《零件的结构工艺性》PPT课件

《《零件的结构工艺性》PPT课件》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、ManufacturingProcessConsiderations零件的结构工艺性Castingstructure铸件结构Commonmachiningstructures机加工常见结构Structureofdrillhole钻孔结构请点击相应标题显示其内容Castingstructure铸件结构SandboxcoverOverflowPouringhead上砂箱冒口浇口1.Draft起模斜度:The120（≈3°）draftalongthedrawingdirectionofthepatternfacilitatestotakeoutthepatternwhilemo

2、lding.铸件造型时，为便于取出木模，沿脱模方向的表面做出120（≈3°）的起模斜度。请点击鼠标左键显示后面内容Ifthedraftisverysmall,itcanbeomitted,Ifnecessary,itcanbeincludedintechnical.起模斜度较小时,在图中一般不画出,必要时可注写在技术要求中。Sandbox下砂箱Model模型Cavity型腔Sand型砂2.Filletsincastings铸造圆角:Theremustbearadiuswheretwosurfacesmeet,inordertoavoidsanddropswhileremo

3、vingthemouldandshrinkagecavityandshrinkagecrackwhilecooling.在铸件表面相交处应有圆角,以免脱模时砂型落砂,同时防止铸件冷却时产生裂纹或缩孔。Machinesymbol机加工符号请点击鼠标左键显示后面内容Castingstructure铸件结构Theintersectionlineisneededinordertodistinguishthevarioussurfaces.Theonewehaveprovidediscalledrun-outline.Therepresentationofatransitionlin

4、eissimilartothatofintersectionline.Theonlydifferenceisthattheendoftherun-outlineisnotconnectedwiththecontourlineoftheradius,andthelinestyleisathinsolidline.为了区分不同形体的表面,仍要画出相贯线,这种相贯线称为过渡线。过渡线的画法和相贯线相同,只是其端点处不与圆角轮廓线接触,且线型为细实线。3.Wallthickness铸件的壁厚:Toavoidshrinkagecavityandshrinkagecrackcaused

5、bydifferentcoolingspeeds.Duringthedesignphase,itisamusttomaintainuniformwallthicknessorasmooth.Onemustavoidunequaldesignssuchasthicknessabruptvaryingorlocalthickpartialareas.为防止浇铸零件时,由于壁厚不匀而冷却速度不同产生的缩孔和裂纹,在设计铸件时,应使壁厚尽量均匀或逐渐过渡,以避免壁厚突变或局部肥大的不匀现象。Dedectivness有缺陷Defectivness有缺陷请点击鼠标左键显示后面内容Smo

6、othtransition平滑过渡Castingstructure铸件结构Maintainuniformwallthickness壁厚均匀1.Bossclubandrecessedsurface凸台与凹坑：Usually,allsurfacesmountedonotherpartsneedtobemachined.Thebossorrecessedsurfaceisaddedtokeepgoodcontactbetweenthesurfacesoftwopartsandtoreducethemachiningareaandmanufacturingcost.零件上凡与其他零

7、件接触的表面一般都要加工，为了保证两零件表面的良好接触，同时减少加工面积，以降低制造费用，在零件的需接触表面处常设计成凸台、凹坑的形式。请点击鼠标左键显示后面内容凸台凹坑高度不一致,导致加工调刀工时费、成本高Commonmachiningstructures机加工常见结构Onemustavoidunequaldesigns应避免凸台凹坑高度不一致2.Chamferandround倒角与圆角:Toeliminateburrsandflashesinordertopreventhumanhandsfromcutting