Noise transmission path of brake vacuum pump

 Vehicle NVH performance mainly refers to the noise, vibration and discomfort directly felt by the drivers and passengers in the vehicle during driving, also known as sound vibration roughness. Vibration and noise are often inseparable and occur at the same time. Excessive vibration will cause damage to the engine and vehicle parts; Noise is generally caused by vibration, which not only pollutes the environment, but also makes drivers and passengers tired; Acoustic vibration roughness refers to the discomfort directly felt by the drivers and passengers by the vibration and noise in the vehicle. The vibration in the vehicle mainly refers to the vibration generated during the operation of the engine and its accessories and power transmission system and the vibration generated by road excitation, which is transmitted to the steering wheel through the tire, suspension and suspension system through the frame and body The floor and seats are perceived by the personnel in the vehicle. The noise in the vehicle mainly comes from two aspects:

First, the combustion noise and mechanical noise generated during the operation of the engine and its accessories, the friction noise and wind excitation noise between the tire and the ground during rolling are transmitted to the vehicle through the air medium;
The second is the structural noise induced by the vibration generated by the chassis, body and other structural parts due to the excitation of the engine powertrain and uneven road surface. The noise generated during the operation of the brake vacuum pump is directly transmitted by the solid, transmitted to the body through the engine compartment, radiated to the vehicle through the structure, and perceived by the personnel in the vehicle. After stepping on the brake pedal in the state of low-voltage power supply, When the brake vacuum pump starts to work, the working noise generated by the vacuum pump is large, and the inflation noise of the vacuum pump can be clearly heard in the vehicle

high-vacuum flapper valve Used In extracting the CO2 Application