汽車(che)(che)(che)(che)要跑得快，就必(bi)須要有(you)強勁的(de)(de)動(dong)(dong)力(li)。目(mu)前汽車(che)(che)(che)(che)的(de)(de)動(dong)(dong)力(li)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)可粗分為自(zi)(zi)(zi)然(ran)(ran)進氣系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)及增壓(ya)(ya)(ya)進氣系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)兩大(da)類(lei)。在(zai)歐洲跑車(che)(che)(che)(che)中，除了寶馬(ma)汽車(che)(che)(che)(che)公司(si)依然(ran)(ran)堅(jian)持使用(yong)自(zi)(zi)(zi)然(ran)(ran)進氣發(fa)動(dong)(dong)機外，其他各汽車(che)(che)(che)(che)公司(si)為了提(ti)升(sheng)車(che)(che)(che)(che)輛的(de)(de)動(dong)(dong)力(li)性能，紛紛采(cai)用(yong)增壓(ya)(ya)(ya)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)，例如(ru)：奔馳跑車(che)(che)(che)(che)使用(yong)機械增壓(ya)(ya)(ya)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)，紳寶汽車(che)(che)(che)(che)則為渦(wo)(wo)輪(lun)增壓(ya)(ya)(ya)的(de)(de)開(kai)山(shan)鼻祖(zu)。近年日(ri)系(xi)(xi)(xi)(xi)(xi)汽車(che)(che)(che)(che)也開(kai)始(shi)大(da)量采(cai)用(yong)渦(wo)(wo)輪(lun)增壓(ya)(ya)(ya)技(ji)術。自(zi)(zi)(zi)然(ran)(ran)進氣系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)沒有(you)安裝任何形(xing)式的(de)(de)增壓(ya)(ya)(ya)器，只(zhi)是利用(yong)活塞下行(xing)所產生的(de)(de)負壓(ya)(ya)(ya)來吸(xi)進混合氣。雖然(ran)(ran)自(zi)(zi)(zi)然(ran)(ran)進氣系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)通過可變氣門(men)正時系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)能夠得到較大(da)的(de)(de)馬(ma)力(li)輸出(chu)，但動(dong)(dong)力(li)的(de)(de)提(ti)升(sheng)很(hen)有(you)限。為了有(you)效增加(jia)發(fa)動(dong)(dong)機的(de)(de)輸出(chu)功率(lv)，采(cai)用(yong)增壓(ya)(ya)(ya)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)可說是最有(you)效的(de)(de)方(fang)式。

最常(chang)見的發動機(ji)(ji)增(zeng)(zeng)壓系統(tong)有機(ji)(ji)械增(zeng)(zeng)壓與廢氣渦輪增(zeng)(zeng)壓兩種。

機械增壓

發動(dong)(dong)機(ji)(ji)(ji)(ji)以機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)方(fang)式驅(qu)動(dong)(dong)機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)進(jin)行增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)，稱為機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)。當(dang)發動(dong)(dong)機(ji)(ji)(ji)(ji)采用(yong)(yong)機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)時，通(tong)常(chang)由(you)發動(dong)(dong)機(ji)(ji)(ji)(ji)曲軸通(tong)過齒輪(lun)(lun)驅(qu)動(dong)(dong)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)。增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)一般(ban)采用(yong)(yong)離心式或(huo)羅茨壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)，個(ge)別的(de)(de)采用(yong)(yong)螺桿式壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)。近年(nian)來(lai)，在(zai)國外也開始采用(yong)(yong)新型(xing)的(de)(de)機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)渦旋(xuan)式增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)。因(yin)為驅(qu)動(dong)(dong)壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)消耗(hao)了(le)發動(dong)(dong)機(ji)(ji)(ji)(ji)一定(ding)的(de)(de)輸出功率(lv)(lv)，所以機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)機(ji)(ji)(ji)(ji)的(de)(de)熱效(xiao)率(lv)(lv)不(bu)一定(ding)得(de)到改(gai)善，有時反而比非增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)內燃(ran)機(ji)(ji)(ji)(ji)還(huan)低些(xie)。選擇增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)時，首先要保證能(neng)達到所要求(qiu)的(de)(de)平(ping)均有效(xiao)壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)，其次要獲得(de)盡可能(neng)低的(de)(de)燃(ran)油(you)消耗(hao)率(lv)(lv)。擔這兩個(ge)要求(qiu)對于機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)來(lai)說常(chang)常(chang)是相互矛(mao)盾(dun)的(de)(de)。如果追求(qiu)平(ping)均有效(xiao)壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)，則必然(ran)導致機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)效(xiao)率(lv)(lv)降低，燃(ran)油(you)消耗(hao)率(lv)(lv)升(sheng)高。因(yin)此，增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)值的(de)(de)選取應在(zai)功率(lv)(lv)和燃(ran)油(you)消耗(hao)率(lv)(lv)兩者之間尋求(qiu)最佳的(de)(de)妥(tuo)協方(fang)案。機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)系統目前在(zai)歐洲(zhou)車上用(yong)(yong)得(de)較普遍(bian)。由(you)于機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)是在(zai)曲軸的(de)(de)帶動(dong)(dong)下持續地(di)運轉，因(yin)此不(bu)動(dong)(dong)產生像渦輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)渦輪(lun)(lun)遲滯現(xian)象。機(ji)(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)雖然(ran)只能(neng)提升(sheng)約10%20%的(de)(de)動(dong)(dong)力(li)輸出，但平(ping)順連續性是渦輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)機(ji)(ji)(ji)(ji)所不(bu)及的(de)(de)。

