Base structure of a motor saw

摘要

A base structure of a motor saw forms fuel and oil tanks (16,17) and a crankcase bottom in one piece. This piece is injection moulded in plastics with closed tank cavities obtained by means of cores in the mould which are made of a metal having a melting temperature lower than the softening temperature of the plastic material. After moulding the cores are melted by heat treatment and the metal runs out through filling holes (18,19) of the tanks. Armouring pieces are moulded in the plastics to reinforce the attachments of crankshaft bearings and the guide bar.