挖掘機發動機在工作過程中自動熄火，再次起動時起動機正常工作，但發動機無法起動，排氣管冒出少量黑煙。安徽挖掘機翻新需要通過經驗豐富的維修者在進行適當的程序以后來完成修復工作，通過維修人員的清洗，保障在其內部沒有污物。安徽挖掘機修理廠直接完成挖掘任務的裝置。它由動臂、斗桿、鏟斗等三部分鉸接而成。為了適應各種不同施工作業的需要，液壓挖掘機可以配裝多種工作裝置，如挖掘、起重、裝載、平整、夾鉗、推土、沖擊錘，旋挖鉆等多種作業機具。挖掘機修理廠最初挖(wa)掘(jue)機(ji)是手(shou)動(dong)的(de)，從發(fa)明(ming)到現在已經有一百三十多年了，期間經歷了由蒸汽(qi)驅動(dong)斗(dou)回轉(zhuan)挖(wa)掘(jue)機(ji)到電力驅動(dong)和內燃機(ji)驅動(dong)回轉(zhuan)挖(wa)掘(jue)機(ji)、應用機(ji)電液一體化技術的(de)全自動(dong)液壓挖(wa)掘(jue)機(ji)的(de)逐(zhu)步發(fa)展過程。

根據機(ji)器(qi)維修(xiu)手冊中的(de)相關(guan)故(gu)(gu)障診(zhen)斷(duan)程序和以往(wang)的(de)維修(xiu)經驗，維修(xiu)人員首先(xian)檢(jian)查(cha)了機(ji)器(qi)保險絲盒內的(de)所(suo)有(you)保險絲、發動(dong)(dong)機(ji)油(you)門(men)步進(jin)電機(ji)動(dong)(dong)作(zuo)系(xi)統(tong)、發動(dong)(dong)機(ji)停機(ji)電機(ji)動(dong)(dong)作(zuo)系(xi)統(tong)和發動(dong)(dong)機(ji)燃油(you)供(gong)給系(xi)統(tong)，以及燃油(you)噴嘴的(de)霧化等相關(guan)因(yin)(yin)素(su)，未(wei)發現異常。進(jin)一步分析表(biao)明，發動(dong)(dong)機(ji)的(de)故(gu)(gu)障與發動(dong)(dong)機(ji)啟動(dong)(dong)時的(de)負荷有(you)關(guan)。因(yin)(yin)此(ci)，故(gu)(gu)障很可能是(shi)由主(zhu)機(ji)控制(zhi)電路(lu)引起的(de)。主(zhu)機(ji)控制(zhi)電路(lu)圖如附圖所(suo)示(shi)。

經(jing)檢(jian)查，發(fa)(fa)動(dong)機系統啟動(dong)時，繼(ji)電(dian)(dian)(dian)(dian)器A、B、C均能(neng)夠正(zheng)常吸合，從而(er)排除了因繼(ji)電(dian)(dian)(dian)(dian)器未吸合而(er)導致汽車發(fa)(fa)動(dong)機工作不能(neng)及時啟動(dong)的(de)(de)可能(neng)性(xing)；隨后用(yong)萬(wan)用(yong)表可以(yi)測量控制電(dian)(dian)(dian)(dian)磁閥(fa)(fa)a和(he)b的(de)(de)電(dian)(dian)(dian)(dian)信號數(shu)據輸入端(duan)，結果分(fen)析發(fa)(fa)現(xian)問題均無電(dian)(dian)(dian)(dian)流主要(yao)通過(guo)，而(er)此時我們電(dian)(dian)(dian)(dian)路4是在(zai)閉(bi)俁(yu)狀(zhuang)態(tai)，若無電(dian)(dian)(dian)(dian)流以(yi)及通過(guo)，這只能(neng)說明液壓泵和(he)閥(fa)(fa)控制器的(de)(de)電(dian)(dian)(dian)(dian)源未接(jie)通。進一步提高檢(jian)查后發(fa)(fa)現(xian)，由于我國(guo)(guo)發(fa)(fa)電(dian)(dian)(dian)(dian)機向蓄電(dian)(dian)(dian)(dian)池供(gong)電(dian)(dian)(dian)(dian)的(de)(de)線路其絕(jue)緣材料性(xing)能(neng)產生(sheng)不好，致使(shi)安(an)裝在(zai)蓄電(dian)(dian)(dian)(dian)池正(zheng)上方的(de)(de)50A的(de)(de)可熔接(jie)頭D因短(duan)路而(er)熔斷。在(zai)檢(jian)修管理(li)人(ren)員將線路信息進行(xing)研(yan)究絕(jue)緣技(ji)術處理(li)并更換可熔接(jie)頭后，再次開始(shi)啟動(dong)中國(guo)(guo)發(fa)(fa)動(dong)機時，故障(zhang)出現(xian)癥狀(zhuang)已消失(shi)。

