Foamed resin oil pan and method of fabrication thereof

摘要

A foamed resin oil pan has a body portion and a flange portion for mounting the body portion on the cylinder block is disclosed. The bubble fraction of the resin constituting the body portion is higher than that of the resin constituting the flange portion. As a result, the strength and rigidity of the flange portion are maintained at high level while at the same time increasing the sound insulating properties and the heat insulating properties.