制動液的分類及選購標準
制(zhi)動(dong)(dong)(dong)液(ye)俗稱“剎(cha)車(che)(che)油”,它是(shi)機(ji)動(dong)(dong)(dong)車(che)(che)液(ye)壓制(zhi)動(dong)(dong)(dong)系統(tong)中傳遞(di)壓力(li)、制(zhi)止車(che)(che)輪(lun)轉(zhuan)動(dong)(dong)(dong)的(de)(de)(de)(de)介質(zhi),目(mu)前,90%的(de)(de)(de)(de)車(che)(che)輛均采(cai)用(yong)液(ye)壓制(zhi)動(dong)(dong)(dong)系統(tong)。因其特殊性(xing)(xing),它必須要有(you)適宜的(de)(de)(de)(de)高(gao)溫粘度和良好的(de)(de)(de)(de)低溫流動(dong)(dong)(dong)性(xing)(xing);有(you)良好的(de)(de)(de)(de)化學穩定(ding)性(xing)(xing);有(you)較高(gao)的(de)(de)(de)(de)平衡回流沸點;有(you)較低的(de)(de)(de)(de)吸(xi)濕性(xing)(xing);有(you)良好的(de)(de)(de)(de)橡(xiang)膠適應性(xing)(xing);有(you)良好的(de)(de)(de)(de)金屬抗腐(fu)蝕性(xing)(xing)。制(zhi)動(dong)(dong)(dong)液(ye)既然重(zhong)要,那什(shen)么(me)時候更換、怎么(me)選擇合(he)適的(de)(de)(de)(de)型號以及要注意(yi)哪些問題也(ye)是(shi)許(xu)多(duo)車(che)(che)友急于想了解的(de)(de)(de)(de)。
制動液的分類
由(you)于配制的原料不同(tong),制動(dong)(dong)液的種類比較多(duo),目前大體上分為3種類型(xing):醇(chun)型(xing)、礦物油型(xing)和合成型(xing)。其中(zhong)醇(chun)型(xing)制動(dong)(dong)液有醇(chun)型(xing)1號(hao)(蓖麻油+乙醇(chun))和醇(chun)型(xing)3號(hao)(蓖麻油+丁醇(chun)),醇(chun)型(xing)制動(dong)(dong)液工(gong)藝簡單、潤滑性(xing)好且價格低廉(lian),但(dan)在炎熱季節(jie)使(shi)用時易產生氣(qi)阻,在嚴寒地(di)區的冬(dong)季使(shi)用時會變稠分層(ceng),使(shi)制動(dong)(dong)沉重,甚至失靈,故已被(bei)淘(tao)汰。
礦(kuang)物油(you)型(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)液是以(yi)(yi)精制(zhi)(zhi)(zhi)(zhi)的輕柴油(you)餾分經深度脫臘得到的C12~C19異(yi)構烷烴及烷烴組分經添加(jia)稠化劑、抗氧劑和助劑調合而成。按運動(dong)粘度分為7號和9號兩種類(lei)型(xing)。礦(kuang)物型(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)液的溫度適應范圍很寬(kuan),可以(yi)(yi)從-50℃~150℃,低溫流動(dong)性和潤滑(hua)性較好,對金屬無腐蝕作(zuo)用(yong)。但對制(zhi)(zhi)(zhi)(zhi)動(dong)系統的橡膠部件(如皮碗)有溶解作(zuo)用(yong),如使用(yong)這種類(lei)型(xing)的制(zhi)(zhi)(zhi)(zhi)動(dong)液,必須換用(yong)耐(nai)礦(kuang)物油(you)的橡膠零件。
目前使用較(jiao)為(wei)普遍(bian)的(de)是合成(cheng)型制(zhi)動(dong)液,它是以有(you)機溶劑(ji)中的(de)醇(chun)、醚和(he)(he)酯為(wei)基(ji)礎,加入添(tian)加劑(ji)調制(zhi)而成(cheng)。合成(cheng)性制(zhi)動(dong)液的(de)成(cheng)分(fen)比較(jiao)復雜(za),性質差異很大,為(wei)此國家頒布了合成(cheng)型制(zhi)動(dong)液標準。有(you)1號、4603、4603~1和(he)(he)4604等牌號。4603和(he)(he)4603~l號合成(cheng)制(zhi)動(dong)液適用于(yu)各(ge)類載貨(huo)汽車(che)的(de)制(zhi)動(dong)系(xi);4604則適用于(yu)高檔(dang)轎車(che)和(he)(he)各(ge)種汽車(che)的(de)制(zhi)動(dong)系(xi)。
