第8章零件結(jié)構(gòu)工藝性

ManufacturingProcessesofparts

零件的結(jié)構(gòu)工藝性Castingstructure

鑄件結(jié)構(gòu)Commonmachiningstructures機加工常見結(jié)構(gòu)Structureofdrillholes鉆孔結(jié)構(gòu)請點擊相應標題顯示其內(nèi)容

Castingstructure鑄件結(jié)構(gòu)CopeboxOverflowPouringhead上砂箱

冒口澆口1.

Draft起模斜度：The1

20（≈3°）draftalongthedrawingdirectionofthepatternfacilitatestotakeoutthepatternwhilemolding.

鑄件造型時，為便于取出木模，沿脫模方向的表面做出1

20（≈3°）的起模斜度。請點擊鼠標左鍵顯示后面內(nèi)容Ifthedraftisverysmall,itcanbeomitted,Ifnecessary,itcanbeincludedintechnical.起模斜度較小時,在圖中一般不畫出,必要時可注寫在技術(shù)要求中。Castingbox下砂箱Model模型Cavity型腔Sand型砂2.Filletsincastings鑄造圓角：

Theremustbearadiuswheretwosurfacesmeet,inordertoavoidsanddropswhileremovingthemould,andpreventthefissuresorshrinkageholeswhilecooling.在鑄件表面相交處應有圓角,以免脫模時砂型落砂,同時防止鑄件冷卻時產(chǎn)生裂紋或縮孔。Machinesymbol機加工符號請點擊鼠標左鍵顯示后面內(nèi)容

Castingstructure鑄件結(jié)構(gòu)Theintersectionlineisneededinordertodistinguishthevarioussurfaces.Theonewehaveprovidediscalledrun-outline.Therepresentationofarun-outlineissimilartothatofintersectionline.Theonlydifferenceisthattheendoftherun-outlineisnotconnectedwiththecontourlineoftheradius,andthelinestyleisathinsolidline.

為了區(qū)分不同形體的表面,仍要畫出相貫線,這種相貫線稱為過渡線。過渡線的畫法和相貫線相同,只是其端點處不與圓角輪廓線接觸,且線型為細實線。Toavoidshrinkageholesandfissures

causedbydifferentcoolingspeeds.Duringthedesignphase,itisamusttomaintainuniformwallthicknessorasmooth.Onemustavoidunequaldesignssuchasthicknessabruptvaryingorlocalthickpartialareas.為防止?jié)沧⒘慵r,由于壁厚不勻使冷卻速度不同所產(chǎn)生的縮孔和裂紋,在設(shè)計鑄件時,應使壁厚盡量均勻或逐漸過渡,以避免壁厚突變或局部肥大的不勻現(xiàn)象。3.Wallthickness鑄件的壁厚：Shrinkagehole縮孔Fissure裂紋請點擊鼠標左鍵顯示后面內(nèi)容Smoothtransition

逐漸過渡

Castingstructure鑄件結(jié)構(gòu)Maintainuniformwallthickness壁厚均勻1.Bossclubandrecessedsurface凸臺與凹坑：

Usually,allsurfacesmountedonotherpartsneedtobemachined.Thebossorrecessedsurfaceisaddedtokeepgoodcontactbetweenthesurfacesoftwopartsandtoreducethemachiningareaandmanufacturingcost.零件上凡與其他零件接觸的表面一般都要加工，為了保證兩零件表面的良好接觸，同時減少加工面積，以降低制造費用，在零件的需接觸表面處常設(shè)計成凸臺、凹坑的形式。請點擊鼠標左鍵顯示后面內(nèi)容凸臺凹坑高度不一致,導致加工調(diào)刀工時費、成本高Commonmachiningstructures機加工常見結(jié)構(gòu)Onemustavoidunequaldesigns

應避免凸臺凹坑高度不一致2.

