汽車性能檢測方法四輪定位儀檢測設備

汽車四輪(lun)定(ding)位(wei)參數(shu)進行檢測，不僅能確(que)知所有(you)車輪(lun)定(ding)位(wei)的正(zheng)確(que)與(yu)否(fou)，而且還可(ke)以確(que)知前(qian)(qian)軸(zhou)后軸(zhou)懸架車架等的技術狀況(kuang)，為(wei)底盤不解體(ti)診斷提供可(ke)靠(kao)依據。 四輪(lun)定(ding)位(wei)儀(yi)(yi)是專(zhuan)門用來測量車輪(lun)定(ding)位(wei)參數(shu)的設備。四輪(lun)定(ding)位(wei)儀(yi)(yi)可(ke)檢測的項目(mu)包 括(kuo)：前(qian)(qian)輪(lun)前(qian)(qian)束前(qian)(qian)輪(lun)外(wai)傾角主銷(xiao)(xiao)后傾角主銷(xiao)(xiao)內傾角后輪(lun)前(qian)(qian)束后輪(lun)外(wai)傾角輪(lun)距(ju)軸(zhou)距(ju)推力角和左右軸(zhou)距(ju)差等。目(mu)前(qian)(qian)常見的國產或進口的四輪(lun)定(ding)位(wei)儀(yi)(yi)與(yu)。

汽車(che)(che)性(xing)能檢(jian)測(ce)(ce)與試驗通用方法標準(zhun):都可以測(ce)(ce)量上述檢(jian)測(ce)(ce)項目中幾(ji)項或全部項目。在這些檢(jian)測(ce)(ce)項目中，車(che)(che)輪(lun)前束車(che)(che)輪(lun)外傾(qing)角主(zhu)(zhu)銷后傾(qing)角和主(zhu)(zhu)銷內(nei)傾(qing)角統稱為前輪(lun)定位，又稱前輪(lun)定位四要素，各(ge)種前輪(lun)定位儀都能完成其(qi)檢(jian)測(ce)(ce)任務。但汽車(che)(che)的操縱穩定性(xing)不僅僅由前輪(lun)定位來保證，后輪(lun)定位也起著至關(guan)重要的作用，所以，最好使(shi)用四輪(lun)定位儀檢(jian)測(ce)(ce)調整。

四(si)輪(lun)定(ding)(ding)位(wei)(wei)儀的(de)結構與工作原理拉(la)線式(shi)四(si)輪(lun)定(ding)(ding)位(wei)(wei)儀拉(la)線式(shi)四(si)輪(lun)定(ding)(ding)位(wei)(wei)儀的(de)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)如(ru)圖所示（圖為右前輪(lun)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)。它由傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)上(shang)體(ti)(ti)(ti)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)下體(ti)(ti)(ti)和(he)(he)側端蓋等部件組(zu)成(cheng)。在(zai)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)上(shang)體(ti)(ti)(ti)上(shang)布置有兩個(ge)相(xiang)互垂(chui)直(zhi)(zhi)的(de)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)插孔(kong)，一(yi)個(ge)是(shi)用(yong)于(yu)測(ce)量(liang)主銷內傾(qing)角的(de)安(an)(an)裝(zhuang)插孔(kong)，另(ling)一(yi)個(ge)是(shi)用(yong)于(yu)測(ce)量(liang)主銷后傾(qing)角和(he)(he)前束的(de)安(an)(an)裝(zhuang)插孔(kong)。在(zai)安(an)(an)裝(zhuang)插孔(kong)內裝(zhuang)有滾針軸承，以保(bao)證傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)安(an)(an)裝(zhuang)到車輪(lun)卡具上(shang)以后，傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)擺動輕(qing)便自如(ru)。傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)上(shang)蓋的(de)水(shui)準泡用(yong)于(yu)檢驗傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)安(an)(an)裝(zhuang)是(shi)否(fou)垂(chui)直(zhi)(zhi)。鎖緊旋鈕(niu)用(yong)于(yu)鎖定(ding)(ding)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)，使傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)外(wai)殼能(neng)隨車輪(lun)一(yi)起轉動。在(zai)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)下體(ti)(ti)(ti)內裝(zhuang)有兩支(zhi)精(jing)密電位(wei)(wei)計(ji)。精(jing)密電位(wei)(wei)計(ji)的(de)外(wai)殼固定(ding)(ding)在(zai)傳(chuan)(chuan)(chuan)感(gan)器(qi)(qi)(qi)下體(ti)(ti)(ti)上(shang)。

