有关影响数控刀具寿命因素的总结

在数控加(jia)工(gong)中，刀(dao)具寿(shou)命是指从开始加(jia)工(gong)到刀(dao)尖(jian)报废整个过程(cheng)(cheng)中刀(dao)尖(jian)切(qie)削工(gong)件的(de)时间或切(qie)削过程(cheng)(cheng)中在工(gong)件表面实际的(de)长度。那么影响刀具寿命(ming)的因素有哪些呢？

1. 线(xian)(xian)速(su)度对刀(dao)具(ju)寿命的影响最大。如果线(xian)(xian)速(su)度高于样(yang)本规定(ding)线(xian)(xian)速(su)度的20％，刀具寿命将降低为原来的1/2；如果提高到50％，刀具寿命将只有原来的1/5。要提高刀具的使用寿命，必须要知道每种被加工工件的材质、状态以及选用刀具的线速度范围。线速度在粗加工和精加工时的数据并不一致，粗加工以去余量为主，线速度要低；精加工以保证尺寸精度和粗糙度为主，线速度要高。

2. 切(qie)深(shen)对刀(dao)(dao)具(ju)寿命的影响(xiang)没有线速(su)度大(da)。每(mei)种槽(cao)型(xing)都有一个比较大(da)的切(qie)深(shen)范(fan)围(wei)。粗加(jia)工(gong)时，切(qie)深(shen)尽(jin)量加(jia)大(da)，保证最大(da)的余量去除(chu)率(lv)；精(jing)加(jia)工(gong)时，切(qie)深(shen)尽(jin)量小，保证工(gong)件的尺(chi)寸精(jing)度和(he)表面质量。但切(qie)深(shen)不(bu)能(neng)超过槽(cao)型(xing)的切(qie)削(xue)范(fan)围(wei)。如(ru)(ru)果(guo)切(qie)深(shen)过大(da)，刀(dao)(dao)具(ju)无(wu)法承受切(qie)削(xue)力，导致刀(dao)(dao)具(ju)崩刃；如(ru)(ru)果(guo)切(qie)深(shen)过小，刀(dao)(dao)具(ju)只是在(zai)工(gong)件表面进(jin)行刮削(xue)和(he)挤压(ya)，导致后刀(dao)(dao)面严重磨(mo)损，从而降(jiang)低刀(dao)(dao)具(ju)寿命。

3. 进给相比较线速度(du)和切(qie)深，进给(ji)对刀具寿(shou)命(ming)的(de)影响最小，但对工件的(de)表(biao)面质(zhi)量(liang)影响最大(da)。粗(cu)(cu)加工时，加大(da)进给(ji)可(ke)以提(ti)(ti)高余(yu)量(liang)的(de)去除率(lv)(lv)；精加工时，降(jiang)低进给(ji)可(ke)以提(ti)(ti)高工件的(de)表(biao)面粗(cu)(cu)糙(cao)度(du)。在粗(cu)(cu)糙(cao)度(du)允许的(de)情(qing)况下，可(ke)以尽量(liang)加大(da)进给(ji)，提(ti)(ti)高加工效(xiao)率(lv)(lv)。

