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近期,受益于(yu)排放(fang)法(fa)規(gui)升級、超(chao)載治理從嚴以(yi)(yi)及(ji)基建(jian)投資拉動等(deng)(deng)(deng)多重(zhong)利好因素,國內載貨汽(qi)車(che)(che)市場產(chan)銷兩(liang)旺。載貨汽(qi)車(che)(che)作為典型(xing)的(de)(de)(de)生產(chan)資料,客(ke)戶在關注(zhu)車(che)(che)輛的(de)(de)(de)可(ke)靠性(xing)與(yu)經(jing)濟性(xing)的(de)(de)(de)同時,也對車(che)(che)輛的(de)(de)(de)涂(tu)(tu)(tu)裝(zhuang)(zhuang)(zhuang)(zhuang)質(zhi)(zhi)量(liang)提出了更高要求。其中,載貨汽(qi)車(che)(che)底(di)(di)盤(pan)零(ling)件涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)防(fang)腐(fu)(fu)性(xing)與(yu)耐候(hou)性(xing)的(de)(de)(de)提升就是(shi)涂(tu)(tu)(tu)裝(zhuang)(zhuang)(zhuang)(zhuang)質(zhi)(zhi)量(liang)改善的(de)(de)(de)重(zhong)點工作之一,主(zhu)要是(shi)解(jie)決牽引(yin)車(che)(che)與(yu)二類底(di)(di)盤(pan)車(che)(che)底(di)(di)盤(pan)零(ling)件的(de)(de)(de)早期銹(xiu)蝕以(yi)(yi)及(ji)涂(tu)(tu)(tu)層(ceng)(ceng)失光、變色、粉化等(deng)(deng)(deng)問題,減少客(ke)戶抱怨。隨著涂(tu)(tu)(tu)裝(zhuang)(zhuang)(zhuang)(zhuang)技術(shu)不斷進步以(yi)(yi)及(ji)環保法(fa)規(gui)日趨(qu)嚴格,應依據各類底(di)(di)盤(pan)零(ling)件的(de)(de)(de)產(chan)品特點與(yu)技術(shu)要求,選(xuan)取適(shi)宜的(de)(de)(de)涂(tu)(tu)(tu)裝(zhuang)(zhuang)(zhuang)(zhuang)材料與(yu)工藝,在重(zhong)點關注(zhu)涂(tu)(tu)(tu)層(ceng)(ceng)防(fang)腐(fu)(fu)性(xing)能(neng)的(de)(de)(de)同時,兼顧涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)外觀質(zhi)(zhi)量(liang)、機械性(xing)能(neng)、耐候(hou)性(xing)能(neng)以(yi)(yi)及(ji)涂(tu)(tu)(tu)料的(de)(de)(de)施工性(xing)能(neng)等(deng)(deng)(deng)。
本文(wen)針(zhen)對車(che)架(jia)、車(che)輪(lun)、車(che)橋與鋼板彈簧等(deng)載(zai)貨汽(qi)車(che)主(zhu)要底盤(pan)零件,從產(chan)品特點、涂(tu)層(ceng)質量要求、涂(tu)裝工藝、涂(tu)裝材料等(deng)方面進行簡要解析(xi),提出(chu)改善底盤(pan)零件涂(tu)層(ceng)質量的若干思路(lu)與建議。
1 車架
車(che)(che)(che)架是載貨(huo)汽車(che)(che)(che)的(de)(de)整車(che)(che)(che)骨(gu)架,起到支撐連接汽車(che)(che)(che)各零部件(jian)(jian)的(de)(de)作用(yong),承受多種載荷,是載貨(huo)汽車(che)(che)(che)關鍵的(de)(de)部件(jian)(jian)總(zong)成(cheng)之(zhi)一 。車(che)(che)(che)架涂層(ceng)除(chu)了要(yao)求具(ju)有優良的(de)(de)防腐(fu)性(xing),同時也要(yao)求具(ju)有良好的(de)(de)耐候性(xing),例如,有的(de)(de)廠(chang)家要(yao)求車(che)(che)(che)架涂層(ceng)耐中(zhong)性(xing)鹽(yan)霧≥504 h、耐氙燈老化≥400 h,有的(de)(de)廠(chang)家要(yao)求車(che)(che)(che)架涂層(ceng)耐中(zhong)性(xing)鹽(yan)霧性(xing)≥480 h、耐紫外(QUV)老化≥300 h 等(deng)。根據車(che)(che)(che)架生(sheng)產及涂裝類型(xing),大(da)體(ti)(ti)分為兩類:車(che)(che)(che)架裝配后總(zong)成(cheng)整體(ti)(ti)涂裝與車(che)(che)(che)架散件(jian)(jian)單獨涂裝后再(zai)裝配為總(zong)成(cheng)。