合成(cheng)型制動液沸(fei)點較(jiao)高(gao),不(bu)易產生氣阻(zu);良(liang)好的(de)低溫流(liu)動性(xing),不(bu)因低溫而粘度增大(da)、流(liu)動性(xing)變(bian)(bian)差,使制動發硬;吸水性(xing)小,不(bu)影響沸(fei)點和低溫流(liu)動性(xing);良(liang)好的(de)化學穩定性(xing),對金屬有(you)防(fang)(fang)腐(fu)(fu)、防(fang)(fang)銹作用(yong),不(bu)易分解變(bian)(bian)質而產生沉淀物;對橡膠(jiao)件的(de)腐(fu)(fu)蝕和溶脹性(xing)小,以保證密封件不(bu)會嚴(yan)重變(bian)(bian)形等。這類制動液在我國各(ge)地一年四季均(jun)可使用(yong),因而正逐漸成(cheng)為通(tong)用(yong)型制動液。
制動液的質量等級
制(zhi)動液(ye)與(yu)機油一樣,也(ye)有質量等級(ji)之分(fen)。國(guo)(guo)產制(zhi)動液(ye)的質量等級(ji):國(guo)(guo)產制(zhi)動液(ye)根據其平衡回(hui)流、沸點分(fen)為JG3、JG4、JG5三個(ge)質量等級(ji)。序號越(yue)(yue)大(da)平衡回(hui)流沸點越(yue)(yue)高,高溫抗氣(qi)阻性越(yue)(yue)好,行車制(zhi)動安全性越(yue)(yue)高。我國(guo)(guo)還將合成(cheng)制(zhi)動液(ye)分(fen)為:HZY3、HZY4和(he)HZY5。
國外(wai)制(zhi)動(dong)(dong)(dong)液的質量(liang)等(deng)級(ji)(ji):美(mei)(mei)國汽車(che)工程學(xue)會(hui)(SAE)規格有SAEJ1704(高溫地區使(shi)用(yong))、SAEJ1703(正常)、SAEJ1702(嚴寒(han)地區使(shi)用(yong))。另外(wai)美(mei)(mei)國聯邦機(ji)動(dong)(dong)(dong)車(che)輛(liang)安全(quan)標準規格分為DOT3、DOT4和DOT5等(deng),后者比(bi)前者的綜合性能好。DOT3與DOT4的不(bu)同之處(chu)主要在于沸點不(bu)同,DOT4比(bi)DOT3更耐高溫。DOT3和DOT4級(ji)(ji)制(zhi)動(dong)(dong)(dong)液是(shi)以聚二醇(chun)為基礎(chu)和乙二醇(chun)及乙二醇(chun)衍(yan)生物為主的醇(chun)醚型合成(cheng)制(zhi)動(dong)(dong)(dong)液,再加潤滑劑(ji)、稀釋劑(ji)、防銹劑(ji)、橡膠抑制(zhi)劑(ji)等(deng)調(diao)和而成(cheng),也是(shi)各國汽車(che)最普(pu)遍使(shi)用(yong)的一種制(zhi)動(dong)(dong)(dong)液。JG3、JG4、JG5分別對應(ying)DOT3、DOT4、DOT5級(ji)(ji)別。
這(zhe)里需(xu)要給大(da)家(jia)說明一下(xia)的是,目前國內家(jia)用(yong)轎車(che)(che)多(duo)使用(yong)合成(cheng)型制動(dong)(dong)(dong)液(ye),所采用(yong)的標(biao)準(zhun)(zhun)也多(duo)以(yi)美國聯邦機動(dong)(dong)(dong)車(che)(che)輛安全標(biao)準(zhun)(zhun)規格(ge)的DOT標(biao)準(zhun)(zhun)為主。而國標(biao)多(duo)用(yong)在商用(yong)車(che)(che)以(yi)及貨車(che)(che)等大(da)型車(che)(che)輛的制動(dong)(dong)(dong)液(ye)上。
級別
制動液主要特性
對應牌號
推薦使用范圍
JG3
具有良(liang)好的高(gao)溫(wen)抗氣阻性(xing)能(neng)和優良(liang)的低(di)溫(wen)性(xing)能(neng)
DOT3、HZY3
SAEJ1703
我(wo)國廣(guang)大(da)地區均可(ke)使(shi)用
JG4
具有良好的(de)高(gao)溫抗(kang)氣阻性(xing)能(neng)和(he)良好的(de)低溫性(xing)能(neng)
DOT4、HZY4
SAEJ1704
我(wo)國廣大地區(qu)均可使用(yong),適用(yong)于制動(dong)操作時溫度(du)較高的轎車
JG5
具(ju)有優(you)異的高(gao)溫(wen)抗氣阻性能(neng)(neng)和低溫(wen)性能(neng)(neng)
DOT5、HZY5
SAEJ1705
有特殊要求的車輛使用制動液的更換和選用