4. 振动(dong)(dong)(dong)是除三大(da)切削要(yao)(yao)素(su)外，对刀(dao)(dao)具(ju)(ju)寿(shou)命(ming)影(ying)响最大(da)的(de)因素(su)。振动(dong)(dong)(dong)产(chan)生(sheng)的(de)原(yuan)因很多，包(bao)括(kuo)机(ji)床刚(gang)性、工装(zhuang)刚(gang)性、工件(jian)刚(gang)性、切削参(can)数、刀(dao)(dao)具(ju)(ju)槽型、刀(dao)(dao)尖(jian)圆(yuan)弧半(ban)径、刀(dao)(dao)片(pian)后角(jiao)、刀(dao)(dao)杆悬(xuan)伸长(zhang)度(du)(du)等(deng)，但主要(yao)(yao)是由(you)于系(xi)统刚(gang)性不够(gou)，不能抵抗加(jia)工时(shi)的(de)切削力，导致(zhi)加(jia)工时(shi)刀(dao)(dao)具(ju)(ju)在(zai)工件(jian)表(biao)面(mian)不停的(de)振动(dong)(dong)(dong)所致(zhi)。要(yao)(yao)消(xiao)除或减小振动(dong)(dong)(dong)必须要(yao)(yao)综合考虑(lv)。刀(dao)(dao)具(ju)(ju)在(zai)工件(jian)表(biao)面(mian)振动(dong)(dong)(dong)可以理解为刀(dao)(dao)具(ju)(ju)与工件(jian)之间不停地进(jin)行敲击，而不是正常的(de)切削，会使(shi)刀(dao)(dao)尖(jian)产(chan)生(sheng)一(yi)些微(wei)小的(de)裂纹和崩(beng)刃，而这些裂纹和崩(beng)刃又导致(zhi)切削力加(jia)大(da)，使(shi)振动(dong)(dong)(dong)进(jin)一(yi)步加(jia)剧，反过来进(jin)一(yi)步增大(da)裂纹和崩(beng)刃的(de)程度(du)(du)，使(shi)刀(dao)(dao)具(ju)(ju)寿(shou)命(ming)大(da)幅度(du)(du)降低。

5. 刀片(pian)材质工(gong)(gong)(gong)(gong)件加(jia)(jia)工(gong)(gong)(gong)(gong)时，我们(men)主要考虑的(de)是工(gong)(gong)(gong)(gong)件材质、热(re)处理要求以及是否断续(xu)(xu)加(jia)(jia)工(gong)(gong)(gong)(gong)等(deng)(deng)。例如：加(jia)(jia)工(gong)(gong)(gong)(gong)钢件的(de)刀(dao)片(pian)和(he)加(jia)(jia)工(gong)(gong)(gong)(gong)铸(zhu)铁的(de)刀(dao)片(pian)、加(jia)(jia)工(gong)(gong)(gong)(gong)硬(ying)度为HB215和(he)HRC62的(de)刀(dao)片(pian)都不一(yi)定相同；断续(xu)(xu)加(jia)(jia)工(gong)(gong)(gong)(gong)和(he)连续(xu)(xu)加(jia)(jia)工(gong)(gong)(gong)(gong)用(yong)的(de)刀(dao)片(pian)也不会相同。对于同一(yi)种工(gong)(gong)(gong)(gong)件材质，如果(guo)是连续(xu)(xu)加(jia)(jia)工(gong)(gong)(gong)(gong)，要用(yong)到硬(ying)度更高的(de)刀(dao)片(pian)，可(ke)以提高工(gong)(gong)(gong)(gong)件切削(xue)速度，降低刀(dao)尖磨损(sun)，减少加(jia)(jia)工(gong)(gong)(gong)(gong)时间；如果(guo)是断续(xu)(xu)加(jia)(jia)工(gong)(gong)(gong)(gong)，要用(yong)到韧性更好的(de)刀(dao)片(pian)，可(ke)以有效减少崩刃等(deng)(deng)非正常磨损(sun)，提高刀(dao)具使用(yong)寿命。

6. 刀片使用次(ci)数(shu)刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)具(ju)(ju)使(shi)用过程中会产生大量的(de)热(re)量，使(shi)刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)温(wen)度(du)(du)大幅度(du)(du)升(sheng)高(gao)，而(er)不加(jia)工时或(huo)用冷(leng)却水冷(leng)却，又会使(shi)刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)温(wen)度(du)(du)降(jiang)低(di)，因此刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)一直处于一种较高(gao)的(de)温(wen)度(du)(du)变(bian)化范围内，使(shi)刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)不停(ting)地热(re)胀冷(leng)缩，导(dao)(dao)致刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)出现细小的(de)裂(lie)纹。在刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)片(pian)用第一个刃加(jia)工时，刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)具(ju)(ju)寿(shou)(shou)命(ming)正(zheng)常；但随着刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)刃使(shi)用的(de)增加(jia)，裂(lie)纹会扩(kuo)展到(dao)其他刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)刃，导(dao)(dao)致其他刀(dao)(dao)(dao)(dao)(dao)(dao)(dao)刃的(de)寿(shou)(shou)命(ming)降(jiang)低(di)。

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有关影响数控刀具寿命因素的总结