廢氣渦輪(lun)增壓

利用發(fa)(fa)動(dong)(dong)機(ji)(ji)廢(fei)(fei)(fei)氣(qi)(qi)能量(liang)驅動(dong)(dong)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)器(qi)，稱(cheng)為廢(fei)(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)（簡(jian)稱(cheng)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)），如(ru)圖(tu)所示是(shi)(shi)廢(fei)(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)系(xi)統。廢(fei)(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)的(de)(de)特點是(shi)(shi)在(zai)(zai)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)器(qi)和(he)發(fa)(fa)動(dong)(dong)機(ji)(ji)之(zhi)間沒有(you)機(ji)(ji)械(xie)連接。它(ta)們(men)之(zhi)間靠氣(qi)(qi)路(lu)相(xiang)通(tong)。因為壓(ya)(ya)(ya)氣(qi)(qi)機(ji)(ji)消(xiao)耗的(de)(de)功是(shi)(shi)渦(wo)(wo)(wo)輪從(cong)廢(fei)(fei)(fei)氣(qi)(qi)中回收的(de)(de)一(yi)部分(fen)能量(liang)，所以渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)發(fa)(fa)動(dong)(dong)機(ji)(ji)不僅(jin)可以增(zeng)加發(fa)(fa)動(dong)(dong)機(ji)(ji)的(de)(de)功率(lv)，而且可以提(ti)高其熱效率(lv)，降低(di)燃(ran)油消(xiao)耗率(lv)。如(ru)果(guo)在(zai)(zai)轎車(che)尾部看到Turbo或者T的(de)(de)標識，即表明該車(che)采(cai)用的(de)(de)發(fa)(fa)動(dong)(dong)機(ji)(ji)是(shi)(shi)渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)的(de)(de)。渦(wo)(wo)(wo)輪增(zeng)壓(ya)(ya)(ya)器(qi)實際(ji)上是(shi)(shi)臺空氣(qi)(qi)壓(ya)(ya)(ya)縮(suo)機(ji)(ji)，它(ta)是(shi)(shi)利用發(fa)(fa)動(dong)(dong)機(ji)(ji)排出(chu)的(de)(de)廢(fei)(fei)(fei)氣(qi)(qi)慣(guan)性推動(dong)(dong)渦(wo)(wo)(wo)輪，渦(wo)(wo)(wo)輪又帶動(dong)(dong)同(tong)軸的(de)(de)葉(xie)輪壓(ya)(ya)(ya)縮(suo)由空氣(qi)(qi)濾清器(qi)管道送來的(de)(de)空氣(qi)(qi)，使空氣(qi)(qi)增(zeng)壓(ya)(ya)(ya)后進(jin)入氣(qi)(qi)缸。當(dang)發(fa)(fa)動(dong)(dong)機(ji)(ji)轉(zhuan)速(su)提(ti)高，廢(fei)(fei)(fei)氣(qi)(qi)排出(chu)速(su)度與渦(wo)(wo)(wo)輪轉(zhuan)速(su)也同(tong)步提(ti)高，葉(xie)輪就(jiu)(jiu)壓(ya)(ya)(ya)縮(suo)更(geng)多的(de)(de)空氣(qi)(qi)進(jin)入氣(qi)(qi)缸，空氣(qi)(qi)的(de)(de)壓(ya)(ya)(ya)力(li)和(he)密度增(zeng)大可以燃(ran)燒更(geng)多的(de)(de)燃(ran)油，相(xiang)應(ying)增(zeng)加油量(liang)和(he)調整一(yi)下發(fa)(fa)動(dong)(dong)機(ji)(ji)的(de)(de)轉(zhuan)速(su)，就(jiu)(jiu)可以增(zeng)加發(fa)(fa)動(dong)(dong)機(ji)(ji)的(de)(de)輸出(chu)功率(lv)。