國(guo)內(nei)載貨汽車普(pu)遍采(cai)用(yong)(yong)車架裝(zhuang)(zhuang)配后總成(cheng)(cheng)整體(ti)涂(tu)(tu)(tu)裝(zhuang)(zhuang)工(gong)藝,基本以陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)單涂(tu)(tu)(tu)層(ceng)(ceng)體(ti)系(xi)為主。有(you)(you)的(de)(de)(de)涂(tu)(tu)(tu)裝(zhuang)(zhuang)線選用(yong)(yong)中厚(hou)膜環(huan)(huan)氧(yang)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)型(xing)陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)料,要(yao)求(qiu)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)層(ceng)(ceng)具(ju)有(you)(you)優(you)異的(de)(de)(de)耐鹽(yan)霧性(xing)(xing)和良(liang)好(hao)的(de)(de)(de)銳邊涂(tu)(tu)(tu)覆效果,但(dan)耐候(hou)(hou)性(xing)(xing)普(pu)遍較(jiao)差,極(ji)(ji)(ji)易出現涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)早期失光(guang)、變色,甚至粉化(hua)。有(you)(you)的(de)(de)(de)涂(tu)(tu)(tu)裝(zhuang)(zhuang)線選用(yong)(yong)“底(di)面(mian)合一(yi)”型(xing)陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)料,一(yi)般要(yao)求(qiu)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)層(ceng)(ceng)具(ju)有(you)(you)良(liang)好(hao)的(de)(de)(de)耐鹽(yan)霧性(xing)(xing)的(de)(de)(de)同(tong)(tong)時也要(yao)具(ju)備較(jiao)好(hao)的(de)(de)(de)耐候(hou)(hou)性(xing)(xing)。這一(yi)體(ti)系(xi)的(de)(de)(de)主體(ti)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)為2種(zhong)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)或(huo)多(duo)種(zhong)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)組(zu)(zu)分的(de)(de)(de)混(hun)合物(wu),其(qi)中一(yi)種(zhong)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)是環(huan)(huan)氧(yang)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi),其(qi)他是耐候(hou)(hou)型(xing)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi),如,丙(bing)烯酸樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)或(huo)聚氨酯(zhi)(zhi)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)等,通過化(hua)學接枝改性(xing)(xing)或(huo)冷拼技術達到特定(ding)性(xing)(xing)能(neng)(neng)要(yao)求(qiu)。