預應力軋機的(de)(de)原理及特點： 采(cai)用(yong)(yong)(yong)(yong)預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)的(de)(de)方法可(ke)減(jian)少軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)彈跳(tiao)變(bian)(bian)(bian)(bian)形(xing)(xing),預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)也是(shi)一(yi)(yi)種高(gao)(gao)剛(gang)(gang)度(du)(du)(du)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)。它(ta)的(de)(de)基本(ben)原理是(shi)：利用(yong)(yong)(yong)(yong)受(shou)(shou)(shou)壓(ya)(ya)(ya)零件(jian)(jian)在(zai)軋(ya)(ya)(ya)(ya)制(zhi)前對(dui)(dui)機(ji)(ji)(ji)架(jia)(jia)施加預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)，使其處于(yu)(yu)受(shou)(shou)(shou)力(li)(li)(li)狀態。這樣在(zai)軋(ya)(ya)(ya)(ya)制(zhi)時，由(you)于(yu)(yu)預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)的(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)，機(ji)(ji)(ji)架(jia)(jia)的(de)(de)彈性變(bian)(bian)(bian)(bian)形(xing)(xing)變(bian)(bian)(bian)(bian)化減(jian)小，從而(er)(er)提高(gao)(gao)了軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)剛(gang)(gang)度(du)(du)(du)。預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)在(zai)機(ji)(ji)(ji)架(jia)(jia)的(de)(de)橫(heng)梁與(yu)下(xia)(xia)支(zhi)撐輥軸承座之間增(zeng)設預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)拉桿，以及在(zai)下(xia)(xia)橫(heng)梁與(yu)下(xia)(xia)軸承座之間裝設預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)加載液(ye)壓(ya)(ya)(ya)缸。軋(ya)(ya)(ya)(ya)制(zhi)前，液(ye)壓(ya)(ya)(ya)缸 對(dui)(dui)機(ji)(ji)(ji)座進行(xing)預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)加載，此時機(ji)(ji)(ji)架(jia)(jia)受(shou)(shou)(shou)拉力(li)(li)(li)，而(er)(er)下(xia)(xia)軸承座7和(he)壓(ya)(ya)(ya)桿 則受(shou)(shou)(shou)壓(ya)(ya)(ya)力(li)(li)(li)，其大(da)小都等于(yu)(yu)預(yu)(yu)(yu)(yu)緊力(li)(li)(li)(通常預(yu)(yu)(yu)(yu)緊力(li)(li)(li)要大(da)于(yu)(yu)1.5 倍的(de)(de)軋(ya)(ya)(ya)(ya)制(zhi)力(li)(li)(li)。 在(zai)預(yu)(yu)(yu)(yu)緊力(li)(li)(li)，機(ji)(ji)(ji)架(jia)(jia)產(chan)生拉伸(shen)變(bian)(bian)(bian)(bian)形(xing)(xing)l1件(jian)(jian)產(chan)生壓(ya)(ya)(ya)縮(suo)變(bian)(bian)(bian)(bian)形(xing)(xing) 。直(zhi)線AB 表示(shi)機(ji)(ji)(ji)架(jia)(jia)受(shou)(shou)(shou)力(li)(li)(li)與(yu)變(bian)(bian)(bian)(bian)形(xing)(xing)的(de)(de)關系(xi)，直(zhi)線CD 則表示(shi)受(shou)(shou)(shou)壓(ya)(ya)(ya)零件(jian)(jian)的(de)(de)受(shou)(shou)(shou)力(li)(li)(li)與(yu)變(bian)(bian)(bian)(bian)形(xing)(xing)的(de)(de)關系(xi)。 軋(ya)(ya)(ya)(ya)制(zhi)時， 在(zai)軋(ya)(ya)(ya)(ya)制(zhi)力(li)(li)(li)P 的(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)下(xia)(xia)，機(ji)(ji)(ji)架(jia)(jia)上的(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)力(li)(li)(li)由(you)0P 變(bian)(bian)(bian)(bian)為(wei)(wei)1P ，變(bian)(bian)(bian)(bian)形(xing)(xing)由(you)1l 變(bian)(bian)(bian)(bian)為(wei)(wei)'1l，增(zeng)加了一(yi)(yi)個(ge)δ 。受(shou)(shou)(shou)壓(ya)(ya)(ya)件(jian)(jian)的(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)力(li)(li)(li)由(you)0P變(bian)(bian)(bian)(bian)為(wei)(wei)2P ，變(bian)(bian)(bian)(bian)形(xing)(xing)由(you)2l 變(bian)(bian)(bian)(bian)為(wei)(wei)'2l ，減(jian)少了一(yi)(yi)個(ge)δ 。所(suo)以，由(you)軋(ya)(ya)(ya)(ya)制(zhi)力(li)(li)(li)P 引起的(de)(de)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)彈性變(bian)(bian)(bian)(bian)形(xing)(xing)δ 12PKKδ=+    此時，預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)剛(gang)(gang)度(du)(du)(du)系(xi)數(shu)為(wei)(wei)K = K1 + K2 。對(dui)(dui)于(yu)(yu)一(yi)(yi)般(ban)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)，在(zai)軋(ya)(ya)(ya)(ya)制(zhi)力(li)(li)(li)P 作(zuo)(zuo)用(yong)(yong)(yong)(yong)下(xia)(xia)，機(ji)(ji)(ji)架(jia)(jia)和(he)受(shou)(shou)(shou)壓(ya)(ya)(ya)件(jian)(jian)的(de)(de)彈性變(bian)(bian)(bian)(bian)形(xing)(xing)之和(he)即(ji)為(wei)(wei)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)彈性變(bian)(bian)(bian)(bian)形(xing)(xing) 故一(yi)(yi)般(ban)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)剛(gang)(gang)度(du)(du)(du)系(xi)數(shu)可(ke)見，預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)剛(gang)(gang)度(du)(du)(du)系(xi)數(shu)要比普通軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)的(de)(de)剛(gang)(gang)度(du)(du)(du)系(xi)數(shu)大(da)。但(dan)是(shi)預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)采(cai)用(yong)(yong)(yong)(yong)液(ye)壓(ya)(ya)(ya)螺母和(he)壓(ya)(ya)(ya)桿，使軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)結(jie)構變(bian)(bian)(bian)(bian)的(de)(de)復(fu)雜，加工精度(du)(du)(du)要求提高(gao)(gao)，尤(you)其對(dui)(dui)壓(ya)(ya)(ya)桿的(de)(de)制(zhi)造質量要求較(jiao)高(gao)(gao)，為(wei)(wei)了施加預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)，還需(xu)備(bei)有高(gao)(gao)壓(ya)(ya)(ya)油(you)泵和(he)一(yi)(yi)套油(you)壓(ya)(ya)(ya)系(xi)統(tong)。當換(huan)(huan)輥或改變(bian)(bian)(bian)(bian)軋(ya)(ya)(ya)(ya)輥直(zhi)徑時，需(xu)要換(huan)(huan)上軋(ya)(ya)(ya)(ya)輥軸承座與(yu)半機(ji)(ji)(ji)架(jia)(jia)之間的(de)(de)調整墊(dian)片(pian)，而(er)(er)且預(yu)(yu)(yu)(yu)應(ying)(ying)(ying)(ying)(ying)力(li)(li)(li)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)不能(neng)實現對(dui)(dui)稱調整。