抄録
A diesel engine is mainly used to commercial vehicles from the viewpoint of fuel economy. But its exciting force is larger than that of petrol engine, which causes the uncomfortable vibration at an idling revolution. Therefore, in this study, an air spring is newly applied to the actual engine mount system of a medium duty truck and many vehicle tests are conducted for checking its vibration isolation effect and its big displacement caused by engine shock torque. As a result, the significant vibration isolation effect could be not only obtained, but the big displacement was within the limit.