汽車制動總泵的作用
剎車總泵是(shi)汽車(che)(che)行車(che)(che)剎車(che)(che)系(xi)統(tong)當中的主(zhu)(zhu)要(yao)控(kong)制(zhi)裝(zhuang)置,在雙(shuang)回路(lu)主(zhu)(zhu)制(zhi)動系(xi)統(tong)的制(zhi)動過程和釋放過程中實現靈敏(min)的隨動控(kong)制(zhi)。
汽車制動總泵結構
總泵(beng)通常是由缸(gang)(gang)(gang)(gang)體、活(huo)塞、活(huo)塞回(hui)位彈簧(huang)、復(fu)式閥(fa)(油(you)液(ye)(ye)控制閥(fa))、皮碗、皮圈(quan)(quan)等部(bu)分(fen)組(zu)成(cheng)。缸(gang)(gang)(gang)(gang)體上下(xia)分(fen)貯(zhu)液(ye)(ye)室(shi)、工作(zuo)缸(gang)(gang)(gang)(gang)室(shi),活(huo)塞從缸(gang)(gang)(gang)(gang)體的后(hou)(hou)端(duan)裝(zhuang)進(jin)缸(gang)(gang)(gang)(gang)內,將(jiang)缸(gang)(gang)(gang)(gang)體分(fen)為前(qian)(qian)、后(hou)(hou)兩室(shi),皮碗前(qian)(qian)的前(qian)(qian)工作(zuo)缸(gang)(gang)(gang)(gang)通向(xiang)貯(zhu)液(ye)(ye)室(shi)的小孔(kong)(kong)為回(hui)油(you)孔(kong)(kong),皮圈(quan)(quan)前(qian)(qian)、活(huo)塞頂部(bu)之后(hou)(hou)的后(hou)(hou)工作(zuo)缸(gang)(gang)(gang)(gang)通向(xiang)貯(zhu)掖室(shi)的大孔(kong)(kong)為進(jin)液(ye)(ye)孔(kong)(kong)(補(bu)償孔(kong)(kong))。總泵(beng)安裝(zhuang)位置都以活(huo)塞進(jin)口處為后(hou)(hou)。
汽車制動總泵工作原理
當(dang)踩下(xia)制(zhi)(zhi)動踏(ta)板(ban)時,推桿(gan)向前推動總泵(beng)活塞,在皮碗遮(zhe)閉回(hui)油(you)孔后,活塞前室油(you)液壓力增高,復式(shi)閥門中間的(de)(de)出油(you)閥被壓開,油(you)液經過管路(lu)流向各制(zhi)(zhi)動車輪(lun)分(fen)泵(beng)缸(gang)。油(you)液推動分(fen)泵(beng)活塞,克服(fu)制(zhi)(zhi)動蹄回(hui)位彈簧的(de)(de)拉力而推開制(zhi)(zhi)動蹄.蹄片(pian)壓緊制(zhi)(zhi)動鼓,產生制(zhi)(zhi)動作用。
當駕駛者踩下(xia)制動踏板(ban)并保持(chi)(chi)不(bu)動時,總泵(beng)前工作室及分泵(beng)缸內(nei)油(you)壓不(bu)再(zai)(zai)增加(jia),出油(you)閥(fa)在(zai)彈簧的(de)(de)(de)作用下(xia)關(guan)(guan)閉(bi),回油(you)閥(fa)也是關(guan)(guan)閉(bi)的(de)(de)(de),復式(shi)閥(fa)門(men)處于(yu)雙關(guan)(guan)閉(bi)狀態,總泵(beng)缸不(bu)再(zai)(zai)向車輪分泵(beng)缸供油(you),分泵(beng)缸內(nei)的(de)(de)(de)油(you)液也不(bu)能(neng)回流,整個(ge)管路處于(yu)等壓,制動系維持(chi)(chi)一(yi)定的(de)(de)(de)制動強度。