電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)層(ceng)(ceng)固化(hua)過程中,試圖通過不同(tong)(tong)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)界面(mian)張力梯度的(de)(de)(de)作用(yong)(yong),使得兩相流動形成(cheng)(cheng)一(yi)定(ding)程度的(de)(de)(de)涂(tu)(tu)(tu)層(ceng)(ceng)分層(ceng)(ceng)結構,耐候(hou)(hou)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)在(zai)上層(ceng)(ceng)具(ju)有(you)(you)高(gao)(gao)耐候(hou)(hou)性(xing)(xing),環(huan)(huan)氧(yang)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)在(zai)下層(ceng)(ceng)具(ju)有(you)(you)高(gao)(gao)防腐性(xing)(xing)。如何(he)選擇具(ju)有(you)(you)適當表面(mian)張力差的(de)(de)(de)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)組(zu)(zu)分,并穩定(ding)控制電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)雙(shuang)層(ceng)(ceng)結構與性(xing)(xing)能(neng)(neng)是涂(tu)(tu)(tu)料開發的(de)(de)(de)技術難點(dian)。目前來(lai)看,常規環(huan)(huan)氧(yang)樹(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)型(xing)陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)料無(wu)法滿足涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)耐候(hou)(hou)性(xing)(xing)要(yao)求(qiu),而“底(di)面(mian)合一(yi)”型(xing)陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)涂(tu)(tu)(tu)料在(zai)兼顧耐候(hou)(hou)性(xing)(xing)的(de)(de)(de)同(tong)(tong)時,涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)防腐性(xing)(xing)均有(you)(you)不同(tong)(tong)程度的(de)(de)(de)調整。為了提(ti)升涂(tu)(tu)(tu)層(ceng)(ceng)質量,有(you)(you)的(de)(de)(de)車架涂(tu)(tu)(tu)裝(zhuang)(zhuang)線針對(dui)高(gao)(gao)端(duan)產品采(cai)用(yong)(yong)“陰(yin)極(ji)(ji)(ji)電(dian)(dian)泳(yong)(yong)+噴(pen)漆(qi)或(huo)噴(pen)粉”工(gong)藝,噴(pen)漆(qi)采(cai)用(yong)(yong)雙(shuang)組(zu)(zu)分丙(bing)烯酸聚氨酯(zhi)(zhi)面(mian)漆(qi)或(huo)高(gao)(gao)固體(ti)分聚脲面(mian)漆(qi),噴(pen)粉采(cai)用(yong)(yong)聚酯(zhi)(zhi)粉末涂(tu)(tu)(tu)料,較(jiao)好(hao)地保證(zheng)了車架涂(tu)(tu)(tu)層(ceng)(ceng)的(de)(de)(de)綜(zong)合性(xing)(xing)能(neng)(neng)。
