Large composite material skinned die and manufacturing method thereof

Abstract

The invention discloses a large composite material skinned die and a manufacturing method thereof. The die comprises a combined welding supporting base, a combined welding supporting frame, a glass steel layer and an epoxy resin layer which is stuck on the glass steel layer, wherein a layer of fluorinated polyurethane lusterless porcelain varnish is coated on the surface of the epoxy resin layer. Pits on the surface of epoxy resin are completely filled through the fluorinated polyurethane lusterless porcelain varnish, which can be tightly combined with the epoxy resin and has high permeability; the defect that micro air vents are formed on the surface of the epoxy resin of the large composite material skinned die is overcome substantially; and the surface quality and the air tightness reliability of the large composite material skinned die are obviously improved.

Description

technical field [0001] The invention relates to a large-scale skin mold and a manufacturing method thereof, in particular to a super-large composite material skin of a rail vehicle and a manufacturing method thereof. technical background [0002] In order to reduce the weight of the carriages of high-speed rail vehicles, composite materials are used in the prior art to manufacture body skins, and the huge body skins are divided into blocks, with a minimum size of 2 meters and a maximum size of 12 meters. In order to ensure the assembly precision quality and appearance quality of rail vehicles, the precision and appearance quality requirements of each composite material part are very high. For the forming of such large precision composite parts, the supporting base welded with rectangular steel and the supporting frame mold composed of steel plates are currently used. Due to the large size and area of ​​the composite material skin, there are more than 20 sets of large-scale ...

AI Technical Summary

Problems solved by technology

Due to the large size and area of ​​the composite material skin, there are more than 20 sets of large-scale molds that often have slight or even severe air leakage when forming composite material parts, which cannot meet the airtightness requirements required for the manufacture of composite parts

Due to the fact that the FRP layer that makes up the composite material mold cannot completely remove the air between the large-area lamination layers during the manual operation, there are large and small air bubbles; the epoxy resin layer generates gas and heat during curing, forming many micro-depressions inside and on the surface. Pit, the air bubbles in the FRP layer and the pits in the epoxy resin layer form countless micro-channels. Some of these micro-channels can be observed with the naked eye, but most of them cannot be observed with the naked eye. In actual work, air blowing method and magnifying glass have been used. Observation method cannot find and eliminate these defects. These defects are inevitable and cannot be completely eliminated, which has become a difficulty restricting the progress of rail vehicle projects.

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