精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)的作(zuo)用(yong)(yong)是(shi)測(ce)量(liang)角(jiao)度(du)。水(shui)平(ping)布(bu)置的精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)用(yong)(yong)于(yu)測(ce)量(liang)車輪前束(shu)(shu)和驅動(dong)軸(zhou)推力角(jiao)，垂直布(bu)置的精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)用(yong)(yong)于(yu)測(ce)量(liang)主銷(xiao)內傾(qing)角(jiao)主銷(xiao)后(hou)傾(qing)角(jiao)和車輪外(wai)傾(qing)角(jiao)。拉(la)線(xian)(xian)擺臂(bei)的一(yi)端有孔(kong)，用(yong)(yong)于(yu)掛彈性(xing)拉(la)線(xian)(xian)。通(tong)過(guo)彈性(xing)拉(la)線(xian)(xian)，連(lian)接(jie)后(hou)軸(zhou)傳感器拉(la)線(xian)(xian)擺臂(bei)。拉(la)線(xian)(xian)擺臂(bei)的另一(yi)端與(yu)精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)的轉軸(zhou)緊(jin)固(gu)連(lian)接(jie)。精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)內的電(dian)(dian)刷可隨拉(la)線(xian)(xian)擺臂(bei)的擺動(dong)而(er)移動(dong)，改(gai)變輸(shu)出(chu)電(dian)(dian)阻，從而(er)傳送出(chu)與(yu)前束(shu)(shu)有一(yi)定比例(li)關系(xi)的電(dian)(dian)壓量(liang)，由儀(yi)表計(ji)算和顯示出(chu)前束(shu)(shu)值。兼作(zuo)阻尼器活塞(sai)的重錘通(tong)過(guo)電(dian)(dian)位(wei)計(ji)擺臂(bei)與(yu)精(jing)密(mi)(mi)(mi)電(dian)(dian)位(wei)計(ji)的轉軸(zhou)緊(jin)固(gu)連(lian)接(jie)。重錘的作(zuo)用(yong)(yong)是(shi)保(bao)證電(dian)(dian)位(wei)計(ji)擺臂(bei)始(shi)終處于(yu)鉛垂狀態。

當傳(chuan)(chuan)感(gan)(gan)器(qi)外(wai)殼隨車(che)輪(lun)(lun)外(wai)傾(qing)(qing)角(jiao)變(bian)(bian)化或車(che)輪(lun)(lun)轉動(dong)(dong)時(shi)，帶動(dong)(dong)電位(wei)(wei)計電刷移動(dong)(dong)，改變(bian)(bian)輸出電阻，從而傳(chuan)(chuan)送出與車(che)輪(lun)(lun)外(wai)傾(qing)(qing)角(jiao)主(zhu)銷(xiao)后(hou)傾(qing)(qing)角(jiao)的測(ce)(ce)量值(zhi)(zhi)或主(zhu)銷(xiao)內傾(qing)(qing)角(jiao)的測(ce)(ce)量值(zhi)(zhi)有一(yi)定(ding)比例關系(xi)的電壓量，由(you)(you)儀表計算(suan)和顯示出車(che)輪(lun)(lun)外(wai)傾(qing)(qing)角(jiao)主(zhu)銷(xiao)后(hou)傾(qing)(qing)角(jiao)或主(zhu)銷(xiao)內傾(qing)(qing)角(jiao)度值(zhi)(zhi)。由(you)(you)兼(jian)作(zuo)阻尼(ni)器(qi)活塞(sai)的重(zhong)錘和阻尼(ni)器(qi)工(gong)作(zuo)腔組(zu)成減振阻尼(ni)器(qi)，防(fang)止重(zhong)錘的擺振，提高測(ce)(ce)試速(su)度和檢(jian)測(ce)(ce)精度。在傳(chuan)(chuan)感(gan)(gan)器(qi)電纜接頭上用屏蔽(bi)電纜導線(xian)連接到儀表上，將角(jiao)度信(xin)息傳(chuan)(chuan)給計算(suan)機進(jin)行測(ce)(ce)量。側(ce)端蓋的內側(ce)粘有金屬板用來屏蔽(bi)外(wai)界電磁(ci)波(bo)的干擾。光學(xue)(xue)式四輪(lun)(lun)定(ding)位(wei)(wei)儀光學(xue)(xue)式四輪(lun)(lun)定(ding)位(wei)(wei)儀幾大部件的結構和功能。

目(mu)前使(shi)用的(de)光學式(shi)(shi)和微機拉線(xian)式(shi)(shi)四輪定(ding)(ding)位儀，雖(sui)然測(ce)量(liang)原理基本相同，但使(shi)用方法有(you)一定(ding)(ding)差異(yi)。因此，在使(shi)用前應詳細(xi)閱讀(du)儀器(qi)使(shi)用說明書，按(an)儀器(qi)使(shi)用說明書的(de)要(yao)求和規(gui)定(ding)(ding)方法進行檢測(ce)。下面以(yi)電腦拉線(xian)式(shi)(shi)四輪定(ding)(ding)位儀為例，說明四輪定(ding)(ding)位儀的(de)使(shi)用方法。