當(dang)(dang)鑰(yao)匙開關處于(yu)START位置時(shi)，一(yi)(yi)方(fang)面，通(tong)過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)路(lu)1的(de)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)使發動(dong)(dong)機(ji)(ji)(ji)(ji)節(jie)氣(qi)門步(bu)進(jin)(jin)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器B和液(ye)(ye)壓(ya)系統泵(beng)控(kong)制(zhi)(zhi)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器C接(jie)(jie)(jie)(jie)合，并且繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器C接(jie)(jie)(jie)(jie)合。 接(jie)(jie)(jie)(jie)通(tong)將液(ye)(ye)壓(ya)泵(beng)的(de)閥控(kong)制(zhi)(zhi)器(pvc)連接(jie)(jie)(jie)(jie)到液(ye)(ye)壓(ya)泵(beng)控(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)磁閥a和b的(de)電(dian)(dian)(dian)(dian)(dian)路(lu)5，另一(yi)(yi)方(fang)面，電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)通(tong)過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)路(lu)2供給起動(dong)(dong)控(kong)制(zhi)(zhi)器(e，c)以(yi)接(jie)(jie)(jie)(jie)通(tong)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)湖； 此外，電(dian)(dian)(dian)(dian)(dian)池繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)器A被通(tong)過(guo)(guo)回(hui)路(lu)3的(de)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)接(jie)(jie)(jie)(jie)通(tong)，從(cong)而電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)通(tong)過(guo)(guo)回(hui)路(lu)4向液(ye)(ye)壓(ya)泵(beng)的(de)閥控(kong)制(zhi)(zhi)器供電(dian)(dian)(dian)(dian)(dian)。 當(dang)(dang)挖掘機(ji)(ji)(ji)(ji)的(de)液(ye)(ye)壓(ya)泵(beng)的(de)發動(dong)(dong)機(ji)(ji)(ji)(ji)控(kong)制(zhi)(zhi)器和閥控(kong)制(zhi)(zhi)器的(de)電(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)接(jie)(jie)(jie)(jie)通(tong)時(shi)，來(lai)自發動(dong)(dong)機(ji)(ji)(ji)(ji)、液(ye)(ye)壓(ya)泵(beng)和主控(kong)制(zhi)(zhi)閥的(de)傳(chuan)感器的(de)信(xin)號一(yi)(yi)起被處理(li)。 然(ran)后，液(ye)(ye)壓(ya)泵(beng)控(kong)制(zhi)(zhi)螺線(xian)管a和b被給予信(xin)號以(yi)確(que)定(ding)其內部線(xian)軸(zhou)的(de)排(pai)量(liang)。因此，通(tong)過(guo)(guo)調節(jie)進(jin)(jin)入主液(ye)(ye)壓(ya)泵(beng)的(de)伺(si)服(fu)系統的(de)先導(dao)液(ye)(ye)壓(ya)泵(beng)的(de)油流(liu)(liu)量(liang)來(lai)改變主液(ye)(ye)壓(ya)泵(beng)的(de)斜盤的(de)傾(qing)角。 以(yi)調節(jie)主液(ye)(ye)壓(ya)泵(beng)的(de)排(pai)量(liang)，以(yi)配合發動(dong)(dong)機(ji)(ji)(ji)(ji)的(de)啟動(dong)(dong)。