1 engine noise. In addition to the mechanical sound emitted by the engine, but also including the intake system noise, that is, high speed gas through the air filter, air intake pipe, valve into the cylinder, in the flow process, will produce a strong noise. The noise of the engine is mainly composed of a front wall and bottom parts of the cab into the cockpit.
2 tire noise. General tire noise mainly consists of three parts: Tire clearance of the air flow and the circumference of a tire air disturbance consisting of air noise; the second is the carcass and a tread part vibration caused by tire vibration noise; three is caused by uneven road pavement noise.
3 air noise. Is wind noise, is by the airflow around the body separation led to pressure for change and noise; second wind leakage, or call suckout tone, by cab and auto body slot suction and interaction between the airflow around the body and produce noise; three is other noises, including cavity sympathetic chord and so on.
4 body structure noise. Is mainly affected by two factors, one is the transfer mode of the vibration of the body structure, the second is the metal component body due to the inside and out under the action of vibration and noise.