曲柄零件工艺及钻Φ5锥销孔夹具设计说明书.doc

XX大学XXXX学院课程设计（论文）1目录1引言·········································································································22机械加工工艺规程的制定····································································22.1零件的工艺分析·····················································································22.1.1零件的作用及技术要求····································································22.1.2零件的主要表面的加工····································································32.2毛坯及其尺寸的确定···············································································42.2.1选择毛坯······················································································42.2.2确定机械加工余量··········································································42.3制定零件的机械加工路线·········································································52.3.1选择定位基准················································································52.3.2零件表面加工方法的选择·································································52.3.3制定工艺路线···············································································63机械加工工序设计·························································································83.1选择加工设备与工艺装备·········································································83.1.1选择机床······················································································83.1.2选择夹具······················································································83.1.3选择刀具······················································································83.1.4选择量具······················································································93.2确定工序尺寸························································································93.2.1孔的工序尺寸的设计·······································································93.3确定切削用量及基本时间········································································103.3.1工序粗、精铣端面切削用量··························································103.3.2钻削加工切削用量的选择································································113.3.3基本时间·····················································································123.3.4基本时间的计算············································································123.3.5其他时间计算···············································································154专用夹具设计·······························································································164.1确定定位方案，选择定位元件··································································164.2确定导向装置·······················································································174.3确定夹紧机构·······················································································174.4确定其他装置·······················································································174.5设计夹具体··························································································17参考文献········································································································17XX大学XXXX学院课程设计（论文）2设计曲柄的机械加工工艺规程及工艺装备XXXXXXX大学XXXX学院，XX，XXXXXX摘要：本次课程设计的课题是曲柄的机械加工工艺规程及工艺装备的设计，主要的设计内容包括曲柄的毛坯图，零件图，夹具装配图及装配图上的两个零件图，还有工艺过程卡片和工序卡各一张。