirconia ceramic layer 1-1, The transition layer 1-2 and the ordinary ceramic layer 1-3; the content of micron zirconia ceramics in the transition layer 1-2 gradually decreases, and the content of ordinary ceramics gradually increases. The thickness of the micron zirconia ceramic layer 1-1 is 10mm higher than the cast iron seat at the root, and the thickness H of the transition layer 1-2 is not less than the top of the micron zirconia ceramic layer to the first shed on the insulator body (1-4 ) 20% of the distance between heights.

In the mud sintering manufacturing process, the transition layer is formed by the green sheet lamination method, and the specific steps are:

(1) A series of green sheets with different composition ratios are prepared by casting method. The proportion of micron zirconia ceramics in the green sheets changes in a gradient from 95% to 5%, and the gradient of each layer does not exceed 5%. The thickness of the layer blank is determined according to the thickness H of the transition layer;

(2) Cutting and stacking—cut the prepared blanks according to the diameter of the root of the insulator to cut blanks of corresponding sizes, and stack the blanks in sequence according to the composition gradient and press molding to form a transition layer.

Combining the micron zirconia ceramic layer, the transition layer and the ordinary ceramic layer and adopting an appropriate method to closely combine the three before sintering and forming.

The invention can effectively reduce the probability of cracks and fractures at the root of the insulator and effectively prolong the service life of the insulator.

Claims (2)

1. A post insulator, characterized in that it comprises an insulator body and a cast iron seat (2) fixed to the root and top of the insulator body through a cement fixing layer (3), and the insulator body includes micron oxide from the root to the top. Zirconium ceramic layer (1-1), transition layer (1-2) and ordinary ceramic layer (1-3); the content of micron zirconia ceramics in the transition layer (1-2) gradually decreases from bottom to top, and the content of ordinary ceramics gradually increase; In the mud sintering manufacturing process, the transition layer is formed by the green sheet lamination method, and the specific steps are: (1) A series of green sheets with different composition ratios are prepared by casting method. The mass or volume ratio of micron zirconia ceramics in the green sheets changes in a gradient from 95% to 5%, and the gradient of each layer does not exceed 5% %, the thickness of the single-layer blank is determined according to the thickness H of the transition layer; (2) Cutting and lamination: Cut out the prepared green sheets according to the diameter of the root of the insulator to cut out corresponding size green sheets, and stack the green sheets sequentially according to the composition gradient and press molding to form a transition layer. 2. The post insulator according to claim 1, characterized in that the longitudinal thickness of the micron zirconia ceramic layer (1-1) is 10 mm higher than the cast iron seat (2) at the root, and the thickness of the transition layer (1-2) is The thickness H is not less than 20% of the distance from the micron zirconia ceramic layer to the first shed (1-4) on the insulator main body.