High-temperature compression molding process of aircraft engine nacelle inlet

Abstract

The invention discloses a high-temperature compression molding process of an aircraft engine nacelle inlet. The high-temperature compression molding process comprises the following steps of (1) determining the damage type of a damaged engine nacelle inlet; (2) conducting filling and sealing protection on aging damage to a glue joint area through a foaming type filling agent; and (3) maintaining alarge unglued damage area containing an old repair area through the following steps of 3.1, stripping a damaged wire mesh in the nacelle inlet and removing old bonding agents on the surface of a porous skin and in sound attenuation holes; 3.2, conducting vacuum impurity removal; 3.3, conducting dehumidification; and 3.4, replacing the wire mesh, and conducting high-temperature compression moldingon a bonding agent in the nacelle inlet through a mold. According to the high-temperature compression molding process, heating blankets are used for dehumidification; the mold matched with the outer surface of the aircraft engine nacelle inlet is used for pressure shaping; the multiple heating blankets are spliced for heating and assisting a temperature insulation device in high-temperature compression molding; and the high-temperature compression molding process is suitable for repairing various types of common nacelle parts and is low in cost, capable of saving time and labor and more beautiful in repair effect.

Description

technical field [0001] The invention belongs to the technical field of aircraft maintenance, and in particular relates to a high-temperature molding process for an air intake channel of an aircraft engine nacelle. Background technique [0002] The nacelle high-temperature compression molding process is the core technology of the composite material maintenance industry, especially the integrated molding process of the air inlet silencer net, which has extremely high process thresholds, many risk points, and a high probability of construction damage. [0003] Some air intake components have been in service for more than 20 years, and there are certain environmental damage and body creep in the structural adhesive connection area, which cannot withstand the overall closed high-temperature molding, which may easily cause overall bonding failure. Moreover, for the air intake components with a long service life, the old simple repair (paste glue potting repair) will cause a large ...

AI Technical Summary

Problems solved by technology

[0003]Some air intake components have been in service for more than 20 years, and there are certain environmental damage and body creep in the structural adhesive connection area, which cannot withstand the overall closed high-temperature molding, which is easy to cause overall bond failure

Moreover, for the air intake components with a long service life, the old simple repair (paste glue potting repair) will cause a large amount of water to be sealed inside the honeycomb core layer. The dehumidification method in the operation manual has limited effect and cannot be eradicated. In a high-vacuum pressure environment, liquid water can boil at 80 degrees (the operating temperature of compression molding exceeds 170 degrees), which is likely to cause air-induced impact damage to the honeycomb and penetrating damage to the carbon fiber skin.

[0004] The air inlet has a complex structure, which is made of various materials such as metal structure skeleton, carbon fiber structure skin, aluminum honeycomb core, stainless steel wire mesh, carbon fiber woven mesh, etc. Combined, with irregular curved surface shape, it is difficult to evenly distribute and conduct temperature in it, and the repair area is relatively wide and open, a single heating blanket cannot cover, and can only be spliced ​​​​for heating, but it will cause thermal degradation at the spliced ​​edge

[0005]The mold involved in the existing process is a pressure equalizing mold, the purpose is to maintain the aerodynamic shape of its surface contour, but the molding effect is not ideal

If the mold is too thick, it is easy to form a closed air-tight chamber on the molding surface, and the external pressure cannot be effectively transmitted. If the mold is too thin, it will lose the pressure equalization effect and cannot reproduce its surface contour, which will affect the smoothness and aerodynamics of the molding surface.

In addition, the mold is made of fiber resin reinforced material, with the accumulation of high-temperature molding times, there will be obvious local hardening phenomenon, which will also form a sealed air-flow closed chamber, resulting in the ineffective transmission of external pressure

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