1, engine noise
First, the vehicle engine is a source of noise. Its noise generation varies with engine speed, and is mainly generated and transmitted through the front fender, hood, fire wall, and exhaust pipe.
In addition to the mechanical sound from the engine body, it also includes the intake system noise, that is, the high-speed gas enters the cylinder through the air filter, the intake pipe, and the valve. During the flow, a strong pneumatic force is generated. noise.
The engine noise is mainly transmitted to the cockpit by the fire wall and the front floor of the cab.
2, tire noise
Then there is the tire noise. The tire noise is the noise generated by the friction between the tire and the road after the car is turned on. The noise level of the tire depends on the condition of the road. The worse the road condition, the louder the tire noise.
In addition, the tire noise generated by the tarmac road and the concrete road surface is also very different. Tire noise is mainly generated and transmitted through the door, the trunk, the front fender, and the front wheel arc.
3, wind noise
There is wind noise. Wind noise refers to the sound produced by the friction between the air and the vehicle and the corners after the car is turned on.
The faster the speed, the greater the wind noise. He mainly produces and transmits through the door seal gap and the integral steel plate.
4, resonance noise and other
In addition, the body itself is a box, and the sound has the nature of refraction and overlap.
When the sound is transmitted into the car, if there is no sound absorption and sound insulation material to absorb and block, the noise will refract and overlap constantly, forming a resonance noise, which is mainly caused by noise entering the car, superimposed reflection It is.