1. The interior noise
vehicle noise, that is, when the cars on the road, the internal combustion engine, horn, tires, etc. will issue a large number of human beings do not like the sound.
First, the interior noise is generated:
The noise is mainly vehicle (road noise) noise from the mechanical components (engine noise), and the tire ground friction sound such as an engine, car break collision and friction sound generated by the air curtain (wind noise), the incoming vehicle environment external sound (such as a large truck whistling sound..), the internal noise and vibration generated cockpit interior panels and other components like member occurs .
car noise is mainly low frequency noise (250hz — 500hz) its strong penetrating power, part of the acoustic noise is difficult to deal with in the art.
survey showed that 85.5 percentage of the motor vehicle noise of urban traffic noise. And a measure of how much traffic is closely related to the size and spread of road vehicle noise. In the narrow path, crowded city of high-rise buildings on both sides, the noise bounces back and forth, even more noisy. The same sources of noise on the streets relatively empty on the ground, it sounds great 5-10 dB. In motor vehicles, the noise trucks, buses and other heavy vehicles in the 89-92 decibels, while cars, jeeps and other light vehicles is about 82-85 decibels of noise. Vehicle speed and the noise level is also greatly dependent, the faster the speed the greater the noise, the vehicle speed increased by 1, 6-10 dB increase in noise.
Second, the source of noise:
chassis:.
A material of poor insulation of the floor panel, the road noise is easily transmitted to the cockpit. Many middle and low vehicle chassis when the factory installed only a few small damping rubber plate, and a small amount of sound blankets.
b. Poor suspension system assembly, loose, or aging in parts, can not effectively reduce vibration.
c. Automobile sheet metal and the process does not use metal thicknessenough.
tires:.
A process of the tire with the ground and the friction sound incoming from the wheel arch cockpit.
b. Uneven pavement caused by vibration, noise coming cockpit.
Column door:.
A vehicle body due to defective assembly or resonance.
b. Post of initiator slits wind noise at high speed.
c. Resonated cleared and the interior cavity of the body.
engine:.
a running engine noise and vibration by the incoming firewall cockpit.
b. Below the dashboard, passed by the firewall cockpit road noise.
Top vehicle:
is too thin sheet metal roof, causing the vehicle body resonance.
assembled:
due to assembly or poor design caused by various noise, such as common screw loosening damping rubber aging.