放松制(zhi)(zhi)動(dong)踏(ta)板時,在(zai)(zai)踏(ta)板回(hui)位(wei)(wei)彈(dan)(dan)簧和活塞回(hui)位(wei)(wei)彈(dan)(dan)贊的(de)(de)作用(yong)下(xia),總(zong)泵(beng)(beng)(beng)(beng)活塞向后退,總(zong)泵(beng)(beng)(beng)(beng)缸(gang)前工作室油壓(ya)(ya)降低,分(fen)泵(beng)(beng)(beng)(beng)缸(gang)內高(gao)壓(ya)(ya)油液壓(ya)(ya)開復式閥門口外的(de)(de)回(hui)油閥流回(hui)總(zong)泵(beng)(beng)(beng)(beng)前室。隨著制(zhi)(zhi)動(dong)液的(de)(de)流回(hui),制(zhi)(zhi)動(dong)蹄在(zai)(zai)其回(hui)位(wei)(wei)彈(dan)(dan)簧的(de)(de)拉力下(xia)合攏,制(zhi)(zhi)動(dong)狀態解除。由(you)于總(zong)泵(beng)(beng)(beng)(beng)活塞回(hui)位(wei)(wei)彈(dan)(dan)簧在(zai)(zai)裝配狀態下(xia)就(jiu)有一定的(de)(de)預壓(ya)(ya)力,當油液回(hui)流油壓(ya)(ya)降低到不(bu)能克(ke)服預壓(ya)(ya)力時,回(hui)油閥又關(guan)閉(bi),制(zhi)(zhi)動(dong)液停止流回(hui),于是管道及分(fen)泵(beng)(beng)(beng)(beng)缸(gang)內油壓(ya)(ya)比總(zong)泵(beng)(beng)(beng)(beng)缸(gang)內油壓(ya)(ya)高(gao)出約0.5公斤/平方(fang)厘米。這(zhe)就(jiu)是所謂分(fen)泵(beng)(beng)(beng)(beng)缸(gang)及管道中的(de)(de)殘(can)余壓(ya)(ya)力,這(zhe)個(ge)殘(can)余壓(ya)(ya)力可以為(wei)下(xia)次制(zhi)(zhi)動(dong)的(de)(de)迅速實現提供條件(jian)。
當迅速放松制(zhi)(zhi)動(dong)踏板時(shi),總(zong)泵活(huo)(huo)塞(sai)(sai)(sai)在(zai)回(hui)位(wei)彈簧作用下(xia)迅速后(hou)退,總(zong)泵缸(gang)的(de)前(qian)工(gong)(gong)作室(shi)(shi)內容積擴大(da),油(you)壓(ya)迅速降低(di),各分(fen)泵缸(gang)內油(you)液受(shou)管(guan)道阻力的(de)影響,來不及流(liu)回(hui)并充滿活(huo)(huo)塞(sai)(sai)(sai)前(qian)工(gong)(gong)作室(shi)(shi),活(huo)(huo)塞(sai)(sai)(sai)前(qian)工(gong)(gong)作室(shi)(shi)會出現(xian)負壓(ya),而(er)活(huo)(huo)塞(sai)(sai)(sai)后(hou)工(gong)(gong)作室(shi)(shi)油(you)壓(ya)相對(dui)較(jiao)高(gao)。在(zai)此壓(ya)力差(cha)的(de)作用下(xia),貯液室(shi)(shi)內的(de)油(you)液便(bian)(bian)經進液大(da)孔(kong)、活(huo)(huo)塞(sai)(sai)(sai)后(hou)室(shi)(shi)、活(huo)(huo)塞(sai)(sai)(sai)頂部的(de)六個小孔(kong),翻過皮(pi)碗的(de)邊緣流(liu)入活(huo)(huo)塞(sai)(sai)(sai)前(qian)工(gong)(gong)作室(shi)(shi)。此時(shi)再踩下(xia)制(zhi)(zhi)動(dong)踏板,又會有制(zhi)(zhi)動(dong)液供給各分(fen)泵缸(gang),以(yi)增(zeng)強制(zhi)(zhi)動(dong)效率。踩一腳(jiao)制(zhi)(zhi)動(dong)感(gan)覺到制(zhi)(zhi)動(dong)力不足時(shi),二(er)腳(jiao)制(zhi)(zhi)動(dong)便(bian)(bian)會生(sheng)效。
汽車制動總泵常見故障診斷
1、剎車偏軟