當今汽車(che)(che)的(de)設計車(che)(che)速(su)越來(lai)越高(gao)、結構越來(lai)越緊湊,導(dao)致制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)工作溫度很(hen)高(gao)而散熱(re)通風條件較差,因此,對(dui)制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)性(xing)能要(yao)求也越來(lai)越高(gao)。目前,世界(jie)各國使(shi)用(yong)的(de)制(zhi)動(dong)液(ye)(ye)(ye)(ye)一般(ban)都(dou)是(shi)合成制(zhi)動(dong)液(ye)(ye)(ye)(ye)。關于制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)更(geng)(geng)(geng)換周(zhou)期(qi)(qi),目前尚無統一規(gui)定,通常是(shi)根據汽車(che)(che)生產(chan)(chan)廠商或(huo)(huo)制(zhi)動(dong)液(ye)(ye)(ye)(ye)生產(chan)(chan)廠商規(gui)定的(de)時間進(jin)(jin)行(xing)更(geng)(geng)(geng)換。制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)更(geng)(geng)(geng)換周(zhou)期(qi)(qi)主要(yao)以行(xing)駛里程和(he)使(shi)用(yong)時間來(lai)確定。一般(ban)使(shi)用(yong)低級別制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)中(zhong)、低檔(dang)車(che)(che)輛,換油(you)(you)周(zhou)期(qi)(qi)為每年1次(ci)或(huo)(huo)者2~4萬(wan)(wan)公里;使(shi)用(yong)中(zhong)、高(gao)級別制(zhi)動(dong)液(ye)(ye)(ye)(ye)的(de)中(zhong)、高(gao)檔(dang)車(che)(che)輛,換油(you)(you)周(zhou)期(qi)(qi)為每兩年1次(ci)或(huo)(huo)者4~5萬(wan)(wan)公里;另外在對(dui)制(zhi)動(dong)系統進(jin)(jin)行(xing)修理和(he)更(geng)(geng)(geng)換制(zhi)動(dong)主缸、制(zhi)動(dong)輪缸的(de)活塞(sai)、皮碗(wan)等零部件的(de)同時需(xu)要(yao)更(geng)(geng)(geng)換制(zhi)動(dong)液(ye)(ye)(ye)(ye)。在實(shi)際使(shi)用(yong)中(zhong),如果(guo)出現制(zhi)動(dong)踏(ta)板忽(hu)輕忽(hu)重、制(zhi)動(dong)皮碗(wan)溶脹、換季(ji)時(尤其在冬(dong)季(ji))出現制(zhi)動(dong)無力這些情況就需(xu)要(yao)及(ji)時對(dui)制(zhi)動(dong)液(ye)(ye)(ye)(ye)進(jin)(jin)行(xing)更(geng)(geng)(geng)換。
對(dui)于(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)選(xuan)(xuan)(xuan)擇問題,原則上根據汽(qi)車生(sheng)(sheng)產(chan)廠家使用(yong)(yong)(yong)(yong)說(shuo)明書推薦的(de)(de)(de)(de)(de)(de)質(zhi)(zhi)(zhi)量等(deng)級(ji)、品(pin)(pin)牌(pai)、型(xing)(xing)(xing)(xing)(xing)號等(deng)進行選(xuan)(xuan)(xuan)擇。按照國標(biao)(biao)(biao)或(huo)DOT標(biao)(biao)(biao)準(zhun)選(xuan)(xuan)(xuan)擇制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)的(de)(de)(de)(de)(de)(de)質(zhi)(zhi)(zhi)量等(deng)級(ji),盡量使用(yong)(yong)(yong)(yong)合(he)成(cheng)(cheng)型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye),并優(you)先選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)高等(deng)級(ji)的(de)(de)(de)(de)(de)(de);車輛使用(yong)(yong)(yong)(yong)說(shuo)明書在給(gei)出了標(biao)(biao)(biao)準(zhun)品(pin)(pin)牌(pai)號外,一(yi)(yi)般還提供了可供代用(yong)(yong)(yong)(yong)的(de)(de)(de)(de)(de)(de)品(pin)(pin)牌(pai)號。