首先是设计机械加工工艺规程，然后是机械加工工序设计，最后是机床夹具的设计。1引言机械制造技术基础是机械设计制造及其自动化专业的一门主干专业基础课，内容覆盖金属切削原理和刀具、机械加工方法及设备、机械制造工艺学及工艺装备等知识，贯穿大学的整个专业课程，是一门要求实践性和综合性的课程，通过我们做课程设计这个实践性环节才使我们对机械设计制造技术基础的基础理论有更加深刻的认识，为以后的工作打下扎实基础。课程设计是我们在学完了机械制造技术基础后进行的、这个课程设计是我们在进行毕业设计之前对所学各专业课程的一次综合性的复习。这次设计使我们能综合运用机械制造技术基础中的基本理论，并结合生产实习中学到的实践知识，独立地分析和解决了零件机械制造工艺问题，分析零件的工艺机构，对其工艺性进行分析，然后确定加工的路线，最后设计出机床夹具。设计机床专用夹具这一典型的工装，是我们对工程训练的提升，是实践运用到理论上来，这个对提高我们认识机械制造技术基础的基本知识，为今后的毕业设计及未来从事的机械加工工艺方向的工作打下了良好的坚实的基础。2机械加工工艺规程的制定2.1零件的工艺分析2.1.1零件的作用及技术要求通过对该零件的零件图的重新绘制知原图样的视图是符合要求的，尺寸、公XX大学XXXX学院课程设计（论文）3差及技术要求比较齐全。该零件属于典型的曲柄类零件，而且为曲柄。因此，其主要的要素应该包括两侧面，大、小头孔。另外，还有其他的辅助要素：小头和大头的径向孔以及柄身部分的铸造结构。它的所有表面均需切削加工，各表面的加工精度和表面粗糙度都不难获得。表面质量要求也不是很高，还是比较容易加工得到的，应该说，这个零件的工艺性较好。2.1.2零件的主要表面的加工零件的材料为HT250，灰铸铁铸造性能好，生产的工艺简单，但塑性较差、脆性高，这也是它的缺点，因此不适合磨削，适合铣削加工，为此以下是曲柄需要加工的表面以及加工表面之间的位置要求：1、小头孔10H9以及与此孔相贯的4的孔和9的端面，并且还要倒角。2、大头孔18H8以及与此孔相贯的4的孔和9的端面，并且还要倒角。3、端面A和B、小头孔1和小头孔2与大头端面的垂直度误差为0.05mm。4、对小孔10H9还有一定的位置要求，小头孔1与大头孔相隔100mm；小孔2与大头孔相70mm。由上面分析可知，可以粗加工曲柄的端面A和B，然后以此作为基准采用专用夹具进行加工大头孔和小头孔以及径向孔和径向孔的端面，并且保证位置精度要求。再根据各加工方法所能达到的的经济精度及机床所能达到的位置精度，因为曲柄零件没有复杂的加工曲面，所以根据上述技术要求采用常用的加工方法和常用的加工工艺均可保证上述的精度和要求。各个零件的加工要求和位置精度加工面加工精度要求Ra值大头两端面17，未注公差尺寸，是小头孔的基准面1.6小头两端面17.，未注公差尺寸，是小头孔的基准面1.6相贯孔端面3个的端面均需加工，表面质量不高12.5大头孔18H8，并且还要倒角1.6小头孔110H9，与大头孔相隔100mm，并且还要倒角1.6小头孔210H9，与大头孔相70mm，并且还要倒角1.6大头孔径向孔4与孔相贯3.2小头孔1径向孔4与孔相贯3.2XX大学XXXX学院课程设计（论文）4小头孔2径向孔4与孔相贯3.22.2毛坯及其尺寸的确定2.2.1选择毛坯该零件材料为HT250。综合考虑到材料的性能及该零件在工作中所受冲击不大，轮廓尺寸不大而且零件的零件结构又比较简单，生产类型为成批、大批大量的生产，因此应该选用铸件生产比较合适，从提高生产率、保证加工精度，也是应该选金属型铸造。金属型铸造的参数毛坯种类制造精度（CT）毛坯尺寸公差（mm）原材料工件尺寸工件形状加工余量等级生产率生产类型金属型铸造81013灰铸铁中小型复杂G高大批大量生产2.2.2确定机械加工余量查机械制造工艺设计简明手册确定各个加工面的铸件机械加工余量，铸件的分型面的选用及加工余量，如下表所示铸件的最小壁厚，查表可以得到铸件的最小壁厚。铸件的最小壁厚为2.5mm。铸件的拔模斜度铸件外表面的拔模斜度030铸件内表面的拔模斜度1铸件的圆角半径铸件壁部连接处的转角应有铸造圆角。主要是为减少应力集中，防止冲砂、裂纹等缺陷。根据国标GB/T2822-2005，查得，对于金属型铸件一般取R3或者取R5。本次取R5mm。铸件的浇注位置及分型面的选择铸件的重要加工面或主要工作面一般应处于底面或侧面，应避免气孔、砂眼、疏松、缩孔等缺陷出现在工作面上；大平面尽可能朝下或采用倾斜浇铸，避免夹砂或夹渣缺陷；铸件的薄壁部分放在下部或侧面，以免产生浇铸不足的情况。分型面的选择一般在中心位置上。本零件的分型面选择在中心上。毛坯尺寸的确定选择的毛坯铸造方法是金属模机器造型，零件的最大尺寸250mm，铸件的XX大学XXXX学院课程设计（论文）5机械加工余量等级则为57级（机械制造技术基础课程设计），选择6级。对于本次零件按照要求毛坯尺寸只有孔和端面是加工的对象，所以只需要对毛坯的孔的尺寸进行设计，其具体尺寸见后面的工序尺寸。2.3制定零件的机械加工路线2.3.1选择定位基准本零件是曲柄类零件，孔是其设计基准，为了避免由于基准不重合而产生的误差，应该选择孔为定位基准，遵守基准重合的原则，选择18H8及它的端面为基准，由于本零件的全部表面都需要加工，而孔作为精基准要先加工，故应该选择端面为粗基准。粗基准的选择：以零件的端面A（大头上端面）为主要的定位粗基准，以两个小头孔端面为辅助粗基准。精基准的选择：考虑要保证零件的加工精度和装夹准确方便，依据“基准重合”原则和“基准统一”原则，以粗加工后的端面B为主要的定位精基准，以两个小头孔端面为辅助的定位精基准2.3.2零件表面加工方法的选择本零件的加工表面有端面，孔，小孔，材料为HT250，按照公差的等级和表面的粗糙度的要求，参考机械制造技术基础课程设计，选择的机械加工方法如下：端面A和B：未注公差尺寸，表面粗糙度Ra为1.6mm，需要进行粗铣和精铣。相贯孔端面：未注公差尺寸，表面粗糙度为Ra12.5mm，粗铣即可。大头孔18H8：表面粗糙度为Ra1.6mm，并进行倒角，需要进行钻半精镗精镗。小头孔10H9：表面粗糙度为Ra1.6mm，并进行倒角，需要进行钻半精镗精镗。大小头孔径向孔4：表面粗糙度为Ra3.2mm，进行钻孔和半精镗就可以了。各表面的加工方法见下表曲柄零件表面加工方法的选择加工面加工方法的选择Ra值端面A和B粗铣上粗铣下精铣上精铣下1.6