汽車起重機先導控制(zhi)油路三故障
一是先導(dao)(dao)手柄操作(zuo)的微動性(xing)變(bian)(bian)差,即起(qi)重機(ji)變(bian)(bian)幅(fu)(fu)、起(qi)升機(ji)構在(zai)(zai)吊(diao)重作(zuo)業時(shi)(shi)柔性(xing)變(bian)(bian)差,操作(zuo)變(bian)(bian)幅(fu)(fu)時(shi)(shi)變(bian)(bian)幅(fu)(fu)缸不(bu)(bu)能(neng)緩慢伸縮,整個(ge)吊(diao)臂起(qi)落幅(fu)(fu)度很(hen)大,不(bu)(bu)能(neng)完成精吊(diao)裝作(zuo)業;起(qi)升機(ji)構也存在(zai)(zai)同樣的問題,重物起(qi)吊(diao)不(bu)(bu)能(neng)微動,經測量,先導(dao)(dao)油(you)路的控制壓力正(zheng)常(一般(ban)為3MPa)。
其次(ci),檢查先導比例閥(fa)(操作手柄(bing)閥(fa)),沒(mei)有泄漏。最(zui)后(hou),懷疑回(hui)油(you)(you)壓力高,使(shi)主閥(fa)芯(xin)(xin)兩側壓差(cha)變小(xiao),導致主閥(fa)芯(xin)(xin)開(kai)口量與(yu)先導比例閥(fa)位(wei)移量不(bu)成比例。經(jing)詢問用(yong)戶,兩年中不(bu)曾清洗過(guo)回(hui)油(you)(you)濾(lv)芯(xin)(xin)。打(da)開(kai)回(hui)油(you)(you)濾(lv)油(you)(you)器發現,回(hui)油(you)(you)濾(lv)芯(xin)(xin)已(yi)被污物堵(du)塞,更換新濾(lv)芯(xin)(xin)后(hou)動作恢復正常。
二是吊重(zhong)時(shi)(shi)(shi)起升(sheng)機構抖動(dong)(dong)(dong),在吊重(zhong)作業時(shi)(shi)(shi)發現(xian),卷筒時(shi)(shi)(shi)轉(zhuan)時(shi)(shi)(shi)停,不(bu)能(neng)連續工作,并有明(ming)顯的(de)(de)振動(dong)(dong)(dong)。當加大發動(dong)(dong)(dong)機油(you)(you)門時(shi)(shi)(shi),故(gu)障依舊(jiu),同時(shi)(shi)(shi)還伴有發動(dong)(dong)(dong)機憋(bie)車的(de)(de)現(xian)象。經測量,在起升(sheng)機構液壓(ya)油(you)(you)路(lu)中,節流(liu)閥(fa)之(zhi)(zhi)前進入(ru)制動(dong)(dong)(dong)活塞(sai)的(de)(de)控制油(you)(you)壓(ya)力(li)正常(1.5-1.8MPa)。其次,排除了起升(sheng)平衡閥(fa)被(bei)污物卡住的(de)(de)可能(neng)性(xing)。最后,判斷制動(dong)(dong)(dong)油(you)(you)路(lu)單向節流(liu)閥(fa)可能(neng)被(bei)堵,拆檢(jian)單向節流(liu)閥(fa)發現(xian),閥(fa)芯上0.6mm的(de)(de)節流(liu)孔(kong)已被(bei)污物堵塞(sai),使節流(liu)閥(fa)之(zhi)(zhi)后進入(ru)制動(dong)(dong)(dong)活塞(sai)的(de)(de)壓(ya)力(li)油(you)(you)被(bei)節流(liu),壓(ya)力(li)低于(yu)1.8MPa,制動(dong)(dong)(dong)活塞(sai)不(bu)能(neng)完全(quan)打開,清除污物后,起升(sheng)機構工作恢復正常。
三(san)是某些動(dong)(dong)作失足(zu),如,起(qi)升機構只(zhi)能(neng)(neng)(neng)使重物下落(luo)而(er)不(bu)能(neng)(neng)(neng)起(qi)升、變(bian)幅(fu)缸只(zhi)能(neng)(neng)(neng)伸不(bu)能(neng)(neng)(neng)縮,吊臂只(zhi)能(neng)(neng)(neng)縮不(bu)能(neng)(neng)(neng)伸。分(fen)析先導油(you)(you)路液壓原理知,安全(quan)卸(xie)荷電磁(ci)(ci)閥(fa)可(ke)能(neng)(neng)(neng)有(you)故障,該閥(fa)由力矩限制器控(kong)制,當起(qi)重力矩超(chao)過規定值時,其(qi)某些動(dong)(dong)作的(de)先導控(kong)制壓力油(you)(you)卸(xie)荷,整機只(zhi)能(neng)(neng)(neng)向安全(quan)方向動(dong)(dong)作,拆檢安全(quan)卸(xie)荷電磁(ci)(ci)閥(fa)發現,閥(fa)芯被卡住,故障排除后,起(qi)重機所有(you)動(dong)(dong)作均恢(hui)復正(zheng)常。