用(yong)(yong)(yong)(yong)戶應(ying)(ying)盡可能(neng)選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)標(biao)(biao)(biao)準(zhun)品(pin)(pin)牌(pai)號的(de)(de)(de)(de)(de)(de)產(chan)品(pin)(pin),缺乏時才(cai)(cai)考慮選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)代用(yong)(yong)(yong)(yong)品(pin)(pin)。如(ru)果(guo)推薦的(de)(de)(de)(de)(de)(de)代用(yong)(yong)(yong)(yong)品(pin)(pin)牌(pai)也缺乏,才(cai)(cai)可以選(xuan)(xuan)(xuan)擇相(xiang)應(ying)(ying)等(deng)級(ji)的(de)(de)(de)(de)(de)(de)代用(yong)(yong)(yong)(yong)品(pin)(pin);對(dui)有(you)特殊(shu)要求(qiu)的(de)(de)(de)(de)(de)(de)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)系(xi)統(tong),應(ying)(ying)加注(zhu)特定牌(pai)號的(de)(de)(de)(de)(de)(de)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)。有(you)的(de)(de)(de)(de)(de)(de)合(he)成(cheng)(cheng)型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)溫(wen)(wen)(wen)度(du)(du)范圍在-60℃~60℃之(zhi)間(jian)(jian),低溫(wen)(wen)(wen)下粘(zhan)度(du)(du)比較小,非常適合(he)于(yu)嚴寒地區冬季(ji)使用(yong)(yong)(yong)(yong);如(ru)果(guo)汽(qi)車制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)系(xi)統(tong)的(de)(de)(de)(de)(de)(de)橡(xiang)膠零件是耐(nai)油的(de)(de)(de)(de)(de)(de),應(ying)(ying)優(you)先選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)礦物油型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye),它不(bu)(bu)(bu)受地區、季(ji)節和(he)車型(xing)(xing)(xing)(xing)(xing)的(de)(de)(de)(de)(de)(de)限制(zhi)(zhi)(zhi)(zhi),潤滑性(xing)(xing)好,無(wu)腐(fu)蝕作用(yong)(yong)(yong)(yong),換油周期(qi)長;但制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)系(xi)統(tong)橡(xiang)膠零件不(bu)(bu)(bu)是耐(nai)油的(de)(de)(de)(de)(de)(de),則不(bu)(bu)(bu)能(neng)使用(yong)(yong)(yong)(yong)礦物型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye);不(bu)(bu)(bu)同(tong)類(lei)型(xing)(xing)(xing)(xing)(xing)的(de)(de)(de)(de)(de)(de)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)由(you)于(yu)成(cheng)(cheng)分不(bu)(bu)(bu)同(tong),混(hun)合(he)后可能(neng)發(fa)生(sheng)(sheng)化學(xue)反(fan)(fan)應(ying)(ying),堵塞制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)系(xi)統(tong),所以通(tong)常不(bu)(bu)(bu)允許混(hun)用(yong)(yong)(yong)(yong)。