零件的結構工藝性課件

ManufacturingProcessConsiderations

零件的結構工藝性Castingstructure

鑄件結構Commonmachiningstructures機加工常見結構Structureofdrillhole鉆孔結構請點擊相應標題顯示其內(nèi)容ManufacturingProcessConsider1

Castingstructure鑄件結構SandboxcoverOverflowPouringhead

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要求中。Sandbox下砂箱Model模型Cavity型腔Sand型砂Castingstructure鑄件結22.Filletsincastings鑄造圓角:

Theremustbearadiuswheretwosurfacesmeet,inordertoavoidsanddropswhileremovingthemouldandshrinkagecavityandshrinkagecrackwhilecooling.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鑄件結構

Theintersectionlineisneededinordertodistinguishthevarioussurfaces.Theonewehaveprovidediscalledrun-outline.Therepresentationofatransitionlineissimilartothatofintersectionline.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。2.Filletsincastings鑄造圓角:33.Wallthickness鑄件的壁厚:Toavoidshrinkagecavityandshrinkagecrackcausedbydifferentcoolingspeeds.Duringthedesignphase,itisamusttomaintainuniformwallthicknessorasmooth.Onemustavoidunequaldesignssuchasthicknessabruptvaryingorlocalthickpartialareas.為防止?jié)茶T零件時,由于壁厚不勻而冷卻速度不同產(chǎn)生的縮孔和裂紋,在設計鑄件時,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。Dedectivness

有缺陷Defectivness

有缺陷請點擊鼠標左鍵顯示后面內(nèi)容Smoothtransition

平滑過渡

Castingstructure鑄件結構Maintainuniformwallthickness壁厚均勻3.Wallthickness鑄件的壁厚:41.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機加工常見結構Onemustavoidunequaldesigns

應避免凸臺凹坑高度不一致1.Bossclubandrecessedsurf52.

Chamferandround倒角與圓角:Toeliminateburrsandflashesinordertopreventhumanhandsfromcuttingandtofacilitatemounting,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°degreeapexangle.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機加工常見結構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。2.Chamferandround倒角與圓角:6Commonmachiningstructures機加工常見結構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.

Escapeandgrindingundercut螺紋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Thedimensionoftheescapeisidentifiedas‘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”。Commonmachiningstructures機加7Theaxisofthedrillshouldbeperpendiculartothesurfacetobedrilled,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Structureofdrillhole鉆孔結構Theintersectionpointwheretheholeandtheobliqueplanemeetisnecessarytosettoplatformandnotchstructure.Iftheanglebetweenthedrillandtheobliqueplaneislargerthan60°,onecandrilltheholedirectly.在與孔軸線傾斜的表面處,常需設計出平臺或凹坑結構,但當鉆頭與傾斜面的夾角大于60°時,也可以直接鉆孔。Theaxisofthedrillshoul8本小節(jié)結束謝謝您的認真學習！退出前一頁本小節(jié)結束謝謝您的認真學習！退出前一頁9

Castingstructure鑄件結構不與輪廓線接觸在圖片上點擊鼠標左鍵“暫?！被蛟俅巍安シ拧盋astingstructure鑄件結10

Castingstructure鑄件結構在切點附近斷開在圖片上點擊鼠標左鍵“暫?！被蛟俅巍安シ拧盋astingstructure鑄件結11

Castingstructure鑄件結構在圖片上點擊鼠標左鍵“暫?！被蛟俅巍安シ拧盋astingstructure鑄件結12

Castingstructure鑄件結構在圖片上點擊鼠標左鍵“暫停”或再次“播放”Castingstructure鑄件結13Commonmachiningstructures機加工常見結構Commonmachiningstructures機加14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機加工常見結構請Grindingsurfacebygrinding15Structureofdrillhole鉆孔結構

Surfacestructureofthedrillhole鉆孔的表面結構

Representationoftheholeanddimensionofadrill鉆孔的尺寸標注Structureofdrillhole16Grindingexternaldiameterbygrindingwheel

砂輪正在精磨斜齒軸的外圓面Grinding