精密平面磨床電力拖動及控制要求
2021-08-24 來自: 威海豐潤機械有限公司 瀏覽(lan)次數:37
基于精密平面磨床的工作性質和加工精度要求,對電力拖動控制方案提出如下要求:
(1)精(jing)密平(ping)面(mian)磨床(chuang)(chuang)是一種精(jing)密加工(gong)機床(chuang)(chuang),為了保證其加工(gong)精(jing)度要求,機床(chuang)(chuang)運行(xing)時要求平(ping)穩。工(gong)作臺往(wang)復(fu)運動(dong)在換向(xiang)時要求慣性要小,無沖擊力,因(yin)此,工(gong)作臺的(de)(de)往(wang)復(fu)運動(dong)采用液(ye)(ye)壓(ya)(ya)傳動(dong)。由電動(dong)機拖動(dong)液(ye)(ye)壓(ya)(ya)泵(beng),供應壓(ya)(ya)力油,通過液(ye)(ye)壓(ya)(ya)傳動(dong)裝置實現工(gong)作臺的(de)(de)縱向(xiang)進給運動(dong),并通過工(gong)作臺上(shang)的(de)(de)撞塊操縱床(chuang)(chuang)身(shen)上(shang)的(de)(de)液(ye)(ye)壓(ya)(ya)換向(xiang)閥(開關),改變壓(ya)(ya)力油的(de)(de)流(liu)向(xiang),實現 工(gong)作臺的(de)(de)換向(xiang)和(he)自動(dong)往(wang)復(fu)運動(dong)。
(2)為了(le)簡化磨床(chuang)的(de)(de)(de)機(ji)(ji)械傳(chuan)動(dong)(dong)(dong)機(ji)(ji)構,采(cai)(cai)用多電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)單獨拖(tuo)動(dong)(dong)(dong)。精(jing)密平面磨床(chuang)采(cai)(cai)用三臺(tai)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)拖(tuo)動(dong)(dong)(dong),砂輪的(de)(de)(de)旋轉運動(dong)(dong)(dong)由(you)裝入式電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)直接拖(tuo)動(dong)(dong)(dong)。液壓泵由(you)液壓泵電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)拖(tuo)動(dong)(dong)(dong),經液壓傳(chuan)動(dong)(dong)(dong)裝置(zhi)完成工(gong)作(zuo)臺(tai)的(de)(de)(de)往復(縱向(xiang)進給)運動(dong)(dong)(dong),砂輪架(jia)(jia)的(de)(de)(de)橫(heng)向(xiang)進給運動(dong)(dong)(dong),砂輪架(jia)(jia)的(de)(de)(de)快速橫(heng)向(xiang)移(yi)動(dong)(dong)(dong)以及工(gong)作(zuo)臺(tai)導(dao)軌的(de)(de)(de)潤滑等。拖(tuo)動(dong)(dong)(dong)冷(leng)卻泵的(de)(de)(de)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)為磨削加工(gong)提供(gong)冷(leng)卻液。
(3)為了提高磨削質量,要求(qiu)砂(sha)輪有(you)較高轉(zhuan)速,通常采用兩極(理(li)想空(kong)載轉(zhuan)速為3000r/min頻(pin)率為50Hz)的籠型異步電動(dong)(dong)(dong)機拖動(dong)(dong)(dong)。為了提高調(diao)整運轉(zhuan)的砂(sha)輪主軸(zhou)的風度,采用裝(zhuang)入式電動(dong)(dong)(dong)機拖動(dong)(dong)(dong),電動(dong)(dong)(dong)機與(yu)砂(sha)輪主軸(zhou)同軸(zhou),從而提高了磨床的加工精度。
(4)平面磨(mo)削加(jia)工中,由于磨(mo)削溫(wen)度高,為減(jian)少工件(jian)的(de)熱變形,必須使工件(jian)得到(dao)充分的(de)冷(leng)卻,同時冷(leng)卻液能沖(chong)走磨(mo)屑和砂粒,以保證磨(mo)削精度。
(5)精密平面磨床常用(yong)電磁(ci)吸盤,利(li)用(yong)電磁(ci)吸力很(hen)方便地(di)(di)安裝(zhuang)和加工(gong)小工(gong)件,且(qie)工(gong)件在(zai)加工(gong)過程(cheng)中由于發(fa)熱(re)變形,電磁(ci)吸盤允許工(gong)件有(you)自(zi)由伸縮余(yu)地(di)(di),從而保證加工(gong)精度。
為(wei)了滿足上述電力拖(tuo)動控制方案的(de)要求(qiu)(qiu),對精密平面(mian)磨床的(de)電力拖(tuo)動控制系統提出以下幾點要求(qiu)(qiu):
(1)砂輪、液壓泵(beng)、冷卻泵(beng)三臺電動機都(dou)只(zhi)要求單方向旋轉。
(2)冷卻(que)泵(beng)電(dian)(dian)動(dong)機應隨砂(sha)輪電(dian)(dian)動(dong)機的開動(dong)而開動(dong),若(ruo)加工中不需要冷卻(que)液時(shi),可單獨(du)斷(duan)開冷卻(que)泵(beng)電(dian)(dian)動(dong)機。
(3)在(zai)正常(chang)加(jia)工(gong)中,若電(dian)磁(ci)吸(xi)盤吸(xi)力不(bu)足或消失時,砂輪(lun)電(dian)動(dong)(dong)機與(yu)液(ye)壓泵電(dian)動(dong)(dong)機應立即(ji)停止(zhi)工(gong)作,以防止(zhi)工(gong)件被砂輪(lun)切身力打飛而發生人身和設備(bei)事故(gu)。不(bu)加(jia)工(gong)時,即(ji)電(dian)磁(ci)吸(xi)盤不(bu)工(gong)作的(de)情況(kuang)下,允(yun)許砂輪(lun)電(dian)動(dong)(dong)機與(yu)液(ye)壓泵電(dian)動(dong)(dong)機開支(zhi),機床(chuang)作調整運動(dong)(dong)。
(4)電(dian)磁(ci)(ci)(ci)吸盤(pan)勵(li)磁(ci)(ci)(ci)線圈具(ju)有吸牢工件(jian)的正向(xiang)勵(li)磁(ci)(ci)(ci)、松開工件(jian)的斷(duan)開勵(li)磁(ci)(ci)(ci)、以(yi)及為抵消剩磁(ci)(ci)(ci)便(bian)于取下(xia)工件(jian)的反(fan)勵(li)磁(ci)(ci)(ci)控(kong)制環節。
(5)具有完善的(de)(de)保(bao)護(hu)環節。各電路(lu)的(de)(de)短路(lu)保(bao)護(hu),各電動機的(de)(de)長(chang)期過載保(bao)護(hu),零壓(ya)(ya)、欠壓(ya)(ya)保(bao)護(hu),電磁吸力不足的(de)(de)欠電流保(bao)護(hu),以(yi)及(ji)線圈斷開時產生高電壓(ya)(ya),而(er)危及(ji)電路(lu)中其它電器設備(bei)的(de)(de)過壓(ya)(ya)保(bao)護(hu)等(deng)等(deng)。
(6)機床 照明電路與工件去磁的控制環節。