Method of manufacture of a blade is not variable as a composite material for the rotor of helicopter, and the blade is not variable that can be obtained by such a process

摘要

A process for mfg. a composite material, variable pitch, helicopter rotor blade comprises: (i) making a preform having a part (22) forming a foot for connection to a mechanism and an aerodynamically profiled blade, the foot of the preform including a stack of reinforcing fabric extending transversally to the blade axis and projecting with respect to the part forming the foot to form a control lever (44); (ii) placing the preform in an injection mould; (iii) injecting liquid thermosetting resin; and (iv) hot moulding until cured. Also claimed is the finished rotor blade. Production is by resin transfer moulding under vacuum, from the bottom to the top of the mould and progressing along the blade. The blade centre (52) is filled with a lightweight foam, pref. of density less than 100 kg/m3. The blade contains stringer(s) comprising principally longitudinally structural carbon fibre layers and transversal glass cloth between them.