車子是怎么啟動的
開車之前下意識地要發動車子,好了,那車子怎么發動?所有人都知道的是,坐進車里扭扭鑰匙(現在很多車直接按按鍵就行),車子抖(dou)三抖(dou),好了,發動(dong)(dong)機(ji)就啟(qi)動(dong)(dong)了。再(zai)深入一點,很(hen)多人也都知道,起動(dong)(dong)機(ji)帶動(dong)(dong)發動(dong)(dong)機(ji)旋轉,然后就好了。這貌(mao)似是極(ji)簡單的(de)問(wen)題,但,你(ni)是否知道,發動(dong)(dong)機(ji)到(dao)底是怎么啟(qi)動(dong)(dong)的(de)呢?
確實,發動(dong)機是通過起動(dong)機帶動(dong)旋轉啟(qi)動(dong)。但這個過程并沒(mei)有(you)那么簡單,我們以無鑰(yao)匙啟(qi)動(dong)的車型來說,分幾個步驟,詳細(xi)分析一下,就在(zai)發動(dong)機啟(qi)動(dong)的幾秒鐘(zhong)內,車子(zi)的引(yin)擎(qing)艙(cang)到底都發生了什么。
1、啟動前
你(ni)坐上(shang)車(che),你(ni)的(de)(de)車(che)不需要先插入鑰匙(chi)再點火。但車(che)內(nei)的(de)(de)射頻接收(shou)器(qi)已(yi)經收(shou)到了(le)車(che)鑰匙(chi)的(de)(de)RFID射頻信號,車(che)內(nei)低壓電路通電,為你(ni)提供諸如(ru)照明、音響等設備使用。這(zhe)時候,你(ni)看(kan)了(le)看(kan)啟動(dong)按(an)鈕,伸出手按(an)下它。
就在你按下啟動按鈕后,汽車電腦接收到啟動的信號后,接通ECU(發動機管理電腦)供電(dian),ECU開始(shi)對行駛系(xi)統(tong)(包括發動機、變(bian)速箱(xiang)和諸(zhu)如ESP、安(an)全氣(qi)囊等基礎安(an)全系(xi)統(tong))所有(you)電(dian)子(zi)系(xi)統(tong)進行自檢,在車(che)子(zi)的儀(yi)(yi)表(biao)板上,所有(you)燈光會全部亮起。很快,電(dian)子(zi)系(xi)統(tong)自檢完成(cheng),儀(yi)(yi)表(biao)板燈光熄滅。這時,ECU開始(shi)進行以(yi)下操作。
2、啟動中
在電(dian)子(zi)系統自檢通(tong)過后,行車電(dian)腦(nao)發送一個(ge)“可以(yi)執(zhi)行啟動(dong)(dong)(dong)(dong)程序”的(de)(de)(de)指令(ling)給(gei)ECU。ECU接通(tong)起(qi)動(dong)(dong)(dong)(dong)機(ji)(ji)電(dian)路,同時接通(tong)起(qi)動(dong)(dong)(dong)(dong)機(ji)(ji)繼電(dian)器(qi),繼電(dian)器(qi)接合,高壓電(dian)流(liu)輸送到起(qi)動(dong)(dong)(dong)(dong)機(ji)(ji)的(de)(de)(de)定子(zi)內,起(qi)動(dong)(dong)(dong)(dong)機(ji)(ji)電(dian)機(ji)(ji)開(kai)始加速,帶動(dong)(dong)(dong)(dong)啟動(dong)(dong)(dong)(dong)齒輪旋(xuan)轉(zhuan)。而在啟動(dong)(dong)(dong)(dong)齒輪的(de)(de)(de)前(qian)方,就是(shi)發動(dong)(dong)(dong)(dong)機(ji)(ji)的(de)(de)(de)啟動(dong)(dong)(dong)(dong)齒輪,這個(ge)齒輪直接和曲軸連接,啟動(dong)(dong)(dong)(dong)齒輪的(de)(de)(de)目的(de)(de)(de),就是(shi)要帶動(dong)(dong)(dong)(dong)曲軸旋(xuan)轉(zhuan)。