Chamferandround倒角與圓角：Toeliminateburrsandflashesinordertoavoidcutting

handsandtofacilitateassembly,theendsofboththeshaftandtheholeusuallyneedtobechamfered.為了去除零件的毛刺、銳邊，以防止劃傷人手和便于裝配，在軸和孔的端部通常需加工出倒角。Avoidcracks避免斷裂Thatis,thesharpedgeofshaftendiscutbyaconicalcuttingtoolwitha45°apexangle.即用一錐頂角為45°的圓錐刀頭切除其端部銳邊。請點擊鼠標左鍵顯示后面內(nèi)容Commonmachiningstructures機加工常見結(jié)構(gòu)C22×C2Anarctransitionusuallyremainsattheshaftshoulder,whichiscalledround,inordertoavoidcrackscausedbypressureconcentration.在軸肩處，常常制成圓弧過渡，即圓角，以避免因應力集中而產(chǎn)生裂紋。Commonmachiningstructures機加工常見結(jié)構(gòu)Undercut退刀槽Undercut退刀槽Grindingundercut砂輪越程槽Grindingundercut砂輪越程槽Grindingsurface精磨表面Grindingsurface精磨表面3.Undercut

andgrindingundercut退刀槽和砂輪越程槽：Anescape,grindingortravelinglimitundercutneedstobeproducedattheendofthesurfacetobemachined,inordertoeasilywithdrawthecutterorgrindingwheelwhiletappingorgrindingexternaldiameter.在車削螺紋或磨外圓時,為便于退刀或使用砂輪,需要在待加工面末端先切出退刀槽或砂輪越程槽。請點擊鼠標左鍵顯示后面內(nèi)容Thedimensionoftheundercut

isidentifiedas‘width×depth’or‘width×diameter’.

退刀槽及越程槽的尺寸注成“寬度×深度”或“寬度×直徑”。Theaxisofthedrillshouldbeperpendiculartothesurfacetobedrilled,inordertoensurecorrectdrillingpositionandpreventthedrillfrombreakingcausedbyunequalimpactforce.

用鉆頭鉆孔時，為保證鉆孔位置準確和避免鉆頭因受力不均而折斷，應使鉆頭軸線垂直于被鉆孔零件的表面。請點擊鼠標左鍵顯示后面內(nèi)容Structureofdrillholes鉆孔結(jié)構(gòu)Theintersectionpointwheretheholeandtheobliqueplanemeetisnecessarytosettoplatformandnotchstructure.Iftheanglebetweenthedrillandtheobliqueplaneislargerthan60°,onecandrilltheholedirectly.在與孔軸線傾斜的表面處,常需設(shè)計出平臺或凹坑結(jié)構(gòu),但當鉆頭與傾斜面的夾角大于60°時,也可以直接鉆孔。本小節(jié)結(jié)束謝謝您的認真學習！退出前一頁

Castingstructure鑄件結(jié)構(gòu)在圖片上點擊鼠標左鍵“暫停”或再次“播放”

Castingstructure鑄件結(jié)構(gòu)在圖片上點擊鼠標左鍵“暫?！被蛟俅巍安シ拧?/p>

Castingstructure鑄件結(jié)構(gòu)在圖片上點擊鼠標左鍵“暫停”或再次“播放”

Castingstructure鑄件結(jié)構(gòu)在圖片上點擊鼠標左鍵“暫?！被蛟俅巍安シ拧盋ommonmachiningstructures機加工常見結(jié)構(gòu)請點擊鼠標左鍵顯示后面內(nèi)容Grindingsurfacebygrindingwheel

砂輪正在精磨工件的表面Commonmachiningstructures機加工常見結(jié)構(gòu)Structureofdrillholes鉆孔結(jié)構(gòu)

Surfacestructureofthedrillhole

鉆孔的表面結(jié)構(gòu)

Representationoftheholeanddimensionofadrill鉆孔的尺寸標注鉆孔示意Grindingexternaldiameterbygrindingwheel

砂輪正在精磨斜齒軸的外圓面Grindingundercut砂輪越程槽Commonmachiningstructures機加工常見結(jié)構(gòu)在圖片上點擊鼠標左鍵可以“暫停”或再次“播放”在圖片上點擊鼠標左鍵可以“暫停”或再次“播放”在圖片上點擊鼠標左鍵可以“暫停”或再次“播放”在圖片上點擊鼠標左鍵可以“暫?！被蛟俅巍安シ拧秉c擊鼠標左鍵可以繼續(xù)演示Twistdrill麻花鉆鉆不通孔鉆通孔鉆階梯孔

Castingstructure鑄件結(jié)構(gòu)在圖片上點擊鼠標左鍵“暫停”或再次“播放”

Castingstructure