近年(nian)來,借鑒國外車(che)企(qi)成熟技(ji)術,國內有(you)(you)的(de)(de)(de)(de)車(che)架生產線采用(yong)散(san)件(jian)(jian)單獨涂(tu)(tu)裝后再進行車(che)架總成裝配的(de)(de)(de)(de)工藝(yi),可以(yi)在保證(zheng)涂(tu)(tu)層性(xing)能(neng)(neng)的(de)(de)(de)(de)同時,有(you)(you)效解決車(che)架縫(feng)隙、夾層以(yi)及零(ling)件(jian)(jian)裝配貼合面等(deng)(deng)部(bu)位(wei)的(de)(de)(de)(de)銹蝕問題(ti)。車(che)架縱梁經(jing)拋丸、漆前(qian)磷化(hua)處理(li)后噴涂(tu)(tu)聚酯粉末涂(tu)(tu)料,涂(tu)(tu)層的(de)(de)(de)(de)外觀質量、機械性(xing)能(neng)(neng)、防(fang)腐性(xing)能(neng)(neng)與耐候(hou)性(xing)能(neng)(neng)俱佳;車(che)架橫(heng)梁等(deng)(deng)散(san)件(jian)(jian)推薦“陰極電泳+噴漆或(huo)噴粉”涂(tu)(tu)裝工藝(yi)。采用(yong)這種生產工藝(yi)方式,車(che)架的(de)(de)(de)(de)涂(tu)(tu)裝成本較(jiao)高,車(che)架總成裝配作業較(jiao)多,應重點關注粉末涂(tu)(tu)層的(de)(de)(de)(de)摩擦系(xi)數(shu)、縱梁粉末涂(tu)(tu)層的(de)(de)(de)(de)膜厚(hou)控(kong)制、緊固件(jian)(jian)(螺栓、螺帽(mao)與鉚釘)的(de)(de)(de)(de)表面處理(li)質量以(yi)及裝配零(ling)件(jian)(jian)的(de)(de)(de)(de)連接(jie)可靠性(xing)等(deng)(deng)問題(ti)。
2 車輪
載貨汽車車輪(lun)是重(zhong)要的保安零部件,在整車中(zhong)(zhong)處于特殊(shu)位(wei)置,工作環(huan)境(jing)比(bi)較惡劣(lie),與(yu)車架(jia)涂層(ceng)類(lei)似(si),不僅要求(qiu)具(ju)有(you)優良(liang)的防(fang)腐性(xing)(xing)(xing),同時也要求(qiu)具(ju)有(you)良(liang)好的耐(nai)候性(xing)(xing)(xing),如,有(you)的廠家(jia)要求(qiu)車輪(lun)涂層(ceng)耐(nai)中(zhong)(zhong)性(xing)(xing)(xing)鹽霧(wu)(wu)≥400 h、耐(nai)氙(xian)燈老(lao)化≥400 h,有(you)的廠家(jia)要求(qiu)車輪(lun)涂層(ceng)耐(nai)中(zhong)(zhong)性(xing)(xing)(xing)鹽霧(wu)(wu)≥504 h、耐(nai)氙(xian)燈老(lao)化≥200 h。
國內載貨汽車(che)(che)鋼(gang)質車(che)(che)輪(lun)(lun)涂(tu)(tu)(tu)裝(zhuang)普(pu)遍采(cai)用“陰(yin)極電泳(yong)+面(mian)漆”工藝。電泳(yong)采(cai)用中厚膜(mo)常規環氧樹(shu)脂型陰(yin)極電泳(yong)涂(tu)(tu)(tu)料,涂(tu)(tu)(tu)層的(de)防腐性能優良(liang),但(dan)耐候性能較差。為了提升車(che)(che)輪(lun)(lun)的(de)裝(zhuang)飾性以(yi)及滿足(zu)涂(tu)(tu)(tu)層的(de)性能要求,再進行單涂(tu)(tu)(tu)層面(mian)漆涂(tu)(tu)(tu)覆,一般為銀色金屬面(mian)漆(無罩光清漆)。同時,為了保證后續車(che)(che)輪(lun)(lun)螺栓連接的(de)可靠性,重點部位應(ying)做(zuo)好面(mian)漆涂(tu)(tu)(tu)層的(de)厚度控制或者(zhe)進行必要的(de)涂(tu)(tu)(tu)裝(zhuang)遮(zhe)蔽處理。
為了(le)(le)降低(di)涂(tu)(tu)(tu)裝成(cheng)本(ben),不少鋼質車(che)輪(lun)涂(tu)(tu)(tu)裝線(xian)已采用(yong)“底面(mian)合(he)(he)一(yi)(yi)”型陰(yin)極電泳涂(tu)(tu)(tu)料(liao),部分取消了(le)(le)面(mian)漆工藝。由于車(che)輪(lun)焊接(jie)(jie)部位(wei)高溫氧化(hua)(hua)皮(pi)電阻過大(da),極易(yi)導致焊接(jie)(jie)部位(wei)無(wu)法電泳上(shang)涂(tu)(tu)(tu)層(ceng),車(che)輪(lun)上(shang)電泳線(xian)前必須進行細(xi)致的(de)(de)拋丸(wan)處(chu)(chu)理去除氧化(hua)(hua)皮(pi)。“底面(mian)合(he)(he)一(yi)(yi)”型陰(yin)極電泳涂(tu)(tu)(tu)料(liao)生(sheng)產應用(yong)中暴(bao)露出的(de)(de)主要(yao)(yao)問(wen)題(ti)是涂(tu)(tu)(tu)層(ceng)的(de)(de)耐腐蝕性下(xia)降,車(che)輪(lun)表面(mian)易(yi)出現點狀銹蝕,零件(jian)的(de)(de)邊緣、夾縫與焊縫等(deng)部位(wei)也(ye)易(yi)生(sheng)銹“流黃水(shui)”。