在啟(qi)動(dong)(dong)齒輪開(kai)始旋轉的(de)(de)幾乎同時(shi),起(qi)動(dong)(dong)機電(dian)路內另外一(yi)個繼電(dian)器(qi)接(jie)通,在起(qi)動(dong)(dong)機主電(dian)機上方(fang)的(de)(de)一(yi)個電(dian)磁(ci)(ci)離(li)合器(qi)結(jie)(jie)合,這個電(dian)磁(ci)(ci)離(li)合器(qi)控制著(zhu)一(yi)個推(tui)桿(gan),電(dian)磁(ci)(ci)離(li)合器(qi)的(de)(de)往(wang)(wang)后結(jie)(jie)合會推(tui)動(dong)(dong)拉(la)桿(gan)向前推(tui),拉(la)桿(gan)連接(jie)著(zhu)啟(qi)動(dong)(dong)齒輪,把(ba)啟(qi)動(dong)(dong)齒輪往(wang)(wang)前推(tui)到和發動(dong)(dong)機啟(qi)動(dong)(dong)齒輪結(jie)(jie)合為止。
這時,起動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)啟(qi)動(dong)(dong)(dong)(dong)(dong)(dong)齒輪已(yi)經和發動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)啟(qi)動(dong)(dong)(dong)(dong)(dong)(dong)齒輪連接,功率巨大的起動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)帶(dai)著發動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)曲軸開始(shi)旋轉(zhuan)。而在發動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)這邊(bian),曲軸傳感(gan)器檢(jian)測(ce)到的曲軸旋轉(zhuan)信號,讓ECU開始(shi)對發動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)實現啟(qi)動(dong)(dong)(dong)(dong)(dong)(dong)過(guo)程,在濃混合(he)氣下,發動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)轉(zhuan)速開始(shi)快速上升。
3、啟動結束
當發(fa)動(dong)機轉(zhuan)(zhuan)速上升到(dao)足以依靠自(zi)身(shen)力(li)量完成(cheng)啟(qi)動(dong)后(hou),ECU控制起(qi)動(dong)機的(de)電(dian)磁(ci)離合(he)器斷開(kai)連接(jie),把啟(qi)動(dong)齒輪與發(fa)動(dong)機啟(qi)動(dong)齒輪斷開(kai)(避免過高的(de)發(fa)動(dong)機轉(zhuan)(zhuan)速損(sun)壞起(qi)動(dong)機)。隨后(hou),起(qi)動(dong)機電(dian)機斷電(dian),起(qi)動(dong)機停轉(zhuan)(zhuan),發(fa)動(dong)機依靠自(zi)身(shen)力(li)量完成(cheng)啟(qi)動(dong)。
最后一個問題
說完了啟動過程之后,大家可能會有個疑問,啟動機的每一次使用都會造成一些機械磨損,那么現在標配自動啟停的車子,頻(pin)繁啟動(dong)發動(dong)機會不會導致起動(dong)機過快掛(gua)掉?
其實,搭(da)載這種系統(tong)的(de)(de)(de)車子,它的(de)(de)(de)起(qi)動機都是特別設計的(de)(de)(de),比普(pu)通起(qi)動機有高得多的(de)(de)(de)壽(shou)命(ming),但(dan)確實,頻繁啟動發動機確實會對起(qi)動機壽(shou)命(ming)帶來(lai)不利影(ying)(ying)響,甚至(zhi)會影(ying)(ying)響 到發動機的(de)(de)(de)壽(shou)命(ming)。但(dan)至(zhi)于能有多大的(de)(de)(de)影(ying)(ying)響,由于教授也沒有權威的(de)(de)(de)實驗(yan)數據(ju),無法量化分析(xi),但(dan)既然廠家能搭(da)載這樣的(de)(de)(de)功能,相(xiang)信對壽(shou)命(ming)方面影(ying)(ying)響應該是不大的(de)(de)(de)。