發動機(ji)的排氣(qi)噪聲,并使高(gao)溫廢氣(qi)能有效(xiao)地排出。消聲器作為排氣(qi)管道的一部分(fen),應保(bao)證其(qi)排氣(qi)暢通(tong)、阻力(li)小及足夠強度。消聲器要經受(shou)500℃~700℃高(gao)溫排氣(qi),保(bao)證在汽車規定(ding)的行駛里程(cheng)內,不(bu)損(sun)壞、不(bu)失去消聲。
汽(qi)車噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)主要來(lai)自汽(qi)車排氣噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)。若不加消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi),噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)可(ke)(ke)(ke)達(da)(da)100分(fen)貝以(yi)上(shang)(shang)。其次為(wei)(wei)引(yin)(yin)(yin)擎噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)和輪胎噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng),引(yin)(yin)(yin)擎噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)在汽(qi)車正常運轉時(shi)(shi),可(ke)(ke)(ke)達(da)(da)90分(fen)貝以(yi)上(shang)(shang),而輪胎噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)在車速為(wei)(wei)90公里/時(shi)(shi)以(yi)上(shang)(shang)時(shi)(shi),可(ke)(ke)(ke)達(da)(da)95分(fen)貝左右(you)。因此,在排氣系統中加上(shang)(shang)消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi),可(ke)(ke)(ke)使汽(qi)車排氣噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)20-30分(fen)貝。在引(yin)(yin)(yin)擎方面,以(yi)汽(qi)油(you)引(yin)(yin)(yin)擎代替柴油(you)引(yin)(yin)(yin)擎,可(ke)(ke)(ke)以(yi)引(yin)(yin)(yin)擎噪(zao)(zao)(zao)(zao)聲(sheng)(sheng)(sheng)6-8分(fen)貝。