汽(qi)車(che)(che)(che)要(yao)跑得快，就必須要(yao)有(you)強勁的(de)(de)動(dong)力(li)(li)。目前汽(qi)車(che)(che)(che)的(de)(de)動(dong)力(li)(li)系統(tong)(tong)(tong)可粗分(fen)為自(zi)然進(jin)(jin)氣(qi)系統(tong)(tong)(tong)及增(zeng)(zeng)壓進(jin)(jin)氣(qi)系統(tong)(tong)(tong)兩(liang)大類。在歐洲跑車(che)(che)(che)中，除了寶(bao)馬(ma)汽(qi)車(che)(che)(che)公司(si)依然堅持(chi)使用(yong)(yong)(yong)自(zi)然進(jin)(jin)氣(qi)發(fa)動(dong)機外，其他(ta)各(ge)汽(qi)車(che)(che)(che)公司(si)為了提升(sheng)車(che)(che)(che)輛(liang)的(de)(de)動(dong)力(li)(li)性能(neng)，紛紛采用(yong)(yong)(yong)增(zeng)(zeng)壓系統(tong)(tong)(tong)，例如(ru)：奔馳跑車(che)(che)(che)使用(yong)(yong)(yong)機械增(zeng)(zeng)壓系統(tong)(tong)(tong)，紳寶(bao)汽(qi)車(che)(che)(che)則為渦輪增(zeng)(zeng)壓的(de)(de)開山鼻祖。近年日系汽(qi)車(che)(che)(che)也開始大量采用(yong)(yong)(yong)渦輪增(zeng)(zeng)壓技術。自(zi)然進(jin)(jin)氣(qi)系統(tong)(tong)(tong)沒有(you)安(an)裝(zhuang)任(ren)何形式的(de)(de)增(zeng)(zeng)壓器，只是(shi)(shi)利(li)用(yong)(yong)(yong)活塞下行所產生的(de)(de)負壓來(lai)吸進(jin)(jin)混合氣(qi)。雖然自(zi)然進(jin)(jin)氣(qi)系統(tong)(tong)(tong)通(tong)過可變氣(qi)門正時(shi)系統(tong)(tong)(tong)能(neng)夠得到較(jiao)大的(de)(de)馬(ma)力(li)(li)輸出，但動(dong)力(li)(li)的(de)(de)提升(sheng)很有(you)限。為了有(you)效(xiao)增(zeng)(zeng)加發(fa)動(dong)機的(de)(de)輸出功率，采用(yong)(yong)(yong)增(zeng)(zeng)壓系統(tong)(tong)(tong)可說(shuo)是(shi)(shi)最有(you)效(xiao)的(de)(de)方式。

最(zui)常見的發動機增(zeng)壓(ya)(ya)系統有機械(xie)增(zeng)壓(ya)(ya)與廢氣渦輪增(zeng)壓(ya)(ya)兩種。

機械增(zeng)壓(ya)

發動(dong)(dong)(dong)機(ji)(ji)(ji)以機(ji)(ji)(ji)械(xie)(xie)方(fang)式(shi)驅(qu)動(dong)(dong)(dong)機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)進行增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)，稱(cheng)為(wei)機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)。當發動(dong)(dong)(dong)機(ji)(ji)(ji)采(cai)用(yong)機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)時(shi)，通常(chang)由發動(dong)(dong)(dong)機(ji)(ji)(ji)曲(qu)軸通過齒輪驅(qu)動(dong)(dong)(dong)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)一般采(cai)用(yong)離心式(shi)或(huo)羅茨壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)(ji)，個別的(de)(de)(de)(de)采(cai)用(yong)螺(luo)桿式(shi)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)(ji)。近(jin)年來，在國外也開始采(cai)用(yong)新(xin)型的(de)(de)(de)(de)機(ji)(ji)(ji)械(xie)(xie)渦(wo)旋式(shi)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)。因為(wei)驅(qu)動(dong)(dong)(dong)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)(ji)消(xiao)耗了發動(dong)(dong)(dong)機(ji)(ji)(ji)一定的(de)(de)(de)(de)輸出功率(lv)，所(suo)以機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)機(ji)(ji)(ji)的(de)(de)(de)(de)熱效率(lv)不一定得(de)到改(gai)善，有時(shi)反而比非增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)內(nei)燃(ran)機(ji)(ji)(ji)還低(di)些。選(xuan)擇增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)力(li)時(shi)，首先(xian)要(yao)保證能達到所(suo)要(yao)求(qiu)的(de)(de)(de)(de)平均有效壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)力(li)，其(qi)次要(yao)獲得(de)盡(jin)可(ke)能低(di)的(de)(de)(de)(de)燃(ran)油(you)消(xiao)耗率(lv)。擔這兩個要(yao)求(qiu)對于機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)來說常(chang)常(chang)是(shi)相互(hu)矛盾的(de)(de)(de)(de)。如(ru)果追(zhui)求(qiu)平均有效壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)力(li)，則(ze)必(bi)然(ran)(ran)導致(zhi)機(ji)(ji)(ji)械(xie)(xie)效率(lv)降低(di)，燃(ran)油(you)消(xiao)耗率(lv)升(sheng)高。因此，增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)力(li)值(zhi)的(de)(de)(de)(de)選(xuan)取(qu)應在功率(lv)和燃(ran)油(you)消(xiao)耗率(lv)兩者之(zhi)間(jian)尋求(qiu)最佳(jia)的(de)(de)(de)(de)妥協(xie)方(fang)案。機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)系統(tong)目前在歐洲車上(shang)用(yong)得(de)較普遍(bian)。由于機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)是(shi)在曲(qu)軸的(de)(de)(de)(de)帶(dai)動(dong)(dong)(dong)下持續地運轉，因此不動(dong)(dong)(dong)產生(sheng)像渦(wo)輪增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)渦(wo)輪遲滯現象。機(ji)(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)雖然(ran)(ran)只能提(ti)升(sheng)約10%20%的(de)(de)(de)(de)動(dong)(dong)(dong)力(li)輸出，但平順(shun)連續性是(shi)渦(wo)輪增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)機(ji)(ji)(ji)所(suo)不及的(de)(de)(de)(de)。