需(xu)要(yao)(yao)嚴格(ge)控制車(che)輪(lun)工件(jian)經拋丸(wan)處(chu)(chu)理后的(de)(de)表面(mian)粗糙(cao)度(du),同時保證“底面(mian)合(he)(he)一(yi)(yi)”型陰(yin)極電泳涂(tu)(tu)(tu)料(liao)的(de)(de)涂(tu)(tu)(tu)層(ceng)厚(hou)度(du)滿足(zu)性能要(yao)(yao)求。
3 車橋
載貨汽車(che)車(che)橋是非常重要的(de)底盤(pan)零(ling)件,承(cheng)(cheng)擔著傳(chuan)動、承(cheng)(cheng)載等功能,主要有(you)沖焊橋與(yu)鑄造橋兩種類(lei)型(xing)。涂(tu)(tu)層要求具(ju)有(you)良好(hao)的(de)防腐性,如,有(you)的(de)廠(chang)(chang)家(jia)要求車(che)橋總成(外(wai)表面)涂(tu)(tu)層厚度≥50 μm、耐(nai)中性鹽霧≥168 h,有(you)的(de)廠(chang)(chang)家(jia)要求車(che)橋總成(外(wai)表面)涂(tu)(tu)層厚度≥60 μm、耐(nai)中性鹽霧≥240 h。
國(guo)內載貨汽車(che)(che)車(che)(che)橋總(zong)成涂(tu)(tu)裝普遍采用總(zong)成噴漆(qi)工藝。由于車(che)(che)橋總(zong)成的熱容量大,部分(fen)配件(jian)(油(you)封、墊圈等)不能耐(nai)(nai)高溫(wen),一(yi)般選用低溫(wen)烘(hong)烤型(xing)防(fang)腐涂(tu)(tu)料,溶劑型(xing)涂(tu)(tu)料有(you)氯(lv)化橡膠、氯(lv)醚(mi)、氯(lv)磺化等品(pin)種,水性涂(tu)(tu)料有(you)丙烯(xi)酸改性環(huan)氧(yang)酯、丙烯(xi)酸改性醇酸等。目前(qian),低溫(wen)烘(hong)烤型(xing)單組分(fen)水性防(fang)腐涂(tu)(tu)料應重點解(jie)決涂(tu)(tu)層的干燥速度慢,涂(tu)(tu)層初始硬度低的問題。車(che)(che)橋做(zuo)為載貨汽車(che)(che)底(di)盤的典型(xing)零件(jian),要(yao)求涂(tu)(tu)層具有(you)良好的防(fang)腐性的同時,有(you)的產(chan)品(pin)也考核耐(nai)(nai)候性,單涂(tu)(tu)層體系需要(yao)防(fang)腐涂(tu)(tu)料在(zai)配方設計上(shang)綜(zong)合考慮。高端(duan)車(che)(che)橋產(chan)品(pin)采用“環(huan)氧(yang)防(fang)腐底(di)漆(qi)+丙烯(xi)酸聚氨酯面漆(qi)”的雙涂(tu)(tu)層體系,涂(tu)(tu)層綜(zong)合性能優異。
為了(le)提高噴(pen)(pen)(pen)涂(tu)效率(lv)、保證噴(pen)(pen)(pen)涂(tu)質量,產量較大(da)的(de)車橋總成涂(tu)裝線采用地樁(zhuang)式噴(pen)(pen)(pen)涂(tu)機(ji)器人(ren),高壓無(wu)氣或(huo)(huo)混氣噴(pen)(pen)(pen)涂(tu)工(gong)藝。由(you)于車橋外觀形狀與結構比較復雜,通常采用“機(ji)器人(ren)+人(ren)工(gong)”的(de)噴(pen)(pen)(pen)涂(tu)方(fang)式,人(ren)工(gong)噴(pen)(pen)(pen)涂(tu)的(de)目的(de)是彌補機(ji)器人(ren)噴(pen)(pen)(pen)涂(tu)無(wu)法達到(dao)或(huo)(huo)噴(pen)(pen)(pen)涂(tu)不到(dao)位(wei)的(de)區域,以提高整體噴(pen)(pen)(pen)涂(tu)質量。對于外觀質量要(yao)求不高的(de)非(fei)重(zhong)要(yao)部位(wei),可以使(shi)用漆(qi)刷(shua)進行點補或(huo)(huo)刷(shua)涂(tu)。