一(yi)(yi)般相(xiang)溶性(xing)(xing)較好的(de)(de)(de)(de)(de)(de)同(tong)一(yi)(yi)類(lei)型(xing)(xing)(xing)(xing)(xing)的(de)(de)(de)(de)(de)(de)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye),也不(bu)(bu)(bu)能(neng)混(hun)用(yong)(yong)(yong)(yong),以防相(xiang)互(hu)間(jian)(jian)產(chan)生(sheng)(sheng)化學(xue)反(fan)(fan)應(ying)(ying),影(ying)響(xiang)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)效果(guo);選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)正規優(you)質(zhi)(zhi)(zhi)產(chan)品(pin)(pin),避免使用(yong)(yong)(yong)(yong)質(zhi)(zhi)(zhi)量低劣產(chan)品(pin)(pin)。選(xuan)(xuan)(xuan)購制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)時,首先看產(chan)品(pin)(pin)說(shuo)明書或(huo)標(biao)(biao)(biao)簽(qian)上的(de)(de)(de)(de)(de)(de)說(shuo)明,是什么類(lei)型(xing)(xing)(xing)(xing)(xing),有(you)無(wu)質(zhi)(zhi)(zhi)量標(biao)(biao)(biao)準(zhun)和(he)質(zhi)(zhi)(zhi)量指(zhi)標(biao)(biao)(biao),若(ruo)沒有(you)標(biao)(biao)(biao)注(zhu)這(zhe)些內容(rong)則不(bu)(bu)(bu)能(neng)使用(yong)(yong)(yong)(yong),而(er)只(zhi)標(biao)(biao)(biao)有(you)類(lei)型(xing)(xing)(xing)(xing)(xing)的(de)(de)(de)(de)(de)(de)應(ying)(ying)慎用(yong)(yong)(yong)(yong)。千萬(wan)不(bu)(bu)(bu)要選(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)國家早(zao)已(yi)淘(tao)汰的(de)(de)(de)(de)(de)(de)醇(chun)型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)。合(he)成(cheng)(cheng)型(xing)(xing)(xing)(xing)(xing)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)液(ye)(ye)(ye)(ye)型(xing)(xing)(xing)(xing)(xing)號很(hen)多,顏色各異,要注(zhu)意其(qi)質(zhi)(zhi)(zhi)量指(zhi)標(biao)(biao)(biao)中的(de)(de)(de)(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)范圍,常溫(wen)(wen)(wen)和(he)低溫(wen)(wen)(wen)下的(de)(de)(de)(de)(de)(de)粘(zhan)度(du)(du)、透明度(du)(du),有(you)無(wu)沉淀(dian)和(he)異味。
有ABS裝置的車輛的制動系統產生的摩擦熱比未裝ABS裝置的車高,制動液的惡化變質也可能會相對早地出現,如果在制動液變質的情況下繼續使用,將會使制動主缸、輪缸、油壓控制器等產生損傷、吸濕率增加,使制動力下降。因此,要對裝有ABS裝置車輛的制動液從嚴選用,嚴格遵守汽車制造廠商推薦的更換周期。另外還要根據使用條件,在必要時提前進行更換。有ABS系統的車輛一般都選用DOT4的制動液。盡管DOT5的制動液具有更高的沸點,但是,由于DOT5是硅基制動液.會對橡膠件產生較強的損害。因此。在ABS系統中,一般不選用DOT5的制動液。但是,由于DOT3和DOT4是醇基制動液,具有較強的吸濕性,隨著使用時間的延長,其中的含水量會不斷增多。當制動液中含有較多的水分時,會使制動壓力調節裝置中的精密零件發生銹蝕;在寒冷的氣候條件下,還會使制動液的粘度變大,影響制動液在制動系統中的流動,使制動變得遲緩,從而導致制動距離延長。另外,制動液中的含水量會對制動液的沸點產生非常明顯的影響,發生氣阻現象。DOT3和DOT4制動液一般經過12個月的使用以后其中的含水量為2%,經過18個月的使用以后.其中的含水量平均可達3%。因此建議每12個月更換一次制動液。