Manufacturing method of composite insulator with high electromechanical performance

Abstract

The invention discloses a method for manufacturing a high-electromechanical-property composite insulator. The method comprises a fitting manufacturing process, a core bar manufacturing process, a fitting and core bar assembling process, an inner protective sleeve forming process and an outer umbrella skirt protective sleeve forming and end sealing process. The method is characterized in that when a core bar is manufactured, the shape of the end of the core bar is firstly machined to be identical to the inner hole structure of a fitting, then the end of the core bar is polished, surface skin release agents are removed, then the polished end of the core bar is assembled in the fitting, the inner diameter of the fitting and the outer diameter of the core bar are controlled to be in interference fit, and the clearance is 0.1 mm. According to the method, the bonding quality of an interface between the insulation core bar in the composite insulator and an umbrella skirt protective sleeve can be improved, the end connecting mode and the control method are improved innovatively, and it is guaranteed that the electromechanical property of the composite insulator is stable and reliable for a long time.

Description

technical field [0001] The invention relates to the field of electric equipment manufacturing industry, mainly relates to the technical field of composite insulators, in particular to the manufacturing process of composite insulators with high electromechanical performance. Background technique [0002] At present, the molding process of composite insulator outer insulating shed sheath mainly includes integral injection molding and extruded sheath back shed sheath set. These molding processes determine and affect the macroscopic interface between inner insulating mandrel and shed sheath Combined with quality. The connection of the end accessories mainly adopts the crimping process, which determines and affects the macroscopic interface bonding quality between the inner insulating mandrel and the end fittings. The overall injection molding process is to put the semi-finished product assembled with the end fittings into the mold, and use the rubber injection machine to form t...

AI Technical Summary

Problems solved by technology

The overall molding process requires high-temperature vulcanized silicone rubber to be cross-linked and vulcanized in the injection mold, so the temperature of the injection mold is generally 150-200°C. In addition, the fluidity of the silicone rubber after mixing is very poor, and a corresponding injection pressure is required to be in the injection mold. Flow to fill the entire mold cavity, so its injection pressure is generally around 100bar, but the mandrel made of glass fiber filled epoxy resin will undergo thermal oxidation decomposition at around 160°C, and the decomposition will intensify as time goes on ; In addition, in order to prevent the silicone rubber flowing under pressure from impacting the mandrel during the injection process, resulting in molding failure, the protruding steel core is used for positioning in the mold. Unevenness, the most important thing is that it is difficult to avoid the mandrel that begins to thermally oxidize and decompose in a high temperature state. Due to the impact of pressure-flowing silicone rubber, it is damaged at the location of the steel core due to excessive pressure

Secondly, since the semi-finished product taken out has been completely covered by silicone rubber, this potential hazard is difficult to eliminate

In addition to the entire interface of the overall injection molding process, the shed shed set process after the sheath is extruded also has a special bonding interface between the sheath and the shed. The weak link of the outer insulation can easily cause partial discharge due to moisture in the inner interface of the outer insulation, resulting in failure of the insulator

In addition, the sealing quality of the multiple interfaces of the mandrel, fittings and sheath at the end of the product produced by this process is not high

Therefore, the disadvantage of this process is that more macroscopic interfaces and low-quality end seals can easily lead to failure of composite insulators in long-term high-voltage operation