由于車(che)橋總成(cheng)零部(bu)件品種較多,需要加強對毛(mao)坯與零部(bu)件的底漆(qi)質(zhi)量(liang)管控(kong),選用防(fang)腐性(xing)能優良(liang)的底漆(qi);車(che)橋總成(cheng)裝(zhuang)(zhuang)配后(hou)(hou)難涂(tu)裝(zhuang)(zhuang)或涂(tu)不到涂(tu)料的部(bu)位,需要結合零部(bu)件特點進行(xing)涂(tu)裝(zhuang)(zhuang)工(gong)藝改善或防(fang)銹(xiu)處(chu)理;車(che)橋總成(cheng)噴漆(qi)前應(ying)(ying)進行(xing)脫脂、磷化處(chu)理,水(shui)洗工(gong)序應(ying)(ying)考(kao)慮防(fang)銹(xiu),避免工(gong)件工(gong)序間(jian)生銹(xiu);根據車(che)橋產品及后(hou)(hou)續裝(zhuang)(zhuang)配要求(qiu),應(ying)(ying)對突緣、車(che)輪螺栓、安裝(zhuang)(zhuang)孔(kong)等部(bu)位進行(xing)遮蔽處(chu)理。
4 鋼板彈簧
鋼(gang)板(ban)彈簧(huang)(huang)是典(dian)型、特殊的(de)汽車(che)底盤零件(jian),在車(che)輛行駛中(zhong)承受(shou)高頻往復運(yun)動,起著(zhu)(zhu)緩沖減震(zhen)作(zuo)用(yong)(yong),對車(che)輛平(ping)穩性與安全性起著(zhu)(zhu)重要(yao)作(zuo)用(yong)(yong),是載貨(huo)汽車(che)廣泛應用(yong)(yong)的(de)懸架(jia)彈性元件(jian),分為(wei)(wei)多片簧(huang)(huang)和少(shao)片簧(huang)(huang)。有(you)資料顯(xian)示,由涂層(ceng)缺陷(xian)引起的(de)鋼(gang)板(ban)彈簧(huang)(huang)的(de)早(zao)期銹(xiu)蝕(shi),銹(xiu)蝕(shi)點將成為(wei)(wei)鋼(gang)板(ban)彈簧(huang)(huang)新的(de)疲(pi)勞(lao)源,從而影響鋼(gang)板(ban)彈簧(huang)(huang)的(de)疲(pi)勞(lao)壽命(ming)。鋼(gang)板(ban)彈簧(huang)(huang)涂層(ceng)要(yao)求(qiu)具(ju)有(you)良好的(de)防腐(fu)性能,如,有(you)的(de)廠(chang)家(jia)要(yao)求(qiu)涂層(ceng)耐(nai)(nai)中(zhong)性鹽(yan)霧≥120 h,有(you)的(de)廠(chang)家(jia)要(yao)求(qiu)涂層(ceng)耐(nai)(nai)中(zhong)性鹽(yan)霧≥240 h。
為了提高強度(du)(du)與(yu)疲勞壽(shou)命,鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)均要求(qiu)進(jin)(jin)行(xing)應(ying)(ying)(ying)力噴(pen)(pen)丸,但(dan)國(guo)內廠(chang)家有的(de)(de)僅單面(mian)(mian)(凹面(mian)(mian))進(jin)(jin)行(xing)應(ying)(ying)(ying)力噴(pen)(pen)丸,板(ban)簧(huang)(huang)(huang)(huang)(huang)(huang)片(pian)另一面(mian)(mian)(凸面(mian)(mian))表面(mian)(mian)不同(tong)程度(du)(du)存有氧化皮,嚴重(zhong)影響涂(tu)(tu)層的(de)(de)附著(zhu)力與(yu)防(fang)腐性(xing)(xing)(xing)。建(jian)(jian)議(yi)采用(yong)(yong)“一般噴(pen)(pen)丸+應(ying)(ying)(ying)力噴(pen)(pen)丸”工(gong)藝,既清除氧化皮,又可達成(cheng)(cheng)(cheng)產(chan)(chan)品特性(xing)(xing)(xing)要求(qiu)。由(you)于鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)為疊接(jie)結構,夾縫部位容易出(chu)現早期銹蝕,應(ying)(ying)(ying)采用(yong)(yong)板(ban)簧(huang)(huang)(huang)(huang)(huang)(huang)單片(pian)涂(tu)(tu)裝(zhuang)(陰極(ji)電泳或噴(pen)(pen)漆(qi)),裝(zhuang)配后鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)總成(cheng)(cheng)(cheng)再噴(pen)(pen)漆(qi)或補漆(qi)。鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)熱容量大,建(jian)(jian)議(yi)使用(yong)(yong)低溫固化型陰極(ji)電泳涂(tu)(tu)料(liao),固化溫度(du)(du)低至(zhi)150 ℃的(de)(de)陰極(ji)電泳涂(tu)(tu)料(liao)已(yi)有生產(chan)(chan)應(ying)(ying)(ying)用(yong)(yong)案例(li),可低溫解封的(de)(de)封閉異氰酸酯交聯劑的(de)(de)選用(yong)(yong)以及復合催化體系的(de)(de)引用(yong)(yong)是新型電泳涂(tu)(tu)料(liao)開(kai)發的(de)(de)關(guan)鍵技(ji)術。板(ban)簧(huang)(huang)(huang)(huang)(huang)(huang)單片(pian)電泳后再裝(zhuang)配的(de)(de)鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)總成(cheng)(cheng)(cheng)進(jin)(jin)行(xing)面(mian)(mian)漆(qi)噴(pen)(pen)涂(tu)(tu),建(jian)(jian)議(yi)選用(yong)(yong)兼具(ju)防(fang)腐性(xing)(xing)(xing)與(yu)耐(nai)候(hou)性(xing)(xing)(xing)的(de)(de)涂(tu)(tu)料(liao)。板(ban)簧(huang)(huang)(huang)(huang)(huang)(huang)單片(pian)噴(pen)(pen)漆(qi)應(ying)(ying)(ying)選用(yong)(yong)防(fang)腐底(di)漆(qi),裝(zhuang)配后的(de)(de)鋼(gang)(gang)板(ban)彈(dan)簧(huang)(huang)(huang)(huang)(huang)(huang)總成(cheng)(cheng)(cheng)進(jin)(jin)行(xing)面(mian)(mian)漆(qi)噴(pen)(pen)涂(tu)(tu),也應(ying)(ying)(ying)選用(yong)(yong)兼具(ju)防(fang)腐性(xing)(xing)(xing)與(yu)耐(nai)候(hou)性(xing)(xing)(xing)的(de)(de)涂(tu)(tu)料(liao),建(jian)(jian)議(yi)采用(yong)(yong)低溫快干(gan)型水(shui)性(xing)(xing)(xing)防(fang)腐涂(tu)(tu)料(liao)與(yu)“底(di)面(mian)(mian)合一”型水(shui)性(xing)(xing)(xing)防(fang)腐涂(tu)(tu)料(liao)。
5 結語
底盤(pan)(pan)零件(jian)(jian)的(de)涂裝(zhuang)是國內載貨汽車涂裝(zhuang)中較為薄弱的(de)環(huan)節,底盤(pan)(pan)零件(jian)(jian)的(de)涂層(ceng)質(zhi)量提(ti)升一(yi)直是涂裝(zhuang)質(zhi)量改善的(de)主要(yao)內容之一(yi)。隨著(zhu)涂裝(zhuang)材(cai)料與(yu)(yu)工(gong)藝的(de)不斷進(jin)(jin)步,以(yi)水(shui)性涂料、高固體分涂料與(yu)(yu)粉末涂料為代表的(de)綠(lv)色涂裝(zhuang)技(ji)術正(zheng)在越來(lai)越多地應用于各類底盤(pan)(pan)零件(jian)(jian)的(de)涂裝(zhuang)生產。需(xu)(xu)要(yao)更(geng)加重視底盤(pan)(pan)零件(jian)(jian)各類基材(cai)的(de)表面(mian)質(zhi)量以(yi)及前處理質(zhi)量。底盤(pan)(pan)零件(jian)(jian)涂層(ceng)在滿足防腐性與(yu)(yu)耐候(hou)性要(yao)求(qiu)的(de)同時,還需(xu)(xu)要(yao)考慮車輛底盤(pan)(pan)整體的(de)防護性與(yu)(yu)裝(zhuang)飾(shi)性的(de)提(ti)升。針對底盤(pan)(pan)零件(jian)(jian)某(mou)些涂覆防護難度較大的(de)部位,如,腔型(xing)結構部位、裝(zhuang)配(pei)貼合面(mian)、運動(dong)連接面(mian)等,如何進(jin)(jin)行(xing)有效的(de)表面(mian)防護仍需(xu)(xu)要(yao)深入研究