廢(fei)氣渦(wo)輪增(zeng)壓

利(li)用(yong)發(fa)動(dong)(dong)(dong)機(ji)(ji)廢(fei)(fei)氣(qi)(qi)能量(liang)(liang)驅動(dong)(dong)(dong)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器(qi)，稱(cheng)為(wei)廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)（簡稱(cheng)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)），如圖所示是(shi)廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)系統。廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)的(de)特點是(shi)在渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器(qi)和(he)發(fa)動(dong)(dong)(dong)機(ji)(ji)之間(jian)沒有機(ji)(ji)械連接。它們之間(jian)靠氣(qi)(qi)路(lu)相通(tong)。因為(wei)壓(ya)(ya)(ya)(ya)氣(qi)(qi)機(ji)(ji)消(xiao)耗的(de)功是(shi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)從廢(fei)(fei)氣(qi)(qi)中回收的(de)一部(bu)分能量(liang)(liang)，所以(yi)(yi)(yi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)發(fa)動(dong)(dong)(dong)機(ji)(ji)不僅可(ke)以(yi)(yi)(yi)增(zeng)(zeng)(zeng)加發(fa)動(dong)(dong)(dong)機(ji)(ji)的(de)功率，而且可(ke)以(yi)(yi)(yi)提高其熱效率，降低燃油消(xiao)耗率。如果在轎(jiao)車尾部(bu)看到(dao)Turbo或者(zhe)T的(de)標識，即表明該車采用(yong)的(de)發(fa)動(dong)(dong)(dong)機(ji)(ji)是(shi)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)的(de)。渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器(qi)實際上是(shi)臺空(kong)氣(qi)(qi)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)，它是(shi)利(li)用(yong)發(fa)動(dong)(dong)(dong)機(ji)(ji)排出(chu)的(de)廢(fei)(fei)氣(qi)(qi)慣性推動(dong)(dong)(dong)渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)，渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)又帶動(dong)(dong)(dong)同(tong)軸(zhou)的(de)葉輪(lun)(lun)(lun)(lun)壓(ya)(ya)(ya)(ya)縮(suo)由(you)空(kong)氣(qi)(qi)濾(lv)清器(qi)管道送來的(de)空(kong)氣(qi)(qi)，使空(kong)氣(qi)(qi)增(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)后進(jin)入(ru)氣(qi)(qi)缸(gang)(gang)。當發(fa)動(dong)(dong)(dong)機(ji)(ji)轉速(su)提高，廢(fei)(fei)氣(qi)(qi)排出(chu)速(su)度與渦(wo)(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)(lun)轉速(su)也同(tong)步提高，葉輪(lun)(lun)(lun)(lun)就(jiu)(jiu)壓(ya)(ya)(ya)(ya)縮(suo)更(geng)多的(de)空(kong)氣(qi)(qi)進(jin)入(ru)氣(qi)(qi)缸(gang)(gang)，空(kong)氣(qi)(qi)的(de)壓(ya)(ya)(ya)(ya)力和(he)密度增(zeng)(zeng)(zeng)大可(ke)以(yi)(yi)(yi)燃燒更(geng)多的(de)燃油，相應增(zeng)(zeng)(zeng)加油量(liang)(liang)和(he)調整一下發(fa)動(dong)(dong)(dong)機(ji)(ji)的(de)轉速(su)，就(jiu)(jiu)可(ke)以(yi)(yi)(yi)增(zeng)(zeng)(zeng)加發(fa)動(dong)(dong)(dong)機(ji)(ji)的(de)輸(shu)出(chu)功率。