汽車(che)行駛中(zhong)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)時(shi),制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)減速度(du)小,制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)距離長,液壓制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)系統產生制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)效能(neng)不(bu)良的(de)原因,一般可根據制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)踏(ta)(ta)(ta)板(ban)行程、踏(ta)(ta)(ta)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)踏(ta)(ta)(ta)板(ban)時(shi)的(de)軟硬感(gan)覺、踏(ta)(ta)(ta)下(xia)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)踏(ta)(ta)(ta)板(ban)后的(de)穩定性來(lai)判斷。維持制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)時(shi),踏(ta)(ta)(ta)板(ban)的(de)高(gao)度(du)若緩慢下(xia)降,說(shuo)明(ming)(ming)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)管路(lu)某(mou)處(chu)破裂(lie)、接頭密閉不(bu)良、總泵或(huo)分泵活塞密封不(bu)良、回油閥及出油閥不(bu)良。可首先踏(ta)(ta)(ta)下(xia)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)踏(ta)(ta)(ta)板(ban),觀察有無制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)液滲漏部(bu)(bu)位。若外部(bu)(bu)正常,則應檢查(cha)分泵或(huo)總泵故障(zhang)。連續幾腳(jiao)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)時(shi)踏(ta)(ta)(ta)板(ban)高(gao)度(du)稍(shao)有增高(gao),并(bing)有彈性感(gan),說(shuo)明(ming)(ming)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)管路(lu)中(zhong)滲入了空氣。
2、剎車跑偏
剎車(che)(che)時(shi),方向(xiang)(xiang)跑(pao)偏,特別(bie)是沒有裝(zhuang)ABS剎車(che)(che)防抱死裝(zhuang)置的汽車(che)(che),方向(xiang)(xiang)控制不了,其原因為(wei)剎車(che)(che)磨損不均,總泵一個(ge)活塞油(you)封膨脹(zhang)、一個(ge)分泵漏油(you)所致(zhi)。
3、剎車抖動
剎(cha)車時擺振(zhen),方向盤彈(dan)手(shou)。原因為(wei)剎(cha)車盤擺差超限(xian),剎(cha)車鉗(qian)變形,剎(cha)車片磨成(cheng)錐形。發生此類(lei)情(qing)況必須進廠檢修。
4、剎車吱吱響
一般為剎車(che)盤、片或(huo)制動鼓、蹄(ti)片磨損不平所致(zhi)。
5、剎車突然失靈
汽車在行駛中,一腳或連續幾腳剎車,剎車均被踏到底,剎車突然失靈。原因:制動總泵或分泵(beng)漏(lou)油嚴重;制動(dong)(dong)總(zong)泵(beng)或分泵(beng)活(huo)塞密封圈破損,或剎車(che)油路中(zhong)有過多的(de)(de)空氣(qi)。如發生此情況,司(si)機應(ying)迅速(su)連續兩腳剎車(che)。發生制動(dong)(dong)失靈的(de)(de)故障,應(ying)立即停車(che)檢(jian)查。首先觀察制動(dong)(dong)液罐中(zhong)的(de)(de)制動(dong)(dong)液有無(wu)虧損,然后觀察制動(dong)(dong)總(zong)泵(beng)、分泵(beng)、油管(guan)有無(wu)泄(xie)漏(lou)制動(dong)(dong)液處。
6、剎車不回
踏下制動踏板(ban)時感到既高又硬或沒有自(zi)由行程,汽(qi)車起(qi)步困(kun)難或行駛費力。故障現象:踩剎車踏板(ban),踏板(ban)不升高,無阻力。需判斷制動液是否缺失;制動分泵(beng)、管路(lu)及接頭處是否漏油;總(zong)泵(beng)、分泵(beng)零部件(jian)是否損(sun)壞(huai)。